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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of copending commonly assigned application Ser. No. 908,459 filed Sept. 16, 1986, by Drachnik and Kheder, now abandoned, the entire disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to anodes suitable for use in corrosion protection systems, especially for the protection of reinforcing bars ("rebar") in concrete.
2. Introduction to the Invention
Anodes for use in corrosion protection systems are disclosed for example in U.S. Pat. Nos. 4,520,929 (Stewart), 4,473,450 (Nayak), 4,319,854 (Marzocchi), 4,255,241 (Kroon), 4,267,029 (Massarsky), 3,868,313 (Gay), 3,789,142 (Evans), 3,391,072 (Pearson), 3,354,063 (Shutt), 3,022,242 (Anderson), 2,053,314 (Brown) and 1,842,541 (Cumberland), UK Patent Specification Nos. 1,394,292 and 2,046,789A, Japanese Patent Specification Nos. 35293/1973 and 48948/1978, and European Patent Application No. 0,147,977. Especially for the corrosion protection of reinforcing bars in concrete, mesh anodes are particularly suitable. However, the known mesh anodes are not satisfactory. Either they are difficult to manufacture (especially if they are to be manufactured, in whole or in part, at the installation site, e.g. on the surface of a reinforced concrete structure), or damage caused by physical abuse or by corrosion failure, at one or only a few locations of the anode, can disconnect large portions of the anode from the power supply.
SUMMARY OF THE INVENTION
We have now discovered that these disadvantages can be overcome through the use of resiliently deformable clips which secure together portions of the same or different elongate electrodes at spaced-apart junctions of a mesh formed by the electrode(s), and provide both electrical and mechanical connection between the electrode portions at the junctions. It is not necessary that such clips be provided at each of the junctions of the mesh, though it is preferred. The clips initially provide a convenient and rapid method of securing the elongate electrode(s) in the desired mesh configuration. They may continue to provide this function if no other measure is taken to preserve the mesh configuration (e.g. a layer of concrete applied directly or indirectly over the anode after it is in place). The clips need not play any substantial electrical part in the operation of the anode if the anode is undamaged. But if the anode is damaged, so that current can no longer flow directly to all parts of the anode through the elongate electrode(s), the clips provide an alternative current path so that substantially the whole of the anode remains operational. The fact that the clips are resiliently deformed not only helps them to remain effective when (as is preferred) the anode is flexible, but also helps to ensure that they provide good electrical connection both initially and in subsequent operation if a dimension of the elongate electrode changes, e.g. through electrochemical erosion. This can be particularly important if, as is preferred, the elongate electrode comprises a conductive polymer (i.e. a dispersion of carbon black or graphite or other corrosion-resistant particulate filler in a polymeric matrix) especially if the electrode has been made by a process, e.g. a melt-extrusion process, which results in a resin-rich surface layer (i.e. a surface layer containing a relatively small proportion of the filler). The pressure exerted by the clip on the electrode portion is generally at least 0.01 psi (0.0007 kg/cm 2 ), preferably at least 0.05 psi (0.0035 kg/cm 2 ), but is generally less than 10 psi (0.7 kg/cm 2 ), preferably less than 5 psi (0.35 kg/cm 2 ), e.g. 0.1-1 psi (0.007-0.07 kg/cm 2 ).
In one aspect, the present invention provides a mesh electrode which is suitable for use as an anode in a corrosion protection system and which comprises
(1) one or more elongate electrodes arranged in the form of a mesh having a plurality of spaced-apart junctions at which portions of the elongate electrode or electrodes are secured together, and
(2) a plurality of clips, each of the clips providing mechanical and electrical connection between the electrode portions at one of said junctions, the electrical connection with each electrode portion being over an electrical contact area of at least 25 mm 2 , preferably at least 50 mm 2 , particularly at least 100 mm 2 , more particularly at least 200 mm 2 , especially at least 300 mm 2 , and the connection being maintained by resilient bias so that if the size of the connected electrode portions is reduced, such mechanical and electrical connection is maintained by elastic recovery of the clip.
In another aspect, the invention provides a method of making such a mesh electrode which comprises:
(1) laying out one or more elongate electrodes in a desired mesh pattern, preferably on the surface of a concrete structure containing reinforcing bars, and
(2) connecting the electrode portions at the junctions of the mesh by resiliently deforming the clips around said portions.
In another aspect, the invention provides a method of cathodically protecting a corrodible substrate, particularly reinforcing bars embedded in concrete, which comprises establishing a potential difference between the substrate as cathode and a mesh anode as defined above.
In another aspect, the invention provides a method of rendering a reinforced concrete structure suitable for cathodic protection of the reinforcing bars therein, which method comprises securing a mesh electrode as defined above to the surface of the structure.
In another aspect, the invention provides a clip suitable for use in the manufacture of a mesh anode as defined above, the clip comprising
(1) electrical interconnection means which has at least two recesses, each of the recesses having an exposed surface composed of a conductive material and being capable of receiving and electrically contacting an electrode portion over a surface area of at least 25 mm 2 , said exposed surfaces being electrically connected to each other; and
(2) mechanical interconnection means which restrict movement between the recesses and which can maintain said electrical contact by resilient bias.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated by the accompanying drawing in which FIG. 1 is an exploded view of a rebar-reinforced concrete slab which incorporates a mesh electrode of the invention;
FIG. 2 is a plain view of the mesh electrode;
FIGS. 3A and 3B show plain views of alternative mesh electrode designs; and
FIGS. 4 to 16 illustrate various clips useful in constructing a mesh electrode of the invention, FIGS. 4, 7 and 13 to 15 being shown in perspective and FIGS. 5, 6 and 8 to 12 being shown in cross-section; and
FIG. 17 is a perspective view of a clip useful with the mesh electrode of FIG. 3B.
DETAILED DESCRIPTION OF THE INVENTION
The exposed conductive surfaces of the recesses need not provide the whole of the surface of the recess which contacts the electrode portion. In one embodiment, the clip is composed entirely of a conductive polymer. However, in such a clip it is difficult to provide a satisfactory compromise between the desired attributes of low electrical resistance and high physical strength and resilience. In another embodiment, therefore, the clip comprises an element which is composed of a conductive polymer and which provides at least part of each of the recesses, e.g. a bridging member between the recesses, and has for example a resistivity of 1 to 5 ohm.cm, with the remainder of the clip being composed of a less conductive or non-conductive polymeric material. In another embodiment, the electrical interconnection means is provided by a non-polymeric corrosion-resistant material, e.g. a foil or mesh or wire having at least an outer surface which is composed of a noble metal, e.g. niobium, titanium or stainless steel. The expense of most such materials is so great that it is not practical to construct the entire clip from them. Instead the material provides a partial or complete lining for each of the recesses, and a bridge between the recesses, and the rest of the clip is composed of a non-conductive material, preferably a polymer, which provides the desired mechanical interconnection means, including the resilient bias. In all of the clips, it is possible to provide a deformable, usually a non-elastically deformable, conductive material, e.g. a conductive mastic or grease, within the recesses of the clip, to improve electrical contact between the clip and the electrode.
The invention is illustrated by the accompanying drawings. In the following description of the invention with reference to the drawings, it is to be understood that the various features which are illustrated in or discussed with reference to a particular Figure or Figures are also applicable, with any necessary or appropriate changes, to other embodiments of the invention, whether or not illustrated in the Figures, as broadly disclosed herein.
The invention is particularly applicable to cathodic protection of reinforcements in concrete, as illustrated in FIG. 1. FIG. 1 shows concrete 1, reinforced by rebars 2 which are shown partially exposed for illustrative purposes.
An electrode 3, as anode, is placed on a surface of the concrete 1 and an overlay 4 generally of a conductive material, particularly an ionically conductive material, is applied. Material 4 may comprise concrete or cement, conductive concrete or cement, plaster-based material or polymeric material. Particular examples are Portland cement concrete and asphalt concrete, or Portland cement modified concrete (for example latex or acrylic modified concrete). A potential difference is applied between electrode 3 as anode and the rebars 2 as cathode by means of a power source 5.
The electrode 3 is preferably in the form of a mesh, and is preferably flexible. The minimum dimension of the apertures of such a mesh (i.e. the shortest side of the aperture) will generally be at least 0.5 inch (1.3 cm), preferably at least 1 inch (2.5 cm), particularly at least 2 inches (5.0 cm), more particularly at least 4 inches (10.0 cm), especially at least 6 inches (15 cm). The maximum dimension of the aperture (i.e. the length of the longest side of the aperture) will generally be less than 48 inches (120 cm), particularly less than 24 inches (60 cm), and for some applications less than 8 inches (20 cm). Preferably the shortest and longest sides of the apertures differ by less than a factor of about 3, especially less than about 2. The apertures in the mesh can be of any shape, e.g. substantially square or other substantially rectangular shape. The size and shape of the apertures will usually be substantially the same throughout a particular mesh, but they may be different. By mesh, we mean merely an array where adjacent elements are connected together, for example by them being integral and looped, or being connected together by conductive clips etc. Generally, a given element may be connected to an adjacent element at more than one location, but this need not be so.
The mesh is preferably flexible, this term being used herein to mean that it can be bent, along at least one axis, and preferably along two perpendicular axes, through an angle of 180° around a round mandrel of diameter 12 inches (30 cm), and preferably around a round mandrel of diameter 6 inches (15 cm), without suffering damage. This property results in a very significant advantage, namely that the mesh can easily be transported in rolls to an installation site, and can be installed in a wide variety of different situations with a minimum of difficulty.
In order to provide such flexibility, the electrode elements 6 of which it is at least in part composed may be flexible. Where the electrode elements 6 run in substantially perpendicular directions, those in only one, or those in both, directions may be flexible.
Flexibility may, however, result from or be enhanced by the construction of the electrode from its elements. For example the configuration of the elements, and the way they are held together will affect flexibility. In particular we prefer that where a clip is used to hold together portions of the electrode element or elements, that clip allows some movement, for example rotational movement.
The anode 3 illustrated in FIG. 2 comprises a series of electrode elements 6 of generally zig-zag shape. Each electrode element 6 is interconnected to an adjacent element by means of a clip 7 positioned at each peak of the zig-zag pattern. It can be seen that this electrode 3 will be flexible in that it could be rolled around a mandrel whose axis was parallel to the length of the arrow, without need for the elements 6 themselves to be flexible (the depth of the zig-zag may be small) This flexibility may result from an ability of the clips 7 to bend, or from an ability of the elements 6 to rotate in the clips. In FIG. 2, each element 6 is independent of all of the others except for the clips 7. It will therefore be necessary for the clips 7 to provide electrical interconnection between the elements, if the desired substantially uniform potential is to exist over the entire surface of the electrode. It will not in general be necessary for clips 7 to be employed at every available position, as illustrated.
A different design of electrode mesh is shown in FIGS. 3A and 3B; here a single electrode element 6 is configured in a series of loops 8a and 8b over the desired area to which an electrical potential is to be applied. In FIG. 3A, clips 7 are positioned such that each of the loops is connected at or adjacent its distal end to another portion of the electrode (generally to an adjacent loop). ("Distal" in general means far from a point of attachment, and in the present context therefore means, in relation to any given loop, that part of the loop remote from those parts of the element forming it that attach that loop to, for example, adjacent loops.) In FIG. 3A, five clips 7 have been used with the nine loops (reckoned by regarding loops 8a and 8b as separate) to ensure that any double cut, such as that shown by the dotted line, does not isolate any part of the electrode, so long as the power 5 is supplied to both ends as shown. Such a double cut may occur in practice since two portions of an electrode element may be close at many points. Damage may occur for example in the case of concrete bridges through road work etc. It can be seen that the double cut shown by the dotted line will isolate none of the illustrated electrodes even if it is powered through one only of the two ends; there are however some positions where a double cut would then isolate some part of the electrode, but this can be avoided by employing more clips. It may be noted that the number of clips that achieves this preferred level of protection is five as illustrated, i.e. equal to the number of loops 8a.
In FIG. 3B several novel features are shown, including the configuration of the electrode mesh, and arrangement whereby loops thereof are bussed, and the use of curved clips 7A.
The electrode element 6 is configured into a plurality of loops 8a and 8b, interconnected by portions 8c that are substantially straight along their entire length (in FIG. 3C the interconnecting portions were curved or zig-zag). The peaks, or other portions, or each loop may be bussed by an extension of the electrode element 6a, or other bus 6b. In the embodiment illustrated, the loops 8a are interconnected by an extension of the electrode element 6a, and the loops 8b by a separate bus 6b. This need not be so, and both sets may be bussed by separate busses, or both by extensions of the electrode element. One end of the electrode element 6 (or a bus) is connected to a power source 5, and the other end (or another bus) may also be connected to the source 5 via a portion of the element 6 near the first end, as shown at clip 7b.
A third feature shown in FIG. 3B is the curved clips 7a, whose function is to help maintain the desired configuration of the loops 8a and 8b. These clips 7a, which are illustrated in more detail in a later figure, may serve also to secure the electrode to a bridge deck or other substrate to be cathodically protected, and may serve also to help locate clips 7 by means of which electrical connection is made between loops 8a,8b, and busses 6a,6b.
In addition to clips 7 connecting the loops and the busses, clips 7 may be provided for electrical connection between interconnecting portions 8c. As in the previous embodiment, the number of clips 7 used will in general depend on the degree of redundancy required. "Redundancy" in this context means the extent to which electrode element 6 may be accidentally severed whilst retaining all of it (or a desired portion of it) powerable. We prefer that the two interconnecting portions 8c at each edge of the overall structure are interconnected by clips 7 spaced about by a distance X of no more than 20 ft., particularly 15 ft., especially 12 ft. Connection between other pairs of interconnecting portions may also be provided. For a typical installation, at least 10 clips 7 would be employed, preferably at least 20.
The number of clips used, will depend not only on the desired avoidance of parts of the electrode becoming isolated, but also on the resistivity of the clips and of the electrode elements 6 and on the way the electrode is powered, for example whether some form of bussing is employed. It will generally be desirable that a substantially uniform potential exist over the surface of the electrode, and this may be facilitated by the provision of a larger number of clips than that desired to prevent isolation. Also, two or more clips may be positioned adjacent one another. The above considerations apply in general to other electrode configurations, and the following discussion of preferred designs of clip applies to these and other electrode configurations.
FIGS. 4-15 illustrate various clips, FIGS. 13 and 14 showing clips in conjunction with electrode elements. Any of various features illustrated and discussed may be combined with any other, and any clip illustrated or discussed may comprise a conductive polymer and/or may comprise electrical interconnection means (preferably contacting each of two electrode elements over surface areas of at least 25 mm 2 more preferably at least 50 mm 2 ) and mechanical interconnection means (preferably restricting movement between electrode portions and maintaining an electrical contact by resilient bias). Where carbon black is used as a filler, we prefer at least 40% especially at least 50% of carbon black of particle size 0.1 mm or less, especially 0.01 mm or less. Other fillers include fibrous fillers (generally up to 30%) such as carbon fibre of fibre length 6 mm or less, graphite and metal oxides.
FIG. 4 shows a clip 7 having means 9, particularly recesses, for locating portions of electrode elements. The mouth of each recess is preferably slightly smaller than the electrode portion that it is to receive, such that the electrode is a snap fit within the clip and will not fall out. Also, we prefer that the cross-sectional size of the recesses 9 is sightly smaller than the electrode portions such that the clip applies some pressure to the portion. Thus, the clip, which preferably comprises a conductive material provides an electrical connection between two electrode portions, which connection is maintained by resilient bias due to elasticity or resilience of the clip and the small size of the recesses. Thus, the means for electrical interconnection and for mechanical interconnection are both provided by a single piece of conductive, resilient material. The clip preferably allows rotation of the electrode portions, and the portions and the recesses are therefore preferably substantially circular in cross-section. We prefer that each clip has only two recesses, but more than two recesses may be preferred for some applications.
Where the electrode portions have an electrochemically active surface, it may be desirable that chemical action at that portion which contacts the clip be retarded in order that a good contact remain between that portion and the clip. A good contact between clip and electrode portion will not only improve electrical contact, but may reduce chemical degradation of electrode (and of the clip where appropriate) since electrolyte will be prevented or hindered from reaching the contacting surfaces. If desired the contacting surfaces may be coated with some electrochemically inactive material to help maintain contact. The extent to which such an electrochemical reaction need be retarded will be reduced if elasticity of the clip (or of the electrode portion) is sufficient to compensate for significant reduction in size of the portion and/or increase in size of the recess 9.
The surface area of the recess (or other contact area) is preferably at least 25 mm 2 more preferably at least 50 mm 2 , more preferably at least 100 mm 2 , particularly at least 200 mm 2 , especially at least 300 mm 2 . The value chosen will depend on the tendency of the materials in question to react and on their resistivity.
We prefer that the resistance of the clip (by which we mean the resistance it offers between two electrode portions when positioned in respective recesses or otherwise properly located) is preferably 25 ohms or less, more preferably 15 ohms or less, particularly 10 ohms or less, especially 5 ohms or less, more especially 3 ohms or less. Where two or more clips join the same portions together with substantially no space between them, these values refer to their resistance in combination.
Where the electrode is used under conditions that it is an anode, it will be desirable that the clips do not corrode, or do so at a reasonably slow rate, especially at least as slowly as that of the electrode portions. One preferred material for at least a portion of the clips is therefore a conductive polymer. Others are non-conductive polymers, carbonaceous materials and noble metals. A preferred polymer comprises an olefinic polymer such as polyethylene, which may be cross-linked.
If desired, the clip may be dimensionally-recoverable, for example heat-shrinkable, such that on heating or other treatment, the recesses 9 close around electrode portions producing good electrical contact and restricting ingress of electrolyte.
The dimensions of the clip shown in FIG. 4 are preferably 0.5-10 mm, more preferably 1-5 mm thickness of material between the two recess and between each recess and the base, and 5-100 mm, more preferably 10-50 mm in length (i.e. along the recesses).
The clip may be used to interconnect two similar or two different electrode portions. For example, one may comprise a carbonaceous anode portion and another may comprise, for example, a titanium or platinum anode. One or both of the recesses may be used to hold a power supply wire or cable, or to hold a splice between two wires or cables. The clip may be used as the means by which power is applied to the electrode. For example, a cable supplying power may be stripped of insulation at its end, or an end portion thereof otherwise rendered conductive at its outer surface. That end is then located with respect to the clip, by placing it in the recess 9 or otherwise. The conductive clip, now live, is then connected to some convenient portion of the electrode. One way of terminating the power supply cable for this purpose is to remove its insulation, and then build the revealed conductor up to the correct diameter for location in the recess by means of a conductive (for example conductive polymer) plug or wrap (such as a tape wrap). The plug or wrap may be held in place by heat shrinking some locating means such as a sleeve over the cable end and bridging the plug or wrap. More simply, perhaps, the plug could be of a heat-shrinkable conductive polymer.
FIG. 5 shows a clip having means 10 for reducing the resistance between the two recesses Such means may comprise a metal set within the clip as shown. The metal has a low resistivity and the conductive polymer provides a less corrosive coating This idea can be taken further by providing a clip (which may be more or less in strip rather than block form), and coat it with a polymeric, and therefore inert, coating at all regions except where it will contact the electrode elements, at which regions the coating may be either absent or may comprise a conductive polymer.
FIG. 6 shows a clip 7 of similar design to that of FIG. 4, except that recesses 6 are disposed on opposite faces.
In FIG. 7, recesses 9 are provided on opposite faces, and are mutually perpendicular. Such a design may be useful for a mesh electrode having rows and columns of perpendicular electrode elements, such as that shown in FIG. 1.
The clip of FIG. 8 comprises a base 11 and two blocks 12, each of which has a recess for an electrode portion. The base 11 may be flexible.
In FIG. 9 the functions of electrical interconnection and mechanical interconnection have been split between a conductive member 12 and a block 14. The block 14 may deform the member 12 around the electrode members and hold it in place.
In FIG. 10, the member 15 provides electrical interconnection and some mechanical interconnection. The blocks 16 serve merely to locate the member 15 with respect to the electrode portions. If member 15 is a metal, it should preferably be a passivating metal such as titanium, tantalum, or niobium.
FIG. 11 shows an additional securing means 17 which may retain or help to retain the electrode portions in the recesses 9. In this case, the recesses need not of course be reentrant (i.e. have a neck) in cross-section to stop the electrode portions falling out. FIG. 11 also shows means such as a pin extending from the base of the clip or a screw or bolt that extends through the clip, by means of which the clip maybe secured to some other article, for example a layer of concrete. Any of the clips illustrated may be provided with such a connecting means.
In FIG. 12, there is a single recess for location of two (or more) electrode members. Whilst direct electrical connection between the two members may be insignificant, due to the small area of contact, this design may provide sufficient electrical contact for some purposes although the surface contact between each electrode portion and the clip is less than in the earlier designs.
FIG. 13 shows a clip 7 having a flange 19 by means of which it may be held in position, for example against a concrete or other surface. Flange 19 may have a hole therein, as illustrated, through which a pin or bolt etc. may be driven into concrete. In another embodiment a pin etc. may be affixed to the underside of the flange 19. The clip 7 of FIG. 13 may be provided with a cover 20 which may provide additional pressure on the electrode portions that are to lie in the recesses 9. The cover 20 may but need not be electrically conductive, and it may be retained at least in part by catches 21. Where such a cover is provided recesses 9 need not have a re-entrant or necked configuration in cross-section.
In FIG. 14, the clip 22 is provided with one hole, closed in cross-section, and one recess 9. The clip has to be slid along an electrode portions 6 from its end, after which it may be clipped to another electrode portion in the usual fashion. A clip could be provided having both (or all) holes closed in cross-section, but this may make achievement of the desired mesh or other electrode configuration rather difficult. Where the design of FIG. 14 is to be used, a suitable number of clips 22 could be slid along an electrode member, the member arranged in a mesh or other configuration, and then the clips, which may need to be slid to desired positions, clipped to nearby electrode portions to stabilize the structure and electrically interconnect its various parts.
A variation of the design of FIG. 14 is shown in FIG. 15, where the clip 7 is an integral protection 23 (or is permanently joined to) the electrode portion 6.
FIG. 16 shows a preferred design of clip 7 having a central portion 24 of low resistivity, shown dotted at its end. In this way desired electrical properties may be combined with desired mechanical properties. Thus, in one embodiment, a conductive portion 24 comprising for example a conductive polymer (such as a polymer loaded with carbon black or other conductive filler) is provided within a support portion 25 which is not, or which is less, conductive. The conductive portion 24 could comprise a non-corrosive metal particularly a metal that forms a conductive oxide. Such metals, often referred to as valve metals, include titanium, palladium and platinum etc. A reason for employing such a portion 24 is that conductive polymers may under unfavourable conditions be stress sensitive, i.e. cracking or loss of resilience may occur especially under corrosive conditions. In the embodiment illustrated, a conductive material bridges electrode elements (not shown) that lie in recesses 9, and a non-conductive material holds the elements and the conductive material in electrical contact. The non-conductive (or less conductive) material preferably has an elongation under service conditions of at least 10%, more preferably at least 20%. The conductive portion 24 illustrated is shown secured to the portion 25 at least in part by an interlocking profile 26 by means of which it may be slid longitudinally or snapped transversely in place and retained. It may, however, be merely bonded, injection moulded, or otherwise fixed. Furthermore, the portion 24 may be smaller than illustrated, being merely a strip extending from one recess 9 to the other; or it may be larger, extending substantially all around one or both of the recesses 9. The portion 24 preferably has a resistivity of less than 5 ohm cm, more preferably less than 3 ohm cm. The clip 7 maybe provided with a recess 27, or other fixing means, by means of which it may be fixed to, for example, the curved clips 7a illustrated in FIG. 3b above, and FIG. 17 below.
FIG. 17 shows a clip 28 that can be used as curved clip 7a as illustrated in FIG. 3b. The clip 28 may be naturally curved, or it may be naturally straight and serve merely to ensure that a loop in an electrode does not kink, such loop being maintained in some other way. The clip 28 comprises a member 29 to which are attached (or with which are integrally formed) connection members 30 each of which having a recess 9 therein, or having means for retaining an electrode element. The electrode element is snapped or slid into the recesses. The clip 28 also has a flange, or other attachment member, 31 for securing it, and therefore the electrode element it carries, to the substrate.
The clip 7 of FIG. 16 (or other clip designs, for example of uniform construction) may be used with another clip, for example the curved clip 28 of FIG. 17. This may be done by engaging a recess 27 of the clip 7 and a portion 32 of the clip 28. The result is as shown in FIG. 3b, where the loops 8a,8b are connected to busses 6a,6b.
In some instances, particularly where a straight recess of a clip is to receive a curved electrode element, a conductive paste or liquid may be provided around the element within the recess to enhance electrical connection. In general, such a paste or liquid may be desirable where the configuration or size or shape of the element differs from that of the recess, or where the element is likely to be deformed after insertion in the recess.
Thus, the electrical interconnection means of the clip (when installed) may comprise a conductive liquid or paste. Paste is here used as a general term to indicate a deformable material of high viscosity that will not readily flow, and which will not therefore leach away. The paste (or liquid) preferably comprises an electrically conductive material dispersed in a fluid medium. The conductive material may comprise carbon black, especially acetylene black, graphite, carbon fibers, or metal fibers or powder particularly metals having an adhesive oxide (the so-called valve metals) such as titanium, palladium or platinum. The fluid medium is preferably repellent to undesirable fluids such as water. Preferred fluid media comprise a silicone oil, although some hydrocarbon oils are suitable. A typical loading of conductive material is 1-50%, especially 10-30%, by weight, these values being particularly suitable for acetylene black in silicone oil. These two components should be thoroughly mixed so that the black is wetted by the oil. This may take 5-10 minutes, with some shear. We prefer that the paste have a volume resistivity of less than 7 ohm cm, more preferably less than 3.5 ohm cm, particularly less than 2.5 ohm cm. | Mesh anodes, particularly suitable for use in the cathodic protection of reinforcing bars in concrete, make use of resiliently deformable conductive clips. The clips secure together portions of the same or different elongate electrodes at spaced-apart junctions of a mesh formed by the electrode(s), thus providing electrical and mechanical connection between the electrode portions at the junctions. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to telecommunications wall outlets.
Telecommunications wall outlets are commonly known. These conventionally have a modular jack providing terminals for a customer's internal wiring for connection by a plug to telecommunication equipment which may be in the form of telephones or data processing terminals. Two modular jacks may be provided and these may be wired for use for different purposes, e.g. one for telephone use and the other for data processing use.
Recently, telecommunications outlets have been used in which a housing, suitably sized to fit into ordinary household electrical wall outlet boxes, carries a modular jack and another connector upon a support. With such outlets, the modular jacks need to be manually wired in a factory environment to the other connector. With the outlet then on site, the other connector then requires connecting to the customer's internal wiring as the outlet is being fitted into the wall outlet box. Because of the small size of the support to enable it to be fitted into a household electrical wall outlet box, there is a complication in that the wiring procedure within the factory is difficult to perform and, when on site, the presence of the factory wiring may be confusing to the installer.
The present invention seeks to provide a telecommunications wall outlet in which the above problems are minimized.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a telecommunications wall outlet comprising a housing for a circuit assembly, and a circuit assembly for mounting within a chamber in the housing: the housing comprising a base and a plurality of walls extending from the base to define the chamber of the housing, and an opening to the chamber remote from the base; and at least one region of a wall of the housing providing guide means projecting inwardly into the chamber and extending in a direction from the opening towards the base, for guiding the circuit assembly into a desired operational position within the chamber; and said region of the wall also defining a cable guide formed in an outer surface of the wall for receiving and guiding cable along the wall from the base towards the opening to the chamber; and the circuit assembly comprising a circuit member, which provides a support element rigidly carrying electrical pathways in intimate contact with the support element, a modular telecommunications jack and a connector; the circuit member having two sides, the jack and the connector both mounted upon the circuit member and both having electrical terminal members, electrical pathways on the support element interconnecting terminal members of the jack with terminal members of the connector; and the circuit member having an edge with a recessed part cooperable with the guide means of the housing for guiding the circuit assembly as it is moved through the opening into the desired operational position with one of the two sides of the circuit member facing the base of the housing.
The circuit member may be in the form of a printed circuit board or a resistor network which comprises a ceramic base with electrical pathways added by thick film techniques.
The invention provides the advantage that with the use of the circuit member which may be in the form of a printed circuit board or resistor network, the wall outlet is of compact form devoid of wiring extending from the modular jack to the connector. Thus, there is no wiring present when the outlet is installed which may confuse the installer as he adds his own wiring to connect the connector to the internal wiring of a customer's premises. Furthermore, the use of the circuit member enables the electrical pathways between the jack and the connector to be made by automatic means devoid of manual control so that the difficult wiring procedure which has previously been followed for wall outlets is completely avoided thereby simplifying the manufacturing process and the cost of the article. The use of a circuit member also avoids rejects caused by bad or incorrect manual wiring.
In addition, wall outlets according to the invention while being of substantially the same size provide different end functions. As examples of this, where a wall outlet has a single modular jack, the jack may be connected to the connector in such a manner by the electrical pathways, that the outlet is either designed for use with a telephone or is designed for use with a data processing terminal. In other examples, where two modular jacks form part of the wall outlet, the end use of these jacks is either designed for the use of both jacks with telephones, designed for the use of both jacks with data processing terminals, or for the use of one jack with a telephone and the other with a terminal. These design differences are accommodated by the use of different design of circuit members, i.e. the design of electrical pathways is different from one design of circuit member to another. A design change in wall outlets may thus be easily controlled by changing the design of circuit member to be used in the wall outlets at a specific time, i.e. upon the total quantity of wall outlets of a first design having met requirements. Such a design change is easily made during continuous in-line production of wall outlets as the assembly procedure of a circuit member with a modular jack and the connector need not change even if the design of circuit member changes if it is understood that the positions of the jack and connector do not change upon the circuit member. Design changes for different end uses of conventional wall outlets would not be easily implemented as this would involve the retaining of assembly personnel to deal with different wiring procedures. Not only would this be time consuming, but would increase the percentage of wall outlet rejects because of confusion.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is an exploded isometric view of a telecommunications wall outlet according to a first embodiment;
FIG. 2 is a front view of a circuit assembly forming part of the wall outlet of FIG. 1;
FIG. 3 is a side elevational view of the circuit assembly taken in the direction of arrow III in FIG. 2;
FIG. 4 is a rear view of the circuit assembly taken in the direction of arrow IV in FIG. 3;
FIG. 5 is a cross-sectional view taken along line V--V in FIG. 2 of a connector forming part of the circuit assembly and shown a larger scale;
FIG. 6 is a cross-sectional view taken along line VI--VI in FIG. 5 of the connector;
FIG. 7 is an isometric view of a terminal member of the connector of FIGS. 5 and 6 and shown to a larger scale;
FIG. 8 is an isometric view from the underside of a body connector of the of FIGS. 5 and 6;
FIG. 9 is a view similar to FIG. 5 showing the connector of FIG. 5 forming part of the circuit assembly;
FIG. 10 is a front view of the completed wall outlet installed in an electrical wall outlet box in a wall;
FIG. 11 is a cross-sectional view of part of the wall outlet taken along line XI--XI in FIG. 10;
FIG. 12 is an isometric view of part of the wall outlet assembly showing a method of leading insulated customer's internal wiring into the outlet;
FIG. 13 is a cross-sectional view taken along line XIII--XIII in FIG. 12;
FIG. 14 is a front view showing a cover plate over the installed wall outlet;
FIG. 15 is a cross-sectional view through the installed wall outlet cover plate and electrical wall outlet box taken along line XV--XV in FIG. 14; and
FIG. 16 is an exploded isometric view showing parts of a wall outlet according to a second embodiment with a housing of the outlet installed upon a wall.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, in a first embodiment, a telecommunications wall outlet 10 comprises a housing 12 and a circuit assembly 14 for mounting within a chamber 16 of the housing.
As shown by FIGS. 1, 2, 3 and 4, the circuit assembly comprises a planar circuit member provided by a planar support element which rigidly carries electrical pathways in intimate contact with the support element. Generally such a circuit member may comprise a resistor network which has a ceramic base and electrical pathways formed by thick film techniques, but, in this embodiment the circuit member comprises a printed circuit board 18 made in conventional manner. The printed circuit board 18 carries two connectors 20, disposed at opposite ends of the board, and two modular telephone jacks 22 located between the two connectors 20, the two modular jacks being aligned across the circuit board.
The connectors 20 are of the construction described in U.S. patent application No. 275,811 in the name of R. Paradis. With reference to FIGS. 5 to 9, the construction of each connector 20 is briefly as follows. Each connector has a single molded planar dielectric body 24 which has along one of its sides a plurality of molded slots 26. A plurality of terminal members 28 extend through the body, each terminal member having a longitudinally extending main portion 30 which is bifurcated for substantially the whole of its length to provide two arms 32 located substantially side-by-side in the same plane. The arms 32 extend into a slot 26 with the arms providing an insulation displacement terminal by defining a slot 34 between them for acceptance of a conductor wire, the slot 34 being in alignment with the corresponding slot 26. As shown in FIGS. 6 and 7, free ends of the two arms are inclined at positions 36 to provide cutting edges for cutting insulation around conductor wires to enable the wires to be forced between the arms with insulation locally removed to cause the wires to make electrical contact with the arms. Such insulation displacement terminals are well known in the art and will be described no further.
To minimize the size of the connector and thus of the circuit board 18 to enable the outlet 10 to be disposed within a conventional domestic electrical wall outlet, the insulation displacement terminals are arranged in two staggered rows in the body 24. For this purpose, the body has cavities 38 for accommodating the terminal members, the cavities themselves overlapping in two rows as shown particularly by FIG. 8.
Each terminal member 28 also comprises a terminal pin 40 which is remote from the arms 32. Each terminal pin 40 lies in a plane displaced laterally from the plane of the arms 32 (see particularly FIGS. 5 and 7) so that when the terminal members are positioned within the cavities 38, the pins lie in two staggered rows with the terminal pins of each row displaced laterally of the plane of the body away from the other row (FIGS. 5 and 9).
Each of the terminal members 28 is inserted into the respective cavity 38 through an opening to the cavity remote from the slots 26. The terminal members are moved into the cavities 38 until shoulders 42 at each side of each terminal member engage with a seating abutment 44 formed within the cavity. To prevent removal of each of the terminal members, each member is also provided with two projections 46 which are inclined relative to the arms 32 so that the projections 46 become embedded into the plastics material of the body 24 as the terminal member is being inserted into the body. As can be seen from FIGS. 5 and 9, the projections 46 embed themselves into the material of the body so as to resist removal of the terminal members.
For mounting the connectors 20 into the circuit board 18, the body 24 of each connector is formed with two molded mounting pins 48 which extend outwardly in the same direction as the terminal pins 40. These pins 48 are received within suitably positioned holes in the circuit board 18 (FIGS. 4, 5 and 9) for assisting in locating the connectors 20 correctly in position with the pins 40 extending through pin receiving holes in the circuit board. The pins 40 are soldered in position within the holes and are thus electrically connected with electrical pathways of the circuit board, these pathways 50 being on the rear surface of the circuit board 18 as shown in FIG. 4.
Each of the modular jacks 22 is of conventional construction in that it has a molded dielectric body 52 formed with a suitable opening to accept a plug for connecting it to customer end user equipment such as a telephone or a data processing terminal. Each modular jack 22 also has a plurality of leaf spring terminals 54 (see FIG. 3) with ends of the leaf springs extending into a chamber of the modular jack for electrical contact with terminals of the plug. The leaf spring terminals 54 extend through the body 52 to terminate in terminal pins 56 (FIG. 3) on a rear side of the body. The body is also formed with a molded pin 58. The modular jacks are assembled onto the circuit board 18 with the pins 58 locating the jacks correctly in position by location through suitably positioned holes in the circuit board. The terminal pins 56 extend into and are soldered within holes 60 in the circuit board (FIG. 4). Thus in the final circuit assembly, the terminal pins 40 of the connectors 20 are electrically connected by the printed circuit pathways 50 with the terminal pins 56 of the modular jacks.
As may be seen from the above description, the circuit assembly 14 may be completely manufactured non-manually. The connectors, modular jacks and the printed circuit board are made by established automatic processes. Automatic operations also mount the connectors and the modular jacks onto the printed circuit board and solder the pins 40 and 56 into position. Thus, the need for manually applied wiring between terminal jacks and connectors is completely avoided together with the problems associated with incorrect wiring. Also, because of the total lack of wiring in the complete circuit assembly, the assembly appears to be of simple construction and is easier for an installer to connect the wall outlet to a customer's internal wiring on site.
As shown in FIG. 1, the housing 12 has two long parallel walls 62 and two short parallel walls 64 forming a rectangular opening to the chamber 16. A base 66 to the chamber extends between the walls in the position opposite the opening.
The housing 12 is provided with guide means for guiding the circuit assembly 14 into a desired operational position within the housing. This guide means comprises at least one region of a wall which projects into the chamber for cooperating with an inwardly extending region of the circuit board 18 as it is moved into the chamber 16 through the opening. In this embodiment, two projecting regions of each wall 62 are provided, each projecting region being in the form of a curved part 68 of its respective wall 62. Each curved part of the wall 62 extends longitudinally from the opening to the chamber as far as the base 66 and is of part cylindrical shape. The curved part of each wall lies opposite to a curved part of the other wall 62 and as can be seen from FIGS. 1, 2 and 4, the circuit board 18 is formed with corresponding convex surface parts 70 in opposite side edges for guiding cooperation with the curved parts 68.
The curved parts 68 of the wall 62 also provide another function in that they provide cable retainers on the housing for supply of telecommunications cable to the connectors 20 when the circuit board is carried within the housing 12. As is shown particularly by FIGS. 1 and 12, each cable retainer is provided by a concave surface 72 formed by the curved part 68 on the outside of the wall 62. An outer projection 74 of the wall extends partially across and is spaced from each concave surface 72 to act as a cable retainer for cable seated against the concave surface. As shown in FIG. 12, a cable 76 may be inserted between a projection 74 and against the concave surface 72 so as to hold it firmly in position so that the conductors 78 of the cable may be connected to the terminals of a connector 20 as will be described.
Each of the curved parts 68 of the wall 62 is also formed with a slot 80 which extends from the opening to the chamber towards the base for passage therethrough of the conductors 78 of the cable as shown by FIGS. 1 and 12. Hence, the curved parts 68 of the walls 72 provide a multifunction in that they serve to guide the circuit assembly 12 into position, provide seating surfaces 72 for a cable while a holding projection 74 holds a cable in position, and also provide access for conductors of the cable from outside of the housing into the chamber 16.
For locating the circuit assembly 12 in its desired operational position, the housing is provided with a stop means for terminating the movement of the circuit assembly along the guides provided by the curved parts 68. The stop means comprises four short projections 82 extending upwardly from the base 66 and outwardly from the walls 64, two projections from each wall. FIG. 1 shows two of the projections for one wall 64 and a projection 82 is also shown in FIGS. 11 and 13.
The housing is also provided with latch means for retaining the circuit assembly in its desired operational position with the rear face of the circuit board 18 engaging the ends of the projections 82 as shown in FIGS. 11 and 13. The latch means is provided by the walls 62. As can be seen from FIG. 1, each of the walls 62 is provided towards each of its ends with two parallel slots 84 extending upwardly from the base for a certain distance to define between the slots a resilient prong 86 which is also separated from the base by a gap 88 as shown in FIG. 11. Each prong 86 is provided with an inward latch projection 90 having an abutment surface facing towards the base 66.
As may be seen, when the circuit assembly 14 is located at the opening to the chamber 16 and with the curved surface parts 70 aligned with the curved parts 68 of the walls, the circuit assembly may be guided into the chamber 16 along the curved parts 68. As the edges of the circuit board 18 engage inclined surfaces 92 of the projections 90, continued inward movement of the circuit assembly towards the base 66 forces the prongs 86 outwardly. Upon the circuit board engaging the projections 82, the circuit board has passed just beyond the ends of the latches 90 thereby allowing the prongs 86 to return resiliently to their normal positions in alignment with the remainder of the walls 62. Hence, the latches 90 hold the circuit board against the stops 82. To enable the circuit board and thus the circuit assembly 12 to be removed from the housing, it is simply necessary to insert a suitable thin instrument into the gaps 88 to flex the prongs 86 outwardly and away from the circuit board so that the latching effect is removed.
The housing 14 is also provided with conductor receiving holes for accepting the ends of conductors extending through the insulation displacement terminals of each of the connectors 20. These conductor receiving holes 94 (FIGS. 1 and 12) extend inwardly towards the base in each of the walls 64 from a recessed surface 96 of each wall 64, the holes being positioned for alignment with corresponding slots 26 of the connectors 20.
As may be seen also from FIG. 1, the housing 14 is formed at opposite ends with two outwardly extending flanges 98 formed with suitable screw receiving slots 100 for location of mounting screws to assemble the housing 14 to an electrical wall outlet box in the conventional manner for mounting electrical sockets into outlet boxes in a domestic premises.
It is a relatively simple matter to assemble together the wall outlet, locate it within an electrical wall outlet box, and to connect incoming telecommunication conductors to the appropriate terminals of the connectors 20.
The assembly of the outlet may be first completed by disposing the circuit assembly 14 within the housing 12 so that their relative positions are as shown in FIG. 10. With the outlet 10 held outside of but closely to the electrical wall outlet box 102, the ends of the internal telecommunications cables 76 which project from the wall through the box 102 are seated and held against the concave surfaces 72 by the projections 74 as described above and shown in FIG. 12. The conductors 78 of these cables are then passed through the slots 80 and are located through slots 26 of connectors 20 to be positioned between the arms 32 of the insulation displacement terminals to make electrical connections therewith. The insulated ends of the conductors 78 which project through the terminals are then bent at right angles and are pushed into the conductor receiving holes 94 for the purpose of protecting the ends of the conductors from short circuiting. As may be seen, when the conductors 78 are fed through the slots 80 and located in the insulation displacement terminals, there are no other wires visible within the housing 14 which may cause confusion to the installer as the printed circuit board pathways take care of the necessary electrical connections and these are in any case on the rear side of the circuit board 18. Hence it is a relatively simple matter for the installer to make the necessary electrical connections in this embodiment.
After assembly of the wires to the outlet, the outlet is then secured to the wall outlet box 102 within the wall 104 (FIG. 14) by captive screws 106 accepted through the slots 100. A suitable cover 108 is then located over the outlet 10. This cover 108 may be resiliently pressed into position. For this purpose, the cover may have shallow inward projections 110 for acceptance within corresponding recesses 112 on the rear free edge of each of the flanges 98 as shown in FIG. 14. The cover 108 has two openings 114 (FIGS. 14 and 15) which are aligned with the openings to the two jacks for acceptance of plugs of telecommunications equipment. These openings 114 may be normally closed by a spring loaded slidable door 116 received between a front wall 118 of the cover and a localized back wall 120 as shown in FIG. 14.
In a second embodiment of the invention as shown in FIG. 16, the structure of an outlet 122 is as described in the first embodiment with the exception that flanges 124 are provided as extensions to the base 66 of the housing 125 instead of having flanges 98 disposed remote from the base as in the first embodiment. The circuit assembly 14 is omitted for clarity and simplicity. As shown in FIG. 16, the outlet of the second embodiment is for location upon the exterior surface of a wall 126 where wiring within the wall and a suitable electrical outlet are not provided. The housing 125 may be shrouded by a suitably shaped box cover 128 having walls 130 which extend around the sides of the housing 125 and are resiliently located in position upon the flanges 124 in a manner similar to the location of the cover 108 in the first embodiment. | A telecommunications wall outlet having a circuit assembly, i.e. a printed circuit or a resistor network within a housing. A modular jack and a connector are electrically connected together by the circuit assembly and are mounted upon it. Preferably, the housing wall and circuit assembly cooperate to hold the circuit assembly in position and the walls have provision for holding conductors in place as they are led from a wall into the outlet. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for opening and shutting selectively in two directions a lid on an automobile console box or any other lid (inclusive of a door) rotatably disposed on an opening of a box body.
2. Description of the Prior Art
An apparatus for opening and shutting the lid of an automobile console box selectively in two directions has been already disclosed in Japanese Utility Model Public Disclosure No. 60-90042, for example.
The conventional apparatus, though not illustrated specifically herein, comprises supporting shafts of a circular cross section disposed laterally one each along the opposite sides of the edge of an opening of a box body and bearings of a C-shaped cross section disposed integrally along the corresponding edges of a lid and adapted to be detachably wrapped one each around the supporting shafts so that the opening of the box body can be completely shut with the lid by rotatably wrapping the bearings around the corresponding supporting shafts. The exposure of the opening of the box body is attained either by removing one of the bearings from the corresponding supporting shaft and rotating the lid about the other supporting shaft as a fulcrum or by removing the other bearing from the corresponding supporting shaft and rotating the lid about the other supporting shaft as a fulcrum, thereby revealing the opening of the box body suitably in either of the two directions.
In accordance with the conventional apparatus, therefore, the lid provided for the box boy can be opened and shut selectively in two directions by adopting the very simple construction having the supporting shafts of a circular cross section disposed on the box body side and the bearings of a C-shaped cross section disposed on the lid side.
However, the conventional apparatus thus constructed has a structural fault in that since one of the bearings subjected to an operation of shutting or opening the lid must be forcibly fastened around the corresponding supporting shaft or forcibly relieved of the fastened state and since the other bearing must be immoderately rotated around the corresponding supporting shaft in response to the aforementioned operation, when the opening and shutting motions are frequently repeated, the C-shaped cross sections of the bearings are radially expanded or deformed and eventually prevented from allowing smooth opening and shutting motions or infallibly producing a perfectly open or shut state.
In view of the problems of the conventional apparatus described above, the present inventor has already proposed a lid switching device in U.S. application Ser. No. 07/764,192 filed on Sep. 23, 1991.
The switching device has the concept of movably supporting a pair of operating members independently on the opposite lateral sides of a lid, disposing on the inner side of the lid a pair of rotary shafts capable of advancing or retreating under influence of resilient pressure of spring means, connecting the rotary shafts one each to the operating members, thereby urging the operating members outwardly from each other by the resilient pressure of the spring means, forming upright lock members integrally on the opposite side edges of an opening of a box body so as to detachably fasten the rotary shafts thereto, and allowing the rotary shafts connected to the operating members to be severally unfastened from the corresponding lock members.
According to the switching device, therefore, the state of the box body closed with the lid is attained by setting the operating members, rotary shafts and spring means on the lid side and covering the opening of the box body with the lid and, as a result, enabling the rotary shafts connected to the operating members to be automatically fastened to the corresponding lock members on the box body side in consequence of the resilient pressure of the spring means. The selective release of the lid in the two directions from the box body is accomplished by pressing the operating member on the side to be opened inwardly against the resilient pressure exerted thereon, thereby enabling the rotary shaft connected to the operating member to be released from the corresponding lock member on the box body side and thereafter rotating the lid upwardly spontaneously around the rotary shaft still remaining fastened to the lock member and serving as a fulcrum of rotation.
Owing to the construction described above, the switching device always ensures production of an infallible opening or shutting operation with a click and a firmly opened or shut state. Even when the opening and shutting operations are frequently repeated, the switching device is free from the possibility of eventually ceasing to produce a smooth opening or shutting motion and an infallible opened or shut state as experienced with the aforementioned conventional apparatus.
In the switching device, however, since the upright lock members are integrally formed in advance on the edge of the opening of the box body, the lock member on the side to be opened is thrust out upwardly as raised from the edge of the opening of the box body when the lid is released in either of the two directions. Thus, the raised lock member has a fair possibility of impairing the attractiveness of appearance and seriously interfering with the insertion or extraction of an object into or from the box body.
SUMMARY OF THE INVENTION
The main object of the present invention is to provide a lid opening and shutting apparatus making full use of the formally proposed switching device and, at the same time, offering an effective solution to the problems encountered by the same switching device.
To accomplish this object, according to the present invention there is provided an apparatus for opening and closing a lid disposed rotatably on an opening of a box body selectively in two directions, which comprises a pair of operating members independently movably supported one each at opposite ends of the lid, spring means having a pair of rotary shafts disposed on an inner side of the lid so as to advance or retreat under the influence of resilient pressure of the spring means, the rotary shafts being connected to the operating members so as to urge the operating members outwardly away from each other by virtue of the resilient pressure of the spring means, two pairs of storage mouths formed in the edge of the opening of the box body at four corner portions thereof, two pairs of lock members pivotally supported inside the storage mouths for detachably supporting the rotary shafts above the storage mouths, each of the rotary shafts connected to the operating members being released from the lock members by a pressing operation of the corresponding operating member, and two pairs of rotary gear mechanisms attached to the lock members so that each pair of rotary gear mechanisms are interconnected to each other and the two pairs of rotary gear mechanisms are interlocked with each other, whereby the pressing operation of one of the operating members to open the lid in one direction causes one pair of lock members on the side being opened to be rotated and plunged into the corresponding pair of storage mouths due to the interlocking between the two pairs of rotary gear mechanisms.
The above and other objects, characteristic features and advantages of the present invention will become more apparent to those skilled in the art from the description of the invention made hereinbelow with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view illustrating one embodiment of the lid opening and shutting apparatus according to the present invention.
FIG. 2 is a front view illustrating the essential part of a rotary gear mechanism attached to a lock member.
FIG. 3 is a side view of the rotary gear mechanism.
FIG. 4 is a front view illustrating the state of the apparatus when a lid is shut relative to a box body.
FIG. 5 is an enlarged explanatory view illustrating the state in which a rotary shaft of spring means has been released from a lock hole of a lock member.
FIG. 6 is an enlarged explanatory view illustrating the state in which a fourth large gear and a first small gear of the rotary gear mechanism are held in a meshed state.
FIG. 7 an enlarged explanatory view illustrating the state in which the lock member is rotated toward a storage mouth.
FIG. 8 is an explanatory view illustrating the state in which the lid is opened in one direction.
FIG. 9 is an explanatory view illustrating the state in which the lid is opened in the opposite direction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Now, the present invention will be described in detail below with reference to the illustrated embodiment.
In the illustrated lid opening and shutting apparatus, a lid 1 is rotatably disposed on a body 2 of an automobile console box, for example so that it is opened and shut selectively in two direction. Basically this apparatus adopts substantially the whole construction of the switching device proposed formerly by the present inventor and explained hereinbefore.
To be specific, as illustrated in FIG. 1, on the side of the lid 1 the apparatus comprises a depressed part 3 formed in the lid 1, two opposed through holes 4 perforated one each in the opposite terminal walls of the lid 1 defining the depressed part 3, two operating buttons 5 each having a communicating hole 6 and each movably supported in the corresponding through hole 4, rectangular linear spring means 7 provided integrally with a pair of rotary shafts 8 and a pair of resilient parts 9 and disposed in a bent state within the depressed part 3, and collars 10 placed one each around the pair of rotary shafts 8 of the spring means 7 so that the resilient pressure derived from bending of the resilient parts 9 of the spring means 7 urge the operating buttons 5 outwardly away from each other inside the through holes 4. The rotary shafts 8 are idly inserted through the communicating holes 6 of the operating buttons 5.
On the side of the box body 2, the apparatus comprises four metallic lock members 11 each provided with a tapered guide part 12 and an L-shaped lock hole 13 and disposed on the opposite terminal parts of the opposed edges of an opening of the box body 2 so as to form two pairs and so that each of the rotary shafts 8 of the spring means 7 may be detachably fastened to the lock holes 13 of one pair of lock members 11.
In addition to the basic construction described above, the lid opening and shutting apparatus of the present invention comprises four storage mouths 14 bored in the opposite terminal parts of the opposed edges of the opening of the box body 2 and adapted to allow submersion therein or emersion therefrom of the lock members 11, common connecting shafts 15 serving to support the lock members 11 rotatably inside the storage mouths 14 positioned in the terminal parts, and double torsion springs 16 attached to the common connecting shafts 15, so that the resilient pressure of the torsion springs 16 continues to urge the lock members 11 in the terminal parts upwardly from the storage mouths 14 and, while the lid 1 is being opened, rotates the lock members 11 on the open side through gear mechanisms G to be specifically described hereinbelow and forces them to submerge in the storage mouths 14.
The double torsion springs 16 are so adapted that when the opposite terminal hook parts thereof are directly fastened to the corresponding lock members 11 and the central hook parts thereof are fastened to stationary shafts 17 disposed in parallel to the connecting shafts 15, the torsional resilient pressure produced serves the purpose of keeping the lock members 11 in their raised state at all times. These stationary shafts 17 and the connecting shafts 15 as well as the double torsion springs 16 are kept consealed with suitable means such as covers, for example.
The gear mechanisms G are provided one each for the lock members 11 and those on each side of the box body 2 are interconnected through a rack 25 to be specifically described hereinbelow so as to be driven in cooperation with each other. Each of the gear mechanisms G comprises a gear-shaped ring member 18 disposed on the side of the lid 1 and a plurality of gears disposed on the side of the box body 2. The gean-shaped ring members 18 have teeth formed on the their own circumferential surfaces and have bored in the central parts thereof oblong holes 19 for allowing the terminals 8a of the pair of rotary shafts 8 to be idly inserted therein. They are integrally projected from the opposed inner surfaces of the depressed part 3 of the lid 1 in the proximity of the terminal parts thereof.
As illustrated in FIGS. 2 and 3, the gears of each gear mechanism G comprise a first small gear 20 fixed to the terminal part of the connecting shaft 15, a second medium gear 21 meshed with the gear-shaped ring member 18 on the side of the lid 1, a third large gear 22 meshed with the second medium gear 21, a fourth large gear 23 disposed co-axially with the third large gear 22 and being meshed with the first small gear 20 when the lid is opened to a prescribed extent, and a fifth small gear 24 disposed coaxially with the third and fourth large gears 22 and 23. These gears are laid out inside the lateral walls of the box body 2, with the fifth small gears 24 on each side of the box body 2 interconnected with the rack 25. A toothed part 23a is formed only in part of the circumference of the fourth large gear 23 so that the toothed part 23a is meshed with the first small gear 20 as shown in in FIGS. 6 and 7 at a fixed time interval. The oblong hole 19 formed in the ring member 18 lies in parallel to the longitudinal direction of the lid 1 and also to the direction of motion of the operating button 5 and further in parallel to the lengthwise direction of the bottom of the L-shaped lock hole 13 of the lock member 11 and has a length roughly eequal to the length of the bottom of the L-shaped lock hole 13.
In the lid opening and shutting apparatus, since the operating buttons 5 are movably supported in the corresponding through holes 4 of the lid 1 and the rotary shafts 8 of the spring means 7 are idly inserted in the corresponding communicating holes 6 of the operating buttons 5, the resilient parts 9 of the spring means 7 are bent inwardly inside the depressed part 3 of the lid 1 and the operating buttons 5 are urged outwardly from the through holes 4 by virtue of the resilient pressure generated by the resilient parts 9.
When, in the state described above, the lid 1 is set to cover the opening of the box body 2, the rotary shafts 8 of the spring means 7 are guided and retracted by the corresponding tapered guide parts 12 of the lock members 11 and, on arrival at the L-shaped lock holes 13 of the lock members 11, are automatically locked at the terminal edges thereof. Thus, the lid assumes the state of unfailing closure with respect to the box body as illustrated in FIG. 4.
While the lid 1 is kept in the state of closure, the rotary shafts 8 of the spring means 7 serving as axes of rotation are infallibly fastened to the lock holes 13 of the corresponding lock members 11 while being urged by the resilient pressure derived from the bending of the pair of resilient parts 9 of the spring means 7 and, at the same time, the ring members 18 on the side of the lid 1 are meshed with the second medium gears 21 on the side of the box body 2 respectively and consequently positioned safely outside the corresponding lock members 11. Thus, the oblong holes 19 of the ring members 18 are allowed to coincide with the bottoms of the lock holes 13.
When the lid 1 is to be released from the state of closure on the left side in FIG. 4, for example, the operating button 5 on the left side accompanied by the rotary shaft 8 of the spring means 7 idly inserted in the communicating hole 6 is pressed inwardly against the resilient pressure and rotated upwardly. As a result, the rotary shaft 8 of the spring means 7 is moved inside the bottoms of the lock holes 13 of the lock members 11 and then moved upwardly as illustrated in FIG. 5 and consequently readied for easy separation from the lock holes 13 of the lock members 11.
In this operation for opening the lid 1, the gear-shaped ring members 18 on the open side are disengaged from the second medium gears 21 and put to motion in concert with the rotation of the lid 1 as indicated by the arrow in FIG. 5. At this time, the terminals 8a of the rotary shaft 8 are allowed to move inside the oblong holes 19 of the corresponding ring members 18 and go to aid in the separation of the rotary shaft 8 from the lock holes 13 of the lock members 11. On the open side, therefore, the presence of the gear-shaped ring members 18 has absolutely no possibility of constituting an obstacle.
On the right side now seating the fulcrum of rotation of the lid 1, the gear-shaped ring members 18 on the right side are rotated while being synchronized with the opening motion of the lid 1 so as to rotate the second medium gears 21 meshed with the ring members 18 in a prescribed direction as indicated by an arrow in FIG. 4. As a result, when the third large gears 22 meshed with the second medium gears 21 are rotated, the fifth small gears 24 disposed coaxially therewith are rotated in the same direction and the rack 25 meshed with the fifth small gears 24 is consequently moved horizontally in the rightward direction in the bearings shown in FIG. 4.
In consequence of the horizontal motion of the rack 25, the fifth small gears 24 on the left side, i.e. on the open side, are rotated in the direction indicated by an arrow in FIG. 6 so as to rotate the fourth large gears 23 disposed coaxially therewith in the same direction and, after the lapse of a prescribed time, bring the toothed parts 23a of the fourth large gears 23 into engagement with the first small gears 20 fixed on the connecting shaft 15.
When the upward rotation of the lid 1 around the rotary shaft 8 fastened to the lock members 11 on the right side as a fulcrum is continued further, the lock members 11 on the left side are synchronously rotated gradually in the direction of the respective storage mouths 14 in spite of the resilient pressure of the double torsion spring 16 as illustrated in FIG. 7 and are finally submerged completely within the corresponding storage mouths 14 as illustrated in FIG. 8. The construction for causing the fourth large gears 23 to be engaged with the first small gears 20 at a fixed time interval is intended to prevent the lock members 11 from being rotated in the direction of the storage mouths 14 until the rotary shafts 8 are completely separated from the lock holes 13 of the lock members 11.
The rotation of the fifth small gears 24 on the open side results in rotation of not only the fourth large gears 23 but also the third large gears 22 disposed coaxially therewith. This operation only keeps the second medium gears 21 in an idling state and has absolutely no bearing on the rotation of the lock members 11.
While the lid 1 is in its completely open state, the lock members 11 on the open side are wholly concealed in the storage mouths 14 as illustrated in FIG. 8. Thus, there is precluded the possibility of the lock members protruding upwardly in an erected state and impairing the attractiveness of the appearance of the lid in an open state as has been experienced in the formerly proposed lid switching device. The apparatus of the present invention has absolutely no possibility of the presence of the lock members 11 constituting an obstacle during the insertion or removal of an object into or from the box body 2.
On the rotary fulcrum side, the rotary shaft 8 fastened with the resilient pressure to the lock members 11 need not be relied on as a sole fulcrum of rotation, because the ring members 18 on the same side are rotated at one same position while being simultaneously meshed with the second medium gears 21, and the lid 1 is consequently rotated stably in the opening direction. The possibility that during the release of the lid 1 from its shut state, the rotary shaft 8 serving as a fulcrum of rotation will accidentally move out of its position and clatter is completely removed. Furthermore, the rotation of the lid 1 and the consequent sympathetic rotation of the ring members 18 entail a gradual change in the direction of the oblong holes 19 in the ring members 18 and disrupt the coincidence between the directions of the oblong holes 19 and the bottoms of the lock holes 13 in the lock members 11 as shown in FIG. 8. Even when an external force is exerted accidentally on the operating bottons 5 during the absence of this coincidence, the possibility that the rotary shaft 8 on the rotary fulcrum side will readily separate from the lock holes 13 of the lock members 11 and the lid 1 will consequently break off the box body 2 is completely eliminated by the regulating action of the oblong holes 19 in the ring members 18.
The lid having been opened on the left side is rotated downwardly to be shut. As a result, the ring members 18, second medium gears 21, third large gears 22 and fifth small gears 24 on the rotary fulcrum side are rotated in their respective directions opposite those mentioned in the case of opening the lid on the left side as described above, and the racks 25 are moved in the leftward direction in the bearings shown in FIG. 8. Consequently, the fourth large gears 23 and first small gears 20 are disengaged from each other and the lock members 11 are automatically rotated again with the resilient pressure of the double torsion springs 16 and synchronously erected upwardly out of the storage mouths 14 on the open side.
Then, the downward rotation of the lid 1 around the rotary shaft 8 fastened to the lock members 11 on the right side as a fulcrum of rotation is continued. As a result, the rotary shaft 8 of the spring means 7 on the left side collides against the tapered guide parts 12 of the erected lock members 11 and are guided by the guide parts 12 and automatically fastened again to the lock holes 13 of the lock members 11. Consequently, the lid 1 assumes the same infallibly shut state as described above.
Conversely, for the purpose of opening the lid 1 on the right side in the bearings shown in FIG. 4, the operating button 5 on the right side is depressed inwardly against the resilient pressure accompanied by the rotary shaft 8 of the spring means 7 idly inserted in the communicating holes 6. As a result, the rotary shaft 8 of the spring means 7 is readily removed from the lock holes 13 of the lock members 11 in the same manner as described above. Consequently, the lid 1 can be readily opened from the right side as illustrated in FIG. 9 by rotating the lid 1 straight upwardly around the rotary shaft 8 fastened to the lock holes 13 of the lock members 11 on the left side as a fulcrum of rotation.
In this case, the ring members 18 on the left side rotate the second medium gears 21 synchronously with the opening action of the lid 1 on the rotary fulcrum side. As a result, the third gears 22 meshed with the second medium gears 21 are rotated and, at the same time, the fifth small gears 24 disposed coaxially therewith are rotated and the racks 25 meshed with the fifth small gears 24 are consequently moved in the leftward direction in the bearings shown in FIG. 9. In consequence of the motion of the racks 25, the fifth small gears 24 on the right side are rotated and the fourth large gears 23 disposed coaxially therewith are rotated in the same direction and, after the lapse of a prescribed time interval, meshed with the first small gears 20 fixed to the connecting shaft 15.
Similarly when the lid 1 is opened on the right side, therefore, the lock members 11 on the open side are gradually rotated in the direction of the storage mouths 14 against the resilient pressure of the double torsion spring 16 while being synchronized with the opening action of the lid 1 and are finally submerged in the corresponding storge mouths 14. While the lid 1 is in the finally open state, the possibility of the lock members 11 protruding upwardly and impairing the attractiveness of the appearance of the apparatus and consequently constituting an obstacle to the insertion or extraction of an object into or from the box body 2 is precluded in the same manner as when the lid 1 is opened on the left side.
Although the gear mechanisms G are provided one each for the lock members 11, the necessity for removing the lid 1 from the box body 2 can be readily fulfilled by simultaneously depressing the two operating buttons 5 inwardly and consequently removing the two rotary shafts 8 of the spring means 7 together from the lock holes 13 of the lock members.
The embodiment described above, for the purpose of promoting structural simplicity, has the rotary shafts disposed integrally in the opposite lateral parts of the rectangular spring means 7 to serve concurrently as fulcra of rotation of the lid. Optionally, these rotary shafts may be formed separately of the spring means.
Furthermore, the present embodiment has been described as applied to the lid for an autobobile console box. The present invention is not limited to this particular application, but may be easily practised otherwise without departing from the spirit of the invention and without reference to the designation of the subject matter of application as in various lids and doors including refrigerator doors, on the sole condition that the lid or door should be capable of being opened or shut in two directions.
Owing to the adoption of the construction described above, the present invention enables the lid disposed rotatably on the opening of the box body to be opened or shut selectively in two directions. Thus, the present invention ensures that the lid always produces an infallible opening or shutting motion with a click and assumes a safe open or shut state. Even if the opening and shutting operatons of the lid is frequently repeated, the present invention is free from the possibility of eventually failing to meet the expectation of a smooth opening or shutting motion or an infallible open or shut state as experienced with the conventional apparatus.
Moreover, in the present invention, owing to the construction having the lock members rotatably supported in place in the storage mouths dug in the box body and the gear mechanisms for rotation provided one each for the lock members supported pivotally in the storage mouths so that the gear mechanisms are interconnected to each other, the lock members on the open side can be rotated and automatically submerged inside the storage mouths by the synchronized drive of the gear mechanisms on the rotary fulcrum side and the gear mechanisms on the open side without reference to the choice of the direction for opening the lid. During the release of the lid from its shut state, therefore, the possibility of the lock members protruding upwardly, impairing the attractiveness of the appearance of the apparatus and constituting an obstacle to the insertion or extraction of an object into or from the box body is completely eliminated. | An apparatus for opening and closing a lid disposed rotatably on an opening of a box body selectively in two directions includes a pair of operating members independently movably supported one each at opposite ends of the lid, a spring member having a pair of rotary shafts disposed on an inner side of the lid so as to advance or retreat under the influence of resilient pressure of the spring member, two pairs of storage mouths formed in the edge of the opening of the box body at four corner portions thereof, two pairs of lock members pivotally supported inside the storage mouths for detachably supporting the rotary shafts above the storage mouths, and two pairs of rotary gear mechanisms attached to the lock members so that each pair of rotary gear mechanisms are interconnected to each other and the two pairs of rotary gear mechanisms are interlocked with each other. The rotary shafts are connected to the operating members so as to urge the operating members outwardly away from each other by virtue of the resilient pressure of the spring member. Each of the rotary shafts connected to the operating members is released from the lock members by a pressing operation of the corresponding operating member. The pressing operation of one of the operating members to open the lid in one direction causes one pair of lock members on the side being opened to be rotated and plunged into the corresponding pair of storage mouths due to the interlocking between the two pairs of rotary gear mechanisms. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to an overrunning, one-way drive device, such as a brake or clutch, whose engaged and disengaged states are selectively controllable.
2. Description of the Prior Art
Conventionally a one-way brake (OWB) or one-way clutch requires two circular rings or raceways, because the raceway that transmits input torque contains the locking elements, such as rollers, struts, or rockers. The input race contains the struts because centrifugal forces are used to move the locking elements away from the output race, which reacts torque. The output raceway is annular, because the locking elements may stop at any location against the output raceway.
Centrifugal force is used to move the locking elements away from the output raceway to limit the duty cycle on the locking elements and springs during the overrun phase of the OWB. If centrifugal force were not employed in this way, the locking elements would wear prematurely and the spring duty cycle could cause premature failure.
The raceways should be annular to satisfy the need to distribute the mass of the rotating components evenly, thereby avoiding an objectionable amount of unbalance.
But conventional raceways for one-way clutches and brakes are expensive, heavy and require too much space.
SUMMARY OF THE INVENTION
A drive device includes a first one-way coupling including a cam plate, pocket plate and struts, a second one-way coupling including a second cam plate driveably connected to the pocket plate, second pocket plate extending in a partial circular arc and secured to the cam plate, and second struts for opening and closing a drive connection between said second plates, and electromagnets for causing the second struts to close said drive connection.
The raceways are the largest components in a one-way brake or one-way clutch, the heaviest components, and the most expensive components.
The second pocket plate has the form of a circular arc, whose includes angle is substantially less than ninety degree, large enough to contain the necessary number of struts, thereby reducing the cost and weight of the raceway and minimizing space required for it in the transmission.
The scope of applicability of the preferred embodiment will become apparent from the following detailed description, claims and drawings. It should be understood, that the description and specific examples, although indicating preferred embodiments of the invention, are given by way of illustration only. Various changes and modifications to the described embodiments and examples will become apparent to those skilled in the art.
DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood by reference to the following description, taken with the accompanying drawings, in which:
FIG. 1 is a front view of a selectable OWC in which the rings are aligned axially;
FIG. 2 is side perspective view of the selective OWC of FIG. 1 ;
FIG. 3 is a perspective view of the electromagnets, second struts and second pocket plate of the selective OWC of FIG. 1 ; and
FIG. 4 is a side showing the second struts and coils assembled in the second pocket plate.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The selectable OWB 10 shown in FIGS. 1 , 2 and 3 includes a radial outer, first cam plate 12 ; a first pocket plate 14 ; a radial inner, second cam plate 16 ; and a radial inner, second pocket plate 18 . A lead frame 20 is removed to show three coils 24 of electromagnets and three second struts 26 . Plates 12 , 14 , 16 , 18 are aligned with an axis 22 .
The radial outer surface of first cam plate 12 is formed with spline teeth 28 , by which cam plate 12 is secured against rotation to a stationary component of a transmission assembly, preferably to a transmission case. Similarly, the radial inner surface of first pocket plate 14 is formed with spline teeth 30 , by which pocket plate 14 is secured to a reaction carrier of a transmission gearset. The carrier transmits torque to the OWB 10 , causing the first pocket plate 14 -second cam plate 16 subassembly to rotate.
First pocket plate 14 supports struts 32 , each strut being urged by a respective spring 34 to pivot radially outward into engagement with one of the cams 36 on first cam plate 12 , thereby driveably connecting first pocket plate 14 and first cam plate 12 and holding cam plate 12 against rotation. A retainer plate 21 , located between an axial surface of pocket plate 14 and an axial surface of the second cam plate 16 , prevents interference with the struts 32 .
Centrifugal force produced on each of the struts 32 overcomes the force of the respective spring 34 , which pivots the strut toward the cams 36 . At high speed, each strut 32 pivots away from the cams 36 , reducing the duty cycle on the spring. The first cam plate 12 must be a complete circle because the first pocket plate 14 can stop rotating at any angular position.
The first cam plate 12 , first pocket plate 14 and struts 32 comprise a first drive coupling, in this case a one-way brake, which locks or engages when the first pocket plate rotates clockwise (when viewed as shown in FIG. 1 ) relative to the first cam plate, and overruns when the first pocket plate rotates counterclockwise (when viewed as shown in FIG. 1 ) relative to the first cam plate.
The inner surface of the second cam plate 16 is formed with internal spline teeth 38 , which mesh with external spline teeth 39 on the outer surface of the first pocket plate 14 .
The second pocket plate 18 is bolted to the first cam plate 12 , which is fixed against rotation. A retainer plate 40 and a member 23 connect the opposite ends of the second pocket plate 18 . Each of the second struts 26 is pivotably supported on the second pocket plate 18 . A spring 42 , preferably a helical spring, at each pocket location urges the respective strut 26 to pivot radially outward away from the cams 44 on the second cam plate 16 , thereby opening a drive connection between the second cam plate 16 and the second pocket plate 18 .
The second cam plate 16 , second pocket plate 18 and struts 26 comprise a second drive coupling, also a one-way brake, which locks or engages when the first pocket plate 14 rotates counterclockwise (when viewed as shown in FIG. 1 ) relative to the first cam plate and electric current is supplied to coils 24 , and overruns when the first pocket plate rotates clockwise (when viewed as shown in FIG. 1 ) relative to the first pocket plate 14 .
In operation, when electric current is supplied to each coil 24 of the electromagnets, the magnetic field carried through the respective strut 26 causes the strut to pivot radially inward toward the cams 44 , thereby closing a drive connection between the second cam plate 16 and the second pocket plate 18 . When at least one of the struts 26 engages one of the cams 44 , the second cam plate is fixed against rotation through struts 26 , second pocket plate 18 and first cam plate 12 .
When the coils are deenergized and the springs 42 pivot the second struts 26 out of engagement with cams 44 , each second strut contacts a standoff or stop 46 , supported on a radial surface of the second pocket plate 18 . Preferable the stop is of a plastic or another material having relatively low magnetic permeability.
Because the coils 24 that produce electromagnets are supplied with electric current, they must be in the second pocket plate 18 , which is a static race. Because magnetic flux forces struts 26 into engagement with the second pocket plate 18 , i.e., the static race, unbalance is not an issue and pocket plate 18 may have a shape that is other than a full circle.
FIG. 4 shows one of the second struts 26 located in a pocket 50 formed in the second pocket plate 18 , the strut being disengaged from the cams 44 of the second cam plate 16 and contacting stop 46 due to the effects of gravity and the force Fs produced by spring 42 . Each spring 42 is located in a cylindrical recess 52 formed in plate 18 .
Each pocket 50 is formed with concave cylindrical surface 54 , on which a complementary convex surface of strut 26 pivots. Each pocket 50 is also formed with concave cylindrical surface 56 , which guides movement of the strut 26 and limits its radial movement.
When electric current is supplied to coil 24 , a magnetic field is produced such that its lines of magnetic flux or magnetic induction pass between the opposite poles and along the axial width of strut 26 due to its high magnetic permeability. The magnetic field produces distributed force Fm on the strut 26 and magnetically induces a moment on the strut, which causes the strut to pivot clockwise on surface 54 and into engagement with the cams 44 of the second cam plate 16 . FIG. 1 shows one of the struts 26 engaged with one of the cams 44 and two struts disengaged from the cams 44 and contacting stops 46 .
Surface 54 applies force Fg to the strut 26 at the pivot, and surface 56 applies force Fp to the strut.
A transmission controller opens and closes a connection between a source of electric current and the coils 24 . Because centrifugal force is not used to pivot the struts 26 into engagement with second cam plate
Second pocket plate 18 extends along a circular arc that is less than 360 degrees. Radial lines drawn from axis 22 to the angular extremities of second pocket plate 18 form an included angle A, whose magnitude is about 75 degrees. The second pocket plate 18 is large enough to contain the necessary number of struts 26 , thereby reducing the cost and weight of the raceway and minimizing space required in the transmission.
In accordance with the provisions of the patent statutes, the preferred embodiment has been described. However, it should be noted that the alternate embodiments can be practiced otherwise than as specifically illustrated and described. | A drive device includes a first one-way coupling including a cam plate, pocket plate and struts, a second one-way coupling including a second cam plate driveably connected to the pocket plate, second pocket plate extending in a partial circular arc and secured to the cam plate, and second struts for opening and closing a drive connection between said second plates, and electromagnets for causing the second struts to close said drive connection. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/972,332, filed on Sep. 14, 2007. This application is related to U.S. patent application Ser. Nos. 11/557,715 filed on Nov. 8, 2006, 11/561,108 filed on Nov. 17, 2006, 11/561,100 filed on Nov. 17, 2006, and 11/956,722 filed on Dec. 14, 2007. The disclosures of the above applications are incorporated herein by reference in their entirety.
STATEMENT OF GOVERNMENT RIGHTS
[0002] This disclosure was produced pursuant to U.S. Government Contract No. DE-FC-04-03 AL67635 with the Department of Energy (DoE). The U.S. Government has certain rights in this disclosure.
FIELD
[0003] The present disclosure relates to particulate matter (PM) filters, and more particularly to electrically heated PM filters.
BACKGROUND
[0004] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0005] Engines such as diesel engines produce particulate matter (PM) that is filtered from exhaust gas by a PM filter. The PM filter is disposed in an exhaust system of the engine. The PM filter reduces emission of PM that is generated during combustion.
[0006] Over time, the PM filter becomes full. During regeneration, the PM may be burned within the PM filter. Regeneration may involve heating the PM filter to a combustion temperature of the PM. There are various ways to perform regeneration including modifying engine management, using a fuel burner, using a catalytic oxidizer to increase the exhaust temperature after injection of fuel, using resistive heating coils, and/or using microwave energy. The resistive heating coils are typically arranged in contact with the PM filter to allow heating by both conduction and convection.
[0007] Diesel PM combusts when temperatures above a combustion temperature such as 600° C. are attained. The start of combustion causes a further increase in temperature. While spark-ignited engines typically have low oxygen levels in the exhaust gas stream, diesel engines have significantly higher oxygen levels. While the increased oxygen levels make fast regeneration of the PM filter possible, it may also pose some problems.
[0008] PM reduction systems that use fuel tend to decrease fuel economy. For example, many fuel-based PM reduction systems decrease fuel economy by 5%. Electrically heated PM reduction systems reduce fuel economy by a negligible amount. However, durability of the electrically heated PM reduction systems has been difficult to achieve.
SUMMARY
[0009] A system includes a particulate matter (PM) filter that includes an upstream end for receiving exhaust gas and a downstream end. A zoned heater is arranged spaced from the upstream end and comprises N zones, where N is an integer greater than or equal to one, wherein each of the N zones comprises M sub-zones, where M is an integer greater than one, and wherein the N zones and the M sub-zones are arranged in P layers, where P is an integer greater than one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates non-selected ones of the N zones.
[0010] A method includes providing a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end, arranging a zoned heater spaced from the upstream end that includes N zones, where N is an integer greater than one, wherein each of the N zones comprises M sub-zones, and where M is an integer greater than or equal to one, and wherein the N zones and the M sub-zones are arranged in P layers, where P is an integer greater than one, and selectively activating at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates non-selected ones of the N zones.
[0011] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0012] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
[0013] FIG. 1 is a functional block diagram of an exemplary engine including a particulate matter (PM) filter with a zoned inlet heater that is spaced from the PM filter;
[0014] FIG. 2 illustrates exemplary zoning of the zoned inlet heater of the electrically heated particulate matter (PM) filter of FIG. 1 in further detail;
[0015] FIG. 3 illustrates exemplary zoning of the zoned inlet heater of the electrically heated PM filter of FIG. 1 in further detail;
[0016] FIG. 4 illustrates an exemplary resistive heater in one of the zones of the zoned inlet heater of FIG. 3 ;
[0017] FIG. 5 illustrates the electrically heated PM filter having a zoned electric heater that is spaced from the PM filter;
[0018] FIG. 6 illustrates heating within the zoned electric heater;
[0019] FIG. 7 is a flowchart illustrating steps performed by the control module to regenerate the PM filter;
[0020] FIG. 8A illustrates exemplary overlapping zoning of a zoned inlet heater including multiple layers;
[0021] FIG. 8B illustrates a cross-section of exemplary overlapping zoning of the zoned inlet heater of FIG. 8A ;
[0022] FIG. 9A illustrates exemplary overlapping zoning of a zoned inlet heater including three layers; and
[0023] FIG. 9B illustrates a cross-section of exemplary overlapping zoning of the zoned inlet heater of FIG. 9A .
DETAILED DESCRIPTION
[0024] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
[0025] As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
[0026] The present disclosure utilizes a heater with zones. The electrical heater is spaced from the PM filter. In other words, the electric heater is located in front of the PM filter but is not in contact with the downstream PM filter. The heater selectively heats portions of the PM filter. The PM heater may be mounted close enough to the front of the PM filter to control the heating pattern. The length of the heater is set to optimize the exhaust gas temperature.
[0027] Thermal energy is transmitted from the heater to the PM filter by the exhaust gas. Therefore the PM filter is predominantly heated by convection. The electrical heater is divided into zones to reduce electrical power required to heat the PM filter. The zones also heat selected downstream portions within the PM filter. By heating only the selected portions of the filter, the magnitude of forces in the substrate is reduced due to thermal expansion. As a result, higher localized soot temperatures may be used during regeneration without damaging the PM filter.
[0028] The PM filter is regenerated by selectively heating one or more of the zones in the front of the PM filter and igniting the soot using the heated exhaust gas. When a sufficient face temperature is reached, the heater is turned off and the burning soot then cascades down the length of the PM filter channel, which is similar to a burning fuse on a firework. In other words, the heater may be activated only long enough to start the soot ignition and is then shut off. Other regeneration systems typically use both conduction and convection and maintain power to the heater (at lower temperatures such as 600 degrees Celsius) throughout the soot burning process. As a result, these systems tend to use more power than the system proposed in the present disclosure.
[0029] The burning soot is the fuel that continues the regeneration. This process is continued for each heating zone until the PM filter is completely regenerated.
[0030] The heater zones are spaced in a manner such that thermal stress is mitigated between active heaters. Therefore, the overall stress forces due to heating are smaller and distributed over the volume of the entire electrically heated PM filter. This approach allows regeneration in larger segments of the electrically heated PM filter without creating thermal stresses that damage the electrically heated PM filter.
[0031] A largest temperature gradient occurs at edges of the heaters. Therefore, activating one heater past the localized stress zone of another heater enables more actively heated regeneration volume without an increase in overall stress. This tends to improve the regeneration opportunity within a drive cycle and reduces cost and complexity since the system does not need to regenerate as many zones independently.
[0032] Referring now to FIG. 1 , an exemplary diesel engine system 10 is schematically illustrated in accordance with the present disclosure. It is appreciated that the diesel engine system 10 is merely exemplary in nature and that the zone heated particulate filter regeneration system described herein can be implemented in various engine systems implementing a particulate filter. Such engine systems may include, but are not limited to, gasoline direct injection engine systems and homogeneous charge compression ignition engine systems. For ease of the discussion, the disclosure will be discussed in the context of a diesel engine system.
[0033] A turbocharged diesel engine system 10 includes an engine 12 that combusts an air and fuel mixture to produce drive torque. Air enters the system by passing through an air filter 14 . Air passes through the air filter 14 and is drawn into a turbocharger 18 . The turbocharger 18 compresses the fresh air entering the system 10 . The greater the compression of the air generally, the greater the output of the engine 12 . Compressed air then passes through an air cooler 20 before entering into an intake manifold 22 .
[0034] Air within the intake manifold 22 is distributed into cylinders 26 . Although four cylinders 26 are illustrated, the systems and methods of the present disclosure can be implemented in engines having a plurality of cylinders including, but not limited to, 2, 3, 4, 5, 6, 8, 10 and 12 cylinders. It is also appreciated that the systems and methods of the present disclosure can be implemented in a V-type cylinder configuration. Fuel is injected into the cylinders 26 by fuel injectors 28 . Heat from the compressed air ignites the air/fuel mixture. Combustion of the air/fuel mixture creates exhaust. Exhaust exits the cylinders 26 into the exhaust system.
[0035] The exhaust system includes an exhaust manifold 30 , a diesel oxidation catalyst (DOC) 32 , and a particulate filter (PM filter) assembly 34 with a zoned inlet heater 35 . Optionally, an EGR valve (not shown) re-circulates a portion of the exhaust back into the intake manifold 22 . The remainder of the exhaust is directed into the turbocharger 18 to drive a turbine. The turbine facilitates the compression of the fresh air received from the air filter 14 . Exhaust flows from the turbocharger 18 through the DOC 32 , through the zoned heater 35 and into the PM filter assembly 34 . The DOC 32 oxidizes the exhaust based on the post combustion air/fuel ratio. The amount of oxidation increases the temperature of the exhaust. The PM filter assembly 34 receives exhaust from the DOC 32 and filters any soot particulates present in the exhaust. The zoned inlet heater 35 is spaced from the PM filter assembly 34 and heats the exhaust to a regeneration temperature as will be described below.
[0036] A control module 44 controls the engine and PM filter regeneration based on various sensed information. More specifically, the control module 44 estimates loading of the PM filter assembly 34 . When the estimated loading is at a predetermined level and the exhaust flow rate is within a desired range, current is controlled to the PM filter assembly 34 via a power source 46 to initiate the regeneration process. The duration of the regeneration process may be varied based upon the estimated amount of particulate matter within the PM filter assembly 34 .
[0037] Current is applied to the zoned heater 35 during the regeneration process. More specifically, the energy heats selected zones of the heater 35 of the PM filter assembly 34 for predetermined periods, respectively. Exhaust gas passing through the heater 35 is heated by the activated zones. The heated exhaust gas travels to the downstream filter of PM filter assembly 34 and heats the filter by convection. The remainder of the regeneration process is achieved using the heat generated by the heated exhaust passing through the PM filter.
[0038] Referring now to FIG. 2 , an exemplary zoned inlet heater 35 for the PM filter assembly 34 is shown in further detail. The zoned inlet heater 35 is arranged spaced from the PM filter assembly 34 . The PM filter assembly 34 includes multiple spaced heater zones including zone 1 (with sub-zones 1 A, 1 B and 1 C), zone 2 (with sub-zones 2 A, 2 B and 2 C) and zone 3 (with sub-zones 3 A, 3 B and 3 C). The zones 1 , 2 and 3 may be activated during different respective periods.
[0039] As exhaust gas flows through the activated zones of the heater, regeneration occurs in the corresponding portions of the PM filter that initially received the heated exhaust gas (e.g. areas downstream from the activated zones) or downstream areas that are ignited by cascading burning soot. The corresponding portions of the PM filter that are not downstream from an activated zone act as stress mitigation zones. For example in FIG. 2 , sub-zones 1 A, 1 B and 1 C are activated and sub-zones 2 A, 2 B, 2 C, 3 A, 3 B, and 3 C act as stress mitigation zones.
[0040] The corresponding portions of the PM filter downstream from the active heater sub-zones 1 A, 1 B and 1 C thermally expand and contract during heating and cooling. The stress mitigation sub-zones 2 A and 3 A, 2 B and 3 B, and 2 C and 3 C mitigate stress caused by the expansion and contraction of the heater sub-zones 1 A, 1 B and 1 C. After zone 1 has completed regeneration, zone 2 can be activated and zones 1 and 3 act as stress mitigation zones. After zone 2 has completed regeneration, zone 3 can be activated and zones 1 and 2 act as stress mitigation zones.
[0041] Referring now to FIG. 3 , another exemplary zoned inlet heater arrangement is shown. A center portion may be surrounded by a middle portion including a first circumferential band of zones. The middle portion may be surrounded by an outer portion including a second circumferential band of zones.
[0042] In this example, the center portion includes zone 1 . The first circumferential band of zones includes zones 2 and 3 . The second circumferential band of zones comprises zones 1 , 4 and 5 . As with the embodiment described above, downstream portions from active zones are regenerated while downstream portions from inactive zones provide stress mitigation. As can be appreciated, one of the zones 1 , 2 , 3 , 4 and 5 can be activated at a time. Others of the zones remain inactivated.
[0043] Referring now to FIG. 4 , an exemplary resistive heater 100 arranged adjacent to one of the zones (e.g. zone 3 ) from the first circumferential band of zones in FIG. 3 is shown. The resistive heater 100 may comprise one or more coils that cover the respective zone to provide sufficient heating.
[0044] Referring now to FIG. 5 , the PM filter assembly 34 is shown in further detail. The PM filter assembly 34 includes a housing 200 , a filter 202 , and the zoned heater 35 . The heater 35 may be arranged between a laminar flow element 210 and a substrate of the filter 202 . An electrical connector 211 may provide current to the zones of the PM filter assembly 34 as described above.
[0045] As can be appreciated, the heater 35 may be spaced from the filter 202 such that the heating is predominantly convection heating. Insulation 212 may be arranged between the heater 35 and the housing 200 . Exhaust gas enters the PM filter assembly 34 from an upstream inlet 214 and is heated by one or more zones of the PM filter assembly 34 . The heated exhaust gas travels a distance and is received by the filter 202 . The heater 35 may be spaced from and not in contact with the filter 202 .
[0046] Referring now to FIG. 6 , heating within the PM filter assembly 34 is shown in further detail. Exhaust gas 250 passes through the heater 35 and is heated by one or more zones of the heater 35 . The heated exhaust gas travels a distance “d” and is then received by the filter 202 . The distance “d” may be ½ or less. The filter 202 may have a central inlet 240 , a channel 242 , filter material 244 and an outlet 246 located radially outside of the inlet. The filter may be catalyzed. The heated exhaust gas causes PM in the filter to burn, which regenerates the PM filter. The heater 35 transfers heat by convection to ignite a front portion of the filter 202 . When the soot in the front face portions reaches a sufficiently high temperature, the heater is turned off. Combustion of soot then cascades down a filter channel 254 without requiring power to be maintained to the heater.
[0047] Referring now to FIG. 7 , steps for regenerating the PM filter are shown. In step 300 , control begins and proceeds to step 304 . If control determines that regeneration is needed in step 304 , control selects one or more zones in step 308 and activates the heater for the selected zone in step 312 . In step 316 , control estimates a heating period sufficient to achieve a minimum filter face temperature based on at least one of current, voltage, exhaust flow and exhaust temperature. The minimum face temperature should be sufficient to start the soot burning and to create a cascade effect. For example only, the minimum face temperature may be set to 700 degrees Celsius or greater. In an alternate step 320 to step 316 , control estimates current and voltage needed to achieve minimum filter face temperature based on a predetermined heating period, exhaust flow and exhaust temperature.
[0048] In step 324 , control determines whether the heating period is up. If step 324 is true, control determines whether additional zones need to be regenerated in step 326 . If step 326 is true, control returns to step 308 . Otherwise control ends.
[0049] In use, the control module determines when the PM filter requires regeneration. Alternately, regeneration can be performed periodically or on an event basis. The control module may estimate when the entire PM filter needs regeneration or when zones within the PM filter need regeneration. When the control module determines that the entire PM filter needs regeneration, the control module sequentially activates one or more of the zones at a time to initiate regeneration within the associated downstream portion of the PM filter. After the zone or zones are regenerated, one or more other zones are activated while the others are deactivated. This approach continues until all of the zones have been activated. When the control module determines that one of the zones needs regeneration, the control module activates the zone corresponding to the associated downstream portion of the PM filter needing regeneration.
[0050] Referring now to FIGS. 8A and 8B , a zoned inlet heater 400 that includes a plurality of overlapping layers is shown. The plurality of layers are spaced apart in different planes (i.e. are not coplanar) as shown in cross section in FIG. 8B . When heater zones are activated as described above in FIGS. 1-7 , the zones may thermally expand and/or shift. Individual heater zones may be spaced apart to allow for possible expansion and shifting. Consequently, soot may collect between heater zones within the PM filter. Overlapping layers of zones provide regeneration heating to regions of the PM filter that would typically correspond to spaces between heater zones.
[0051] For example, the zoned inlet heater 400 may include a first layer 402 (including zones 1 , 4 , and 5 ) and a second layer 404 (including zones 2 and 3 ). The zones of the first layer 402 are located in a first plane and the zones of the second layer 404 are located in a second plane and are spaced apart from the zones of the first layer 402 . The zones of the first layer 402 overlap the zones of the second layer 404 .
[0052] Referring now to FIGS. 9A and 9B , a zoned inlet heater 500 includes a first layer 502 (including zones 1 , 4 , and 5 ), a second layer 504 (including zones 2 and 3 ), and a third layer 506 (including zones 6 and 7 ). The zones of the first layer 502 are located in a first plane, the zones of the second layer 504 are located in a second plane, and the zones of the third layer 506 are located in a third plane. Each of the layers 502 , 504 , and 506 are spaced apart from each other. The zones of the first layer 502 overlap the zones of each of the second layer 504 and the third layer 506 .
[0053] As shown in FIGS. 8A and 8B , the heater zones are located in two different layers. As shown in FIGS. 9A and 9B , the heater zones are located in three different layers. Those skilled in the art can appreciate that other implementations may include two, three, or more heater layers including zones arranged in any suitable configuration. The heater zones of each of the layers may be selectively activated and deactivated in any suitable manner such as those described in previous implementations shown in FIGS. 1-7 . For example only, the heater zones may be activated sequentially such that when zone 1 is activated, zones 2 - 7 are deactivated and when zone 2 is activated, zones 1 and 3 - 7 are deactivated.
[0054] In another implementation, zones in non-adjacent layers may be activated at the same time. For example, as shown in FIGS. 9A and 9B , when zone 1 is activated, zone 6 may be activated and zones 2 - 5 and 7 may be deactivated. In other words, one of the zones in the first layer 502 may be activated at the same time as one of the zones in the non-adjacent third layer 506 .
[0055] In another implementation, zones of adjacent layers may be activated at the same time when there is sufficient space between the zones (i.e. the zones of one layer do not overlap the zones of an adjacent layer). For example, as shown in FIG. 9B , the zones in the third layer 506 are spaced apart radially from the zones of the second layer 504 . Accordingly, when zone 2 in the second layer 504 is activated, zone 7 in the third layer 506 may be activated and the remaining zones 1 and 3 - 6 may be deactivated. In another implementation, each of the second layer 504 and the third layer 506 includes zones 2 and 3 . In other words, the third layer 506 may include the same zones as the second layer 504 .
[0056] The present disclosure may substantially reduce the fuel economy penalty, decrease tailpipe temperatures, and improve system robustness due to the smaller regeneration time. | A system includes a particulate matter (PM) filter that includes an upstream end for receiving exhaust gas and a downstream end. A zoned heater is arranged spaced from the upstream end and comprises N zones, where N is an integer greater than one, wherein each of the N zones comprises M sub-zones, where M is an integer greater than or equal to one, and wherein the N zones and the M sub-zones are arranged in P layers, where P is an integer greater than one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates non-selected ones of the N zones. | 1 |
FIELD OF INVENTION
This invention relates to control of timing of a charge pump.
BACKGROUND
Various configurations of charge pumps, including Series-Parallel and Dickson configurations, rely of alternating configurations of switch elements to propagate charge and transfer energy between the terminals of the charge pump. Energy losses are associated with propagation determine the efficiency of the converter.
Referring to FIG. 1 , a single phase Dickson charge pump 100 is illustrated in a step-down mode coupled to a low voltage load 110 and high voltage source 190 . In the illustrated configuration, generally the load is driven (on average) by a voltage that is ⅕ times the voltage provided by the source and a current that is 5 times the current provided by the source. The pump is driven in alternating cycles, referred to as cycle 1 and cycle 2, such that the switches illustrated in FIG. 1 are closed in the indicated cycles. In general, the duration of each cycle is denoted T and the corresponding switching frequency F=½T.
FIGS. 2A-B illustrate the equivalent circuit in each of cycles 2 and 1, respectively, illustrating each closed switch as an equivalent resistance R. Each of the capacitors C 1 through C 4 has equal capacitance C. In a first conventional operation of the charge pump, the high voltage source is a voltage source, for example, a v in =25 volt source, such that the load is driven by v out =5 volts. In operation the voltage across capacitors C 1 through C 4 are approximately 5 volts, 10 volts, 15 volts, and 20 volts, respectively.
One source of energy loss in the charge pump relates the resistive losses through the switches (i.e., through the resistors R in FIGS. 2A-B ). Referring to FIG. 2A , during cycle 2, charge transfers from capacitor C 2 to capacitor C 1 and from C 4 to C 1 . The voltages on these pairs of capacitors equilibrate assuming that the cycle time T is sufficiently greater than the time constant of the circuit (e.g., that the resistances R are sufficiently small. Generally, the resistive energy losses in this equilibration are proportional to the time average of the square of the current passing between the capacitors and therefore passing to the load 110 . Similarly, during cycle 1, capacitors C 3 and C 2 equilibrate, capacitor C 4 charges, and capacitor C 1 discharges, also generally resulting in a resistive energy loss that is proportional to the time average of the square of the current passing to the load 110 .
For a particular average current passing to the load 110 , assuming that the load presents an approximately constant voltage, it can be shown than the resistive energy loss decreases as the cycle time T is reduced (i.e., switching frequency is increased). This can generally be understood by considering the impact of dividing the cycle time by one half, which generally reduces the peak currents in the equilibration by one half, and thereby approximately reduces the resistive energy loss to one quarter. So the resistive energy loss is approximately inversely proportional to the square of the switching frequency.
However, another source of energy loss relates to capacitive losses in the switches, such that energy loss grows with the switching frequency. Generally, a fixed amount of charge is lost with each cycle transition, which can be considered to form a current that is proportional to the switching frequency. So this capacitive energy loss is approximately proportional to the square of the switching frequency.
Therefore, with a voltage source and load there an optimal switching frequency that minimizes the sum of the resistive and capacitive energy losses, respectively reduced with increased frequency and increased with increased frequency.
SUMMARY
In one aspect, in general, cycle timing of a charge pump is adapted according to monitoring of operating characteristics of a charge pump and/or peripheral elements coupled to the charge pump. In some examples, this adaptation provides maximum or near maximum cycle times while avoiding violation of predefine constraints (e.g., operating limits) in the charge pump and/or peripheral elements.
In another aspect, in general, an apparatus has a charge pump having a plurality of switch elements arranged to operate in a plurality cycles. These cycles switch according to a timing pattern. Each cycle is associated with a different configuration of the switch elements, with the switch elements being configured to provide charging and discharging paths for a plurality of capacitive elements. A controller is coupled to the charge pump with an output for controlling the timing pattern of the switching of the cycles of the charge pump and one or more sensor inputs for accepting sensor signals charactering operation of the charge pump and/or operation of peripheral circuits coupled to the charge pump. The controller is configured adjust the timing pattern of the cycles of the charge pump according variation of the one or more sensor inputs within cycles of operation of the charge pump.
Aspects may include one or more of the following features.
The controller is configured to adjust the timing pattern of the switching of the cycles of the charge pump by adjusting a cycles switching frequency of the charge pump.
The controller is configured to adjust the timing pattern of the switching of the cycles of the charge pump by determining a switching time to end each successive cycle according to variation of the or more sensor inputs during said cycle.
The one or more sensor inputs comprise an output voltage sensor input representing an output voltage of the charge pump, and wherein the controller is configured to adjust the timing pattern according to variation of the output voltage sensor input.
The controller is configured to adjust the timing pattern to maintain the variation of the output voltage with a desired range, for instance, the desired range comprises a fixed range.
The desired range comprises a range dependent on a second sensor input of the controller.
The second sensor input represents an output voltage of a regulator coupled to the output of the charge pump, and the controller is configured to adjust the timing pattern to maintain a desired voltage margin between the output of the charge pump and the output of the regulator.
The one or more sensor inputs comprise a regulator sensor input representing operating characteristic of a regulator coupled to the output of the charge pump.
The regulator sensor input represents an output voltage of the regulator.
The regulator sensor input represents a duty cycle of switching operation of the regulator.
The one or more sensor inputs comprise an internal sensor input representing an internal signal of the charge pump.
The internal signal comprises a voltage across a device in the charge pump, and wherein the controller is configured to adjust the timing to maintain the voltage across the device within a predetermined range.
The charge pump comprises a Dickson charge pump.
Advantages of one or more aspects can include providing efficient power conversion while maintaining voltages and/or currents within desired operating ranges. For example, switching frequency may be reduced while still maintaining internal voltages or currents across circuit elements (e.g., voltages across transistors or capacitors) within desired ranges for those elements.
Other features and advantages of the invention are apparent from the following description, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is a single-phase 1:5 Dickson charge pump;
FIGS. 2A-B are equivalent circuits of the charge pump of FIG. 1 in two states of operation;
FIGS. 3 and 4 are circuits having a switchable compensating circuit coupled to the charge pump;
FIG. 5 is a circuit for measuring a charge pump current;
FIG. 6 is a schematic illustrating charge transfer during one cycle of the charge pump illustrated in FIG. 4 ;
FIGS. 7A-C are graphs of output voltage of the charge pump illustrated in FIG. 4 at different output current and switching frequency conditions; and
FIG. 8 is a single-phase series-parallel charge pump.
DESCRIPTION
As introduced above, as one example, a charge pump 100 illustrated in FIG. 1 may be operated in an “adiabatic” mode in which one or both of a low-voltage peripheral 110 and a high-voltage peripheral 190 may comprise a current source. For example, Patent Publication WO 2012/151466, published on Nov. 8, 2012, and incorporated herein by reference, describes configurations in which the source and/or load comprise regulating circuits. In particular, in FIGS. 1 and 2A -B, the low-voltage load 110 can effectively comprise a current source rather than a voltage source in an example of what is referred to as “adiabatic” operation of a charge pump. If the current source maintains a constant current from the charge pump, then currents illustrated in FIG. 2A maintain substantially constant values during the illustrated state. Therefore, the resistive losses in the switches through which the current passes are lower than the resistive loss in the voltage load case, and also substantially independent of the switching frequency and the cycle time T. As in the voltage driven case, there capacitive losses in the switches grow with increasing switching frequency, which suggests that lowering the switching frequency is desirable. However, other factors, which may depend on internal aspects of the charge pump, voltage or current characteristics at the terminals of the charge pump, and/or internal aspects of the peripheral elements, such as the source and/or load, may limit the cycle time (e.g., impose a lower limit on the switching frequency).
Referring to FIG. 3 , in a first mode of operation, a load 320 can be considered to comprise a constant current source 312 with an output current IO. In some implementations, the load 320 also includes an output capacitor, which for the analysis below can be considered to be small enough such that current passing to the load 320 can be considered to be substantially constant. As introduced above with reference to FIGS. 2A-B , the charge transfer between capacitors in the charge pump 100 during the alternating states of operation of the charge pump 100 are therefore substantially constant in the adiabatic mode of operation.
Continuing to refer to FIG. 3 , a compensation circuit 340 is introduced between the charge pump 100 and the load 320 . A switch 344 is controllable to selectively introduce a compensation capacitor 342 to the output of the charge pump 100 .
Various factors can affect the efficiency of the power conversion illustrated in FIG. 3 , including the voltage of an input voltage source 392 , the switching frequency of the charge pump 100 , and the output current IO (or somewhat equivalently the input or output current of the charge pump 100 ). The efficiency is also dependent on whether or not the compensation capacitor 342 is coupled to the output path via the switch 344 . As a general approach, a controller 350 accepts inputs that characterize one or more factors that affect efficiency and outputs a control signal that sets the state of the switch 344 according to whether efficiency is expected to be improved introducing the compensation capacitor versus not. A further discussion of logic implemented by the controller 350 is provided later in this Description.
Referring to FIG. 4 , in another example, a configuration of a charge pump 100 has a regulator 320 coupled via a compensation circuit 340 to the low-voltage terminal of a charge pump 100 , and a voltage source 392 coupled to the high-voltage terminal of the charge pump 100 . The regulator 320 (also referred to below generally interchangeably as a “converter”) illustrated in FIG. 4 is a Buck converter, which consists of switches 322 , 324 , an inductor 326 , and an output capacitor 328 . The switches open and close (i.e., present high and low impedance, respectively) in alternating states, such that the switch 322 is open when then the switch 324 is closed, and the switch 322 is closed when the switch 324 is open. These switches operate at a frequency than can be lower, higher, or equal to the switches in the charge pump 100 , with a duty cycle defined as the fraction of time that the switch 322 in the regulator 320 is closed. A preferred embodiment is when the switching frequency of the charge pump 100 is lower than the regulator 320 . However, in the case the charge pump 100 is at a higher frequency than the regulator 320 , the charge-pump 100 is disabled when the regulator 320 is off (low duty cycle) and the charge-pump 100 is enabled when the regulator 320 is on.
In general, the regulator 320 operates at its highest power efficiency when it operates at its highest duty cycle. In some examples, a controller of the regulator (not shown) adjusts the duty cycle in a conventional manner to achieve a desired output voltage VO. During the cycles of the regulator 320 in which the switch 322 is closed, the current passing from the charge pump 100 to the regulator 320 is effectively constant, equal to the current through the inductor 326 . Assuming that the switching frequency of the regulator 320 is substantially higher than the switching frequency of the charge pump 100 , the charge pump 100 can be considered to be driven by a pulsed current source with an average current equal to the duty cycle times the inductor current.
Note that as introduced above, in situations in which the regulator 320 sinks a pulsed current, then for a particular average current, the resistive energy loss generally increases as the duty cycle of the current decreases, approximately inversely with the duty cycle. There is a range of low duty cycles, and thereby high peak current relative to the average current, in which the resistive losses with a pulsed current exceed the losses for the same average current that would result from the charge pump 100 driving a relatively constant output voltage, for example, across a large output capacitor. Therefore, for a selected range of low duty cycles, the controller 350 closes the switch 344 and introduces a relatively large compensation capacitor 342 at the output of the charge pump 100 . The result is that the charge pump 100 is presented with a substantially constant voltage, and therefore operates in a substantially “non-adiabatic” mode. Therefore, the controller 350 is effectively responsive to the output voltage because the duty cycle is approximately proportional to the output voltage. Thereby operating the charge pump 100 in an adiabatic mode at high output voltage and in a non-adiabatic mode at low output voltage; and switches between the adiabatic and non-adiabatic modes at a threshold duty cycle to maintain an optimum efficiency of the overall power conversion.
Examples of control logic implemented in the controller 350 in configurations such as those illustrated in FIGS. 4 and 5 can be under in view of the following discussion.
In general, a charge pump can operate in one of two unique operating conditions, or in the region in between them. In a slow switching limit (SSL) regime the capacitor currents in the charge pump have the time to settle to their final values and capacitor voltages experience significant change in magnitude from beginning to end of a cycle of the charge pump operation. In the fast switching limit (FSL) regime, the capacitors do not reach equilibrium during a cycle of the charge pump operation, for instance, due to a combination of one or more of high capacitances, high switching frequency, and high switch resistances.
Another factor relates to the capacitance at the output of the charge pump 100 , which in the circuits of FIG. 4 can be increased by closing the switch 344 to add the compensation capacitor 342 to the output. For small output capacitance, the output current of the charge pump 100 is effectively set by the pulsed current characteristic of the regulator 320 . As discussed above, for a given average current, the resistive power losses in the pulsed current case are approximately inversely proportional the duty cycle.
For large output capacitance, the RMS of the output current of the charge pump 100 is effectively determined by the equilibration of the internal capacitors of the charge pump 100 with the compensation capacitor 342 and the regulator 320 . For a given average current, this resistive power loss is approximately inversely proportional to the square of the peak-to-peak voltage across the internal capacitors in the charge pump 100 .
Four combinations of FSL/SSL and constant/pulsed IO modes of operation are possible. In some examples, each of these four modes is affected in different ways based on the addition of a compensation capacitor 342 as shown in FIGS. 3 and 4 .
Case one: In FSL mode, with constant output current IO as in FIG. 3 , introduction of the compensation capacitor 342 does not substantially affect conversion efficient.
Case two: In FSL mode with pulsed output current as in FIG. 4 , efficiency increases when the compensation capacitor 342 is introduced, thereby reducing the RMS current seen by the charge pump 100 .
Case three: In SSL mode, with constant output current IO as in FIG. 3 , efficiency generally increases without introduction of the compensation capacitor 342 , thereby yielding adiabatic operation.
Case four: In SSL mode, with pulsed load current as in FIG. 4 , efficiency depends on the relation between the average output current, the duty cycle, and how far the charge pump 100 is operating from the SSL/FSL boundary. For example, at low duty cycle, efficiency generally increases with introduction of the compensation capacitor 342 , thereby yielding non-adiabatic operation. In contrast, at high duty cycle, efficiency generally increases without introduction of the compensation capacitor 342 , thereby yielding adiabatic operation. Furthermore, when the charge pump 100 is in SSL mode, the farther from the SSL/FSL boundary, the lower the duty cycle at which the efficiency trend reverses.
Depending on the relative values of charge pump capacitors, switch resistances and frequency, it is possible that the charge pump operate in a regime between FSL and SSL. In this case, there is effectively a transition point between case four and case two at which the compensation capacitor is introduced according to the overall efficiency of the conversion. As described above, knowledge of the average charging current and its duty cycle is necessary in case four for determining if introduction of the compensation capacitor will improve efficiency.
In some implementations, the controller 350 does not have access to signals or data that directly provide the mode in which the power conversion is operating. One approach is for the controller to receive a sensor signal that represents the input current of the charge pump, and infer the operating mode from that sensor signal.
As an example, a sensor signal determined as a voltage across the switch at the high voltage terminal of the converter (e.g., the switch between source 109 and the capacitor C 4 in FIG. 1 ) can be used to represent the current because when the switch is closed, the voltage is the current times the switch resistance.
An alternative circuit shown in FIG. 5 provides a scaled version of the input current IIN. The input switch 510 , with closed resistance R is put in parallel with a second switch with closed resistance kR, for example, fabricated as a CMOS switch where the factor k depends on the geometry of the switch. When the switches are closed the differential amplifier 530 controls the gate voltage of a transistor 540 such that the voltage drop across the two switches are equal, thereby yielding the scaled input current IIN/k, which can be used to form a sensor input signal for the controller.
The sensed input current can be used to determine whether the compensation capacitor should be switched in, for example, according to a transition between case four and case two described above.
One possible method for determining the operation mode of the charge pump 100 consists of taking two or more measurements of the input current IIN and establishing that the difference between the values of consecutive samples is substantially zero for SSL mode, or is above a pre-determined threshold for FSL mode.
Another method is to measure the difference in the voltage of a capacitor in the charge pump 100 . Once the input current IIN is known, the controller 350 can infer the operating mode based upon the voltage ripple on the capacitor over a full cycle. Note that the controller 350 does not necessarily know the particular sizes of capacitors that are used in the charge pump 100 , for example, because the capacitors are discrete capacitors that are not predetermined. However, the capacitor values can be inferred from knowledge of the current, voltage ripple, and frequency, thereby allowing the controller 350 to determine whether the charge pump 100 is operating in the FSL or SSL mode. The controller 350 can then select adiabatic or non-adiabatic charging by controlling the switch 344 to selectively introduce the compensation capacitor 342 .
Other controller logic is used in other implementations. For example, an alternative is for the controller to measure efficiency given by:
η= VO /( N*VIN )
where η is the efficiency, VO is the measured converter output voltage, VIN is the measured converter input voltage, and N is the charge pump conversion ratio.
The controller directly measures the effect of selecting adiabatic vs. non-adiabatic charging on converter efficiency by comparing the average value of the output voltage VO over a complete charge pump cycle.
Other controller logic uses combinations of the approaches described above. For instance, the controller can confirm that the assessment of charge pump operating mode and estimation of efficiency increase by changing the charge pump charging mode.
A traditional method for operating the charge pump 100 at a fixed frequency in which the switching occurs independently of the load requirement (i.e., the switches in FIG. 1 operate on a fixed time period). Referring to FIG. 6 , during one cycle of the switching of the charge pump 100 , a current I 1 discharges from the capacitor C 1 and a current IP discharges other of the capacitors in the charge pump 100 . For a particular intermediate current IX, the longer the cycle time T, the larger the drop in voltage provided by the capacitor C 1 . A consequence of this is that the switching frequency generally limits the maximum intermediate current IX because the switching frequency for a particular load determines the extent of voltage excursions, and in some cases current excursions (i.e., deviations, variation), at various points and between various points within the charge pump 100 and at its terminals. For a particular design of charge pump 100 , or characteristics of load and/or source of the charge pump 100 , there are operational limits on the excursions.
Referring to FIGS. 7A-C , the intermediate voltage VX of the charge pump 100 is shown in various current and timing examples. Referring to FIG. 7A , at a particular intermediate current IX, the intermediate voltage VX generally follows a saw-tooth pattern such that it increases rapidly at the start of each state, and then generally falls at a constant rate. Consequently, the rate of voltage drop depends on the output current IO. At a particular output current IO and switching time, a total ripple voltage 6 results, and a margin over the output voltage VO is maintained, as illustrated in FIG. 7A . (Note that the graphs shown in FIGS. 7A-B do not necessarily show certain features, including certain transients at the state transition times, and related to the high frequency switching of the regulator 320 ; however these approximations are sufficient for the discussion below).
Referring to FIG. 7B , in the output current IO in the circuit in FIG. 4 increases, for instance by approximately a factor of two, the ripple of the intermediate voltage VX increases, and the minimum intermediate voltage VMIN decreases and therefore for a constant output voltage VO the margin (i.e. across inductor 316 ) in the regulator 320 decreases. However, if the voltage margin decreases below a threshold (greater than zero), the operation of the regulator 320 is impeded.
Referring to FIG. 7C , to provide the regulator 320 with a sufficient voltage margin voltage the switching frequency can be increases (and cycle time decreased), for example, to restore the margin shown in FIG. 7A . Generally, in this example, doubling the switching frequency compensates for the doubling of the output current IO. However more generally, such direct relationships between output current IO or other sensed signals and switching frequency are not necessary.
In general, a number of embodiments adapt the switching frequency of the charge pump 100 or determine the specific switching time instants based on measurements within the charge pump 100 and optionally in the low-voltage and/or high-voltage peripherals coupled to the terminals of the charge pump 100 .
In a feedback arrangement shown in FIG. 4 , the controller 350 adapts (e.g., in a closed loop or open loop arrangement) the switching frequency. For any current up to a maximum rated current with a fixed switching frequency, the charge pump 100 generally operates at a switching frequency lower than (i.e., switching times greater than) a particular minimum frequency determined by that maximum rated current. Therefore, when the current is below the maximum, capacitive losses may be reduced as compared to operating the charge pump 100 at the minimum switching frequency determined by the maximum rated current.
One approach to implementing this feedback operation is to monitor the intermediate voltage VX and adapt operation of the charge pump to maintain VMIN above a fixed minimum threshold. One way to adapt the operation of the charge pump 100 is to adapt a frequency for the switching of the charge pump 100 in a feedback configuration such that as the minimum intermediate voltage VMIN approaches the threshold, the switching frequency is increased, and as it rises above the threshold the switching frequency is reduced. One way to set the fixed minimum threshold voltage is as the maximum (e.g., rated) output voltage VO of the regulator 320 , plus a minimum desired margin above that voltage. As introduced above, the minimum margin (greater than zero) is required to allow a sufficient voltage differential (VX−VO) to charge (i.e., increase its current and thereby store energy in) the inductor 326 at a reasonable rate. The minimum margin is also related to a guarantee on a maximum duty cycle of the regulator 320 .
A second approach adapts to the desired output voltage VO of the regulator 320 . For example, the regulator 320 may have a maximum output voltage VO rating equal to 3.3 volts. With a desired minimum margin of 0.7 volts, the switching of the charge pump 100 would be controlled to keep the intermediate voltage VX above 4.0 volts. However, if the converter is actually being operated with an output voltage VO of 1.2 volts, then the switching frequency of the charge pump 100 can be reduced to the point that the intermediate voltage VX falls as low as 1.9 volts and still maintain the desired margin of 0.7 volts.
In a variant of the second approach, rather than monitoring the actual output voltage VO, an average of the voltage between the switches 312 , 314 may be used as an estimate of the output voltage VO.
In yet another variant, the switching frequency of the charge pump 100 is adapted to maintain the intermediate voltage VX below a threshold value. For example, the threshold can be set such that the intermediate voltage VX lowers or rises a specific percentage below or above the average of the intermediate voltage VX (e.g. 10%). This threshold would track the intermediate voltage VX. Similarly, a ripple relative to an absolute ripple voltage (e.g. 100 mV) can be used to determine the switching frequency.
Note also that the voltage ripple on the output voltage VO depends (not necessarily linearly) on the voltage ripple on the intermediate voltage VX, and in some examples the switching frequency of the charge pump 100 is increased to reduced the ripple on the output voltage VO to a desired value.
Other examples measure variation in internal voltages in the charge pump 100 , for example, measuring the ripple (e.g., absolute or relative to the maximum or average) across any of the capacitors C 1 through C 4 . Such ripple values can be used instead of using the ripple on the intermediate voltage VX in controlling the switching frequency of the charge pump 100 . Other internal voltages and/or currents can be used, for example, voltages across switches or other circuit elements (e.g., transistor switches), and the switching frequency can be adjusted to avoid exceeding rated voltages across the circuit elements.
In addition to the desired and/or actual output voltages or currents of the regulator 320 being provided as a control input to the controller 350 , which adapts the switching frequency of the charge pump 100 , other control inputs can also be used. One such alternative is to measure the duty cycle of the regulator 320 . Note that variation in the intermediate voltage VX affects variation in current in the Buck converters inductor 326 . For example, the average of the intermediate voltage VX is generally reduced downward with reducing of the switching frequency of the charge pump 100 . With the reduction of the average output voltage VO, the duty cycle of the regulator 320 generally increases to maintain the desired output voltage VO. Increasing the duty cycle generally increases the efficiency of a Buck converter. So reducing the switching frequency of the charge pump 100 can increase the efficiency of the regulator 320 .
It should be understood that although the various signals used to control the switching frequency may be described above separately, the switch frequency can be controlled according to a combination of multiple of the signals (e.g., a linear combination, nonlinear combination using maximum and minimum functions, etc.). In some examples, an approximation of an efficiency of the charge pump is optimized.
The discussion above focuses on using the controller 350 to adjust the switching frequency of the charge pump 100 in relatively slow scale feedback arrangement. The various signals described above as inputs to the controller 350 can be used on an asynchronous operating mode in which the times at which the charge pump 100 switches between cycles is determined according to the measurements. As one example, during state one as illustrated in FIG. 6 , the intermediate voltage VX falls, and when VX−VO reaches a threshold value (e.g., 0.7 volts), the switches in the charge pump 100 are switched together from state one to state two. Upon the transition to state two, the intermediate voltage VX rises and then again begins to fall, and when VX−VO again reaches the threshold value, the switches in the charge pump 100 are switched together from state two back to state one.
In some examples, a combination of asynchronous switching as well as limits or control on average switching frequency for the charge pump are used.
Unfortunately, as the intermediate current IX decreases the switching frequency of the charge pump 100 decreases as well. This can be problematic at low currents because the frequency could drop below 20 kHz, which is the audible limit for human hearing. Therefore, once the frequency has dropped below a certain limit, a switch 344 closes and introduces a compensation capacitor 342 . This force the converter into non-adiabatic operation allowing the frequency to be fixed to a lower bound (e.g. 20 kHz). Consequently, the compensation capacitor 342 is introduces when either the duty cycle is low or when the output current IO is low.
Note that the examples above concentrate on a compensation circuit that permits selectively switching a compensation capacitor of a certain fixed capacitance onto the output of the charge pump. More generally, a wide variety of compensation circuits can be controlled. One example is a variable capacitor, which can be implemented as a switched capacitor bank, for example, with power of two capacitances. The optimal choice of capacitance generally depends on the combination of operating conditions (e.g., average current, pulsed current duty cycle, etc.) and/or circuit configurations (e.g., type of regulators, sources, load, pump capacitors), with the determining of the desired capacitance being based on prior simulation or measurement or based on a mechanism that adjusts the capacitance, for instance, in a feedback arrangement. In addition, other forms of compensation circuits, for example, introducing inductance on the output path, networks of elements (e.g., capacitors, inductors).
Note that the description focuses on a specific example of a charge pump. Many other configurations of charge pumps, including Dickson pumps with additional stages or parallel phases, and other configurations of charge pumps (e.g., series-parallel), can be controlled according to the same approach. In addition, the peripherals at the high and/or low voltage terminals are not necessarily regulators, or necessarily maintain substantially constant current. Furthermore, the approaches described are applicable to configurations in which a high voltage supply provides energy to a low voltage load, or in which a low voltage supply provides energy to a high voltage load, or bidirectional configurations in which energy may flow in either direction between the high and the low voltage terminal of the charge pump. It should also be understood that the switching elements can be implemented in a variety of ways, including using Field Effect Transistors (FETs) or diodes, and the capacitors may be integrated into a monolithic device with the switch elements and/or may be external using discrete components. Similarly, at least some of the regulator circuit may in some examples be integrated with some or all of the charge pump in an integrated device.
Implementations of the approaches described above may be integrated into an integrated circuit that includes the switching transistors of the charge pump, either with discrete/off-chip capacitors or integrated capacitors. In other implementations, the controller that determines the switching frequency of the charge pump and/or the compensation circuit may be implemented in a different device than the charge pump. The controller can use application specific circuitry, a programmable processor/controller, or both. In the programmable case, the implementation may include software, stored in a tangible machined readable medium (e.g., ROM, etc.) that includes instructions for implementing the control procedures described above.
It is to be understood that the foregoing description is intended to illustrate and not to limit the scope of the invention, which is defined by the scope of the appended claims. Other embodiments are within the scope of the following claims. | Cycle timing of a charge pump is adapted according to monitoring of operating characteristics of a charge pump and/or peripheral elements coupled to the charge pump. In some examples, this adaptation provides maximum or near maximum cycle times while avoiding violation of predefine constraints (e.g., operating limits) in the charge pump and/or peripheral elements. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to an improved shower curtain rod and fixture. More particularly, the invention encompasses a shower curtain rod that can be used safely and securely in the motel/hotel industry. This invention further includes inventive features, such as, a shower rod that has substantially straight ends and a portion that is visibly curved to allow for “elbow room” for upper body movement of a person using a shower, a non-twist or non-sagging feature that prevents the inventive shower curtain rod from rotating or twisting after it has been installed, a fixture to securely and safely secure the inventive shower curtain rod to a surface, such as a wall, to name a few.
BACKGROUND INFORMATION
[0002] In the construction of most bathrooms, it is common to position a shower head or shower nozzle which is mounted on the wall in an enclosure above a bath tub or a shower stall to thereby provide the option of a shower for the resident or the guest using the bathroom facility. In defining such enclosures, splashing water out of the enclosure is limited by the use of a sliding door, typically a translucent plastic or shatter proof glass, or more conveniently, a shower curtain. The shower curtain is ordinarily constructed and arranged to drape loosely from a set of eyelets or curtain rings which slide along the curtain rod. A set of such rings is normally mounted slidably on the shower curtain rod which is positioned normally at the height of the sprinkler head or other nozzle. The shower curtain is draped in the bath tub below or around a shower stall so that water is not splashed out of the bath tub or the shower stall. Because the bath tub is below the shower nozzle, the bath tub also functions to collect water which drains from the bath tub during the shower.
[0003] Many bath tubs and shower stalls are constructed in a rectangular manner having one side exposed while the other three sides have a wall or an enclosure. For such straight side bath tubs a straight shower rod can be easily positioned above the straight edge. A shower curtain can then be secured to the straight shower rod so as to prevent the splashing of the water to an area outside of the tub or the shower stall and also to direct the water from a shower head towards a shower drain.
[0004] It is well know in the art to provide a shower curtain rod which is shaped and profiled to fit above and in cooperation with a particular type shower or tub construction. These types of shower curtain rods are intended to be used to support a shower curtain so as to prevent water from splashing out of the enclosure bordered by the shower curtain as the curtain is draped into a bath tub below the curtain rod.
[0005] A curved shower rod is particularly adapted for use with an oval or an elliptical shaped bath tub so as to follow the contours of the oval or the elliptical shaped bath tub so as to direct the water coming from a shower head towards the drain or just to provide an extra “elbow room” to the user or guest.
[0006] U.S. Pat. No. 4,754,504 (Cellini), the disclosure of which is incorporated herein by reference, discloses a shower enlarger where the shower area can be enlarged to provide a greater stall space for upper body movement of a person using the shower. The one-piece curtain rod has an offset medial section for outwardly displacing an upper area of a shower curtain to allow for greater space in shower stall for upper body movement while showering. The offset medial section also includes a pair of angular curtain rod sections that extend in diverging relation away from opposite ends of the offset medial section.
[0007] U.S. Pat. No. 5,022,104, (Miller), the disclosure of which is incorporated herein by reference, discloses a shower curtain support for a straight sided bath tub where the shower rod is provided with a central straight portion having a length approximately equal to that of the bath tub and which also includes offset end rod portions which enable connection with the tile wall which surrounds the bath tub. In this construction, the bath tub is positioned below the shower curtain rod so that the shower curtain can drape in the tub. The overhead shower rod has a straight length portion which approximately conforms to the length or profile of the bath tub when viewed from above.
[0008] U.S. Pat. No. 6,216,287 (Wise), the disclosure of which is incorporated herein by reference, discloses a shower curtain rod having two end portions with angled fittings to enable the shower curtain rod to be attached between a pair of parallel walls at a bath tub enclosure. The shower curtain rod is constructed with a central portion curving to follow the edge or profile of an oval or elliptical bath tub. This curving central portion enables the shower curtain to hang into the bath tub. When positioned above the bath tub, the shower curtain rod is particularly useful to deflect splashed water into the tub by enabling a user to simply slide the shower curtain along the length of the shower curtain rod so that it hangs into the tub therebelow.
[0009] U.S. Pat. No. 7,076,815 (Orpilla), the disclosure of which is incorporated herein by reference, discloses a curved shower curtain rod having two end portions that are bent at 70 degrees. The curved shower curtain rod is straight in the middle but curved at both ends. The middle of the curtain rod is still along the outside edge of the tub, but the ends curve towards inside to the middle of the tub.
[0010] However, one of the problems that exists with the present shower rods is that they twist and/or sag and/or rotate thus creating an unsafe environment and this movement of the curved shower rod also weakens the associated fixtures. This is primarily due to the fact that the center of gravity of the curved shower rod is at a location which forces the central curved portion to move or rotate or sag down towards the earth.
[0011] Thus, it is clear that the shower rods and shower rod fixtures of the prior art have a problem that needs an inventive solution. These and other problems are overcome by the present invention.
PURPOSES AND SUMMARY OF THE INVENTION
[0012] The invention is an improved shower rod and a shower rod fixture.
[0013] Therefore, one purpose of this invention is to provide a shower rod with at least one opening to secure said shower rod to a shower rod fixture so as to prevent twisting and/or rotating and/or sagging of the shower rod.
[0014] Another purpose of this invention is to provide a shower rod fixture with at least one opening so as to secure a shower rod to said shower rod fixture so as to prevent twisting and/or rotating and/or sagging of the shower rod.
[0015] Yet another purpose of this invention is to provide a shower rod with at least one portion that is substantially straight and at least one portion that has a visible curvature.
[0016] Therefore, in one aspect this invention comprises a straight and curved shower curtain rod, comprising:
(a) a shower curtain rod having a central portion having a curvature, (b) said shower curtain rod having end portions that are substantially straight, (c) said substantially straight end portions having at least one opening, wherein at least a portion of said opening has spiraling rings, (d) a shower rod end fixture having a substantially flat surface and a protruding portion, wherein said protruding portion has at least one opening, and wherein at least a portion of said opening has spiraling rings, (e) at least one securing device, wherein at least a portion of said securing device has spiraling rings, and (f) wherein said at least one securing device passes through said at least one opening in said substantially straight end portion and through said at least one opening in said protruding portion and securely mates with said spiraling rings in said substantially straight end portion and said spiraling rings in said protruding portion, so as to prevent any movement between said shower curtain rod and said shower rod end fixture.
[0023] In another aspect this invention comprises a straight and curved shower curtain rod, comprising:
(a) a shower curtain rod having a length of between about 36 inches to about 78 inches, (b) said shower curtain rod having a central portion having a curvature, and wherein said curvature has a bow of between about 4 inches to about 8 inches, (c) said shower curtain rod having end portions that are substantially straight, and wherein said substantially straight end portions are between about 3 inches to 9 inches long, (d) said substantially straight end portions having at least one opening, wherein at least a portion of said opening has spiraling rings, (e) a shower rod end fixture having a substantially flat surface and a protruding portion, wherein said protruding portion has at least one opening, and wherein at least a portion of said opening has spiraling rings, (f) at least one securing device, wherein at least a portion of said securing device has spiraling rings, and (g) wherein said at least one securing device passes through said at least one opening in said substantially straight end portion and through said at least one opening in said protruding portion and securely mates with said spiraling rings in said substantially straight end portion and said spiraling rings in said protruding portion, so as to prevent any movement between said shower curtain rod and said shower rod end fixture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The features of the invention believed to be novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The drawings are for illustration purposes only and are not drawn to scale. Furthermore, like numbers represent like features in the drawings. The invention itself, however, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which:
[0032] FIG. 1A is a first embodiment of the invention showing front view of the inventive shower rod fixture.
[0033] FIG. 1B is a side view of the inventive shower rod fixture of FIG. 1A .
[0034] FIG. 2A is a second embodiment of the invention showing a side view of the inventive shower rod fixture.
[0035] FIG. 2B is a front view of the inventive shower rod fixture of FIG. 2A .
[0036] FIG. 3 is a top plan view of the inventive shower rod.
[0037] FIG. 4A is an enlarged top view of one end of the inventive shower rod of FIG. 3 .
[0038] FIG. 4B is an enlarged side view of one end of the inventive shower rod of FIG. 3 .
[0039] FIG. 5 is an enlarged side view of a securing device.
[0040] FIG. 6 is an enlarged view of an embodiment showing a portion of the inventive shower rod as secured to the inventive shower rod fixture of this invention.
DETAILED DESCRIPTION
[0041] FIGS. 1A and 1B illustrate a first embodiment of the invention showing a front view and a side view, respectively, of the inventive shower rod fixture or flange 23 . The shower rod fixture 23 , has a base 10 , having a back surface 11 , and a protruding section 12 , having an opening 13 , to accommodate a shower rod (as more clearly shown in FIG. 6 ). The protruding section 12 , preferably has an upper flattened section 15 , and a lower flattened section 17 . The upper flattened section 15 , has at least one upper opening 14 , and the lower flattened section 17 , has at least one lower opening 16 . It is preferred that the opening 14 , and opening 16 , are substantially aligned so as to allow for the passage of at least one securing device 20 . The base 10 , preferably has at least one opening 18 , so as to allow the mounting of the shower rod fixture 23 , to a flat surface, such as, a wall (not shown), using a secure device, such as a screw (not shown). It is preferred that the upper opening 14 , has a recessed area 19 , to accommodate a head of the securing device 20 . For some applications it is also preferred that the upper opening 14 , has grooves or spiraling rings 21 , shown in FIGS. 2A and 2B , to accommodate corresponding grooves in the securing device 20 . Similarly, for some applications it is also preferred that the lower opening 16 , has grooves or spiraling rings 27 , to accommodate corresponding grooves in the bottom of the securing device 20 . It is preferred that the upper opening 14 , in the shower rod end fixture 23 , has a recess portion 19 , to accommodate a head portion 24 , in the securing device 20 , as more clearly shown in FIG. 5 .
[0042] FIGS. 2A and 2B illustrate a second embodiment of the invention showing a side view and a front view, respectively, of the inventive shower rod fixture 23 . The shower rod fixture 23 , is similar to fixture 23 , as illustrated in FIGS. 1A and 1B , except that the openings 14 and 16 , have grooves or spiraling rings 21 and 27 , respectively, to accommodate the grooves of the securing device 20 . Furthermore, the openings 18 , to secure the fixture 23 , to a flat surface, such as a wall are in line with the upper opening 14 and the lower opening 16 .
[0043] Also shown in FIG. 2A is an optional spacer or gasket 41 . The spacer or gasket 41 , could be used in order to prevent gouging of a flat surface, such as a wall (not shown), or as a cushioning device 41 . It is preferred that the gasket 41 , is provided between the back surface 11 , of the fixture 23 , and the wall (not shown). Furthermore, in order to accommodate the unevenness of a wall or to accommodate variations of a length of a shower rod 30 (shown in FIG. 3 ) one or more spacers or gaskets 41 , could be provided between the back surface 11 , of the shower rod fixture 23 , and a wall (not shown). It should be appreciated that at least one spacer 41 , can be used to separate the shower rod end fixture 23 , from a wall, and wherein the spacer 41 , can be selected from a group comprising of a metal spacer, a polymer spacer, a silicon spacer, a composite-material spacer, a rubber spacer, a plastic spacer, to name a few.
[0044] FIG. 3 is a top plan view of the inventive shower or spacious rod 30 . The spacious or shower rod 30 , having an interior 33 , preferably has a central curved portion 39 , and end portions 31 , that are substantially straight. The shower rod 30 , at one end 31 , preferably has at least one opening 34 , to allow the passage of the securing device 20 , and a second opening 36 , which is shown in FIG. 4B , which is directly opposite the opening 34 , for the passage of the securing device 20 . For some applications the shower rod 30 , at another end 31 , preferably has an end 32 , that has no opening similar to opening 34 and/or 36 . For most applications the shower rod 30 , would be hollow to make the shower rod 30 , a tube like structure, but the shower rod 30 could also have the interior area 33 , that is a solid. It should be appreciated that when the rod 30 , is securely secured to the shower rod fixture 23 , the central portion having a curvature 39 , is substantially in a horizontal plane, so as to prevent the twisting, sagging or rotating of the rod 30 , with respect to the shower rod fixture 23 .
[0045] FIG. 4A is an enlarged top view of one end 31 , of the inventive shower rod 30 , of FIG. 3 , showing the opening 34 , and with a solid interior 33 , having a solid or inner core 37 .
[0046] FIG. 4B is an enlarged side view of one end 31 , of the inventive shower rod 30 , of FIG. 3 , showing the first opening 34 , on the surface of the shower rod 30 , and a second opening 36 . For most applications the second opening 36 , is directly opposite the first opening 34 , and with a hollow, tube-like interior 33 , and a hollow tube or outer shell 35 .
[0047] For some applications it is preferred that the straight and curved shower curtain rod 30 , is a hollow tube, as shown in FIG. 4B , or a solid tube, as shown in FIG. 4A . For some applications it may be preferred that the material for the outer shell 35 , of the rod 30 , is different than the material for the inner core 37 , for the rod 30 . The material for the outer shell 35 , could be selected from a group comprising of stainless steel, rustproof zinc, nickel, chrome, plastic, rubber, metallic material, composite material, to name a few. The outer shell 35 , could also be a hollow metal tube or a hollow rigid plastic tube. Furthermore, the material for the inner core 37 , could be selected from a group comprising of stainless steel, rustproof zinc, nickel, chrome, plastic, rubber, metallic material, composite material, to name a few.
[0048] The straight and curved shower curtain rod 30 , could also have a finish which could be selected from a group comprising of a polished finish, a bright finish, a brushed finish, a satin finish, a powder coated finish, a white powder coat finish, to name a few.
[0049] FIG. 5 is an enlarged side view of the securing device 20 . The securing device 20 , preferably has a head portion 24 , and a bottom portion 26 . The head portion 24 , preferably has an securing area 22 , which can be used in conjunction with a flat screwdriver, a Phillips screwdriver, an Allan wrench, a star wrench, to name a few. The outer surface 28 , preferable has means, such as grooves or circular rings 28 , to securely mate with the holes 34 and 36 in the shower rod 30 , and the holes 14 and/or 16 , in the shower rod fixture 23 .
[0050] FIG. 6 is an enlarged view of an embodiment showing a portion of the inventive shower rod 30 , as secured to the inventive shower rod fixture 23 , of this invention. As one can clearly see that one end 31 , of the shower rod 30 , has a securing device 20 , that passes through openings 14 , 34 , 36 and 16 , and securely secures the shower rod 30 , to the shower rod fixture 23 . However, at the other end 31 , which is the no-hole end 32 , a securing device 20 , such as a set-screw 20 , is used to securely secure the other end 31 , or the no-hole end 32 , of the inventive shower rod 30 , to the inventive shower rod fixture 23 .
[0051] The shower curtain rod 30 , when viewed from above, preferably has a curving portion 39 . The curving portion 39 , of the instant inventive shower rod may or may not conform to the curvature of a corresponding bath tub. The bath tub could be of any shape or size and similarly the bath or shower stall could be of any shape or size, however with the inventive straight and curved shower rod one would still get more “elbow” room for upper body movement.
[0052] For some applications it would be preferred that the shower curtain rod 30 , conforms with the curvature of a correspondingly curved bath tub. The bath tub or Jacuzzi many be of an oval or it may be elliptical in shape, and thus the shower rod 30 , has at least a central curved portion 39 , which matches that curvature and is located the requisite distance above the bath tub (not shown) so that the shower curtain, (not shown) hangs loosely from the shower rod 30 , on a set of rod hangers, drapes into the tub and to prevent splashed water from escaping from the bath tub around the ends of the curtain.
[0053] It is preferred that the shower curtain rod 30 , is a hollow tube 35 , having an opening 33 . However, for some applications the shower curtain rod 30 , could be made from a light weight solid material which is inexpensive to produce but which can withstand the normal weight of a shower curtain (not shown). Similarly, the shower curtain rod 30 , could be made from a composite material. For some applications the shower curtain rod 30 , could be made from a material that is strong on the outside but relatively soft and light weight on the inside, such as for example, the outside shell 35 , could be of a metallic or a plastic material, while the inside or inner core 37 , could be of a light weight material which is well known in the art, such as, for example, a Styrofoam material or a light-weight composite material, to name a few.
[0054] The securing device 20 , could be selected from a group comprising, a screw, a bolt, a set-crew, a rivet, a pin, to name a few.
[0055] The shower rod fixture or flange 23 , is preferably made from a material, such as for example stainless steel, rustproof zinc, nickel, chrome, plastic, rubber, metallic material, composite material, to name a few.
[0056] The shower rod 30 , is preferably made from a material, such as for example stainless steel, rustproof zinc, nickel, chrome, plastic, rubber, metallic material, composite material, to name a few.
[0057] For some applications, it is preferred that the central portion 39 , is between about 20 percent to about 80 percent of the total length of the straight and curved shower curtain rod 30 .
[0058] For some applications the straight and curved shower curtain rod 30 would be about 60 inches long, with a one inch outer diameter, and wherein the central curved portion 39 , has a bow of between about 4 inches to about 8 inches in the middle, and the straight end portions 31 , are between about 3 inches to about 9 inches in length. However, it is preferred that the straight and curved shower curtain rod 30 , is between about 36 inches to about 78 inches long, with about a diameter of between about one half inch to about one inch, and wherein the central curved portion 39 , has a bow in the middle of between about 4 inches to about 8 inches, and the straight end portions 31 , are between about 4 inches to about 8 inches in length.
[0059] While the present invention has been particularly described in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention. | The present invention relates to an improved shower curtain rod and fixture. More particularly, the invention encompasses a shower curtain rod that can be used safely and securely in the motel/hotel industry. This invention further includes inventive features, such as, a shower rod that has substantially straight ends and a portion that is visibly curved to allow for “elbow room” for upper body movement of a person using a shower, a non-twist or non-sagging feature that prevents the inventive shower curtain rod from rotating or twisting after it has been installed, a fixture to securely and safely secure the inventive shower curtain rod to a surface, such as a wall, to name a few. | 0 |
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/835,271, filed Aug. 2, 2006.
FIELD OF INVENTION
[0002] This invention relates to retraction systems for rudders for small boats.
BACKGROUND OF INVENTION
[0003] Beachable boats have used retractable rudders for many years and there have been many variations of methods to retract the rudder.
[0004] Rudder assemblies commonly have the ability to;
1) Securely hold the rudder in a vertical or down position for use while the vessel is underway. 2) Securely hold the rudder in a retracted or up position for times when it is desirable to have the rudder in the retracted position. 3) Break free of the vertical or down position when the rudder strikes a submerged object of the lake/ocean bottom without causing damage to the rudder assembly. 4) Raise or lower the rudder to the desired positions using one of a combination of a variety of devices including ropes, levers, cams, and springs.
[0009] One problem with the existing rudder assemblies is that the rudder is still standing proud and is vulnerable to damage when it is retracted.
1) U.S. Pat. No. 6,739,276 describes a mechanism for retracting the rudder, but the rudder is always vulnerable in all of the positions. 2) U.S. Pat. No. 6,684,804 describes a design that is not vulnerable because it is flexible, but it does not have good authority to turn the boat and the rudder adds dimension to the boat. 3) U.S. Pat. No. 5,713,295 describes a rudder that is not vulnerable, but it would not have good authority to turn the boat. 4) U.S. Pat. No. 4,556,006 describes a retracting system but the rudder is vulnerable in all positions.
SUMMARY OF THE INVENTION
[0014] A retraction system for rudders for small boats having hull, cockpit and a deck comprising
[0015] a rudder
[0016] means connecting said rudder to the rear of a boat enabling said rudder to pivot on an axis such that when the rudder is retracted, it rotates upwardly through about 270° from the normal operating position in the water while twisting about 90° so as to lay flat on said deck.
[0017] In the present invention in which the rudder retraction system allows the rudder to lay flat on the deck of the stern when the rudder is retracted, the rudder pivots on an axis that is at an angle such that when the rudder is retracted it rotates through about 270° from the normal operating position and twists about 90°.
[0018] The angle of the axis that the rudder head rotates about is a compound angle. First, while looking down on the rudder, the rudder head rotates counter clockwise about 45° and then in the orthogonal and vertical plane rotates aft about 55°.
[0019] The rudder has one control line to rotate the rudder down and one to rotate the rudder up. Tension in the down control line holds the rudder in the down position. When the rudder is in the down position and the rudder hits an object or the beach there is enough stretch or give in the down control line that the rudder can swing back and out of the way. A bungi cord may be used in series with the down control line to increase stretch. After the encounter the rudder will swing back into the down position.
[0020] The up/down control lines lead forward to a lever on the right side of the boat just behind the cockpit. A 180° rotation of the lever will move the rudder from full retracted position to the full down or operation position and visa versa.
[0021] When the rudder begins to swing up the motion of the rudder is back and to the side. Tension in the down control line is enough to prevent the rudder from swinging back, but the rudder can generate large force to the side and these side forces must be transmitted to the hull as these are the forces required to turn the boat. The rudder must not be allowed to rotate up as a result of side loads and tension in the down control line is not enough to prevent the rudder from rotating up as a result of side loads.
[0022] The rudder mount has a hook that engages a detent in the rudder head when a side force is applied to the rudder. This hook withstands the pressure and prevents the rudder from rotating up under side loading.
[0023] In the preferred embodiment, the rudder head has 6 holes to receive 6 screws for attaching the rudder blade. A normal or large rudder blade can be attached.
[0024] The rudder mount has two bearings to allow the rudder mount to pivot about a vertical axis. This rotation rotates the rudder to steer the boat. Both up/down control lines enter the rudder mount through a small hole near this vertical axis or point of rotation so that tension in these control lines does not change as the rudder turns from right to left. After the control lines enter the rudder mount they split and go in opposite direction around a quadrant which is part of the rudder head. The up control line goes up and around the quadrant so that tension in this line will cause the rudder head to rotate up. The down control line goes down and around the quadrant so that tension in this line will cause the rudder head to rotate down.
[0025] There are two more control lines for turning the rudder to the left or right. These control lines lead forward to a lever on the left side of the boat near the cockpit. A 70 degree rotation of this lever will rotate the rudder from full left turn to full right turn. The rudder turns approximately ±45° from straight ahead.
OBJECTS AND ADVANTAGES
[0026] The main objective of the design is to make rudder as compact and invulnerable as possible when it is in the retracted position. Since the rudder is generally flat and the deck of the back of the boat is flat, it makes sense to stow the rudder flat on the back of the deck. When the rudder is retracted it adds very little dimension to the boat. This feature was very desirable because the rudder can be installed at the factory and the boat can be shipped with the rudder installed.
[0027] A further benefit is that the rudder provides a very low profile or no windage when it is retracted. If the rudder is exposed to the wind it may tend to turn the boat into the wind which is not desirable.
[0028] The rudder retraction system allows the rudder to be positioned on the deck when not in use and yet is readily deployed when the boat is put to use. The rudder in use in the normal operating position is effective in steering the boat. At the same time, should the rudder strike a submerged object, the rudder gives way and thereby avoids being damaged.
THE DRAWINGS
[0029] FIG. 1 is a side view of the rudder assembly in the down position with the rudder in the water on a typical kayak.
[0030] FIG. 2 is a top view of the rudder assembly in the down position on a typical kayak.
[0031] FIG. 3 is an isometric view of the rudder assembly going through the full motion from down position or operation position to the up or retracted position.
[0032] FIG. 4 shows the up and down control lines wrapping around the quadrant.
[0033] FIG. 5 shows the steering lines going to the steering handle lever and the up/down lines going to the up/down control lever.
[0034] FIG. 6 shows the hook engaging the detent to keep the rudder from rotating up under side loads and FIG. 6A shows these parts shortly after disengagement. More particularly,
[0035] FIG. 6 shows the following:
1. A partial side view of the hull, rudder, rudder head, rudder mount. 2. A section taken along the line E-E in 1 to show the engagement of the hook on the rudder mount and detent on the rudder head. 3. A section taken at F in 2 showing an enlargement of the hook and detent as engaged. 4. A side view of a small boat with the retraction system at A, the rudder being directly down in the water.
[0040] FIG. 6A depicts the same parts and views as FIG. 6 , showing, however, the hook and detent shortly after disengagement and the beginning of the rotation of the rudder so that the leading edge of the rudder is starting to move away from the hull.
[0041] FIG. 7 shows the exploded view of the parts in the rudder assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0042] Considering the drawings in more detail, the rudder mount 1 is pinned to the hull 2 with pin 5 . The rudder head 3 is pivotally bolted to the rudder mount 1 with bolt 6 . The rudder blade 4 is fastened to the rudder head 3 with six 10-32 screws 7 and six 10-32 lock nuts 8 .
[0043] The rudder mount 1 is free to pivot on the transom 25 of the hull 2 . The left steering line 13 exits the hull 2 and passes through a hole through the center of bolt 6 . The left steering line 13 is then clamped under the 10-32 screw 11 . The right steering line 14 exits the hull 2 at small hole 26 and passes through a hole in the rudder mount 1 and is clamped under the 10-32 screw 12 .
[0044] The forward end of the left steering line 13 attaches to the right hand end of the steering control lever 17 . The forward end of the right steering line 14 attaches to the left hand end of the steering control lever 17 . Turning the steering handle 18 adjacent cockpit 29 to the right will rotate the rudder to the left which will turn the boat to the right.
[0045] The trim of the rudder and the tension in the steering lines 13 and 14 can be adjusted with these screws 11 and 12 . The lines 13 and 14 should be adjusted so that the rudder blade 4 is pointed straight ahead when the steering handle 18 is in the middle of its travel. The tension in the lines 13 and 14 should be adjusted so they are tight enough so that there is no play, but not so tight that there is excessive friction in the system.
[0046] The up control line 15 exits the transom of hull 2 and passes through two small holes in the rudder mount 1 . After the second hole it goes up and around the quadrant 30 on the rudder head 3 . The line passes through a small hole 21 in the rudder head 3 and then it is clamped under the 10-32 screw 9 . The down control line 16 exits the transom of hull 2 and passes through the same two holes in the rudder mount 1 . After the second hole it goes down and around the quadrant 30 on the rudder head 3 . The line goes through the small hole 22 on the rudder head 3 and it is clamped under 10-32 screw 22 .
[0047] The forward end of the down control line 16 goes forward and around the cheek block 23 and back to the up/down control lever 19 so that when the up/down control lever 19 adjacent cockpit 29 is moved forward the rudder goes down. The up control line 15 goes forward directly to the up/down control lever 19 .
[0048] FIG. 3 shows the rudder blade 4 as it rotates upwardly starting at the normal down or vertical position in the water at the rear of hull 2 . As shown in FIG. 3 , as the rudder blade 4 moves upwardly through 270°, from positions A through E, simultaneously the rudder blade 4 rotates through 90° so that the rudder blade 4 lays flat on the deck or top surface 10 of hull 2 .
[0049] The tension in the up/down control lines 15 and 16 can be adjusted with the screws 9 and 10 . The tension in the down control line 16 should be adjusted so that when the rudder is in the down position and up/down control handle 20 adjacent cockpit 29 is in the forward position there should be about 5 pounds of tension in the line. In this position the up control line should have about a ¼″ of slack in it. When the up/down control handle is rotated 180° to the back position the rudder will rotate through 270° and lay flat on the deck 10 in the retracted position.
[0050] Tension in the down control line 16 is sufficient to keep the rudder down ordinarily. If the rudder blade 4 generates a significant lateral load while making a right turn or while sailing on a starboard tack the tension in the down control line is not sufficient to keep the rudder down. This lateral load will cause the rudder head 3 to move to the left and the hook 24 will engage the detent 23 . In order for the rudder head 3 to move to the left there needs to be some freedom of movement between the rudder mount 1 and the rudder head 3 . If the rudder head 3 rotates straight back as if the rudder hit a submerged object or if the up control line 15 is pulled, the hook 24 will not engage the detent 28 .
[0051] Freedom of movement between the rudder mount 1 and the rudder head 3 is provided by about 0.022″ clearance between the bolt 6 and the mating hole in the rudder head 3 . The bolt is tightly threaded into the rudder mount 1 . The bolt cannot be too tight. | A retraction system for rudders for small boats having a deck comprising
a rudder means connecting said rudder to the rear of a boat enabling said rudder to pivot on an axis such that when the rudder is retracted, it rotates upwardly through about 270° from the normal operating position in the water while twisting about 90° so as to lay essentially flat on said deck. | 1 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a shift control apparatus for a vehicle, which protects the driving mechanism of the vehicle and inhibits excessive loads from acting on a torque converter by preventing the shifting to an opposite direction gear when the speed of the vehicle exceeds a threshold value.
[0002] In a vehicle that includes a torque converter transmission, such as a forklift that requires a high net working rate and that is repeatedly frequently moved backward and forward, for example, a reverse (R) mode gear might be engaged before the vehicle stops. Thereby, a powerful engine braking force is exerted and the vehicle changes direction in a short time. The foregoing type of operation, however, gives rise to repeated loading and unloading forces on the drive transmission and can overload the torque converter. Therefore, solutions have been proposed for preventing reverse-direction gears from being engaged during times when the speed of the vehicle exceeds a predetermined value. FIG. 3 depicts one such solution.
[0003] In the apparatus of FIG. 3, a speed sensor 50 detects when the vehicle is stopped, i.e., when velocity=0. The signal from the speed sensor 50 is supplied to an electronic control unit ECU, which thereupon energizes two relays 51 , 52 . The contacts of the relays 51 , 52 are supplied with battery current through the ignition switch 60 and contacts in the shift selector switch 53 . Thus, as the shift selector switch 53 is shifted to a forward (F) position to move the vehicle forward, electric current flows through the F contacts of the switch 53 to a conductor 54 . This current then flows through the energized (closed) contacts of the relay 51 to energize a first solenoid 55 , which is assumed to permit or effect engagement of a forward gear. This same current also energizes the coil of the latching relay 56 , which latches in the closed position as long as F is selected. Current thereby continues to be supplied to the solenoid 55 even after the vehicle is moving.
[0004] If the shift selector is later shifted into the reverse (R) position, the current path through the shift selector switch 53 to the conductor 54 is broken. Consequently, both the relay 56 and the solenoid 55 become de-energized, and the solenoid 55 can be re-energized only if the vehicle is brought to a stop, since only then are the relays 51 and 52 energized. Further, for the same reason, the reverse drive mode is not activated until the vehicle is brought to a stop. At that time, current is supplied through the energized contacts of the relay 52 to the solenoid 58 and coil of the latching relay 59 . This keeps the solenoid 58 energized after the vehicle is in motion. In this manner, both F and R can be engaged when the vehicle is at rest; at other times, moving the shift selector from one position to the another position results in the de-energization of one of the drive solenoids 55 and 58 .
[0005] From the foregoing, it will be understood that the relays 51 and 52 are controlled by a signal from the ECU in response to the vehicle speed. Accordingly, once the shift selector is moved from either the F or the R position, the latching relays 56 , 59 become de-energized and the solenoids 55 , 58 cannot be re-energized until the vehicle speed is again brought to zero (or some value below a threshold level). Thus, once the shift switch is shifted from one drive direction to another, the previous drive direction cannot be re-entered until the vehicle stops. This is disadvantageous because it limits the versatility of conditions under which the vehicle can be operated. For example, the vehicle operator cannot disengage the drive mechanism momentarily and then re-engage the drive mechanism in the same direction, since the FIG. 3 configuration does not allow that shifting sequence.
SUMMARY OF THE INVENTION
[0006] The present invention addresses the above-mentioned limitation and provides an improved shift control apparatus and method that prevents the shifting into a reverse-direction gear when the vehicle velocity exceeds a threshold value, but nevertheless allows the disengagement and re-engagement of the drive direction in the same direction even when the vehicle velocity exceeds the threshold value.
[0007] In preferred embodiments of the invention, the foregoing operation is attained by supplying current to the drive mechanism control solenoids from the shift selector through switches that are controlled to remain closed as long as either (1) the vehicle velocity remains below the threshold value or (2) if velocity is above the threshold value, the previously selected directional mode is re-selected. If the velocity exceeds the threshold value, the switch controlling the opposite direction solenoid is opened to prevent engagement of the drive mechanism in the opposite direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings, in which:
[0009] [0009]FIG. 1 is a circuit diagram according to a first embodiment of the present invention;
[0010] [0010]FIG. 2 is a circuit diagram according to a second embodiment of the present invention; and
[0011] [0011]FIG. 3 is a circuit diagram of prior art apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] As shown in FIG. 1, the negative (minus) terminal of a battery 1 connects with a ground GND, and the positive (plus) terminal of the battery 1 connects with an ignition key switch 2 . The ignition terminal IG of the key switch 2 connects with the terminal IG 1 of a shift switch 3 , and also connects with an electrical control unit ECU. The ECU receives the output signal of a speed sensor 4 representing information about the speed of the vehicle. In practice, the ECU generates a signal on the conductor 9 when the vehicle speed exceeds a threshold value. In the shift switch 3 , the terminal IG 1 and a terminal VF 1 become interconnected upon positioning a shift lever in the forward position F, and the terminal IG 1 and a terminal VR become interconnected upon positioning the shift lever in the reverse position R.
[0013] A first solenoid 5 for controlling a drive mechanism (not shown) allowing forward vehicle movement is energizable through connection with the terminal VF 1 of the shift switch 3 via the conductor 14 and the normally closed contacts of a control relay 6 . Similarly, a second solenoid 7 controls the drive mechanism for moving the vehicle in the reverse direction. It is energizable through connection with the terminal VR of the shift selector switch 3 via a conductor 15 and the normally closed contacts of a relay 8 . When the ECU detects, by the signal from the speed sensor 4 , that the vehicle speed is above a threshold value, the ECU supplies an energizing electric current on the conductor 9 .
[0014] The conductor 9 is connected to the common terminal of each of a latching F relay 10 and a latching R relay 11 , respectively. The normally closed contact terminals of the latching relays 10 , 11 are connected to the coils of the respective control relays 6 and 8 . Consequently, only when the relays 10 and 11 are de-energized, the control relays 6 and 8 become energized and open the circuit path to the drive solenoids 5 , 7 . On the other hand, if either the relay 10 or the relay 11 is energized, then the corresponding control relay will be de-energized and current can flow from the shift selector switch through the normally closed contacts of the control relays 6 , 8 to a respective drive solenoid. Accordingly, with the latching relay 10 de-energized, moving the shift selector switch 3 to the F position at any time will result in the drive solenoid 5 becoming actuated. Likewise, with the latching relay 11 energized, moving the shift selector switch 3 to the R position at any time will cause the reverse drive solenoid 7 to become actuated.
[0015] Whenever current is supplied to the solenoid 5 by selecting a forward F gear, current also is supplied via the diode 16 to the coil of the latching relay 10 to interconnect the common contact terminal with the normally open contact terminal b. This conditions the relay 10 to be latched through the diode 12 by current placed on the conductor 9 by the ECU. Similarly, whenever current is supplied to the solenoid 7 by selecting a reverse R gear, current also is simultaneously sent via the diode 17 to the coil of the latching relay 11 to interconnect its common contact terminal with its normally open contact terminal b. This conditions the relay 11 to be latched through the diode 13 by current placed on the conductor 9 by the ECU. With this circuit, once the vehicle is driven to its threshold speed, the two latching relays 10 , 11 will always be in opposite states of energization, thus preventing the vehicle from being shifted into a reverse direction at speeds exceeding the threshold speed.
[0016] The function of the present embodiment upon forward movement will now be described. As the shift switch 3 is shifted to the F position, the current through the shift switch 3 passes through the conductor 14 via the normally closed contacts of the control relay 6 and energizes the first drive solenoid 5 , thus permitting forward movement of the vehicle. The electric current also flows through the diode 16 , and actuates the F latching relay 10 , interconnecting the conductor 9 with the normally open contact terminal b. As the speed of the vehicle increases and the value of the speed detected by the speed sensor 4 exceeds a predetermined threshold value, the ECU supplies the conductor 9 with current that latches the relay 10 in the energized state via the diode 12 . Conversely, the current on the conductor 9 flows through the normally closed contacts of the R relay 11 and energizes the coil of the relay 8 . The normally closed contacts of the relay 8 thereupon open. In this state, if the shift switch 3 is shifted to the R position, the second drive solenoid 7 is not actuated due to the opened state of the relay 8 contacts. Accordingly, shifting the gear into the reverse mode is prevented. Meanwhile, since the F latching relay 10 is latched “closed” due to the signal on the conductor 9 , the control relay 6 contacts remain closed. Therefore, if the shift switch 3 is shifted out of the F position to a different (N or R) position and returned to the F position, the first control solenoid 5 is de-energized and then energized again.
[0017] Upon initial shifting of the vehicle into the R position, the sequence of events that occur with the first and second solenoids 5 , 7 , the relays 6 , 8 and the F and R relays 10 , 11 only exchange their actuation states. The function is similar to those with a forward gear selection.
[0018] It should be apparent from the foregoing that the embodiment of FIG. 1 achieves certain advantages not obtained with the arrangements of the prior art. First, when the speed of the vehicle exceeds a certain threshold value (which can be either a fixed value or a variable rate computed by the ECU in accordance with instantaneous operating conditions), shifting the gear to a reverse direction mode relative to the moving direction of the vehicle is precluded. Importantly, however, even if the shift lever is shifted out of the initially selected direction gear to an opposite direction gear relative to the moving direction, or to a neutral position, the vehicle can be shifted again into the originally selected direction by returning the shift lever to the originally selected drive mode without regard to the speed of the vehicle. Thereby, both engine braking and acceleration can be recognized.
[0019] A second embodiment of the present invention is shown in FIG. 2. In the second embodiment, when the shift lever is shifted to the position opposite to the moving direction during an operation of the shift control apparatus, the apparatus alarms an operator such as by a warning light or by beeping a buzzer.
[0020] In the embodiment of FIG. 2, the same reference numerals denote the same or similar components to those in the embodiment of FIG. 1. As illustrated, the two-pole relays 21 , 22 are implemented in place of the single-pole relays 6 , 8 . The common contact terminals of the relays 21 , 22 are connected to the conductors 14 , 15 respectively. Terminal a of the relay 21 connects with the first solenoid 5 and terminal a of the relay 22 connects with the second solenoid 7 . Terminal b of the relays 21 , 22 each connect with a warning means, a buzzer 25 in the present embodiment.
[0021] In operation of the embodiment of FIG. 2, as the switch shift is shifted to the F position, battery current is supplied through the ignition switch 2 , the shift switch 3 , the conductor 14 , and terminal a of the relay 21 (assuming the vehicle speed is below the threshold), and energizes the first solenoid 5 , thus permitting the forward movement. Current also flows through the diode 16 , and actuates the latching F relay 10 , connecting contact terminal b of that relay to the conductor 9 . As the speed of the vehicle increases and the value of the speed detected by the speed sensor 4 exceeds a predetermined threshold value, the ECU supplies a current to the conductor 9 . Electric current therefore flows through the diode 12 via terminal b of the F relay 10 and keeps that relay energized. Because the relay 11 is not energized, current on the conductor 9 flows through contact terminal a of the R relay 11 and actuates the relay 22 , thereby connecting the conductor 15 to contact terminal b of the relay 22 . This activates the alarm 25 .
[0022] In sum, if the shift switch 3 is shifted to the R position, the second solenoid 7 is not actuated due to the open state of contact terminal a of the relay 22 . Accordingly, shifting the gear to the reverse mode is precluded. Meanwhile, the electric current supplied to terminal b of the relay 22 from the conductor 15 actuates the buzzer 25 and alarms the operator, thus informing the operator of the status of the shift control apparatus. Moreover, since the F relay 10 is electrically latched in its actuated state by the signal on the conductor 9 , the relay 21 remains de-energized and the conductive path between the conductor 14 and the solenoid 5 is maintained. Therefore, if the shift switch 3 is shifted out of the F position and then returned again to the F position, the first solenoid 5 is first de-energized and then immediately energized again. This operation is similar to that of the first embodiment.
[0023] If, instead, the reverse gear R were selected initially, then the states of the first and second solenoids 5 , 7 , the relays 21 , 22 and the F and R relays 10 , 11 will be reversed. Thus, the relay 10 will be de-energized and the relay 11 will be energized, resulting in the relay 21 being energized and relay 22 being de-energized when the vehicle speed is over the threshold value. This precludes actuation of the forward drive solenoid 5 , but allows the reverse drive solenoid to be actuated, de-actuated and re-actuated without bringing the vehicle to a speed below the threshold value. At the same time, the vehicle cannot be placed into the F drive mode because the relay 11 is activated and its normally closed contacts are held open by continued energization of the coil of the relay 21 due to the current signal on the conductor 9 .
[0024] Since the buzzer informs the operator of the operation of the shift control apparatus, the vehicle may be appropriately operated immediately. However, a warning lamp or other types of indicators may be used instead of the buzzer in order to call the operator's attention to the state of the shift control apparatus and the inability to change direction of the drive mechanism at the current vehicle speed.
[0025] According to the present invention described above, the gear is shifted to the mode corresponding to the moving direction even if the shift lever is shifted to the neutral position or the opposite position relative to the moving direction during times when the vehicle exceeds the predetermined value of speed. Thereby, engine braking remains operative, and acceleration in the originally selected direction of motion can be invoked without decreasing the speed of the vehicle in order to reset the shift control apparatus.
[0026] Although the invention has been described with reference to representative embodiments thereof, such embodiments are illustrative only, and the invention is not restricted or otherwise limited to the details given herein, but may be modified within the scope of the appended claims. For example, the disclosed embodiments have been described as implementing specific types of switch devices, i.e., single-pole and double-pole relays. However, those skilled in the art may find other types of switching devices (such as solid-state switches) preferable or desirable in certain implementations. Also, the shift selector switch can take a number of forms and itself may be electronic rather than electromechanical. Moreover, the switched states of the relays could be readily exchanged without altering the operative nature of the invention. | A vehicular shift control apparatus, including a drive mechanism, has first and second solenoids, first and second switches, a shift switch and a controller. The first and second solenoids control the drive mechanism in forward and reverse modes, respectively, and connect with the first and second switches, respectively, which supply the solenoids with a current when actuated. The shift switch selectively supplies the first and second switches with the current. The controller actuates and de-actuates the first and second switches based on the speed of the vehicle. The first and second switches can be actuated when the speed is lower than a predetermined value and a corresponding forward or reverse gear is selected when one of the first and second switches corresponding to the shift mode of the moving vehicle remains closed the other switch is open and cannot be closed except when the speed is below the predetermined value. | 5 |
This is a division, of application Ser. No. 665,585 filed Mar. 10, 1976
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
This invention pertains to an oil recovery method, and more specifically to a method for recovering oil or petroleum from a subterranean viscous petroleum containing formation such as a tar sand deposit in which a fluid comprising superheated steam and air is introduced into the formation to displace the oil.
2. DESCRIPTION OF THE PRIOR ART
There are known to exist throughout the world many subterranean petroleum containing formations from which the petroleum cannot be recovered by conventional means because of the relatively high viscosity thereof. The best known of such viscous petroleum containing formations are the socalled tar sands or bituminous sand deposits. The largest and most famous such deposit is in the Athabasca area in the northeastern part of the Province of Alberta, Canada which is known to contain over 700 billion barrels of petroleum. Other extensive deposits are known to exist in western part of the United States, and Venezuela, and lesser deposits in Europe and Asia.
Tar sands are frequently defined as sand saturated with a highly viscous crude petroleum material not recoverable in its natural state through a well by ordinary production methods. The hydrocarbon contained in tar sand deposits are generally highly bituminous in character. The tar sand deposits are generally arranged as follows. Fine quartz sand is coated with a layer of water and the bituminous material occupies most of the void space around the wetted sand grains. The balance of the void volume may filled with connate water, and occasionally a small volume of gas which is usually air or methane. The sand grains are packed to a void volume of about 35%, which corresponds to about 83% by weight sand. The balance of the material is bitumen and water. The sum of bitumen and water will almost always equal about 17% by weight, with the bitumen portion varying from about 2% to around 16%.
It is an unusual characteristic of tar sand deposits that the sand grains are not in any sense consolidated, that is to say the sand is essentially suspended in the solid or nearly solid hydrocarbon material. The API gravity of the bitumen usually ranges from about 6 to about 8, and the specific gravity at 60° F. is from about 1.006 to about 1.027. Approximately 50% of the bitumen is distillable without cracking, and the sulfur content averages between 4 and 5% by weight. The bitumen is also very viscous, and so even if it is recoverable by an in situ separation technique, some on-site refining of the produced petroleum must be undertaken in order to convert it to a pumpable fluid.
Bitumen may be recovered from tar sand deposits by mining or by in situ processes. Most of the recovery to date has been by means of mining, although this is limited to instances where the ratio of the overburden thickness to tar sand deposit thickness is economically suitable, generally defined as one or less. In situ processes have been proposed which may be categorized as thermal, such as fire flooding or steam injection, and steam plus emulsification drive processes. Generation of thermal heat necessary to mobilize the bitumen by means of a subterranean atomic explosion has been seriously considered, although has not yet been attempted.
Despite the many proposed methods for recovering bitumen from tar sand deposits, there has still been no successful exploitation of such deposits by in situ processing on a commercial scale up to the present time. Accordingly, there is a definite need in the art for a satisfactory in situ combustion process, and especially in view of the enormous reserves present in this form which are needed to help satisfy present energy needs, there is a substantial need for a workable method for recovery of bitumen from tar sand deposits.
SUMMARY OF THE INVENTION
In its broadest aspect this invention relates to a method for recovering petroleum from subterranean, viscous petroleum containing formations including tar sand deposits, said formations being penetrated by at least one injection well and by at least one production well, comprising;
(a) establishing a fluid communication path in the formation between the injection well and the production well;
(b) injecting via an injection well a fluid comprising superheated steam and air under pressure into the formation whereby in situ combustion is initiated in the formation providing heat and pressure for driving the petroleum in the formation toward the production well, and
(c) recovering petroleum from the formation via the production well.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE depicts an injection well through which the superheated steam-air mixture is injected into the formation which is equipped to serve as a superheater.
DETAILED DESCRIPTION OF THE INVENTION
In the first step of this process a communication path is established in the formation. The ideal communication path is an essentially horizontal, pancake shaped zone of high permeability preferably at or near the bottom of the tar sand or petroleum reservoir.
It is sometimes discovered that there is a water saturated zone in the very bottom of the petroleum reservoir, and this may be utilized successfully to establish the fluid communication path in accordance with our process. The water-saturated zone may be opened up by injecting into the zone a heated fluid such as steam, which will channel preferentially through this water saturated zone to the production well. Asphaltic or other solid or semi-solid hydrocarbon materials present in the water saturated zone will be melted and rendered mobile, and the permeability will be opened up considerably thereby.
Generally, it will be necessary to open up the communication path through the formation by some other means such as hydraulic fracturing. Hydraulic fracturing is a well known technique for establishing a communication path between an injection well and a production well. Fracturing is usually accomplished by forcing a liquid such as water, oil or any other suitable hydrocarbon fraction into the formation at pressures of from about 300 to about 1,500 psig which are sufficient to rupture the formation and to open up channels therein. By use of this method it is possible to position the fracture at any desired vertical location with respect to the bottom of the oil filled zone. It is not essential that the fracture planes be horizontally oriented, although it is of course preferable that they be.
In any event, a communication path of some sort is created, generally confined to the lower portion of the petroleum reservoir. After the fracture has been established, and without diminishing the fracture pressure, a propping agent may be injected into the fracture in order to prevent healing of the fracture which would destroy its usefulness for fluid flow communication purposes. Gravel and sand or mixtures thereof are employed as propping agents, and it is desirable in the instance of tar sand deposits that a wide variation of particle sizes be employed to avoid flowing of the tar sand materials back into the propped fracture zone.
In the next step of the process of this invention a fluid comprising about 20 to about 80 percent by weight of superheated steam and from about 80 to about 20 percent by weight of air at temperatures ranging from about 200° to about 1800° F and pressures ranging from 50 to about 2000 psig is injected into the communication path previously formed in the formation.
In preparing the superheated steam and air mixtures generally steam at a pressure of about 300 to about 1000 psig. is generated in conventional boilers at temperatures preferably above 800° F.
An alternate procedure for injecting the superheated steam-air mixture is to equip the well to serve as a superheater.
By this method air and superheated steam are injected via an injection well into a subterranean hydrocarbon-bearing formation with a minimum of heat loss to extraneous earth formations by a method which comprises:
(a) placing three tubular means inside the well casing so as to provide an annular space between each tubular means and the casing, wherein the said three tubular means comprise an open-end innermost tubular means in communication with a closed end intermediate tubular means and an outer tubular means extending into the formation and being perforated so that there is communication with the hydrocarbon reservoir and wherein said casing extends into the hydrocarbon reservoir,
(b) injecting steam into the annular space between the open end innermost tubular means and the closed end intermediate tubular means and withdrawing condensate via the openend innermost tubular means whereby the intermediate tubular means is heated,
(c) injecting steam having a temperature below that of the steam injected in step (b) into the annular space between the outer tubular means and the intermediate tubular means whereby the steam injected in (c) is superheated and forcing the superheated steam into the hydrocarbon-bearing formation via the perforations in the outer tubular means, and
(d) injecting air into the annular space between the casing and the outer tubular means and forcing the said air into the hydrocarbon formation.
Such an injection well is shown in the FIGURE. In this arrangement three strings of concentrically located tubing, that is 10, 11, and 12, are employed inside of casing 9. Closed-end tubing string 10 penetrates the well to a depth above perforations 13. A smaller open-ended tubing string 12 penetrates the closed end tubing 10 to a depth just above that of the closure in tubing string 10. Tubing string 11 which as a larger diameter than string 10 penetrates the oil-bearing formation and is equipped with perforations 13 which are positioned so that they open into the oil-bearing zone. Well casing 9 is seated at a point just below the top of the oil-bearing formation and is open at the lower end.
Steam of about 80 percent quality is formed in generator 20 and passed via line 22 into the annular space 21 between tubing strings 10 and 12. As the steam passes down this annular space the walls are heated and the steam which condenses collects at the bottom of closed-end tubing 10 after which the condensate is returned to steam generator 20 via tubing 12 and line 24. Steam from steam boiler 26 having a temperature below that of the steam-flowing in line 22 is injected via line 28 into annular space 30 where it is superheated as it passes downwardly through annular space 30. This superheated steam is then forced into the oil-bearing formation via perforations 30 of tubing strings. Air is injected into annular space between casing 9 and tubing 11 and enters the oil-bearing formation at 34. Thus, in the above-described well arrangement the injection well serves as a superheater.
If desired, the fluid, that is the oil-displacing fluid, injected into the formation may comprise an alkaline fluid or an alkaline fluid containing a minor amount of a useful group of the water-soluble, oxyalkylated, nitrogen-containing aromatic compounds are those having the formation:
R(OR').sub.n OH,
wherein R is selected from the group consisting of: ##STR1## wherein R' is alkylene of from 2 to 4 inclusive carbon atoms and n is an interger of from about 5 to about 50 and preferably from about 5 to about 20. These novel water-soluble oxyalkylated products can be conveniently prepared by a number of processes well known in the art and their preparation is more completely described in U.S. Pat. No. 3,731,741 which is incorporated herein by reference in its entirety.
Another group of solubilizing agents which are highly useful in the process of this invention include compounds of the formula: ##STR2## wherein r is an interger of from about 3 to about 10, s is an interger of from about 5 to about 50 and wherein the sum of 5 plus s is not more than 55.
Solubilizing agents of this type can be formed in the same manner as described in U.S. Pat. No. 3,731,741 employing as starting aromatic compounds 8-quinolinesulfonic chloride, 6-quinolinesulfonyl bromide, etc., as initiators and reacting the initiator first with the necessary amount of propylene glycol of the required molecular weight followed by the necessary amount of ethylene glycol of the required molecular weight. The quinoline starting, material may also be substituted by other innocous groups such as alkoxy of from 1 to 4 carbon atoms, alkyl, etc.
EXAMPLE I
This invention is best understood by a reference to the following examples which are offered only as illustrative embodiments of this invention, and are not intended to be limitative or restricted thereof.
A tar sand deposit is located at a depth of 875 feet and it is determined that the thickness of the formation is 120 feet. It is also determined that the petroleum is in the form of a highly bituminous hydrocarbon, and its viscosity at the formation temperature is much too high to permit recovery thereof by conventional means. An injection well is drilled to the bottom of the formation, and perforations are formed between the interval of 850-875 feet, i.e., the bottom of the petroleum saturated zone. A production well is drilled approximately 600 feet distance from the injection well, and perforations are similarly made slightly above the bottom of the petroleum saturated zone. The production well is also equipped with a steam trap so that only liquids can be produced from the formation, and vapors are excluded therefrom.
A fluid communication path low in the formation is formulated by fracturing the formation using conventional hydraulic fracturing techniques, and injecting a gravelsand mixture into the fracture to hold it open and prevent healing of the fracture.
In the next step a fluid comprising a mixture of about 50 weight percent steam and about 50 weight percent air at a temperature of about 1000° F and at a pressure of about 300 psig. is introduced into the formation at the rate of 5000 lbs/hour. via the previously prepared fluid communication path. Injection of the steam-air mixture is continued and the production of viscous oil via the production well commences after about 30 days and gradually increases an injection of the oil-displacing fluid is continued. At the end of 60 days production of the viscous hydrocarbons is significantly increased over production of similar wells in the same formation utilizing only steam injection.
EXAMPLE II
In this example viscous oil is recovered from a tar sand at a depth of 700 feet and having a thickness of about 28 feet. An injection well is drilled to the bottom of the hydrocarbon bearing structure and the casing perforated in the interval 705 to 715 feet. In a like manner a production well drilled at a distance of about 465 feet from the injection well is perforated at a depth of 700-710 feet, i.e., near the center of the tar sand formation at that location.
In the next step a fluid communication path is formed by fracturing the formation in both wells using conventional hydraulic fracturing technique. A gravel-sand mixture is injected into the formation to hold it open and to prevent healing of the fracture. A mixture fluid comprising a mixture of about 40 percent by weight of steam and about 60 percent by weight of air at a temperature of about 1200° F and at a pressure of about 1000 psig together with 0.001 weight percent of sodium hyroxide and 0.002 weight percent of a solubilizing agent of the formula: ##STR3## is injected into the fluid communication path via the injection well at a rate of 600 lbs/hour. Injection of this fluid is continued and after about 20 days production of viscous oil is commenced via the production well. Production increases gradually as injection of the fluid is continued. At the end of 60 days the level of production reached is substantially in excess of that obtained with similar wells in the same formation utilizing only steam injection. | Petroleum may be recovered from viscous petroleum containing formations including tar sand deposits by first creating a fluid communication path in the formation, followed by injecting via an injection well a fluid comprising superheated steam and air into the formation via the fluid communication path whereby in situ combustion occurs providing heat and pressure for driving the petroleum in the formation toward the production well. Recovery of the displaced petroleum is accomplished via the production well. | 4 |
BACKGROUND
Embodiment generally relate to electronic circuit designs, and more specifically to improvements in architectural arrangements which enable enhanced performance and/or features for direct sampling tuner, and specifically to direct conversion sampling receivers which include a successive approximation analog-to-digital converter (SAR-ADC) to enhance quality of sampling receivers, where the SAR-ADC incorporates a current redistribution digital-to-analog converter (DAC), with gain control.
Direct conversion sampling receivers (DSRs) are a relatively new realization and are highly suited to implementation on an ultra-high speed digital process since the receiver architecture eliminates the requirement for significant analogue circuits such as operational amplifier (op-amp) based continual time filters. DSRs are used in, for example, cable modems, satellite set top boxes, cable set top boxes, and the like. However, in many DSRs in order to compensate for a wide amplitude range of received signals, the input signals are subjected to amplitude adjustment using fine digital gain control (“FDGC”). FDGC allows for the selection and adjustment of gain to be applied to an input signal. Amplitude adjustment or so called gain adjustment of an incoming signal by an FDGC is used to achieve an amplitude level well above the noise and offset thresholds. Without the application of gain adjustment, it may not be feasible to perform further post processing of an incoming signal, such as adaptive equalization and digital conversion.
Many techniques are known for implementing fine digital gain control such as switched gm stages, field effect transistor (FET) switched R-2R ladders and the like. All these approaches have major disadvantages such as adding to thermal noise, intermodulation associated with the additional circuits, adding to circuit complexity, and since they are typically preceded by an amplifier stage with a fixed gain or with a small range of coarse gain steps the output amplitude will increase in sympathy with the input and so potentially lead to compression and further intermodulation distortion in the output.
Therefore, there is a need in the art for an architectural arrangement which substantially overcomes the aforementioned undesired characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:
FIG. 1 is an illustration of a direct sampling tuner/receiver (DSR) having charge redistribution SAR-ADC architecture with variable gain control component in accordance to an embodiment;
FIG. 2 is an illustration of the DSR of FIG. 1 during the sample phase in accordance to an embodiment.
FIG. 3 is an illustration of the DSR of FIG. 1 during the conversion phase in accordance to an embodiment;
FIG. 4 is an illustration of gain control characteristic with C GAIN expressed as a ratio to C ADC in accordance to an embodiment;
FIG. 5 is an illustration of gain control characteristic with C Tot ratio of 4:2:1 in frequency domain in accordance to an embodiment; and
FIG. 6 is an illustration of gain control characteristic with C Tot ratio of 4:2:1 in time domain in accordance to an embodiment; and
FIG. 7 is a flow diagram illustrating actions in a method 700 for introducing variable gain control to an analog to digital conversion based on the architecture of FIG. 1 in accordance to an embodiment.
It will be appreciated that for simplicity and clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals have been repeated among the figures to indicate corresponding or analogous elements.
DETAILED DESCRIPTION
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the preset invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present invention.
Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, “processing,” “computing,” “calculating,” “determining,” “establishing”, “analyzing”, “checking”, or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulate and/or transform data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer's registers and/or memories or other information storage medium that may store instructions to perform operations and/or processes.
Although embodiments of the invention are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. For example, “a plurality of stations” may include two or more stations. The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
FIG. 1 is an illustration of a direct sampling tuner/receiver 100 (DSR) having charge redistribution SAR-ADC architecture with variable gain control component in accordance to an embodiment. The illustrated direct sampling receiver (DSR) 100 is implemented to process received signals 105 , such as signal V in (t), with charge redistribution SAR-ADC 125 . A front end of the DSR 100 includes a low noise amplifier (LNA). The LNA may be a gm stage 110 outputting a current which is switched to the SAR-ADC. The Gm stage 110 amplifies the received signal 105 (Vin (t)). In one example, the front end of the DSR 100 also includes a sampling switch 120 . The sampling switch 120 is selectively switched in accordance with a sampling clock signal (sample clock 121 ), switched to pass a selected sample of the amplified signal to the SAR-ADC 125 .
In one example, the DSR 100 further includes a variable gain control component 180 , which provide a variable load to the Gm stage 110 . Known techniques for implementing gain control include switched gm stages, FET switched R2R ladders and the like. These devices are known for introducing thermal noise, adding circuit complexity, and causing or increasing inter-modulation. Some of these known techniques additionally tend to cause compression and inter-modulation distortion with down stream components which tends to manifest in the output. Gain control component 180 is implemented as a capacitor or an array of capacitors. A gain control capacitor (C Gain ) component can deliver an accurate and predictable gain step that overcomes additive noise and intermodulation associated with traditional techniques. Gain control component 180 comprises capacitor 182 , which may consist of a multiple component array, and switch 185 . Switch 185 is positioned based on the operation of SAR-ADC 125 , i.e., the sample and conversion phases. During the sampling phase, switch 185 like mode switch 160 is placed in sample period position. As shown there is one mode switch 160 per capacitor. During the sample period the switches form a circuit with the output side of sampling switch 120 . During the conversion phase the connection with the sampling switch is broken.
SAR ADC 125 can include various subcircuits, including comparator circuit 125 , internal digital-to-analog converter (DAC) 150 , SAR logic 140 , and control logic block 170 with result register. Comparator 130 can compare an input voltage (Vin(*) 106 ) which is the output voltage 152 (Vcomp) of DAC 150 against a reference voltage Vref 131 and can output the result of the comparison to SAR LOGIC block 140 . SAR logic 140 can include a successive approximation register designed to supply an approximate digital code of the input voltage, Vin(*) 106 , to DAC 150 . DAC 150 is shown associated with comparator 130 , capacitor banks or array of capacitors 155 , mode switches 160 each coupled to a capacitor in the array of capacitors, and sampling switch 120 is associated with a low noise amplifier (LNA) and one element of the array of capacitors. An input of comparator 130 is coupled to a reference voltage Vref. The closing or opening of each of the mode switches 160 is controlled by control block 170 . The closing or opening of the sampling switch 120 is controlled by a sampling clock signal to selectively activate. A resulting code of a digital approximation of the sampled input voltage Vin (*) 106 can be outputted at the end of a conversion to an output register 172 at control block 170 or as a separate circuit block. In accordance with various embodiments, SAR-ADC 125 can be implemented as a charge redistribution SAR-ADC. For clarity, power supplies (positive Vdd, negative Vee), as well as ground connections, are assumed to be present, but not shown in the Figure.
The closing or opening of each of the mode switches 160 and/or switch 185 is controlled by control block 170 . The closing or opening of sampling switch 120 is controlled by a sampling clock signal to selectively activate the sampling switch. The sample clock may be externally generated, generated by control block 170 , or by a programmed multivibrator in DSR 100 .
A control block 170 based on the stored instructions such as values and/or number of iterations that correspond to a predetermined resolution, determines the switching of switch 160 . The opening and closing of the switch is predetermined by the number of samples from sample switch 120 which sets the sampling phase duration, and the number of cycles required to run the logic to switch the charge redistribution digital-to-analog converter output. Switch 160 is controlled to two distinct configurations or phases. These configurations are (a) a sampling mode configuration and (b) a conversion mode configuration.
In the first configuration, referred to as the sampling phase/mode, the Gm stage, 110 , through the switch, 120 , charges the array of capacitors 155 , i.e., mode switch 160 couples the capacitors to the output of sampling switch 120 , to integrate the current output sampled by the sampling switches; each capacitor in the array of capacitors would normally be discharged before this period. In addition during the sampling period capacitor 182 in gain control element 180 is also connected to the output of sampling switch 120 . ADC capacitor array and capacitor 182 create a parallel bank of capacitors during the sampling phase.
In the second configuration, referred to as the conversion mode/phase, After the requisite number of samples the DAC array of capacitors is then isolated from the input sampling switches and transitioned back to normal charge distribution function within the SAR-ADC wherein the array of capacitors are switched between supply voltage (Vdd) and ground (Vss) which redistributes the stored charge between the elements such that the resultant voltage on the capacitor is V=Q/C trends towards the reference voltage of the comparator 130 . The output of comparator 130 then processed through quantization loop of SAR logic 140 and CDAC 150 until the number of iterations is produced and a predetermined resolution. Since the illustrated architecture is based on charge sampling and redistribution around the SAR-ADC capacitors the performance can be enhanced by redistribution of the capacitors and amplifiers (gm) during the sampling phase.
While a single stage is shown in this embodiment the gain control component can be deployed in an interleaved system, in which case the C GAIN may be preferably reused between multiple placements of the SARADC which may be incorporated so that when a first SARADC 125 is sampling the second is converting, and vice versa. More than 2 SAR ADCs 125 may be deployed in this manner for example if the conversion periods are substantially longer than the sampling; for example consider a sampling to conversion period ratio of 1:2, three segments may be deployed so that when one segment is converting firstly a second segment samples the input for half the conversion period of the first and then a third segment samples for the other half conversion period of the first. In all such cases the capacitor 182 can be reused for the sampling period of each and all segments, since it is only used during the sampling period.
FIG. 2 is an illustration of the DSR of FIG. 1 during the sample phase in accordance to an embodiment. Here, a gain control component 180 , capacitor 182 (C Gain ), can be introduced to scale the dynamic input range of the SAR-ADC 125 . During the sampling phase, the SAR-ADC 125 can be connected to the output of Gm stage 110 via sampling switch 120 . The total charge stored in SAR-ADC 125 and the gain control components after the sampling phase can be defined as: Q tot =(C ADC +C Gain )*Vin; where Vin is the voltage at sampling switch 120 after it was amplified and C ADC +C Gain =C TOT . As shown, from the point of view of the front end of DSR 100 it appears that the load is two capacitors, ADC capacitor array 155 and capacitor 182 , connected in parallel. The theoretical load is represented in the “s” domain by: 1/SC TOT where C TOT =C ADC +C GAIN . By switching the capacitor 182 in during the sample phase the voltage generated (Vin) will be reduced by the additional capacitance, so providing gain control. The Gain control can be raised or lowered by changing the overall capacitance of gain control component 180 .
FIG. 3 is an illustration of the DSR of FIG. 1 during the conversion phase in accordance to an embodiment. After the requisite number of samples the array of capacitors 155 is then isolated from the input sampling switch 120 and transitioned back to normal charge distribution function within the SAR-ADC wherein the array of capacitors are switched (mode switch 160 ) between supply voltage (Vdd) and ground (Vss) which redistributes the stored charge between the elements such that the resultant voltage on the capacitor is V=Q/C trends towards the reference voltage 131 of comparator 130 . The output of comparator 130 then processed through quantization loop of SAR logic 140 and DAC 150 until the number of iterations is produced and a predetermined resolution. Additionally, during the conversion stage the additional capacitance in gain control component 180 (Capacitance 182 ) must be switched or isolated away from the SAR-ADC capacitor to allow correct operation of the charge redistribution DAC, i.e., ADC capacitor array 155 . Switching the additional capacitance away from the ADC capacitor array 155 will not modify the voltage stored in the ADC capacitor hence the reduced signal amplitude generated during the sampling period will be maintained into the conversion period. Further, the isolated additional capacitor may be discharged (connecting capacitor 182 to ground) to allow correct operation during the next sample/conversion cycle.
FIG. 4 is an illustration of gain control characteristic with C GAIN expressed as a ratio to C ADC in accordance to an embodiment. The variation in gain with C GAIN is shown in FIG. 4 .
FIG. 5 is an illustration of gain control characteristic with C Tot ratio of 4:2:1 in frequency domain in accordance to an embodiment. The gain control characteristic is constant with frequency offset as displayed in FIG. 5 . This figure shows the gain characteristic for C TOT a 1:2:4 for a 4 segment (Gm segment 1 . . . Gm segment 4 ) direct sampling receiver. As can be seen the gain offset between simulations is approximately six (6) dB as predicted and furtherly that the relative attenuation is constant with frequency maintaining the sampled filter characteristic.
FIG. 6 is an illustration of gain control characteristic with C Tot ratio of 4:2:1 in time domain in accordance to an embodiment. As can be seen from FIG. 6 , an additional feature of this architecture is that since the signal is input as a current there is theoretically no change in phase as the gain is adjusted Phase shift can be a particularly problematic effect since digital modulation techniques employ phase information of the carrier as part of the encoding, for example 64 QAM has 64 data locations each with a unique phase and amplitude information, therefore any phase shift associated with a gain change can lead to a corruption in the data location and corruption in the data.
FIG. 7 is a flow diagram illustrating actions in a method 700 for introducing variable gain control to an analog to digital conversion based on the architecture of FIG. 1 in accordance to an embodiment. Method 700 begins with start 710 . Control is then passed to action 715 . Action 715 is based on the positioning of mode switch 160 . If the sampling mode has been selected then control is passed to action 720 for further processing in accordance to a sampling process. Action 720 introduces variable gain control into the process by toggling switch 185 to the sample phase. After action 720 control is passed to action 725 . In action 725 if switch 160 is in the conversion mode then control is passed to action 730 for further processing. If switch 160 is not set to conversion mode then control is passed to action 715 for further processing. When control is passed to action 730 the gain control component is isolated from the array of capacitors at SAR-ADC 125 and the resultant voltage in the capacitors are compared against a reference voltage Vref 131 at comparator 130 . Control is then passed to action 750 where SAR-ADC is performed on the charges (Q) in the array of capacitors. After a predetermined number of iterations control is then passed to action 710 and the process is restarted.
The techniques described herein may be embodied in a computer-readable medium for configuring a computing system to execute the method. The computer readable media may include, for example and without limitation, any number of the following: magnetic storage media including disk and tape storage media; optical storage media such as compact disk media (e.g., CDROM, CDR, and the like) and digital video disk storage media; holographic memory; nonvolatile memory storage media including semiconductor-based memory units such as FLASH memory, EEPROM, EPROM, ROM; ferromagnetic digital memories; volatile storage media including registers, buffers or caches, main memory, RAM, and the like; and data transmission media including permanent and intermittent computer networks, point-to-point telecommunication equipment, carrier wave transmission media, the Internet, just to name a few. Other new and various types of computer-readable media may be used to store and/or transmit the software modules discussed herein. Computing systems may be found in many forms including but not limited to mainframes, minicomputers, servers, workstations, personal computers, notepads, personal digital assistants, various wireless devices and embedded systems, just to name a few. A typical computing system includes at least one processing unit, associated memory and a number of input/output (I/O) devices. A computing system processes information according to a program and produces resultant output information via I/O devices.
Realizations in accordance with the present invention have been described in the context of particular embodiments. These embodiments are meant to be illustrative and not limiting. Many variations, modifications, additions, and improvements are possible. Accordingly, plural instances may be provided for components described herein as a single instance. Boundaries between various components, operations and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific illustrative configurations. Other allocations of functionality are envisioned and may fall within the scope of claims that follow. Finally, while certain features of the embodiment have been illustrated and described herein, many modifications, substitutions, changes, and equivalents may occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. | A method and system for implementing a gain control with fine resolution and minimal additional circuitry. The fine digital gain control may be deployed in conjunction with a coarse switched gain at the front end of a sampling receiver. The fine digital gain control mechanism is configured to receive an input signal and moderate gains applied to the received input signal. The output of a low noise amplifier (LNA) is connected to a switched attenuator which provides fine gain stepped gain control. The output of this stage is connected to the switch stage whose output is connected to a charge redistribution successive approximation register digital-to-analog converter (SAR ADC) configured to convert an analog waveform into a digital representation. | 7 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is based upon Provisional Application No. 61/030,177, filed Feb. 20, 2008, which is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] The invention is related to a system of simulating readings on portable detection devices through both hardware device and software to provide simulated immediately dangerous to life and health (IDLH) environments for hazardous materials (HazMat) first responder training.
[0003] Currently there are few options for effective and realistic hands-on training with the many meters made by various manufacturers. Post-9/11, we have seen a tremendous increase in the number of handheld hazardous materials detection instruments for Chemical, Biological, Radioactive, Nuclear, and Explosive (“CBRNE”) environments. Proper interpretation of and reaction to data received on detection meters is vital to life safety (evacuations, suit compatibility, IDLH) in a hazardous atmosphere or HOTZONE. Technology applied to the development of HazMat meters has increased their functionality but technology to train users on these meters has not advanced at the same pace. Additionally, the number of new first responders requiring training, including those from outside traditional emergency response agencies, has increased multi-fold. This training deficiency puts first responders at risk when an actual incident occurs.
[0004] Emergency response agencies from all over the United States utilize grant funds to send personnel to a handful of remote training sites that specialize in certain areas of CBRNE. Those offsite training opportunities result in increased cost to cover personnel with only marginal benefit, given the limited exposure to live agent hands on training. The hazardous materials meter simulator of the invention would allow better, more effective training to be conducted locally at a fraction of the cost of present methods.
[0005] Live fire training (e.g., active burns creating an IDLH atmosphere) in the Fire Service are used to establish vital real-life and safety decision skills in an environment that approximates the responder's real world as closely as possible. However, this same model of live training in HazMat, using actual CBRNE agents for training HazMat first responders, is dangerous, expensive, difficult to construct, and unrealistic for most, if not all, municipal fire/hazmat teams. The live agents that are used are typically very small amounts in a controlled environment that does not simulate actual distribution of the substance, initial contact with or training stress likely experienced in the field. The HazMat response service needs the ability to train front line responders with realistic and real-time simulations on their detection devices. The hazardous materials meter simulator of the present invention would use existing technology to create realistic and controlled responses on the detection meter without the use of CBRNE. Because the hazardous materials meter simulator of the invention will provide a more realistic reading, a trainee or experienced HazMat responder using the hazardous materials meter simulator of the invention would more likely pay closer attention to the meter response as well as experience critical decision-making in the simulated HOTZONE.
[0006] This system allows local fire, police, and emergency response agencies to set up effective life safety training anywhere and at any time without traveling from their district or being exposed to any real hazardous materials. Nationally accepted protocols and local Policy and Procedure could be adapted easily into the training scenarios. Local jurisdictions would be able to set up realistic trainings easily at their own ‘Target Hazard’ locations.
SUMMARY OF THE INVENTION
[0007] Briefly, and in general terms, the present invention provides for a training simulation device and method for improving life-safety skills in the response to hazardous incidents by first responders using computer interface, wireless technology, simulation software, simulation data and meter parameters to replicate a hazardous environment without the use of hazardous substances. The system integrates chemical, radioactive, and other hazardous substance parameters to closely replicate a hazardous environment.
[0008] The present invention provides a computer based simulation training system for improving the response to actual hazardous incidents by first responders. The system includes a master control, peripheral devices, and a software module that can be used on laptop, portable, or PDA computer devices which are used at a training scenario to simulate a hazardous atmosphere in real time. The present invention can be used to provide direct manipulation of the peripheral devices or control via a group simulation environment. This system integrates the specific technical functions and readings of various detection meters currently on the market that are used to measure chemical, biological, radiological, energetic, or other hazards, or a combination of two or more hazards. In the group simulation environment, the present invention will emulate the simulated environment throughout multiple devices by controlling each separate parameter.
[0009] These and other aspects and advantages of the invention will become apparent from the following detailed description and the accompanying drawings, which illustrate by way of example the features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a flow chart illustrating master control of three types of hazardous materials meter simulators of the invention, by direct control of an individual peripheral apparatus, group control of multiple peripheral apparatus, and control of multiple apparatus by programs or combination of programs reflecting selected environmental settings, such as for dirty bomb contamination, an oxygen deficient environment, and chlorine contamination.
[0011] FIG. 2 a illustrates the features of the embodiment of the hazardous materials meter simulator implemented as an external display attached to a meter.
[0012] FIG. 2 b illustrates the features of the embodiment of the hazardous materials meter simulator implemented as control of an internal display of a meter.
[0013] FIG. 2 c illustrates the features of the embodiment of the hazardous materials meter simulator implemented as a stand alone interactive training meter.
[0014] FIG. 3 is a schematic diagram of a hazardous materials meter simulator master control unit implemented as a PDA, notebook, or PC tablet containing software and hardware that controls one or more peripheral units.
[0015] FIG. 4 is a schematic diagram of a hazardous materials meter simulator master control unit operated by a remote touch screen.
[0016] FIG. 5 is a schematic diagram of the hazardous materials meter simulator master control unit and a peripheral hazardous materials meter simulator unit attached to a hazardous materials meter for training HazMat teams.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] In the following detailed description of the embodiments, reference is made to the accompanying drawings, which form a part hereof, and which are presented by way of illustration, and not by way of limitation. 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 and electrical changes may be made without departing from the spirit and scope of the present invention.
[0018] The hazardous materials (HazMat) meter simulator 10 enables a display, either externally attached or as part of the unit, to mimic a hazardous atmosphere environment for training purposes. Hazardous materials meter simulator enabled devices are able to have their display controlled remotely with the intention of simulating various modes of the detection device in all atmospheres. A hazardous materials meter simulator interactive hazardous simulation training involves a control unit, which wirelessly controls the display on each remote unit. A hazardous materials meter simulator enabled meter allows its display to be controlled remotely for training purposes.
[0019] The hazardous materials meter simulator master control unit 12 is the main computer enabled control device (PDA, notebook, tablet) 28 containing software 30 and hardware that controls one or more peripheral hazardous materials meter simulator units 14 , 16 . The control unit is based within a ruggedized tablet or PDA device capable of sending wireless signals to one or more of the remote hazardous materials meter simulator devices. Optionally the control unit would receive data from the interactive training mode via remote unit touch screen 20 . The operations screen on the control unit as shown in the accompanying FIG. 5 would indicate which meter it was controlling, what type of meter, and a display of the meter. Touch screen ‘toggles’ or buttons 22 would be visually displayed and when pressed would send a signal to the remote hazardous materials meter simulator's changing their display. The control unit would optionally have direct buttons 24 for a ‘type’ of environment 13 to be sent to all meters as a group. For instance: by pressing a button called dirty bomb—the rad meters would pick up RAM, and any LEL meter may pick up residual atmosphere related to an explosion. More specifically, a meter could be directly controlled with a simple up or down arrow and the ability to change the rate and/or increment of change.
[0020] The hazardous materials meter simulator peripheral unit can be the hazardous materials detection device or meter itself, or can be an attachment 18 to such a device/meter for the end user. The master control unit controls this device/meter or attachment, replacing the display on a meter. When implemented as an attachment, the peripheral unit is typically an approximately 3″×5″ external device that is attached over the detection meter's display. The display mimics the actual display of the meter on which it is placed. The hazardous materials meter simulator is completely independent of the meter but during training the user reads the hazardous materials meter simulator display. Built-in memory files preprogrammed of the actual meter's display are controlled via wireless interface (“wifi”) 26 from a master training hazardous materials meter simulator handheld device. The master hazardous materials meter simulator changes the display on the training meter to reflect various environments/readings. The advantage to this approach is that the hardware and software requirements including wifi are currently available and there is no need to infiltrate the meter and its proprietary specifications. The user gets an actual reading on the display and needs to take necessary actions. The hazardous materials meter simulator could not be mistaken for an actual meter. The master hazardous materials meter simulator could operate multiple hazardous materials meter simulators simultaneously.
[0021] The external device for attachment to a meter is made within a ruggedized shock proof/water resistant plastic case consisting typically of a display (LCD) on one side (touch screen option on certain models), a battery, a memory, power switch, microprocessor, wireless Rx (TX option), and an external USB interface port.
[0022] Display
[0023] The display screen is on one side of the unit as indicated in drawings. The display will be specified to be scratch resistant and weather proof. The display will have adequate resolution to show meter function images. The screen will have adequate glare resistance and backlighting ability. Color is optional, based on cost.
[0024] Battery
[0025] The battery will supply enough voltage to run the CPU 28 and screen for extended periods between charging and/or battery replacement. Intrinsically safe operation is not required. The system can have an optional external charge port.
[0026] Memory
[0027] The memory is capable of storing screen shots and active screen movies (looped) of each selected meter function. The files are stored based on meter type, model, manufacturer, and desired display. When called upon by the CPU, the memory file will be displayed on the screen.
[0028] Microprocessor (CPU)
[0029] The processor 28 will need the ability to interface with the wireless signal and pull the appropriate file from memory to be displayed on the screen. Optionally the CPU will be required to take touch screen input from the screen and wirelessly return the data to the control unit. The CPU will receive power and initiate activity upon activation of the power switch.
[0030] Power Switch
[0031] Externally located on the side of the unit. Water resistant/proof.
[0032] External Ports
[0033] External battery charge and or optional docking, data port to cpu/memory for updating files and downloading data. Additional ports as needed.
[0034] Hazardous Materials Meter Simulator Software Design:
[0035] Interactive Training Component:
[0036] Software 30 controls the control unit, the peripheral units, and their interaction. The control unit displays and controls all of the controls on the peripheral units. Features include:
Direct control of peripheral units Scenario control of multiple peripheral units Interactive feature and data logging Internal control of peripheral unit
[0041] Direct Control of Peripheral Units
[0042] This feature allows the control unit to directly control via buttons or touch toggles the display on the peripheral unit. An input (e.g. Increase mR/hr) given on the control unit sends a wireless transmission to the peripheral unit. The peripheral unit receives the signal, which is translated into displaying the appropriate image or video on the display.
[0043] Scenario Control (Including Control of Multiple Peripheral Units)
[0044] This feature allows a training officer, typically one or more persons that would use the hazardous materials meter simulator master control unit and peripherals for the purpose of training personnel in a simulated environment, to select a type of environment via the master control. This environment ‘group’ will trigger each peripheral device appropriately to simulate a potentially complex environment. Multiple peripheral devices are used at the same time and each will respond appropriately. The types of scenario environments may include, but are not limited to, normal background, radioactive, chemical, explosive, and any combination thereof.
[0045] The software first operates to find out how many and what type of meters are going to be used in the scenario; more can always be added. The peripheral meters are set as a group. Instead of direct control of each individually, the training officer can select an overall environment (i.e., post blast of dirty bomb). A time component is necessary to set up the scenario. At the start of the scenario, realistic readings for each type of meter are given (this is also preselected) and over time, each may change. The scenario may be location based, including the location of the meter, as determined by a global positioning system, for example, and will determine readings throughout the training. Overall this feature will make management of multiple meters easier for one training officer. Meter response can also be controlled by the type of hazard in this group mode (as compared to a direct change of reading). During training, radio contact can be used to determine participant understanding of the simulated environment.
[0046] Meters controlled individually, or as a group, or as an environment group/type, and may change based on time, or location or direct input. Custom environments can be created, including the parameters in the following table:
[0000]
Parameters
Oxygen Percent
H 2 S ppm
CH 4 LEL (lower explosive limit) vol percent
CH 4 LEL (lower explosive limit) percent
RAM (radioactive material) Beta
RAM (radioactive material) Gamma
RAM (radioactive material) Alpha
Chlorine ppm
CO ppm
G (nerve agent)
V (nerve agent)
B (nerve agent)
H (nerve agent)
T (mustard gas additive)
Phosgene
Custom
[0047] The participating teams utilizing the peripheral device will obtain simulated readings on their detection instrumentation thus experiencing the critical decision making experience in real time. The display will mimic exactly what is desired by the master control unit. FIG. 1 illustrates master control for three ways of implementing the hazardous materials meter simulator of the invention, by direct control of an individual peripheral apparatus, group control of multiple peripheral apparatus, and control of multiple apparatus by programs or combination of programs reflecting selected environmental settings, such as for dirty bomb contamination, an oxygen deficient environment, and chlorine contamination.
[0048] The master control meter utilizes the hazardous materials meter simulator software 30 on a computer device (tablet, notebook) 28 and is used by the training officer to control the peripheral meters held by the first responder. The master control sends a wireless signal to the peripheral devices in order to change the display to match what is desired from the master control.
[0049] The peripheral control may be implemented in three different ways: (1) An external attachment display device may be provided containing a display screen with touch ability, ruggedized case, internal power supply, internal cpu, internal memory. The internal CPU receives direction from a wireless signal from a master control unit cueing the display of the desired memory file that mimics the desired meter function. (2) The hazardous materials meter simulator may be implemented by direct control from a master control unit of an internal display of a meter. (3) The hazardous materials meter simulator may be implemented as a specialized stand-alone interactive training meter.
[0050] In the group simulation environment, the present invention will emulate the simulated environment throughout multiple devices by controlling separate parameters, such as mR/hr as measured by a radioactive materials detector, such as the detector available from Ludlum Measurements, Inc., of Texas, for measuring beta and gamma radiation, for example, or such as the parameters listed in the following table.
[0000]
Parameter
Environment
Normal Range
CH 4
LEL vol percent
TBD
CH 4
LEL percent
TBD
O2
Oxygen Deficient/Sat
TBD
CO
Carbon Monoxide
TBD
H 2 S
Hydrogen Sulfide
TBD
mR/hr
Radiation
TBD
Chlorine
Chlorine
TBD
Phosgene
Phosgene
TBD
Vx (nerve agent)
TBD
G/B/H (nerve agents)
TBD
Pepper Spray
TBD
cpm
TBD
[0051] It will be apparent from the foregoing that while particular forms of the invention have been illustrated and described, various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims. | The system and method for simulating hazardous environments provides simulated meter readings of hazardous environment for training first responder entry teams by controlling a simulated display provided to portable detection meters, such as via a wireless interface. The simulator provides meter reading displays for selected environments and allows for two-way interactive response. A master control unit allows direct control of individual meter displays and scenarios representing various hazardous environments. A hazardous environment is reflected by parameters indicating the presence of hazardous substances, and the apparatus can be implemented by external placement on current meters, as part of a general training meter, or using technology to internally control existing meters. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to liquid cooling devices and especially to cooling towers adapted to cool and aerate large volumes of water.
In the past, various types of liquid cooling towers have been used for heat exchangers for cooling the liquid which has been heated in industrial processes, such as in air conditioning equipment. Such cooling towers typically utilize water which is fed to the top of a tower and allowed to fall through the tower where it may be broken up so as to cool the water by the water/air contact with the ambient air passing through the tower.
A typical prior art cooling tower can be seen in U.S. Pat. No. 2,606,008 to Laubach. A more recent cooling system can be seen in U.S. Pat. No. 3,864,442 in which a tower is mounted over a liquid reservoir, and in which a conduit discharges a liquid through a discharge nozzle to provide a downward spray of the cooling water which precipitates into a reservoir. Contra air flow is induced through the cooling water to assist in the cooling, and baffle plates are located in the reservoir to direct the cooling water over conduits of the heat exchanger.
The present invention, on the other hand, sprays a cooling liquid into a cooling tower through a special nonclogging spray nozzle for producing a better atomization of the liquid and utilizes forced air both against the collected liquid and passing through the tower. The tower forms only one part of the cooling system which is mounted on a terraced structure to increase the cooling operation of the liquid as it trickles over the terraced structure along grooves having baffles or retarders and rocks thereon.
SUMMARY OF THE INVENTION
A liquid cooling system having a multi-level terraced structure forming a plurality of liquid flow paths over each level of the structure, with each grooved flow path on each level having baffling thereon, and also being adapted for rocks to break up the flow of the liquid. A central tower is mounted on top of the top level of the terraced structure, which tower has an open top but closed sides, and one or more non-clogging spray nozzles mounted therein to spray liquids being cooled into the tower. Cooling air is forced under pressure through pipes opening in the bottom of the cooling tower into cones which direct the forced air against liquid collectng on the bottom of the cooling tower where the air is then directed up through the cooling tower contra to the falling spray and out the top of the cooling tower. The liquid spray nozzles include a rapidly spinning deflector member having vanes thereon for spraying and breaking up the liquid being sprayed in the tower.
BRIEF DESCRIPTION OF THE DRAWINGS
OTher objects, features and advantages of the present invention will be apparent from the written description and the drawings, in which:
FIG. 1 is a partial perspective view of a cooling system in accordance with the present invention;
FIG. 2 is a sectional view of the cooling tower of a cooling system in accordance with FIG. 1;
FIG. 3 is a sectional view of the cooling system taken through the cooling tower;
FIG. 4 is an exploded view of the spray nozzle and the support bracket taken on the circle 4 of FIG. 2;
FIG. 5 is a fragmentary sectional view of the terraced structure of the cooling system;
FIG. 6 is a sectional view of the air nozzles for the cooling tower;
FIG. 7 is a perspective view of a second embodiment of a rotating element of the liquid discharge nozzle; and
FIG. 8 is a fragmentary sectional view of the liquid paths for the terraced structure having baffles located therein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, and especially to FIGS. 1 through 6, a cooling system 10 can be seen to have a terraced base structure 11 and a cooling tower 12 mounted on top of the base structure 11. The structure 11 may typically be a concrete structure having a series of terraced levels 13 each having a plurality of grooved liquid paths 14 formed in the shape of a series of elongated Vs, forming an accordionlike structure. The terraced structure 11 can be set in a reservoir 15 of liquid if desired or can be collected and directed off to a separate reservoir. In operation, the liquid is sprayed in the cooling tower 12 and collects on the uppermost terrace 13 and follows the flow paths 14 as it moves from one terrace to the next. The grooved liquid flow paths 14 may have baffles or retarders, as shown in FIG. 8 to break up the flow of water, and may include rocks thereon, as also shown in FIG. 8. The cooling system advantageously not only cools the liquid, but aerates and treats it much like a trickle filter in a sewage treatment system flowing around a large number of baffles and rocks.
The cooling tower 12 has outside wall 16 and a roof section 17, having a plurality of slotted openings 18 and a plurality of slotted openings 20. Inside the walls 16, the interior surface may be formed of a plurality of V-shaped grooves 21 which may have an inwardly angled V-grooved wall 22 on the bottom portion of the tower 12 for directing liquid that is thrown against the walls toward the bottom of the tower. A liquid input line 23 directs liquid to be cooled through the structure 11 into the tower 12, which pipe is supported by lower support bracket 24 and upper support bracket 25. A non-clogging liquid distribution nozzle 26 is mounted on the end of the pipe 23, which nozzle may be supported by nozzle support bracket 27 attached to the side 16. The nozzle and support bracket may be more clearly seen in FIG. 3, in which the pipe 23 has a spinning nozzle element 28 having a shaft 30 which fits into the pipe end 31 of the water pipe 23 and has a plurality of curved vanes 32 thereon and a top supporting member 33. The top support 33 is of a generally pointed shape with a curved tip and is positioned inside of a sleeve 34. Sleeve 34 has a plurality of holes 35 passing therethrough and is attached to base bracket member 36 which in turn is bolted with a bolt 37 to a bracket member 38 connected to an arm 40 which in turn is connected to a bracket 41 which is attached to the sides 16 of the cooling tower. The sleeve 34 has a weighted rod 42 having a plurality of openings 43 passing therethrough and has a cone shaped opening 44. The bar member 42 rides in the sleeve 34 so that the cone 44 engages the tip 33 of the spray nozzle 28, thereby centering the spray nozzle 28. A pin 45 may be passed through the openings 35 of the sleeve 34 and through the openings 43 of the rod 42 to position the rod 42 in the sleeve 34 for predetermined adjustments for holding the rotating nozzle member 28. In addition, the sleeves 34 may be enlarged openings with sufficient slack to vary the pressure applied against the tip 33 of the nozzle member 28.
Liquid passing out of the pipe 23 is directed against the vanes 32 spinning the vanes 32 which spray water similar to certain types of lawn and irrigation sprinkler systems except that the head is designed to distribute a very fine spray of liquid adjusted for the pressure being applied to the liquid leaving the pipe 23. When liquid is not flowing out of the pipe 23, an angled support 46 on the shaft 30 is shaped to be supported by the lip 31 of the pipe 23. The raising of the spray nozzle 28 when water under pressure is applied thereagainst along with the simultaneous spinning prevents clogging in the nozzle head. The discharge sprinkler member 28 is centered by the connection between the point 33 and the cone 44 and the rod 42 and by the gyroscopic action of the spinning. The sprayed liquid falls in the tower 12 except for small portions that may be thrown against the interior surface 21 of the walls 16, which will flow down the grooved walls.
A plurality of air lines 47 have cone-shaped heads 48 mounted to the ends 50 thereof and pass through a bottom member 51 of the cooling tower 12. The air under pressure is fed, as shown in FIG. 6, out the line 47 directed into the cones 48 downwardly towards the water accumulating on the bottom 51 of the cooling tower 12 and adjacent rocks 52 located on the bottom of the cooling tower 12. The air is then directed upward within the enclosed walls 16 contra to the flow of the sprayed water from the spray nozzle 26. The flowing air not only cools the finely divided water particles, but aerates the water as well. The air under pressure is directed out the openings 18 and 20 of the roof section 17.
The cooled liquid from cooling tower 12, which collects on the bottom of the cooling tower, then flows out along the top level of the terraced structure through the V-shaped grooved liquid flow paths, and from one terraced level to the next, and then back into a central reservoir. In FIG. 8, an alternate embodiment of the grooves 14 has a plurality of alternately spaced baffles 52 are spaced against one inverted V wall 54 on one side and on the wall 55 on the other side. A plurality of rocks 56 can be interspaced between the baffles 53 to break up the flow path and to treat the water as it flows over the terraced structure. FIG. 7 shows an alternate rotating water nozzle element 57 having a shaft 58, an angled support 60, a pointed upper support 61 and a pair of curved vanes 62 which curved vanes have an arcuate curve 63 and are angled along their walls 64 for distribution of the liquid leaving inlet liquid pipe 23.
It should be clear at this point that a cooling system has been provided which both cools and treats liquids, such as water, but it should also be clear that other liquids could be cooled and treated in a similar manner without departing from the spirit and scope of the invention. Accordingly, the present invention is not to be construed as limited to the forms shown, which are to be considered illustrative rather than restrictive. | A liquid cooling apparatus having a multi-level terraced structure capped by a central cooling tower. The central cooling tower has one or more non-clogging liquid spray nozzles mounted therein for spraying the liquid in the tower while compressed air is fed into the bottom of the tower into the sprayed liquid. The liquid collects on the terraced structure which has a plurality of channels formed therein having baffles mounted to break up the flow of water as it passes over each level of the terraced structure. Flow paths on the terraced structure may also have rocks placed along the channels between the baffling members. | 5 |
BACKGROUND OF THE INVENTION
This application is a division of Patent Application Ser. No 703,577 filed July 8, 1976.
STATEMENT OF INVENTION
This invention relates to tenter frames and more particularly to means between guide rail joints which provide a smooth path of travel for the tenter clips arranged in a chain.
Tenter frames are commonly employed in web treating processes of the textile and thermoplastic film manufacturing industries.
Such frames consist of a multiple number of guide rails pivotally connected together. Each guide rail has opposite and parallel guide surfaces which provide a working surface and a return surface for an endlessly moving tenter clip chain.
Each tenter frame consists of two oppositely located guide rails. Two saddles, one for each guide rail, are slidably mounted upon a cross member of the machine frame. A shaft having a left hand thread and a right hand thread is rotatably mounted to the cross member. The two saddles are, respectively, connected to the left hand thread and the right hand thread. Rotation of the shaft moves the two saddles toward and away from each other to decrease or increase the distance between the two oppositely located saddles and guide rails. This movement causes adjacent guide rails to pivot around a connecting pivot pin and thereby increase or decrease the gap between adjacent guide rails.
The tenter clips pivotally connected together form a tenter chain. The clips ride against the working surfaces and return surfaces of the guide rails which form a guide path. The tenter clips located in the oppositely located guide rail paths grasp the edges of the webs being treated and convey these webs across the tenter frame.
Thermoplastic film is commonly stretched in the transverse direction by use of such tentering means. The tenter clips passing from one guide rail section to the pivotally connected adjacent guide rail section encounter a gap between adjacent guide rail sections. This gap causes the tenter clip to jar, jump and shockingly abut the opposite edges of the gap and in general hinder the smooth gentle passage of the tenter clips around the, respective, guide rail paths.
The jarring causes a ripple and thereby the destruction of a section of the thermoplastic film web. The jumping hinders the speed of movement of the tenter chain in the guide path. The shocking physically destroys both the guide path and the tenter clips and significantly increases the requirement of the driving motor. The gap also causes the tenter chain to vibrate. The result is nonuniformity of product, web breaks, and a major cause of equipment failure.
OBJECTS OF THE INVENTION
Accordingly, it is an object of the present invention to obviate the gap between guide rail sections.
Other objects of the present invention will be pointed out in part and become apparent in part in the following specification and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings in which similar characters of reference indicate corresponding parts in all the figures:
FIG. 1 is a schematic plan view of a tenter frame, showing the pivotally connected guide rail sections, the shafts with left hand and right hand threads and a few tenter clips which form a section of a tenter chain;
FIG. 2 is a right side elevational view of FIG. 1;
FIG. 3 is a diagrammatic view illustrating the relative position of the guide rail sections in parallel and divergent positions and showing the discontinuous boundaries or gaps between sections, showing the gaps in convergent and divergent position;
FIG. 4 is a fragmentary cross sectional view taken on line 4--4 of FIG. 1, showing the pivotal mechanism between adjacent guide rail sections;
FIG. 5 is a fragmentary cross sectional view, taken on line 5--5 of FIG. 1, showing one form of a guide rail; and one style of tenter clip;
FIG. 6 is a perspective view of another form of tenter clip adapted to ride in the track provided by the guide rail section shown in FIG. 5;
FIG. 7 is a perspective view of still another form of tenter clip;
FIG. 8 is a vertical cross-sectional view showing the tenter clip of FIG. 7 riding in a guide rail having a modified form when compared to the guide rail shown in FIG. 5;
FIG. 9 is a fragmentary perspective view of the guide rail section (shown in FIG. 5) pivotally attached to a saddle which is slidably mounted upon a cross member;
FIG. 10 is an enlarged view, partly in cross-section, of pivotally connected adjacent guide rail sections, showing the gap between the ends of guide rail sections, and one form of the present invention which obviates the gap for the traveling tenter clips;
FIG. 11 is a view, similar to FIG. 10, showing a modified form of gap crossing mechanism in position between adjacent guide rail sections;
FIG. 12 is a perspective view of the modified form of gap crossing mechanism, per se, shown in FIG. 11;
FIG. 13 is a fragmentary vertical cross sectional view taken on line 13--13 of FIG. 1 with the adjacent section omitted;
FIG. 14 is a vertical cross sectional view similar to FIG. 5 showing a modified form of guide rail construction;
FIG. 15 is a fragmentary plan view of pivotally connected adjacent guide rail sections illustrating another modified form of gap crossing mechanism mounted upon the guide rail shown in FIG. 14;
FIG. 16 is a fragmentary vertical cross sectional view taken on line 16--16 of FIG. 15;
FIG. 17 is a view similar to FIG. 16 taken on line 17--17 of FIG. 15;
FIG. 18 is a fragmentary cross sectional view, taken on line 18--18 of FIG. 15;
FIG. 19 is a fragmentary vertical cross sectional view, similar to FIG. 18, taken on line 19--19 of FIG. 15; and
FIG. 20 is a diagrammatic view illustrating the maximum divergence angle between adjacent pivotally connected guide rail sections in accordance with the modified form shown in FIG. 15 through 19.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In proceeding with this invention, reference is made to the drawings, wherein is illustrated then new and improved tenter frame gap crossing mechanism.
The tenter frame comprises major structural sections, all generally indicated as follows: A plurality of stands 10 in FIG. 2, a frame 11 in FIGS. 1 and 2, with cross members 12 in FIGS. 1, 4 and 9, a plurality of saddles 13 in FIGS. 2, 4 and 9, a plurality of shafts 14 in FIGS. 1, 2, 4 and 9, and a plurality of pivotally connected guide rail sections 15 in FIGS. 1, 2, 3, 4, 5, 8, 9, 10, 11, 13, 14, 15, 18, 19 and 20.
Stands 10 consist of a unitary structure 16 having a base 17 and top surface 18 (see FIG. 2), to be used in a plurality of units in a horizontal line, and in a plurality of units in a longitudinal line, oppositely disposed unit for unit with the first horizontal line.
The frame 11 consists of a left side 20 and a right side 21 fastened, respectively, to the stands 10 arranged in the, respective, longitudinal line. Cross members 12 are fastened on opposite ends to left side 20, and right side 21. Cross members 12 are provided with a horizontal top sliding surface 23 and two opposite and parallel sliding surfaces 24 and 25. (see FIG. 9) A plurality of left side bearings 26 are fastened to left side 20. A plurality of right side bearings 27 are fastened to right side 21 and are located opposite and parallel to bearings 26, respectively. A plurality of center bearings 28 are fastened to the, respective, cross members 12 in alignment with the, respective, left side 26 and right side 27 bearings.
A plurality of shafts 14, each provided with a left hand thread 31 and a right hand thread 32 are rotatably mounted on opposite ends in the, respective, left side bearings 26, right side bearings 27 and centrally in center bearing 28.
A plurality of hand wheels 33 are provided, with one hand wheel fastened to one end of each shaft 14.
A plurality of saddles 13, two for each cross member 12, are provided with a body 40 having sliding faces 41 and sliding ends 42, 43, to slidingly engage, respectively, top sliding surface 23 and opposite and parallel sliding surfaces 24, 25.
With reference to FIG. 13, saddle body 40 is provided with a plurality of inverted "U" shaped projections 50, 51, 52, 53, 54 and 55 which form chambers 56, 57, 58, 59 and 60. Inverted "U" shaped projections 50, 51, 52, 53, 54, 55 straddle shaft 14 to allow shaft 14 to freely rotate. A nut 61 provided with a screw thread of a hand adapted to rotatively engage left hand thread 31 or right hand thread 32, is located in chamber 56 and is held therein by means of inverted "U" shaped projections 51, 51.
Rotation of hand wheel 33 causes nut 61 to engage either inverted "U" shaped projection 50 or 51 to slide saddle 13 upon cross member 12 toward or away from center bearing 28.
With reference to FIGS. 9 and 13, saddle body 40 is provided with a longitudinal groove 62. A block 63 is slidably mounted in longitudinal groove 62. A pivot pin 64 is fastened in block 63.
The plurality of pivotally connected, grooved guide straight rail sections 15, are each provided with two tenter clip tracks, vis, a working side track 66 and a return side track 67. Each rail section 15 has a pivotal recess 68 on one end and a pivotal tongue 70 on the opposite end. (see FIGS. 1, 9 and 10) Pivotal tongues 70 are adapted to pivotally engage pivot pins 64 and lie in the, respective, pivotal recess 68. In this manner a plurality of pivotally connected straight or longitudinally grooved guide rail sections 15 provide a left side guide path, generally indicated at 72 (in FIG. 1) for tenter clips formed into a closed loop circulating tenter chain and a similar right side guide path, generally indicated at 73.
The diagrammatic view, FIG. 3, shows that the guide rail sections 15, while constituting straight sections, may constitute straight sections of varying lengths so that in pivoted relationship, gaps 5 of varying widths exist between adjacent guide rail sections 15. As will presently appear, the shafts 14 and saddles 13 adjust the guide rail sections 15 in divergent and convergent relationship to provide curved paths for the tenter clip chains.
The two guide paths 72, 73 provide an infinite variety of curves which are equal but opposite for processing web material gripped on opposite sides by the tenter clips of the, respective, tenter chains.
The tenter frame is provided with two driving sprockets 120, 121 (see FIG. 1), driven by motors 122, 123 by means of shafts 124, 125, respectively, and two driven sprockets 126, 127. Tentering chain 111 is operatively connected to sprockets 121, 127. Tentering chain 110 is operatively connected to sprockets 120, 126. Tentering chains 110, 111 are driven in the direction of arrows "A" and "B."
In operation, the movement of tenter chains 110, 111 in guide paths 72, 73, respectively, carry a web to be stretched from the pick up end or web receiving region of the tenter frame between sprockets 126, 127 to the delivery end or web discharge region of the tenter frame between sprockets 120, 121. Suitable cams 120A, 121A engage upstanding arms 130 or the pivot jaws 90 causing lower edges 91 to swing away from base 81 and disengage the web (not shown). At the web receiving region cams 126A, 127A engage arms 130 to pivot jaws 90 away from base 81. As arms 130 of the tenter clips of chains 110, 111 move in the direction of arrows A and B, the arms 130 disengage cams 126A, 127A to release pivoted jaws 90 to the action of gravity to grip the web between bases 81 and lower edges 91. Pin 198 pivotally connects jaw 90 to tenter clip body 300.
Rotation of hand wheels 33 cause the, respective, saddles 13 to slide upon cross members 12, whereby, the guide rail sections 15 and the tenter clip tracks 66, 67 thereby provided, are moved in relation one to the other to provide a preselected path of movement for the respective tenter clip chains 110, 111. That preselected path is under very close tolerance adjustment due to threads 31, 32 on shafts 14. FIGS. 1, 2, 3, 10 and 11 clearly illustrate the gap 5 or space between adjacent divergent guide rail sections 15. The gap 5 must permit the tenter clip to pass from one guide rail section to the adjacent divergent guide rail section, smoothly and without the slightest jar or vibration or the plastic film in a heat softened condition will have imparted to it, a wrinkle, a ridge or a tear.
One form of guide rail section 15 construction is shown in FIGS. 5, 9 and 10 wherein the guide rail section comprises a tenter clip working side 225, a tenter clip return side 226 connected together on opposite ends by a front rib 227 and a rear rib 228. Working side 225 is provided with a working side depending arm 230 having a first supporting face 131 and a depending first rib 132. Return side 226 is provided with a return side sepending arm 133 having a second supporting face 134 and a depending second rib 135. Working side 225 is provided with a working side track 66 comprising a front flange 136 having an upper forward tenter clip engaging face 137, a rear flange 229 having a lower rear tenter clip engaging face 138 and a base 139, which combine to form a "U" shaped grooved track 66. Similarly, body 226 is provided with a return side track 67 comprising a front flange 140 having an upper forward tenter clip engaging face 141, a rear flange 145 having a lower rear tenter clip engaging face 142 and a base 143, which combine to form a "U" shaped grooved track 67.
Front flange 136 is provided on opposite ends with chambers 144, 144A having, respectively, a window in upper forward working face 137. Similarly, front flange 140 is provided on opposite ends with chambers 147, 147A having, respectively, a window in upper forward working face 141.
Rear flange 229 is provided on opposite ends with chambers 146, 146A having, respectively, a window in lower rear working face 138. Similarly, rear flange 145 is provided on opposite ends with chambers 148 having, respectively, windows in lower rear working face 142.
Reference is made to FIGS. 5 and 10, wherein a coil spring 150 having a flat tenter clip engaging surface "S" is located on opposite ends in a rear chamber 144 and a front chamber 144A provided in opposite ends of pivotally connected adjacent guide rail sections 15. A first dowel pin 160, shorter in length than rear chamber 144 is inserted into one end of coil spring 150. A tapered ended dowel pin having a medial area 161 is inserted into the medial area of coil spring 150. A second dowel pin 162 shorter in length than front chamber 144A is inserted into the other end of coil spring 150. A first space 163 is provided between the end of first dowel pin 160 and one end of tapered ended dowel pin 161. A second space 164 is provided between the end of second dowel pin 162 and the other end of tapered ended dowel pin 161. A first set screw 165 rotatably fastened in rail 15 secures one end of coil spring 150 in rear chamber 144 by forcing the coils against dowel pin 160. A second set screw 166 rotatably fastened in rail 15 secures the opposite end of coil spring 150 in front chamber 144A by forcing the coils against dowel pin 162.
The medial area 161 reinforces coil spring 150 at the gap 5 to support the spring when a tenter clip rides across flat tenter clip engaging surface "S."
In like manner a coil spring 150A is located in rear and front chambers 146, 146A respectively, provided in opposite ends of pivotally connected adjacent guide rail sections 15. With first dowel pin 160A and second dowel pin 162A inserted, respectively, in opposite ends of coil spring 150A. A tapered ended dowel pin 161A is inserted into the medial area of coil spring 150A. First set screw 165A and second set screw 166A, rotatably fastened in adjacent rails 15, secure one end of coil spring 150A in rear chamber 146 at the dowel pin 160A and the other end of spring 150A in front chamber 146A at the dowel pin 162A.
The tenter clip shown in FIGS. 5 and 6 is provided with an upper roller 170 and a lower roller 171, both rollers are rotatively mounted to a shaft 302 held in tenter clip body 300. Reference is made to FIGS. 5 and 10, as rollers 170, 171 ride against working faces 141, 142, respectively, they encounter the gap 5 now closed by coil springs 150, 150A as a continuation of working faces 141, 142, respectively. In this manner, the rollers 170, 171 smoothly pass from one rail 15 to the adjacent rail 15 without jar.
The coil springs 150, 150A fastened in the respective chambers, expand and contract with the opening and closing of gap 5.
The rails 15 are provided with ledges 367, which are complimentary tapered on opposite ends, as at 368, so as to engage with a clearance therebetween when the rails are in alignment.
The style of tenter clip shown in FIG. 5 is provided with a front roller 69. Roller 69 may pass from one ledge 367 to the adjacent ledge 367 without jar due to the complimentary taper of the ends of adjacent rail sections 15, whether the gap is minimal or maximal. There is always a gap between adjacent rail sections 15 to accommodate expansion and contraction of the rail sections 15 when subjected to a heating oven environment.
FIGS. 11 and 12 illustrate a modified form of crossing gap mechanism. Whatever means are used to close the gap 5 between adjacent rail sections, that means must yield to the arcuate relative movement between the ends of adjacent straight guide rail sections.
A bar, generally indicated at 180 comprises two compatible half sections 185, 185A which slidably engage. One face 181 of bar 180 is made flat to provide a tenter clip engaging face. Three (more or less) slits 182 are made in the surface opposite said tenter slip track surface so that bar 180 will bend or yield in an arcuate direction, thereby arcuately shaping flat face 181. The bar 180 is then separated into two opposite but identical half sections, upper 185 and lower 185A, so that each half section has a sliding surface 183, a head 186 and a shoulder 184 formed in the nead at the juncture of the sliding surface 183. In this construction, the upper section 185 may slide relative to lower section 185A, when as shown in FIG. 11 the half sections are fastened in chambers 144, 144A by means of set screws 165A and 166A. The slits 182 permit the two sections 185, 185A to yield when the rail sections 15 pivot around pin 64 causing the sections 185, 185A to arcuately bend relative to pivot pin 64 which is the center of the radius of the arc.
Bar 180 functions in the same manner as coil spring 150 in relation to adjacent rail sections 15 and the accommodated tenter clips.
FIGS. 7 and 8 depict a modified form of tenter clips and tenter rail. This form is generally used on material woven from cotton, wool and/or synthetic fibers. The rail and tenter clips shown in FIG. 5 are the form generally used on thermoplastic web material.
Both forms use tenter clips, formed in a pair of closed loops, which travel in a pair of sectionalized grooved guide rail sections arranged in closed loop paths, spaced in parallel relation to provide a uniform distribution of transverse stretching forces.
The tenter clips, generally indicated by reference numeral 190 (see FIGS. 7 and 8) is provided with a horizontal body 191 having a plate 192 and a projection 193 providing a tenter clip engaging face 194. A pair of arms 195, 196 integrally connected to said body 191 overlie plate 192. A pivotal jaw 90 pivotally connected to arms 195, 196 through pin 198, pivotally engages plate 192 through the force of gravity.
The guide rail section, generally indicated at 15A comprises a body 199 having a groove 200, a tenter clip engaging face 201 and a base 202. The tenter clip 190 is slidably mounted in groove 200, with tenter clip engaging face 194 slidably engaging tenter clip engaging face 201 while being supported upon base 202. A top case 203 is fastened to guide rail section 15A, by means of screws 204, which overlies horizontal body 191 so as to retain tenter clip 190 in groove 200. The tenter clips 190 are pivotally connected into a closed loop as shown in FIG. 1 and operationally described for the specie tenter clip shown in FIG. 5.
Chamber 247 is provided in body 199 and coil spring 150 or bar 180 may be housed therein as previously described in relation to FIGS. 5, 9, 10, 11 and 12.
FIG. 14 depicts a modified form of pivotally connected grooved guide rail section. The structure described in relation to FIG. 5 applies to FIG. 14 with one modification. The reference numerals of FIG. 5 and the description which applies to FIG. 14 have an "A" applied when used on FIG. 14.
Guide rail section 15A having a body 226A is provided with a return side track 67A in the form of a groove formed by a front projection 251, a rear flange 145A and a base 143A. A front projection wear strip 140A having an upper forward tenter clip engaging face 141A is fastened to front projection 251 as by means of screws 253. Rear flange 145A is cut back to provide a seat 252 and a longitudinal surface 254. A rear wear strip comprises a body 255 having an upstanding arm 256 and a lower tenter clip engaging face 142A, is slidably mounted upon seat 252. A plurality of clearance orifices 257 are provided in upstanding arm 256. A plurality of machine screws 258 pass through clearance orifices 257 and are rotatably supported in rear flange 145A. A split washer 259 may be interposed between the head of screw 258 and arm 256. A spring or a compression washer 260 is supported upon screw 258 and interposed between upstanding arm 256 and rear flange 145A to yieldingly urge tenter clip engaging face 142A toward tenter clip engaging face 141A. In this manner, tenter clip rollers 170A and 171A, engaging tenter clip engaging faces 141A and 142A, respectively, are yieldably held in return side track 67A or in the working side track (not shown because the structure is a duplication of track 67A).
Front flange wear strip 140A being a part of the pivotally connected grooved guide rail section 15A is provided on opposite ends with chambers 147 and 147A as described in structure and purpose with reference to FIGS. 5, 10, 11 and 12.
Similarly, wear strip body 255 being a part of the same pivotally connected grooved guide rail section 15A is provided on opposite ends with chambers 148, 148A as described in structure and purpose with reference to FIGS. 5, 10, 11 and 12.
Reference is now made to FIGS. 15, 16, 17, 18 and 19 wherein is depicted a modified form of gap crossing mechanism as applied to the pivotally connected grooved guide rail sections described in relation to FIG. 14. The structural features in FIG. 19 corresponding to the identical structural features described with reference to FIG. 14 will have a suffix "C" added to the reference numerals.
The form of pivotally connected grooved guide rail sections 15C shown in FIGS. 15 through 19, comprise a body 226C having a return side track 67C in the form of a groove formed by a front projection 251C, a rear flange 145C and a base 143C. Body 226C terminates on opposite ends in an edge E. (see FIG. 15)
The tenter clip working side of rail section 15C is identified as 66C and the tenter clip return side is identified as 67C which are connected together on opposite ends by a front rib 227C and a rear rib 228C. As previously described, each rail section 15C has a pivotal recess 68C on one end and a pivotal tongue 70C on the opposite end (see FIG. 15). Pivotal tongues 70C are adapted to pivotally engage pivot pins 64C and lie in the, respective, pivotal recesses.
Each guide rail section 15C is provided with a plurality of front projection wear strips 140C, having an upper tenter clip engaging face 141C. Each wear strip 140C is fastened to front projection 251C as by means of screws 253C. The rear flange 145C is cut back to provide a seat 252C and a longitudinal surface 254C. A rear wear strip comprises a body 255C having an upstanding arm 256C and a lower tenter clip engaging face 142C, is slidably mounted upon seat 252C. A plurality of clearance orifices 257C are provided in upstanding arms 256C. A plurality of machine screws 258C pass through clearance orifices 257C and are rotatably supported in rear flange 145C. A split washer 259C may be interposed between the head of screw 258C and arm 256C. A spring or a compression washer 260C is supported upon screw 258C and interposed between upstanding arm 256C and rear flange 145C to yieldingly urge tenter clip engaging face 142C toward tenter clip engaging face 141C. Each wear strip body 255C is provided with a plurality of enlarged bolt holes 303. A plurality of bolts 304, one for each bolt hole 303 passes through the, respective, bolt hole 303 and is rotatably mounted in body 226C so that wear strip 255C is able to move laterally and longitudinally. In this manner, tenter clip rollers 170C and 171C, engaging tenter clip engaging faces 141C and 142C, respectively, are yieldingly held in return side track 67C or in the working side track 66C (see FIG. 15).
Each section "L" (see FIGS. 15, 16, 17) of the plurality of front projection wear strips 140C and the rear wear strip body 255C are provided with a lower cut-away or lower shelf on one end 275 and an upper cut-away or upper shelf 276 on the opposite end. In this manner, the upper shelf 276 is slidably mounted upon the lower shelf 275 of the adjacent wear strip for thermal expansion and contraction and pivotal movement.
The last section "L" of the plurality of front projection wear strips 140C and the last section of rear wear strip body 255C are made round (as seen in FIG. 15).
The last section "L--L" of the plurality of front projection wear strips 140C and the last section "L--L" of rear wear strip body 255C are provided with elongated slots 280.
Shoulder bolts 306 pass through elongated slots 280 and are fastened in body 226C.
The upstanding arms 256C attached to sections "L--L" are provided with elongated slots 307 to permit sections "L--L" to move relative to machine screws 258C.
Pivotal movement of guide rail sections 15C relative to each other causes sections "L--L" pivotally connected to an adjacent section "L" on one end, to move laterally relative to the section "L" on the opposite end.
As previously described, hand wheels 33 cause the saddles 13 to slide upon cross members 12, thereby the grooved guide straight rail sections 15C are moved in relation one to the other and thereby, pivot on pivot pins 64C to cause a divergence or convergence of the ends E of adjacent guide rail sections to increase or decrease the gap between adjacent rail sections 15C.
As will be noted in FIGS. 15, 16, and 17 wear strip body 255C provided with the elongated slots 280 will slide in relation to the adjacent guide rail sections on opposite ends and will pivot around pivot pin 264C, thereby to provide a smooth arcuate guide rail gap crossing mechanism.
FIG. 20 is a diagrammatic view illustrating a roller 170C or 171C riding against the tenter clip engaging face of pivotally connected adjacent grooved guide straight rail sections 15C. Empirically, it is believed that the angle between pivotally connected guide rail sections 15 will approximate 21/2 degrees. This numerical value is an observation and not a limitation.
FIG. 18 illustrates the rollers 170C and 171C engaging the guide rail gap crossing mechanism shown in FIGS. 15, 16, 17 and 19.
Having shown and described preferred embodiments of the present invention, by way of example, it should be realized that structural changes could be made and other examples given without departing from either the spirit or scope of this invention. | This invention relates to tenter frames and more particularly to a tenter rail provided with a gap crossing mechanism whereby the tenter clip engaging surfaces of the tenter guide rails, at the rail joints, are smooth for the gentle passage of the tenter clips arranged in a chain. | 3 |
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/715,968, filed on Dec. 14, 2012 and entitled “INTEGRATION OF INTRA-ORAL IMAGERY AND VOLUMETRIC IMAGERY,” the entire contents of which are incorporated herein by reference.
FIELD
[0002] The disclosure relates to a system, method, and computer readable storage medium for the integration of intra-oral imagery and volumetric imagery.
BACKGROUND
[0003] An intra-oral imaging system is a diagnostic equipment that allows a dental practitioner to see the inside of a patient's mouth and display the topographical characteristics of teeth on a display monitor. Certain three-dimensional (3D) intra-oral imagers may be comprised of an intra-oral camera with a light source. The 3D intra-oral imager may be inserted into the oral cavity of a patient by a dental practitioner. After insertion of the intra-oral imager into the oral cavity, the dental practitioner may capture images of visible parts of the teeth and the gingivae. The 3D intra-oral imager may be fabricated in the form of a slender rod that is referred to as a wand or a handpiece. The wand may be approximately the size of a dental mirror with a handle that is used in dentistry. The wand may have a built-in light source and a video camera that may achieve an imaging magnification, ranging in scale from 1/10 to 40 times or more. This allows the dental practitioner to discover certain types of details and defects of the teeth and gums. The images captured by the intra-oral camera may be displayed on a display monitor and may be transmitted to a computational device.
[0004] Cone beam computed tomography (CBCT) involves the use of a rotating CBCT scanner, combined with a digital computer, to obtain images of the teeth and surrounding bone structure, soft tissue, muscle, blood vessels, etc. CBCT may be used in a dental practitioner's office to generate cross-sectional images of teeth and the surrounding bone structure, soft tissue, muscle, blood vessels, etc. During a CBCT scan, the CBCT scanner rotates around the patient's head and may obtain hundreds of distinct CBCT images that may be referred to as CBCT imagery. The CBCT imagery may be transmitted to a computational device. The CBCT imagery may be analyzed to generate three-dimensional anatomical data. The three-dimensional anatomical data can then be manipulated and visualized with specialized software to allow for cephalometric analysis of the CBCT imagery.
SUMMARY
[0005] Provided are a system, method, and computer readable storage medium in which shape data of a patient's crown and volumetric imagery of the patient's tooth are received. A determination is made of elements that represent one or more crowns in the shape data. A computational device is used to register the elements with corresponding voxels of the volumetric imagery.
[0006] In additional embodiments, a determination is made of volumetric coordinates and radiodensities corresponding to the voxels.
[0007] In further embodiments, at least one of the patient's root is determined via region growing from starting locations that include one or more of the determined volumetric coordinates and radiodensities at the voxels.
[0008] In further embodiments, the region growing is performed by identifying adjacent voxels that possess correlated radiodensities along a longitudinal direction of the patient's tooth.
[0009] In certain embodiments, the shape data of the patient's crown is obtained via an impression, a plaster model or an intra-oral scan. The volumetric imagery is selected from a group consisting of tomographic imagery, ultrasonic imagery, cone beam computed tomography (CBCT) imagery and magnetic resonance imagery (MRI).
[0010] In further embodiments, the elements are vectors, and boundaries in the shape data correspond to the one or more crowns. The one or more crowns are represented by a plurality of limited length vectors and the volumetric imagery is represented by a plurality of voxels. Intersections of the plurality of limited length vectors and the plurality of voxels are determined subsequent to the registering.
[0011] In further embodiments, the volumetric imagery is represented by a first plurality of voxels, and the one or more crowns are represented by a second plurality of voxels. The first plurality of voxels and the second plurality of voxels are registered.
[0012] In further embodiments, one or more crowns are determined in the shape data via segmentation of the shape data.
[0013] In yet further embodiments, the shape data is from intra-oral imagery, and the volumetric imagery is cone beam computed tomography (CBCT) imagery. The intra-oral imagery is of a higher precision than the CBCT imagery. The volumetric imagery includes both roots and crowns of teeth. The intra-oral imagery includes at least the crowns of the teeth but does not include an entirety of the roots of the teeth.
[0014] In still further embodiments, a determination is made of an area of interest in the intra-oral imagery, wherein the area of interest corresponds to a location of the one or more crowns determined in the intra-oral imagery. An extraction is made within the volumetric imagery of the area of interest to reduce a size of the volumetric imagery.
[0015] Provided also are a method, system, and a computer readable storage medium in which a computational device receives shape data of a patient's crown and volumetric imagery. A determination is made of elements that represent one or more crowns in the shape data. The elements are registered with corresponding voxels of the volumetric imagery. Volumetric coordinates and radiodensities are determined to determine a tooth shape.
[0016] In additional embodiments, determining the tooth shape comprises filling missing or degraded data in the shape data.
[0017] In yet additional embodiments, determining the tooth shape comprises filling missing or degraded data in the volumetric imagery.
[0018] In further embodiments, the tooth shape is determined with greater precision in comparison to the received volumetric imagery, and the tooth shape is determined with greater precision with usage of lesser radiation. At least one of the patient's root is determined via region growing from starting locations that include one or more of determined volumetric coordinates and radiodensities at the voxels.
[0019] In yet further embodiments, the volumetric imagery is represented by a first plurality of voxels. The one or more crowns are represented by vectors or a second plurality of voxels. The first plurality of voxels are registered to the vectors or the second plurality of voxels.
[0020] Provided also are a method, system, and a computer readable storage medium in which for improving shape data of a patient's crown, the shape data of the patient's crown is registered with volumetric data of the patient's tooth.
[0021] Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
[0023] FIG. 1 illustrates a block diagram of a computing and imaging environment that includes a computational device that integrates intra-oral imagery and volumetric imagery, such as CBCT imagery, in accordance with certain embodiments;
[0024] FIG. 2 illustrates a diagram in which an exemplary intra-oral imagery and advantages and disadvantages of intra-oral imagery are shown, in accordance with certain embodiments;
[0025] FIG. 3 illustrates a diagram in which an exemplary CBCT imagery and advantages and disadvantages of CBCT are shown, in accordance with certain embodiments;
[0026] FIG. 4 illustrates a diagram that shows how an intra-oral imagery is segmented to determine crowns represented via limited length vectors, in accordance with certain embodiments;
[0027] FIG. 5 illustrates a diagram that shows how the surface data obtained via intra-oral imagery may be represented via limited length vectors or voxels, in accordance with certain embodiments;
[0028] FIG. 6 illustrates a diagram that shows how voxels represent CBCT imagery, in accordance with certain embodiments;
[0029] FIG. 7 illustrates a diagram that shows how the boundary between root and crown is determined in CBCT imagery by integrating intra-oral imagery with CBCT imagery, in accordance with certain embodiments;
[0030] FIG. 8 illustrates a diagram that shows how surface data and volumetric data are fitted to each other, in accordance with certain embodiments;
[0031] FIG. 9 illustrates a diagram that shows how surface data of the crown is merged to volumetric data of the tooth, in accordance with certain embodiments;
[0032] FIG. 10 illustrates a diagram that shows characteristics of different types of imagery, in accordance with certain embodiments;
[0033] FIG. 11 illustrates a diagram that shows how surface data extracted from intra-oral imagery is fitted to model data maintained as a library dataset;
[0034] FIG. 12 illustrates a flowchart for augmenting CBCT imagery with data from intra-oral imagery to determine boundary between roots and crowns, in accordance with certain embodiments;
[0035] FIG. 13 illustrates a flowchart for determining a localized area in CBCT imagery to generate a reduced size CBCT imagery, by augmenting CBCT imagery with data from intra-oral imagery, in accordance with certain embodiments;
[0036] FIG. 14 illustrates a diagram that shows how holes are filled in intra-oral imagery by integrating CBCT imagery with intra-oral imagery, in accordance with certain embodiments;
[0037] FIG. 15 illustrates a flowchart that shows how holes are filled in intra-oral imagery by integrating CBCT imagery with intra-oral imagery, in accordance with certain embodiments;
[0038] FIG. 16 illustrates a flowchart that shows how CBCT imagery is integrated with intra-oral imagery, in accordance with certain embodiments;
[0039] FIG. 17 illustrates a block diagram that shows how limited length vectors of intra-oral imagery are registered to voxel data of CBCT imagery, in accordance with certain embodiments;
[0040] FIG. 18 illustrates a block diagram that shows how region growing is performed to determine the entire tooth by following adjacent voxels with correlated radiodensities at each and every intersecting voxel along the direction of the centroid or any other longitudinal direction of a tooth, in accordance with certain embodiments;
[0041] FIG. 19 illustrates a flowchart that shows how the root of a tooth is built from intersections of limited length vectors and voxels and region growing, in accordance with certain embodiments; and
[0042] FIG. 20 illustrates a flowchart that shows how voxels of tomography imagery and limited length vectors of shape data are integrated, in accordance with certain embodiments;
[0043] FIG. 21 illustrates a flowchart that shows how missing or degraded data in shape data is filled by integrating voxels of tomography imagery and limited length vectors of shape data, in accordance with certain embodiments;
[0044] FIG. 22 illustrates a flowchart that shows registration of elements in shape data with corresponding voxels in tomographic imagery to determine volumetric coordinates and radiodensities at the voxels, in accordance with certain embodiments;
[0045] FIG. 23 illustrates a flowchart that shows registration of elements in shape data of a patient's crown with corresponding voxels in volumetric imagery, in accordance with certain embodiments;
[0046] FIG. 24 illustrates a flowchart that shows registration of elements in shape data of a patient's crown with corresponding voxels in volumetric imagery to determine tooth shape, in accordance with certain embodiments; and
[0047] FIG. 25 illustrates a block diagram of a computational device that shows certain elements of the computational device shown in FIG. 1 , in accordance with certain embodiments.
DETAILED DESCRIPTION
[0048] In the following description, reference is made to the accompanying drawings which form a part hereof and which illustrate several embodiments. It is understood that other embodiments may be utilized and structural and operational changes may be made.
[0049] Intra-Oral Imagery and CBCT Imagery
[0050] Generally intra-oral images are of a significantly higher precision in comparison to CBCT images. Furthermore, CBCT data can be noisy. Also, the use of CBCT results in ionizing radiation to the patient and it is best to use CBCT systems with as little radiation as possible.
[0051] In certain embodiments, a computational device receives shape data of a patient's crown and volumetric imagery of the patient's tooth. The shape data may be generated from intra-oral images and may correspond to the surface data of the patient's crown. The volumetric imagery may comprise CBCT imagery or other types of volumetric imagery. A determination is made of voxels that represent one or more crowns in the shape data. The voxels in the shape data are registered with corresponding voxels of the volumetric imagery.
[0052] In certain embodiments, segmented crowns determined from intra-oral imagery are registered to voxels of CBCT images. This allows more accurate determination of the boundary between the crown and the root of a tooth in the CBCT data. It may be noted that without the use of the intra-oral imagery the boundary between the crown and the root of a tooth may be fuzzy (i.e., not clear or indistinct) in CBCT imagery.
[0053] In certain embodiments, the surface scan data of an intra-oral imaging system is registered to the volumetric data obtained from a CBCT system. The 3-D coordinates of the crown boundaries that are found in the intra-oral imagery are mapped to the voxels of the CBCT imagery to determine the boundary between roots and crowns at a sub-voxel levels of accuracy in the CBCT imagery. As a result, the roots can be extracted, even from noisy CBCT scan data.
[0054] In additional embodiments, holes in intra-oral imagery may be filled in by integrating CBCT imagery with intra-oral imagery.
Exemplary Embodiments
[0055] FIG. 1 illustrates a block diagram of a computing and imaging environment 100 that includes a computational device 102 that integrates intra-oral imagery 104 and CBCT imagery 106 , in accordance with certain embodiments. The computational device 102 may include any suitable computational device such as a personal computer, a server computer, a mini computer, a mainframe computer, a blade computer, a tablet computer, a touchscreen computing device, a telephony device, a cell phone, a mobile computational device, a dental equipment having a processor, etc., and in certain embodiments the computational device 102 may provide web services or cloud computing services. In certain alternative embodiments, more than one computational device may be used for storing data or performing the operations performed by the computational device 102 .
[0056] The intra-oral imagery 104 provides surface data of a patient's crown and the CBCT imagery 106 provides volumetric imagery of a patient's tooth, where the tooth may include both the crown and the root. In alternative embodiments, the surface data of the patient's crown may be provided by imagery that is different from intra-oral imagery, and the volumetric imagery may be provided by other types of tomographic imagery, ultrasonic imagery, magnetic resonance imagery (MRI), etc. The volumetric imagery comprises three dimensional imagery and may be represented via voxels.
[0057] The computational device 102 may include an integrating application 108 , implemented in certain embodiments in software, hardware, firmware or any combination thereof. The integrating application 108 integrates the intra-oral imagery 104 and the CBCT imagery 106 to provide additional functionalities that are not found in either the intra-oral imagery 104 or the CBCT imagery 106 when they are not integrated.
[0058] The computational device 102 is coupled via one or more wired or wireless connections 110 to an intra-oral imaging system 112 and a CBCT imaging system 114 , over a network 116 . In certain embodiments, the network 116 may comprise a local area network, the Internet, and intranet, a storage are network, or any other suitable network.
[0059] The intra-oral imaging system 112 may include a wand 116 having an intra-oral imaging sensor 118 , where in certain embodiments the intra-oral imaging sensor 118 is an intra-oral camera that generates intra-oral imagery of the oral cavity of a patient. The CBCT imaging system 114 may include a rotating X-ray equipment 120 that generates cross-sectional CBCT imagery of the soft tissue, hard tissue, teeth, etc. of a patient.
[0060] Therefore, FIG. 1 illustrates certain embodiments in which an integrating application 108 that executes in the computational device 102 integrates intra-oral imagery 104 generated by an intra-oral imaging system 112 with CBCT imagery 106 generated by a CBCT imaging system 114 . In certain additional embodiments, the intra-oral imagery 104 and the CBCT imagery 106 may be stored in a storage medium (e.g., a disk drive, a floppy drive, a pen drive, a solid state device, an optical drive, etc.), and the storage medium may be coupled to the computational device 102 for reading and processing by the integrating application 108 .
[0061] FIG. 2 illustrates a diagram 200 in which an exemplary intra-oral imagery 202 is shown, in accordance with certain embodiments. Certain exemplary advantages 204 and certain exemplary disadvantages 206 of the intra-oral imagery 202 are also shown, in accordance with certain embodiments.
[0062] The intra-oral imagery 206 shows exemplary crowns (e.g., crowns 208 a , 208 b , 208 c ) in the upper arch of the oral cavity of a patient, where the intra-oral imagery 206 may have been acquired via the intra-oral imaging system 112 . The crown is the portion of the tooth that may be visually seen, and the root is the portion of the tooth that is hidden under the gum.
[0063] FIG. 2 shows that the intra-oral imagery is typically of a high precision 210 in comparison with CBCT imagery. Additionally, no radiation that may cause harm to the patient (shown via reference numeral 212 ) is needed in acquiring the intra-oral imagery 202 . However, the intra-oral imagery 202 does not show the roots of teeth (reference numeral 214 ) and may have holes 216 , where a hole is a portion of the tooth that is not visible in intra-oral imagery. Holes may arise because of malocclusions or for other reasons. While, small and medium sized holes may be filled (i.e. the hole is substituted via a simulated surface generated programmatically via the computational device 102 ) by analyzing the intra-oral imagery 202 , larger holes (i.e. holes that exceed certain dimensions) may not be filled by just using data found in intra-oral imagery. Additionally, shiny surfaces f crowns may generate poor quality intra-oral imagery (reference numeral 218 ).
[0064] Therefore, FIG. 2 illustrates certain embodiments in which intra-oral imagery may have holes and do not show the entirety of the roots of teeth.
[0065] FIG. 3 illustrates a diagram 300 in which an exemplary CBCT imagery 302 , and certain advantages 304 and certain disadvantages 306 of CBCT imagery are shown, in accordance with certain embodiments.
[0066] In the CBCT imagery the entire tooth (i.e., the root and the crown) is imaged (reference number 310 ) and there are few holes (reference number 312 ). The few holes that exist may be caused by artifacts as a result of amalgam fillings on tooth (reference numeral 320 ). However, the CBCT images may be of a lower precision and may be more noisy in comparison to intra-oral imagery (reference numeral 314 ). There is a potential for ionizing radiation to the patient in the acquisition of CBCT imagery (reference numeral 316 ) unlike in intra-oral imagery in which there is no ionizing radiation in the acquisition process. Furthermore, while the complete tooth is imaged in CBCT imagery, the boundary between the root and the crown may not be clear (reference numeral 318 ) as may be seen (reference numeral 320 ) in the exemplary CBCT imagery 302 . The fuzzy and indistinct boundary 320 between the crown 322 and the root 324 may be caused by varying radiodensities during the process of acquiring CBCT images. In certain embodiments, motion of the patient may generate inferior quality CBCT imagery.
[0067] Therefore, FIG. 3 illustrates certain embodiments in which CBCT images may have low precision and have noisy data with the boundary between the root and crown not being clearly demarcated.
[0068] FIG. 4 illustrates a diagram 400 that shows how an intra-oral imagery 202 is segmented to determine crowns 402 represented via limited length vectors 404 , in accordance with certain embodiments. The segmentation of the intra-oral imagery 202 to determine crowns 402 may be performed via the integrating application 108 that executes in the computational device 102 . Exemplary segmented crowns are shown via reference numerals 406 a , 406 b , 406 c . The segmented crowns are of a high resolution and show clearly defined edges and are represented via limited length vectors 404 . A vector has a direction and magnitude in three-dimensional space. A limited length vector is a vector whose length is limited. In other embodiments, the segmented crowns may be represented via data structures or mathematical representations that are different from limited length vectors 404 .
[0069] Therefore, FIG. 4 illustrates certain embodiments in which intra-oral imagery is segmented to determine crowns represented via limited length vectors.
[0070] FIG. 5 illustrates a diagram that shows how an intra-oral imaging system 410 scans the inside of a patient's mouth and generates surface samples of the crowns of a patient's teeth, where the aggregated surface samples may be referred to as a point cloud 412 .
[0071] The point cloud 412 may processed by the integrating application 108 executing the computational device 102 to represent the surface of the crowns. The crown of the tooth is a solid object, and the surfaces of the crown correspond to the boundaries of the solid object. The crown surface may be represented by a surface mesh of node points connected by triangles, quadrilaterals or via different types of polygon meshes. In alternative embodiments, a solid mesh may also be used to represent the crown surface. The process of creating the mesh is referred to as tessellation.
[0072] In certain embodiments, the surface corresponding to the crown is represented in three dimensional space via limited length vectors 414 or via voxels 416 or via other data structures 418 . The voxels 416 correspond to three-dimensional points on the surface of a crown. In certain embodiments, the limited length vectors 414 may be converted to vowel representation via appropriate three dimensional coordinate transformations 420 . The limited length vectors 414 may correspond to the sides of the different types of polygon meshes (e.g., triangles, quadrilaterals, etc.) in the surface representation of the crown.
[0073] Therefore, FIG. 5 illustrates certain embodiments in which intra-oral imagery is processed to determine crowns represented via limited length vectors or via voxels. The limited length vectors or voxels correspond to a surface data representation 422 of the crown. Surface data may also be referred to as shape data.
[0074] FIG. 6 illustrates a diagram 500 that shows how voxels 502 represent CBCT imagery 302 , in accordance with certain embodiments. A voxel (e.g., voxel 504 ) is a volumetric pixel that is a digital representation of radiodensity in a volumetric framework corresponding to the CBCT imagery 302 . The radiodensity may be measured in the Hounsfield scale. In FIG. 6 an exemplary voxel representation 502 of part of the CBCT imagery 302 is shown,
[0075] The voxel representation 502 has a local origin 504 , with X, Y, Z coordinates representing width, depth, and height respectively (shown via reference numerals 506 , 508 , 510 ). The coordinate of the voxel where the X, Y, Z values are maximum are shown via the reference numeral 512 . An exemplary voxel 504 and an illustrative column of voxels 514 are also shown. Each voxel has a volume defined by the dimensions shown via reference numerals 516 , 518 , 520 .
[0076] In certain embodiments, limited length vectors of intra-oral imagery are registered to the voxel representation of the CBCT imagery, to determine where the limited length vectors intersect the voxels of the CBCT imagery. In an exemplary embodiments, an intersecting limited length vector 522 is shown to intersect the voxels of the CBCT imagery at various voxels, wherein at least one voxel 524 at which the intersection takes place has a volumetric coordinate of (X,Y,Z) with an associated radiodensity.
[0077] Therefore, FIG. 6 illustrates certain embodiments in which CBCT imagery is represented via voxels. The limited length vectors of the intra-oral imagery intersects the voxels of the CBCT imagery when both are placed in the same coordinate system, wherein each intersection has a X,Y,Z coordinate and a radiodensity. In certain embodiments, the limited length vectors may be one or more of the sides of triangulated tessellations used to represent shape data. The limited length vectors may be chained in shape representations.
[0078] FIG. 7 illustrates a diagram 600 that shows how the boundary between root and crown is determined in CBCT imagery by integrating intra-oral imagery with CBCT imagery, in accordance with certain embodiments. In certain embodiments, the voxel representation 606 of CBCT imagery is integrated (via the integrating application 108 ) with the limited length vector representation or voxel representation 607 of the intra-oral imagery to overlay the high resolution clearly segmented crowns of the intra-oral imagery on the low resolution fuzzy crowns of the CBCT imagery (as shown via reference numeral 608 ), to clearly demarcate the boundary between roots and crowns in the CBCT imagery 602 . In certain embodiments the integration of CBCT imagery and intra-oral imagery results in a type of filtration operation that sharpens the CBCT imagery to determine the boundary between roots and crowns.
[0079] Therefore, FIG. 7 illustrates certain embodiments in which CBCT imagery is augmented with data from intra-oral imagery to determine the boundary between roots and crowns with a greater degree of accuracy in comparison to using the CBCT imagery alone. As a result of the augmentation, high precision crowns and low precision roots are obtained.
[0080] FIG. 8 illustrates a diagram 609 that shows how surface data and volumetric data are fitted to each other, in accordance with certain embodiments. In certain embodiments, the surface data (i.e., the crown surface data) may be represented with reference to a first coordinate system (shown via reference numeral 610 ) The volumetric data that represents the tooth may be represented in a second coordinate system (shown via reference numeral 612 ).
[0081] In certain embodiments one or both of the crown surface data and the tooth volumetric data may have to be rotated 614 , translated 616 , morphed 618 , scaled 620 , or made to undergo other transformations 622 to appropriately overlap the crown surface data and the tooth volumetric data in a single unified coordinate system. For example, in certain embodiments the tooth volumetric data is fitted to the crown surface data in the coordinate system of the tooth surface data by appropriate rotations, translations, morphing, scaling, etc., of the tooth volumetric data (as shown via reference numeral 624 ). In other embodiments, crown surface data is fitted to the tooth volumetric data in the coordinate system of the tooth volumetric data by appropriate rotations, translations, morphing, scaling, etc., of the crown surface data (as shown via reference numeral 626 ). In other embodiments, both the crown surface data and the tooth volumetric data may undergo rotations, translations, morphing, scaling, etc. to fit the crown surface data and tooth volumetric data in a new coordinate system (as shown via reference numeral 628 ).
[0082] FIG. 9 illustrates a diagram 650 that shows how surface data of the crown is merged to volumetric data of the tooth, in accordance with certain embodiments. An empty cube of voxels in the three dimensional space is populated with the shape data of a crown. As a result, the surface data of the crown is represented via voxels of a three dimensional space 652 .
[0083] The three dimensional space 652 with surface data is overlaid on the three dimensional space 654 that has the volumetric representation of the tooth, to generate the overlay of the surface data on the volumetric data shown in the three dimensional space 656 . The fitting of the surface data to the volumetric data may be performed via an iterative closest point (ICP) registration. ICP may fit points in surface data to the points in volumetric data. In certain embodiment, the fitting may minimize the sum of square errors with the closest volumetric data points and surface data points. In certain embodiments, the limited length vectors of the surface data are represented as voxels prior to performing the ICP registration.
[0084] The anatomy of brackets, wires, filling or other features on the tooth may often assist in properly registering the surface data to the volumetric data. The registration may in various embodiments be performed via optimization techniques, such as simulated annealing, correlation techniques, dynamic programming, linear programming etc.
[0085] In certain embodiments a multiplicity of representations of the same object obtained by CBCT, magnetic resonance imagery (MRI), ultrasound imagery, intra-oral imagery based surface data, etc., may be registered to generate a better representation of a crown in comparison to embodiments that do not use data from the multiplicity of representations.
[0086] FIG. 10 illustrates a diagram 670 that shows characteristics of different types of imagery, in accordance with certain embodiments. The intra-oral imagery 672 may provide not only the surface data 676 but may also be processed to provide information on reflectivity 678 and translucency 680 of the surface of the objects that are imaged. For example, the reflectivity and the translucency of the crown may be different from that the gingiva, and the intra-oral imagery 672 may be processed to distinguish the crown from the gingiva based on the reflectivity and the translucency differences and the segmentation of the crown may be improved by incorporating such additional information. In certain embodiments where interferometry fringe patterns are used for capturing the intra-oral imagery the reflectivity and translucency information may be generated with greater precision in comparison to embodiments where such fringe patterns are not used.
[0087] In certain embodiments, the volumetric data 682 and the radiodensity information 684 corresponding to the CBCT imagery 674 may be used in association with the surface data 676 , reflectivity information 678 and translucency information 680 of the intra-oral imagery 672 to provide additional cues for performing the registration of the surface data 676 and the volumetric data 682 . Ray tracing mechanisms may also be used for simulating a wide variety of optical effects, such as reflection and refraction, scattering, and dispersion phenomena (such as chromatic aberration) for improving the quality of the different types of images and for registration.
[0088] FIG. 11 illustrates a diagram 688 that shows how surface data 690 extracted from intra-oral imagery is fitted to one or more of model data 694 a , 694 b , . . . 694 n maintained as a library dataset 692 . The library dataset 692 may include model data for various types of teeth (e.g., incisors, canines, molars, etc.) and also model data for various patient parameters, such as those based on age, gender, ethnicity, etc. In certain embodiments where the CBCT imagery is unavailable, the surface data 690 may be registered (reference numeral 696 ) to an appropriately selected model data 694 a . . . 694 n to provide better quality information to a dental practitioner. When the roots of a tooth are well formed and the crowns are relatively regular, then such fusion with model data is often adequate for treatment purposes. However, with as little as two to three degrees of error in alignment, such embodiments may have to be substituted with embodiments in which surface data from intra-oral imagery is registered with CBCT imagery to provide better quality information to the dental practitioner. In certain additional embodiments, the surface data is registered with the CBCT imagery with additional cues obtained from the model data.
[0089] FIG. 12 illustrates a flowchart 700 for augmenting CBCT imagery with data from intra-oral imagery to determine the boundary between roots and crowns, in accordance with certain embodiments. The operations shown in flowchart 700 may be performed via the integrating application 108 that executes in the computational device 102 .
[0090] Control starts at block 702 in which the computational device 102 receives intra-oral imagery 104 and CBCT imagery 106 . The integrating application 108 determines (at block 704 ) one or more crowns in the intra-oral imagery, wherein the one or more crowns of the intra-oral imagery are represented by limited length vectors or voxels, and the CBCT imagery is represented by voxels. Control proceeds to block 706 , in which the integrating application 108 integrates the one or more crowns determined in the intra-oral imagery into the CBCT imagery by registering the limited length vectors pr voxels that represent the one or more crowns in the intra-oral imagery with the voxels of the CBCT imagery, to determine a boundary between at least one crown and at least one root in the CBCT imagery.
[0091] FIG. 13 illustrates a flowchart 800 for determining a localized area in CBCT imagery to generate a reduced size CBCT imagery, by augmenting CBCT imagery with data from intra-oral imagery, in accordance with certain embodiments. The operations shown in flowchart 800 may be performed via the integrating application 108 that executes in the computational device 102 .
[0092] Control starts at blocks 802 and 804 in which CBCT imagery and intra-oral imagery are provided to the integrating application 108 . The integrating application 108 determines (at block 806 ) an area of interest in the intra-oral imagery, wherein the area of interest corresponds to a location of the one or more crowns determined in the intra-oral imagery via segmentation.
[0093] Control proceeds to block 808 in which the integrating application 108 extracts from the CBCT imagery the area of interest to reduce the size of the CBCT imagery, and the reduced size CBCT imagery is stored (at block 810 ) in the computational device 102
[0094] Therefore FIG. 8 illustrates certain embodiments in which the size of CBCT imagery is reduced by incorporating an area of interest determined from intra-oral imagery.
[0095] FIG. 14 illustrates a diagram 900 that shows how holes are filled in intra-oral imagery by integrating CBCT imagery with intra-oral imagery, accordance with certain embodiments.
[0096] In FIG. 9 an exemplary intra-oral imagery 104 has holes 902 (i.e., areas of the crown of teeth that are not imaged by the intra-oral imaging system 112 ). The integrating application 108 uses the CBCT imagery 106 to fill the holes via the low precision crowns without holes that are found in the CBCT imagery 106 , to generate augmented intra-oral imaging data 904 in which all holes are filled. In certain embodiments, a range of radiodensities are determined in voxels of a determined boundary between roots and crowns, and based on the range of radiodensities and the determined boundary, the holes in the intra-oral imagery are filled from selected voxels of the CBCT imagery.
[0097] FIG. 15 illustrates a flowchart 1000 that shows how holes are filled in intra-oral imagery by integrating CBCT imagery with intra-oral imagery, accordance with certain embodiments. The operations shown in flowchart 1000 may be performed via the integrating application 108 that executes in the computational device 102 .
[0098] Control starts at block 1002 in which the computational device 102 receives intra-oral imagery 104 and volumetric imagery, such as, cone beam computed tomography (CBCT) imagery 106 . Control proceeds to block 1004 , in which the integrating application 108 determines one or more crowns in the intra-oral imagery 104 and the CBCT imagery 106 , where the one or more crowns determined by the intra-oral imagery 104 has one or more holes, and where a hole is a part of a tooth that is not visible in the intra-oral imagery. The one or more crowns determined in the CBCT imagery are integrated (at block 1006 ) into the intra-oral imagery 104 , to fill the one or more holes in the intra-oral imagery.
[0099] Therefore FIGS. 14 and 15 illustrate how holes are filled in intra-oral imagery by integrating information from CBCT imagery. Conversely, if missing or degraded data is found in volumetric imagery, such missing or degraded data may be filled from surface data found in the intra-oral imagery.
[0100] FIG. 16 illustrates a flowchart 1100 that shows how CBCT imagery 106 is integrated with intra-oral imagery 104 , in accordance with certain embodiments. The operations shown in flowchart 1100 may be performed via the integrating application 108 that executes in the computational device 102 .
[0101] Control starts at block 1102 in which a computational device 102 receives intra-oral imagery 104 and CBCT imagery 106 . The intra-oral imagery 104 and the CBCT imagery 106 are integrated (at block 1104 ), to determine a boundary between at least one crown and at least one root in the CBCT imagery 106 , and to fill one or more holes in the intra-oral imagery 104 .
[0102] FIG. 17 illustrates a block diagram 1200 that shows how limited length vectors of intra-oral imagery are registered to voxel data of CBCT or other volumetric imagery, in accordance with certain embodiments.
[0103] In FIG. 17 the hatched area indicated via reference numeral 1202 indicates an uncertainty region of the CBCT imagery in which the actual tooth boundary of the patient is likely to found. The limited length vectors (or voxels) of the intra-oral imagery are registered to the voxels of the CBCT imagery to determine the intersections 1204 . At each of the intersections 1204 there is an X,Y,Z coordinate and an associated radiodensity (shown via reference numeral 1206 ), where adjacent voxels may have similar radiodensities or correlated radiodensities in the uncertainty region 1202 (as shown via reference numeral 1208 ).
[0104] FIG. 18 illustrates a block diagram 1300 that shows how region growing is performed to determine the entire tooth by following adjacent voxels with correlated radiodensities at each and every intersecting voxel along the direction of the centroid 1302 of a tooth, in accordance with certain embodiments. The centroid is located along a longitudinal direction of the tooth. The correlated radiodensities may be determined via correlation windows of different sizes. For example, a cube of voxels with length, breadth, and height of three voxels each may be used as a correlation window to determine which adjacent voxel is most correlated to a previously determined voxel in terms of radiodensities.
[0105] Reference numeral 1306 shows the entire tooth outlined via region growing with seed values starting from the voxels and limited length vector (or surface voxel) intersections 1204 and the associated radiodensities. Other mechanisms may also be adopted for region growing to determine the entire tooth.
[0106] FIG. 19 illustrates a flowchart 1400 that shows how the root of a tooth is built from intersections of limited length vectors (or surface voxel) and voxels and region growing, in accordance with certain embodiments. Control starts at block 1402 where the voxel information at each voxel of a CBCT image is given by a volumetric coordinate X,Y,Z and the radiodensity. Control proceeds to block 1404 in which a determination is made as to which voxels of CBCT image and limited length vectors (or voxel) of the boundary of the crown of intra-oral image intersect. The root of the tooth is built (at block 1406 ) from the determined intersections via region growing techniques based on following adjacent radiodensities that are correlated (i.e., similar in magnitude) to each other.
[0107] FIG. 20 illustrates a flowchart 1500 that shows how voxels of tomography (i.e. volumetric) imagery and limited length vectors of shape data are integrated, in accordance with certain embodiments. A computational device receives (at block 1502 ) shape data of a patient's dentition and tomography imagery. Vectors that represent one or more crowns in the shape data are determined (at block 1504 ). The vectors are registered with corresponding voxels of the tomography imagery, and volumetric coordinates and radiodensities at the voxels are determined (at block 1506 ). At least one of the patient's teeth is determined via region growing from starting locations that include one or more of the determined volumetric coordinates and the radiodensities at the voxels, and the region growing is performed by following adjacent voxels with closest radiodensities along a direction of a centroid of a tooth (at block 1508 ). In alternative embodiments voxels (referred to as surface voxel) corresponding to the limited length vectors of the surface data may be used instead of the limited length vectors for registration.
[0108] FIG. 21 illustrates a flowchart 1600 that shows how missing or degraded data in shape data is filled by integrating voxels of tomography imagery and limited length vectors of shape data, in accordance with certain embodiments. A computational device receives (at block 1602 ) shape data of a patient's dentition and tomography imagery. Vectors that represent one or more crowns in the shape data are determined, wherein the one or more crowns has degraded data or missing data (at block 1604 ). The vectors are registered with corresponding voxels of the tomography imagery, and volumetric coordinates and radiodensities at the voxels are determined (at block 1606 ). At least one of the patient's teeth is determined via region growing from starting locations that include one or more of the determined volumetric coordinates and the radiodensities at the voxels to fill the degraded or the missing data in the one or more crowns of the shape data (at block 1606 ).
[0109] In certain alternative embodiments vectors are registered with corresponding voxels of the tomography imagery to determine volumetric coordinates and radiodensities at the voxels, to determine a tooth with greater precision and to fill missing or degraded data in the shape data. In certain embodiments, by determining the tooth with greater precision the received tomography imagery is obtained with usage of lesser radiation.
[0110] FIG. 22 illustrates a flowchart 1700 that shows registration of elements (e.g., vectors) in shape data with corresponding voxels in tomographic imagery to determine volumetric coordinates and radiodensities at the voxels, in accordance with certain embodiments. A computational device receives (at block 1702 ) shape data of a patient's dentition and tomography imagery. Elements (e.g. vectors or voxels) that represent one or more boundaries in the shape data are determined (at block 1704 ). The elements are registered with corresponding voxels of the tomography imagery, and volumetric coordinates and radiodensities at the voxels are determined (at block 1706 ). In certain embodiments, the boundaries in the shape data delineate one or more crowns of teeth.
[0111] FIG. 23 illustrates a flowchart 2300 that shows registration of elements in shape data of a patient's crown with corresponding voxels in volumetric imagery, in accordance with certain embodiments.
[0112] Control starts at block 2302 in which shape data of a patient's crown and volumetric imagery of the patient's tooth is received. A determination is made (at block 2304 ) of elements that represent one or more crowns in the shape data. A computational device is used to register (at block 2306 ) the elements with corresponding voxels of the volumetric imagery.
[0113] FIG. 24 illustrates a flowchart 2400 that shows registration of elements in shape data of a patient's crown with corresponding voxels in volumetric imagery to determine tooth shape, in accordance with certain embodiments.
[0114] Control starts at block 2402 in which shape data of a patient's crown and volumetric imagery are received. A determination is made (at block 2404 ) of elements that represent one or more crowns in the shape data. The elements are registered (at block 2406 ) with corresponding voxels of the volumetric imagery by using a computational device, and volumetric coordinates and radiodensities are determined to determine a tooth shape.
[0115] Therefore, FIGS. 1-24 illustrate certain embodiments in which the tooth of a patient is determined more accurately by integrating information extracted from intra-oral imagery and CBCT imagery. Also, degraded or missing data in the crowns of intra-oral imagery are filled by integrating information extracted from CBCT imagery. By integrating intra-oral imagery with CBCT imagery, both intra-oral imagery and CBCT imagery are enhanced to have greater functionalities and CBCT imagery may be obtained with usage of a lower amount of radiation.
Further Details of Embodiments
[0116] In a volumetric data representation there may be areas of high contrast and low contrast. When segmenting via thresholding (e.g., by thresholding radiodensities) it may be easier to threshold crowns than roots. This is because crowns appear with high density against soft tissue. It may be noted that roots appear with low contrast against the bone. High contrast junctions may be easier to segment this manner. In certain embodiments, the crowns may be thresholded and the borders may be used to seed the segmentation to isolate the roots. Thus the volumetric data set may be used to segment itself. This may automatically register the crown root object. This may even be used to register the crown surface data.
[0117] In certain embodiments, instead of segmenting roots, certain embodiments may extract only the centroid of the root.
[0118] Certain embodiments may link the shape and tomography imagery data together in a file system. For example, information may be added to the headers of the image files of both the CBCT and intra-oral scan data to enable viewing software to easily reference one from the other. Alternatively, the viewing software may keep track of which intra-oral scan image and CBCT image files have been registered with one another and store the information in a separate file. In certain embodiments correlation or optimization techniques may be used to find the intersection points in the image data.
[0119] In certain embodiments, the output of the processes is a data structure that is an advanced representation of the surface or a volumetric data enhanced by the fusion process of registration of multiple sources of imagery. Multidimensional data representation and visualization techniques may be used to display such enhanced surfaces or volumes. In certain embodiments, the collected image data may after processing and registration be rendered and displayed as three dimensional objects via volumetric rendering and segmentation.
Additional Details of Embodiments
[0120] The operations described in the figures may be implemented as a method, apparatus or computer program product using techniques to produce software, firmware, hardware, or any combination thereof. Additionally, certain embodiments may take the form of a computer program product embodied in one or more computer readable storage medium(s) having computer readable program code embodied therein.
[0121] A computer readable storage medium may include an electronic, magnetic, optical, electromagnetic, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. The computer readable storage medium may also comprise an electrical connection having one or more wires, a portable computer diskette or disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, etc. A computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
[0122] Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages.
[0123] Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, system and computer program products according to certain embodiments. At least certain operations that may have been illustrated in the figures show certain events occurring in a certain order. In alternative embodiments, certain operations may be performed in a different order, modified or removed. Additionally, operations may be added to the above described logic and still conform to the described embodiments. Further, operations described herein may occur sequentially or certain operations may be processed in parallel. Yet further, operations may be performed by a single processing unit or by distributed processing units. Computer program instructions can implement the blocks of the flowchart. These computer program instructions may be provided to a processor of a computer for execution.
[0124] FIG. 25 illustrates a block diagram that shows certain elements that may be included in the computational device 102 , in accordance with certain embodiments. The system 2500 may comprise the computational device 102 and may include a circuitry 2502 that may in certain embodiments include at least a processor 2504 . The system 2500 may also include a memory 2506 (e.g., a volatile memory device), and storage 2508 . The storage 2508 may include a non-volatile memory device (e.g., EEPROM, ROM, PROM, RAM, DRAM, SRAM, flash, firmware, programmable logic, etc.), magnetic disk drive, optical disk drive, tape drive, etc. The storage 2508 may comprise an internal storage device, an attached storage device and/or a network accessible storage device. The system 2500 may include a program logic 2510 including code 2512 that may be loaded into the memory 2506 and executed by the processor 2504 or circuitry 2502 . In certain embodiments, the program logic 2510 including code 2512 may be stored in the storage 2508 . In certain other embodiments, the program logic 2510 may be implemented in the circuitry 2502 . Therefore, while FIG. 25 shows the program logic 2510 separately from the other elements, the program logic 2510 may be implemented in the memory 2506 and/or the circuitry 2502 .
[0125] The terms “an embodiment”, “embodiment”, “embodiments”, “the embodiment”, “the embodiments”, “one or more embodiments”, “some embodiments”, and “one embodiment” mean “one or more (but not all) embodiments of the present invention(s)” unless expressly specified otherwise.
[0126] The terms “including”, “comprising”, “having” and variations thereof mean “including but not limited to”, unless expressly specified otherwise.
[0127] The enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise.
[0128] The terms “a”, “an” and “the” mean “one or more”, unless expressly specified otherwise.
[0129] Devices that are in communication with each other need not be in continuous communication with each other, unless expressly specified otherwise. In addition, devices that are in communication with each other may communicate directly or indirectly through one or more intermediaries.
[0130] A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary a variety of optional components are described to illustrate the wide variety of possible embodiments.
[0131] When a single device or article is described herein, it will be readily apparent that more than one device/article (whether or not they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be readily apparent that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features.
[0132] The foregoing description of various embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. | Systems and methods are described for identifying a sub-gingival surface of a tooth in volumetric imagery data. Shape data is received from a surface scanner and volumetric imagery data is received from a volumetric imaging device. The shape data of the super-gingival portion of a first tooth is registered with the volumetric imagery data of the super-gingival portion of the first tooth to obtain a registration result. At least one criterion is then determined for detecting a surface of the first tooth in the volumetric imagery data of the super-gingival or the sub-gingival portion using the registration result. The surface of the sub-gingival portion of the first tooth is detected in the volumetric imagery data using the at least one criterion. | 6 |
BACKGROUND
1. Field of the Invention
The present invention relates to flashing systems used to control and redirect water and, more specifically, to flashing systems used to control and redirect water from the junction of a deck with a wall or post.
2. Description of the Related Art
A common problem in the construction business is that of weatherproofing structural junctures, such as those between vertical walls or posts and roofs, decks, balconies, terraces and the like. Weatherproofing serves the goal of protecting the underlying structure from the damage associated with water seepage, e.g., rotting wood and cracking of masonry. The standard practice is to cover the seams associated with such junctures with flashing.
In applications for generally vertical structures such as decks, balconies, terraces and roofs with a low pitch, the prior flashing arrangements have been prone to leakage at best and commonly have been ineffective. Generally, such prior arrangements have left seams or junctures with cracks that allow water seepage and have not been effective at channeling or draining the water away from the support structure of the deck. Accordingly, it would be advantageous to have better flashing systems to control and redirect water away from the juncture and support structure.
SUMMARY OF THE INVENTION
In one embodiment of the invention there is provided a termination pocket for preventing intrusion of water at a junction of a generally vertical support structure and a deck. The deck has an upper surface; a first side in contact with the support structure and forming a first edge with the upper surface; and a second side connected to the first side at a generally right angle, forming a second edge with the upper surface and extending out from the support structure so that the first side, the second side and the upper surface form the junction with the support structure. The termination pocket comprises a set of flashing members connected in waterproof connections and covering the upper surface and the second side in the area around the junction and covering the support structure in the area around and above the junction. The termination pocket further comprises an upward facing pocket extending parallel to the second side and spaced from the second side wherein the upward facing pocket is connected to the set of flashing members such that a flashing bridge is formed extending from the upper surface to the upward facing pocket, thus creating a downward facing pocket between the second side and the upward facing pocket.
In another embodiment of the invention there is provided a deck assembly comprising a generally vertical support structure, a deck and a termination pocket. The deck has an upper surface; a first side in contact with the support structure, and forming a first edge with the upper surface; and a second side connected to the first side at a generally right angle. The second side forms a second edge with the upper surface and extends out from the vertical support structure so that the first side, the second side and the upper surface form a junction with the support structure. The termination pocket has a set of flashing members connected in waterproof connections and covering the upper surface and the second side in the area around the junction and covering the support structure in the area around and above the junction. The termination pocket further has an upward facing pocket extending parallel to the second side and spaced from the second side wherein the upward facing pocket is connected to the set of flashing such that a flashing bridge is formed extending from the upper surface to the pocket, thus creating a downward facing pocket between the second side and the upward facing pocket.
In yet another embodiment there is provided a termination pocket comprising a generally horizontal flashing member, a first generally vertical flashing member and a pocket flashing member. The generally horizontal flashing member has a top surface, a bottom surface, a first side edge, a second side edge, a front edge and a back edge, with the back edge being perpendicular to the first side edge. The first generally vertical flashing member extends from the bottom surface of the generally horizontal flashing member. The pocket flashing member has a first vertical wall having a top edge and a bottom edge; a second vertical wall having a top edge and a bottom edge; and a bottom extending from the bottom edge of the first vertical wall to the bottom edge of the second vertical wall. The first generally vertical flashing member is substantially parallel to and spaced from the first wall. The top edge of the first wall is attached to the first side edge of the generally horizontal flashing member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a termination pocket in accordance with one embodiment of the current invention,
FIG. 2 is a perspective view of the embodiment of FIG. 1 from a different angle.
FIG. 3 is a perspective view of a termination pocket in accordance with another embodiment of the current invention. The termination pocket illustrated is shown attached to a support column and a deck.
FIG. 4 is a perspective view of the embodiment of FIG. 3 from a different angle.
FIG. 5 is a perspective view of a termination pocket in accordance with an embodiment of the current invention. The termination pocket is illustrated as installed on a deck.
FIG. 6 is an elevation view taken along line 6 of FIG. 5 .
DETAILED DESCRIPTION
As used herein, “deck” refers to a structural platform such as used in roofs, balconies, terraces and the like. “Support structure” generally means the structural element to which the deck is attached for support, for example, a wall, column or post. The inventive termination pocket is a set of flashing members and an upward facing pocket for use at the junction of a deck and a support structure to control and redirect water away from the ends of the deck and away from the support structure. Additionally, the inventive termination pocket creates a substrate to tie-in to for other structural and waterproofing components of the deck. The inventive termination pocket will now be more fully described with reference to the figures. Within the figures like components will generally be referred to with the same reference numerals even when referring to different embodiments.
Referring now to FIGS. 1 and 2 , a first embodiment of the present invention is shown generally by reference numeral 10 . The termination pocket 10 has a set of flashing members connected with imperforated seams, i.e., the flashing members are connected so that the seams are waterproof and have no holes or gaps that could allow water seepage. The set of flashing members comprises a generally horizontal flashing member 12 , first generally vertical flashing member 26 and second generally vertical flashing member 40 .
Generally horizontal flashing member 12 has a top surface 14 , a bottom surface 16 , opposing side edges 18 and 20 , back edge 22 and front edge 24 , with back edge 22 and side edge 18 being perpendicular. First generally vertical flashing member 26 is connected to the bottom surface 16 at top edge 28 . Additionally, first generally vertical flashing member 26 has opposing side surfaces 30 and 32 , back edge 34 , front edge 36 and bottom edge 38 . Back edge 34 of first generally vertical flashing member 26 is connected to second generally vertical flashing member 40 at vertical edge 42 . Additionally, second generally vertical flashing member 40 has vertical edges 44 and 46 , top edge 48 , bottom edge 50 and horizontal edge 52 . Horizontal edge 52 of second generally vertical flashing member 40 is connected to the generally horizontal flashing member 12 at back edge 22 .
As described above and shown in FIGS. 1 and 2 , generally horizontal flashing member 12 and first vertical flashing member 26 form an inverted L-shape. This inverted L-shape is connected to second generally vertical flashing member 40 so that second generally vertical flashing member 40 extends above and to the backside of the inverted L-shape. As is further discussed below with regard to FIGS. 5 and 6 , the resulting configuration for the set of flashing members snuggly fits into the junction of a support structure and deck covering the surrounding surfaces.
Returning now to FIGS. 1 and 2 , termination pocket 10 further has an upward facing pocket 54 . Upward facing pocket 54 generally will have opposing vertical walls 56 and 58 , and a bottom 59 extending between the two vertical walls. Upward facing pocket 54 can have third vertical wall or back 60 , which, as illustrated in FIGS. 1 and 2 , can be the second generally vertical flashing member 40 . Accordingly, opposing vertical walls 56 and 58 and back 60 define a top opening 62 (best seen in FIG. 6 ) and a front opening 64 , which allow water to drain into upward facing pocket 54 through top opening 62 and out of upward facing pocket 54 through front opening 64 ; thus directing water away from the deck and support structure, as further described below. The opposing walls can be any suitable height, e.g., equal height, wall 56 extending higher than wall 58 or wall 58 extending higher than wall 56 . However, in the illustrated embodiment, wall 58 extends higher than wall 56 so that upward facing pocket 54 is a J-shaped flashing member. The J-shaped configuration provides protection from water entering upward facing pocket 54 spilling over wall 58 .
Upward facing pocket 54 is connected at the top edge 66 of wall 56 to generally horizontal flashing member 12 so as to define a downward facing pocket 68 by first generally vertical flashing member 26 , upward facing pocket 54 and generally horizontal flashing member 12 . The portion of horizontal flashing member 12 extending between first generally vertical flashing member 26 and wall 56 serves as a bridge extending from deck 76 to upward facing pocket 54 , as will be more fully appreciated by reference to FIGS. 3 and 6 . Additionally, in the embodiment of FIGS. 1 and 2 , second generally vertical flashing member 40 extends across the back of downward facing pocket 68 and is connected thereto by imperforated seams so as to prevent water intrusion to the surface adjacent to the back of second generally vertical flashing member 40 .
As will be appreciated, the embodiment of termination pocket 10 illustrated in FIGS. 1 and 2 is for use with a wall that extends beyond the side of the deck to which the termination pocket 10 is attached. Thus, the deck and deck side are received in the afore described inverted L-shape at the junction of the deck and wall, and second generally vertical flashing member 40 extends along the wall above the junction and around the side of the deck to thus protect the wall from water intrusion.
Turning now to FIGS. 3 and 4 , a termination pocket 70 is illustrated. Termination pocket 70 is useful where support structure 78 is a column or beam support structure or to wall support structure where a wall corner is located at the wall deck junction. For termination pocket 70 , like components have been labeled with like reference numerals to those of termination pocket 10 . For termination pocket 70 , first generally vertical flashing member 26 extends behind second generally vertical flashing member 40 and has an L-shaped configuration so that the upper portion 72 of the L-shaped configuration extends above generally horizontal flashing member 12 on the back side of second generally vertical flashing member 40 . Thus, first and second generally vertical flashing members 26 and 40 form a corner flashing piece 73 having imperforated seam 74 so as to at least partially encase the corner of the wall, column or beam above generally horizontal flashing member 12 . Additionally, downward facing pocket 68 can have a back or be open on both front and back as illustrated in FIGS. 3 and 4 .
Turning now to FIGS. 5 and 6 , an installed termination pocket 70 is illustrated. In FIGS. 5 and 6 , a deck 76 is connected along one side to a generally vertical support structure 78 , in this case a column or beam. The connection is along edge junction line 80 located where edge 84 of deck 76 meets with support structure 78 . In past flashing systems, edge junction 80 has been particularly problematic with respect to water seepage due to numerous seams and junction points in the flashing and because of inadequate direction of water away from edge junction 80 .
Termination pocket 70 is located at edge junction 80 such that the inverted L-shape formed by first generally vertical flashing member 26 and generally horizontal flashing member 12 is mated with the inverted L-shape formed by upper surface 86 and side 88 of deck 76 . Additionally, corner flashing piece 73 is mated with sides 90 and 92 of support structure 78 . Because the flashing members are joined with imperforated seams, the seams and area around the junctions are covered by flashing members 12 , 26 and 40 in a waterproof layer.
Generally horizontal flashing member 12 extends out from the upper surface 86 of deck 76 to form a bridge to upward facing pocket 54 such that water tends to flow off upper surface 86 out and away from the deck to upward facing pocket 54 . Upward facing pocket 54 channels the water away from the support structure and can be connected at opening 64 to a gutter or other drainage system. To ensure drainage away from the support structure, upward facing pocket 54 can have a slope. As will be appreciated from the drawings, downward facing pocket 68 , allows for the installation of further flashing, fascia boards, siding and other decking components between the upward facing pocket 54 and first generally vertical flashing member 26 . Also, among other advantages, downward facing pocket helps ensure that water is channeled away from the deck.
Generally, the upward facing pocket 54 and downward facing pocket 68 can be any size and shape to ensure adequate control and redirection of water away from the support structure and deck. Typically, the slope of upward facing pocket 54 will be downward from the back 60 to the front opening 64 at about 5 degrees from horizontal but can be from about 2 degrees to 45 degrees, or from about 2 degrees to about 10 degrees or from about 4 degrees to about 7 degrees. Upward facing pocket 54 can generally have a width of about 1.25 inches but can have a width of from 0.5 inch or greater, and can be about 0.5 inch to a about 2.0 inches or can be from about 1.0 inch to about 1.5 inches. Downward facing pocket 68 will generally have a width of about 1.0 inch but can have a width of about 0.5 inch or greater and can be about 0.5 inch to about 1.5 inches or can be from about 0.75 inch to about 1.25 inches. Additionally, typically, wall 58 of upward facing pocket 54 will be greater in height than wall 56 . As illustrated, wall 58 can have its greatest height near back 60 of upward facing pocket 54 and can angle down to a lower height towards front opening 64 . This lower height can be the same height as wall 56 or, preferably, can be greater in height than wall 56 . Thus, adjacent to back 60 , wall 58 can be about 2.25 inches greater in height than wall 56 and can, more generally, be about 1 inch to about 3 inches greater than the height of wall 56 , or can be about 2 inches to about 2.5 inches greater than the height of wall 56 . Adjacent to front opening 64 , wall 58 can be about 1.75 inches greater in height than wall 56 and can, more generally, be about 0.5 inch to about 3 inches greater than the height of wall 56 , or can be about 1 inch to about 2.5 inches greater than the height of wall 56 . The inventive termination pocket can be made from any suitable material. Generally, the material can be selected from materials that can be cast, molded and/or welded, such as metals plastics, polymers and carbon composites. Generally, most metals are suitable for use as the material, but typically the material can be selected from the group comprising aluminum, copper and galvanized steel. More preferably, the material can be aluminum.
The size of the flashing members can depend on the particular decking and support structure and will be apparent to one skilled in the art based on the disclosure herein. Generally, the flashing members can extend out from the edge junction at least about 2 inches and can be from about 2 inches to about 5 inches.
Returning now to FIGS. 5 and 6 , the installation of the termination pocket on a deck with additional flashing elements and water membranes can be seen. In FIGS. 5 and 6 , termination pocket 70 is installed as described above. A second set of flashing members can further cover the deck and surface of the support structure. The second set of flashing members can comprise flashing edge piece 96 , which covers at least a portion of the upper surface of deck 76 , extends out over edge 84 , across downward facing pocket 68 and over into upward facing pocket 54 . Additional flashing members can be installed along the upper surface and support structure so as to extend over a portion of the wall adjacent to junction line 80 and overlapping on top of second generally vertical flashing member 40 (not seen in FIG. 6 ). A water resistant or waterproof membrane known in the art, such as membrane 100 , can be on top of the second set of flashing members and on portions of the deck and support structure not covered by flashing.
Other embodiments of the current invention will be apparent to those skilled in the art from a consideration of this specification or practice of the invention disclosed herein. Thus, the foregoing specification is considered merely exemplary of the current invention with the true scope thereof being defined by the following claims. | The present invention relates to flashing systems used to control and redirect water and, more specifically, to flashing systems used to control and redirect water from the junction of a deck with a wall or post. The present invention utilizes a set of flashing members and an upward facing pocket to create a system that drains water away from the decking assembly, including the support structure and decking. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/393,825, filed Oct. 15, 2010.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to water conservation systems, and more specifically to a gray water recycling system for converting laundry wastewater into water that can be used for toilets and similar applications.
2. Description of the Related Art
In a world of ever diminishing natural resources, it is imperative that consumption of such resources should be maximized to the fullest extent. That requires recycling as one of several ways to help preserve the environment and prevent unnecessary waste.
One of most common resources subject to waste is water. Activities such as lavatory use, laundry, dishwashing, showers and baths consume water inefficiently either by using much more than necessary and/or non-recovery of the used water. This places additional strain on the sewage systems, which inevitably leads to increased costs to the average consumer.
Water recovery systems have been proposed that recycle gray water from laundry and washbasins to be used as flushing water for toilets. These usually involve filtering and storing the gray water in holding tanks to be pumped whenever needed. While generally sufficient for normal use, there does not appear to be a system to adequately clean the water to a reusable state and control the use thereof in a wide range of situations.
Thus, a gray water recycling system solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
The gray water recycling system includes a first holding tank for filtering and storing gray water from a washer. The processed water passes through an inline filter to a second holding tank. The second holding tank includes a first float switch operatively associated with a pump that shuts off power to the pump when the second tank contains less than a predetermined amount of processed water. An outlet pipe inside the second tank includes another filter to clean the processed water as the water passes through an outlet pipe. A second float switch activates the pump to pump the processed water to a toilet tank when the toilet tank water drains below a predetermined level. A battery power unit is operatively connected to the pump, providing power for selective operation thereof.
These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing an overall view of the components of a gray water recycling system according to the present invention.
FIG. 2 is a side view in section of a first holding tank in a gray water recycling system according to the present invention.
FIG. 3 is a side view in section of a second holding tank in a gray water recycling system according to the present invention.
FIG. 4 is a perspective view of a toilet tank in a gray water recycling system according to the present invention, shown with the water tank broken away and partially in section to show details thereof.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to a gray water recycling system, generally referred to by reference number 10 in the drawings, for recovering or recycling used or gray water from a washer W in a domicile to be used as flushing water for a toilet T. As shown in FIG. 1 , the gray water recycling system 10 includes a primary or first holding tank 12 for filtering and holding gray water. The processed water P is piped to a secondary or second holding tank 28 . A selectively operated pump 48 pumps the processed water from the second holding tank 28 to a toilet tank 62 .
Referring to FIGS. 1 and 2 , the gray water is pumped through a flexible pipe 14 to a gray water distribution assembly 16 near the top of the first holding tank 12 . In the exemplary embodiment, the first holding tank 12 may have a capacity of one hundred gallons. Alternatively, any other desired capacity tanks may be used. The force for pumping the gray water is supplied by the wastewater discharge pump in the washer W. The gray water distribution assembly 16 includes a planar arrangement of pipes with a plurality of slits 18 formed at the bottom thereof. As the gray water enters the pipes, the gray water is sprayed through the slits 18 towards the bottom of the first holding tank 12 . It is preferable that any open ends in the pipes be capped to preserve water pressure for spraying the gray water.
A two-stage filtration assembly is disposed below the gray water distribution assembly 12 . The spraying action of the gray water distribution assembly 12 efficiently distributes the gray water over the entire surface of the filtration assembly. The filtration assembly includes a first filter 20 and a second filter 22 . The first filter 20 may be a layer of activated charcoal for performing a coarse filtration of the gray water, which will also prevent a range of relatively large solid matter from passing through. The second filter 22 may be a layer of polypropylene with a fine mesh for cleaning the remainder of smaller size particulate matter. Moreover, either one or both of the filters may include biocide agents to help eliminate potentially harmful bacteria. As an additional measure, the first holding tank 12 may include a top or cover 13 with a plurality of holes 15 for the gray water to pass towards the two-stage filtration assembly. The cover 13 may overlie the first filter 20 to capture even larger sized debris such as twigs and bits of fabric.
The processed water P from the first holding tank 12 is then passed to the second holding tank 28 through an intermediate pipe 24 . The intermediate pipe 24 may include an inline or third filter 26 to further clean the processed water P. The third filter 26 may be another form of polypropylene fine mesh. Since the second holding tank 28 is disposed at a lower level from the first holding tank 12 , gravity is sufficient to move the water from the first holding tank 12 to the second holding tank 28 . If more pressure is needed, a pump may be operatively connected to the intermediate pipe 24 .
As shown in FIGS. 1 and 3 , the second holding tank 28 includes a vent 30 at one end and an exit or outlet pipe 36 . The second holding tank 28 preferably has a capacity of about one hundred twenty gallons, but again, any desired capacity may be used. As the processed water P from the first holding tank 12 enters the second holding tank 28 , any trapped air inside the second holding tank 28 can prevent efficient flow and fill of the same. Hence, the vent 30 allows air to escape. Depending on regulations, the vent 30 may be a long pipe permitting air to escape outside the dwelling, or a short pipe to permit air to escape within the confines of the second holding tank 12 storage space, e.g., a basement.
In case of an overflow, the second holding tank 28 includes an overflow pipe 32 directing excess processed water P to sewage or ground. A one-way check valve 34 on the overflow pipe 32 prevents any water from flowing back into the second holding tank 28 .
The second holding tank 28 is the main tank supplying water to flush the toilet T. As such, a selectively operable pump 48 is connected to the second holding tank outlet 36 and to the toilet tank supply pipe 56 . The outlet 36 may include a fourth filter 40 to further clean the processed water P prior to being pumped into the toilet tank 62 . The fourth filter 40 may be a foam sleeve 42 surrounding perforations 44 at the outlet end inside the second holding tank 28 . If desired, a similar fourth filter 40 may be provided on the inlet side of the intermediate pipe 24 as shown in FIG. 2 . However, a second pump may be needed to move the processed water P between the holding tanks 12 , 28 to overcome the restrictive flow through the additional fourth filter 40 .
The second holding tank 28 also includes a first float switch 46 disposed inside the second holding tank 28 . The first float switch 46 is operatively connected to the pump 48 so that when the water level is below a predetermined amount, the first float switch 46 is in the OFF position (shown in phantom lines), resulting in power to the pump 48 being shut off. This indicates that insufficient water is available to flush the toilet T. When the water level is at or above the predetermined level, the first float switch 46 is in the ON position (shown in solid lines). This allows the power supply to the pump 48 to be activated when needed.
The power source for the pump 48 is a battery 54 . The battery 54 may be a 12-volt type, and the battery 54 may be charged by a solar panel 50 through the interconnecting wires 52 . Other alternative energy sources, such as windmills, may also be used.
As shown in FIGS. 1 and 4 , the supply pipe 56 directs water from the pump 48 into the toilet tank 62 . The supply pipe 56 includes an intake valve 58 , which opens or closes to regulate the flow of processed water P, and a one-way check valve 60 downstream of the intake valve 58 . The check valve 60 prevents back flow through the supply pipe 56 . The outlet end of the supply pipe 56 may be bent over the top rim of the toilet tank 62 to minimize any substantial alterations to the toilet tank 62 , e.g., drilled holes. As a result, the rim is uneven due to the additional height formed by the bent portion of the supply pipe 56 , which can prevent the toilet tank cover from covering the toilet tank 62 in a level fashion. To level the rim, a gasket ring 63 may be disposed along the rim of the toilet tank 62 , the ring 63 having a height or thickness substantially equal to the height of the bent portion. The gasket ring 63 may be rubber, plastic or foam.
As shown in FIG. 4 , the toilet tank 62 also includes a second float switch 64 adjustably mounted on a bracket. The second float switch 64 performs the same function as a typical float valve in standard toilets. However, the second float switch 64 operates in a reverse manner with respect to the first float switch 46 . In the down position as shown in FIG. 4 , the second float switch 64 is in the ON position to thereby activate the pump 48 and fill the toilet tank 62 . As the supplied water fills the tank to a predetermined level, the second float switch 64 rises to an OFF position, which deactivates the pump 48 . If there is insufficient supply of water in the second holding tank 28 , the user may shut off the intake valve 58 and open the standard intake valve 66 to utilize the normal water in the domicile. Hence, the standard intake valve 66 would normally be closed when using the gray water recycling system 10 .
The gray water recycling system 10 may include additional means of cleaning and purifying the waste in the form of chlorine tablets 70 . These chlorine tablets may be placed in the first holding tank 12 , the second holding tank 28 and/or the toilet tank 62 to help destroy potentially harmful germs and bacteria. Moreover, a tablet holder or basket 72 may be disposed below the second filter 22 to help sanitize the filtered gray water as the gray water flows into the first holding tank 12 .
Thus, it can be seen that the gray water recycling system 10 recovers and recycles gray water for use as toilet tank flushing water. The numerous filters within the system sufficiently clean the gray water to a usable state, and the float switches insure operation of the pump 48 only when needed. The gray water recycling system 10 also includes safeguards for overflow and emergency issues.
It is noted that the gray water recycling system 10 encompasses a variety of alternatives. For example, the first and second float switches 46 , 64 may use alternative float switch systems having a buoyant element that rises and lowers with the level of water. Instead of two holding tanks, the gray water recycling system 10 may use a single tank connected to the pump 48 when the tank and the toilet are on the same elevation. Moreover, the gray water recycling system 10 may also be employed with washbasins, sinks and baths.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims. | The gray water recycling system includes a first holding tank for filtering and storing gray water from a washer. The processed water passes through an inline filter to a second holding tank. The second holding tank includes a first float switch operatively associated with a pump that shuts off power to the pump when the second tank contains less than a predetermined amount of processed water. An outlet pipe inside the second tank includes another filter to clean the processed water as the water passes through the outlet pipe. A second float switch activates the pump to pump the processed water to a toilet tank when the toilet tank water drains below a predetermined level. A battery power unit is operatively connected to the pump, providing power for selective operation thereof. | 8 |
[0001] This application is a continuation-in-part of application Ser. No. 09/672,550, filed on Sep. 28, 2000.
FIELD OF THE INVENTION
[0002] The present invention relates to a fence post assembly for use in a portable fencing system and related method. The fence post assembly of the invention is particularly suited for use in forming a variety of animal enclosures, such as a portable horse corral and the like. However, the fence post assembly, fencing system and method also have utility in forming other types of enclosures or in defining other bounded areas.
BACKGROUND OF THE INVENTION
[0003] Often times it is necessary to define a temporary enclosure or bounded area in a location that does not have an existing enclosure(s) or in which one or more additional enclosures are necessary. One example of a situation in which such a need arises is when one or more horses are brought to a location not having existing enclosures or where the existing enclosures are inadequate and must be supplemented by temporary enclosures. Rodeos, horse shows, and temporary training and/or grazing sites are examples of locations at which a temporary enclosure(s) may be necessary.
[0004] Previously, when a temporary enclosure was needed, such as for one or more horses, metallic fencing sections were generally hauled to the appropriate site and assembled to form an enclosure or horse corral. Typically, the fencing sections are heavy and difficult to assemble into a complete enclosure, as well as being hard to transport due to their weight and size. In addition, an enclosure made from metallic fencing can often be considered excessive when it is realized that an enclosure made from simpler components can adequately perform the intended function.
[0005] Therefore a need exists for an improved fencing system for use in forming a temporary enclosure or bounded area.
SUMMARY OF THE INVENTION
[0006] The general purpose of the present invention is to provide an improved fence post assembly, as well as a fencing system and related method utilizing the improved fence post assembly, for forming a temporary enclosure, such as a horse corral for restraining horses. The fence post assembly is provided with an extensible and retractable fence strand, such as polytape or wire, as well as a ground anchor at one end of the fence post to enable the fence post to be anchored into the ground.
[0007] According to one aspect of the invention as defined in the claims, a fence post assembly is provided that comprises a fence post having first and second opposite ends, a ground anchor connected to the fence post adjacent the first end for anchoring the fence post, and a fence strand assembly connected to the fence post. The fence strand assembly includes an extendable and retractable fence strand, and the extendable and retractable fence strand is selectively positionable along the length of the fence post between the first and second opposite ends thereof.
[0008] According to another aspect of the invention as defined in the claims, a portable fencing system for forming an enclosure is provided that comprises at least one fence post assembly, with the at least one fence post assembly including: a fence post having first and second opposite ends, a ground anchor connected to the fence post adjacent the first end for anchoring the post; and a fence strand assembly connected to the post. The fence strand assembly includes an extendable and retractable fence strand, and the extendable and retractable fence strand is selectively positionable along the length of the fence post between the first and second opposite ends thereof.
[0009] In yet another aspect of the invention as defined in the claims, a method of forming an enclosure comprises providing a first fence post assembly having a fence post with first and second opposite ends, a ground anchor connected to the fence post adjacent the first end for anchoring the post and a fence strand assembly connected to the post. The fence strand assembly includes an extendable and retractable fence strand, and the extendable and retractable fence strand is selectively positionable along the length of the post between the first and second opposite ends thereof. The method further includes anchoring the fence post to the ground, extending the fence strand a sufficient amount to at least partially form an enclosure; and positioning the fence strand along the length of the fence post to achieve the desired fence strand height.
[0010] In still another aspect of the invention, as defined in the claims, a fence strand assembly for a fence post is provided. The fence strand assembly includes a housing that includes a clamp assembly configured for releasable engagement with the fence post whereby the housing can be connected to and selectively positioned along the fence post. In addition, a fence strand material is at least partially disposed within the housing, with the fence strand material being extendable and retractable relative to the housing.
[0011] Another aspect of the invention, as defined in the claims, provides a fencing kit that comprises a plurality of fence post assemblies. Each fence post assembly includes a fence post, a ground anchor for anchoring the post, and a fence strand assembly. The fence strand assembly includes an extendable and retractable fence strand, and means for selectively positioning the fence strand along the length of the post.
[0012] These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages and objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying description, in which there is described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Referring to the drawings, wherein like numerals represent like parts throughout the several views:
[0014] [0014]FIG. 1 illustrates a fence post assembly in accordance with the principles of the invention.
[0015] [0015]FIG. 2 is an exploded view of the components of the fence post assembly.
[0016] [0016]FIG. 3 is a top perspective view of the fence strand assembly used on the fence post assembly.
[0017] [0017]FIG. 4 is a bottom perspective view of the fence strand assembly.
[0018] [0018]FIG. 5 illustrates the spindle used in the fence strand assembly.
[0019] [0019]FIGS. 6 a and 6 b are perspective views of the lock lever associated with the fence strand assembly.
[0020] [0020]FIG. 7 is a perspective view of the hook disposed at the end of the extensible/retractable fence strand.
[0021] [0021]FIG. 8 is a perspective view of the handle that is connected to the extensible/retractable fence strand.
[0022] [0022]FIG. 9 illustrates a plurality of the fence post assemblies forming an enclosure.
[0023] FIGS. 10 A-C illustrate perspective, top and bottom views of the ground anchor.
[0024] [0024]FIG. 11 illustrates a fence strand assembly for use in an electric fence system.
[0025] [0025]FIG. 11A illustrates the bottom of the fence strand assembly in FIG. 11.
[0026] [0026]FIG. 12 illustrates a gate handle that is used to connect a bi-polar tape to an adjacent fence strand assembly.
[0027] [0027]FIGS. 13A and 13B illustrate the two primary parts of the gate handle of FIG. 12.
[0028] [0028]FIG. 14 schematically illustrates the power supply and control used in the electric fence system.
[0029] [0029]FIG. 15 is a perspective view of an alternative embodiment of a ground anchor according to the invention.
[0030] [0030]FIG. 16 is cross sectional view taken through the center of the ground anchor of FIG. 15.
[0031] [0031]FIGS. 17A and 17B illustrate how the ground anchor cooperates with the post.
[0032] [0032]FIG. 18 illustrates a fence controller that is partially inserted within a post.
[0033] [0033]FIG. 19 illustrates a back side of the controller.
[0034] [0034]FIG. 20 is an exploded perspective view of the components of the controller.
[0035] [0035]FIG. 21 is a perspective view of a cover that cooperates with the bottom of the housing to close the bottom of the housing.
[0036] [0036]FIG. 22 is a perspective view of an alternative embodiment of a lock lever.
DETAILED DESCRIPTION
[0037] With reference to FIG. 1, a fence post assembly 10 in accordance with the principles of the present invention is illustrated. The fence post assembly 10 generally includes a fence post 12 , a fence strand assembly 14 connected to the post 12 and adjustable along the length thereof, and a ground anchor 16 at one end of the post 12 to enable the post 12 to be anchored into the ground.
[0038] It is to be realized that although FIG. 1 illustrates the fence post assembly 10 as having a single fence strand assembly 14 , multiple fence strand assemblies 14 can be connected to the post 12 to permit a multi-strand fence. In addition, multiple fence post assemblies 10 can be stacked together to provide a multi-strand fence. For instance, a second post 12 of a second fence post assembly 10 could be designed for securement to the end of a first post 12 , such as by using removable fasteners such as screws, whereby the second post 12 is stacked on the first post 12 to increase the height of the resulting enclosure. The second fence post assembly 10 can include one or more fence strand assemblies 14 , that cooperate with the one or more fence strand assemblies on the first post in defining the enclosure.
[0039] With continued reference to FIG. 1, as well as to FIG. 2, the post 12 has a generally elongated, hollow, rectangular shape with a first end 18 and a second end 20 . The post 12 is made from suitable material, such as metal, plastic or fiberglass. The post 12 can have a cross-sectional shape other than rectangular, such as triangular or round, if desired. Further, it is also contemplated that, in certain embodiments, the post 12 could be made solid rather than hollow.
[0040] Connected adjacent to the first end 18 of the post 12 is the ground anchor 16 . The ground anchor 16 is preferably made of metal, although plastic could be used as well. As best shown in FIGS. 2 and 10A, the ground anchor 16 includes a sleeve 22 that fits over the post 12 adjacent the first end 18 . A pin, bolt, rivet or other suitable fastener (not shown) preferably extends through holes 24 provided in the sleeve 22 and through the post 12 in order to secure the ground anchor 16 to the post 12 . Extending from the bottom of the sleeve 22 is a shaft 26 with an auger 28 disposed at the bottom end of the shaft 26 . The auger 28 permits the post 12 to be screwed into the ground, thereby anchoring the fence post 10 into the ground. The ground anchor 16 could also be designed to fit within the end 18 of the post 12 , rather than over the end 18 of the post 12 . In one implementation, a shaft 26 having a length of about 8 to about 12 inches has been found to be effective. Other shaft lengths could be used if desired.
[0041] The details of an exemplary design of the ground anchor 16 are illustrated in FIGS. 10 A-C. Between the bottom of the sleeve 22 and the shaft 26 is a plate 21 . The plate 21 is designed to engage the ground when the anchor 16 is screwed into the ground, thereby providing stability to the post 12 . As is evident from FIG. 10A, the plate 21 is preferably a square with sides having dimension d 2 so that the plate extends beyond the sides of the sleeve 22 a certain distance d 1 to provide the stabilizing effect. In one implementation, it has been found that a plate 21 having a dimension d 2 equaling about 3 inches, and a distance d, equaling about 0.5 inches, provides adequate stability. However, it is to be realized that other plate dimensions could be used as well.
[0042] To permit drainage of any moisture that may enter the post 12 or the sleeve 22 , at least one, and preferably two or more, weep holes 23 are provided in the plate 21 as best seen in FIG. 10B. In addition, the auger 28 is designed to facilitate insertion into the ground. If the auger is too wide, it is difficult to screw the anchor into the ground. Therefore, the dimensions of the auger 28 are selected to facilitate insertion into the ground. By way of example, the auger 28 can have the following dimensions:
[0043] d 3 —about 2.5 inches
[0044] d 4 —about 0.5 inches
[0045] d 5 —about 0.5 inches
[0046] d 6 —about 0.25 inches
[0047] R—about 1.0 inch
[0048] about 0.666 threads per inch.
[0049] It is to be realized that the auger 28 can have other dimensions as well, without departing from the spirit and scope of the invention.
[0050] An alternate embodiment of a ground anchor 210 for anchoring the post 12 into the ground is illustrated in FIGS. 15 - 17 . The anchor 210 is designed to releasably self-lock with the post 12 and permit manual disconnection of the anchor from the post. In this embodiment, the end of the post 12 that interacts with the anchor 210 must be hollow. The anchor 210 is preferably formed entirely from plastic, such as polycarbonate, acrylonitrile butadiene styrene (ABS) or other engineering grade plastics.
[0051] Referring to FIGS. 15 - 16 , the anchor 210 comprises a central body 212 that is generally hollow and has a shape that generally matches the shape of the post 12 so that the central body 212 fits within the end of the post in close fitting relation therewith. The close fit between the body 212 and the interior of the post 12 secures the anchor and the post and prevents excessive relative movement therebetween. In the illustrated embodiment, the central body 212 is generally rectangular in shape so as to match the generally rectangular shape of the hollow end of the post 12 . However, the central body 212 could have other shapes, such as circular or triangular, corresponding to the shape of the post that is used.
[0052] As shown in FIGS. 15 and 16, a cylindrical sleeve 214 through the center of the body 212 defines a passage 216 . The passage 216 permits a spike or other similar supplemental anchoring member (not shown) to extend through the center of the anchor 210 and into the ground to supplement the anchoring action of the anchor 210 . A plurality of ribs 218 (only one rib 218 is visible in FIG. 16) extend between the exterior surface of the sleeve 214 and the interior surface of the body 212 to reinforce the sleeve 214 .
[0053] Surrounding the exterior of the body 212 adjacent the base end thereof is a skirt 220 . The skirt 220 includes a first flange portion 222 that extends outwardly from the body 212 , an upwardly extending portion 224 , a second flange portion 226 that extends outwardly from the end of the portion 224 , and a downwardly extending portion 228 . A groove 230 is defined between the exterior of the body 212 , the flange portion 222 and the portion 224 , which is angled slightly away from the exterior of the body 212 . In use, the groove 230 receives the end of the post 12 therein, as is illustrated in FIG. 17B.
[0054] To releasably secure the post to the anchor 210 , the anchor 210 is provided with a pair of integral locking members 232 a , 232 b . The locking members 232 a , 232 b are identical to each other, so the construction and operation of only the member 232 a will be described in detail. Referring to FIGS. 15 and 16, it is seen that the exterior of the body 212 is formed with a channel 234 that receives the locking member 232 a . In the illustrated embodiment, the channel 234 extends approximately the entire height of the portion of the body 212 that projects above the flange portion 226 , with the sleeve 214 defining the rear of the channel 234 along the upper end, and with the portion of the channel 234 below the sleeve 214 opening into the interior of the body 210 via a passage 236 .
[0055] The locking member 232 a comprises a locking arm 238 that extends parallel to the channel 234 , with the exterior surface of the arm 238 preferably being generally even or flush with the exterior surface of the body 212 . The arm 238 is connected adjacent one end thereof to the sleeve 214 by a connector 240 , whereby the arm 238 is cantilevered so as to permit the opposite end of the arm 238 to resiliently flex. The opposite end of the arm 238 is circular in shape and has an enlarged thickness compared to the remainder of the arm 238 (see FIG. 16) so as to form a lock button 242 . The lock button 242 is sized to interact with an aperture 244 formed in the post 12 adjacent the bottom end thereof, whereby, in use, the button 242 fits into the aperture 244 when the post 12 and anchor 210 are engaged to lock the post to the anchor. The button 242 is generally tapered in thickness, with the thickness increasing from its juncture with the remainder of the arm 238 to the bottom end of the button 242 . The tapering of the button 242 helps the post slide over the arm 232 a as the post and anchor are being connected.
[0056] The anchor 210 further includes a plurality of integral ground engaging spikes 250 which, in use, are intended to be driven into the ground for anchoring the post. In the preferred embodiment, the anchor 210 includes four integral spikes 250 . It is to be realized, however, that a larger or smaller number of spikes could be used. The spikes 250 extend from the bottom of the central body 212 at each corner thereof. Each spike 250 is formed from a plurality, preferably four, circumferentially even spaced ribs 252 . The ribs 252 are tapered such that the spikes 250 taper from adjacent the body 212 to their distal ends. The tapering of the spikes 250 facilitates insertion of the spikes 250 into the ground, with the ribs 252 providing adequate securement once the spikes are driven into the ground. Further, as described above, a spike or other member, if desired, can be inserted through the passage 216 to supplement the spikes 250 .
[0057] The locking members 232 a , 232 b are designed to releasably connect the post 12 to the anchor 210 . With reference to FIGS. 17A and 17B, to connect the post and anchor, the end of the post is slid over the body 212 of the anchor, and into the groove 230 until the end of the post 12 engages the flange portion 222 . During this time, the tapered buttons 242 are pushed inward by the post. When the apertures 244 become aligned with the buttons 242 , the resilient return force of the arms 238 force the buttons 242 outward through the apertures 244 , thereby locking the post and the anchor together. To release the post and anchor, the buttons 242 must be pushed inward to disengage from the apertures 244 , at which point the post 12 and anchor 210 can be pulled apart.
[0058] One embodiment of the fence strand assembly 14 , best seen in FIG. 2, includes a housing 30 that is slidably connected to the post 12 to permit adjustment of the housing 30 along the length of the post 12 . The housing 30 is preferably formed from injection molded plastic, such as polycarbonate, acrylonitrile butadiene styrene (ABS) or other engineering grade plastics. However, in certain constructions such as a non-electric fence strand version, the housing or portions thereof could be formed from a metal material if desired.
[0059] Disposed within the housing 30 in a cup-shaped depression 32 thereof (best seen in FIG. 4) is a roll of fence strand material 34 . The fence strand material 34 is illustrated in the figures as being a tape, such as polytape. However, it is to be recognized that other fence strand members, such as wire, rope and other slender fence strand members, could be used as well. In addition, as will be described in more detail later in the description, the fence strand material 34 can be electrified to provide an electric fence system.
[0060] One end of the fence strand material 34 extends through a slot 36 formed in the side of the housing 30 , while the opposite end of the fence strand material 34 is secured to a spindle 38 . The spindle 38 , best seen in FIG. 5, includes a plurality of slots 40 therein through which the end of the fence strand material 34 extends such that rotation of the spindle in the appropriate direction causes the fence strand material 34 to be wound onto the spindle. The bottom end of the spindle 38 forms a pivot 42 which fits through a hole provided in the bottom of the cup-shaped depression 32 (see FIG. 4 ), with the spindle secured in place by a locking clip 44 engaging with a slot 46 in the pivot 42 .
[0061] As shown in FIGS. 2 - 3 , a spool 48 is rotatably received at the top of the housing 30 and closes off the cup-shaped depression 32 so that the roll of fence strand material 34 is enclosed within the housing. The spool 48 and housing 30 prevent ingress of water, dirt and other contaminants to the roll of fence strand material 34 thereby increasing the reliability and operational life of the fence strand assembly 14 . The spool 48 includes a hole therein that receives a correspondingly shaped head 50 on the spindle 38 . As illustrated in the figures, the hole and head 50 are rectangular in shape, although it is to be realized that other shapes, such as triangular, pentagonal or the like, could be used.
[0062] The housing 30 is illustrated in FIG. 4 as having an open bottom. However, the housing preferably cooperates with a housing cover 300 , illustrated in FIG. 21, that closes the bottom of the housing 30 . The housing cover 300 has a shape that is complementary to the shape of the open bottom of the housing 30 , and is secured to the housing using screws that extend through bosses 302 on the cover 300 and into threaded boss 304 (shown in FIG. 4) formed on the housing 30 . The cover 300 preferably includes a plurality of weep holes 306 to allow drainage of the interior of the housing 30 .
[0063] As best seen in FIG. 3, a crank handle 52 is disposed on, formed on, or otherwise connected to the top surface of the spool 48 . The crank handle 52 is sized and shaped so as to permit manual or mechanical rotation of the spool 48 . Rotation of the spool 48 causes rotation of the spindle 38 , due to the fit of the head 50 into the spool hole. Thus, the spool 48 can be rotated via the crank handle 52 , thereby rotating the spindle 38 , to either pay-out (i.e. extend) the fence strand material 34 or wind-up (i.e. retract) the fence strand material 34 .
[0064] With reference to FIGS. 3, 4, 6 a and 6 b , a locking mechanism is preferably provided in order to lock the fence strand material 34 and prevent further retraction/extension of the fence strand material 34 . The lock mechanism includes a lock lever 54 that is pivotally secured on the housing 30 adjacent the slot 36 to control ingress/egress of the fence strand material 34 through the slot 36 . The lock lever 54 includes a pair of pivot pins 56 that snap fit into suitably provided holes in the housing 30 . A clamp bar 58 formed on the lock lever 54 forcibly clamps the fence strand material 34 against a wire finger 60 (see FIG. 4) and against the housing 30 , when the lock lever 54 is in the position shown in FIGS. 3 and 4, and prevents further ingress/egress of the fence strand material 34 through the slot 36 . A scalloped depression 62 is formed on the lock lever 54 to permit a persons finger(s) to get behind the lever to facilitate pivoting of the lever to an unlock position where the lever 54 projects from the outline of the housing 30 .
[0065] An alternate embodiment of a lock lever 54 ′ is illustrated in FIG. 22. The lock lever 54 ′, which is preferably used with the construction illustrated in FIG. 11, includes a series of projections 59 on the clamp bar 58 ′ enhance the clamping action of the lock lever 54 ′.
[0066] The wire finger 60 discussed above forms one end of a wire 64 that extends beneath the cup-shaped depression 32 as best seen in FIG. 4. The opposite end of the wire 64 extends through a slot 66 in the housing 30 and forms a loop 68 . The loop 68 permits connection of fence strand material 34 to the housing 30 . As shown in FIG. 4, the housing 30 , such as on the bottom of the cup-shaped depression 32 , includes a plurality of wire supports 320 that holds and secure the wire 64 . In addition, the housing cover 300 in FIG. 21 includes a plurality of wire supports 322 for holding and securing the wire 64 when the cover is mounted on the bottom of the housing 30 .
[0067] With reference now to FIGS. 1, 2 and 7 , a strand connector 70 is connected to the end of the fence strand material 34 . The strand connector 70 is preferably formed from a metal, such as stainless steel, or from a suitable plastic material. The connector 70 includes a buckle end 72 provided with a series of slots 74 through which the end of the fence strand material 34 is woven like a buckle so that the end of the fence strand material and the connector 70 are securely fastened. The opposite end of the connector 70 is formed into a hook 76 which is intended to engage the loop 68 on the wire 64 to connect the end of the fence strand material 34 to an adjacent housing 30 . The construction of the connector 70 is particularly suited for use with a tape, such as polytape, as the fence strand material. If the fence strand material 34 is slender, such as wire or rope, an alternate connector that is more suited for connection to a slender fence strand member, but which also is able to connect to the housing, could be used.
[0068] In certain electric fencing systems, the connector 70 would preferably be formed from metal so that electrical current is transferred from the fence strand material of one housing, through the connector 70 which connects to the loop 68 and into the wire 64 of an adjacent housing which carries the current across the adjacent housing to the finger 60 which in turn is in electrical contact with the fence strand material of the adjacent housing as a result of the clamping action provided by the lock lever 54 . In this manner, electrical continuity can be maintained. When the fence is not electrified, the connector 70 can be either metal or plastic, and connects to the housing in the manner described or in any other suitable manner.
[0069] An optional gate handle 78 , illustrated in FIGS. 1 and 8, can be provided to facilitate handling of the end of the fence strand material 34 . When used, the gate handle 78 is preferably formed of extruded polyvinylchloride (PVC) or other suitable plastic, and includes a channel 80 formed therethrough. The fence strand material 34 slides through the channel 80 and the buckle end 72 of the connector 70 wedges tightly into the channel 80 . Thus, when used, the gate handle 78 provides a convenient handle by which a user can grasp and hold the end of the fence strand material 34 .
[0070] As mentioned, the fence strand assembly 14 is adjustable along the length of the post 12 . To accomplish the adjustment, the housing 30 is provided with a clamp assembly 82 that defines a shape, corresponding to the shape of the post 12 , to permit clamping engagement of the housing 30 with the post 12 , as shown in FIGS. 14. The clamp assembly 82 includes a bolt 84 , a washer 86 and a knob 88 that cooperate in a manner known in the art to tighten and loosen the clamp assembly 82 . Through appropriate rotation of the knob 88 , the clamp assembly 82 is loosened and the fence strand assembly 14 can be adjusted along the length of the post 12 to the desired height. Rotation of the knob 88 in the opposite direction tightens the clamp assembly 82 and locks the fence strand assembly 14 in position. As shown in FIGS. 1 and 2, a cap 90 fits into and closes off the second end 20 of the post 12 . The cap could also fit over, rather than within, the second end of the post.
[0071] Although a clamp assembly 82 has been described herein as permitting adjustment of the housing 30 , other means permitting adjustment of the housing 30 could be utilized as well. For instance, an indexing system including a plurality of indexing holes along the length of the post 12 and an indexing pin inserted through a portion of the housing 30 and into a selected one of the indexing holes could be used.
[0072] As described previously, the fence post assembly 10 can be used to form an electric fence or enclosure. In an electric fence version, the fence strand material 34 must be constructed so as to permit conduction of electricity. When the fence strand material 34 is a tape, as illustrated in the figures, the type of tape used can be a bi-polar tape. Bi-polar tapes, which are generally known in the art, include a hot wire(s) and a ground wire extending along the length thereof. The fence strand tape, for either non-electric or electric uses, also preferably includes a reflective strand r extending through the center of the tape, as shown in FIG. 12, to indicate the presence of the tape at night when light reflects off of the reflective strand.
[0073] A conducting wire, rather than tape, can be used as the fence strand material 34 if desired. A suitable type of wire is polywire. The use of wire permits a longer length of fence strand material 34 to be used on the spool 48 , as compared to using tape. By way of example, for the same size spool, it has been found that the length of the wire that can be used can be up to about four time greater than the length of the tape.
[0074] As discussed above, in an electric fence version, electrical continuity is required between a fence strand that connects to the housing 30 and the fence strand that exits the housing 30 . As discussed for FIGS. 1 - 8 , the wire 64 is one means that can be used to transfer electricity between fence strands. In this regard, the wire 64 , which is made of metal or other conducting material, provides the necessary electrical path through the housing 30 which in this version is made from a non-conducting material such as plastic.
[0075] FIGS. 11 - 13 illustrate a construction that is designed for use when the fence strand material 34 is a bi-polar tape. Because bi-polar tape has ground and hot wires, the wire 64 ′ is constructed differently than the wire 64 , in that the loop 68 ′ of the wire 64 ′ is provided with a plastic or other non-conducting piece 69 that divides the loop 68 ′ into separate wires 68 a , 68 b . One wire, for example bottom wire 68 a , is designed to electrically connect to the hot wire(s) in the bi-polar tape, and runs under the cup shaped depression as shown in FIG. 11A. The other wire, for example top wire 68 b , is designed to electrically connect to the ground wire(s) in the bi-polar tape, and runs through the housing, as shown in dashed lines in FIG. 11, without interfering with the rotation of the roll of bi-polar tape disposed in the housing. Likewise, the finger 60 ′ is also provided with a non-conducting piece 61 that divides the finger 60 ′ into separate wires 60 a , 60 b . The wire 60 a is connected to the wire 68 a via the portion that runs under the cup shaped depression, and the wire 60 b is connected to the wire 68 b as shown by the dashed lines in FIG. 11. Therefore, the wires 60 a , 68 a form a first electrical path through the housing while the wires 60 b , 68 b form a second electrical path. The non-conducting pieces 61 , 69 separate the first and second electrical paths from each other.
[0076] As further illustrated in FIG. 11, the lock lever 54 ′ shown in FIG. 22 having the projections 59 is used. When the lock lever 54 ′ is pivoted to the clamping position, the projections 59 press the bi-polar tape against the wires 60 a , 60 b . The projections 59 provide an improved electrical connection between the hot and ground wires in the tape exiting the housing and the wires 60 a , 60 b.
[0077] In addition, as illustrated in FIG. 11A, screws 330 , 332 are threaded into bosses disposed adjacent to the wires 68 a , 68 b , with the heads of the screws contacting the wires. Wire leads 334 , 336 contact the screws 330 , 332 , respectively, and lead to a circuit board 338 located in the housing. In this manner, electricity can be supplied to the wire 64 ′ and to the tape. Moreover, as shown in FIGS. 11 and 12, the housing preferably includes a window 339 on the top surface thereof. A signal element, such as a light emitting diode or other illumination device, is disposed underneath the window 339 and is connected to the circuit board 338 so as to illuminate when electricity is provided to the wire 64 ′. The window 339 thus provides a readily visible indicator that the fence post assembly is powered, and that the fence strand material is electrified.
[0078] [0078]FIGS. 12, 13A and 13 B illustrate a gate handle 110 that is used to connect the bi-polar tape to the housing 30 while maintaining electrical continuity across the housing. The gate handle 110 replaces the connector 70 and gate handle 78 arrangement described in FIGS. 1 - 8 . A first clamping plate 112 , shown in FIG. 13A, of the gate handle 110 cooperates with a second clamping plate 114 , shown in FIG. 13B, to clamp the bi-polar tape 34 therebetween whereby the gate handle 110 is securely attached to the end of the tape 34 , as well as providing for an electrical connection between the hot and ground wires of the bi-polar tape 34 and the hook 68 ′ on the housing. Each clamping plate 112 , 114 is formed from a non-conducting plastic material. The tape 34 is shown diagrammatically in FIG. 12.
[0079] With reference to FIG. 13A, the first clamping plate 112 includes a first end 116 adjacent which there is provided a plurality of ribs 118 . Projecting from the interior surface of the plate 112 are a plurality of stepped ribs 120 . The ribs 120 generally increase in height as they extend from the first end 116 toward a second, connecting end 122 of the plate 112 , with each rib including a series of relatively sharp, pointed tips 124 . The plate 112 further includes a trough 132 in which a pair of channels 130 a , 130 b are formed. A pair of projecting ribs 134 a , 134 b , each of which has a relatively sharp tip, extends from the interior surface of the plate 112 adjacent the channels 130 a , 130 b . In addition, an internally threaded boss 136 projects from the interior surface of the plate 112 between the trough 132 and the connecting end 122 and between the ribs 134 a , 134 b , while an internally threaded boss 137 projects from the interior surface of the plate adjacent the first end 116 .
[0080] With reference to FIGS. 12 and 13A, the trough 132 forms a channel 138 that opens toward the exterior surface of the plate 112 . When the tape 34 is clamped between the plates 112 , 114 , portions of the tape adjacent the channels 130 a , 130 b are disposed within the channel 138 so that the tape portions are accessible from outside the gate handle 110 . It is the portions of the tape disposed within the channel 138 that are to contact the wires 68 a , 68 b when the gate handle 110 is connected to the housing. As shown in FIG. 12, the tape 34 preferably includes a hot wire h and a ground wire g that will be located within the channel 138 as discussed above, so that the hot wire h is able to contact the wire 68 b , while the ground wire g is able to contact the wire 68 a.
[0081] With reference to FIG. 13B, the interior surface of the clamping plate 114 that in use faces the interior surface of the clamping plate 112 is visible. A series of projections 140 project from the interior surface of the plate 114 adjacent a first end 142 thereof. The projections 140 are sized and shaped to fit between corresponding pairs of the ribs 118 on the plate 112 when the two plates 112 , 114 are brought together, thereby helping to firmly clamp the tape 34 between the plates 112 , 114 .
[0082] In addition, a boss 144 having a through hole 146 , and a boss 145 having a through hole 147 , project from the interior surface of the plate 114 at locations that correspond to the locations of the bosses 136 , 137 on the plate 112 when the two plates 112 , 114 are secured together. The bosses 136 , 144 and 137 , 145 cooperate with each other to form a means whereby the two plates 112 , 114 are securely fastened together in a releasable manner. Preferably, threaded screws (not illustrated) are used to secure the two plates, with the screws extending through the through holes 146 , 147 of the bosses 144 , 145 and into threaded engagement with the bosses 136 , 137 . The screws are preferably inserted through the exterior side of the plate 114 , and the bosses 144 , 145 are preferably countersunk on the exterior sides thereof so that the heads of the screws are recessed into the gate handle 110 .
[0083] Further ribs 148 project from the interior surface of the plate 114 , with the ribs 148 positioned to cooperate with the ribs 120 on the plate 112 in a manner to be discussed below. Each rib 148 also includes a relatively sharp, pointed tip 152 . The positioning, size and spacing of the ribs 148 are such that when the plates 112 , 114 are secured together, each pair of ribs 148 are located between a corresponding pair of ribs 120 . As a result, the tape 34 is firmly clamped between the plates 112 , 114 , with the pointed tips 124 , 152 engaging with the tape 34 and helping to prevent the tape 34 from being pulled from the gate handle 110 .
[0084] The plate 114 further includes a flange 154 adjacent an end thereof opposite the end 142 . The flange 154 cooperates with and is positioned closely adjacent to a wall 156 on the plate 112 when the plates 112 , 114 are connected together in order to substantially close off the interior of the gate handle 110 from the exterior thereof.
[0085] Returning to FIG. 13A, it is seen that the plate 112 includes a lip 158 at the connecting end 122 . In use, the interior surface of the lip 158 rests on one surface of the housing 30 , as shown in FIG. 12, while the surface formed by the flange 154 and wall 156 rest on another surface.
[0086] After the tape 34 is placed between the two plates 112 , 114 and the plates are fastened together, the gate handle 110 is connected to the housing 30 in the following manner. As illustrated in FIG. 12, the connecting end 122 is inserted through the loop 68 ′. The gate handle 110 is then rotated so that the connecting end 122 engages with the corner of the housing 30 . In particular, the interior surface of the lip 158 rests on one corner surface, while the surface formed by the flange 154 and wall 156 rest on another corner surface, thereby achieving a secure connection of the gate handle to the housing.
[0087] Further, rotation of the gate handle 110 disposes the loop 68 ′ and the wires 68 a , 68 b thereof within the channel 138 of the trough 132 , where the wires 68 a , 68 b contact the ground and hot wires of the tape disposed within the channel 138 . Thus, electrical continuity is maintained between the tape that connects to the housing, and the tape that exits the housing. Disconnection is achieved by rotating the gate handle 110 to an extent that permits the connection end 122 to be removed from the loop 68 ′.
[0088] With reference to FIG. 14, in the electric fence version, electricity can be provided by the use of one or more solar panels 150 , either mounted on the fence post assembly 10 or provided as a stand alone structure. Alternatively, one or more batteries 160 provided on or in the fence post assembly 10 can be used to provide electrical power. Preferably, the batteries are used in combination with the solar panels, with the solar panels being used to recharge the batteries. A fence controller 170 is provided for controlling operation of the fence post assembly 10 . The controller 170 can be mounted in a variety of locations, for example within the fence post 12 or on the exterior thereof, or it can be provided as a stand-alone unit.
[0089] FIGS. 18 - 20 illustrate a preferred embodiment of the fence controller 170 . In this embodiment, the controller 170 is designed to be inserted as a single integral unit into the upper end of the post 12 which must be made hollow to accommodate the controller 170 . The controller 170 includes a chassis 172 that has a battery accommodation section 174 and a circuit board section 176 , as best seen in FIG. 20. The chassis 172 , which is formed from a molded plastic such as polycarbonate, ABS or other engineering grade plastics, has a shape that is similar to the shape of the hollow end of the post 12 to allow the chassis 172 to be inserted into the post as shown in FIGS. 18 and 19. In the preferred embodiment, the chassis 172 is generally triangular in shape which allows the chassis to be inserted into the post 12 .
[0090] The battery section 174 of the chassis 172 is constructed to receive a plurality of batteries 160 for use in powering the controller 170 and/or in providing electricity to the fence strands, as shown in FIG. 20. In the preferred embodiment, four “D” sized batteries 160 are used. However, it is to be realized that a larger or smaller number of batteries, as well as other battery types, could be used, depending upon the power requirements.
[0091] Mounted within the circuit board section 176 is a circuit board 178 that contains circuitry for operating the controller 170 and the electric version of the fence post assembly 10 . The circuitry on the circuit board is designed to distribute electricity to the electric fence strand member, such as the tape 34 of FIG. 12, to electrify the fence strand member. In addition, the circuitry includes a light 180 , such as a light emitting diode (LED), which flashes when the controller is on to indicate that the controller 170 is functioning. A pair of indicator lights 182 , 184 , one of which is preferably green and the other is preferably red, are also provided in order to provide an indication of the state of the batteries 160 . When the batteries 160 have sufficient charge, the green light is illuminated indicating that the battery level is sufficient; on the other hand, when the battery charge is not sufficient, the red light is illuminated to indicate that the batteries need to be recharged or replaced. A switch 186 , such as a toggle switch, turns the controller 170 on and off.
[0092] In use, when the fence strand members are to be electrified, the switch 186 is turned to the “on” position. Once the controller is on, the LED 180 flashes thereby indicating to the user that the controller is operating. In addition, one of the lights 182 , 184 will also be illuminated to indicate the condition of the batteries 160 .
[0093] If desired, the circuitry on the circuit board 178 could also be designed to permit remote operation of the controller. In this case, the circuitry would include equipment, such as a receiver and a transmitter, that could receive remote control commands and transmit information concerning the operation to a remote location.
[0094] Referring to FIGS. 18 - 20 , a cap 188 disposed at the upper end of the chassis 172 replaces the cap 90 for closing the end of the post 12 . The cap 188 is provided with a cut-out 190 on one side through which the LED 180 is visible and the switch 186 is accessible. In addition, the indicator lights 182 , 184 extend through suitable holes in the opposite side of the cap 188 so that the lights 182 , 184 are visible, as best seen in FIG. 19.
[0095] [0095]FIG. 9 illustrates four fence post assemblies 10 A-D in accordance with the invention that are arranged to form an enclosure 100 . An exemplary assembly procedure to form the enclosure 100 is as follows: the four fence post assemblies 10 A-D are located at the corners of the enclosure that is to be formed. The anchors, e.g. anchors 16 or 210 , are then inserted into the ground, and the posts 12 are then attached to the anchors. The fence strand material 34 is then unwound from the roll of fence post assembly 10 A by pulling on the end of the fence strand material and/or by rotating the spool 48 in the appropriate direction. The end of the fence strand material 34 is then connected to the housing on the fence post assembly 10 B. A similar procedure is repeated for fence post assemblies 10 B-D, with the fence strand material of fence post assembly 10 B connecting to fence post assembly 10 C, the fence strand material of fence post assembly 10 C connecting to fence post assembly 10 D, and the fence strand material of fence post assembly 10 D connecting to fence post assembly 10 A. The housings are adjusted up or down along the posts as needed to provide the desired fence strand height. Although an exemplary procedure for forming the enclosure 100 has been described, other assembly procedures could be used as well.
[0096] It should be realized that when the enclosure shown in FIG. 9 is to be electrified, the electrical continuity between the fence strand material of one fence post assembly and the fence strand material of another fence post assembly is maintained in the manner described above.
[0097] Instead of using four fence post assemblies 10 A-D, a larger or smaller number of fence post assemblies could be used to form the enclosure. For instance, if sufficient quantity of fence strand material 34 is available on the roll, the enclosure could be formed by running the material 34 from the housing of one fence post assembly 10 , around man-made objects such as fence posts that do not have fence strand material rolls and housings as described herein, or around natural objects such as trees, and back to the original fence post assembly where it would connect to the housing. This type of enclosure using a fence post assembly with a single housing is particularly useful when the fence strand material that is used is wire, as the length of wire that can be used on a spool is much greater than the length of tape that can be used on the spool.
[0098] In addition, one or more of the fence post assemblies could be used in combination with existing structure(s) to form the enclosure. For instance, one or more fence post assemblies 10 could be used in combination with a side wall of a building or vehicle structure to form the enclosure. Moreover, the end of the fence strand material 34 could be connected to the structure, rather than to an adjacent fence post assembly.
[0099] Each fence post assembly can be provided individually or as part of a kit along with one or more additional fence post assemblies. Moreover, the components of the fence post assembly 10 , including the fence strand assembly 14 , the fence post 12 and the ground anchor 16 , can be provided as separate elements, thereby permitting replacement of one of the components in the event that a component should break, fail or otherwise need replacement.
[0100] To provide added stability to the fence post assembly 10 , a guy wire 200 can extend from a portion of the fence post assembly 10 with the opposite end of the guy wire 200 anchored to the ground. As an example, as shown in FIG. 1, the guy wire 200 can connect to the clamp assembly 82 .
[0101] It is to be understood that while certain embodiments of the present invention have been illustrated and described, the invention is not limited to the specific forms or arrangements of parts described and shown. Rather, the invention is defined by the following claims. | A fence post assembly, as well as a fencing system and related method utilizing the fence post assembly, for forming a temporary enclosure, such as a horse corral for restraining horses. The fence post assembly is provided with an extensible and retractable fence strand, such as polytape or wire, as well as a ground anchor at one end of the post to enable the post to be anchored into the ground. The extendable and retractable fence strand is selectively positionable along the length of the post between the first and second opposite ends thereof. In addition, the fence strand can be electrically conductive to permit the enclosure to be electrified. Provision is made to maintain electrical continuity between fence strands. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a friction clutch, especially for motor vehicles. Such a clutch includes a counterpressure plate, a clutch housing attached to the counterpressure plate, and a pressure plate that runs in rotation-proof fashion in the clutch housing and can be prestressed by the force of a diaphragm or plate spring in the direction of the counterpressure plate. A clutch disk with cushion friction covers is clampable between the pressure plate and the counterpressure plate and transmits a torque from the counterpressure plate/pressure plate to a gear shaft by means of friction clamping.
2. Description of the Prior Art
German Patent 44 36 111 teaches a friction clutch in which a plate spring applies the pressure force for clamping the clutch disk. A disengaging element is also provided and has a spring action directed counter to the force of the plate spring.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a friction clutch with a plate spring or diaphragm spring, which can transmit an increased torque by means of an increased pressure force without overtaxing the material of the diaphragm spring or the plate spring.
Pursuant to this object, and others which will become apparent hereafter, one aspect of the present invention resides in a friction clutch comprising a counterpressure plate, a clutch housing attached to the counterpressure plate, and a pressure plate non-rotatable relative to the clutch housing. First spring means are provided for apply a portion of a pressure force needed for prestressing the pressure plate toward the counterpressure plate to transmit torque. A clutch disk having friction linings is arranged between the pressure plate and the counterpressure plate so as to transmit the torque. Second spring means are arranged to apply an additional portion of the pressure force for transmitting the torque. The second spring means is arranged to act parallel to and in a common direction with the first spring means.
Because support is lent to diaphra gm spring or the plate spring by at least one additional spring, which acts parallel to the former spring and in the same direction, it is possible to increase transmission capacity when the existing diaphragm spring has reached its material limits. It has been found that this solution is substantially simpler than an enlargement of the diaphragm spring, because often the diameter ratios do not allow a larger spring to be used and also because further strengthening of the material may be impossible, due to internal stresses. Of course, the additional spring can be composed of multiple individual springs.
The additional spring can be responsible for an additional portion of pressure force, which can be on same order of magnitude as the portion provided by the diaphragm/plate spring.
The respective force portions can be in the range between 60 to 40% and 80 to 20%, i.e., the diaphragm or plate spring will apply approximately 60 to 80% of the pressure force.
Advantageously, in the engaged state (EB), both springs have a spring characteristic that declines in the disengagement direction. This ensures that the force needed to lift the friction clutch can be kept at a low level. The higher pressure force that can be attained with a clutch of this type thus requires operation with a greater force to only a small extent.
In the end region of the disengagement path, the additional spring can have a prestress at least approaching zero. With this type of design, a low disengaging force can be realized in an especially simple manner.
However, it is also possible for the additional spring to have a zero passage in the end region of the disengagement path. With such adjustment, the disengaging force can be further lowered; however, care must be taken that after the zero passage the additional spring does not tip into its other stable position, but rather is prevented from tipping.
Additionally, a suitable coupling is provided to prevent the additional spring from snapping after the zero passage. For example, this can be done by the arrangement of simple stops.
Advantageously, the additional spring is designed as a diaphragm or plate spring. Using such a spring, it is possible to easily produce a spring characteristic that declines as the disengagement path increases.
To facilitate adjustment of the two springs and to permit the same pressure force to be applied at all times, in another embodiment of the invention, a device is provided that compensates for the wear that occurs on the friction covers. In this way the installation position at least of the diaphragm or plate spring relative to the pressure plate or the clutch housing is kept substantially constant.
According to the invention, the additional spring is preferably supported on one side by the clutch housing and on the other side by the diaphragm spring. This permits a simple and space-saving arrangement of the additional spring.
In another embodiment, the diaphragm spring is supported on the clutch housing via holding elements. The additional spring is supported in the region of the holding elements on one side and, on the other side, at a radial distance from the elements, directly on the diaphragm spring. In this configuration, the holding elements for the diaphragm spring also serve to support the additional spring. As a result, the number of components of the friction clutch can be kept within certain limits. On the other hand, the additional spring is supported directly on the diaphragm spring at a radial distance from the holding elements, without the need for complicated transmitting elements.
In still another embodiment of the invention, the diaphragm spring is supported at a mean diameter by spacing bolts on the clutch housing. The diaphragm spring acts upon the pressure plate with a larger diameter and with the interconnection of elements of a device to compensate for the cover wear that occurs. In the region acting upon the diaphragm spring, the additional spring is axially connected to the diaphragm spring in a positive-locking fashion. This design ensures that the diaphragm spring always maintains its relative position, even when there is wear on the friction covers of the friction disk, and thus that the pressure force produced by the diaphragm spring can be kept constant over the useful life of the friction clutch. Furthermore, the additional spring, because it is supported on the holding elements and on the diaphragm spring, also maintains its relative position, and the additional pressure force produced by the additional spring remains constant as well. A positive-locking connection between the diaphragm spring and the additional spring makes it possible to allow the spring characteristic of the additional spring to pass through the zero point, so that a very favorable force curve for the operating system is obtained as the result of the sharply declining spring characteristic of the additional spring.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings show:
FIG. 1 shows the upper half of a longitudinal section through a friction clutch, pursuant to the present invention;
FIGS. 2 & 3 are spring force curves, with differently adjusted additional springs; and
FIG. 4 is a view similar to FIG. 1, of a further embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, the friction clutch 1 consists of a pressure plate, which is attached to a counterpressure plate 2 in the form of a flywheel of an internal combustion engine. The clutch housing 3 is attached to the counterpressure plate 2. The clutch housing 3 contains a pressure plate 4, which is arranged in rotation-proof but axially movable fashion relative to the clutch housing 3. A clutch disk 6 with friction facings 7 is clamped between the pressure plate 4 and the counterpressure plate 2 in order to transmit a torque to a gear shaft (not shown). The friction facings 7 are preferably equipped with cover springs 8, which apply an axial spring force. All parts of the friction clutch 1 are arranged concentric to and rotatable around the rotational axis 21.
To produce a pressure force on the pressure plate 4 in keeping with arrow A, a diaphragm spring 5 is mounted pivotally on the clutch housing 3 and acts upon the pressure plate 4. Between the diaphragm spring 5 and the pressure plate 4, a device 12 is provided to compensate for wear that occurs on the friction facings 7. Among other components, this device 12 has two adjustment rings 16, which are acted upon in the circumferential direction by a spring 17 and which, in keeping with the wear on the friction covers 7, upon reciprocal relative turning, increase the distance between the spring 5 and the pressure plate 4 by the extent of the wear. The device 12 also has at least one clearance-providing member 15, which can be moved axially in the pressure plate 4 counter to a clamping force and which, when wear occurs, is moved relative to the pressure plate 4 away from the counterpressure plate 2 in keeping with the wear and constitutes an adjustment limit for the adjustment rings 16.
In the illustrated embodiment, the diaphragm spring 5 is mounted pivotally at a mean diameter by means of multiple spacing bolts 13 distributed around the circumference on the clutch housing 3. In the region of its outer diameter, the diaphragm spring 5 acts on the pressure plate 4 via the adjustment rings 16. In the radially inward direction, the diaphragm spring 5 is equipped with multiple flexible tongues 14. which can be activated by a disengagement system (not shown). Two wire rings 18 are provided between the heads 19 of the spacing bolts 13 and the clutch housing 3. The rings 18 permit the tipping movement of the diaphragm spring 5 without greater losses.
An additional spring 9, 10 is provided, which is supported on one side on the clutch housing 3 and on the other side on the diaphragm spring 5. In the engaged state of the diaphragm spring 5, the additional spring 9, 10 is arranged so that its prestress force acts on the pressure plate 4 together with the prestress force of the diaphragm spring 5, so as to increase the prestress force in keeping with arrow A. In this arrangement of the spring 9, the spring 9 is supported in the region of its outer diameter on projections 20 of the spacing bolts 13 and is supported in its inner diameter region directly on the spring tongues 14 of the diaphragm spring 5. However, it is also possible to arrange the additional spring in the form of the spring 10, specifically, that is, in the diameter region radially outside of the spacing bolts 13, as shown in FIG. 4. In the region of its outer diameter, the spring 10 is arranged to rest on the diaphragm spring 5. In the region of its inner diameter, the spring 10 rests on the inside of the clutch housing 3. Here, too, the prestress of the spring 10 is directed so as to support the clamping force of the diaphragm spring 5. Given a certain layout of the springs 9, 10, care must be taken--for example, in the disengaged state of the friction clutch 1--that the spring cannot snap into its second rest position. For this purpose, when the spring 9 is used, multiple rivets 11 are distributed on the inner circumference, which are attached to corresponding spring tongues 14.
The function of the friction clutch 1 is explained in greater detail in conjunction with the treatment of FIGS. 2 and 3.
FIG. 2 shows spring force curves along the disengagement path. The installation position of the springs in the engaged state of the friction clutch 1 is indicated by EB. The spring characteristics or the spring force curves are marked as follows: The spring force curve B is that of the diaphragm or plate spring 5. The spring force curve C is that of the additional spring 9, 10. The spring force curve D is the sum of B and C. It should be noted that the diaphragm spring 5 alone, with only its spring force, cannot apply the desired transmitting capacity of the friction clutch. Only in connection with the additional spring 9 is a clamping force that can transmit the desired torque achieved for the pressure plate 4, in keeping with arrow A. As a result, the diaphragm spring 5 can be designed, in respect to its material properties, erring on the side of safety. Starting from the installation position, the spring characteristic of the additional spring 9 falls sharply along the disengagement path. As a result, the sum curve according to D has a sharply declining characteristic. This is advantageous in respect to low disengagement force. In addition, it should be pointed out that when cushioned friction covers are used with a characteristic E of the cover springs, a disengagement force curve F is attained. Because the spring forces of the cover springs 8 act, in keeping with the curve E, counter to the two springs 5 and 9 according to curve D, it is not necessary for the full force according to characteristic D to be applied by the disengagement system in the effective region of the cover spring means. This results in characteristic F, which reflects the disengagement force on the pressure plate 4. It should be noted that the disengagement force at the ends of the spring tongues 14 has the same curve, in principle, but is reduced to a clearly lower level in keeping with the lever ratios, i.e., the length of the flexible tongues relative to the radial extension of the diaphragm springs between their pivot support and their support on the pressure plate.
The spring force curves in FIG. 3 differ from those in FIG. 2 only in that the characteristic C of the additional springs 9, 10 is adjusted so that a zero passage occurs while still in the region of the disengagement path. This zero passage is explained by the fact that the additional spring 9, 10 in the form of a diaphragm or plate spring desires to snap out of its first stable position into its other stable position. As in FIG. 1, however, such snapping is prevented because the spring 9 is connected to the flexible tongues 14 in a positive-locking, for example, by rivets 11. By selecting such a curve, it is possible to clearly reduce the disengagement force needed, in keeping with curve F, compared to the design in FIG. 2. Nonetheless, it is ensured that a sufficiently great pressure force can be achieved at the installation point with the help of the additional spring 9, 10, in keeping with Arrow A.
The invention is not limited by the embodiments described above which are presented as examples only but can be modified in various ways within the scope of protection defined by the appended patent claims. | A friction clutch, wherein the pressure force is obtained from the interaction of two different types of spring. A plate spring, which is unable by itself to apply the pressure force for transmitting the torque, is used, and at least one additional spring, which produces a force effect in the same direction and the force of which is added to the force of the diaphragm spring, is also used. | 5 |
BRIEF DESCRIPTION OF THE DRAWINGS
[0001] The accompanying drawings illustrate implementations of the concepts conveyed in the present application. Features of the illustrated implementations can be more readily understood by reference to the following description taken in conjunction with the accompanying drawings. Like reference numbers in the various drawings are used wherever feasible to indicate like elements. Further, the left-most numeral of each reference number conveys the figure and associated discussion where the reference number is first introduced (where feasible).
[0002] FIGS. 1-2 and 7 are perspective views of an example of a hand-operable vacuum device in accordance with some of the present concepts.
[0003] FIGS. 3-6 and 8 - 12 are sectional views of a portion of a hand-operable vacuum device in accordance with some of the present concepts.
[0004] FIGS. 13-15 are sectional views of a portion of hand-operable vacuum devices in accordance with some of the present concepts.
[0005] FIGS. 16-19 are perspective views of examples of hand- operable vacuum devices in accordance with some of the present concepts.
[0006] FIGS. 20-21 are elevational views of examples of a hand-operable vacuum device in accordance with some of the present concepts.
DETAILED DESCRIPTION
Overview
[0007] The present description relates to hand-operable vacuum devices. In some cases, hand-operable vacuum devices can be manipulated by a user to draw material into the device and/or expel material from the device. The hand-operable vacuum device can be constructed such that a user can squeeze and deform the device and then the device is resiliently biased to return to an original configuration. The construction of the hand-operable vacuum device can include generally longitudinally arranged resilient outwardly-biasing structures that bias the device back to its original configuration more effectively than existing technologies. This effective bias can create relatively strong vacuum forces for drawing material into the hand-operable vacuum device.
EXAMPLES
[0008] FIGS. 1-11 collectively show an example of a hand-operable vacuum device 100 . FIGS. 1 , 3 , and 5 show the hand-operable vacuum device 100 in a first configuration. FIGS. 2 , 4 , and 6 show the hand-operable vacuum device 100 manipulated into a second configuration by a human user. FIGS. 7-11 collectively show how the construction of the hand-operable vacuum device 100 promotes returning to the first configuration of FIGS. 1 , 3 , and 5 when the user stops manipulating the device. Briefly, the hand-operable vacuum device 100 can be resiliently biased to assume and/or return to the first configuration after user manipulation.
[0009] FIGS. 1 and 2 show perspective views of the hand-operable vacuum device. FIGS. 3-4 show sectional views of the hand-operable vacuum device taken along section AA indicated in FIG. 1 . Section AA is transverse to the x-reference axis and parallel to the yz-reference plane. FIGS. 5-6 show a component of the hand-operable vacuum device taken parallel to the xz-reference plane as indicated along section BB.
[0010] In some cases, the hand-operable vacuum device 100 can be thought of as having a deformable portion 102 and an interface portion 104 that can include a nozzle 105 . The deformable portion 102 can extend along a long axis that runs parallel to the x-reference axis. The deformable portion can be generally elongated, spherical, or other shape. The deformable portion can include one or more resilient outwardly-biasing structures 106 . In some implementations the resilient outwardly-biasing structures can be longitudinally oriented (i.e., parallel to the long axis). In this case, the hand-operable vacuum device includes a pair of resilient outwardly-biasing structures 106 ( 1 ) and 106 ( 2 ).
[0011] The deformable portion 102 can be manipulated or squeezed by a user as indicated by arrows 402 and 404 to deform or squish the deformable portion. The squishing can bend the resilient outwardly-biasing structures as can be seen by comparing FIGS. 5 and 6 which show resilient outwardly-biasing structure 106 ( 1 ). FIG. 5 shows the resilient outwardly-biasing structure in a resting or biased configuration. FIG. 6 shows a bowed configuration of the resilient outwardly-biasing structure produced by user manipulation.
[0012] FIGS. 7-11 show how the resilient outwardly-biasing structures 106 ( 1 ) and 106 ( 2 ) can return the deformable portion 102 to the resting configuration when the user stops applying pressure. Specifically, upward arrows 702 ( 1 ) and 702 ( 2 ) indicate the outward bias exerted by resilient outwardly-biasing structures 106 ( 1 ) and 106 ( 2 ), respectively. The outward bias returns the resilient outwardly-biasing structures from the bowed configuration of FIG. 8 to the more linear configuration of FIG. 9 . (In another implementation, the resilient outwardly-biasing structures could be outwardly bowed at rest such that user manipulation causes them to be less bowed.) The outward bias exerted by resilient outwardly-biasing structures 106 ( 1 ) and 106 ( 2 ) facilitates returning the deformable portion from the manipulated configuration of FIG. 10 to the resting configuration of FIG. 11 . Returning the deformable portion to the resting configuration can increase the volume thereof and can thereby create a very strong vacuum that can be utilized to draw material into the interface portion 104 via nozzle 105 .
[0013] FIG. 12 illustrates an example of how the resilient outwardly-biasing structures 106 ( 1 ) and 106 ( 2 ) can extend from a perimeter 1202 of the deformable portion 102 . In various implementations the resilient outwardly-biasing structures can extend from the perimeter at an angle a that is oblique or a right angle relative to the perimeter proximate to the outwardly-biasing structure. In some implementations, the angle α can be in a range from about 90 degrees to about 135 degrees. Other implementations may be outside this range.
[0014] The example implementations above include a pair of outwardly-biasing structures 106 ( 1 ) and 106 ( 2 ). FIGS. 13-14 illustrate some alternative implementations of hand-operable vacuum devices.
[0015] FIG. 13 shows first and second pairs of outwardly-biasing structures 1302 ( 1 ), 1302 ( 2 ) and 1304 ( 1 ), 1304 ( 2 ) on deformable portion 1306 . In this example the first and second pairs are generally opposing one another, but such need not be the case. However, the present example can be useful in facilitating the user's grip.
[0016] FIG. 14 shows an alternative implementation that includes three outwardly-biasing structures 1402 ( 1 ), 1402 ( 2 ), and 1402 ( 3 ) on deformable portion 1404 . In this case the outwardly-biasing structures extend outwardly from perimeter 1406 rather than inwardly as illustrated in the example implementations of FIGS. 1-13 .
[0017] FIG. 15 offers another implementation with two outwardly-biasing structures 1502 ( 1 ) and 1502 ( 2 ) on deformable portion 1504 . In this case, the outwardly-biasing structures are generally elliptical rather than linear when viewed in cross-section. Other shapes and/or configurations can alternatively or additionally be utilized.
[0018] FIG. 16 shows an example hand-operated vacuum device 1600 that can be employed as a specimen collector, among other uses.
[0019] FIG. 17 shows an example hand-operated vacuum device 1700 that can be employed as a throat aspirator, among other uses.
[0020] FIG. 18 shows an example hand-operated vacuum device 1800 that can be employed as a dental squirt pick, among others.
[0021] FIG. 19 shows an example hand-operated vacuum device 1900 that can be employed as a nose aspirator, among others.
[0022] FIGS. 20-21 collectively show another example of a hand-operated vacuum device 2000 that can be employed to various uses. In this case, the hand-operated vacuum device 2000 includes deformable portion 2002 and interface portion 2004 . The deformable portion 2002 includes resilient outwardly-biasing structures 2006 ( 1 ) and 2006 ( 2 ). The interface portion 2004 includes a removable cap 2008 that covers a nozzle 2010 .
[0023] FIG. 20 shows the removable cap 2008 in place on the interface portion 2004 . FIG. 21 shows the hand-operated vacuum device 2000 with the cap removed to expose nozzle 2010 . The removable cap 2008 can be formed during manufacture of the hand-operated vacuum device 2000 and/or added to the hand-operated vacuum device. For instance, the removable cap can be formed as part of the hand-operated vacuum device to help maintain internal conditions of the hand-operated vacuum device. For instance, the removable cap could be utilized to maintain sterile conditions in the hand-operated vacuum device until the cap is removed at the time of use. The user can remove the removable cap, such as by twisting. The user can then squeeze the deformable portion and place the nozzle 2010 near a sample to be collected. The user can reduce and/or release the pressure on the deformable portion to create a vacuum that draws the sample into the hand-operated vacuum device. In some implementations, the removable cap 2008 can be re-installed to maintain the sample and avoid cross-contamination.
[0024] In other configurations, the hand-operated vacuum device 2000 can be manufactured and filled with a liquid, such as a wound cleansing antiseptic solution or a mouthwash. The removable cap can then be added to maintain the integrity of the hand-operated vacuum device until use. A user can remove the removable cap and propel the liquid from the nozzle by squeezing the deformable portion 2002 .
[0025] Hand-operated vacuum devices can be manufactured utilizing various techniques and/or materials. For instance, in some implementations the hand-operated vacuum devices can be formed via a molding process, such as injection molding or blow molding. Various materials can be utilized including but not limited to various polymers. In some cases the hand-operated vacuum devices can be manufactured as a single piece, yet the interface portion can be thicker than the deformable portion so that the interface portion is relatively rigid while the deformable portion is readily deformed by a user. For instance, such a configuration can be achieved by blow molding where the polymer is introduced at the interface end of the hand-operated vacuum device. In one such example, the deformable portion can have an average thickness of 0.1-0.3 millimeters while the interface portion has an average thickness of 0.3-0.6 millimeters.
[0026] In summary, hand-operable vacuum devices are described that can allow great vacuum (and/or expulsion) forces to be created by a user. The hand-operable vacuum devices can be inexpensively manufactured and can be disposable and/or reusable. In some instances, the hand-operable vacuum devices can be manufactured and/or packaged so that the devices are sterile until the packaging is opened. Further, the hand-operable vacuum devices lend themselves to construction from materials that can be transparent so that the user can see the contents (if any).
Conclusion
[0027] Although specific examples of hand-operable vacuum devices are described in language specific to structural features, it is to be understood that the subject matter defined in the appended claims is not intended to be limited to the specific features described. Rather, the specific features are disclosed as exemplary forms of implementing the claimed statutory classes of subject matter. | This patent relates to devices that can be manipulated by a user to expel or draw in a material. In one example, a hand-operable vacuum device can include an interface portion configured to contact a material. The hand-operable vacuum device can also include a deformable portion that extends along an axis that passes through the interface portion and wherein the deformable portion includes at least one longitudinally-oriented resilient structure that extends generally parallel to the axis. | 0 |
BACKGROUND OF INVENTION
1. Field of Invention
This invention relates to digital communications networks and related apparatus. More particularly, the invention relates to receivers using thresholds on queues of received information to generate transmit rates and communicating those rates to senders for prevention of underflow and overflow of said queues.
2. Description of Prior Art
In Fibre Channel networks, one flow control mechanism for congestion control is the monitoring in a receiver of queue lengths of data awaiting processing by the receiver. The receiver informs the sender of a “credit” value that can be translated into a rate at which the sender sends data. A tutorial on credit based flow control systems for Fibre Channel is described in notes by InterOperability Lab of the University of New Hampshire at
http://www.iol.unh.edu/training/fc/fc_tutuorial.html#Flow_Control
updated May 4, 1998. Typically, the credit or, as it is called herein, transmit rate is determined heuristically and performance may not be guaranteed. What is needed in the art is a receiver which periodically refreshes the transmit rates it generates and thereby provides transmit rates which can be guaranteed to prevent overflow or underflow of the receiver.
U.S. Pat. No. 5,515,359, of Zheng issued May 7, 1996 describes a system for controlling traffic in a digital communication network to avoid data loss due to congestion utilizes an integrated credit-based and rate-based traffic control approach, and adjusts the rate at which data is transmitted from a source in accordance with feedback in the form of rate and credit adjustment information from a network reflecting the ability of the network to transmit data and the destination to receive data. In one embodiment, a source end system sends out resource management cells composed of various fields containing rate and credit information. The intermediate systems of the network and the destination end system update the corresponding fields according to their congestion status and send the resource management cells back to the source end system so that the source end system controls the data transmission accordingly. In a preferred embodiment, a source end system calculates an allowed sending rate from each of the fields in a resource management cell, and the minimum one among them is used to control data transmission.
U.S. Pat. No. 5,777,987 of Adams et al. issued Jul. 7, 1998, describes a method and apparatus for using a primary FIFO and one or more secondary FIFOs in parallel to simplify flow control and routing in packet communication operations wherein at least one FIFO (buffer) is associated with each of a plurality of receiving nodes or components within a receiving node. The received packets are applied simultaneously to a primary FIFO and to all associated secondary FIFOs in the receiver of a packet communications link. After receipt of a packet, the packet is removed from any secondary FIFOs which correspond to receiver nodes or components to which the packet was not routed. For all receiving nodes or components to which the packet was routed, if the packet was stored in each associated secondary FIFO without overflow, then the packet is also purged from the primary FIFO. If any secondary FIFO overflowed by storage of the received packet, then the packet is purged from the overflowed FIFO and the packet remains stored in the primary FIFO for further processing. Flow control signals are generated and applied to the transmitting source as required in accordance with the status of the primary FIFO. The secondary FIFOs are not directly relevant to flow control logic. The receiving component corresponding to each secondary FIFO locates the next packet for processing by inspecting the associated secondary FIFO as well as the primary FIFO if the secondary FIFO overflowed. These methods and apparatus simplify flow control and routing control in packetized communication receivers
U.S. Pat. No. 5,748,613 of Kilk, et al. issued May 5, 1998 describes a method of pacing a stream of data transmitted from a data source to a buffered data destination with a determined number of available storage units, the data destinations being configured to consume data and thereby to free storage units for receipt of additional data. The pacing of data communication includes: (1) identifying a beginning transmit rate; (2) incrementing the beginning transmit rate with each storage unit freed to identify an present transmit rate; (3) transmitting units of data in accordance with determined limits, the number of data units sent providing a transmission count; (4) selectively updating the determined number of available storage units by determining the difference between the beginning transmit rate and the present transmit rate, and determining the sum of the result and the previously determined number of available storage units to provide an updated determined number of available storage units; and (5) selectively updating the determined number of available storage units by determining the difference between the transmission count and the previously determined number of available storage units to provide an updated determined number of available storage units.
U.S. Pat. No. 6,097,705 of Ben-Michael, et al. issued Aug. 1, 2000, describes a repeater device for forwarding a data packet from a first Ethernet collision domain to a second Ethernet collision domain, the device having a plurality of ports, each port for connection to an independent Ethernet collision domain. Furthermore, each port has an associated receive buffer and an associated transmit buffer, and there is a means for forwarding a data packet from the receive buffer of a receiving port to the transmit buffer of a transmitting port. A data packet received at the receiving port is then first stored in that port's the receive buffer, is forwarded to the transmit buffer of the transmitting port, and is then transmitted from the transmit buffer by the transmitting port.
None of the above prior art discloses a credit based receiver which periodically adjusts transmit rates and storage thresholds and guarantees the prevention of overflow and underflow in the receiver
INVENTION SUMMARY
A credit based digital communication network is adapted to prevent overflow or underflow of a data storage queue in a receiver by generating a transmit rate value as a feedback to the sender. The rate adjustments are performed periodically with a fixed time period denoted by Dt. It is assumed that the sender always has a superabundance of data to send. The data transmit rates are fractions of the maximum possible data transmit speed, designated Max. The value of Dt is assumed to be greater than the transmit delay. Since the sender always has a superabundance of data to send, a flow control mechanism can specify any transmit rate up to and including Max at any time. In a preferred embodiment, the transmit rates are explicitly 0, Max/2, and Max. The receiver queue is itself drained at a rate R that at any time satisfies 0<=R<=Max. The level of occupancy (in bits or other data units) of the receiver storage queue is denoted by Q. The maximum capacity of the receiving queue is designated Qmax, so at any time, 0<=Q<=Qmax. Two thresholds T 1 and T 2 (with 0<T 1 <T 2 <Qmax) of levels of the receiver queue value Q are determined based upon queuing analysis. A transmit rate is then selected from the possible values by comparison of the receiver queue Q to the thresholds. The transmit rate value so calculated achieves the desired goals of avoiding overflow and, once the lower threshold has been a positive value at least once, avoiding underflow. As a result the receiver queue is never completely full and never completely empty, regardless of the rate R at which the receiver queue is drained, with 0<=R<=Max.
DESCRIPTION OF THE DRAWINGS
The invention will be further understood from the following description of a preferred embodiment taken in conjunction with an appended drawing, in which:
FIG. 1 is representation of a credit-based digital communication network adapted to prevent overflow or underflow of a data storage queue in a receiver and incorporating the principles of the present invention.
FIG. 2 is a flow diagram of a process implemented in the network of FIG. 1 for preventing overflow and underflow of a credit-based receiver.
FIGS. 3A–C are graphs of the network of FIG. 1 demonstrating the credit based receiver storage (Qmax) is not subject to overflow or underflow for different transmit rates and thresholds.
DESCRIPTION OF PREFERRED EMBODIMENT
In FIG. 1 , one embodiment of a credit based communication system 100 is disclosed.
The system 100 includes a sending station 102 including a transmitter 104 responsive to data packets 106 and a speed or transmit rate controller 108 . The speed controller sets the transmit rate (Tr) of the transmitter 104 at transmit rates Tr=0, Tr=Max/2 and Tr=Max where Max denotes the maximum transmit rate of the transmitter. The speed controller is responsive to an updated transmit rate 110 received from a destination 112 via a signal receiving unit 114 .
The destination 112 receives the data packets 106 in a packet processor 122 . The data packets 106 are provided to a buffer queue 124 having a maximum capacity of Qmax. A threshold circuit compares the occupancy of the queue 124 with thresholds T 1 and T 2 specified by the present invention. The threshold circuit 130 periodically provides an updated transmit rate to a transmit rate register 119 via connection 131 . The threshold circuit 130 calculates and sets a lower threshold T 1 and an upper threshold T 2 in the buffer 124 based upon Max value 134 , Qmax value 132 . The details of calculating the thresholds T 1 and T 2 are based on queuing analysis which will be provided hereinafter. The thresholds T 1 and T 2 are the thresholds in the buffer 124 used to prevent underfiow and overflow, respectively. While two thresholds are described, any number of thresholds may be calculated for the buffer as will be described hereinafter. The transmit rate stored in the register 119 is then periodically communicated from a transmit rate unit 136 to the sender 102 via a communications link 142 .
The threshold values T 1 and T 2 are calculated by a threshold circuit 134 and then compared by the threshold circuit to the level of data packets awaiting processing and temporarily stored in the buffer 124 . In one embodiment, if the data packet level stored in the buffer is greater than T 2 , then an updated transmit rate of 0 is communicated to the sender. Else, if the level of data packets stored in the buffer is greater than T 1 , then a transmit rate of Max/2 is communicated to the sender. Else, a transmit rate of Max is communicated to the sender. The transmit rate is processed by a transmit rate unit 136 and communicated over a communications link 142 to a signal receiving unit 114 . The flow control transmit rate is updated periodically every Dt time units and communicated to the sending unit whereupon the sender 102 sends some data at a rate equal to a fraction of the maximum rate to the receiver 112 .
Queuing analysis demonstrates underflow and overflow can be prevented in the receiver provided the following conditions are met:
(1) Dt is much larger than the time delay of communicating the computed transmit rate from receiver to sender or time delay in transmission of data from sender to receiver. This is a lower limit on Dt.
(2) The maximum possible change in one time period Dt of signal update in receiver queue level is by definition Dt*Max. This value should fulfill the inequality Dt*Max<Qmax/8. This is an upper limit on Dt.
The transmit rate signals are as follows:
1. if Q>=T 2 , then transmit rate=0
2. else if Q>=T 1 , then transmit rate=Max/2
3. else transmit rate=Max.
That is, if T 2 <=Q<=Qmax, then the sender is signaled to send nothing. If T 1 <=Q<T 2 , then the sender is signaled to send at the rate Max/2. If 0<=Q<T 1 , then the sender is signaled to send at the rate Max.
The present invention also includes specification of the values of T 1 and T 2 . That is, T 1 and T 2 must fulfill conditions (a), (b), and (c), where:
T 1 >Q max/8 Eq(a)
T 2<15 *Q max/16 Eq(b)
T 1 <=T 2 −Q max/16 Eq(c)
Theorem 1. The conditions (a), (b), (c) on T 1 and T 2 imply the queue occupancy Q will never reach Qmax. Also, once queue occupancy Q has exceeded 0, it will always thereafter be positive.
Proof:
The maximum value of queue occupancy will occur after a flow control interval Dt in which the transmit rate was either Max/2 or Max.
Suppose the first case, that is, that maximum value of queue occupancy occurs after a flow control interval in which the transmit rate was Max/2. Therefore the previous value of Q was less than T 2 . Therefore there must be a positive value X so that the previous Q value was T 2 −X. Thus, given a receiver drain rate R of at least 0, condition (2) on Dt and condition (b) on T 2 , the new Q value is at most:
T 2 −X +Max* Dt /2−0 *Dt<T 2 −X+Q max/16<15 *Q max/16 +Q max/16 =Q max Eq(1)
Suppose the alternative case, namely, that maximum value of queue occupancy occurs after a flow control interval in which the transmit rate was Max. Then there must be a positive value X such that the old Q value is T 1 −X. Given a receiver drain rate R of at least 0, condition (2) on Dt, and conditions (b) and (c), the new queue occupancy Q is at most:
T 1 −X +Max* Dt −0 *Dt<T 2 −Q max/16 −X+Q max/8 <Q max. Eq(2)
Thus, in both cases, the deductions of equations 1 and 2 show the maximum queue occupancy possible ever is less than Qmax.
Concerning underflow, after Q occupancy has been positive at least once, a transmit rate of Max could not lead to a decrease in Q, given the restrictions on R. Therefore the minimum Q occupancy will occur after a flow control interval Dt in which the transmit rate is either 0 or Max/2.
Suppose the first case, that is, that minimum value of queue occupancy occurs after a flow control interval in which the transmit rate was 0. Therefore there must be a nonnegative value X so that the old Q value was T 2 +X. Since the drain rate R from the receiver is at most Max, the new Q value is at least T 2 +X−Max*Dt. Given condition (2) on Dt and conditions (a) and (b) the new Q value is at least:
T 2+ X−Q max/8 >=T 1+ Q max/16 −Q max/8 >Q max/8 −Q max/16. Eq(3)
Therefore the new Q value is at least Qmax/16.
If Suppose the alternative case, namely, that minimum value of queue occupancy occurs after a flow control interval in which the transmit rate was Max/2. Therefore there must be a nonnegative value X so that the old Q value was T 1 +X. With a drain rate R limited by Max, the new Q value is at least T 1 +X−Max*Dt. Given condition (2) on Dt and condition (a), the new Q value is therefore greater than Qmax/8−Qmax/8=0. Therefore the new Q value is greater than 0. This deduction and the deduction leading to equation 3 show that the new Q value must be positive.
End of proof of theorem.
Alternative embodiment: More thresholds could be specified with a finer granularity of transmit rates. For example, let N positive thresholds 0<T 1 <T 2 < . . . <TN<Qmax satisfy
Q max*(1/16 +i /16)< Ti<Q max*(1−1/(8 *i )) for i= 1, 2, . . . , N Eq(4)
Let flow rates be specified as functions of Q as follows:
1. if Q>=TN then transmit rate=0
2. else if Q>=TN−1 then transmit rate=Max/N
3. else if Q>=TN−2 then transmit rate=Max/N−1)
4. else if Q>=TN−3 then transmit rate=Max/(N−2)
5. else if Q>=Ti then transmit rate=Max/(i+1)
6. else if Q>=T 2 then transmit rate=Max/3
7. else if Q>=T 1 then transmit rate=Max/2
8. else transmit rate=Max
Theorem 2. Given the above N thresholds and rates, the queue occupancy Q will never reach Qmax. Also, once queue occupancy has exceeded 0, it will always thereafter be positive.
Proof.
Suppose previous Q was at or above TN. Then the rate was 0, so no increase is possible. Suppose previous Q was just below Ti, so rate was Max/i. Then the maximum value Q can attain less than
Ti +Max* Dt/i<Q max*(1−1/(8 *i ))+(Max/ i )*( Q max/(8*Max))= Q max. Eq (5)
Thus, the deduction leading to equation 5 shows overflow is impossible.
Suppose the previous Q was at or above Ti, so rate is Max/(i+1). Then the smallest Q can be is
Ti +Max* Dt/ ( i+ 1)−Max* Dt>Q max*(1/16+ i/ 16)+( Q max/8)*(1/( i+ 1))− Q max/8 =Q max*(−1/16+1/(8*( i+ 1))+ i/ 16)>0. Eq (6)
Suppose previous Q was below T 1 . Then the rate is Max, which is greater than or equal to the drain rate R, so depletion to zero is impossible. Thus, this observation and the deduction leading to equation 6 show underflow is impossible.
End of proof of theorem.
Now turning to FIG. 2 a process 200 will be described in conjunction with FIG. 1 for implementing the prevention of underflow and overflow in a credit-based receiver in the digital communication network 100 of FIG. 1 , as follows:
In step 202 , data packets are transmitted to a destination 112 . The rate of transmission is controlled by a speed controller 108 .
In step 204 , the data packets are received by a packet processor 122 and temporarily stored in buffer 124 while awaiting further processing. The updated transmit rate is determined by comparing buffer queue level Q with maximum capacity Qmax 132 and with thresholds T 1 and T 2 in the threshold circuit 130 , and then the updated transmit rate is stored in register 119 in step 206 .
In step 208 the updated transmit rate is communicated from the receiver 112 by action of the transmit rate unit 136 to the signal receiving unit 114 in the sender 102 .
In step 210 the updated transmit rate 110 is stored in a register. In step 212 a speed controller 108 transmits data at the updated transmit rate from the transmitter 104 .
Thresholds T 1 and T 2 are computed at initialization time from Qmax in a threshold circuit 130 by means of three equations described herein, namely,
T 1 >Q max/8 Eq(a)
T 2<15 *Q max/16 Eq(b)
T 1 <=T 2 −Q max/16 Eq(c).
FIGS. 3A–C show test results of a credit-based receiver implementing the principles of the present invention and demonstrating overflow and underflow are prevented in the receiver.
FIG. 3A shows time units along the horizontal axis and the queue processing or service rate R of a queue on the vertical axis. In the example, the value of Qmax is 1 unit of data (for example, one megabit). The maximum service rate Max of the queue is 0.125 data units per time step Dt. The variable service rate R 302 is shown. For 500 time steps of duration Dt, the rate R is random and between 0 and 0.04 in units of data per time. For the next 500 time steps the rate R is constantly equal to the maximum rate Max=0.125 data units per time step.
FIG. 3B shows the transmit rates 304 calculated by the algorithm for the above conditions. Note that the transmit rate is 0 or Max/2 for the first 500 time steps. Then, as the service rate changes, the transmit rate is Max/2 or Max for the next 500 time steps.
FIG. 3C shows the level of queue occupancy 106 during the above experiment. Not that the value of Q does not enter into an overflow state. Likewise the value of Q does not enter into an underflow condition.
Thus, FIGS. 3A–3C demonstrate that the setting of transmit rate in accordance with the capacity of the buffer queue 124 relative to the thresholds T 1 and T 2 prevents the buffer from underflowing or overflowing for the transmit fractions.
While the invention has been described in conjunction with a preferred embodiment various changes can be made without departing from the spirit and scope of the invention as defined in the appended claims, in which: | A receiver may be adapted to prevent overflow or underflow of its data storage by generating a transmit rate value as a feedback to the sender. Speed adjustments are performed periodically with a fixed time period denoted by Dt. Transmission rates are explicitly 0, Max/2, and Max. The receiver queue is itself drained at a rate R that at any time satisfies 0<=R<=Max. The level of occupancy of the receiver storage queue is denoted by Q. The maximum capacity of the receiving queue is designated Qmax, so at any time, 0<=Q<=Qmax. Two thresholds T 1 and T 2 (with 0<T 1 <T 2 <Qmax) of levels of the receiver queue value Q are determined. A transmit rate is then determined by the level of the receiver queue Q compared to the thresholds. The transmit rate feedback value achieves the desired goal of avoiding overflow and, once the value of Q has been positive at least once, avoiding underflow. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to an improvement in providing a more customized window covering valence fit while eliminating the need for an exacting miter box with exacting dimensioning and custom installation.
BACKGROUND OF THE INVENTION
[0002] Valence structures have traditionally been utilized to complete a window treatment. Custom installed valences require ordering and custom cutting of what is typically a linear molding. Of course, non-extruded style valences can be used which have specific decorative patterns or lengths of constant cross sectional area punctuated with an intermittent pattern, such as a flower or the like. Custom installations with high cost and high labor rates have the relative luxury of custom cutting and fitting and significant scrap. For custom installations, a high scrap rate is tolerable both economically and in terms of availability of a large supply of materials. Conversely, for home installation a high scrap rate creates an intolerable rise in cost, and an impossible expectation that the home installer will have the tools necessary to cut and fit the valence members.
[0003] One technique for valence joinder at the corners has been to form a 45° miter cut on each end of the meeting valence so that the outside or inside corners form a 90° angle. A cut also means that a thin, black crack will be left between the two members. The thin, black crack can occur through the edge effect of the saw on cutting, as well as any deviation from a completely planar cut. The alternatives to eliminate the crack are associated with further time and effort on the part of the custom installer. Putty, followed by spot painting can be performed. Complete re-painting of the valence can be accomplished, as well as installation of un-painted valence followed by initial painting.
[0004] Another problem with valences is the manner of joining of the segments. Glue can be unsatisfactory and can leave an unsightly appearance. Some valence hardware can include right angle supports which are attached with threaded members. Others utilize slots which accommodate right angle hardware. With these latter two cases, any deviation by the installer can leave a mis-matched angle or mis-matched gap which will require filler, painting, or other space and color correction.
[0005] Another problem with the 45° miter cut is the necessity to re-perform this cut for each 90° angle. Where the cut is too short, even by a millimeter, the length of valence must be discarded. Attempted use of any length which is too short or too long will result in corner angles deviating from 90°. Where the ends are 45° miter cut, even larger gaps will result.
[0006] Most people who self-install lack a high precision miter saw, but have the ability to cut at an angle orthogonal to the main extent of the valence. Most cuts are not high precision, and self-installers very likely lack the ability to finely sand the ends to insure a match fit. Even where precision cut and sanding are present, the use of a 45° sharp end is more susceptible to dents and nicks during cutting. The production of a sharp edge, especially with the fanciful shape of most valences has the potential to produce even more scrap and wasted time.
[0007] What is needed is a simple valence system for self-installers which can utilize cuts orthogonal to lengths of molding, regardless of the shape of the molding. The system should be forgiving of small errors in measurement and sawing, and should provide a finish which is compatible with the molding used and which eliminates open gaps. The system should also be forgiving of angularity and should facilitate an angle which deviates slightly from 90° where needed.
SUMMARY OF THE INVENTION
[0008] A specialized angle valence junction fitting forms a joint for connecting two lengths of valence molding. The fitting has a pair of openings directed 90° apart and has an internal shape matching an external shape of the molding utilized. The specialized angle joint may have a color to match or accent two lengths of molding and has an external dimension which is only about 1.5 millimeters greater than the dimension of the molding which it surrounds. Valence junction fitting can have an end edge which is straight, or beveled to imply a more stabilized or substantial relationship to the molding. The fitting can have channels which are uneven to assist in the order of attachment, with the shorter fitting providing the necessity for lesser deflection of a first member to which it is attached in order to interfit with another section of molding, when a shape is being completed. Further, the longer channel can be used to better support a length of molding which is cut slightly short of the target.
[0009] The fitting can be affixed by the addition of a threaded member, staple, glue, or an interference fit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention, its configuration, construction, and operation will be best further described in the following detailed description, taken in conjunction with the accompanying drawings in which:
[0011] FIG. 1 is a plan view of a short section of valence showing the fanciful pattern that valence molding is expected to assume;
[0012] FIG. 2 is a view looking into one of two flange openings of connector of the valence junction fitting of the invention, with the other connector shown in profile;
[0013] FIG. 3 is a view of the valence junction fitting of claim 2 turned ninety degrees and looking into the other of two flange openings of connector of the valence junction fitting of the invention;
[0014] FIG. 4 is a top view of the valence junction fitting seen in FIGS. 2 and 3 and illustrating the dimensioning thereof and giving a direct comparison of the flange lengths;
[0015] FIG. 5 is an outside plan view of the valence junction fitting seen in FIGS. 2-4 and illustrating the external shape of the valence junction fitting;
[0016] FIG. 6 is a view similar to that seen in FIG. 2 and illustrating a valence junction fitting having vertical symmetry; and
[0017] FIG. 7 is a side view of a constant cross sectional shape material which interfits with the valence junction fitting seen in FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] The description and operation of the valence junction fitting of the invention will be best begun with reference to FIG. 1 which illustrates a typical, fairly complex surface detail of an extruded valence 21 which can be used for other purposes. The valence 21 is typically a molding made of wood and having an extruded-type design. By “extruded type” it is meant that it may have a constant cross sectional area and profile. The short section is seen in perspective and is seen to have a flat rear side 23 , and a front complex surface 25 . The front complex surface 25 includes an undulating up and down pattern across one side of a width of the valence 21 .
[0019] The valence 21 is typically made of wood and may be formed by moving a plank through a shaped planer which selectively removes the wood to yield the shape seen in FIG. 1 . Valence 21 could also be made of plastic or other material. It is also understood that the constant cross sectional area shown need not extend over the entire length of the valence 21 . For example, a valance 21 could be formed in an intricate pattern having a non-uniform cross sectional area, with only so much of the ends formed in constant cross section as are expected to provide material for cutting. As an example, a six inch diameter rose pattern could be placed at the center of a valence. The rose could be used for the center of the valence with the remaining material to be used for the sides, and the remainder discarded. In a similar fashion, the non-uniform portion of the pattern could take up progressively more of the valence 21 length with remaining portions of the valence 21 length left to provide enough material for the sides. In other words, there needs to be only enough constant cross sectional area as will interfit with a valence junction fitting to be shown in FIG. 2 .
[0020] Referring to FIG. 2 , a plan view of a valence junction fitting 31 is seen. The valence junction fitting 31 has a first flange 33 and a second flange 35 . The flanges 33 and 35 are angled ninety degrees apart, but valence junction fitting 31 can have flanges 33 and 35 which have a different angular relationship, including more than ninety degrees for polygonal valence shapes, and less than ninety degrees for triangular and more complex valence shapes.
[0021] The flanges 33 and 35 seen in FIG. 2 are annular, each having a shaped bore, the shaped bore 37 of flange 33 being visible. As can be sheen, the overall shape of the flange 33 bore 37 matches the shape of the constant cross section valence 21 . Further, the inside dimension of the flange 33 bore 37 closely matches the external dimension and shape of the constant cross section valence 21 .
[0022] The thickness of the wall of the flange 33 can vary based upon the material utilized. One possibility to make the valence junction fitting 31 out of plastic and this may require a thickness of from one to one and a half millimeters. The flange 33 can be made of thin aluminum or other metal. The material selected may be specially prepared to support paint, appliques or other color and pattern bearing structures.
[0023] The inside of the bore 37 may be so open as to allow the material of the valence 21 to continue into the flange 33 and extend to the outer wall of the flange 35 , or an interference structure could be added within the bore 37 to cause the valence 21 to stop short of any potential interference with the section of valence 21 extending through the flange 35 which might otherwise extend through to contact with the inner wall of the flange 33 .
[0024] Where the path of occupation of the lengths of valence material can interfere, the individual cutting the valence 21 may take to account which valence sections are to be made to overlap. Further, in terms of layout, the valence material 21 may be cut so that one flat cut end of one length of material will touch the side of another. This will aid in layout and cutting, and will preclude the individual installing the valence system from having to add or account for an inner dimension within the valence junction fitting 31 in which the valence 21 may not extend.
[0025] As can be seen in FIG. 2 , the amount of overlap within the valence junction fitting 31 will be no deeper within the flange 35 than the nearest point of the back wall of flange 33 and which is seen by an innermost point of a curved portion 39 , or possibly a curvature of a bottom inside corner 41 . Where such overlap is possible, the installer can either account for such overlap, or cut the lengths of valence 21 to leave the corner of the valence junction fitting 31 un-occupied.
[0026] In the alternative, small stop structures can be molded or added to the inside of the valence junction fitting 31 to force the inside corner of the valence junction fitting 31 to remain unoccupied. It may be useful to have an indication of the un-occupied space indicated to the user or perhaps faintly marked on the outside of the valence junction fitting 31 .
[0027] As by example, a typical valence 21 having a width of about three to four centimeters and a thickness at its shortest dimension of about 0.7 cm will give a difference of about 0.5 cm. In other words when one valence 21 is backed out of the common space to an extent that such movement just clears the common space, the other valence 21 can move forward by the same amount, which is about 0.5 cm for a valence 21 and the valence junction fitting 31 . FIG. 2 also illustrates other details of valence junction fitting 31 , including flange 33 outside wall 45 , flange 33 inside wall 47 . Also seen is flange 35 inside wall 49 .
[0028] Referring to FIG. 3 , a view of the valence junction fitting 31 is seen similar to that seen in FIG. 2 , but turned ninety degrees. The view of FIG. 2 was one looking into the bore 37 of first flange 33 . The view of FIG. 3 looks directly into a shaped bore 51 of flange 35 with flange 33 seen extending to the right. An outside wall 53 is seen, similar to outside wall 45 . The outside walls 45 and 53 extend to an adjacent corner line 57 . The corner line 55 will have a shape proportional to the outside shapes of the valence 21 . The shapes of the outside walls 45 and 53 surrounding the corner line 55 are a mirror images of each other.
[0029] Comparing FIG. 2 and FIG. 3 , it can be seen that Flange 33 may be a little longer than flange 35 . This can be the case regardless of whether the space within the valence junction fitting 31 will provide an overlap space within which the ends of the valences 21 can compete. Such differences in the lengths of flanges can accomplish several objectives. First, different lengths of flanges 33 and 35 can help the user in fitting the longer length flange first, and then provide a lesser length of flange causing reduced bending of the last length of extruded valence to complete a closed shape before fitting the shorter length flange. Of course, both flanges 33 and 35 can be made of the same length, the difference in length being shown to emphasize all possibilities.
[0030] For example, where a valence box structure is made by extending two lengths of valence 21 from the wall and joining the front length of valence, the longer flanges 33 might be directed in the direction toward the wall and perpendicular to the plane of the wall, so that a smaller angular deflection of the lengths of valence 21 extending from the wall could be used to make the final inserted construction. Regardless of the lengths of the flanges 33 and 35 , the arrangement of which of two competing ends of two valences 21 which occupy the corner of the valence junction fitting 31 is made by the installer by simply backing one of the valences 21 from the corner most position and allowing the other valence 21 to occupy the corner. The slightly greater width of flange 33 with respect to flange 35 is normally not visually discernible in a rectangular valence application.
[0031] A second reason for having different flange lengths may relate to a competing occupancy within the valence junction fitting 31 where the inside of the valence junction fitting 31 allows extruded valence 21 inserted within the valence junction fitting 31 to compete for the space at the apex of the two flange bores 37 and 51 . Where it is desired to have equal support of the valence 21 by the valence junction fitting 31 , a longer flange should be provided to secure the section of valence 21 not occupying the corner-most occupancy within the valence junction fitting 31 . This side is the “backed off” section of valence, and by providing it a longer flange 33 it will derive about the same support as the shorter flange 35 . Again, the slightly greater length of flange 33 with respect to flange 35 is normally not visually discernible in a rectangular valence application.
[0032] Again, both flanges 33 and 35 can be of the same length, and where the length of the flanges 33 and 35 are more than sufficient to support the valence material 21 , the use of even length flanges will give a more balanced appearance. Further, the use of flanges 33 and 35 which are of the same length, and which are more than sufficient for support of either the backed off valence 21 or the valence 21 occupying the corner position of the valence junction fitting 31 , enables a user to select which of the valences 21 which will occupy the corner-most position in the valence junction fitting 31 in order to make a final adjustment for any length of valence 21 which was cut inadvertently too long or too short. For example, where the lengths of two valences 21 line up to complete a corner where one is slightly longer than the other, it can be selected to occupy the “common space” or corner-most section of the valence junction fitting 31 .
[0033] The valence junction fitting 31 of FIGS. 2 and 3 interfits with the valence 21 of FIG. 1 . Note that the pattern is not symmetrical with respect to a midpoint of the width of the valence 21 . In this case it would be desirable to make valence junction fittings 31 with the same pattern and in half the cases with flange 35 longer than flange 33 and half with flange 33 longer than flange 35 . As before, both flanges 33 and 35 may be of the same length. In the case where the flanges are of the same length only one version of valence junction fitting 31 need be made.
[0034] Also shown is a pair of optional internal depth limiting members 55 which may be employed where it is desired to limited the extent to which the valence 21 can be inserted into the valence fitting 31 . The depth limiting members 55 , based upon their corner position within the valence fitting 31 will also act to limit the depth to which valence 21 can be inserted into flange 33 .
[0035] Referring to FIG. 4 , a bottom view of the valence junction fitting 31 seen in FIGS. 2 and 3 emphasize the relative lengths of the flanges 33 and 35 . FIG. 4 also illustrates that the patterns converge at an outside corner and that the outside corner is not vertically linear. FIG. 4 also illustrates the geometric extent of the optional internal depth limiting members 55 . FIG. 5 illustrates an angled plan view which illustrates various lines of the pattern seen in the other figures.
[0036] Referring to FIG. 6 , an example of a smaller, symmetrical valence junction fitting 61 is seen with the same type of view seen in FIG. 2 . The valence junction fitting 61 has a first flange 63 and a second flange 65 . The flanges 63 and 65 are also annular, each having a shaped bore, bore 67 of flange 63 being visible. Other structures are similar to the structures seen with respect to valence junction fitting 31 and includes pair of innermost points 69 which may set the maximum extent to which a matching valence (not shown) could enter flange 65 and extend toward an outside wall 65 . Further structures include flange 63 inside wall 77 and flange 65 inside wall 79 . In this configuration, if the length of the flanges 63 and 65 are different, the valence junction fitting 61 can simply be inverted top to bottom and rotated to present the other of the flanges 63 and 65 to a length of valence or molding.
[0037] Referring to FIG. 7 , a side view of a valence 81 illustrates a constant cross sectional shape compatible with the valence junction fitting 61 seen in FIG. 6 . In the case of both o the valence junction fittings 31 and 61 , a seeming line across the height of the valence 21 or 81 may be created by the thickness of the side walls 45 , 53 , or 65 . The prominence of the line will be determined by the thickness of the side walls 45 , 53 , or 65 , their coloring, and the relative size and complexity of the valence 21 and 81 . The valence junction fittings 31 and 61 will appear as corner thickenings. Further, there is no limit on the axial length of the flanges 33 , 35 , 63 and 65 . Where the flanges 33 , 35 , 63 and 65 have an expanded length, the flange can begin to assume a predominant part of the design.
[0038] Another desirable effect for the valence junction fittings 31 and 61 is the use of a high finish. A high finish can be achieved by utilizing a metallic material of construction and applying a high polish. Brass, silver, gold or other material can be used. Vacuum metalization can be applied to plastic to give the same high reflective finish as metal, and will give a wider range of color choice. In this case, the valence junction fittings 31 and 61 will appear as if they were binding fittings. Other finishes can be applied to the valence junction fittings 31 and 61 to help match the pattern of the valences 21 and 81 .
[0039] While the present invention has been described in terms of a valence junction fitting having a pair of orthogonally extended flanges, the present invention can be used in any situation where a balance between ease of structural construction is to be struck with providing a high degree of the appearance of a custom finish. One skilled in the art will realize that the structure and techniques of the present invention can be applied to many structures, including any structure where the above goals can be achieved by the above goals in an interfitting manner.
[0040] Although the invention has been derived with reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. Therefore, included within the patent warranted hereon are all such changes and modifications as may reasonably and properly be included within the scope of this contribution to the art. | A specialized angle valence junction fitting forms a joint for connecting two lengths of valence molding. The fitting has a pair of openings angled apart and has an internal shape matching an external shape of the molding utilized. The specialized angle joint may have a color to match or accent two lengths of molding and has an external dimension which is only about 1.5 millimeters greater than the dimension of the molding which it surrounds. Valence junction fitting can have an end edge which is straight, or beveled to imply a more stabilized or substantial relationship to the molding. | 4 |
TECHNICAL FIELD
[0001] The present invention relates to vane-type camshaft phasers for varying the phase relationship between crankshafts and camshafts in internal combustion engines; more particularly, to such phasers wherein a locking pin assembly is utilized to lock the phaser rotor with respect to the stator at certain times in the operating cycle; and most particularly, to a phaser having a bias spring system to assist in locking a phaser rotor at a rotational position intermediate between full phaser advance and full phaser retard positions.
BACKGROUND OF THE INVENTION
[0002] Camshaft phasers for varying the phase relationship between the crankshaft and a camshaft of an internal combustion engine are well known. A prior art vane-type phaser generally comprises a plurality of outwardly-extending vanes on a rotor interspersed with a plurality of inwardly-extending lobes on a stator, forming alternating advance and retard chambers between the vanes and lobes. Engine oil is supplied via a multiport oil control valve (OCV), in accordance with an engine control module, to either the advance or retard chambers as required to meet current or anticipated engine operating conditions.
[0003] In a typical prior art vane-type cam phaser, a locking pin, disengage-able by oil pressure, is slidingly disposed in a bore in a rotor vane to permit rotational locking of the rotor to the stator (or sprocket wheel or pulley) under certain conditions of operation of the phaser and engine. In older prior art phasers, it is desired that the rotor be locked at its parked position at an extreme of the rotor authority, either at the full retard position as in the case of an intake camshaft phaser or at the full advance position as in the case of an exhaust camshaft phaser. To assist in positioning the rotor for lock pin engagement, it is known to incorporate a mechanical stop for the rotor and a torsional bias spring acting between the rotor and the stator to urge the rotor against the stop for locking.
[0004] In newer prior art phasers as disclosed in co-pending application having Ser. No. 11/225,772, it is desirable that the rotor be lockable to the stator at an intermediate position, preferably within an increased rotor range of rotational authority. A known problem in such phasers is that there is no mechanical means such as a stop to assist in positioning the rotor for locking in an intermediate position; thus, locking is not reliable, and an unacceptably high rate of locking failures may occur.
[0005] Further, in prior art phasers, the torsion spring may generate an unwanted torque on the rotor about an axis orthogonal to the rotor axis, causing the rotor to become slightly cocked within the stator chamber before the phaser is installed onto the end of a camshaft during engine assembly. This cocking is permitted by necessary clearances between the rotor and the stator. Although relatively slight, such cocking can be large enough to prohibit entry of the camshaft into the rotor during engine assembly.
[0006] What is needed in the art is an improved vane-type camshaft phaser having additional range of rotational authority wherein the rotor may be reliably locked to the stator at an intermediate position within the range of authority.
[0007] What is further needed in the art is an improved vane-type camshaft phaser wherein the rotor of an assembled phaser may be reliably entered onto the end of a camshaft during engine assembly.
[0008] It is a principal object of the present invention to cause a rotor lock pin to be properly positioned for engagement with a stator.
[0009] It is a further object of the present invention to increase the reliability of entry of the rotor of an assembled phaser onto an engine camshaft during engine assembly.
SUMMARY OF THE INVENTION
[0010] Briefly described, a vane-type camshaft phaser in accordance with the invention for varying the timing of combustion valves in an internal combustion engine includes a rotor having a plurality of vanes disposed in a stator having a plurality of lobes, the interspersion of vanes and lobes defining a plurality of alternating valve timing advance and valve timing retard chambers with respect to the engine crankshaft. The rotational authority of the rotor within the stator with respect to top-dead-center of the crankshaft is preferably between about 40 crank degrees before TDC (valve timing advanced) and about 20 crank degrees after TDC (valve timing retarded). It is generally desirable that an engine be started at a camshaft position of about 10 crank degrees valve retard. Thus, an improved phaser in accordance with the present invention includes a lock pin seat formed in the stator at the appropriate position of intermediate rotation and a locking pin slidably disposed in a vane of the rotor for engaging the seat to lock the rotor at the intermediate position for engine starting.
[0011] A pre-loaded bias spring system disposed on the phaser cover plate urges the rotor toward the locking position from any rotational position retarded of the locking position. When the rotor is moving in a phase-advance direction, at or near the rotor locking position the bias spring system becomes disengaged from the rotor. When the rotor is moving in a phase-retard direction, at or near the rotor locking position the bias spring system is engaged, causing the rotor to decelerate and thereby increasing the reliability of locking.
[0012] Two embodiments of such a bias spring system are presented, one comprising a torsion spring and the other comprising a pair of compression springs. In each embodiment, the phaser may be assembled without having the spring system coupled to the rotor, thereby overcoming the rotor cocking problem inherent in prior art phasers and assuring reliable mounting of an assembled phaser onto a camshaft during engine assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0014] FIG. 1 is an elevational cross-sectional view of a prior art vane-type camshaft phaser, showing direct entry of an engine camshaft into a rotor, and also showing an internal torsion bias spring for biasing the rotor to a fully retarded position within the stator;
[0015] FIG. 1 a is an exploded isometric view of a partial cam phaser including the pulley/sprocket, the stator, the rotor and the locking pin mechanism.
[0016] FIG. 2 is a plan view of an improved camshaft phaser showing a first embodiment of a bias spring system in accordance with the invention;
[0017] FIG. 3 is an isometric view of the phaser and bias spring system shown in FIG. 2 ;
[0018] FIG. 4 is an exploded isometric view of an improved camshaft phaser showing a second embodiment of a bias spring system in accordance with the invention;
[0019] FIG. 5 is an assembled view of the phaser shown in FIG. 4 ; and
[0020] FIG. 6 is a cutaway isometric view from below of a portion of the second embodiment shown in FIGS. 4 and 5 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Referring to FIG. 1 , a typical prior art vane-type camshaft phaser 10 includes a pulley or sprocket 12 for engaging a timing chain or belt (not shown) operated by an engine crankshaft (not shown). A stator 14 is disposed against pulley/sprocket 12 and is rotationally immobilized with respect to pulley/sprocket 12 . Stator 14 is provided with a central chamber 16 for receiving a rotor 18 having a hub 20 . Hub 20 is provided with a recess 22 that is coaxial with a central bore 24 in pulley/sprocket 12 , allowing access of an end of engine camshaft 26 into rotor hub 20 during mounting of phaser 10 onto an internal combustion engine 27 during assembly thereof. Central chamber 16 is closed by a cover plate 28 , forming advance and retard chambers between the rotor and the stator in chamber 16 . A rotor hub extension 30 is pressed into a recess in rotor hub 20 and extends rotatably through a central opening in cover plate 28 . A target wheel 32 is mounted onto rotor hub extension 30 by an axial mounting bolt (not shown) that attaches phaser 10 to camshaft 26 during assembly of engine 27 . Thus target wheel 32 turns with and is indicative of the rotational position of rotor 18 and camshaft 26 . Cover plate 28 and stator 14 are secured to pulley/sprocket 12 via a plurality of binder screws 34 extending through stator 14 outside of chamber 16 . A torsional bias spring 36 is disposed coaxially of rotor hub extension 30 , having a first tang 38 anchored to sprocket/pulley 12 , as for example, by engagement with the protruding head of a binder screw 34 , and having a second tang 40 anchored to rotor 18 , as for example, by engagement with a stop 42 on target wheel 32 . Bias spring 36 is pre-loaded between the rotor and stator during assembly of phaser 10 to urge rotor 18 toward the full operational retard position within chamber 16 , thereby causing the rotor cocking problem described above.
[0022] Referring now to FIG. 1 a, locking pin mechanism 44 comprises locking pin 46 having annular shoulder 47 , return spring 48 , and bushing 49 . Spring 48 is disposed inside pin 46 , and bushing, pin, and spring are received in a longitudinal bore 50 formed in oversized vane 52 of rotor 18 , an end of pin 46 being extendable by spring 48 from the underside of the vane. A pin seat 54 is formed in the inside surface of pulley/sprocket 12 for receiving an end portion of pin 46 when extended from bore 50 to rotationally lock rotor 18 to pulley/sprocket 12 and, hence, stator 14 . The operation of locking mechanism 44 is described in co-pending application Ser. No. 11/225,772. Note that, by angularly positioning bore 54 on the inside surface of pulley/sprocket 12 , within the range of rotational authority 56 of rotor 18 , engagement of the locking mechanism can cause the rotor to be locked in its full retard position ( 54 a ), its full advance position ( 54 c ), or any intermediate position ( 54 b ) therebetween.
[0023] Referring now to FIGS. 2 and 3 , a first embodiment 110 of an improved camshaft phaser in accordance with the invention includes an improved bias spring system 136 that replaces prior art torsional bias spring 36 . System 136 comprises at least one compression spring assembly 160 disposed on cover plate 128 and a torque arm 162 mounted for rotation with a phaser rotor (not visible in FIGS. 2 and 3 ) as by being secured thereto by a nut 164 screwed onto a threaded stud 165 extending from a phaser mounting bolt. (A conventional target wheel, not shown, also may be mounted by obvious means onto stud 165 .) Compression spring assembly 160 comprises a coil spring 166 mounted in a bore formed in a housing 168 on cover plate 128 and having a plunger 170 extending therefrom for engagement with torque arm 162 . Housing 168 is rotationally formed on cover plate 128 , and torque arm 162 is rotationally positioned on the rotor after the phaser is installed onto a camshaft, such that in all positions of rotor advance phase angle (advance direction 172 ) from the position shown in FIGS. 2 and 3 , rotor motion is not influenced by bias spring system 136 because torque arm 162 is moving away from plunger 170 . However, in all positions of rotor retard phase angle (retard direction 174 ) from the position shown in FIGS. 2 and 3 , rotor motion is influenced by bias spring system 136 because torque arm 162 is engaged by spring-loaded plunger 170 . In a currently preferred embodiment, the position of the rotor and torque arm shown in FIGS. 2 and 3 , wherein retard motion of the torque arm is braked by bias spring system 136 , corresponds to the intermediate locking position ( 54 b in FIG. 1 a ) of an internal lock pin system (not visible in FIGS. 2 or 3 ). Further in a currently preferred embodiment, the intermediate locking position separates the rotor range of authority into a phase-advance range ( 58 b in FIG. 1 a ) and a phase-retard range ( 58 a in FIG. 1 a ), and a bias spring system in accordance with the invention is engageable with the rotor only within the phase-retard range.
[0024] Thus, in operation bias spring system 136 creates a time window wherein the lock pin and seat are roughly aligned for locking. Bias spring system 136 is active only in retard modes of phaser operation, wherein system 136 will always tend to return the rotor to its locking position when the retard mode is deactivated. Further, bias spring system 136 cannot cause the undesirable rotor cocking described above in prior art phasers. Preferably, improved phaser 110 is assembled and installed with the rotor in a locked position within the stator, and then torque arm 162 is secured in position against plungers 170 by nut 164 .
[0025] In a presently preferred embodiment, improved bias spring system 136 comprises two torque arms 162 disposed 180° apart and two compression spring assemblies 160 disposed 180° apart, as shown in FIGS. 2 and 3 , which arrangement imposes a balanced torque on the rotor in operation.
[0026] Referring now to FIGS. 4 through 6 , a second embodiment 210 of an improved camshaft phaser in accordance with the invention includes an improved bias spring system 236 that replaces prior art torsional bias spring 36 . In spring system 236 , the torsion bias spring is mounted substantially as shown for prior art spring 36 in FIG. 1 . Spring 236 is mounted on rotor hub extension 230 , and first tang 238 engages a bolt head 34 to ground the spring to sprocket 12 . However, in an improvement over prior art spring system 36 , a spring stop 280 extends from cover plate 228 toward modified target wheel 232 for engaging second spring tang 240 . Stop 280 is located radially inboard of target wheel modified stop 242 . Further, stop 280 is located substantially coaxially with the locking position of an internal lock pin system (not visible). Thus the torsion spring as installed, and shown in FIG. 4 , is grounded at both tangs 238 , 240 to the cover plate and exerts no torque or cocking moment on the rotor hub extension 230 or the rotor, permitting reliable installation of the improved phaser 210 onto a camshaft end 26 during assembly of engine 27 ( FIG. 1 ). During such installation, after the phaser is positioned on the camshaft end, target wheel 232 is installed over spring 236 and rotated counterclockwise (retard direction 274 ) until stop 242 engages second spring tang 240 outboard of spring stop 280 . The camshaft mounting bolt (not shown) is then tightened, fixing the rotational relationship between stop 280 , second tang 240 , and target wheel stop 242 .
[0027] The operational characteristics of improved phaser 210 are identical with those of improved phaser 110 as previously described. In operation, during all phase-advance modes ( 58 a in FIG. 1 a ), target wheel stop 242 is not engaged with second tang 240 , and thus spring 236 has no influence on motion of the rotor. As in first embodiment 110 , in all positions of rotor retard phase angle (retard direction 274 ) from the position shown in FIGS. 4 and 6 rotor motion is influenced by bias spring system 236 because second tang 240 is engaged by target wheel stop 242 . As noted above, the position of the target wheel and second tang shown in FIGS. 4 and 6 , wherein retard motion of the rotor is braked by bias spring system 236 , corresponds to the locking position of an internal lock pin system (not visible) into the stator. Thus, bias spring system 236 creates a time window where the lock pin and seat are roughly aligned for locking. Bias spring system 236 is active only in retard modes of phaser operation, wherein the spring system will always tend to return the rotor to its locking position when the retard mode is deactivated.
[0028] While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims. | A vane-type camshaft phaser for varying the timing of combustion valves in an internal combustion engine includes a seat formed in the sprocket at the appropriate position of intermediate rotation and a locking pin slidably disposed in a vane of the rotor for engaging the seat to lock the rotor at the intermediate position. A bias spring system disposed on a cover plate urges the rotor toward the locking position from any position retarded of the locking position. A first spring system embodiment comprises a pair of compression spring assemblies. A second spring system embodiment comprises an internal torsion spring. In each embodiment, the phaser may be assembled without having the spring system coupled to the rotor, thereby overcoming a rotor cocking problem inherent in prior art phasers, assuring reliable mounting of an assembled phaser onto an engine camshaft. | 5 |
BACKGROUND
1. Field of the Invention
This invention relates to a method of constructing an underground structure, and more particularly to a method of construction of a basement that can be used as a foundation for the upper portion of the house.
2. Description of the Related Art
Basements have traditionally been constructed using either a concrete formed structure or a cinder block construction method, both of which involve extensive labor and increase the cost substantially compared to the construction cost of a typical slab foundation. Builders often lament that it is cheaper to go up than down. Nevertheless, there are some benefits to having a basement, particularly in climates or geographic regions where tornados or other weather events are likely to be encountered.
In certain parts of the country and the world, basements are almost non-existent because of conditions such as soil type. Clay soil, for example, has the tendency to expand when wet, applying significant pressure to the walls of the basement that can cause cracking or movement of the basement wall. For the same reason, the structure of the basement may shift relative to other parts of the structure because it is typically made of different component parts. Generally, the floor of the basement is usually poured first and the walls of the basement are typically poured on top of the floor after the floor has set.
There is a need for a new method of constructing a basement or other underground structure that is both cost efficient and reliable. It would be desirable to have such a structure that is easy to construct and is comparable in cost to pouring a traditional concrete slab foundation. It would also be desirable for the structure to be such that water and moisture present in the basement are kept to a minimum.
SUMMARY
This summary is provided to describe certain aspects of exemplary embodiments that can be practiced. It is not intended to show the essential features of the invention, nor is it intended to limit the scope of the claims of any issued patent.
In one exemplary embodiment, an underground structure is constructed using the steps: creating a cutout in the earth at a desired location to generally match a desired shape of an interior of the underground structure; applying a reinforcement structure to an outer perimeter of the cutout; and applying shotcrete over the reinforcement structure to create a monolithic underground structure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an underground structure in accordance with an exemplary embodiment of the invention.
FIG. 2 is a top view of an underground structure in accordance with an exemplary embodiment of the present invention.
FIG. 3 is a cross-sectional view of an underground structure used as a foundation for a house in accordance with an exemplary embodiment of the invention.
DETAILED DESCRIPTION
Referring now to FIG. 1 , a perspective view of an underground structure in accordance with an exemplary embodiment of the invention is illustrated. The underground structure 100 is constructed from shotcrete reinforced with traditional rebar, steel mesh and/or fibers. Shotcrete is pneumatically applied concrete and can be applied using either a wet mix or a dry mix. The term “gunite” is often used in the industry to refer to the dry-mix shotcrete process in which the dry cementious mixture is blown through a hose to the nozzle, with water being injected at the nozzle immediately before it exits the nozzle. The dry-mix process allows for effective placement in overhead and vertical applications.
In one embodiment of the invention, the corners 105 , 110 , 115 of the underground structure 100 are all rounded, including the transitions between the walls and the floor. Moreover, the floor is also rounded such that a cross section of the floor can form the shape of an inverted arch to provide a more even distribution of the weight supported by the walls of the structure through the floor of the structure.
To build the structure shown in FIG. 1 , first a hole is excavated in the ground generally in the shape desired for the underground structure. Although a rectangular shape is illustrated, the desired shape could be any shape desired by the end user although it is preferred that all corners are rounded to avoid stress concentrations. Rebar or other reinforcing means such as synthetic fiber is placed in the structure along the walls and the floor of the structure to provide reinforcement and to serve as a guide for how thick the shotcrete should be applied. A separate wire or string can also be used to mark the inner surface of the underground structure to ensure that he walls and floor are of sufficient thickness to support the loads for a given project. The rebar is formed in curved shapes to match the desired end shape of the structure. Ideally, the re-bar should be constructed of one piece through the walls and floor of the structure and/or should be secured together to effectively create a single piece.
Several cutouts may also be formed in the structure to provide a means of supporting both the floor beams 120 and the ceiling beams 125 of the underground structure. Additionally, cutouts in the sidewalls of the walls of the hole cut in the ground can be created such that pilasters 130 are formed behind where the ceiling joist and floor joist will be located to provide additional strength. The size of the rebar and the thickness of the shotcrete to be applied can be varied to meet the specific structural requirements. Although not shown, a plurality of pipes can be inserted through the walls and the floor at desired locations to allow for the creation of weep holes for the purpose of allowing water to weep into the interior of the underground structure so that it can be collected and drained into a suitable sump.
After the reinforcement structure is in place, dry concrete is pneumatically applied to the structure through a nozzle that mixes the concrete with water. A plaster can be applied to the inner surfaces of the concrete to smooth out imperfections or alternatively can be left as is. The structure can be completed in a single application or multiple applications could be utilized if a composite wall is desired.
Referring now to FIG. 2 , a top view of an underground structure in accordance with an exemplary embodiment of the present invention is illustrated. Wood beams 125 can be placed across the underground structure by cutting the wood beam to fit between the cutouts 204 and 206 . The wood beams can rest on a traditional stud wall that is placed inside the underground structure (not illustrated) to support the ceiling of the basement and the floor of the above-ground structure. Alternatively the beams can rest on the ledge of the cutouts 204 , 206 . The purpose of the pilasters 130 in FIG. 2 is to provide additional strength at the area which will receive more of the load as a result of the beams. This allows the structure to have an effective increased thickness, thus creating a stronger structure. Alternatively, the thickness of the entire underground structure could be increased to support the desired load.
Referring now to FIG. 3 , a cross-sectional view of the underground structure 100 is illustrated. The structure having rebar 305 placed within it has generally upright walls 310 that are connected to an inverted arch-shaped bottom 315 . The inverted arch 315 provides better distribution of weight than a structure with a slab or footings for this purpose. Alternatively, the structure could be made with a flat bottom having rounded corners underneath the walls depending on the weight that must be supported by the walls. Floor beams 120 can be placed across the bottom of the structure and supported by ledges 320 formed in the structure that keep the floor beams spaced away from the bottom structure of the basement. The ledges can be sloped to help prevent the accumulation of moisture underneath the beams. The edges of the beams can also be spaced away from the wall to further aid in avoiding the accumulation of moisture. In this manner, water that runs along the inside walls of the basement structure and collects at a low point in the bottom of the basement structure, which can then be drained using a sump through the drain 325 . Alternatively, a sump pump can be placed at the lowest point of the structure to evacuate water to a drain line.
To help prevent “floating” of the underground structure, weep holes 330 can be placed in the bottom of the structure to allow water that collects underneath the structure to move to the inside of the structure where it can be drained away by the drain or a sump pump. The weep holes in one embodiment can be placed at the center of the bottom of the structure as well as at a distance of approximately 6 feet from each wall.
In addition to using the underground structure for traditional home construction, the underground structure could also be placed underneath or adjacent a mobile home to allow a storm shelter for someone who resides in a mobile home. The structure could also be used in a stand-alone manner near an existing home. So instead of providing ceiling beams for building up structure from the top of the basement structure, a waterproof top can be placed on the structure with an opening that allows the occupant of the mobile home to enter the underground structure in the event of a storm.
Shotcrete is traditionally made at the construction site. Sand and portland cement are mixed together and a machine is used to shoot the mixture onto the wall. The mixture can be semi-dry compared to pouring a traditional concrete foundation. This typically results in a stronger structure because less water in the concrete mixture generally results in a stronger structure once the mixture has cured. There is also a tendency when pouring traditional foundations and walls to wet the mixture after it arrives at the site to make it easier to pour even though this is not a recommended practice. When it does happen, it results in structures that are weaker than specified and the consequent foundation cracking problems.
By utilizing the reinforced shotcrete construction method disclosed herein, home builders can save significant money in the construction of a basement. This would lead to more home owners choosing to build a basement because it has benefits that are not available in homes without such a basement and the cost of going down into the ground to build additional living structures is now significantly cheaper.
While various embodiments in accordance with the principles disclosed herein have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of this disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with any claims and their equivalents issuing from this disclosure. Furthermore, the above advantages and features are provided in described embodiments, but shall not limit the application of such issued claims to processes and structures accomplishing any or all of the above advantages.
Additionally, the section headings herein are provided for consistency with the suggestions under 37 CFR 1.77 or otherwise to provide organizational cues. These headings shall not limit or characterize the invention(s) set out in any claims that may issue from this disclosure. Specifically and by way of example, although the headings refer to a “Technical Field,” the claims should not be limited by the language chosen under this heading to describe the so-called field. Further, a description of a technology in the “Background” is not to be construed as an admission that certain technology is prior art to any embodiment(s) in this disclosure. Neither is the “Summary” to be considered as a characterization of the embodiment(s) set forth in issued claims. Furthermore, any reference in this disclosure to “invention” in the singular should not be used to argue that there is only a single point of novelty in this disclosure. Multiple embodiments may be set forth according to the limitations of the multiple claims issuing from this disclosure, and such claims accordingly define the embodiment(s), and their equivalents, that are protected thereby. In all instances, the scope of such claims shall be considered on their own merits in light of this disclosure, but should not be constrained by the headings set forth herein. | A method of constructing an inhabitable underground structure is disclosed that comprises the steps: creating a cutout in the earth at a desired location to generally match a desired shape of an interior of the underground structure; applying a reinforcement structure to an outer perimeter of the cutout; and applying shotcrete over the reinforcement structure to create a monolithic underground structure. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to the control of the type element of a single element typewriter.
U.S. Pat. No. 4,094,397 to Hughes and commonly assigned herewith illustrates a shuttle and slider blocks useful in controlling and defining the amount of rotation of a typehead or type element on a single element typewriter, such as disclosed in U.S. Pat. No. 3,983,984 to deKler, and similarly commonly assigned herewith.
U.S. Pat. No. 4,094,397 incorporates by reference the disclosure of U.S. Pat. No. 3,983,984 and discloses an improvement to the system of U.S. Pat. No. 3,983,984 in the replacement of the slider blocks 18 contained in the deKler patent.
This specification incorporates by reference U.S. Pat. No. 4,094,397 filed Jan. 3, 1977, patented June 13, 1978, to Frank M. Hughes which, in turn, incorporates by reference U.S. Pat. No. 3,983,984 filed June 26, 1975 and patented Oct. 5, 1976 to Dirk deKler.
To eliminate the need for reduntant and unnecessary additional disclosure, the shuttle and slider block arrangement of U.S. Pat. No. 4,094,397 is disclosed together with the improvement thereto, herein.
OBJECTS OF THE INVENTION
It is an object of the invention to increase the forces between the slider block of the selection control system and the rotate defining stop members, without increasing peak motor loading.
It is another object of the invention to reduce the amount of undesired movement of the typehead to improve locational predictability of the typehead.
The objects of the invention are accomplished by the improvement of the invention described herein.
In the selection system of the type described in U.S. Pat. No. 4,094,397, a shuttle and slider blocks are spring forced against stops which define the extent of movement of the slider blocks which, in turn, define the rotational movement of the typehead of the typewriter.
In order to increase the force with which the slider blocks engages the stops, it is necessary to increase the spring bias forces against the slider block which, in turn, will be transmitted to the stops. This may be accomplished by adding a tension spring between the typewriter frame and the rack of the rack and pinion portion of the selection system found in the print rocker and more completely described in U.S. Pat. No. 3,983,984 which is, in turn, incorporated into U.S. Pat. No. 4,094,397 by reference therein. By adding the spring between the frame of the typewriter and the rack, rather than increasing the spring force between the slider block and the shuttle, forces exerted by the added spring are utilizable for the desired result of increasing the engagement force between the slider block and the stop members while not increasing the peak load on the selection drive motor and thereby not necessitating the increase in the motor size. This is accomplished by virtue of the fact that the drive motor is storing energy in or doing work on only one of the two springs at any one time during the typical machine cycle and, thus, utilizes a period during the machine cycle which is otherwise wasted insofar as drive motor capacity is concerned. The tension spring can be replaced by a compression spring acting on the opposite end of the rack positioned between the rack and the typewriter frame although the tension spring is easier to work with. The inclusion of this improvement spring acts to increase the reliability of the selection system inasmuch as it constantly biases the entire system in one direction to eliminate accumulated tolerances and thereby reduce the headplay of the type element. By reducing the play of the type element, the detenting of the type element prior to printing is more easily accomplished and much more reliable.
A better understanding of the invention may be had by referring to the drawing and detailed description to follow.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates the shuttle and slider block arrangement disclosed in U.S. Pat. No. 4,094,397, with the improvement of the present invention added thereto.
FIG. 2 illustrates a compressive spring force exerted on the rack in lieu of the tension spring force found in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Insofar as possible, the reference numerals of the incorporated patents are used for the same parts in this disclosure where shown and duplication is avoided.
Referring to FIG. 1, motor driven shaft 10 is driven by motor 8 rotationally. The rotation of shaft 10 will cause the oscillation of shuttle 100 axially along shaft 10 in response to the rotation of shaft 10. The interaction of shaft 10 and particularly groove 116 illustrated in U.S. Pat. No. 4,094,397 in FIG. 2 acting against pin 126 on a part of shuttle 100, likewise illustrated in FIG. 2 of U.S. Pat. No. 4,094,397 causes the movement of the shuttle 100 along shaft 10. As slider block 118 translates with shuttle 100 and stop surface 122 thereon engages one of the stop members 34 as shown in FIG. 1 of U.S. Pat. No. 3,983,984, slider block 118 will stop and further movement of the shuttle 100 is accommodated by springs 108. Springs 108 provide a biasing force to insure that stop surface 122 remains against the stop member 34. A more detailed understanding of this operation may be had by a thorough review of U.S. Pat. Nos. 4,094,397 and 3,983,984.
Shuttle 100 carries slider block 118 and slider block 118 may move relative to the shuttle 100. Springs 108 are flexed to span between slider block 118 and shuttle 100 to bias slider block 118 and to provide spring relief for slider block movement.
As slider block 118 translates axially along the axis of shaft 10, movement multiplier arm 30 attached to the block 118 will pivot with respect to grounding point 31. Grounding point 31 is part of the typewriter frame 27. As movement multiplier arm 30 translates in response to the movement of slider block 118, the displacement of the outer end thereof 29 will be in proportion to the respective lever arm lengths. End 29 of movement multiplier arm 30 is attached to link 54 to transmit motion from arm 30 to rack 56 located in and supported by the rocker 68 as shown in U.S. Pat. 3,983,984. Rack 56 is provided with two sets of gear teeth in the form of oppositely arranged racks. Pinion 57 is engageable with one of the racks forming rack 56 and is coupled as illustrated in FIG. 1 of U.S. Pat. No. 3,983,984 to type element 60.
Attached to rack 56 and urging rack 56 down and to the right in FIG. 1 is a tension spring 90. Tension spring 90 acts to urge rack 56 toward frame member 27 to which the opposite end of tension spring 90 is attached. This urging will act to accumulate all the play in the system which will be eliminated and type element 60 will be consistently positioned for each and every position of slider block 118.
An alternative embodiment is illustrated in FIG. 2 wherein a spring arrangement similar to the springs 108 are used as a compressive biasing force between the frame of the rocker 68 and the rack 56. The compressive force of spring 92 may be made substantially equivalent to the tension force exerted by spring 90 in FIG. 1 inasmuch as both tend to urge rack 56 in the identical direction which is the same direction as the spring biasing forces on slider block 118.
As the shaft 10 rotates and shuttle 100 oscillates initially toward the right as a result of the rotation of shaft 10 and the interaction between groove 116 and pin 126 as shown in FIG. 2 of U.S. Pat. No. 4,094,397, the springs 108 will maintain slider block 118 against the end 101 of shuttle 100 until such time as surface 122 will come in contact with stop members 34 or stop 20 as shown in FIGS. 1 and 3 of U.S. Pat. No. 3,983,984.
At the point that surface 122 engages a resistance force, spring 108 will begin to collapse and buckle, storing energy, maintaining a substantially uniform force against the stop 34. During the movement described immediately above, tension spring 90 will be collapsing and releasing energy as movement multiplier arm 30 also moves with slider block 118 until such time as slider block 118 is stopped. The remaining tension in spring 90 will add to the force urging block 118 along shaft 10 and will effectively assist springs 108 in maintaining slider block 118 against the end 101 of shuttle 100. Upon engagement of surface 122 with the stop member 20, 34 of U.S. Pat. No. 3,983,984 and the stopping of slider block 118 from further translation, the force exerted by spring 90 through rack 56 and link 54 will be additive to that exerted by springs 108 and being transmitted to block 118. This effectively raises the engagement force between surface 122 and any stop member 20, 34 engaged thereby. As spring 108 is being collapsed by further rotation of shaft 10 and the further shifting of shuttle 100, spring 90 is in a condition of stability and equilibrium and is not affected by drive motor 8. Energy is only being stored at this point of the cycle in spring 108.
As the shaft 10 continues to rotate, slider block 118 will be engaged by shuttle 100 on its return throw and as shuttle 100 moves leftward as seen in FIG. 1 with respect to slider block 118, spring 108 will give up energy previously stored therein. This force assists in the reverse movement of shuttle 100. Upon the restoration of slider block 118 against the end 101 of shuttle 100, further movement of shuttle 100 will effect the movement of multiplier arm 30 in a clockwise direction as viewed in FIG. 1, thus pushing on link 54 and rack 56 to return pinion 57 and type element 60 to the home position normally occupied during times when no selection is occurring.
As this movement of rack 56 occurs in response to the pushing by link 54, tension spring 90 is extended and energy stored therein. As can be seen from the above, energy is stored in tension spring 90 only after the slider block 118 has been returned to abutting engagement with the end 101 of shuttle 100 and there is no work being performed on spring 108.
Conversely, spring 108 is only being worked on during the portion of the cycle after surface 122 engages a restraining force and spring 108 is being collapsed thereafter by further movement of shuttle 100. Inasmuch as the stopping of slider 118 also stops rack 56, at that point there is not further movement with respect to spring 90. Inasmuch as spring 90 is not being deformed or allowed to deform, there is no work input or output from spring 90 during the period of time when work is being performed on spring 108.
This arrangement allows motor 8 to drive shaft 10 and only perform work on spring 90 or spring 108 but not to allow work to be performed on both sets of spring biasing means 90, 108 at the same time. Inasmuch as there is substantial portion of the cycle during which spring 108 is not having energy stored in it by the rotation of shaft 10, this allows work to be performed by motor 8 without increasing the peak loads on motor 8 and thereby requiring an increase in the motor size or drive capability.
Referring to FIG. 2, an alternative embodiment involves the use of a spring 92 equivalent to that of spring 108 in structure and characteristics. The spring 90 may be attached between the rocker frame 68 and rack 56 to provide a compressive force against rack 56 which, in turn, will act through link 54. The functional result is the same as the embodiment involving the tension spring 90 as illustrated in FIG. 1.
The loading or work performed on spring 92 will be done during that portion of the cycle when the shuttle 100 is returning to its home position and not during a time when the spring 108 is being compressed or flexed. Thus, regardless of whether tension spring 90 of flex spring 92 are utilized as illustrated, the loading of these respective springs 90, 92 occurs during a portion of the cycle during which no work is being performed on spring 108 and, thus, does not increase peak load on drive motor 8.
The holding members 102, 104, spring 106, and attachment point 109 are all described in U.S. Pat. No. 4,094,397 and record sheet 72 and platen 74 are described in U.S. Pat. No. 3,983,984, and are not essential to an understanding of the present invention and, as such, are adequately described by incorporation.
Having described the invention in two embodiments, it is understood that minor variations may be made in the invention without departing from the spirit of the invention and from the following claims. | An improvement to the shuttle selection control system disclosed in U.S. Pat. No. 4,094,397 is described where a biasing spring is urgingly engaged with the rack of a rack and pinion arrangement used to rotate the type element, and thereby place a spring load on the system such that the force between the slider blocks of the selection system and the stop member engaged by the slider block will be reliably increased, while at the same time, preventing an increase in the drive requirements of the drive motor for the system. This spring biasing has a secondary benefit in that it tends to uniformly cause consolidation of all tolerances and relative movement in the system due to wear and thus stabilize the system for improved detenting of the typehead. | 1 |
FIELD OF THE INVENTION
This invention relates to the field of cutting drums useful for shredding small trees, shrubs and undergrowth. More specifically, it relates to a shredder assembly, the component parts thereof, and the use of a shredder in land clearance.
BACKGROUND OF THE INVENTION
Typically, powered devices useful for clearing debris from land may vary in size from small hand held weed trimmers to large rotatable shredding drums capable of rapidly clearing vast tracts of land. These large shredding drums typically have a plurality of cutting teeth disposed circumferentially on their outer surface. A large shredder can be powered by a chain drive, by gears or belts, or by direct drive. It may be mounted at the end of a movable boom that is driven by a diesel or gasoline engine. The shredding drum commonly encounters more than just weeds, shrubs and trees when performing its tasks. The drum may contact rocks and all manner of surface debris, such as boulders, re-bar, wire, cinder block and other materials of construction. Accordingly, the shredding operation places tremendous radial and axial stress loads on the drum, the cutting teeth, the drive shaft, and other component parts associated with the drum assembly and its operation.
BRIEF DESCRIPTION OF THE INVENTION
It is an objective of the present invention to increase the length of the in-service time intervals for a shredder.
Another objective is to reduce the time and expense for maintenance of a shredder.
Yet another objective is to provide a shredder capable of quickly and effectively clearing large areas of land.
These and other objectives and advantages will become apparent upon a reading of the description that follows.
The present invention relates to a drum assembly for a shredder. The assembly comprises a cylindrical drum having a plurality of blocks mounted around the circumference thereof and secured thereto. Each block has a leading surface and a trailing surface, two sides generally co-linear with the sides of the drum, a top surface, and a bottom surface in contact with the drum surface. The block has a V-shaped notch in the top surface, but otherwise is in the shape of a parallelepiped. Each of the blocks holds a cutting tooth.
Each of the cutting teeth has a hard, typically carbide, cutting surface. The tooth includes a shank that is removably inserted into a hole in the V-shaped notch in the cutter block. Each shank has a free end and an abutment end, the abutment end terminating in a rearwardly extending shoulder that cooperates with the block to serve as a stop to limit linear and rotational movement of the shank in the block. An extension on the tooth projects rearwardly of the tooth face and rests against the adjacent surface of a block to provide additional support for the tooth to resist shock and bending moments. Each cutter block is aligned with the rotational direction of the drum so that the cutting surface of the tooth faces at right angle to the rotational direction of the drum and parallel to the drum axis. The shank on each tooth includes a circumferential groove, and a spring clip or a spring pin engages the groove to anchor the tooth in a corresponding hole in the block.
The invention further comprises a shredder drum including a cutting tooth and block assembly adapted to be removably mounted on the circumference of the drum. The block is generally in the shape of a parallelepiped with a leading surface and a trailing surface, two coplanar sides, and a base. The top surface of the block includes a V-shaped notch with a front surface and a rear surface of the notch meeting at an angle of about 90°. A hole extends into the rear surface of the notch at a right angle to the surface. The tooth comprises a planar cutting surface adapted to form an angle generally orthogonal to the top of said block when the tooth is engaged therewith. It also includes a shank to be inserted into the hole in the rear surface of the notch, said shank having a free end and an abutment end. The abutment end terminates in a shoulder formed at right angles to the shank. The shoulder abuts the rear notch surface where it cooperates with the block to limit the linear and rotational movement of the shank within the block. An extension projects rearwardly of the tooth face and is adapted to rest against the planar top surface of a block when the tooth is inserted into the block, said extension serving to provide reinforcing support for the tooth when the shredding drum is in use. The shank typically includes a circumferentially extending groove and a lock pin engaging the groove for the purpose of providing a compressive fit of the tooth in the corresponding hole in a block. The shank forms an interior or acute angle between about 30° and about 60°, preferably about 45°, with respect to the rearward extension of the tooth. The shank forms an obtuse angle between about 120° and about 150°, preferably about 135°, with respect to the cutting face of the tooth. The angle serves to provide the proper pitch for the cutting face when the shank of the tooth is mounted in the block.
The invention also relates to a method of clearing brush and debris from land. The method comprises providing a shredding drum assembly having a cylindrical surface. A plurality of replaceable cutter blocks are secured on the drum surface. A plurality of cutting teeth are provided, each tooth having a shank with a free end and an abutment end, the abutment end terminating in a shoulder, and an extension projecting rearward of the tooth face. The shank of each cutting tooth is inserted into a hole in the block whereby the shoulder cooperates with the block to serve as a stop to limit movement of the shank into the block, and the rearward projecting extension rests against the adjacent surface of a block to provide additional support for the tooth against shock and bending moment. The drum assembly is mounted on a powered shaft to provide rotational movement to the drum. Each block is provided with a first hole to receive the cutting tooth. The tooth has a cutting surface that, when inserted into the hole, is parallel to the drum axis and faces the direction of rotation of the drum. Each block is generally in the shape of a rectangular parallelepiped having two sides, a top surface and a bottom surface orthogonal to the axis of the drum, and a front surface and a rear surface parallel to the axis of the drum. A V-shaped notch is provided in the top surface and a first hole extends into the block from the notch at right angles to one side of the notch to receive the shank of the tooth. A second hole extends into the block at right angles from one side of the block, said hole intercepting the first hole that receives a cutting tooth. Each cutting tooth is provided with a circumferentially extending groove, and an insert in the second hole intercepts the circumferentially extending groove to prevent removal of the shank of the cutting tooth from the first hole. Each tooth has a cutter face typically having a width of about 1 inch. The teeth in each row are spaced, for example, about 2½ inches apart, and the teeth in adjacent rows are axially offset by about 1¼ inch.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of the overall assembly showing the shredding drum of the present invention;
FIG. 2 is a perspective view showing an arrangement of blocks and teeth on the surface of the shredding drum;
FIG. 3 shows an assembly of a cutter tooth and a block; and
FIG. 4 is an exploded perspective view of a tooth and cutter block useful in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a boom end shredding drum mounted on a shaft driven by a suitable power source. For purposes of illustration, the shredder may comprise a 20 inch diameter cutter drum between 60 inches and 80 inches in length, with between 80 and 110 cutter teeth mounted in cutter blocks on the drum surface. The drum is mounted on a shaft driven by an internal combustion engine, such as a 200 or 275 horsepower Cummins diesel engine. The engine is directly coupled to the shaft onto which the cutter drum is mounted, or it is joined to the shaft through a series of belts and/or gears. The engine is capable of driving the shredding drum at a rotational speed typically between about 1000 rpm and about 1200 rpm.
Shredders of this type are manufactured by Sneller Machine Co., Cleveland, Ohio, and are referred to as the Sneller Shredder 275. The drive shaft rotates in two sets of roller bearings. Because of the encounters with miscellaneous debris during shredding, the bearings are subject to tremendous lateral and axial stress. The bearings and grease seals are exposed to entanglement with wire that can become wrapped around the shaft possibly damaging or destroying the grease seals around the bearings, causing premature failure of the bearings. Furthermore, with improper tolerances and clearances between the rotating and non-rotating parts of the assembly, bearing wear can be substantial, thus necessitating shutdown and repair of the shredder. Because of the costs associated with the disassembly and repair of the equipment, and the associated non-productive time, ways are constantly being sought for reducing downtime.
The bearings used in the Sneller Shredder typically are non-adjustable, two row, tapered roller bearings having a one-piece double outer race, and two inner races. Bearings of this type are available from various manufacturers, such as The Timken Company of Canton, Ohio. To function properly, these bearings require proper lubrication. Details relating to the sealing and lubrication of the bearings are disclosed in U.S. Pat. No. 6,640,851 B1 entitled SHAFT ASSEMBLY FOR STUMP CUTTER, issued Nov. 4, 2003 to the inventor hereof. The contents of this patent are incorporated herein.
According to this patent, each bearing is lubricated by grease supplied from two separate reservoirs, each of which is designed to avoid leakage and to protect from ingress of dirt and debris. Accordingly, it is believed that the shredder can be used for 5000 hours or more without bearing failure or before fatigue spall develops. At 1000-1200 revolutions per minute, this is equivalent to at least five million revolutions.
The overall shaft assembly may be mounted within a pair of arms of a frame of the shredder. The arms in turn extend out from a boom. The frame arm and the boom also are not part of the present invention but are identified as representative of the environment in which the present invention is used.
The shaft assembly includes a shaft having a drive end connected through belts and gears to the output of the engine (none of which is shown). Next to the drive end, the shaft includes a first threaded surface that receives a nut and a lock washer. The nut and washer abut a ring on which a grease seal runs. An inboard, tapered roller bearing is pressed onto the shaft until the inner race abuts a shoulder on the shaft. An end cap is bolted or otherwise secured to a flange of an inboard cast iron shell and serves to limit any axial movement of the outer race of the bearing. The nut is threaded onto the shaft to prevent axial movement of the inner race. The outer race of the bearing is fitted into a recess formed by and between the cast iron shell and the outer plate.
The shredder drum is mounted on a rim of the inboard hub. An outboard shell made of cast iron abuts a shoulder on the shaft. The shell is supported in the second arm of the frame. An outboard hub slips around a bolt ring that abuts a shoulder of the shaft. The bolt ring is secured to the inboard hub by a plurality of bolts which draw the left-hand hub against the tapered portion of the shaft to insure a tight fit between the hub and the shaft. A slotted keyway (not shown) in the outboard hub and the shaft engages a key in a manner that is well known in the art, serving to prevent relative rotation of the outer hub with respect to the shaft. Obviously, with the two hubs bolted together, the inner hub is prevented from slippage as well. A plurality of bolts and nuts serve to secure the cutter drum between the two hubs.
The use of cast iron instead of steel for the annular inboard and outboard shells serves to prevent freeze welding of the stationary shells to the rotating steel shaft.
The outer end of the shaft receives a sleeve having a flange which abuts the shoulder on the shaft. The sleeve is prevented from relative rotation with respect to the shaft by the key engaging slots that form a keyway in the shaft and sleeve. The outer end of the sleeve is threaded on the exterior surface to receive a nut and lock washer. The outboard bearing is press fit onto the sleeve and is secured in place by the nut threaded onto the sleeve. The lock washer prevents the nut from coming loose. The use of the threaded sleeve has been found to minimize maintenance problems by reducing the likelihood of the outboard bearing becoming loose on the shaft. A loose outer bearing has been found to place a substantial additional strain on the inboard bearings and on the shaft. This can cause breakage of the shaft at the inboard end. Furthermore, any lateral forces applied through the grinder drum or hub to the shaft when the shaft is suspended only in the inboard bearing can cause serious misalignment of the shaft and damage to the drive train.
A flanged outer cap is secured to the outer shell, preferably with the use of bolts passing through the flange to protect the shaft from dirt and debris. In like manner, the cap and shell are secured to the outboard arm of the frame of the shredder using suitable fastening means, such as bolts (not shown).
Permanent lubrication is provided between the hubs and the shells by a labyrinth filled with grease. The labyrinth includes a first layer of grease in the narrow gap between the shaft and the cast iron sleeve. This gap has a radial width less than about 0.10 inch and preferably less than 0.08 inch, and is filled with grease from the labyrinth. Grease from the labyrinth also fills a gap between the shell and the axial flange of the inboard hub. This gap is less than about 0.15 inch and preferably is less than 0.125 inch. A grease seal forms the separation between the labyrinth and a grease reservoir. A double seal separates the bearing from the reservoir.
The inboard hub and the outboard hub each have an axially extending flange portion that has a width that extends at least about one inch along the axis of the shaft. This extended flange has been found to prevent cable or wire, often encountered at a construction site, from winding around the shaft and working its way into a labyrinth. It also serves to provide an improved seal to prevent the leakage of grease between the steel hubs and the cast iron shells. Maintaining a preferred clearance of 0.125 inch or less between the relatively moving parts further reduces the likelihood of leakage of grease or the ingress of dirt and debris into the labyrinth.
Turning now to the drawings, FIG. 1 shows a self powered brush shredder 110 comprising a shredder drum 112 mounted between the arms 114 of frame 116 . The drum is driven by a self contained diesel engine 120 . The frame 116 is mounted at the end of a hydraulic boom 122 under the control of an operator stationed in an enclosed cab 130 sitting atop a diesel engine 134 driving a pair of track treads 132 .
FIG. 2 shows one end of the drum 212 and one end of the shaft 242 adapted to be mounted within the frame arms 114 (not shown) through a set of lubricated and sealed bearings as previously described. On the circumference 238 of the drum 212 are several blocks 244 that are secured to the drum, preferably by welds 246 . Each of the blocks is provided with a cutting tooth 250 .
FIGS. 3 and 4 show the details of a block and tooth according to the present invention. For simplicity, the same numbers will be used in both figures. The block 310 is generally rectangular with a front surface 352 , two coplanar sides 354 a , 354 b , a base 356 , a rear surface 358 and a top 370 . Although the base is seen as being flat, it can also be slightly curved to conform to the contour of the cylindrical drum surface. Near the front surface 352 , the top 370 of the block includes a V-shaped notch 372 with the front surface 374 and the rear surface 376 of the notch forming an angle of 90°. The intersection between the two surfaces forms a line that extends in a direction that is parallel to the axis of the drum. A hole 380 extends into the block at an angle of 90° with respect to the rear surface 376 of the notch. A second hole 398 extends between the two sides of the block, intercepting a segment of the hole 380 . This second hole 398 receives a lock pin (not shown) which is used to secure the shank of a tooth in the block.
Each tooth 350 includes a planar cutting face 382 , a tooth body 384 , and a cylindrical shank 386 having a free end 388 and an abutment end 390 which forms a generally rectangular shoulder 392 where it intersects the body 384 of the tooth. The shank 386 typically forms an angle between about 120° and 150°, preferably about 135°, with respect to the cutting face 382 of the tooth. The shank forms an interior or acute angle between about 30° and about 60°, preferably about 45°, with respect to the rearward extension of the tooth. The shank typically includes a groove 390 , which cooperates with a spring clip or a lock pin 400 . The tooth 350 includes an extension 394 projecting rearward from the tooth face 382 . This extension includes a planar surface 396 that rests against the top 370 of the block when the tooth shank 386 is inserted into the tooth hole 380 . This gives support to the tooth and also keeps the tooth from turning in the hole 380 when the drum is rotating. A pin is driven in to the hole 398 and intercepts the groove 390 of the shank to hold the tooth securely in the block. The tooth can be removed from the block using a punch and hammer to remove the lock pin from the hole 398 in the block. The tooth can be loosened by striking the free end 388 of the shank, accessible from the back surface of the block. A block can be changed or replaced as needed by removing the block using a chisel, saw or blow torch followed by grinding of the drum face if necessary to remove residual traces of the block left on the drum.
A tooth of this general description is shown and claimed in U.S. Pat. No. 6,698,477 B1, the subject matter of which is incorporated by reference herein. The patent was issued on Mar. 2, 2004 to the instant inventor.
The blocks are mounted on the drum generally in accordance with the arrangement shown in FIG. 2 so that a 100% sweep or coverage of the terrain is obtained with each revolution of the drum. This coverage is achieved, for example, on a 20 inch diameter by 60 inch wide drum by placing 96 blocks and teeth in four rows of 24 blocks and teeth. A total sweep is achieved if each tooth has a face with a width of about 1 inch, mounted in a block having a width of 1¼ inches. The teeth in each row are spaced 2½ inches apart. The teeth in alternate rows are axially offset by 1¼ inches to provide the complete coverage. Each row extends across the perimeter of the drum from one side to the other at an axial angle between about 4° and about 10°, preferably about 7°. This facilitates the removal and replacement of a tooth in a block, and also serves to sweep debris to the side of the shredder drum as the debris is dislodged or cut. Other angles can be used as well. For example, the blocks and teeth can be aligned in a V-configuration across the drum. When using four rows, each row is spaced 90° around the face of the drum with each row parallel to one another. Obviously, with a larger or smaller diameter drum, the number of rows can be increased or decreased as appropriate, with suitable adjustments being made in the size of the blocks and the cutting face of each tooth, as well as the spacing between blocks so as to obtain complete coverage with each revolution of the drum.
The tooth is typically fabricated by suitable means, such as forging or casting. The face of the tooth preferably is made from a hard, impact resistant material, such as carbide steel brazed onto the body of the tooth. The block is generally made from steel by forging. The thickness of the wall of the drum is between about ⅜ inch and about ¾ inch. The drum may be made from hot rolled steel pipe.
Typically, the number and the placement of teeth in the cutter block, as well as the angles and height of the cutting teeth with respect to the rotational direction of the cutting drum, can be altered in accordance with established practices. For example, a wider block could accommodate more than one tooth, arranged in a staggered arrangement in the top of the block. Furthermore, other means, such as cotter pins, can be used for anchoring each tooth in a hole in the block. Likewise, the number of removable cutter blocks can be increased or decreased depending on the overall size of the drum and the blocks.
The shredder of the present invention may be assembled typically in the same manner as described in the aforementioned patents. The inboard hub is slipped into place around the tapered portion of the shaft. The cutter drum is slipped onto the rim of the hub. The outboard hub is placed around the outboard end of the shaft until it abuts the shoulder of the shaft. The hubs are then drawn together with a plurality of bolts that extend through holes aligned in the outboard hub and the drum, and that are threaded into tapped holes in the inboard hub. The shaft sub-assembly is mounted in the arms of the frame. The inboard shell is placed around the shaft. The grease seal is inserted into place and the second grease seal is placed over the shaft. The inboard bearing is pressed onto the shaft until it abuts the shoulder on the shaft, after which the ring is threaded onto the shaft. The outer grease seal is placed therearound and the inboard end plate is bolted through the flange of the inboard sleeve into the frame arm. The lock washer is placed around the shaft and a nut is threaded onto the shaft and is tightened to anchor the inboard bearing securely in position.
In like manner, the outboard shell is placed around the shaft. The grease seal is inserted into place and an additional grease seal is placed over the shaft. The sleeve is pressed onto the outboard end of the shaft and is prevented from slipping on the shaft by a key inserted into a slotted keyway in the shaft and the sleeve. The sleeve includes a flange. The outboard bearing is pressed on the sleeve until the bearing abuts the flange and the flange on the outboard shell. A nut and lock washer secure the outboard bearing in place. This arrangement of the external threads on the sleeve and the nut to secure the outboard bearing in place unexpectedly reduces the likelihood of damage to the inboard end of the shaft.
The end cap includes a flange having a plurality of holes that match up with corresponding holes in the flange of the outboard shell and the arm of the frame. A plurality of bolts are used to secure the outboard end of the shaft assembly to the frame.
After the components have been assembled, the grease reservoir and labyrinth are filled with grease by providing grease fittings and passages extending through the bearing housings and into the reservoirs. The grease is then forced into each of the reservoirs, and from there passes through the grease seals into the labyrinths. As part of the routine maintenance of the assembly, it should be regreased on a regular basis after a few hours of operation.
While the invention has been described in combination with embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing teachings. Accordingly, the invention is intended to embrace all such alternatives, modifications and variations as fall within the spirit and scope of the appended claims. For example, instead of the cutter blocks being secured to the drum surface by welding or brazing, suitable threaded fasteners may be used to secure the blocks to the drum. Furthermore, the alignment of the blocks with the drum can be achieved by using a plurality of alignment pins instead of a key and slotted keyway.
The teeth used in the teachings of the present invention can be used with other types of cutter drums, such as solid drums, with improved results. Likewise, the blocks of the present invention can be mounted on unitary cutting drums, thereby enjoying the benefit and ease of replacing the blocks when worn or broken. | A shredding apparatus includes a shredding drum capable of quickly and effectively clearing large tracts of land. Several cutter blocks are positioned in axial rows across the periphery of the drum and are secured to the drum by welding. The blocks in each row are evenly spaced from one another and may be offset from the axial direction of the drum by angle of between about 4°°and about 10°. Each of the blocks includes a cutter tooth. Each tooth includes a shank that is removably anchored in a hole in each block. The teeth are typically reinforced with an extension projecting back from the face. The blocks are placed around the drum to enable the teeth collectively to fully sweep the ground surface during each revolution of the drum. | 0 |
TECHNICAL FIELD
The invention pertains to a coupling for a fluid conducting system, having a coupling part into which an insertion section of a counterpart can be inserted, and having a locking part which is mounted in movable fashion on the coupling part and which possesses a detent structure which in a detent position interacts with a complementary structure configured on the insertion section for locking the counterpart and the coupling part.
BACKGROUND
Such a coupling is known from DE 10141315 C1. The previously known coupling possesses a coupling part into which an insertion section of a counterpart can be inserted. Also present is a C-˜shaped locking part which is mounted on the coupling part so that it can rotate around the longitudinal axis of the coupling. As the detent structure, the locking part possesses sections which are like segments of a circle and which in a detent position interact, through the fact that they engage in recesses configured on the coupling part and the insertion section, with a complementary structure configured on the insertion segment for locking the counterpart and the coupling part in a locking position. When the locking part is rotated around the longitudinal axis of the coupling, the sections which are like segments of a circle slide out of the recesses while bending the locking part upward, and release the insertion section in a release position. To facilitate the rotation, gripping grooves or nubs are present on the outside of the locking part.
When operating the previously known coupling, however, in a certain sense it turned out to be disadvantageous that the release position exhibited a certain instability, since under the effect of a relatively low force on the coupling part, the latter changes over directly from the release position into the locking position in an abrupt fashion. In addition, the transfer of the coupling part from the locking position into the release position by rotating it has not proven to be optimal because of the relatively large amount of space required for doing this. Finally, performing the rotating movement with a locking part having smooth walls, after the gripping grooves or nubs have worn off, for example, is sometimes not without problems.
SUMMARY OF THE INVENTION
The invention is based on the task of suggesting a coupling of the type mentioned at the beginning which is distinguished by improved operation.
With a coupling of the type mentioned at the beginning, this task is inventively solved in that the locking part is configured with two side sections that are parallel to each other, that at least one longitudinal detent element is configured on each of the side sections' insides facing the coupling part, that a latching structure is present in the region of the free ends of the side sections, that the coupling part is configured with guide recesses that lie opposite each other and into which the detent elements engage, and that the coupling part is equipped in the region of one end of the guide recesses with a latching structure that is configured complementary to the detent structure.
Through the inventive configuration of the coupling, the movement of the locking part between the release position and the locking position takes place essentially in a linear direction perpendicular to the longitudinal direction of the coupling so that relatively problem-free operation is possible even in narrow spaces. In addition, this results in the advantage that the release position in particular exhibits relatively high stability against the effects of external forces, so that an unintentional snapping of the locking part into the locking position is made more difficult at the least.
Additional useful developments of the invention are the objects of the subclaims.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional useful developments and advantages arise from the following description of a preferred embodiment of the invention, including references to the figures of the drawing. The following are shown:
FIG. 1 a perspective view of a preferred embodiment of the invention, having a coupling part and a locking part that is arranged in a release position in the representation according to FIG. 1 , and an insertion section of a counterpart that is arranged at a distance from the coupling part,
FIG. 2 a perspective view of the embodiment according to FIG. 1 in a cutaway through the coupling part and the locking part arranged in a locking position, and through the insertion section that is inserted into the coupling part, and
FIG. 3 a perspective view, partially cut away in the longitudinal direction, of the embodiment according to FIG. 1 and FIG. 2 .
DETAILED DESCRIPTION
FIG. 1 shows a perspective view of an embodiment of an inventive coupling, having a elongated coupling part 1 which possesses a connection fitting 2 on one side. A flexible hose of, for example, a fluid conducting system, not shown in FIG. 1 , can be slipped onto the connection fitting 2 , which is preferably configured with a cross section that varies in the longitudinal direction and is tapered at the end. At an insertions side 3 that is opposite the connection fitting 2 , coupling part 1 is configured with an insertion opening 4 that is round in cross section, into which a counterpart, shown in FIG. 1 at a distance from the coupling part 1 and with an elongated, essentially cylindrical insertion section 5 , can be inserted.
The insertion section 5 of the counterpart possesses a circumferential securing recess 6 , which is delimited on the edge side by a first edge shoulder 7 , which is arranged on the edge side in the region of the free end of the insertion section 5 , and a second edge shoulder 8 that lies opposite the first edge shoulder 7 . The insertion section 5 is, for example, configured as an end fitting that is placed on a fluid reservoir of the fluid conducting system or that can be connected to one end of another flexible hose of the fluid conducting system. On its end section that faces the insertion side 3 immediately before insertion, when operated properly, into the coupling part 1 , the insertion section 5 exhibits an insertion bevel 9 to facilitate insertion into the coupling part 1 .
Between the connection fitting 2 and the insertion side 3 , the coupling part 1 is configured with a coupling section 10 , which is thicker than the connection fitting 2 and in which there are guide recesses 13 , which are placed laterally and which extend from a top element 11 to a base element 12 , and thus perpendicular to the longitudinal direction of the coupling part 1 . Present in the longitudinal direction of the coupling part 1 on both sides of the guide recesses 13 are sliding surfaces 14 , 15 , which are offset inward relative to the outside of the coupling section 10 and are slightly convex, and which are configured in their end regions facing the base element 12 with locking recesses 16 , 17 as a detent structure, and in their end regions facing the top element 11 with the releasing recesses 18 , 19 as a releasing structure. The locking recesses 16 , 17 and the releasing recesses 18 , 19 are aligned in the longitudinal direction of the coupling part 1 .
In addition, the preferred embodiment shown in FIG. 1 is equipped with an essentially U-shaped locking part 20 , which is detachable mounted on the coupling part 1 and which possesses a top section 21 that is flat on the outside and two side sections 22 , 23 , which are configured onto the top section 21 at a right angle and which are also flat on the outside. Configured on the inside of each side section 22 , 23 are inwardly concave detent elements 24 , 25 , which are matched to the dimensions of the guide recesses 13 and which engage in the latter. The inside diameter of the locking part 20 in the region of the concavities of the detent elements 24 , 25 is slightly smaller than the outside diameter of the insertion section 5 in the region of the securing recesses 6 in order to generate a prestress. Configured as a latching structure on the side sections 22 , 23 in the region of the ends of the detent elements 24 , 25 that face away from the top section 21 and aligned therefrom in the longitudinal direction of the coupling part 1 are protruding latching projections 26 , 27 that are dimensioned for engagement into the locking recesses 16 , 17 and the releasing recesses 18 , 19 .
In the representation according to FIG. 1 , the locking part 20 is positioned in a sprung releasing position in which the latching projections 26 , 27 are in engagement with the locking recesses 18 , 19 .
FIG. 2 shows a perspective view of the embodiment according to FIG. 1 in cutaway through coupling part 1 and the locking part 20 , which is arranged in a locking position, and through the insertion section 5 that is inserted into the coupling part 1 . It can be seen from FIG. 2 that starting from the releasing position shown in FIG. 1 , the locking part 20 has assumed the locking position in that, while a force sufficient to overcome the engagement of the latching projections 26 , 27 with the releasing recesses 18 , 19 is exerted on the top section 21 in the direction of the side sections 21 , 22 by means of a fingertip or a tool, for example, with the action of additional force, the insides of the side sections 22 , 23 slide along the sliding surfaces 14 , 15 and the detent elements 24 , 25 engage further into the guide recesses 13 of the coupling part 1 . In the locking position, the latching projections 26 , 27 , which are not visible in FIG. 2 , engage in the locking recesses 16 , 17 , also not visible, so that locking part 20 is also fixed in the locking position.
FIG. 3 shows a perspective view, partially cut away in the longitudinal direction in the transition region from one side section 22 into the top section 21 , of the embodiment according to FIG. 1 and FIG. 2 with the locking part 20 in the locking position. It can be seen from FIG. 3 that a sealing ring 32 is arranged between the coupling part 1 and the insertion section 5 in the region of the insertion bevel 9 of the insertion section 5 in order to achieve a leakproof connection in the fluid conducting system. It can also be seen from FIG. 3 that the edge sides of the detent elements 24 , 25 that face the connection fitting 2 rest on the first edge shoulder 7 , which is adjacent to the free end of the insertion section 5 , and thus hold the insertion section 5 in the coupling part 1 in an essentially play-free manner.
When the insertion section 5 is inserted into the coupling part 1 with the locking part 20 in the locking position, the detent elements 24 , 25 of the locking part 20 , which are also advantageously tapered in the direction of the insertion side 3 in the insertion direction, slide onto the insertion taper 9 until the detent elements 24 , 25 engage behind the first edge shoulder 7 and the concavities of the detent elements 24 , 25 enclose the insertion section 5 in sections in the region of the securing recess 6 . The counterpart is thus coupled with the coupling part 1 .
To transfer the locking part 20 from the locking position into the releasing position in order to release the insertion section 5 , a fingernail or the front end of a screwdriver blade, for example, is applied alternately against the front faces 28 , 29 , which face away from the top section 21 , in the region of the engagement recesses 30 , 31 that are provided as a relief structure, in order to release the engagement of the latching projections 26 , 27 with the locking recesses 16 , 17 by means of a pushing movement on each in the direction of the top section 21 . | A coupling for a fluid conducting system comprises an elongated coupling part ( 1 ) and a locking part ( 20 ), which can be displaced in a direction perpendicular to the longitudinal direction and which can be mounted on the coupling part ( 1 ) in a manner that enables it to slide. The guiding of the locking part ( 20 ) ensues via detent elements ( 24, 25 ) that engage inside guide recesses ( 13 ) of the coupling part ( 1 ). The locking part ( 20 ) can be fixed in a releasing position or in a locking position by the engagement of detent projections ( 26, 27 ) inside releasing recesses ( 18, 19 ) or inside locking recesses ( 16, 17 ). This enables a relatively problem-free operating of the coupling during opening and closing. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 08/992,934, entitled “Network communications link,” filed Dec. 17, 1997, now U.S. Pat. No. 6,256,296, which is a continuation-in-part of U.S. patent application Ser. No. 09/444,422, filed Nov. 19, 1999, now abandoned, entitled “Network Communications Link”. Both of these applications are assigned to the assignee of the present patent application and are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to communication networks, and specifically to wireless communication networks based on infrared radiation.
BACKGROUND OF THE INVENTION
The Internet is the world's fastest developing mass media channel. Not only are increasing numbers of home computer users using the Internet, but most major television manufacturers are also developing or introducing Internet-connectable television sets. Since Internet connections are made primarily over telephone lines, any Internet-connectable device, whether a television or a conventional computer, must generally be placed in proximity to an existing telephone outlet, or telephone wires must be run to the location of the device.
Wireless computer communication devices and systems are known in the art. For example, cellular modems may be used without the need for telephone wires, but such modems are expensive both to purchase and to use.
A number of industry standards have also been developed for wireless infrared (IR) computer communications, including ASK, IrDA 1.0/1.1 and new, emerging standards, such as an IR bus for control of computer peripherals. Existing IR wireless communications links generally operate at low speed, however, and carry only limited digital signals, rather than video and voice information. A clear line of sight (LOS) is generally required between the two ends of the link.
Computer local area networks (LANs) based on diffuse infrared transmission are also known in the art, for example, the ControLan System, produced by Moldat of Lod, Israel, and the AndroDat System produced by Androdat GmbH of Puchheim, Germany. Diffuse signals, in contrast to direct signals, are transmitted in all directions, and therefore can create a communication link with any receiver within a given radius of the transmitter. However, the above-mentioned diffuse IR systems require ceiling-mounted relay units, which need to be fixedly mounted and connected to a source of electrical power. Generally speaking, they are not suited for connection of a single computer or Internet-enabled television to a communication line in a home or small office.
Elcom Technologies, of Canada, has recently announced the “EZONLINE” modem, which operates by modulating AC power lines, but this new technology is not yet widely used or available, nor is it really wireless, since it simply uses the AC lines in place of the telephone wires. Other companies which produce products for the communication of information over power lines, or which distribute information useful for understanding this technique, include ABP Power T&D Corp. (Raleigh, N.C.), Adaptive Networks (Brighton, Mass.), CEBus Industry Council (Indianapolis, Ind.), Echelon Corp. (Palo Alto, Calif,), Elcom Technologies Corp. (Malvern, Pa.), Electric Power Research Institute (Palo Alto, Calif.), Electronics Industries Association (Washington, D.C.), Intellon Corp. (Ocala, Fla.), Novell, Inc. (Provo, Utah), and X-10 USA, Inc. (Closter, N.J.).
SUMMARY OF THE INVENTION
It is an object of some aspects of the present invention to provide improved devices and systems for wireless computer communications.
It is another object of some aspects of the present invention to provide a wireless link between a television set and a computer network, such as the Internet.
It is a further object of some aspects of the present invention to provide a wireless control link between a television set or a computer and peripheral devices associated therewith.
It is still a further object of some aspects of the present invention to provide devices and systems for wireless telephone communications within a home or office. It is an additional object of some aspects of the present invention to provide wireless communication devices and systems that do not require a clear line of sight between the communication devices.
In preferred embodiments of the present invention, a wireless IR communications link comprises a base unit and one or more remote units. The base and remote units communicate with one another by transmitting and receiving modulated, diffuse IR radiation. The base unit is connected to a wired communication line, such as a telephone line, a cable television line, or an alternating current (AC) power line, which carries modulated communication signals, as is known in the art. Each of the remote units is preferably connected to a respective audiovisual device, such as a personal computer (PC) having a universal serial bus (USB) outlet or modem connection, or a suitably-equipped television set. Alternatively, the remote units are connected to a peripheral device, such as a keyboard, associated with such an audiovisual device. The communications link allows the audiovisual device or devices to receive and send signals over the communications line, without any wired connection to the line. The peripheral device may be used to control and interact with the audiovisual device, similarly without the need for a wired connection therewith.
Unlike IR data links known in the art, the communications link of the present invention operates at high speed, preferably between 192 kbps and 2 Mbps, most preferably at least 1 Mbps, suitable for interactive multimedia transmission. The link may therefore be used to couple the audiovisual device to a network, such as the Internet, via the telephone line or other suitable data line, including ISDN and PTSN lines, as are known in the art. The link is also suitable for conveying voice communications.
Furthermore, because the link is based on transmission and reception of diffuse IR radiation, there need not be a clear line of sight between the base and remote units. The radiation transmitted by one of the units is received by the other unit after reflection (generally diffuse reflection) from one or more surfaces in a vicinity of the units. The link is preferably used in an enclosed, indoor area, in which the IR radiation is reflected from the walls and ceiling of the area. There is no need for IR relay units mounted on the ceiling or on other surfaces, as in diffuse IR systems known in the art, and no requirement for any special wiring or installation. In some preferred embodiments of the present invention, the base unit is fixed to (a) a telephone wall outlet, (b) a cable television wall outlet, or (c) an AC power line outlet, and one of the one or more remote units is fixed to a personal computer. The communications link enables a user of the PC or television set to connect to a computer network, preferably the Internet, and to browse and view multimedia programs transmitted on the network.
Although in some preferred embodiments, only a single remote unit may be used, in other preferred embodiments of the present invention, the link connects the base unit with multiple remote units simultaneously. The base unit may communicate with the multiple remote units one at a time, in sequence, or over multiple, parallel channels. One of the units, preferably one of the remote units that is connected to a PC or Internet-enabled television, is assigned to serve as a master unit, which synchronizes and monitors transmissions from the other units. Preferably, each of the units transmits during a predetermined time slot, in accordance with a time-division multiple access (TDMA) scheme. In this manner, multiple units, preferably up to four units, but alternatively even greater numbers of units, can be linked simultaneously substantially without mutual interference.
Although preferred embodiments are described herein with reference to certain types of audiovisual devices and their connections primarily to (a) telephone communication lines, (b) cable television lines, or (c) AC power lines, it will be appreciated that the principles of the present invention may similarly be applied to produce wireless, diffuse IR communication links for other purposes. For example, such communications links may be used to connect a cordless telephone handset to a receiver, or to connect a portable Personal Digital Assistant (PDA) to a desktop computer, or to connect a digital camera to a PC or a printer. IR communication links in accordance with the principles of the present invention may carry either digital or analog data, and may operate in either half-duplex or full-duplex mode.
There is therefore provided, in accordance with a preferred embodiment of the present invention, a wireless communications link between a communication line connector and at least one audio-visual device, said communications link including:
a communication line side unit including:
a communication line side connector for engagement with said communication line connector for bidirectional audio-visual data communication, providing communication between a communication line and said at least one audio-visual device; a communication line side infrared transmitter adapted to transmit diffuse infrared radiation corresponding to said data communication; and a communication line side infrared receiver adapted to receive diffuse infrared radiation corresponding to said data communication; and
an audio-visual device side unit including:
an audio-visual device side connector for engagement with said at least one audio-visual device for bidirectional signal communication therewith via a universal serial bus (USB); an audio-visual device side infrared transmitter adapted to transmit diffuse infrared radiation to said communication line side infrared receiver; and an audio-visual device side infrared receiver adapted to receive diffuse infrared radiation from said communication line side infrared transmitter.
Preferably, said communication line includes a telephone line, and said communication line side connector is adapted to provide communication between said telephone line and said at least one audio-visual device. Alternatively or additionally, said communication line includes a cable television line, and said communication line side connector is adapted to provide communication between said cable television line and said at least audio-visual device. Further alternatively or additionally, said communication line includes a power line, and said communication line side connector is adapted to provide communication between said power line and said at least one audio-visual device.
In a preferred embodiment, said at least one audio-visual device includes a television, and said signal communication includes communication of television information over the internet.
In a preferred embodiment, said communication line side unit also includes a unitary housing enclosing said communication line side connector, said communication line side infrared transmitter and said communication line side infrared receiver.
In a preferred embodiment, said audio-visual device side unit also includes a unitary housing enclosing said audio-visual device side connector, said audio-visual device side infrared transmitter, and said audio-visual device side infrared receiver.
In a preferred embodiment, said at least one audio-visual device includes a computer. Alternatively or additionally, said audio-visual device side unit is external to said at least one audio-visual device. Further alternatively or additionally, said signal communication is full-duplex communication.
There is further provided, in accordance with a preferred embodiment of the present invention, a wireless communications adapter between a cable television line (CTL) connector and at least one audio-visual device, said communications link including:
a CTL side connector for engagement with said CTL connector for bidirectional audio-visual data communication, providing data communication between a CTL and said at least one audio-visual device;
a CTL side infrared transmitter adapted to transmit diffuse infrared radiation corresponding to said data communication; and
a CTL side infrared receiver adapted to receive diffuse infrared radiation corresponding to said data communication.
Preferably, the wireless communications adapter includes:
an audio-visual device side connector for engagement with said at least one audio-visual device for bidirectional signal communication therewith;
an audio-visual device side infrared transmitter adapted to transmit diffuse infrared radiation to said CTL side infrared receiver; and
an audio-visual device side infrared receiver adapted to receive diffuse infrared radiation from said CTL side infrared transmitter.
In a preferred embodiment, said at least one audio-visual device includes a television. Preferably, said data communication includes communication of television information over the internet.
In a preferred embodiment, a unitary housing is provided, enclosing said CTL side connector, said CTL side infrared transmitter and said CTL side infrared receiver.
There is still further provided, in accordance with a preferred embodiment of the present invention, a wireless communications adapter between an alternating current (AC) power line connector and at least one audio-visual device, said power line connector providing a connection to an AC power line over which communication signals are modulated, said communications link including:
an AC power line side connector for engagement with said AC power line connector;
a line modem, for providing bidirectional audio-visual data communication over said AC power line with said at least one audio-visual device;
an AC power line side infrared transmitter adapted to transmit diffuse infrared radiation corresponding to said data communication; and
an AC power line side infrared receiver adapted to receive diffuse infrared radiation corresponding to said data communication.
Preferably, there is provided:
an audio-visual device side connector for engagement with said at least one audio-visual device for bidirectional signal communication therewith;
an audio-visual device side infrared transmitter adapted to transmit diffuse infrared radiation to said AC power line side infrared receiver; and
an audio-visual device side infrared receiver adapted to receive diffuse infrared radiation from said AC power line side infrared transmitter.
In a preferred embodiment, there is provided a unitary housing enclosing said AC power line side connector, said AC power line side infrared transmitter and said AC power line side infrared receiver.
There is yet further provided, in accordance with a preferred embodiment of the present invention, a method for wireless communications between a communication line and at least one audio-visual device, including exchanging audio-visual data in a bidirectional manner, using diffuse infrared radiation, between an infrared unit coupled to said communication line and an infrared unit coupled via a universal serial bus (USB) to said at least one audio-visual device.
There is also provided, in accordance with a preferred embodiment of the present invention, a method for wireless communications between a cable television line and at least one audio-visual device, including exchanging audio-visual data in a bidirectional manner, using diffuse infrared radiation, between an infrared unit coupled to said cable television line and an infrared unit coupled to said at least one audio-visual device.
There is additionally provided, in accordance with a preferred embodiment of the present invention, a method for wireless communications between an alternating current (AC) power line and at least one audio-visual device, including exchanging audio-visual data in a bidirectional manner, using diffuse infrared radiation, between an infrared unit coupled to said power line and an infrared unit coupled to said at least one audio-visual device.
The present invention will be more fully understood from the following detailed description of the preferred embodiments thereof, taken together with the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic, pictorial illustration showing a wireless communications link in accordance with a preferred embodiment of the present invention;
FIG. 1B is a schematic, pictorial illustration showing a wireless communications link in accordance with another preferred embodiment of the present invention;
FIG. 1C is a schematic, pictorial illustration showing a wireless communications link in accordance with still another preferred embodiment of the present invention;
FIG. 2A is a schematic, pictorial illustration showing a wireless communication link in accordance with a preferred embodiment of the present invention;
FIG. 2B is a schematic, pictorial illustration showing a wireless communication link in accordance with another preferred embodiment of the present invention;
FIG. 3A is a schematic block diagram of a base unit in the link of FIG. 1 , in accordance with a preferred embodiment of the present invention;
FIG. 3B is a schematic block diagram of a remote unit in the link of FIG. 1 , in accordance with a preferred embodiment of the present invention;
FIG. 3C is a schematic block diagram of another remote unit in the link of FIG. 1 , in accordance with a preferred embodiment of the present invention;
FIG. 4 is a schematic timing diagram illustrating a time-division multiple access (TDMA) scheme used in the link of FIG. 1 , in accordance with a preferred embodiment of the present invention;
FIG. 5A is a schematic block diagram of a base unit in the link of FIG. 2A , in accordance with an alternative embodiment of the present invention;
FIG. 5B is a schematic block diagram of a remote unit in the link of FIG. 2A , in accordance with an alternative embodiment of the present invention;
FIG. 5C is a schematic timing diagram illustrating a time-division multiple access (TDMA) scheme for use with the base and remote units of FIGS. 5A and 5B , in accordance with a preferred embodiment of the present invention;
FIG. 6A is a schematic illustration of an optical receiver, for use in the base and remote units of FIGS. 5A and 5B , in accordance with a preferred embodiment of the present invention; and
FIG. 6B is a schematic illustration of an optical receiver, for use in the base and remote units of FIGS. 5A and 5B , in accordance with another preferred embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference is now made to FIGS. 1A , 1 B, and 1 C, which are illustrations of a network communications link 20 , in accordance with respective preferred embodiments of the present invention. Link 20 comprises a base unit 22 , which transmits and receives modulated diffuse IR radiation to/from remote units 24 and 26 . Remote unit 24 is preferably located on, or built into a web-enabled television 28 . Remote unit 26 is preferably located in or fixed to a keyboard 30 .
Alternatively or additionally, base unit 22 may transmit and receive radiation to/from remote units located on or built into a digital camera 27 or a personal data assistant 29 .
Link 20 enables a user of television 28 to communicate over the Internet or other computer network through base unit 22 . The term “web-enabled” as used herein means that the television includes circuitry for computer network communications, using the television screen as a computer monitor.
It is noted that although in FIGS. 1A , 1 B, and 1 C, the remote units are in the preferred form of printed circuit boards installed in television 28 and keyboard 30 , the remote units may also be fabricated in different forms. Other preferred forms include external assemblies that can be plugged into the television, keyboard or other remote device.
In the embodiment shown in FIG. 1A , base unit 22 is connected to a wired communication line 32 , preferably a telephone wire, located in a wall 34 . Alternatively, as shown in FIG. 13 , base unit 22 is connected to a cable television line 36 . Further alternatively, as shown in FIG. 1C , base unit 22 is connected through a line modem 39 to an AC power line 38 . In this latter case, unit 22 preferably receives power from line 38 , in addition to exchanging data therewith. Typically, unit 22 and line modem 39 comprise, or are configured to operate in conjunction with, data communication products made or described by the companies or organizations listed in the Background section of the present patent application.
In preferred embodiments of the present invention, base unit 22 communicates with remote units 24 and 26 via diffuse IR radiation, and therefore the location of base unit 22 on wall 34 does not have to be in the line of sight (LOS) of remote units 24 and 26 . The wireless communication link may be created by the reflection of the diffuse IR radiation form wall 34 , or from other surfaces within a radius of several meters at least.
FIG. 2A is an illustration of a network communications link 40 in accordance with another preferred embodiment of the present invention. Base unit 22 transmits and receives modulated diffuse IR radiation to/from a remote unit 42 . Remote unit 42 preferably connects to a connector 48 located on a modem card 46 , installed in a personal computer 50 . Base unit 22 is connected to a wired communication line, substantially as described above. In this case, link 40 enables a user of computer to communicate over a computer network. Remote unit 42 is preferably self-contained and plugs into connector 48 on the rear panel of the computer, as shown in the figure.
FIG. 2B is an illustration of a network communications link 41 , in accordance with a preferred embodiment of the present invention. Link 41 is generally similar to link 40 described hereinabove with reference to FIG. 2B , but differs in that a universal serial bus (USB) 58 couples computer 50 to remote unit 42 . By virtue of the use of USB 58 in this embodiment, remote unit 42 enables IR communications over link 41 at higher speed than can typically be achieved using a modem connection.
FIG. 3A is a schematic block diagram of base unit 22 . Wired communication line 32 is linked to a line interface chip 60 , for example, a Cermtec DAA model CH 1837 , in the base unit. Chip 60 receives and demodulates electrical signals from line 32 , as is well known in the communications art, and conveys the demodulated signals to an ASIC chip 62 . ASIC 62 preferably comprises a FPGA, and includes a CODEC and modulator and demodulator blocks. Such blocks are known in the art, and the design and production of ASIC 62 are within the capabilities of those skilled in the art of semiconductor devices. ASIC 62 encodes the electrical signals from chip 60 as pulses which drive an IR transmitter 64 , which preferably comprises an LED with suitable driver circuitry. The IR signals transmitted by transmitter 64 are received by remote units 24 and 26 , as described below.
Unit 22 further includes an IR receiver 66 , comprising a photodiode with suitable optics for receiving diffuse IR signal from remote units 24 and 26 . ASIC 62 receives electrical signals from receiver 66 , decodes these signals and conveys them to chip 60 . The chip generates appropriately modulated signals for transmission over line 32 .
The transmission and reception of the data by chip 60 and ASIC 62 are controlled by a microcontroller 68 , which performs line switching and signaling functions. Microcontroller preferably comprises a Philips 8051 microcontroller chip. Alternatively, the microcontroller may be embedded in ASIC 62 . Unit 22 is preferably powered by rechargeable batteries (not shown in the figure), which are preferably recharged from the telephone line power.
FIG. 3B is a schematic block diagram of remote unit 24 . Remote unit 24 , in its preferred configuration, comprises a printed circuit card which is installed in an audiovisual device, such as television 28 .
The circuitry of television 28 , preferably personal computer circuitry embedded in the television, connects to a personal computer (PC) interface chip 70 in unit 24 . Chip 70 may be identical to line interface chip 60 , shown in FIG. 3A , and interacts with ASIC 62 and microcontroller 68 in a manner substantially similar to that described in detail above with reference to chip 60 in unit 22 .
FIG. 3C is a schematic block diagram remote unit 26 . Remote unit 26 , in its preferred configuration, comprises a printed circuit card which is installed in a peripheral device, such as keyboard 28 . ASIC 62 , located on unit 26 , communicates with IR transmitter 64 and IR receiver 66 in a manner similar to that described in detail above. Microcontroller 68 receives user input data from keyboard 30 in a manner well known in the art, and conveys the data to ASIC 62 for transmission via transmitter 64 , as described above.
In an alternative preferred embodiment, the functions of some or all of the components in units 22 , 24 and 26 , including chip 60 , ASIC 62 , IR transmitter 64 , IR receiver 66 , microcontroller 68 and chip 70 , may be incorporated into one device or component, and relevant modules in that device may be enabled as applicable.
FIG. 4 is a schematic timing diagram representing a time-division multiple access (TDMA) scheme, or time sequencing, for transmission and reception of IR signals by units 22 , 24 and 26 making up link 20 , in accordance with a preferred embodiment of the present invention. As shown in FIG. 4 , each communication frame is divided into multiple time slots. Preferably, the data transmission rate is between 192 kbps and 2 Mbps. In the example shown in the figure, there are 16 time slots in a frame, the transmission rate is 1.024 Mbps, and each slot includes 64 bytes of data. Thus, each slot occupies 0.5 msec, and the frame length is 8 msec. Other data rates and TDMA schemes may also be used, however. The TDMA scheme facilitates orderly data transfer over link 20 , with as many as four different transmit/receive units operating simultaneously, and avoids data/communication overlap among the units.
One unit, preferably unit 24 , connected to the computer, acts as the master, with all the other units as slaves. Unit 24 issues a System Sync signal during the first slot, which synchronize the other (slave) units. The slave units, which are normally in a low-power standby mode, use the second time slot to signal master unit 24 to enter an active communication mode. Slots 4 , 5 , 6 and 7 are allotted for master unit 24 to transmit signals to the slaves. During times other than the allotted time, unit 24 receives signals from units 22 and 26 . Unit 22 is slotted to transmit in slots 8 , 9 , 10 and 11 , and similarly, keyboard unit 26 slotted in slots 12 , 13 , 14 and 15 .
FIGS. 5A and 5B are schematic block diagrams illustrating a base unit 70 and a remote unit 80 , respectively, in accordance with an alternative embodiment of the present invention. Base unit 70 and remote unit 80 may be used, for example, in place of base unit 22 and remote unit 42 , respectively, in link 40 , as shown in FIG. 2 . Units 70 and 80 each comprise a line interface chip 72 , which is preferably of a type suitable for interfacing to a PSTN telephone line, as is known in the art. Each of units 70 and 80 also comprises a two-channel, full-duplex analog transceiver 74 , coupled to IR transmitter 64 and IR receiver 66 and controlled by microprocessor 68 . These transceivers enable units 70 and 80 to communicate with one another over a full-duplex analog link at two carrier frequencies (CARRIER 1 and CARRIER 2 in the figure), preferably between 2 and 10 MHz, for example, 3.6 and 4.0 MHz.
FIG. 5C is a schematic timing diagram representing a full-duplex TDMA scheme based on carrier wave modulation, for transmission and reception of IR signals by units 70 and 80 , in accordance with a preferred embodiment of the present invention. One of the units, for example, unit 70 , is chosen to be the master unit, and transmits signals over CARRIER 1 while receiving signals over CARRIER 2 . The other unit, in this case unit 80 , functions as a slave, receiving signals on CARRIER 1 and transmitting on CARRIER 2 . As in the example of FIG. 4 , each communication frame is divided into multiple time slots. Following a synchronization slot, two slots are preferably respectively allocated for units 70 and 80 to transmit two channels of data, so as to communicate with one another and with any peripheral units, such as keyboard 30 , shown in FIGS. 1A , 1 B, and 1 C. Thereafter, time slots (marked P 1 , P 2 and P 3 ) are allocated to the peripheral units, to communicate with units 70 and 80 . It will be understood that greater or lesser numbers of time slots, data channels and peripheral units may similarly be used.
FIG. 6A is a schematic illustration showing details of IR receiver 66 , in accordance with a preferred embodiment of the present invention. Receiver 66 is shown in FIG. 6A as communicating with transceiver 74 , shown in FIGS. 5A and 5B , but it will be understood that this receiver may equally be used in any of the other base or remote units described herein.
Receiver 66 comprises a photodiode 82 , which includes an optically active area 86 , and whose output is preferably coupled via a preamplifier 92 to transceiver 74 . A non-imaging dielectric totally-internally-reflecting concentrator 88 is optically coupled at an exit surface 84 thereof to area 86 , preferably using a suitable optical bonding material. Concentrator 88 preferably comprises an optical plastic having a refractive index in the range 1.45 to 1.65, such as acrylic or polycarbonate, or alternatively may comprise an optical glass or other suitable dielectric material. Bonding material 84 preferably comprises optical epoxy or UV-cured optical cement, as are known in the art, and is chosen to give good index matching between concentrator 88 and active area 86 in order to reduce reflection losses. Alternatively, the entire assembly of receiver 66 may be molded as an integral unit, preferably by methods of injection molding known in the art.
Concentrator 88 has an acceptance angle theta, as shown in FIG. 6A , which is designed to meet the needs of a diffuse IR communications link, in accordance with preferred embodiments of the present invention, by proper selection of the shape of the concentrator and of an entrance surface 90 of the concentrator. In FIG. 6A , surface 90 is convex, so as to reduce the overall size of concentrator 88 while providing a relatively large acceptance angle, but a flat entrance surface may also be used. IR light passing through surface 90 undergoes total internal reflection at the side walls concentrator 88 , with the result that the concentrator has a high, substantially uniform light collection efficiency over substantially the entire acceptance angle theta. Preferably, concentrator 88 is designed to give theta in the range of 40-50° (half angle), which has been found to be optimal for diffuse IR communication links such as link 20 ( FIGS. 1A , 1 B, and 1 C) or links 40 and 41 (FIGS. 2 A and 2 B).
Although photodiodes with integral lenses are known in the art, their collection efficiency is typically non-uniform and may drop substantially at angles away from the optical axis. Such non-uniform response tends to cause poor and/or inconsistent reception in diffuse IR systems. By providing substantially uniform reception over a wide angle, receiver 66 using concentrator 88 improves the signal/noise ratio, reliability and insensitivity to angular alignment of IR communication links such as those described hereinabove.
FIG. 6B is a schematic illustration showing a compound parabolic concentrator 92 , coupled to photodiode 82 , in accordance with another preferred embodiment of the present invention. Concentrator 92 has a generally flat entrance surface 94 and paraboloidal side walls. Light entering through surface 94 is concentrated onto active area 86 by internal reflection at the side walls, providing a high degree of concentration. Concentrator 92 is preferably produced and bonded to photodiode 82 substantially as described above with reference to concentrator 88 .
Other types of concentrators may also be designed based on the principles of concentrators 88 and 92 . For example, an astigmatic concentrator (not shown in the figures) may be designed to concentrate radiation in only one angular direction, but not in an orthogonal direction, in a manner similar to a cylindrical lens, or to concentrate radiation over a different acceptance angle in one direction than in the other. Alternatively or additionally, multiple photodiodes, each with its own concentrator and pointed in different directions, may be used together to provide wider angular coverage. It will further be appreciated that similar concentrators may be coupled to a LED or laser diode emitter in transmitter 64 , in order to give uniform, wide-angle IR output therefrom. Such concentrators may be used in any of base or remote IR communication units 22 , 24 , 26 , 42 , 70 or 80 , as described hereinabove, as well as in other diffuse IR communication links in accordance with the principles of the present invention.
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 includes both combinations and sub-combinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art which would occur to persons skilled in the art upon reading the foregoing description. | A wireless communications link between a communication line connector and at least one audio-visual device is provided. The communications link preferably includes a communication line side unit, including: (a) a communication line side connector for engagement with the communication line connector for bidirectional audio-visual data communication, providing communication between a communication line and the at least one audio-visual device, (b) a communication line side infrared transmitter adapted to transmit diffuse infrared radiation corresponding to the data communication, and (c) a communication line side infrared receiver adapted to receive diffuse infrared radiation corresponding to the data communication. The communications link preferably also includes an audio-visual device side unit, including: (a) an audio-visual device side connector for engagement with the at least one audio-visual device for bidirectional signal communication therewith via a universal serial bus (USB), (b) an audio-visual device side infrared transmitter adapted to transmit diffuse infrared radiation to the communication line side infrared receiver, and (c) an audio-visual device side infrared receiver adapted to receive diffuse infrared radiation from the communication line side infrared transmitter. | 7 |
This is a continuation of application Ser. No. 860,462, filed May 7, 1986, which was abandoned upon the filing hereof.
BACKGROUND OF THE INVENTION
Penicillamine is a non-physiological aminoacid, namely a dimethyl derivative of cysteine.
Penicillamine can occur in two enantiomeric forms. One enantiomer form, the D-penicillamine, can be produced from natural penicillin by hydrolysis or can be produced completely synthetically.
The completely synthetic D-penicillamine can be obtained, for example, by racemic resolution of D,L-penicillamine with the help of optically active bases such as, for example, brucine, d-pseudoephedrine or 1-ephedrine (see "The Chemistry of Penicillin" 1949 Princeton University Press; compare British Pat. No. 585413, U.S. Pat. No. 2,450,784, Belgian Pat. No. 7385207) or 1-norephedrin (German Pat. No. 2138122).
An advantage of D-penicillamine over other -SH compounds, as well as over other cysteine derivatives, is its relative stability in the metabolism, through which its activity is well developed.
D-penicillamine since about 1960 has been employed in the therapy of various illnesses, thus, for example, in the progressive chronic polyarthritis, heavy metal poisonings, chronic-aggressive hepatitis, cirrhosis of the liver, cystinuria, cystine stones, sclerodermia, Morbus Wilson, Morbus Waldenstrom, schizophrenic deficiency, arteriosclerotic disorders, Lupus erythematodes and fibrosis of various genesis.
In the previous long time use of D-penicillamine its toxicology and pharmacokinetics have become well known so that even at a high dosage therapy the side effects associated therewith and the incompatibilities are controlled.
SUMMARY OF THE INVENTION
It has now been found D- and L-penicillamine as well as the D,L-racemate can also be employed for the therapy of illnesses which are distinguished by an immune deficiency syndrome. An illness with advancing more severe immune deficiency which via the development of tumors and infections lead to death is the Acquired Immune Deficiency Syndrome (AIDS). The illness (disease) was first made known in 1981 and in the meantime a viral genesis could be detected. In the search for the causes of the diseases of the immune deficiency syndrome, there was found a disturbance of the immune regulation and immune defense. The ratio of T 4 (helper cells) to T 8 (suppressor cells) is disturbed. In the year 1983, there were isolated the lymphadenopathy virus (LAV-I) and in the year 1984 there was isolated human-T-cell-leukemia virus, the HTLV-III virus, a virus of the retroviral group and which virus was proven to be the cause of AIDS. The LAV-I virus and the HTLV-III virus were found by two different investigating groups and were regarded as practically the same. To eliminate confusion these viruses are now referred to by the name HIV. The target cells of the AIDS virus are cells of the immune system. The infection remains for months to years unnoticed until finally symptoms occur, which at first appear unspecific, but in their combination and long persistence, together with a frequently arising lymphadenopathy, can be a clear indication of an infection with this virus. In the further progress of the infection, there can be severe functional disturbances of the cellular immune defense.
As a result, there occur infections with opportunistic stimulations and/or tumors, such as, for example, Kaposi sarcoma and non-Hodgkin lymphoma. The infections with opportunistic stimulations, parasites and/or the occurrence of tumors determine the progress and termination of the AIDS disease. Patients in these stages die within 36 months to an extent of above 80% due to these complications.
The following people have an increased risk of getting AIDS disease: homosexual men with frequently changing intimate partners, those dependent on i.v. dispensed drugs (fixes), heterosexual intimate partners of those who are infected and ill, immigrants or tourists to Haiti, the Carribean or equatorial Africa (e.g., Zaire), hemophiliac patients who receive concentrates of clotting factors (e.g., Factor VIII), babies of infected mothers, receivers of AIDS-virus-containing blood.
It has now been found in vitro that penicillamine can greatly inhibit the virus replication and in addition shows no toxicity to the normal cell growth. The inhibition is shown both with D- and L-penicillamine and with the D,L-racemate. At a concentrate of 20 μg/ml the replication of HTLV-III--virus (LAV-I-virus) is prevented in a cell culture with L-penicillamine to an extent of about 95% and with D-penicillamine to about 80%. At a concentration of 40 μg/ml, the effectiveness of both L-penicillamine and D-penicillamine in vitro is nearly 100%.
It is known that L-penicillamine and the D,L-racemate exhibit a higher toxicity so that for use on human the D-enantiomer is preferred.
Naturally, not only patients with clinical AIDS-symptons can be treated with the new medicament. Patients who are already infected in whose blood corresponding antibodies have been detected, without already showing the illness picture can be treated in the same manner.
The medicines which contain penicillamine as well as mixtures of it with other pharmaceutically active materials, as well as in a given case with addition of further pharmaceutical carriers can be used enterally, parenterally, vially, locally, perlingually as well as in the form of sprays.
The dispensation can be carried out, for example, in the form of tablets, capsules, pills, dragees, plugs, salves, jellies, creams, powders, dusts, aerosols, or in liquid form. As liquid forms of the use there can be employed, for example, oily or alcoholic or aqueous solutions as well as suspensions and emulsions.
Especially there are used the following medicaments:
(a) Oral forms of medicine such as granulates, tablets, dragees, capsules, etc., as well as solutions, emulsions, suspensions and the like. Thereby the dosage of D-penicillamine, for example, 125 mg, 250 mg, 300 mg, or 500 mg per individual dosage.
(b) Parenteral forms of medicine, for example, for intravenous or intramuscular injection with, for example, an active material dosage of 50 to 2000 mg per individual dosage.
Hereby penicillamine can be present, for example, in the form of D-penicillamine hydrochloride and/or D-penicillamine paratoluenesolfonate.
(c) Forms of the medicine for rectal and vaginal application. Dosage, for example, of 50 to 1000 mg per individual dosage.
The production of the medicine can be carried out using the known and customary pharmaceutical carriers and diluents as well as other customary assistants. These types of carriers and assistants are set forth, for example, in Ullmann's Encyklopadie der technischen Chemie, Vol. 4 (1953), pages 1-39; Journal of Pharmaceutical Sciences 52 (1963), pages 918 et seq.; H. v. Czetsch-Lindenwald, Hilfsstoffe fur Pharmazie und angrenzende Gebiete; Phar. Ind. 2 (1961), pages 72 et seq.; Dr. H. P. Fiedler, Lexicon angrenzende Gebiete, Cantor Kg. Aulendorf in Wurttemberg (1971).
Examples of such materials include gelatin, natural sugars such as sucrose or lactose, lecithin, pectin, starch (for example cornstarch), alginic acid, tylose, talc, lycopodium, silica (for example collodial silica), glucose, cellulose, cellulose derivatives for example, cellulose ethers in which the cellulose hydroxyl group are partially etherified with lower aliphatic alcohols and/or lower saturated oxyalcohols (for example, methyl hydroxypropyl cellulose, methyl cellulose, hydroxyethyl cellulose), stearates, e.g., methylstearate and glyceryl stearate, magnesium and calcium salts of fatty acids with 12 to 22 carbon atoms, especially saturated acids (for example, calcium stearate, calcium laurate, magnesium oleate, calcium palmitate, calcium behenate and magnesium stearate), emulsifiers, oils and fats, especially of plant origin (for example, peanut oil, castor oil, olive oil, sesame oil, cottonseed oil, corn oil, wheat germ oil, sunflower seed oil, cod-liver oil), mono, di, and triglycerides of saturated fatty acids (C 12 H 24 O 2 to C 18 H 36 O 2 and their mixtures), e.g. glyceryl monostearate, glyceryl disterate, glyceryl tristearate, glyceryl trilaurate), pharmaceutically compatible mono- or polyvalent alcohols and polyglycols such as glycerine, mannitol, sorbitol, pentaerythritol, ethyl alcohol, diethylene glycol, triethylene glycol, ethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol 400, and other polyethylene glycols, as well as derivatives of such alcohols and polyglycols, esters of saturated and unsaturated fatty acids (2 to 22 carbon atoms, especially 10 to 18 carbon atoms), with monohydric aliphatic alcohols (1 to 20 carbon atom alkanols), or polyhydric alcohols such as glycols, glycerine, diethylene glycol, pentaerythritol, sorbitol, mannitol, ethyl alcohol, butyl alcohol, octadecyl alcohol, etc., e.g., glyceryl stearate, glyceryl palmitate, glycol disterate, glycol dilaurate, glycol diacetate, monoacetin, triacetin, glyceryl oleate, ethylene glycol stearate; such esters of polyvalent alcohols can in a given case be etherified, benzyl benzoate, dioxolane, glycerine formal, tetrahydrofurfuryl alcohol, polyglycol ethers with 1 to 12 carbon atom alcohols, dimethyl acetamide, lactamide, lactates, e.g., ethyl lactate, ethyl carbonate, water, dimethyl sulfoxide, etc.
In the production of solutions, it can be necessary to produce the desired D-penicillamine concentration to employ organic solvents alone or in admixture with water. As physiologically compatible organic solvents, there can be used, for example, mono or polyhydric alcohols such as ethanol, isopropanol, butanol, ethylene glycol, propylene glycol, glycerine, diglycerine, triglycerine, polyglycerines (having 4 to 12 glycerine units), polyethylene glycols, e.g., diethylene glycol or triethylene glycol, polypropylene glycols, e.g., dipropylene glycol as well as their ethers with lower aliphatic alcohols, e.g., the mono methyl and mono ethyl ether, ethylene glycol, diethylene glycol and propylene glycol, as well as the esters with lower aliphatic carboxylic acids, e.g., ethylene glycol monoacetate, diethylene glycol monoacetate, aliphatic carboxylic acid amides (containing 1 to 10 carbon atoms), e.g., formamide, acetamide, propionamide, butyramide, decanoamide, N-alkyl substituted carboxylic acid amides such as dimethylformamide or dimethylacetamide, etc.
Furthermore, there can be added preservatives, stabilizers, buffers, for example, calcium hydrogen phosphate, collodial aluminum hydroxide, taste correctives, antioxidants and complex formers (for example, ethylene diamine tetraacetic acid, and the like, see also U. Olthoff and R. Huttenrauch, Die Pharmazie Vol. 26 No. 4 page 217 (1971). In a given case for stabilization of the D-penicillamine, there is established with physiologically compatible acids or buffers a pH in the range of 4.0-4.5.
As antioxidants, there can be used, for example, sodium metabisulfite, as preservative, for example, sorbic acid, p-hydroxybenzoic acid ethyl ester and the like. The addition of carbonyl compounds generally is not suitable.
The pharmacological and galenical handling of the compounds of the invention is carried out according to the customary standard methods (see, for example, Hagers Handbuch der Pharmazeutischen Praxis, 4th new edition Vol. VII Part A; Arzneiformen).
The addition of other medically active materials inert to D-penicillamine, above all analgetics, antihistamines, antiphlogistics, spasmolytics, geriatrics, liver therapeutics, vitamins, trace elements, and steroids especially is possible or favorable.
Preferably, the additional materials should possess no optical activity on their own, since through this it is easier to control the rotary value of the D-penicillamine.
The pharmaceutical preparations generally contain between 0.5 to 100 weight percent D-penicillamine.
It is proper to use, for example, 4 times daily 1 to 6 tablets, preferably 2 to 4 tablets, having a content of 125 mg to 500 mg, preferably 300 mg, of active material (commercial preparation Trolovol® Bayer/Degussa Pharma group). The dosaging at the beginning of the treatment should be relatively low and after about two weeks increased according to the medical necessity. With intravenous injection, it is proper to employ 1-2 times daily a 10 ml ampoule containing 1000 mg of material. It is known from research that D-penicillamine is bound to plasma proteins (preponderantly albumen). Since the concentration of the free, i.e., not protein bound D-penicillamine obviously increases with increasing dosage, for therapeutic practice there is the necessity of not having a too low dosage. The medicament after oral administration is resorbed about 60% within 2 to 3 hours. As is true with other aminoacids, it is distributed relatively quickly over the entire organism, and the non-eliminated fraction has a half-life time of 75 respectively 90 hours. Elimination is carried out predominantly via the kidneys, the greatest part as disulfide, up to 10% in unchanged form.
The accute toxicity of the D-penicillamine on the mouse (expressed by the LD 50 mg/kg; method according to Miller & Tainter, Proc. Soc. Exper. Biol. a Med. Vol. 57 (1944), pages 261 et. seq.) is for example with oral application between 7000 and 10,500 mg/kg.
In place of the D-penicillamine base, there can also be used the salts obtained by means of customary methods. As acid components for the salts there can be employed the customary pharmacologically usable acids, such as, for example, hydrochloric acid, hydrobromic acid, sulfuric acid, acetic acid, citric acid, succinic acid, maleic acid, fumaric acid, lactic acid, para toluenesulfonic acid, and the like.
Especially there can be used, for example, the anions of the following acids: HBr, HCl, HI, HNO 3 , H 2 SO 4 (SO 4 = ); H 3 PO 4 , (HPO 3 = ); camphor sulfonic acid, aliphatic or aromatic sulfonic acids, for example, C 1 -C 6 -alkylsulfonic acids (for example, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid or hexanesulfonic acid), benzenesulfonic acid or naphthalenesulfonic acid, which in a given case are substituted by one or two methyl groups (toluenesulfonic acid, especially o- or p-toluenesulfonic acid; aliphatic C 2 -C 4 -monocarboxylic acids, which in a given case are substituted by one, two, or three halogen atoms (especially Cl, F) (for example, acetic acid, propionic acid, butyric acid, chloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifuloroacetic acid; aliphatic C 2 -C 11 -dicarboxylic acids, which in a given case contain a double bond (for example, oxalic acid, malonic acid, malonic acid substituted in the 2-position by one or two C 1 -C 4 -alkyl groups, e.g., 2-methylmalonic acid, 2,2-dimethylmalonic acid, 2-propylmalonic acid, maleic acid, fumaric acid, succinic acid, decanedioic acid); aliphatic monohydroxy and dihydroxy monocarboxylic acids having 2 to 6, especially 2 to 3 carbon atoms, whereby there are preferably used--monohydroxycarboyxlic acids such as lactic acid, glyceric acid, or glycolic acid; aliphatic monohydroxy- and dihydroxy di- and tricarboxylic acids having 3 to 8 carbon atoms, especially 3 to 6 carbon atoms such as tartronic acid, malic acid, tartaric acid, malonic acid, which is substituted on the middle carbon atom by a hydroxy group and in a given case also by a C 1 -C 4 -alkyl group, isocitric acid or citric acid; phthalic acid, which in a given case is substituted by a carboxyl group (especially in the 4-position); gluconic acid; glucuronic acid; 1,1-cyclobutanedicarboxylic acid; organophosphorus acids, such as aldose and ketosephosphoric acids (for example, the corresponding mono- and diphosphoric acids) for example, aldose-6-phosphoric acids such as D- or L-glucose-6-phosphoric acid, --D-glucose-1-phosphoric acid, D-fructose-6-phosphoric acid, D-galactose-6-phosphoric acid, D-ribose-5-phosphoric acid, D-fructose-1,6-diphosphoric acid; glycerine phosphoric acids (in which case the phosphonic acid radical can be bound on a terminal or middle glycerine oxygen atom) such as α-D,L-glycerine phosphoric acid; β-glycerine phosphoric acid; N-phosphonoacetyl-aspartic acid (for example, L-aspartic acid).
It is recommended to make investigations of the blood picture and the urine before beginning the treatment with D-penicillamine. During the therapy corresponding medicine control investigations are undertaken in known manner. The effect of the treatment in addition to the improvement of the clinical symptoms is especially recognized through detecting the immunological parameter (ratio of T 4 helper cells to T 8 suppressor cells).
Pharmaceutical preparation containing completely synthetic D-penicillamine, for example, are described in British Pat. No. 1,424,432, the entire disclosure of which is hereby incorporated by reference and relied upon.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph of the effect of D- and L-penicillamine on the propagation of HTLV-III in H9 cells through the function of the concentration determined by the formation of the viral protein 15; and
FIG. 2 is a similar graph where the determination was by the formation of viral protein p24.
The process can comprise, consist essentially of, or consist of the recited steps employing a composition comprising, consisting essentially of, or consisting of the stated materials.
DETAILED DESCRIPTION
Carrying Out of Experiments
HTLV-III virus infection of H9 cells (human T-cell line of a leukemia patient of the National Cancer Institute, Bethesda, Md., USA); the H9 cells were trreated with Polybrene (Hexadimethrine bromide) (2 μg/ml) for 30 minutes at 37° C., subsequently the Polybrene was washed out and the cells were infected with 2×10 8 HTLV virus particles per 4×10 5 H9 cells. Before the infection, the virus was incubated with the material at various concentrations for 45 minutes at 37° C. For controls, the virus was incubated under the same experimental conditions but without addition of the material. The cell cultures were analyzed on the 4th day after infection as follows:
Immunofluorescence analysis: The effect of D- and L-penicillamine on the propagation of the HTLV-III virus in H9 cells was determined by measuring the proteins p15 and p24 (molecular weight 15,000 respectively 24,000) present in HTLV-III. The immunofluorescence analysis was carried out on fixed methanol:acetone (1:1) cells using monoclonal antibodies (National Cancer Institute USA) against HTLV-III p15 and p24. The infected cells treated with or without penicillamine were secured on toxoplasmosis glass slides. After 30 minutes treatment with methanol-acetone (1:1) at room temperature, the glass slides were stored in closed plastic containers at -20° C. until use. The monoclonal antibodies were added to duplicate wells, incubated at room temperature in a moist chamber for 1 hour and washed with PBS (phosphate buffered saline) solution containing 0.25% Triton X-100 for two hours. The cells were then exposed to goatantimouse IgG (Capell Labs.) bound with fluorescein (FITC) for 1 hour and washed with PBS buffer solution containing 0.25% Triton X-100 overnight. The glass sides were mounted with 50% glycerine and the cell fluorescence observed with a Zeiss fluorescence microscope.
The effect of D- and L-penicillamine on the propagation of HTLV-III in H9 cells was determined through the function of the material concentration by the formation of the viral proteins p15 (FIG. 1) and p24 (FIG. 2) in an immunofluorescence assay with monoclonal antibodies.
FIG. 1 shows a concentration dependent prevention of the formation of p15 virus protein both with L-penicillamine (black dots) and with D-penicillamine (clear dots). At lower concentration L-penicillamine is more effective than D-penicillamine. In order to reach an inhibition of 98.5% to 99.4%, a concentration of 40 μg/ml for both isomers is needed.
FIG. 2 shows the inactivation of HTLV-III by D- and L-penicillamine with the help of immunofluorescence analysis using monoclonal antibodies against viral protein p24. Both materials prevent the formation of p24 in the same manner as with viral protein p15. In order to attain a complete inactivation of the viral replication with the isomers, there is needed a concentration of 40 μg/ml.
In order to show the selectivity of the effect on the replication of HTLV-III virus, the effect of D- and L-penicillamine on the growth of H9 cells can be examined. The effects of the two materials on infected and non-infected cells is shown in Table 1.
TABLE 1______________________________________Effect of D- and L-Penicillamine on the Growthof Infected and Non-Infected H9 Cells Number of cells/ml × 10.sup.-6 non-infected InfectedExperiment 1.24 0.18μg/ml DP* LP* DP LP______________________________________ 20 30 0.27 0.35 40 1.30 1.31 0.35 0.38100 1.30 1.31 0.8 0.98500 0.84 0.94750 0.18 0.53______________________________________ *DP and LP indicate D and LPenicillamine
The number of cells was determined 4 days after the experiment began.
D-penicillamine prevents the growth of non-infected cells only from a concentration over 100 μg/ml. At a concentration of 500 μg/ml D-penicillamine shows an inhibition of cell growth of 32%, at the same concentration L-penicillamine shows an inactivation of cell growth of approximately 24%, material concentrations of more than 50 μg/ml prevent the growth of non-infected cells very greatly.
The effect of D- and L-penicillamine on the growth of infected cells in Table 1 shows the following:
4 days after the infection with the HTLV-III virus the number of H9 cells is reduced from 1.24×10 6 to 0.18×10 6 . In the presence of D- and L-penicillamine, there is found with increasing concentration a considerable increase of the cell number. This means that both materials have a protective effect on T-cells.
In general, the amount of penicillamine in the blood of the patient is between 10 and 400, preferably between 30 and 300 respectively 40 to 200, especially 40 to 100 respectively 40 to 50 micrograms per ml of blood. In order to attain this serum concentration with humans, with peroral application the following dosage is recommended.
0.5 to 3 grams, especially 0.9 grams to 2.1 grams, preferably 1.5 grams to 2 grams of D-penicillamine per day upon awakening, whereby a dosage of 3 grams per day can be given only over a time span of about 1 week, or 2 grams per day over a time span of 12 months. With intravenous application, there is recommended the giving of 1 gram to 2 grams of active material per day upon awakening, whereby from 0.5 to 1.5 grams, preferably 1 gram of D-penicillamine is dispensed in a suitable solution. With patients in infancy, the recommended dosages are reduced accordingly. The dosages also can be dispensed individually in smaller doses over the day, for example, with peroral application 1 to 6 times daily, preferably 2-4 times daily 200 mg to 500 mg D-penicillamine. An overdosage of about 4 grams of D-penicillamine over a long time span should be avoided.
All amounts added in the application refer to the penicillamine base. When using penicillamine salts, the corresponding amounts in each case are correspondingly increased.
EXAMPLE 1
Tablets
300 grams of D-penicillamine were mixed in a suitable mixer with 0.25 grams of ethylenediaminetetraacetic acid disodium salt, 30 grams of cornstarch, and 5.25 grams of highly dispersed silica and wet granulated with a solution which consisted of 12 grams of Luviskol VA 64 (high polymeric vinyl pyrrolidone/vinyl acetate copolymer in a ratio of 60:40), 102 grams of isopropanol and 6 grams of demineralized water. The wet mass is then passed through a suitable granulating machine and dried. The outer phase consisting of 90 g of corn starch, 50 g of cellulose, 10 g of highly disperse silica and 1.5 g of magnesium stearate, is then added to and homogeneously mixed with the dry, sifted granulate. The mixture is then pressed into tablets weighing 500 mg.
EXAMPLE 2
Lacquered Tablets
The tablets produced according to Example 1 are coated with a protective film soluble in gastric juices to protect them against the effect of moisture and atmospheric oxygen and also to conceal the unpleasant taste and odour of the D-penicillamine. The protective film can be applied to the tablets in a dragee vesel or suitable fluidised-bed arrangement.
87.5 ml of a suspension of the following composition are applied per 500 g=1000 tablets in the usual way (for example, in a Wurster machine):
______________________________________ in % by weight/weight______________________________________ethyl cellulose* 2%hydroxypropyl cellulose* 1%polyethylene glycol 2.5%5/6000glycerol 0.5%titanium dioxide 3.5%talcum 1.5%isopropanol 44.5%1,1,1-trichloroethane 44.5% 100.0%______________________________________ *Various ethyl and hydroxypropyl celluloses of the kind marketed by the Dow, Hercules and Syntana organisations under the names: Ethocel and Klucel, can be used as film formers.
EXAMPLE 3
Production of Gelatin Insertion Capsules With D-Penicillamine HCl
185 g of D-penicillamine HCl, 3 g of highly disperse silica and 9 g of tricalcium-phosphate are mixed and granulated in known manner with 60 g of a solution consisting of 5% of hydroxypropylmethyl cellulose, 75% by weight/volume of ethanol and 20% of demineralised water. The dry granulate is packed into gelatin insertion capsules in individual quantities of 200 mg. 1 capsule contains 185 mg of d-penicillamine HCl.
EXAMPLE 4
Production of D-penicillamine Dry Ampoules
123 g of D-penicillamine HCl (corresponding to 100 g of D-penicillamine) are dissolved under gentle heat on a water bath with distilled water to make a total volume of 500 ml. The solution is passed through a sterilising filter and introduced in 5 ml portions into suitable multidose ampoules. The aqueous content of the ampoule is frozen by generally known methods, for example by spinfreezing, and lyophilised. On completion of lyophilisation, the multidose ampoules are sealed under sterile conditions with rubber stoppers and aluminum caps.
In order to prepare an injectable solution from the dry ampoule, the lyophilisate is dissolved in 10 ml of sterile solvent. The solvent consists of an aqueous solution of tris-(hydroxymethyl)-aminomethane or of any other suitable organic base, the base having to be used in such a quantity that the injectable solution has a pH-value of from 4.0 to 4.5. 1 dry ampoule contains 1.23 g of D-penicillamine HCl corresponding to 1.0 g of D-penicillamine.
EXAMPLE 5
Production of D-Penicillamine Suppositories
300 g of D-penicillamine are worked into 1700 g of molten suppository compound (for example Hartfett DAB 7, generally with a hydroxy number of 1 to 15 preferably 2 to 5) and then poured in known manner into moulds for 2.0 g suppositories. 1 suppository contains 300 mg of D-penicillamine.
EXAMPLE 6
Production of a D-Penicillamine Ointment
50 g of D-penicillamine are dissolved in 660 g of demineralised water. The solution is introduced with continuous stirring into a melt consisting of 125 g of Emulsan MD,.sup.(1) 14 g of Lanette E.sup.(2) and 15 g of Cetiol V..sup.(3) Stirring is contained until an ointment with the active principle homogeneously distributed in it is formed. 5 g of D-penicillamine are genuinely dissolved in 100 g of ointment.
EXAMPLE 7
Production of an Inhalation Solution
100 g of D-penicillamine are dissolved under gentle heat on a water bath is distilled water, in which 0.5 g of the disodium salt and ethylene diaminotetra-acetic acid and 0.5 g of sodium metabisulphite have previously been dissolved under nitrogen, up to a total volume of 1000 ml. The solution is passed through a sterilising filter and introduced under nitrogen into 50 ml bottles. 1 ml of inhalation solution contains 50 mg of D-penicillamine.
EXAMPLE 8
Production of Gelatin Insertion Capsules with D-Penicillamine and Salicylamide
185 g of D-penicillamine HCl, 75 g of mannitol and 500 g of salicylamide are mixed and granulated in known manner with 150 g of a solution consisting of 5% of hydroxypropylmethyl cellulose, 75% by weight/volume of ethanol and 20% of demineralised water. The dried granulate is packed into gelatin insertion capsules in individual quantities of 700 mg. 1 capsule contains 185 mg of D-penicillamine HCl and 500 mg of salicylamide.
The entire disclosure of German priority application No. P.3520624.1 is hereby incorporated by reference.
The process of the invention can be used to treat humans and other animals, e.g., dogs, cats, horses, and cattle having immune deficiency illnesses. | The invention is directed to the use of penicillamine for controlling illnesses, e.g., AIDS, which are distinguished by an immune deficiency syndrome. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of co-pending U.S. application Ser. No. 14/134,292, filed on Dec. 19, 2013, now U.S. Pat. No. 9,051,206, which claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Ser. No. 61/740,790, filed on Dec. 21, 2012, and U.S. Provisional Application Ser. No. 61/909,612 filed on Nov. 27, 2013, the entire contents of each are hereby incorporated by reference.
FIELD
[0002] The present disclosure is directed to compositions and methods for making glass sheets capable of use in high performance video and information displays.
BACKGROUND
[0003] The production of liquid crystal displays, for example, active matrix liquid crystal display devices (AMLCDs) is very complex, and the properties of the substrate glass are extremely important. First and foremost, the glass substrates used in the production of AMLCD devices need to have their physical dimensions tightly controlled.
[0004] In the liquid crystal display field, thin film transistors (TFTs) based on poly-crystalline silicon are preferred because of their ability to transport electrons more effectively. Poly-crystalline based silicon transistors (p-Si) are characterized as having a higher mobility than those based on amorphous-silicon based transistors (a-Si). This allows the manufacture of smaller and faster transistors, which ultimately produces brighter and faster displays. One problem with p-Si based transistors is that their manufacture requires higher process temperatures than those employed in the manufacture of a-Si transistors. These temperatures range from 450° C. to 600° C. compared to the 350° C. peak temperatures typically employed in the manufacture of a-Si transistors. At these temperatures, most AMLCD glass substrates undergo a process known as compaction. Compaction, also referred to as thermal stability or dimensional change, is an irreversible dimensional change (shrinkage) in the glass substrate due to changes in the glass' fictive temperature. “Fictive temperature” is a concept used to indicate the structural state of a glass. Glass that is cooled quickly from a high temperature is said to have a higher fictive temperature because of the “frozen in” higher temperature structure. Glass that is cooled more slowly, or that is annealed by holding for a time near its annealing point, is said to have a lower fictive temperature. When a glass is held at an elevated temperature, the structure is allowed to relax its structure towards the heat treatment temperature. Since the glass substrate's fictive temperature is almost always above the relevant heat treatment temperatures in thin film transistor (TFT) processes, this structural relaxation causes a decrease in fictive temperature which therefore causes the glass to compact (shrink/densify).
[0005] It would be advantageous to minimize the level of compaction in the glass because compaction creates possible alignment issues during the display manufacturing process which in turn results in resolution problems in the finished display.
[0006] There are several approaches to minimize compaction in glass. One is to thermally pretreat the glass to create a fictive temperature similar to the one the glass will experience during the p-Si TFT manufacture. There are several difficulties with this approach. First, the multiple heating steps employed during the p-Si TFT manufacture create slightly different fictive temperatures in the glass that cannot be fully compensated for by this pretreatment. Second, the thermal stability of the glass becomes closely linked to the details of the p-Si TFT manufacture, which could mean different pretreatments for different end-users. Finally, pretreatment adds to processing costs and complexity.
[0007] Another approach is to increase the anneal point of the glass. Glasses with higher anneal will have a higher fictive temperature and will compact less than when subjected to the elevated temperatures associated with panel manufacture. The challenge with this approach, however, is the production of high annealing point glass that is cost effective. The main factors impacting cost are defects and asset lifetime. Higher anneal point glasses typically employ higher operational temperatures during their manufacture thereby reducing the lifetime of the fixed assets associated with glass manufacture.
[0008] Yet another approach involves slowing the cooling rate during manufacture. While such an approach has merits, some manufacturing techniques such as the fusion process result in rapid quenching of the glass sheet from the melt and a relatively high temperature structure is “frozen in”. While some controlled cooling is possible with such a manufacturing process, it is difficult to control.
SUMMARY
[0009] What is disclosed is a glass substrate with exceptional total pitch variability (TPV), as measured by three metrics: (1) compaction in the High Temperature Test Cycle (HTTC) less than 40 ppm, (2) compaction in the Low Temperature Test Cycle (LTTC) less than 5.5 ppm, and (3) stress relaxation rate consistent with less than 50% relaxed in the Stress Relaxation Test Cycle. By satisfying all three criteria with a single glass product, the substrate is assured of being acceptable for the highest resolution TFT cycles. Recent understanding of the underlying physics of glass relaxation has allowed the applicants to disclose glasses that satisfy all three criteria.
[0010] The present disclosure describes a glass sheet for use in high performance video or information displays meeting the following performance criteria: compaction in the low temperature test cycle of less than or equal to 5.5 ppm, compaction in the high temperature test cycle of less than or equal to 40 ppm, and less than 50% of an induced stress level in the stress relaxation test cycle. More specifically, the present disclosure provides glass compositions satisfying the above criteria and having a coefficient of thermal expansion compatible with silicon, being substantially alkali-free, arsenic free and antimony free. More specifically, the glasses of the present disclosure further exhibit densities less than 2.6 g/cc, transmission at 300 nm greater than 50% for a 0.5 mm thick sheet, and (MgO+CaO+SrO+BaO)/Al 2 O 3 less than 1.25.
[0011] In accordance with certain of its other aspects, the glasses possess high annealing points and high liquidus viscosities, thus reducing or eliminating the likelihood of devitrification on the forming mandrel. As a result of specific details of their composition, the disclosed glasses melt to good quality with very low levels of gaseous inclusions, and with minimal erosion to precious metals, refractories, and tin oxide electrode materials. Additional advantages will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the aspects described below. The advantages described below will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying figures, which are incorporated in and constitute a part of this specification, illustrate several aspects described below.
[0013] FIG. 1 is a graphical representation of the high thermal temperature cycle as described in the disclosure in terms of temperature over a set time period.
[0014] FIG. 2 is a graphical representation of the low thermal temperature cycle as described in the disclosure in terms of temperature over a set time period.
[0015] FIG. 3 is a graphical representation of compaction as measured in the High Temperature Test Cycle (HTTC) as a function of annealing points (in C) of studied glasses.
[0016] FIG. 4 is a graphical representation of compaction as measured in the Low Temperature Test Cycle (LTTC) as a function of annealing points (in C) of studied glasses.
[0017] FIG. 5 is a graphical representation of the percent of stress relaxed after the Stress Relaxations Test Cycle (SRTC)—60 minutes at 650 C—plotted as a function of annealing points (in C) of studied glasses. Glasses relaxing less than 50% of the stress are pointed out as key to this disclosure.
[0018] FIG. 6A is a graphical representation of glasses satisfying the compaction aspect of the present disclosure as contained in region “ 1 ”. Glasses located in region 1 also possess the stress relaxation rates embodied in the disclosure.
[0019] FIG. 6B is a graphical representation showing the enlgaed region “ 1 ” from FIG. 6A .
DETAILED DESCRIPTION
[0020] Historically, panel makers have generally made either “large, low resolution” or “small, high resolution” displays. In both of these cases, glasses were held at elevated temperatures, causing the glass substrates to undergo a process known as compaction.
[0021] The amount of compaction exhibited by a glass substrate experiencing a given time/temperature profile can be described by the equation
[0000]
T
f
(
t
)
-
T
=
(
T
f
(
t
=
0
)
-
T
)
exp
[
-
(
t
τ
(
T
)
)
b
]
[0022] where T f (t) is the fictive temperature of the glass as a function of time, T is the heat treatment temperature, T f (t=0) is the initial fictive temperature, b is the “stretching exponent”, and τ(T) is the relaxation time of the glass at the heat treatment temperature. While increasing the heat treatment temperature (T) lowers the “driving force” for compaction (i.e. making “T f (t=0)−T” a smaller quantity), it causes a much larger decrease in the relaxation time τ of the substrate. Relaxation time varies exponentially with temperature, causing an increase in the amount of compaction in a given time when the temperature is raised.
[0023] For the manufacturing of large, low-resolution displays using amorphous silicon (a-Si) based TFTs, the processing temperatures are relatively low (roughly 350° C. or less). These low temperatures, coupled with the loose dimensional stability requirements for low resolution displays, allow the use of low annealing point (T(ann)) glasses with higher fictive temperatures. The annealing point is defined as the temperature where the glass's viscosity is equal to 10 13.18 Poise. T(ann) is used as a simple metric to represent the low temperature viscosity of a glass, defined as the effective viscosity of the glass at a given temperature below the glass transition temperature. A higher “low temperature viscosity” causes a longer relaxation time through the Maxwell relationship
[0000]
τ
(
T
)
≈
η
(
T
)
G
[0000] where η is the viscosity and G is the shear modulus. Higher performance small, high-resolution displays have generally been made using poly-silicon based (p-Si) TFTs, which employ considerably higher temperatures than a-Si processes. Because of this, either higher annealing point or lower fictive temperature glasses were required to meet the compaction requirements for p-Si based TFTs. Considerable efforts have been made to create higher annealing point glasses compatible with existing manufacturing platforms or improve the thermal history of lower annealing point glasses to enable use in these processes and both paths have been shown to be adequate for previous generations of high performance displays. Recently, however, the p-Si based displays are now being made on even larger “gen size” sheets (many small displays on a single large sheet of glass) and the registry marks are placed much earlier in the TFT process. These two factors have forced the glass substrate to have even better high temperature compaction performance and have caused compaction in lower temperature steps to become a relevant (and perhaps even dominant) source of total pitch variability. Total pitch variability (TPV) refers to the variation in alignment of features (such as registry marks). TPV results from different sources during the processing of a large sheet of glass. As will be shown, adequate high temperature compaction does not necessarily translate to adequate low temperature performance or adequate TPV.
[0024] In order to reach higher mobilities in large displays, panel makers have begun making large, high-resolution displays using oxide thin film transistors (OxTFTs). While OxTFT processes are often run with peak temperatures similar to a-Si based TFTs (and often using the same equipment), the resolution requirements are considerably higher, which means low temperature compaction must be considerably improved relative to that of a-Si substrates. In addition to the tight requirements placed on low temperature compaction, the film stresses accumulated in the OxTFT processes have caused stress relaxation in the glass to become a major contributor to the overall TPV.
[0025] The applicants have realized that thermal cycles indicate TPV to be the most important description of dimensional stability, which incorporates compaction as well as the stress relaxation component. This coexistence of high and low temperature compaction in the same processes and the introduction of stress relaxation as a key substrate attribute in this new generation of high performance displays has shown all present commercially available substrates to be insufficient. Table 1 discloses glass compositions that can simultaneously manage all three aspects of TPV—low temperature compaction, high temperature compaction and stress relaxation.
[0026] Described herein are glasses that are substantially free of alkalis that possess high annealing points and, thus, good dimensional stability (i.e., low compaction) for use as TFT backplane substrates in amorphous silicon, oxide and low-temperature polysilicon TFT processes. The glasses of the present disclosure are capable of managing all three aspects of TPV—low temperature compaction, high temperature compaction and stress relaxation.
[0027] A high annealing point glass can prevent panel distortion due to compaction/shrinkage during thermal processing subsequent to manufacturing of the glass. In one embodiment, the disclosed glasses also possess unusually high liquidus viscosity, and thus a significantly reduced risk to devitrification at cold places in the forming apparatus. It is to be understood that while low alkali concentrations are generally desirable, in practice it may be difficult or impossible to economically manufacture glasses that are entirely free of alkalis. The alkalis in question arise as contaminants in raw materials, as minor components in refractories, etc., and can be very difficult to eliminate entirely. Therefore, the disclosed glasses are considered substantially free of alkalis if the total concentration of the alkali elements Li 2 O, Na 2 O, and K 2 O is less than about 0.1 mole percent (mol %).
[0028] In one aspect, the substantially alkali-free glasses have annealing points greater than about 765° C., preferably greater than 775° C., and more preferably greater than 785° C. Such high annealing points result in low rates of relaxation—and hence comparatively small amounts of dimensional change—for the disclosed glass to be used as backplane substrate in a low-temperature polysilicon process. In another aspect, the temperature of the disclosed glasses at a viscosity of about 35,000 poise (T 35 k ) is less than about 1310° C. The liquidus temperature of a glass (T liq ) is the highest temperature above which no crystalline phases can coexist in equilibrium with the glass. In another aspect, the viscosity corresponding to the liquidus temperature of the glass is greater than about 150,000 poise, more preferably greater than 200,000 poise, and most preferably greater than 250,000 poise. In another aspect, the disclosed glass is characterized in that T 35 k −T liq >0.25 T 35 k −225° C. This ensures minimum tendency to devitrify on the forming mandrel of the fusion process.
[0029] In one aspect, the substantially alkali-free glass comprises in mole percent on an oxide basis:
SiO 2 50-85 Al 2 O 3 0-20 B 2 O 3 0-10 MgO 0-20 CaO 0-20 SrO 0-20 BaO 0-20
wherein
[0000] 0.9≦(MgO+CaO+SrO+BaO)/Al 2 O 3 ≦3,
[0000] where Al 2 O 3 , MgO, CaO, SrO, BaO represent the mole percents of the respective oxide components.
[0037] In a further aspect, the substantially alkali-free glass comprises in mole percent on an oxide basis:
SiO 2 68-74 Al 2 O 3 10-13 B 2 O 3 0-5 MgO 0-6 CaO 4-9 SrO 1-8 BaO 0-5
wherein
[0000] 1.05≦(MgO+CaO+SrO+BaO)/Al 2 O 3 ≦1.2,
[0000] where Al 2 O 3 , MgO, CaO, SrO, BaO represent the mole percents of the respective oxide components.
[0045] In one aspect, the disclosed glass includes a chemical fining agent. Such fining agents include, but are not limited to, SnO 2 , As 2 O 3 , Sb 2 O 3 , F, Cl and Br, and in which the concentrations of the chemical fining agents are kept at a level of 0.5 mol % or less. Chemical fining agents may also include CeO 2 , Fe 2 O 3 , and other oxides of transition metals, such as MnO 2 . These oxides may introduce color to the glass via visible absorptions in their final valence state(s) in the glass, and thus their concentration is preferably kept at a level of 0.2 mol % or less.
[0046] In one aspect, the disclosed glasses are manufactured into sheet via the fusion process. The fusion draw process results in a pristine, fire-polished glass surface that reduces surface-mediated distortion to high resolution TFT backplanes and color filters. The downdraw sheet drawing processes and, in particular, the fusion process described in U.S. Pat. Nos. 3,338,696 and 3,682,609 (both to Dockerty), which are incorporated by reference, can be used herein. Compared to other forming processes, such as the float process, the fusion process is preferred for several reasons. First, glass substrates made from the fusion process do not require polishing. Current glass substrate polishing is capable of producing glass substrates having an average surface roughness greater than about 0.5 nm (Ra), as measured by atomic force microscopy. The glass substrates produced by the fusion process have an average surface roughness as measured by atomic force microscopy of less than 0.5 nm. The substrates also have an average internal stress as measured by optical retardation which is less than or equal to 150 psi.
[0047] While the disclosed glasses are compatible with the fusion process, they may also be manufactured into sheets or other ware through less demanding manufacturing processes. Such processes include slot draw, float, rolling, and other sheet-forming processes known to those skilled in the art.
[0048] Relative to these alternative methods for creating sheets of glass, the fusion process as discussed above is capable of creating very thin, very flat, very uniform sheets with a pristine surface. Slot draw also can result in a pristine surface, but due to change in orifice shape over time, accumulation of volatile debris at the orifice-glass interface, and the challenge of creating an orifice to deliver truly flat glass, the dimensional uniformity and surface quality of slot-drawn glass are generally inferior to fusion-drawn glass. The float process is capable of delivering very large, uniform sheets, but the surface is substantially compromised by contact with the float bath on one side, and by exposure to condensation products from the float bath on the other side. This means that float glass must be polished for use in high performance display applications.
[0049] Unfortunately, and in unlike the float process, the fusion process results in rapid cooling of the glass from high temperature, and this results in a high fictive temperature T f , the fictive temperature can be thought of as representing the discrepancy between the structural state of the glass and the state it would assume if fully relaxed at the temperature of interest. We consider now the consequences of reheating a glass with a glass transition temperature T g to a process temperature T p such that T p <T g ≦T f . Since T p <T f , the structural state of the glass is out of equilibrium at T p , and the glass will spontaneously relax toward a structural state that is in equilibrium at T p . The rate of this relaxation scales inversely with the effective viscosity of the glass at T p , such that high viscosity results in a slow rate of relaxation, and a low viscosity results in a fast rate of relaxation. The effective viscosity varies inversely with the fictive temperature of the glass, such that a low fictive temperature results in a high viscosity, and a high fictive temperature results in a comparatively low viscosity. Therefore, the rate of relaxation at T p scales directly with the fictive temperature of the glass. A process that introduces a high fictive temperature results in a comparatively high rate of relaxation when the glass is reheated at T p .
[0050] One means to reduce the rate of relaxation at T p is to increase the viscosity of the glass at that temperature. The annealing point of a glass represents the temperature at which the glass has a viscosity of 10 13.2 poise. As temperature decreases below the annealing point, the viscosity of the supercooled melt increases. At a fixed temperature below T g , a glass with a higher annealing point has a higher viscosity than a glass with a lower annealing point. Therefore, to increase the viscosity of a substrate glass at T p , one might choose to increase its annealing point. Unfortunately, it is generally the case that the composition changes necessary to increase the annealing point also increase viscosity at all other temperature. In particular, the fictive temperature of a glass made by the fusion process corresponds to a viscosity of about 10 11 -10 12 poise, so an increase in annealing point for a fusion-compatible glass generally increases its fictive temperature as well. For a given glass, higher fictive temperature results in lower viscosity at temperature below T g , and thus increasing fictive temperature works against the viscosity increase that would otherwise be obtained by increasing the annealing point. To see a substantial change in the rate of relaxation at T p , it is generally necessary to make relatively large changes in annealing point. An aspect of the disclosed glass is that it has an annealing point greater than about 765° C., in another aspect greater than 775° C., and in yet another aspect greater than 785° C. Such high annealing points results in acceptably low rates of thermal relaxation during low-temperature TFT processing, e.g., typical low-temperature polysilicon rapid thermal anneal cycles.
[0051] In addition to its impact on fictive temperature, increasing annealing point also increases temperatures throughout the melting and forming system, particularly the temperatures on the isopipe as utilized as the forming apparatus in the fusion process. For example, Eagle XG® and Lotus™ (Corning Incorporated, Corning, N.Y.) have annealing points that differ by about 50° C., and the temperature at which they are delivered to the isopipe also differ by about 50° C. When held for extended periods of time above about 1310° C., zircon refractory shows thermal creep, and this can be accelerated by the weight of the isopipe itself plus the weight of the glass on the isopipe. A second aspect of the disclosed glasses is that their delivery temperatures are less than 1310° C. Such delivery temperatures permit extended manufacturing campaigns without replacing the isopipe.
[0052] In manufacturing trials of glasses with high annealing points and delivery temperatures below 1310° C., it was discovered that they showed a greater tendency toward devitrification on the root of the isopipe and—especially—the edge directors relative to glasses with lower annealing points. Careful measurement of the temperature profile on the isoipe showed that the edge director temperatures were much lower relative to the center root temperature than had been anticipated due to radiative heat loss. The edge directors typically must be maintained at a temperature below the center root temperature in order to ensure that the glass is viscous enough as it leaves the root that it puts the sheet in between the edge directors under tension, thus maintaining a flat shape. As they are at either end of the isopipe, the edge directors are difficult to heat, and thus the temperature difference between the center of the root and the edge directors may differ by 50° or more.
[0053] Since radiative heat loss increases with temperature, and since high annealing point glasses generally are formed at higher temperatures than lower annealing point glasses, the temperature difference between the center root and the edge director generally increases with the annealing point of the glass. This has a direct consequence as regards the tendency of a glass to form devitrification products on the isopipe or edge directors. The liquidus temperature of a glass is defined as the highest temperature at which a crystalline phase would appear if a glass were held indefinitely at that temperature. The liquidus viscosity is the viscosity of a glass at the liquidus temperature. To completely avoid devitrification on an isopipe, it is desirable that the liquidus viscosity be high enough to ensure that glass is no longer on the isopipe refractory or edge director material at or near the liquidus temperature.
[0054] In practice, few alkali-free glasses have liquidus viscosities of the desired magnitude. Experience with substrate glasses suitable for amorphous silicon applications (e.g., Eagle XG®) indicated that edge directors could be held continuously at temperatures up to 60° below the liquidus temperature of certain alkali-free glasses. While it was understood that glasses with higher annealing points would require higher forming temperatures, it was not anticipated that the edge directors would be so much cooler relative to the center root temperature. A useful metric for keeping track of this effect is the difference between the delivery temperature onto the isopipe and the liquidus temperature of the glass, T liq . In the fusion process, it is generally desirable to deliver glass at about 35,000 poise, and the temperature corresponding to a viscosity of 35,000 poise is conveniently represented as T 35 k . For a particular delivery temperature, it is always desirable to make T 35 k −T liq as large possible, but for an amorphous silicon substrate such as Eagle XG®, it is found that extended manufacturing campaigns can be conducted if T 35 k −T liq is about 80° or more. As temperature increases, T 35 k −T liq must increase as well, such that for T 35 k near 1300°, it is desirable that T 35 k −T liq at least about 100°. The minimum useful value for T 35 k −T liq varies approximately linearly with temperature from about 1200° C. to about 1320° C., and can be expressed as
[0000] minimum T 35 k −T liq =0.25 T 35 k −225,
[0000] where all temperatures are in ° C. Thus, a further aspect of the disclosed glass is that T 35 k −T liq >0.257T 35 k −225° C.
[0055] In addition to this criterion, the fusion process requires a glass with a high liquidus viscosity. This is necessary so as to avoid devitrification products at interfaces with glass and to minimize visible devitrification products in the final glass. For a given glass compatible with fusion for a particular sheet size and thickness, adjusting the process so as to manufacture wider sheet or thicker sheet generally results in lower temperatures at either end of the isopipe (the forming mandrel for the fusion process). Thus, disclosed glasses with higher liquidus viscosities provide greater flexibility for manufacturing via the fusion process.
[0056] In tests of the relationship between liquidus viscosity and subsequent devitrification tendencies in the fusion process, it has been observed that high delivery temperatures such as those of the disclosed glasses generally require higher liquidus viscosities for long-term production than would be the case for typical AMLCD substrate compositions with lower annealing points. While not wishing to be bound by theory, this requirement appears to arise from accelerated rates of crystal growth as temperature increases. Fusion is essentially an isoviscous process, so a more viscous glass at some fixed temperature must be formed by fusion at higher temperature than a less viscous glass. While some degree of undercooling (cooling below the liquidus temperature) can be sustained for extended periods in a glass at lower temperature, crystal growth rates increase with temperature, and thus more viscous glasses grow an equivalent, unacceptable amount of devitrification products in a shorter period of time than less viscous glasses. Depending on where they form, devitrification products can compromise forming stability, and introduce visible defects into the final glass.
[0057] To be formed by the fusion process, it is desirable that the disclosed glass compositions have a liquidus viscosity greater than or equal to 200,000 poises, more preferably greater than or equal to 250,000 poises, higher liquidus viscosities being preferable. A surprising result is that throughout the range of the disclosed glasses, it is possible to obtain a liquidus temperature low enough, and a viscosity high enough, such that the liquidus viscosity of the glass is unusually high compared to compositions outside of the disclosed range.
[0058] Of course, the present disclosure is not limited to use with the fusion process and accordingly for the float process, the liquidus viscosity conditions as well as other fusion specific criteria described above would not be necessary, thereby extending the composition windows for those processes.
[0059] In the glass compositions described herein, SiO 2 serves as the basic glass former. The SiO 2 content may be from 50-80 mole percent. In certain aspects, the concentration of SiO 2 can be greater than 68 mole percent in order to provide the glass with a density and chemical durability suitable for a flat panel display glass (e.g., an AMLCD glass), and a liquidus temperature (liquidus viscosity), which allows the glass to be formed by a downdraw process (e.g., a fusion process). In one embodiment, the SiO 2 concentration may be less than or equal to about 74 mole percent to allow batch materials to be melted using conventional, high volume, melting techniques, e.g., Joule melting in a refractory melter. As the concentration of SiO 2 increases, the 200 poise temperature (melting temperature) generally rises. In various applications, the SiO 2 concentration is adjusted so that the glass composition has a melting temperature less than or equal to 1,725° C. In one aspect, the SiO 2 concentration is between 70 and 73 mole percent.
[0060] Al 2 O 3 is another glass former used to make the glasses described herein. In one embodiment, the Al 2 O 3 concentration is 0-20 mole percent. In another embodiment and as a consideration for glasses made by the fusion process, an Al 2 O 3 concentration greater than or equal to 10 mole percent provides the glass with a low liquidus temperature and high viscosity, resulting in a high liquidus viscosity. The use of at least 10 mole percent Al 2 O 3 also improves the glass's annealing point and modulus. For embodiments having the ratio (MgO+CaO+SrO+BaO)/Al 2 O 3 greater than or equal to 1.05, it is desirable to keep the Al 2 O 3 concentration below about 13 mole percent. In one aspect, the Al 2 O 3 concentration is between 10 and 13 mole percent.
[0061] B 2 O 3 is both a glass former and a flux that aids melting and lowers the melting temperature. Its impact on liquidus temperature is at least as great as its impact on viscosity, so increasing B 2 O 3 can be used to increase the liquidus viscosity of a glass. In one embodiment, the B 2 O 3 content is 0-10 mole percent, and in another embodiment between 0-6 mole percent. In another embodiment, the glass compositions described herein have B 2 O 3 concentrations that are equal to or greater than 1 mole percent. As discussed above with regard to SiO 2 , glass durability is very important for LCD applications. Durability can be controlled somewhat by elevated concentrations of alkaline earth oxides, and significantly reduced by elevated B 2 O 3 content. Annealing point decreases as B 2 O 3 increases, so it is desirable to keep B 2 O 3 content low relative to its typical concentration in amorphous silicon substrates. Thus in one aspect, the glasses described herein have B 2 O 3 concentrations that are between 1 and 5 mole percent. In another aspect, the glasses have a B 2 O 3 content between 2 and 4.5 mol percent. In yet another aspect, the glasses of the present invention have a B 2 O 3 content of between 2.5 and 4.5 mol percent.
[0062] The Al 2 O 3 and B 2 O 3 concentrations can be selected as a pair to increase annealing point, increase modulus, improve durability, reduce density, and reduce the coefficient of thermal expansion (CTE), while maintaining the melting and forming properties of the glass.
[0063] For example, an increase in B 2 O 3 and a corresponding decrease in Al 2 O 3 can be helpful in obtaining a lower density and CTE, while an increase in Al 2 O 3 and a corresponding decrease in B 2 O 3 can be helpful in increasing annealing point, modulus, and durability, provided that in some embodiments where (MgO+CaO+SrO+BaO)/Al 2 O 3 control is sought, increase in Al 2 O 3 does not reduce the (MgO+CaO+SrO+BaO)/Al 2 O 3 ratio below about 0.9 in one embodiment and 1.05 in another embodiment. For (MgO+CaO+SrO+BaO)/Al 2 O 3 ratios below about 1.0, it may be difficult or impossible to remove gaseous inclusions from the glass due to late-stage melting of the silica raw material. Furthermore, when (MgO+CaO+SrO+BaO)/Al 2 O 3 ≦1.05, mullite, an aluminosilicate crystal, can appear as a liquidus phase. Once mullite is present as a liquidus phase, the composition sensitivity of liquidus increases considerably, and mullite denitrification products both grow very quickly and are very difficult to remove once established. Thus in one aspect, the glasses described herein have (MgO+CaO+SrO+BaO)/Al 2 O 3 ≧1.05. An upper end of (MgO+CaO+SrO+BaO)/Al 2 O 3 may be as high as 3, depending on the forming process, but in one embodiment and as described immediately below, are less than or equal to 1.2. In another embodiment, less than or equal to 1.6; and in yet another embodiment, less than or equal to 1.4.
[0064] In addition to the glass formers (SiO 2 , Al 2 O 3 , and B 2 O 3 ), the glasses described herein also include alkaline earth oxides. In one aspect, at least three alkaline earth oxides are part of the glass composition, e.g., MgO, CaO, and BaO, and, optionally, SrO. The alkaline earth oxides provide the glass with various properties important to melting, fining, forming, and ultimate use. Accordingly, to improve glass performance in these regards, in one aspect, the (MgO+CaO+SrO+BaO)/Al 2 O 3 ratio is greater than or equal to 1.05. As this ratio increases, viscosity tends to increase more strongly than liquidus temperature, and thus it is increasingly difficult to obtain suitably high values for T 35 k −T liq . Thus in another aspect, ratio (MgO+CaO+SrO+BaO)/Al 2 O 3 is less than or equal to 1.2.
[0065] For certain embodiments of this invention, the alkaline earth oxides may be treated as what is in effect a single compositional component. This is because their impact upon viscoelastic properties, liquidus temperatures and liquidus phase relationships are qualitatively more similar to one another than they are to the glass forming oxides SiO 2 , Al 2 O 3 and B 2 O 3 . However, the alkaline earth oxides CaO, SrO and BaO can form feldspar minerals, notably anorthite (CaAl 2 Si 2 O 8 ) and celsian (BaAl 2 Si 2 O 8 ) and strontium-bearing solid solutions of same, but MgO does not participate in these crystals to a significant degree. Therefore, when a feldspar crystal is already the liquidus phase, a superaddition of MgO may serves to stabilize the liquid relative to the crystal and thus lower the liquidus temperature. At the same time, the viscosity curve typically becomes steeper, reducing melting temperatures while having little or no impact on low-temperature viscosities. In this sense, the addition of small amounts of MgO benefits melting by reducing melting temperatures, benefits forming by reducing liquidus temperatures and increasing liquidus viscosity, while preserving high annealing point and, thus, low compaction.
[0066] Glasses for use in AMLCD applications should have CTEs (0-300° C.) in the range of 28-42×10 −7 /° C., preferably, 30-40×10 −7 /° C., and more preferably, 32-38×10 −7 /° C., or in other embodiments 33-37×10 −7 /° C. For certain applications, density is important as weight of the final display may be an important attribute.
[0067] Calcium oxide present in the glass composition can produce low liquidus temperatures (high liquidus viscosities), high annealing points and moduli, and CTE's in the most desired ranges for flat panel applications, specifically, AMLCD applications. It also contributes favorably to chemical durability, and compared to other alkaline earth oxides, it is relatively inexpensive as a batch material. However, at high concentrations, CaO increases the density and CTE. Furthermore, at sufficiently low SiO 2 concentrations, CaO may stabilize anorthite, thus decreasing liquidus viscosity. Accordingly, in one aspect, the CaO concentration can be greater than or equal 0 to 20 mole percent. In another aspect, the CaO concentration of the glass composition is between about 4 and 9 mole percent. In another aspect, the CaO concentration of the glass composition is between about 4.5 and 6 mole percent.
[0068] SrO and BaO can both contribute to low liquidus temperatures (high liquidus viscosities) and, thus, the glasses described herein will typically contain at least both of these oxides. However, the selection and concentration of these oxides are selected in order to avoid an increase in CTE and density and a decrease in modulus and annealing point. For glasses made by a downdraw process, the relative proportions of SrO and BaO can be balanced so as to obtain a suitable combination of physical properties and liquidus viscosity.
[0069] On top of these considerations, the glasses are preferably formable by a downdraw process, e.g., a fusion process, which means that the glass' liquidus viscosity needs to be relatively high. Individual alkaline earths play an important role in this regard since they can destabilize the crystalline phases that would otherwise form. BaO and SrO are particularly effective in controlling the liquidus viscosity and are included in the glasses of the invention for at least this purpose. As illustrated in the examples presented below, various combinations of the alkaline earths will produce glasses having high liquidus viscosities, with the total of the alkaline earths satisfying the RO/Al 2 O 3 ratio constraints needed to achieve low melting temperatures, high annealing points, and suitable CTE's.
[0070] The glass compositions are generally alkali free; however, the glasses can contain some alkali contaminants. In the case of AMLCD applications, it is desirable to keep the alkali levels below 0.1 mole percent to avoid having a negative impact on thin film transistor (TFT) performance through diffusion of alkali ions from the glass into the silicon of the TFT. As used herein, an “alkali-free glass” is a glass having a total alkali concentration which is less than or equal to 0.1 mole percent, where the total alkali concentration is the sum of the Na 2 O, K 2 O, and Li 2 O concentrations. In one aspect, the total alkali concentration is less than or equal to 0.1 mole percent.
[0071] On an oxide basis, the glass compositions described herein can have one or more or all of the following compositional characteristics: (i) an As 2 O 3 concentration of at most 0.05 mole percent; (ii) an Sb 2 O 3 concentration of at most 0.05 mole percent; (iii) a SnO 2 concentration of at most 0.25 mole percent.
[0072] As 2 O 3 is an effective high temperature fining agent for AMLCD glasses, and in some aspects described herein, As 2 O 3 is used for fining because of its superior fining properties. However, As 2 O 3 is poisonous and requires special handling during the glass manufacturing process. Accordingly, in certain aspects, fining is performed without the use of substantial amounts of As 2 O 3 , i.e., the finished glass has at most 0.05 mole percent As 2 O 3 . In one aspect, no As 2 O 3 is purposely used in the fining of the glass. In such cases, the finished glass will typically have at most 0.005 mole percent As 2 O 3 as a result of contaminants present in the batch materials and/or the equipment used to melt the batch materials.
[0073] Although not as toxic as As 2 O 3 , Sb 2 O 3 is also poisonous and requires special handling. In addition, Sb 2 O 3 raises the density, raises the CTE, and lowers the annealing point in comparison to glasses that use As 2 O 3 or SnO 2 as a fining agent. Accordingly, in certain aspects, fining is performed without the use of substantial amounts of Sb 2 O 3 , i.e., the finished glass has at most 0.05 mole percent Sb 2 O 3 . In another aspect, no Sb 2 O 3 is purposely used in the fining of the glass. In such cases, the finished glass will typically have at most 0.005 mole percent Sb 2 O 3 as a result of contaminants present in the batch materials and/or the equipment used to melt the batch materials.
[0074] Compared to As 2 O 3 and Sb 2 O 3 fining, tin fining (i.e., SnO 2 fining) is less effective, but SnO 2 is a ubiquitous material that has no known hazardous properties. Also, for many years, SnO 2 has been a component of AMLCD glasses through the use of tin oxide electrodes in the Joule melting of the batch materials for such glasses. The presence of SnO 2 in AMLCD glasses has not resulted in any known adverse effects in the use of these glasses in the manufacture of liquid crystal displays. However, high concentrations of SnO 2 are not preferred as this can result in the formation of crystalline defects in AMLCD glasses. In one aspect, the concentration of SnO 2 in the finished glass is less than or equal to 0.25 mole percent.
[0075] Tin fining can be used alone or in combination with other fining techniques if desired. For example, tin fining can be combined with halide fining, e.g., bromine fining. Other possible combinations include, but are not limited to, tin fining plus sulfate, sulfide, cerium oxide, mechanical bubbling, and/or vacuum fining. It is contemplated that these other fining techniques can be used alone. In certain aspects, maintaining the (MgO+CaO+SrO+BaO)/Al 2 O 3 ratio and individual alkaline earth concentrations within the ranges discussed above makes the fining process easier to perform and more effective.
[0076] As described, the glasses described herein can be manufactured using various techniques known in the art. In one aspect, the glasses are made using a manufacturing process by which a population of 50 sequential glass sheets are produced from the melted and fined batch materials and has an average gaseous inclusion level of less than 0.10 gaseous inclusions/cubic centimeter, where each sheet in the population has a volume of at least 500 cubic centimeters.
[0077] In one embodiment, the glasses of the present disclosure exhibit transmission at 300 nm of greater than 50% for a 0.5 mm thick article. In another embodiment, the glasses of the present disclosure exhibit transmission at 300 nm of greater than 60% for a 0.5 mm thick article. In one embodiment, the glasses of the present disclosure exhibit densities of between 2.3 and 2.6 g/cc. In another embodiment, the glasses of the present disclosure exhibit densities of less than 2.58 g/cc. In one embodiment, the glass articles of the present invention exhibit an internal fusion line indicating their method of manufacture by a fusion downdraw process. In one embodiment, the Young's modulus is between 70-90 GPa. In another embodiment, the Young's modulus is between 75-85 GPa.
[0078] In one embodiment, the glasses of the present disclosure will have a CTE less than 36×10 −7 /° C., a density less than 2.6 g/cc, at 200 poise temperature of less than 1700° C., a T 35 k of less than 1350° C., and a T 35 k −T liq greater than 100° C.
EXAMPLES
[0079] The following examples are set forth below to illustrate the methods and results according to the disclosed subject matter. These examples are not intended to be inclusive of all aspects of the subject matter disclosed herein, but rather to illustrate representative methods and results. These examples are not intended to exclude equivalents and variations of the present invention which are apparent to one skilled in the art.
[0080] Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.) but some errors and deviations should be accounted for. Unless indicated otherwise, temperature is in ° C. or is at ambient temperature, and pressure is at or near atmospheric. The compositions themselves are given in mole percent on an oxide basis and have been normalized to 100%. There are numerous variations and combinations of reaction conditions, e.g., component concentrations, temperatures, pressures and other reaction ranges and conditions that can be used to optimize the product purity and yield obtained from the described process. Only reasonable and routine experimentation will be required to optimize such process conditions.
[0081] The glass properties set forth in Table 1 were determined in accordance with techniques conventional in the glass art. Thus, the linear coefficient of thermal expansion (CTE) over the temperature range 25-300° C. is expressed in terms of ×10 −7 /° C. and the annealing point is expressed in terms of ° C. These were determined from fiber elongation techniques (ASTM references E228-85 and C336, respectively). The density in terms of grams/cm 3 was measured via the Archimedes method (ASTM C693). The melting temperature in terms of ° C. (defined as the temperature at which the glass melt demonstrates a viscosity of 200 poises) was calculated employing a Fulcher equation fit to high temperature viscosity data measured via rotating cylinders viscometry (ASTM C965-81).
[0082] The liquidus temperature of the glass in terms of ° C. was measured using the standard gradient boat liquidus method of ASTM C829-81. This involves placing crushed glass particles in a platinum boat, placing the boat in a furnace having a region of gradient temperatures, heating the boat in an appropriate temperature region for 24 hours, and determining by means of microscopic examination the highest temperature at which crystals appear in the interior of the glass. More particularly, the glass sample is removed from the Pt boat in one piece, and examined using polarized light microscopy to identify the location and nature of crystals which have formed against the Pt and air interfaces, and in the interior of the sample. Because the gradient of the furnace is very well known, temperature vs. location can be well estimated, within 5-10° C. The temperature at which crystals are observed in the internal portion of the sample is taken to represent the liquidus of the glass (for the corresponding test period). Testing is sometimes carried out at longer times (e.g. 72 hours), in order to observe slower growing phases. The temperature corresponding to 200 poise and the viscosity at the liquidus (in poises) were determined from fits to high viscosity data using the Vogel-Fulcher-Tammann equation,
[0000] log(η)= A+B /( T−T o )
[0000] in which T is temperature and A, B and T o are fitting parameters. To determine liquidus viscosity, the liquidus temperature is used as the value for T. Young's modulus values in terms of GPa were determined using a resonant ultrasonic spectroscopy technique of the general type set forth in ASTM E1875-00e1.
[0083] As can be seen in Table 1, the exemplary glasses have density, CTE, annealing point and Young's modulus values that make the glasses suitable for display applications, such as AMLCD substrate applications, and more particularly for low-temperature polysilicon and oxide thin film transistor applications. Although not shown in Table 1, the glasses have durabilities in acid and base media that are similar to those obtained from commercial AMLCD substrates, and thus are appropriate for AMLCD applications. The exemplary glasses can be formed using downdraw techniques, and in particular are compatible with the fusion process, via the aforementioned criteria.
[0084] The exemplary glasses of Table 1 were prepared using a commercial sand as a silica source, milled such that 90% by weight passed through a standard U.S. 100 mesh sieve. Alumina was the alumina source, periclase was the source for MgO, limestone the source for CaO, strontium carbonate, strontium nitrate or a mix thereof was the source for SrO, barium carbonate was the source for BaO, and tin (IV) oxide was the source for SnO 2 . The raw materials were thoroughly mixed, loaded into a platinum vessel suspended in a furnace heated by silicon carbide glowbars, melted and stirred for several hours at temperatures between 1600 and 1650° C. to ensure homogeneity, and delivered through an orifice at the base of the platinum vessel. The resulting patties of glass were annealed at or near the annealing point, and then subjected to various experimental methods to determine physical, viscous and liquidus attributes.
[0085] These methods are not unique, and the glasses of Table 1 can be prepared using standard methods well-known to those skilled in the art. Such methods include a continuous melting process, such as would be performed in a continuous melting process, wherein the melter used in the continuous melting process is heated by gas, by electric power, or combinations thereof.
[0086] Raw materials appropriate for producing the disclosed glass include commercially available sands as sources for SiO 2 ; alumina, aluminum hydroxide, hydrated forms of alumina, and various aluminosilicates, nitrates and halides as sources for Al 2 O 3 ; boric acid, anhydrous boric acid and boric oxide as sources for B 2 O 3 ; periclase, dolomite (also a source of CaO), magnesia, magnesium carbonate, magnesium hydroxide, and various forms of magnesium silicates, aluminosilicates, nitrates and halides as sources for MgO; limestone, aragonite, dolomite (also a source of MgO), wolastonite, and various forms of calcium silicates, aluminosilicates, nitrates and halides as sources for CaO; and oxides, carbonates, nitrates and halides of strontium and barium. If a chemical fining agent is desired, tin can be added as SnO 2 , as a mixed oxide with another major glass component (e.g., CaSnO 3 ), or in oxidizing conditions as SnO, tin oxalate, tin halide, or other compounds of tin known to those skilled in the art.
[0087] The glasses in Table 1 contain SnO 2 as a fining agent, but other chemical fining agents could also be employed to obtain glass of sufficient quality for TFT substrate applications. For example, the disclosed glasses could employ any one or combinations of As 2 O 3 , Sb 2 O 3 , CeO 2 , Fe 2 O 3 , and halides as deliberate additions to facilitate fining, and any of these could be used in conjunction with the SnO 2 chemical fining agent shown in the examples. Of these, As 2 O 3 and Sb 2 O 3 are generally recognized as hazardous materials, subject to control in waste streams such as might be generated in the course of glass manufacture or in the processing of TFT panels. It is therefore desirable to limit the concentration of As 2 O 3 and Sb 2 O 3 individually or in combination to no more than 0.005 mol %.
[0088] In addition to the elements deliberately incorporated into the disclosed glasses, nearly all stable elements in the periodic table are present in glasses at some level, either through low levels of contamination in the raw materials, through high-temperature erosion of refractories and precious metals in the manufacturing process, or through deliberate introduction at low levels to fine tune the attributes of the final glass. For example, zirconium may be introduced as a contaminant via interaction with zirconium-rich refractories. As a further example, platinum and rhodium may be introduced via interactions with precious metals. As a further example, iron may be introduced as a tramp in raw materials, or deliberately added to enhance control of gaseous inclusions. As a further example, manganese may be introduced to control color or to enhance control of gaseous inclusions. As a further example, alkalis may be present as a tramp component at levels up to about 0.1 mol % for the combined concentration of Li 2 O, Na 2 O and K 2 O.
[0089] Hydrogen is inevitably present in the form of the hydroxyl anion, OH − , and its presence can be ascertained via standard infrared spectroscopy techniques. Dissolved hydroxyl ions significantly and nonlinearly impact the annealing point of the disclosed glasses, and thus to obtain the desired annealing point it may be necessary to adjust the concentrations of major oxide components so as to compensate. Hydroxyl ion concentration can be controlled to some extent through choice of raw materials or choice of melting system. For example, boric acid is a major source of hydroxyls, and replacing boric acid with boric oxide can be a useful means to control hydroxyl concentration in the final glass. The same reasoning applies to other potential raw materials comprising hydroxyl ions, hydrates, or compounds comprising physisorbed or chemisorbed water molecules. If burners are used in the melting process, then hydroxyl ions can also be introduced through the combustion products from combustion of natural gas and related hydrocarbons, and thus it may be desirable to shift the energy used in melting from burners to electrodes to compensate. Alternatively, one might instead employ an iterative process of adjusting major oxide components so as to compensate for the deleterious impact of dissolved hydroxyl ions.
[0090] Sulfur is often present in natural gas, and likewise is a tramp component in many carbonate, nitrate, halide, and oxide raw materials. In the form of SO 2 , sulfur can be a troublesome source of gaseous inclusions. The tendency to form SO 2 -rich defects can be managed to a significant degree by controlling sulfur levels in the raw materials, and by incorporating low levels of comparatively reduced multivalent cations into the glass matrix. While not wishing to be bound by theory, it appears that SO 2 -rich gaseous inclusions arise primarily through reduction of sulfate (SO 4 = ) dissolved in the glass. The elevated barium concentrations of the disclosed glasses appear to increase sulfur retention in the glass in early stages of melting, but as noted above, barium is required to obtain low liquidus temperature, and hence high T 35 k −T liq and high liquidus viscosity. Deliberately controlling sulfur levels in raw materials to a low level is a useful means of reducing dissolved sulfur (presumably as sulfate) in the glass. In particular, sulfur is preferably less than 200 ppm by weight in the batch materials, and more preferably less than 100 ppm by weight in the batch materials.
[0091] Reduced multivalents can also be used to control the tendency of the disclosed glasses to form SO 2 blisters. While not wishing to be bound to theory, these elements behave as potential electron donors that suppress the electromotive force for sulfate reduction. Sulfate reduction can be written in terms of a half reaction such as
[0000] SO 4 − →SO 2 +O 2 +2e-
[0000] where e- denotes an electron. The “equilibrium constant” for the half reaction is
[0000] K eq ═[SO 2 ][O 2 ][e-] 2 /[SO 4 = ]
[0000] where the brackets denote chemical activities. Ideally one would like to force the reaction so as to create sulfate from SO 2 , O 2 and 2e-. Adding nitrates, peroxides, or other oxygen-rich raw materials may help, but also may work against sulfate reduction in the early stages of melting, which may counteract the benefits of adding them in the first place. SO 2 has very low solubility in most glasses, and so is impractical to add to the glass melting process. Electrons may be “added” through reduced multivalents. For example, an appropriate electron-donating half reaction for ferrous iron (Fe 2+ ) is expressed as
[0000] 2Fe 2+ →2Fe 3+ +2e-
[0092] This “activity” of electrons can force the sulfate reduction reaction to the left, stabilizing SO 4 = in the glass. Suitable reduced multivalents include, but are not limited to, Fe 2+ , Mn 2+ , Sn 2+ , Sb 3− , As 3+ , V 3+ , Ti 3+ , and others familiar to those skilled in the art. In each case, it may be important to minimize the concentrations of such components so as to avoid deleterious impact on color of the glass, or in the case of As and Sb, to avoid adding such components at a high enough level so as to complication of waste management in an end-user's process.
[0093] In addition to the major oxides components of the disclosed glasses, and the minor or tramp constituents noted above, halides may be present at various levels, either as contaminants introduced through the choice of raw materials, or as deliberate components used to eliminate gaseous inclusions in the glass. As a fining agent, halides may be incorporated at a level of about 0.4 mol % or less, though it is generally desirable to use lower amounts if possible to avoid corrosion of off-gas handling equipment. In a preferred embodiment, the concentration of individual halide elements are below about 200 ppm by weight for each individual halide, or below about 800 ppm by weight for the sum of all halide elements.
[0094] In addition to these major oxide components, minor and tramp components, multivalents and halide fining agents, it may be useful to incorporate low concentrations of other colorless oxide components to achieve desired physical, optical or viscoelastic properties. Such oxides include, but are not limited to, TiO 2 , ZrO 2 , HfO 2 , Nb 2 O 5 , Ta 2 O 5 , MoO 3 , WO 3 , ZnO, In 2 O 3 , Ga 2 O 3 , Bi 2 O 3 , GeO 2 , PbO, SeO 3 , TeO 2 , Y 2 O 3 , La 2 O 3 , Gd 2 O 3 , and others known to those skilled in the art. Through an iterative process of adjusting the relative proportions of the major oxide components of the disclosed glasses, such colorless oxides can be added to a level of up to about 2 mol % without unacceptable impact to annealing point, T 35 k −T liq or liquidus viscosity.
[0000]
TABLE 1
Batch Material
1
2
3
4
SiO 2
72.88
71.93
71.92
70.82
Al 2 O 3
10.18
11.06
11.21
12.27
B 2 O 3
5.03
4.62
4.48
4.9
MgO
0.1
1.51
1.59
2.12
CaO
4.5
4.91
4.92
4.98
SrO
7.14
5.82
5.71
4.78
BaO
0.07
0.06
0.07
0.05
SnO 2
0.07
0.07
0.08
0.07
Fe 2 O 3
0.01
0.01
0.01
0.01
ZrO 2
0.01
0.01
0.01
0
As 2 O 3
RO/Al 2 O 3
1.16
1.11
1.10
0.97
Properties
density
2.514
2.509
2.505
2.494
strain-BBV
712.6
719.4
723.2
724.4
anneal-BBV
767.2
773.4
776.6
777.5
softening point (PPV)
1025.1
1024.3
1028
1023.8
CTE (0-300) cooling
36.6
35.9
35
33.2
Poisson's ratio
0.238
0.233
0.233
Shear modulus (Mpsi)
4.556
4.574
4.624
GPa per Mpsi
Young's modulus (Mpsi)
11.284
11.281
11.406
6.8947573
Youngs mod (GPa)
77.8
77.8
78.6
Specific modulus (Gpa/density)
31.0
31.0
31.5
Viscosity
A
−3.460
−3.515
−3.540
B
8151.30
8164.10
8018.80
To
284.90
288.90
299.80
200
200 p
1700
1693
1673
700
700 p
1578
1573
1556
2000
2 kp
1491
1487
1472
20000
20 kp
1335
1333
1322
35000
35 kp
1303
1302
1292
200000
200 kp
1215
1215
1207
Liquidus-72 h
internal
1180
1190
1190
1195
phase
Crist
Cristobalite
Cristobalite
Mullite
second phase
72 h liquidus viscosity (int)
3.5E+05
3.5E+05
2.6E+05
5
6
7
8
SiO 2
70.99
72.03
71.45
71.18
Al 2 O 3
12.02
12.31
12.36
12.38
B 2 O 3
4.73
1.87
1.84
1.97
MgO
2.93
3.94
5.1
4.35
CaO
4.97
5.34
5.59
6.09
SrO
4.24
4.34
3.49
3.85
BaO
0.03
0.04
0.02
0.03
SnO 2
0.07
0.09
0.11
0.1
Fe 2 O 3
0.01
0.02
0.01
0.01
ZrO 2
0
0.02
0.02
0.02
As 2 O 3
RO/Al 2 O 3
1.01
1.11
1.15
1.16
Properties
density
2.488
2.523
2.518
2.526
strain-BBV
722.8
748.9
748
748.2
anneal-BBV
777
802
799.3
799.8
softening point (PPV)
1021.1
1043.6
1034
1034.4
CTE (0-300) cooling
34
34.5
Poisson's ratio
0.234
0.237
0.221
0.229
Shear modulus (Mpsi)
4.656
4.898
4.968
4.936
GPa per Mpsi
Young's modulus (Mpsi)
11.494
12.121
12.134
12.131
6.8947573
Youngs mod (GPa)
79.2
83.6
83.7
83.6
Specific modulus (Gpa/density)
31.9
33.1
33.2
33.1
Viscosity
A
−3.339
−3.440
−3.135
−3.138
B
7567.50
7683.50
6971.90
7013.90
To
326.00
345.00
379.60
377.50
200
200 p
1668
1683
1665
1669
700
700 p
1550
1567
1546
1551
2000
2 kp
1466
1485
1463
1467
20000
20 kp
1317
1338
1316
1320
35000
35 kp
1286
1307
1287
1290
200000
200 kp
1202
1224
1205
1208
Liquidus-72 h
internal
1190
1240
1245
1240
phase
Cristobalite
Cristobalite
Cristobalite
Cristobalite
second phase
Anorthite
72 h liquidus viscosity (int)
2.6E+05
1.4E+05
8.3E+04
9.9E+04
9
10
11
12
SiO 2
71.24
71.67
70.47
72.42
Al 2 O 3
12.38
11.34
11.75
11.07
B 2 O 3
1.82
3.34
5.01
3.06
MgO
5.7
2.96
2.9
3.54
CaO
5.55
8.43
5.45
7.38
SrO
3.15
2.11
4.28
2.37
BaO
0.03
0.02
0.04
0.02
SnO 2
0.11
0.12
0.07
0.11
Fe 2 O 3
0.01
0.02
0.01
0.01
ZrO 2
0.02
0
0.01
0.01
As 2 O 3
RO/Al 2 O 3
1.17
1.19
1.08
1.20
Properties
density
2.514
2.476
2.49
2.471
strain-BBV
744.7
728.4
716.6
732.9
anneal-BBV
795.7
781.8
770.6
785.3
softening point (PPV)
1030
1017.6
1012.4
1025.3
CTE (0-300) cooling
35
33.9
33.9
Poisson's ratio
0.234
0.219
0.201
0.222
Shear modulus (Mpsi)
4.979
4.844
4.68
4.807
GPa per Mpsi
Young's modulus (Mpsi)
12.284
11.812
11.238
11.743
6.8947573
Youngs mod (GPa)
84.7
81.4
77.5
81.0
Specific modulus (Gpa/density)
33.7
32.9
31.1
32.8
Viscosity
A
−3.106
−2.948
−3.365
−2.844
B
6924.50
6833.70
7612.50
6833.00
To
378.70
368.60
316.30
367.60
200
200 p
1659
1670
1660
1696
700
700 p
1542
1548
1542
1569
2000
2 kp
1459
1462
1458
1480
20000
20 kp
1314
1311
1309
1324
35000
35 kp
1284
1281
1279
1292
200000
200 kp
1202
1197
1195
1207
Liquidus-72 h
internal
1250
1245
1190
1270
phase
Cristobalite
Cristobalite
Cristobalite
Cristobalite
second phase
72 h liquidus viscosity (int)
6.9E+04
7.1E+04
2.2E+05
5.3E+04
13
14
15
16
SiO 2
71.21
72.32
72.66
73.9
Al 2 O 3
11.52
12.82
12.65
10.86
B 2 O 3
4.77
0
0
3.14
MgO
1.76
5.65
4.88
2.17
CaO
4.99
5.57
5.75
6.68
SrO
5.62
3.5
3.91
3.1
BaO
0.06
0.03
0.03
0.03
SnO 2
0.07
0.1
0.1
0.11
Fe 2 O 3
0.01
0.01
0.01
0.01
ZrO 2
0
0.01
0
0.01
As 2 O 3
RO/Al 2 O 3
1.08
1.15
1.15
1.10
Properties
density
2.508
2.537
2.541
2.47
strain-BBV
714.6
785.5
775.9
739.2
anneal-BBV
769.3
837.5
825.9
793.8
softening point (PPV)
1014.4
1068.5
1047.6
1040.1
CTE (0-300) cooling
34.9
35.3
34.8
Poisson's ratio
0.229
0.218
0.226
0.221
Shear modulus (Mpsi)
4.579
5.047
5.123
4.727
GPa per Mpsi
Young's modulus (Mpsi)
11.258
12.299
12.562
11.538
6.8947573
Youngs mod (GPa)
77.6
84.8
86.6
79.6
Specific modulus (Gpa/density)
30.9
33.4
34.1
32.2
Viscosity
A
−3.413
−2.508
−2.721
−3.050
B
7814.10
5771.50
6345.70
7393.00
To
304.40
484.80
435.80
345.50
200
200 p
1672
1685
1699
1727
700
700 p
1553
1563
1576
1600
2000
2 kp
1468
1478
1490
1510
20000
20 kp
1317
1332
1339
1351
35000
35 kp
1286
1303
1309
1319
200000
200 kp
1201
1224
1227
1231
Liquidus-72 h
internal
1170
1270
1260
1275
phase
Cristobalite
Cristobalite
Cristobalite
Cristobalite
second phase
72 h liquidus viscosity (int)
4.1E+05
7.0E+04
9.5E+04
8.0E+04
17
18
19
20
SiO 2
68.11
71.23
72.2
70.74
Al 2 O 3
12.72
12.41
12.49
13
B 2 O 3
4.5
2.54
0.95
2.48
MgO
4.38
3.62
4.5
3.35
CaO
6.44
5.23
5.58
4.58
SrO
3.7
1.42
3.16
1.43
BaO
0.02
3.43
1.01
4.28
SnO 2
0.09
0.1
0.09
0.1
Fe 2 O 3
0.01
0.01
0.01
0.01
ZrO 2
0.03
0.01
0.01
0.02
As 2 O 3
RO/Al 2 O 3
1.14
1.10
1.14
1.05
Properties
density
2.517
2.57
2.548
2.605
strain-BBV
720.7
743.3
759.8
743.1
anneal-BBV
771.6
798.2
810.9
795.9
softening point (PPV)
996.1
1043.7
1050.1
1043.1
CTE (0-300) cooling
34.3
34.9
36.7
36.4
Poisson's ratio
0.234
0.234
0.238
0.219
Shear modulus (Mpsi)
4.805
4.757
4.968
4.802
GPa per Mpsi
Young's modulus (Mpsi)
11.86
11.746
12.3
11.708
6.8947573
Youngs mod (GPa)
81.8
81.0
84.8
80.7
Specific modulus (Gpa/density)
32.5
31.5
33.3
31.0
Viscosity
A
−2.879
−3.526
−3.374
−3.612
B
6338.60
7900.35
7576.99
8055.85
To
389.30
330.76
356.08
318.86
200
200 p
1613
1687
1691
1681
700
700 p
1497
1571
1574
1566
2000
2 kp
1415
1488
1491
1484
20000
20 kp
1272
1340
1343
1337
35000
35 kp
1243
1310
1313
1307
200000
200 kp
1164
1226
1230
1223
Liquidus-72 h
internal
1185
1195
1260
1190
phase
anorthite
Cristobalite
Cristobalite
mullite
second phase
72 h liquidus viscosity (int)
1.2E+05
4.1E+05
1.0E+05
4.3E+05
21
22
23
24
SiO 2
72.16
72.29
70.62
71.68
Al 2 O 3
11.86
11.6
13.09
12.38
B 2 O 3
0
0
1.5
0.76
MgO
5.53
4.83
4.84
4.99
CaO
5.4
5.95
5.75
5.29
SrO
1.59
0.99
1.52
1.47
BaO
3.31
4.18
2.58
3.36
SnO 2
0.11
0.11
0.08
0.08
Fe 2 O 3
0.02
0.02
0.01
ZrO 2
0.02
0.02
0.02
As 2 O 3
RO/Al 2 O 3
1.33
1.38
1.12
Properties
density
2.616
2.604
2.575
strain-BBV
764
762
752
anneal-BBV
816
817
805
softening point (PPV)
1050.7
1057.8
1041.3
CTE (0-300) cooling
36.7
34.9
34.6
Poisson's ratio
Shear modulus (Mpsi)
GPa per Mpsi
Young's modulus (Mpsi)
6.8947573
Youngs mod (GPa)
84.8
83.6
84.1
Specific modulus (Gpa/density)
Viscosity
A
−3.02159
−2.98998
−3.10916
B
6981.809
6990.12
6956.355
To
386.1695
387.4732
383.4808
200
200 p
1698
1709
1669
700
700 p
1576
1585
1552
2000
2 kp
20000
20 kp
35000
35 kp
1309
1315
1292
200000
200 kp
Liquidus-72 h
internal
1210
1210
1190
phase
second phase
72 h liquidus viscosity (int)
[0095] What is disclosed is a glass substrate with exceptional total pitch variability (TPV), as measured by three metrics: (1) compaction in the High Temperature Test Cycle (HTTC) less than 40 ppm, (2) compaction in the Low Temperature Test Cycle (LTTC) less than 5.5 ppm, and (3) stress relaxation rate consistent with less than 50% relaxed in the Stress Relaxation Test Cycle (SRTC). By satisfying all three criteria, the substrate is assured of being acceptable for the highest resolution TFT cycles. A brief description of these test cycles follows:
High Temperature Test Cycle (HTTC)
[0096] The samples were heat treated in a box furnace according to the thermal profile shown in FIG. 1 . First, the furnace was preheated to slightly above 590° C. The stack of five samples was then plunged into the furnace through a small slit in the front of the furnace. After thirty minutes the samples are quenched out of the furnace into ambient air. The total time the samples reside at the peak temperature 590° C. is about 18 minutes. For purposes of this disclosure, this test criteria shall be defined as high temperature test cycle or HTTC. In one embodiment, the HTTC compaction is less than or equal to 40 ppm. In another embodiment, the HTTC compaction is less than or equal to 38 ppm. In another embodiment, the HTTC compaction is less than or equal to 36 ppm. In another embodiment, the HTTC compaction is less than or equal to 30 ppm. In another embodiment, the HTTC compaction is less than or equal to 25 ppm. In another embodiment, the HTTC compaction is less than or equal to 20 ppm.
Low Temperature Test Cycle (LTTC)
[0097] The thermal compaction magnitude resulting from typical TFT array or CF substrate thermal cycles is insufficient to make reliable quality assurance measurements. A 450° C./1 hour thermal cycle is used to achieve a greater compaction signal, enabling the identification of real changes in performance. The furnace is held at just above 450° C. prior to plunging in a stack of five samples (four experimental and one control). The furnace requires approximately 7 minutes recovery time to the target hold temperature. Samples are held at 450° C. for one hour and then plunged out to room temperature. An example thermal trace is shown in FIG. 2 . For purposes of this disclosure, this test criteria shall be defined as low temperature test cycle or LTTC. In one embodiment, the LTTC compaction is less than or equal to 5.5 ppm. In another embodiment, the LTTC compaction is less than or equal to 5 ppm. In another embodiment, the LTTC compaction is less than or equal to 4.6 ppm.
Stress Relaxation Test Cycle (SRTC)
[0098] The glass plates were cut into beams of 10.00 mm width. The thickness of the glass was maintained at its as-formed thickness (between 0.5 mm and 0.7 mm). The stress relaxation experiment started by loading the glass sample onto two rigid supports placed inside a resistively heated electrical furnace, placing an S-type thermocouple in close proximity to the center of the beam, and adjusting the push rod position. The span length of the two rigid supports was 88.90 mm. The lower end of the push rod was about 5 mm above the surface of the glass at room temperature. The temperature of the furnace was rapidly brought up to the final experimental temperature of 650° C. and idled there for about 5 minutes in order to achieve thermal equilibrium of all parts placed inside the furnace. The experiment continued by lowering the push rod at a rate of 2.54 mm/min and monitoring the signal of the load cell (LC). This was done in order to find a contact of the push rod with the glass beam. Once the LC signal reached 0.1 lb, it triggered an acceleration of the loading rate to 10.16 mm/min. The loading was stopped when the central deflection of the beam reached the final target value (e.g., 2.54 mm), and the program switched from a stress controlled mode to a strain controlled mode. The strain was held constant during the rest of the experiment whereas the stress was variable. The total time from the first contact of the push rod with the glass to the point where the maximum strain of 2.54 mm was achieved was about 12 s. The experiment ended after several hours of data had been collected. It is worth noting that no significant overshoot in temperature was observed at the beginning of the isothermal hold due to careful optimization of the proportional-integral-derivative parameters of the furnace controller.
[0099] All the stress relaxation experiments were conducted under isothermal conditions, where the temperature was constantly monitored by an S-type thermocouple placed close to the center of the flat beam of glass. Temperature fluctuations during the experiments did not exceed 0.5° C. Separate experiments regarding the temperature homogeneity across the length of the glassy beam were conducted prior the actual stress relaxation experiments. Temperature homogeneity should not exceed 2° C. at any given experimental time and condition. In principle the stress experiment mimics a classic three point bending experiment where the load is applied on a well-defined center of the beam, deflecting it for 2.54 mm from the original zero line, and then holding it at this constant strain. The central push rod transfers the load (stress) when it comes into the contact with the glassy beam. The end of the central push rod has a knife edge shape, and the width of the wedge is slightly greater than that of the glassy beam. The top-line of the wedge-shaped push rod is perfectly parallel with the surface of the glass beam. Such a configuration assures a homogeneous distribution of the stress across the width of the beam. The push rod is coupled with a linearly variable displacement transducer which controls the displacement. The instrument was also equipped with a well calibrated LC, which maintained the central load applied to the glassy beam during the ongoing relaxation. Due to the nonlinearity of the relaxation process—where the relaxation is initially fast and then gradually slows down—for data recording purposes we split each relaxation experiment into three segments. The first one collected data at 0.5 s intervals; the second segment collected data every 1.0 s, and the third every 10.0 s. Regarding the possibility of stress relaxation during the loading period (i.e., the first 12 s of the experiment) all the loading curves for the glass compositions under study were plotted and in each case the loading curve exhibited a linear stress/strain relationship indicating a primarily elastic response during loading. Hence, the zero time point of the stress relaxation measurements was taken as the time at which the experiment switched from a stress controlled mode to a strain controlled mode, as described above. Percent stress relaxed R during the cycle is defined by
[0000]
R
=
100
(
1
-
S
60
S
0
)
[0000] where S 60 is the stress imposed by the controlled push rod at 60 minutes (the end of the SRTC) and S 0 is the stress imposed at 0 minutes (the start of the SRTC). For purposes of this disclosure, the above test criteria shall be defined as stress relaxation test cycle (SRTC). In one embodiment, the percent stress relaxed in the SRTC is equal to or less than 50%. In another embodiment, the percent stress relaxed in the SRTC is equal to or less than 45%. In another embodiment, the percent stress relaxed in the SRTC is equal to or less than 40%. In another embodiment, the percent stress relaxed in the SRTC is equal to or less than 35%.
The Test Cycles and TPV
[0100] These three measurements are capable of representing the total pitch variability performance of a glass substrate since they capture the primary drivers for total pitch variability under a thermal process: structural relaxation (or compaction) at high and low temperatures and stress relaxation. Historically, the contribution of compaction to total pitch variability has been dominated by high temperature behaviors since registry marks were placed later in customers' TFT processes, making many of the low temperature steps early in these processes irrelevant. This high temperature compaction is described by the HTTC compaction and is reduced by either reducing the cooling rate of the glass ribbon during manufacture, annealing the glass sheet offline, and/or increasing the viscosity of the glass (as captured by T(ann)). FIG. 3 shows a general reduction of compaction as the T(ann) is increased, with the main exceptions being glasses made with significantly different thermal histories (such as via the float process instead of the fusion draw process). This illustrates how glass manufacturers have handled total pitch in the past: they have either slowed cooling rates and/or increased annealing point to suppress compaction in the temperature regime that mattered (i.e. high temperatures).
[0101] Recent changes in the TFT market have now forced panel makers to place their registry marks at the beginning of their process, making many previously irrelevant low temperature steps critical to the variability in measured total pitch. As a general rule, compaction at low temperatures (captured by the LTTC in FIG. 4 ) follows a similar trend as in the HTTC but, at high T(ann) (e.g. greater than 750° C.), the compaction seems to decouple from the T(ann) and become a flat line at roughly 6 ppm. This shows that one of the traditional paths to reducing compaction, increasing T(ann), is no longer a viable solitary solution. The high annealing point glasses that have reduced LTTC compaction in FIG. 4 are the result of the management of a relaxation mechanism in the glass that is operating at a considerably faster rate than would be predicted based on traditional understanding of glass relaxation kinetics. This mechanism has been linked to highly mobile tramp constituents in the glass, such as alkali and water and, additionally, a lower (MgO+CaO+SrO+BaO)/Al 2 O 3 has been correlated with lower LTTC compaction. Coupling this newfound understanding of a compositional basis for control of this fast relaxation mechanism with optimized cooling curve control has resulted in lower LTTC compaction in certain compositions independent of T(ann) (as evidenced by the high LTTC compaction (5.8 and 6.5 ppm at 0.7 and 0.5 mm, respectively) of Glass 8 (see Table 2) despite a high T(ann)=808° C.). It is quite possible that a glass with excellent HTTC compaction may have unacceptable LTTC compaction due to this decoupling and the simultaneous management of both is important in today's TFT processes.
[0102] In both compaction cycles, glasses cooled with exceptionally slow cooling rates (such as those experienced during the float process) have very good compaction performance, as shown by several of the Glass 2 samples from Table 2. These glasses perform well in old TFT processes but are struggle in the new cycles needed for the highest resolution displays made on large gen sizes. This is due to the other aspect of TPV: stress relaxation, which scales directly with low temperature viscosity. FIG. 5 shows the percent of an induced stress that relaxes in the SRTC, and the virtually linear dependence on T(ann) is clearly observed. This helps explain why lower annealing point glasses with slow quench rates that previously worked for panel makers are no longer viable. In FIG. 5 , glasses relaxing less than 50% of the stress satisfy the SRTC criteria of the disclosure.
[0103] It has been discovered that the management of all three aspects of TPV is advantageous and considerable interactions with many customers have helped us to define the “success criteria” for all three test cycles (indicated by the red lines on FIGS. 3 , 4 , and 5 ). FIG. 6 a plots the HTTC compaction against the LTTC compaction with glasses satisfying the success criteria falling in Region 1 as identified. Glasses satisfying the stress relaxation requirements are indicated by diamonds while the glasses failing the stress relaxation requirement are indicated by squares. The glasses disclosed in this invention are, therefore, the diamonds that fall within Region 1 (more easily seen in FIG. 6 b ).
[0104] Previously disclosed substrates have attempted to accomplish low TPV through higher annealing points or process control (e.g. slow cooling during manufacture). As evidenced by FIG. 6 , these efforts have always resulted in a substrate failing one of these three criteria, thereby rendering the substrate sub-optimal for certain TFT cycles. In addition to these important attributes for TPV, a glass of this disclosure could also be consistent with other attributes advantageous for the manufacture of TFTs (such as low density, high UV transmission, etc.).
[0000]
TABLE 2
LTTC
HTTC
SRTC
Compaction
Compaction
%
Glass ID
T(ann)
(ppm)
(ppm)
Relaxed
Glass 1 0.5 mm
798
5.1
23.6
33.3
Glass 2 0.5 mm
721
5.4
34.2
72.3
Glass 2 0.5 mm
721
4.7
36.5
72.3
Glass 2 0.5 mm
721
3.9
37.6
72.3
Glass 2 0.5 mm
721
5.7
59.3
72.3
Glass 3 0.5 mm
795
6.7
32.4
33.3
Glass 3 0.7 mm
795
5.6
26.3
33.3
Glass 4 0.5 mm
768
7.1
43.7
56.2
Glass 4 0.7 mm
768
7.2
46.3
56.2
Glass 4 0.63 mm
768
7.6
48.2
56.2
Glass 4 1.1 mm
768
5.2
29.6
56.2
Glass 4 0.7 mm
768
6.1
37.5
56.2
Glass 4 0.5 mm
768
7.0
44.9
56.2
Glass 4 0.5 mm
768
7.1
47.7
56.2
Glass 5 0.63 mm
743
8.2
69.6
69
Glass 6 0.63 mm
775
4.6
35.5
46.2
Glass 6 0.7 mm
775
4.8
32.4
46.2
Glass 7 0.7 mm
798
5.5
26.4
33.3
Glass 8 0.5 mm
808
6.5
29.7
31.7
Glass 8 0.7 mm
808
5.8
26.2
31.7
Glass 9 0.7 mm
785
5.7
32.5
Glass 10 0.5 mm
722
12.0
116.8
Glass 10 0.5 mm
722
17.7
147.9
Glass 11 0.63 mm
722
18.3
152.0
Glass 12 0.5 mm
774
8.4
49.6
Glass 13 0.5 mm
786
6.9
41.2
Glass 14 0.5 mm
791
7.4
36.3
Glass 15 0.5 mm
710
6.4
62.6
88.75
Glass 16 0.5 mm
710
8.8
87.8
88.75
Glass 17 0.5 mm
762
4.4
45.0
55.6
[0105] Table 2 is a sampling of glasses both experimental and commercially available that were tested according to the HTTC, LTTC and SRTC criteria described herein. Glasses 1, 6 and 7 are experimental glasses that were tested and met the criteria as described in one embodiment (HTTC less than or equal to 40 ppm, LTTC less than or equal to 5.5 ppm and SRTC less than 50%). Glasses 2, 4, 9, 10, 11, 15, 16 and 17 represent present or past commercial glasses that were tested and failed the testing criteria as demonstrated by the results. Glasses 5, 8, 12, 13 and 14 are experimental glasses that failed the testing criteria.
[0106] Various modifications and variations can be made to the materials, methods, and articles described herein. Other aspects of the materials, methods, and articles described herein will be apparent from consideration of the specification and practice of the materials, methods, and articles disclosed herein. It is intended that the specification and examples be considered as exemplary. | Described herein are alkali-free, boroalumino silicate glasses exhibiting desirable physical and chemical properties for use as substrates in flat panel display devices, such as, active matrix liquid crystal displays (AMLCDs) and active matrix organic light emitting diode displays (AMOLEDs). In accordance with certain of its aspects, the glasses possess excellent compaction and stress relaxation properties. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 643,178, filed Dec. 22, 1975 now abandoned.
BACKGROUND OF THE INVENTION
As is known in the art, blood plasma (blood from which white and red blood cells and blood platelets have been removed) is a fluid containing about 90 percent water and 10 percent solids. Reduced amounts of blood plasma are used today since processes have been developed whereby the water from the plasma is removed and the solids then divided into a number of therapeutically useful fractions. Patients receive only the fraction they need and not the entire plasma. Among these plasma fractions which are clinically used are the fibrinogen fraction and the anti-hemophilic factor (AHF, Factor VIII) fraction. The latter fraction normally contains some fibrinogen as well.
Both of these fractions are generally freeze-dried to remove the water and, just prior to use, are dissolved in a liquid aqueous media to form a solution which is then injected into the patient. Time is of considerable importance to the person (e.g. the doctor or nurse) administering the fibrinogen fraction or the AHF fraction, because loss of blood by the hemophiliac and/or injury to the joints is aggravated during the time required for preparation of the solution. Thus it is desirable that the solid product dissolve in the aqueous media in a relatively short period of time.
It is known that the time of solubilization of the fibrinogen fraction can be reduced by adding dextrose thereto. Dextrose has also been added to AHF. For example, the "Journal of Thrombosis Research", Volume 1, pages 191-200, 1972, published by Pergamon Press, Inc. reported that dextrose was added to AHF in order to facilitate the chromatography of AHF. The article concluded that the yield of bovine Factor VIII from chromatography on anion exchange media can be greatly improved by the inclusion of a low-molecular weight carbohydrate, such as dextrose, in the solvents. In addition to the foregoing, the inventor is also aware that Cutter Laboratories, Inc. has added sufficient dextrose to its commercial AHF preparation so that when the preparation is reconstituted according to the instructions, the resulting AHF solution contains about one gram of dextrose per 100 milliliters of solution.
U.S. Pat. No. 2,826,533 discloses the addition of dextrose to the fibrinogen fraction. U.S. Pat. No. 3,057,781 discloses stabilizing plasma with invert sugar and levulinic acid; the carbohydrates herein, however are free of levulinic acid.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a clinically useful freeze dried solid composition containing AHF and fibrinogen which is rapidly soluble in an aqueous medium at room temperature, said solubility being due to the presence of a critical threshold amount of a water soluble carbohydrate in the system during solubilization.
A further object of the present invention is to provide a method for producing a freeze-dried solid composition containing AHF and fibrinogen by fractionating blood plasma with polyethylene glycol to obtain a precipitate comprising AHF and fibrinogen, dissolving the precipitate in aqueous media and freeze-drying the resulting solution to obtain essentially a dry solid composition useful for clinical purposes, said freeze-dried composition being readily soluble in an aqueous medium at room temperature.
Other and further objects of the present invention will be apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 graphically depicts the unexpected dramatic improvement in the rate of solubilization of solid compositions containing AHF which is obtained when the composition is solubilized in the presence of from 0 to 5 grams of dextrose per 100 ml. of reconstituted solution. The various curves are obtained using different reconstitution temperatures and volumes.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The foregoing objects, and others, are accomplished by the present invention by the inclusion of a water soluble carbohydrate in the solid material comprising AHF. When one desires to use the composition, one need only add the requisite amount of water to obtain the desired concentration of AHF. Because of the presence of the carbohydrate, the composition dissolves in a very short period of time, for example, less than 1 minute, and can then be injected into the patient.
The amount of carbohydrate to be added is critical in the sense that mere addition of carbohydrate does not in itself result in significant solubilization time improvements. A threshold concentration of carbohydrate must be reached before useful improvements in solubilization time are achieved, after which addition of more carbohydrate again exerts no significant effect on solubilization time. This threshold concentration will vary within the ranges infra depending upon factors which are believed to include the amount and identity of protein and salts in the AHF preparations as well as the identity of the carbohydrate selected. The exact optimum quantity of carbohydrate will thus vary with the carbohydrate chosen, the method of AHF preparation and even with separate runs using the same preparatory method. Thus the appropriate quantity should be determined by elementary and conventional solubilization time assays for each lot of AHF.
The amount of carbohydrate should be sufficient to bring the solid AHF preparation into solution within about 90 seconds, and preferably 65 seconds, the AHF being present in the solid composition in an amount sufficient to form a therapeutically effective AHF concentration upon solubilization of the composition. A therapeutically effective concentration of AHF in such solutions illustratively ranges about from 3 to 100 International Units of AHF per ml. with a preferred range of about from 3 to 40 International Units per ml. The amount of carbohydrate present in the solid AHF composition typically provides, upon reconstitution with water, an aqueous solution or other suitable reconstituting liquid, a therapeutically effective solution of AHF containing at least about 2 weight units of carbohydrate (computed in grams) for every 100 volume units of solution (computed as milliliters). The amount of carbohydrate will generally vary about from 2 to 10 grams, preferably about 2 to 5 grams of carbohydrate per 100 ml. of solution, with about 3 grams appearing to be optimum.
To provide the desired concentration of carbohydrate in solution, the carbohydrate is illustratively present in the solid composition in an amount of about 1.6 to 7.5 times the amount of total protein in the solid AHF composition. Preferably, the amount of carbohydrate is about 2.0 to 5.0 times the weight of total protein. The preferred embodiment is about 2.0 times the weight of total protein. This solid composition can contain anywhere from about 2 to 200 International Units of AHF/gm. protein, and still produce as a practical matter a solution of AHF upon reconstitution which has a therapeutically significant effect.
The water soluble carbohydrates useful in the invention include any which are capable of hydrating the AHF-containing composition. This includes without limitation the monosaccharides such as the commonly available hexoses, including dextrose (glucose), mannose, galactose and fructose; the disaccharides such as maltose, lactose and sucrose; the trisaccharides, such as raffinose; and the short chain dextrins, e.g. dextrins having a chain length of less than about four monosaccharide units. Mixtures of suitable carbohydrates may also be employed. The preferred carbohydrates are dextrose, sucrose, maltose and lactose, with dextrose being an especially preferred material. The carbohydrate must be biologically acceptable and otherwise comply with appropriate Federal regulations when the AHF is commercially marketed for human administration. The carbohydrate can be admixed with the AHF-containing composition at any point during or prior to preparation of the lyophilized composition.
There are of course numerous procedures known to those skilled in the art to prepare AHF compositions whose rate of solubility is enhanced by the addition of carbohydrate in accordance with the present invention. In the preferred embodiment, the solid mixture comprising AHF and fibrinogen is obtained by starting with plasma frozen at about minus 25° C. which is then thawed to 4° to 5° C. to produce a cryoprecipitate which is collected by centrifugation.
The cryoprecipitate is suspended in heparinized, citrated saline to which is added 3.5% by weight, of polyethylene glycol. The resulting mixture is centrifuged and the resulting fibrinogen precipitate is discarded and the supernatant retained. To the supernatant is added about 7.5 weight units of polyethylene glycol (expressed as grams) per 100 volume units of supernatant (expressed as milliliters). The resulting suspension is mixed for about 15 minutes at room temperature and is then centrifuged and the resulting precipitate collected. This precipitate or solid mixture comprises AHF and fibrinogen and can be used as such or can be further purified by glycine fractionation. In any event, the water soluble carbohydrate can be added to either of such mixtures. Preferably, the solid mixture is dissolved in an aqueous medium, for example, a dextrose citrated saline aqueous solution containing about 0.72% sodium chloride, 0.02M sodium citrate and an appropriate amount of dextrose to produce the desired effect of an enhanced rate of solubilization. It is neither necessary nor desirable at this stage to add water to the point where the solution contains about 2 weight units of dextrose per 100 volume units of solution since such a dilute solution may unnecessarily extend the time required for lyophilization.
The dissolved solid mixture containing the dextrose is further clarified by passing it through a coarse filter which removes some of the fibrinogen and other insoluble proteins. Thereafter, the sample is further diluted with citrated saline, as desired, to a potency of about 3 to 75 International Units/ml. or left as a concentrate which normally contains from 250 to 1000 International Units/ml. The dissolved product is then sterile filtered through a "Millipore" membrane filter having an average pore size of about 0.3 microns. The filtered solution is filled under aseptic conditions into 10 ml. to 30 ml. capacity vials, as desired, rapidly frozen and freeze-dried.
To administer the AHF preparation to a patient, the normal procedure is to reconstitute the lyophilized material to a solution containing about 3 to about 100 International Units of AHF per ml., and more commonly about 24 to about 28 Units per ml., about 2 to about 10 grams of dextrose per 100 ml., about 1.4 to about 1.6 grams of protein per 100 ml., about 0.6 to about 0.8 grams of fibrinogen per 100 ml., and about 0.7 gram to about 6 grams of salts such as NaCl, sodium citrate, glycine and unidentified residual solids per 100 ml. Typically a 10 ml. vial of reconstituted AHF solution will contain about 270 International Units of AHF, about 0.3 gram of dextrose, about 0.15 gram of protein including about 0.07 gram of fibrinogen, about 0.51 gram of residuals and sufficient water to 10 ml. volume.
The lyophilized product is readily soluble in sterile water at room temperature and after the addition of the water is almost immediately ready for administration to hemophilic patients as a result of the dextrose levels in the solution.
In order to show the dramatic unexpected results obtained by the present invention the following tests were conducted wherein various concentrations of dextrose were added to lyophilized AHF product obtained as above. 10 ml. and 30 ml. capacity vials containing the product were filled with 10 ml. and 30 ml., respectively, of water at room temperature and 37° C. The 30 ml. vials contained approximately three times as much product as the 10 ml. vials. The time required for complete dissolution of each sample was recorded. The results are presented below in Table 1 and in FIG. 1.
Table 1__________________________________________________________________________grams dextrose/ FIG. 1 Curve:100 ml. of recon- Reconstituting A B C Dstituted composi- Volume: 10 ml 10 ml 30 ml 30 mltion Diluent Temp.: 37° C. Room Temp. 37° C. Room Temp.__________________________________________________________________________1 176 secs. 195 secs. 100 secs. 330 secs.3 35 secs. 85 secs. 50 secs. 65 secs.5 48 secs. 55 secs. 52 secs. 75 secs.None (control) 185 secs. 210 secs. 105 secs. 210 secs.__________________________________________________________________________
The control in the above table was identical to the other samples in all respects except that the control contained no dextrose.
The results of Table 1 are plotted in FIG. 1. The plotted data clearly shows the marked improvement in rate of solubility once a dextrose concentration exceeding 2 grams per 100 mls. of solution is obtained. Similar desirable results are obtained with the other carbohydrates discussed hereinabove.
In the preceding example, polyethylene glycol was used to fractionate the blood plasma. However, other compounds can be used such as ethylene oxide-propylene glycol condensation products, and other procedures for fractionation can be employed to produce a product which is rapidly soluble according to the teachings herein. | The rate of solubility of a freeze-dried solid composition containing therapeutic amounts of anti-hemophilic factor (AHF) is greatly increased by carrying out the solubilization in the presence of at least a critical threshold amount of a water soluble carbohydrate. The carbohydrate is incorporated into the AHF composition in sufficient quantity to provide at least 2 weight units of carbohydrate (expressed in grams) per 100 volume units of AHF solution (expressed in milliliters). This enhanced rate of solubility permits rapid treatment of hemophilic patients. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional application Ser. No. 60/003,340, filed Sep. 6, 1995.
BACKGROUND OF THE INVENTION
This invention relates generally to the completion of wellbores. More particularly, this invention relates to new and improved methods and devices for completion of a branch wellbore extending laterally from a primary well which may be vertical, substantially vertical, inclined or even horizontal. This invention finds particular utility in the completion of multilateral wells, that is, downhole well environments where a plurality of discrete, spaced lateral wells extend from a common vertical wellbore.
Horizontal well drilling and production have been increasingly important to the oil industry in recent years. While horizontal wells have been known for many years, only relatively recently have such wells been determined to be a cost effective alternative (or at least companion) to conventional vertical well drilling. Although drilling a horizontal well costs substantially more than its vertical counterpart, a horizontal well frequently improves production by a factor of five, ten, or even twenty in naturally fractured reservoirs. Generally, projected productivity from a horizontal well must triple that of a vertical hole for horizontal drilling to be economical. This increased production minimizes the number of platforms, cutting investment and operational costs. Horizontal drilling makes reservoirs in urban areas, permafrost zones and deep offshore waters more accessible. Other applications for horizontal wells include periphery wells, thin reservoirs that would require too many vertical wells, and reservoirs with coning problems in which a horizontal well could be optimally distanced from the fluid contact.
Some horizontal wells contain additional wells extending laterally from the primary vertical wells. These additional lateral wells are sometimes referred to as drain holes and vertical wells containing more than one lateral well are referred to as multilateral wells. Multilateral wells are becoming increasingly important, both from the standpoint of new drilling operations and from the increasingly important standpoint of reworking existing wellbores including remedial and stimulation work.
As a result of the foregoing increased dependence on and importance of horizontal wells, horizontal well completion, and particularly multilateral well completion have posed important concerns and have provided (and continue to provide) a host of difficult problems to overcome. Lateral completion, particularly at the juncture between the vertical and lateral wellbore is extremely important in order to avoid collapse of the well in unconsolidated or weakly consolidated formations. Thus, open hole completions are limited to competent rock formations; and even then open hole completion is inadequate since there is no control or ability to re-access (or re-enter the lateral) or to isolate production zones within the well. Coupled with this need to complete lateral wells is the growing desire to maintain the size of the wellbore in the lateral well as close as possible to the size of the primary vertical wellbore for ease of drilling and completion.
Conventionally, horizontal wells have been completed using either slotted liner completion, external casing packers (ECP's) or cementing techniques. The primary purpose of inserting a slotted liner in a horizontal well is to guard against hole collapse. Additionally, a liner provides a convenient path to insert various tools such as coiled tubing in a horizontal well. Three types of liners have been used namely (1) perforated liners, where holes are drilled in the liner, (2) slotted liners, where slots of various width and depth are milled along the liner length, and (3) prepacked liners.
Slotted liners provide limited sand control through selection of hole sizes and slot width sizes. However, these liners are susceptible to plugging. In unconsolidated formations, wire wrapped slotted liners have been used to control sand production. Gravel packing may also be used for sand control in a horizontal well. The main disadvantage of a slotted liner is that effective well stimulation can be difficult because of the open annular space between the liner and the well. Similarly, selective production (e.g., zone isolation) is difficult.
Another option is a liner with partial isolations. External casing packers (ECPs) have been installed outside the slotted liner to divide a long horizontal well bore into several small sections. This method provides limited zone isolation, which can be used for stimulation or production control along the well length. However, ECP's are also associated with certain drawbacks and deficiencies. For example, normal horizontal wells are not truly horizontal over their entire length, rather they have many bends and curves. In a hole with several bends it may be difficult to insert a liner with several external casing packers.
Finally, it is possible to cement and perforate medium and long radius wells are shown, for example, in U.S. Pat. No. 4,436,165.
While sealing the juncture between a vertical and lateral well is of importance in both horizontal and multilateral wells, re-entry and zone isolation is of particular importance and pose particularly difficult problems in multilateral well completions. Reentering lateral wells is necessary to perform completion work, additional drilling and/or remedial and stimulation work. Isolating a lateral well from other lateral branches is necessary to prevent migration of fluids and to comply with completion practices and regulations regarding the separate production of different production zones. Zonal isolation may also be needed if the borehole drifts in and out of the target reservoir because of insufficient geological knowledge or poor directional control; and because of pressure differentials in vertically displaced strata as will be discussed below.
When horizontal boreholes are drilled in naturally fractured reservoirs, zonal isolation is seen as desirable. Initial pressure in naturally fractured formations may vary from one fracture to the next, as may the hydrocarbon gravity and likelihood of coning. Allowing them to produce together permits crossflow between fractures and a single fracture with early water breakthrough jeopardizes the entire well's production.
As mentioned above, initially horizontal wells were completed with uncemented slotted liners unless the formation was strong enough for an open hole completion. Both methods make it difficult to determine producing zones and, if problems develop, practically impossible to selectively treat the right zone. Today, zone isolation is achieved using either external casing packers on slotted or perforated liners or by conventional cementing and perforating.
The problem of lateral wellbore (and particularly multilateral wellbore) completion has been recognized for many years as reflected in the patent literature. For example, U.S. Pat. No. 4,807,704 discloses a system for completing multiple lateral wellbores using a dual packer and a deflective guide member. U.S. Pat. No. 2,797,893 discloses a method for completing lateral wells using a flexible liner and deflecting tool. U.S. Pat. No. 2,397,070 similarly describes lateral wellbore completion using flexible casing together with a closure shield for closing off the lateral. In U.S. Pat. No. 2,858,107, a removable whipstock assembly provides a means for locating (e.g., re-entry) a lateral subsequent to completion thereof. U.S. Pat. No. 3,330,349 discloses a mandrel for guiding and completing multiple horizontal wells. U.S. Pat. No. 5,318,122, which is assigned to the assignee hereof and incorporated herein by reference, discloses deformable devices that selectively seal the juncture between the vertical and lateral wells using an inflatable mold which utilizes a hardenable liquid to form a seal, expandable memory metal devices or other devices for plastically deforming a sealing material. U.S. Pat. Nos. 4,396,075; 4,415,205; 4,444,276 and 4,573,541 all relate generally to methods and devices for multilateral completion using a template or tube guide head. Other patents and patent applications of general interest in the field of horizontal well completion include U.S. Pat. Nos. 2,452,920, 4,402,551, 5,289,876, 5,301,760, 5,337,808, Australian patent application 40168/93, U.S. application Ser. No. 08/306,497 filed Sep. 15, 1994, now U.S. Pat. No. 5,526,880, which is assigned to the assignee hereof and incorporated herein by reference, and U.S. Ser. No. 08/188,998 filed Jan. 26, 1994, now U.S. Pat. No. 5,474,131, which is also commonly assigned and incorporated herein by reference.
Notwithstanding the above-described attempts at obtaining cost effective and workable lateral well completions, there continues to be a need for new and improved methods and devices for providing such completions, particularly sealing between the juncture of vertical and lateral wells, the ability to re-enter lateral wells (particularly in multilateral systems) and achieving zone isolation between respective lateral wells in a multilateral well system.
SUMMARY OF THE INVENTION
The above-discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by the lateral seal and control system of the invention.
The invention is most broadly related to sealing the junction between a primary and a lateral borehole where a flange is provided on a lateral tubular member having an angle which closely mimics the angle of the whipstock used to deflect the original drill string that created the lateral.
Important to borehole operation is that the lateral be properly sealed above and below the joint (by, for example, packers) and that the joint itself be tightly sealed. In order to achieve the desire end, the invention provides a properly oriented production pipe with a flange and a flange seal and most preferably a pre-machined window joint. The flange and seal are of a larger dimension than that of the window against which they will seal. The pipe is kicked into the lateral and penetrates the lateral until the flange seals in the window to seal the joint (under pressure from above or tensile stress from below or both). The kicker can be mechanical, hydraulic or electrical and is positioned at the downhole end of the production pipe. The window may be in a pre-machined pipe (which would carry the production pipe) or the window may be the casing of the lateral where that casing intersects the casing of the primary. The flange, which generally comprises a substantially rigid support and an elastomeric or other suitable sealing component is affixed to the uphole end of the production pipe. With increasing pressure applied to the mating surfaces the seal is better. The pressure may be applied in a number of ways including pressure from other components within the window joint or down hole tensile stress from below in the form of a pulling mechanism. The device also could employ both mechanisms to provide redundancy of the seal. The latter is more fully expressed in connection with the detailed description of the preferred embodiments. The arrangement seals the joint itself. The invention then provides annular seals both above the joint and below the joint which fill the annulus created around the string. Packers may be employed for this function, with particular types being chosen for particular effects. It will be understood, however, that other seals are also applicable providing they are effective in preventing the leakage of fluid. Leakage of such fluid which may occur at the joint between primary and lateral is undesirable due to the potential for contamination of the target fluid. The invention provides a structure which can be employed as a unit in one trip or as separate parts in a series of trips if desired.
The above-discussed and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings wherein like elements are numbered alike in the several FIGURES:
FIG. 1 is a lower section elevation/cross-section view of the invention in a down hole condition before deployment;
FIG. 1a is an enlarged portion of FIG. 1 which is circumscribed in FIG. 1 as 1a--1a;
FIG. 2 is an upper section elevation/cross-section view of the invention in the undeployed condition;
FIG. 3 is an elevation/cross-section view of the lower lateral section of the invention in the deployed condition.
FIG. 4 is an elevation view of the window joint of the invention;
FIG. 4a is an elevation view turned 90° from FIG. 4;
FIG. 4b is an end view of the window joint of the invention;
FIG. 5 is a cross-section of the production pipe taken along section line 5--5 in FIG. 1 which illustrates the position of the kickers of the invention;
FIG. 6 is a perspective view of the energizing sleeve; and
FIG. 6a is a sectional view taken along section line 6a--6a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, 10 indicates the "primary" wellbore which may or may not be vertical as suggested above. 12, then, indicates the "lateral" wellbore which likewise may or may not be horizontal. For purposes of clarity of discussion, these terms are assigned and the primary is considered to be more uphole than the lateral or in other words is a parent hole to the lateral. In other respects, primary and lateral do not have the general meanings of respectively vertical and horizontal. It must be understood that the primary for purposes of this specification may be horizontal or some degree thereof and the lateral may be vertical or some degree thereof.
As one of skill in the art will recognize, when a lateral wellbore is drilled, there generally is a whipstock (not shown) placed in primary 10 to deflect the drill string, in a predetermined direction. The whipstock is usually oriented and supported by a packer 16 such as a Baker Oil Tools' ML packers (product #415-62), which packer includes an orientation key 18. Because the packer 16 is left in position down hole after removal of the whipstock orientation and positioning of the apparatus of the invention is rendered reliable and efficient by employing an orientation anchor which is commercially available from Baker Oil Tools in Houston, Tex. as product #783-59.
The invention itself, in the most preferred embodiment, provides a device for reentering a lateral accurately and for providing an excellent window joint seal capable of withstanding 3500 psi and substantial heat which are common down hole conditions.
Still referring to FIG. 1, wellbore 10 is left with packer 16 (after removal of previously used tools) which now supports the assembly of the invention. Immediately at the lowest (in the drawing, not necessarily in the field) or most downhole point of the undeployed assembly, an orientation anchor 20 is illustrated. Orientation anchor 20 includes orienting slide 22 and keyway 24 so that as the assembly is lowered, the slide 22 and keyway 24 will engage key 18 and ensure proper orientation of the several other elements of the invention as discussed hereunder.
Packer 16 provides both a support structure and a seal by tightly mating with the circumferential perimeter of seal 26 located immediately above the keyway 24 and forming a part of orientation anchor 20. Seal 26 preferably possesses an outside diameter slightly larger than the inside diameter of packer 16 so that when seal 26 is forced into an equiplanar and coaxial position with respect to packer 16, by the substantial weight of the string thereabove, a very effective seal is obtained.
Connected to orientation anchor 20 referring to FIGS. 1, 4, 4a and 4b (moving upwardly in the figures and uphole in the field) is pre-machined window joint 28. Window joint 28 can be connected to orientation anchor 20 in a number of known ways. Window joint member 28 is pre-machined to mate substantially exactly with a machined flange and seal to be described hereunder. This provides a substantial degree of accuracy in sealing the lateral 12 which would otherwise be significantly more uncertain because of unknowns such as exact location, size and degree of collapse of a pre-existing lateral. Window joint 28 comprises an elongated tubular structure having an ellipsoidal opening 30. The opening is pre-machined to precise dimensions and location with respect to the orientation anchor 20. In this manner, the operator can be assured that the opening is aligned with the lateral 12 and that a sufficient seal can be made against the window periphery 31. As one of skill in the art will recognize, the opening is ellipsoidal because the lateral 12 intersects the primary 10 at an angle thus creating an ellipsoidal intersection. The particular dimensions of the ellipse are determined by the angle of divergence of lateral 12 to primary 10.
To ensure that the production tube 34 (shown in FIGS. 1, 1a, 2, 3 and 4b) is oriented properly within window joint member 28, and thus will kick off into the lateral as desired, alignment plates 32 are positioned within window joint member 28, one on either side of window opening 30. With plates 32 installed, either by being milled in initially or being affixed to the i.d. of member 28 by conventional methods, only two orientations for tube 34 are possible, the correct one and 180° off. The likelihood of the tube 34 being assembled with window joint member 28 backwards is small. Alignment plates 32 also assist in preventing rotation of the production tube 34.
Referring now to FIGS. 1, 1a, 2, 3, 5 and 6a, the production tube 34 which is to be placed in lateral 12 includes several unique features. Initially, it should be noted that production tube 34 is installed within the window joint member 28, preferably on the surface, and is then tripped down hole as a unit. As above mentioned, alignment plates 32 maintain the production tube in the proper orientation.
Prior to the production tube 34 being actuated, a stabilizing arrangement 33 is installed above opening 30 of window member 28 which locks the window member 28 in the desired position. More preferably, the stabilizing arrangement is a SAB-LT packer (commercially available from Baker Oil Tools of Houston, Tex., product #409-17), The SAB-LT packer does not move down hole when it is set and, therefore, is the choice of this operation. It will be appreciated that packer 16 is already set and will not allow downward movement of the inventive assembly, thus the static packer 33.
Once the assembly of the invention is orientated and stabilized, known means (hydraulic, mechanical, etc.) are employed to begin moving production tube 34 down hole toward window opening 30. When nose 36 is exposed to the lateral 12 by being moved into opening 30, kickers 38 are actuated to push nose 36 through opening 30 and into lateral 12. Kickers 38 are pivotable winglike members and as shown in FIGS. 1 and 5 are pivotable on pins 41 (disposed in pin bore 41a) under the bias of springs 43 as shown or other mechanical or hydraulic or electrical means. Motive means are continued until the entirety of tube 34 is pushed into lateral 12 and flange 40, having sealing element 42, is in contact with a periphery 31 of opening 30. It will be appreciated that in order for tube 34 to follow the angle of the lateral 12 from primary 10, bendable section 44 must be included as shown (FIGS. 1 and 3). Preferred embodiments of bendable section 44 include flexible tubing, an articulated joint, etc. one of skill in the art can substitute many arrangements for this feature without departing from the scope of the invention. It will also be apparent to the skilled artisan that the substitution of a bent sub for bendable section 44 may eliminate the need for the otherwise inherently weaker link and additionally may obviate the need for kickers 38. Because of inherent movements of tube 34 while being pushed into lateral 12 and the potentially great frictional forces between tube 34 and window opening 30 or lateral casing 13, a protective sleeve 37 is disposed around a section of tube 34 stretching from nose 36 to the uphole extent of packer 39 (which is preferably an SAB packer from Baker Oil Tools #409-07). The sleeve 37, therefore, protects packer 39 from damage while moving through window joint 28 and opening 30 as well as while the production tube 34 is moving down lateral 12. The sleeve is later "pumped off" as described hereinafter. It should be recognized that while the provision of sleeve 37 is preferred, it is not necessary and the invention will work without the sleeve, albeit at greater risk of damage to the packer 39.
Flange 40 and sealing element 42 (referring to FIGS. 2 and 3) are disposed up hole from the elements described immediately hereinabove. The distance by which the above elements are separated is a function of the application and, therefore, may be relatively long or relatively short without departing from the scope of the invention. Flange 40 is carefully attached to tube 34 whether milled, welded, fastened, secured or otherwise attached, at an angle and curvature which is preselected to provide a substantially mating interface between the seal 42 and opening periphery 31. The tolerances are reasonably precise such that a seal capable of withstanding about 3500 psi and high temperature, common to down hole conditions is formable. In the most preferred embodiment seal 42 is an elastomeric compound, however, it will be understood that other compounds including ductile metal compounds are applicable and may be preferable in some conditions.
In order to energize the seal 42, and depending upon conditions and application, it may be desirable to physically bias the flange 40 from within the window joint 28 or by introducing a down hole pull from a mechanism further downhole in lateral 12. In the most preferred embodiment of the present invention both of the arrangements are employed.
Referring to FIGS. 1, 2, 3, 6 and 6a, the energizing sleeve 46 is illustrated in the preferred embodiment of a cylinder having a section removed as shown, and a ramp 48 at a downhole end thereof. Sleeve 46 is urged downhole within the window joint 28 and is in a set position when stop 50 abuts crown 52 of flange 40. In this position, sleeve 46 is in contact with flange 40. It should be noted that, as shown in FIG. 6a, sleeve 46 also is possessed of flattened or milled sides to maintain its position and orientation within window member 28 by embracing with alignment plates 32. As will be apparent to one of skill in the art, the flat edged sleeve 46 would appear to make contact with flange 40 only at the side apices of the ellipsoidal opening 30 because of the curvature of the window member 28, however, the flange 40 is of a thicker cross-section at uphole 40a and downhole 40b ends and of a narrower cross-section at the sides 40c. This provides for a much more constant surface upon which pressure from the energizing sleeve 46 is distributed. A good seal can thus be maintained. Moreover, with careful machining and precise tolerance, the energizing sleeve 46 alone may be sufficient for withstanding the high temperature and pressure (about 3500 psi).
Alternatively or conjunctively a downhole pulling arrangement, the most preferred being a packer 39 such as a Baker Hughes SB packer (product #40907), may be employed to assist or solely provide the bias of the seal of flange 40 against window opening periphery 31. As will be appreciated by one of skill in the art the SB type packer moves downhole as it is set, to allow the slips to set properly. This downhole movement is, in the context of this invention, harnessed to pull the production tube 34 farther downhole thereby creating an even tighter interface between flange 40/seal 42 and opening periphery 31. The most preferred embodiment of this invention employs the energizing sleeve and the packer.
Referring now to FIGS. 1 and 3, the above mentioned protective sleeve 37 is illustrated in various positions on or off the packer 39. As was stated hereinabove, the sleeve is not necessary to the operation of the invention, however, is preferred to prevent damage to packer 39. Where the sleeve 37 is utilized, the preferred method and apparatus for operating the sleeve is as follows. Provision (not shown) is made for conventionally supplying a pressurized fluid to the vicinity of sleeve release port 54 and packer expansion port 56. Fluid then travels in the direction of arrows through ports 54 and 56 into chamber 58 and chamber 66, respectively. Sleeve 37 is initially maintained in the protective position by at least one shear pin (the use and position of which are known to the art) having a predetermined shear point calibrated to a particular amount of pressure. When the pressure of fluid flowing through port 54 into chamber 58 exceeds the shear point of the pin(s) the sleeve 37 is pumped off revealing the packer 39. As can be ascertained by a review of FIGS. 1 and 3, the port 54 leads to a chamber 58 which is forced to expand longitudinally under the influence of the fluid pressure. Chamber 58 is defined by an annular segment 60 which retains its position and sleeve 37 which is slidable. Sleeve 37 will continue to slide downhole under fluid pressure until stop nub 62 impacts end brace 64 which is fixedly connected to anchor segment 60. It will be appreciated in FIG. 3 that when the sleeve 37 stops downhole movement it has exposed packer 39 for deployment. At this time, pressure increases from the fluid because it can no longer escape into chamber 58 whose volume had been increasing. Upon system pressure reaching a second predetermined amount, a second at least one shear pin is sheared allowing packer slide 65 to move as fluid enters chamber 66 through port 56. Packer slide 65 impacts packer 39 and initiates deployment thereof against the i.d. of lateral 12 to both stabilize production tube 34 and draw the same downhole for purposes of sealing the window joint as stated above.
In another embodiment of the invention, the window joint member 28 possesses an opening 30 which is substantially larger than flange 40 and seal 42 and which will allow deposition of production tube 34 into and sealing of flange 40 immediately against the casing 13 of lateral 12. This allows the window member 28 to be removable, freeing internal pipe space in primary 10.
In this embodiment it will be understood that energizing sleeve 46 is not utilized. This, of course, means that the downhole pulling device (e.g., packer 39) must provide the seal 42 tightness. There is also, however, another embodiment wherein there is no window joint member 28 at all. Rather, the casing of primary 10 is treated as the window member, and the lateral seal is created directly at the casing 13 of lateral 12. One of skill in the art is easily able to visualize that which is here disclosed. In this case, the energizing sleeve may be positioned against the primary 10 casing 15 to urge flange 40 and seal 42 into pressurized contact with the lateral casing 13. It is also possible, of course, as in the previous embodiment that the energizing sleeve may be omitted or the packer may be omitted.
The latter two embodiments are generally directed to newer wells where reasonable certainty may be had regarding the condition of the lateral (i.e., breakdown, occlusion, etc) whereas the former preferred embodiment is a superior arrangement for older wells when said conditions and thus the ability to effect a seal are more elusive.
Obviously, the preferred embodiment is also quite suited to newer wells.
While preferred embodiments have been shown and described, various modification and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation. | A downhole multilateral completion tool is disclosed which includes a premachined window joint and a production tube adapted to be moved downhole through the window joint and kicked off into the pre-drilled lateral. A flange and seal form a part of the uphole end of the production tube and provide a 3500 psi seal after the production tube is placed in the lateral. The invention, moreover, includes an energizing sleeve which biases the flange into a sealed position and a packer which by pulling the production tube, enhances the seal of the flange. | 4 |
This application is a division of application Ser. No. 08/840,839, filed Apr. 17, 1997, now U.S. Pat. No. 5,912,321.
This application claims the priority of German patent document 196 16 968.2-43, the disclosure of which is expressly incorporated by reference herein.
BACKGROUND AND SUMMARY OF THE INVENTION
Patent document EP-A-0 557 943 describes phosphazene compounds that can be cured by radical polymerization, the polymerization of which is initiated by adding initiators or by electron radiation. Patent document EP-A-0 368 165 describes curable resin compositions that contain a curable phosphazene compound and a pentaerythritol acrylate compound and/or a bis(4-acryloxydialkoxpheyl)alkane compound mixed together. These known phosphazene derivatives have one or more of the following drawbacks. They tend to polymerize prematurely, so that stabilizers have to be added. High storage temperatures have to be avoided, which in turn results in drawbacks for shelf life and choice of conditions for synthesis, yields, and absence of chlorine. Radical polymerization is inhibited by atmospheric oxygen and thermal curing in particular frequently leads to incompletely hardened surfaces. Curing often occurs very slowly and leads to products that discolor with time. During the curing, severe shrinkage frequently occurs that leads to deterioration of behavior and cracking. So, such phosphazene derivatives, or their mixtures pursuant to the state of the art, cannot be used for many applications, including use as binders for paints and coatings in particular.
The invention makes available new phosphazene derivatives that avoid these drawbacks of the state of the art and provides polymerizable products with improved properties. In particular, it is desirable to avoid a radical mechanism for polymerization of the phosphazene derivatives.
In one aspect, the invention provides polymerizable phosphazene derivatives with the following structural formula
[--NP(A).sub.a (B).sub.b --].sub.x
wherein the groups A and B are bonded to phosphorus atoms through --O--, --S--, --NH--,or --NR-- (R=C 1 -C 6 alkyl); A contains at least one vinyl ether group of the general formula Q--O--CR'═CHR" and/or styrene ether group of the general formula ##STR1## wherein R' and/or R" stands for hydrogen or C 1 -C 10 alkyl; B stands for a reactive or nonreactive hydrocarbon group optionally containing O, S, and/or N, and optionally containing at least one reactive group; Q is an aliphatic, cycloaliphatic, aromatic, and/or heterocyclic hydrocarbon group, optionally containing O, S, and/or N; a is a number greater than O; b is 0 or a number greater than 0 and a+b=2; x stands for a whole number that is at least 2; and z stands for 0 or 1.
The open bonds in the formulae above indicate either joining into a ring with alternating atoms of N and P, or a bonding to groups A or B or the usual catalyst or initiator molecule groups. The later, for example, can be found in Makromol. Chem., 183; 1833-1841 (1982) and Makromol. Chem., 183; 1843-1854 (1982) or can be those of Lewis acids, SbCl 3 , AlCl 3 , or sulfur compounds.
The phosphazene derivatives of the invention can contain two or more different vinyl ether groups and/or both vinyl ether groups and styrene ether groups in one molecule. The phosphazene derivatives of the invention, which can be polymerized cationically at least when substituted by vinyl ether groups, and whose polymerization can be initiated by acids, have one or more of the following advantages over known phosphazene derivatives: complete substitution of the phosphazene and thus absence of chlorine can be achieved in high yields; oxygen does not inhibit the curing of the phosphazene derivatives of the invention; even thin coatings are completely cured in the presence of atmospheric oxygen, which makes thermally initiated curing possible in particular; they have no tendency to discolor the polymerized product; they are ordinarily less viscous and therefore more suitable for low-solvent application; and they have less tendency to shrink.
All of these properties make the polymerizable phosphazene derivatives of the invention suitable as curable binders for paints, coatings, fillers, mastics, adhesives, moldings, or films, especially as binders for paints and coatings. For example, they can be used advantageously as binders in transparent coatings for exterior varnishing, or for varnishing interior wood trim in motor vehicles. They can also be used in transparent coatings for polycarbonate headlight diffusion lenses or the like. The usual additive substances such as initiators, pigments, leveling agents, pigments, UV stabilizers, fillers, and the like, can be added to formulations containing the polymerizable phosphazene derivatives of the invention.
The structural formula for the phosphazene derivatives of the invention, shown above, states that they are necessarily at least partially substituted on the phosphorus atoms by groups that contain at least one vinyl ether group and/or styrene ether group, as shown and described. Therefore, the substituent B may be, but does not have to be, present in the phosphazene molecule (i.e., b may be 0).
The phosphazene derivatives of the invention can be cyclic or acyclic compounds, which have a structural skeleton of alternating nitrogen and phosphorus atoms in every case. The cyclic compounds in which x stands for 3 or 4 and which, therefore, consist of 6- or 8-membered rings are preferred. The 6-membered ring, in which x stands for 3, is particularly preferred.
Q is a spacer group that is bonded to a phosphorus atom through an oxygen atom, a sulfur atom, an NH group, or an NR group, and that has at least one vinyl ether group and/or styrene ether group, in which R' and R" have the meanings given above, at its free end and/or as a side group. R' and/or R" in these groups are preferably hydrogen, methyl, or ethyl, and preferably are hydrogen.
Compounds especially preferred according to the invention are those with the general structural formula ##STR2## wherein Z and Z' are the same or different and each stands for --O--, --S--, --NH, or --NR-- (R=C 1 -C 6 alkyl); Q stands for an aliphatic, cycloaliphatic, aromatic, and/or heterocyclic hydrocarbon group optionally containing O, S, and/or N; YH stands for an aliphatic, cycloaliphatic, aromatic, and/or heterocyclic hydrocarbon group optionally containing O, S, and/or N and/or optionally containing a reactive group different from a vinyl ether group or a styrene ether group; y is O or 1; x stands for a whole number from 2 to 20; and a, b, R', and R" are as defined above.
R in the above formulas is alkyl with 1 to 6 carbon atoms, preferably methyl or ethyl. In the last formula given above, Z and Z' are preferably --O--.
The spacer group Q and the YH group can have such structures that they control the properties of the phosphazene derivative. Thus, the Q and YH groups can have very diverse structures. Examples of such Q and Y groups can be found in German patent document DE-A-4 325 776. They are usually alkaline groups with various chain lengths, straightchained or branched, preferably with 2 to 20 carbon atoms, and especially with 2 to 6 carbon atoms, biphenylene, phenylene or oxyalkylene groups, or combinations thereof. In the case of oxyalkylene groups, they are preferably oxyalkylene groups with the formula --(CH 2 -CH 2 -0) n , wherein n is 1 to 20, preferably 1 to 6. The spacer groups Q and Y can optionally contain substituents on this preferred structural formula, or can be interrupted by other groups. Examples of such substituents are ester groups, keto groups, OH groups, or NH 2 groups. Examples of groups inserted into the alkaline chain in turn are ester groups, keto groups, urethane groups, or NH groups.
The YH group can be straight-chained or branched, and can consist of a reactive or nonreactive group or can contain a group that differs from the vinyl ether and styrene ether groups of the above formulas. Preferred reactive YH groups are or contain isocyanate groups, carboxyl groups, allyl groups, vinyl acetate groups, N-methylol groups, epoxide groups, glycidyl ether groups, acrylate groups, methacrylate groups, silyl groups (such as C 1 -C 6 alkoxysilyl or aceeoxysilyl groups), OH groups, or NH 2 groups. The reactive groups can also be blocked in the usual way. The selection of the YH group, however, is not to be limited to the above enumerated groups.
The preferred phosphazene derivatives of the invention are those in which y is O or 1, i.e., those that are vinyl ether derivatives. In any case, they can be cured with cationic initiation using at least one acid. This can be done by direct addition of acid. Instead of this, initiators can be added to the formulation that split off acids when irradiated with UV light or electron beams or when the temperature is raised, which in turn then initiate the polymerization. If the molecule contains other reactive groups in addition to the vinyl ether groups, multicure procedures can be used, for example, combinations of thermal curing, curing by atmospheric humidity or atmospheric oxygen, and UV curing.
The phosphazene derivatives containing styrene ether groups of the invention are ordinarily polymerized in the usual way by a radical mechanism. Thus, optionally, either initiators that split off radicals when irradiated with UV light or in some other way are added, or radicals are generated without addition of initiator by, for example, introducing thermal energy or by electron irradiation. Anionic or cationic polymerization is also possible in certain cases.
The phosphazene derivatives pursuant to the invention can be prepared by reacting a chlorophosphazene with at least one compound of the general formula MA, alone or in combination with at least one compound of the general formula MB, or successively with MA and MB, in an inert solvent. In these compounds, A and B are as defined above and M stands for a hydrogen atom, an alkali metal, an alkaline earth metal, or a basic group. The basic group M, for example, can be a pyridyl group or a tertiary amino group such as a triethylamino group, or it can be a 1,8-diazabicyclo[5,4,0]undec-7-ene(1,5-5) group. It is preferred for M to be sodium. The compounds MA and MB can be obtained by reacting the compounds HA and/or HB with sodium hydride, sodium metal, or sodium hydroxide, for example, by the procedure of U.S. Pat. No. 4,775,732 (US-A-1 4 775 732).
In accordance with the above embodiments, the preferred compounds MA are those with the formula ##STR3## and the compounds MB are those with the general formula M--Z'--YH, wherein M, Z, Z', Q, Y, R', R", and y are as defined above.
The preferred process for preparing the phosphazene derivatives of the invention consists of using compounds MA and MB in which M is bonded to an oxygen atom, and thus Z and Z' stand for --O-- in the above preferred formulas for MA and MB. Examples of practical inert solvents in which the reaction is carried out are tetrahydrofuran, toluene, dimethyl sulfoxide, dimethylformamide, chloroform, methylene chloride, and pyridine. Suitable reaction temperatures are between 15 and 110° C., preferably between 18 and 70° C., with lower temperatures requiring longer reaction times. Depending on the temperature selected, it is desirable for the reaction times to be between 5 and 60 hours.
DETAILED DESCRIPTION OF THE INVENTION
The invention is described in detail by the following examples.
EXAMPLE 1
The compound 2,2,4,4,6,6-Hexakis(vinyloxyethylenoxy)-2,2,4,4,6,6-hexahydro-1,3,5,2,4,6-triazatriphosphorine is prepared by the following reaction. ##STR4##
16.80 g (0.10 mole) of sodium hydride (95%) is suspended in 700 ml of anhydrous THF and/or argon in a 2-liter three-necked flask with internal thermometer, dropping funnel, and reflux condenser.
While cooling in an ice bath, 61.67 g (0.70 mole) of ethylene glycol monovinyl ether is then added slowly through a dropping funnel over a period of 90 min. The internal temperature rises slightly, but remains below 20° C. Stirring is then continued at room temperature for a total of 48 h (alternatively 20 h at about 50° C.). The contents of the flask gradually assume a brown color.
A solution of 34.79 g (0.10) mole of phosphonitrile chloride (NPCl 2 ) 3 in 200 ml of anhydrous THF is then added slowly (90 min) through a dropping funnel. Water bath cooling is necessary during this addition to keep the temperature below 30° C. Stirring is continued for 1 h longer at room temperature, and the batch is then heated to an internal temperature of 50° C. Stirring is continued overnight (total 24 h) at this temperature.
The mixture is then allowed to cool to room temperature and is filtered by suction. Almost all of the THF is removed from the brown filtrate in a rotary evaporator, 250 ml of diethyl ether and 250 ml of deionized water are added, and the mixture is transferred to a separatory funnel. The ether phase is separated, and the aqueous phase is extracted two more times with 125 ml portions of diethyl ether. The combined ether phases are shaken three times with 50 ml portions of deionized water, which can lighten the mixture considerably. The ether phase is separated and dried over sodium sulfate. After filtering off the drying agent and evaporating the solvent in a rotary evaporator, 62.84 g (0.096 mole, corresponding to 96% of the theoretical amount) of a clear yellow liquid is obtained.
For further purification, the crude product can be stirred with diethyl ether and activated charcoal, filtered through a short silica gel column (Silica Gel 60, mobile phase diethyl ether), and then evaporated. The product is then pure in TLC and HPLC. Yield after purification: 60.23 g (0.092 mole, corresponding to 92% of the theoretical amount). The purified product crystallizes after trituration with a glass rod (crystal nucleation).
The phosphonitrile chloride was recrystallized from n-heptane. The vinyl ether was not further purified. The tetrahydrofuran was stored over Deperox molecular sieve and is anhydrous. The other chemicals are used without additional purification.
Properties of the product:
White, sticky solid; melting point 26-27° C., gradual brown discoloration (without polymerization) above 230° C.; index of refraction (of the noncrystallized liquid) n d 25 =1.4914.
______________________________________Elemental analysis: N % P % O % H % Cl % O %______________________________________Calculated: 6.39 14.13 43.84 6.44 0.00 29.20Found: 6.20 14.29 44.07 6.54 0.00______________________________________
Molecular weight 657.53; readily soluble in chloroform, tetrahydrofuran, diethyl ether, isopropanol, ethyl acetate, toluene, poor solubility in n-heptane, n-pentane; thin layer chromatographic test, developer n-heptane/ethyl acetate 1:1, material silica gel with UV indicator Roth Co., Rf=0.40; detection TV 254 nm; indicator Methyl Red, iodine; Beilstein test for halogens negative.
EXAMPLE 2
2,2,4,4,6,6-Hexakis(vinyloxyhexyloxy)-2,2,4,4,6,6-hexahyd ro-1,3,5,2,4,6-triazatriphosphorine:
The compound named above is prepared by the process described in Example 1, from 14.42 g (0.10 mole) 1,6-hexanediol divinyl ether, 2.40 g (0.10 mole) sodium hydride, and 4.29 g (0.012 mole) (NPCl 2 ) 3 .
Properties:
Clear, viscous, slightly yellow-colored liquid; yield 10.64 g (0.011 mole, corresponding to 89% of the theoretical amount); molecular weight 993.57 g/mole; index of refraction n d 25 =1.4804; Beilstein test for halogens negative; thin layer chromatographic test: mobile phase ethyl acetate, material silica gel with UV indicator Roth Co., Rf=0.27; detection UV 254 nm, indicator Methyl Red, iodine.
EXAMPLE 3
2,2,4,4,6,6-Hexakis (vinyloxybutyloxy)-2,2,4,4,6,6-hecxahy dro-1,3,5,2,4,6-triazatripnosphorine:
This compound is prepared by the method described in Example 1 from 11.62 g (0.10 mole) 1,4-butanediol divinyl ether, 2.40 g (0.10 mole) sodium hydride, and 4.97 g (0.014 mole) (NPCl 2 ) 3 .
Properties:
Clear, viscous, pale yellow-colored liquid; yield 7.60 g (0.009 mole corresponding to 67% of the theoretical amount), molecular weight 825.39 g/mole; index of refraction n d 25 =1.4814; Beilstein test for halogens negative; thin layer chromatographic test: mobile phase n-haptene/ethyl acetate 1:1; material silica gel with UV indicator Roth Co., Rf=0.55, detector UV 254 nm, indicator Methyl Red, iodine.
EXAMPLE 4
2,2,4,4,6,6-Hexakis[vinyloxydl(ethylenoxy)]-2,2,4,4,6,6-h exahydro-1,3,5,2,4,6-triaztriphosphorine:
This compound is prepared by the method described in Example 1, with a somewhat longer reaction time, from 13.27 g (0.10 mole) diethylene glycol; monovinyl ether, 2.40 g (0.10 mole) sodium hydride, and 4.97 g (0.014 mole) (NPCl 2 ) 3 .
Properties:
Clear, viscous, slightly yellow-colored liquid; yield 9.68 g (0.011 mole, corresponding to 75% of the theoretical amount), molecular weight 921.36 g/mole; Beilstein test for halogens negative; thin layer chromatographic test: mobile phase ethyl acetate; material silica gel with UV indicator Roth Co., Rf=0.70, detector UV 254 nm, indicator Methyl Red, iodine; readily soluble in dichloromethane, chloroform, tetrahydrofuran; poor solubility in water, n-haptene.
EXAMPLE 5
The compound 2,2,4,4,6,6-Hexakis(3'-vinyloxypropylamino)-2,2,4,4,6,6-hexahydro-1,3,5,2,4,6-triazatriphosphorine is prepared by the following reaction: ##STR5##
20.23 g (0.20 mole) of 3-amino-1-propanol vinyl ether is placed in a 259-ml three-necked flask with dropping funnel, reflux condenser, and internal thermometer, and 50 ml of anhydrous toluene is added. A solution of 4.97 g (0.014 mole) of (NPCl 2 ) 3 in 50 ml of toluene is then added over a period of 20 min while cooling with a water bath. The internal temperature rises slightly. After the addition is about half complete, a white precipitate of hydrochloride is formed. Stirring is continued for 150 min at room temperature, and the mixture is then heated to an internal temperature of 50° C. The mixture is stirred at this temperature for 18 h, and is then allowed to cool to room temperature. The mixture is filtered by suction, and the filtrate is shaken with 15 ml of deionized water, dried over anhydrous sodium sulfate, and filtered. The solvent is then drawn off from the organic phase obtained in a rotary evaporator. After brief drying under high vacuum, 12.21 g of an orange, highly viscous, clear liquid is obtained.
The product is taken up in toluene and filtered through a short silica gel column (Silica Gel 60); yield after removal of solvent and drying under high vacuum 9.70 g (0.013 mole, corresponding to 94% of the theoretical amount) of clear, yellow, highly viscous liquid.
Properties:
Molecular weight 735.78 g/mole; thin layer chromatographic test: mobile phase ethyl acetate, material silica gel, with UV indicator Roth Co., Rf=0.80; detection: indicator MethYl Red, iodine.
EXAMPLE 6
Vinyl ether phosphazene derivative with mixed substitution are prepared according to the following reaction: ##STR6##
a) 9.60 g (0.40 mole) of sodium hydride is placed in a 1000-ml three-necked flask with KPG stirrer, dropping funnel, and internal thermometer, and is slurred with 100 ml of anhydrous tetrahydrofuran. While cooling with ice/salt, a solution of 65.68 g (0.40 mole) of eugenol in 50 ml of anhydrous tetrahydrofuran is then added dropwise (gas evolution, addition time 45 min).
Stirring is continued for 1 h at room temperature, and then a solution of 46.36 g (0.133 mole) of (NPCl 2 ) 3 in 150 ml of anhydrous tetrahydrofuran is added, likewise while cooling with ice/salt (addition time 15 min, gelatinous precipitation of NaCl, flask contents gray-green).
The mixture is stirred for 60 h at room temperature, transferred to a single-necked flask, and the solvent is evaporated by rotation. The product is taken up in 150 ml of diethyl ether and 150 ml of deionized water, and the phases are separated in a separatory funnel. The aqueous phase is washed twice with 10 ml portions of deionized water. The combined orange-colored ether phases are dried over anhydrous sodium sulfate. The drying agent is filtered off and the clear filtrate is stirred for 30 min at room temperature with activated charcoal. After repeated filtration and solvent removal by rotary evaporation, 94.94 g (0.130 mole, corresponding to 98% of the theoretical amount) of a viscous, clear, brown-colored liquid is obtained.
For purification, the product is filtered through a short silica gel column (Silica Gel 60) mobile phase n-heptane/ethyl acetate 1.1). The solvent is removed by rotary evaporation and the product is dried on an oil pump. Yield 87.62 g (0.120 mole, corresponding to 90% of the theoretical amount) of highly viscous, light yellow clear liquid.
Properties of the intermediate:
Molecular weight 730.89 g/mole; Beilstein test for halogen-positive; index of refraction n d 20 -1.5723; readily soluble in toluene, chloroform, ethyl acetate, diethyl ether, tetrahydrofuran, acetone; poor solubility in water, n-heptane; the product consists of isomeric compounds.
______________________________________Elemental analysis: C % H % N % O % Cl % P %______________________________________Calculated: 49.38 4.56 5.76 13.10 13.39 12.76Found: 49.63 4.66 5.61 14.61 12.81______________________________________
Thin layer chromatographic test: developer ethyl acetate; material silica gel with UV indicator Roth Co., Rf=0.71; detection UV 254 nm, indicator Methyl Red, iodine.
b) 4.46 g (0.144 mole) of sodium hydride is placed in a 250-ml three-necked flask with dropping funnel, reflux condenser, and internal thermometer, and is slurried with 100 ml of anhydrous tetralydrofuran. The mixture is stirred for 5 min, and a solution of 12.69 g (0.144 mole) of ethylene glycol monovinyl ether in 20 ml of anhydrous tetrahydrofuran is then added over a period of 30 min while cooling with a water bath. The mixture is then heated to an internal temperature of 50° C. and stirred for 40 hours. The flask contents are then cooled down to room temperature.
While cooling with a water bath, a solution of 30.00 g (0.041 mole) of (NP[O--C 6 H 3 {OCH 3 }C 3 H 5 ]Cl) 3 in -70 ml of anhydrous tetrahydrofuran is then added dropwise over a period of 1 hour. The mixture is stirred for 3 h at room temperature and is then heated to an internal temperature of 50° C. After stirring for 40 h at the temperature the brown contents of the flask are allowed to cool to room temperature, transferred to a single-necked flask, and the solvent is evaporated by rotation. The product is taken up in 130 ml deionized water and 130 ml of chloroform, and the phases are separated in a separatory funnel. The aqueous phase is again shaken with 50 ml of chloroform. The combined organic phases in turn are washed twice with 50 ml portions of 5% sodium chloride solution, and then dried over anhydrous sodium sulfate. After filtering off the drying agent, removing the solvent by rotary drying, and drying under high vacuum, 35.83 g (0.040 mole, corresponding to 99% of the theoretical amount) of a pasty, caramel-colored compound is obtained.
For purification, the product is stirred with activated charcoal and filtered through a short silica gel column (Silica Gel 60). After drawing the solvent off from the filtrate and drying the product under high vacuum, 28.37 g (0.032 mole, corresponding to 78% of the theoretical amount) of pale-colored pasty product is obtained.
Properties of the end product:
Molecular weight 885.2 g/mole; Beilstein test for halogen negative; thin layer chromatographic test: mobile phase n-heptane/ethyl acetate 1:1; material silica gel with UV indicator Roth Co., Rf=0.47; detection UV 254 nm, indicator Methyl Red, iodine.
______________________________________Elemental analysis: C % H % N % O % Cl % P %______________________________________Calculated: 56.95 6.14 4.74 21.67 0.00 10.19Found: 57.41 6.33 4.68 0.00 11.00______________________________________
EXAMPLE 7
The compound 2,2,4,4,6,6-Hexakis(styrenoxy)-2,2,4,4,6,6-hexahydro-1,3,5,2,4,6-triazatriphosphorine is prepared according to the following reaction: ##STR7##
a) 38.88 g (0.24 mole) of p-acetoxystyrene is placed in a 500-ml three-necked flask with internal thermometer, and 400 ml of a 10% potassium hydroxide solution is added over a period of 2 min while stirring and cooling in a water bath. The flask contents turn yellow, two phases form, and the internal temperature rises slightly. The mixture is first stirred for 2 h longer while cooling in a water bath, and is then stirred overnight at room temperature (about 15 h).
On the next day, the contents of the flask are orange-colored and consist of one phase only. It is neutralized with about 175 ml of 3 N hydrochloric acid (pH control). The voluminous product precipitates out. It is filtered off by suction and washed with some n-heptane. The crude product is dried under oil pump vacuum to determine the crude yield.
Crude yield 24.84 g (0.207 mole, corresponding to 86% of the theoretical amount) of light pink powder. It is dissolved in 200 ml of chloroform and shaken twice with 50 ml portions of deionized water. The organic phase is dried over anhydrous sodium sulfate and, after filtering off the drying agent, it is stirred for 10 min with activated charcoal. It is filtered repeatedly and the solvent is drawn off in a rotary evaporator.
Crude yield was 18.11 g (0.151 mole, corresponding to 63% of the theoretical amount) of white powder. For further purification, it is recrystallized from a mixture of 100 ml of chloroform and 50 ml of n-heptane (white crystals form quickly on standing in a refrigerator). Yield after suction filtration and drying was 12 84 g (0.107 mole, corresponding to 54% of the theoretical amount) of white powder. The prepared p-hydroxystyrene should be used immediately since it can become discolored on lengthy storage.
Properties of p-hydroxystyrene:
White solid; melting point 68 to 70° C.; molecular weight 120.15 g/mole, readily soluble in acetone, tetrahydrofuran, ethanol, diethyl ether, poorly soluble in n-heptane, water; thin layer chromatographic test: developer n-heptane/ethyl acetate 1:1; material silica gel with UV indicator Roth Co., Rf=0.50; detection UV 254 nm, indicator Methyl Red, iodine.
______________________________________Elemental analysis: C % H % O %______________________________________Calculated: 79.97 6.71 13.32Found: 79.73 6.66______________________________________
b) 2.08 g (0.087 mole) of NaH is suspended in 130 ml of anhydrous tetrahydrofuran in a 500 ml three-necked flask and the mixture is stirred for 5 min at room temperature. A solution of 12.84 g of p-hydroxystyrene and 0.01 g of sulfur (inhibitor) in 100 ml of anhydrous tetrahydrofuran is then added dropwise over a period of 30 min (gas evolution, rise of internal temperature to 30° C.; the contents of the flask quickly become brown-colored).
The mixture is stirred for 30 min longer at room temperature, and the alkoxide formation is then complete (no further evolution of gas, clear brown solution). A solution of 3.77 g (0.011 mole) of (NPCl 2 ) 3 (recrystallized from n-heptane) in 40 ml of anhydrous tetrehydrofuran is then added dropwise over a period of 15 min (slight internal temperature rise). After the addition is complete, stirring is continued for 1 h longer at room temperature, and the mixture is then heated to an internal temperature of 60° C. (immediate precipitation of NaCl). Stirring is continued overnight at this temperature (15 h in all).
The mixture is allowed to cool to room temperature and the contents of the flask are transferred with a little tetrahydrofuran into a 1-liter round-bottomed flask. Most of the solvent is evaporated by rotation, and the crude product is transferred into a separatory funnel by means of 100 ml or diethyl ether and 100 ml of deionized water. The phases are separated, and the brown aqueous phase is extracted twice with 50 ml portions of diethyl ether. The combined ether phases (yellow-orange) are shaken in succession with 30 ml each of 2 N hydrochloric acid, 5% sodium carbonate solution, and 5% sodium chloride solution, and are then dried over anhydrous sodium sulfate. The mixture is filtered, the filtrate is stirred for 10 minutes with activated charcoal, filtered again, and the ether is evaporated by rotary evaporation. Crude yield was 11.90 g (0.014 mole, corresponding to >100% of the theoretical amount) of white powder.
For further purification, the product is recrystallized from 50 ml, of isopropanol. Final yield was 7.90 g (0.009 mole, corresponding to 85% of the theoretical amount) of white powder.
Properties:
White solid; melting point 99 to 100° C.; thermal behavior: gradual polymerization above 120° C.: molecular weight 849.89 g/mole; readily soluble in tetrahydrofuran, dichlcromethane, diethyl ether, toluene, acetone; poorly soluble in water, n-heptane; thin layer chromatographic test: developed system n-heptane/ethyl acetate 1:1; material silica gel with UV indicator Roth Co., Rf=0.03; detection UV 254 nm, indicator Methyl Red, iodine; Beilstein test for halogens negative.
______________________________________Elemental analysis: C % H % N % O % Cl % P %______________________________________Calculated: 67.84 4.98 4.94 11.30 0.00 10.93Found: 67.88 5.12 4.82 0.00 10.76______________________________________ | This invention relates to a polymerizable phosphazene derivative with a general structural formula
.brket open-st.NP(A).sub.a (B).sub.b).brket close-st..sub.x
wherein the groups A and B are bonded to phosphorus atoms through --O--, --S--, --NH--, or --NR-- (with R=C 1 -C 6 ) alkyl), and wherein A stands more precisely for a vinyl ether group or a styrene ether group, and B stands more precisely for a hydrocarbon group. The invention also relates to procedures for synthesizing such phosphazene derivatives. The phosphazenes derivatives of the invention can be cured by a process that is initiated cationically, which leads to a large number of advantages. The phosphazene derivatives of the invention can, in particular, be used as curable binders for paints, coatings, fillers, mastics, adhesives, moldings, or films. Paints or coatings comprising the phosphazene derivatives of the invention show especially high mechanical resistance and scratch resistance. | 2 |
BACKGROUND OF THE INVENTION
The field of the invention relates to microsurgical equipment, and particularly to apparatus for providing irrigation to a surgical situs and aspiration for removing tissue and fluid therefrom.
Microsurgical systems are used for performing many operations today, including ophthalmic surgery. Systems for removing cataracts, for example, typically include a cutting probe and associated aspiration device for removing mascerated tissue to a collection vessel. An irrigation supply is also provided to replace the fluid removed through aspiration. The cutting probe and associated irrigation/aspiration lines are often mounted to the same handpiece which is in turn connected to a machine for controlling the cutting (or emulsifying), aspiration and irrigation procedures. Such machines include irrigation/aspiration manifolds including a roller pump and vacuum source for controlling aspiration, and valve means for controlling irrigation.
The irrigation/aspiration manifolds of most modern systems include disposable cassettes which maintain the irrigation and aspiration tubing in the desired positions with respect to the machine. U.S. Pat. Nos. 4,493,695, 4,626,248, 4,627,833, 4,713,051 and 4,735,558 disclose various cassettes and mounting assemblies therefor which have been proposed for use in ophthalmic surgery systems.
One of the problems encountered in the use of some cassettes is the unintentional pinching of the flexible aspiration tube as the roller pump operates. The roller pump includes a plurality of rollers which are rotated about an axis and bear against the tube. In addition to the desired occlusion of the tube between the rollers and a selected portion of the cassette manifold, the tube tends to be pulled in the direction of rotation of the pump rollers. The tube may accordingly become partially or completely occluded at the point where it is pulled against the manifold.
Another difficulty with respect to cassettes is in mounting them to the emulsifier/aspirator unit. Such units typically include horizontally disposed slots for receiving the cassettes. Latch mechanisms are provided for maintaining the cassette in the desired position with respect to the pump rollers, vacuum source and irrigation control means. Some cassette receptacles require the user to push the cassette into the correct position within the slot. This can sometimes result in improper seating if the proper force is not applied.
Another type of latching mechanism includes a pair of spring-loaded cams which resiliently urge the cassette towards the pump rollers. The cassette will accordingly tend to oscillate within the slot when the roller pump is actuated.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a cassette assembly for an ophthalmic surgery system which allows the reliable operation thereof.
It is another object of the invention to provide a cassette having means for preventing the occlusion of a tube mounted thereon except where the tube contacts a pump roller.
In accordance with the above and other objects of the invention, a cassette and a cassette receptacle assembly are provided for use in an ocular surgical system. The cassette according to the invention includes an arcuate race. One end of the race includes a slot therein for receiving a flexible tube. The slot exerts pressure in the vertical direction upon the tube. If the pump rollers tend to pull the tube as they move away from the slot, the upper and lower walls of the slot prevent the tube from flattening against the inner, vertical slot surface. The tube is accordingly maintained in the open position at this point to allow proper aspiration of the surgical situs.
The cassette is locked into position by a pair of opposing, spring-loaded cams which engage the cassette upon insertion and thereupon automatically move and lock it into proper position. The cassette remains stationary when locked in position, even during the operation of the roller pump which causes the pump rollers to exert a force against the cassette. In addition, means are provided for maintaining the cassette at a fixed distance from the pump rollers. This fixed distance is crucial for maintaining the desired aspiration rate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a cassette according to the invention;
FIG. 2 is a partially sectional bottom plan view thereof;
FIG. 3 is a side elevation view thereof;
FIG. 4 is an enlarged front elevation view thereof;
FIG. 5 is a rear elevation view thereof;
FIG. 6 is a sectional view thereof taken along line 6--6 of FIG. 1;
FIG. 7 is a partially sectional top plan view of a bottom portion of a cassette receptacle assembly; and
FIG. 8 is a sectional side elevation view of a cassette receptacle assembly.
DETAILED DESCRIPTION OF THE INVENTION
A disposable or reusable cassette 10 for use in irrigation/aspiration systems is shown in FIGS. 1-6. The cassette 10 includes an integral plastic housing 12 having specifically designed channels, openings and passages to accommodate various tubes, fittings, and a hydrophobic filter.
Referring to FIG. 1, a U-shaped channel 14 is defined within the upper surface of the plastic housing 12 for receiving a flexible irrigation tube 16. The channel extends through a circular notch 18, the bottom of the notch including a narrow ridge 20 passing through the center thereof and running substantially perpendicular to the tube 16. The ridge facilitates the pinching of the tube when a plunger is inserted within the notch 18.
Each end of the U-shaped channel 14 opens into the front face 22 of the housing 12. A pair of plastic fittings 24 are secured to the housing walls defining the channel openings by an adhesive. Each fitting also includes an annular ring 26 which projects partially within a pair of lobes 28 extending laterally from the end portions of the channel to provide a mechanical retention. A first flexible tube 30 extends between one of the fittings and an IV bottle (not shown). An IV connector 32 is secured to the end of this tube. A second tube 34 is connected between the other of the two fittings 24 and a tapered male fitting 36. This tube supplies irrigation fluid from the IV bottle to the patient.
A second, generally Y-shaped channel 38 is defined within the upper surface of the cassette housing. A cylindrical passage 40 extends between the bottom surface of this channel and the bottom surface 42 of the cassette housing. An aspiration tube 44 is positioned within the channel, one end of which extends through the hole 40 and to a drainage bag or other waste receptacle (not shown). The other end is connected to one part of a tee 46 positioned in a slotted opening 48 adjoining the front face 22 of the housing. This arrangement is shown in FIGS. 2 and 4, the tube and tee being omitted in FIG. 4. A second aspiration tube 50 is connected between the opposite port of the tee 46 and a pinch bulb 51. A third aspiration tube 52 is connected between the pinch bulb and a tapered female fitting 53.
An arcuate race 54 is defined by the upper rear surface of the cassette housing. A slot 56, as shown most clearly in FIGS. 5 and 6, is defined by the housing walls at the inlet side of the race. The depth of the slot is slightly larger than as the diameter of the aspiration tube 44 while the height thereof is slightly less than said diameter to provide strain relief.
Referring to FIGS. 1-3 and 6, the tee 46 includes a third port which is connected to a hydrophobic filter 58. The filter is connected to a fitting 60 secured within a horizontal cylindrical passage 62 within the cassette housing. This passage adjoins a vertically extending passage 64 which terminates at an opening 65 in the upper surface of the housing 12.
Each side of the housing 12 includes a pair of opposing indentations 66 as shown in FIGS. 1 and 3. Each indentation is defined in part by a laterally extending flange 68 having an arcuate front and side surfaces.
FIG. 7 illustrates a bottom housing 70 of an irrigation/aspiration system prior to insertion of a cassette. A pair of cams 72, 74 are mounted to the bottom housing by a pair of shafts 76 and bearing assemblies 78, respectively. Each cam includes a vertically extending pin 80 mounted thereto and a finger 81 projecting therefrom. A second pair of vertically extending pins 82 are mounted to the bottom housing. A pair of coil springs 84 are connected to the respective pairs of pins 80, 82 and are maintained under tension thereby. A first pair of stop pins 86 are provided for restricting the rotation of the cams 72, 74 in a first direction. A second pair of stop pins 88 prevents the cams from rotating beyond a selected arc in a second rotational direction. A phototransistor 89 is mounted near one of the cams and detects when a cassette is inserted within the unit. Unless the cam is fully rotated to insure the cassette is in the proper operative position, the phototransistor will not allow the system to be operated. A pair of opposing, pins 90 are mounted near the front end of the bottom housing. These pins are operatively connected to a spring-loaded door (not shown) which automatically closes the slot once the cassette is removed therefrom.
FIG. 8 shows the bottom housing 70 mounted to a top housing 92, and a slot 94 defined by the two housing portions for receiving the cassette. A roller pump 96 is positioned near the rear end of the slot, the rollers of which bear against the aspiration tube 44 as they travel along the race 54. A pair of stop pins 97 (FIGS. 1 and 8) extending from the top housing 92 maintain the cassette 10 a precise distance from the rollers of the roller pump.
An aspiration solenoid 98, an irrigation solenoid 100, a support 102, and a twelve volt D.C. motor 104 are all mounted to the top housing. A valve assembly 106 is mounted to the support while a tube 108, shown in part in FIG. 8, is connected between the valve manifold assembly 110 and the aspiration solenoid 98. A vacuum sensor (not shown) is also connected to the valve manifold assembly.
The aspiration solenoid 98 includes a hollow plunger 112 having a suction cup 114 mounted to the bottom end thereof. The suction cup is positioned either directly over or upon the top surface of the cassette so that the passage 116 therein is in fluid communication with passage 64 when the cup is in the latter position.
The irrigation solenoid is used for controlling the passage of irrigation fluid through the irrigation tube 16. When the plunger 118 thereof is caused to move downwardly towards the cassette, the tip thereof enters the circular notch 18 and pinches the tube between itself and narrow ridge 20. A spring assembly 120 is provided for urging the plunger 118 towards the upper position so that irrigation fluid will continue to be supplied if the unit fails.
In operation, the cassette 10 is inserted within the slot 94 such that the flanges 68 thereof urge the fingers 81 of the cams 72, 74 rearwardly. This causes the cams to rotate about the shafts 76. Once the overcenter springs 84 have crossed the axes of the respective shafts 76, the cams will continue to rotate. The motion of the cassette will continue until the front face of the cassette engages the stop pins located in the top cover. This movement of the cams, which takes place automatically once the cassette is partially inserted, causes the cassette to be pushed by the cams into the proper position as the cam surfaces 81' trailing the fingers 81 engage the flanges 68. The aspiration tube 44 accordingly bears against the rollers of the roller pump 96, the aspiration opening 65 is positioned beneath the suction cup 114, and the circular notch 18 is positioned beneath the plunger tip of the irrigation solenoid 100. The pins 97 and springs 84 insure that the cassette 10 is maintained in a substantially fixed position relative to the roller pump in order to provide consistent and reliable aspiration. The springs exert sufficient force to prevent the cassette from moving as the pump rollers bear against the aspiration tube 44. As discussed above, the phototransistor 89 allows the system to be operated when the cam 74 has been rotated to the operating position. The cassette is precluded from moving with respect to the pump rollers during the operation of the roller pump.
Irrigation is provided to the patient when the plunger 118 of the irrigation solenoid is in the raised position. Actuation of the solenoid causes the plunger to descend, thereby pinching the irrigation tube 16 between the plunger tip and the narrow ridge 20 within notch 18.
The surgery situs may be aspirated by causing the plunger 112 of the aspiration solenoid to descend. The suction cup 114 is thereby pushed into sealing engagement with the smooth upper surface of the cassette housing 12. Fluid and mascerated tissue travel through tubes 52, 50 and 44, respectively, and out through the bottom of the cassette. The hydrophobic filter 58 prevents the fluid and tissue from traveling into passages 62, 64, 116 and to the vacuum sensor (not shown).
The roller pump causes the fluid and tissue to move through the tube 44 by peristaltic action in the direction shown by the arrow in FIG. 1. Although the rollers tend to pull the tube 44 in the direction of the arrow, the positioning of the tube within the slot 56 prevents it from assuming an excessively elliptical shape which would decrease the area through which the aspirated materials could flow. The upper and lower surfaces of the slot prevent the height of the tube from changing significantly, thereby preventing it from flattening when pulled against the portion of the cassette housing which defines the race 54. The aspiration process accordingly will proceed without interruption.
Once the operation has been completed, the voltage to the irrigation solenoid is discontinued to allow the plunger 118 to be moved to a raised position. The plunger 112 within the aspiration solenoid 98 is also moved to the raised position by energizing the aspiration solenoid. The cassette is then withdrawn from the slot 94 as the cams 72, 74 rotate back to the initial position by virtue of the cassette withdrawal process.
Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention. | A cassette and a cassette receptacle assembly are provided for use in an ocular surgical system. The cassette includes a housing which defines an arcuate race. A flexible tube extends across the race and conveys a fluid when compressed by the rollers of a roller pump. A slot is defined by the housing at the point where the tube forms a bend prior to entering the race. The slot has a height which is preferably smaller than the diameter of the tube and therefore prevents the tube from flattening as the rollers urge it away from the slot. The cassette mounting assembly includes a pair of cams which urge the cassette into a locked position with respect to the roller pump. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This invention is related to application Ser. No. 09/454,073, filed on Dec. 1, 1999, entitled “Efficient Arrangement for Coupling Light From a Light Source to a Light Guide,” by Roger F. Buelow et al. It is also related to application Ser. No. 09/470,156, filed Dec. 22, 1999, and entitled “Method of Making Optical Coupling Device,” by Juris Sulcs et al. The entirety of the disclosures of both these applications is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to systems for delivering light to one or more light guides, and, more particularly, to a waterproof system.
BACKGROUND OF THE INVENTION
Lighting fixtures adapted for operation in outdoor environments are commonly used to illuminate optical fibers. These systems mounted above ground, employ exterior shields to protect the internal components from rain and water splashed from adjacent pools or ponds. The optical fibers may be positioned in decorative arrays around a pool or pond, and also illuminate the pool. Often, a color wheel is interposed between the light source and the inlet ends of the optical fibers to enhance the visual effects with colored light from the fibers. Cooling air is drawn into the housing, circulated around the inlet ends of the optical fibers and the light source, and then channeled from the fixture under a pressure differential established by a fan positioned along the cooling path of air flowing through the fixture.
Various attempts have been made to configure these lighting fixtures with a low profile above the ground, and to prevent the internal light source from leaking (spurious) light from the light box to the adjacent area. However, such above-ground fixtures are vulnerable to collision with people and moving equipment such as carts and bicycles, and to associated damage from such collisions. They are also vulnerable to intrusion by wildlife such as insects or rodents that may disturb sensitive components, or to dirt and dust that accumulates over time on the optics to reduce their light output.
Another approach is to channel the spurious light into a translucent globe and so make the light box visible. See, for example, U.S. Pat. No. 5,779,353, entitled “Weather-Protected Lighting Apparatus and Method.” This approach, however, draws attention to the light source and away from the dramatic and aesthetically pleasing fiberoptic pool-lighting display.
It would be desirable to provide a lighting fixture with fiber connections that could be buried beneath the surface of the ground. This would require the lighting fixture to be completely sealed. This, in turn, would require the lighting fixture to be efficient enough to deliver ample illumination at a sufficiently low power to avoid the need for external cooling air.
SUMMARY OF THE INVENTION
In a preferred form, the invention provides a light delivery system including a light source. A first generally tubular, hollow coupling device with an interior light-reflective surface receives light from the source at an inlet and transmits it to an outlet. The coupling device increases in cross sectional area from inlet to outlet in such manner as to reduce the angle of light reflected from the surface as it passes through the device. A thermal-isolating region has an inlet positioned in proximity to an outlet of the coupling device and has an outlet for passing light to an optical member, the thermal-isolating region comprising one or more members. A waterproof container for the light source and coupling device has an aperture allowing light to pass out of the container. The aperture is sealed in part by a portion of a member of the thermal-isolating region.
Advantageously, the foregoing system can be buried beneath the ground. This avoids the problems of people or equipment colliding with the system. The components in the sealed container are protected from intrusion by wildlife or deterioration from dirt and dust. In some embodiments, the container may be free of a fan, reducing the complexity and noise of the system.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of several elements of a light delivery system in accordance with the invention.
FIG. 2 is a side plan view, partially in section and partially cut away, showing arrangements for sealing a thermal-isolating member to a waterproof container and for sealing a termination of a light guide.
FIG. 3 is a side plan view, partially in cross section and partially cut away, of the structure shown in FIG. 2 .
FIGS. 4A and 4B are side plan views, in simplified form, an arrangement for sealing a thermal-isolating region to a waterproof container when a light coupling device and an elliptical reflector are respectively used to deliver light to such region.
FIGS. 4C and 4D are side plan views, in simplified form, an arrangement for sealing another thermal-isolating region to a waterproof container when a light coupling device and an elliptical reflector are respectively used to deliver light to such region.
FIG. 5 is an exploded view of a framework for holding the light coupling devices and lamp of FIG. 1 .
FIGS. 6A and 6B are front and side view respectively of a wave washer used in the framework of FIG. 5 .
FIG. 7 is an assembled view, in perspective, of the framework of FIG. 5 .
FIG. 8 is a side plan view of a lamp used in the framework of FIG. 5 .
FIG. 9 is a simplified, perspective view of a light-coupling device in accordance with the invention.
FIG. 10 is a view of a light delivery system using principles of the coupling device of FIG. 9, partially shown in block diagram form.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an exploded view of several elements of a light delivery system in accordance with the invention. A light source or lamp 12 , shown partially cut away, has upper and lower legs 12 a and 12 b, and a central, bulbous portion 12 c. When lamp 12 comprises a metal halide gas discharge lamp, for instance, the bulbous portion 12 c contains electrodes 14 a and 14 b. These electrodes are connected to in-leads 16 a and 16 b respectively, which, in turn, are connected to foil in-leads 18 a and 18 b, respectively. Lamp 12 may alternatively comprise a formed halogen or other filament-type lamp (not shown), for instance, or an electrodeless lamp (not shown).
In a preferred arrangement, light from lamp 12 is captured by optical devices 20 and 22 , and directed through thermal-isolating members 24 and 26 , respectively, to respective light guides (not shown) for distribution to remote locations. Members 24 and 26 (and other “thermal-isolating members” described herein) are necessary to thermally isolate temperature-sensitive light guides (not shown) from the heat of lamp to prevent premature deterioration of the light guides. Plastic light guides are typically thermally sensitive, as well as glass light guides including thermally sensitive glue or other components. Each of devices 20 and 22 has an inlet facing the lamp, and an outlet facing a respective one of thermal-isolating members 24 and 26 . The interior surface of each device is reflective to light from the lamp. Each coupling device increases in cross sectional area from inlet to outlet in such manner as to reduce the angles of light reflected from the inner surface as it passes through the device. It is preferred that substantially all cross-sectional segments along the interior of each coupling device taken through a central axis of light propagation 28 be substantially parabolic, or substantially conform to a CPC shape. CPC is a specific form of an angle-to-area converter, as described in detail in, for instance, W. T. Welford and R. Winston, High Collection Nonimaging Optics, New York: Academic Press, Inc. (1989), chapter 4 (pp. 53-76).
The inlet of coupling device 20 has recesses 30 a and 30 b, and similarly the inlet of coupling device 20 has recesses 32 a and 32 b. These recesses receive respective portions of upper and lower legs 12 a and 12 b of the lamp, and enable the coupling devices to hold the lamp. In the case of an electrodeless lamp (not shown), the recesses could receive a gas probe of a starting aid projecting from one side of a bulbous portion of the lamp and another projection from another side of the bulbous portion.
The outlet of coupling device 20 has recesses 34 a, 34 b, 34 c and 34 d, and similarly the outlet of coupling device 22 has recesses 36 a, 36 b, 36 c and 36 d. These recesses may be used to align the coupling devices with a framework (not shown), as will be described below.
Each of thermal-isolating members 24 and 26 may comprise a single device, or it may comprise multiple devices such as a pair of semi-cylindrical devices (not shown) or four quarter-cylindrical devices (not shown). Each of members 24 and 26 or any of its included devices could be hollow if desired. Quartz may be used for member 24 or 26 , although other refractory materials that can withstand the heat from lamp 12 without degrading the lamp or light guide can be used, such as high temperature borosilicate glass. Alternatively, each of members 24 and 26 may comprise an extension (not shown) of its associated coupling device with a cross section in the direction of light propagation that may be substantially constant, as opposed to the changing cross sections of members 24 and 26 as shown.
FIG. 2 shows a waterproof container 40 having an aperture 42 through which a portion of thermal-isolating member 24 extends. Aperture 42 , which allows light to pass outside of the container, is sealed in part by thermal-isolating member 24 . It is further is sealed by a sealing arrangement including a first hub member 44 and a second hub member 46 . Hub member 44 may be sealed to the left-shown side of container 40 by a ring-like seal 48 . Second hub member 46 is coupled to the first hub member, preferably by threads as shown, and together press a ring-like seal 50 against the circumference of thermal-isolating member 24 . To minimize surface contact between seal 50 and member 24 , the thickness of the seal is preferably small, such as 1 mm where member 24 has a diameter of 19 mm. This minimizes light leakage from member 24 . To further reduce light leakage, the exterior of seal 50 preferably comprises material with a substantially lower index of refraction (e.g., 1.3) than that of region 24 (e.g., 1.5). Such low index material may comprise a fluoroelastomer from the family of copolymers and terpolymers made with tetra-fluro-ethylene and hexa-fluro propylene. One such material is sold by DuPont Corp. of Wilmington, Delaware, under the trademark TEFLON.
For compactness, a third hub member 52 (FIG. 2) may be coupled to second hub member 50 for scaling a termination 54 of a light guide 56 against water, etc. Where light guide 56 is stranded, as shown, its termination 54 may take the form of a nipple as shown. In contrast, a solid-core light guide (not shown) does not typically require additional structure such as a nipple at its termination; it may properly terminate simply by being cut to a desired length. Hub members 50 and 52 cooperate to press a ring-like seal 57 against the outer circumference of termination 54 .
FIG. 3 shows a side view of first hub member 44 mounted on container 40 , with third hub member 52 coupled to second hub member 46 . Termination 54 surrounds fibers 56 , which are shown in cross section. To secure the first hub member to the container, bolts 58 a and 58 b (shown in phantom) may pass through holes 59 a and 59 b in the first hub member and corresponding holes (not shown) in container 40 .
First hub member 44 may include partial holes 60 so that a bolt 61 (shown in phantom) may pass between outward projections 46 a and 46 b of hub member 46 and into one of such a holes for locking the position of such hub member.
The features of FIGS. 2 and 3 regarding thermal-isolating member 24 and light guide 56 , for instance, are preferably duplicated for thermal-isolating member 26 (FIG. 1) and a further light guide (not shown).
FIG. 4A shows in simplified form various parts of a light delivery system, to illustrate different sealing arrangements. Thermal-isolating member 26 passes through aperture 42 of container wall 40 and through a hub arrangement 62 representing a simplified view of the hub arrangement of FIG. 2 that comprises first and second hub members 44 and 46 . Ring-like seals 48 and 50 may be the same as those shown in FIG. 2 . Lamp 12 provides light that is directed through coupling device 22 and an air gap 63 to reach thermal-isolating member 26 , where it is then passed to a light guide 64 , shown in simplified form. Collectively, air gap 63 and thermal-isolating member 26 form a thermal-isolating region 65 , which isolate the typically thermally sensitive light guide 64 from the heat of lamp 12 .
In the embodiment of FIG. 4A, the ratio of the average diameter of the main light-transmitting portion of aperture 42 (e.g., 66 ) to the average (i.e., left-to-right shown) length of the main light-transmitting portion of member 26 is less than one.
FIG. 4B is substantially similar to FIG. 4A except for the use of a lamp 67 whose rays 68 are directed by a generally semi-spherical, elliptical reflector 69 to the left-shown side of member 26 . Lamp 67 may be substantially similar to lamp 12 of the various figures herein. In FIG. 4B, the thermal-isolating region includes an air gap 71 between reflector 69 and member 26 , in addition to member 26 itself. The foregoing ratio mentioned in connection with FIG. 4A also applies to FIG. 4 A.
FIG. 4C shows a further variation on a light delivery system in which a thermal-isolating region 200 includes a member in the form of a plate 202 sealed to container wall 40 by a ring-like seal 204 . The mechanical details of placing seal 204 under pressure, which will be routine to those of ordinary skill in the art, have been omitted. Thermal-isolating region 200 additionally includes a cylindrical extension 206 of a coupling device 208 , which otherwise may be similar to coupling device 22 of FIG. 1, and also includes an air gap 210 .
In the embodiment of FIG. 4C, the ratio of the average diameter of the main light-transmitting portion of aperture 42 (e.g., 212 ) to the average length of a main light-transmitting portion of thermal-isolating member 202 (e.g., 214 ) most proximate the aperture is greater than one.
FIG. 4D is substantially similar to FIG. 4C except for showing a lamp 67 and reflector 69 (as in FIG. 4B) focusing rays 68 from lamp 67 onto the right-shown surface of light guide 64 . Lamp 67 may be substantially similar to lamp 12 of the various figures herein. Additionally, a thermal-isolating region 215 includes an air gap 216 between reflector 69 and thermal-isolating member 202 , and an air gap 218 between member 202 and light guide 64 . The foregoing ratio mentioned in connection with FIG. 4C also applies to FIG. 4 D.
Preferably, the inside of container 40 is free of a fan. This can result from one or more of: (1) isolating the temperature-sensitive, typically plastic light guide (e.g., 56 , FIG. 2) from the heat of the lamp by use of a thermal-isolating region including a thermal-isolating member (e.g., 24 or 26 , FIG. 1 ); (2) using light coupling devices as described above, which are highly efficient; (3) using an electronic ballast (not shown) mounted in a separate chamber (not shown) from the lamp and coupling devices; (4) forming container 40 of a thermally conductive material, such as aluminum, so that its large surface area radiates a substantial portion of the heat produced by the lamp; and (5) designing components within the container to operate in a high ambient temperature without lowering their expected life; for example, for the lamp, increasing the length of its foil in-leads so that heat from its environment and from its arc source does not cause such leads to destructively oxidize.
FIG. 5 shows an exploded view of a framework including frame members 70 and 72 of zinc, for instance, for holding coupling devices 20 and 22 (FIG. 1) and lamp 12 . One or more wave washers 76 and 78 , or other resilient means, are used to achieve an arrangement for holding the coupling devices in a manner allowing considerable manufacturing tolerances in their length, for instance.
A supporting wall 80 of frame member 72 supports the right-hand shown side of wave washer 78 , which may have the shape of a cross-section of a clamshell, i.e., a shape formed by joining two arcs each of less than 180 degrees. A lateral support wall 82 maintains proper rotational alignment of the wave washer by, for instance, also having the shape of a cross-section of a clamshell, as shown. Washer 78 has inward projections 84 for being received by recesses 36 a - 36 d of coupling device 22 . This limits axial movement of the device along a main axis of light propagation, while also maintaining proper rotational alignment of the coupling device. FIGS. 6A and 6B respectively show a front view and a side view of washer 78 to better illustrate projections 84 and preferred bends in the washer that flatten to accommodate manufacturing tolerances in the axial length of coupling device 22 , for instance. Similarly, frame member 70 has a supporting wall 86 (shown in dashed lines) and a lateral support wall 88 corresponding to the like-named walls of frame member 72 for interacting in a similar manner with wave washer 76 and coupling device 20 .
Axial movement of coupling device 22 can also be achieved other than by using recesses 36 a - 36 b. For instance, the outer perimeter of the outlet of such device can be configured with radially outward facing bumps (not shown) that cooperate with inward projections (not shown) of wave washer 78 that may be generally similar to projections 84 . If desired to maintain proper rotational alignment of the coupling device, one or more inward projections can be each configured to partially wrap around both sides of an associated bump along a main axis of light propagation.
If desired, one of the wave washers may be omitted. Alternatively, a wave washer may be replaced by other resilient means, such as a plurality of small coil springs (not shown) for pressing against a plurality of points of the outlet of an adjacent coupling device.
Arms 92 of frame member 72 preferably join respective arms 94 of frame member 70 in a non-telescoping manner as results, for instance, from the configuration of the ends of such arms as shown. This assures that the resilient force placed on coupling devices 20 and 22 is governed by the wave washers (or alternative resilient means) rather than by any additional resilient force (not shown) pressing together the frame members. Such additional resilient force may be provided by upper and lower coil springs 96 and 98 , respectively, as shown in the assembled view of frames 70 and 72 in FIG. 7 .
As shown in FIG. 5, both foil in-leads 18 a and 18 b of the lamp incorporate bends, as well as in-lead portions 90 a and 90 b. FIG. 8 shows these bends in more detail. Thus, bends 110 a and 100 b in in-leads 18 a and 18 b result in a compact profile for the lamp. In-lead portion 90 a incorporates “knee”-type (or generally orthogonal) bends 102 and 104 , while in-lead portion 90 b incorporates knee-type bends 106 , 108 , 108 and 112 . The foregoing bends allow in-leads 90 a and 90 b to flex relative to the vitreous-covered in-lead portions 18 a and 18 b (e.g., by 4 mm) so that the coupling of these leads to respective female conductors (not shown) will not dislodge the lamp from a desired position supported, for instance, by coupling members 20 and 22 (e.g., FIG. 7 ).
Alignment structure 114 a and 114 b (FIG. 7) may be provided for aligning in-leads 90 a and 90 b.
Example of Forming Coupling Device
Coupling devices having a circular cross-section along a main axis of light propagation provide good results. However, because the thermal isolating device (e.g., a quartz rod) receives only a portion of the output, a design that has a smaller output area while giving the same or better angular transformation would be more efficient.
In order to decrease the output area without harming the angular transformation, the input area must be decreased. This is not possible with a circular cross-sectioned device, but is possible with a modified coupling device (or angle-to area converter) with a clamshell shaped (or oblong) cross section that more closely matches the shape of the arc chamber. FIG. 9 shows such a design for a coupling device 120 , simplified to omit recesses at either end.
One way to make an oblong cross section is to brine together two arc-shaped segments of less than 180 degrees. If two 142° segments of a 14 mm diameter circle are brought together the resulting shape is 13.25 mm tall by 9.5 mm wide, large enough to accept a 68-watt metal halide DC arc lamp.
The shape of an oblong coupling device (or angle-to-area converter) was constructed by first designing a device with a 14 mm input and a 38 degree output. This shape was then sectioned and replicated such that its input was the union of two 142° arc segments 122 and 124 of a 14 mm input circle (not shown).
In order to make sure that the angular conversion of the device was at most 38 degrees, the angle of the segment 122 or 124 of each section was increased as the diameter increased. This translates to greater area and therefore conversion to even lower angles.
The output of the oblong angle-to-area converter is the union of two 156 ° segments 126 and 128 of a 22.8 mm diameter circle (not shown). Coupling device 120 works in much the same manner as a device defining a compound parabolic concentrator (CPC). The shape of each of the two sections follows the equations for a CPC as described by the above-cited Winston and Welford reference except for the location of the optical axis. The majority of the light (e.g., more than 75%) reflects from a wall only once. For these single-reflection rays, the oblong device acts exactly as it would in the case of a true CPC that the section emulates. The oblong device gives increased efficiency over the true CPC because:
1. The ratio of output area to input area is greater in the oblong converter described here, resulting in light converted to lower angles;
2. The output area of the CPC is 15% larger than the oblong converters. Since our thermal isolator collects only a set area of the output, and this area is a greater percentage of the smaller oblong converter, the isolator therefore collects more light.
Oblong device 120 formed according to the foregoing principles has an output 126 , 128 with a ratio of minor axis 130 to major axis 132 that substantially exceeds the ratio of minor axis 134 to 136 of its input 122 , 124 . Preferably, the increase in such ratios from input to output causes substantially all light to be received by a first light guide (not shown) having a first acceptance angle (e.g., 38 degrees) while ensuring that a second, alternative light guide (not shown) having a substantially lower acceptance angle (e.g., 30 degrees) receives a substantial (i.e., useful) amount of light. More preferably, the increase in such ratios is sufficient to maximize the amount of light received by the second light guide. In this way, a single coupling device can efficiently accommodate either the first or second light guides, which may typically be a solid-core light guide and a stranded-core light guide, respectively.
FIG. 10 shows a light delivery system including a light source 300 , light-coupling devices 302 and 304 , thermal-isolating regions 306 and 308 , and light guides 310 and 312 . These parts are like the like-named parts above. The system provides a useful light level to both light guides 310 and 312 when they are of the stranded-core and solid-core types, respectively, and when devices 302 and 304 are substantially identical to each other and made according to the principles of FIG. 9 . Alternatively, the system provides a useful light level to light guide 310 , for instance, whether embodied as a stranded-core or a solid-core fiber, when light-coupling device is made according to the principles of FIG. 9 .
When made of ceramic, casting can form a coupling device. When made of quartz or other vitreous material, a coupling device can be formed by blow molding in a similar way as a quartz arc tube with a bulbous region (not shown) along a main axis of the arc tube. The bulbous region typically has a maximum diameter at its midpoint along the axis, and tapers in diameter towards both of its axial ends. A respective coupling device can be cut from each tapered section, with its interior made reflective.
For either circular or non-circular cross-sectioned devices, an outwardly extending ridge (not shown) preferably extends around the bulbous region at the midpoint to facilitate alignment of a cutting instrument and to reduce the chance of fracturing the bulbous region during cutting. The ridge can be formed by applying a narrow zone of heat to the region in a special gathering step.
In making coupling devices, reference can generally be made to prior art techniques for making arc tubes for forming a structure similar to an arc tube with a bulbous region. Additionally, manufacturing tolerances should be kept especially low to substantially achieve an optically desired shape. Maintaining an accurate mold shape, accurately centering a tube of quartz, etc., and accurately positioning the mold on the tube can accomplish this, for instance. These measures will be routine to those of ordinary skill in the art from the present specification.
A special consideration arises when making devices with non-circular (e.g., oblong) cross sections along the central axis of light propagation. Since a mold directly shapes only the exterior of the device whereas only the interior surface is used for reflection, the bulbous region is varied in thickness to result in a desired interior surface topology.
When forming coupling devices from the foregoing molding process, the thickness of the device wall will typically be greater at its inlet than at its outlet.
The foregoing describes a process of producing an arc tube-like structure. Cutting the structure at axial points can then produce axial sections of such structure. This is preferably accomplished with a cutting device, such as a diamond wheel, preferably wet, or a laser. Alternatively, by way of example, the technique of score-snapping can be used by circumferentially scoring, or scratching, the structure at an axial point, and then bending the ends of the structure about such point.
Cuts may and then be made in the resulting axial sections to form the various recesses described above, e.g., recesses 32 a, 32 b and 36 a - 36 b of coupling device 22 shown in FIG. 1 . The cutting may be made by a diamond wheel (not shown), preferably wet, used in the manner of a radial arm saw; that is, with the wheel in the plane of the central longitudinal access (not shown) of the structure. Such diamond wheel is preferably shaped to conform to the desired shape of a recess. Thus, for a round recess, the tip of the wheel is preferably rounded in cross section taken transverse to its axis.
While the invention has been described with respect to specific embodiments by way of illustration, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true scope and spirit of the invention. | A light delivery system includes a light source. A first generally tubular, hollow coupling device with an interior light-reflective surface receives light from the source at an inlet and transmits it to an outlet. The coupling device increases in cross sectional area from inlet to outlet in such manner as to reduce the angle of light reflected from the surface as it passes through the device. A thermal-isolating region has an inlet positioned in proximity to an outlet of the coupling device and has an outlet for passing light to an optical member, the thermal-isolating region comprising one or more members. A waterproof container for the light source and coupling device has an aperture allowing light to pass out of the container. The aperture is sealed in part by a portion of a member of the thermal-isolating region. Advantageously, the system can be buried beneath the surface of the ground. This avoids the problem of people or equipment colliding with the system. The components in the sealed container are protected from intrusion by wildlife or deterioration from dirt and dust. In some embodiments, the container may be free of a fan, reducing the complexity and noise of the system. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Phase Entry of PCT/IL01/01 167 filed 16 Dec. 2001, which claims priority from U.S. Provisional Patent Application Ser. No. 60/256,149 filed 15 Dec. 2000.
FIELD OF THE INVENTION
The present invention relates to a system and method for providing individuals with the ability to access information about prevailing weather conditions, on demand. More particularly, the present system and method permit users to request and receive an accurate, immediate, location-based, localized and customized meteorological report which is valid for a short time period. Such weather reporting will be referred to hereinafter as “nowcasting”.
BACKGROUND OF THE INVENTION
The weather is a matter that concerns almost all individuals on practically a daily basis. We use weather information for [i] planning what to wear, [ii] how to travel to work, [iii] whether to proceed with planned activities indoors or outdoors, [iv] whether to engage in outside recreational activates, and [v] whether to expect and prepare for days of particularly severe allergen, smog or ultraviolet exposure.
However, the present methods for obtaining information that could aid with making these plans has, until now, been subject to various constraints, which severely limits the usefulness of the preparation. Most broadcast and Internet-available weather reports provide fairly generalized guidance relating to the weather. In particular, the type of information available is usually related to large periods of time, meteorologically speaking, i.e. time periods can range from as short as 6 hours to as long as 5–7 days. Additionally, the geographical constraints of the reporting are usually confined to large areas, ranging from 25 km 2 to as much as continental distances, common for satellite and radar-image-based reporting on national and international broadcast programming. Even for weather forecasting provided by “local” broadcasts, the geography of any given report is usually based on areas of 5 km radius (about 78 km 2 ), and it is not known at resolutions of areas less than 5 km, 3 km or even 1 km in radius.
Another deficiency of known systems for providing weather information is that the systems usually and necessarily address only a limited number of atmospheric conditions, i.e. precipitation, average temperature or temperature range, very general statements regarding cloudiness and wind conditions (sunny, partly cloudy, overcast, cloudy, stormy, light winds with gusting, high winds, etc.) and always with respect to large geographical areas, not necessarily of concern to the individual listener or viewer. One only hears about smog, ultraviolet or pollen conditions in extreme circumstances. Despite the existence of data gathering systems for many atmospheric conditions and at relatively high resolutions or degrees of localization, there is no known system or method for making the power of such data gathering and processing systems available to the general public. Nor has there been a method or system for permitting the general public to extract specifically desired information.
Known systems for on-demand weather forecasting provided by Websites such as the Weather Channel website or the UK's Met Office Website are available for obtaining limited weather-related information based on relatively low-resolution geographical limitations such as zip (postal) code by clicking on a map. However, these systems are similarly limited in the frequency of the updates of the underlying weather information database from which the user receives the answer to his query. Additionally, the type of information available is essentially completely determined by the information provider and does not in any way relate to the specific real-time needs of the user. Moreover, while the information purports to be postal-code localized, it is in fact often simply drawn from a weather map having information regarding a much larger area, i.e. at a fairly low resolution, and which is refreshed once every hour or less frequently. Such weather forecast is extremely probabilistic, due to the extended periods of time which are sought to be covered (e.g. six hours or more).
People today are more time-constrained than ever before and their leisure time is increasingly fragmented and subject to the mercy of the weather. In general, people need help to make the most from the limited time they have and to improve the quality of their decision-making. In fact, the effects of the weather impacts many aspects of human endeavors.
Thus, there is a demonstrated need for a system that is capable of providing weather information for highly localized areas. Furthermore, there is a need for a system which provides answers to highly individualized weather-related queries. Additionally, the information provided by such a system should offer accurate guidance, i.e. over a short time period (less than one hour).
The system should be able to answer individual needs and demands, and offer information that is both accurate and easily and cheaply accessible.
The information offered should cover all various angles of interest—a person suffering from asthma or allergies could find out, for example, the fog status in London or the pollen count in Teaneck, N.J. with the same kind of ease and convenience as finding out rain predictions for the following weekend.
OBJECTS AND SUMMARY OF THE INVENTION
Therefore it is an object of the present invention to provide a user with easy access to individualized information regarding meteorological conditions.
It is a further object of the present invention to provide a user with a user-friendly means for obtaining highly localized meteorological condition reporting.
It is a further objective of the present invention to enable a mobile user to get real-time information about the environmental and meteorological changes that are expected with a high level of certainty to occur in the immediate future.
It is a further objective of the present invention to enable a user to get personal environmental and meteorological data for different specified geographical locations based on a preselectable personal profile.
It is yet a further object of the present invention to create a direct weather-interactive relationship between point-of-sale marketing and the immediate weather, for example emphasizing an on-sale item according to real-time weather conditions. For example, offering “new umbrellas at $9.99” in the face of an eminent rapid-onset rain storm.
Yet a further object of the present invention can be integration into a “smart” house that can be proactive in advance of real-time weather changes, for example: closing the windows when heavy rain/dust storm is expected, adjusting an air-conditioning system to a real-time change in pollution levels or local sunshine levels, etc.
Still a further object of the present invention is to provide integration of public transportation arrival/departure information with local, immediate nowcast information, thereby enabling commuters to decide, for example, whether to wait in pleasant weather for a delayed train or to start looking for a more immediate transportation alternatives in view of an oncoming or merely apparent thunder storm.
Yet a further object of the present invention can permit the creation of individualized weather alerts to notify an individual of the occurrence or impending occurrence of a specific weather condition. For example, a mother can request notification, by e-mail, SMS text, paging or cell phone call-back or any wireless data related warning such as animated icon with sound on GPRS network, if the weather in the park where her children are playing is presently or about to become adverse.
These objectives and others not mentioned hereinabove are accomplished by the system and method of the present invention in which an end-user uses a simple, user-friendly interface on an Internet browser, WAP, GPRS or any other data/voice network interface to either activate a saved nowcast profile (saved locally or on a nowcast provider's server), or to construct and execute a new query to obtain selectable meteorological information. The interface and/or query are transmitted over a public communication network, such as the Internet or a cellular phone network (or by any other means) to a nowcast-provider's system. Once the end-user selects the parameters of the data she wants, i.e. the type of meteorological condition that interests her, the location of interest, and the time frame and time intervals of interest (up to one hour, as frequent as one-minute intervals based on data-refresh intervals as often as once every 5 minutes), the software of the present invention builds and initiates a request for the development and delivery of a time evolution for the end-user-selected nowcast parameters based either on the actual location of the end-user as determined for example by cellular locating technology, GPS location, or end-user input (especially if the end-user is interested in a location remote from her immediate network connection vicinity).
The nowcast-provider's server communicates with servers at meteorological centers (private or governmental), downloads and Processes raw meteorological data such as satellite and radar maps using special meteorological methods and algorithms to provide a nowcasting map of the location of interest, comprising a series of time slice intervals as small as 1 km 2 in area for a variety of meteorological and environmental information for time periods of from 1 minute to 60 minutes. The maps are translated to user-friendly tables and a reply is generated and returned to the end-user.
Different maps may be generated according to their end-user demands. Exemplary embodiments of uses include when a extreme sports tour company asks to receive accurate data that concerns them and their clients with real-time information of severe weather heading towards their location. Nursing home personnel may be interested in local smog density mapping as that may affect residents that remain outdoors or that are on field trips. Teacher's may want UV radiation mapping to be warned of changes in potential sun exposure due to changing local cloud conditions, etc.
In an exemplary embodiment of the present invention, end-users can create an alert enquiry whereby the nowcast-provider updates the mapping for particular parameters and creates an alert which is sent to the end-user upon the occurrence of the under-defined trigger.
In another exemplary embodiment, a smart house or other intelligent structure can be programmed to respond to now-cast alerts by preparing or adjusting the home's environmental control settings for the current climactic conditions. For example, a house connected to the Internet that also has automated environmental controls can close it's windows and activate air filters when alerted that a smog condition or brush fire smoke condition is approaching. The same house can close windows before a rainstorm starts, and reopen them when the rain has passed. The house can lower shades before the sun starts to shine intensely. A home in a region where outside temperatures are shifting dramatically can anticipate the shifting outside temperature fluctuations with more energy-conserving measures like opening or closing windows, as appropriate, rather than remaining closed all day and relying solely on an air-conditioning system's thermostat. Similarly, a smart house can be informed of impending strong wind conditions and store, move or otherwise protect outside fixtures, such as a satellite dish.
In another exemplary embodiment of the present invention, communications companies can use the information from nowcasting to anticipate and prevent weather-related service outages, for example, when a satellite television company receives an alert of severe incoming weather at a particular download station, it can temporarily reroute the traffic to and from that station to a station outside the impact zone until the severe weather condition subsides and or alert its end users of possible difficulties in receptions and when the broadcast is expected to return to normal quality.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description of exemplary embodiments of the present invention can best be understood by reference to the accompanying drawings, in which:
FIG. 1 is a block diagram representing a location-based nowcasting system according to an exemplary embodiment of the present invention;
FIG. 2 depicts two zone maps and a personal nowcasting matrix according to an an exemplary embodiment of the present invention;
FIG. 3 is a flowchart illustrating an example of some of the possible components of an end-user's personal nowcasting profile in accordance with an exemplary embodiment of the present invention;
FIG. 4 illustrates an exemplary embodiment of a flow chart describing an algorithm in accordance with one exemplary embodiment of the present invention;
FIGS. 5 a–e illustrate components of an example of the input fields for establishing or modifying an end-user's personal nowcast profile and alerts; and
FIG. 6 illustrates application of an exemplary embodiment of the present invention to an intelligent building structure.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1 , an exemplary embodiment of a location-based nowcasting system 10 according to the present invention comprises a processing unit 18 and a meteorological database 20 located at a nowcast request processor 30 . Nowcast request processor 30 can be a server and can be located at or in communication with meteorological centers or as privately owned or operated centers by private companies, such as cellular communications, news and weather information providers and the like.
End-users 36 use various means of communication, such as Internet enabled PCs, wireless PDAs, cellular phones, alphanumeric pagers, and the like to be connected with a WAN such as the Internet, or a cellular communications network, via local clients 22 , 24 and 26 , with examples here shown as wireless content providers, WAP service providers, Internet service providers (ISPs) and third-party content and data providers, respectively. Local clients 22 , 24 and 26 could each have incorporated therein a nowcast request processor 30 , or they could be communicatively connected to a remote nowcast request processor 30 .
A nowcast request is initiated by an end-user 36 , or may be programmed to auto-initiate, and is transmitted to the nowcast request processor 30 , via its appropriate local client 22 , 24 , or 26 , which transmits the request to a nowcast request processor 30 . Methods for user creation and initiation of the request will be described in further detail herein below with reference to FIGS. 6 a–e
In one exemplary embodiment, the processing unit 18 receives a request and first determines if the request relates to a geographical region which is “covered” by the particular nowcast request processor 30 or if the region about which the request is concerned is covered by a different nowcast request processor 30 . If the latter, the request is forwarded to the appropriate nowcast request processor 30 and if the former, a processing stage is entered. In another exemplary embodiment, the determination of which nowcast request processor 30 should process the request can be made by the local client 34 . The processing unit 18 is in a constant state of requesting, receiving and analyzing a variety of data such as Doppler and radar images 12 and satellite images 14 wind direction and speed measurements, supplied by local or external meteorological services 16 or by private sources 32 , in addition to data from environmental air sampling stations for pollen, smog, and pollutants, and topographical data.
EXAMPLES OF DATA SOURCES AND DATA DERIVED THEREFROM
1. Weather satellites
Data source: Met-Service or Nooly's own reception station.
Satellite type: METEOSAT Second Generation (for Israel and the European coverage). GOES for the western hemisphere.
Data frequency: Every 15 minutes.
Satellite parameters: Radiation at 12 wavelengths in the visible and infra-red.
Satellite data resolution: 4 km.
Retrieved meteorological parameters:
Surface temperature Cloud properties:
Existence Height Thickness Type: rain bearing or nice weather cloud Movement Development trend
Dust storms or large scale air pollution
2. Weather radars
Data source: Met-Service.
Radar type: Doppler radar transmitting at a wavelength of 5 or 10 cm.
Data frequency: Every 1 to 5 minutes. Data resolution: 1 km radially by 1 degree azimuthally.
Radar parameters:
Precipitation reflectivity Radial velocity
Retrieved meteorological parameters:
Precipitation existence and type: rain, hail, snow Precipitation intensity: light, moderate, heavy Precipitation Movement Precipitation Development trend Winds
3. Automatic weather stations
Data source: Met-Service.
Data frequency: Every 10 minutes
Reported parameters:
Wind direction and velocity Temperature Humidity Solar radiation UV radiation Rain intensity Barometric pressure
4. Air pollution monitoring stations
Data source: EPA, Municipalities, power generation utilities, etc.
Data frequency: Every 10 minutes to 1 hour.
Reported parameters:
Pollutant gases: Ozone, SO 2 , Nox, CO Pollutant particles: PM10, PM2.5
5. Short range forecasts standard meteorological gridded data:
Data source: Met-Service. Forecast range: The forecast is based on data collected 6 to 12 hours before present. The forecast range can be for anywhere from 0 to 5 days.
Forecast methodology: The forecast is computed by weather models that calculate the meteorological parameters at grid resolution of several tens of km. The forecasted fields are for air pressure, temperature, humidity, winds, clouds and precipitation.
Forecast accuracy: The shorter the time into the future about which one is producing a forecast, the greater will be the accuracy of the forecast. The best accuracy therefore is for the immediate future. However, even an “immediate future” that is based on data collected 6 to 12 hours before the present (because the collection and calculation times take that long) will have accuracy that is already degraded to the extent that it cannot resolve events (e.g., start and stop of rain) and provide only probabilistic forecast, at geographical accuracy of many tens of km. 6. Geographical information:
Topographical maps Pollution sources and their dependence on time of the day and day of the week. Geographical latitude, longitude, and the time of the day, as they determine the position of the sun and its energy output reaching the atmosphere and the surface. Sea surface temperature.
As mentioned hereinabove, the above data sources, at a level of detail necessary for producing a truly accurate nowcast, are not available for the general public, and even if they were, the analysis of the data to the accuracy required to produce an individualized nowcast in a few minutes (or less) is beyond human skills without the aid of the algorithms for data-gathering and processing which are described herein.
The processing unit 18 uses algorithms for analyzing meteorological data (as will be described further herein below with reference to FIGS. 3 and 4 ). In the processing stage, the processing unit 18 extracts the specific time slice maps relevant to answering the request and prepares a weather nowcast, in layman's terms, to be sent back to the end-user in response, relating to a tightly focused target area for up to a 60 minute total time period in increments as small as 1 minute apart.
After the processing stage, the nowcasts are sent from the nowcast request processor 30 to the end-user's device (PC, notepad, cel phone, wireless PDA, pager, embedded device, 3 rd party application etc), via the appropriate local clients 22 , 24 , 26 . It should be understood that the nowcast request processor can be physically located in the same place as the local client 34 .
A 3 rd party application user can be a private, or a governmental company giving its clients essential nowcasting information. For example a 3 rd party application can be placed at local branches of a national supermarket chain. In those branches where heavy rain is about to begin falling, large screens can anticipate the weather change by recommending that customers buy an umbrella due to the heavy rain that will start falling in about 10 minutes for an hour, or be prepared to have a cup of hot chocolate at the store's café to wait out the rain, rather than go wandering aimlessly in the downpour. In branches where the temperature is about to spike upwards to 35° C. for the next 40 minutes, customers at the checkout counter can be advised to buy a cold drink and a hat to beat the coming heat.
In one exemplary embodiment, each local client 34 can choose from a large variety of meteorological data that sort and level of data which it wishes to make available to its end-users 36 . Local clients 34 receive personal requests from end-users 36 , and provide a personalized nowcasting service to each end-user 36 based on the end-user location and personal profile (as will be described below in reference to FIGS. 5 a–e ).
For example traffic web sites, or cellular companies that give information about traffic jams, can use the nowcast system to recommend to the end local client 34 the best and driest way to their home, work or any place they want to get to. For safety, end users 34 may receive nowcast data from the nowcast request processor 30 with information regarding foggy and freezing roads in their path. The local clients 34 receive detailed maps of a wanted zones with information about the exact places it will rain, or stop raining in the next 10, 20, 30 . . . 60 minutes and other meteorological and environment information (as will be described below in reference to FIG. 2 ) and transmit the nowcasting data to their end-user's 36 . In a further exemplary embodiment, a cellular local client 22 , can even use cellular locating technology to pinpoint the end-user's location and direction of travel or profiled destination to automatically provide specific meteorological information to the end-user about his path home or to work. In cars equipped with trip computers, the information regarding weather-related road conditions could even be fed to the driver via the computer or even used to automatically adjust the vehicle for dealing with the upcoming weather (for example automatically shifting from 2-wheel drive to 4-wheel drive, or turning on fog lights).
With reference to FIG. 2 , an example of the process 80 of building a time slice matrix 90 incorporates taking data from radar maps 82 and satellite imagery maps 84 as well as topographical maps and whatever other data maps are relevant to the request (UV, smog, pollen) to build a master map by overlaying the maps. The master map 86 is then compartmentalized and the data from each strip of compartments 87 is then stored in a matrix 90 .
In order to supply the end user 36 with personal and exact weather nowcasting data according to his present and future position in the next 10, 20 . . . 60 minutes timeslice maps are made which are based on the data in the matrix 90 for the relevant strip of compartments 87 .
The general map 86 includes different weather data (parameters) such as temperature, humidity, and wind direction, solar radiation data, and other environmental parameters. The uniqueness and the advantages of the general map 86 are mainly due to the exact weather data the map supplies. This data is achieved by using an algorithms that are highly accurate for stating weather conditions in the immediate future, i.e. a period of less then 60 minutes, and for areas of 5 km radius or less (as will be further explained in FIG. 3 ).
For example, general map 86 comprises accurate forecasts over a broad geographical region for a given time. General map 86 is divided into a large number of small, defined zone cells 87 as depicted by zone map. From zone map 88 , personal nowcasting matrix 90 is built for each zone cell 87 . Weather data such as pollution, humidity, rainfall, and temperature 92 are placed at the perpendicular side of the table 90 , while a time line 1 to 60 minutes 94 is placed at the horizontal column of the table 90 . Each cell 87 of the zone map 88 has up to 60 columns of data, one row for each kind of data and one column for each minute (although the number 60 could be raised to accommodate the development of more more highly accurate weather algorithms ro to reflect the user's willingness to accept nowcasts with a larger margin of error, particularly as time wears on).
With reference to FIGS. 3 and 6 a–e, a customer service unit 60 shows different nowcast parameters 61 an end-user 36 can activate by transmitting his request (including his personal profile) 100 to a local client 34 . The personal profile may be user-defined by using the input fields shown in FIGS. 6 a – 6 e. the parameters 61 are shown here as divided into 4 groups based on the complexity of the underlying algorithms and the difficulty of deriving data therefor. However, it should be understood that further (or fewer) subdivisions may be used in building a nowcasting system and this arrangement has been selected solely to aid in the understanding of the present invention.
The process begins by initializing a nowcast query list containing a user location and personal profile 100 . The user location may be determined based on a handset location using a GPS-based service or cell locating technology enabling the end-user to transmit his exact location in real time. The location could also be at a remote location or defined according to a user's needs in the near future, for example if end-user 36 wants to receive nowcasting information or weather alerts, about weather at the park where his children are playing, he can input the exact location of the park directly into his PC, mobile device, interactive TV and receive back the nowcast of the relevant area. Or end user 36 can input the location where he expects to be about one half-hour hence.
After the query list 100 is appropriately filled by the end-user 36 it is transmitted to the local client 34 , where the request is handled and sent back to the end-user 36 . The end-user 36 receives individualized nowcasting data, based on parameters specified in his personal profile 100 such as, general nowcasting weather parameters 64 (wind, air temperature, surface temperature relative humidity etc.), precipitation 66 , solar radiation 68 , and air pollution 70 .
With respect to a request which includes a query for general nowcasting weather parameters 64 , one of two different processes occurs depending on the end-user request. If the request refers to real-time weather parameters the end user will receive real-time measurements of the weather parameter downloaded from a meteorological service network (where available). However, if the end-user 36 asks for a nowcast for weather parameters 10, 20 . . . 60 minutes later, then the requested parameters are extrapolated in time by according to the principles of applying a regional numerical model.
In one exemplary embodiment, end-user 36 derives nowcasting data concerning precipitation 66 , by extracting precipitation intensity from nowcasting maps 86 , 88 (as described in FIG. 2 ) using a nowcasting algorithm at the time and location requested by the end-user 36 . At the end of the process the end-user receives results of precipitation intensity selected from one of the four intensity categories: 1) no rain; 2) light; 3) moderate; and 4) heavy. The user not only gets information about the rain intensity but also its pattern i.e. will it suddenly become a heavy rain or will it slowly become moderate, etc. and when these changes are expected to occur.
Solar and UV radiation data 68 are derived and transmitted to the end-user 36 , taking into account astronomical configurations, and by subtracting cloud scattering retrieved from satellite maps. Air pollution data 70 is transmitted to the end-user 36 by activating two different processes according to the end-user request (personal profile 100 ). If the end-user 36 asks for real-time air pollution data the system will send him at least an average (if not more precise) pollutant concentration data based on a monitoring station within a given radius. If the end-user asks for air pollution data for the next 10, 20 . . . 60 minutes, the nowcasting system 10 activates an extrapolating process using a regression model with input from a regional numerical model.
For further guidance on how to implement the above-described methods for deriving UV and air pollution data, reference may be had to: Atmospheric Environment, Shi, Ji Ping and Harrison, Roy M., Oxford, England, 31(24): 4081–4094, December 1997, Refs., FIGS., tables; and A 3 D regional scale photochemical air quality model application to a 3 day summertime episode over Paris. Jaecker-Voirol, A. et al. , Air pollution IV: monitoring, simulation and control., Caussade, B.; Power, H. and Brebbia, C. A. (eds.), Computational Mechanics Publications, 1996. pp. 175–194, Refs., FIGS.
Referring now to FIG. 4 , the precipitation nowcasting algorithm may be based on combinations of different analytic weather forecast methods combining different meteorological maps (radar maps, satellite maps, topographic maps etc.). The process begins 42 by receiving radar maps 12 for the last 5 minutes from meteorological sources as mentioned in FIG. 1 .
In step 46 automatic echo tracking is activated after at least 3 radar maps 12 are available 44 . Precipitation echo tracking and forecasting is a known procedure for tracking evolution and motion of individual clouds. It is known that young clouds are small with strong intensities, and with the maturing of the clouds they dissipate by spreading over large areas with weak intensities. In order to identify the growth and decay of cloud areas it is needed to track the time histories of the echo cells to determine in what stage of their lifecycle they are in.
The radar tracking examines the following two elements:
a. Vertical profile of intensity: At the growing stage, the precipitation is still at the upper portion of the cloud, and its top is gaining height. At the decaying stages the top descends, and the intensities are greatest near the surface and decaying aloft. b. Horizontal profile: A developing storm has compact structure-growing intensities in time, and sharp horizontal gradient of the intensities. A decaying rain cloud is spreading out to larger area on expense on its intensities.
To complete the picture from radar tracking, satellite images are used. The satellite images are received from meteorological resources as mentioned hereinabove, and are used to seek areas of growth of new elements that still aren't precipitating. The new growing cloudy areas precede the precipitation by 15 to 30 minutes. The cloud tops have to grow above a certain height for start producing precipitation. That height is determined by comparison the satellite data with the radar, finding out what is the cloud with the warmest top that still develops precipitation.
Three more meteorological analyzing methods, that contribute to completing the nowcasting process are:
[1] the use of Doppler winds to identify areas of converging winds, which precede the formation of clouds. Such features are the basis of forecasting cloud and precipitation development at the time range of one to three hours; [2] use of topographical features 330 for modifying the precipitation forecast. The measures are based on the fact that clouds develop more extensively while ascending on a higher ground, and dissipate while moving downhill; [3] use of surface temperature for better prediction of the evolution of clouds. Clouds prefer to develop over warmer surface, feeding on the heat energy. For example, on a hot summer day, clouds would form preferentially on the heat island generated by a city. That heat is mapped already by the other data sources, and be used quantitatively in the forecast.
The above operations can be performed, in a simple form, based on the following algorithm:
1. Take the time series of the radar maps for the last 5 minutes 42. 2. Identify the linear movement of the weather radar echoes, by cross correlation or other methods. 3. Advance the current radar map according to the movement found in step 2, for 1, 2, 3, . . . 60 minutes in the future, and by that obtain forecasted radar maps for that time interval. 4. Interpret the radar echoes into the various weather elements over the point of interest 87 (the location selected by the end-user), and obtain the weather in that location as a function of time, in 1-minute increments, for the next one hour. The interpretation takes into account the temperature and humidity near the surface and structure of the radar echoes, according to principles known in radar meteorology. 5. Extract from this forecasted weather record the parameters of interest to the user, and transmit them per request, or initiate the transmission if conditions for an alert were fulfilled.
Methods for automatic echo tracking using cross correlation methods have been known since 70's; for example, see, Dixon, M., and G. Wiener, 1993: TITAN: Thunderstorm Identification, Tracking, Analysis, and Nowcasting a radar-based methodology. Journal of Atmospheric and Oceanic Technology, Boston, Mass., 10(6): 785–797, December 1993; Golding, B. W. (1998): Nimrod: a system for generating automated very short range forecasts. Meteorological Applications, Reading Berkshire, UK, 5(1):1–16; and Leese, J. A., C. S. Novak, and B. B. Clark (1971): An automatic technique for obtaining cloud motion from geostationary satellite data using cross correlation. J. Appl. Meteorology, 10, 118–132.
For each location 87 a linear movement and a forecast quality index are obtained 48 . The process continues in step 50 with improving the linear extrapolation by incorporating trend analysis, external meteorological data and geographical information for example as follows:
1. Combining our existing radar map data with high frequency multispectral geostationary satellite data (GOES and MSG satellite series, providing scans at least once every 15 minutes), thereby allowing identification of growing cloud elements before precipitation starts, usually an area of great deficiency in radar-based forecasting, i.e. the identification of newly developing rain areas that are not observed at the current time; 2. Identification of the development trends according to 3-dimensional evolution of the radar echo field. For example, new developing showers have small intensities over small horizontal areas and large vertical extent, with peak intensities aloft. Over time the intensities spread to cover larger horizontal area and lower altitudes. In the dissipation stage small intensities are spread over relatively large area; and 3. Additional geographical factors, such as topographically induced enhancement.
The process 52 ends by storing in the processing unit 18 a nowcasting data map for each minute.
With reference to FIG. 5 a screen shot 100 depicting an exemplary embodiment of a nowcasting graphical user interface (GUI) input screen shows different sections the end-user can fill in order to request nowcasting data on a customized and individualized basis, to indicate personal preferences and to establish parameters for alerts relating to various weather conditions. Section 102 illustrates the different meteorological parameters 104 the end-user 36 can select for receiving warnings and alerts during any time of the day concerning the meteorological parameters he selected. For example a sea surfer can get alerts for good wind and surfing conditions directly to his cel phone. Sections 106 illustrate an end-user personal skin profile according to the end-user 36 requests for a selected time 108 . Section 110 illustrate a 3 rd party location personal profile used to receive meteorological data at a 3 rd party location selected from list 112 , to any kind of device 114 the end user selects. The end-user can select his favorite location from section 116 .
With reference to FIG. 6 , there is shown an exemplary embodiment of a combination between a “smart” house 152 (or any smart intelligent structure, like a warehouse, greenhouse, office building, factory or any other commercial or industrial improvement) and a nowcast server provider 151 . A central automation controller 153 in the smart house 152 is connected to the nowcast provider server 151 , via a network and is programmed to respond to nowcast alerts, the response being to prepare or adjust the home's environmental control settings 160 for the current climactic conditions. | A method for providing a mobile user with updated weather nowcasts comprises: receiving a request from a user, the request being associated with a location, and for a period such as about an hour sending the user regular meteorological information regarding the location. The user may be a mobile telephone user and the location may be determined from the location of the mobile telephone. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of our prior co-pending application Ser. No. 273,296, filed June 15, 1981 and isued on Oct. 12, 1982 as U.S. Pat. No. 4,353,812, incorporated herein by reference.
BACKGROUND OF THE INVENTION
The field of art to which this invention pertains is fluid particle cooling. It particularly relates to the combustion of combustible material from a particulated solid such as fluidizable catalyst which has been contaminated by the deposition thereupon of the combustible material, coke. The present invention will be most useful in a process for regenerating coke-contaminated fluid cracking catalyst, but it should find use in any process in which combustible material is burned from solid, fluidizable particles.
DESCRIPTION OF THE PRIOR ART
The fluid catalyst cracking process (hereinafter FCC) has been extensively relied upon for the conversion of starting materials, such as vacuum gas oils, and other relatively heavy oils, into lighter and more valuble products. FCC involves the contact in a reaction zone of the starting material, whether it be vacuum gas oil or another oil, with a finely divided, or particulated, solid, catalytic material which behaves as a fluid when mixed with a gas or vapor. This material possesses the ability to catalyze the cracking reaction, and in so acting it is surface-deposited with coke, a by-product of the cracking reaction. Coke is comprised of hydrogen, carbon and other material such as sulfur, and it interferes with the catalytic activity of FCC catalysts. Facilities for the removal of coke from FCC catalyst, so-called regeneration facilities or regenerators, are ordinarily provided within an FCC unit. Regenerators contact the coke-contaminated catalyst with an oxygen containing gas at conditions such that the coke is oxidized and a considerable amount of heat is released. A portion of this heat escapes the regenerator with flue gas, comprised of excess regeneration gas and the gaseous products of coke oxidation, and the balance of the heat leaves the regenerator with the regenerated, or relatively coke free, catalyst. Regenerators operating at superatmospheric pressures are often fitted with energy-recovery turbines which expand the flue gas as it escapes from the regenerator and recover a portion of the energy liberated in the expansion.
The fluidized catalyst is continuously circulated from the reaction zone to the regeneration zone and then again to the reaction zone. The fluid catalyst, as well as providing catalytic action, acts as a vehicle for the transfer of heat from zone to zone. Catalyst exiting the reaction zone is spoken of as being "spent", that is partially deactivated by the deposition of coke upon the catalyst. Catalyst from which coke has been substantially removed is spoken of as "regenerated catalyst".
The rate of conversion of the feedstock within the reaction zone is controlled by regulation of the temperature, activity of catalyst and quantity of catalyst (i.e. catalyst to oil ratio) therein. The most common method of regulating the temperature is by regulating the rate of circulation of catalyst from the regeneration zone to the reaction zone which simultaneously increases the catalyst/oil ratio. That is to say, if it is desired to increase the conversion rate an increase in the rate of flow of circulating fluid catalyst from the regenerator to the reactor is effected. Inasmuch as the temperature within the regeneration zone under normal operations is considerably higher than the temperature within the reaction zone, this increase in influx of catalyst from the hotter regeneration zone to the cooler reaction zone effects an increase in reaction zone temperature.
Recently, politico-economic restraints which have been put upon the traditional lines of supply of crude oil have made necessary the use, as starting materials in FCC units, of heavier-than-normal oils. FCC units must now cope with feedstocks such as residual oils and in the future may require the use of mixtures of heavy oils with coal or shale derived feeds.
The chemical nature and molecular structure of the feed to the FCC unit will affect that level of coke on spent catalyst. Generally speaking, the higher the molecular weight, the higher the Conradson carbon, the higher the heptane insolubles, and the higher the carbon to hydrogen ratio, the higher will be the coke level on the spent catalyst. Also, high levels of combined nitrogen, such as found in shale derived oils, will also increase the coke level on spent catalyst. The processing of heavier and heavier feedstocks, and particularly the processing of deasphalted oils, or direct processing of atmospheric bottoms from a crude unit, commonly referred to as reduced crude, does cause an increase in all or some of these factors and does therefore cause an increase in coke level on spent catalyst.
This increase in coke on spent catalyst results in a larger amount of coke burnt in the regenerator per pound of catalyst circulated. Heat is removed from the regenerator in conventional FCC units in the flue gas and principally in the hot regenerated catalyst stream. An increase in the level of coke on spent catalyst will increase the temperature difference between the reactor and the regenerator, and in the regenerated catalyst temperature. A reduction in the amount of catalyst circulated is therefore necessary in order to maintain the same reactor temperature. However, this lower catalyst circulation rate required by the higher temperature difference between the reactor and the regenerator will result in a fall in conversion, making it necessary to operate with a higher reactor temperature in order to maintain conversion at the desired level. This will cause a change in yield structure which may or may not be desirable, depending on what products are required from the process. Also there are limitations to the temperatures that can be tolerated by FCC catalyst without there being a substantial detrimental effect on catalyst activity. Generally, with commonly available modern FCC catalyst, temperatures of regenerated catalyst are usually maintained below 1400° F., since loss of activity would be very severe about 1400°-1450° F. If a relatively common reduced crude such as that derived from Light Arabian crude oil were charged to a conventional FCC unit, and operated at a temperature required for high conversion to lighter products, i.e. similar to that for a gas oil charge, the regenerator temperature would operate in the range of 1600°-1800° F. This would be too high a temperature for the catalyst, require very expensive materials of construction, and give an extremely low catalyst circulation rate. It is therefore accepted that when materials are processed that would give excessive regenerator temperatures, a means must be provided for removing heat from the regenerator, which enables a lower regenerator temperature, and a lower temperature difference between the reactor and the regenerator.
A common prior art method of heat removal provides coolant filled coils within the regenerator, which coils are in contact with the catalyst from which coke is being removed. For example, Medlin et al. U.S. Pat. No. 2,819,951, McKinney U.S. Pat. No. 3,990,992 and Vickers U.S. Pat. No. 4,219,442 disclose fluid catalytic cracking processes using dual zone regenerators with cooling coils mounted in the second zone. These cooling coils must always be filled with coolant and thus be removing heat from the regenerator, even during start-up when such removal is particularly undesired, because the typical metallurgy of the coils is such that the coils would be damaged by exposure to the high regenerator temperature (up to 1350° F.) without coolant serving to keep them relatively cool. The second zone is also for catalyst disengagement prior to passing the flue gas from the system, and may contain catalyst in a dense phase (Medlin et al. and Vickers) or in a dilute phase (McKinney). Coolant flowing through the coils absorbs heat and removes it from the regenerator.
The prior art is also replete with disclosures of FCC processes which utilize dense or dilute phase regenerated fluid catalyst heat removal zones or heat exchangers that are remote from and external to the regenerator vessel to cool hot regenerated catalyst for return to the regenerator. Examples of such disclosures are as set forth in Harper U.S. Pat. No. 2,970,117; Owens U.S. Pat. No. 2,873,175; McKinney U.S. Pat. No. 2,862,798; Watson et al. U.S. Pat. No. 2,596,748; Jahnig et al. U.S. Pat. No. 2,515,156; Berger U.S. Pat. No. 2,492,948; and Watson U.S. Pat. No. 2,506,123. At least one of the above U.S. Patents (Harper) discloses that the rate of return of the cooled catalyst to the regenerator may be controlled by the regenerator (dense catalyst phase) temperature.
An important consideration in the above FCC processes involving regenerator heat removal is the method of control of the quantity of heat removed. For example, in Vickers U.S. Pat. No. 4,219,442 the method involves the control of the extent of immersion of cooling coils in a dense phase regenerated catalyst fluidized bed. In Harper U.S. Pat. No. 2,970,117 and Huff U.S. Pat. No. 2,463,623, the sole method involves regulation of the rate of flow of regenerated catalyst through external catalyst coolers. The disadvantages of the first above heat removal method have been previously discussed, i.e. interference of the cooling coils with unit start-up and catalyst disengagement. The above second method of heat removal, utilizing external coolers and varying the rate of catalyst circulation through them as the exclusive means of control of the heat exchanger duty, involves the continual substantial changing of the catalyst loading on the regenerator with the associated difficulty or impossibility of maintaining convenient steady state operations.
It is known to those skilled in the art of chemical engineering that the heat transfer coefficient of a heat exchange surface varies in relation to the mass velocity across such surface for fluidized systems. See, for example, the article "Fluidized-bed Heat Transfer: A Generalized Dense-phase Correlation"; A.I.Ch.E. Journal; December, 1956: Vol. 2, No. 4; ppg. 482-488.
The present invention enables a high degree of flexibility and efficiency of operation of a fluidized particle cooler, particularly when associated with an FCC regenerator, with the cooler remote from the FCC regenerator, but unlike the above prior art FCC processes, the present invention controls the rate of cooling by the heat exchanger in a manner based upon principles involving the relationship between heat transfer coefficients and mass velocity, and not just by varying the flow rate of circulating catalyst.
SUMMARY OF THE INVENTION
Accordingly, the invention is, in one embodiment, a process for the cooling of hot fluidized solid particles contained in a first dense phase fluidized bed of the particles. The hot particles are circulated from the first bed through a cooling zone separate from the first bed and in open communication therewith. On the cooling zone the hot particles are continuously backmixed and heat is withdrawn from the hot particles by indirect heat exchange with a cooling fluid enclosed in a heat exchange means inserted into the cooling zone to produce relatively cool particles. The particles are maintained in the cooling zone as a second dense phase fluidized bed by passing a fluidizing gas upwardly through such second bed. The first and second beds comprise a continuum throughout which the particles are continuously circulated. The quantity of heat withdrawal from the particles in the cooling zone is controllably maintained by controlling the variable comprising the quantity of the fluidizing gas into the second bed. The heat transfer coefficient between the heat exchange means and the second fluidized bed and thus the quantity of heat transferred is thereby controlled.
In a second embodiment, the invention is an apparatus for cooling hot fluidized solid particles which apparatus comprises in combination; (a) a hot particle collection chamber; (b) a shell and tube heat exchanger or vertical orientation, remote from the collection chamber, having the shell closed at the bottom and having the upper portion of the shell of the heat exchanger in sealed communication with the collection chamber such that particles can circulate to and from the collection chamber through the shell; (c) a fluidizing gas inlet conduit connected to a bottom portion of the shell side of the heat exchanger, such that fluidizing gas can pass into the shell side and maintain a continuously backmixed fluidized catalyst bed therein; (d) a control valve placed in the fluidizing gas inlet conduit and a control system comprising means to sense a controlled variable controlled by the duty of the heat exchanger, control means having an adjustable set point connecting with the controlled variable sensing means and developing output signals, and means for transmitting the output signals to the control valve whereby the latter is adjusted responsive to the controlled variable, thereby regulating the flow of fluidizing gas into the heat exchanger and the quantity of particles circulating to and from the collection chamber through the heat exchanger, thereby regulating the heat transfer coefficient between the outside surface of the tubes of the heat exchanger and the fluidized catalyst bed, and thereby regulating the duty; and, (e) inlet and outlet conduits connected to the tubes of the heat exchanger, such that a cooling fluid can flow through the tubes.
Other embodiments of the present invention encompass further details such as process streams and the function and arrangement of various components of the apparatus, all of which are hereinafter disclosed in the following discussion of each of these facets of the invention.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE 1 is a sectional, elevation view of a regeneration apparatus according to one embodiment of the present invention, showing combustion zone 1, disengagement zone 2, and cooling zone (heat exchanger) 3.
The above described drawing is intended to be schematically illustrative of the present invention and not be a limitation thereon.
DETAILED DESCRIPTION OF THE INVENTION
The present invention, in its process aspects, consists of steps for the cooling of a fluidized particulate solid. An important application of the invention will be for a process for the combustion of a combustible material from fluidized solid particles containing the combustible material, including the step of introducing oxygen containing combustion gas and the fluidized solid particles into a combustion zone maintained at a temperature sufficient for oxidation of the combustible material. The combustible material will be oxidized therein to produce the first dense phase fluidized bed of hot fluidized solid particles cooled by the process of the invention.
The above combustion zone may be in dilute phase with the hot particles transported to a disengaging zone wherein the hot particles are collected and maintained as the first bed, or the combustion zone may be in dense phase and in itself comprise the first bed.
In a particularly important embodiment of the invention, there will be included steps for the regenerative combustion within a combustion zone of a coke contaminated FCC catalyst from a reaction zone to form hot flue gas and hot regenerated catalyst, disengagement and collection of the hot regenerated catalyst, cooling of the hot regenerated catalyst by backmixing and continuously circulating it through a heat removal or cooling zone, and the use of at least a portion of the cooled regenerated catalyst for control of the temperatures of the combustion zone. As used herein, the term "hot regenerated catalyst" means regenerated catalyst at the temperature leaving the combustion zone, from about 1300° to about 1400° F., while the term "cool regenerated catalyst" means regenerated catalyst at the temperature leaving the cooling zone, the latter of which is about 200° F. less than the temperature of the hot regenerated catalyst. There will be a temperature gradient at the bottom of the disengagement zone, with the coolest catalyst being approximate to the opening to the heat removal zone and the hottest catalyst being at the portion of the bottom of the disengagement zone furthest from such opening.
Reference will now be made to the attached drawing for a discussion of an example of the regeneration process embodiment and associated apparatus of the invention. In the FIGURE regeneration gas, which may be air or another oxygen-containing gas, enters in line 7 and mixes with coke contaminated catalyst entering in conduit 8. These streams are shown as flowing together into mixing conduit 11, although each stream could flow individually into combustion zone 1. The resultant mixture of coke contaminated catalyst and regeneration gas are distributed into the interior of combustion zone 1, at a lower locus thereof, via conduit 11 and distributor 13. Coke contaminated catalyst commonly contains from about 0.1 to about 5 wt.% carbon, as coke. Coke is predominantly comprises of carbon, however, it can contain from about 5 to about 15 wt.% hydrogen, as well as sulfur and other materials. The regeneration gas and entrained catalyst flows upward from the lower part of combustion zone 1 to the upper part thereof in dilute phase. The term "dilute phase", as used herein, shall mean a catalyst/gas mixture of less than 30 lbs/ft 3 , and "dense phase" shall mean such mixture equal to or more than 30 lbs/ft 3 . Dilute phase conditions, that is, a catalyst/gas mixture of less than 30 lbs/ft 3 , and typically 2-10 lbs/ft 3 , are the most efficient for coke oxidation. As the catalyst/gas mixture ascends within combustion zone 1, the heat of combustion of coke is liberated and absorbed by the now relatively carbon-free catalyst, in other words by the regenerated catalyst.
The rising catalyst/gas system flows through passageway 10 and impinges upon surface 12, which impingement changes the direction of flow of the stream. It is well known in the art that impingement of a fluidized particulate stream upon a surface, causing the stream to turn through some angle, can result in the separation from the stream of a portion of the solid material therein. The impingement of the catalyst/gas stream upon surface 12 causes almost all of the hot regenerated catalyst flowing from the combustion zone to disengage from the flue gas and fall to the bottom portion of disengagement zone 2 which comprises a hot particle collection chamber or fluid particle collection section. The catalyst collection area of the disengagement zone may be a cone-shaped annular receptacle, as shown, or any other shape appropriate for collecting catalyst particles. The gaseous products of coke oxidation and excess regeneration gas, or flue gas, and the very small uncollected portion of hot regenerated catalyst flow up through disengagement zone 2 and enters separation means 15 through inlet 14.
These separation means may be cyclone separators, as schematically shown in the FIGURE, or any other effective means for the separation of particulated catalyst from a gas stream. Catalyst separated from the flue gas falls to the bottom of disengagement zone 2 through conduits 16 and 17. The flue gas exits disengagement zone 2 via conduit 18, through which it may proceed to associated energy recovery systems. Having the disengagement zone in upward communication with the combustion zone is advantageous, in comparison to schemes in which the gas/catalyst mixture flows upward into a relatively dense phase heat removal zone, in that with the former, there is a substantial reduction in the loading of the regenerator cyclones which virtually eliminates large losses of catalyst from FCC units during operational upsets.
With further reference to the FIGURE, heat exchanger 3 is of vertical orientation with the catalyst in the shell side and the heat exchange medium passing through the tubes via lines 9 and 9'. The preferred heat exchange medium would be water, which would change at least partially from liquid to gas phase (steam) when passing through the tubes. The tube bundle in the heat exchanger will preferably be of the "bayonet" type wherein one end of the bundle is unattached, thereby minimizing problems due to the expansion and contraction of the heat exchanger components when exposed to and cooled from the very high regenerated catalyst temperatures. The heat transfer that occurs is, from the catalyst, through the tube walls and into the heat transfer medium. The bottom of the shell is sealed to catalyst flow and the top of the shell is in sealed communication with the bottom portion of the disengagement zone. The level of the dense phase catalyst bed in the disengagement zone will be kept above the opening into the shell and the catalyst may, thus, freely backmix and circulate throughout the inside of the shell and the bottom of the disengagement zone. Fluidizing gas, preferably air, is passed into a lower portion of the shell side of heat exchanger 3 via line 7', thereby maintaining a dense phase fluidized catalyst bed in the shell side and effecting turbulent backmixing and flow to and from the disengagement zone. Control valve 20 is placed in line 7'. Unlike in the prior art systems, catalyst will not leave the system via the external heat exchanger, thus precluding variable catalyst loading on the regenerator to achieve the cooling function and resultant disruption of steady state operations.
Experiments have determined that sufficient backmixing is attainable within the heat exchanger at reasonable superficial gas velocities to totally dispense with a net catalyst flow requirement. This concept does, however, necessitate increased air requirements (as compared to a system where catalyst flow is a second independent variable available for controlling heat exchanger duty) but eliminates the expensive lower standpipe, expansion joint and slide valve requirements. The air affects the heat transfer coefficient directly by affecting the superficial velocity over the heat exchanger tubes and indirectly by influencing the extent of mass flow of catalyst from the disengagement zone through the heat exchanger. The higher mass flow will result in a higher heat exchanger duty also because the average catalyst temperature in the heat exchanger will be higher thereby providing a higher temperature difference (ΔT) to which the amount of heat transfer is directly proportional.
The FIGURE shows a preferred embodiment of heat exchanger 3 and the manner of the interconnection of heat exchanger 3 with disengagement zone 2. Heat exchanger 3 is shown with the shell side completely filled with a dense phase fluidized catalyst bed which has a level well above the connection between the heat exchanger and disengagement zone. Catalyst freely circulates and backmixes throughout the heat exchanger shell and disengagement zone forming a dense phase continuum. Fluidizing air which enters the shell via line 7' (air may be introduced at one or more points in the shell in addition to that shown) rises upward and flows into the disengagement zone where it ultimately leaves the system with the flue gases.
The tube bundle shown is of the aforementioned bayonet type in which the tubes are attached at the bottom or "head" of the heat exchanger, but not at any other location. A typical configuration of tubes in the bayonet-type bundle would be one inch tubes each ascending from inlet manifold 40 in the head up into the shell through a three inch tube sealed at its top, each one inch tube emptying into the three inch tubes in which it is contained just below the sealed end of the three inch tube. A liquid, such as water, would be passed up into the one inch tubes, would empty into the three inch tubes, would absorb heat from the hot catalyst through the wall of the three inch tubes as it passed downward through the annular space of the three inch tubes and would exit the heat exchanger, at least partially vaporized, from outlet manifold 41 in the head. It is essential that the quantity of hot particles or catalyst which enter heat exchanger 3 be sufficient to maintain a depth of dense phase fluid catalyst bed which substantially submerges the tubes in the dense phase bed and that, of course, is achieved by the design of the apparatus in accordance with this invention.
It is assumed that the flow of hot catalyst into the disengagement zone will always exceed the hot catalyst exit (via conduit 33) flow requirements and the operation will be set up so that will in fact be the case. At least a portion of catalyst not exiting via conduit 33 will be circulated to the combustion zone. Shown in the FIGURE is external conduit 42 and control valve 43 through which the catalyst may pass to the combustion zone. Also shown is dipleg or standpipe 45 with bottom flapper valve 46 and upper weir 44. Catalyst which does not flow through conduit 42 will overflow weir 44 and fill dipleg 45. When the force exerted by the head of catalyst filling dipleg 45 on flapper valve 46 exceeds that pressure required to open valve 46, i.e. overcome the force exerted by the spring or counterweight holding the valve closed, catalyst will empty from the dipleg into combustion chamber 1. The flapper valve and/or head of catalyst in the dipleg also serve to prevent undesired reversal of flow up the dipleg. The dense phase bed level and thus the catalyst head available to heat exchanger 3 will therefore be held at the level of the lip of weir 44.
One control system comtemplated by the present invention for regulating the amount of catalyst flowing through conduit 42 comprises means 21 to sense the temperature in a portion of combustion zone 1, such as the upper portion shown, temperature control means 22 having an adjustable set point connecting with temperature sensing means 21 and developing output signals, and means 23 for transmitting the output signals to control valve 43, whereby the valve may be adjusted responsive to the temperature at the upper portion of combustion zone 1.
The inlet to conduit 42 will be placed in the vicinity of the connection between disengagement zone 2 and heat exchanger 3 and, thus, will receive catalyst from a relatively cool portion of the above discussed temperature gradient, thereby enabling the necessary temperature difference between the combustion zone and circulating catalyst to achieve a cooling effect.
Although the FIGURE illustrates a single heat exchanger with associated circulating catalyst conduit, it should be understood that other configurations are possible, such as two heat exchangers, of the design illustrated, side by side with the conduit 42 between them.
With regard to control of the duty of heat exchanger 3, the preferred mode of operation would be where the controlled variable is the amount of steam generated with such amount controllably maintained by controlling the quantity of fluidizing gas to the catalyst bed in the heat exchanger shell. The quantity of steam generated and flowing through line 9' may be measured by meter 24 which will develop and transmit an output signal via means 25 to flow control means 36. The latter will have an adjustable set point connecting with control valve 20 via means 27. For simplicity, meter 24 is shown as an orifice meter in line 9', but it should be understood that in practice, there will be liquid and gas phases in line 9' which will have to be separated, i.e. via a "steam drum", with the steam rate measured downstream of such separation. Flow control means 36, which may incorporate an analogue or digital computer, will have the capability of selecting the optimum amount of fluidizing gas. Such capability may be built or programmed into means 36 for a given system by one skilled in the art and probably be based on empirical relationships derived from the observed operation of the system. The flow of fluidizing gas to the shell side of heat exchanger 3 will thereby be regulated which in turn regulates the mass velocity of the fluidized bed over the outside surfaces of the tubes by affecting the extent of turbulence and mass flow of the bed, which in turn regulates the heat transfer coefficient across such surfaces, and thus the quantity of heat transfer.
The net effect of the preceding mode of operation is that there will be a heat sink available to the combustion system, the magnitude of which may be closely controlled by the simple positioning of a set point. The operation will thereby be made far more flexible or even made possible by the availability of the heat sink that can dispose of heat that might otherwise constitute a process bottleneck. There would, of course, be the additional benefit of a source of a constant quantity of high pressure steam being made available for use wherever needed.
A different mode of operation could be controlling the quantity of the fluidizing gas to the shell side of the heat exchanger to controllably maintain the temperature of the catalyst passed into the combustion zone. The latter temperature is directly affected by the quantity of heat withdrawn from the catalyst in the heat exchanger. For this mode, of course, the quantity of steam generated would vary.
The above preferred heat exchanger duty control scheme provides the ability to remove heat from the FCC regenerator as required to maintain the desired heat sink and at the same time maintain an acceptable degree of stable steady state operation conducive to the controllability and efficiency of the regenerator, all while enjoying flexibility and ease of operation of an external catalyst cooler or heat exchanger (particularly the ability to not have to utilize cooling during start-up) and the efficiency of catalyst-flue gas separation achieved by a disengagement zone unencumbered by a dense catalyst phase and heat removing paraphernalia.
It should be emphasized, however, that the FCC embodiment illustrated by the FIGURE is only one possible application of the present invention which in its broadest sense is a process for cooling any hot fluidized particles for any purpose. The apparatus aspect of the present invention in its broadest sense as summarized above may also be identified in the FIGURE. Thus, the bottom of disengagement zone 2 comprises the hot particle collection chamber or fluid particle collection section, heat exchanger 3 is the shell and tube heat exchanger of vertical orientation, line 7' is the fluidizing gas inlet conduit, valve 20 regulates the flow of fluidizing gas in line 7' and lines 9 and 9' are the cooling fluid inlet and outlet conduits. The controlled variable may be the temperature of the particles in or entering conduit 42 or the volume of steam in line 9'. | A process and associated apparatus for the cooling of hot fluidized solid particles. The particles flow from a first dense phase fluidized bed into the shell side of a vertically oriented shell and tube heat exchanger where cooling occurs via indirect heat exchange with a cooling medium circulating in the tubes. The extent of cooling is controlled by the varying of the heat transfer coefficient between the tubes and particles in the heat exchanger which are maintained as a second dense phase fluidized bed. The coefficient is varied by varying the quantity of fluidizing gas to the fluidized bed in the heat exchanger. The particles flow freely to and from the first and second dense phase fluidized beds through which the particles recirculate and are backmixed. The process has particular applicability to a combustive regeneration process and most particular applicability to the FCC process. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the invention
[0002] The present invention relates to a vane type hydraulic actuator for controlling the timing of opening and closing of an intake and/or exhaust valve, corresponding to an operational state of an engine.
[0003] 2. Description of the prior art
[0004] [0004]FIG. 18 is a cross sectional view of a vane type hydraulic actuator invented by the inventors of this application and is disclosed in JP-9-314069-A. FIG. 19 is a detailed cross sectional view of the plunger part shown in FIG. 18. FIG. 20 is a cross sectional view of the plunger part in a state that a hydraulic pressure is applied.
[0005] Reference numeral 19 denotes an intake side cam shaft having an intake side cam 19 a . An actuator 40 is connected to an end of the intake side cam shaft 19 , and a timing pulley 21 is disposed around the actuator 40 . The working oil of the actuator 40 is lubrication oil, delivered from an engine (not shown). The actuator is actuated by the working oil so as to adjust phase angle of the rotation of the intake side cam shaft 19 so that the opening and closing timings of intake valves of the engine can be continuously adjusted. The intake side cam shaft 41 is supported by a bearing 19 . The actuator 40 has a housing 42 , which can freely rotate around the intake side cam shaft 19 .
[0006] A case 43 is fixed to the housing 42 . And a vane type rotor 44 is received in the case 43 . The vane rotor 44 is fixed to the intake side cam shaft 19 by means of bolts 45 . The rotor 44 is rotatable relative to the case 43 in a predetermined anglular region.
[0007] The case 43 and the rotor 44 form hydraulic pressure chambers separated from each other. A chip seal 46 is disposed between the case 43 and the rotor 44 so that no oil leakage between the oil pressure chambers can occur. A back spring 47 made of an iron plate is disposed to push the chip seal 46 towards the rotor 44 .
[0008] The housing 42 , the case 43 and a cover 48 connected to the case 43 are fixed by a common volt 49 . An O-ring 50 is disposed between the case 43 and the bolt 50 . A plate 51 is fixed to the cover 48 by a bolt 52 . Reference numerals 53 , 54 denote O-rings. A cylindrical holder 55 is disposed in the rotor 44 . The cylindrical holder 55 has an engaging hole 55 a , which can engage with a plunger 56 , as will be explained below.
[0009] The plunger 56 disposed in the housing 42 can slide therein and has an engaging shaft 56 a , which can engage with the engaging hole 55 a of the holder 55 . The plunger 56 is pushed by a spring 57 towards the holder 55 . Working oil is delivered into the engaging hole 55 a of the holder 55 through a plunger oil channel 58 . When working oil is delivered into the engaging hole 55 a of the holder 55 , the plunger 56 moves opposingly to the spring 57 so that the plunger 56 is unlocked from the holder 55 . The rotor 44 is fixed to the intake side cam shaft 19 by means of a bolt 60 . Reference numerals 59 , 61 denote air holes.
[0010] A first and second oil channels 62 , 63 are disposed in the intake side cam shaft 19 and the rotor 44 . The first oil channel 62 communicates with an oil pressure chamber for timing retard 73 , and the second oil channel 63 communicates with an oil pressure chamber for timing advance 74 .
[0011] The amount of the working oil to be delivered to the actuator 40 is controlled by an oil control valve 80 , which will be abbreviated to OCV hereinafter.
[0012] The OCV 80 comprises a valve housing 81 , a spool 82 which can slide in the valve housing 81 , a spring 83 urging the spool 82 toward one direction, and a linear solenoid 84 for displacing the spool 82 resisting the spring 83 . The OCV is connected with an oil pan 91 through an oil supplying pipe 85 a . An oil pump 92 and an oil filter 93 are disposed in the oil supplying pipe 85 a . The first and second oil channels 62 , 63 are connected with the OCV 80 through a first and second oil pipes 89 , 90 , respectively. The working oil returns to the oil pan 91 from the OCV 80 through an oil drain pipe 88 . The oil pan 91 , the oil pump 92 , the oil filter 93 are a part of a lubrication system for lubricating portions to be lubricated in the engine (not shown), and simultaneously they form a working oil delivery system to the actuator 40 .
[0013] An electronic control unit 100 , which is abbreviated to ECU hereinafter, controls the amount of fuel injection into the engine, the timings of the ignition, and the timing of the opening and closing of valves. The control corresponds to the inputs from an intake air amount sensor, a throttle sensor, crank angle sensor and a cam angle sensor, which are not shown. The electronic control unit 100 further controls the closing timing of valves after the switching off of the ignition switch.
[0014] [0014]FIG. 21 is a cross sectional view of FIG. 18 along the line X-X. FIG. 22 shows a state in which a slide plate shown in FIG. 21 is displaced. FIG. 23 is a cross sectional view of FIG. 18 along the line Y-Y, FIG. 24 is a cross sectional view of FIG. 18 along the line Z-Z.
[0015] As shown in the figures, a first to fourth vanes 64 - 67 project radially from the rotor 44 . A chip seal 68 is disposed at the tip of each vane 64 - 67 . The chip seal 68 contacts with the inner surface of the case 43 and can slide along the surface. The chip seals 68 seal between the chambers disposed at both sides of the vanes. By the way, a back spring (not shown) is disposed behind each chip seals 68 for increasing the capacity of the sealing.
[0016] Four shoes 71 project inwardly from the inner surface of the case 43 . The shoe 43 has a bolt hole 72 , into which the bolt 49 shown in FIG. 18 is screwed.
[0017] The tip portion of each shoe 71 contacts with a vane supporting portion 69 of the rotor, namely the hub of the rotor, which supports the vanes. The tip portion of each shoe 71 slides along the outer surface of the vane supporting portion 69 . Each room between the adjacent shoes 71 is divided by the corresponding shoe 71 into an oil pressure chamber for timing retard 73 and an oil pressure chamber for timing advance 74 . These chambers 73 , 74 are formed alternatively and have a form of a sector like room contoured peripherally by the inner surface of the case 43 and the outer surface of the rotor 44 and contoured radially by one of the shoes 71 and one of the vanes 64 - 67 of the rotor 44 .
[0018] The oil pressure chamber for timing retard 73 is used for swing the first to fourth vanes 64 - 67 so that the timing of the opening and closing of valves is retarded. And the oil chamber for timing advance 74 is used for swing the first to fourth vanes 64 - 67 so that the timing of the opening and closing of valves is advanced.
[0019] The oil pressure chamber for timing retard 73 and the oil pressure chamber for timing advance 74 disposed at both side of the first vane 64 are communicated through a communicating channel 75 , which passes through the first vane 64 . A groove 76 is disposed in the communicating channel 75 , and the plunger oil channel 58 communicates with the groove 76 .
[0020] A slide plate 77 is disposed in the groove 76 . The slide plate 77 divides the communicating channel 75 into two parts in such a manner that the oil leakage between the oil pressure chamber for timing retard 73 and the oil pressure chamber for timing advance 74 is prevented.
[0021] The slide plate 77 moves toward the oil pressure chamber for timing advance 74 , when the oil pressure in the oil pressure chamber for timing retard 73 is higher. It moves towards the oil chamber for timing retard 73 , when the pressure in the oil pressure chamber for timing advance 74 is higher. The arrow marks in FIGS. 21, 23, 24 show the rotation direction of the actuator 40 as a whole.
[0022] The oil pressure chambers for timing retard and advance 73 , 74 are surrounded by the housing 42 , case 43 , rotor 44 and cover 48 . The oil pressure chamber for timing retard 73 communicates with the first oil channel 62 so that working oil is delivered to the chamber 73 through the first oil channel 62 . And the oil pressure chamber for timing advance 74 communicates with the second oil channel 63 so that working oil is delivered to the chamber 74 through the second oil channel 63 . The rotor 44 rotates relatively to the housing 42 , when the volumes of the oil pressure chambers 73 , 74 change, corresponding to the amount of working oil delivered to each of the oil pressure chambers 73 , 74
[0023] The function of the actuator 40 and the OCV 80 is explained below.
[0024] At first, when the engine is stopping, the rotor 44 is positioned, as shown in FIG. 21, at the maximum timing advance position, namely, the rotor 44 has rotated at most in the timing advance direction. Also the oil pump 92 is stopping, therefore, no working oil is delivered either to the first and second oil channels 62 , 63 , as a result, no working oil is supplied to the plunger oil channel 58 . Consequently, the oil pressure in the actuator 40 is low. As a result, the plunger 56 is pushed by the urging force of the spring 57 towards the holder 55 so that the engaging shaft 56 a of the plunger 56 engages with the engaging hole 55 a of the holder 55 , that is to say, the rotor 44 is locked to the housing 42 .
[0025] In this specification and claims, a “timing advance direction” is a rotation direction of the rotor relative to the housing to advance the timing of the opening and closing of the valves, and a “timing retard direction” is a rotation direction of the rotor relative to the housing to retard the timing of the opening and closing of the valves.
[0026] Starting from this state, when the engine is started, the oil pump 92 functions to increase the oil pressure to the OCV 80 so that working oil is delivered through the first oil pipe 89 and the first oil channel 62 to the oil pressure chamber for timing retard 73 in the actuator 40 . Due to the high oil pressure in the oil pressure chamber for timing retard 73 , the slide plate 77 moves towards the oil pressure chamber for timing advance 74 . As a result, the oil pressure chamber for timing retard 73 communicates with the plunger oil channel 58 so that the working oil is delivered through this plunger oil channel 58 into the engaging hole 55 a of the holder 55 . As a result, the plunger 56 is urged toward the spring, resisting the spring force, so that the engaging shaft 56 a of the plunger 56 is pushed out from the engaging hole 55 a of the holder 55 a . That is to say, the engaging or locking between the plunger 56 and the rotor 44 is released.
[0027] Also in this state, due to the working oil delivered into the oil pressure chamber for timing retard, each vane 65 - 67 of the rotor 44 is pressed to a shoe 71 from the oil pressure chamber 73 , and contacts with a flank of the shoe 71 . Therefore, even in the unlocked state between the plunger 56 and the rotor 44 , the housing 42 and the rotor 44 are pressing to each other due to the oil pressure in the oil pressure chamber for timing retard 73 . As a result, the vibration or clashing in the actuator can be reduced or eliminated.
[0028] For changing the opening and closing timing of the valves, working oil is delivered from the OCV 80 to the oil chamber for timing advance 74 through the second oil pipe 90 and the second oil channel 63 . The oil pressure in the oil chamber for timing advance 74 is delivered to the communicating channel 75 so that the slide plate 77 is pushed to move towards the oil pressure chamber for timing retard 73 . Due to this movement of the slide plate 77 , the plunger oil channel 58 communicates with the communicating channel 75 at the oil pressure chamber for timing advance 74 side so that the oil pressure in the oil pressure chamber for timing advance 74 is supplied to the plunger oil channel 58 . Due to this high oil pressure, the plunger 56 moves towards the housing 42 resisting the force of the spring 57 , so that the engaging or locking between the plunger 56 and the holder 55 is released.
[0029] In this unlocked state, the opening and closing of the OCV 80 is controlled so as to control the oil delivery to the oil pressure chambers for timing retard and advance 73 , 74 so that the rotation angle of the rotor 44 relative to the rotation angle of the housing 42 is changed, that is to say, the rotor 44 is rotated in the timing advance direction or in the timing retard direction. For example, when the rotor 44 is rotated at most in the timing advance direction, the rotor rotates at a state that each vane 64 - 67 of the rotor 44 is contacting with a shoe 71 from the oil pressure chamber for timing retard 73 side, as shown in FIG. 22. When the oil pressure in the oil pressure chamber for timing retard 73 is higher than that in the oil pressure chamber for timing advance 74 , the rotor 44 rotates in the timing retard direction relatively to the housing 42 .
[0030] As explained above, the rotor 44 is controlled to rotate relatively to the housing 42 in the timing advance direction or in the timing retard direction, by adjusting the oil delivery to the oil pressure chambers for timing advance and retard 73 , 74 . The oil leakage at the oil delivery between the oil pressure chambers 73 , 74 is prevented by means of chip seals 46 , 68 .
[0031] By the way, the oil pressure provided from the OCV 80 is controlled by the ECU 100 , corresponding to the outputs from a position sensor, which detects the rotation angel of the rotor 44 relative to the housing 42 , and a crank angle sensor, which determines the pressure to be supplied from the oil pump 92 .
[0032] Another apparatus for adjusting the timings of the opening and closing of valves in an internal combustion engine using a vane type hydraulic actuator is disclosed in JP-9-60507-A, which employs a structure that one stopper pin, as a locking means, locks the rotor in the maximum timing retard position or in the maximum timing advance position, while the timings of the opening and closing of valves are adjusted at the starting of the engine.
[0033] As explained above, vane type actuators in the prior art employ a structure that one plunger 56 or one stopper pin, as a locking means, locks the rotor in the maximum timing retard position or in the maximum timing advance position, while the timings of the opening and closing of valves are adjusted at the starting of the engine.
[0034] In general, for optimizing the timings of opening and closing of valves in an intake/exhaust system of an engine, for example, the engine shall be started from a state, in which the rotor in the intake side is shifted a little from the maximum timing retard position towards the maximum timing advance position, and the rotor in the exhaust side is shifted a little from the maximum timing advance position towards the maximum timing retard position. As a result, the rotors in the intake side and the exhaust side have to be locked at an intermediate position. However, the locking at an intermediate position was difficult, when the structures of the vane type hydraulic actuators in the prior art are employed. The apparatus will be of more complex, when such structure in the prior art is modified to lock the rotors in an intermediate position. That is to say, the vane type hydraulic actuator in the prior art has the drawback that an optimization of timings of opening and closing of valves using a simplified structure was impossible.
SUMMARY OF THE INVENTION
[0035] An object of the present invention is to eliminate the drawback of the vane type hydraulic actuator in the prior art.
[0036] Another object is to propose a vane type hydraulic actuator, in which the rotor can be locked securely at an arbitrary timing retard or timing advance position, when the engine is stopping, so that the timing of opening and closing of valves can be optimized.
[0037] Another object is to propose a vane type hydraulic actuator, in which an unbalanced rotation of the rotor can be prevented.
[0038] Another object is to propose a vane type hydraulic actuator, in which the assembling of the components for locking the rotor is easy.
[0039] Another object is to propose a vane type hydraulic actuator, in which the rotor can be smoothly displaced to an arbitrary position, and the displaced rotor can be securely locked at the position.
[0040] Another object is to propose a vane type hydraulic actuator, in which the relative velocity between the rotor and the case can be rapidly decreased, and simultaneously the allowance of dimensions of the components required in the assembling process can be loosened.
[0041] Another object is to propose a vane type hydraulic actuator, in which the locking of the rotor can be released smoothly, using either of the oil pressure in the oil pressure chambers for timing retard or timing advance.
[0042] Another object is to propose a vane type hydraulic actuator, in which the rotor can be held securely at any position where the locking of the rotor is released.
[0043] Another object is to propose a vane type hydraulic actuator, in which the misassembling of components of the actuator in the production process can be absolutely prevented so that the efficiency of the assembling of components of the actuator can be improved.
[0044] Another object is to propose a vane type hydraulic actuator, in which drawing back of locking elements from a rotor retaining position can be prevented.
[0045] Another object is to propose a vane type hydraulic actuator, in which, when the rotor is offset from a locking position, the offset of rotor can be corrected, and the rotor can be securely locked at the corrected locking position.
[0046] These objects are attained by a vane type hydraulic actuator according to the present invention, more specifically, a vane type hydraulic actuator comprising:
[0047] a case having a plurality of shoes and being installed on the cam shaft of an engine so as to be rotatable independently therefrom;
[0048] a rotor having a plurality of vanes and being received in the case, the rotor is fixed to the cam shaft of the engine and is rotatable relatively to the case in a predetermined angle region;
[0049] an oil pressure chambers for timing retard and for timing advance disposed between the vanes of the rotor and the shoe of the case;
[0050] and a locking means for retaining the rotor to the case so that the relative rotation between the case and the rotor is prevented;
[0051] wherein the locking means comprises:
[0052] a guide locking means for guiding the rotor to a predetermined locking position to lock the rotor to the case;
[0053] and a retaining locking means for retaining the rotor to the case after that the rotor is guided to a predetermined locking position by the guide locking means.
[0054] In an embodiment of the present invention, the guide locking means is disposed in a first vane, and the retaining locking means is disposed in a second vane located symmetrically with the first vane in respect with the axis of the rotor.
[0055] In an embodiment of the present invention, the guide locking means and the retaining locking means are disposed in either of a vane of the rotor or a shoe of the case and are arranged to be adjacent to each other in the direction of the axis of the rotor, they are configured to move in the radial direction of the rotor so that the rotor can be locked to the case and can be disengaged from the case.
[0056] In an embodiment of the present invention, the guide locking means has a first engaging boss formed as a tapered pin;
[0057] the retaining locking means has a second engaging boss formed as a parallel pin;
[0058] and the first and second bosses are received, respectively, in a first and second engaging recesses, each of which are formed so as to disengageably receive the bosses and are disposed in a portion rotating together with the case or alternately in the rotor.
[0059] In an embodiment of the present invention, the guide locking means has a first engaging boss formed as a parallel pin; a first engaging recess is disposed in a portion rotating together with the case; and a friction increasing means is disposed in the base region of the first engaging recess so that the first engaging boss can contact with the friction increasing means.
[0060] In an embodiment of the present invention, further comprising a lock releasing oil pressure channel for supplying oil pressure to the guide locking means and the retaining locking means so as to release the engagement between the rotor and the case; and an oil channel switching means for connecting the lock releasing oil pressure channel to either of the oil pressure chambers for timing retard or the oil chamber for timing advance.
[0061] In an embodiment of the present invention, a fluid channel is disposed in a portion rotating together with the case so that spaces, which are formed behind each of the guide locking means and the retaining locking means when the rotor is locked to the case, communicate to the atmosphere through the fluid channel, only when the rotor is locked to the case.
[0062] In an embodiment of the present invention, the cross section of the guide locking means is different from that of the retaining locking means.
[0063] In an embodiment of the present invention, each of the guide locking means and the retaining locking means is urged so as to lock the rotor to the case by urging means; and the urging force of the urging means for the guide locking means is designed to be stronger than that of the urging means for the retaining locking means.
[0064] In an embodiment of the present invention, the length in the peripheral direction of the tip portion of the vane having the guide locking means is substantially identical to that of the retaining locking means.
[0065] In an embodiment of the present invention, the vane having the guide locking means and/or the vane having the retaining locking means have a weight balancing hole so as to balance the rotation of the rotor.
[0066] In an embodiment of the present invention, the first engaging recess for receiving the guide locking means is tapered in such a manner that the tapering angle of the first engaging recess is larger than the tapering angle of the first engaging boss.
[0067] In an embodiment of the present invention, the first engaging recess for receiving the first engaging boss of the guide locking means is disposed in a sliding means which is resiliently held in a portion rotating together with the case.
[0068] According to the present invention, the locking means for retaining the rotor to the case is a combination of a guide locking means for guiding the rotor to a predetermined locking position and a retaining locking means for retaining the rotor to the rotor, which has been guided to the locking position. Therefore advantages are obtained in that, though the structure is simple, the rotor can be guided to a predetermined locking position using the guide locking means to lock it temporarily, and after temporarily locking, the rotor can be retained securely at an arbitrary position for a desired timing retard or for timing advance, using the retaining locking means, so that the timing of the opening and closing of the valves can be optimized.
[0069] When the guide locking means is disposed in a first vane of the rotor, and the retaining locking means is disposed in a second vane symmetrical to the first vane in respect with the axis of the rotor, unbalanced rotation of the rotor can be prevented.
[0070] When the guide locking means and the retaining locking means are designed to be disposed either in a common vane of the rotor or in a common shoe of the case, and they are arranged so as to be adjacent in the direction of the axis of the rotor, further they can move in the radial direction of the rotor, the efficiency of the production process is improved, because they can be assembled side by side. And the preciseness of the positioning of the rotor can be improved, because the rotor is temporarily locked by the guide locking means, which is found in the adjacent position of the retaining locking means.
[0071] When the guide locking means has a first engaging boss formed as a tapered pin, and the retaining locking means has a second engaging pin formed as a parallel pin; and their corresponding engaging recess, having a recessed portion corresponding to those first and second engaging boss, are disposed in either of a portion rotating together with the case or the rotor so that they receive the first and second engaging boss, the tapered first engaging boss of the guide locking means can easily enter the corresponding tapered engaging recess. Therefore the rotor can be smoothly positioned to a predetermined locking position. And even when the position of the second engaging boss, formed as a parallel pin, of the retaining locking means is offset from the corresponding engaging recess, the offset can be corrected easily using the guide locking means. After correcting the position, the second engaging boss of the retaining means enters into the second engaging recess so that the rotor can be retained securely at an arbitrary position for timing retard and the timing advance, therefore the timing of opening and closing of the valves can be optimized.
[0072] When the guide locking means has a first engaging boss formed as a parallel pin, and the first engaging recess for receiving loosely the first engaging boss is disposed in a portion rotating together with the case, further a friction increasing member is disposed in the base portion of the first engaging recess so that the first engaging boss can contact with it, the relative velocity between the rotor and the case decreases, due to the increased friction resistance between the first engaging boss and the first engaging recess. Thus, though the first engaging boss of the guide locking means is formed as a parallel pin, the retaining locking means can be easily and securely positioned to the retaining position of the rotor. And the retaining locking means can be securely driven to retain the rotor.
[0073] When the vane type hydraulic actuator comprises a lock releasing oil channel for supplying oil pressure to the guide locking means and the retaining locking means so as to release the locking, and an oil channel switching means for switching the oil channel so that the lock releasing oil channel communicates with either of the oil chambers for timing retard or for timing advance, the oil channel from either of the oil chambers for timing retard or for timing advance can be supplied securely to both of the guide locking means and the retaining locking means so that they can be securely driven.
[0074] When a fluid channel is disposed in a portion rotating together with the case so that spaces, which are formed behind the guide locking means and the retaining locking means when the rotor is locked, communicate with the atmosphere only when the rotor is locked, the guide locking means and the retaining locking means can be driven smoothly from a locking state to a locking releasing state.
[0075] When the cross sectional area of the guide locking means is different from that of the retaining locking means, misassembling of guide locking means and the retaining locking means to an erroneous position in the production process can be prevented, so that the efficiency of the production can be ameliorated.
[0076] When the urging force of the urging member for the guide locking means is designed to be stronger than that of the retaining locking means, once the first engaging boss of the guide locking means, formed as a tapered pin, engages with the first engaging recess for locking the rotor to the case, even when the rotation of rotor tends to disengage the first engaging boss from the first engaging recess, the first engaging boss does not disengage from the first engaging recess. Thus the rotor can be securely locked to a predetermined locking position. Additionally, the retaining locking means can be smoothly driven to release the locking, using small oil pressure, because the retaining locking means is urged by a small urging force.
[0077] When the peripheral length of the tip portion of the vane having the guide locking means is designed to be substantially identical to that of the vane having the retaining locking means, the unbalancing of the rotor due to the installation of the guide locking means and the retaining locking means can be prevented.
[0078] When a weight balancing hole is disposed in the first vane having the guide locking means and/or the second vane having the retaining locking means, the unbalanced rotation of the rotor due to the installation of the guide locking means and the retaining locking means can be prevented.
[0079] When the tapering angle of the first engaging boss of the guide locking means is larger than that of the first engaging recess for receiving the first engaging boss, the first engaging boss can smoothly enter into the first engaging recess, therefore, even when the rotor is offset from the locking position, the offset can be easily and securely corrected.
[0080] When the first engaging recess for loosely receiving the first engaging boss of the guide locking means is disposed in a slide means, which is resiliently held in a portion rotating together with the case, the first engaging boss of the guide locking means can easily enter into the first engaging recess so that the temporal positioning of the rotor using the guide locking means is easy. And the relative velocity between the rotor and the case decreases, due to the temporal positioning of the guide locking means. Therefore, the retaining locking means can be smoothly and securely driven to lock the rotor to the case.
BRIEF DESCRIPTION OF THE DRAWINGS
[0081] [0081]FIG. 1 is a cross sectional view of a vane type hydraulic actuator according to first embodiment of the present invention.
[0082] [0082]FIG. 2 is a cross sectional view of the vane type hydraulic actuator of FIG. 1, seen from the cover side, in which the cover and the housing are removed.
[0083] [0083]FIG. 3 is a cross sectional view of the vane type hydraulic actuator of FIG. 1, seen from the housing side, in which the cover and the housing are removed.
[0084] [0084]FIG. 4 is a detailed cross sectional view of the guide stopper pin receiving portion shown in FIG. 1.
[0085] [0085]FIG. 5 is a cross sectional view of the retaining stopper pin, showing the movement when the oil pressure in the oil pressure chamber for timing advance is applied.
[0086] [0086]FIG. 6 is a cross sectional view of the retaining stopper pin, showing the movement when the oil pressure in the oil pressure chamber for timing retard is applied.
[0087] [0087]FIG. 7 is a cross sectional view of a main part of the vane type hydraulic actuator according to third embodiment of the present invention.
[0088] [0088]FIG. 8 is a cross sectional view of the vane type hydraulic actuator of FIG. 7, seen from the cover side, when the cover is removed.
[0089] [0089]FIG. 9 is a cross sectional view of the vane type hydraulic actuator of FIG. 7, seen from the housing side, when the housing is removed.
[0090] [0090]FIG. 10 is a cross sectional view of a vane type hydraulic actuator according to fourth embodiment of the present invention.
[0091] [0091]FIG. 11 is a cross sectional view of the main portion of the vane type hydraulic actuator according to the fifth embodiment of the present invention.
[0092] [0092]FIG. 12 is a front view of the pin holder portion in FIG. 11.
[0093] [0093]FIG. 13 is a cross-sectional view of the vane type hydraulic actuator according to the sixth embodiment of the present invention, showing along the axis of the rotor.
[0094] [0094]FIG. 14 is a cross-sectional view of FIG. 13, showing along the line A-A in FIG. 13.
[0095] [0095]FIG. 15 is a radial cross sectional view of the actuator, showing the oil channel switching system for driving the guide stopper pin and the retaining guide pin in FIGS. 13, 14.
[0096] [0096]FIG. 16 is a cross sectional view of a vane type hydraulic actuator according to the seventh embodiment of the present invention.
[0097] [0097]FIG. 17 is a cross sectional view of FIG. 16, showing along the line B-B.
[0098] [0098]FIG. 18 is a cross sectional view of the vane type hydraulic actuator in the prior art.
[0099] [0099]FIG. 19 is a detailed cross sectional view of the plunger portion in FIG. 18.
[0100] [0100]FIG. 20 is a cross sectional view of the plunger portion at a state that an oil pressure is applied to the plunger.
[0101] [0101]FIG. 21 is a cross sectional view of FIG. 18 along the line X-X.
[0102] [0102]FIG. 22 is a partial sectional view of FIG. 21, at a state that the slide plate is displaced.
[0103] [0103]FIG. 23 is a cross sectional view of FIG. 18 along the line Y-Y.
[0104] [0104]FIG. 24 is a cross sectional view of FIG. 18 along the line Z-Z.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0105] Embodiment 1:
[0106] Embodiment 1 of the present invention is explained below, referring to FIGS. 1 - 6 . Components in these figures equivalent or corresponding to those in FIGS. 16 - 22 are referred to the same reference numerals, and their explanations are omitted.
[0107] The rotor 44 is guided to a predetermined retaining position in respect with the case 43 by a guide stopper pin 1 , as a guide locking means, so that a phase angle between them is corrected. The guide stopper pin 1 has a first engaging boss 1 a at its one end, which is formed as a tapered pin so that the diameter is decreasing towards the tip direction, and a spring receiving hole 1 b at the opposite side of the guide stopper pin 1 . A first pin holding hole 2 is disposed in one vane 66 of four vanes of the rotor 44 , and is configured in the longitudinal direction of the rotor. The guide stopper pin 1 is received in the first pin holding hole 2 and can slide in the hole 2 .
[0108] The housing 42 , which rotate together with the case 43 , has a first engaging recess 42 a on the surface where the rotor 44 contacts and slide along it. The first engaging recess 42 a is tapered so that the diameter increases in the direction towards the opening. The first engaging boss 1 a of the guide stopper pin 1 can be disengageably received in the first engaging recess 42 a . The tapering angle θ2 of the first engaging recess 42 a is designed to be larger than the tapering angle θ 1 of the first engaging boss 1 a so that the first engaging boss 1 a can easily enter into the first engaging recess 42 a.
[0109] The guide stopper pin 1 is urged by a spring 3 towards the housing 42 . Namely the spring 3 functions as an urging means. When the first engaging boss 1 a of the guide stopper pin 1 is pushed into the first engaging recess 42 a , due to the force of the first spring 3 , namely when they are engaged to each other, a first gap 2 a is found between the housing 42 and the end surface of the guide stopper pin 1 where the first engaging boss 1 a is disposed. The first gap 2 a communicates with a first oil channel 58 a , which will be explained later, so that an oil pressure can be applied to the guide stopper pin 1 in the direction resisting the force of the spring 3 .
[0110] Reference numeral 4 denotes a retaining stopper pin, which functions as a retaining locking means for retaining securely the rotor 44 to the case 43 , after that the phase angle between them is corrected by the guide stopper pin 1 . The retaining stopper pin 4 has a second engaging boss 4 a formed as a parallel pin at a longitudinal end thereof, and a second spring holding hole 4 b at the other end thereof. A second pin holding hole 5 is disposed in a vane of the rotor 44 , which is found at a symmetrical position of the vane 66 . The second pin holding hole 5 extends along the longitudinal direction of the rotor 44 , and the retaining stopper pin 4 is inserted therein so as to be able to slide in the longitudinal direction. That is to say, the guide stopper pin 1 and the retaining stopper pin 4 are disposed, respectively, in vanes 66 , 64 , which are configured at a substantially symmetrical position on the rotor 44 in respect with the rotation axis of the rotor 44 . A second engaging recess 42 b is disposed on a surface of the housing 42 where the rotor contacts and slide thereon. The second engaging hole 42 b has a diameter which allow to insert the second engaging boss 4 a of the retaining stopper pin 4 and to release the engagement of the second engaging boss 4 a therefrom.
[0111] The first engaging boss 1 a of the guide stopper pin 1 and the first engaging recess 42 a as well as the second engaging boss 4 a of the retaining stopper pin 4 and the second engaging recess 42 b are configured at, for example, a position shifted a little in the timing advance direction from the maximum timing retard position and a position shifted a little in the timing retard direction from the maximum timing advance position so that the vanes 64 - 67 of the rotor 44 can be locked at an arbitrary intermediate position apart from the shoes 71 of the case 43 .
[0112] A second spring 6 , as an urging means, presses the retaining stopper pin 4 towards the housing 42 . The resilient force of the first spring 3 for the guide stopper pin 1 is designed stronger than that of the second spring 6 . When the second engaging boss 4 a of the retaining stopper pin 4 is pushed into the second engaging recess 42 b , due to the force of the second spring 6 , namely when they are engaging to each other, a second gap 5 a is found between the housing 42 and the end surface of the retaining stopper pin 4 where the second engaging boss 4 a is disposed. The second gap 5 a communicates with a second oil channel 58 b , which will be explained later, so that an oil pressure can be applied to the retaining stopper pin 4 in the direction resisting the force of the second spring 6 .
[0113] The first and second pin holding holes 2 , 5 communicate with the atmosphere, respectively, through drain channels 7 , 8 , which functions simultaneously as an oil drain channel and as an air releasing hole.
[0114] A first oil channel 58 a is disposed in the vane 66 which has the guide stopper pin 1 . The first oil channel 58 a connecting the groove 76 and the first gap 2 a is comprised of a through-hole penetrating the vane 66 in parallel with the axis direction of the rotor. The groove 76 is disposed in the communicating channel 75 . The oil pressure chambers for timing retard and timing advance 73 , 74 are connected through the groove 76 , as shown in FIG. 2. A slide plate 77 for opening and closing the first oil channel 58 a is disposed in the groove 76 so as to function as a channel switching valve. When an oil pressure from the oil pressure chamber for timing retard is applied to the slide plate 77 , the slide plate 77 connects the first oil channel 58 a to the oil pressure chamber for timing retard 73 , and cuts off the channel to the oil pressure chamber for timing advance 74 . On the other hand, when an oil pressure from the oil pressure chamber for timing advance 74 is applied to the slide plate 77 , the slide plate 77 connects the first oil channel 58 a to the oil pressure chamber for timing advance 74 and cuts off the oil channel to the oil pressure chamber for timing retard 73 .
[0115] The first gap 2 a , the first oil channel 58 , the communicating channel 75 and the groove 76 form an oil channel for releasing the locking of the guide stopper pin 1 , by delivering oil pressure to release the locking of the guide stopper pin 1 . And the slide plate 77 forms an oil channel switching means for connecting the oil channel for releasing the lock of the guide stopper pin to either of the oil pressure chambers for timing retard and timing advance.
[0116] A second oil channel 58 b is disposed in the vane 64 , which is found at a symmetrical position to the vane 66 having the first oil channel 58 . The vane 64 has a retaining stopper pin 4 . The second oil channel 58 b is comprised of a through-hole penetrating the vane 64 , and the groove 76 and the second gap 5 a is connected through the second oil channel 58 b.
[0117] Also in this oil pressure system for the retaining stopper pin 4 , similar to the oil pressure system for the guide stopper pin 1 , the second gap 5 a , second oil channel 58 b , communicating channel 75 and the groove 76 form a lock releasing oil pressure channel for supplying oil pressure to the retaining stopper pin 4 in the direction to release the locking of the retaining stopper pin 4 . And the slide plate 77 functions as an oil channel switching means for connecting the lock releasing oil channel either to the oil pressure chamber for timing retard 73 or to the oil pressure chamber for timing advance 74 .
[0118] In FIG. 2, the length L 1 is the peripheral width of the tip portion of the vane 64 having the retaining stopper pin 4 . The length L 2 is the peripheral width of the tip portion of the vane 66 having the guide stopper pin 1 . The lengths L 1 and L 2 are designed to be substantially equal.
[0119] The function of the first embodiment is explained below.
[0120] When first and second bosses 1 a , 4 a of the guide stopper pin 1 and the retaining stopper pin 4 are inserted respectively in the first and second engaging recesses 42 a , 42 b , so that the case 43 incorporated in the housing 42 is engaging with the rotor 44 so as to rotate together with, as shown in FIG. 1, oil pressure is supplied to the guide stopper pin 1 and the retaining stopper pin 4 from the oil pressure chambers for timing retard 73 or timing advance 74 through the first or second gaps 2 a , 5 a . When the oil pressure exceeds the resilient force of the springs 3 , 6 , the first and second bosses 1 a , 4 a of the guide stopper pin 1 and the retaining stopper pin 4 pushed out from the first and second engaging recesses 42 a , 42 b . As a result the locking between the case 43 and the rotor 44 is released, so that they can rotate independently. While the locking is released, the relative position between the case 43 and the rotor 44 can be adjusted so as to optimize the timing of opening and closing of the valves.
[0121] Starting from this lock released state, when the oil pressure supplied to the guide stopper pin 1 and the retaining stopper pin 4 is decreased to be lower than the resilient force of the springs 3 , 6 , the guide stopper pin 1 and the retaining stopper pin 4 displace, respectively, to enter into the first and second engaging recesses 42 a , 42 b . However, there may be a case that the position of the case 43 and the position of the rotor 44 , are offset from a regular engaging position, where the second engaging boss 4 a can enter into the second engaging recess 42 b . Namely there is a case that they are not aligned exactly to each other. Even in such a case, the offset can be corrected and the first engaging boss 1 a can enter smoothly into the first engaging recess 42 a , because the first engaging boss 1 a of the guide stopper pin 1 and the corresponding first engaging recess 42 a are tapered, more specifically, the tapering angle θ2 of the engaging recess 42 a is designed smaller than the tapering angle θ1 of the engaging boss 1 a . When the offset of the position of the rotor is corrected, the second engaging boss 4 a of the retaining stopper pin 4 aligns to the second engaging recess 42 b , then, the retaining stopper pin 4 advances due to the resilient force of the spring 6 so that the engaging boss 4 a enters into the engaging recess 42 b . As a result, the rotor 44 is locked to the case 43 , and they can rotate synchronously. To sum up, even when the relative position of the case 43 and the rotor 44 is offset from a regular engaging position, the offset can be corrected by the guide stopper pin 1 , and the rotor 44 can be locked securely by the retaining stopper pin 4 to the case 43 at the corrected position.
[0122] While the position of the rotor 44 is adjusted either to the direction of the timing retard or the timing advance, the slide plated 77 takes either of the two positions, a position in which the first oil channel 58 a and the second oil channel 58 b are connected to the oil pressure chamber for timing advance 74 , as shown in FIG. 5 (only the second oil channel 58 b is shown), or a position in which the first oil channel 58 a and the second oil channel 58 b are connected to the oil pressure chamber for timing retard 73 , as shown in FIG. 6 (only the second oil channel 58 b is shown). Therefore, while the position of the rotor 44 is adjusted either to the direction of the timing retard or the timing advance, oil pressure can be applied securely to both of the guide stopper pin 1 and the retaining stopper pin 4 either from the oil pressure chambers for the timing advance 74 or the timing retard 73 so that the both the guide stopper pin 1 and the retaining stopper pin 4 can be displaced smoothly in the lock releasing direction due to oil pressure. The other functions of this vane type hydraulic actuator according to the first embodiment of the present invention are substantially identical to that of the prior art, thus their explanations are omitted.
[0123] According to the first embodiment, advantages can be obtained in that, although the structure of the vane type hydraulic actuator is simple, the rotor 44 can be securely retained at a position for timing retard or at a position for timing advance while the engine is stopping so that the timing of opening and closing of the valves can be optimized. Because, after the rotor 44 is guided to a regular engaging position, where the second engaging boss 4 a of the retaining stopper pin 4 aligns to the second engaging recess 42 b , the second engaging boss 4 a , formed as a parallel pin, of the retaining stopper pin 4 is pushed into the second engaging pin 42 b by the resilient force of the spring 6 so that the rotor 44 engages with the case 2 at the position.
[0124] Another advantage is that the engaging position between the first engaging boss 1 a of the guide stopper pin 1 and the first engaging recess 42 a and the engaging position between the second engaging boss 4 a of the retaining stopper pin 4 and the second engaging recess 42 b can be so designed that the vanes 64 - 67 of the rotor 44 lock the rotor 44 and the case 43 at an intermediate position apart from the shoes 71 of the case 43 , thus, the rotor 44 can be locked securely at an arbitrary timing retard position or at an arbitrary timing advance position. As a result, the timing of the opening and closing timing of the valves can further optimized.
[0125] Another advantage is that the first engaging boss 1 a can enter smoothly into the first engaging recess 42 a , even when the position of the rotor 44 relative to the case 43 is offset from the regular locking position. Because the tapering angle θ2 of the second engaging recess 42 a is larger than the tapering angle θ1 of the first engaging boss 1 a of the guide stopper pin 1 . The difference between the angles θ1 and θ2 is an allowance for the engagement of the rotor 44 and the case 43 . Within the allowance, the position of the rotor 44 can be corrected to the regular engaging position, and the rotor 44 can be locked securely by means of the retaining stopper pin 4 .
[0126] Another advantage is that an unbalanced rotation of the rotor 44 can be avoided. Because the vane 66 having the guide stopper pin 1 and the vane 64 having the retaining stopper pin 4 are disposed symmetrically in respect with the axis of the rotor 44 , and the lengths L 1 , L 2 of their tip portions in the peripheral direction are substantially equal.
[0127] Another advantage is that, once the first engaging boss 1 a of the guide stopper pin 1 enters into the first engaging recess 42 a , disengagement of the first engaging boss 1 a and the first engaging recess 42 a due the rotation of the rotor 44 can not occur. Because the resilient force of the spring 3 urging the guide stopper pin 1 is stronger than the resilient force of the spring 3 urging the retaining stopper pin 4 . If the resilient force for the guide stopper pin 1 having a tapered engaging boss 1 a is weak, there is an apprehension that the tapered engaging boss 1 a will disengage from the first engaging recess 42 a . In this embodiment, such an apprehension is removed, and the resilient force of the spring 3 for the retaining stopper pin 4 can be designed to be weak.
[0128] Embodiment 2:
[0129] In the first embodiment, the peripheral lengths L 1 , L 2 of the tip portion of the vane 66 having the guide stopper pin 1 and the tip portion of the vane 64 having the retaining stopper pin 4 are designed to be substantially equal, from a view point of the rotation balance of the rotor 44 . In the second embodiment, a weight balancing recess (not shown) is disposed in either of the vanes 66 , 64 , for maintaining the rotation balance of the rotor 44 . The other structure, function, and advantage are identical to those of the first embodiment.
[0130] Embodiment 3:
[0131] A vane type hydraulic actuator according to the third embodiment of the present invention is explained below, referring to FIGS. 7 to 9 .
[0132] Reference numeral 48 a in FIG. 7 denotes a fluid channel disposed on the contacting surface of the cover 48 , which rotates together with the case 43 . The rotor 44 contacts with this contacting surface and slides along it. Only when the retaining second stopper pin 4 is engaging with the second engaging recess 42 b and the rotor 44 is retained, a fluid channel 8 behind the rotor 44 communicates with the fluid channel 48 a so that the space behind the rotor 4 including the second pin holding hole 5 is opened to the atmosphere.
[0133] When the second engaging boss 4 a of the retaining stopper pin 4 is disengaged from the second engaging recess 42 b and the retaining of the rotor 44 is released, the cover 48 integrating case 43 rotates relatively to the rotor 44 , therefore the position of the fluid channel 48 in the cover 48 is offset from the fluid channel 8 in the rotor 44 , as a result, the fluid channel 8 in the rotor 44 is cut off by the cover 48 .
[0134] In addition to the fluid channel 48 a , another fluid channel (not shown) is disposed in the cover 48 , which is connected to a similar fluid channel 7 for the system of the guide stopper pin 1 . The structure and the function of the fluid channel is identical to the fluid channel 48 a , thus their explanations are omitted.
[0135] In this embodiment, the cross sectional area of the guide stopper pin 1 is not always equal to that of the retaining stopper pin 4 . For example, the cross sectional area of the guide stopper pin 1 , shown in FIG. 9, is smaller compared to that of the retaining stopper pin 4 . Otherwise, the cross sectional area of the guide stopper pin 1 can be larger than that of the retaining stopper pin 4 .
[0136] The other features of the third embodiment of the present invention are identical to those of the first embodiment. Thus the components equivalent or corresponding to those in the first embodiment are referred to the same reference numerals, and their explanations are omitted.
[0137] According to the third embodiment, advantages can be obtained in that the retaining stopper pin 4 and the guide stopper pin 1 can be smoothly displaced from a position retaining the rotor 44 to a retaining releasing position. Because a fluid channel 48 a for the system of the retaining stopper pin 4 and a fluid channel (not shown) for the system of the guide stopper pin 1 are disposed on the contacting surface of the cover 48 , where the rotor 44 contacts and slides along it, so that, only when the rotor 44 is locked, the fluid channels can, respectively, communicate with the fluid channel 8 in the system for the retaining stopper pin 4 and the fluid channel (not shown) in the system for the guide stopper pin 1 .
[0138] Another advantage is that miss-assembling of the guide stopper pin 1 and the retaining stopper pin 4 in the fabrication process can be avoided, when the cross-sectional area of the guide stopper pin 1 and that of the retaining stopper pin 4 are different. For example, miss-assembling of the retaining stopper pin 4 , instead of the guide stopper pin 1 , into the first pin holding hole 2 corresponding to tapered first engaging recess 42 a can be prevented. As a result, the efficiency of the assembling of the components of the apparatus can be improved.
[0139] Embodiment 4:
[0140] Fourth embodiment of the present invention is explained below, referring to FIG. 10.
[0141] Reference numeral 1 c in FIG. 10 denotes a first engaging boss disposed at an end in the longitudinal direction of the guide stopper pin 1 . The first engaging boss 1 c is formed as a parallel pin. The first engaging boss 1 c engages into a first engaging recess 42 c disposed on the contacting surface of the housing 42 having a diameter larger than that of the first engaging boss 1 c . The rotor 44 contacts with this contacting surface and slides on it. When the first engaging boss 1 c enters into the first engaging recess 42 c , the first engaging boss 1 c contacts with a friction increasing member 9 disposed in the base region of the first engaging recess 42 c . That is to say, in the fourth embodiment, the first engaging boss disposed at an end of the guide stopper pin 1 is formed as a parallel pin; the diameter of the first engaging recess 42 c , into which the first engaging boss 1 enters, is larger than that of the first engaging boss 1 c ; a friction increasing member 9 is disposed in the base region of the first engaging recess 42 c ; and the tip portion of the first engaging boss 1 c contacts with the friction increasing member 9 . The other features of the fourth embodiment is identical to those of the first embodiment of the present invention. Thus components identical or equivalent to those in the first embodiment are referred to the same reference numeral, and their explanation is omitted.
[0142] The function of the vane type hydraulic actuator according to the fourth embodiment is explained below.
[0143] When the guide stopper pin 1 is urged by the resilient force of the spring 3 so that the first engaging boss 1 c enters into the first engaging recess 42 c , and the tip of the first engaging boss 1 c contacts with the friction increasing member 9 , the relative velocity between the rotor 4 and the housing 42 decreases corresponding to the increased friction resistance of the first engaging boss 1 c . As a result, the movement of the retaining stopper pin 4 to lock the rotor 4 is rendered smooth.
[0144] The features of the fourth embodiment is found in that the first engaging boss 1 c of the guide stopper pin 1 is formed as a parallel pin; the diameter of the first engaging recess 42 c is larger than the diameter of the first engaging boss 1 c , which enters into the first engaging recess 42 c ; a friction increasing member 9 is disposed in the base portion of the first engaging recess 42 c ; and the first engaging boss 1 c contacts with the friction increasing member 9 . Once the first engaging boss 1 c of the guide stopper pin 1 contacts with the friction increasing member 9 for locking the rotor 44 , the relative velocity between the rotor 4 and the housing 42 decreases due to the increased friction resistance.
[0145] Consequently, according to these features of the fourth embodiment of the present invention, advantages can be obtained in that, though the first engaging boss 1 c of the guide stopper pin 1 is formed as a parallel pin, the positioning of the rotor 44 to the locking position by means of the retaining stopper pin 4 is easy, and the retaining stopper pin 4 can move smoothly and securely in the engaging direction to lock the rotation of the rotor 44 .
[0146] Embodiment 5:
[0147] The vane type hydraulic actuator according the fifth embodiment of the present invention is explained below, referring to FIGS. 11 and 12.
[0148] A pin holder 11 is installed in a recessed groove 10 disposed on the contacting surface of the housing 42 , which rotates together with the case 43 . The rotor 44 contacts with the contacting surface and slides along it. The pin holder 11 has a second engaging recess portion 42 d , which is tapered so that the engaging boss 1 a of the guide stopper pin 1 can enter in it and disengage from it. The pin holder 11 can slide in the recessed groove 10 .
[0149] A pair of balance springs 12 A, 12 B are disposed in the recessed groove 10 at both sides of the pin holder 11 . The balance springs functions as a resilient holding means for holding the pin holder 11 so that the pin holder 11 can move in the radial direction of the rotor 44 . The recessed groove 10 is covered by a cover 13 , which has an opening 13 a communicating with the second engaging recess portion 42 d . The diameter of the opening 13 a is larger than the diameter of the second engaging recess portion 42 d at the larger diameter side. The inner surface of the cover 13 is coplanar with the inner surface of the housing 42 (the contacting surface of the rotor 44 ). Otherwise, the pair of the balance springs 12 A, 12 B can be arranged so that the pin holder 11 can move in the rotation direction of the rotor 44 . The other structure and function of the fifth embodiment are identical to those of the first embodiment.
[0150] The function of the fifth embodiment is explained below.
[0151] When the rotor 44 is locked, the guide stopper pin 1 is pushed by the resilient spring 3 so that the first engaging boss 1 a of the guide stopper pin 1 enters into the first engaging recess 42 d through the opening 13 a and the guide stopper pin 1 is temporarily locked to the housing 42 , in a similar way as in the first embodiment.
[0152] Even when the first engaging boss 1 a of the guide stopper pin 1 is not positioned just in front of the first engaging recess 42 d in the pin holder 11 and they are not aligned to each other, the first engaging boss 1 a can enter easily into the first engaging recess 42 d and can be held at a center portion of the balance springs 12 A, 12 B, that is an equilibrium position of the resilient force of the balance springs. After the temporal locking, the relative velocity between the rotor 44 and the housing 42 decreases so that the retaining stopper pin 4 can move smoothly and securely in the direction to lock the rotor 44 .
[0153] As explained above, the features of the fifth embodiment are such that the first engaging boss 1 a of the guide stopper pin 1 is tapered; a pin holder 11 having a tapered engaging recess 42 d , in which the first engaging boss 1 a can engage, is installed in a groove 10 disposed in the housing 42 ; the pin holder 11 is resiliently held by a pair of balance springs 12 A, 12 B. Thus, the first engaging boss 1 a of the guide stopper pin 1 can easily enter into the first engaging recess 42 d in the pin holder 11 so that the rotor 44 can be smoothly locked temporarily, and the relative velocity between the rotor 44 and the housing 42 decreases because of the temporal locking of the rotor 44 . Consequently, advantages can be obtained in that the retaining stopper pin 4 can be displaced smoothly and securely in the direction to lock the rotor 44 , and that a large allowance in assembling of the pin holder 11 into the housing 42 is permissible, because the pin holder 11 is held by a pair of balance springs 12 A, 12 B.
[0154] Embodiment 6:
[0155] The vane type hydraulic actuator according to the sixth embodiment is explained, referring to FIGS. 13 to 16 . Components identical or corresponding to those explained referring to FIGS. 1 - 9 are referred to the same reference numerals, and their explanations are omitted.
[0156] A first pin holding hole 102 and a second pin holding hole 105 penetrate a shoe 71 of the case 43 in the radial direction. The first and second holding holes 102 , 105 are arranged side by side in the direction of the axis of the rotor 44 . There is a shoulder portion in each of the first and second pin holding holes 102 , 105 , more specifically, the inner diameter of each of the first and second pin holding holes 102 , 105 is small at the radially inner portion.
[0157] The first pin holding hole 102 receives a guide stopper pin 101 , which can slide in the radial direction in the hole 102 . The guide stopper pin has a first engaging boss 101 a formed as a tapered pin at its radially inner end portion and a spring holding hole 101 b which has an opening at its radially outer end. The guide stopper pin 101 functions as a guide locking means for securely guiding the rotor 44 to a predetermined position to engage with the housing. The guide stopper pin 101 is pushed towards the rotor 44 by a first spring 103 . The first spring 103 is held by a plug 102 a , which is plugged into the radially outer opening of the first pin holding hole 102 .
[0158] A first engaging recess 142 a is disposed in the hub portion of the rotor 44 , which contacts with the shoe 71 , having the first pin holding hole 102 , and slides along it. The first engaging recess 142 a is tapered so that the inner diameter increases gradually outwardly. Thus the first engaging boss 101 a of the guide stopper pin 101 can enter into the first engaging recess 142 a and exit from there. When the first engaging boss 101 a enters in it, the position of the rotor 44 in respect with the case 43 can be corrected, the correction facilitates the engagement of the retaining locking means, as will be explained below.
[0159] The second pin holding hole 105 A receives a retaining stopper pin 104 , which can slide in the radial direction of the case 43 . The retaining stopper pin has a second engaging boss 104 a , formed as a parallel pin with small diameter, in its radially inner portion, and a second spring holding hole 104 b , which has an opening at its radially outer end portion. The retaining stopper pin 104 functions as a retaining locking means for retaining securely the rotor 44 at a predetermined position. The retaining stopper pin 104 is pushed towards the rotor 44 by a second spring 106 . The outer opening of the second spring holding hole 104 b is plugged by a plug 105 a , which holds the second spring 106 .
[0160] A second engaging recess 142 b is disposed in the hub portion of the rotor 44 , with which the shoe 71 having the retaining stopper pin 104 contacts. The second engaging recess 142 b is arranged adjacently to the first engaging recess 142 a , which belongs to the system for the guide stopper pin 101 , and is formed as a cylindrical hole matched with the second engaging boss 104 a so that the second engaging boss 104 a of the retaining stopper pin 104 can enter and exit from it. Preferably, the resilient force of the first spring 103 for the guide stopper pin 101 is designed to be stronger than that of the second spring 106 for the retaining stopper pin 104 .
[0161] In the first and second embodiments, each of the vane 66 having the guide stopper pin 1 and the vane 64 having the retaining stopper pin 4 has an oil channel for releasing the locking (oil channel 58 a , 58 b , communicating oil channel 75 , and groove), and an oil channel switching means (slide plate 77 ). On the other hand, in the sixth embodiment, the guide stopper pin 101 and the retaining stopper pin 104 have a common lock releasing oil pressure channel (oil channel 58 a , communicating channel 75 , and groove 76 ) and an oil channel switching means (slide plate 77 ) on a shoe 71 projecting towards the rotor shaft. And the guide stopper pin 101 and the retaining stopper pin 104 are simultaneously activated. The function of these lock releasing oil pressure channel and the oil channel switching means are substantially identical to those in the first embodiment. Thus their explanation is omitted.
[0162] By the way, the oil channel 58 a of the lock releasing oil channel supplies oil pressure, which is delivered either from the oil chambers for timing retard 73 and the for timing advance 74 , to the guide stopper pin 101 and the retaining stopper pin 104 . The oil pressure urges the guide stopper pin 101 and the retaining stopper pin 104 in the direction resisting the resilient force of the first and second springs 103 , 106 . Of course, also in the sixth embodiment, it is possible to dispose two sets of the lock releasing oil pressure channel and the oil switching means for independently activating the guide stopper pin 101 and the retaining stopper pin 104 . In such a structure, it is preferable to arrange a set of the lock releasing oil pressure channel and the oil switching means on each inner and outer end surfaces of the shoe 71 .
[0163] The function of the vane type hydraulic actuator according to the sixth embodiment of the present invention is explained below.
[0164] When the engine is running, the case 43 and the rotor 44 have to rotate independently to each other. In this state, the oil pressure urging the guide stopper pin 101 and the retaining stopper pin 104 is set larger than the resilient force of the first and second spring 103 , 106 , so that the first and second engaging boss 101 a , 104 a of the guide stopper pin 101 and the retaining stopper pin 104 are pushed out from the first and second engaging recesses 142 a , 142 b . As a result, the locking of the rotor is released in this state.
[0165] Starting from this locking released state, when the oil pressure urging the guide stopper pin 101 and the retaining stopper pin 104 decreases to be lower than the resilient force of the first and second springs 103 and 106 , if, in this moment, the first engaging boss 101 a of the guide stopper pin 101 and the second engaging boss 104 a of the retaining stopper pin 104 are positioned exactly aligned to the corresponding first and second engaging recesses 142 a , 142 b the first and second engaging bosses 101 a , 104 a of the guide stopper pin 101 and the retaining stopper pin 104 will enter into the first and second engaging recess 142 a , 142 b due the resilient force of the first and second spring 103 , 106 , so that the case 43 and the rotor 44 are locked to each other.
[0166] However, when the oil pressure urging the guide stopper pin 101 and the retaining stopper pin 104 decreased to be lower than the resilient force of the first and second springs 103 , 106 , the first engaging boss 101 a of the guide stopper pin 101 and the second engaging boss 104 a of the retaining stopper pin 104 are not always positioned exactly aligned to the corresponding first and second engaging recesses 142 a , 142 b , namely they can be offset a little from a regular engaging position.
[0167] When the offset is within the difference between the diameter of the smaller diameter side tip portion of the first engaging boss 101 a of the guide stopper pin 101 , which is formed as a tapered pin, and the diameter of the opening of the tapered first engaging recess 142 a at the largest end, the first engaging boss 101 a can be pushed into the first engaging recess 142 a by the resilient force of the first spring 103 urging the guide stopper pin 101 . As a result, the offset can be corrected. And the second engaging boss 104 a , which is formed as a cylindrical pin, of the retaining stopper pin 104 and the cylindrically formed second engaging recess 142 b align to each other, then the cylindrically formed second engaging boss 104 a enters into the cylindrically formed second engaging recess 142 b , due to the resilient force of the second spring 106 urging the retaining stopper pin 104 . Finally, the rotor 44 can be locked to the case 43 .
[0168] The resilient force of the first spring 103 of the guide stopper pin 104 can be designed to be larger than that of the retaining stopper pin 104 . In such a case, when the oil pressure, which urges commonly the guide stopper pin 101 and the retaining stopper pin 104 , is decreased to be lower than the resilient force of the first and second springs 103 , 106 , even when the first and second engaging bosses 101 a , 104 a and the first and second engaging recesses 142 a , 142 b are not aligned, the first engaging boss 101 a of the guide stopper pin 101 enters into the first engaging recess 142 a , because the resilient force of the first spring 103 of the guide stopper pin 101 is larger than that of the second spring 106 of the retaining stopper pin 104 . Then the second engaging boss 104 a of the retaining stopper pin 104 and the second engaging recess 142 b align to each other, and the second engaging boss 104 a can smoothly enter into the second engaging recess 142 a.
[0169] According to the sixth embodiment of the present invention, advantages can be obtained in that the efficiency of the assembling in the production process of the vane type hydraulic actuator is improved, because the guide stopper pin 101 and the retaining stopper pin 104 are disposed on the shoe 71 so as to be adjacent to each other in the direction of the axis of the rotor 44 . And even when the position of the second engaging boss 104 a of the retaining stopper pin 104 is offset form the position of the second engaging recess 142 b , the first engaging boss 101 a of the guide stopper pin 101 can enter smoothly into the first engaging recess 142 a , because the first engaging boss 101 a of the guide stopper pin is tapered and the first engaging recess 142 a is tapered so as to allow to receive the first engaging boss 101 a , so that the offset of the position of the second engaging boss can be corrected when the first engaging boss 101 a enters into the first engaging recess 142 a . As a result, the second engaging boss 104 a of the retaining stopper pin 104 can enter smoothly into the second engaging recess 142 b , Consequently, the rotor 44 can be locked securely at a predetermined position. Furthermore, the preciseness of the correction of the offset can be improved, because the offset of the retaining stopper pin 104 is corrected by the guide stopper pin 101 disposed at a position very close to the retaining stopper pin 104 .
[0170] In the aforementioned example of the sixth embodiment, the guide stopper pin 101 and the retaining stopper pin 104 are disposed on a shoe 71 of the case 43 so as to be arranged side by side in the direction of the axis of the rotor, and is possible to slide in the radial direction of the rotor. However, they can be disposed in one of the vanes 64 - 67 of the rotor 44 so as to be arranged side by side in the direction of the axis of the rotor 44 and be possible to slide in the radial direction. In such a case, similar advantages such as obtained in the explained example of the sixth embodiment can be obtained, by disposing the first and second engaging recesses 142 a , 142 b on the inner surface of the case 43 , where the vane having the guide stopper pin 101 and the retaining stopper pin 104 contact and slide along it.
[0171] Furthermore, also in the sixth embodiment, the guide stopper pin 101 as well as the first engaging recess 142 a and that of the retaining stopper pin 104 as well as the second engaging recess 142 b can have different cross sectional areas. The advantages derived from such a structure are identical to that of the third embodiment.
[0172] Embodiment 7:
[0173] The vane type hydraulic actuator according to the seventh embodiment of the present invention is explained below, referring to FIGS. 16, 17. Components in FIGS. 16, 17 identical or equivalent to those in FIGS. 1 to 9 and 13 to 15 are referred to the same reference numerals, and their explanations are omitted.
[0174] In the sixth embodiment, the guide stopper pin 101 and the retaining stopper pin 104 are disposed in a common shoe 71 of case 43 so as to be adjacent in the direction of the rotor 44 . On the other hand, in the seventh embodiment, the guide stopper pin 101 (guide locking means) and the retaining stopper pin 104 (retaining locking means) are disposed on different shoes 71 , which are located symmetrically in respect with the axis of the rotor 44 . The guide stopper pin 101 and the retaining stopper pin 104 are configured symmetrically in respect with the axis of the rotor 44 and can slide in the radial direction of the rotor 44 .
[0175] The first engaging recess 142 a for disengageably receiving the first engaging boss 101 a of the guide stopper pin 101 and the second engaging recess 142 b for disengageably receiving the second engaging boss 104 a of the retaining stopper pin 104 are disposed in the hub portion of the rotor 44 symmetrically in respect with the axis of the rotor 44 .
[0176] The functions of the guide stopper pin 101 and the retaining stopper pin 104 are similar to those of the sixth embodiment, thus, their explanation is omitted.
[0177] According to the seventh embodiment, advantages can be obtained in that the longitudinal length of the hydraulic actuator can be shortened compared to that of the sixth embodiment, in which the guide stopper pin 101 and the retaining stopper pin 104 are disposed adjacent in the direction of the rotor axis. Because, in the seventh embodiment, the guide stopper pin 101 and the retaining stopper pin 104 are disposed symmetrically in respect with the rotor axis, and the first engaging recess 142 a for disengageably receiving the first engaging boss 101 a of the guide stopper pin 101 and the second engaging recess 142 b for disengageably receiving the second engaging boss 104 a of the retaining stopper pin 104 are disposed in the hub portion of the rotor 44 symmetrically in respect with the axis of the rotor 44 . As a result, the hydraulic actuator 40 can be downsized. Further, the weight of the hydraulic actuator 40 can be balanced, because the guide stopper pin 101 and the retaining stopper pin 104 are disposed symmetrically in respect with the rotor axis, as explained above, therefore the rotation of the actuator 40 can be stabilized. | The vane type hydraulic actuator in the prior art has a drawback that the locking of the rotor at a best position was difficult, therefore, the optimization of the timing of opening and closing of the valves, using a simple apparatus, was impossible.
The vane type hydraulic actuator according to the present invention comprises a guide locking means (guide stopper pin) ( 1 ) for guiding the rotor ( 44 ) to a locking position where the rotor ( 44 ) can be locked to the case ( 43 ), and a retaining locking means (retaining stopper pin) ( 4 ) for retaining the rotor ( 44 ) to the case ( 43 ), after the rotor ( 44 ) is guided to the locking position. | 5 |
BACKGROUND OF THE INVENTION
[0001] The present invention is directed to processing of substrates or wafers used in the manufacture of semiconductor devices. In particular, the present invention is directed to a mobile cart-based self-evacuating micro-environment system designed to transport a group of substrates in a vacuum-sealed container between processing chambers during the manufacture of semiconductor devices.
[0002] Silicon wafers having diameters up to 300 mm, and gallium arsenide wafers are used in the manufacture of semiconductor devices. Large substrates are also used in the manufacture of flat panel display devices. Many processing steps are required to fabricate devices on the surfaces of these wafers and panels (herein referred to as substrates). The steps are performed inside various tools within a fabrication building. These tools perform specialized functions, for example, layering, patterning, doping and heat treating. The partially completed devices are highly sensitive to contamination during the fabrication process. Therefore the substrates must remain in controlled environments within the tools. However, the substrates must also be transported between the various tools during fabrication. Consequently, the substrate surfaces must be protected from ambient contamination during transport. In some cases, groups of substrates are transported between tools in closed containers, or micro-environments, often referred to as standard mechanical interface (SMIF) pods. Typically, 300 mm wafers are transported in Front Opening Universal Pods (FOUPs). These containers are typically filled with clean ambient air or filtered inert gas, such as nitrogen.
[0003] The internal pressure in these transport containers is typically near the atmospheric value. Atmospheric pressure containers are convenient when interfacing with atmospheric operations such as wet processing and photolithography. However, many processing steps are conducted at reduced pressures. For example, sputter deposition is performed at pressures as low as 10-6 Torr. Substrates received from SMIF pods must therefore be placed in intermediate loadlock chambers designed to evacuate the atmosphere around the substrates prior to processing, and to return the substrates to atmospheric pressure after processing. Such cyclic evacuation and venting of loadlock chambers consumes significant quantities of energy, thereby increasing substrate processing cost. These additional steps also reduce the productivity of the tool, since no processing can occur in an individual loadlock during evacuation or venting, although tools are typically used with multiple loadlocks, wherein while one loads, the other can be processed. The present invention can eliminate the need for these multiple loadlocks.
[0004] The above productivity problem can be lessened by evacuating and venting the loadlock chamber as quickly as possible. However, rapid evacuation, accomplished through high pumping speeds, can cause excessive adiabatic cooling of the gas, leading to condensation of trace moisture in the loadlock chamber. The condensed moisture consists partially of aerosol droplets suspended in the loadlock chamber atmosphere. The resulting water droplets scavenge and react with trace contaminants in the loadlock chamber environment, thereby producing reaction products in the form of suspended residue particles. These particles can rapidly deposit on the substrate surfaces by turbulent and convective motion, or by gravitational settling. As the pressure continues to drop in the loadlock chamber, the settling speed of the particles increases, resulting in an increased rate of particle deposition on the substrates.
[0005] The above described adiabatic cooling is opposed by natural warming provided by the loadlock chamber walls. Thus, the condensation process can be prevented by pumping-down at a sufficiently low rate that heat transfer from the loadlock chamber walls prevents excessive gas cooling. B. Y. H. Liu, T. H. Kuehn and J. Zhao in “Particle Generation During Vacuum Pump Down”, Proceedings of the 37 th Annual Technical Meeting of the Institute of Environmental Sciences , San Diego, Calif., May 6-10, 1991, pp. 737-740, show that the suspended particle concentration in pumped chambers is directly related to a Z number given as:
Z=τω/ξ,
[0006] where τ is the pumping time constant,
τ= V/S ( sec ),
[0007] V is the chamber volume, S is the pumping speed, and
ξ= V/A ( cm )
[0008] is the chamber volume to surface area ratio. The rate of heat penetration w from the chamber walls to the gas is given by:
ω=[ gα/Pr] 1/3 ( cm/sec ),
[0009] where g is the gravitational constant, the Prandtl number Pr is given by:
Pr=v/α,
[0010] v is the kinematic viscosity, and a is the thermal diffusivity of the gas.
[0011] Experimental tests by Liu et al. (see B. Y. H. Liu, T. H. Kuehn and J. Zhao in “Particle Generation During Vacuum Pump Down”, Proceedings of the 37 th Annual Technical Meeting of the Institute of Environmental Sciences , San Diego, Calif., May 6-10, 1991) showed that higher values for Z, as produced by lower pumping speeds, resulted in lower concentrations of suspended residue particles in the gas. For example, at Z=4.17, the measured particle concentration reached ˜ 10 4 per cm 3 , while at Z=18.5, the suspended particle concentration reached only ˜1 per cm 3 . However, as stated above, low pumping speeds significantly increase processing time and thereby increase the costs associated with use of the tool. Alternatively, more rapid pumping speeds tend to produce higher concentrations of deposited residue particles on substrate surfaces, thereby significantly reducing semiconductor device yield, and increasing processing cost.
[0012] An additional significant problem encountered during the storage and transport of substrates between tools is exposure to molecular contamination released (or outgassed) particularly from the internal surfaces of plastic SMIF pods and the like. It is well known in the field of semiconductor fabrication that such molecular contaminants can produce deleterious effects on sensitive device surfaces. Such molecular contaminants tend to accumulate and increase in concentration in the pod's internal atmosphere. D. Hou, P. Sun, M. Adams, T. Hedges, and S. Govan in “Comparative Outgassing Studies on Existing 300 mm Wafer Shipping Boxes and Pods”, Proceedings of the ICCCS 14 th International Symposium on Contamination Control , Phoenix Ariz., Apr. 26-May 1, 1998, pp. 419-428, show that wafer pods can outgas significant quantities of volatile organic contamination, and that such contaminants can deposit on wafer surfaces. Test results showed that commonly used polymer additives with high boiling points were absorbed on wafer surfaces. Such contaminants tend to cause a further reduction in device yield.
[0013] Additional molecular contaminants, such as atmospheric moisture or oxygen, can cause undesired native oxide growth on substrate surfaces. Additionally, atmospheric contaminants, such as organics and metallics, reduce device performance and limit production yields. Such molecular and ionic contaminants can enter substrate containers during exposure to the atmosphere, or through minor leaks in non-hermetically sealed containers.
[0014] An additional problem encountered during the storage and transport of substrates between tools is exposure to particulate contamination generated internally by the substrates, transport mechanisms and containers. When substrates and loading/unloading machinery rub against other surfaces, microscopic particles are produced through abrasion. It is well known in the field of semiconductor fabrication that particles as small as 0.01 micrometer can produce substantial defects on modern semiconductor devices. Particles of this size can remain suspended for prolonged periods inside substrate containers. FIG. 1 shows that the settling time of such microscopic particles under atmospheric pressure (760 Torr) is very long. Only under reduced container pressure can a rapid gravitational settling of such particles occur. Under a perfect vacuum, particles enter free-fall and settle-out rapidly, regardless of size. During their prolonged periods of suspension, such particles may be readily transported onto substrate surfaces by gas turbulence and convection, or by Brownian motion phenomena within the closed container.
[0015] Previous attempts to solve the problems of molecular contaminant accumulation and particle motion in substrate containers include continuously purged containers, vapor drain systems and statically evacuated containers. The term “statically evacuated container” as used herein refers to a closed container having a hermetic seal, and holding a previously established internal vacuum, without benefit of continuous pumping.
[0016] U.S. Pat. No. 5,644,855 (McDermott et al.) discloses a portable transport container, including an attached cryogenically liquefied inert gas insulated storage vessel, from which vaporized liquefied inert gas is used to generate a continuous gaseous nitrogen purge to the container. The purge gas prevents accumulation of contamination from outgassing or minor atmospheric leaks.
[0017] U.S. Pat. No. 4,668,484 (Elliott) discloses a portable transport container, including an attached compressed gas cylinder mounted above the wafer container, from which inert gas is used to generate a continuous gaseous nitrogen purge to the container.
[0018] A similar purged container for silicon wafers was described by T. Yabune, T. Futatsuki, K. Yamada, and T. Ohmi in “Isolation Performance of a Wafer Transportation System Having a Continuous N 2 Gas Purge Function”, Proceedings, 40 th Annual Technical Meeting of the Institute of Environmental Sciences , Chicago, Ill., May 1-6, 1994, pp. 419-424. The Yabune et al. container also uses an attached mini cylinder of pressurized nitrogen to purge the wafer container. The Yabune, et al. system uses an aluminum container and a high purity, all-metal gas distribution system.
[0019] U.S. Pat. No. 5,351,415 (Brooks et al.) discloses a container for storage or transport of semiconductor wafers that uses a purge of ionized gas, such as gaseous nitrogen. The nitrogen is supplied from a cylinder of compressed gas that is typical in the industry. The compressed gas cylinder is not affixed directly to the container, but is connected through a gas line.
[0020] U.S. Pat. No. 5,346,518 (Baseman et al.) discloses a vapor drain system, consisting of an activated carbon or other suitable vapor removal element located inside the sealed substrate container. This vapor drain reduces the accumulation of vapors emitted inside the container using a continuous scavenging process.
[0021] Continuously purged containers and vapor drain systems, such as those described above, reduce the accumulation of outgassed molecular contamination. However, purged containers vent their purge gas into the surrounding atmosphere, and, therefore, must be held at internal pressures near or above the atmospheric value. Additionally, vapor drain systems have only been developed for containers held at near atmospheric pressure. Therefore, the problems described above regarding evacuation and venting of loadlock chambers cannot be solved by using such methods.
[0022] U.S. Pat. No. 4,966,519 (Davis et al.) and U.S. Pat. No. 4,943,457 (Davis et al.) disclose vacuum tight wafer containers, held at less than 10 −5 Torr internal pressure, and a loadlock chamber suitable for use with the wafer container. The container is evacuated and hermetically sealed at a processing station, and the wafers are then transported to the next station or stored under a static hard vacuum within the container. The evacuated interior of the container eliminates gas movement and Brownian motion, while inducing rapid particle settling. Particulate contamination of wafer surfaces within the containers is therefore reduced.
[0023] U.S. Pat. No. 5,255,783 (Goodman et al.) discloses a container and a method of storing semiconductor wafers under static vacuum. The container includes a valve designed to remove the internal atmosphere subsequent to loading wafers into the container. The valve is then closed to provide a hermetic seal to the container. The same valve is then used to re-pressurize the container at the destination site prior to unloading the wafers.
[0024] U.S. Pat. No. 5,810,062 (Bonora et al.) discloses a SMIF pod-type wafer container having a valve designed to permit gas flow into or out of the pod. The pod design permits wafers to be transported between processing stations under static vacuum.
[0025] U.S. Pat. No. 4,886,162 (Ambrogio) discloses a single-wafer container that can be packaged in a statically evacuated plastic wrapper. The hermetic seal packaging prevents moisture and other atmospheric contaminants from entering the container during extended periods of storage or transport.
[0026] Containers having static vacuums, such as those described above, minimize exposure of substrates to particulate contamination, but do not prevent accumulation of outgassed molecular contamination or atmospheric contamination entering through minor leaks. A further disadvantage of hermetically sealed containers is that any required evacuation or venting of the container must be performed at a substrate processing station, or special pumping/venting station, thereby reducing process productivity as described above.
BRIEF SUMMARY OF THE INVENTION
[0027] A mobile, self-evacuating, micro-environment system for transit and storage of substrates between two or more processing chambers in the manufacture of semiconductor devices is provided. The system includes a mobile cart and a vacuum sealable container having an internal volume to hold a plurality of the substrates. The container is located on the cart. A vacuum source having a portable power source is located on the cart which is capable of generating a vacuum in the internal volume of the container. A docking valve is included to mate with a corresponding valve on each of the processing chambers. The docking valve and the corresponding valve are securable to one another to form a substantially vacuum-tight seal and openable, while mated, to permit unloading and loading of substrates between the container and the processing chamber. The docking valve provides a seal for the container when the container is detached from any of the processing chambers.
[0028] The vacuum source preferably includes at least one sorption pump, for example, a cryogenic molecular sieve sorption pump operable solely by liquid nitrogen.
[0029] The sorption pump is preferably capable of pumping down the container to a base pressure of about 10 −2 Torr. The vacuum source is preferably controlled using a selected pumping rate and vacuum conductance by adjustable valves to eliminate impurities condensation and residue particle formation. The vacuum source may additionally include one or more ion pump or turbo-molecular pump, which is preferably operated by battery power and controlled by a battery powered controller. The ion or turbo-molecular pump can preferably achieve a pressure of about 10 −6 to 10 −9 Torr and provides continuous removal of trace molecular contaminants. The vacuum source preferably provides continuous, active pumping of the container with power connection only to the portable power source to remove substantially any molecular contaminants that may outgas from the internal surfaces of the container or enter the container through minor leaks and preferably is capable of creating a vacuum sufficient to eliminate particle motion inside the container caused by gas movement and Brownian motion. The vacuum source also preferably provides continuous pumping of the containers, to provide continuous removal of released surface moisture and other contaminants that may be subsequently transferred into the processing chambers. Finally, in the preferred embodiment, the vacuum source gradually and controllably adjusts the internal pressure of the container during transit of the system from a first one of the processing chambers to a second one of the processing chambers such that the internal pressure of the container matches that of the second one of the processing chambers and minimizes particle motion to prevent accumulation of molecular contaminants within the container.
[0030] The mobile, self-evacuating, micro-environment system also evacuates the small space between the docking valve and the processing chamber which is at 1 atmosphere.
[0031] A method for transit and storage of substrates between two or more processing chambers in the manufacturing of semiconductor devices is also provided which includes the steps of providing the above system, processing the substrates in a first one of the processing chambers, mating the docking valve with the corresponding valve on the first one of the processing chambers, activating the vacuum source to the container to equalize pressure of the container with the one of the processing chamber, opening the docking valve and the corresponding valve while the chambers are sealed to one another to provide access between the container and the one of the processing chambers, moving the substrates from the one of the processing chambers to the container, closing the docking valve to seal the container, controlling the vacuum source to slowly change pressure in the container to that of a second one of the processing chambers, and mating the docking valve with the corresponding valve on the second one of the processing chambers.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0032] [0032]FIG. 1 is a graphical depiction of settling time of microscopic particles sized from 0.01 micrometers to 10 micrometers, caused by, e.g., abrasion of two surfaces, in a 760 Torr (atmospheric pressure) environment.
[0033] [0033]FIG. 2 is a mobile cart-based self-evacuating micro-environment system in accordance with one preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] The present invention is intended to provide protection against ambient contamination for various substrates, including wafers made from, for example, silicon, gallium arsenide and other semiconductor materials, and flat panel display devices, thus increasing their yield rate during fabrication. This protection is provided as the substrates are held in storage between processing steps or transported between processing tools during fabrication. The invention is further intended to minimize the exposure of semiconductor substrates to molecular contamination released (or outgassed) from the internal surfaces of substrate storage and transport containers, and from particulate contamination generated from substrates, transport mechanisms and containers. The invention is further intended to minimize the time required to load I unload substrates as they enter or exit semiconductor processing tools, thus saving valuable processing time, and improving the cost of ownership for tools. This savings in time is achieved by eliminating the pump-down and vent (re-pressurization) steps normally performed in a tool loadlock chamber.
[0035] The above productivity problems caused by evacuation and venting of loadlock chambers can be eliminated by pumping-down and venting the substrate container's atmosphere while it is in transport (or storage) between loadlock chambers. The method of the present invention permits evacuation and venting of the container at a controlled, slower rate that does not promote internal condensation and aerosol formation. Furthermore, the method of the present invention allows the wafers to arrive at the processing tool's loadlock chamber already under vacuum, and ready for processing. Also, the problems related to particle motion, and accumulation of contaminants through outgassing and minor leakage, can be eliminated by continuous pumping (also referred to as active evacuation) of the vessel during use.
[0036] Referring now to the drawings, there is seen in FIG. 2, a mobile cart-based self-evacuating micro-environment (SEME) system 10 in accordance with one preferred embodiment of the present invention. The SEME system 10 is designed to perform this controlled, active evacuation and venting. The SEME system 10 transports a group of wafers 11 in a vacuum-sealed container 12 . Cryogenic molecular sieve sorption pumps 13 and 14 , located on the cart, generate a clean vacuum in the container 12 . Such sorption pumps 13 , 14 require only liquid nitrogen to operate. Sorption pump 13 performs an initial pump-down of the container when valves 15 and 16 are opened. Sorption pump 14 then pumps the container to a base pressure of about 10 −2 Torr when valves 17 and 16 are opened. This pressure is low enough to allow immediate transfer of the wafers 11 into many processing tools without further pump-down.
[0037] The pumping speed for the container 12 during pump-down is set using a selected pumping rate and vacuum conductance in the system. The vacuum conductance in the system 10 can be set using adjustable gate valves and other such devices (not shown in FIG. 2) well known in the field of vacuum science. The pumping speed during pump-down is set to eliminate impurities condensation and residue particle formation as described in the Background of the Invention above. The ultimate pressure in the container following pump-down can be matched to the requirements of the destination tool, thereby permitting immediate loading of wafers 11 into an evacuated processing chamber. The ultimate pressure requirements typically depend upon the permissible amounts of surface contamination. For instance, at 10 −6 Torr, one monolayer of contaminants can land on a wafer in one second, while at 10 −9 Torr, it takes 1000 seconds to accumulate one monolayer of contaminants.
[0038] The SEME container 12 can be subsequently pumped to pressures lower than 102 Torr. Lower pressures can be achieved in the container 12 using an ion pump or turbo-molecular pump 18 backed by one or more sorption pump. This ion or turbo-molecular pump 18 is preferably operated by a battery powered controller 19 . The ion or turbo-molecular pump 18 evacuates the container 12 when valves 17 , 20 and 21 are opened. Typical turbo-molecular pumps 18 can pump at a rate of 40 liters per second while achieving pressures of about 10 −6 to 10 −9 Torr. Such pumps can operate using, for example, 24 Volt batteries 18 a , and consume, for example, only 20 Watts of power after initial pump-down. This pumping of the container 12 to high vacuum provides continuous removal of trace molecular contaminants and allows immediate interfacing with high vacuum processing tools.
[0039] The system 10 is contained in a mobile cart 22 . The combination of sorption and ion, or turbo-molecular, pumps provides continuous, active pumping of the wafer container with no connection to external power. This continuous pumping removes any molecular contaminants that may outgas from the internal surfaces of the container 12 or enter the container 12 through minor leaks. The low pressures produced by the system 10 also eliminate particle motion inside the container 12 caused by gas movement and Brownian motion.
[0040] In the preferred embodiment, the mobile cart 22 is equipped with linear motion drive and a gate-type docking valve 23 designed to mate with a corresponding valve 24 on a robot chamber or processing tool 32 . During the docking process, the two valves are securely clamped together, forming a vacuum-tight seal. The small space located between the gate valves 23 , 24 is then evacuated by the SEME system 10 pumps. The initial pump-down of this space is accomplished by opening valves 15 and 25 to sorption pump 13 . The final (high vacuum) pump-down of the space is accomplished by opening valves 17 , 20 and 26 to the ion or turbo-molecular pump 18 . The two gate valves 23 , 24 are then opened to permit unloading/loading of wafers to the robot chamber or processing tool 32 .
[0041] Pressure gauges 33 are monitored by an on-board computer 27 . The computer 27 automatically controls the sequencing of the valves and pumps, and the regeneration of the sorption pumps 13 , 14 , while displaying the status of the system.
[0042] The sorption pumps 13 , 14 are charged with liquid nitrogen by opening valve 28 . The boiled-off gaseous nitrogen can be continuously vented through external vent valve 29 . Alternatively, the boiled-off gaseous nitrogen can be used as a pure, inert gas to re-pressurize (vent) the SEME container 12 or inter-gate valve space when necessary. This re-pressurization can be accomplished by closing the external vent valve 29 , and opening the internal vent valve 30 , along with valves 16 or 25 . Preferably, a purifier/filter unit 31 is located in an internal vent line 34 to further reduce contamination in the gaseous nitrogen.
[0043] A pure cylinder gas, stored onboard, or filtered ambient air can also be used to vent the container or the inter-gate valve space.
[0044] The container 12 can be re-pressurized at a controlled, slow rate while the SEME system 10 is in transport, without affecting the productivity of the processing tools 32 . Such controlled venting can be used to reduce the rate of particle re-suspension, shear-off, or “shedding”, well known to occur during high velocity or turbulent gas flow. The result is a lower concentration of suspended particulate contamination in the re-pressurized container 12 . The flow rate of gaseous nitrogen during internal venting is controlled by setting the flow resistance of the internal vent line. Flow resistance in the system 10 can be set using in-line orifices, metering valves, flow controllers, and other such devices (not shown) well known in the field of gas flow.
[0045] The boiled-off gaseous nitrogen released by the sorption pumps 13 , 14 can also be used under moderate pressure to operate pneumatically actuated valves in the SEME system 10 , or to operate a small gas turbine/generator (not shown). The generator would recharge the onboard battery 18 a used to operate the ion or turbomolecular pump 18 . When not in transit between processing stations, the SEME system 10 can be connected to a gaseous nitrogen vent line, an electrical power source to recharge the battery 18 a , and a liquid nitrogen source to recharge the sorption pumps.
[0046] A current trend in semiconductor fabrication is process sequence integration, where a sequence of processing steps such as plasma-enhanced chemical vapor deposition, etching, polishing, and physical vapor deposition from one tool vendor are guaranteed to produce a stack of thin films for device manufacturing. The SEME system 10 improves the throughput of this sequence by moving the wafers between processing tools 32 under vacuum, and without intermediate re-pressurization, thus allowing the tool 32 set to be considered as one virtual cluster tool. Operation in this way also reduces energy consumption associated with pressure cycling in loadlock chambers. Most tools can be configured to accept two SEME systems 10 simultaneously. If a vacuum process follows a photolithography step or wet processing step (performed at atmospheric pressure), the SEME system 10 permits controlled evacuation of the wafer container 12 as it moves through the fabrication area.
[0047] Continuous pumping of semiconductor substrate containers 12 , as performed by the SEME system 10 , provides continuous removal of released surface moisture and other contaminants that may be subsequently transferred into the tools. Such surface contaminants, which are slowly released from containers or substrates, are especially important in large area substrates, such as thin-film transistor flat panel displays. The SEME system 10 provides continuous pumping of wafer containers 12 to assist in removal of these contaminants without loss of processing time.
[0048] Previous methods for storing and transporting semiconductor substrates have attempted to control particle motion or accumulation of molecular contaminants within portable containers using static vacuum, continuous purge flow, or vapor drains. However, previous methods have not included capabilities for on-board, active vacuum pumping or controlled re-pressurization.
[0049] Consequently, previous methods cannot gradually and controllably adjust the internal pressure of the mobile container during transit to match that of the next processing station, while at the same time minimizing particle motion and preventing the gradual accumulation of molecular contaminants within the container.
[0050] Furthermore, previous methods cannot improve the productivity of substrate processing tools through elimination of the loadlock chamber pressure cycling step. The SEME system 10 accomplishes this productivity improvement by performing the pressure cycling during transit.
[0051] The SEME system can be essentially operated with liquid cryogenic nitrogen and uses low vibration vacuum pumps, such as sorption pumps or ion pumps. Such low vibration systems tend to release a minimum amount of particulate contamination onto substrate surfaces.
[0052] Although illustrated and described herein with reference to specific embodiments, the present invention nevertheless is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims without departing from the spirit of the invention. | A mobile, self-evacuating, micro-environment system for transit and storage of substrates between two or more processing chambers in the manufacture of semiconductor devices is provided where the system includes a mobile cart, a vacuum sealable container to hold the substrates, a vacuum source having a portable power source, located on the cart and capable of generating a vacuum in the container, and a docking valve to mate with a corresponding valve on each of the processing chambers, where the docking valve and the corresponding valve are securable to one another to form a substantially vacuum-tight seal and openable, while mated, to permit unloading and loading of substrates between the container and the processing chamber. A method of using the system is also provided. | 8 |
FIELD OF THE INVENTION
The present invention relates to a gear-jumping-proof positive-locking clutch.
BACKGROUND INFORMATION
Such a gear-jumping-proof positive-locking clutch is described in German Published Patent Application No. 1 101 172. This positive-locking clutch is used to connect a vehicle transmission shaft to an idler pulley rotatably mounted coaxially with the shaft. The positive-locking clutch includes an axially displaceable sliding sleeve having a bevel on which are supported locking balls which, due to a radial force component, can be displaced into radial depressions in the gear wheel with axial displacement of the sliding sleeve. When the positive-locking clutch is disengaged, the locking balls are arranged directly outside the depressions radially, i.e., in the same position axially as when engaged. Due to the resulting constantly present radial mobility of the locking bodies, this unfortunately results in transmission noise, which is perceived as unpleasant by occupants of the vehicle.
Furthermore, German Published Patent Application No. 39 30 173 describes a synchronizer device having a radially displaceable lock.
U.S. Pat. No. 5,651,435 describes a synchronizer unit with which a transmission shaft can be braked against the gearbox.
Furthermore, German Published Patent Application No. 198 39 154 describes a shiftable square-tooth clutch in which the loads on the square teeth in starting up are reduced. With this shiftable square-tooth clutch, one part of the clutch is provided with a spring force-loadable locking pin by which displacement of a locking ball out of a radial recess in a transmission shaft into an outer radial position is prevented when the clutch part is in an intermediate position. In this intermediate position, no torque transmitting connection is established between the second clutch part and an idler pulley to be coupled, i.e., the square-tooth clutch is in the disengaged position.
It is an object of the present invention to provide a gear-jumping-proof positive-locking clutch which does not cause any transmission noise when disengaged.
SUMMARY
The above and other beneficial objects of the present invention are achieved by providing a gear-jumping-proof positive-locking clutch as described herein.
One advantage of the present invention is that the locking roller elements, e.g., locking balls, may be pushed away from the radial recess, e.g., depression, due to an axial displaceability in the disengaged state of the positive-locking clutch without necessarily leaving their position on the periphery. Therefore, chattering of the balls in the axially displaced position is reliably suppressed because freedom of radial movement is no longer required in the area of the depression.
Furthermore, the lack of friction elements for transmission of torque results in a further noise reduction because the transmission chatter typical of synchronous rings is suppressed.
Roller elements of roller bearings may be used as the locking roller elements because they have high-quality material properties and are inexpensive despite the long lifetime associated therewith.
In one example embodiment of the present invention, the forces of inertia, axial forces and impacts on positive-locking clutch parts, e.g., in braking or accelerating the motor vehicle, may not result in disengagement of the positive-locking clutch. Therefore, the locking roller elements are supported primarily in the radial direction on the sliding sleeve when the positive-locking clutch is engaged. Consequently, forces originating from a transmission component to be coupled to the vehicle transmission shaft into the locking roller elements are supported on the sliding sleeve primarily in the radial direction and do not displace it axially due to the self-locking effect or the relatively low axial force component. Thus, the locking effect may be cancelled only by axial forces (or shifting forces) introduced directly into the sliding sleeve. Therefore, the area of contact of the sliding sleeve with the locking roller element extends parallel to the vehicle transmission shaft in the locked state. Thus, no axial forces are introduced from the locking roller element into the sliding sleeve.
In another example embodiment of the present invention, the radial force component for displacement of the locking roller element is established radially inward into the depression by an inexpensively manufactured bevel, e.g., inclined at 45°.
In another example embodiment of the present invention, a synchromesh body is connected in a rotationally fixed manner to the vehicle transmission shaft by a shaft-hub connection. Locking roller elements are arranged on it. This synchromesh body increases the diameter of the positive-locking clutch, so that when it is used, for example, for connection to idler pulleys arranged coaxially with the vehicle transmission shaft, it is possible to overcome the radial installation space which is to be reserved for the installation of the idler pulley. When using the present invention as a parking lock mechanism for locking the vehicle transmission shaft with respect to the gearbox, this makes is possible to overcome the radial installation space to be reserved for the installation of the transmission shaft in the gearbox.
In another example embodiment of the present invention, the locking roller element is guided inside a roller element support which is rotationally fixed and axially displaceable with respect to the vehicle transmission shaft. Thus, the locking roller element is always held in an axial or peripheral position and transmission noise such as chattering of the locking roller elements is largely suppressed. Furthermore, due to the roller element support, a small axial installation space is possible for the positive-locking clutch. The reason for this is the possibility of arranging the locking depression on the axial end of the synchromesh body or a vehicle transmission shaft shoulder without the locking roller element falling out of the positive-locking clutch. Due to the roller element support establishing the rotationally fixed connection between the vehicle transmission shaft and the transmission component, the locking roller elements are entirely free of the function of transmitting torque, which extends their service life.
In another example embodiment of the present invention, the positive connection between the vehicle transmission shaft and the transmission component is established by gearing which is responsible for the rotationally fixed and axially displaceable property of the supporting body with respect to the synchromesh body. Since the gearing thus assumes two different functions, it may have a different configuration on its end areas where the coupling occurs than in its middle area.
Another example embodiment of the present invention includes a parking lock mechanism. In the case of such a parking lock mechanism, the transmission shaft is locked with respect to the gearbox.
End gearing may be provided to connect the vehicle transmission shaft to the gearbox. In the case of such end gearings as a Hirth serration, an engagement angle which ensures that the parking lock mechanism may always be released is selected to avoid a self-locking effect when the parking lock mechanism is engaged, the necessary result being that the parking lock mechanism may not be released on a gradient. A combination with the positive-locking clutch according to the present invention may provide that the necessary axial force due to the inclined top, which increases with the gradient, may not result in the parking lock mechanism being released, regardless of the magnitude of the gradient.
Another example embodiment of the present invention may save axial installation space, where the transmission component fixed on the gearbox receives the bearing ring of the bearing for support of the transmission shaft. Thus, both the transmission component and the bearing ring may be arranged in one plane.
Another example embodiment of the present invention is easy to assemble and saves axial installation space, the bearing ring being provided directly with the gearing for fixed coupling of the vehicle transmission shaft to the gearbox.
Another example embodiment of the present invention is especially short in the axial direction, a single positive-locking clutch being provided for coupling two transmission components. The arrangement of the sliding sleeve between the reverse gear on and a parking lock mechanism may be provided, because with these two transmission components, it is possible to eliminate synchromesh bodies without any sacrifice in comfort.
In another example embodiment of the present invention, both transmission components may be locked.
Another example embodiment of the present invention is especially short in the axial direction, and the locking roller elements are arranged in alternation around the periphery. This arrangement creates the possibility of arranging the locking elements in one plane so that a correlation of one lock with one transmission component may be established entirely without any loss of axial space with respect to an example embodiment of the present invention having just one lockable transmission component.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a partial area of a vehicle transmission in which a vehicle transmission shaft having idler pulleys is arranged with a positive-locking clutch that may be shifted by a shift fork being arranged between them, this positive-locking clutch being arranged in symmetry with a plane of symmetry and includes:
a sliding sleeve; a locking roller element; a roller element support; two shift gearings, each assigned to one idler pulley; and a synchromesh body;
the positive-locking clutch illustrated in the neutral position.
FIG. 2 illustrates a partial area of the sliding sleeve and a locking roller element behind it illustrated FIG. 1 , the latter also being indicated with broken lines, like the concealed pan-shaped depressions in the sliding sleeve.
FIG. 3 is a cross-sectional view along a plane perpendicular to the longitudinal axis of the transmission shaft, illustrating:
the sliding sleeve; the locking roller element; the roller element support; and the synchromesh body;
which are illustrated partially in cross-section to illustrate the functioning of the locking roller elements.
FIG. 4 illustrates the partial area of the vehicle transmission illustrated in FIG. 1 , with the positive-locking clutch in an engaged state.
FIG. 5 illustrates a second example embodiment illustrating a partial area of a vehicle transmission having a positive-locking clutch which has an especially short roller element support in the axial direction, the positive-locking clutch being indicated with solid lines in a neutral position and with dash-dot lines in the engaged state.
FIG. 6 illustrates in the second example embodiment illustrated in FIG. 5 a partial area of the sliding sleeve with the locking roller elements behind it, with the latter being indicated with broken lines like the concealed pan-shaped depressions on the sliding sleeve.
FIG. 7 is a view in direction VII illustrated in FIG. 5 of a sectional plane perpendicular to the longitudinal axis of the transmission shaft and illustrates:
the sliding sleeve; the locking roller elements; the roller element support; and the synchromesh body;
both the locking roller element assigned to the first transmission component and the locking roller element assigned to the second transmission component being illustrated.
In a third example embodiment, FIG. 8 is a schematic view of a vehicle transmission having a positive-locking clutch arranged between an unsynchronized reverse gear and a parking lock mechanism.
FIG. 9 illustrates a partial area of a vehicle transmission having a positive-locking clutch corresponding to the schematic view illustrated in FIG. 8 in the neutral position.
FIG. 10 illustrates a partial area of the roller element support and a locking ring mounted fixedly on the gearbox illustrated in FIG. 9 .
FIG. 11 illustrates the parking lock mechanism illustrated in FIG. 9 in the engaged state, with the original neutral position of the shift fork indicated with dash-dot lines.
FIG. 12 is a detail view of the portion XIII illustrated in FIG. 11 .
FIG. 13 in a fourth example embodiment illustrates a partial area of a vehicle transmission having a parking lock mechanism with a positive-locking clutch in neutral position, a locking ring fixedly mounted on the gearbox receiving the bearing outer race of a bearing of the vehicle transmission shaft.
FIG. 14 in a fifth example embodiment illustrates a partial area of a vehicle transmission having a parking lock mechanism with a positive-locking clutch in neutral position, a locking ring fixedly mounted on the gearbox forming the bearing outer race of a tapered roller bearing of the vehicle transmission shaft.
DETAILED DESCRIPTION
FIG. 1 illustrates a partial area of a vehicle transmission in which a vehicle transmission shaft 1 is arranged with two idler pulleys 2 , 3 . A positive-locking clutch 62 which may be shifted by a shift fork 12 is arranged axially between these two idler pulleys 2 , 3 , this positive-locking clutch 62 being symmetrical with a plane of symmetry 63 and also including:
locking roller elements 15 a , 15 b , designed as conventional ball bearings; a roller element support 10 ; two shift gearings 25 a , 25 b , each assigned to one of the two idler pulleys 2 , 3 ; and a synchromesh body 5 .
The positive-locking clutch is illustrated in the neutral position in FIG. 1 , i.e., it is disengaged with respect to both idler pulleys 2 , 3 .
A plurality of idler pulleys are arranged so they may rotate by roller bearings coaxially with vehicle transmission shaft 1 of the vehicle transmission in a conventional manner, only two idler pulleys 2 , 3 being illustrated here as an example. Synchromesh body 5 is connected to vehicle transmission shaft 1 by a shaft-hub gearing 6 in a rotationally fixed manner in the peripheral direction. Furthermore, synchromesh body 5 is provided with an outer gearing 7 on the periphery extending in the axial direction, engaging with internal gearing 9 on roller element support 8 , thus establishing a rotationally fixed but axially displaceable connection. Roller element support 8 is arranged radially inside sliding sleeve 10 which has a concentric ring groove 11 on its outer circumference, engaging with shifter fork 12 which introduces axial forces/displacements in the conventional manner.
Several continuous bores 14 a , 14 b extending radially and distributed uniformly around the circumference are provided in roller element support 8 , arranged in two axially adjacent planes perpendicular to a transmission shaft axis 13 of vehicle transmission shaft 1 . One of two locking roller elements 15 a and 15 b is arranged so it is guided in these bores 14 a , 14 b , only two of which are illustrated. Locking roller elements 15 a , 15 b project radially beyond lateral surface 16 b of roller element bracket 8 in the disengaged condition of positive-locking clutch 62 which is illustrated in FIG. 1 , thus locking sliding sleeve 10 . For this purpose, sliding sleeve 10 has pan-shaped oval recesses 17 a , 17 b in which the exterior spherical areas of locking roller elements 15 a , 15 b which project beyond lateral surface 16 engage. Pan-shaped recesses 17 a , 17 b extend mainly axially as illustrated in detail in FIG. 2 . Pan walls 19 a , 19 b of the two pan-shaped recesses are configured with an inclination.
Two locking roller elements 15 a , 15 b rest on one tooth of external gearing 7 of synchromesh body 5 . On both of its axial ends, this tooth is provided with recesses 66 a , 66 b , the depth of which corresponds exactly to the radial depth of pan-shaped recesses 17 a , 17 b . A crown circle of the tooth leads over edges 64 a , 64 b and bevels 21 a , 21 b connected to them into recesses 66 a , 66 b . Bevels 21 a , 21 b , like pan walls 19 a , 19 b , form a 45° angle.
The functioning of positive-locking clutch 62 of the first example embodiment is explained below with reference to FIGS. 1 to 4 for the case when vehicle transmission shaft 1 is coupled with idler pulley 3 , referred to below as right idler pulley 3 according to the perspective illustrated. The functioning is explained in simplified terms on the basis of only two locking roller elements 15 a , 15 b as illustrated.
For positive-locking coupling, shift fork 12 is shifted to the right. Sliding sleeve 10 , which is supported axially on gear shift 12 , is therefore also shifted to the right. Then, due to the support of right locking element body 15 b on pan wall 19 b , roller element support 8 is also shifted to the right. In this shifting, left locking roller element 15 a remains essentially in the same axial position with respect to pan-shaped depression 17 a due to its being guided in bore 14 a , as long as perpendicular mid-plane 65 of the ball of right locking roller element 15 b does not go beyond edge 64 b . As soon as this edge 64 b has been crossed, locking roller element 15 b is shifted radially inwardly. Reactive forces act against locking roller element 15 b with this inward displacement:
on a left area of pan wall 19 b of right pan-shaped depression 17 b ; and on bevels 21 b of right recess 66 b ; and on a right wall area of bore 14 b of roller element support 8 .
After having reached a locked position in which pan edge 67 b axially crosses perpendicular mid-plane 65 of the ball, locking roller element 15 b has reached lower recess plane 18 b and no longer projects above outer lateral surface 16 of roller element support 8 . In this locked position, roller element support 8 comes to rest on a stop 75 b of shifting gearings 25 b . Sliding sleeve 10 is further displaceable due to right locking roller element 15 b which has “dropped.” Sliding sleeve 10 is further displaced up to an end position of the sliding sleeve in which a left area of left pan wall 19 a comes to rest against left locking roller element 15 a . As illustrated in FIG. 4 , before this contact of locking roller element 15 with the left area of left pan wall 19 a , pan edge 67 b is crossed to the right beyond mid-plane 65 of the ball up to an overshoot 99 , which is determined by the contact. The contact area of locking roller element 15 b with sliding sleeve 10 is in perpendicular mid-plane 65 of the ball. Sliding sleeve 10 is parallel with transmission shaft axle 13 in this contact area. Thus, in the end position of the sliding sleeve, forces may also be transmitted from the locking roller element to sliding sleeve 10 only perpendicularly to transmission shaft axis 13 . This reliably prevents external axial forces acting on locking roller element 15 b from causing positive-locking clutch 62 to become disengaged.
To release the clutch described here from right idler pulley 3 , i.e., to disengage it, sliding sleeve 10 is shifted axially to the left by using the shift fork. After initial displacement of sliding sleeve 10 alone, a right edge area of left pan wall 19 a of sliding sleeve 10 strikes against left locking roller element 15 a and thus entrains roller element support 8 toward the left. With increasing axial displacement of roller element support 8 , right locking roller element 15 b thus also rolls radially outward on bevel 21 b until edge 64 b is again crossed by perpendicular mid-plane 65 of the ball. Following this, sliding sleeve 10 is still displaceable into the neutral position together with roller element support 8 by a slight residual amount.
Both engaging and disengaging of left idler pulley 2 with transmission shaft 1 occur in a similar manner.
FIG. 5 illustrates in a second example embodiment a partial area of a vehicle transmission having a positive-locking clutch 162 having a roller element support 108 that is especially short axially. The axially displaceable components of positive-locking clutch 162 are indicated with solid lines in a neutral position and with dash-dot lines in an engaged position, i.e., with the clutch engaged. A few parts which are similar to those described in the first example embodiment are not described in greater detail below. Furthermore, additional parts similar to those in the first example embodiment are provided with reference characters that are increased by 100 in comparison with the reference characters used in the first example embodiment.
FIG. 6 illustrates a partial area of a sliding sleeve 110 and locking roller elements 115 a , 115 b behind it illustrated in FIG. 1 , the latter being indicated with broken lines along with concealed pan-shaped recesses 117 a , 117 b of sliding sleeve 110 . In order to save axial space as illustrated in FIG. 5 , both locking roller elements 115 a , 115 b assigned to locking a left idler pulley 102 as well as those assigned to locking a right idler pulley are arranged in the same plane in the disengaged position. Both sliding sleeve 110 and roller element support 108 as well as a synchromesh body 105 are configured to be shorter axially.
FIG. 7 is a view in direction VII illustrated in FIG. 5 illustrating a sectional plane perpendicular to the longitudinal axis of the transmission shaft, including:
sliding sleeve 110 ; locking roller elements 115 a , 115 b; roller element support 108 ; and synchromesh body 105 ;
also illustrating locking roller element 115 a assigned to left idler pulley 102 and locking roller element 115 b assigned to right idler pulley 103 .
FIG. 8 illustrates in a third example embodiment a schematic view of a parking lock having a positive-locking clutch 262 illustrated in FIG. 9 . This view corresponds to the movement sequence followed by a shift lever in manual operation. The view illustrates, in addition to conventional selection path 68 , a first shift path 69 for first and second gears and a second shift path 70 for third and fourth gears. Furthermore, this view illustrates a third shift path 71 between park “P” and reverse “R.” The shift fork lever is kinematically linked to a shift fork 212 illustrated in FIG. 9 so that movements of the shift fork lever along third shifting channel 71 necessarily lead to axial displacement of shift fork 212 .
FIG. 9 illustrates a partial area of a vehicle transmission having positive-locking clutch 262 in a neutral position, i.e., both a first idler pulley 202 assigned to reverse gear “R” and a locking ring 203 assigned to park “p” and rigidly mounted on the gearbox “R” uncoupled from vehicle transmission shaft 201 and may rotate relative to it. Parts similar to those in the first example embodiment are indicated by reference characters that are higher by 200.
Positive-locking clutch 262 which may be shifted by shift fork 212 is arranged axially between idler pulley 202 and locking ring 203 , this positive-locking clutch 262 including: locking roller elements 215 designed as conventional ball bearings;
roller element support 208 ; a shift gearing 225 a assigned to idler pulley 202 and a case gearing 225 b assigned to locking ring 203 ; and a synchromesh body 205 .
A plurality of idler pulleys are arranged so they may rotate by roller bearings coaxially with vehicle transmission shaft 201 of the vehicle transmission having a parking lock mechanism inherent in the transmission, idler pulley 202 which is provided for the reverse gear being illustrated as an example. Synchromesh body 205 is connected in a rotationally fixed manner in the peripheral direction to vehicle transmission shaft 201 by a shaft-hub gearing 206 . Furthermore, synchromesh body 205 is provided at the circumference with external gearing 207 which extends in the axial direction and meshes with internal gearing 209 of roller element support 208 , thus establishing a rotationally fixed but axially displaceable connection. Roller element support 208 is arranged on the inside radially of sliding sleeve 210 which has a concentric ring groove 211 engaging in the conventional manner with shift fork 212 which initiates axial forces/displacements.
A plurality of bores 214 distributed uniformly around the circumference and extending radially are provided in roller element support 208 and are in a plane perpendicular to a transmission shaft axis 213 of vehicle transmission shaft 201 . A locking roller element 215 is guided in these bores 214 , only one of which is illustrated. In the neutral position of positive-locking clutch 262 illustrated in FIG. 9 , locking roller elements 215 project radially beyond shifting body support 208 . Sliding sleeve 210 has a ring groove 217 on its inside, which is open on its side facing locking ring 203 . Locking roller elements 215 which project beyond an outer lateral surface 216 of roller element support 208 engage in this ring groove. Locking roller elements 215 are in contact with sliding sleeve 210 in the area of an inclined ring groove wall, i.e., a ring groove bevel 219 of ring groove 217 .
Sliding sleeve 210 is supported axially indirectly on roller element support 208 by a locking ring 282 in the direction pointing toward idler pulley 202 , i.e., to the left.
The tooth of external gearing 207 on which locking roller element 215 rests is in contact with a bevel 221 which leads into a radial recess 266 via an edge 264 .
Roller element support 208 is provided with an end gearing 240 which corresponds to gearbox gearing 225 b which is bolted to the gearbox. End gearing 240 and gearbox gearing 225 b form a pair of Hirth serrations.
The functioning of positive-locking clutch 262 of the third example embodiment is described below with reference to FIGS. 8 to 12 for the case when parking lock mechanism “P” is engaged from the neutral position. The functioning is explained in simplified terms on the basis of one locking roller element 215 illustrated.
Shift fork 212 is shifted to the right for positive-locking clutching or engagement of parking lock mechanism “P.” Sliding sleeve 210 which is supported axially on shift fork 212 is consequently also shifted to the right. Due to the support of locking roller element 215 on ring groove bevel 219 , roller element support 208 is then also shifted to the right. As soon as edge 264 which is illustrated in greater detail in FIG. 12 , is crossed by a ball mid-plane 265 of locking roller element 215 , locking element 215 is shifted radially inwardly. With this inward shift, reactive forces act on locking roller element 215 :
on ring groove bevel 219 of ring groove 217 ; and on bevel 221 of recess 266 ; and on a right bore wall area of roller element support 208 .
Depending on the angle of ring groove bevel 219 or bevel 221 , support element 208 begins to lag somewhat behind the displacement of sliding sleeve 210 . After a locked position in which ring groove edge 267 crosses over perpendicular mid-plane 265 of the ball, locking roller element 215 has reached a lower plane 218 of the depression and no longer projects above outer lateral surface 216 of supporting body 208 . After reaching this locked position of roller element support 208 in which a stop end position of end gearing 240 has been reached, there is only a slight displacement of sliding sleeve 210 to a sliding sleeve end position. In this sliding sleeve end position, sliding sleeve 210 comes to rest against a rear stop 284 arranged radially on the outside of end gearing 240 .
Contact of end gearing 240 with gearbox gearing 225 b is associated with a high force arising from the static torque, such as that which occurs in parking on a gradient, for example. Tooth flanks 245 and 246 are configured with a tooth angle α which is greater than a self-locking angle, thus reliably preventing jamming due to the support of the high torque. An axial reactive force which depends on the coefficient of friction between tooth flanks 245 and 246 and occurs due to the force arising from the static torque or tooth angle α and acts constantly when parking lock mechanism “P” is engaged does not lead to disengagement of positive-locking clutch 262 due to the lock. Disengagement of positive-locking clutch 262 is impossible because locking roller element 215 applies a normal force to sliding sleeve 210 in the radial direction due to an angle β of tooth 221 . This normal force is incapable of displacing the sliding sleeve in the axial direction.
In alternative arrangements of the third example embodiment illustrated in FIGS. 8 to 12 , the stop end position of the end gearing may be accomplished by contact of the tooth flanks or by contact of tip and root diameter planes of the end gearing.
FIG. 13 illustrates in a fourth example embodiment a partial area of a vehicle transmission having a parking lock mechanism which is engaged by a positive-locking clutch 362 . In contrast with the third example embodiment, a bearing outer race 381 of a roller bearing 380 of transmission shaft 301 is accommodated directly in a locking ring 303 which is immovably bolted to a gearbox.
FIG. 14 illustrates in a fifth example embodiment a partial area of a vehicle transmission having a parking lock mechanism which is engaged by a positive-locking clutch 462 .
A gearing 425 is brought directly onto an end face of a bearing outer race 481 of a tapered roller bearing 480 of transmission shaft 401 . Bearing outer race 481 is pinned immovably to the gearbox. The bearing outer race forms an angle which opens toward the inside of the gearbox, so that the axial force component acting on bearing outer race 481 constantly presses bearing outer race 481 against an axial contact surface of the gearbox.
In another example embodiment of the present invention, in order to-lock the positive-locking clutch in an engaged position only one ball is provided. Furthermore, in other example embodiments, any desired number of locking roller elements may be provided for locking in which case they are arranged symmetrically on the perimeter or in the case of an even number they may be arranged in diametric opposition to prevent tilting movements of the three components:
synchromesh body; roller element support; and sliding sleeve.
The locking roller elements may also be configured as cylindrical rollers or as barrel-shaped elements, for example.
In other example embodiments of the present invention, rocker arms are used instead of shift forks.
In other variants of the third example embodiment, the parking lock mechanism is operated with a shift fork assigned to a different gear than reverse gear. Depending on the type of shift actuators, among other things, the parking lock mechanism is engaged and disengaged by a final controller element assigned exclusively to it.
In other example embodiments, the pan walls or the bevels leading into the radial recesses have angles other than 45°.
In other example embodiments of the present invention, the bevel of the recess or the pan wall of the pan-shaped recess is configured as a concave or convex curve.
In another example embodiment, instead of the pan-shaped recess, a ring-shaped peripheral bevel is worked in the sliding sleeve. Furthermore, the sliding sleeve may also have any desired shapes, as long as they permit displaceability with respect to the roller element support and the synchromesh body in introducing a radial force component into the locking roller element. Shapes of the sliding sleeve which permit rotatability of the sliding sleeve with respect to the vehicle transmission shaft as well as shapes which permit a rotationally fixed but axially displaceable guidance with respect to the transmission shaft and the support body are possible.
The example embodiments described are merely examples of possible embodiments. A combination of the features described for different embodiments is also possible. Other features of the device parts belonging to the present invention, in particular features that are not described, may be derived from the geometric relationships of the device parts as illustrated in the Figures. | In a gear-jumping-proof positive-locking clutch for connecting a vehicle transmission shaft to a transmission component mounted coaxially and rotationally with it, the positive-locking clutch includes an axially displaceable sliding sleeve on which at least one locking roller element may be supported which is displaceable in a radial locking recess with axial displacement of the sliding sleeve due to a radial force component. In a gear-jumping-proof positive-locking clutch which does not cause any transmission noise when disengaged, the positive-locking clutch is free of synchromesh bodies and the locking roller element is axially displaceable. | 5 |
RELATED APPLICATIONS
[0001] This application claims priority benefit from U.S. Ser. No. 61/720,569, filed Oct. 31, 2012, entitled “Smart 3-Way Valve with High and Low Pressure Sensing,” which is incorporated by this reference herein in its entirety. This application expressly incorporates by reference U.S. Pat. No. 8,043,313, issued Oct. 25, 2011, and U.S. patent application Ser. No. 12/564,892, filed on Sep. 22, 2009, the contents of which are incorporated by this reference as if fully set forth herein, in their entirety, along with U.S. Pat. No. 8,298,252, issued Oct. 30, 2012, along with U.S. patent application Ser. No. 13/644,022 filed on Oct. 3, 2012 and U.S. patent application Ser. No. 13/655,688 filed on Oct. 19, 2012, all owned by a common assignee, along with full Paris Convention priority.
BACKGROUND OF THE DISCLOSURE
[0002] Angioplasty (percutaneous transluminal angioplasty (PTA) or percutaneous transluminal coronary angioplasty (PTCA) is a procedure that is used to dilate occluded vessels in the vascular system. The procedure typically consists of multiple steps. First, an introducer sheath is placed in the patient to provide a point of access for catheter placement. Once access has been obtained, sometimes a guiding catheter is placed in to the vessel near the occlusion and injected with an x-ray sensitive dye (contrast) that is to be infused into the blood stream. The contrast can also be injected through the introducer sheath depending on the location of the occlusion relative to the introducer sheath. The farther the distance the more likely a guiding catheter will be used to facilitate localizing the contrast for improved image quality and to minimize the amount of contrast for patient safety.
[0003] The contrast is viewed under a fluoroscope as it travels through the blood stream to identify the block or constricted vessel. After the location of the blockage is identified, the guiding catheter is extracted and replaced with an angioplasty balloon catheter used to dilate the vessel. The standard angioplasty balloon catheter is constructed with a high-pressure, non-compliant balloon on the distal tip and a means for inflating the balloon on the proximal end. This catheter is inserted into the introducer sheath and guided into position by radiopaque marker bands on the catheter shaft. Once the catheter is appropriately placed at the point of the blockage, the balloon is inflated at high pressure using an inflation syringe (insufflator) to dilate the vessel. After dilation the catheter is extracted and the guiding catheter is once again placed into the vessel to inject the contrast to confirm the blockage has been fully opened.
[0004] Inflation syringes are available, for example, Taut® System One, Teleflex Medical, Research Triangle Park, N.C.; Medflator®, Smiths Medical, St. Paul, Minn.; Basix Compak®, Merit Medical, South Jordan, Utah. Insufflation devices for inflating angioplasty balloons have been described (see, e.g., Miley et al (2011) Neurosurgery. 69:ons161-ons168). Inflation syringe or insufflator may be configured to deliver pressure in the range of 0-25 atmospheres. Processes for delivering inflation media, diagnostic agents, therapeutic agents to a vascular lumen (or other lumen in the body) or to a balloon, by way of syringe and catheter, are disclosed by U.S. Pat. No. 8,043,313 of Krolik et al, and of U.S. Pat. No. 8,298,252 of Krolik et al, where are each incorporated by reference in their entirety. Therapeutic agent can include agent to reduce re-stenosis, such as anti-proliferative drug (see, e.g., U.S. Ser. No. 13/644,022 of Krolik, which is incorporated herein in its entirety).
[0005] Some physicians prefer to measure the intravascular pressure before and after the dilatation of the vessel. This measurement can be achieved by using disposable pressure transducers connected to the balloon catheter's inner lumen, which is exposed to the bloodstream. This technique allows for a more precise method of measuring the performance of the angioplasty procedure.
SUMMARY OF THE DISCLOSURE
[0006] Briefly stated, the disclosure provides apparatus and methods for managing delivery of fluid into a vessel. A balloon catheter with a 3-way valve is introduced into an occluded vessel. The 3-way valve permits fluid, such as a contrast dye, to be injected into the vessel lumen. The valve is also configured to permit the balloon portion of the catheter to be inflated by means of the same lumen used to inject the contrast dye into the vessel. Bloodstream pressure can also be measured before and after dilation to confirm the procedure was successful. This apparatus and method provides for a quick, safe, and reliable treatment of an occluded vessel, among other things and works with known and later developed systems.
[0007] The disclosure provides a valve unit configured for directing a high pressure fluid to a balloon that comprises a balloon lumen, and configured for directing low pressure fluid to a vascular lumen, the valve unit comprising: (i) a 3-way valve operably linked with a high pressure fluid port, a low pressure fluid port, and an exit port; and (ii) a high pressure fluid input port, a low pressure fluid port, and an exit port; wherein the 3-way valve has a first position that is configured to receive the high pressure fluid via the high pressure fluid port, wherein the 3-way valve has a second position that is configured to receive the low pressure fluid via the low pressure fluid port, wherein the 3-way valve is configured to transmit the high pressure fluid to the exit port, and is configured to transmit the low pressure fluid to the exit port; and wherein the valve has a third position that is configured to simultaneously prevent flow of high pressure fluid from the high pressure fluid port to the exit port and flow of low pressure fluid from the low pressure port to the exit port, (iii) a high pressure sensor that detects pressure of the high pressure fluid, wherein the high pressure sensor is segregated from and not exposed to the low pressure fluid; and (iv) a low pressure sensor that detects pressure of the low pressure fluid, wherein the low pressure sensor is segregated from and not exposed to the high pressure fluid.
[0008] What is also provided is the above valve unit that does not comprise a balloon.
[0009] Also provided is the above valve unit, wherein the balloon is an angioplasty balloon.
[0010] What is also embraced, is the above valve unit, wherein the low pressure sensor is located upstream of the 3-way valve, or wherein the high pressure sensor is located upstream of the 3-way valve, or wherein the low pressure sensor is located upstream of the 3-way valve, and the high pressure sensor is located upstream of the 3-way valve.
[0011] Moreover, what is also provided is the above valve unit, wherein the low pressure sensor, the high pressure sensor, or both the low pressure sensor and the high pressure sensor are located in the valve body of the 3-way valve.
[0012] Further contemplated is the above valve unit, wherein the low pressure fluid comprises a contrast agent, a therapeutic agent, or a contrast agent and a therapeutic agent.
[0013] In an embodiment that includes a catheter and longitudinally-moving valve, the present disclosure provides the above valve unit, further comprising: (i) an outer catheter body that comprises a proximal end, a distal end, and an outer catheter body lumen extending between the proximal and distal end, wherein the outer catheter body defines a first longitudinal axis; (ii) an inner catheter body (inner shaft) that resides, at least in part, in the outer catheter body lumen, wherein the inner catheter body defines a second longitudinal axis, and wherein the first longitudinal axis is parallel to the second longitudinal axis, wherein the inner catheter body comprises a proximal end and a distal end, wherein the inner catheter body distal end comprises a longitudinally-moving valve that (A) is capable of forming a sealed contact with the outer catheter body distal end, wherein the sealed contact prevents fluid flow from the outer catheter body lumen to a vascular lumen, and (B) is also capable of forming an unsealed gap with the outer catheter body distal end, wherein the unsealed gap allows fluid flow from the outer body lumen to the vascular lumen; (iii) wherein the inner catheter body distal end comprises an inflation lumen, wherein the inflation lumen comprising a third longitudinal axis that is parallel to the first and second longitudinal axes, wherein the inflation lumen passes through the longitudinally-moving valve, and is configured to allow high pressure fluid to pass through the inflation lumen when the longitudinally-moving valve is in sealed contact with the distal end of the outer catheter body.
[0014] Also provided is the above valve unit, further comprising a thumb slide that is operably linked to the 3-way valve, wherein the thumb slide is configured to control the 3-way valve to allow either passage of the high pressure fluid to the exit port, or passage of the low pressure fluid to the exit port.
[0015] Moreover, what is also provided is the above valve unit, that comprises a thumb slide that is operably linked to a longitudinally-moving valve, wherein proximal-to-distal movement of thumb slide, opens longitudinally-moving valve, and distal-to-proximal movement of thumb slid closes longitudinally-moving valve.
[0016] In an embodiment that includes a thumb slide that can control the 3-way valve, the longitudinally-moving valve, or both, the present disclosure provides the above valve unit that comprises a thumb slide, wherein the thumb slide is: (i) operably linked to the 3-way valve, wherein the thumb slide is configured to control the 3-way valve to allow either passage of the high pressure fluid to the exit port, or passage of the low pressure fluid to the exit port, and (ii) operably linked to the longitudinally-moving valve, wherein proximal-to-distal movement of thumb slide, opens longitudinally-moving valve, and distal-to-proximal movement of thumb slid closes longitudinally-moving valve.
[0017] Also provided is the above valve unit, further comprising a low pressure fluid syringe, an insufflator, or both a low pressure fluid syringe and an insufflator. Also provided is the above valve unit, further comprising a display that is capable of displaying the pressure detected by the low pressure sensor and by the high pressure sensor. Further provided is the above valve unit, further comprising the high pressure fluid, the low pressure fluid, or both the high pressure fluid and the low pressure fluid.
[0018] Also provided is the above valve unit, that is configured for controlling the flow and transmission of a high pressure fluid that is under a pressure of at least 30 atmospheres (atm). Moreover, what is also provided is above valve unit, further comprising an angioplasty balloon that is operably linked with the high pressure fluid port.
[0019] In another aspect, what is provided is above valve unit, further comprising an angioplasty balloon that is operably linked with the high pressure port and with the inflation lumen.
[0020] Also embraced, is above valve unit, further comprising: (i) an insufflator or high pressure syringe, and (ii) a low pressure syringe.
[0021] In a method of use embodiment, the disclosure provides a method for dilating a vessel to treat an occlusion of the vessel, the method comprising the steps of: providing an apparatus comprising the 3-way valve unit that is described above, wherein the 3-way valve unit further comprises an angioplasty balloon operably linked with the high pressure port and inflation lumen, and wherein the angioplasty balloon is downstream of the inflation lumen, introducing the inner catheter body (inner shaft) into the vessel; injecting a low pressure fluid that comprises a contrast dye through the inflation lumen into the vessel; directing the inner catheter body (inner shaft) to the occlusion; and inflating the balloon by injecting a high pressure fluid that is an inflation fluid through the inflation lumen to dilate the vessel at the occlusion.
[0022] Also provided is the above method, wherein all of the steps can be performed without needing to remove any portion of the apparatus from the vessel.
[0023] Another method that is provided, is a method for dilating a vessel to treat an occlusion of the vessel, the method comprising the steps of: Step 1 . Providing a valve unit configured for directing a high pressure fluid to a balloon that comprises a balloon lumen, and configured for directing low pressure fluid to a vascular lumen, the valve unit comprising: (i) a 3-way valve operably linked with a high pressure fluid port, a low pressure fluid port, and an exit port; and (ii) a high pressure fluid input port, a low pressure fluid port, and an exit port; wherein the 3-way valve has a first position that is configured to receive the high pressure fluid via the high pressure fluid port, wherein the 3-way valve has a second position that is configured to receive the low pressure fluid via the low pressure fluid port, wherein the 3-way valve is configured to transmit the high pressure fluid to the exit port, and is configured to transmit the low pressure fluid to the exit port; and wherein the valve has a third position that is configured to simultaneously prevent flow of high pressure fluid from the high pressure fluid port to the exit port and flow of low pressure fluid from the low pressure port to the exit port, (iii) a high pressure sensor that detects pressure of the high pressure fluid, wherein the high pressure sensor is segregated from and not exposed to the low pressure fluid; (iv) a low pressure sensor that detects pressure of the low pressure fluid, wherein the low pressure sensor is segregated from and not exposed to the high pressure fluid; (v) an outer catheter body that comprises a proximal end, a distal end, and an outer catheter body lumen extending between the proximal and distal end, wherein the outer catheter body defines a first longitudinal axis; (vi) an inner catheter body (or inner shaft) that resides, at least in part, in the outer catheter body lumen, wherein the inner catheter body defines a second longitudinal axis, and wherein the first longitudinal axis is parallel to the second longitudinal axis, wherein the inner catheter body comprises a proximal end and a distal end, wherein the inner catheter body distal end comprises a longitudinally-moving valve that (A) is capable of forming a sealed contact with the outer catheter body distal end, wherein the sealed contact prevents fluid flow from the outer catheter body lumen to a vascular lumen, and (B) is also capable of forming an unsealed gap with the outer catheter body distal end, wherein the unsealed gap allows fluid flow from the outer body lumen to the vascular lumen; (vii) wherein the inner catheter body distal end comprises an inflation lumen, wherein the inflation lumen comprising a third longitudinal axis that is parallel to the first and second longitudinal axes, wherein the inflation lumen passes through the longitudinally-moving valve, and is configured to allow high pressure fluid to pass through the inflation lumen when the longitudinally-moving valve is in sealed contact with the distal end of the outer catheter body, wherein the 3-way valve unit further comprises an angioplasty balloon operably linked with the high pressure port and inflation lumen, and wherein the angioplasty balloon is downstream of the inflation lumen; Step II. Introducing the inner catheter body (inner shaft) into the vessel; Step III. Injecting a low pressure fluid that comprises a contrast dye through the inflation lumen into the vessel; Step IV. Directing the inner catheter body (inner shaft) to the occlusion; and Step V. Inflating the balloon by injecting a high pressure fluid that is an inflation fluid through the inflation lumen to dilate the vessel at the occlusion; wherein all of the steps can be performed without needing to remove any portion of the apparatus from the vessel.
[0024] The disclosure also provides the following device. What is provided is a valve unit configured for directing a high pressure fluid to a balloon that comprises a balloon lumen, and configured for directing low pressure fluid to a vascular lumen, the valve unit comprising: (i) a 3-way valve operably linked with a high pressure fluid port, a low pressure fluid port, and an exit port; and (ii) a high pressure fluid input port, a low pressure fluid port, and an exit port; wherein the 3-way valve has a first position that is configured to receive the high pressure fluid via the high pressure fluid port, wherein the 3-way valve has a second position that is configured to receive the low pressure fluid via the low pressure fluid port, wherein the 3-way valve is configured to transmit the high pressure fluid to the exit port, and is configured to transmit the low pressure fluid to the exit port; and wherein the valve has a third position that is configured to simultaneously prevent flow of high pressure fluid from the high pressure fluid port to the exit port and flow of low pressure fluid from the low pressure port to the exit port, (iii) a high pressure sensor that detects pressure of the high pressure fluid, wherein the high pressure sensor is segregated from and not exposed to the low pressure fluid; (iv) a low pressure sensor that detects pressure of the low pressure fluid, wherein the low pressure sensor is segregated from and not exposed to the high pressure fluid; (v) an outer catheter body that comprises a proximal end, a distal end, and an outer catheter body lumen extending between the proximal and distal end, wherein the outer catheter body defines a first longitudinal axis; (vi) an inner catheter body (or inner shaft) that resides, at least in part, in the outer catheter body lumen, wherein the inner catheter body defines a second longitudinal axis, and wherein the first longitudinal axis is parallel to the second longitudinal axis, wherein the inner catheter body comprises a proximal end and a distal end, wherein the inner catheter body distal end comprises a longitudinally-moving valve that (A) is capable of forming a sealed contact with the outer catheter body distal end, wherein the sealed contact prevents fluid flow from the outer catheter body lumen to a vascular lumen, and (B) is also capable of forming an unsealed gap with the outer catheter body distal end, wherein the unsealed gap allows fluid flow from the outer body lumen to the vascular lumen; (vii) wherein the inner catheter body distal end comprises an inflation lumen, wherein the inflation lumen comprising a third longitudinal axis that is parallel to the first and second longitudinal axes, wherein the inflation lumen passes through the longitudinally-moving valve, and is configured to allow high pressure fluid to pass through the inflation lumen when the longitudinally-moving valve is in sealed contact with the distal end of the outer catheter body. What is also provided is the above valve unit that does not comprise a balloon.
[0025] Briefly stated, the instant disclosure reduces the number of steps required to complete the angioplasty procedure, among others. A specialized catheter (GPS OATH® available from Teleflex Medical, Inc., Reading, Pa.) utilizes a 3-way injection valve which gives the balloon catheter the ability to inject contrast at the proximal end of the balloon as well as utilize the lumen to inflate the balloon. This advancement significantly reduces procedural time and the amount of contrast required to identify the blockage.
[0026] According to embodiments, the 3-way valve allows any catheter to be placed in a vessel in proximity to the occlusion where contrast can be injected into the bloodstream to locate the exact location of the occlusion. The valve is switched to an inflation position such that the balloon is inflated to dilate the vessel. At any point during the process, pressure transducers can be used to measure the bloodstream pressure, contrast fluid pressure, or the inflation fluid pressure.
[0027] While there are many inflation syringes on the market that incorporate a pressure gauge/ sensor for monitoring high balloon inflation pressure, such syringes are commonly fitted with an analog gauge and, in some cases, a digital readout on the distal end of the syringe body. Since the development of the Hotspur GPS CATH in conjunction with its VisioValve® (Arrow International, Reading, Pa.), a new design incorporating a means for measuring both high and low pressures integrated with a 3-way stopcock is both timely and effective. This new design will allow precise pressure measurement of both high inflation pressure for the balloon (0-30 ATM) and low pressure measurement (0-300 mm Hg) for contrast injection into the blood stream/blood pressure measurement, inter alia. In the present disclosure, the term “3-way stopcock” is synonymous with the term, “3-way valve,” unless expressly stated otherwise, or unless dictated otherwise by the context.
[0028] The present invention could be integrated onto the distal end of an inflation syringe barrel or be provided as a standalone device containing ports for connecting both the insufflator and contrast syringe. The proposed method allows a physician to use a single insufflator and balloon catheter to measure both intra-balloon and intravascular pressure.
[0029] According to embodiments, there is disclosed an apparatus for the treatment of an occluded vessel comprising: a catheter with a proximal end and a distal end and a lumen extending between the proximal and distal end; a balloon disposed on the distal end of the catheter; and, at least a valve; wherein the at least a valve is configured to permit a first fluid to be introduced into the occluded vessel through the lumen and inflation of the balloon by injecting a second fluid through the lumen.
[0030] According to embodiments, there is disclosed a valve comprising: an exit port; one or more input ports; and a mechanism capable of switching between more than one stage such that multiple fluids may enter a conduit through the exit port from the one or more input ports.
[0031] According to embodiments, there is disclosed a method for dilating a vessel to treat an occlusion of the vessel, the method comprising the steps of: providing an apparatus comprising a catheter having at least a valve with a proximal end and a distal end and a lumen extending between the proximal and distal end, and a balloon disposed on the distal end of the catheter; introducing the catheter into the vessel; injecting a contrast fluid through the lumen into the vessel; directing the catheter to the occlusion; and inflating the balloon by injecting an inflation fluid through the lumen to dilate the vessel at the occlusion.
DETAILED DESCRIPTION
[0032] The present disclosure encompasses all possible combinations of the above embodiments, and encompasses all possible disclosures of each independent claim with its dependent claims. For example, what is encompassed is an invention that is the combination of: Claim 1 +Claim 2 ; or the combination of: Claim 1 +Claim 2 +Claim 3 ; or the combination of Claim 1 +Claim 3 +Claim 4 ; or the combination of Claim 1 +Claim 2 +Claim 3 +Claim 4 ; and the like.
[0033] As used herein, including the appended claims, the singular forms of words such as “a,” “an,” and “the” include their corresponding plural references unless the context clearly dictates otherwise. All references cited herein are incorporated by reference to the same extent as if each individual publication, patent, and published patent application, as well as figures and drawings in said publications and patent
[0034] The terms “adapted to,” “configured for,” and “capable of,” mean the same thing. Where more than one of these terms are used in a claim set, it is the case that each and every one of these terms, as they might occur, means, “capable of.”
BRIEF DESCRIPTIONS OF THE FIGURES
[0035] FIG. 1 shows a schematic of embodiments of the instant teachings.
[0036] FIGS. 2A and 2B show a 3-way valve unit. FIG. 2A show ports, and FIG. 2B show internal channels.
[0037] FIG. 3A and FIG. 3B each disclose a valve in open position, resulting in delivery of contrast fluid to vascular lumen. FIG. 3C and FIG. 3D each disclose a valve in closed position, resulting in inflation of balloon.
[0038] FIGS. 4A and 4B illustrate a thumb controller. FIG. 4A show an assembled thumb controller, and FIG. 4B show a blow-up of the thumb controller.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0039] The inventors have developed and discovered novel systems, methods, and designs, relating to smart 3-way valves. The apparatus disclosed herein includes a balloon catheter and a 3-way valve. The particular type of catheter to be used with the valve is the GPS OATH® from Hotspur. This balloon catheter is configured so that in one state fluid introduced into its lumen will enter the vessel and in another state fluid will inflate the balloon to dilate the vessel. The advantage to such a catheter is that separate catheters do not need to be used to perform these separate tasks. Likewise, inflation and pressure measurement are seamlessly linked. The present disclosure encompasses valves, such as those of U.S. Pat. No. 8,043,313 of Krolik et al, which is hereby incorporated by reference in its entirety.
[0040] The term “downstream” refers to the direction of flow of a fluid or gas in a tube, conduit, hose, or through a component of a medical device, during ordinary or typical clinical use. Unless specified otherwise, or unless dictated otherwise by context, “downstream” does not refer to the direction of flow of a fluid or gas during non-typical uses, such as during experimental testing or during cleaning of the medical device, where test solutions and cleaning solutions might be used in a direction that is the reverse of the direction in ordinary and typical clinical use.
[0041] In embodiments, low pressure sensor, high pressure sensor, or both sensors, are mounted in a position downstream of couplers that are associated with low pressure fluid port and high pressure fluid port, respectively. In another embodiment, low pressure sensor, high pressure sensor, or both sensors, are mounted in a position upstream of the 3-way valve. Alternatively, the low pressure sensor, high pressure sensor, or both sensors are mounted inside the 3-way valve, where the position of mounting is in a location that segregates the low pressure valve from contact with high pressure fluid, and that segregates the high pressure valve from contact with low pressure fluid. In an alternative embodiment, low pressure sensor, high pressure sensor, or both low pressure sensor and high pressure sensor, are mounted upstream of the low pressure port and high pressure port, respectfully, where this mounting is by way of a snap-on module, or a permanently attached module that is exterior to the 3-valve unit, or attached to tube or hose that leads from insufflator to valve unit, or attached to tube or hose that leads from low pressure syringe to valve unit.
[0042] Also, the sensor(s) need to be connected to circuit board (most likely surface mounted). Regarding hoses, tubes, pipes, extension lines, and such, these require the ability to tolerate at least 30 ATM of pressure, at least 35 ATM, at least 40 ATM, at least 50 ATM, at least 60 ATM, at least 70 ATM, at least 80 ATM, and so on. In embodiments, the hoses are braid reinforced. In exclusionary embodiments, the present disclosure excludes a medical device, such as a valve or catheter, that is not able to tolerate greater than 30 ATM, that is not able to tolerate greater than 28 ATM, that is not able to tolerate greater than 26 ATM that is not able to tolerate greater than 25 ATM, that is not able to tolerate greater than 20 ATM, that is not able to tolerate greater than 15 ATM, and so on.
[0043] In a non-limiting embodiment, the low pressure sensor is damaged when exposed to fluids at pressures greater than 5 atm, greater than 10 atm, greater than 15 atm, greater than 20 atm, greater than 25 atm, greater than 30 atm, and so on. In embodiments, damage occurs with exposure to a fluid under a given pressure for at least 5 seconds, at least 10 seconds, at least 20 seconds, at least 1 minute, at least 2 min, at least 5 min, at least 10 min, at least 20 min, at least 60 min, at least 2 hours, at least 5 hours, at least 10 hours, and so on.
[0044] Damage can be assessed, for example, by data demonstrating that the readings given by the low pressure sensor, when used to measure a low pressure fluid, are inaccurate. An inaccurate reading, for example, can be a reading that is greater than 5% greater than the true reading, greater than 10%, greater than 20%, greater than 50%, greater than 100%, greater than 2-fold, than the true reading, and the like. Also, an inaccurate reading can be one that is less than 95% of the true reading, less than 90%, less that 80%, less than 70%, less than 60%, less than 50%, less than 20%, and so on. An inaccurate reading can be one where the low pressure sensor is damaged to the point where it fails to provide any reading.
[0045] The following concerns the use of the terms “high pressure fluid” and “low pressure fluid.” These terms refer to fluid from the insufflator and from the syringe, respectfully, usually without regard to the actual pressure of these fluids. For example, where the pressure of the “high pressure fluid” is ramping up, and where its pressure transitions from a relatively low pressure such as atmospheric pressure, to two or three atmospheres, then to 15 or 20 atmospheres, and finally to 25 atmospheres or greater, it is always the case that the same fluid is the “high pressure fluid,” unless expressly stated otherwise, or unless dictated otherwise by the context.
[0046] Braid reinforced hoses and tubing are available, for example, with braid construction of 2-24 French outer diameter, with braids made of steel, polyester, nylon, nitrinol, and the like, with braids made in the form of round wire or flat wire, with jacket made of PE, PEBA, polyurethane, nylon, with liner made of PTFE, FEP, PE, PEBA, polyurethane, nylon, and so on (Teleflex Medical OEM, Research Triangle Park, N.C.; Merit Medical OEM, South Jordan, Utah; Argon Medical Devices, Plano, Tex.). The present disclosure also provides hoses, tubing, and other components of medical devices, that are rated for high pressure fluids, that do not use braid constructions.
[0047] The 3-way valve of the present disclosure is operably linked with a catheter that contains two lumens, one lumen for inflating balloon and the other lumen for delivering a fluid, such as a contrast dye or a therapeutic agent, to the blood vessel lumen. The 3-way valve is housed in a 3-way valve unit, where the unit also includes pressure sensors.
[0048] What is included in the 3-way valve unit, is a low pressure sensor for sensing pressure in the lumen of the bloodstream, for example, in the vicinity of an occlusion, and a high pressure sensor, for sensing pressure in the angioplasty balloon. Both pressure sensors are inside the 3-way valve unit, and are in hydraulic communication with the lumen of the bloodstream, and in hydraulic communication with the interior of the balloon.
[0049] In alternate embodiments, what is provided is a catheter with more than two lumens, for example, with three, four, or more lumens. In alternative embodiments, what is provided is more than two pressure monitors, for example, three, four, or more pressure monitors, each sensitive to a different region inside, or a different region outside, of the catheter and associated structures.
[0050] In exclusionary embodiments, what can be excluded is a device that has only one pressure sensor, or more than two pressure sensors, and so on. In exclusionary embodiments, what can be excluded is a device that has only one lumen, or that has more than two lumens, and the like.
[0051] To further reduce the time required to perform the procedure, a valve system has been developed to allow multiple injection means to be attached simultaneously to the valve. In turn, these injection means do not need to be switched in and out for each other when a different fluid needs to be injected into the catheter.
[0052] According to embodiments, the at least a valve uses a smart 3-way stopcock in one embodiment. According to embodiments a valve includes 3 ports. The balloon catheter, an insufflator, and a syringe are attached to the ports. The insufflator is used to inflate the balloon and the syringe may be filled with any desired fluid, such as a contrast dye or therapeutic fluid. The user may switch the valve between different positions such that the fluid path is either from the insufflator, the syringe, or closed entirely. Other valve means known in the art are also within the scope of this invention.
[0053] According to embodiments, pressure sensors are located in relation to each fluid path. According to embodiments, a high pressure sensor is used to measure the pressure of the balloon upon inflation. A low pressure sensor is used to measure blood pressure or the fluid pressure from the syringe. The valve isolates these sensors from each other to allow for accurate readings of each.
[0054] According to embodiments, the valve includes an LCD screen (liquid crystal display) to display various data to the user, such as pressure, position of the valve, and any other desirable information. LED lights (light emitting diode) on the valve indicate the position of the stopcock. One light will turn on to indicate the fluid path from the syringe is in the open position. Another light is used to indicate the fluid path from the insufflator is in the open position. The valve may also include an audible tone, additional LED light, and/or LCD image display to alert the user that an out of range or maximum pressure has been reached in relation to the pressure sensors.
DETAILED DESCRIPTIONS OF THE FIGURES
[0055] FIG. 1 is a schematic diagram showing the Hotspur GPS CATH® along with the necessary components for inflating balloon ( 101 ), injecting contrast and 3-way stopcock ( 103 ) for switching the fluid paths between inflation syringe ( 105 ) and contrast filled syringe ( 111 ), is shown. With this configuration only balloon inflation pressure can be acquired. An alternate configuration (not shown) used by some clinicians eliminates the need for the 3-way stopcock. When using this alternate method inflation syringe ( 105 ) and/or contrast filled syringe ( 111 ) is connected directly to the Hotspur GPS CATH but requires the clinician to switch syringes pending the procedure step; balloon inflation or contrast injection. This is costly and time-consuming for clinicians and this has not been indicated to be preferred.
[0056] FIG. 1 also shows contrast dye ( 112 ) in contrast syringe ( 111 ), inflation device ( 20 ), thread lock ( 21 ), LED to indicate flow path (red/green) ( 22 ), luer connection ( 23 ), low pressure sensor ( 24 ), LED display ( 25 ) that displays balloon pressure, blood pressure, time, and the like, luer connection ( 26 ), 3-way valve ( 27 ), high pressure sensor ( 28 ), 50% saline/contrast ( 29 ), balloon ( 101 ), 3-way stopcock ( 103 ), and inflation syringe ( 105 ). The figure shows devices from, e.g., the Cardiac Care division of Teleflex Medical, Inc., of S.C., Hotspur GPS CATH, inflation syringe, 3-way stopcock, and contrast syringe.
[0057] FIG. 2 is a schematic of a standalone device ( 103 ) integrated with a smart 3-way stopcock. According to embodiments, a standard inflation syringe and contrast syringe are used in conjunction with the device. Standalone device ( 103 ) incorporates all the features as Design 1 with the exception of the insufflator. In this design the insufflator will not be part of the device but supplied separately. Contrast ( 30 ), balloon inflation ( 31 ), P 1 ( 32 ), P 2 ( 33 ), 3-way ( 34 ), and board/electronics ( 35 ), are shown. Port ( 30 ) is low pressure port, for receiving fluid from contrast dye syringe. Port ( 31 ) is port for the insufflator. Exit port ( 32 ) leads directly to a catheter, that is, a balloon angioplasty catheter. FIG. 2A shows ports, and FIG. 2B shows internal channels. The 3-way valve unit, which contains 3-way stopcock or valve, is integrated with other components, to include, e.g., Hotspur® GPS CATH, inflation syringe, and contrast syringe.
[0058] FIG. 3A and FIG. 3B shows valve in open position, resulting in delivery of contrast fluid to vascular lumen. FIG. 3C and FIG. 3D shows valve in closed position, resulting in inflation of balloon. In the open position, the figures show that the longitudinally-moving valve ( 204 ) forms a gap ( 206 ), where this configuration allows low pressure fluid to enter the vascular lumen. In the closed position, the figures show that the longitudinally-moving valve ( 204 ) forms a seal ( 213 ) that prevents low pressure fluid from entering the vascular lumen and directs high pressure fluid to the balloon ( 205 ). Vascular lumen is indicated by ( 214 ).
[0059] Thumb controller ( 200 ) is operably linked to inner shaft ( 208 ). Handle ( 201 ) is configured for holding by a clinician. Outer catheter body ( 202 ) defines outer catheter lumen, where the outer catheter lumen is configured to direct flow of low pressure fluid (contrast dye; therapeutic agent) to vascular lumen ( 214 ). Inflation lumen ( 203 ) traverses longitudinally-moving valve ( 204 ). The inflation lumen ( 203 ) directs high pressure fluid to balloon ( 205 ).
[0060] In another non-limiting embodiment, diameter of inflation lumen ( 203 ) is small and similar to that of a capillary tube, and does not readily facilitate passage of fluids unless the fluids are under a relatively high pressure. Longitudinally-moving valve ( 204 ) is shown in open position ( FIGS. 3A , B) and in closed position ( FIGS. 3C , D). Balloon ( 205 ) is angioplasty balloon. Gap ( 206 ) is formed when longitudinally-moving valve ( 204 ) is in open position. Inner shaft lumen ( 207 ) and inner shaft ( 208 ) are shown. Inner shaft lumen, optionally, can be used to contain an imaging material for use in proper positioning the medical device. The 3-valve unit ( 210 ) includes low pressure fluid port ( 209 ) and high pressure fluid port ( 211 ). Exit port is disclosed in FIG. 3 , and in FIG. 2 has structure number ( 32 ).
Distal Terminus of Inner Catheter Body
[0061] The distal end (or distal terminus) of inner catheter body (inner shaft) is closed and does not allow fluid communication with vascular lumen. The distal end is closed or blocked in order to ensure that fluid under pressure, as transmitted by inflation lumen, remains under pressure and that pressure is not dissipated by flowing into vascular lumen. Where distal end of inner catheter body has a tubular extension, the distal end of this tubular extension is closed, in order to ensure that high pressure fluid is able to inflate angioplasty balloon. Distal terminus of inner catheter body can be used as a point of attachment of a medical device, such as scraper, a guide member, one or more echogenic apertures, an expandable structure, a helix, a second balloon, a radiopaque member, a supply of releasable therapeutic agent, and so on.
Positions of Pressure Sensors
[0062] High and low pressure sensors are located at any point from fluid port ( 209 ; 211 ) to any point that is upstream of the 3-way valve. Pressure sensor can be located at or near the most exterior part of fluid port, or it can be located at a more interior position of the valve unit. In an alternate embodiment, pressure sensor is located within the 3-way valve.
[0063] The present disclosure encompasses a valve unit that comprises a plurality of low pressure sensors, that comprises a plurality of high pressure sensors, or that comprises a plurality of both high pressure and low pressure sensors.
[0064] Therapeutic agent encompasses, e.g., an anti-cancer agent, anti-proliferative agents, an anti-thrombotic agent, an enzyme, a small molecule, tissue plasminogen activator (tPA), urokinase, streptokinase, an anti-platelet drug such as eptifibatide. Labeled diagnostic agents are encompassed. A composition that is “labeled” is detectable, e.g., by spectroscopic, photochemical, biochemical, immunochemical, isotopic, chemical methods, magnetic resonance imaging (MRI), sonography, and the like. For example, labels include radioactive isotopes of phosphorous, iodine, sulfur, carbon, stable isotopes, epitope tags, fluorescent dyes, electron-dense reagents, substrates, or enzymes, e.g., as used in enzyme-linked immunoassays, or fluorettes (see, e.g., Rozinov and Nolan (1998) Chem. Biol. 5:713-728).
[0065] The term “longitudinally moving valve” refers to valves that allow or prevent fluid from outer catheter body lumen to vascular lumen, and where sealing contact of the “fluid-switch valve” with outer catheter body distal prevents fluid flow to vascular lumen, where “longitudinally moving valve” is operably linked to inner shaft, and where longitudinal movement of “longitudinally moving valve” is urged by longitudinal movement of inner shaft. “Longitudinally moving valve” encompasses valve ( 204 ), and is not limited to the shape of valve ( 204 ). The shape disclosed by structure ( 204 ) is exemplary and is not limiting.
[0066] The following describes a guidewire embodiment. In a non-limiting, alternate embodiment, inner shaft ( 208 ) contains a guidewire. In this guidewire embodiment, it is not the case that the guidewire passes through the inflation lumen.
[0067] FIG. 3B shows flow of low pressure fluid ( 215 ), and FIG. 3D shows flow of high pressure fluid ( 216 ).
[0068] FIG. 4 illustrates thumb controller ( 400 ). FIG. 4A shows assembled thumb controller, and FIG. 4B shows a blow-up of the thumb controller. Thumb controller includes a gear rack and spur gear. Thumb controller is operably linked to the 3-way valve. In use, the thumb controller manually reversibly switches the 3-way valve from a position that directs high pressure fluid from insufflator to balloon, to a position that directs low pressure fluid, e.g., contrast fluid or a drug, to vascular lumen.
[0069] The handle ( 201 ) of the device allows the clinician to easily hold the device, to advance the device in or out of vasculature, and to engage in fine-tuning of position of device in vasculature, while simultaneously permitting the clinician to operate the thumb controller and thereby control deliver of the contrast fluid and the balloon inflation fluid.
[0070] Thumb slide ( 403 ), contrast fluid line ( 404 ), low pressure sensor ( 405 ), high pressure sensor ( 406 ), insufflator line ( 407 ), 3-way valve ( 408 ), and 3-way valve ( 409 ), are shown. The spur gear can switch the valve by 90 degrees. The rack can be supported within a channel formed within the handle. The two injection ports can exit the same side of the handle. Two extension lines are attached to the stopcock (3-way valve), one for the insufflator and one for contrast fluid injection. In a non-limiting embodiment, the thumb advancer can provide a linear travel of about an inch. The thumb slide switches the two infusion ports from one another.
[0071] Regarding control by the thumb controller ( 400 ), the thumb controller can be capable of controlling only the 3-way valve ( 210 ), it can be capable of controlling only the longitudinally-moving valve ( 204 ) (e.g., Visiovalve®), or it can be capable of controlling both the 3-way ( 210 ), and the longitudinally-moving valve ( 204 ).
[0072] The thumb controller is optional, and a similar function can be provided by manual controls that are part of the 3-way valve unit. The present disclosure, in one embodiment, provides controls for switching the 3-way valve only on the 3-way valve unit. In another embodiment, what is provided is controls for switching the 3-way valve only with the thumb controller. In yet another embodiment, manual operation can be with either controls that are part of the 3-way valve unit, or with the thumb controller. The thumb controller automatically switches the 3-way valve as the longitudinally-moving valve ( 204 ) is being opened and/or closed. In a but non-limiting embodiment, longitudinally-moving valve ( 204 ) can be a Visiovalve®. The valve comprises a body or region that is substantially conical.
Longitudinally-Moving Valve
[0073] The longitudinally-moving valve can have a conical region that is configured for an angled fit against outer catheter body distal end. Alternatively, the longitudinally-moving valve can have a flush region that is configured for a flush fit against outer catheter body distal end. In another alternative, the catheter body distal end can have an opening that defines a first hemisphere, and the longitudinally-moving valve can possess a second hemisphere, where the first hemisphere and second hemisphere can fit sealingly together. The sealing fit is reversible, and the fit can be controlled by back or forth longitudinal movement of inner shaft, where movement is relative to outer catheter body.
[0074] The conical region is symmetrical about the longitudinal axis of the inner catheter body. In this context, the conical has a proximal narrower portion and a wider distal portion, where the proximal narrower portion is configured to fit sealingly in distal aperture of outer catheter member. The sealing fit is reversible. The conical region has an outer face, and an inner face that defines a conical region lumen. The conical region can be shaped like a cone, in that a cross-section along the longitudinal axis reveals faces that are straight, alternatively, the conical region can be outwardly flared as the bell of a trumpet, or the conical region can be inwardly flared as the bell of a tulip, or the conical region can be partly outwardly flared and partly inwardly flared as is the case with the Liberty Bell, where the general shape is frustroconical.
[0075] Structure number ( 210 ) of FIG. 3 can be used to refer to both the 3-way valve, as well as to the 3-way valve unit that houses the 3-way valve. The 3-way valve unit includes housing, display, and electronics. Structure number ( 27 ) in FIG. 1 is dedicated to referring only to the 3-way valve.
[0076] Arrow® GPSCath® can be used for angioplasty with, for example, the femoral, ileac, or renal arteries, and for treating obstructive lesions. Visiovalve® allows physicians to use one catheter to target (locate) the lesion, and also to inflate antioplasty balloon. This valve (the Visiovalve) is located at proximal end of the angioplasty balloon. A medical device that comprises a valve that is the Visiovalve, or a valve that is similar to Visovalve, avoids the need for catheter exchange and avoids the need to re-adjust the guidewire when changing from one mode to another mode. Mode I is balloon inflation. Mode 2 is targeted fluid injection. In a non-limiting embodiment, the valve can be activated on the handle, and switched to allow performance of Mode I or Mode II. Thus, with the Visiovalve, or a similar valve, there is no need to re-establish the position of the guidewire, and there is no need to cross the lesion a second time with the guidewire.
[0077] In a non-limiting embodiment, the inner shaft has a closed distal end. In another embodiment, the inner shaft has an open distal end. In a non-limiting embodiment, distal end of inner shaft is connected to proximal end of balloon. In another embodiment, distal portion of inner shaft is connected to balloon, where a substantial part of the longitudinal axis of inflation balloon surrounds the inner shaft. In another embodiment, balloon is connected to only inflation lumen, or to only inner shaft, or to both inflation lumen and to inner shaft. The term “inflation lumen” can refer to a tube, not just to the lumen that is defined by the tube.
[0078] Regarding FIG. 1 , the disclosure shows an inflation syringe integrated with a smart 3-way stopcock. In this design the stopcock is incorporated onto the distal end of an insufflator. The stopcock can be positioned such that the fluid path is from the insufflator to the Hotspur GPS CATH/balloon or can be switched such that the fluid path is from the contrast syringe to the Hotspur GPS CATH®/VisioValve. With this design, the stopcock switches the fluid path as well as isolates the pressure sensors from one another.
[0079] The isolation of pressure sensors is necessary due to the pressure differential from the low pressure side contrast syringe/blood pressure measurement and the high pressure side inflation syringe. Exposing the low pressure sensor to the high pressure would be detrimental. Upon switching the device to the desired fluid path an internal sensor will detect the position and trigger an LED light which will inform the user that to which path is open. In addition, this switch will also change the display on LCD screen ( 107 ). The screen will indicate the active fluid path, the pressure reading (mm Hg for low pressure side and ATM (atmospheres) for high pressure side) and any additional desired features such as time and or max pressure obtained. An audible tone could also be incorporated as an alert of an out of range condition or max pressure per device label.
[0080] According to embodiments, device features include, but are not limited to, the following: A 3-way Stopcock/Switch, 25 cc Syringe Barrel w/Thread Locking Plunger, (i) LCD Screen (ii) LED Indicating Lights, Pressure Transducer (low pressure), Pressure Transducer (high pressure), Audible-Beeper, (iii) Luer Connections. The LED screen, LED indicating lights, LCD screen, beeper, and the like, are optional and are disclosed herein without implying any limitation.
[0081] Device features include but not limited to the following: A 3-way Stopcock/Switch, (i) LCD Screen, (ii) LED Indicating Lights, Pressure Transducer (low pressure), Pressure Transducer (high pressure), Audible-Beeper, (iii) Luer Connections, (3) Luer Connections
Pressure Sensors
[0082] The skilled artisan has access to various pressure sensors (see, e.g., Merit Sensor Systems, South Jordan, Utah; Measurement Specialties, Inc., Fremont, Calif.; Miller Instruments, Houston, Tex.; Bullister et al (2002) Artific. Organs. 26:931-938; Giridharan and Skliar (2006) Artific. Organs. 30:301-307; Potkay (2008) Biomed Microdevices. 10:379-392, Kashi, B (November/December 2006) Choosing Sensors for Medical Applications in Passive Component Industry, p. 28-30). The present disclosure provides a valve unit that contains two different pressure sensors that are segregated from each other. The first pressure sensor is for low pressure and the second pressure sensor is for high pressure, where distinct types of sensors are used in order to maximize accuracy in readings, and to prevent fluids under high pressure from damaging the low pressure sensor.
Ports and Hubs
[0083] For convenience, the term port, or “fluid port,” ( 30 , 31 , 32 ) is used to refer to the apertures leading to and from the 3-way valve. The term “fluid port” can also be used to refer to any connector or hub that is used for connecting to hoses, tubes, fluid lines. The connectors or hubs may reside in a recess located in the wall of the 3-way valve unit, or they may protrude from the exterior surface of the 3-way valve unit. In an embodiment, low pressure syringe and insufflator are reversibly connected to valve unit by way of coupler or hub. In an alternate embodiment, low pressure syringe and insufflator are permanently connected to valve unit, and here there is a need for port, but not a need for a coupler or hub.
[0084] The hub can take the form of a coupler, it can comprise a coupler, or it can consist of a coupler. Couplers involving rotatably engaging studs and complimentary slots, slots in channels, tapered fits, exterior clips, and ring and collar mechanisms, are available (see, e.g., U.S. Pat. No. 6,336,914 of Gillespie; U.S. Pat. No. 4,609,370 of Morrison; US 2010/0204654 of Mulholland; US 2007/0123825 of King and Wortley; U.S. Pat. No. 6,663,595 of Spohn and Dinsmore; US2008/0262430 of Anderson et al; U.S. Pat. No. 5,885,217 of Gisselberg; and US 2005/0090779 of Osypka, each of which is incorporated herein in its entirety. Storz-type couplers are available (see, U.S. Pat. No. 489,107 of Storz, U.S. Pat. No. 6,695,816 of Casidy; U.S. Pat. No. 4,648,630 of Bruch, and U.S. Pat. No. 7,128,091 of Istre, each of which is incorporated herein in its entirety).
[0085] While the method and apparatus have been described in terms of what are presently considered to be the more practical embodiments, it is to be understood that the disclosure need not be limited to the disclosed embodiments. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures. The present disclosure includes any and all embodiments of the following claims.
[0086] It should also be understood that a variety of changes may be made without departing from the essence of the invention. Such changes are also implicitly included in the description. They still fall within the scope of this invention. It should be understood that this disclosure is intended to yield a patent covering numerous aspects of the invention both independently and as an overall system and in both method and apparatus modes.
[0087] Further, each of the various elements of the invention and claims may also be achieved in a variety of manners. This disclosure should be understood to encompass each such variation, be it a variation of an embodiment of any apparatus embodiment, a method or process embodiment, or even merely a variation of any element of these.
[0088] Particularly, it should be understood that as the disclosure relates to elements of the invention, the words for each element may be expressed by equivalent apparatus terms or method terms—even if only the function or result is the same.
[0089] Such equivalent, broader, or even more generic terms should be considered to be encompassed in the description of each element or action. Such terms can be substituted where desired to make explicit the implicitly broad coverage to which this invention is entitled.
[0090] It should be understood that all actions may be expressed as a means for taking that action or as an element which causes that action.
[0091] Similarly, each physical element disclosed should be understood to encompass a disclosure of the action which that physical element facilitates.
[0092] Any patents, publications, or other references mentioned in this application for patent are hereby incorporated by reference.
[0093] Finally, all references listed in the Information Disclosure Statement or other information statement filed with the application are hereby appended and hereby incorporated by reference; however, as to each of the above, to the extent that such information or statements incorporated by reference might be considered inconsistent with the patenting of this/these invention(s), such statements are expressly not to be considered as made by the applicant.
[0094] In this regard it should be understood that for practical reasons and so as to avoid adding potentially hundreds of claims, the applicant has presented claims with initial dependencies only.
[0095] Support should be understood to exist to the degree required under new matter laws—including but not limited to United States Patent Law 35 USC §132 or other such laws—to permit the addition of any of the various dependencies or other elements presented under one independent claim or concept as dependencies or elements under any other independent claim or concept.
[0096] To the extent that insubstantial substitutes are made, to the extent that the applicant did not in fact draft any claim so as to literally encompass any particular embodiment, and to the extent otherwise applicable, the applicant should not be understood to have in any way intended to or actually relinquished such coverage as the applicant simply may not have been able to anticipate all eventualities; one skilled in the art, should not be reasonably expected to have drafted a claim that would have literally encompassed such alternative embodiments.
[0097] Further, the use of the transitional phrase “comprising” is used to maintain the “open-end” claims herein, according to traditional claim interpretation. Thus, unless the context requires otherwise, it should be understood that the term “compromise” or variations such as “comprises” or “comprising”, are intended to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of elements or steps.
[0098] Such terms should be interpreted in their most expansive forms so as to afford the applicant the broadest coverage legally permissible. | Apparatus and methods are provided for managing delivery of fluid into a vessel. A balloon catheter with a 3-way valve is introduced into an occluded vessel. The 3-way valve permits fluid, such as a contrast dye, to be injected into the vessel lumen. The valve is also configured to permit the balloon portion of the catheter to be inflated by means of the same lumen used to inject the contrast dye into the vessel. Bloodstream pressure can also be measured before and after dilation to confirm the procedure was successful. This apparatus and method provides for a quick, safe, and reliable treatment of an occluded vessel, among other things and works with known and later developed systems. | 0 |
The present application is a continuation-in-part of application Ser. No. 172,806, filed Mar. 28, 1988, now abandoned, which is a continuation-in-part of application Ser. No. 031,752, filed Mar. 30, 1987, now abandoned, for which all equitable rights are claimed.
BACKGROUND OF THE INVENTION
The present invention relates to a process for mounting glass panels in curved window bays of motor vehicles and the like, and in particular, to a method for utilizing flat, uncurved glass panels to form curved windows in such vehicles.
In modern automobiles, the use of highly curved pre-contoured and pre-stressed front windshields is very apparent to all observers. Not so apparent, is the fact that the rear window and the side quarter windows are also curved, although to an extent which is considerably less than that of the front windshield. Further, the curvature is generally only in a single and longitudinal direction of the glass. however, at present, the process of installing even these slightly curved panels is basically identical to the process by which the highly complexedly curved front windshield is installed. Specifically, even the slightly curved windows are pre-contoured by expensive, annealing and tempering processes, employing expensive molds, and are then set in the conforming recessed flange of window bays.
The conventional process has many disadvantages, amongst which is the fact that the glass panel is distorted during the tempering and contouring process and is caused to become less flexible and more brittle. In addition, problems arise in packaging such glass for transportation and storage. While, glass that is pre-contoured does, however, become stronger relative to perpendicular shock and strain, it does become significantly weaker at the same time in other respects, in that it does not thereafter readily flex. Consequently, in a vehicular accident, it can easily dislodge from the bay in which it is set, "pop" out of the vehicle, and easily shatter. On the other hand, untreated flat glass, or even chemically treated flat glass which has not been pre-contoured or tempered, is less rigid and less brittle thereby being more flexible and bendable so that in the event of a vehicular accident, it is less likely to shatter and more likely to absorb any shock and strain applied to it.
Additionally, when pre-contoured glass breaks during an accident, the vehicular body is less able to resist crushing because the window is without the structural support furnished by the glass normally filling the same. Thus, during an accident, the roof of the car is apt to collapse upon the occupants during a turn-over where there is no glass in the window opening than when the glass remains intact therein.
Most importantly, the cost of a comparably sized flat glass panel is at least one eighth to one tenth the cost of a pre-treated, pre-contoured glass. Coupling such cost with the added cost for packaging and shipment of pre-contoured glass panels, the difference in eventual expense to the consumer is considerable.
It is the object of the present invention to provide an improved process, overcoming the disadvantages enumerated above. In particular, it is an object of the present invention, to provide a process wherein flat uncontoured glass can be applied in the vehicle window, wherein it is made to assume in situ a curved shape.
It is a further object of the present invention to provide a process for economically and inexpensively installing glass windows of a curved nature in vehicle windows and the like.
More particularly, in the within inventive method in which a flat glass is flexed and used as a closure for a curved window opening and, as will be described in greater detail herein, a phenomenon that has been organized and underlies the present invention is that flexing of the flat glass producing an urgency therein to return from its flexed to its flat shape. This urgency is used to advantage to enable the application of adhesive sealant which, when cured, permanently holds the glass in place within the cooperating window opening. More specifically, in the within inventive method, one of the steps consists of, after placing the flexed glass in place against reveal molding, applying a continuous bead of adhesive sealant into the space between the edge of the glass window panel and the window opening by the flexing of the window panel outwardly against said reveal molding.
The foregoing objects and advantages, together with numerous advantages are set forth in the following disclosure.
SUMMARY OF THE INVENTION
According to the present invention, the method for installing a window panel in a curved opening of a vehicle, comprises the steps of placing a flat uncontoured glass panel within the curved window bay, securing along the edge of the bay bounding the curved window opening, a holding means sufficient to engage and maintain the flat glass in the curved window opening, said glass panel being flexed from its initial flat configuration into the conforming curvature of the window, and thereafter applying a weather sealant and adhesive compound in situ along the confronting edges of the window panel and allowing said adhesive to cure until the panel becomes fixed permanently in the window opening in its conforming curvature.
The fastening means comprises a plurality of resilient clips uniformly spaced about the perimeter of the window bay and a reveal molding cooperatively secured to the clips, so that the reveal molding is provided with a resilient bias, pressing on the outer surface of the glass panel, pushing the glass into conforming engagement with the bay of the window opening.
Full details of the present invention are set forth in the following description of the preferred method, as illustrated in the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially exploded perspective view of the rear window of an automobile, showing the application of a conventionally pre-curved window thereto, according to the prior art;
FIG. 2 is a top view of the glass panel of the prior art taken in the direction of 2--2 of FIG. 1;
FIG. 3 is a view similar to that of FIG. 1 showing the application of the present method to the installation of a flat glass panel in an automobile window;
FIG. 4 is a top view of the flat glass panel employed in the method shown in FIG. 3; and
FIG. 5 is a sectional view, greatly enlarged, showing the completed window installation.
DESCRIPTION OF THE INVENTION
The present invention is illustrated and described herein for simplicity, with reference only to the installation of glass in the rear window of an automobile. It will be understood, however, that the same principles apply to installations in other vehicle windows, or the like.
As seen in FIG. 1, the rear window bay, generally depicted by the numeral 10, of automobile 12 is defined by the roof flange into a rectalinear frame 14 having an L-shaped cross-section. A panel of curved glass 16, as seen in FIG. 2 is inserted, into the frame 14 and a metal reveal molding 18 is secured thereabout. In this arrangement, the glass panel 16, is pre-contoured in the manner illustrated in FIG. 2 by being bowed an amount 16A in the longitudinal direction, to have a concave/convex configuration. Similarly, the reveal molding 18 is bowed accordingly. As seen in FIG. 1, the pre-contouring of both the glass panel 16 and the reveal molding 18, enables the installation of the two quite easily. The reveal molding 18, is held from falling out by a plurality of clips 20 uniformly spaced about the periphery of the window opening or bay. The glass 16 is held by continuous bead 22 of curable adhesive material applied along the perimeter of the glass panel 16 forming a bond and weatherproof seal between the panel 16 and the frame 14. The reveal molding encloses the peripheral edge of the glass panel, but it does not co-act with the clips and/or with the glass to hold the glass, let alone effect any flexing of the glass.
In comparison to the prior art, the present invention as illustrated in FIGS. 3 to 5, provides for the installation of inexpensive flat glass and the in situ flexing of the glass to conform to a curved window bay. The vehicle 12 and its window opening or bay 10, are of course, identical with that shown in FIG. 1 since such is solely within the purview of the automobile designer and would be prohibitive to change. Nevertheless, in accordance with the invention, a glass panel 24, rather than being pre-contoured, is supplied flat, uncontoured and untempered, but sized and shaped overall so as to readily fit the opening bay 10 of the window. The flat glass panel 24 is placed within the bay 10 being flexed slightly by hand to conform to the contour of the bay and placed into engagement with perimeter fastening means generally depicted by the numeral 26 provided to hold the glass panel 24 to least temporarily in place.
As seen in FIG. 5, the fastening means 26 is formed of a combination of individual resilient clips 28 and a reveal molding 30. The individual clips 28 are arranged uniformly about the perimeter of the bay 10 and are secured firmly in place by an anchoring screw 32, tapped into the back wall of the frame 14. Each clip 28 has an outwardly extending leaf portion 34 on which is integrally formed a detent 36.
The reveal molding 30 is uniform through its perimeter, and as seen in cross-section (FIG. 5) is provided with a triangular shaped head 38 having a flange 40 adapted to engage the detent 36 on the clip. The triangular shaped head 38 is adapted to snap on to the leaf part 34 of each clip 28 so as to be held firmly between the back wall of the frame 14 and detent 36. Each of the clips 28 simultaneously urge the reveal molding 30, in cross-section, in clockwise arc, (arrow A) inwardly and downwardly into the window bay 10 whereby the lower end 42 of the molding 30 engages and presses onto the face of the glass panel 24. Under this collective urging, the lower end 42 or inner edge of the reveal molding acts as a securing element effecting and maintaining flexure of the glass panel continuously about its perimeter. The lower end 42 of the molding 30 is bent to provide an inturned edge on which a continuous band of weather stripping 44 is secured, the weather stripping extending into engagement with the leaf portion 34 of clip 28.
At this point it is significant to note that the glass panel 24 is not yet permanently mounted in its position in the window opening 10 and relative to the reveal molding 30. The permanent mounting thereof is achieved using the same prior art adhesive sealant 22 that is inserted in the compartment between the panel 16 and the frame 14. However, it is one of the features of the within inventive method that there will be adequate clearance for the placement of the adhesive sealant 22 behind the peripheral edge of the flexed glass panel 24 because the flexing produces an urgency therein which forces this peripheral edge outwardly and thus into contact with the reveal molding clip portions 30, and thus providing an opening for inserting the adhesive sealant mass 22 in the glass-holding position as illustrated in FIG. 5.
Within the frame 14 and after insertion of the adhesive sealant 22, the within inventive method contemplates the placement of a continuously extending dam 46 of elastic material placed so that it lodges along the inner wall of the frame 14 adjacent the periphery of the window bay 10 in contact with the inner surface of the glass panel 24. The dam 46 acts as a closure for the continuous bead 22 of adhesive sealant of material which was previously placed within frame 14 in an amount sufficient to engage with, and bond with, the confronting inner surface and peripheral edge of the glass panel 24. The flat uncontoured glass 24 is held in place by engagement with the fastener means 26 until the adhesive 22 cures and bonds, thereby setting the glass panel permanently in place. The action of the biased reveal molding and the adhesive, maintains the glass panel 24 permanently curved and in place.
Conventional tempered or untempered flat glass panels of rear vehicle window size, e.g., 18×60 inches and 1/8 inch thick, are easily flexed in situ and can be employed here.
Preferably the reveal molding 30 is also supplied and used as a straight member being unbent and uncontoured prior to installation in the window. It is, however, sufficiently flexible to be held by the clips 28 spaced along the flange bounding the window bay 10.
The curable adhesive is preferably polysulfide, having suitable fillers and solvents added thereto so that when cured, this material exhibits the property of rubber in that it is capable of accepting sheer stress without cracking or corroding in changeable climate or other atmospheric conditions. Such curable adhesives are well known, commercially available and widely used, so that further description here is unnecessary.
Various changes and modifications have been suggested and others will be obvious to those skilled in the art. Thus, it is intended that the present disclosure be taken as illustrative only and not limiting of the scope of the present invention. | A glass window installed in a curved window opening of a vehicle by placing along the edge bounding said curved window opening, window-engaging fastening means. A window pane sized to fit into said window opening is flexed from an initial flat configuration into a conforming curvature of said window, while establishing engagement between said flexed window pane and said window-engaging fastening means, to temporarily hold said window pane in said conforming curvature. A weather-sealing adhesive compound placed along the confronting edges of said window pane and window opening to complete a weatherproof installation of said window pane. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit, under the treaty of Paris, of the French Pat. App. Demand No. 1153052 and Submission No. 1000108664 (filed Apr. 8, 2011) and that patent application is appended hereto, along with a certified translation, and both documents are hereby incorporated by reference in their entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention pertains to a stocking and removal system comprised of an initial linear conveyor system and a second linear conveyor system parallel to the first system and aligned so that an object placed on the first conveyor system may be transferred to the second conveyance system. The invention also concerns a procedure for the usage of this system.
2. Background
Stocking systems and collection devices are commonly used in food processing for items such as breads. EP 0 368 699 A2, for example, is a known automated baguette distributor. The distributor is composed of a stocking zone and a conveyor belt. The stocking zone is composed of several inclined trays, placed one over the other. The lowest extremity of each tray ends by a support which prevents the baguettes from slipping from the tray. The conveyor system is met with a transfer unit fixed on an endless chain so that the transfer may be displaced from bottom to top before the trays in order to transport the baguettes then from top to bottom of the other side of the conveyor in order to deposit them on a ramp which conducts them to be reheated and then to the distribution area. The collection device consists of two hooks fixed by an axle on an endless chain and fixed with a counterweight. When not in use, the two hooks are inclined in the direction of the trays as a result of the counterweight. Two openings in the tray supports allow the hooks to enter them while they are in the inclined position. If a baguette is on the lower portion of the tray, it is caught by the hooks which rise and, with the weight of the baguette, tip vertically so that they do not pass over the trays. For this system to function, it is imperative that the baguettes or other food products do not stick to the trays so that they are prevented from sliding to the tray supports to be caught. Moreover, the order of the baguette transfer is imposed by the procedure of the collection devices: the baguettes of the lower trays are transferred first, then those of the tray directly above and so on until the highest tray. Therefore, it is necessary to wait for all of the baguettes to be transferred before refilling the unit. Finally, during the stocking process and distribution, the baguette risks flipping over so that when put into position to prepare for distribution, it is not oriented properly. It becomes impossible, for example, to bake a raw or frozen baguette with the upper side containing slits placed systematically on top.
The document EP 0 337 836 A1 describes a machine used in the preparation and distribution of hamburgers. It consists of a series of conveyors placed one after the other. A fresh or frozen hamburger patty is placed on the first conveyor. It is then transferred to the second conveyor that passes through an oven. Once out of the oven, the hamburger leaves the second conveyor to pass onto the third conveyor on which half of a bun was placed beforehand. The hamburger patty and bun half pass under sauce distributors before the other half of the bun is placed on top. The hamburger leaves the third conveyor to pass onto a forth conveyor on which it is wrapped. In any case, the hamburger rests clearly in the same path during the whole course of the preparation. The transfer can only be made by means of a single conveyor belt.
SUMMARY OF THE INVENTION
The objective of this invention is to permit the distribution of an object transferred in a plan different from that which it was initially stocked, while still conserving the orientation of the object to be transferred. The second objective is to permit the utilization of a second conveyor unit with different initial conveyor units. A third objective of the invention is to assure the reliable, seamless transfer of a sole object without need of support.
The first objective is obtained by the fact that the means are provided for by moving the second conveyor unit in a movement perpendicular to its direction so that the second conveyor unit may be moved from its position situated in the alignment of the first conveyor system to a distribution position. It is possible to move the second conveyor system of the stocking plan in the second plan located above or below, so that the object, for example, a baguette, is accessible by the technician or machine handling it.
In a closed trial of the invention, the system is comprised of several identical initial conveyor units arranged one over the other. The means of transport can place the second conveyor unit in the interchangeable alignment of each one so that an object placed on the first conveying unit then passes to the second conveying unit and may be transmitted to the last. Thus, the second conveying system may be used with several initial conveyor systems, which allows an augmentation in the quantity of objects stocked.
In an initial trial variation of the invention, the first conveyor unit consists of at least two parallel conveyor belts placed side by side; the first belt extends farther in advance in the direction of the second conveyor unit, of a distance (d) from the second belt. Similarly, the second conveyor unit consists of at least two parallel conveyor belts placed side by side; the first belt extends less in the direction behind the initial conveyor unit for distances (d) than the second belt, the first conveyor belts are at least partially aligned one after the other, and the second belts are at least partially aligned one after the other; the initial attempted trials were anticipated in order to train in the same movements of the two belts of the first conveying unit and the second trial was anticipated to train in the same movement of the two belts of the second conveying system.
It is preferable in this case that the first conveyor system incorporate a third conveyor belt identical to the first, arranged symmetrically in relation to the second belt and lead by the first channel, and so that the second conveyor system consists of a third conveyor belt identical to the first, arranged symmetrically in relation to the second belt and lead by the second channel, the third belts are at least partially extended one after the other.
Two or three belts are anticipated, and these systems assure the best transfer of the object from the first conveying system on the second conveyor system. In fact, the object, when it leaves the second conveyor belt of the first conveyor system to pass to the second belt of the second conveyor system, is found in the unsupported space between the two belts. But at the same time, a part of the object is always on the first belt, and if necessary on the third belt, of the first conveyor system. A part of the object is then always carried by one or two belts of the first conveyor system. There is not a discontinuity in the support of the object when it passes from the first to the second conveying system.
After finding the object's position on the second conveyor system, it is recommended to anticipate a support at the edge before the second conveyor system, that is, opposite the first conveyor system.
After allowing the stocking and removal of several objects stacked perpendicular to the direction of the movement of the conveyor system, it is possible to anticipate that the first conveying systems should consist of several rounds of first and second belts, or of the first round, of second and third belts, arranged side by sister, and that the second conveying system should consist at the same time of rounds of first and second belts, or of rounds of the first, of second and third belts, arranged side by side so that each round of the first conveying system corresponds to a round of the second conveying system.
According to necessity, the conveyor belts may be made up by belts of joined plates or grills.
The invention also concerns a method for system utilization of the invention to stock an object on the first conveying system and the removal on a second conveying system after being channeled to a distribution position, characterized by the following steps:
(a) the second conveying system is moved by the channel to be aligned with one of the initial conveying units; (b) the second conveying system and the first conveying system in the alignment where the second conveying system is found is put into use before so that the object situated on the first conveying system is moved in the direction of the second conveying system while the other initial conveying units remain at rest; (c) The object leaves a part of the first conveying system and passes a part to the second conveying system; (d) The second conveying system is moved upwards to a predetermined height (h); (e) The first conveying system is stopped and the second conveying system is stopped once the object reaches a position determined by the second conveying system; (f) The second conveying system is moved by channels until it reaches a position for distribution.
It is preferable that step (d) is accomplished as soon as the object has left the second belt of the first conveying system, all while resting on the first belt and third belt, if there is one, and it passes to the second belt of the second conveyor system without having to pass through the first and third belt, if there is one.
Additionally, it is recommended that at step (e), the first conveying system should first be run in reverse before being switched off.
After repositioning an object which has been put through the second conveying system during the transfer, it is possible at step (e) to maintain the second conveying system operational until the object bumps into the support. In this case, it can be anticipated to start the second conveying system after the object bumps into the support until the object has reached an intermediary position determined by the second conveying system.
BRIEF DESCRIPTION OF THE FIGURES
The invention is described in detail below with the help of an example presented in the figures shown:
FIG. 1 : a schematic view from above the unit;
FIG. 2 : a side view of the invention's system, the mobile portion is (a) in an aligned position and (b) in a raised position;
FIG. 3 : a schematic view of the invention's system in the perspective of the mobile portion is (a) in an aligned position and (b) in a raised position;
FIG. 4 : a schematic representation of the invention's system of different steps of the removal process;
FIG. 5 : a schematic view of the invention's system integrated in an automated machine for stocking and cooking bread.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The invention concerns a system of stocking and distribution. The example of fulfillment presented in FIGS. 1-5 is designed for stocking and removal of precooked baguettes ahead of being then put into the oven to finish baking. During this the invention's system may be utilized in a completely different domain.
As is standard, the forefront of the system is found at the side of the second conveyor system ( 200 ) opposite the first conveyor system ( 100 ). In practical terms, the forefront is found on the left of the figures, while the rear is found on the right. To operate a conveyor system means that the upper side, on which the objects to be transmitted rest, move to the left. In contrast, to operate a system in reverse means to move the upper side of the conveyor to the right.
The invention's system is composed of two principle portions: one fixed portion ( 100 ) and one mobile portion ( 200 ).
The fixed portion ( 100 ) is composed of a horizontal tray fixed in a frame ( 101 ). The tray consists of three, endless, and parallel conveyor belts ( 110 , 120 , 130 ) placed side by side. These three belts may be carried in the same movement by a motor not represented and making the first sources of conveyance. Each belt is suspended by two rollers ( 111 , 112 ; 121 , 122 ; 131 , 132 ). The six rollers are parallel. The three rear rollers ( 111 , 121 , 131 ), situated to the right of the diagrams, are aligned and may be joined into a single common roller. The front roller ( 122 ) of the central belt is placed farther back of a distance (d) than the front rollers ( 112 , 132 ), the two exterior belts. This fixed portion makes the first conveyor system.
The mobile portion is composed of a mobile, horizontal tray. The mobile tray is comprised also of three conveyor belts ( 210 , 220 , 230 ) placed side by side, parallel to one another and also to the conveyor belts ( 110 , 120 , 130 ) of the fixed tray. These three belts may be carried in the same movement by a motor not represented and this makes up the second source of conveyance. Each belt is suspended between two rollers ( 211 , 212 ; 221 , 222 ; 231 , 232 ). The six rollers are parallel to one another and to rollers ( 111 , 112 ; 121 , 122 ; 131 , 132 ) of the fixed tray. The three front rollers ( 212 , 222 , 232 ) at left in the figures are aligned and may be joined by a single, common roller. The rear roller ( 221 ) of the central belt ( 220 ) is placed farther back at a distance (d) than the rear rollers ( 211 , 231 ) of the two exterior belts ( 210 , 230 ): the central belt ( 220 ) is longer than the two exterior bands ( 210 , 230 ). This mobile portion makes up the second conveyor system.
The length difference between the two exterior belts ( 110 , 130 ) and the central belt ( 120 ) of the fixed plate is logically equal to the length difference between the central belt ( 220 ) and the exterior belts ( 210 , 230 ) of the mobile tray.
Seen from above ( FIG. 1 ), the first belts ( 110 , 210 ) are logically in the same extension one after the other. It is the same for both the second belts ( 120 , 220 ) and the third belts ( 130 , 230 ). It is possible that two belts in the same extension, one after the other, do not have exactly the width and/or that their lateral edges are not exactly facing one another without disrupting the function of the system.
The mobile tray ( 200 ) can move along a frame ( 201 ) in a vertical movement propelled by the nonrepresented source. It may also be aligned with the mobile tray, meaning that the conveyor belts ( 210 , 220 , 230 ) are found in the same horizontal as the belts ( 110 , 120 , 130 ) of the fixed tray. It may also be moved into another position that will be described further on.
In the aligned position represented in FIGS. 2 a and 3 a , the front rollers ( 112 , 122 , 132 ) of the fixed tray's conveyor belts are also as close as possible to the rear rollers ( 211 , 221 , 231 ) of the mobile tray so that the space that separates the conveyor belts of the fixed tray and those of the mobile tray are as low as possible in order to prevent friction between them.
The conveyor belts ( 110 , 120 , 130 , 210 , 220 , 230 ) may be presented in different forms. This may include different forms: straps, bands, or joined grills.
The system may contain several fixed, identical trays ( 100 ) placed one over the other in the frame ( 101 ) so that the front rollers ( 112 , 132 ) of the exterior belts are placed in the same vertical plane and the front roller ( 122 ) of the central belt in the same vertical plane in the background, meaning more to the right un the figures. Thus, the mobile portion ( 200 ) may be placed by alternating the sources of conveyance in aligning different fixed trays ( 100 ) so that an object places on the fixed tray in the alignment may be passed onto the mobile tray and transferred to the last.
The invention's system may be integrated with a machine for automated cooking similar to the one schematically represented in FIG. 5 . Several fixed trays ( 100 ) are placed one over the other in a frame ( 101 ) forming a five sided enclosure. In front of the fixed trays is the mobile tray ( 200 ) mounted on a frame ( 201 ) located in the frame's extension ( 101 ). Above the highest tray, there is a device ( 500 ) to take a baguette in the distribution position from the mobile tray ( 200 ) and put it in an oven ( 400 ) located in front of the device which places the item in the oven ( 500 ). The enclosure made by the frame ( 101 ) and the frame ( 201 ) are closed in front by a wall that extends into the space above the door ( 401 ) of the oven. This enclosure may be refrigerated to guarantee an optimal conservation of the precooked baguettes.
The invention's system functions in the following manner. The precooked baguettes ( 301 , 302 , 303 ) are placed on the fixed trays ( 100 ), parallel to one another and perpendicular to the conveyor belts ( 110 , 120 , 130 ). Removal is achieved through the following steps:
a) The mobile tray ( 200 ) is moved to align it with one of the fixed trays ( 100 ), like those of FIGS. 2 a , 3 a , 4 b. b) The conveyor belts of the fixed trays and mobile trays are operated so that their upper sides move at the same speed to the left in the direction of the arrow (F 1 ). The baguettes ( 301 , 302 , 303 ) of the fixed tray move in the same direction. c) The first baguette ( 301 ) leaves the central belt ( 120 ) of the fixed tray to pass to the central belt ( 220 ) of the mobile tray all while resting with its extremities on the exterior belts ( 110 , 130 ) of the fixed tray. d) As soon as the central part of the baguette is passed through the central belt ( 220 ) of the mobile tray, which gently rises to the elevated position represented in FIGS. 2 b , 3 b and 4 d . The extremities of the removed baguette leave the exterior belts ( 110 , 130 ) of the fixed belt. e) At the same time, the belts of the fixed tray are stopped while the belts of the mobile tray continue to move forward in the direction of the arrow (F 1 ) until the extremities of the removed baguette ( 301 ) are found on the exterior band ( 210 , 230 ) of the mobile tray. The conveyor belts ( 210 , 220 , 230 ) are stopped in turn. f) The mobile tray ( 200 ) is displaced in a vertical movement until the reaching the distribution position. In the example presented here, this position faces of the entrance to the oven ( 400 ), in front of the device for placing items into the oven ( 500 ).
At step e), while the mobile tray is in the elevated position, it can be useful to put the conveyor belts ( 110 , 120 , 130 ) of the fixed tray into reverse so that the upper part goes back in the direction of the arrow (F 2 ). This ensures that a second baguette placed too close is not removed at the same time as the baguette before.
It can be useful to anticipate a support at the extremity before (at left in the figures) the conveyor belts ( 210 , 220 , 230 ) of the mobile tray to correct a baguette which may have been put askew during removal. Thus, the first end reaches the support before the other which still moves along the conveyor belt until the baguette is once again perpendicular to the belt. Once the baguette is repositioned, it can be useful to center it on the mobile tray by putting the mobile tray in reverse for a necessary time.
The support can be an integral part of the mobile tray. However, in the case presented in the figures, such a support would prevent the baguette from being placed into the oven. It can be considered then as part of the oven ( 401 ); in which case, the repositioning of a skewed baguette cannot be that of a distributing position. It may consist equally of the front wall ( 102 ) of the stocking magazine, the wall ( 102 ) along which the mobile tray moves ( 200 ).
The control of the system may be assured by a unit of command not represented. The choice of fixed tray from which the baguettes will be removed for distribution depends on the criteria stored in the control unit. Notably, it will be possible to recharge one or another of the trays and to program the hour for refilling. It is then not necessary to wait until the device is empty before refilling it. The control unit then chooses to remove a baguette for distribution from a tray while the trays higher up are stocked. If this duration surpasses a time limit, the control unit will freeze actions with the corresponding tray and dispatch the mobile tray towards another tray.
Sensors may be placed at strategic locations. In particular, a sensor can be anticipated to determine the moment when the center of the baguette will pass entirely to the central belt ( 220 ) of the mobile tray in order to trigger the belt's rise. Another sensor can determine if the baguette is correctly perpendicular to the conveyor belts of the mobile tray, or if it is necessary to launch a process to adjust the baguette's position. Sensors can also determine the vertical position of the mobile tray.
Thanks to the system of the invention, the transmission of properly oriented baguettes is assured, meaning that the upper side rests facing up. This is important particularly if the system must deliver a baguette to be baked in an oven. In placing several trays one over the other, the system's stocking capacity augments considerably while requiring only a mobile tray system. With a central belt turning between two exterior conveyor belts, the transfer of a single object is assured without disrupting the flow of the process.
The trial example represented here may be generalized.
The transition between two trays is accomplished by the central, shorter conveyer belt on the fixed tray and the longer one on the mobile tray, permitting a transfer without disruption of the fixed tray to the mobile tray: at no moment is the baguette found to be without support from the fixed tray and from that of the mobile tray.
However, if the object passing from the fixed tray to the mobile tray is sufficiently large and/or rigid enough, it is possible to compensate for the excess or difference so that the three front rollers ( 112 , 122 , 132 ) of the fixed tray are aligned the same as the rear rollers ( 211 , 221 , 231 ) of the mobile tray. In this case, it becomes possible to abandon the three belts in order to conserve one of them.
On the other hand, if the objects stocked on the fixed trays have dimensions that make it possible to put several on the same row perpendicular to the transport, it becomes possible to anticipate several groups of transfers, and then several periods of disruption. Take, for example, pizzas that can be placed by rows of three. The mobile tray will then have three sets of three conveyor belts; the central belts will be shorter than the exterior belts in each set. Similarly, the mobile tray will have three sets of three conveyor belts; the central belts will be shorter than the exterior belts in each of the sets. A common conveyor belt can even be joined from the exterior, adjacent belts of the two successive sets.
The patent claims in the prior French patent application are translated as follows:
1. A stocking and removal system consisting of an initial linear conveyor system and of a second linear conveyor system parallel to the first system and aligned so that an object placed on the first conveyor system can be transfer to the second conveyor system, characterized in that means are anticipated to move it to the second conveyor system in a movement perpendicular to the direction it is being moved in so that the second conveyor system can move from its position aligned with the first conveyor system to a distribution position. 2. A stocking system and collection device according to the previous claim, characterized in that the first conveyor system ( 100 ) consists of at least two parallel conveyor belts ( 110 , 120 ) placed side by side, the first belt ( 110 ) extends farther in advance in the direction of the second conveyor system ( 200 ) at a distance (d) from the second belt ( 220 , the first belts ( 110 , 210 ), at least in part, one after the other, the first means of conveyance are anticipated to drive the two belts ( 110 , 120 ) in the same movement, the first conveyor system and the second means of conveyance are anticipated to convey in the same movement the two belts ( 210 , 220 ) of the second conveyor system. 3. A stocking system and collection device according to the previous claims, characterized in that the first conveyor system ( 100 ) contains a third conveyor belt ( 130 ) identical to the first ( 110 ), located symmetrically in relation to the second belt ( 120 ) and driven by the second means of conveyance, and wherein the second conveyor system ( 200 ) contains a third conveyor belt ( 230 ) identical to the first ( 210 ), located symmetrically in relation to the second belt ( 220 ) and driven by the second means of conveyance, the third belts ( 130 , 230 ) are, at least in part, in the extension of the other. 4. A stocking system and collection devices according to the previous claims, characterized in that it contains several identical, first conveyor systems ( 100 ) placed one over the other so that the means of conveyance can align the second conveyor system ( 200 ) with each of them by turn so that an object placed on the first conveying system may be transferred to the second conveying system ( 200 ). 5. A stocking system and collection device according to the previous claims, characterized in that a support ( 102 ) is anticipated at the edge of the second conveyor system ( 200 ), opposite the first conveyor system ( 100 ). 6. A system according to the claims 2 to 5, characterized in that the belts ( 110 , 120 , 130 , 210 , 220 , 230 ) consist of straps, bands, and jointed grills. 7. A system according to the claims 2 to 6, characterized in that the first conveyor systems ( 100 ) consist of several sets of first and second conveyor belts ( 110 , 120 ), or of several sets of first, second, and third belts ( 110 , 120 , 130 ) placed side by side and that the second conveyor system consists at the same time, of sets of the first and second belts ( 210 , 220 ), or of sets of first, second and third belts ( 210 , 220 , 230 ); these sets are placed side by side so that each set of the first conveyor system corresponds to set off the second conveyor system. 8. Utilizing the device according to one of previous claims to stock an object ( 301 ) on the first conveyor system ( 100 ) and transfer it on a second conveyor system ( 200 ) and finally to channel it to a position for distribution, characterized by the following steps:\
a. the second conveyor system ( 200 ) is moved by a driver to be aligned with one of the first conveyor systems ( 100 ); b. the second conveyor system ( 200 ) and the first conveyor system ( 100 ) in the alignment in which the second conveyor system ( 200 ) is operated so that the object ( 301 ) situated on the first conveyor system ( 100 ) is moved in the direction of the second conveyor system ( 200 ); the other first conveyor systems remain at rest; c. the object ( 301 ) leaves a part ( 120 ) of the first conveyor system ( 100 ) and reaches a part ( 220 ) of the second conveyor system ( 200 ); d. the second conveyor system ( 200 ) is moved to a predetermined height (h); e. the first conveyor system ( 100 ) is stopped and the second conveyor system ( 200 ) is stopped once the object ( 301 ) has reached a position determined by the second conveyor system; f. the second conveyor system ( 200 ) is moved by a driver until a point of distribution.
9. Proceeding according to the previous claim, characterized in that step (d) occurs once the object leaves the second belt ( 120 ) of the first conveyor system, all while staying on the first belt ( 120 ) and, if necessary, on the third belt ( 130 ), and that it reaches the second belt ( 220 ) of the second conveyor system without having reached the first belt ( 2110 ) and, if necessary, the third belt ( 230 ). 10. Proceeding according to the previous claims 8 or 9, characterized in that at step (e), the first conveyor system is first run in reverse before being turned off. 11. Proceeding according to the previous claims 8 or 9, characterized in that at step (e), the second conveyor system ( 200 ) continues to operate in a forward direction until the object collides against the support ( 104 ). 12. Proceeding according to the previous claim, characterized in that after the object collides with the support ( 104 ), the second conveyor system ( 200 ) is operated in reverse until the object assumes an intermediary position on the second conveyor system. | A stocking and vending machine may have first and second linear conveyor systems which are initially parallel and aligned so that an object may be transferred from the first conveyor system to the second conveyor system. The machine may be configured to move the second conveyor system so that it carries the object to a position for distribution thereof. The first conveyor system may feature three parallel and side-by-side conveyor belts wherein the outer belts extend farther in the direction of the second conveyor system than the middle belt. Correspondingly, the second conveyor system may feature three parallel and side-by-side conveyor belts wherein the outer belts extend less in the direction of the first conveyor system than the middle belt so that the middle belt may extend between the outer belts of the first conveyor system when in said initial position. The conveyor systems may be driven by separate drivers. | 6 |
[0001] The present application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 62/364,141 filed on Jul. 19, 2016, which is incorporated herein by reference.
BACKGROUND
Field
[0002] The present disclosure relates to knitting needles with improved functionality. In particular, the present disclosure relates to a knitting needle that includes a cord with an adjustable stop for supporting a knitted workpiece as it is being created that holds the work securely while knitting. The present disclosure further relates to a method for using such knitting needles.
Description of the Related Art
[0003] Knitting needles allow a knitter to form yarn into fabric by creating a pattern of interlinked stitches of yarn that result in a fabric workpiece. While a workpiece is being knitted the stitches forming the leading edge of the fabric is held on one of the needles. A stitch from the leading edge of the workpiece is moved to the tip of the needle and linked with a loop of yarn, forming a new stitch of the subsequent row of the workpiece. That newly created stitch is transferred to the other needle. The process is repeated until a complete new row of stitches is formed and the workpiece is transferred entirely from one needle to the other needle. The leading edge of the workpiece is now formed by the new row of stitches. The knitter then creates another new row of stitches by joining stitches to the leading edge of the workpiece and transferring those stitches back to the first needle. The length of the workpiece is not limited because the knitter can continually add rows to the workpiece.
[0004] Known knitting needles may, however, limit the width of the workpiece. As the knitter stiches a row, the row must be stored on the needle itself. If a stitch were to become disengaged from the supporting needle before it is linked with a stitch on the subsequent row the stitch would unravel, potentially ruining the workpiece. Thus, the workpiece must remain engaged with one or the other of the needles until it is finished and “cast off” with a binding row.
[0005] The number of stitches that can fit on a needle is limited by the length of the needle. To make wider panels of fabric using standard knitting needles, the knitter must use longer needles or create multiple panels that are later joined together. Both approaches have drawbacks. Creating a piece from multiple panels is cumbersome and may not result in the same look and feel as a continuously knitted piece. Longer needles have more weight and thus, can cause greater fatigue. Also, longer needles are more likely to break, particularly if light weight material is used. At some point, the length of the needles becomes impractical.
[0006] Wider workpieces can also be formed on so-called circular needles. Circular needles are formed by connecting the ends of two needles together by a cable. Using such needles is referred to as “knitting in the round.” Stitches at the leading edge of the workpiece remain engaged with the cable as they are created. The knitter knits continuously in one direction so that the stiches form a tubular workpiece.
[0007] There are a number of problems with circular needles used to knit in the round. Many users find “knitting in the round” uncomfortable because the weight of the workpiece is borne by the cable supported by the knitter's hands holding the needles. The weight of the workpiece on the ends of the needles opposite the tip must be lifted each time the knitter moves the tip up and down. This can cause fatigue and discomfort, particularly when the knitter lacks hand and arm strength due to age or to disease, such as arthritis, carpal tunnel syndrome, and the like.
[0008] Knitting in the round also makes it difficult for the knitter to see the layout of the workpiece while knitting. To create patterns of texture or color in a knitted piece, the knitter may need to see the entire piece laid out flat and may need to make decisions about the type of stitch or color of yarn to use. This may be difficult when the piece is held on a loop of cable.
[0009] To create a new stitch linked to a previously formed stitch, the knitter brings the previously formed stitch to the tip of the needle, links that stitch with a loop of yarn forming the new stitch, and transfers the new stitch to the other needle. This is repeated, one stitch after another as the knitter progresses along the row of previously formed stitches. For a workpiece on circular needles, the knitter must repeatedly slide stitches from the cable onto the needle so they can be delivered to the needle tip. To keep the workpiece in a comfortable position to form the next stitch, the knitter must constantly pull stitches from the cable onto the needle. This can cause fatigue.
SUMMARY
[0010] The present disclosure relates to apparatuses and methods to address these difficulties.
[0011] One aspect of the disclosure describes a knitting needle that includes a cord or cable to hold stitches of the workpiece. The cable has an adjustable stop or slider that can be moved along the cable to a selected distance from the needle. The distance is adjusted to accommodate the number of stitches required for a workpiece of a desired width and to position that workpiece in a desired relationship to the tip of the needle. Another aspect of the disclosure describes a slider mechanism disposed on the cable that the knitter can conveniently adjust to change the distance between the needle and the slider to reposition the workpiece along the cable relative to the needle. The knitter may reposition the slider a number of times when forming each row of stitches. The slider may be formed from materials that reduce wear on the cable as the slider is moved or improve the grip of the slider on the cable to more securely hold the slider in place.
[0012] A further aspect of the disclosure describes a knitting needle, cable, adjustable slider, and a connection mechanism that allows the adjustable cable to be removably connected with the needle. According to this aspect, a variety of needles and cables can be connected with one another to create a desired combination of features.
[0013] Another aspect of the disclosure describes a method of knitting. The knitter uses a first needle comprising a cable, an adjustable slider, and an end stopper that prohibits the slider from moving off the end of the cable. The slider forms a stop that prevents stitches from sliding along the cable so that stitches are captive between the slider and the knitter's hand holding the needle. The knitter adjusts the distance between the slider and the needle so that the stitches are compressed toward the needle. The resiliency of the stitches urges them along the cable and toward the tip of the needle. The knitter holds stitches on the needle so that they remain in place. The knitter moves stitches, one at a time, toward the tip of the needle to knit. The resilient force urges stitches along the cable so that the knitter can easily deliver them to the tip of the needle.
[0014] According to another aspect of the disclosure, the knitter uses a second needle, also comprising a cable and adjustable slider, in combination with the first needle to form a new row of stitches interlocked with the previously formed row. The distance of the slider along the cable of the second needle is adjusted to hold a number of stitches sufficient to form the desired width of the workpiece without compression. The knitter puts newly created stitches onto the second needle as they are interlocked and allows them to slide along the second needle and its cable. Because the distance between the needle and slider is adjusted to hold the width of the workpiece, the newly created stitches can be placed on the second needle without having to compress them.
[0015] According to a further aspect of the disclosure there is provided a knitting needle assemble comprising a first needle body having first and second ends, wherein the first end forms a needle tip, a flexible cord connected at a first end to the second end of the needle, and an adjustable stop disposed on the cord, wherein the stop can be adjustably fixed to a selected point along the length at the cord. The adjustable stop may comprise a slider and where the cord extends through a passage of the slider. The assembly may comprise a fixed stop disposed at a second end of the cord opposite the first end connect with the needle body, wherein the fixed stop is configured to prevent the slider from moving off the end of the cord. The cord may be formed from one or more of a metal wire, a polymer, a woven fabric, and a combination thereof and may include a friction-reducing or wear-reducing coating. The first needle body may be formed from one or more of hardwood, including rosewood, sheesham, or ebony; bamboo; polymer; metal or metal alloy, including aluminum, steel, brass, bronze, copper, gold, silver; and/or combinations thereof. The first needle body may comprise two sections along its length, the sections set at a non-zero angle to one another.
[0016] According to a further aspect of the disclosure the assembly includes a transition portion that connects the second end of the needle body with the first end of the cord where the transition portion has a smooth variation in diameter between a diameter of the needle body and a diameter of the cord.
[0017] According to a further aspect of the disclosure the assembly further comprises a second needle body, wherein the first and second needles bodies are shaped to allow a user to knit a fabric. The first needle body, cord, and adjustable stop may comprise a first needle assembly and the assembly may comprise a second needle assembly including the second needle body, a second cord attached thereto, and a second adjustable stop disposed on the second cord.
[0018] According to a further aspect of the disclosure there is provided a method of knitting fabric. The method may include the steps of positioning a plurality of stitches on the first needle body and the cord attached thereto, adjusting a position of the adjustable stop of the first needle assembly such that the plurality of stitches are compressed between the needle body and the adjustable stop of the first needle assembly, wherein the compressed stitches create a resiliency force, moving a first stitch of the plurality of stitches to the tip of the needle body of the first needle assembly, interlocking the first stitch with a newly formed stitch using tips of needle bodies of the first and second assemblies, placing the newly formed stitch on the second needle body, and delivering second stitches of the plurality of stitches to the needle body of the first assembly using the resiliency force. The method may further comprise adjusting a position of the second adjustable stop on the second cord so that the distance from a tip of the second needle body to the second adjustable stop is sufficient to hold the plurality of stitches.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
[0020] FIG. 1 shows a knitting needle assembly according to an embodiment of the disclosure;
[0021] FIGS. 2 a - c show a slider according to an embodiment of the disclosure;
[0022] FIG. 3 shows a slider according to a further embodiment of the disclosure;
[0023] FIGS. 4 a - b show a slider according to a still further embodiment of the disclosure;
[0024] FIG. 5 show two knitting needle assemblies according to an embodiment of the disclosure used to form a knitted workpiece;
[0025] FIG. 6 shows a knitting needle assembly according to a further embodiment of the disclosure;
[0026] FIG. 7 shows a knitting needle assembly according to a still further embodiment of the disclosure.
DETAILED DESCRIPTION
[0027] FIG. 1 shows a knitting needle assembly 100 according to an embodiment of the disclosure. A knitting needle 102 is connected with a cord 106 by a transition portion 104 . At the end of the cord opposite the needle is a stopper 110 . A moveable slide 108 is positioned on the cord 106 . Typically, two such assemblies are used by a knitter to form a knitted workpiece from interlocking stitches.
[0028] The needle 102 may be formed from any of a variety of materials and is preferably light in weight. Exemplary materials including hardwood such as rosewood, sheesham, or ebony, bamboo, polymer, metal or metal alloy, such as aluminum, steel, brass, bronze, copper, gold, silver, and/or combinations thereof. The surface of the needle 102 is preferable smooth to facilitate sliding of stitches across its surface. The needle has a tip 101 at the end opposite the transition portion 104 with a shape suitable for forming interlinked stitches of yarn.
[0029] The transition portion 104 provides a smooth surface between the needle 102 and the cord 106 over which stiches of yarn can slide as the needle assembly is used to knit. In this exemplary embodiment, the transition portion 104 has a frustoconical shape with the end connected with the needle 102 equal to the needle diameter and the end connected with the cord 106 equal to the cord diameter. Other shapes are also possible, including providing cylindrical portions equal to the needle and cord diameters, respectively, and a frustoconical portion between the cylindrical portions. According to another embodiment, the transition portion 104 is omitted and the cord 106 is connected directly with the needle 102 .
[0030] The transition portion 104 may be formed from the same material as the needle 102 or may be formed from a different material and joined to the needle 102 . According to one embodiment, the transition portion 104 is formed from a metal or metal alloy such as steel, brass, bronze, copper, gold, silver, a polymer, an elastomer, a composite material, and/or a combination of these.
[0031] Cord 106 is flexible and has a smooth surface to facilitate sliding of stitches of yarn along its length. According to one embodiment cord 106 is between about 12 inches and 60 inches long. According to a preferred embodiment, cord 106 is between about 24 inches and 48 inches long. According to a most preferred embodiment, cord 106 is about 36 inches long. Cord 106 may be formed from a plastic, a metal, a natural fiber, a composite material, or a combination thereof. Cord 106 may be a single filament or may be woven from strands of material or may be a formed from twisted or braided strands, metal wire, or combination thereof. According to a further embodiment, the cord includes a coating that reduces friction with the yarn and/or that resists wear.
[0032] According to one embodiment, cord 106 has a round cross section. According to another embodiment, cord 106 is formed as a flat strip of material. Cord 106 may have a curl so that it tends to form a curled-up configuration when not forced into a straight configuration. By providing a curl, cord 106 can be made to more easily assume a compact configuration when not in use. Cord 106 may include markings along its length, such as inch or centimeter markings or markings that correspond to a number of stiches forming a workpiece. Such markings may be useful during use to allow the knitter to easily measure the width of the workpiece as it is being formed or to determine a pattern of colors or stitch textures to use.
[0033] According to one embodiment, the cord can rotate with respect to the needle. This reduces twisting of the cord and eases knitting. The rotatable connection can be formed by swivel mechanism comprising part of the transition portion, by a rotatable connection, such as a ball-in-socket arrangement, between the cord and the transition portion or between the transition portion and the needle, or a combination thereof.
[0034] Slider 108 is disposed on the cord 106 . FIGS. 2 a - c show a slider according to one embodiment of the disclosure. FIG. 2 a shows a perspective view the slider 108 disposed on cord 106 . FIG. 2 b shows the slider before assembly. FIG. 2 c shows a cross section of the assembled slider 108 disposed on cord 106 . As shown in FIG. 2 b , the slider 108 consists of a button portion 112 , a receiver portion 114 , and a spring 116 . A through-hole 118 extends through the button 112 . Through-holes 120 are provided through opposing sides of the receiver 114 . As shown in FIG. 2 c , when the slider 108 is assembled, cord 106 extends through holes 118 , 120 . The inner diameter of holes 118 , 120 is somewhat larger than the outer diameter of cord 106 so that, when holes 118 , 120 are aligned, cord 106 moves easily through the holes. Spring 116 provides a force pushing button 112 out of cavity 122 . This force causes holes 118 , 120 to tend to misalign, thus engaging with and fixing the slider 108 to the cord 106 at a desired location along the cord. Pressing button 112 toward receiver 114 compresses spring 116 and causes holes 118 , 120 to align, thus unlocking slider 108 from cord 106 . When the slider 108 is unlocked, it can be repositioned along the length of cord 106 .
[0035] According to one embodiment, slider 108 is cylindrical. According to another embodiment, slider 108 is square, rectangular, oval, or other shape. Button 112 and receiver 114 may be formed from hardwood, metal, plastic, composite materials, or a combination thereof. According to a further embodiment, the slider may be a different mechanism suitable for releasably fixing to the cord such as a screw clamp or spring loaded clip.
[0036] As shown in FIG. 1 , stopper 110 is affixed to the end of cord 106 . Stopper 110 is larger than the diameter of hole 120 in the slider 108 and prevents the slider from moving off the end of cord 106 . Stopper 110 may be a knot formed in the end of cord 106 . Stopper 110 may also be an object such as a ball or a decorative item such as a crystal. Stopper 110 may include an embossable surface to allow a trademark, a logo, or personalized information, such as a monogram to be displayed. Stopper 110 may include a tool, such as a yarn cutter, scissors, row or stich counter, and the like.
[0037] According to one embodiment, stopper 110 includes a clip, magnetic catch, or other engagement mechanism designed to securely and removably connect the stopper 110 with the needle 102 or transition portion 104 . By engaging the engagement mechanism with the other portion of the assembly, the cord 106 is formed into a closed loop. A partially finished workpiece can be securely retained, stored, and transported with the cord in such a loop configuration. According to another embodiment, the engagement mechanism is disposed on the slider 108 , again forming the cord 106 into a closed loop to securely retain a partially finished workpiece. According to a further embodiment, the stopper 110 or slider 106 comprises a needle cap that securely and removably engages with the tip of the needle.
[0038] FIG. 3 shows cross section views of the button 112 and receiver 114 according to an alternative embodiment of the slider 108 . As with the embodiment described above, the button portion 112 and a receiver portion 114 have through-holes 118 and 120 for engaging cord 106 . Surrounding the through-hole in the button 112 is a liner 119 . The through-holes 120 in receiver 114 are likewise surrounded by a liner 121 . The liner 119 , 121 may be formed from an elastomer, such as silicone rubber, natural rubber, polyurethane, and the like that provides a high-friction contact with the surface of the cord 106 and/or that reduces wear or damage to the cord 106 as the slider is moved along the cord 106 .
[0039] Top and bottom surfaces of the button 112 and receiver 114 may also include features that improve grip. These features may include grooves or textured surfaces or coatings such as non-slip coatings that allow the knitter to securely hold the slider while repositioning it along the cord. The top and/or bottom surfaces of the button 112 and receiver 114 , respectively, may also be concave to allow the knitter to securely hold and operate the slider.
[0040] FIGS. 4 a and 4 b show another embodiment of a slider 108 . According to this embodiment, slider 108 is formed from an elastomeric material such as polyurethane or silicone rubber. The slider body 130 includes an opening 132 extending through the length of the slider 108 . Cord 106 extends through the opening 132 . The opening 132 has a lens-shaped cross section. As shown in FIG. 4 a , when no force is applied to the body 130 , the sides of the opening 132 press against the cord 106 , holding the slider 108 in place on the cord. As shown in FIG. 4 b , when force is applied in the directions shown by arrows 134 , the body 103 deforms, causing the lens-shaped opening 132 to expand away from the surface of cord 106 . In this configuration, slider 108 can be repositioned along cord 106 . When the force is release, body 130 rebounds to the configuration shown in FIG. 4 a , again fixing the slider to the cord.
[0041] According to one embodiment, both stopper 110 and transition portion 104 are larger than holes 120 of the slider. Stopper 110 is permanently affixed to cord 106 . When needle assembly 100 is assembled as shown in FIG. 1 , slider 108 cannot slide past stopper 110 and transition portion 104 and is captive on cord 106 . This arrangement prevents the slider 108 from becoming separated from the assembly 100 and misplaced. According to another embodiment, stopper 110 is removable from cord 106 , allowing the slider 108 to be removed from the cord 106 . According to this embodiment, the slider 108 can be replaced with a different slider.
[0042] The needle 102 , transition portion 104 , slider 108 and/or stopper 110 may include a surface suitable for holding markings such as a product logo, needle size information, and the like.
[0043] FIG. 5 shows two needle assemblies 100 l , 100 r used to form a workpiece 202 . The knitter manipulates needles 102 l , 102 r to form interlocking stitches of yarn 204 . If the knitter is knitting to the left as shown in FIG. 5 , the knitter moves a previously formed stitch to the tip of left needle 102 l and uses the tips of the left and right needles to form a new stitch that is moved onto right needle 102 r . The process is repeated, with newly stitches sliding along right needle 100 r and along cord 106 r . The position of slider 108 r on cord 106 r may be selected to accommodate the desired width of the workpiece.
[0044] The needle assembly of the present disclosure allows shorter needles to be used, regardless of the size of the workpiece because the workpiece is supported and retained on the cord. This arrangement is especially useful in the knitting of large garments, such as blankets and afghans where standard straight needles are generally too short to hold the amount of stitches needed. According to one embodiment, cords 106 l and 106 r can rest on a tabletop or in the knitters lap to support the weight of the workpiece and relieve strain on the knitter's hands. This is advantageous for knitting heavy, bulky or large items.
[0045] When stitches encounter slider 106 r they stop moving along the cord and accumulate on the cord. The position of slider 106 r is selected so that the required number of stitches needed to form the width of the workpiece 202 can accumulate on cord 106 r without interfering with the knitter's manipulation of the needles.
[0046] A method of knitting according to one embodiment of the disclosure adjustable sliders 108 l and 108 r allow the knitter to conveniently deliver previously formed stitches to the tips of needles 102 l and 102 r . Again, assuming the knitter is knitting to the left as shown in FIG. 5 , stitches are taken from left needle 102 l , joined with newly formed stitches by manipulating the yarn with needles 102 l and 102 r , and transferred to right needle 102 r . The newly formed stitches slide along needle 102 r and onto cord 106 r , as described above. As previously formed stitches are being removed from left assembly 100 l , the knitter moves left slider 108 l toward left needle 102 l while holding a grip on previously formed stitches on left needle 102 l . This pushes previously formed stitches toward the knitters left hand, compressing the stitches against one another and biasing them to move toward the tip of the left needle 102 l . The knitter can then conveniently deliver stitches from left needle 102 l to the tip of the needle for knitting. As previously formed stitches on the left needle are knitted to newly formed stitches and transferred to the right needle, the resilience of the stitches compressed between the knitter's left hand and the slider 108 l causes more stitches to move to the right from cord 106 l and onto the needle 106 l . The knitter does not have to continually move stitches from the bottom of the cord to the needle. Periodically, as previously formed stitches are knitted and transferred from the left needle 102 l the knitter repositions slider 108 l to maintain compression on the previously formed stitches.
[0047] With an embodiment of the present invention, by pulling slider 108 l closer to needle 102 l , the resilience of the stitches causes a force pushing the stitches toward the needle tip. The knitter can then control the delivery of previously formed stitches by allowing the stitches to slide toward the needle tip. Also, when the knitter is knitting to the left as shown in FIG. 5 , right slider 108 r can be moved farther out along cord 106 r so that newly formed stitches are not compressed, but instead, move easily away from the knitter's right hand. Once a row knitted to the left is complete, the knitter can adjust sliders 108 l , 108 r to reverse the process, this time compressing stitches on right assembly 100 r so that they are delivered to the tip of right needle 102 r and slide without interference onto cord 106 l of left assembly 100 l.
[0048] FIG. 6 shows another embodiment according to the disclosure. Assembly 400 is formed from needle 402 including threaded portion 403 at the end opposite the tip 401 . Transition portion 404 includes threaded hole 405 . Needle 402 is connected with transition portion 404 by threading threaded portion 403 into hole 405 . Cord 406 , slider 408 , and stopper 410 are similar to the cord, slider and stopper described above with respect to FIG. 1 . Needle 402 can be disconnected from transition portion 404 by disconnecting the threaded portions and connected with the transition portion 404 of a different assembly. This allows a variety of needles 402 to be interchangeably connected with the same cord 406 , slider 408 , and stopper 410 assembly. According to another embodiment, instead of a threaded connection between needle 402 and transition portion 404 , these elements can be removably connected with one another using a friction fit, a snap, a twist lock, or other removable connection mechanism.
[0049] According to a further embodiment of the disclosure, the components of assembly 400 are provided as part of a kit. The kit may include a plurality of needles 402 that can be interchangeably connected with a transition portion 404 , cord 406 , slider 408 , and stopper 410 . The plurality of needles 402 may have differing diameters, lengths, and/or cross sectional shapes that are appropriate for a variety of knitting projects. For example, the kit may include needles with sizes US# 11, 13, 15, 19, but is not limited to those sizes. The kit may also include a plurality of cord and slider assemblies of differing lengths to allow a knitter to select a cord with a length appropriate for a particular project. The kit may also include other materials, including instruction manuals, media containing instructional diagrams or video tutorials demonstrating the use of the assembly, patterns for projects, yarns, and/or other accessories.
[0050] FIG. 7 shows a further embodiment according to the disclosure. Needle 502 includes an angled portion 503 . Cord 506 , slider 508 , and stopper 510 are similar to the cord, slider and stopper described above.
[0051] While illustrative embodiments of the disclosure have been described and illustrated above, it should be understood that these are exemplary of the disclosure and are not to be considered as limiting. Additions, deletions, substitutions, and other modifications can be made without departing from the spirit or scope of the disclosure. Accordingly, the disclosure is not to be considered as limited by the foregoing description. | A knitting needle assembly has a needle body including a tip at one end and a cord connected to the needle body at other end. An adjustable slider is disposed on the cord. The cord stabilizes and holds stitches of yarn used to create a knitted workpiece. The distance between the needle tip and the slider can be adjusted by the user to accommodate the width of the knitted workpiece. Two such assemblies are used to knit. The sliders on each assembly can be adjusted to compress previously formed stiches of the workpiece so that the stitches are delivered to the needle body under a resiliency force. The sliders can also be adjusted to accommodate newly formed stitches without compression so they move freely away from the needle tip once they are formed. | 3 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The present disclosure relates to a flow meter having a cone shaped flow element. The present disclosure also relates to a flow meter having a flow element with dimensions that are selectively changeable.
2. Description of Prior Art
Facilities that handle fluids, such as refineries, chemical processing plants, terminals for loading and offloading fluids, transmission pipelines, and the like, typically employ flow meters within flow lines for measuring fluid flowrates through the flow lines. While some flow meters monitor flow external to a flow line, most flow meters have components within the flow line that interact with the fluid to obtain a measure of the flowrate. Some flow meters include rotating, elements, such as spinners or propellers that rotate in response to the fluid flowing past the flow meter. These flow meters monitor the rotational velocity of the rotating element and correlate it to the fluid velocity.
Other types of flow meters introduce a temporary restriction in the cross sectional area of the fluid stream and monitor a pressure differential created by flowing the fluid across the restriction. One type of restriction is an orifice plate, which as the name implies, is a plate set transverse to the flow with an orifice through axially formed through its mid portion. Another restrictive flow meter incorporates a Venturi tube with a reduced diameter throat through which the fluid flow being monitored is directed. Additional examples of flow meters restrict the cross sectional area of flow by suspending an obstruction in the path of the fluid flowing through the flow meter.
SUMMARY OF THE INVENTION
Disclosed herein is an example of a flow meter for measuring a flow of fluid that includes a housing, an obstacle suspended in the flow of fluid that is selectively changeable between configurations that occupy different percentages of a cross sectional area of the flow of fluid, and a pressure sensor in communication with the flow of fluid and that is selectively monitors pressure in the flow of fluid. The pressure sensor can be made up of an upstream pressure sensor that is disposed upstream of the obstacle; here the flow meter includes a downstream pressure sensor that is disposed downstream of the obstacle. Further in this example, the upstream pressure sensor can include an upstream pressure tap formed through a sidewall of a tubular in which the flow of fluid is directed, and wherein the downstream pressure sensor includes a downstream pressure tap formed through the sidewall of the tubular. The flow meter can further include a differential pressure sensor that is in communication with the upstream and downstream pressure sensors. In an example, the obstacle has an upstream end that is conically shaped and that has an outer surface that converges to a point, wherein a downstream end of the obstacle is conically shaped and has an outer surface that converges to a downstream point that is oriented in a direction away from the upstream point, and wherein the upstream and downstream ends are directly adjacent one another to define a ridge that circumscribes a mid-portion of the obstacle. The flow meter can include struts mounted to the upstream and downstream ends of the obstacle and that suspend the obstacle in the flow of fluid. In an embodiment, the obstacle has a downstream end with a shape that can include a planar surface or a hemispherical surface. A support may be included that mounts to the obstacle and which can selectively exert a radial force onto the obstacle for changing configurations of the obstacle. The obstacle can include a flexible frame. Optionally included is a cover over the frame that is substantially fluid impermeable. The support can be an upper support that includes a connecting rod that couples to the obstacle and a stud that extends from the connecting rod through a sidewall of the housing. The flow meter can further include a lower support that includes a connecting rod coupled to the obstacle and a stud that extends from the connecting rod through a sidewall of the housing. In one example, the flow meter includes spring coupled between the upstream end of the obstacle and a strut.
Also described herein is an example of a flow meter for measuring a flow of fluid and which includes a tubular housing intersected by the flow of fluid, and that is set inline in a flow line that handles the flow of fluid, an obstacle suspended in the tubular housing and in the path of the flow of fluid that is selectively changeable into multiple configurations that have varying diameters, and pressure taps formed through a sidewall of the tubular housing that are in communication with the flow of fluid. A differential pressure sensor can optionally be included that is in communication with the pressure taps. Changing the obstacle into different configurations changes a cross sectional percentage that the obstacle occupies in the flow of fluid. A support can be included that connects to the obstacle for selectively changing the obstacle into different configurations. In one example, the support includes a connecting rod having an end coupled with the obstacle, a stud having an end connected to an end of the connecting rod distal from the obstacle, and wherein an end of the stud projects radially through a sidewall of the tubular housing. The obstacle configuration can be changed manually or automatically. In one example of manually changing the configuration, threaded adjustment members couple to the obstacle, so that rotating the adjustment member alters obstacle diameter. An example of automatic changing includes sensing differential pressure across the obstacle, and making adjustments based on the sensed pressure.
An example of a method of measuring a flow of fluid is described herein and which includes monitoring a flow of fluid across a conically shaped obstacle, changing a configuration of the obstacle to change a percentage of the cross sectional area of the flow of fluid occupied by the obstacle, and sensing a pressure in the flow of fluid proximate the obstacle. The step of changing a configuration of the obstacle can be based on a value of pressure sensed in the flow of fluid.
BRIEF DESCRIPTION OF DRAWINGS
Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a side partial sectional view of an example of a flow meter having a flow element of varying configurations.
FIG. 2 is a side partial sectional view of an alternate embodiment of a flow meter having a flow element of varying configurations.
FIG. 3 is a schematic representation of a process circuit having flow meters that can be one or more of the types of FIGS. 1 and 2 .
While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout. In an embodiment, usage of the term “about” includes +/− 5% of the cited magnitude. In an embodiment, usage of the term “substantially” includes +/− 5% of the cited magnitude.
It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation.
FIG. 1 shows in a side partial sectional view an example of a flow meter 10 that is set between upstream and downstream portions 12 , 14 of a fluid flow line. Flow meter 10 includes an annular housing 16 with an upstream flange 18 on its upstream end and downstream flange 20 on its downstream end. Upstream and downstream flanges 18 , 20 respectively connect to flanges 22 , 24 on the upstream and downstream portions 12 , 14 . Shown suspended within housing 16 is a flow element 25 with upstream and downstream ends 26 , 27 . In the illustrated example, upstream end 26 has a generally conical in shape, and converges to a point distal from downstream end 27 and directed into a flow of fluid F. Downstream end 27 has a generally domelike shape with an apex that is substantially coaxial with upstream end 26 and on a side of downstream end 27 distal from upstream end 26 . The base portion of each of the upstream and downstream ends 26 , 27 meet at a middle portion of the flow element 25 . Struts 29 , 30 are shown mounted in the inner surface of the housing 16 and respectively couple with the upstream and downstream ends 26 , 27 to provide anchoring supports for the flow element 25 .
An upstream pressure tap 32 is shown formed through a sidewall of the housing 16 and upstream of strut 29 . A downstream tap 34 extends through a sidewall of housing 16 and downstream of strut 30 . Embodiments exist wherein the taps 32 , 34 are adjacent to struts 29 , 30 , or on the opposite side thereof. Lengths of tubing 36 , 38 have ends that connect respectively to the upstream and downstream pressure taps 32 , 34 . On ends opposite to their connection to the taps 32 , 34 , the lengths of tubing 36 , 38 communicate with a differential pressure sensor 40 . Thus, when the flow of fluid F makes its way through the upstream portion 12 and into the flow meter 10 , the cross-sectional area of the flow of fluid F is reduced by the presence of the flow element 25 , thereby introducing a pressure drop within flow meter 16 . By sensing pressures of the flow of fluid F at the pressure taps 32 , 34 , and comparing the sensed pressures with the differential pressure sensor 40 , a pressure drop due to the presence of the flow element 25 can be measured. Further, applying Bernoulli's theorem to the measured pressure drop along with physical parameters of the flow element 25 and the fluid F, a value for a fluid flow rate can then be calculated.
The flow element 25 of FIG. 1 is selectively changeable into different configurations; winch in turn can selectively change the diameter of the flow element 25 to one or more designated values. Embodiments exist where the changing configurations also changes the percentage of the cross-sectional area of the flow of fluid F that is occupied by the flow element 25 . In this example, the flow element 25 includes a frame 44 made of elongate structural elements that form the general outline of the flow element 25 . Arranged over the frame 44 is a rib array 46 , where rib array 46 is a collection of elongate elements, which in one example is greater than the number of elongate elements making up frame 44 . The application of the rib array 46 over frame 44 helps to give the outer surface of the flow element 25 a more uniform and continuous shape and to resemble a solid member. Over the rib array 46 and frame 44 is a membrane like cover 48 that is formed from a material that is generally impermeable by fluid. In an embodiment, cover 48 is pliable and generally conforms to the outer surface of the rib array 46 and frame 44 . Sample materials for cover 48 include polymers, elastomers, composites, metals, and combinations thereof.
Further included in the embodiment of the flow meter 10 of FIG. 1 are springs 50 , 52 which mount respectfully on the upstream and downstream ends 26 , 27 of flow element 25 . On ends opposite to their connection to flow element 25 , springs 50 , 52 couple with the struts 29 , 30 to thereby exert a stabilizing force on the flow element 25 . Further illustrated is that the cover 48 couples to spring 52 on the downstream end of flow element 25 . Sleeves 53 are provided over each of springs 50 , 52 that provide a protective covering and shield the springs 50 , 52 from debris. Optional push rods 54 , 56 are shown on the upstream and downstream ends 26 , 27 that insert into the struts 29 , 30 and which provide support of the flow element 25 within housing 16 as well as radially centering flow element 25 within the housing 16 .
Still referring to FIG. 1 , a lower support 58 is shown that contributes to radially propping the flow element 25 within housing 16 . Lower support 58 includes a lower connecting rod 59 shown attached to flow element 25 , and could be connected to the frame 44 , rib array 46 , or both. A stud 60 that is at least partially threaded on its outer surface has an end connected to an end of lower connecting rod 59 distal from flow element 25 . A bellows 62 is included within lower support 58 which is axially resilient, and circumscribes a portion of stud 60 within housing 16 . Stud 60 projects through a bore 64 formed in a sidewall of housing 16 . Nuts 66 , 68 coaxially thread onto the lower end of the stud 60 for securing the lower support 58 to housing 16 . Bellows 62 can optionally be welded to the lower connecting rod 59 and to the inner surface of housing 16 . A seal (not shown) lines bore 64 to prevent fluid leakage across the lower support 58 and to the outside of housing 16 . An upper support 69 provides attachment of the flow element 25 to housing 16 , and includes an upper connecting rod 70 shown connected to frame 44 of flow element 25 on an end that is distal from where flow element 25 attaches to lower support 58 . Connecting rod 70 can be connected to the flow element 25 in the same manner lower connecting rod 59 connects to flow element 25 . A stud 71 has an end that attaches to an end of upper connecting rod 70 distal from flow element 25 . A bellows 72 circumscribes a portion of stud 71 disposed within housing 16 , and opposing ends of the bellows 72 can be welded to the upper connecting rod 70 and inner surface of housing 16 . An end of stud 71 projects through a bore 74 formed radially in the housing 16 . Portions of the outer surface of stud 71 are threaded. Nuts 76 , 78 threadingly mount onto the end of stud 71 outside of housing 16 . A seal (not shown) provides sealing around bore 74 to prevent fluid from leaking therethrough. It should be pointed out that bores 64 , 74 can be on opposite sides of the housing 16 (i.e. 180° apart around the axis of the housing 16 ), or angularly spaced apart at less than 180° from one another. Further, the bores 64 , 74 can be at the same or different axial locations along the housing 16 .
In one example of operation, selectively loosening or tightening nuts 76 , 78 radially displaces the actuation rod 70 with respect to the sidewall housing 16 ; which in turn pulls or pushes against the rib array 46 and frame 44 and changes their respective diameters. As the diameters of the rib array 46 and frame 44 change, so do the diameters of the cover 48 and flow element 25 . As the bellows 62 , 72 connect between the connecting rods 59 , 70 and inner surface of housing 16 , the bellows 62 , 72 will expand or compress with changing diameter of the flow element 25 . Providing sealing interfaces between the bellows 62 , 72 and connecting rods 59 , 70 , and bellows 62 , 72 and housing 16 forms a flow barrier between the inside of the housing 16 and bores 64 , 74 . Altering the configuration of flow element 25 modifies the cross-sectional area occupied by the flow element 25 in the overall flow of fluid F. As such, reconfiguring the flow element 25 can selectively affect a pressure reading(s) taken by the differential pressure sensor 40 . In this example, springs 50 , 52 may elongate to allow for the radial expansion of the flow element 25 . Changing the physical dimensions of the flow element 25 during use allows flow meter 10 to readily adapt to changes in the fluid flow, such as variations in the fluid flow rate due to different process scenarios or upset conditions. In one embodiment, a flow rate of the fluid F is based on a pressure sensed in the flow meter 10 . The pressure sensed can be pressure at taps 32 , 34 , or a difference between the pressure at taps 32 , 34 , such as that measured by differential pressure sensor 40 .
One or more forms of the Bernoulli equation can be used to estimate a flow rate of the fluid F based on the sensed pressure(s). It is within the capabilities of one skilled in the art to correlate the sensed pressures to a rate of the flow of fluid F. Moreover, factors relating to the changing shape and/or configuration of the flow element can be determined without undue experimentation. In one alternate embodiment, the configuration of the flow element 25 can be changed in response to pressure sensed upstream of the flow element 25 , downstream of the flow element 25 , across the flow element 25 , or combinations thereof. A controller (not shown) can be included that is in communication with the pressure taps and automatically alters the configuration of the flow element 25 based on comparing a sensed pressure with a designated pressure.
Shown in FIG. 2 is another example of a flow meter 10 A, which has a flow element 25 A, like the flow element 25 of FIG. 1 , has an outer diameter that can be selectively changed via manipulation of an actuation rod 70 A. Unlike the flow element 25 A of FIG. 1 , however, flow element 25 A has a downstream end 27 A that has a generally conical shape and whose outer surface converges to a point proximate its coupling with spring 52 A and adjacent strut 30 A. Similarly, the flow element 25 A includes a frame 46 A with elongate elements that give the general shape of the double-ended cone, and an overlay of the rib array 46 A which provides a better approximation of a continuous outer surface of the flow element 25 A. Also included in the example of FIG. 2 , is a cover 48 A which spans the outer surface of frame 44 A and rib array 46 A, and made from a material that is generally impermeable to fluid, thereby giving characteristics of the flow element 25 A to be that of a substantially solid element. Also, similar to the embodiment of FIG. 1 is that the :flow meter 10 A of FIG. 2 . includes upper and lower supports 69 A, 58 A that respectfully include connecting rods 70 A, 59 A, bellows 72 A, 62 A, and studs 71 A, 60 A. The percentage of the cross sectional area of the flow of fluid F occupied by the flow elements 25 , 25 A is (D FE 2 /D F 2 )*100, where D FE is diameter of the flow elements, and D F is the diameter of the flow of fluid F.
FIG. 3 is a schematic representation of an example of a process circuit 80 in which the flow elements described herein may be employed. In the example, a column 82 is shown having a bottoms line 84 which corrects fluid within column 82 to a pump 86 for pressurization. Downstream of pump 86 is one example of an application of a flow meter 88 and where flow meter 88 is positioned just upstream of a control valve 90 . In this example, flow information is forwarded from the flow meter 88 to the control valve 90 . A reflux line 92 routes fluid exiting control valve 90 back into column 82 . A gravity line 94 is shown branching from bottoms line 84 and upstream of pump 86 which delivers fluid in bottoms line 84 to a destination vessel 96 . A flow meter 98 , which can be any of the other flow meters described herein, is shown provided in gravity line 94 . As such, flow meters 88 , 98 can provide information about the flow of fluid flowing within lines 92 , 94 respectively.
The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. for example, the fluid being monitored by the flow meters described herein can be liquid, vapor, or multi-phase flow. Additionally, pressures at each of the pressure taps 32 , 32 A, 34 , 34 A can be monitored and recorded in addition to monitoring a pressure differential between axially spaced apart taps. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims. | A flow meter for measuring fluid flow in a tubular that includes an obstruction suspended in a path of the fluid flow, and where the obstruction has a conical shape. The obstruction can be conically shaped on its upstream and downstream ends, or can be conically shaped only on its upstream end. When only the upstream end is conically shaped, the downstream end can be substantially planar or shaped like a hemisphere. Optionally, the aspect ratio of the obstruction can be changed by manipulating supports that suspend the obstruction within the flow meter. | 6 |
FIELD AND BACKGROUND OF THE INVENTION
This invention relates to a tridimensional plotter, that is to say a machine in which a tool support, in particular an operating head on which tools of different types can be mounted, can move following a tridimensional surface defined through a CAD system or detected and digitized directly by the machine through proper instruments which are also provided for being mounted on the abovementioned mobile support.
SUMMARY OF THE INVENTION
The control software of the machine includes also a CAM system and a post-processor, so as to allow a direct connection between the plotter and a CAD system, to avoid the need of devices which carry out the intermediate processings of the surface file generated by the latter.
This characteristic makes the machine use very simple and easy even for not very expert personnel.
In accordance with the invention, the plotter is a system able to carry out many machinings, such as drawings, surveys, scannings, digitizings, millings, etc. and is very useful in engineering and design offices where, after drawing a structure, it is necessary to make a model in real scale to check both the aspect and to perform tests, carry out modifications, etc.
For example this need is found in several design offices, such as offices where complicated surfaces like cars bodyworks are studied and designed.
In cases such as that given in the example it is necessary, once the drawing is ready, to make a rapid and cheap model in order to see how it really is and then, after making all the necessary modifications, bring them to the CAD surface for the subsequent production and die manufacturing phases, etc.
It is clear that in situations/like the aforementioned one using the traditional instruments has serious problems. As a matter of fact it is very difficult to carry out with accuracy the drawing of a model to which a series of modifications has been carried out manually.
There are already several appliances used to carry out the single above mentioned operations, either one or the other.
For example, there are devices capable of scanning surfaces in which a probe moves along the surface taking the coordinates of each point and giving a series of signals allowing the consequent mathematization and computer data processing.
Moreover, there are machines, e.g. the bidimensional plotters, capable of reproducing the drawing and machine tools to reproduce the model starting from the drawing or better from a file containing all the data relevant to this drawing once it has been properly processed.
All these devices are not suitable for the use in a technical office because of their often very big dimensions, and because it would be necessary to have different machines available and their use is rather complicated.
In compliance with the known techniques a CAD-CAM system able to create a mathematical model of the tridimensional surface is necessary as well as a system able to process this mathematical model by means of a milling processor; all that because the CAD-CAM systems create tool paths having formats independent of the machine's format.
In order to better understand the process used for the models realization with the means now available, we could make a reference to FIG. 1, where the blocks scheme of the processing and development process of the data generated by the CAD system is given in order to get the realization of the 3D model. The CAD system generates a surface file which shall be input or sent to a CAM system; some undelayable inputs, e.g. tool profile and dimensional tolerances, shall then be given to this CAM system.
On the basis of these data the CAM system processes, starting from the surface file, a series of tool paths or "CL file". po However, this CL file is not compatible with the format of the CNC file and therefore it is necessary for further processing by means of a second processor or "post-processor".
It is also necessary to supply the system with other guidelines for the programmation at the tool pivot point, e.g. tool length, linearization tolerance, feed control at the tool centre, etc. The post-processor in output gives a file called "NC file", usually recorded on a magnetic means.
All these operations usually take place in the data processing center, while the following ones are carried out in the workshop where the machine tool is placed.
Once the NC file of the machine tool has been loaded, the parameters for checking the remaining freedoms (compensation, tool diameter and length, feed alteration and spindle rate, symetry, piece slot, etc.) shall be set; after these operations, the machining can be started.
It is clear that applying the abovementioned procedure costs a lot of money and takes a lot of time.
Several equipments and skilled workers are necessary and the machining times become very long, too.
That is why, in this field there is the need for a device, that is a kind of tridimensional plotter able to automatically carry out all the above operations.
A device like that, which shall be used in a technical office, shall be of limited dimensions, but will have a ratio between the volume of the piece to be machined and the outer volume of the machine apt to allow the production of models having dimensions not too limited and however comparable with the real ones. Moreover it shall be easy to use, so that it can be used also by technicians without a specific training in the field, nevertheless it shall be capable of carrying out every kind of required machinings with high accuracy so as to allow the use of the product, which can be a model or a surface file, even for mass production with no need for further operations, data reprocessing, etc.
Therefore, it is clear that the realization of a device like that can solve some serious technical problems in the production of both the mechanical and the electronic part of the machine.
The device shall be able to carry out machinings with tolerances of a few hundredths of a millimeter, which brings about the necessity for a rigid structure able to take up--without strains--the reactions transmitted by the tool during the machining and the consequently high accelerations (up to 0.5 G) given to the tool support during its shiftings.
This characteristic does not help in meeting the requirement of a light and solid structure to be placed in an office together with the necessary cabinet and sound-proofing system.
Furthermore the piece insertion shall be easy to carry out, even when the available space is poor.
Moreover the machine, in order to be really practical, shall be easy to use even for unskilled personnel, so as to avoid several intermediate steps in the processing of the surface file, which now requires the participation of skilled technicians.
Even as far as the parameters to be given to the machine during the different phases of the processing cycle are concerned, it is necessary for this operation to be as simple as possible.
The problem is then worsened by the fact that, unlike the bidimensional plotters in which the tool position--in this case a pen point--is defined through just two Cartesian coordinates, in a 3D plotter it is necessary to define both the tool position in the space--by means of three Cartesian coordinates--and its orientation, by means of direction cosines of the normal to the surface.
Besides the abovementioned ones, there are also other parameters intervening according to the kind of machining to be carried out and to the used tool; these parameters will be later specifically discussed in the description of the electronic part of the machine.
From the foregoing, it is clear that the problem is rather complicated.
BRIEF DESCRIPTION OF THE DRAWINGS
This and other problems can be solved by the plotter of the invention, which will now be described in detail by giving a nonlimiting example with reference to the enclosed figures in which:
FIG. 1 is a flowchart illustrating the process for using the invention; FIG. 2 is an overall view of the plotter; FIG. 3 is a front partially sectional view of the plotter of the invention; FIG. 4 is a side partially sectional view of the machine; FIG. 5 is a magnified detail of FIG. 4; FIG. 6 is the plotter plan view; FIG. 7 is a vertical section of the plotter; FIG. 8 is a vertical section with reference to a plane orthogonal to that of FIG. 7; FIG. 9 is the horizontal section of the machine base; FIG. 10 is the block diagram of the machine control devices; FIGS. 11 and 12 are block diagrams of the hardware structure of the plotter; and figures from 13 to 15 show the operating diagrams of the linear interpolator, of the control loop and of the axes control CPU.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 2, the plotter in accordance with the invention consists of a base 1 on which there are two parallel portal structures or beams 2 and 2' supported by four uprights 3 placed at the machine corners.
A cross support 4 of a sleeve 5 is supported on the two beams and slides on them.
At the lowest extremity of the sleeve 5, which vertically slides inside the cross support, there is a head 6 having 2 degrees of freedom. In this way the head 6 moves on the plane XZ between the uprights 3 along axis X and between the beams 2 and a piece-holding table 7 along the axis Z.
The piece-holding table 7 moves in a direction orthogonal to the axes X and Z (Y axis) and is the last one of the three movement orthogonal axes.
Besides the abovementioned working axes X, Y and Z there are the polar axes A and C the head 6 is provided with, making a total amount of five degrees of freedom. This overall configuration gives remarkable advantages: by making the head 6 slide in the space between a couple of box beams 2 and 2' it is possible to limit the structure dimensions giving at the same time the max. stiffness.
Moreover it is possible to place the head support at a lower height, thus lowering the application point of the reaction forces applied to the structure when the machine is working, with a resulting decrease of the strains.
Thanks to the abovementioned characteristics, it is possible for a compact machine to have an inner machining area having dimensions near to those of the machine itself.
This utmost compactness is also reached thanks to the fact of providing the head 6 holding a cantilevered spindle instead of a fork-mounted spindle, which causes a further reduction of the necessary space.
In FIG. 4, 6' is an electrospindle mounted on the head 6.
The FIGS. 7, 8 and 9 show the composition of the plotter structure.
The uprights 3 consist of a round tube 8 and of a square tube 9 linked to a sheet 10 connected through seam welding (FIG. 9).
In the upper part (FIG. 8), the tubes couples 8 connect to similar tubes 11 and 11' being the edges of the beams 2 and 2'.
In the lower part a trestlework consisting of square tubes 12 welded to basis section bars 13 (FIG. 7) acts as support for the mobile table 7, which slides along two recirculating ball guides on a framework 27 (FIG. 3) fixed to the base 1 through the supports 14 (FIG. 7).
The trestlework defines the spaces for the electronic part and for the control systems of the machine (FIG. 3).
In this structure the cross support 4 moves along the beams 2 and 2' sliding on a couple of prismatic ball guides by means of as many couples of sliding-blocks indicated with 15 and 16 respectively, the former placed on a vertical plane and the other on a horizontal plane thus allowing an easier adjustment of the cross support, for example by means of micrometer screws or the like.
The shifts of the support 4 with the head 6 along the X axis are controlled by a D.C. motor 17 operating a ball screw 18, which engages a slider 19 integral with the support 4 (FIG. 5). An encoder, not shown, takes these movements.
Even the movements of the axes Y and Z (piece-holding table and sleeve) of the machine are obtained through recirculating ball screws and motors and detected by as many encoders.
In FIG. 4 the number 20 is the motor controlling the shifting of the piece-holding table 7 along the axis Y, by transmitting the motion through a belt 21 to a recirculating ball screw 22 connected to the table 7.
An encoder or detecting cell 23 is connected to, and is in line with the motor 20, a solution common to detecting systems of the axes X, Y and C. A couple of pneumatic cylinders 24 (FIG. 3) are placed beside the sleeve 5 to give a thrust upwards able to counterbalance the weight of the sleeve.
Openings 25 for dust suction are in the base near the plane 7.
As the beams 2 are supported by 4 uprights placed at the machine corners, it is possible to enter the machine from all four sides, thus making the loading of the pieces to be machined easier, even if of big dimensions.
To this aim, near the edges of the plane 7 and at the same height, there are the rolls 26.
As said before, in the plotter according to the invention, the post-processor processing the file of data coming from the CAD is integrated with other electronic control devices of the machine. This subject needs further precise information.
Usually downstream the CAD system there is a CAM system producing a file (CL file) which is then translated by a post-processor in order to obtain a working file (NC-file). This, once transferred to the machine tool, controls its operation.
Once the CAM has a surface available (e.g. imported from the CAD using the Bezier Poles or the multinomial coefficients, etc.) it is necessary to define the procedure for generating the tool trajectories.
In order to obtain the tool center movements, it is necessary to previously set compulsory paths on the surface (e.g. isoparametric lines) for the tangency point between tool and piece and then, taking into account the tool axis orientation, the positioning is fully determined by the tangency condition; as an alternative it is possible to bind directly in a partial way the movement of the tool centre by keeping a residual degree of freedom allowing the tangency condition in an unset point between tool and piece (as in the case of milling for parallel planes).
Then it is necessary to code--by means of a proper transducer (post-processor)--the calculated paths in a format understandable by the machine controller.
The present calculation method of the machining paths in CAM brings about the necessity of coming back to the data processing centre to correct the programs which have shown NC programming errors in the machine. The result is an unconfortable two-way information flow between two systems which are logically and physically separated. The flexibility of the segmented paths is scanty, since a programm for the production of a standard piece is indissolubly linked to the use of a particular tool and by the dimensional accuracy required by the CAM system. Finally, the quantity of information contained in a NC-file is usually far higher than that being sufficient to define the machined surface. All these circumstances prevent the creation of piece-programs archives at the machine.
In the plotter according to the invention a local subsystem is provided including a non-linear interpolator able to create trajectories and paths with compensation of the tool dimensions, which works the surfaces in standard format taking into account a set of simple guidelines defined at the moment of the execution and directly controls the addresses of the machine axes.
As a consequence the CAM processing steps, the post-processing and the NC-file interpretation are gathered in just one phase by the machine controller.
There is the possibility of managing archives of compact and flexible information for the immediate execution of inventory pieces and, moreover, of carrying out modifications, geometrical parametrizations, etc. by means of utility programs implemented on the machine.
The system is able to process traditional NC files, which can be even produced in site for later execution when the performances of the whole machine-control are to be fully exploited by eliminating complicated calculations in real time.
The technician shall just tranfer the surface file created by CAD in the 3D plotter in accordance with the invention and set in the machine the values necessary to obtain the model.
FIGS. 11 and 12 show the block diagrams of the hardware structure of the machine control unit.
Characteristic of the system is the standard MULTIBUS II, which is a BUS architecture independent of the processor, with a parallel system 32 Bit BUS, local store BUS and I/O expansion BUS.
This structure with multiple BUSes gives the advantage that every BUS is optimized for a specific function and that different BUSes can carry out parallel operations, thus increasing the processing speed.
The connections C01 . . . C06 allow the access to the MULTIBUS of as many CPUS, in order to carry out the listed activities.
In particular the I/O expansion BUS connects the interface cards with the sensors and the actuators present on the machine. The connection between the I/O EXPANSION BUS and the AXES CONTROL CPU is shown in detail in FIG. 12.
Element 28 is a card having the AXES CONTROL CPU, consisting of a connection interface to MULTIBUS II and a local BUS connecting such interface to the processing CPU and to a 1/0 MIX interface. The I/O MIX interface is linked to a similar I/O MIX interface present on a card 29 and linked to a DATA DRIVER, a CONTROL LOGIC and a memory labeled Config. Data
The DATA DRIVER is made of a series of logical gates in order to uncouple the processing of signals coming from the interface I/O MIX, with the LOCAL BUS TOWARDS THE FIELD.
The CONTROL LOGIC is a control logic of Data Drivers and of the LOCAL BUS TOWARDS THE FIELD; it defines the timing for the synchronization between the signals created by the I/O MIX BUS and going to the LOCAL BUS TOWARDS THE FIELD.
The store 30 is a RAM non-volatile memory containing information about the personalization for the interface card configuration. The AXES CONTROL CPU obtains from the temporary file created by the Post-Processor CPU, the movement blocks given with reference to the coordinates of the milling cutter center and of the orientation of the operating head. By means of the abovementioned information the linear interpolator is steered, thus producing the data to be supplied to the Control Loop.
The task of the linear interpolator is to generate, for each sampling interval, the increase in space and the relevant speed, starting from initial and final positions and orientations of the operating head, so as to be able to steer the machine "axes interlockings". The operating diagramm of the linear interpolator is given in the blocks diagramm shown in FIG. 12. The linear interpolator is activated at each sampling interval of the system and, after calculating the new position as well as the new speed, it activates the CONTROL LOOP.
The task of the CONTROL LOOP is to maintain the real position of the machine as near as possible to the theoretical position generated by the interpolator.
To this aim, after each system sampling interval the axes values are read and compared with the theoretical position value calculated by the interpolator. The result of such comparison, changed into an analog signal, is supplied to the axes interlockings. The operating scheme is shown in FIG. 13.
The AXES CONTROL CPU receives the file containing the linear blocks generated by the SURFACES MANAGING CPU and carries them out, by controlling at the same time the machine axes, in compliance with the scheme given in FIG. 14.
A technician expert in this field will be then able to design several modifications and changes, which shall be deemed as falling within the scope of this invention. | The invention relates to a tridimensional multifunction plotter, comprising a support of a tool which can move with a high precision following a predetermined tridimensional surface.
The mobile part of the machine comprises a multifunction head to which several devices like laser distance measuring devices, digital and analogic probes for the surveying and digitizing of a bidimensional and/or tridimensional surface, or tools of various kinds for making a tridimensional model starting from a surface defined through a CAD system.
A hardware-software subsystem is provided, parallel connected with the CPU of the machine, to obtain an integrated system which allows a direct connection of the machine with a CAD system so allowing the operator to input the various working parameters directly to the plotter, without the need of an external processing the data file generated by the CAM system, to convert it into a file compatible with the numeric controls of the machine. | 6 |
RELATED APPLICATION
[0001] This application claims priority and benefit from Swedish patent application No. 0400219-2, filed Feb. 3, 2004, the entire teachings of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a method and a device for forming patterns for bead-inlaid plates.
BACKGROUND
[0003] Bead-inlaid plates are laid using artificial resin beads, also called tube beads, comprising short thick-walled cylindrical tube pieces of different colours. They can be laid to form various motifs. Computer programs for producing patterns for bead-inlaid plates are previously known, the programs including a drawing program part for producing a picture from which a pattern then is obtained. In the published European patent application 0 829 378 a method and a device for automatically producing a bead-inlaid plate from a given picture are disclosed. A picture is converted to an electronic format or already exists in an electronic format, the electronic representation is fed to an image processing unit that divides the picture in square areas and analyzes the colour of each area and determines a suitable colour for a bead to be placed on a position corresponding to the place of the analyzed area in the original picture, and thereupon the information determined by the image processing unit is input to an apparatus in which beads are placed on a base according to said information.
SUMMARY OF THE INVENTION
[0004] It is an object of the invention to provide a method and a device for forming patterns for bead-inlaid plates that can use previously produced, original pictures.
[0005] In a method of forming patterns for bead-inlaid plates original pictures such as photographs are used which are converted to a digital, bitmapped representation. Thereupon, a pattern is produced from the digital representation by dividing the original picture using a grid of intersecting lines and then a colour matching for each square.
[0006] The method is performed by a user using a computer including associated software that is divided in various blocks or units. The computer including the software is an aid or assisting device for interactively creating patterns for bead-inlaid plates from pictures. Thus, the patterns are individually created and hence each pattern is unique. Thus, a personal interpretation of a photograph or another digital picture can be obtained. The individual patterns are created by adjusting colours, the light and contrast thereof. The number of different colours used in the grid dividing process can be determined by the user. The possibility of manual adjustment of individual beads after a grid dividing step gives the final personal interpretation.
[0007] The method offers the possibility for the user herself/himself or for her/him together with other persons to compose a bead-inlaid plate according to the new, created bead pattern which can also be seen as a new, created picture. Then, tube beads are placed having the calculated/chosen colours on a base, that can be a plate having upstanding pins and thereafter they can also be glued or melted to each other. Alternatively, they can obviously also be placed on a base having a frame and be adhesively bonded thereto.
[0008] The method cannot be compared to the previously known automatic apparatus for producing bead-inlaid plates mentioned above.
[0009] Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the methods, processes, instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] While the novel features of the invention are set forth with particularly in the appended claims, a complete understanding of the invention, both as to organization and content, and of the above and other features thereof may be gained from and the invention will be better appreciated from a consideration of the following detailed description of non-limiting embodiments presented hereinbelow with reference to the accompanying drawings, in which:
[0011] FIG. 1 is a schematic view of a computer monitor including a digitalized picture shown thereon,
[0012] FIG. 2 is a schematic view of a computer monitor including input fields for selection of format,
[0013] FIG. 3 is a schematic view of a computer monitor including a pattern for a bead inlaid plate and input fields for selection of colour quantities,
[0014] FIG. 4 is a schematic view similar to FIG. 3 including input fields for changing individual beads,
[0015] FIG. 5 is the digitalized picture according to FIG. 1 including a superposed grid of intersecting lines,
[0016] FIG. 6 is a picture including colour codes for beads obtained from FIG. 5 ,
[0017] FIG. 7 is a flow chart of a method of creating patterns for bead-inlaid plates, and
[0018] FIG. 8 is a block diagram of a device for creating patterns for bead-inlaid plates.
DETAILED DESCRIPTION
[0019] In creating a pattern for a bead-inlaid plate one starts from an original picture that is converted or has been converted to a digitalized bitmapped picture, e.g. a picture that is defined by an image file intended for processing in computers and to be shown on a monitor. The picture or image file can for example be obtained using an electronic image scanner. The picture file is processed by a specially designed program 1 in a computer 3 , see FIG. 8 , that also includes a monitor 5 , input means such as a keyboard 7 and a computer mouse 9 , and a printer 11 . The receiving operation is executed by a unit 13 in the program, see also block 81 in the flow chart of FIG. 7 . Then is first shown, by a program unit 15 , a schematic image on the monitor of the computer, as is also seen in FIG. 1 , see also block 103 in FIG. 7 . In the displayed image, in a field 17 , a picture 19 is shown that is obtained from the image file.
[0020] Thereupon, either the total picture can be selected or a part thereof using suitable input operations, by means of the program unit 21 , see also block 105 in FIG. 7 . On the shown picture two delimiting lines 23 can be provided extending horizontally and two delimiting lines 25 extending vertically, said lines being in their initial position placed at the edges of the picture. A user can, by operating the mouse 9 associated with the computer, displace selected ones of the delimiting lines to selected positions so that a selected area of the picture is delimited. Alternatively, an area can be delimited by first depressing a mouse button 27 with the cursor at the first corner of the desired area and thereupon pulling the cursor to the corresponding corner and there releasing the mouse button. A third possibility of selecting the size of the area is to set, using the computer mouse, a suitable size as a percentage of the total area by operating an indicator 29 in a field 31 or, using the keyboard 7 , to write the size as a percentage of the size of the total area in an input field 33 . The position of the area in the picture is selected by clicking on arrow symbols 35 using the computer mouse. By clicking on a suitable button 37 in the image displayed on the monitor, thereupon the delimited area is selected, see block 105 in FIG. 7 .
[0021] Then the format of the bead-inlaid plate is selected, i.e. the dimensions of the bead-inlaid plate. They can either be given as the dimension of the plate in lateral and height directions and preferably as the numbers of beads that the bead-inlaid plate is to obtain in the lateral and height directions. In order to perform this selection, a new image is displayed on the monitor, see FIG. 2 , including suitable input fields and buttons, by means of a program unit 39 , see also block 107 in FIG. 7 . The input fields can for example include fields 41 for selecting predetermined numbers of beads in the side and height directions and fields 43 for input of numerical values. By clicking on a suitable button 45 in the image displayed on the monitor thereupon the delimited area is selected, see block 109 in FIG. 7 . By clicking on another button 47 the user can if desired also return to the image previously displayed on the monitor to modify the selected area.
[0022] The image file is now processed by the program 1 , see block 111 in FIG. 7 . For the selected area, see block 113 in FIG. 7 , the numbers of beads which are to be used horizontally and vertically are determined if they have not been indicated by the user in the preceding step. The picture is divided in a grid of intersecting lines so that squares having an equal size are formed, each of which corresponds to a bead, see FIG. 5 , by a program unit 49 , see also block 115 in FIG. 7 . For each square the image information in the bitmap file, i.e. those pixels that correspond to the area of the square, is processed by a program unit 51 , see block 117 in FIG. 7 , and according to a suitable algorithm a colour hue is determined, selected among colour hues that are available for the artificial resin beads, for a best agreement between the colour hue in the square and the colour hue of the selected bead, see block 119 in FIG. 7 . The beads can for example be provided in 30 different colour hues numbered Nos. 1-30. A resulting pattern including numbers for calculated colour hues is shown in FIG. 3 . The program 1 shows, by means of a program unit 53 , the result of the determination on the computer monitor by displaying a new image, see FIG. 3 , in which, in the image 55 of the selected area for each square, only the calculated colour hue is shown or a picture of a bead having the colour hue calculated for this square is shown, see block 121 in FIG. 7 .
[0023] In the selection of format the program can also by itself suggest a format and show a picture such as in FIG. 5 having a grid of intersecting lines. Thereupon the user can modify the format by changing the number of beads horizontally or vertically. After such a modification a new grid of intersecting lines can be shown which can be again modified, compare the block 123 in FIG. 7 . Such a modification of format can also be made after the image on the monitor screen according to FIG. 3 has been displayed, by operating a suitable button such as 56 in FIG. 3 . When the user is satisfied with the format she/he can click on a suitable confirming button that is displayed in the same time as the picture having the grid of intersecting lines.
[0024] Using the image displayed on the monitor and suitable input operations, the user can change, as is executed by a program unit 58 , different colour quantities of the shown picture 55 , such as its lightness, its colour saturation and colour mapping, by operating suitable symbols or changing suitable fields, that are simultaneously displayed on the monitor. Such symbols and fields can for example include colour scales, “colour scale mappings”, scales having a movable field, “indicator field”, that can be pulled in one of opposite directions by clicking and pulling, using the computer mouse, and input fields for suitable quantities. Such a scale and such an input field for brightness are shown at 57 , 59 , for contrast at 61 , 63 , for shading or tinting in red at 65 , 67 , for shading or tinting in blue at 69 , 71 . A particular colour hue or a plurality of colour hues can be excluded by the user clicking on a indicator field 73 existing in each colour hue field 75 in a colour palette 79 that is included in the image displayed on the monitor. The user's inputs in regard of the changes are confirmed by clicking on a suitable button, such as the button 79 , “Create pattern”, see block 125 in FIG. 7 . After such a change, see block 127 in FIG. 7 , the resulting picture including the overlaid grid of intersecting lines or including images of individual beads, such as in FIG. 3 , is shown. When the user is satisfied with the colour quantities, she/he can click on a suitable confirming button such as 81 , compare block 129 in FIG. 7 .
[0025] The user can thereafter, according to her/his desire, individually change the colour hue of each bead. Then, a new imaged on the monitor is displayed by a program unit 83 , see FIG. 4 . Then, the user can indicate a square or bead selected in the shown picture 85 and thereupon click on a colour hue in a colour palette 87 displayed on the monitor, in which palette the colour hues of all available beads are shown, see block 131 in FIG. 7 . Thereupon, again the picture 85 is shown including the changed colour hue in the previously indicated square field, see block 133 in FIG. 7 . The user can repeat the same procedure for each square and finally terminate the changes by clicking on a suitable button 89 in the image displayed on the monitor, compare block 135 in FIG. 7 . The user can also return to the previous step of selecting colour quantities by clicking on another button 91 .
[0026] Finally, the selected pattern can be saved as a file that indicates the resulting pattern including numbers of selected colour hues of each square/bead, see block 137 in FIG. 7 . The number of beads of each colour hue that is needed is calculated, see block 1379 in FIG. 7 . Pictures can be printed by means of a program unit 91 that show the selected pattern for the laying operation including colour hues and including numbers of colour hues together with information about the number of beads of each colour hue that is required, see block 141 in FIG. 7 . Alternatively, only a black and white picture including numbers of each colour hue for each square can be printed, compare FIG. 6 , see block 143 in FIG. 7 .
[0027] While specific embodiments of the invention have been illustrated and described herein, it is realized that numerous additional advantages, modifications and changes will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative devices and illustrated examples shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. It is therefore to be understood that the appended claims are intended to cover all such modifications and changes as fall within a true spirit and scope of the invention. | In a method of forming patterns for bead-inlaid plates original pictures such as photographs are used which are converted to digital, bitmapped representations. From such a representation a pattern is then produced by a user selecting an area of the represented picture, by dividing the picture using a grid of intersecting lines forming squares and then a color matching in each square. In an interactive process, the colors in the squares are modified. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 15/237,229, filed Aug. 15, 2016, which is a continuation of U.S. application Ser. No. 14/718,794, filed May 21, 2015, now U.S. Pat. No. 9,419,758, issued Aug. 16, 2016, which is a continuation of U.S. application Ser. No. 13/982,318, filed Jul. 29, 2013, now U.S. Pat. No. 9,042,305, issued May 26, 2015, which is a 371 National Stage of PCT/CN2012/070409, filed Jan. 16, 2012, and is based upon and claims the benefit of priority from prior Chinese Patent Application No. 2011 10 045 560.5, filed Feb. 22, 2011, the entire content of each of the foregoing applications is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of wireless communications and in particular to an apparatus and a method for antenna management.
BACKGROUND OF THE INVENTION
[0003] Global information networks are evolving rapidly toward Internet Protocol (IP)-based Next Generation Networks (NGNs) along with the dramatic development of computer and communication technologies. Another important feature of the next generation networks lies in coexistence of a plurality of radio technologies to form heterogeneous radio access networks.
[0004] FIG. 1 illustrates a schematic diagram of heterogeneous radio access networks in the prior art. As illustrated in FIG. 1 , there are a variety of heterogeneous radio access networks which can be divided into a Wide Area Network (WAN), a Metropolitan Area Network (MAN), a Local Area Network (LAN) and a Personal Area Network (PAN) in terms of their coverage ranges, a point-to-multipoint single-hop network, a multi-hop network, a mesh network and an ad-hoc network in terms of their network architectures, etc. All or a part of these radio access network access an IP-based core network in a wired or wireless manner to obtain service for a user. Thus, the access networks can be connected to a heterogeneous access network manager by which the access networks are managed.
[0005] The heterogeneous radio access networks are significant from the respective perspectives of a radio technology, a coverage range, a network architecture, network performance, etc., and they form three-dimensional coverage in terms of geographical distribution and cooperate to provide a user with Ubiquitous radio multimedia services with various contents. Radio spectrum resources available to these access networks are relatively rare.
[0006] In the next generation networks, the radio access networks interconnected over the IP-based core network can exchange information to offer an opportunity for an improved utilization rate of resources on one hand. On the other hand, the heterogeneous radio access networks form three-dimensional coverage with resource contention and interference to make it difficult to utilize the resources effectively. It is thus desirable to design an effective antenna management apparatus and method for efficient utilization of the resources of the next generation networks.
SUMMARY OF THE INVENTION
[0007] A brief summary of the invention is given below to provide basic understanding on some aspects of the invention. It is noted that the summary is not an exhaustive description of the invention. It is not intended to define a key or important part of the invention, nor is it intended to define the scope of the invention. It only aims to give some concepts in a simplified form as a preface to the detailed description that follows.
[0008] The invention is intended to address at least the foregoing technical problem in the prior art to improve a chance of multiplexing spectrum resources in order for efficient utilization of resources of next generation networks.
[0009] According to an aspect of the invention, there is provided an antenna management method including: collecting resource use information from managed access networks; selecting the access networks joining antenna scheduling from the managed access networks according to the resource use information to form an antenna scheduling set, wherein the access networks using the same spectrum resource form the same antenna scheduling set; grouping wireless links of each access network in the antenna scheduling set into one or more wireless link clusters, wherein each wireless link cluster includes one or more wireless links of the same access network which have the same transmitting node or the same receiving node; allocating wireless resources to all the wireless link clusters of the antenna scheduling set such that interference between all the wireless link clusters of the antenna scheduling set is within a predetermined range; and sending a wireless resource allocation result to the access network in which each wireless link cluster is located.
[0010] According to another aspect of the invention, there is provided an antenna management apparatus including: a resource use information collector configured to collect resource use information from managed access networks; and an antenna scheduler including: an antenna selector configured to select the access networks joining antenna scheduling from the managed access networks according to the resource use information to form an antenna scheduling set, wherein the access networks using the same spectrum resource form the same antenna scheduling set; a link cluster determiner configured to group wireless links of each access network in the antenna scheduling set into one or more wireless link clusters, wherein each wireless link cluster includes one or more wireless links of the same access network which have the same transmitting node or the same receiving node; and a resource scheduler configured to allocate wireless resources to all the wireless link clusters of the antenna scheduling set such that interference between all the wireless link clusters of the antenna scheduling set is within a predetermined range, and to send a wireless resource allocation result to the access network in which each wireless link cluster is located.
[0011] In the method and apparatus according to the above aspects of the invention, access networks joining antenna scheduling among managed access networks are grouped into different antenna scheduling sets, where access networks using the same spectrum resource form the same antenna scheduling set; wireless links in each access network are grouped into one or more wireless link clusters; and wireless resources are allocated to all the wireless link clusters in the antenna scheduling set so that interference between all the wireless link clusters of the antenna scheduling set is within a predetermined range Thus, access networks as many as possible can operate concurrently over the same spectrum resource within a tolerant interference range to thereby improve a chance of spectrum multiplexing in order for efficient utilization of the resources. Furthermore, as compared with the case that a resource is allocated per wireless link, a wireless resource is allocated per wireless link cluster to thereby lower the amount of calculation required for antenna scheduling.
[0012] Furthermore, another aspect of the invention further provides a computer program product on which computer readable instruction codes are stored, the instruction codes upon being read and executed by a computer causing the computer to perform an antenna management process, the antenna management process including: collecting resource use information from managed access networks; selecting the access networks joining antenna scheduling from the managed access networks according to the resource use information to form an antenna scheduling set, wherein the access networks using the same spectrum resource form the same antenna scheduling set; grouping wireless links of each access network in the antenna scheduling set into one or more wireless link clusters, wherein each wireless link cluster includes one or more wireless links of the same access network which have the same transmitting node or the same receiving node; allocating wireless resources to all the wireless link clusters of the antenna scheduling set such that interference between all the wireless link clusters of the antenna scheduling set is within a predetermined range; and sending a wireless resource allocation result to the access network in which each wireless link cluster is located.
[0013] Furthermore, another aspect of the invention further provides a storage medium carrying a program product on which computer readable instruction codes are stored, the instruction codes upon being read and executed by a computer causing the computer to perform an antenna management process, the antenna management process including: collecting resource use information from managed access networks; selecting the access networks joining antenna scheduling from the managed access networks according to the resource use information to form an antenna scheduling set, wherein the access networks using the same spectrum resource form the same antenna scheduling set; grouping wireless links of each access network in the antenna scheduling set into one or more wireless link clusters, wherein each wireless link cluster includes one or more wireless links of the same access network which have the same transmitting node or the same receiving node; allocating wireless resources to all the wireless link clusters of the antenna scheduling set such that interference between all the wireless link clusters of the antenna scheduling set is within a predetermined range; and sending a wireless resource allocation result to the access network in which each wireless link cluster is located.
[0014] These and other advantages of the invention will become more apparent from the following detailed description of preferred embodiments of the invention with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The foregoing and other objects, features and advantages of the invention will become easier to understand from the following description of embodiments of the invention with reference to the drawings. Components in the drawings are merely intended to illustrate the principle of the invention. In the drawings, identical or similar technical features or components will be denoted with identical or similar reference numerals.
[0016] FIG. 1 illustrates a schematic diagram of heterogeneous radio access networks in the prior art.
[0017] FIG. 2 illustrates a schematic diagram of a relationship between an antenna management apparatus according to embodiments of the invention and radio access network.
[0018] FIG. 3 illustrates a schematic block diagram of an antenna management apparatus according to one embodiment of the invention.
[0019] FIG. 4 illustrates a flow chart of an antenna management method performed by the antenna management apparatus according to the embodiment.
[0020] FIG. 5 illustrates a flow chart of collecting information by a resource use information collector according to one embodiment of the invention.
[0021] FIG. 6 illustrates a flow chart of collecting information by a resource use information collector according to another embodiment of the invention.
[0022] FIG. 7 illustrates a flow chart of initiating antenna scheduling by a resource use efficiency analyzer according to one embodiment of the invention.
[0023] FIG. 8 illustrates a flow chart of forming an antenna scheduling set by an antenna selector according to one embodiment of the invention.
[0024] FIG. 9 illustrates a flow chart of forming an antenna scheduling set by an antenna selector according to another embodiment of the invention.
[0025] FIG. 10 illustrates a schematic diagram of a representation of an antenna-scheduled object according to one embodiment of the invention.
[0026] FIG. 11 illustrates a flow chart of allocating a wireless resource by a resource scheduler according to one embodiment of the invention.
[0027] FIG. 12 illustrates a flow chart of selecting an independently-scheduling link cluster group by a resource scheduler according to one embodiment of the invention.
[0028] FIG. 13 illustrates a schematic diagram of an antenna beam setting according to one embodiment of the invention.
[0029] FIG. 14 illustrates a schematic block diagram of a computer in which the method and apparatus according to the embodiments of the invention can be embodied.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Embodiments of the invention will be described below with reference to the drawings. An element and a feature described in one drawing or one implementation of the invention can be combined with an element and a feature illustrated in one or more other drawings or implementations. It shall be noted that a representation and a description of components and processes irrelevant to the invention and known to those ordinarily in the art have been omitted in the drawings and the description for the sake of clarity.
[0031] The location of an antenna management apparatus according to an embodiment of the invention can be set flexibly. FIG. 2 illustrates a schematic diagram of a relationship between the antenna management apparatus according to the embodiments of the invention and radio access network. For example, as illustrated in the (a) part of FIG. 2 , the antenna management apparatus according to the embodiment of the invention can reside in a heterogeneous access network manager to perform antenna management on heterogeneous radio access networks in a service range of the heterogeneous access network manager. As illustrated in the (b) part of FIG. 2 , the antenna management apparatus can reside in a backbone network of a specific access network to perform antenna management on several proximate cells in the access network. As illustrated in the (c) part of FIG. 2 , the antenna management apparatus can alternatively reside in a base station BSI of a specific access network to perform antenna management on the access network itself and heterogeneous access networks consisted of other proximate access networks.
[0032] FIG. 3 illustrates a schematic block diagram of an antenna management apparatus according to one embodiment of the invention, where the antenna management apparatus 300 includes: a resource use information collector 310 configured to collect resource use state data from managed access networks; and an antenna scheduler 320 configured to perform antenna scheduling on the access networks according to the resource use state data collected by the resource use information collector 310 and to transmit an antenna scheduling result to the access networks.
[0033] Optionally, the antenna management apparatus 300 can further include a resource use efficiency analyzer 330 , represented by a dotted box in FIG. 3 , configured to analyze the resource use state data, to locate access networks with a low resource utilization rate and to initiate antenna scheduling. Furthermore, optionally, the antenna management apparatus 300 can further include a storage device configured to store the collected resource use state data of the radio access networks. For example, the storage device is a resource use state database (illustrated as DB in FIG. 3 ) 340 represented by a dotted box in FIG. 3 . It can be appreciated that the resource use state data can alternatively be stored in a storage device in another form.
[0034] It shall be appreciated that the respective components represented by the dotted boxes relate to only preferred or alternative implementations but may not necessarily be included in the antenna management apparatus 300 . Furthermore, it shall be appreciated that the antenna management apparatus 300 can further include any combination of the respective components represented by the dotted boxes in addition to the resource use information collector 310 and the antenna scheduler 320 .
[0035] An operation flow of the antenna management apparatus according to the embodiment of the invention will be described below with reference to FIG. 4 to FIG. 13 .
[0036] FIG. 4 illustrates a flow chart of an antenna management method performed by the antenna management apparatus according to this embodiment. In the step S 410 , the resource use information collector 310 of the antenna management apparatus collects resource use state data from managed access networks. Those skilled in the art can appreciate that the resource use state data collected by the resource use information collector 310 include, for example, available wireless resources, adopted radio technologies, time or space-dependent variations of resource utilization rates, etc., of the respective access networks.
[0037] Furthermore, the resource use information collector 310 can further collect an antenna scheduling request from the managed access networks as will be described below. In this context, both the resource use state data and the antenna scheduling request can be referred to resource use information.
[0038] In the step S 420 , an antenna selector 321 in the antenna scheduler 320 selects the access networks joining antenna scheduling from the managed access networks according to the resource use state data to form an antenna scheduling set, where the access networks using the same spectrum resource form the same antenna scheduling set.
[0039] In the step S 430 , a link cluster determiner 322 in the antenna scheduler 320 groups wireless links of each access network in the antenna scheduling set into one or more wireless link clusters. Here, each wireless link cluster includes one or more wireless links of the same access network which have the same transmitting node or the same receiving node, for example.
[0040] Then in the step S 440 , a resource scheduler 323 in the antenna scheduler 320 allocates wireless resources to all the wireless link clusters of the antenna scheduling set such that interference between the wireless link clusters is within a predetermined range. Here, the wireless resource may be resources in the time domain, resources in the frequency domain, resources in the code domain or any combination thereof.
[0041] The antenna scheduler 320 performs antenna scheduling by selecting the access networks joining antenna scheduling to form an antenna scheduling set and grouping wireless links of each access network into a wireless link cluster and allocating wireless resources to all the wireless link clusters in the antenna scheduling set.
[0042] Thereafter in the step S 450 , the resource scheduler 323 in the antenna scheduler 320 sends a wireless resource allocation result to the access networks in which the wireless link clusters are located as the antenna scheduling result.
[0043] It shall be noted that the steps given here will not necessarily be performed in a defined order. For example, the step S 430 of grouping into a wireless link cluster alternatively can be performed before the step S 420 of forming an antenna scheduling set and wireless links can be grouped into a cluster for each managed access network.
[0044] A process of collecting information by the resource use information collector 310 will be described below with reference to the flow charts illustrated in FIG. 5 and FIG. 6 . The resource use information collector 310 can collect resource use information by sending an information collecting request to the managed access networks periodically or can collect resource use information by receiving information data transmitted from the managed access networks on their own initiatives. FIG. 5 and FIG. 6 illustrate examples of these two scenarios respectively.
[0045] In the example of FIG. 5 , the resource use information collector 310 collects resource use information on its own initiative. Typically, this collection pattern is performed periodically.
[0046] In the step S 510 , the antenna management apparatus, particularly the resource use information collector 310 , sends an information collecting request, e.g., an information collecting request instruction InfoCollect_request, to the respective access networks. This signaling can carry an identifier of target information to be collected as needed. Thus, the access networks can hereby transport the corresponding information to thereby reduce network traffic.
[0047] In the step S 520 , the respective access networks judge whether to send information according to whether they have updated information upon reception of the information collecting request.
[0048] If there is updated information, then in the step S 530 , the access networks set an information collecting response signaling InfoCollect_reply to True and send the signaling to the antenna management apparatus to notify the antenna management apparatus that the access networks have information to be transmitted. If there is no updated information, then in the step S 560 , the access networks set InfoCollect_reply to False and send the signaling to the antenna management apparatus to notify the antenna management apparatus that the access networks have no information to be transmitted.
[0049] The resource use information collector 310 makes judgment upon reception of the response signaling. If the response signaling InfoCollect_reply is True, then in the step S 540 , the resource use information collector 310 prepares for reception and sends an information reception signaling Info Receive_ready to the access networks. If the response signaling InfoCollect_reply is False then the resource use information collector 310 performs no operation.
[0050] The access networks send information data InfoData to the antenna management apparatus in the step S 550 upon reception of Info Receive_ready.
[0051] In the example of FIG. 6 , the access networks initiate collection of resource use information. Typically, this collection pattern is performed upon dramatic change in performance of the access networks.
[0052] In the step S 610 , the access networks send an information sending request, e.g., information sending request signaling InfoSend_request to the antenna management apparatus 300 , particularly the resource use information collector 310 .
[0053] In the step S 620 , the resource use information collector 310 judges whether to receive information according to a condition upon reception of the request.
[0054] If reception is accepted, then in the step S 630 , the resource use information collector 310 sets an information sending response signaling InfoSend_reply to True and sends the signaling to the access networks to notify the access networks that reception is allowed. If reception is rejected (for example, due to a current heavy network load), then in the step 650 , the resource use information collector 310 sets the information sending response signaling InfoSend_reply to False and sends the signaling to the access networks to notify the access networks that reception is rejected.
[0055] The access networks send information data InfoData to the resource use information collector 310 upon reception of InfoSend_reply which is True. The access network perform no operation if they receive InfoSend_reply which is False.
[0056] According to one embodiment of the invention, the resource use information collector 310 classifies the information data upon reception of the information data. If the information data is an antenna scheduling request signaling AntennaSehedule_request, then the resource use information collector 310 forwards the signaling to the antenna scheduler 320 to initiate antenna scheduling. If the information data is resource use state data, then the resource use information collector 310 stores the data into a storage device, e.g., a resource use state database 340 and sends an information analyzing request signaling InfoAnalyze_request to the resource use efficiency analyzer 330 to initiate a resource use efficiency analysis.
[0057] In an embodiment of the invention, the resource use state database 340 is mainly used to store resource use state data of the access networks served by the antenna management apparatus 300 . Contents of the database 340 can include information internal to the access networks and information between the access networks. The information internal to the access networks is generally obtained by collecting resource use state information. The information internal to the access network includes, for example, available spectrum resources and adopted radio technologies of the access networks, architectures of the access networks (e.g., an antenna feature and distribution thereof, a cell coverage range, a link relationship in a multi-hop network, etc.), statistical data of resource use conditions of the access networks, etc. Particularly, the statistical data of the resource use conditions of the access networks can include a time-dependent variation of power control, a time-dependent variation of the utilization rate of wireless resources, a location-dependent variation of a signal to noise ratio of a user, a time-dependent variation of the number of users and other statistical data. For example, the information between the access networks includes a relative location and distance between the access networks (particularly, a relative location and distance between antennas), statistical information of an interference condition between the access networks, etc. The information between the access networks can be obtained in numerous existing methods. For example, a GPS has been widely applied nowadays, and specific physical locations of the respective access networks can be positioned by a GPS to thereby calculate a relative location and distance between the access networks.
[0058] The resource use state database 340 can be provided by the resource use information collector 310 with data and updates to thereby provide the antenna scheduler 320 and the resource use efficiency analyzer 330 with data required for their operations.
[0059] Operations of the resource use efficiency analyzer 330 will be described below with reference to FIG. 7 . FIG. 7 illustrates a flow chart of analyzing resource use efficiency and initiating antenna scheduling by the resource use efficiency analyzer according to one embodiment of the invention. In the step S 710 , the resource use efficiency analyzer 330 determines access networks with a low resource utilization rate by analyzing the resource use state data collected by the resource use information collector 310 . For example, the resource use efficiency analyzer 330 can inquire the resource use state database 340 and selects access networks with a resource utilization rate below a predetermined threshold UrnizationRate Th as a set U of objects under examination. The resource utilization rate of an access network can be represented as the average of the ratio of the throughput of a system to the capacity of the system over a specific past period of time.
[0060] In the step S 720 , the resource use efficiency analyzer 330 judges whether the resource utilization rate is lower due to interference. The resource utilization rate may be lower due to numerous factors, for example, a smaller number of active users, a low total amount of required traffic bandwidth, interference from another access network, etc. Typically, antenna scheduling need to be performed only if the resource utilization rate is lower due to interference. By way of an example, the resource use efficiency analyzer 330 can judge whether the resource utilization rate is lower due to interference as follows: the analyzer examines the average signal to noise ratio SNR over a specific past period of time of each access network in the set U of access networks selected in the step S 710 . If the average signal to noise ratio is below a predetermined threshold SNR Th , then it indicates that the access network is subject to relatively large interference, and it can be considered that the resource utilization rate thereof is lower due to interference. If the average signal to noise ratio is above the predetermined threshold SNR Th , then it indicates that the access network is subject to relatively small interference, it can be considered that the resource utilization rate thereof is lower due to another factor than interference, and the access network can be removed from the set U. Elements in the set U of access networks finally obtained in this method are access networks with a low resource utilization rate and strong interference for which antenna scheduling are required. Of course, whether the resource utilization rate thereof is lower due to interference can alternatively be judged by another existing method.
[0061] If it is judged in the step S 720 that the resource utilization rate of the access network is lower due to interference, which indicates that antenna scheduling is required to be initiated, then the resource use efficiency analyzer 330 initiates antenna scheduling in the step S 730 . Stated otherwise, when the set U is not null, the resource use efficiency analyzer 330 initiates antenna scheduling. This can be performed by sending an antenna scheduling request signaling AntennaSchedule_request to the antenna scheduler 320 . If it is judged in the step S 720 that the resource utilization rate of the access network is lower due to another factor than interference, then the resource use efficiency analyzer 330 determines that no antenna scheduling is required for the access network in the step S 740 .
[0062] In addition to making a resource utilization rate analysis, the resource use efficiency analyzer 330 can further be used to maintain the resource use state database. A part of the result of a resource utilization rate analysis is helpful for future antenna management and thus can be stored into the resource use state database 340 after it is judged whether to perform antenna scheduling. For example, the access networks are flagged for which it is judged in the step S 720 that the resource utilization rate is lower due to interference and thus antenna scheduling is required. The resource use information collector 310 can collect information specifically for these flagged access networks to thereby improve the efficiency of the antenna management apparatus.
[0063] As described above, the operations of the antenna scheduler 320 to perform antenna scheduling on the access networks to allocate wireless resources may be initiated by the access networks or the resource use efficiency analyzer 330 . The antenna scheduler 320 selects the access networks joining antenna scheduling to form an antenna scheduling set according to the resource use state data accessible from the resource use state database 340 and allocates wireless resources to wireless link clusters in the antenna scheduling set to thereby perform antenna scheduling.
[0064] Operations of the antenna selector 321 in the antenna scheduler 320 to select the access networks joining antenna scheduling to form an antenna scheduling set will be described below with reference to FIG. 8 and FIG. 9 .
[0065] In an embodiment as illustrated in FIG. 8 , in the step S 810 , the antenna selector 321 selects the access networks to form candidate antenna scheduling sets according to network features of the access networks, e.g., coverage ranges, geographical distributions, available spectrum resources, adopted radio technologies, spectrum utilization efficiencies and other factors. The access networks using the same spectrum resource are grouped into the same candidate antenna scheduling set. By way of an example, two methods of selecting access networks to form candidate antenna scheduling sets will be given below.
[0066] In one method, a set of radio access networks served by the antenna management apparatus 300 is assumed as V, where each element represents one access network vεV. A set of available resources is assumed as S, where each element sεS represents a segment of spectrum resource. The antenna selector 321 selects from V the radio access network using a spectrum resource s 1 εS to form a candidate antenna scheduling set U 1 ; selects from V the radio access network using a spectrum resource s 2 εS to form a candidate antenna scheduling set U 2 ; and so on, and selects from V a number I of disjoint candidate antenna scheduling sets U 1 , U 2 , . . . , U I for which antenna scheduling is required, that is, Σ 1≦i≦I U i ⊂ V and U i □U j =φ, 1≦i≠j≦I, as candidate antenna scheduling sets.
[0067] In the other method, a set of radio access networks served by the antenna management apparatus 300 is assumed as V, and the set U of access networks for which antenna scheduling is required is obtained from the resource use efficiency analyzer 330 . Each access network vεU in U has a low resource utilization rate resulting from interference. Access networks in V using the same spectrum resource as v are selected to form a candidate set U 1 ; U-U 1 is taken as a new set U, and the foregoing operations are performed on the new set U until U becomes a null set. Thus, a number I of disjoint sets U 1 , U 2 , . . . , U 1 , that is, Σ 1≦i≦I U i ⊂ V and U i □U j =φ, 1≦i≠j≦I, can be selected from V as candidate antenna scheduling sets.
[0068] Further referring to FIG. 8 , in the step S 820 , the antenna selector 321 inquires the access networks in the candidate antenna scheduling set about whether to join current antenna scheduling. The antenna selector 321 sends a join schedule request signaling JoinSchedule_request(U 1 ) to the access networks in U 1 to inquire them about whether to join current antenna scheduling of the set U 1 and sends a signaling JoinSchedule_request(U 2 ) to the access networks in U 2 to inquire them about whether to join current antenna scheduling of the set U 2 ; and this inquiry process is repeated for all the other sets U 3 , . . . , U 1 in sequence.
[0069] Then, in the step S 830 , the antenna selector 321 receives feedbacks of the respective access networks as to join antenna scheduling. The respective access networks determine whether to join current antenna scheduling according to their own resource occupying priorities, resource utilization rates and performance statistical results and feed it back to the antenna selector with a join schedule response signaling JoinSehedule_reply: if the signaling is True, then it indicates joining; and if it is False, then it indicates no joining. The respective access networks can further return their own amounts of required resources and pre-scheduling results to the antenna selector 321 as reference information for antenna scheduling.
[0070] In the step S 840 , the antenna selector 321 finally determines the respective antenna scheduling sets U 1 , U 2 , . . . , U I according to the feedbacks of the respective access networks. For example, those access networks which do not join current scheduling can be removed from the candidate antenna scheduling set, or those access networks which do not join scheduling can be flagged.
[0071] A feedback of an access network can relate to the following several types:
[0072] (1) The access network v 1 has a high spectrum resource occupying priority and a statistic shows a high resource utilization rate thereof, so the access network v 1 chooses to continue the use of its own scheduling scheme instead of joining antenna scheduling. However, in order to prevent the access network v 1 from being interfered by another access network, the access network v 1 feeds its own scheduling result, i.e., pre-scheduling result, back to the antenna selector 321 hoping that the antenna management apparatus avoids interference thereto while performing antenna scheduling.
[0073] (2) The access network v 2 also with a high priority but with a low resource utilization rate over a past period of time accepts joining antenna scheduling for improved performance thereof.
[0074] (3) The access network v 3 with a low resource occupying priority can not have a resource available upon resource contention with a highly prioritized user, and a statistic shows that the access network has a low chance of accessing a resource over a long period of time. Thus, v 3 wishes to join antenna scheduling for a higher chance of accessing a resource.
[0075] (4) The access network v 4 with a low resource occupying priority has good performance although it did not join antenna scheduling over a past period of time, so it wishes to continue the use of its own scheduling scheme instead of joining antenna scheduling.
[0076] The antenna selector 321 classifies the access networks in the candidate set into four categories according to whether to join antenna scheduling and spectrum use priorities upon obtaining the feedback results: the first category relates to a high spectrum use priority without joining antenna scheduling; the second category relates to a high spectrum use priority and joining antenna scheduling; the third category relates to a low spectrum use priority without joining antenna scheduling; the fourth category relates to a low spectrum use priority and joining antenna scheduling.
[0077] The antenna management apparatus 300 can adopt different process strategies for different types of access networks. For example, for the first category of access network, the pre-scheduling result provided from the access network is taken as a reference for antenna scheduling, and an influence on the scheduling result is avoided as much as possible while allocating a wireless resource. For the second category of access network, antenna scheduling is performed and a wireless resource is allocated preferentially to thereby ensure a high resource utilization rate thereof. For the third category of access network, no operation is performed. For the fourth category of access network, antenna scheduling is performed, but no chance of using a wireless resource will be guaranteed.
[0078] FIG. 9 illustrates another example of operations of the antenna selector 321 to select the access networks joining antenna scheduling to form an antenna scheduling set. A difference of the example in FIG. 9 from that in FIG. 8 lies in that the antenna selector 321 firstly inquires the access networks served by the antenna management apparatus about whether to join antenna scheduling and then selects the access networks joining antenna scheduling to form an antenna scheduling set. As illustrated, in the step S 910 , the antenna selector 321 inquires the access networks served by the antenna management apparatus whether to join antenna scheduling. In the step S 920 , the antenna selector 321 receives feedbacks of the respective access networks as to join antenna scheduling. In the step S 930 , the antenna selector 321 selects the access networks joining antenna scheduling to form an antenna scheduling se according to the feedbacks of the access networks, where the access networks using the same spectrum resource are grouped into the same candidate antenna scheduling set.
[0079] After the antenna scheduling set is formed, the link cluster determiner 322 in the antenna scheduler 320 groups wireless links of each access network in the antenna scheduling set into one or more wireless link clusters. The resource scheduler 323 allocates wireless resources to all the wireless link clusters of the antenna scheduling set so that interference between all the wireless link clusters is within a predetermined range. Actually, an antenna-scheduled object is a wireless link cluster in an access network joining scheduling.
[0080] In a wireless network, a scheduled object is typically a wireless link in an access network to join scheduling. There are a large number of wireless links in a wireless network, particularly a wireless communication network where scheduling is performed periodically. In order to lower the amount of calculation required for scheduling, wireless links are clustered in the invention into a wireless link cluster as a scheduling unit.
[0081] By way of an example, a possible method of clustering wireless links is as follows:
[0082] For a network with a central control node, each wireless link between infrastructure nodes (e.g., a base station and a relay node) forms separately a wireless link cluster; and a wireless link between an infrastructure and a user served directly by the infrastructure forms a wireless link cluster between the infrastructure and the user, particularly downlink wireless links between the infrastructure and a plurality of users served directly by the infrastructure can form one or more wireless link clusters, and uplink wireless links between the infrastructure and the plurality of users served directly by the infrastructure can form one or more wireless link clusters.
[0083] For a peer-to-peer network, each wireless link forms separately one wireless link cluster.
[0084] In general, a wireless link cluster can be formed of one or more wireless links in the same access network which have the same transmitting node or the same receiving node.
[0085] For the sake of a convenient description, a wireless link cluster can be described by the following parameters in an embodiment of the invention.
[0086] (a) Wireless link cluster identifier Link_id
[0087] A wireless link cluster identifier relates to an antenna identifier Antenna_id and a link cluster direction identifier Direction_id. An antenna identifier Antenna_id is a unique identifier of antenna in a range served by a heterogeneous access network manager to which the antenna belongs and can be formed of a cell identifier Cell_id and an antenna identifier Subcell_id of the antenna in a cell. A link cluster direction identifier Direction_id is only for an access network with a central control node. There are two link cluster directions: an uplink link cluster UL is a flow direction of a data stream toward the central control node, and a downlink link cluster DL is a flow direction of a data stream away from the central control node.
[0088] A possible identification method will be given below as an example. For a network with a central control node, a wireless link cluster (including a single wireless link) between infrastructure nodes (e.g., a base station and a relay node) is identified by a transmitting antenna and a receiving antenna denoted as (txAntenna — id, rxAntenna_id). A wireless link cluster between an infrastructure node and a user is identified by an antenna and a link cluster direction. Specifically, a downlink link cluster is identified by a transmitting antenna and a downlink link cluster direction denoted as (txAntenna_id, DL), and the wireless link cluster at this time includes downlink wireless links between the infrastructure and a plurality of users served directly by the infrastructure; and an uplink link cluster is identified by a receiving antenna and an uplink link cluster direction denoted as (rxAntenna_id, UL), and the wireless link cluster at this time includes uplink wireless links between the infrastructure and the plurality of users served directly by the infrastructure.
[0089] When downlink (or uplink) wireless links between an infrastructure and a plurality of users served directly by the infrastructure form a plurality of wireless link clusters, typically a downlink (or uplink) wireless link between one transmitting (or receiving) antenna in the infrastructure and a user served directly by the infrastructure is grouped into one wireless link cluster. Thus in this case, different wireless link clusters can be well distinguished by the wireless link cluster identifier described above.
[0090] For a peer-to-peer network, a wireless link cluster (including a single wireless link) is identified by a transmitting antenna and a receiving antenna of the included wireless link denoted as (txAntenna_id, rxAntenna_id).
[0091] (b) Transmitting antenna type txAntenna_type
[0092] A transmitting antenna type of a wireless link cluster includes an omni-directional antenna, a directional antenna, a smart antenna and a set of antennas, where the set of antennas describes a wireless link cluster formed of a plurality of uplink links with the same receiving node. An antenna type is described by an antenna beam. An antenna beam is described by three parameters (δ, θ, r) as illustrated in the part (a) of FIG. 10 . FIG. 10 illustrates a schematic diagram of a representation of an antenna-scheduled object according to one embodiment of the invention. In the figure, o represents the location of an antenna. x represents a reference direction which will be the same as antennas in a range served by the same heterogeneous access network manager. θ represents the radiation angle of an antenna beam. For example, the value of θ for an omni-directional antenna is 360°, the value of θ for a 120-degree directional antenna is 120°, and the value of θ for a smart antenna ranges from 0˜360°. δ represents a deflection angle of the radiation angle of the antenna beam relative to the reference direction, and the value of δ for an omni-directional antenna is typically 0°. r represents the radiation radius of the antenna beam which can be defined as the average distance from the location of the antenna to a location with a signal field strength attenuated below a predetermined threshold. The result of power control will influence the value of r in that power control typically has r take several discrete values in the range of 0˜r max with r max being the maximum value of r. A beam description of a set of antenna will be described by an envelope of antenna beams of respective transmitting antennas in the set of antennas. The envelope of the beam of the set of antenna is defined as a convex curve with the least area including the antenna beams of all the transmitting antennas. For the least effort of calculation in practice, an antenna beam of a transmitting antenna of a wireless link cluster can be described approximately as a sector (including a round) with the least area including all the antenna beams. If this is approximated as a round, then the transmitting antenna of the wireless link cluster is processed as an omni-directional antenna, that is, the type of the transmitting antenna of the wireless link cluster is an omni-directional antenna; and if this is approximated as a sector, then the transmitting antenna of the wireless link cluster is processed as a directional antenna, that is, the type of the transmitting antenna of the wireless link cluster is a directional antenna. The vertex of the sector or the circumference of the round is the location of the approximate directional antenna or omni-directional antenna. In this context, an antenna beam of a wireless link cluster refers to an antenna beam of a transmitting antenna in the cluster. Following the description above, an antenna beam of an uplink wireless link cluster is an antenna beam approximated from an envelope of antenna beams of respective transmitting antennas in a set of antennas thereof.
[0093] (c) Bandwidth requirement vector BW_req of wireless link cluster
[0094] An element in a bandwidth requirement vector represents a bandwidth requirement of a wireless link in a coverage range of an antenna beam at a different power level in power control.
[0095] In the method of identifying a wireless link cluster in this context, for a network with a central control node, one downlink wireless link cluster between an infrastructure and a user can represent a plurality of wireless links with the same transmitting node but different receiving nodes. In view of a variation of a coverage range with a signal at a high quality due to power control, thus a plurality of points corresponding to the wireless link cluster are naturally grouped. A downlink bandwidth requirement vector is formed as follows: as illustrated in the part (b) of FIG. 10 , where there are three power levels for an antenna beam (δ, θ, r) of an antenna o, and their signals at a high quality cover a region C1, the region C1 and a region C2, and the regions C1 and C2 and a region C3 respectively. Correspondingly, there are three bandwidth requirement regions C1, C2 and C3 divided in the radiation radius direction of the antenna beam, where the antenna o is an antenna of the same transmitting node of wireless links in the wireless link cluster. Here, a bandwidth requirement of C1 is defined as the sum of downlink bandwidth requirements of all the wireless links formed of nodes in the region C1 and the antenna o, and the same applies to C2 and C3. The bandwidth requirement vector of the wireless link cluster (corresponding to a first bandwidth requirement which can be predetermined, for example, typically as a actual bandwidth requirement) is a one-dimension vector including three elements formed of the bandwidth requirements of C1, C2 and C3. In a peer-to-peer network, respective wireless link clusters relate to only a unique transmitting node and a unique receiving node, so all the bandwidth requirement vectors of the wireless link clusters are a one-dimension vector including only one element. For a network with a central control node, one uplink wireless link cluster between an infrastructure and a user represents a plurality of wireless links with the same receiving node but with different transmitting nodes. When a bandwidth demand vector of a downlink wireless link cluster is formed, uplink bandwidth requirements of uplink wireless links in respective bandwidth requirement regions corresponding thereto are summed as a bandwidth requirement vector of an uplink wireless link cluster symmetric to the downlink wireless link cluster, and also a beam of the uplink wireless link cluster is hereby determined. Due to symmetry of a wireless communication link, when communication directions of the respective wireless links in the downlink wireless link cluster are reversed, these reversed wireless links form the uplink wireless link cluster symmetric to the downlink wireless link cluster, and a transmitting node in the downlink wireless link cluster is a receiving node in the uplink wireless link cluster symmetric thereto, and a receiving node in the downlink wireless link cluster is a transmitting node in the uplink wireless link cluster symmetric thereto, or vice versa. Still taking the part (b) of FIG. 10 as an example, a bandwidth requirement of the bandwidth requirement region C1 of the uplink wireless link cluster is defined as the sum of uplink bandwidth requirements of all the wireless links formed of nodes in the region C1 and the antenna o, and a beam of the uplink wireless link cluster is represented as an envelope of beams of all the uplink wireless links formed of the nodes in the region C1 and the antenna o, and the same applies to C2 and C3. The bandwidth requirement vector of the uplink wireless link cluster (corresponding to a first bandwidth requirement which can be predetermined, for example, typically as actual bandwidth requirement) is a one-dimension vector including three elements formed of the uplink bandwidth requirements of C1, C2 and C3.
[0096] With the bandwidth demand vector of a wireless link cluster, a bandwidth requirement of an access network can be zoned in order for a finer granularity of antenna scheduling and a further improved resource utilization rate.
[0097] When the antenna scheduler 320 allocates wireless resources to the wireless link clusters of the access networks in the antenna scheduling set, it is necessary to have interference between the wireless link clusters within a predetermined range. Since access networks in the antenna scheduling set use the same spectrum resource, interference may arise from transmission of data between wireless link clusters over the same resource at the same time, which can also be referred to as exclusion restriction of antenna scheduling. Here, the extent of interference between link clusters can be represented by the concept of exclusion degrees.
[0098] The value of an exclusion degree ranges from [0,1], where 0 represents that there is absolutely no exclusion, that is, data is transmitted between wireless link clusters over the same resource at the same time without any mutual interference, and 1 represents absolute exclusion, that is, the same resource absolutely can not be used at the same time between wireless link clusters. Other values represent exclusion degrees between the two, where a larger value represents a higher exclusion degree. For example, if there is a sufficiently long distance between two wireless link clusters a and b, and when they use the same resource, interference of a transmission signal of a to a receiver of the wireless link cluster b can be neglectable (with a signal to noise ratio above a very high threshold), and then exclusion of a to b can be considered as 0, denoted as a□b=0. In another example, there are two wireless link clusters c and d between a specific transmitting node and two different signal receiving nodes, and if the transmitting node is equipped with only a single transmitting system, then c and d can not operate concurrently, so c and d are absolutely exclusive, denoted as c□d=1 and d□c=1. It is worthy noting that there is no symmetry of the exclusion-restrictive relationship, that is, a□b may not be equivalent to b□a.
[0099] To have interference between wireless link clusters within a predetermined range is to have exclusion degrees between the wireless link clusters below a predetermined value.
[0100] For two wireless link clusters with common transmitting node or receiving node, absolute exclusion between the wireless link clusters due to a physical reason (e.g., an antenna of only a single signal transmission or reception device is equipped) can be inferred directly. This exclusion will not be changed without altering the device.
[0101] For two wireless link clusters without any common transmitting node or receiving node, an exclusion degree can be measured or calculated. Two wireless link clusters a and b are assumed, where transmitting and receiving antennas of a are denoted as a_tx and a_rx, and transmitting and receiving antennas of b are denoted as b_tx and b_rx. Here, when one wireless link cluster includes a plurality of wireless links, the following measurement and calculation can be performed on all the transmitting antennas and receiving antennas in the wireless link cluster. However, for the sake of convenient operations, the following measurement and calculation can be performed only on approximate transmitting antennas corresponding to an envelope of a beam of the set of antennas or only on antennas at the edges of the wireless link cluster. For example, for a downlink wireless link cluster, an antenna of a receiving node at the edge of the cluster can be taken as a receiving antenna; and for an uplink wireless link cluster, an antenna of a transmitting node at the edge of the cluster can be taken as a transmitting antenna, or approximate transmitting antennas corresponding to an envelope of a beam of the set of antennas can be taken as a transmitting antenna.
[0102] Measurement: a signal is transmitted from a_tx to a_rx and a signal is transmitted from b_tx to b_rx in a specific timeslot; and in the meantime, a_rx calculates the signal to noise ratio SNR b a of the received signal of a_tx to noise arising from transmission of the signal from b_tx. Alike, b_rx calculates the signal to noise ratio SNR a b of the received signal of b_tx to noise arising from transmission of the signal from a_tx.
[0103] Calculation: The signal to noise ratio SNR b a can be calculated from the known distance between a_tx and a_rx, distance between b_tx and a_rx, and transmission power of the signals of a_tx and b_tx. Alike, SNR a b can be calculated.
[0104] The measured or calculated signal to noise ratios SNR b a and SNR a b are mapped into the range of [0,1]. By way of an example, the distribution of a signal to noise ratio (SNR min , SNR max ) is discretized, for example, the distribution range of the signal to noise ratio is divided into m>1 intervals (SNR min , SNR 1 ], (SNR 1 , SNR 2 ], . . . , (SNR m-1 , SNR max ), these m intervals correspond respectively to real numbers 1, (m−2)/(m−1), . . . , 1/(m−1), 0. Then, the signal to noise ratio SNR b a can be translated into an exclusion degree of the link cluster b to the link cluster a, and the signal to noise ratio SNR a b can be translated into an exclusion degree of the link cluster a to the link cluster b.
[0105] In order to make scheduling by the antenna management apparatus 300 more reasonable, preferably another scheduling restrictive factor, i.e. preceding restriction can further be taken into account. When there is relay node in an access network, the relay node is responsible only for forwarding data but does not generate new data in itself, so the relay node can transmit data only after receiving the data to be transmitted. Stated otherwise, transmission of data from the relay node can not precede its reception of the corresponding data. This restrictive relationship is described as a preceding restriction. When a wireless resource is allocated, a resource can be allocated to a forwarding link cluster only after a resource is allocated to a preceding link cluster of the forwarding link cluster in view of this preceding restriction. A forwarding link cluster is a wireless link cluster between one relay node and another relay node (a peer node), and a forwarding link cluster typically includes only one wireless link.
[0106] The preceding restrictive relationship can be derived from a relationship between link clusters in a plurality of networks. For example, if there are two adjacent link clusters a and b, and a flow direction of data is from a to b, that is, b will forward data received from a, then forwarding by b can not precede transmission from a to b.
[0107] According to one embodiment of the invention, the link cluster determiner 322 in the antenna scheduler 320 can determine an exclusion degree and a preceding-restrictive relationship between the wireless link clusters.
[0108] Operations of the resource scheduler 323 in the antenna scheduler 320 to allocate wireless resources to the wireless link clusters will be described below with reference to FIG. 11 to FIG. 13 .
[0109] The resource scheduler 323 enables wireless resources to be made full use of as much as possible to maximize the total throughout of the scheduled access networks while satisfying the scheduling restrictive factor in allocation of the wireless resources to the wireless link clusters and sends a scheduling result to the access network after performing scheduling. Taking allocation of resources in the time domain as an example (at this time, antennas of the respective access networks in the antenna scheduling set can use all the resources in the frequency domain and resources in the code domain in the scheduling set concurrently), the wireless resources are allocated based upon the pre-scheduling results of the access networks, and wireless link clusters are selected for each timeslot and their antenna beams thereof are determined under the principle of ensuring interference between the wireless link clusters to be within a tolerance range while having antennas as many as possible operate in each timeslot so that all the data transmission tasks of the access networks can be performed in the least number of timeslots.
[0110] By way of an example, the resource scheduler 323 performs resource scheduling by allocating wireless resources to the wireless link clusters determined by the link cluster determiner 322 in the antenna scheduling sets U 1 , U 2 , . . . , U I obtained by the antenna selector 321 . A method of scheduling a resource will be described taking only U i , iε[1, I] as an example, where there is assumed a set Γ i is formed of wireless link clusters in and elements in Γ i , i.e., wireless link clusters, are φ 1 , φ 2 , . . . , φ J respectively. Each wireless link cluster has a bandwidth requirement which is an intermediate quantity with an initial value being set to a first bandwidth demand of the wireless link cluster. For a forwarding link cluster, i.e., a link cluster between one relay node and another relay node, an initial value of a bandwidth requirement thereof is set to 0. For the sake of convenience for description below, an initial value of a first bandwidth requirement of a forwarding link cluster can also be considered as being set to 0.
[0111] FIG. 11 illustrates a flow chart of allocating a wireless resource by the resource scheduler according to one embodiment of the invention. This figure is for a detailed description of the step S 430 in FIG. 4 .
[0112] As illustrated in FIG. 11 , in the step S 1110 , the resource scheduler 323 selects an independently-scheduling link cluster group from all the wireless link clusters in one antenna scheduling set. The independently-scheduling link cluster group is defined as a group of link clusters in the set of wireless link clusters Γ i with an antenna beam of each wireless link cluster being set so that interference between the wireless link cluster and each other wireless link cluster in the independently-scheduling link cluster group is within a predetermined tolerant range (that is, does not influence the quality of service of a user) to thereby ensure their compliance with the excusive restrictive condition, it is necessary to have antennas as many as possible operate concurrently at each time to thereby make full use of the resources.
[0113] FIG. 12 illustrates a flow chart of selecting an independently-scheduling link cluster group from all the wireless link clusters in one antenna scheduling set by the resource scheduler according to one embodiment of the invention. In the following description, two new intermediate variables will be used respectively as a set of link clusters Λ, which represents an independently-scheduling link cluster group; and a set of link clusters Ψ, which records unexamined link clusters in the set of link clusters Γ i of the antenna scheduling set U i . Before wireless link clusters are selected and added to the independently-scheduling link cluster group, these two intermediate variables are initialized by setting Λ to a null set φ and Ψ to Γ i .
[0114] In the step S 1210 , the resource scheduler 323 selects one wireless link cluster from the wireless link clusters in the antenna scheduling set as an initial wireless link cluster of the independently-scheduling link cluster group and sets an antenna beam of the initial wireless link cluster.
[0115] For the example above, an initial wireless link cluster is selected from the set of link clusters Ψ and denoted as {circumflex over (φ)}εΨ. Only a wireless link cluster with a current bandwidth requirement above 0 needs to be allocated a wireless resource. {circumflex over (φ)} can be selected in numerous ways: any wireless link cluster with a bandwidth requirement above 0 can be selected from Ψ; any wireless link cluster with a bandwidth requirement above 0 at a high spectrum use priority can be selected from Ψ; a wireless link cluster with the highest bandwidth requirement can be selected; or a wireless link cluster in an access network geographically located centrally in Ψ can be selected.
[0116] An antenna beam of the initial wireless link cluster is set. If the type of transmitting antenna of {circumflex over (φ)} is an omni-directional antenna or a directional antenna, then both a radiation angle θ and a deflection angle δ of the antenna beam have been determined, and a radio radius r thereof is determined by a power level. The power level can be selected arbitrarily in a range of values. If the type of transmitting antenna of {circumflex over (φ)} is a smart antenna, then three parameters (δ, θ, r) of the antenna beam thereof can be set freely in ranges of values, where a specific radiation radius r corresponds to a specific power level. Since a smart antenna has flexible ranges of options and thus a higher chance of being scheduled, preferably a link cluster with an omni-directional antenna or a directional antenna can be selected as an initial wireless link cluster as much as possible.
[0117] Then, selected {circumflex over (φ)} is added to Λ and removed from Ψ.
[0118] Next, in the step S 1220 , the resource scheduler 323 judges whether the selecting an independently-scheduling link cluster group has been completed. If not so, then the flow proceeds to the step S 1230 ; otherwise, the process of selecting the independently-scheduling link cluster group ends, and the flow will proceed to the step S 1120 in FIG. 11 . Each time one link cluster in Ψ has been considered, the link cluster will be removed from Ψ, so Ψ will become a null set after all the link clusters have been considered. Thus, the determination in the step S 1220 can be performed as to whether Ψ is a null set. If Ψ is a null set, then it indicates that the selection process has been completed. If Ψ is not null, then it indicates that the selection process has not be completed, and the flow proceeds to the step S 1230 .
[0119] In the step S 1230 , the resource scheduler 323 selects a next candidate wireless link cluster to be added to the independently-scheduling link cluster group from the remaining wireless link clusters between the antennas of the access networks in the antenna scheduling set and sets an antenna beam thereof. In the step S 1240 , the resource scheduler 323 judges whether the next candidate wireless link cluster can be added to the independently-scheduling link cluster group, if so, then in the step S 1250 , the next candidate wireless link cluster is added to the independently-scheduling link cluster group, and then the flow returns to the step S 1220 ; otherwise, the flow returns directly to the step S 1220 .
[0120] For the example above, a wireless link cluster is selected from Ψ, φεΨ, as a next candidate wireless link cluster, and an antenna beam thereof is set, and it is judged whether a new independently-scheduling link cluster group can be formed by setting the antenna beam and adding to Λ. If so, then φ is added to Λ and removed from Ψ; otherwise, φ is removed from Ψ.
[0121] The wireless link cluster φ can be selected randomly from Ψ. In order to further improve a resource utilization rate, φ can be selected sequentially so that more antennas can operate concurrently. For example, φ can be selected as follows. Wireless link clusters are connected according to their exclusion degrees so that the link clusters with exclusion degrees above 0 are connected by directionless lines. The least number of directionless lines through one of two link clusters reach the other link cluster is referred to as an exclusion distance between these two link clusters. In other words, an exclusion distance between two wireless link clusters refers to the least number of wireless link clusters with interference through which one of the two wireless link clusters reach the other wireless link cluster. Link clusters in Γ i can be divided by exclusion distances into sets of link clusters Ψ 1 , Ψ 2 , . . . at the distances of 1, 2, . . . , to the initial wireless link cluster {circumflex over (φ)}. Then, a next candidate wireless link cluster is selected from Ψ 1 , Ψ 2 , . . . in that order. Furthermore, preferably an omni-directional antenna, a directional antenna and a smart antenna can selected in that order in each of the sets of link clusters Ψ 1 , Ψ 2 , . . . . An antenna can be selected randomly among the same type of antennas.
[0122] After the next candidate wireless link cluster φ is selected, φ and each wireless link cluster in Λ, κδΛ, are considered sequentially. For each κ and a setting of an antenna beam thereof, settings of an antenna beam of φ with interference with κ being within a predetermined range (e.g., a tolerant range) is found, and then all these settings of antenna beam of φ are intersected. If there is an intersection set, then it is considered that φ with the settings of an antenna beam in this intersection set can be added to Λ and removed from Ψ. If there is no such an intersection set, then it indicates that no antenna beam of φ can be set so that interference between φ and each wireless link cluster κ in the independently-scheduling link cluster group Λ is within the predetermined range, and φ is only removed from Ψ.
[0123] When an antenna beam of φ is set for each κ, if the type of transmitting antenna of φ is an omni-directional antenna or a directional antenna, then the signal to noise ratio of an edge user of the antenna beam at a preset power level of φ and κ is calculated from the highest power level of φ. If the signal to noise exceeds, for example, a tolerant range, than an attempt is made to lower the power level of φ until the signal to noise reaches the tolerant limit. After the power level is set, a radiation radius is a radius corresponding to a coverage range corresponding to the power level.
[0124] If the type of transmitting antenna of φ is a smart antenna, then a radiation angle of the antenna beam of φ can further be divided equally into a plurality of sub-radiation angles, that is, circumferentially divided equally into a plurality of sectors, in addition to setting the power level and the antenna beam as described above. For the respective sections, appropriate power levels are derived in a way similarly to that for a directional antenna and then combined for the two different purposes of maximizing either the power level or the radiation angle. Stated otherwise, the power level of the combined-into antenna beam is maximized (which means the maximized radiation radius), or the radiation angle of the combined-into antenna beam is maximized. For improved accuracy, bandwidth requirements of the respective sector region can further be taken into account for combination without combining those sectors with a bandwidth requirement of 0.
[0125] FIG. 13 illustrates an example of an antenna beam setting of a smart antenna. In the scenario illustrated in FIG. 13 , there are elements κ 1 and κ 2 in Λ. Antenna beam parameters of κ 1 and κ 2 are (δ 1 , θ 1 , r 1 ) and (δ 2 , θ 2 , r 2 ) respectively. φ is a candidate wireless link cluster for which an antenna beam is to be set. An antenna radiation angle of φ is divided equally into six sectors, and an antenna beam setting of each sector with interference with κ 1 and κ 2 being within a predetermined range is calculated respectively. A calculation result is as follows. With respect to κ 1 , if the radiation angle is maximized, then the radiation radius is o 3 A; and if the radiation radius is maximized, then the radiation angle is θ 3 =300° (⅚ of a circumference), and the deflection angle is δ 3 =240°. With respect to κ 2 , both the radiation angle and the radiation radius can be maximized at the same time. The antenna beams in the respective sectors are combined, and if the power level is maximized, then parameters of φ are (δ 3 240°, θ 3 =300°, r 3 =o 3 B); and if the radiation angle is maximized, parameters of φ are (δ 3 =0°, θ 3 =360°, r 3 =o 3 A).
[0126] The radiation angle of the antenna beam of the smart antenna is divided equally, and then antenna beams of the respective sub-radiation angles are set respectively and further combined in view of an optimization goal to thereby lower effectively the complexity of calculation and determine rapidly the beam setting of the smart antenna.
[0127] Referring back to FIG. 11 , the resource scheduler 323 allocates bandwidth to the wireless link clusters in the independently-scheduling link cluster group in the step S 1120 after selecting the independently-scheduling link cluster group.
[0128] For the example above, interference between each wireless link cluster in the independently-scheduling link cluster group Λ and each other wireless link cluster in the group is within the predetermined range, bandwidths can be allocated concurrently to all the wireless link clusters. A radiation radius of an antenna beam of a wireless link cluster corresponds to a bandwidth requirement value in a bandwidth requirement vector BW_req of the wireless link cluster, i.e., an element in the bandwidth requirement vector. These values are assumed sequentially as β 1 , β 2 , . . . , β |Λ| , where the minimum value is min {β i |iε[1,|Λ|]}, and the maximum value is max{β i |iε[1,|Λ|]}. A bandwidth allocated concurrently to each wireless link cluster in the independently-scheduling link cluster group Λ can be set to any value β between the minimum value and the maximum value, i.e., min{β i |iε[1,|Λ|]}≦β≦max{β i |iε[1,|Λ|]}. β is selected, and a bandwidth requirement of an element in Γ i is modified. For a bandwidth requirement of an element belonging to both Γ i and Λ:
[0000]
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.
[0000] For another element in Γ i , if the element has a preceding relationship with an element in Λ, that is, forwards data received from a link cluster of Λ (a preceding link cluster), then a bandwidth requirement of the element is increased accordingly by β i .
[0129] Then in the step S 1130 it is judged whether antenna scheduling has been completed. As described above, after a bandwidth is allocated to a wireless link cluster in Γ i , the allocated bandwidth is subtracted from a bandwidth requirement of the link cluster (corresponding to a first bandwidth requirement). When all the wireless link clusters have a bandwidth requirement of 0, it indicates that the bandwidth requirements of all the wireless link clusters are satisfied, and then completion of the whole antenna scheduling flow can be judged.
[0130] If it is judged in the step S 1130 that antenna scheduling has not been completed, then the flow returns to the step S 1110 to further select an independently-scheduling link cluster group. If antenna scheduling has been completed, then the flow proceeds to S 440 in FIG. 4 , and the resource scheduler 323 sends a wireless resource allocation result to the access network in which the wireless link cluster is located.
[0131] The wireless resource allocation result can include the wireless resources (e.g., timeslots) allocated to the respective access networks, the antenna beam and the power level of each wireless resource corresponding to each link cluster, etc. Particularly, the bandwidths allocated to the wireless link clusters in the respective access networks can be translated into the wireless resources (e.g., timeslots) allocated to the access networks with existing method.
[0132] By way of an example, the antenna management apparatus sends a scheduling result sending request signaling SendSchedule_request to the access networks in sending of the allocation result. The access networks make judgment according to a condition. If reception is allowed, then a scheduling result sending response signaling SendSchedule_reply is set to True and transmitted to the antenna management apparatus. Otherwise, the scheduling result sending response signaling SendSchedule_reply is set to False and transmitted to the antenna management apparatus. The antenna management apparatus sends the scheduling result upon reception of the response which is True; otherwise, ceases sending the scheduling result and requests again in a subsequent period of time and terminates sending the scheduling result when this period of time or the number of requests exceeds a specific threshold
[0133] Furthermore, the respective components in the antenna management apparatus according to the embodiment of the invention, e.g., the resource use information collector 310 , the resource use efficiency analyzer 320 , the antenna scheduler 330 , the resource use state database 340 , etc., can be centralized on the same network entity or decentralized on different network entities
[0134] In the method and apparatus according to the embodiments of the invention, access networks joining antenna scheduling among managed access networks are grouped into different antenna scheduling sets, where access networks using the same spectrum resource form the same antenna scheduling set; wireless links in each access network are grouped into one or more wireless link clusters; and wireless resources are allocated to all the wireless link clusters in the antenna scheduling set so that interference between all the wireless link clusters of the antenna scheduling set is within a predetermined range. Thus, access networks as many as possible can operate concurrent over the same spectrum resource within a tolerant interference range to thereby improve a chance of spectrum multiplexing in order for efficient utilization of the resources. Furthermore, as compared with the case that a resource is allocated per wireless link, a wireless resource is allocated per wireless link cluster to thereby lower the amount of calculation required for antenna scheduling.
[0135] Furthermore, in the method and apparatus according to the embodiments of the invention, the scope of the invention will not be limited to any specific coverage range, adopted radio technology, network architecture, resource use pattern, etc., of a heterogeneous radio access network. As for an application to the user side, a heterogeneous radio access network in the method and apparatus according to the embodiments of the invention can provide a user with a radio access service by means of various advanced radio technologies including an omni-directional antenna, a directional antenna, a smart antenna, a distributed antenna, etc.
[0136] Additionally, the respective constituent modules and units in the apparatus described above can be configured in software, firmware, hardware or any combination thereof. Specific configuration means or patterns available are well known to those skilled in the art, and a repeated description thereof will be omitted here. In the case of being embodied in software or firmware, program constituting the software or firmware can be installed from a storage medium or a network to a computer with a dedicated hardware structure which can perform various functions when various pieces of programs are installed thereon.
[0137] FIG. 14 illustrates a schematic block diagram of a computer in which the method and apparatus according to the embodiments of the invention can be embodied. In FIG. 14 , a Central Processing Unit (CPU) 1401 performs various processes according to program stored in a Read Only Memory (ROM) 1402 or loaded from a storage portion 1408 into a Random Access Memory (RAM) 1403 in which data required when the CPU 1401 performs the various processes, etc., is also stored as needed. The CPU 1401 , the ROM 1402 and the RAM 1403 are connected to each other via a bus 1404 to which an input/output interface 1405 is also connected.
[0138] The following components are connected to the input/output interface 1405 : an input portion 1406 (including a keyboard, a mouse, etc.); an output portion 1407 (including a display, e.g., a Cathode Ray Tube (CRT), a Liquid Crystal Display (LCD), etc., and a speaker, etc.); a storage portion 1408 (including a hard disk, etc.); and a communication portion 1409 (including a network interface card, e.g., an LAN card, a modem, etc). The communication portion 1409 performs a communication process over a network, e.g., the Internet. A drive 1410 is also connected to the input/output interface 1405 as needed. A removable medium 1411 , e.g., a magnetic disk, an optical disk, an optic-magnetic disk, a semiconductor memory, etc., can be installed on the drive 1410 as needed so that computer program read therefrom can be installed into the storage portion 1408 as needed.
[0139] In the case that the foregoing series of processes are implemented by software, program constituting the software can be installed from a network, e.g., the Internet, etc., or a storage medium, e.g., the removable medium 1411 , etc.
[0140] Those skilled in the art shall appreciate that such a storage medium will not be limited to the removable medium 1411 illustrated in FIG. 14 in which the program is stored and which is distributed separately from the apparatus to provide a user with the program. Examples of the removable medium 1411 include a magnetic disk (including a Floppy Disk (a registered trademark)), an optical disk (including Compact Disk-Read Only Memory (CD-ROM) and a Digital Versatile Disk (DVD)), an optic-magnetic disk (including a Mini Disk (MD) (a registered trademark)) and a semiconductor memory. Alternatively, the storage medium can be the ROM 1402 , a hard disk included in the storage portion 1408 , etc., in which the program is stored and which is distributed together with the apparatus including the same to the user.
[0141] Furthermore, the invention further proposes a product program on which machine readable instruction codes are stored. The instruction codes upon being read and executed by a machine can perform the above-mentioned method according to the embodiment of the invention.
[0142] Correspondingly, a storage medium for carrying the program product on which the machine readable instruction codes are stored will also be encompassed in the disclosure of the invention. The storage medium includes but will not be limited to a floppy disk, an optical disk, an optic-magnetic disk, a memory card, a memory stick, etc.
[0143] In the foregoing description of the specific embodiments of the invention, a feature described and/or illustrated with respect to an implementation can be used identically or similarly in one or more other implementations in combination with or in place of a feature in the other implementation(s).
[0144] It shall be emphasized that the term “including/comprising” as used in this context indicates the presence of a feature, an element, a step or a component but does not preclude the presence or addition of one or more other features, elements, steps or components.
[0145] Furthermore, the method according to the invention will not necessarily be performed in a sequential order described in the specification but can alternatively be performed in another sequential order, in parallel or independently. Therefore, the technical scope of the invention will not be limited to the order in which the method is performed as described in the specification.
[0146] Although the invention has been disclosed above in the description of the specific embodiments of the invention, it shall be appreciated that all the embodiments and examples described above are exemplary but not limiting. Those skilled in the art can make various modifications, improvements or equivalents to the invention without departing from the spirit and scope of the appended claims. These modifications, improvements or equivalents shall also be construed as falling into the claimed scope of the invention. | Disclosed in the present invention are a method and an apparatus for antenna management. The method comprises that resource use status data are collected from managed access networks, access networks which participate antenna scheduling are selected from the managed access networks according to the resource use status data to compose an antenna scheduling set, wherein access networks using same spectrum resources are composed in the same antenna scheduling set; radio links of each access network in the antenna scheduling set are divided into one or more radio link clusters; radio resources are allocated to every radio link cluster in the antenna scheduling set in order that mutual interferences among all the radio link clusters in said antenna scheduling set are within a preset range; and radio resource allocation results are sent to the access network that the radio link clusters belong to. The said method and apparatus enable as many access networks as possible to work at the same time within an interference allowed range using the same spectrum resource, increasing spectrum multiplex opportunity and realizing high resource use rate. | 7 |
BACKGROUND OF THE INVENTION
This invention relates generally to a device adapted to hold multiple spools of wound material for selective dispensing or unwinding of the material from the spools.
More particularly, the invention relates to a portable cart adapted to carry multiple spools of electrical wire. Carts of this type are useful, for example, by electricians who wire industrial, commercial or residential buildings. In such a building, electrical wire of different gauges, types, and color coding is utilized. To maintain existing electrical systems or to install new electrical systems in such a building, various types of wire must be available. Securing spools of wire to a cart enables the wire to be transported to different job sites in the building and frequently avoids the need to make trips to a central storage location to get the necessary wire. Several prior carts adapted to carry spools of wire are well suited to transport a variety of wire.
Not all such job sites, however, are accessible to a cart. For example, some wiring in industrial buildings is only accessible by way of a raised walkway or permanent scaffolding and the electrical wire must be hand-carried up the scaffolding. In this instance, either the wire must be pre-cut before ascending to the job site or the individual spools of wire must be removed from the cart and carried up the scaffolding. In the first case, the length of wire needed for a such a job must either be estimated or measured before being cut from the spools. This leaves open the possibility that the pre-cut lengths of wire will not be long enough and that additional trips to the cart will be necessary. In addition, the pre-cut wire must be hand-wound into manageable bundles before being carried to the job site. While carrying spools of wire to the job site may be preferable for simple jobs, jobs which require several types of wire may require more than one trip between the cart and the job site. Moreover, neither of these alternatives provides for a convenient method of dispensing the wire from the spools or for unwinding the hand-wound bundles at the job site.
SUMMARY OF THE INVENTION
The general aim of the present invention is to provide a new and improved cart adapted to carry spools of electrical wire and having means to facilitate transport of some of the spools to a location which is remote from the cart.
A detailed objective is to achieve the foregoing by providing a cart equipped with racks of spools, each rack being adapted to individually slip onto and off of support brackets on the cart and being equipped with a handle so as to enable transport of the spools.
Another objective of the invention is to provide for relatively easy dispensing or unwinding of the wire from the spools at the remote location.
A detailed objective is to achieve the foregoing by providing racks having feet for supporting the racks when the racks are removed from the cart and for positioning the spools so as to be freely rotatable.
The invention also resides in the provision of a unique wire guide which is transportable with the cart and which facilitates the simultaneous unwinding of multiple wires from different spools on the cart.
These and other objects and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a new and improved cart carrying spools and incorporating the unique features of the present invention.
FIG. 2 is a perspective view of the back of the cart.
FIG. 3 is a perspective view of certain parts shown in FIG. 1.
FIG. 4 is a side view of the cart.
FIG. 5 is an enlarged fragmentary view taken substantially along the line 5--5 of FIG. 4.
FIG. 6 is an enlarged fragmentary view of certain parts shown in FIG. 4.
FIG. 7 is a fragmentary side view similar to FIG. 4 but showing certain parts as they are being removed from the cart, one position of the parts being shown in phantom lines.
FIG. 8 is a perspective view of the cart in a horizontal position and showing multiple wires being drawn from different spools.
While the invention is susceptible of various modifications and alternative constructions, a certain illustrated embodiment hereof has been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
For purposes of illustration, the present invention is shown in the drawings as embodied in a portable cart 10 (FIG. 1) adapted to carry spools 11 of electrical wire 12 (FIG. 8). As shown in FIG. 1, the cart is adapted to normally stand in a generally upright position. For purposes of explaining the invention, the cart will be assumed to be in this position, except where otherwise noted, and the spools will be considered to be located in front of the cart.
In general, the cart 10 includes an elongated and generally vertical frame 14 (FIG. 2), a pair of laterally spaced wheels 15 secured to a solid axle 22 for rotation relative to the frame, and a platform 16 which extends forwardly from the base of the frame. The axle is positioned rearwardly of the frame and near the base of the frame so that the wheels are normally resting on the ground. The platform also normally rests on the ground and coacts with the wheels to support the cart in the upright position. By pivoting the upper portion of the frame rearwardly and downwardly about the wheels, the platform may be raised from the ground and the cart may be moved from place-to-place.
The frame 14 is formed from relatively heavy gauge steel to support the weight of the wire 12. The frame includes vertically extending, elongated side rails 18 and an integrally formed handle 19 which extends generally rearwardly from and laterally between the side rails. The axle 22 is welded to axle support members 24 which, in turn, are welded to the backside of the side rails. Vertically spaced cross-support members 20 welded between the side rails and a vertically extending support member 21 welded to and connecting the cross-support members provide additional structural support for the frame.
In accordance with one aspect of the present invention, the spools 11 are carried on racks 30 which are releasably secured to and selectively removable from the frame 14. Each rack is adapted to carry several spools and is equipped with a handle 31 (FIG. 5). As a result, the racks enable relatively easy transport of several spools of wire 12 to a site which is remote from the cart 10. In addition, each rack is equipped with integral feet 32 (FIG. 3) for supporting the rack at the remote site so as to facilitate unwinding of the wire from the spools.
In general, each rack 30 includes a main bracket 34 formed from relatively heavy gauge steel and a tube 35 which is releasably secured to the main bracket for carrying the spools. More specifically, the main bracket is formed with a back panel 36 which extends laterally across the frame 14 and two integrally formed side panels 38 located at each end of the back panel. The upper and lower laterally extending edge portions 40 (FIG. 6) of the back panel slope forwardly at a relatively small angle to enhance the stiffness of the back panel. The side panels extend forwardly from the back panel and are formed with openings (not shown) aligned with one another and sized to slidably receive the tube. To releasably secure the spools to the main bracket, the tube is slipped through openings formed in the center of the spools, the spools and the tube are raised to a position adjacent the side panels, and one end of the tube is slid through the opening in the adjacent side panel until the opposite end of the tube slips inside of the oppositely located side panel. The opposite end of the tube is then pushed through the opening located in the opposite side panel until both ends of the tube extend outwardly of the side panels. A wear washer 41 is slipped over each end of the tube and cotter pins 42 are installed into openings (not shown) formed through the ends of the tube so as to releasably secure the tube and the spools to the main bracket.
In carrying out the invention, the racks 30 are formed with downwardly opening slots 45 (FIG. 6) sized to slidably receive support brackets 46 which are secured to the frame 14. More specifically, the support brackets extend laterally and outwardly from the side rails 18 and are vertically positioned along the side rails to define vertically spaced pairs of horizontally aligned brackets, each pair being capable of supporting a rack of spools. The racks include support members 44 which extend rearwardly from the back side of the back panel 36 and which are laterally spaced on the back panel so as to be located outwardly of the side rails. In addition, the support members extend generally vertically along the back panel and are formed with upper and lower portions. The upper portions of the support members are welded to the back panel. The lower portions of the support members are formed with cut-outs adjacent the back panel so as to coact with the back panel to define the slots.
With the foregoing arrangement, each rack 30 may be installed onto the frame 14 by positioning the open ends of the slots 45 above and generally aligned with a pair of support brackets 46 and then lowering the rack until the closed ends of the slots rest on the support brackets. When the racks are on the frame, wire may be drawn off of any or all spools when the cart is either upright or lying horizontally.
In this case, the rack is removed from the frame by simply lifting the rack in a generally upwardly direction and off of the support brackets. As a result, the frame is adapted to releasably carry several vertically spaced racks, each rack being adapted to carry several spools 11 of wire 12.
As shown in FIG. 7, the racks 30 may be alternately adapted to be removable from the frame 14 before the lower portions of the support members 44 have completely cleared the support brackets 46 as the racks are lifted upwardly from the frame. To this end, the width of the slots 45 and the angle of the lower edge portions 40 of the back panels 36 are sized to allow the upper portion of the rack to be pivoted forwardly after the support members have been raised substantially but not completely above the support brackets (shown in phantom lines in FIG. 7). As the upper portion of the racks pivot forwardly, the lower portions of the support members pivot upwardly to clear the upper surface of the support brackets. The rack can then be pulled forwardly and away from the cart. A reverse procedure may be used to install the racks onto the support brackets. As a result, this arrangement allows the support brackets to be located relatively close to one another so as to maximize the number of racks that can be placed on a cart 10 of a given height.
In keeping with the invention, the handle 31 is secured to the main bracket 34 of each rack 30. The handle is formed with an elongated grip portion 49 (FIG. 2) and with two legs 50 located at the ends of the grip portion. The legs of the handle are welded to the back side of the back panel 36 such that the handle projects rearwardly from the back panel and does not protrude from the cart 10 when the rack is located on the frame 14. The handle is preferably located in the center of the back panel with the grip portion extending laterally along a substantial length of the back panel and being aligned with the axis of the tube 35. As a result, the rack is adapted to be carried with the spools 11 suspended below the handle and with the weight of the spools acting downwardly in a vertical plane which passes through the grip portion of the handle. Moreover, the handle can be gripped in a lateral position which is generally aligned with the center of gravity of the combined weight of the spools. Accordingly, the handles enable relatively easy transport of several racks with several spools of wire to a site which is remote from the cart.
In further carrying out the invention, the feet 32 are secured relative to the back panel 36 and are adapted to position the tube 35 in a horizontally extending position above the back panel. As a result, the spools 11 are free to be rotated on the tube when the rack 30 is resting on the ground. In the embodiment shown, the feet are defined by flat portions which are integrally formed with the support members 44. The feet extend perpendicular to the axis of the spools and parallel to the back panel. In addition, the feet are centered relative to the axis of the spools such that the feet are located below the center of gravity of the spools when the rack is resting on the ground. Accordingly, the feet provide a relatively stable base for unwinding wire from the spools at the remote site.
Further in accordance with the present invention, the cart 10 is equipped with a portable wire guide 50 (FIG. 8) which is adapted for use when the cart is in a generally horizontal position. The guide is adapted to individually guide wires 12 which are drawn from different spools 11 on the cart and to keep the wires separated from one another until after the wires have passed through the guide. As a result, the guide is especially useful when simultaneously drawing multiple wires from the cart and when assembling multi-wire bundles.
More specifically, the guide 50 is formed with a slot 51 (FIG. 4) sized to slidably receive the platform 16 when the platform is raised from the ground. To use the guide, the upper end of the cart 10 is pivoted rearwardly and downwardly about the wheels 15 until the handle 19 of the cart rests on the ground. With the cart in this substantially horizontal position, the platform extends generally upwardly and the guide can be slipped onto the platform.
The guide 50 is further formed with holes 52 sized to slidably receive the wires 12. The holes are formed in rows which are vertically spaced from one another and which are located above the spools 11 when the guide is positioned on the platform 16. As the wire is drawn through the holes, the guide causes the wire to slope upwardly and away from the spools in a direction which is generally perpendicular to the axis of rotation of the spools. As a result, the guide prevents the wires from becoming entangled with one another as they are unwound from the spools.
In keeping with the invention, the cart 10 includes a storage rack 55 for storing the wire guide 50 when it is not in use. The storage rack is located between the frame 14 and the axle 22 and is formed by welding angled floor members 56 between the base of the frame and the axle. Specifically, the floor members extend downwardly from the axle and then forwardly to the base of the frame. The guide rests on its side on the floor members. In this stowed position, the guide is laterally trapped between the axle support members 24. In addition, a cross support member 57 secured between the axle support members and above the axle prevents the guide from pivoting off of the floor members when the cart is tipped for moving from place-to-place. Accordingly, the guide does not hinder the mobility of the cart and may be transported with the spools 11 of wire 12 on the cart.
From the foregoing it will be apparent that the present invention brings to the art a new and improved cart 10 equipped with a portable wire guide 50 and further equipped with uniquely configured racks 30 for carrying spools 11 of wire 12, the racks being adapted to slip onto and off of the cart and being equipped with feet 32 and a handle 31. Accordingly, multiple spools of wire can to be easily transported to a site which is remote from the cart and the wire may be easily unwound from the spools at such a site. | A cart is adapted to carry spools of electrical wire to enable a variety of different types and gauges of wire to be transported from place-to-place. The cart includes racks for holding the spools, each rack being sized to typically hold three or four spools. The racks are releasably secured to and selectively removable from the cart to enable the spools on the racks to be carried to a site which is remote from the cart. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to the field of automatic interfolding machines which interfold a stack of laminar products such as paper towels, paper tissues, and the like. In such machines, it is known to interfold adjacent products with more than one panel of adjacent products or sheets interfolded. In addition, it is also known to separate a clip or log of a predetermined number of such products from the continuously building interfolding stack. An example of an automatic separator is shown in U.S. Pat. No. 4,770,402. The separator shown in U.S. Pat. No. 4,770,402 separates products where only one panel is interfolded between adjacent products. However, it has been found that this apparatus is also capable of separating products with more than one panel interfolded. Products such as this are known in the industry as "W" folds. When interfolded products are produced by such equipment there are sheets remaining free after separation of the clip from the stack, and it is desirable to refold the loose sheets or panels to provide the highest quality product. Refolding the loose sheets on the bottom of the continuously building stack may be accomplished by the invention shown in U.S. Pat. No. 4,874,158. However, interfolded products with more than one panel interfolded will have multiple loose panels on the separated clip as well and it is desirable to refold those loose panels as well as the loose panels associated with the continuously building stack.
The present invention relates to refolding the loose panels on the separated clip or log.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified side elevation view of a machine which continuously interfolds products into a "W" interfolded stack.
FIG. 2 is a simplified view of a continuously building stack of interfolded "W" products immediately before separation of a clip from the stack with the product folds expanded.
FIG. 3 is a simplified view similar to FIG. 2 immediately after separation of the clip from the stack with the product folds expanded.
FIG. 4 is a simplified view of the certain apparatus of the present invention showing the transfer clamp in various positions in a transfer and refolding cycle.
FIGS. 5, 5a, and 5b are a perspective close-up view of a clip showing certain aspects of the present invention.
FIG. 6 is a partial view similar to FIG. 1 showing the apparatus of the present invention at a beginning of a loose panel refolding cycle.
FIG. 7 is a partial view similar to FIG. 6 of the apparatus of the present invention showing a side view of the transfer clamp in various positions during the process of loose panel refolding similar to FIG. 4.
FIG. 8 is a partial view similar to FIG. 7 showing the transfer clamp apparatus returning to a position ready to begin a new loose panel refolding cycle.
DETAILED DESCRIPTION
Referring now to the Figures, and most particularly to FIG. 1, a "W" interfolding machine 10 may be seen. Machine 10 has a pair of interfoldingrolls 12, 14 shown in phantom which continuously build a stack 16 of "W" interfolded products. Referring now also to FIG. 2, an expanded view of the "W" interfolded product stack may be seen. In the continuously building stack 16, a first product 18 is interfolded with a second product20 such that end panels 18a, b and 20a, b are arranged in an overlapping ornesting relationship. Similarly, a third product 22 has a pair of end panels 22a, b interfolded or nested with end panels 20c, d of product 20. Even though the panels are shown spaced apart in FIG. 2, it is to be understood that the stack and resulting clips formed from the stack preferably have adjacent panels relatively closely spaced together as shown in FIGS. 1 and 5. FIG. 1 shows a completed clip 24 of products supported by a stack building table 26. It is to be understood that stack 16 and clip 24 define a stack building path 27 along which interfolding rolls 12, 14 build the stack 16 of continuously interfolded products 18 etseq. FIG. 1 shows a condition immediately subsequent to insertion of a first count finger assembly 28 and a second count finger assembly 30 resulting in separation of clip 24 from stack 16.
FIG. 2 is a simplified view of stack 16 immediately prior to separation of a clip of interfolded "W" products 18 et seq. wherein the first count fingers 28 and the second count fingers 30 have been inserted into the appropriate folds between respective panels during the stack building process. At this point, stack 16 is supported by the second count fingers 30 (see FIG. 1) and a clip of a predetermined number of paper products is trapped below first count fingers 28 which is subsequently separated from the stack as shown in FIGS. 1 and 3.
FIG. 3 illustrates an expanded view of the position of stack 16 and clip 24in the portion of a clip separating cycle shown in FIG. 1. Loose end panelsof product 22 may be refolded into the bottom of the stack 16 by front and rear fold over assemblies 32, 34 and by a package building finger assembly36 in a manner substantially the same as that disclosed in U.S. Pat. No. 4,874,158 and hence not discussed further here. As may be seen most clearly in FIGS. 1 and 3, to accomplish separation, first count fingers 28capture a clip 24 between fingers 28 and table 26 However, a proximal end panel 20c and a distal end panel 20d remain loose from the clip 24 and aredesirably refolded to maintain product quality of the clip 24 of "W" interfolded products.
Referring now to FIG. 4, a free-body diagram of a transfer clamp apparatus 40 useful for accomplishing refolding of loose end panels 20c, 20d may be seen.
In FIG. 4, clip 24 is retained initially between table 26 and first count finger assembly 28. At this time a pair of loose end panels 20c, 20d, extend from the product at the end of clip 24. Referring now also to FIG. 6, to initiate a clip transfer and panel refolding transfer cycle, transfer clamp 40 moves from the position shown in phantom lines to the position shown in solid lines. Clamp 40 has a set of first clamping fingers 42 longitudinally spaced apart from a set of second clamping fingers 44. Clamp 40 is moved transversely toward clip 24 in the directionof arrow 46 such that second clamping fingers 44 are received below clip 24in respective recesses 48 of table 26. Recesses 48 are interdigitated with a plurality of lands 50 to support clip 24 on table 26. As clamp 40 is extended transversely towards clip 24, an air pressure source 52 (see FIG.6) directs toward loose end panels 20c urge panel 20c against an outer surface of first count finger assembly 28 to prevent trapping panel 20d below first clamping fingers and to prevent tearing product 20.
Referring now also to FIGS. 5, 5a and 5b, it is to be understood that as clip 24 separated from stack 16, first count finger assembly 28 and table 26 hold clip 24 in compression to retain control of clip 24 as shown in FIG. 5a. Once the transfer clamp 40 moves transversely to the position shown in solid lines in FIG. 6, the table 26 and first count finger assembly 28 are moved apart thus transferring control of clip 24 to transfer clamp 40 as indicated in FIG. 5b. This action is indicated by arrows 54 in FIG. 7. Clamp 40 carrying clip 24 is moved transversely in the direction of arrows 56 (see FIG. 4) and then rotated in the direction of arrow 58 inverting the clip 24 such that loose end panel 20d is at the bottom of the clip 24 as shown in position 60 in FIGS. 4 and 7. Clamp 40 is then extended in the direction of arrows 62 (see FIG. 4) inserting clip24 between end plates 64, 66. It is to be understood that end plates 64, 66are preferably positioned apart a distance 80 slightly greater than a distance 82 spanned the first and second clamping fingers 42, 44. Clip 24 is then held between plates 64, 66 by a pusher plate 68 as the first and second clamping finger assemblies 42, 44 retract from between end plates 64, 66, thus leaving clip 24 between end plates 64, 66 in a conveyor 70 which subsequently indexes to move clip 24 away and position a new pair ofempty end plates (not shown) to receive a subsequent clip.
Referring now to FIG. 8, transfer clamp 40 is retracted in a direction of arrows 72 after discharging the clip 24 at a discharge station or destination 69 to conveyor 70. The clamp 40 is then rotated in the direction of arrow 74 (as shown in FIG. 8) to prepare clamp 40 for anothertransfer and refolding cycle. It is to be understood that alternative equipment may replace conveyor 70, for example, a carton infeed apparatus (not shown).
It is to be understood that machine 10 further includes clamp displacement means such as a rotary motor 76 to rotate clamp 40 and a servomotor and chain drive assembly 78 to enable moving the transfer clamp in and out of the stack building path, to traverse to the discharge station 69 and to move the clamp 40 in and out from between the end plates 64, 66 while at the discharge station. Assembly 78 is preferably made up of an endless chain 86 driving a carriage 88 secured thereto, both of which are driven by a servomotor 90 through a sprocket 92. Carriage 88 is positionable at any desired position between a pair of idler sprockets 94,96 on which chain 86 is carried. An air cylinder 84 is preferably used to provide relative motion between pusher plate 68 and clamping fingers 42,44.
Thus it may be seen that in the practice of the present invention, two loose end panels are refolded into the clip. The proximal loose end panel 20c resulting from separation of clip 24 from stack 16 is refolded by transferring the clip to the transfer clamp 40 from between the first count fingers 28 and elevator table 26. The distal loose end panel 20d is subsequently refolded into the clip by the insertion of clip 24 into subsequent machinery having opposing end plates 64, 66 such that end panel20d is refolded into the clip when the first clamping fingers 42 are withdrawn from between clip 24 and end plate 66.
Referring now again more particularly to FIGS. 5a and 5b, certain aspects of the refolding the present invention may be seen. In FIG. 5a, clip 24 iscontrolled or held by the first count finger assembly 28. After the first clamping fingers 42 move transversely to project above clip 24 in the stack building path, loose panel 20c is trapped between fingers 28 and 42.The table 26 and first count fingers 28 are moved apart in a direction of the stack building path such that the products making up clip 24 are allowed to expand against first clamping fingers 42 as shown in FIG. 5b. At this time, panel 20c is arranged in a slightly corrugated fashion between fingers 28 and 42 as may be seen most clearly in FIG. 5b. Subsequently clip 24 is withdrawn transverse to the stack building path 27, thus disengaging fingers 28 from between panels 20a and 20c.
Referring now most particularly to FIGS. 5, 5a and 5b, it may be seen that the first clamping fingers 42 are located above the first count fingers 28initially and that at least one of the first count fingers is positioned intermediate a pair of the first clamping fingers when the transfer clamp 40 is in the stack building path 27 such that a proximal one of the loose end panels (20c) is trapped between the first clamping fingers 42 and the first count fingers 28. The air pressure source 52 provides an air assist means for directing air generally transversely across the first count fingers 28 such that the plurality of loose end panels 20c, 20d are urged in a direction away from the transfer clamp 40.
The movement shown by FIGS. 5a and 5b is such that the first count fingers 28 are moved toward the first clamping fingers 42 a distance large enough to transfer control of the clip 24 to the pair of first clamping fingers and small enough to avoid permanent deformation of the proximal one loose end panel 20c when the stack building table 26 and the first count fingers28 are moved away from the clip 24. The first count fingers 28 are preferably spaced transversely apart from respective adjacent first clamping fingers 42 by a lateral distance sufficient to permit retention of clip 24 by the transfer clamp 40 without permanent deformation of panel20c when it is trapped between first count fingers 28 and first clamping fingers 42 as shown in FIG. 5b.
The invention is not to be taken as limited to all of the details thereof as modifications and variations thereof may be made without departing fromthe spirit or scope of the invention. | An apparatus and method for transferring a clip formed of a predetermined number of interfolded paper products away from a stacking interfolder and refolding a plurality of loose end panels having a stack building table and first count finger assembly initially holding the clip and transferring control of the clip to a transfer clamp which refolds a first loose end panel and further having a clip destination station having a post end panels receiving the clip and finally refolding the final loose end panel. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to a face tracking method, and more particularly to a face tracking method for an electronic camera device having a face database storing data including face position, size and skin color prototype (such as color histogram) of previously stored preview images, which enables the electronic camera device to define a searching space according to the data of known face stored in the face database when a current preview image is obtained, and then detect and track the searching space for the precise position of the face in the current preview image accurately, so as to effectively reduce the large number of operations required for the detection and tracking processes, and greatly enhance the speed and efficiency of the face tracking.
BACKGROUND OF THE INVENTION
[0002] In recent years, digital imaging technology advances day after day, and various different electronic devices (such as digital cameras, digital camcorders, notebook computers and mobile phones) having digital imaging devices (such as CCD and CMOS) are introduced to the market, not only providing increasingly higher imaging quality and smaller size, but also offering an increasingly lower price, and thus these electronic devices become popular. Although many digital electronic camera devices come with advanced functions including auto focus and auto exposure, the electronic camera devices determine a captured image by a sensed scene according to the information of the captured image, wherein a face only occupies a small portion of the whole scene, and thus it is difficult for a photography novice to capture a satisfactory portrait due to the user's lack of ability and experience of adjusting the shutter and diaphragm correctly. Thus, it is an important subject for manufacturers and designer to develop different electronic camera devices having intelligent functions to meet the consumer requirement of the basic photography, compensate their insufficient photographic techniques, and effectively save the long adjusting time or simplify the procedure to shoot high-quality portraits.
[0003] To provide consumers an intelligent imaging function of the electronic camera device to shoot high-quality portraits, some manufacturers have applied a face detection technology to the electronic camera devices, and many face detection algorithms have been disclosed in technical papers and bulletins, and the most popular face detector is based on the Gentle Adaboost (GAB) algorithm, and the face detector uses a Haar-like feature to identify a face, and also uses a specific quantity of face pattern samples to train a required face classifier, and determines whether or not an image of a scene is a face, so that the face in the scene can be detected or identified quickly. In a traditional GAB algorithm, the rules of operation are listed in the table below:
[0000]
A stage of Haar feature classifier construction using GAB
1.
Start with weights w i = 1/2p and 1/2l where p and l are the number of
positive and negative class samples.
2.
Repeat for m = 1, 2, . . . , M.
(a) For each Haar feature j, f m (x) = P w (y = 1|x) − P w (y = −1|x)
using only the feature j values.
(b) Choose the best feature confidence set of values f m (x) giving
the minimum weighted error e m = Ew[1 (y i ≠sign[f m (x i )] ] for all
feature j.
(c) Update F(x) ← F(x) + f m (x)
(d) Set w i ← w i exp[−y i · f m (x i )], i = 1, 2, . . . , N.,
and renormalize so that Σw i = 1.
3.
Output
the
classifier
sign
[
F
(
x
)
]
=
sign
[
∑
m
-
1
M
f
m
(
x
)
]
.
[0004] The GAB algorithm selects the best Haar feature of a minimum weighted error em from all features. For each weak classifier f m (x), the GAB algorithm selects a feature j to minimize the error function by Formula (1):
[0000]
f
m
(
x
)
=
arg
min
j
{
∑
i
w
i
*
v
i
}
(
1
)
[0000] ; where,
[0000]
v
i
=
{
1
represents
-
missclassified
0
represents
-
others
,
w
i
[0000] is a sample weight.
[0005] From the list above and Formula (1), although the GAB algorithm can update each stage classifier in each loop of the iteration by using a confidence-rated real value, the misclassification error defined in the GAB algorithm is discrete. In Formula (1), ν i is a Boolean variable, and ν i is equal to 1 for a misclassification, and 0 for a classification. Similarly, a weak classifier with a binary output in the discrete Adaboost algorithm does not mean that the Haar-like features are in a good distribution, and thus the misclassification error defined in the aforementioned algorithm cannot describe the distribution of the misclassification errors accurately.
[0006] In view of the description above, the inventor of the present invention redefined the misclassification error em of the GAB algorithm in his related patent application as shown in Formula (2) below:
[0000]
e
m
=
∑
i
w
i
*
v
i
=
∑
i
w
i
*
(
y
i
-
f
m
(
x
i
)
)
(
2
)
[0007] where, ν i is the distance between the confidence-rated real value and the expected class label. According to a journal “Face Detection Using Look-up Table Based Gentle Adaboost” authored by Cem Demirkir and Bülent Sankur and published in the Audio- and Video-based Biometric Person Authentication on July, 2005, if f m (x i ) varies within the range of [−1,1], ν i ; is a real variable distributed within the range of [−2,2], and the definition uses a confidence form to describe the misclassification error, and uses a histogram bin in the computer programming to compute the misclassification error. For example, two histogram bins as shown in FIG. 1 are provided to show the difference between two types of definitions, wherein positive samples of the histogram bins have different distributions on the features i and j. For simplicity, the positive samples have the same distribution as the negative samples. If Formula (1) is used, the resultant error summations of the two types of feature spaces are the same, but if Formula (2) is used, the resultant error summation of feature j will be smaller than the computed result of the feature I. As to a greedy searching scheme, the feature j will be selected for building a weak classifier. According to the definition of the weak classifier function, if samples in a histogram bin are difficult to be separated, then the output confidence value is close to zero, or else the output confidence value is close to 1 or −1. This result shows that the output confidence value of the feature j is much greater than the output confidence value of the feature i. In the two histogram bins as shown in FIG. 1 , the sample in the histogram bin space of the feature j is easier to be separated than the sample in the histogram bin space of the feature i, so that the confidence-rated definition of the misclassification error becomes more reasonable.
[0008] Traditionally, a Haar-like feature is defined in a way that, four basic units (as shown in FIG. 2 ) in a feature pool are provided for detecting a feature prototype of an object in an image window, wherein the prototype 10 , 11 represents an edge feature; the prototype 12 represents a line feature; the prototype 13 represents a special diagonal line feature; the black region represents a negative weight; and a white region represents a positive weight. However, the inventor of the present invention attempts to provide separate samples in histogram bins easier based on the definition of the foregoing algorithm by using eight basic units (as shown in FIG. 3 ) in a feature pool for detecting a feature prototype of an object in an image window when the Haar-like feature is defined, and such feature prototype is called an extended Haar feature. The feature prototype 20 , 21 represents an edge feature, wherein the black region represents a negative weight; the white region represents a positive weight; and the black region and the white region are distributed on the same horizontal or vertical line, but a specific distance is maintained between the black and white regions. The feature prototype 22 , 23 represents an edge feature, wherein the black region represents a negative weight; the white region represents a positive weight; the black region and the white region are intersected perpendicularly with each other. The feature prototype 24 , 25 represents a line feature prototype, wherein the black region represents a negative weight; the white region represents a positive weight; and the black region and the white region are intersected diagonally with each other. The prototype 26 , 27 represents a special diagonal line feature, wherein the black region represents a negative weight; the white region represents a positive weight; and ¼ of the area of the black region and the white region is overlapped along their diagonals.
[0009] Although the foregoing definition of the extended Haar feature can separate samples in the histogram bin easier, but the inventor of the present invention also takes the following conditions into consideration for detecting and identifying a face in a preview image:
[0010] 1. To detect a newly present unknown face in a current frame and an unknown face that is not detected in a previous frame, it is necessary to complete a detecting process for the whole image.
[0011] 2. To complete the detecting process for the whole image, a large computing value slows down the processing speed.
[0012] 3. Due to the complexity of the photographic environment, non-face patterns can be rejected accurately when the face in an image is detected.
[0013] 4. When variable factors including pose, expression and illumination are taken into consideration, the known face detected in the previous frame by a face detector cannot be too stringent.
[0014] From the description above, Cases 1 and 2 are contradictive to each other. An image of 120×160 pixels is taken for example. Traditionally, ten searching windows of different sizes are provided for a face detector to search for any face in each preview image, and the sizes of the searching windows are searched one by one along the horizontal and vertical directions. The faces are searched by an iteration of moving horizontally and vertically on the whole image, and thus the number of operations in the detecting process is very large, and the speed and efficiency of the face detection become very low. Obviously, the prior art cannot meet the consumer requirements.
SUMMARY OF THE INVENTION
[0015] In view of the foregoing shortcomings of the prior art wherein the speed and efficiency of a face detection are very low in the process for a face detector of electronic camera devices to search a face in each preview image, the inventor of the present invention based on years of experience to conduct extensive researches and experiments, and finally developed a face tracking method for electronic camera device to reduce a large number of operations during the face detection and tracking processes, so as to enhance the speed and efficiency of the face detection and tracking process effectively.
[0016] Therefore, it is a primary objective of the present invention is to provide a method applied to an electronic camera device, and the method comprises the steps of: obtaining a preview image of the electronic camera device; performing a face tracking, wherein the electronic camera device has a face database for storing data including face position, size and skin color prototype (such as color histogram) of the preview image; obtaining a skin color extraction information according to the data including the position, size and skin color prototype of the known face in the face database to define a searching space, when a current preview image is obtained by the method and an existing known face in the face database is determined; using a preinstalled face classifier for the detection of a searching space in the current preview image to determine whether or not a face exists in the searching space; and automatically updating the corresponding face data in the face database when each face is detected. If a known face exists in the face database, the electronic camera device simply needs to detect the searching space to detect and locate the precise position of the face in the current preview image accurately, so as to enhance the speed and efficiency of the face tracking greatly.
[0017] Another objective of the present invention is to start a face tracking mechanism to define an extended searching region according to the data including a position, a size and a skin color prototype of a known face in the face database to track a corresponding face in the preview image, when the face classifier cannot detect a face in the searching space, and calculate a color histogram of each position in the current searching region and a color histogram matching of the corresponding known face, and use the detected data of a corresponding position having the maximum histogram matching of a face data in the current preview image to automatically update the corresponding face data in the face database, so as to effectively reduce the large number of operations required for the detection and tracking processes, greatly enhance the speed and efficiency of the face tracking, and accurately track the face in the current preview image.
[0018] A further objective of the present invention is to thoroughly search the position and size of each skin color extraction area in a current preview image when it is determined that no known face exists in the face database, and then use a face classifier to detect each skin color extraction area in the current preview image to determine whether or not there is a face in the skin color extraction area. If a face is detected, the corresponding face data in the face database is updated automatically, so that it is only necessary to detect each skin color extraction area in the current preview image of the electronic camera device, if there is no known face in the face database, so as to effectively reduce the large number of operations required for the detecting process and greatly enhance the speed and efficiency of the face tracking.
[0019] Another objective of the present invention is to label a face rectangle of the face position and size for a stabilizing process when each face is detected, in order to effectively prevent a screen dithering of the face rectangle of the electronic camera device, enhance the visual effect, and precisely locate the exact position of the face in the current preview image.
[0020] To make it easier for our examiner to understand the objective, technical characteristics and effects of the present invention, preferred embodiments will be described with accompanying drawings as follows:
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a schematic view of calculating a distribution of misclassification error of features i and j by a traditional histogram bin method;
[0022] FIG. 2 is a schematic view of four basic units used for defining a feature prototype in a traditional Haar-like feature;
[0023] FIG. 3 is a schematic view of eight basic units used by the inventor of the present invention for defining a feature prototype in his previous related patent application;
[0024] FIG. 4 is a schematic view of a system architecture of an electronic camera device in accordance with the present invention;
[0025] FIG. 5 is a flow chart of a face tracking module in accordance with a preferred embodiment of the present invention;
[0026] FIG. 6 is a flow chart of stabilizing a face rectangle in accordance to the preferred embodiment as shown in FIG. 5 ; and
[0027] FIG. 7 is a flow chart of a tracking face in accordance to the preferred embodiment as shown in FIG. 5 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Referring to FIG. 4 for a face tracking method for electronic camera device, the method is applied to an electronic camera device, and the electronic camera device 40 comprises a camera sensor 41 , a processing module 42 , a face tracking module 43 and an application module 44 . The camera sensor 41 is an optical sensing module of the electronic camera device 40 for converting a captured optical signal into an electric signal, and the camera sensor 41 is mainly divided into two types respectively CMOS and CCD. The processing module 42 is installed at an end of the camera sensor 41 for performing a pre-processing including sampling, white balance and color space conversion of an image signal transmitted from the camera sensor 41 to produce a preview image. The face tracking module 43 processes the face detection and tracking for the preview image transmitted from the processing module 42 to obtain the data including face position, size and skin color prototype of the preview image, wherein the skin color prototype can be a color histogram, and the color histogram shows the color statistics of a YUV channel corresponding to the face position and size of the preview image. The application module 44 receives the data including the face position, size and skin color prototype transmitted from the face tracking module 43 , and performs applications and processes mainly including auto focus, color enhancement and white balance adjustment according to the preview image transmitted from the processing module 42 and different user requirements. In the present invention, the face tracking module 43 is improved, so that when the electronic camera device tracks a face in the preview image, the tracking can be performed more quickly and precisely to locate the exact position of the face in the current preview image. Since the components including the camera sensor 41 , processing module 42 and application module 44 are prior arts, and thus will not be described in details here.
[0029] Referring to FIG. 4 for a preferred embodiment of the present invention, the electronic camera device 40 further comprises a face database 45 and a face classifier 46 , wherein if the face tracking module 43 detects and determines that there is a face in the current preview image, the data including the face position, size and skin color prototype in the current preview image will be stored into the face database 45 as a reference data for performing a face tracking for the next preview image. The face tracking module 43 uses a face classifier 46 to detect the current preview image and determine whether or not to read the data including the position, size and skin color prototype of a face if the face exists in the current preview image. In the preferred embodiment, if the electronic camera device obtains a current preview image, the face tracking module 43 performs the detection and tracking to a face in the current preview image according to the following procedure as shown in FIG. 5 :
[0030] Step ( 500 ): Read a current preview image, wherein the preview image can be in a YUV or RGB format, and this embodiment adopts the YUV format for the illustration, but the invention is not limited to the YUV format only.
[0031] Step ( 501 ): Perform a pre-processing including resize, color space transform and skin color extraction to the preview image, wherein the resize is provided for reducing the preview image to a size of 160×120 pixels; the color space transform is provided for converting the YUV pixel format into the YUV 411 planar format; and the skin color extraction is provided to obtain the skin color extraction in the preview image according to the skin color prototype disclosed in the inventor's other patent (U.S. patent application Ser. No. 11/323,653). Since the skin color extraction is not the key point of the present invention, the skin color extraction will not be described in details here.
[0032] Step ( 502 ): Determine whether or not there is a data such as a position, a size and a skin color prototype of the known face in the face database 45 ; if yes, then go to Step ( 503 ) to perform an iteration of detecting each face in the preview image according to the face data in the face database 45 , or else go to Step ( 511 ) to define a first searching space of the preview image.
[0033] Step ( 503 ): Read a data including the position, size and skin color prototype of a known face in the face database 45 .
[0034] Step ( 504 ): Define a second searching space for the preview image according to the read data including the position, size and skin color prototype of a known face, and the method is based the method disclosed and defined by the inventor's other patent (such as U.S. patent application Ser. No. 11/545,423). Since the method of defining the second searching space is not the key point of the present invention and thus will not be described in details here.
[0035] Step ( 505 ): Search each position, size and skin color prototype of the second searching space in the preview image.
[0036] Step ( 506 ): Use the face classifier 46 to determine whether or not a face in the second searching space is detected; if yes, then go to Step ( 507 ), or else go to Step ( 514 ) to track the corresponding face in the preview image.
[0037] Step ( 507 ): Since the position and size of a face rectangle (for labeling the face position and size in a screen) detected or tracked each time vary, a screen dithering frequently occurs in the face rectangle of the electronic camera device. To prevent the dithering occurred at the face rectangle on a screen, a stabilizing process is performed to the face rectangle to enhance the visual effect if a face is detected, and the exact position of the face in the current preview image is located. In this preferred embodiment, the face tracking module 43 processes a procedure as shown in FIG. 6 to stabilize the size and position of the face rectangle:
[0038] Step ( 600 ): Read the position and size information (x i ,y i ,w i ,h i ) of the face rectangles in the recent 3 preview images from the face database 45 , wherein x, y represent the coordinates of a position; w represents the width; and h represents the height; and i=1,2,3. The aforementioned conditions are used in this embodiment, but the invention may use another number of preview images as required.
[0039] Step ( 601 ): Perform a median filtering to the position and size information of the face rectangles in the recent 3 preview images.
[0040] Step ( 602 ): Perform an exponential smooth process to the history data (x i ,y i ,w i ,h i ) of the position and size of the known face in the median filtered result and the face database 45 .
[0041] Step ( 603 ): Label the median filtered and exponential smoothed face rectangle at a corresponding face position on the screen to enhance the visual effect, and precisely locate the exact position of the face in the current preview image.
[0042] Step ( 508 ): Determine whether or not the read known face is the last known face in the face database 45 ; if yes, then end the iteration of the face detection and go to Step ( 509 ), or else return to Step ( 503 ).
[0043] ( 509 ) Write the detected face position, size and skin color prototype (which is a color histogram) into the face database 45 to update the data including the position, size and skin color prototype of the known face in the face database 45 .
[0044] Step ( 510 ): Output the data including the position, size and skin color prototype of the detected face to the application module 44 , such that the application module 44 process an application such as an auto focus, a color enhancement and a white balance adjustment to the current preview image according to the data and user requirements.
[0045] Step ( 511 ): Thoroughly search the preview images, and define each skin color extraction area of the preview image as the first searching space.
[0046] Step ( 512 ): Search the data including each position, size and skin color prototype of the first searching space in the preview image.
[0047] Step ( 513 ): Use the face classifier 46 to determine whether or not a face is detected in the first searching space; if yes, then go to Step ( 509 ), or else go to Step ( 510 ).
[0048] Step ( 514 ): Start a face tracking mechanism and perform a face tracking according to the data including the position, size and skin color prototype of the known face in the face database 45 . In this embodiment, the face tracking module 43 processes the following procedure as shown in FIG. 7 to stabilize the size and position of the face rectangle:
[0049] Step ( 700 ): Read the data including the position, size and skin color prototype of the known face in the face database 45 , wherein the skin color prototype is represented by color histogram information h T (i); the color histogram shows the color statistics of the corresponding YUV channel of the face position and size on the preview image. In this embodiment, each of the three channels of the YUV is divided into 16 regions of the grey levels from 0 to 265 , so that the 3D spaces of the YUV can be divided into 16×16×16 subspaces, and each subspace corresponds to an element in the histogram.
[0050] Step ( 701 ): Define a face searching region. Assumed that a specific continuity exists between two adjacent preview images of the preferred embodiment, the size of the known face in the face database 45 , and the width w and the height h are doubled, and the required searching region S is defined as follows:
[0000] S =( x,y, 2 w, 2 h )
[0051] Step ( 702 ): Perform an iteration of searching a face for each position of each searching region.
[0052] Step ( 703 ): Obtain a color histogram h 1 (i) at the current position to obtain a 16×16×16 dimensional vector.
[0053] Step ( 704 ): Calculate a histogram matching ρ(h T ,h 1 ) between a color histogram h 1 (i) of a current position and a color histogram h T (i) of a corresponding known face in the face database 45 by the following formula:
[0000]
ρ
(
h
T
,
h
I
)
=
∑
i
=
1
N
abs
(
h
T
(
i
)
-
h
I
(
i
)
)
[0054] where, N is the dimension of the histogram, and h T (i) and h 1 (i) are a histogram of the corresponding known face in the face database 45 and a histogram of a position searched by the face tracker respectively, and the two histograms are unified as follows:
[0000] ∫ h T ( i ) di =1 and ∫ h 1 ( i ) di= 1
[0055] If the histogram matching of the two histograms satisfies the condition ρ(h T ,h 1 )>0.5, then the face is tracked, or else no face is tracked and the current tracking result is discarded.
[0056] Step ( 705 ): Determine whether or not the read known face is the last known face in the face database 45 ; if yes, then end the iteration of searching a face and go to Step ( 706 ), or else return to Step ( 702 ).
[0057] Step ( 706 ): Output the corresponding detected position information having the maximum histogram matching to the face tracking module 43 , so that the face tracking module 43 can accurately track a face in the current preview image.
[0058] Step ( 515 ): Determine whether or not the tracked face in the current preview image disappears; if yes, then go to Step ( 508 ) to process the iteration of tracking the next face, or else go to Step ( 507 ) to stabilize the face rectangle.
[0059] When the present invention tracks a face of a preview image obtained by the electronic camera device, a different method is adopted to define a different searching space according to the determination whether or not a known face exists in the face database, and the face classifier is used for detecting a searching space in the current preview image to determine whether or not a face exists in the searching space. If the face classifier cannot detect a face in the searching space, a face tracking mechanism is started to define an extended searching region according to the data including the position, size and skin color prototype of the known face in the face database, and track a corresponding face in the preview image. When each face is detected, the corresponding face data in the face database is updated automatically, such that the electronic camera device needs to detect each skin color extraction area in the current preview image, only if there is no known face in the face database, and such arrangement can effectively reduce the large number of operations required for the detection and tracking processes, so as to greatly enhance the speed and efficiency of the face detection and tracking processes, and precisely locate the exact position of the tracked and fixed face in the current preview image, and the electronic camera device can achieve the advanced functions such as auto focus and auto exposure for shooting high-quality portraits quickly and accurately.
[0060] While the invention has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims. | The present invention discloses a face tracking method for electronic camera devices. The method is applied to an electronic camera device having a face database and a face classifier, and the face database is provided for storing data such as a position, a size and a skin color prototype of a face in a previously stored preview image, and the method includes the steps of: obtaining a current preview image; determining whether or not a known face exists in the face database; defining a searching space on the current preview image; and using the face classifier to detect the searching space in the current preview image, and determining whether or not a face exists in the searching space. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The application is a continuation-in-part of U.S. application Ser. No. 13/280,728, filed on Oct. 25, 2011, which claims priority to U.S. application Ser. No. 11/867,505, filed on Oct. 4, 2007, both of which are incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a thin sheet of tabbed tracing paper, vellum, tissue paper or similar material inserted in a book to allow a user to highlight, mark or annotate a passage in the book without having to mark the actual page.
[0003] While reading or researching a book or other type of document, it is often desirable to make notes or highlight particular passages throughout the book or document and to be able to flip between the different annotated pages. For example, a student may find it helpful to make notes in the margins of a textbook or highlight particular paragraphs. It would be highly preferable if this could be done without permanently marking or damaging the pages. For instance, the prices of college textbooks have created a market for used textbooks and a less marked-up textbook would have a higher resale value. The present invention permits a user to annotate a textbook without negatively affecting its physical condition. The annotating can occur in the context of a real-time lecture in addition to other contexts such as regular reading or study sessions.
[0004] It is sometimes also desirable for multiple persons to review and annotate multiple pages in a large document, such as a group review of a report or a group Bible study, without physically damaging the source document. Preferably, there should be a quick and easy way to annotate multiple pages in the document, index the notes, and flip to between the multiple inserts.
[0005] Transparent overlay devices have been known for some time in the art, for example U.S. Pat. Nos. 1,450,261; 1,510,110; 2,791,040; 3,324,823; 5,029,899 and 5,388,861. These prior art devices typically consist of a transparent overlay permanently or semi-permanently attached to the cover or bindings of the book or document. For example, U.S. Pat. No. 2,791,040 discloses a single sheet of transparent acetate placed over a map to allow a navigator to chart a course without marking the map. The acetate sheet is part of an erasable pocket on the exterior of a map folio holding the map or drawing. Similarly, U.S. Pat. No. 1,510,110 teaches a hinged transparent sheet attached to a map guide, and U.S. Pat. No. 1,450,261 discloses a book with tracing paper attached to the outer edge of the book cover which folds over the pages of text. These transparent overlays are limited in that they are part of bulky covers or document holders and are only used with the books or maps placed within the holder or cover. These devices are not convenient to use if a reader wants to annotate multiple books or documents, or multiple pages within the same book or document while retaining the previous notes.
[0006] U.S. Pat. No. 4,970,984 discloses memo marking tabs which can be easily inserted into a document. These marking tabs, however, are made from heavy gauge paper making them non-transparent. While non-transparent inserts still allow for notes to be placed in the document, they cover the printed information on the page. Additionally, inserts made from heavy gauge paper significantly increasing the thickness of the document if multiple tabs are used.
[0007] What is needed is a device for easily annotating or highlighting one or more pages of printed material without leaving permanent marks while still allowing the printed material to be seen and read. It is also desirable for the notes or highlights to be easily removable, reattached or stored for future reference.
SUMMARY OF THE INVENTION
[0008] The present invention provides an insert for placing over a page of a book or other document so as to allow annotation of the page. The inserts are thin enough so as to allow a large number of inserts to be placed within a document without significantly increasing the document thickness or distorting the shape and size of the document when closed. The inserts of the present invention comprise a sheet of transparent or substantially transparent material, and one or more tabs that extend from the outer edges of the sheet to allow a user to index and quickly find a particular insert and the corresponding document page. The sheet has a front face and rear face where the front face is receptive to pencil and ink marks. Optionally, at least one portion of the rear face of the sheet has an adhesive allowing the insert to be affixed to the page.
[0009] The inserts of the present invention can be used with books and documents of almost any type. For example, business documents such as draft press releases, FDA submissions, or regulatory SEC filings that need to be reviewed by multiple personnel represent possibilities for employing articles and methods of the invention. Another general application of the present invention is in the context of a small study group where there is a common practice of sharing a single source document or study guide by each of the group members.
[0010] The present invention also provides a method of annotating a page of a document (such as book, study guide, report, etc.) comprising the steps of a) providing an insert which comprises a thin sheet of transparent or substantially transparent material having a front face and a rear face, and one or more tabs extending from the sides of the sheet, where the front face is receptive to pencil and ink marks, and at least one portion of the rear face contains an adhesive; b) positioning the insert relative to a desired document page so that the adhesive contacts the document page; and c) annotating the insert. In a further embodiment, the adhesive allows temporary fixation to the document page and allows the entire sheet to be removed without ripping or tearing the page or the insert. In a further embodiment, the removed annotated sheet is later reattached to the same document page or to a different document page and annotated further. In another embodiment, multiple inserts are positioned onto multiple different pages in the same document and annotated. The tabs extend beyond the edges of the document allowing a user to find and turn to a particular insert.
[0011] In a further embodiment, the insert sheet or portions of the insert sheet are tinted with a color and positioned over a desired section of the document page in order to highlight the desired section. It is believed the color highlight makes the desired section easier to read, particularly with individuals with vision or reading disabilities.
[0012] An insert of the present invention is preferably thin. The insert sheet should have a small enough thickness to be flexible, at least substantially transparent, and not significantly add to the weight or thickness of the annotated book or document. The insert sheet should have a sufficient thickness so writing on the insert does not cause ripping or tearing. Thickness is typically described for paper in multiple ways. An absolute measurement of thickness of a single sheet of paper is typically made in mils, where 1 mil=1/1000 inch. Alternatively, thickness can be determined by weight per 500 sheets of a standard size of paper, and by the paper industry standard of grams per square meter (gsm), also called grammage, as set forth by the International Organization for Standardization (ISO). Standard letter size paper (8½ by 11 inches) is often described as 20 pound paper (with 20 pounds being the weight of 500 sheets of uncut 17″×22″ paper, which the paper manufacturer will then cut into 4 letter-sized reams). Therefore, 500 sheets of 20 pound letter sized paper will weigh approximately 5 pounds. Typical letter size paper has a grammage of approximately 80 gsm.
[0013] One embodiment of the present provides inserts comprising a sheet having a thickness of approximately 0.25 to 3 mils, more preferably a thickness of approximately 0.5 to 2.5 mils, even more preferably a thickness of approximately 1 to 1.5 mils.
[0014] Another embodiment of the present invention provides inserts comprising a sheet having between about 10 and about 60 gsm, more preferably between about 10 and about 40 gsm, even more preferably between about 15 and about 30 gsm.
[0015] Another embodiment of the present invention provides inserts where 500 sheets of letter size inserts weigh between approximately 1.25 and 2.5 pounds, more preferably between 1.5 and 1.75 pounds. It should be noted that the thickness values for one embodiment may not completely overlap with another embodiment. For example, an insert sheet having a thickness of approximately 3 mils may have a grammage greater than 60 gsm.
[0016] Particularly for popular conventional paper stocks used in the publishing industry, the thickness of an annotated insert of the present invention can be described relative to the paper stock, i.e., the thickness of the insert is less than or equal to a specified percentage of the thickness of the document page. In one embodiment, the thickness of the insert is no more than about 2% to about 80% of the document sheet thickness, more preferably no more than about 50%.
[0017] In one embodiment, the sheet is flexible enough to allow the insert to be folded while positioned on the document page. In a further embodiment, both the front face and rear face are receptive to pencil and ink marks. This allows the insert to be positioned onto a document page, a portion of the insert to be folded over thereby exposing a portion of the document page, and the rear face of the folded portion of the insert to be annotated. For example, where the text on the document page is provided in columns, the insert is placed over the document page and is folded to expose one or more of the columns of the underlying document page, and the rear face of the insert annotated next to the desired column.
[0018] The inserts of the present invention have one or more tabs extending from the outer edges of the sheet. The one or more tabs are analogous to the size and shape of tabs that are found on a conventional manila file folders or 3-ring binder dividers. In one embodiment, the insert contains two to six tabs depending on the size of the document to be annotated and the size of the insert. The tabs can be positioned anywhere along the top of the sheet, the bottom of the sheet, the side of the sheet opposite from the binding, or a combination thereof. Preferably, no tabs are positioned at the edge of the sheet that is positioned along the binding of the annotated book or document. The tabs may be made from the same material as the sheet and may form a seamless structure with the sheet. Alternatively, the tabs may be made from a different material and attached, such as by glue, to the rest of the sheet.
[0019] The tab feature allows for indexing the annotations made to the book or document and is particularly useful for finding specific annotations or pages in a book or document containing multiple inserts. In one embodiment, the tabs of different inserts are located at different positions along the top, bottom or side of the sheet so that the tabs of the separate inserts will not overlap each other when multiple inserts are placed in the same book or document. In one embodiment, the tabs are also color coded to assist in differentiating between the tabs. In another embodiment, the tabs are thin enough to allow the tab to be more flexible and bend without ripping or tearing compared to harder or thicker tabs. This can enhance the resiliency and durability of the tab. For example, when the insert is left in a book, the book can be repeatedly shelved while not substantially diminishing the tab integrity.
[0020] The adhesive is optionally present in one or more areas on the surface of the rear face of the sheet. In one embodiment, this area is a strip along the side or top of the sheet. This strip can correspond to the margins of the document page so that the adhesive does not contact the text of the document. Adhesive note pads or sticky notes known in the art have relatively thick strips of adhesives which can cause ripping or tearing of the insert or document page when the insert is removed. Preferably the adhesive is present in small enough amounts that the insert or pages of the document are not ripped when the insert is removed. In one embodiment, the adhesive is present as one or more circular areas or dots on the rear face of the sheet. In a further embodiment, the adhesive dots are spread along the side or top of the sheet starting approximately half of an inch to one inch from one edge of the sheet and continuing to approximately half of an inch to one inch from the opposite edge. This strip of adhesive dots can also be positioned so that it contacts the margin of the document page. The use of adhesive dots provides a sufficient adhesive force across the sheet and allows the insert to be removed from the document page without ripping the document page or the insert. The use of adhesive dots is preferable over a solid adhesive strip because a smaller area of the original document will come into contact with the adhesive thereby reducing the chance that the original document will be pulled up, marked or torn when the adhesive is removed. This is especially beneficial if the sheet is being inserted over a piece of art work (an old text of natural science pictures for instance). In a further embodiment, the rear face of the insert sheet does not contain any compound or material that will mark the underlying document page when the front face of the insert sheet is written on or pressed on. This will additionally ensure that the underlying document page is not marked or damaged by using the insert.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1A and FIG. 1B show an insert of the present invention having a tab positioned on the side ( FIG. 1A ) of the sheet or on the top ( FIG. 1B ) of the sheet. FIG. 1C shows an insert having an adhesive strip on the rear face of the sheet. FIG. 1D illustrates the thickness of an insert of the present invention. FIGS. 1E and 1F show an insert having a plurality of circular adhesive dots on the rear face of the sheet in different configurations.
[0022] FIG. 2 shows an insert of the present invention positioned relative to a page in a document.
DETAILED DESCRIPTION
[0023] As used herein, “annotate” and “annotating” broadly refers to writing notes (including but not limited to letters, numbers, symbols and words), drawing, underlining, highlighting, coloring, shading or otherwise marking a writable surface in relation to a printed document. Annotations can be made on the same page of a document of interest; however, it is the objective of the present invention that annotations are made on transparent or substantially transparent inserts placed over the document of interest. Materials suitable for inserts of the present invention include paper of all types, particularly tissue paper and tracing paper, vellum, and similar materials commonly used as writing surfaces that are receptive to pencil and ink marks.
[0024] By “receptive to pencil and ink marks” it is meant that it easy to mark the surface with a ballpoint pen, pencil, highlighter or other common writing utensil. Other protective covers and inserts, such as plastic transparencies, are not easily marked by ballpoint pen or pencil and may require markers adapted for marking that particular material. This makes it inconvenient to annotate the document.
[0025] The inserts of the present invention comprise a sheet that is transparent or at least substantially transparent similar to conventional tracing paper. As used herein, “substantially transparent” should be understood as permitting sufficient passage of light to permit the viewing of an underlying image, particularly the text of a book or other document. The sheet covers at least a portion of the relevant text on the document and is typically rectangular but can be any shape. In the present invention, the sheet is transparent or substantially transparent so that the underlying document can be seen and read while the insert is placed over the document. This allows the notes or highlights to be placed and read in the correct position relative to the original text.
[0026] FIG. 1A and FIG. 1B show an insert 10 of the present invention having a sheet 12 , an interior or binding edge 11 of the sheet 12 , and a projecting tab 14 which can be present on any non-interior edge such as the side ( FIG. 1A ) or the top of the insert ( FIG. 1B ). Typically, the insert 10 will be placed over a document page so that the interior or binding edge 11 is along the side of the page next to the binding. FIG. 1C shows the rear face of an insert 10 having an adhesive section 16 . Preferably when the insert 10 is placed over a document page, the adhesive section 16 is positioned so that it contacts the margin of the page next to the binding. In this embodiment, the adhesive section 16 is a strip that is indented from the edges of the sheet 12 , preferably by at least ½ of an inch from the top and bottom edges and up to ¾ of an inch from the binding edge 11 . FIG. 1D shows an insert 10 having a depth/thickness of dimension 18 . Preferably dimension 18 is comparable to that of conventional tracing paper, vellum, and/or tissue paper. In one embodiment of the present, the insert thickness 18 is approximately 1 to 1.5 mils.
[0027] FIG. 1E shows the rear face of an insert 10 having a plurality of circular adhesive dots 17 instead of an adhesive strip. For an insert that is 7 inches by 9 inches or larger, the adhesive dots 17 need not be more than 2 mm in diameter and are as small as 1 mm in diameter. The adhesive dots are spaced between 1 cm and 3 cm apart from one another and can be arranged in a straight line across the sheet 12 , or can be arranged in other configurations, such as a group of dots at each corner of the sheet 12 , or a groups of dots positioned toward the center of the sheet 12 as shown in FIG. 1F . In one embodiment, each of the adhesive dots 17 are positioned at least 1.27 cm away from the closest edge. In a further embodiment, each of the adhesive dots 17 are positioned at least 2.54 cm away from the closest edge. In a further embodiment, each of the adhesive dots 17 are positioned at least 3.8 cm away from the closest edge. The adhesive dots 17 can be smaller than 1 mm in diameter (as small as 0.5 mm) for smaller sized inserts. The infrequency of the adhesive dots 17 and the minimal size help protect the original document from tearing and are less likely to leave residual adhesive on the document page.
[0028] FIG. 2 shows an insert 10 of the present invention positioned relative to a page in a document 30 . Annotations 20 are provided by a user writing directly on sheet 10 while it is positioned on top of document 30 and can be text or other kind of mark or highlight.
[0029] The adhesive on the rear face of the sheet allows the insert to be temporarily fixed to the document page. The adhesive allows positioning of the insert relative to the document information content. For example, a user can conveniently place text-based lecture notes or study notes on the insert next to the relevant portion of the text.
[0030] The adhesive of the present invention also allows the insert sheet to be completely removed and re-inserted if necessary. This allows multiple users to annotate a single document. For example, User 1 can annotate a document such as a topical study guide that may accompany a small Bible study group. User 2 can similarly annotate the same document. Thus multiple participants can use a single document. Furthermore, by completely removing the annotation sheet so that no part of the annotated sheet remains affixed to the underlying document, the method is conducive to allowing a first participant to annotate while allowing a second participant to independently annotate without having ready access to the annotations of the first participant. This is a desirable advantage that is otherwise generally impeded when a single document is available for annotation. The adhesive aspect of the annotation sheet can conveniently enhance the ability of maintaining the annotations of the first participant proximal to the document. For instance, the annotation sheet of the first participant can be placed inside the back cover of the document.
[0031] The insert can be any size and is preferably substantially the same size as the document of interest (e.g. the page of a book to be annotated). Common page sizes for use with books range from 2½ inches by 3½ inches to 8 by 10½ inches. Additionally, sizes can include larger sizes such as maps and textbooks.
[0032] By “substantially the same size” it is meant that the length and width of the insert, aside from the tabs, is within 10% of the size of the document to be annotated. In one embodiment, the inserts are slightly smaller than the pages of a book so that they can be easily inserted into a book. It may be preferable that the insert be slightly smaller than the page so that the insert can completely fit within the book or document except for the tabs. Preferably, the tabs of the insert will protrude from the pages.
[0033] The reduced thickness allows the insert to have a relatively larger surface area compared to tape flags or smaller Post-it® notes or flags known in the art. The increased surface area provides a larger area to make notes and also enhances the ability to maintain the insert's location in the document. The ability of the insert to remain fixed to the page is affected by a combination of (a) the frictional force between the total surface area of the insert against the annotated page; (b) the frictional force/leverage factor from positioning the annotation sheet towards the binding of the book or document; and (c) the adhesive force from any adhesives on the rear face of the insert. A larger surface area will increase the frictional force between the insert and the page and results in a superior ability of the insert to stay with the document versus the common occurrence where a tape flag or conventional sticky note quickly or eventually falls out of the document. A larger surface area also means that less adhesive is required to keep the insert fixed to the document page.
[0034] Additionally, the reduced thickness allows multiple inserts to be inserted into a book or document while having a minimal effect or no effect on the overall document thickness. This allows for multiple inserts to be used while preserving the document binding structure and reducing potential for damage. This is particularly useful in hardcover bound books. For example, the insert sheet is thin enough so that it is possible to add upwards of 80 insert sheets without negatively affecting an average hard cover book having 280 pages or more. Conventional tape flags or sticky notes can be made to have surface areas as large as the inserts of the present invention, however, the thickness of these conventional inserts would result in significantly increasing the weight or deforming the shape of the book or document if multiple sheets are used.
[0035] The inserts are optionally partially or completely tinted with a color. The inserts can be any color, including but not limited to red, green, blue, white, cream, yellow, grey, mauve, burgundy, orange and combinations thereof, as long as the sheet remains at least substantially transparent. The sheet and tabs of the insert may both be tinted or un-tinted independently of each other, and may be tinted different colors. The colors can be used to emphasize particular inserts or match topics to a particular color. It is believed that colorizing the insert can highlight the underlying text making the text easier to read, particularly to those with reading disabilities such as dyslexia. Optionally, the inserts may also contain lines across the sheet similar to notebook paper. The lines can be any color, including but not limited to white, black and grey, that is easily discernable and should be thin enough so as not to block the underlying document text. For example, white lines can be used where the sheet is a darker color, or black lines can be used where the sheet is a lighter color. Additionally, the lines can be a darker shade of the sheet color, i.e., the sheet is tinted blue or cream color and has dark blue or dark tan lines.
[0036] While the invention has been described with certain preferred embodiments, it is understood that the preceding description is not intended to limit the scope of the invention. It will be appreciated by one skilled in the art that various equivalents and modifications can be made to the invention shown in the specific embodiments without departing from the spirit and scope of the invention. Every formulation or combination of components described or exemplified herein can be used to practice the invention, unless otherwise stated. Whenever a range is given in the specification, for example, a size range, a thickness range or a composition range, all intermediate ranges and subranges, as well as all individual values included in the ranges given are intended to be included in the disclosure. Moreover, any use of a term in the singular also encompasses plural forms. All publications referred to herein are incorporated herein to the extent not inconsistent herewith. | Transparent or substantially transparent sheets of paper or similar material suitable for inserting into a book or placed over a document are used to highlight or annotate a document without permanently marking or damaging the page. The inserts are thin enough so as to allow several inserts to be placed within a book without significantly increasing the book thickness or distorting the shape and size of the book when closed. Additionally, the inserts contain one or more tabs to allow a user to index and quickly find a particular insert and the corresponding page. An adhesive is present on the rear side of the insert to fix the insert to the page being annotated. | 1 |
DISCLOSURE OF THE INVENTION
1. Field of the Invention
This invention relates to polystyrene polymers and to methods of minimizing electrostatic charges thereon. More particularly, the invention relates to methods of imparting antistatic properties to expandable polystyrene beads during the pre-expansion step.
2. Prior Art
All of the prior art teaches methods of rendering polystyrene surfaces having antistatic properties by dipping or spraying techniques, which are slow, and costly. Among these should be noted U. S. Pat. Nos. 2,727,831; 3,575,903; 3,764,376; 3,415,661; 3,419,640; 3,936,422; and 3,873,645. None of the prior art teaches that antistatic materials may be added to expandable polystyrene beads prior to preexpansion.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Polystyrene beads in the sense of this invention are those beads of styrene polymers and mixed polymers of styrene which contain at least 50 percent by weight of styrene in polymerized form. Included among the comonomers are α and p methylstyrene, acrylonitrile, methacrylonitrile, esters of acrylic acid and methacrylic acid, butadiene, and small quantities of divinylbenzene. Molding materials may also contain polymers of butadiene, ethylene or acrylic esters.
Additionally, the beads may contain flame retardants. These are organic chlorine and bromine compounds which preferably contain at least 50 percent by weight of chlorine or bromine. Examples of flame retardants include chloroparaffin, 1,2,5,6,9,10-hexabromocyclododecane, tetrabromodibenzalacetane, pentabromophenylallylether, pentabromomonochlorocyclohexane, 1,1,2,3,4,4-hexabromobutene-2, 2,5-bis (tribromomethyl)-1,3,4-thiadiazol, 2,4,6-tris(tribromomethyl)-1, 3,5 triazine, tetrabromoehane, bromotrichloromethane, 1,2,5,6-tetrabromohexane, hexabromobenzene, pentabromophenol, pentabromodiphenylether, trisdibromopropyl)-phosphate, octabromocyclohexadecane, and α-bromonaphthalene. The amount of flame retardant agent employed ranges from 0.1 to 5 percent by weight based on the weight of the polystyrene.
Expandable polystyrene beads generally contain blowing agents. Blowing agents which may be used include aliphatic or cycloaliphatic hydrocarbons and halogenated hydrocarbons such as butane, pentane, hexane, heptane, cyclohexane, methyl chloride and dichlorodifluoromethane. Also suitable are blowing agents which decompose at elevated temperatures and form gases. Among these are azodicarbonamide or sodium bicarbonate. The concentration of blowing agent ranges from 3 to 15 percent by weight based on the weight of polystyrene polymer.
The polystyrene beads are produced by methods well known to those skilled in the art. The most commonly employed method for producing expandable polystyrene beads is the suspension polymerization process, which utilizes liquid styrene monomer, dispersed in an aqueous medium containing blowing agent and a polymerization catalyst. The dispersion is heated for a predetermined time and temperature producing high molecular weight beads. The beads are then filtered, washed and dried. The bead sizes may vary in diameter from 0.01 to 0.1 inches. The beads are then pre-expanded until the desired density is obtained. The pre-expansion may be conducted by means of steam, hot water, hot air or other heat sources. The desired quantity of antistatic agent may be added as a solution during the pre-expansion operation or if steam is the heat source, then the antistatic agent may be added simultaneously with the steam. An effective amount of antistatic agent is employed. Generally, the concentrations range from about 0.05 to 1.0 weight percent based on the weight of polystyrene polymer. Preferably, the concentrations employed range from about 0.1 to 0.5 weight percent based on the weight of polystyrene polymer.
The antistat compounds which are particularly suited in the process of the invention are N,N-bis(2-hydroxyethyl)-N-(3-dodecyl-2-hydroxypropyl) methylammonium methosulfate,stearamidopropyldimethyl-B-hydroxyethylammonium nitrate,hydrogenated tallow primary amine containing 16 to 18 carbon atoms, and a fatty alcohol phosphate having a formula KO(Q-O) 4 -K wherein Q is ##STR1## in which R is C 12 to C 16 .
The following examples are intended to exemplify the invention.
Abbreviations employed in the Examples are as follows:
Antistat A is N,N-bis(2-hydroxyethyl)-N-(3-dodecyl-2-hydroxypropyl)methylammonium methasulfate
Antistat B is stearamidopropyldimethyl-B-hydroxyethyl-ammonium nitrate
Antistat C is a hydrogenated tallow primary amine containing 16 to 18 carbon atoms
Antistat D is a fatty alcohol phosphate having a formula KO(Q-O) 4 -K wherein Q is ##STR2## in which R is C 12 to C 16
EXAMPLE 1-4
Polystyrene beads having a bead size diameter range of 0.02 to 0.05 inches were fed into a pre-expansion chamber simultaneously with a solution of an antistatic compound as designated below. A steam pressure of 15 psig at 212° F. was employed. The expanded lower density beads were discharged through the top of the chamber and air conveyed to storage bins for aging. The aging time was at least 24 hours at room temperature. The polystyrene was then molded into test specimens using a Springfield molding press employing 18 psig pressure at a temperature of 225° F. The test samples were exposed to an applied charge of 5000 volts as per the military specification MIL-B-81705B. All of the samples treated decayed to a static charge of 500 volts in less than 2 seconds.
TABLE______________________________________Antistat Solvent, % Concentration of Antistat______________________________________A water, 25 1 gm/lb. of polystyreneB water, 25 1 gm/lb. of polystyreneC isopropyl alcohol, 20 1 gm/lb. of polystyreneD isopropyl alcohol, 20 1 gm/lb. of polystyrene______________________________________
COMPARATIVE EXAMPLES A & B
The process of Examples 1-4 was employed to prepare the samples of comparative Examples A & B with the exception that no antistat compound was added during the pre-expansion steps.
Example A -- decayed to a charge greater than 500 volts and remained at this level for greater than 1 minute.
Example B -- decayed to a charge of 500 volts in a time greater than 2 seconds. | Polystyrene beads having antistatic properties are prepared by adding the antistatic compounds to the beads during the pre-expansion step. The beads may then be employed to prepared molded products without any further treatment with antistatic agents. | 1 |
[0001] This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Application No. 60/628,204 entitled PURE-CHIRALITY CARBON NANOTUBES AND METHODS and filed on Nov. 17, 2004, the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to pure-chirality carbon nanotubes (PC-SWNT) in industrially relevant quantities, as well as their production and use in solutions and/or dispersions. Additionally, this invention relates to a new composition of carbon nanotubes consisting essentially of pure-chirality carbon nanotubes of substantially one chirality. Also, this invention relates to perfluorocarbon surfactants that can be used for dissolving and dispersing nanotubes in perfluorocarbon solvents.
[0004] 2. Description of the Related Art
[0005] Fullerene nanotubes originated with studies of fullerenes (C 60 ), also known as “buckyballs.” Tubular relatives of the buckyballs are so-called single-walled nanotubes (hereinafter “SWNT” or “nanotubes” generally), which can be formed in tubular or cylindrical form. Nanotubes, generally, can conduct electricity better than copper and can be 100 times stronger than steel at ⅙ the weight.
[0006] As conventional nanotubes are made in batch processes, nanotubes are conventionally formed as nanotube batches consisting of mixtures of different chiralities or different lattice orientations. For example, a milligram sized nanotube batch can include many different chirality nanotubes therein. The properties of each nanotube in the batch can have a different chirality than the other nanotubes in the batch, wherein the electrical conductivity and optical properties, as well as other properties of each nanotube would be based upon the particular chirality of the individual nanotube.
[0007] Typically, a bulk nanotube batch product contains a ratio of about two-thirds semi-conductive chirality nanotubes to about one-third metallically conductive (i.e., highly conductive) chirality nanotubes. However, as the electrical and mechanical properties of each nanotube depends directly on the chirality of each tube, the specific characterization of the chirality of each nanotube, as well as the separation and/or production of batches or bulk product nanotubes with predetermined chiralities are desired.
[0008] For nanotubes, as illustrated FIGS. 1 and 2 , the chirality can be defined by the nomenclature “(n,m),” wherein “n” relates generally to the size of the nanotube, while “m” relates generally to the inclination of twist, also known as helicity. As illustrated in FIG. 1 a schematic structure for a graphene sheet is shown, wherein nanotubes can be made by folding the sheet along lattice vectors. For example, in FIG. 1 a lattice vectors are shown corresponding (from right to left in FIG. 1 a ) to an armchair (8,8) (see FIG. 1 b ), a zigzag (8,8) (see FIG. 1 c ) and a chiral (10,−2) (see FIG. 1 d ) lattice vector. As shown in FIGS. 1 b - 1 d , the nanotubes corresponding to the different lattice vectors have different helicities based upon their lattice vectors. Another exemplary graphene sheet is illustrated in FIG. 2 , wherein the lattice vector is (6,3) and is rolled along the “tube axis” to form a (6,3) nanotube.
[0009] For nanotubes of type (n,m), the conductivity of the nanotube can be determined by the equation:
n−m= 3 ×I or ( n−m )/3 =I
As a result, if I is zero or any positive integer the nanotubes have metallically conductive or highly electrically conductive properties. On the other hand, if I is not zero or any positive integer (i.e., all other nanotubes), then the nanotubes have semi-conductive electrically conductive properties.
[0010] As illustrated in FIG. 3 , the electronic properties of a metallic nanotube vs. a semiconducting nanotube is shown, wherein the density of states, as well as the differential conductance are clearly different for the different types of nanotubes. As such, it is expected that based upon the electronic properties of a nanotube, certain density of states and differential conductance can be realized.
[0011] Nanotube electrical conductivity, as with any material, is a function of the “fundamental gap,” “gap” or “E gap .” The “gap” is defined as the difference between the HOMO (Highest Occupied Molecular Orbital), which is the highest-energy orbital with one or two electrons, and the LUMO (Lowest Unoccupied Molecular Orbital), which is the lowest-energy orbital with no electrons). For nanotubes, the size of the gap is determined by small variations of the diameter and bonding angle. For example, semi-conductive chirality (hereinafter “semi-conductive”) nanotubes can have a gap on the order of 0.5 eV. On the other hand, highly electrically conductive chirality (hereinafter “metallic”) nanotubes can have a gap on the order of 0.0 eV. The gap can be modeled by the function:
E gap =2 ×y 0 ×acc/d
Where y 0 is the C-C tight bonding overlap energy (2.7-0.1 eV), acc is the nearest neighbor C-C distance (0.142 nm), and d is the diameter. This shows that the gap for a nanotube can range from around 0.4 eV-0.7 eV for semi-conductive nanotubes, which generally corresponds to gap values obtained from one-dimensional dispersement relations.
[0012] In general, based upon the results mentioned above, while not wishing to be bound by theory, the conductivity is believed to be a function of the wrapping angle and circumference (n,m). Therefore, since the conductivity can be predetermined based upon the chirality of a nanotube, the isolation of macroscopic quantities of a single (n,m) type or pure-chirality nanotubes can be useful for providing predetermined properties on an extremely small scale.
[0013] Challenges to pure-chirality nanotube production include: (1) large scale production, and (2) processing issues, such as purification and identification of batch mixed chirality nanotubes into single chirality, or pure chirality nanotubes.
SUMMARY OF THE INVENTION
[0014] A new composition of matter, single-walled carbon nanotubes of specific helical forms on bulk scale and a method for their identification based on their spectral and other properties is provided herein. The “pure composition of matter” is a single type of chirally oriented (n,m) or “pure-chirality” nanotube, wherein n=1 to 100 and m=1 to 100 and n and m are the same for each (n,m) nanotube in the “pure composition of matter” or “pure-chirality” nanotubes.
[0015] Also provided is a bulk product comprising at least 10,000 nanotubes, wherein the nanotubes comprise at least 50% nanotubes of one (n,m) chirality. Also provided is a bulk product comprising at least 1 milligram of at least 50% pure-chirality nanotubes, wherein the at least 1 milligram of nanotubes includes more than 10,000 nanotubes.
[0016] Also provided is a method of reducing aggregation of pure-chirality single-walled carbon nanotubes (SWNTs) during storage, comprising: mixing pure-chirality SWNTs with an inert perfluorocarbon-hydrocarbon hybrid surfactant additive.
[0017] Also provided is a method for growing pure-chirality single-walled carbon nanotubes (PC-SWNTs) comprising: cutting bulk sample/product of PC-SWNT into suitable lengths to provide PC-SWNT seeds for nanotube growth; adding a metal catalyst to one or both ends of the PC-SWNT seeds; exposing the PC-SWNT seeds and the metal catalyst to a carbon feedstock at a predetermined pressure and a predetermined temperature; and growing PC-SWNTs to form bulk quantities of PC-SWNTs with substantially the same chirality as the PC-SWNT seeds.
[0018] Also provided are components for transistors, optical devices, coded-security tagging materials, and/or medical devices and/or applications comprising single-walled carbon nanotubes, wherein the single-walled carbon nanotubes comprise at least 50% nanotubes with the same (n,m) chirality.
[0019] As discussed herein, methods for identifying, characterizing and/or forming nanotubes, for example separating and distinguishing between (4,5) SWNTs from (9,10) SWNTs, as well as selecting semi-conductive or metallic SWNTs are provided herein, including one or more of the following:
[0020] 1. Generating SWNTs using catalytic chemical vapor deposition (CVD) by using a carbon source, wherein a pure-chirality nanotube can be used as a seed for self growth;
[0021] 2. Using near IR fluorescence to decode the fingerprint of helical nanotubes in order to determine chiralities of a sample, and to establish the purity of a sample of a single type of (n,m) SWNT;
[0022] 3. Using hybrid perfluorocarbon-hydrocarbon surfactants and using organic-fluorous phase liquid-liquid separations, such as counter-current chromatography; and
[0023] 4. Using isolated single (n,m) type SWNT to prepare solutions and/or dispersions for production purposes.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0024] FIGS. 1 a - 1 d illustrate lattice vectors and their corresponding nanotube types, wherein FIG. 1 a illustrates lattice vectors corresponding (from right to left) graphene sheets folded along the lattice vectors along an armchair (8,8) lattice vector (see FIG. 1 b ), a zigzag (8,8) lattice vector (see FIG. 1 c ) and a chiral (10,−2) lattice vector (see FIG. 1 d ).
[0025] FIG. 2 illustrates an exemplary (n,m) carbon nanotube formed by wrapping a graphene sheet with a defined chirality angle.
[0026] FIG. 3 illustrates electronic properties of a metallic nanotube vs. a semiconducting nanotube.
[0027] FIG. 4 illustrates an exemplary graphene sheet showing (n,m) chirality numbering for exemplary nanotubes.
[0028] FIG. 5 illustrates an exemplary graphene sheet showing pure-chirality (n,m) nanotubes.
[0029] FIGS. 6-10 illustrate exemplary molecular structures of pure-chirality (n,m) nanotubes.
[0030] FIG. 11 illustrates screws representing mixed chirality nanotubes.
[0031] FIG. 12 illustrates a (n,m) chirality map for exemplary HiPCO nanotubes.
[0032] FIG. 13 illustrates a (n,m) chirality map for exemplary CoMoCAT nanotubes.
[0033] FIG. 14 illustrates exemplary nanotube growth from seeded nanotubes with the same chirality.
[0034] FIG. 15 illustrates exemplary fluorescence signatures of: (A) exemplary mixed chirality nanotubes; and (B) exemplary pure-chirality nanotubes.
[0035] FIG. 16 illustrates exemplary dispersion surfactants for dissolving nanotubes in solvents or solutions.
DETAILED DESCRIPTION
[0036] Pure-chirality single-walled nanotubes (PC-SWNT) can be uniquely suited to many high-end applications, such as molecular electronics and computing, optical devices (photonic crystals and solar cell materials), electromagnetic interference (EMI) shielding, transistors, such as field effect transistors, coded-security tagging materials, medical devices and/or applications, etc.
[0037] As used herein, pure-chirality nanotubes include nanotubes with the same (n,m) chirality as primarily or substantially all of the other nanotubes in a bulk product of nanotubes or a plurality of at least 10,000 nanotubes. For example, in bulk products, nanotubes with at least 50%, 90%, or 98% of nanotubes with the same (n,m) chirality as the (n,m) chirality of the remainder of the bulk, as well as nanotubes which are substantially all one, single (n,m) chirality, are pure-chirality nanotubes and can be used to provide the high-end applications listed above. In addition, individual PC-SWNT molecules can be used as seeds to induce growth of additional PC-SWNT materials of the same chirality.
[0038] Methods for identifying, separating and/or characterizing different helical forms of single-walled carbon nanotubes (SWNTs) on a bulk scale are described herein. The methods can provide for identifying, separating, characterizing and/or forming of the different helical forms based on their spectral and other properties.
[0039] As identification of different helical forms of carbon nanotubes can be achieved, a pure composition of matter for a number of carbon nanotubes of type (n,m), wherein the helical wrapping angle is determined and the molecules can be made in substantially pure form. The pure (n,m) chirality nanotubes can preferentially have n=1 to 20 and m=1 to 20. It is noted, as mentioned above, that n relates generally to the size of the tube, while m relates generally to the inclination of twist. Larger diameter tubes can also be prepared, purified, and identified with n from 1 to 100 or m from 1 to 100.
[0040] An exemplary graphene sheet showing (n,m) numbering for SWNTs is illustrated in FIG. 4 . It is noted that armchairs are shown (n,m, wherein n=m) along the lower left diagonal, while the zigzags (n,0) are shown with along the top horizontal and the chiral are the (n,m) numbers between the armchair and zigzag numbers.
[0041] An example of Pure-chirality SWNTs is illustrated in FIG. 5 , wherein the pure-chirality SWNTs are numbered with (n,m) numbers. A few of the molecular structures of the pure-chirality SWNTs of FIG. 5 are further illustrated in FIGS. 6-10 , wherein these representative examples allows for those skilled in the art to understand that the composition of matter of pure-chirality SWNTs refers to helical twist rather than length.
[0042] SWNT can be tubes wrapped from graphite sheets and can be named (n,m), wherein a chiral vector is defined by n and m. The term in common use is chirality which refers to the angle of wrapping. This does not mean left or right handedness in the usual sense of chirality but would be better termed helicity that refers to the pitch or the helix angle of wrapping normal “as-produced” carbon nanotubes.
[0043] As illustrated in FIG. 2 , for example, the tube wrapped from the sheet therein would have a chiral vector C with (6,3) for (n,m). Additionally, it is noted that when tubes are formed, a mixture of different sizes and helical angles, much like a jar of different sizes of screws, as illustrated in FIG. 11 .
[0044] In an exemplary embodiment, a bulk sample of HiPCO nanotubes, which contain a mixture of at least 26 different chiralities, can be purified to greater than 50% of a single pure-chirality. This bulk sample of HiPCO nanotubes can be purified to give bulk quantities of single pure-chirality nanotube bulk products. Exemplary pure-chirality nanotube bulk product compositions include those (n,m) chiralities illustrated in FIG. 12 . These pure-chirality nanotube bulk product compositions can each have a unique chemical “molecular graphs” (i.e., formulae are chemical structures as shown in FIGS. 6-10 ).
[0045] It is noted that these molecular graphs of pure-chirality (n,m) angles of pure-chirality nanotube bulk product compositions are similar to polymeric monomers, wherein the actual nanotubes can be much longer but are composed of repeating units of these twisted pure-chirality (n,m) graphene sheets. It is further noted that the properties of the pure-chirality nanotube bulk product compositions are believed to be directly related to the pure-chirality (n,m) wrapping angles.
[0046] While SWNTs are discussed herein, it is noted that double walled or multi-walled tubes can also be subjected to the same methods of identifying, separating, characterizing and/or forming different helical forms. For example, SWNTs of different chiralities can be nested, i.e., a (5,5) SWNT can be nested within a (10,10) SWNT to form a double or nested tube.
[0047] Additionally, a chiral surface of known chirality such as crystals of tartaric acid, peptides or amino acids, sugars, etc. can be used to catalyze the formation of one helical form of nanotube. However, it is possible to use chiral surfaces crystals of tartaric acid, peptides or amino acids, sugars, etc to chromatographically separate one helical form of nanotube.
[0048] An improved chiral nanotube method can include creating a selective chiral surface in bulk by lithographic techniques. For example, this method could be done by imaging lines on an oriented graphite surface.
[0049] Other methods are reported for the purification, solubilization, and formation of pure-chirality single walled nanotubes (SWNT). These methods include the use of antibodies and phage display to create affinity purification methods for pure-chirality SWNT, the use of hybrid perfluorocarbon-hydrocarbon block copolymers, and the use of organic-fluorous phase liquid-liquid separations, such as counter-current chromatography.
[0050] 1. Generating SWNTs using catalytic chemical vapor deposition (CVD) by using alcohol or other carbon source, wherein a pure-chirality nanotube can be used as a seed for self growth.
[0051] SWNTs can be generated by catalytic chemical vapor deposition (CVD) by using alcohol as the carbon source. For example, high-purity SWNTs can be generated at relatively low CVD temperatures from metal catalytic particles supported on zeolite or directly dispersed on flat substrates, such as mesoporous silica, quartz and silicon. In exemplary embodiments, a zeolite support can be provided for bulk generation of SWNTs, wherein direct growth of SWNTs on zeolites as a film on a substrate can be used for optical or semi-conductor applications. For example, low-temperature CVD preparation can be used to synthesize SWNTs near armchair nanotubes. It is believed that the near armchair nanotubes can be produced from low-temperature CVD because of the stability of nanotube cap structure for thin nanotubes. Additionally, the growth process of SWNTs simulated by molecular dynamics method also appears to suggest this chirality-selective generation of SWNTs.
[0052] Additionally, ethanol can be used as the alcohol carbon source. By using ethanol for the catalytic CVD, a CVD apparatus can be used to form a vertically aligned SWNTs mat with a couple of microns grown on quartz substrates by employing the activation of catalytic metals.
[0053] Approaches to forming SWNTs include CoMoCAT™, a method developed by SouthWest NanoTechnologies, Inc. (SWeNT™) of Norman, Okla. and High-Pressure CO Conversion (HiPCO). However, the SWNTs formed by CoMoCAT and HiPCO provide mixed chirality SWNTs rather than PC-SWNTs. By using these CoMoCAT™ and HiPCO for synthesizing SWNTs, comparisons of the resolved spectral intensities, and thus an example of the selectivity of different SWNT synthesis processes can be compared. Comparing the two approaches, the % of (n,m) chirality compounds are shown in Table 1, wherein the (n,m) map of HiPCO SWNTs is shown in FIG. 12 (the darkened chiralities being present in the sample) and the (n,m) map of CoMoCAT SWNTs is shown in FIG. 13 (the thicknesses of the cell being proportional to the observed intensity for that structure).
TABLE 1 (n, m)-Resolved Spectral Intensities from SWNT Samples fractional fractional diameter chiral intensity (%), intensity (%), n, m (nm) angle (deg) CoMoCAT HiPco 5, 4 0.620 26.3 0.3 0.0 6, 4 0.692 23.4 2.8 0.3 9, 1 0.757 5.2 0.8 0.2 6, 5 0.757 27.0 28 3.7 8, 3 0.782 15.3 11 2.9 9, 2 0.806 9.8 1.7 0.4 7, 5 0.829 24.5 28 4.9 8, 4 0.840 19.1 14 4.2 10, 2 0.884 9.0 0.0 4.5 7, 6 0.895 27.5 8.5 7.1 9, 4 0.916 17.5 2.3 7.6 10, 3 0.936 12.7 0.0 4.3 8, 6 0.966 25.3 0.8 8.3 9, 5 0.976 20.6 0.3 5.7 9, 5 0.976 20.6 0.0 5.7 12, 1 0.995 4.0 0.0 3.8 11, 3 1.014 11.7 0.0 4.6 8, 7 1.032 27.8 0.3 5.6 10, 5 1.050 19.1 0.0 4.6
[0054] Individual PC-SWNT molecules can be used as seeds to induce growth of additional PC-SWNT materials of the same chirality, as illustrated in FIG. 14 . By using seeds, processes that would ordinarily result in mixed chirality nanotube formation can be used for form PC-SWNTs. For example, bulk PC-SWNT products can be formed using seed PC-SWNT molecules with a HiPCO process using metal catalyst and carbon feedstock. Alternatively, bulk PC-SWNT products can be formed by broadly applying any growth process including H-K arc processes, laser ablation processes, and/or RF-induced processes with PC-SWNT molecular structure seeds, wherein carbons can be added or grown on an existing PC-SWNT molecular structure seeds to form bulk PC-SWNTs.
[0055] 2. Using near infrared ( 1 R) fluorescence to decode the fingerprint of helical nanotubes in order to determine chiralities of a sample, and to establish the purity of a sample of a single type of (n,m) SWNT.
[0056] In addition to generating PC-SWNTs using the methods described above, the chirality distribution of bulk and individual SWNTs can be determined using near infrared (IR) fluorescence to decode the “fingerprint” and thus the chirality of individual nanotubes. Because individual chiralities have individual fluorescence signatures and because each of the individual fluorescence signatures for each type of (n,m) SWNT is known, near IR fluorescence can be utilized to identify individual nanotubes based upon their fingerprints. Thus, this method can be used to determine the exact (n,m) number of a one or more SWNTs, and thus the can be used to determine the precise chiral structure.
[0057] As illustrated in FIG. 15 , a near IR fluorescence of a HiPCO nanotube bulk mixture with about 27 SWNTs with different chiral angles is observed in “A” of FIG. 15 . As illustrated, the different chiral angles appear as different peaks with different fluorescence signatures. On the other hand, the near IR fingerprint of a bulk of pure-chirality nanotubes or PC-SWNTs is observed in “B” of FIG. 15 , which illustrates a single primary peak with a single primary signature for the bulk of nanotubes. As illustrated in FIG. 15 , the spectral lines of the near IR fluorescence spectrum allow the fingerprints for each (n,m) SWNT to be determined based upon helical angle of each peak from the spectrum.
[0058] Thus, by utilizing purification techniques, bulk quantities of PC-SWNTs can be attained, wherein the pure-chirality aspect can be confirmed using near IR fluorescence. Therefore, by utilizing the methods described herein, industrially relevant amounts of PC-SWNT compounds can be produced and confirmed.
[0059] 3. Using hybrid perfluorocarbon-hydrocarbon surfactants and using organic-fluorous phase liquid-liquid separations.
[0060] A. Perfluorocarbon Molecules
[0061] Perfluorocarbon molecules resemble hydrocarbons but with all hydrogen atoms replaced by fluorine atoms. Despite such a structural resemblance, perfluorocarbons (liquids and gases) include a separate class of compounds due to their unique physical and chemical properties, such as high density, low viscosity, overall inertness, high gas dissolving capability, excellent electrical insulating characteristics and immiscibility with water and most of organic solvents. Several extremely interesting fields of application arise from such properties. In particular, surfactants can be used for dispersion of carbon nanotubes. For example, fluorocarbon solvents can be used, wherein one or more carbon nanotubes can be solubilized within the solvents.
[0062] B. Use of Perfluoroalkylated Solvents in Catalysis and Organic Chemistry
[0063] Liquid-liquid biphase systems can be used in synthetic, catalytic and separation processes. The formation of a liquid-liquid biphase system is due to significantly different intermolecular forces of two liquids, which can result in limited or negligible solubility of the two solvents in each other. For example, aqueous biphase systems, which employ water as one phase and a hydrocarbon (or organic or other low polarity solvent) as the other, can result in limited solubility of the two solvents in one another.
[0064] In an aqueous biphase system, the aqueous phase can be used to recover water-soluble reagents and catalysts, while the organic phase can be used to accumulate products of the reaction that are not water-soluble. Unfortunately, aqueous biphasic processes cannot employ water-sensitive reagents or catalysts. The low solubility of organic substrates in water is also a potential limitation of aqueous biphasic systems in catalysis.
[0065] A fluorous biphase system (FBS) can be used to mix otherwise immiscible perfluoroalkyl solvents with water and many common organic solvents (see Table 2 below). See also, Horvath, I. T.; Rabai, J. Science 1994, 266, 72-75, which is incorporated herein by reference in its entirety. These systems include perfluorinated or highly fluorinated fluorous solvent and a second organic or inorganic solvent that is insoluble or poorly soluble in former.
TABLE 2 Solubility of commercial fluorous solvents in common organic solvents. (Source: 3M Inc.) Solvents FC-72 FC-75 FC-40 FC-43 FC-70 FC-71 Acetone sol. sol. s.s. s.s. ins. ins. Benzene s.s. s.s. ins. ins. ins. ins. Ethylene ins. ins. ins. ins. ins. ins. Glycol Diethyl m. m. sol. sol. sol. ins. Ether Hexane m. v.s. sol. sol. sol. s.s. Methanol s.s. s.s. ins. ins. ins. ins. Toluene s.s. s.s. ins. ins. ins. ins. Xylene s.s. s.s. ins. ins. ins. ins. Water ins. ins. ins. ins. ins. ins. ins. = insoluble = less than 1 g per 100 g of solvent s.s = slightly soluble = 1 to 5 g per 100 g of solvent sol. = soluble = 5 to 25 g per 100 g of solvent v.s. = very soluble = greater than 25 g per 100 g of solvent m. = miscible in all proportions
[0066] Perfluorocarbons (PFCs) are commercially available at modest cost and are nontoxic and biologically compatible, consistent with the extensive experience with fluorocarbon coatings in cookware and artificial organ implants.
[0067] C. Examples of Fluorous Separation
[0068] SWNTs can be solubilized in liquid phases for solubilization testing. While water and organic surfactants can be used for solubilization of SWNTs, the presence of water can adversely affect many potential electronic applications of carbon nanotubes and organic solvents can cause SWNTs to aggregate into ropes or bundles. Thus, the use of water and organic surfactants can yield undesirable results. However, dispersion of SWNTs can also be accomplished through the use of organic-fluorous surfactants. For example, organic-fluorous surfactants can be mixed with fluorous solvents, such as C 6 F 14 , and SWNTs to form micelles. By utilizing organic-fluorous surfactants to solubilize SWNTs in a fluorous phase and forming micelles, separation of pure-chirality nanotubes from one another can be achieved, as well as chiral separation, as desired. Exemplary organic-fluorous surfactants include hybrid perfluorocarbon-organic surfactants.
[0069] An exemplary a surfactant for water/organic dispersions is SDS (Sodium Dodecyl Sulfate), which is “A” as illustrated in FIG. 16 . On the other hand, an exemplary hybrid perfluorocarbon-organic surfactant, which is “B” as also illustrated in FIG. 16 . By using the exemplary hybrid perfluorocarbon-organic surfactant, SWNTs can be solubilized in a PFC/organic dispersion and can form micelles to separate pure-chirality nanotubes as desired.
[0070] While the invention has been described in detail with reference to preferred embodiments thereof, it will be apparent to one skilled in the art that various changes can be made, and equivalents employed, without departing from the scope of the invention. | A method of providing bulk products of pure-chirality single walled nanotubes having substantially one chirality, and bulk products of pure-chirality nanotubes having at least 50% one chirality. By providing bulk products of pure-chirality nanotubes, the electrical conductivity of the nanotubes can be predetermined and can be made more electrically conductive or more semi-conductive, as desired. Also provided are methods of purifying bulk products of multiple chirality nanotubes into pure-chirality nanotube bulk products, as well as methods of identifying chiralities of bulk product nanotubes. Moreover, fluorocarbon surfactant systems capable of solubilizing nanotubes in perfluorocarbon solvents and facilitating purification and processing are also provided. | 3 |
FIELD OF THE INVENTION
This invention relates to a radio frequency identification (RFID) systems that use RFID tags to track product inventory, or other mobile items.
BACKGROUND OF THE INVENTION
Information management systems are being developed to track the location and/or status of a large variety of mobile entities such as products, vehicles, people, animals, etc. A widely used tracking technology uses so-called RFID tags that are placed physically on the items being tracked. Reference herein to “items” being tracked is intended to include the variety of entities just mentioned as well as, more commonly, product inventories.
RFID tags may be active or passive. Active tags typically have associated power systems and can transmit data over modest distances. Passive systems lack internal power but derive transmitting signal power from an incoming RF signal. However, transmitting distances with passive RFID tags are very limited. To read a large number of RFID tags, spread over a wide physical area, requires either a large number of RFID readers, or a reliable system of moving RFID readers. One proposed solution to this problem is to use active RFID tags on the products. However, active tags are relatively costly. Although they lend more function to a tracking system, and transmit more effectively, passive tags are typically more cost effective where inventories being tracked are large.
What is needed is an improved system for RFID tracking where the scale of the application exceeds the performance capability of conventional RFID approaches.
STATEMENT OF THE INVENTION
We have developed a new architecture for RFID systems that is adapted to process large numbers of RFID tags and provide information about a large number of items. The system provides for multiple tag readers. The tag readers are active and have both transmit and receive capability. The system includes a new element called a gateway tag that receives information about individual items from the multiple readers and thus contains data on the entire inventory of items. This allows each of the multiple readers to access data for the entire inventory of items. The gateway tag may interface with an information storage center that also contains data for the entire inventory of items.
BRIEF DESCRIPTION OF THE DRAWING
The invention may be better understood when considered in conjunction with the drawing in which:
FIG. 1 is a schematic view of a typical RFID tag system;
FIG. 2 is a representation of a passive RFID tag;
FIG. 3 is a representation of an active RFID reader;
FIG. 4 is a schematic view of the RFID tag system of the invention; and
FIG. 5 is a representation of a gateway RFID tag according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic representation of a typical RFID system wherein the RFID tag is shown at 11 , the RFID reader at 12 and a central information store at 13 . A wide variety of implementations are used for the function of tracking large numbers of items, many of which use the basic elements shown in FIG. 1 . Typically, the RFID tag 11 is a passive device attached to the item being tracked. The reader 12 is an active RFID device that communicates with large numbers of passive RFID tags, and typically either stores data in the reader, and/or relays data to a central database 13 . The central database keeps data for all items in the system. In many applications, for example, large retail outlets, the RFID readers are mobile devices that are moved around the vicinity of the RFID tags to record the RFID tag data. Mobility in this application is necessary since the transmission distance between the RFID tags and the RFID readers is very limited, for example, tens of meters maximum, and typically less than 10 meters. The RFID readers are typically powered, which extends the range of transmission between the RFID readers and a remotely located receiver. That allows the option of using a RFID reader to simply relay RFID tags to a central database. More typically, the reader reads the passive RFID and stores the information locally. This data may be downloaded to the central store periodically, by placing the reader in a docking device that is connected by wireless or hardwired link to the central database. In the latter case, a wireless link between the RFID reader and a remote receiver may or may not be used.
A passive RFID tag is shown at 21 in FIG. 2 . RFID tags are miniaturized as much as practical to allow for the essential elements of a semiconductor IC chip 22 , typically a CMOS chip, and an antenna 23 . The IC chip contains a memory, usually a read-only memory encoded with item data. The antenna is a serpentine metal conductor that receives small amounts of power from the RFID reader by inductive coupling. When the IC chip is powered, it transmits item data back to the RFID reader via antenna 23 .
Passive RFID tag designs are available in many sizes and designs. Common characteristics are a platform, an IC chip, and an antenna. Depending on the application the platform may be glass, ceramic, epoxy, paper, cardboard, or any suitable plastic. An onboard power source is not included in a passive RFID tag. All power for the tag is derived from RF signals in the vicinity of the tag. The tag responds to the reader using RF backscatter, which basically reflects the carrier wave from the reader after encoding data on the carrier wave. Variables in the communication specification include the frequency of the carrier, the bit data rate, the method of encoding and any other parameters that may be needed. ISO 18000 and EPCGlobal are the standards for this interface. The interface may also include an anti-collision protocol that allows more than one tag in the range of the reader to signal concurrently. There are many specific implementations of this, and these form no part of the invention.
A typical schematic for an RFID reader is shown in FIG. 3 . The reader 31 includes RF transceiver chip 32 , microprocessor chip 33 , and battery 34 . The transceiver chip communicates through an attached antenna as indicated. These components allow the reader to not only receive data from the passive RFID tags, but to store and process the data and transmit the data to another device or station. Since the reader is powered, it can transmit data over significant distances, for example, 100 to 3000 thousand feet.
A schematic of an RFID tag system according to the invention is shown in FIG. 4 . The RFID tags are shown organized in groups A, B, and C. These groups may represent different departments in a retail outlet, separate floors or buildings in a warehouse complex, separate railroad cars or shipping containers, etc. In the arrangement shown, each group communicates with an associated RFID reader 41 , 42 , and 43 . It should be understood that this arrangement is shown by way of example only. There are many alternative configurations using RFID tags and readers. The RFID readers communicate with gateway RFID tag 45 . The link between the RFID readers and the gateway RFID tag may operate at a frequency different than the frequency used in the link between the RFID readers and the passive RFID tags. The readers collectively provide data to the gateway RFID tag for all of the items in the system. This arrangement allows any reader in the system to access data on any item in the system via the gateway RFID tag. Since the transmission to and from the gateway RFID tag to the RFID readers is powered, that link may be essentially any distance within the facility served by the RFID system. The gateway RFID tag may be a standalone unit, or, as indicated in FIG. 4 , interfaced via network 46 to a central database and memory store 47 . The network may be a wireless network, or a wired network (land line).
A schematic of the gateway RFID tag 45 in FIG. 4 is shown in FIG. 5 . The gateway RFID tag is an active tag, with battery 54 . It also has a processor 53 , a large memory 56 , and an RF transceiver 52 . The gateway RFID tag interfaces with each of the RFID readers as shown in FIG. 4 , and may interface with a central database via a wireless or wired network. The latter is an optional feature. The system may be designed with a direct interface between the RFID readers and the central database, as described in conjunction with FIG. 1 , and with a parallel link between the RFID readers and the gateway RFID tag. Adding a link between the gateway RFID tag and the central database allows data consistency between the two to be verified. Both of these subsystems typically contain data on all of the items being tracked by the system, i.e. universal system data. However, using an arrangement like that shown in FIG. 4 allows the universal system data stored at the gateway RFID tag to be different (typically less detailed) than the data stored at the central database.
For the purpose of defining terms used herein, a passive RFID tag means a device containing at least an integrated circuit chip operating at a given frequency and an antenna, but no onboard power source. The antenna operates as a low power RF transceiver. The integrated circuit chip contains a memory. An RFID reader means a device containing at least an integrated circuit chip, an antenna, an RF transmitter, an RF receiver, and a power source. The integrated circuit chip in the RFID reader contains a memory. The RFID reader has an RF transmitter that operates at the same frequency as the RFID tags, and an RF transmitter that may operate at a frequency different from that of the RFID tags. A gateway RFID tag means a device containing at least an integrated circuit chip, an antenna, an RF transmitter, an RF receiver, and a power source. The integrated circuit chip in the gateway RFID reader contains a memory. The gateway RFID reader has an RF transmitter that operates at the same frequency as the RFID readers, and may have a communications link to a remote central database. A remote central database has a microprocessor and a memory store. It may or may not be located on the same physical premises as the gateway RFID tag.
Transmitting range means the range over which signals transmitted from a transmitting device can be received by a receiving device.
In summary, an aspect of the invention is that data from an item that is not in the vicinity of an RFID reader, and thus not accessible directly from that reader, can nevertheless be accessed by that reader through the gateway RFID tag. The sequence of operations for accomplishing this involves transmitting an RFID signal between a first RFID reader and a first group of passive RFID tags, receiving at the first RFID reader first data from the first group of passive RFID tags, transmitting said first data from the RFID reader to a gateway RFID tag, receiving and storing the first data at the gateway RFID tag, transmitting an RFID signal between a second RFID reader and a second group of passive RFID tags, receiving at the second RFID reader second data from the second group of passive RFID tags, transmitting said second data from the RFID reader to the gateway RFID tag, receiving and storing the second data at the gateway RFID tag, transmitting to the gateway RFID tag a query from the first RFID reader, receiving the query at the gateway RFID tag, and transmitting second data from the gateway RFID tag to the first RFID reader.
Various additional modifications of this invention will occur to those skilled in the art. All deviations from the specific teachings of this specification that basically rely on the principles and their equivalents through which the art has been advanced are properly considered within the scope of the invention as described and claimed. | The specification describes a new architecture for RFID systems that is adapted to process large numbers of RFID tags and provide information about a large number of items. The system provides for multiple tag readers. The tag readers are active and have both transmit and receive capability. The system includes a gateway tag that receives information about individual items from the multiple readers and thus contains data on the entire inventory of items. This allows each of the multiple readers to conveniently access data for the entire inventory of items. | 6 |
FIELD OF THE INVENTION
[0001] This invention relates to methods, systems, devices and computer code for the noise reduction, compression, storage and transfer of data, particularly data associated with consumption of utilities such as gas, water and electricity, and to transfer the stored utility consumption data for applications such as analysis of household power consumption by an end-user or by a utility supplier, or monitoring occupancy and activity within a household.
BACKGROUND
[0002] There is an ongoing and urgent need to reduce consumption of energy and water both for environmental and cost reasons.
[0003] A large proportion of the energy and water supplied by utilities suppliers is wasted as a result of inefficiencies such as use of electrical appliances that have poor efficiency or for behavioural reasons such as appliances that are left switched on and so consume electricity even when not in use, or excessive consumption of water. This leads to wastage and increased utilities costs. Moreover, with respect to electricity, electrical energy use in buildings accounts for a very large proportion of all carbon emissions. Demand for utilities can vary dramatically between identical buildings with the same number of occupants, and this suggests that reducing waste through behavioural efficiency is essential. Therefore, efforts are required to change the patterns of utilities use by consumers.
[0004] The utilities suppliers recognise three major obstacles to progress in this objective: a shortage of sources of competitive advantage, a lack of detailed understanding of their customers, and a lack of “touch points”, i.e. ways of interacting with the customers. Opportunities for differentiation revolve mainly around price and “green” issues, i.e. reduction of environmental impact. The utilities suppliers have very little information about their customers' behaviour since electricity, gas and water meters collect whole house data continuously and are read infrequently.
[0005] Meters to measure total consumption of utilities of a household are commonplace for each of gas, electricity and water, however this total is not useful in identifying areas in which efficiencies may be possible (for brevity, we refer herein to a “household”, however it will be appreciated that the present invention is not limited to a domestic house but may be applied to any domestic, workplace or other setting that receives its own discrete utilities supplies, in particular mains electricity supply from an electricity grid; water supply; and/or gas supply.).
[0006] Apparatus for monitoring consumption of a resource such as electricity supplied on a cable is disclosed in WO 2008/142425. While a meter of this type is beneficial in assisting a user to review energy consumption patterns, when the meter is operated in a high resolution mode, for example measuring power consumption at one second intervals, there is a problem in storing the relatively large amount of power consumption data produced by the meter. Further, when the power consumption data is stored by the meter and subsequently sent to a remote device for display or analysis of resource consumption there is a problem in selecting and transferring the relatively large amount of power consumption data stored by the meter. Further, when the power consumption data is stored by the meter and subsequently sent to a remote device for display or analysis of resource consumption, if communication between meter and the remote device is interrupted there can be problems in selecting and transferring stored power consumption data to the remote device.
[0007] It is therefore an object of the invention to provide technical means for compression, storage, recovery and transmission of utilities consumption data in a household.
SUMMARY OF THE INVENTION
[0008] According to a first aspect the invention provides a method of noise reduction in data regarding parameter values comprising the steps of:
making a series of measurements of parameter values at times separated by predetermined time intervals; forming an array of measurements of parameter values comprising plural successive measurements of parameter values; performing a plurality n of successive wavelet transforms on the array of measurements of parameter values to produce an array of coefficients; comparing the values of the array of coefficients to a threshold value and, selectively changing the values of said coefficients based on their relationship to the threshold, to produce an array of filtered coefficients; performing n successive inverse wavelet transforms on the array of filtered coefficients to produce an array of filtered measurements.
[0014] In a second aspect, the invention provides a data processing apparatus adapted to carry out the method of the first aspect.
[0015] In a third aspect, the invention provides a data processing apparatus adapted to reduce noise in data regarding parameter values comprising:
sensor means adapted to make a series of measurements of parameter values at times separated by predetermined time intervals; data processor means adapted to process the series of measurements of parameter values to form an array of measurements of parameter values comprising plural successive measurements of parameter values; data processor means adapted to perform a plurality n of successive wavelet transforms on the array of measurements of parameter values to produce an array of coefficients; data processor means adapted to compare the values of the array of coefficients to a threshold value and, selectively change the values of said coefficients based on their relationship to the threshold, to produce an array of filtered coefficients; data processor means adapted to perform n successive inverse wavelet transforms on the array of filtered coefficients to produce an array of filtered measurements.
[0021] In a fourth aspect, the invention provides a data processing apparatus adapted to reduce noise in data regarding electricity consumption comprising:
sensor means adapted to make a series of measurements of electricity consumption values at times separated by predetermined time intervals; data processor means adapted to process the series of measurements of electricity consumption values to form an array of measurements of consumption values comprising plural successive measurements of consumption values; data processor means adapted to perform a plurality n of successive wavelet transforms on the array of measurements of consumption values to produce an array of coefficients; data processor means adapted to compare the values of the array of coefficients to a threshold value and, selectively changing the values of said coefficients based on their relationship to the threshold, to produce an array of filtered coefficients; data processor means adapted to perform n successive inverse wavelet transforms on the array of filtered coefficients to produce an array of filtered measurements of consumption values.
[0027] In a fifth aspect, the invention provides a computer program product adapted to perform the method of the first aspect.
[0028] In a sixth aspect, the invention provides a computer program comprising software code adapted to perform the method of the first aspect.
[0029] In an eighth aspect, the invention provides a computer program comprising software code adapted to perform steps of:
making a series of measurements of parameter values at times separated by predetermined time intervals; forming an array of measurements of parameter values comprising plural successive measurements of parameter values; performing a plurality n of successive wavelet transforms on the array of measurements of parameter values to produce an array of coefficients; comparing the values of the array of coefficients to a threshold value and, selectively changing the values of said coefficients based on their relationship to the threshold, to produce an array of filtered coefficients; performing n successive inverse wavelet transforms on the array of filtered coefficients to produce an array of filtered measurements.
[0035] In an eighth aspect, the invention provides a computer readable storage medium comprising the program of any one of the fifth to seventh aspects.
[0036] In a ninth aspect, the invention provides a computer program product comprising computer readable code according to the eighth aspect.
[0037] In a tenth aspect, the invention provides an integrated circuit configured to perform the steps according to the first aspect of the invention.
[0038] In an eleventh aspect, the invention provides an article of manufacture comprising:
[0000] a machine-readable storage medium; and
executable program instructions embodied in the machine readable storage medium that when executed by a programmable system causes the system to perform the function of noise reduction in data regarding parameter values comprising the steps of: making a series of measurements of parameter values at times separated by predetermined time intervals;
[0041] forming an array of measurements of parameter values comprising plural successive measurements of parameter values;
[0042] performing a plurality n of successive wavelet transforms on the array of measurements of parameter values to produce an array of coefficients;
comparing the values of the array of coefficients to a threshold value and, selectively changing the values of said coefficients based on their relationship to the threshold, to produce an array of filtered coefficients; performing n successive inverse wavelet transforms on the array of filtered coefficients to produce an array of filtered measurements.
[0045] The invention further provides systems, devices, computer-implemented apparatus and articles of manufacture for implementing any of the aforementioned aspects of the invention; computer program code configured to perform the steps according to any one of the aforementioned methods; a computer program product carrying program code configured to perform the steps according to any one of the aforementioned methods; and a computer readable medium carrying the computer program.
DESCRIPTION OF FIGURES
[0046] The invention will now be described in detail with reference to the following figures in which:
[0047] FIG. 1 is a diagram of a smart meter according to the invention;
[0048] FIG. 2 is a flow diagram of a noise reduction method according to the invention;
[0049] FIG. 3 is a table showing an example of operation of the noise reduction method according to the invention;
[0050] FIG. 4 is a table showing an example of operation of the noise reduction method according to the invention;
[0051] FIG. 5 is a graph showing the effect of the noise reduction of FIGS. 3 and 4 ;
[0052] FIG. 6 is a table showing an example of operation of the noise reduction method according to the invention;
[0053] FIG. 7 is a table showing an example of operation of the noise reduction method according to the invention;
[0054] FIG. 8 is a table showing an example of operation of the noise reduction method according to the invention;
[0055] FIG. 9 is a graph showing the effect of the noise reduction of FIGS. 6 to 8 ;
[0056] FIG. 10 illustrates the identification of “corners” in electricity consumption data;
[0057] FIG. 11 illustrates schematically the identification of missing corners; and
[0058] FIG. 12 is a flowchart illustrating the corner detection algorithm.
DETAILED DESCRIPTION OF THE INVENTION
[0059] An example of apparatus for carrying out the method according to the present invention is illustrated in FIG. 1 with respect to electricity consumption.
[0060] While the invention is described hereinafter primarily with respect to measurement, analysis and storage of electricity consumption data, it will be appreciated that the same steps may equally be taken using data relating to consumption of gas or water, or other utilities. Further, although the invention is described herein primarily with respect to electrical power measurement, it will be appreciated that other electrical parameters could be measured, for example admittance, frequency, harmonic distortion, voltage, current, etc.
[0061] A smart meter 1 comprises a sensing device 2 which measures consumed electrical power for a household, or other setting that receives its own discrete utilities, at fixed interval time points, generating a series of measurements at fixed intervals. A higher frequency of measurement will obviously yield more electricity consumption data, which in turn will generally increase the usefulness and value of the measured data. Typically, for the purposes of the present invention, electricity consumption is measured once every second, at a frequency of 1 Hz.
[0062] It will be understood that the amount of power measurement data produced by the sensing device 2 is large, particularly when a relatively high sensing frequency is used, such as 1 Hz. Further, it will be understood that household electricity consumption data is inherently noisy, for example due to random fluctuations in power consumption by household devices and transient effects, so that the measurement data produced by the sensing device 2 is inherently noisy regardless of the performance of the sensing device.
[0063] The sensing device 2 measures consumed electrical power by measuring both real power and reactive power. This is captured as two separate streams of data, one stream comprising measurements of real power, and the other stream comprising measurements of reactive power (“real power” and “reactive power” as used herein have the meanings as understood by a skilled person in the art in relation to power supplied to a load from an alternating current source). For simplicity, the two streams of data are represented by a single line in FIG. 1 . The power data measurements are two dimensional measurements, where each measurement comprises both a real power measurement and a reactive power measurement made at the same time. It would of course be possible for the real power and reactive power values to be treated or shown as separate streams of measurement. It is also possible to measure other parameters simultaneously with power, for example admittance, voltage, current, etc.
[0064] One advantage of measuring both real and reactive power is that, between them, it is possible to measure power demand of most or all appliances. For instance, it may be difficult or impossible to obtain a meaningful measurement of real power for certain appliances such as set-top boxes, however reactive power for these devices can be measured.
[0065] The sensing device 2 could be a clamp on energy meter as disclosed in WO 2008/142431.
[0066] Although the series of measurements are described as being at fixed intervals this is intended only to indicate that they are at fixed intervals during operation. The sensing device 2 may be able to carry out measurements at a range of different time intervals so that the actual time interval used in a specific application can be set to a suitable value.
[0067] As shown in FIG. 1 , the power measurements, comprising consumption data readings relating to real and reactive power made at fixed intervals by the sensing device 2 , is fed into a noise reduction unit 3 .
[0068] The noise reduction unit 3 processes the stream of power measurements from the sensing device 2 to reduce noise in the power measurement data. The operation of the noise reduction unit 3 will be discussed in more detail below.
[0069] The de-noised power measurement data from the noise reduction unit 3 is then supplied to an event identification device 4 , which uses an event identifying algorithm to process the de-noised power measurement data and identify changes in the power consumption values which correspond to events of interest. It will be understood that there are many ways of carrying out such identification, and in any specific application of the invention it will be necessary to select a suitable event identifying algorithm which is appropriate to the fixed interval measurements being made and the events which it is desired to identify. One example of an event identifying algorithm which is suitable for processing fixed interval power measurements to identify events is discussed in detail below.
[0070] The event information from the event identification device 4 is then stored in a memory 5 . The memory 5 may be any suitable form of data storage device. The event data can then be provided to a wireless transceiver 6 for transmission to remote devices. The event data provided to the wireless transceiver 6 for transmission may be event data which has just been produced by the event identification device 4 , or may be taken from the memory 5 .
[0071] One remote device to which event identification data may be sent is a user display unit 7 . The smart meter 1 and the user display unit 7 are arranged for wireless communication thorough a wireless link 8 . It is preferred for this to be a bi-directional wireless link, but this is not essential. Suitable wireless communication techniques and wireless communication components to be included in the smart meter 1 and user display unit 7 are well known and need not be discussed in detail here.
[0072] The user display unit 7 could be a user display unit as disclosed in WO 2008/142425.
[0073] In operation, the smart meter 1 sends the event identification data to the user display unit 7 through the wireless communication link 8 . This can be carried out as a “push” type system where the smart meter 1 sends each new event identification data to the user display unit 7 each time said new event identification data is generated and stored in the memory 5 , or sends any new event identification data to the user display unit 7 at predetermined times. Alternatively, this can be carried out as a “pull” type system where the user display unit 7 sends a request for data to the smart meter 1 through the wireless communication link 8 , and the smart meter 1 responds by sending any new event identification data to the user display unit 7 . In this case the user display unit can send the requests at predetermined times, or based on activity at the user display unit 7 .
[0074] The user display unit 7 may be a data processor able to process and display the event identification data received from the smart meter 1 . The user display unit 7 is able to reconstruct the power consumption measured by the smart meter 1 from the received event identification data. This reconstructed power consumption can then be displayed to a user. The reconstructed power consumption can also be used for other purposes, as is known in the art, for example tracking total cumulative power consumption over time or identifying the particular types of appliances being used.
[0075] The depiction of different functional parts of the smart meter as different elements in the figures does not indicate that the functions must be necessarily provided by separate physical components.
[0076] As explained above the noise reduction unit 3 processes the stream of power measurements from the sensing device 2 to reduce noise in the power measurement data. An example of the operation of the noise reduction unit 3 according to a first embodiment of the invention will now be explained in detail with reference to the flow chart FIG. 2 .
[0077] Firstly, in step 10 , the noise reduction unit 3 takes the received data, in the described embodiment electricity power consumption measurements from the sensing device 2 , and arranges this in an array of measurements. Preferably, the array of measurements comprises 2 n measurements. For example, n may be 8, so that the array has 2 8 , that is 256, measurement values.
[0078] Then, in step 11 , the array of 2 n measurements is subjected to n-level wavelet transformation using a Haar Discrete Wavelet Transform. Thus, where the array has 256, 2 8 , samples the array will be subject to an 8-level wavelet transformation. The use of the Haar discrete wavelet transform is preferred, but not essential. Other wavelet transforms can be used.
[0079] The discrete wavelet transform represents a one-dimensional signal f of length 2 n in terms of shifted versions of a dilated lowpass scaling function Φ(x), and shifted and dilated versions of a bandpass wavelet function Ψ(x). The Haar wavelet function is given by:
[0000] Ψ( x )=1 [0,1/2) −1 [1/2,1) (1)
[0000] The Haar scaling function is given by:
[0000] Φ( x )=1 [0,1) (2)
[0080] In these equations 1 [a,b) denotes the characteristic function, equal to 1 on [a,b) and zero everywhere else.
[0081] The signal f can be expanded in this basis, giving:
[0000]
f
=
∑
i
c
i
n
Φ
i
n
(
x
)
+
∑
j
∑
i
d
i
j
Ψ
i
j
(
x
)
(
3
)
[0082] The multi-level normalized scaling functions is defined to be:
[0000] Φ i j ( x )=2 j/2 Φ(2 j X−i ) (4)
[0000] While the multi-level normalized wavelet function is defined to be:
[0000] Ψ i j ( x )=2 j/2 Ψ(2 j x−i ) (5)
[0000] Where i=0, . . . , 2 j −1 and j=0, . . . , n. The scaling coefficients c i j and wavelet coefficients d i j at a level j can be computed from the coefficients c i j+1 at level j+1 and vice-versa using:
[0000] c i j =( c 2i j+1 +c 2i-1 j+1 )/√{square root over (2)} (6)
[0000] d i j =( c 2i j+1 +c 2i-1 j+1 )/√{square root over (2)} (7)
[0083] After completion of the n-level Haar wavelet transform the resulting coefficients contain all of the information of the original power measurements and could, in principle, be used to reconstruct them by reversing the process.
[0084] In one embodiment of the present invention the set of coefficients output from the final stage, that is the nth stage, of the n-level wavelet compression is subject to a hard threshold filtering in step 12 . For example, where the array has 256, 2 8 , samples the hard threshold filtering is carried out on the wavelet coefficients output by the 8 th level wavelet compression.
[0085] The hard threshold filtering compares the coefficients to a threshold. All of the coefficients having a value below the threshold then have their value set to zero. This is referred to as wavelet shrinkage, or de-noising.
[0086] This hard threshold filtering uses a threshold T set according to:
[0000] T =√{square root over (2 ln( m )SMAD( d i n-1 ))}{square root over (2 ln( m )SMAD( d i n-1 ))} (8)
[0087] Where m is the number of measurements in the original set of power measurements, and SMAD (d i n-1 ) is the scaled median absolute deviation computed from the first level high pass wavelet coefficients, that is, the median of the absolute values of the first level high pass, or detail, wavelet coefficients, given by d 0, . . . ,3 2 .
[0088] Thus, all of the wavelet coefficients at the nth, that is, the last, stage wavelet compression having an absolute value of less than T are set to have a value of zero.
[0089] This hard threshold filtering has the effect of removing noise from the power measurement data. The hard threshold filtering using the threshold T as described above has the effect of measuring the entropy in the power measurement signal and removing the high entropy noise parts of the signal.
[0090] The hard threshold filtered coefficients are then subjected to an n-level, or n-step, inverse discrete wavelet transform, also known as reverse wavelet transformation, using the reverse Haar Transform in step 13 . Thus, where the array has 256, 2 8 , samples the array will be subject to an 8-level wavelet reverse transformation.
[0091] As explained above, absent the hard threshold filtering the n-level reverse transformation would have regenerated the original set of 2 n power measurements. However, because the nth level wavelet coefficients were subjected to wavelet shrinkage by the hard threshold filtering, the output of the nth level reverse wavelet transformation is a reconstructed version of the original power measurements which has been de-noised so that the amount of noise in the power measurements is reduced.
[0092] This de-noised power measurements are then output from the noise reduction unit 3 in step 14 and supplied to the event identification device 4 .
[0093] In addition to the threshold setting method described above, it may be preferred to also set a minimum level for the threshold, and to set the threshold value to this minimum level when the calculated threshold value T is below the minimum level. The setting of a minimum threshold level can be useful to reduce low level noise which is below the smallest amplitude expected to be a real signal corresponding to an event of interest.
[0094] The above example describes the use of a hard threshold. Although this is generally effective, other types of threshold may alternatively be used, if preferred. Further, other options for setting the threshold could be used as alternatives to that set out in equation (8).
[0095] The above example describes the use of the Haar discrete wavelet transform. Other types of wavelet transform can alternatively be used. In general, the wavelet transform used can be selected taking into account the processing which is to be applied after the de-noising process, to match the properties of the de-noised signal with the requirements of the subsequent processing. The wavelet transform used can also be selected taking into account the expected properties of the changes in the input signal which it is desired to detect, and the expected properties of noise, and any other undesired signal components, which it is desired to remove.
[0096] A worked example of the operation of the noise reduction method according to the invention is discussed below.
[0097] The noise reduction method according to the invention has the advantage that it is automatically adaptive to the level of ambient noise in the signal, and removes the noise without affecting the real signal data.
[0098] The method of determining the threshold for the filtering described above is not essential. The formula used to calculate the threshold can be changed and configured to adjust the level of filtering applied, as required in different applications.
[0099] The use of a Haar wavelet transform together with adaptive hard threshold filtering as described above is particularly effective when used in conjunction with an event identification process because this removes noise while preserving the sharp edges and corners in the measurement data which are used for event identification. In contrast, conventional filtering of the power measurements in order to remove noise would tend to smooth out the sharp edges and corners and replace them with smoother and harder to identify features.
[0100] The noise reduction method according to the invention is much more effective than attempting to remove noise after the event detection. Further, unlike a conventional approach of noise reduction by filtering, the noise reduction method according to the invention will not affect the corners and edges in the data which are used in the event detection.
[0101] The event identifying device 4 identifies events by using an event identifying algorithm, which processes the de-noised power measurements and compares changes in values of parameters of the de-noised power measurements to selected criteria and thresholds in order to identify changes in the values which correspond to events of interest. It will be understood that there are many ways of carrying out such identification, and in any specific application of the invention it will be necessary to select a suitable event identifying algorithm which is appropriate to the fixed interval measurements being made and the events which it is desired to identify. One example of an event identifying algorithm which is suitable for processing fixed interval power measurements to identify events is discussed in detail below.
[0102] Since event detection identifies changes in measured parameters it is necessary to ensure that the measurements at the beginning and end of successive arrays of 2 n measurements processed by the noise reduction unit 3 are compared with both preceding and succeeding measurements by the event identifying device to ensure that no changes or events are missed by the event identifying device as a result of the change or event occurring at or close to the boundary between successive arrays. This can be done by ensuring that the end measurements in time in each array of 2 n measurements processed are duplicated as the beginning elements in time in the next array of 2 n measurements processed. The number of end and beginning measurements duplicated in successive processed arrays of measurements will depend on the properties of the event identifying technique used.
[0103] When the event identifying device 4 identifies an event it generates a respective event measurement corresponding to the event and comprising the relevant measured event parameter values together with a timestamp which indicates the time at which the event took place. Accordingly, the event identifying device 4 generates as an output a series of event measurements at variable intervals. It will be understood that the intervals between the event measurements in the series of event measurements are variable because the timing of the event measurements depends on the timing of the identified events. Since the identified events are “real world” events their timing is inherently variable.
[0104] In the described embodiment each variable interval event measurement comprises the real and reactive power consumption value measurements at the time of the identified event together with the corresponding timestamp. Thus, the event parameter values of the event measurements are derived from the de-noised power measurements by selection. It will be understood that other forms of derivation are possible. The form of derivation used may be selected based upon the details of the event identifying algorithm.
[0105] Optionally, each variable interval event measurement can also comprise further parameter values relating to the event and produced during the processing. For example, the further parameter values could be value measurements of admittance, frequency, harmonic distortion, or voltage. In practice, whether such further parameter values are desired, and if so, what the further parameters are, will depend upon what processing is applied and the intended use of the variable interval event measurement in each case.
[0106] As stated above, each event measurement corresponds to a respective event. It will be understood that the generation of each event measurement implicitly identifies that some event has taken place. However, it is not required that the type of the event is identified by the event measurement, although this could optionally be done.
[0107] The event identifying device may be provided by software running on a general purpose processor of the smart meter. Alternatively, the event identifying device may be provided by hardware in the form of an application specific integrated circuit (ASIC) in the smart meter. The series of event measurements at variable intervals from the event identifying device 4 is fed to the memory 5 where the event measurements, including their respective timestamps, are stored.
[0108] In practice, it has been found that most of the power measurements from the power sensor 1 are not associated with events of interest. As a result, use of the present invention reduces the amount of data which must be stored in order to allow power consumption to be tracked over time, and in order to allow the power consumption history to be reproduced from the stored data. It is possible that over some short periods when there are an unusually large number of events there may be no reduction in the amount of data which must be stored. However, even in these cases, there will still be an overall reduction over longer periods. In practice it has been found that a compression ratio in the range 81% to 99%, with an average of 93.7% can be achieved.
[0109] Thus, the amount of data recording the power consumption can be compressed. This data compression is a lossy compression because the data regarding fixed interval measurements which are not associated with an event of interest is not recorded.
[0110] The degree of compression will depend, among other things, on the number, or frequency, of events relative to the number, or frequency, of fixed interval measurements. Thus, for any specific number of events, the degree of compression will increase as the time interval between the fixed interval measurements decreases, that is, as their frequency increases.
Noise Reduction
[0111] An example of the working of the noise reduction algorithm for n=3 will now be discussed in detail with reference to FIG. 3 .
[0112] In the example we start with 8 power measurement values, that is n=3, in this case the measurements are power measurements including random noise which form a signal f=[64, 48, 16, 32, 56, 56, 48, 42]. Accordingly, as shown in FIG. 3 the initial array of 8 power measurement values, the level zero coefficient values are c 0, . . . ,7 3 =[64, 48, 16, 32, 56, 56,48, 24]. This array of zero level values is then subject to a Haar discrete wavelet transform to generate a set of eight level 1 coefficients as shown.
[0113] The four level 1, or first level, wavelet, high pass, coefficients are:
[0000] d 0, . . . ,n 2 =[16,−16,0,24]/√{square root over (5)} (10)
[0114] The four level 1, or first level, scaling, low pass, coefficients are:
[0000] c 0, . . . ,n 2 =[112,48,112,74]/√{square root over (2)} (11)
[0115] Then, the four level 1, or first level, scaling coefficients given in equation 11 are subject to a Haar discrete wavelet transform to generate a set of four level 2, or second level, coefficients as shown.
[0116] The two level 2, or second level, wavelet coefficients are:
[0000] d 0,1 1 =[32,20] (12)
[0117] The two level 2, or second level, scaling coefficients are:
[0000] d 0,1 1 =[80,92] (13)
[0118] Then, the two level 2, or second level, scaling coefficients are subject to a Haar discrete wavelet transform to generate a set of two level 3, or third level, coefficients as shown.
[0119] The level 3, or third level, wavelet coefficient is:
[0000] d 0 0 =−12/√{square root over (2)} (14)
[0120] The level 3, or third level, scaling coefficient is:
[0000] c 0 0 =172/√{square root over (2)} (15)
[0121] In this example where n=3, the initial array of measurements could be written in the Haar wavelet basis as:
[0000] f=c 0 0 Φ 0 0 +d 0 0 Ψ 0 0 +d 0 1 Ψ 0 1 +d 1 1 Ψ 1 1 +d 0 2 Ψ 0 2 +d 1 2 Ψ 1 2 +d 2 2 Ψ 2 2 +d 3 2 Ψ 3 2 (9)
[0122] Another way of looking at this process is from a filter perspective, where the operations to calculate the coefficients may be seen to be averaging and differencing operations. Accordingly, the first level scaling coefficients are the averages of the pairwise data array entries and the first level wavelet coefficients are the results of finding the differences between the pairwise data array entries. Applying these averaging and differencing operations will provide the first level wavelet and scaling coefficients in FIG. 3 .
[0123] If we then calculate the hard threshold T according to equation (8) from the first wavelet level coefficients we find that T=34.2. Then, if all of the third level coefficients having an absolute value less than 34.2 are identified and their value set to zero, the hard threshold filtered third level coefficients are as shown in FIG. 4 .
[0124] When three levels of reverse wavelet transformation are applied to this filtered third level value it is found that the resulting filtered level zero power measurements are a constant value of 43. All of the random noise-like fluctuations have been removed.
[0125] This is shown in FIG. 5 , which shows a graph of the original noisy signal A and the regenerated filtered and de-noised signal B.
[0126] As a further example, consider a power measurement signal which includes 20 W noise and includes a step change of 100 W. This can be simulated by a signal f=[30, 48, 32, 40, 149, 134, 150, 138]. Applying three levels of Haar discrete wavelet transformation as before gives third level coefficients as shown in FIG. 6 .
[0127] In this case the threshold can be calculated as T=35.3, and setting all wavelet coefficients with absolute values below this to zero gives a set of filtered third level coefficients as shown in FIG. 7 . If these filtered coefficients are subject to three levels of reverse wavelet transformation the reconstructed filtered signal shown in FIG. 8 is produced. As can be understood in FIG. 8 , the noise has been removed from this signal, but the 100 W step change is still present and sharply defined.
[0128] This is shown in FIG. 9 , which shows a graph of the original noisy signal C and the regenerated filtered and de-noised signal D.
[0129] A specific example of an event detection algorithm, referred to hereinafter as a “corner detection algorithm”, which can be used in the present invention will now be described in detail.
Corner Detection
[0130] The operation of the corner detection algorithm is illustrated schematically in FIG. 10 . The compression algorithm identifies “corners” in power demand by identifying differences in the gradient representing rate of change in power from one fixed interval time point to the next. These corners in power demand are regarded as events of interest in the present invention.
[0131] A point at which there is change in gradient between two successive time intervals (identified as T( 2 ), P( 2 )) is marked as a “corner” if that change is greater than a predetermined threshold. This is done by measuring the power difference between points T( 3 ), P( 3 ) and T( 2 ), P( 2 ) and between T( 2 ), P( 2 ) and T( 1 ), P( 1 ) to give values A 1 and A 2 respectively. If the difference B between A 1 and A 2 exceeds a predetermined value Tol 1 then a corner is marked.
[0132] Thus, three successive measurements are required to identify a corner with this technique. Accordingly, to ensure that corners close to the boundary between successive arrays of the noise reduction method are not missed the final two end measurements in time in each array of measurements processed in the noise reduction method are duplicated as the first two beginning elements in time in the next array of measurements processed. Thus, in the specific example discussed above, the last two entries in each array of 2 n measurements are duplicated as the first two entries in the following array of 2 n measurements.
[0133] The operation of the algorithm is illustrated in more detail in FIG. 12 in which:
[0000] T(x), T(i) and T(j) represent 32 Bit timestamps
C(x), C(j) and Y(i) represent 16 Bit power readings at a corner
Tol 1 , Tol 2 represent integer numerical values (0-100)
A 1 , A 2 , B represent 16 Bit power reading differences
nI, nMax, nMin, n 2 represent 16 Bit numerical values
M(i), M(i)max represent 16 Bit numerical values
[0134] Section 401 of FIG. 12 illustrates identification of corners as described above with reference to FIG. 3 .
[0135] Section 402 of FIG. 12 illustrates the classification of corners into “Standard” and “Fine” classes depending, respectively, on whether B is greater than predetermined values Tol 1 and Tol 2 or greater than Tol 1 only.
[0136] The skilled person will understand how to select the value of the threshold for marking a point as a corner, and the specific value will vary from case to case.
[0137] By measuring and identifying these corners in the fixed interval power measurements, and outputting data regarding these corners, the corresponding parameter values and the associated timestamp values, the series of event measurements 12 at variable intervals is produced.
[0138] The series of event measurements at variable intervals allows an electricity consumption history to be generated, either in real time from the event measurements as they are produced, or retrospectively from stored event measurements, such as the event measurements stored in the memory 5 .
Correction
[0139] The series of event measurements at variable intervals generated as described above with respect to FIG. 10 and sections 401 and 402 of FIG. 12 contains the majority of corners, however a correction may be applied to identify one or more corners that may have been missed.
[0140] This is illustrated in FIG. 11 which shows a corner C( 2 ) between corners C( 1 ) and C( 3 ) that has been missed by the corner detection algorithm.
[0141] A missing corner may be identified if both the power difference (power at C 1 minus power at C 2 ) and the time difference (time at C 1 minus time at C 2 ) fall outside defined values as illustrated in section 403 of FIG. 12 .
[0142] In this event, a linear interpolation may be conducted to identify any missing corners, as illustrated in Section 403 of FIG. 12 . Referring to FIG. 11 , missing corner C 3 should be inserted at the point giving the most acute angle between lines C 1 -C 2 and C 2 -C 3 .
[0143] The use of the utilities consumption data noise reduction and compression method according to the present invention provides the advantage that noise in the raw measured data can be removed without impairing the compression. Further, the use of the utilities consumption data noise reduction and compression method according to the present invention provides the advantage that for any selected interval between the fixed interval power measurements the amount of data which must be stored at the smart meter 1 , and the amount of data which must be transferred from the smart meter 1 to the user display device 7 can be reduced. Further, the use of the utilities consumption data noise reduction and compression method according to the present invention provides the advantage that the amount of data which must be stored and transferred is not directly related to the frequency of the fixed interval power measurements. Accordingly, the frequency, or interval, of the fixed interval power measurements in any specific application can be selected as required to provide the desired time resolution without having to consider whether the amount of data which will need to be stored or transmitted will be excessive.
[0144] The exemplary embodiment described above explains one example of how the present invention may be carried out. It will be understood that further data processing may be carried out in addition to that described. For example, there may be some pre-processing of the power measurements, such as filtering to remove noise, before the event identification is carried out. Further, in addition to the above described lossy compression techniques according to the present invention, the data to be stored or transmitted may also be compressed using a conventional lossless compression technique.
[0145] It should be understood that the available bandwidth or data transfer rate from the smart meter 1 to the user display device 7 via the wireless communication link 8 may be relatively low or costly so that the transfer of large amounts of data is highly undesirable.
[0146] It will usually be preferred for the user display unit 7 to be in substantially continuous wireless contact with the smart meter 1 so that measurements made by the smart meter 1 are transferred to the user display unit 7 in real time as they are made. However, in some circumstances it may be necessary to transfer historic power consumption data, that is previously recorded power consumption data, from the smart meter 1 to the user display unit 7 . This will be necessary if the user display unit 7 has been temporarily out of contact with the smart meter 1 , and the power consumption data missed during the lost contact period must be transferred. Further, when a new user display unit 7 is installed to an existing smart meter 1 , the user display unit 7 will of course have previously been out of contact with the smart meter 1 , and historic power consumption data for a previous period must be transferred. The length of this previous period will vary from case to case. Further, if a particular previous period of time is of interest to a user it may be necessary to transfer historic power consumption data for this period if it has not been stored in the user display device.
[0147] Using a conventional meter in which only a cumulative total of consumed energy is stored, these data transfers could not be made as the required data would not be present on the meter. Further, using a known smart meter where power measurement readings are stored at fixed intervals it can be very difficult to provide the desired information to the user display device because of the every large amount of power readings which must be transferred, and also because it may be difficult or impossible to determine what time any particular power reading corresponds without working back from the most recent data through all of the series of historic data in sequence, which will require a large amount of processing.
[0148] These problems can be overcome by the present invention because the utilities consumption data compression method of the present invention dramatically reduces the amount of information that must be transferred, and because each variable interval event measurement is stored in association with a timestamp so that the specific time of the measurement can be easily determined.
[0149] In the above described embodiment electrical power consumption is measured. It will be understood that power and energy are closely related so that the skilled person will readily understand how to use the power consumption values to determine values of consumed energy. Further, it will be understood that measured power consumption can be expressed or defined directly in terms of power, or indirectly in terms of the amount of energy consumed since the preceding measurement, provided that the time between the successive measurements is known.
[0150] The above description describes the processing, compression, storage and delivery of a single data stream of electrical power consumption data. This is only by way of example, the present invention is also applicable to other parameters. Further, the smart meter may generate, process, compress, store and deliver multiple data streams relating to respective different parameters, and each data stream can be independently processed, stored and queried. The different parameters may be measured at the same or different fixed measurement intervals, as appropriate to the different parameters.
[0151] The different data streams relating to the different parameters may be separately processed to identify events and stored separately. Alternatively, the fixed interval measurements in the different data streams relating to the different parameters may be processed together to identify events and/or stored together. For example, a smart meter measuring real power, reactive power, voltage, current and frequency of an electrical utility supply at respective fixed intervals could process the real power and reactive power to identify events, and when an event is identified store the real power and reactive power values, and the voltage, current and frequency values, together with the timestamp.
[0152] Typically, the user display device is a domestic client display able to provide real time and historical displays and analyses of utility consumption to a domestic user.
[0153] The user display device may be portable. In this case the user display device may often be out of contact with the smart meter.
[0154] In the above described embodiment of the invention the user display device is connected to the smart meter by a wireless communication link. As an alternative it would be possible for the user display device to be connected to the smart meter by a direct wired connection. The user display device could even be combined with the smart meter in a single unit.
[0155] The above described embodiment describes the invention as employed by a smart meter in communication with a user display device. The smart meter could additionally, or alternatively, be connected to other client devices such as a user PC, a utility supplier billing computer, or third party data collection centre, either directly. Similarly, the user display device could be connected to client devices such as a user PC, a utility supplier billing computer, or third party data collection centre. These connections can conveniently be made through a user internet connection. The smart meter will usually have an advanced metering infrastructure (AMI) or automatic metering system (AMR) data connection, but it will usually be too costly to use these to transfer data to client devices.
[0156] In the above described embodiment of the invention a single user display device is connected to a single smart meter by a wireless communication link. As an alternative it would be possible for a single user display device to be connected to multiple smart meters. The multiple smart meters could measure different utilities, and for supply of the same utility to different households, or other settings that receives their own discrete utilities, of interest to the user. As another alternative it would be possible for multiple user display devices, or other client devices, to be connected to a single smart meter. In this case, data requested by the different devices can be delivered as a series of responses.
[0157] The invention has been discussed primarily with respect to consumption of electricity, however it will be appreciated that the methods described herein can equally be applied to consumption of water or gas supplied to a household.
[0158] Consumption of water and gas can be measured using techniques that are well known to the skilled person, for example based on use of water and gas meters. Water and gas consumption, in particular water consumption, may be measured at a lower rate, for example at least once every 300 seconds or at least once every 60 seconds, in order to generate water consumption data that may be used to identify events associated with consumption of water. The rate of flow of water or gas at each time interval may be measured, along with the total volume consumed over time in a manner analogous to power and energy measurements of electricity consumption. Additionally or alternatively, water and gas consumption may be measured at measurement points after intervals of volume consumption rather than intervals of time, for example a measurement of time elapsed for each unit volume (e.g. litre) of water to be consumed.
[0159] The apparatus described above may be implemented at least in part in software. Those skilled in the art will appreciate that the apparatus described above may be implemented using general purpose computer equipment or using bespoke equipment.
[0160] The hardware elements, operating systems and programming languages of such computers are conventional in nature, and it is presumed that those skilled in the art are adequately familiar therewith. Of course, the server functions may be implemented in a distributed fashion on a number of similar platforms, to distribute the processing load.
[0161] Here, aspects of the methods and apparatuses described herein can be executed on a mobile station and on a computing device such as a server. Program aspects of the technology can be thought of as “products” or “articles of manufacture” typically in the form of executable code and/or associated data that is carried on or embodied in a type of machine readable medium. “Storage” type media include any or all of the memory of the mobile stations, computers, processors or the like, or associated modules thereof, such as various semiconductor memories, tape drives, disk drives, and the like, which may provide storage at any time for the software programming. All or portions of the software may at times be communicated through the Internet or various other telecommunications networks. Such communications, for example, may enable loading of the software from one computer or processor into another computer or processor. Thus, another type of media that may bear the software elements includes optical, electrical and electromagnetic waves, such as used across physical interfaces between local devices, through wired and optical landline networks and over various air-links. The physical elements that carry such waves, such as wired or wireless links, optical links or the like, also may be considered as media bearing the software. As used herein, unless restricted to tangible non-transitory “storage” media, terms such as computer or machine “readable medium” refer to any medium that participates in providing instructions to a processor for execution.
[0162] Hence, a machine readable medium may take many forms, including but not limited to, a tangible storage carrier, a carrier wave medium or physical transaction medium. Non-volatile storage media include, for example, optical or magnetic disks, such as any of the storage devices in computer(s) or the like, such as may be used to implement the encoder, the decoder, etc. shown in the drawings. Volatile storage media include dynamic memory, such as the main memory of a computer platform. Tangible transmission media include coaxial cables; copper wire and fiber optics, including the wires that comprise the bus within a computer system. Carrier-wave transmission media can take the form of electric or electromagnetic signals, or acoustic or light waves such as those generated during radio frequency (RF) and infrared (IR) data communications. Common forms of computer-readable media therefore include for example: a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD or DVD-ROM, any other optical medium, punch cards, paper tape, any other physical storage medium with patterns of holes, a RAM, a PROM and EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave transporting data or instructions, cables or links transporting such a carrier wave, or any other medium from which a computer can read programming code and/or data. Many of these forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to a processor for execution.
[0163] Those skilled in the art will appreciate that while the foregoing has described what are considered to be the best mode and, where appropriate, other modes of performing the invention, the invention should not be limited to specific apparatus configurations or method steps disclosed in this description of the preferred embodiment. It is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings. Those skilled in the art will recognize that the invention has a broad range of applications, and that the embodiments may take a wide range of modifications without departing from the inventive concept as defined in the appended claims.
[0164] Although the present invention has been described in terms of specific exemplary embodiments, it will be appreciated that various modifications, alterations and/or combinations of features disclosed herein will be apparent to those skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims. | A method and apparatus for carrying out noise reduction in data regarding parameter values comprising the steps of, making a series of measurements of parameter values at times separated by predetermined time intervals, forming a plurality of successive measurements into an array of measurements, performing n successive wavelet transforms on the array of measurements to produce an array of coefficients, comparing the values of the array of coefficients to a threshold value and, selectively changing the values of said coefficients based on their relationship to the threshold, to produce an array of filtered coefficients, and performing n successive inverse wavelet transforms on the array of filtered coefficients to produce an array of filtered measurements. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to International Patent Application PCT/DE2014/100155, filed on May 2, 2014, and thereby to German Patent Application 10 2013 210 365.4, filed on Jun. 4, 2013.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] No federal government funds were used in researching or developing this invention.
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
SEQUENCE LISTING INCLUDED AND INCORPORATED BY REFERENCE HEREIN
[0004] Not applicable.
BACKGROUND
[0005] 1. Field of the Invention
[0006] The invention relates to a sealing inner sleeve having a deformable intermediate section.
[0007] 2. Background of the Invention
[0008] Sealing inner sleeves are widely known and described for example in DE 44 01 318 C2. With the help of such sealing inner sleeves leakages can be repaired, e.g., in underground pipes made from concrete or another material, without digging being necessary. For this purpose, the sealing inner sleeve is inserted into the leaking pipe to be repaired until it reaches the place of the leak. Here, initially the sealing inner sleeve is spirally contracted so that it shows a smaller diameter than the pipe to be sealed. Once the sealing inner sleeve has been moved to the place of the leak of the pipe to be repaired, using a mechanical assembly unit said sealing inner sleeve is expanded until, under compression of the sealing rings, it has tightly contacted the interior wall of the pipe. Using a locking device, which comprises a clamping sprocket combing a row of teeth and an elastic blocking latch engaging these teeth, the sealing inner sleeve is kept in its expanded position.
[0009] A locking device, improved in reference thereto, is suggested in EP 0 805 932 B1. Here, a sealing inner sleeve is disclosed with a locking device that allows very small latching steps and thus, upon the expansion being concluded, ensures a tight, lasting contacting of the interior wall of the pipe with a high pressure upon the sealing organs. For this purpose, the improved locking device is provided with a slot arranged in the circumferential direction at the interior end of the band, with a row of teeth being arranged respectively at its two opposite longitudinal edges. Two clamping sprockets are provided in the slot, each of which combing one of the two rows of teeth and simultaneously being impinged by a common blocking sprocket as the latching organ. The blocking sprocket is pressed via a clamping spring into the space between the two clamping sprockets.
[0010] These sealing inner sleeves are best suited to be inserted into straight pipelines, in order to seal here cracked walls, for example. For this purpose, the sealing inner sleeves are provided at their external circumference with a sealing means, particularly an elastic coating, such as a rubber hose for example, which may show one or more circumferential sealing lips, and then it is moved with a so-called packer to the damaged point of the pipeline to be repaired. The packer with the sealing inner sleeve is brought into position and then inflated via the entrained air hose; here the sealing inner sleeve also potentially expands until it seals the pipe section to be repaired. The locking device ensures that the sealing inner sleeve maintains this position even when the packer is removed again.
[0011] However, in practice, pipelines are frequently damaged, in which two adjacent pipe sections show a radial offset. This may be caused particularly by an offset pipe coupling. Additionally, in pipelines it may occur that pipes with different diameters are connected to each other. Damages in such pipes showing a radial offset or different diameters cannot be repaired with the above-described sealing inner sleeves, because the sealing inner sleeves in the locked and exterior-supported state show a high deformation resistance, similar to that of a circumferentially closed pipe and thus they cannot be deformed.
[0012] This problem can be solved with a sealing inner sleeve as described in EP 0 795 714 A1. This sealing inner sleeve is characterized by an intermediate section arranged between two end sections of the sealing inner sleeve, which shows a lesser resistance to deformation when bent about the longitudinal axis compared to the end sections of the sealing inner sleeve. The reduced resistance to deformation is here possible by material weakening and/or a bellow-like embodiment. Here, among other things, a punctual or corrugated punching of the sealing inner sleeve is suggested in the intermediate section as the material weakening. The plurality of slots distributed here in a circumferential direction in the intermediate section of the sealing inner sleeve is arranged in the idle state of the sealing inner sleeve, i.e. in the still non-deformed state of the sealing inner sleeve, axially parallel in reference to each other and the center axis of the sealing inner sleeve.
[0013] This is the foundation for the present invention.
[0014] The objective of the invention is to further develop these sealing inner sleeves of prior art such that on the one hand, good deformation of the sealing inner sleeve in the intermediate section is ensured, but sufficient stability still remains of the sealing inner sleeve when used in pipes to be repaired that show radial offsets and/or different diameters. In particular, with the sealing inner sleeve it should also be possible to repair pipes that are arranged at a slight angle in reference to each other.
[0015] This objective is attained by a sealing inner sleeve showing the features as claimed herein.
BRIEF SUMMARY OF THE INVENTION
[0016] In a preferred embodiment, a sealing inner sleeve ( 10 ) to be inserted into pipe in order to seal leakages there, comprising an annularly contracted and expandable band ( 12 ), preferably made from sheet steel, with its band parts overlapping in the circumferential direction at least partially, and with a locking device ( 20 ) allowing an increase in diameter of the sealing inner sleeve ( 10 ), however blocking any deformation in the opposite direction, whereby the sealing inner sleeve ( 10 ) comprises two end sections ( 14 , 15 ) and an intermediate section ( 16 ) connecting them to a contiguous component, and whereby a plurality of longitudinal slots ( 30 ) is arranged in the intermediate section ( 16 ), separated from each other and distanced by a plurality of longitudinal webs ( 40 ) arranged in the circumferential direction, wherein the longitudinal slots ( 30 , 130 ) and the longitudinal webs ( 40 , 140 ) are arranged with a predetermined angular offset aslant in reference to the center axis (X) of the sealing inner sleeve ( 10 ) on the circumference of said sealing inner sleeve ( 10 ).
[0017] In another preferred embodiment, the sealing inner sleeve ( 10 ) as described herein, wherein a first group of longitudinal slots ( 30 ) and longitudinal webs ( 40 ) is provided, showing an angular offset ranging from approximately 5 degrees to approximately 20 degrees, preferably from approximately 8 degrees to 12 degrees, and furthermore, preferably amounting to approximately 10 degrees, and/or that at least one second group of longitudinal slots ( 130 ) and longitudinal webs ( 140 ) is provided, showing an angular offset in reference to the center axis (X) at a range from approximately more than 45° and less than 90°, preferably amounting to at least approximately 75°.
[0018] In another preferred embodiment, the sealing inner sleeve ( 10 ) as described herein, characterized in that all longitudinal slots ( 30 ) and longitudinal webs ( 40 ) of the first group are arranged parallel in reference to each other.
[0019] In another preferred embodiment, the sealing inner sleeve ( 10 ) as described herein, characterized in that the longitudinal slots ( 30 ) of the first group are at least approximately one to five times wider than the longitudinal webs ( 40 ) in the circumferential direction of the sealing inner sleeve ( 10 ).
[0020] In another preferred embodiment, the sealing inner sleeve ( 10 ) as described herein, characterized in that the longitudinal slots ( 30 ) of the first group are rounded or angular at their end sections ( 41 ), ( 42 ).
[0021] In another preferred embodiment, the sealing inner sleeve ( 10 ) as described herein, characterized in that the longitudinal webs ( 40 ) are enlarged in a bulging fashion, seen in the circumferential direction of the sealing inner sleeve ( 10 ) at a middle section ( 43 ).
[0022] In another preferred embodiment, the sealing inner sleeve ( 10 ) as described herein, characterized in that the intermediate section ( 16 ) of the sealing inner sleeve ( 10 ) amounts to approximately 0.2 to 0.5 of the total length Z, seen in the direction of the center axis (X) of the sealing inner sleeve ( 10 ).
[0023] In another preferred embodiment, the sealing inner sleeve ( 10 ) as described herein, characterized in that the sealing inner sleeve ( 10 ) shows in the first group approximately 10 to 120 longitudinal slots ( 30 ).
[0024] In another preferred embodiment, the sealing inner sleeve ( 10 ) as described herein, characterized in that at least the intermediate section ( 16 ) of the sealing inner sleeve ( 10 ), provided with the longitudinal slots ( 30 , 10 , 130 ), is covered by a cover, particularly a metallic film.
[0025] In another preferred embodiment, the sealing inner sleeve ( 10 ) as described herein, characterized in that the longitudinal slots ( 30 ) of the first group are arranged between the longitudinal slots ( 130 ) of two second groups of longitudinal slots ( 130 ).
[0026] In another preferred embodiment, the sealing inner sleeve ( 10 ) as described herein, characterized in that the longitudinal slots ( 130 ) of the second group are narrower than the longitudinal slots ( 130 ) of the first group.
[0027] In a preferred embodiment, a sealing inner sleeve ( 10 ) according to one of Claims 1 to 11 , characterized in that the longitudinal slots ( 130 ) of the second group show a width of approximately 3 to 7 mm and a length of approximately 10 to 15 cm, and are limited by longitudinal webs ( 140 ), which are approximately 1 to 5 mm wide.
[0028] In another preferred embodiment, the sealing inner sleeve ( 10 ) as described herein, characterized in that the two additional groups of longitudinal slots ( 130 ) are arranged symmetrically in reference to a perpendicular of the center axis (X) and aslant with a predetermined angular offset.
[0029] In another preferred embodiment, the sealing inner sleeve ( 10 ) as described herein, characterized in that the area of the second group of longitudinal slots ( 130 ) is smaller than the area of the first group of longitudinal slots ( 130 ) in reference to the length of the sealing inner sleeve in the direction of the center axis (X).
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a line drawing evidencing an exemplary embodiment of the sealing inner sleeve in the wound state seen diagonally from the front.
[0031] FIG. 2 is a line drawing evidencing the sealing inner sleeve of FIG. 1 in a side view.
[0032] FIG. 3 is a line drawing evidencing an enlarged detail of the sealing inner sleeve shown in FIG. 2 in the area of the longitudinal slots.
[0033] FIG. 4 is a line drawing evidencing a focused view upon a detail inside the sealing inner sleeve in the stressed state in a pipe with a constant diameter.
[0034] FIG. 5 is a line drawing evidencing a focused view upon a detail inside a pipe with different diameters equipped with a stressed sealing inner sleeve according to FIGS. 1 to 4 .
[0035] FIG. 6 is a line drawing evidencing an illustration similar to FIG. 1 , however now additional longitudinal slots are arranged at the exterior circumference of the sealing inner sleeve, in order to allow sealing pipe sections aligned angularly offset in reference to each other.
[0036] FIG. 7 is a line drawing evidencing the sealing inner sleeve of FIG. 6 in a side view.
[0037] FIG. 8 is a line drawing evidencing another exemplary embodiment of a sealing inner sleeve with various longitudinal slots in a side view.
[0038] FIG. 9 is a line drawing evidencing a detailed view of the sealing inner sleeve shown in FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
[0039] The invention is essentially based on the fact that a plurality of longitudinal slots at the exterior circumference of the sealing inner sleeve is arranged, which in reference to the center axis of the sealing inner sleeve show an angular offset. This means that a plurality of longitudinal slots is aligned diagonally in reference to the center axis of the sealing inner sleeve.
[0040] Experiments have shown that a plurality of longitudinal slots at the circumference of the sealing inner sleeve must be distributed ranging from approximately greater than 45° and less than 90° in reference to the center axis X of the sealing inner sleeve, if the sealing inner sleeve shall also be used for leaks of pipes arranged at a slight offset in reference to each other. An angular offset by more than 45° and less than 90° of these longitudinal slots also means that the longitudinal slots show an angle of less than 45° and more than 0° in reference to a perpendicular in reference to the center axis of the sealing inner sleeve.
[0041] In a preferred embodiment of the longitudinal slots, they are preferably placed from 55° to 85° and further preferred at an angle of approximately 75° in reference to the center axis X of the sealing inner sleeve.
[0042] In one embodiment of the invention, the longitudinal slots may be approximately 3 to 7 mm wide and approximately 10 to 15 cm long and limited by longitudinal webs, which are approximately 1 to 5 mm wide. Such an arrangement of longitudinal slots is best suited for sealing leaks in pipes arranged at an angle in reference to each other.
[0043] The pipes to be sealed are generally made from a plurality of abutting pipe sections. Here, it frequently occurs that individual pipe sections are not precisely aligned to each other axially. In addition to a slight angular alignment of abutting pipes, which can be sealed with the above-mentioned longitudinal slots when leaks appear, there are also constellations in which the abutting pipe sections are offset axially in reference to each other, thus showing a radial offset or showing different diameters. In order to allow effective sealing of such pipes as well, the invention provides, in addition to the above-mentioned group of longitudinal slots or instead thereof, another group of longitudinal slots, which are aligned less aslant in reference to the center axis of the sealing inner sleeve. Experiments have shown that the angular offset of this group of longitudinal slots ideally ranges from approximately 5 degrees to 20 degrees and should amount preferably to approximately 10 degrees. With such an angular offset of the longitudinal slots in reference to the center axis of the sealing inner sleeve, good deformation of the sealing inner sleeve is possible here and high stability is ensured as well, even when the sealing inner sleeve is inserted in pipelines showing a radial offset and/or different diameters.
[0044] In the following the group of longitudinal slots with the lesser angular offset, i.e. the longitudinal slots provided to repair pipelines with radial offset and/or different diameters, is called the first group of longitudinal slots, while the other longitudinal slots, aligned more aslant in reference to the center axis than the first group of longitudinal slots, are called the second group of longitudinal slots.
[0045] Preferably, all longitudinal slots are aligned in groups parallel to their diagonal alignment. Here, the individual longitudinal slots are separated from each other by longitudinal webs.
[0046] In a further development of the invention, it is provided that the longitudinal slots of the first group are embodied, in reference to the circumferential direction of the sealing inner sleeve, approximately one to five times wider than the longitudinal webs.
[0047] The longitudinal webs of the first group may be shaped rounded or angular at their ends. Here it is also possible, or in a further development independent there from, that the longitudinal webs in their middle, seen in the circumferential direction, are embodied bulging, i.e. in their central area they are wider than in their two end sections.
[0048] Additionally, it has proven advantageous to size the intermediate section of the sealing inner sleeve such that it is equivalent to approximately 0.2 to 0.5 of the total length of the sealing inner sleeve. Preferably, the intermediate section of the sealing inner sleeve is placed centrally in reference to the two end sections embodied with an equal length. The two end sections of the sealing inner sleeve can here for example each show a length from 0.25 to 0.4 in reference to the total length of the sealing inner sleeve.
[0049] In one embodiment of the invention, it is provided that the sealing inner sleeve in its intermediate section shows a first group of longitudinal slots, with this first group of longitudinal slots at their two sides being framed respectively by a second group of longitudinal slots. The two second groups of longitudinal slots may here show their longitudinal slots at an alignment parallel to each other, or be aligned to one side of the first group of longitudinal slots diagonal in one direction, and at the other end of the first group of longitudinal slot aligned diagonally in the opposite direction in reference to the perpendicular of the center axis of the sealing inner sleeve. In a further development of the invention it is provided that the sealing inner sleeve at its exterior circumference is covered, at least in the area of the intermediate section, i.e. where the longitudinal slots of the first and/or the second group are provided, with a cover, particularly a film or a metal sheet. This may for example involve a metallic film, particularly a stainless steel film or a stainless steel sheet, which shows for example a thickness from approximately 0.3 mm to 0.7 mm. This film and/or sheet is wound about the exterior circumference of the sealing inner sleeve, at least in the area of the longitudinal slots about the sealing inner sleeve. However, it is also possible to wrap up the entire sealing inner sleeve at the exterior with such a film or such a sheet. The sense and purpose of such a cover is to cover the longitudinal slots. The sealing inner sleeve provided with such a cover shall then preferably be provided with a suitable sealing material on the outside. This sealing material may be a rubber-like hose, which is pulled at the outside over the sealing inner sleeve and preferably shows at the exterior circumference one or more circumferential sealing lips. The sealing inner sleeve prepared with such a pulled-on rubber-like hose and cover can then be moved by the packer mentioned at the outset to the point of the pipeline to be repaired and placed there.
[0050] In one embodiment of the invention, the longitudinal slots of the second group are embodied narrower than the longitudinal slots of the first group. Here, the longitudinal slots of the second group may show a width from approximately 3 to 7 mm and a length from approximately 10 to 15 cm, with the longitudinal slots here being limited by longitudinal webs, which show a width from approximately 1 to 5 mm.
DETAILED DESCRIPTION OF THE FIGURES
[0051] FIG. 1 shows a sealing inner sleeve with a perspective view from the front. The sealing inner sleeve is provided with the reference character 10 and shows a coiled, metallic band 12 , with its band parts overlapping at the ends. In this coiled state, the sealing inner sleeve 10 is held by a locking device located in the interior, not discernible in FIG. 1 . The locking device is here embodied such it allows a widening with regard to the diameter of the sealing inner sleeve 10 , however blocks any deformation in the opposite direction. Suitable locking mechanisms and locking devices are widely known, for example from DE 44 01 318 C2 and EP 0 805 932 B1 mentioned at the outset.
[0052] In the state shown, the sealing inner sleeve 10 is a cylindrical body with a center axis X. The sealing inner sleeve 10 shows two end sections 14 , 15 with an intermediate section 16 located between these. Here, the end sections 14 , 15 are massive metal sections, while the intermediate section 16 comprises a plurality of longitudinal slots 30 extending in the circumferential direction of the sealing inner sleeve 10 , which are distanced by the longitudinal webs 40 .
[0053] The longitudinal slots 30 and the longitudinal webs 40 of the sealing inner sleeve 10 are aligned towards the center axis X at an angular offset a and thus placed diagonally in reference to the center axis X. This angular offset a may range from approximately 5 to 20 degrees, preferably amounting at least approximately to 10 degrees. The longitudinal slots 30 and the longitudinal webs 40 are explained in greater detail in the context with FIG. 3 . Overall, for example 10 to 120, preferably 25 to 35 longitudinal slots 30 may be implemented in the sealing inner sleeve 10 by way of punching or cutting out.
[0054] The sealing inner sleeve 10 shows a total length Z, for example from 40 cm to 80 cm. The above-mentioned central section 16 may here range from 0.2 to approximately 0.5 of this total length Z. The two end sections 14 , 15 are preferably each embodied with identical length in reference to the center axis X and show a length from approximately 0.25 to 0.4 of Z. The diameter D of the sealing inner sleeve 10 may for example range from 20 to 80 cm in the stressed state. Nevertheless, other dimensional ratios are also possible.
[0055] FIG. 3 shows the detail of the metallic band 12 in the area of the longitudinal slot 30 and the longitudinal webs 40 in an enlarged view. Once more, the angular offset a from the center axis X is discernible. The longitudinal slot 30 is embodied like a spoon, with respectively rounded sections at its longitudinal ends. The longitudinal slots 30 show a maximum width of B 2 at their ends. The width is reduced in the middle of the longitudinal slots 30 and amounts to B 1 . B 1 may for example be 2 cm, while B 2 is 2.5 cm. The longitudinal webs 40 are designed appropriately and show therefore in the center a maximum width C 1 and at their ends a minimum width C 2 . C 1 may for example be 1 cm and C 2 0.5 cm. Other size ratios are also possible. In the concrete exemplary embodiment of FIG. 3 the slots show a total length of approximately 10 cm. Such an arrangement of the longitudinal slots 30 and the longitudinal webs 40 is optimal with regard to the connection possibilities, on the one hand, and the stability of the sealing inner sleeve 10 , on the other hand.
[0056] This is shown based on the views of the interior of sealing inner sleeve of FIGS. 4 and 5 .
[0057] FIG. 4 shows a view of a detail inside the sealing inner sleeve 10 in the stressed state in a pipeline 50 with a constant diameter and without any radial offset. Two locking devices 20 are discernible from FIG. 4 , which respectively extend to a toothed rod 21 . Both locking devices 20 are located approximately at the same distance from the stop 23 of the toothed rod 21 and are therefore equally stressed. The longitudinal slots 30 and the longitudinal webs 40 are all aligned parallel in reference to each other, because neither any radial offset nor a change in diameter of the pipeline affects the sealing inner sleeve 10 in FIG. 4 .
[0058] FIG. 5 shows the sealing inner sleeve 10 of FIG. 4 stressed in a sealing fashion in a pipeline 50 with a change in diameter and/or radial offset. It is clearly discernible that the rear locking device 20 facing away from the viewer is placed much closer to the stop 23 of the locking device 20 than the frontal locking device 20 facing the viewer. This means that the locking devices 20 have stressed the end sections 14 , 15 to a different extent due to the given radial offset and/or the given change in diameter of the pipeline 50 . Here, the sealing inner sleeve 10 is deformed in the intermediate section with the longitudinal slots 30 and the longitudinal webs 40 , distorted in particular, which is particularly discernible in FIG. 5 in the area marked with the reference character A. Here, the longitudinal slots 30 and/or longitudinal webs 40 intersect between the exterior and interior band section of the band 12 of the sealing inner sleeve 10 .
[0059] The longitudinal slots 30 and the longitudinal webs 40 used in the exemplary embodiments discussed thus far are best suited to seal those sections of pipes that show a radial offset or a change in diameter. The above-mentioned longitudinal slots 30 and the longitudinal webs 40 may well compensate such a radial offset or such a change in diameter based on the particular diagonal position of the longitudinal slots 30 , when the sealing inner sleeve 10 is stressed inside the pipe section to be repaired. These previously discussed longitudinal slots 30 form a first group. When repairing pipes however, pipe sections also appear that may be aligned at a slight angle in reference to each other. This means that the pipe sections abutting each other show center axes extending diagonally in reference to each other. Such diagonal alignments may show a few degrees, for example ranging from 0° to 10 or 20°. In order to allow sealing even such diagonally extending pipeline sections when necessary, the above-mentioned first group of longitudinal slots is not suitable.
[0060] In the following exemplary embodiments of FIGS. 6 to 9 therefore sealing inner sleeves are introduced, in which a second group of longitudinal slots are also provided, which are placed considerably more aslant in reference to the center axis X of the sealing inner sleeve 10 than the above-discussed longitudinal slots 30 . The longitudinal slots discussed in the following are called hereinafter the second group of longitudinal slots and indicated with the reference character 130 . These longitudinal slots 130 of the second group are distanced by the longitudinal webs 140 .
[0061] At this point, it shall once more be pointed out that, depending on the application, it is sufficient to arrange in the sealing inner sleeve 10 longitudinal slots 30 of the first group or longitudinal slots 130 of the second group. However, in order to provide a universally suitable sealing inner sleeve 10 , it is recommended to provide at the circumference of the sealing inner sleeve 10 both the longitudinal slots 30 of the first group, as well as the longitudinal slots 130 of the second group.
[0062] FIGS. 6 to 9 show sealing inner sleeves 10 , in which both the longitudinal slots 30 of the first group as well as the longitudinal slots 130 of the second group are implemented. In this way, FIG. 6 now shows a sealing inner sleeve 10 , as already presented in the context of FIG. 1 , whereby now however a second group of longitudinal slots 130 is also provided, which are considerably more aslant than the longitudinal slots 30 of the first group, distributed at the circumference of the sealing inner sleeve 10 . These longitudinal slots 130 of the second group are placed at both sides of the longitudinal slots 130 of the first group. All of these longitudinal slots 30 of the second group are aligned parallel in reference to each other and placed at an angle β in reference to the center axis X, which is greater than 45° and less than 90°.
[0063] Most preferably, the angle β ranges from 55° to 85°, whereby it has proven beneficial with the concrete exemplary embodiment to adjust the angle to approximately 75°. In FIGS. 6 and 7 the angle β amounts to 75°.
[0064] As shown in FIGS. 6 and 7 the longitudinal slots 130 of the second group are designed considerably narrower than the longitudinal slots 30 of the first group. The longitudinal slots 130 of the second group are separated by longitudinal webs 140 , which are also relatively narrow. This way the longitudinal slots 130 of the second group may show a width from approximately 3 to 7 mm, and a length from approximately 10 to 15 cm. The longitudinal webs 140 are approximately 1 to 5 mm wide, assuming that the sealing inner sleeve 10 shows, for example, an interior diameter of 25 cm to 40 cm.
[0065] The illustration of FIG. 7 shows particularly clearly that the length of the longitudinal slots 130 of the second group is selected such that a virtual parallel P in reference to the center axis X intersects several longitudinal slots 130 on the circumferential surface of the sealing inner sleeve 10 . In the exemplary embodiment of FIG. 7 such a parallel P intersects e.g. three longitudinal slots 130 .
[0066] FIGS. 8 and 9 show another exemplary embodiment of a sealing inner sleeve 10 . This exemplary embodiment is very similar to the sealing inner sleeve of FIGS. 6 and 7 . However, the longitudinal slots 130 of the second group are divided into a first sub-group, which is placed in FIG. 8 at the left of the longitudinal slots 30 and into a second subgroup, which in FIG. 8 is placed at the right of the longitudinal slots 30 . All longitudinal slots 130 of this second sub-group placed at the left of the longitudinal slots 40 [sic: 30] are arranged with an angular offset in reference to the center axis X diagonally towards the left and the longitudinal slots 130 , which are arranged at the right of the longitudinal slots 30 , show an offset towards the center axis X, which points diagonally towards the right. In reference to a virtual level, which is positioned precisely in the center of the sealing inner sleeve 10 and orthogonal to the center axis X, a symmetric arrangement of the longitudinal slot 140 develops here of both subgroups. When once more considering a parallel P on the circumferential surface of the sealing inner sleeve 10 , which extends parallel to the center axis X, it is discernible that this parallel P intersects four longitudinal slots 130 at the left of the longitudinal slots 30 as well as four longitudinal slots 130 at the right of the longitudinal slots 30 of the first group.
[0067] FIG. 9 shows an enlarged detail of the longitudinal slots 130 and the corresponding longitudinal webs 140 of the second group of FIG. 8 .
LIST OF REFERENCE NUMBERS
[0000]
10 Sealing inner sleeve
12 Band
14 End section
15 End section
16 Intermediate section
20 Locking device
21 Toothed rod
23 Stop
30 Longitudinal slot of the first group
31 End section
32 End section
33 Middle section
40 Longitudinal web of the first group
41 End section
42 End section
43 Middle section
50 Pipeline
130 Longitudinal slot of the second group
140 Longitudinal web of the second group
A Section
B 1 Minimum width of 30
B 2 Maximum width of 30
C 1 Maximum width of 40
C 2 Minimum width of 40
D Diameter
X Center axis
α Angular offset of the longitudinal slots of the first group
β Angular offset of the longitudinal slots of the second group
Z Total length
P Parallel
[0098] The references recited herein are incorporated herein in their entirety, particularly as they relate to teaching the level of ordinary skill in this art and for any disclosure necessary for the commoner understanding of the subject matter of the claimed invention. It will be clear to a person of ordinary skill in the art that the above embodiments may be altered or that insubstantial changes may be made without departing from the scope of the invention. Accordingly, the scope of the invention is determined by the scope of the following claims and their equitable equivalents. | The invention is a sealing inner sleeve for insertion into pipes in order to seal leaks therein. Said sealing inner sleeve has a locking device allowing an increase in the diameter of the sealing inner sleeve, but blocking same in the opposite direction, the sealing inner sleeve having two end sections and an intermediate section connecting said end sections to form a contiguous component. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation application of co-pending U.S. application Ser. No. 10/841,314 filed May 7, 2004 and entitled “Expandable Underreamer/Stabilizer”, which is a divisional application of U.S. Patent No. 6 , 732 , 817 issued May 11 , 2004 and entitled “Expandable Underreamer/Stabilizer”, both hereby incorporated herein by reference for all purposes.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not applicable.
FIELD OF THE INVENTION
[0004] The present disclosure relates generally to underreamers for enlarging a borehole below a restriction to result in a borehole that is larger than the restriction. The present disclosure also relates generally to stabilizers for stabilizing a drilling assembly within an underreamed portion of borehole. More particularly, the present disclosure relates to a selectively actuatable, expandable downhole tool that may function as an underreamer, or as a stabilizer, or as a combination thereof.
BACKGROUND
[0005] In the drilling of oil and gas wells, concentric casing strings are installed and cemented in the borehole as drilling progresses to increasing depths. Each new casing string is supported within the previously installed casing string, thereby limiting the annular area available for the cementing operation. Further, as successively smaller diameter casing strings are suspended, the flow area for the production of oil and gas is reduced. Therefore, to increase the annular space for the cementing operation, and to increase the production flow area, it is often desirable to enlarge the borehole below the terminal end of the previously cased borehole. By enlarging the borehole, a larger annular area is provided for subsequently installing and cementing a larger casing string than would have been possible otherwise. Accordingly, by enlarging the borehole below the previously cased borehole, the bottom of the formation can be reached with comparatively larger diameter casing, thereby providing more flow area for the production of oil and gas.
[0006] Various methods have been devised for passing a drilling assembly through an existing cased borehole and enlarging the borehole below the casing. One such method is the use of an underreamer, which has basically two operative states—a closed or collapsed state, where the diameter of the tool is sufficiently small to allow the tool to pass through the existing cased borehole, and an open or partly expanded state, where one or more arms with cutters on the ends thereof extend from the body of the tool. In this latter position, the underreamer enlarges the borehole diameter as the tool is rotated and lowered in the borehole.
[0007] A “drilling type” underreamer is typically used in conjunction with a conventional pilot drill bit positioned below or downstream of the underreamer. The pilot bit can drill the borehole at the same time as the underreamer enlarges the borehole formed by the bit. Underreamers of this type usually have hinged arms with roller cone cutters attached thereto. Most of the prior art underreamers utilize swing out cutter arms that are pivoted at an end opposite the cutting end of the cutting arms, and the cutter arms are actuated by mechanical or hydraulic forces acting on the arms to extend or retract them. Typical examples of these types of underreamers are found in U.S. Pat. Nos. 3,224,507; 3,425,500 and 4,055,226. In some designs, these pivoted arms tend to break during the drilling operation and must be removed or “fished” out of the borehole before the drilling operation can continue. The traditional underreamer tool typically has rotary cutter pocket recesses formed in the body for storing the retracted arms and roller cone cutters when the tool is in a closed state. The pocket recesses form large cavities in the underreamer body, which requires the removal of the structural metal forming the body, thereby compromising the strength and the hydraulic capacity of the underreamer. Accordingly, these prior art underreamers may not be capable of underreaming harder rock formations, or may have unacceptably slow rates of penetration, and they are not optimized for the high fluid flow rates required. The pocket recesses also tend to fill with debris from the drilling operation, which hinders collapsing of the arms. If the arms do not fully collapse, the drill string may easily hang up in the borehole when an attempt is made to remove the string from the borehole.
[0008] Conventional underreamers have several disadvantages, including cutting structures that are typically formed of sections of drill bits rather than being specifically designed for the underreaming function. Therefore, the cutting structures of most underreamers do not reliably underream the borehole to the desired diameter. A further disadvantage is that adjusting the expanded diameter of a conventional underreamer requires replacement of the cutting arms with larger or smaller arms, or replacement of other components of the underreamer tool. It may even be necessary to replace the underreamer altogether with one that provides a different expanded diameter. Another disadvantage is that many underreamers are designed to automatically expand when drilling fluid is pumped through the drill string, and no indication is provided at the surface that the underreamer is in the fully-expanded position. In some applications, it may be desirable for the operator to control when the underreamer expands.
[0009] Accordingly, it would be advantageous to provide an underreamer that is stronger than prior art underreamers, with a hydraulic capacity that is optimized for the high flowrate drilling environment. It would further be advantageous for such an underreamer to include several design features, namely cutting structures designed for the underreaming function, mechanisms for adjustment of the expanded diameter without requiring component changes, and the ability to provide indication at the surface when the underreamer is in the fully-expanded position. Moreover, in the presence of hydraulic pressure in the drill string, it would be advantageous to provide an underreamer that is selectively expandable.
[0010] Another method for enlarging a borehole below a previously cased borehole section includes using a winged reamer behind a conventional drill bit. In such an assembly, a conventional pilot drill bit is disposed at the lowermost end of the drilling assembly with a winged reamer disposed at some distance behind the drill bit. The winged reamer generally comprises a tubular body with one or more longitudinally extending “wings” or blades projecting radially outwardly from the tubular body. Once the winged reamer has passed through any cased portions of the wellbore, the pilot bit rotates about the centerline of the drilling axis to drill a lower borehole on center in the desired trajectory of the well path, while the eccentric winged reamer follows the pilot bit and engages the formation to enlarge the pilot borehole to the desired diameter.
[0011] Yet another method for enlarging a borehole below a previously cased borehole section includes using a bi-center bit, which is a one-piece drilling structure that provides a combination underreamer and pilot bit. The pilot bit is disposed on the lowermost end of the drilling assembly, and the eccentric underreamer bit is disposed slightly above the pilot bit. Once the bi-center bit has passed through any cased portions of the wellbore, the pilot bit rotates about the centerline of the drilling axis and drills a pilot borehole on center in the desired trajectory of the well path, while the eccentric underreamer bit follows the pilot bit and engages the formation to enlarge the pilot borehole to the desired diameter. The diameter of the pilot bit is made as large as possible for stability while still being capable of passing through the cased borehole. Examples of bi-center bits may be found in U.S. Pat. Nos. 6,039,131 and 6,269,893.
[0012] As described above, winged reamers and bi-center bits each include underreamer portions that are eccentric. A number of disadvantages are associated with this design. First, before drilling can continue, cement and float equipment at the bottom of the lowermost casing string must be drilled out. However, the pass-through diameter of the drilling assembly at the eccentric underreamer portion barely fits within the lowermost casing string. Therefore, off-center drilling is required to drill out the cement and float equipment to ensure that the eccentric underreamer portions do not damage the casing. Accordingly, it is desirable to provide an underreamer that collapses while the drilling assembly is in the casing and that expands to underream the previously drilled borehole to the desired diameter below the casing.
[0013] Further, due to directional tendency problems, these eccentric underreamer portions have difficulty reliably underreaming the borehole to the desired diameter. With respect to a bi-center bit, the eccentric underreamer bit tends to cause the pilot bit to wobble and undesirably deviate off center, thereby pushing the pilot bit away from the preferred trajectory of drilling the well path. A similar problem is experienced with respect to winged reamers, which only underream the borehole to the desired diameter if the pilot bit remains centralized in the borehole during drilling. Accordingly, it is desirable to provide an underreamer that remains concentrically disposed in the borehole while underreaming the previously drilled borehole to the desired diameter.
[0014] In drilling operations, it is conventional to employ a tool known as a “stabilizer.” In standard boreholes, traditional stabilizers are located in the drilling assembly behind the drill bit for controlling the trajectory of the drill bit as drilling progresses. Traditional stabilizers control drilling in a desired direction, whether the direction is along a straight borehole or a deviated borehole.
[0015] In a conventional rotary drilling assembly, a drill bit may be mounted onto a lower stabilizer, which is disposed approximately 5 feet above the bit. Typically the lower stabilizer is a fixed blade stabilizer that includes a plurality of concentric blades extending radially outwardly and spaced azimuthally around the circumference of the stabilizer housing. The outer edges of the blades are adapted to contact the wall of the existing cased borehole, thereby defining the maximum stabilizer diameter that will pass through the casing. A plurality of drill collars extends between the lower stabilizer and other stabilizers in the drilling assembly. An upper stabilizer is typically positioned in the drill string approximately 30-60 feet above the lower stabilizer. There could also be additional stabilizers above the upper stabilizer. The upper stabilizer may be either a fixed blade stabilizer or, more recently, an adjustable blade stabilizer that allows the blades to be collapsed into the housing as the drilling assembly passes through the casing and then expanded in the borehole below. One type of adjustable concentric stabilizer is manufactured by Andergauge U.S.A., Inc., Spring, Tex. and is described in U.S. Pat. No. 4,848,490. Another type of adjustable concentric stabilizer is manufactured by Halliburton, Houston, Texas and is described in U.S. Pat. Nos. 5,318,137; 5,318,138; and 5,332,048.
[0016] In operation, if only the lower stabilizer was provided, a “fulcrum” type assembly would be present because the lower stabilizer acts as a fulcrum or pivot point for the bit. Namely, as drilling progresses in a deviated borehole, for example, the weight of the drill collars behind the lower stabilizer forces the stabilizer to push against the lower side of the borehole, thereby creating a fulcrum or pivot point for the drill bit. Accordingly, the drill bit tends to be lifted upwardly at an angle, i.e. build angle. Therefore, a second stabilizer is provided to offset the fulcrum effect. Namely, as the drill bit builds angle due to the fulcrum effect created by the lower stabilizer, the upper stabilizer engages the lower side of the borehole, thereby causing the longitudinal axis of the bit to pivot downwardly so as to drop angle. A radial change of the blades of the upper stabilizer can control the pivoting of the bit on the lower stabilizer, thereby providing a two-dimensional, gravity based steerable system to control the build or drop angle of the drilled borehole as desired.
[0017] When an underreamer or a winged reamer tool is operating behind a conventional bit to underream the borehole, that tool provides the same fulcrum effect to the bit as the lower stabilizer in a standard borehole. Similarly, when underreaming a borehole with a bi-center bit, the eccentric underreamer bit provides the same fulcrum effect as the lower stabilizer in a standard borehole. Accordingly, in a drilling assembly employing an underreamer, winged reamer, or a bi-center bit, a lower stabilizer is not typically provided. However, to offset the fulcrum effect imparted by to the drill bit, it would be advantageous to provide an upper stabilizer capable of controlling the inclination of the drilling assembly in the underreamed section of borehole.
[0018] In particular, it would be advantageous to provide an upper stabilizer that engages the wall of the underreamed borehole to keep the centerline of the pilot bit centered within the borehole. When utilized with an eccentric underreamer that tends to force the pilot bit off center, the stabilizer blades would preferably engage the opposite side of the expanded borehole to counter that force and keep the pilot bit on center.
SUMMARY OF THE INVENTION
[0019] In various embodiments, a downhole expandable tool may be used as an underreamer to enlarge the diameter of a borehole below a restriction, or may be used as a stabilizer to control the directional tendencies of a drilling assembly in an underreamed borehole.
[0020] In one aspect, the present disclosure relates to an expandable downhole tool for use within a wellbore comprising a tubular body having an axial flowbore extending therethrough, at least one moveable arm, and a selectively actuatable sleeve that prevents or allows the at least one moveable arm to translate between a collapsed position and an expanded position. In various embodiments, the tool further comprises, a structure for adjusting the expanded position, at least one nozzle that translates with the at least one moveable arm, a spring to bias the at least one moveable arm to the collapsed position, at least one axial recess for storing the at least one moveable arm in the collapsed position, or a piston that translates the at least one moveable arm from the collapsed position to the expanded position. In an embodiment, the at least one moveable arm comprises a plurality of moveable arms spaced apart circumferentially around the tool body.
[0021] The at least one moveable arm may engage the wellbore in the expanded position, and in various embodiments, the at least one moveable arm may include at least one set of cutting structures for underreaming the wellbore in the expanded position, or at least one wear structure for stabilizing the drilling assembly within the wellbore. In various embodiments, the at least one moveable arm may provide back reaming capability or gauge protection capability. The at least one moveable arm may also translate axially and radially.
[0022] In an embodiment, the sleeve is biased to a first position that prevents fluid communication between a chamber and the flowbore, and the at least one moveable arm may be prevented from translating between the collapsed position and the expanded position when the sleeve is biased to the first position. The sleeve may be selectively actuatable to a second position that allows fluid communication between the chamber and the flowbore, and the at least one moveable arm may be translatable between the collapsed position and the expanded position when the sleeve is in the second position. In an embodiment, the tool further includes an actuator for selectively actuating the sleeve.
[0023] The body may comprise a plurality of angled channels, and in an embodiment, the at least one moveable arm comprises a plurality of extensions corresponding to and engaging the plurality of angled channels. The tool may further comprise at least one borehole engaging pad comprising wear structures.
[0024] In another aspect, the present disclosure relates to a method of expanding a downhole tool within a wellbore comprising disposing the downhole tool comprising at least one moveable arm within the wellbore, biasing the at least one moveable arm to a collapsed position corresponding to an initial diameter of the downhole tool, flowing a fluid through an axial flowbore extending through the downhole tool while preventing the fluid from communicating with a different flowpath of the downhole tool, allowing the fluid to communicate with the different flowpath by introducing an actuator into the wellbore, and causing the at least one moveable arm to translate to an expanded position corresponding to an expanded diameter of the downhole tool. In various embodiments, the method further comprises underreaming the wellbore in the expanded position, or stabilizing a drilling assembly connected to the downhole tool in the expanded position. The different flowpath may comprise a chamber in communication with a piston engaging the at least one moveable arm; and translating the at least one moveable arm to the expanded position may comprise translating the piston when the fluid communicates with the chamber. In an embodiment, the method further comprises adjusting the expanded diameter.
[0025] In yet another aspect, the present disclosure relates to an expandable downhole tool for use within a wellbore comprising a tubular body, and at least one moveable arm, wherein the expandable downhole tool is selectively actuatable to allow or prevent the at least one moveable arm to translate between a collapsed position and an expanded position in response to a fluid flowing through the tubular body.
[0026] Thus, the present invention comprises a combination of features and advantages that enable it to overcome various problems of prior devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] For a more detailed description of the preferred embodiment of the present invention, reference will now be made to the accompanying drawings, wherein:
[0028] FIG. 1 is a schematic, cross-sectional view of an exemplary drilling assembly that employs one embodiment of the invention and that includes a conventional drill bit drilling a borehole within a formation, an underreamer enlarging the borehole above the bit, and a stabilizer above the underreamer controlling the directional tendencies of the drilling assembly in the underreamed borehole;
[0029] FIG. 2 is a schematic, cross-sectional view of another exemplary drilling assembly that employs one embodiment of the invention and that includes a conventional drill bit drilling a borehole within a formation, a winged reamer enlarging the borehole above the bit, and a stabilizer above the winged reamer controlling the directional tendencies of the drilling assembly in the underreamed borehole;
[0030] FIG. 3 is a schematic, cross-sectional view of still another exemplary drilling assembly that employs one embodiment of the invention and that includes a bi-center bit drilling and enlarging a borehole within a formation, and a stabilizer above the bi-center bit controlling the directional tendencies of the drilling assembly in the underreamed borehole;
[0031] FIG. 4 is a cross-sectional elevation view of one embodiment of the expandable tool of the present invention, showing the moveable arms in the collapsed position;
[0032] FIG. 5 is a cross-sectional elevation view of the expandable tool of FIG. 4 , showing the moveable arms in the expanded position;
[0033] FIG. 6 is a perspective view of a “blank” arm for the expandable tool of FIG. 4 ;
[0034] FIG. 7 is a top view of an exemplary arm for the expandable tool of FIG. 4 including a wear pad and cutting structures for back reaming and underreaming;
[0035] FIG. 8 is a side elevation view of the arm of FIG. 7 ;
[0036] FIG. 9 is a perspective view of the arm of FIG. 7 ;
[0037] FIG. 10 is a perspective view of the drive ring of the expandable tool of FIG. 4 ;
[0038] FIG. 11 is a cross-sectional elevation view of an alternative embodiment of the expandable tool of the present invention, showing the moveable arms in the collapsed position; and
[0039] FIG. 12 is a cross-sectional elevation view of the alternative embodiment of FIG. 11 , showing the moveable arms in the expanded position.
NOTATION AND NOMENCLATURE
[0040] Certain terms are used throughout the following description and claims to refer to particular assembly components. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”.
DETAILED DESCRIPTION
[0041] The present invention relates to methods and apparatus for underreaming to enlarge a borehole below a restriction, such as casing. Alternatively, the present invention relates to methods and apparatus for stabilizing a drilling assembly and thereby controlling the directional tendencies of the drilling assembly within an enlarged borehole. The present invention is susceptible to embodiments of different forms. There are shown in the drawings, and herein will be described in detail, specific embodiments of the present invention with the understanding that the disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that illustrated and described herein.
[0042] In particular, various embodiments of the present invention provide a number of different constructions and methods of operation. Each of the various embodiments of the present invention may be used to enlarge a borehole, or to provide stabilization in a previously enlarged borehole, or in a borehole that is simultaneously being enlarged. The preferred embodiments of the expandable tool of the present invention may be utilized as an underreamer, or as a stabilizer behind a bi-center bit, or as a stabilizer behind a winged reamer or underreamer following a conventional bit. The embodiments of the present invention also provide a plurality of methods for use in a drilling assembly. It is to be fully recognized that the different teachings of the embodiments disclosed herein may be employed separately or in any suitable combination to produce desired results.
[0043] It should be appreciated that the expandable tool described with respect to the Figures that follow may be used in many different drilling assemblies. The following exemplary systems provide only some of the representative assemblies within which the present invention may be used, but these should not be considered the only assemblies. In particular, the preferred embodiments of the expandable tool of the present invention may be used in any assembly requiring an expandable underreamer and/or stabilizer for use in controlling the directional tendencies of a drilling assembly in an expanded borehole.
[0044] FIGS. 1-3 show various exemplary drilling assemblies within which the preferred embodiments of the present invention may be utilized. Referring initially to FIG. 1 , a section of a drilling assembly generally designated as 100 is shown drilling into the bottom of a formation 10 with a conventional drill bit 110 followed by an underreamer 120 . Separated from the underreamer 120 by one or more drill collars 130 is a stabilizer 150 that controls the directional tendencies of the drilling assembly 100 in the underreamed borehole 25 . This section of the drilling assembly 100 is shown at the bottom of formation 10 drilling a borehole 20 with the conventional drill bit 110 , while the underreamer cutting arms 125 are simultaneously opening a larger diameter borehole 25 above. The drilling assembly 100 is operating below any cased portions of the well.
[0045] As described previously, the underreamer 120 tends to provide a fulcrum or pivot effect to the drill bit 110 , thereby requiring a stabilizer 150 to offset this effect. In the preferred embodiment of the drilling assembly 100 , various embodiments of the expandable tool of the present invention are provided in the positions of both the underreamer 120 and the stabilizer 150 . In the most preferred embodiment, the stabilizer 150 would also preferably include cutting structures to ensure that the larger borehole 25 is enlarged to the proper diameter. However, any conventional underreamer may alternatively be utilized with one embodiment of the present invention provided in the position of stabilizer 150 in the drilling assembly 100 . Further, one embodiment of the present invention may be utilized in the position of underreamer 120 , and a conventional stabilizer may be utilized in the position of stabilizer 150 .
[0046] Referring now to FIG. 2 , where like numerals represent like components, a drilling assembly 200 is shown disposed within formation 10 , below any cased sections of the well. The drilling assembly 200 is drilling a borehole 20 utilizing a conventional drill bit 110 followed by a winged reamer 220 . The winged reamer 220 may be separated from the drill bit 110 by one or more drill collars 130 , but preferably the winged reamer 220 is connected directly above the drill bit 110 . Upstream of the winged reamer 220 , separated by one or more drill collars 130 , is a stabilizer 150 that controls the directional tendencies of the drilling assembly 200 in the underreamed borehole 25 . The drill bit 110 is shown at the bottom of the formation 10 drilling a borehole 20 , while the wing component 225 of the winged reamer 220 is simultaneously opening a larger diameter borehole 25 above. In the preferred assembly 200 , a preferred embodiment of the present invention would be located in the position of stabilizer 150 . In a most preferred assembly 200 , the stabilizer 150 would also include cutting structures to ensure that the larger borehole 25 is enlarged to the proper diameter.
[0047] Referring to FIG. 3 , where like numerals represent like components, again a drilling assembly 300 is shown disposed within formation 10 , below any cased sections of the well. The drilling assembly 300 utilizes a bi-center bit 320 that includes a pilot bit 310 and an eccentric underreamer bit 325 . As the pilot bit 310 drills the borehole 20 , the eccentric underreamer bit 325 opens a larger diameter borehole 25 above. The bi-center bit 320 is separated by one or more drill collars 130 from a stabilizer 150 designed to control the directional tendencies of the bi-center bit 320 in the underreamed borehole 25 . Again, the function of the stabilizer 150 is to offset the fulcrum or pivot effect created by the eccentric underreamer bit 325 to ensure that the pilot bit 310 stays centered as it drills the borehole 20 . In the preferred embodiment of the drilling assembly 300 , one embodiment of the expandable tool of the present invention would be located in the position of stabilizer 150 . In a most preferred assembly 300 , the stabilizer 150 would also include cutting structures to ensure that the larger borehole 25 is enlarged to the proper diameter.
[0048] Referring now to FIGS. 4 and 5 , one embodiment of the expandable tool of the present invention, generally designated as 500 , is shown in a collapsed position in FIG. 4 and in an expanded position in FIG. 5 . The expandable tool 500 comprises a generally cylindrical tool body 510 with a flowbore 508 extending therethrough. The tool body 510 includes upper 514 and lower 512 connection portions for connecting the tool 500 into a drilling assembly. In approximately the axial center of the tool body 510 , one or more pocket recesses 516 are formed in the body 510 and spaced apart azimuthally around the circumference of the body 510 . The one or more recesses 516 accommodate the axial movement of several components of the tool 500 that move up or down within the pocket recesses 516 , including one or more moveable, non-pivotable tool arms 520 . Each recess 516 stores one moveable arm 520 in the collapsed position. The preferred embodiment of the expandable tool includes three moveable arms 520 disposed within three pocket recesses 516 . In the discussion that follows, the one or more recesses 516 and the one or more arms 520 may be referred to in the plural form, i.e. recesses 516 and arms 520 . Nevertheless, it should be appreciated that the scope of the present invention also comprises one recess 516 and one arm 520 .
[0049] The recesses 516 further include angled channels 518 that provide a drive mechanism for the moveable tool arms 520 to move axially upwardly and radially outwardly into the expanded position of FIG. 5 . A biasing spring 540 is preferably including to bias the arms 520 to the collapsed position of FIG. 4 . The biasing spring 540 is disposed within a spring cavity 545 and covered by a spring retainer 550 . Retainer 550 is locked in position by an upper cap 555 . A stop ring 544 is provided at the lower end of spring 540 to keep the spring 540 in position.
[0050] Below the moveable arms 520 , a drive ring 570 is provided that includes one or more nozzles 575 . An actuating piston 530 that forms a piston cavity 535 , engages the drive ring 570 . A drive ring block 572 connects the piston 530 to the drive ring 570 via bolt 574 . The piston 530 is adapted to move axially in the pocket recesses 516 . A lower cap 580 provides a lower stop for the axial movement of the piston 530 . An inner mandrel 560 is the innermost component within the tool 500 , and it slidingly engages a lower retainer 590 at 592 . The lower retainer 590 includes ports 595 that allow drilling fluid to flow from the flowbore 508 into the piston chamber 535 to actuate the piston 530 .
[0051] A threaded connection is provided at 556 between the upper cap 555 and the inner mandrel 560 and at 558 between the upper cap 555 and body 510 . The upper cap 555 sealingly engages the body 510 at 505 , and sealingly engages the inner mandrel 560 at 562 and 564 . A wrench slot 554 is provided between the upper cap 555 and the spring retainer 550 , which provides room for a wrench to be inserted to adjust the position of the spring retainer 550 in the body 510 . Spring retainer 550 connects at 551 via threads to the body 510 . Towards the lower end of the spring retainer 550 , a bore 552 is provided through which a bar can be placed to prevent rotation of the spring retainer 550 during assembly. For safety purposes, a spring cover 542 is bolted at 546 to the stop ring 544 . The spring cover 542 prevents personnel from incurring injury during assembly and testing of the tool 500 .
[0052] The moveable arms 520 include pads 522 , 524 , and 526 with structures 700 , 800 that engage the borehole when the arms 520 are expanded outwardly to the expanded position of the tool 500 shown in FIG. 5 . Below the arms 520 , the piston 530 sealingly engages the inner mandrel 560 at 566 , and sealingly engages the body 510 at 534 . The lower cap 580 is threadingly connected to the body and to the lower retainer 590 at 582 , 584 , respectively. A sealing engagement is also provided at 586 between the lower cap 580 and the body 510 . The lower cap 580 provides a stop for the piston 530 to control the collapsed diameter of the tool 500 .
[0053] Several components are provided for assembly rather than for functional purposes. For example, the drive ring 570 is coupled to the piston 530 , and then the drive ring block 572 is boltingly connected at 574 to prevent the drive ring 570 and the piston 530 from translating axially relative to one another. The drive ring block 572 , therefore, provides a locking connection between the drive ring 570 and the piston 530 .
[0054] FIG. 5 depicts the tool 500 with the moveable arms 520 in the maximum expanded position, extending radially outwardly from the body 510 . Once the tool 500 is in the borehole, it is only expandable to one position. Therefore, the tool 500 has two operational positions—namely a collapsed position as shown in FIG. 4 or an expanded position as shown in FIG. 5 . However, the spring retainer 550 , which is a threaded sleeve, can be adjusted at the surface to limit the full diameter expansion of arms 520 . The spring retainer 550 compresses the biasing spring 540 when the tool 500 is collapsed, and the position of the spring retainer 550 determines the amount of expansion of the arms 520 . The spring retainer 550 is adjusted by a wrench in the wrench slot 554 that rotates the spring retainer 550 axially downwardly or upwardly with respect to the body 510 at threads 551 . The upper cap 555 is also a threaded component that locks the spring retainer 550 once it has been positioned. Accordingly, one advantage of the present tool is the ability to adjust at the surface the expanded diameter of the tool 500 . Unlike conventional underreamer tools, this adjustment can be made without replacing any components of the tool 500 .
[0055] In the expanded position shown in FIG. 5 , the arms 520 will either underream the borehole or stabilize the drilling assembly, depending upon how the pads 522 , 524 and 526 are configured. In the configuration of FIGS. 5 , cutting structures 700 on pads 526 would underream the borehole. Wear buttons 800 on pads 522 and 524 would provide gauge protection as the underreaming progresses. Hydraulic force causes the arms 520 to expand outwardly to the position shown in FIG. 5 due to the differential pressure of the drilling fluid between the flowbore 508 and the annulus 22 .
[0056] The drilling fluid flows along path 605 , through ports 595 in the lower retainer 590 , along path 610 into the piston chamber 535 . The differential pressure between the fluid in the flowbore 508 and the fluid in the borehole annulus 22 surrounding tool 500 causes the piston 530 to move axially upwardly from the position shown in FIG. 4 to the position shown in FIG. 5 . A small amount of flow can move through the piston chamber 535 and through nozzles 575 to the annulus 22 as the tool 500 starts to expand. As the piston 530 moves axially upwardly in pocket recesses 516 , the piston 530 engages the drive ring 570 , thereby causing the drive ring 570 to move axially upwardly against the moveable arms 520 . The arms 520 will move axially upwardly in pocket recesses 516 and also radially outwardly as the arms 520 travel in channels 518 disposed in the body 510 . In the expanded position, the flow continues along paths 605 , 610 and out into the annulus 22 through nozzles 575 . Because the nozzles 575 are part of the drive ring 570 , they move axially with the arms 520 . Accordingly, these nozzles 575 are optimally positioned to continuously provide cleaning and cooling to the cutting structures 700 disposed on surface 526 as fluid exits to the annulus 22 along flow path 620 .
[0057] The underreamer tool 500 of the one embodiment of the present invention solves the problems experienced with bi-center bits and winged reamers because it is designed to remain concentrically disposed within the borehole. In particular, the tool 500 of the present invention preferably includes three extendable arms 520 spaced apart circumferentially at the same axial location on the tool 510 . In the preferred embodiment, the circumferential spacing would be 120° apart. This three arm design provides a full gauge underreaming tool 500 that remains centralized in the borehole at all times.
[0058] Another feature of the preferred embodiments of the present invention is the ability of the tool 500 to provide hydraulic indication at the surface, thereby informing the operator whether the tool is in the contracted position shown in FIG. 4 , or the expanded position shown in FIG. 5 . Namely, in the contracted position, the flow area within piston chamber 535 is smaller than the flow area within piston chamber 535 when the tool 500 is in the expanded position shown in FIG. 5 . Therefore, in the expanded position, the flow area in chamber 535 is larger, providing a greater flow area between the flowbore 508 and the wellbore annulus 22 . In response, pressure at the surface will decrease as compared to the pressure at the surface when the tool 500 is contracted. This decrease in pressure indicates that the tool 500 is expanded.
[0059] FIGS. 6-10 provide more detail regarding the moveable arms 520 and drive ring 570 of FIGS. 4 and 5 . FIG. 6 shows a “blank” arm 520 with no cutting structures or stabilizing structures attached to pads 522 , 524 , 526 . The arm 520 is shown in isometric view to depict a top surface 521 , a bottom surface 527 , a front surface 665 , a back surface 660 , and a side surface 528 . The top surface 521 and the bottom surface 527 are preferably angled, as described in more detail below. The arm 520 preferably includes two upper pads 522 , one middle pad 524 , and two lower pads 526 disposed on the front surface 665 of the arm 520 . The arm 520 also includes extensions 650 disposed along each side 528 of arm 520 . The extensions 650 preferably extend upwardly at an angle from the bottom 527 of the arm 520 towards pads 522 , 524 and 526 . The extensions 650 protrude outwardly from the arm 520 to fit within corresponding channels 518 in the pocket recess 516 of the tool body 510 , as shown in FIGS. 4 and 5 . The interconnection between the arm extensions 650 and the body channels 518 increases the surface area of contact between the moveable arms 520 and the tool body 510 , thereby providing a more robust expandable tool 500 as compared to prior art tools. The arm 520 depicted in FIG. 6 is a blank version of either an underreamer cutting arm or a stabilizer arm. By changing the structures disposed on pads 522 , 524 and 526 , the tool 500 is converted from an underreamer to a stabilizer or vice versa, or to a combination underreamer/stabilizer.
[0060] Referring now to FIGS. 7, 8 and 9 , an exemplary arm 520 is shown that includes two sets of cutting structures 700 , 710 . FIG. 7 depicts the arm 520 from a top perspective, FIG. 8 provides an elevational side view, and FIG. 9 shows an isometric perspective. The top surface 521 and the bottom surface 527 of the arm 520 are preferably angled in the same direction as best shown in FIG. 7 . These surfaces 521 , 527 are designed to prevent the arm 520 from vibrating when pads 522 , 524 and 526 engage the borehole. Namely, when pads 522 , 524 and 526 engage the borehole, the arms 520 are held in compression by the piston 530 . The angled top surface 521 and the angled bottom surface 527 bias the arms 520 to the trailing side of the pocket recesses 516 to minimize vibration.
[0061] In the top view of FIG. 7 , pads 522 comprise cutting structures 710 such that the arm 520 provides back reaming capabilities. Back reaming is pulling the tool 500 upwardly in the borehole while underreaming. Pad 524 is preferably covered with wear buttons 800 that provide a stabilizing and gauge protection function. Pads 526 comprise cutting structures 700 for underreaming. In the side view of FIG. 8 , the extensions 650 that fit within channels 518 of the body 510 are shown extending upwardly at an angle along the side 528 from the back surface 660 of the arm 520 towards pads 522 , 524 and 526 . FIG. 9 shows the same arm 520 in isometric view.
[0062] To change the arm 520 shown in FIGS. 7, 8 , and 9 from a back reaming and underreaming arm to simply an underreaming arm, the back reaming cutting structures 710 would be replaced with wear buttons, such as buttons 800 . This configuration would result in the underreaming arm 520 shown in FIGS. 4 and 5 . Modifying the tool 500 from an underreamer to a stabilizer simply requires providing stabilizing structures on all of the pads 522 , 524 and 526 . As a stabilizer, surfaces 522 , 524 , and 526 would be covered with a dense plurality of wear buttons 800 without any cutting structures. The preferred material for the wear buttons 800 is a tungsten carbide or diamond material, which provides good wear capabilities. In an alternative embodiment, the pads 522 , 524 , and 526 may be coated with a hardened material called TCI 300H hardfacing.
[0063] Accordingly, the pads 522 , 524 , 526 could comprise a variety of structures and configurations utilizing a variety of different materials. When the tool is used in an underreaming function, a variety of different cutting structures 700 could be provided on surfaces 526 , depending upon the formation characteristics. Preferably, the cutting structures 700 , 710 for underreaming and back reaming, respectively, are specially designed for the particular cutting function. More preferably, the cutting structures 700 , 710 comprise the cutting structures disclosed and claimed in co-pending U.S. patent application Ser. No. 09/924,961, filed Aug. 8, 2001, entitled “Advanced Expandable Reaming Tool,” assigned to Smith International, Inc., which is hereby incorporated herein by reference.
[0064] Referring now to FIG. 10 , additional advantages of the preferred embodiments of the present invention are provided by the one or more nozzles 575 disposed in the drive ring 570 . The underreamer/stabilizer of the preferred embodiments of the present invention preferably includes three moveable arms 520 spaced apart circumferentially at the same axial location along the tool body 510 . In the preferred embodiment, the three moveable arms 520 are spaced 120° circumferentially. This arrangement of the arms 520 is preferred to centralize the tool 500 in the borehole. The drive ring 570 is moveable with the arms 520 and preferably includes three extended portions 576 spaced 120° circumferentially with angled nozzles 575 therethrough that are designed to direct drilling fluid to the cutting structures 700 of the underreamer at surfaces 526 . The boreholes 578 in the extended portions 576 adjacent nozzles 575 accept bolts 574 to connect the drive ring 570 to the drive ring block 572 and piston 530 . An aperture 571 is disposed through the center of the drive ring 570 to enable a connection to the piston 530 . Because the drive ring 570 is connected to the piston 530 , it moves with the piston 530 to push the moveable arms 520 axially upwardly and outwardly along the channels 518 to the expanded position. Accordingly, because drive ring 570 moves with the arms 520 , the nozzles 575 continuously provide drilling fluid to the cutting structures 700 on the underreamer surfaces 526 . The nozzles 575 are optimally placed to move with and follow the cutting structures 700 and thereby assure that the cutters 700 are properly cleaned and cooled at all times.
[0065] FIGS. 11 and 12 depict a second embodiment of the present invention, generally designated as 900 , in the collapsed and expanded positions, respectively. Many components of tool 900 are the same as the components of embodiment 500 , and those components maintain the same reference numerals. There are, however, several differences. The inner mandrel 560 of the first embodiment tool 500 is replaced by a stinger assembly 910 , preferably comprising an upper inner mandrel 912 , a middle inner mandrel 914 , and a lower inner mandrel 916 . The lower inner mandrel 916 includes ports 920 that must align with ports 595 in the lower retainer 590 before fluid can enter piston chamber 535 to actuate the piston 530 . As shown in FIG. 11 , fluid flows through the flowbore 508 of tool 900 , along pathway 605 depicted by the arrows. Because the ports 920 of the lower inner mandrel 916 do not align with the ports 595 of the lower retainer 590 , the fluid continues flowing along path 605 , past ports 595 , down through the tool 900 .
[0066] The tool 900 is selectively actuated utilizing an actuator (not shown), which aligns the ports 920 with the ports 595 to enable the expandable tool to move from the contracted position shown in FIG. 11 to the expanded position shown in FIG. 12 . Below lower inner mandrel 916 , a bottom spring 930 is disposed within a bottom spring chamber 935 and held within the body 510 by a bottom spring retainer 950 . Bottom spring retainer 950 threadingly connects at 952 to the lower retainer 590 . The spring 930 biases the stinger assembly 910 upwardly such that stinger 910 must be forced downwardly by an actuator to overcome the force of bottom spring 930 . By moving the stinger 910 downwardly, the ports 920 disposed circumferentially around the bottom of lower inner mandrel 916 align with the ports 595 of lower retainer 590 that lead into piston chamber 535 .
[0067] FIG. 12 shows the tool 900 in an expanded position. In this position, drilling fluid flows through the flowbore 508 , along pathway 605 . However, because stinger 910 has been actuated downwardly against the force of bottom spring 930 by an actuator, the ports 920 in lower inner mandrel 916 now align with ports 595 in the lower retainer 590 . Therefore, when the drilling fluid proceeds downwardly along flow path 605 through the flowbore 508 to reach ports 920 , it will flow through ports 920 , 595 and into the piston chamber 535 as depicted by flow arrows 610 .
[0068] Due to the differential pressure between the flowbore 508 and the wellbore annulus 22 surrounding tool 900 , the fluid flowing along pathway 610 will actuate the piston 530 upwardly against the force of spring 540 . The piston 530 will push the drive ring 570 , which will push the arms 520 axially upwardly and outwardly as the extensions 650 on the arms 520 move along channels 518 in the body 510 . Once the fluid flows through the nozzles 575 in the drive ring 570 , it exits at an angle along pathway 620 to cool and clean the cutting structures 700 disposed on surfaces 526 that underream the borehole. Accordingly, the second embodiment 900 of FIGS. 11 and 12 is capable of being selectively actuated. Namely, by engaging the upper surface 975 of stinger 910 with an actuator, the tool 900 can be selectively actuated at the election of the operator to align the ports 920 and 595 . The preferred actuator is the flow switch described and claimed in U.S. Pat. No. 6,289,999 entitled “Fluid Flow Control Devices and Methods for Selective Actuation of Valves and Hydraulic Drilling Tools,” hereby incorporated herein by reference.
[0069] Referring again to FIGS. 11 and 12 , typically a gap is provided between the upper end 975 of the stinger 910 and the actuator when the tool is in the collapsed position. That gap length must be maintained to ensure that actuation occurs only when it is meant to occur. Accordingly, upper inner mandrel 912 may include an adjustment ring portion 918 , which is just a spacer ring that makes up any discrepancies in the area between the upper inner mandrel 912 and the middle inner mandrel 914 such that the appropriate gap dimension can be maintained.
[0070] As one of ordinary skill in the art will readily appreciate, any actuating mechanism can be utilized to selectively actuate the tool 900 of FIGS. 11 and 12 . However, the preferred flow switch provides the advantage of additional hydraulic indications to the surface, in addition to the pressure indications provided by the increased flow area in the piston chamber 535 when the tool 900 is in the expanded position of FIG. 12 . Namely, the preferred flow switch includes an uplink pulser capable of providing position and status information to the surface via mud pulse telemetry. Accordingly, the preferred embodiment comprises the tool 900 of FIGS. 11 and 12 , and more preferably comprises the tool 900 in combination with the referenced flow switch.
[0071] In operation, an expandable tool 500 or 900 is lowered through casing in the collapsed position shown in FIGS. 4 and 11 , respectively. The first embodiment of the tool 500 would then be expanded automatically when drilling fluid flows through flowbore 508 , and the second embodiment of the tool 900 would be expanded only after selectively actuating the tool 900 . Whether the selective actuation feature is present or not, the tools 500 , 900 expand due to differential pressure between the flow bore 508 and the wellbore annulus 22 acting on the piston 530 . That differential pressure may be in the range of 800 to 1,500 psi. Therefore, differential pressure working across the piston 530 will cause the one or more arms 520 of the tool to move from a collapsed to an expanded position against the force of the biasing spring 540 .
[0072] Before the drilling assembly is lowered into the borehole, the function of the present invention as either an underreamer or as a stabilizer would be determined. Referring again to FIG. 1 , one example would be to use either embodiment of the tool 500 , 900 in the position of underreamer 120 , and preferably to use the second embodiment of the tool 900 in the position of stabilizer 150 . As another example, referring to FIGS. 2 and 3 , if a winged reamer 220 or a bi-center bit 320 is used instead of an underreamer 120 , the second embodiment of the tool 900 would preferably be used in the position of stabilizer 150 . As an underreamer, the preferred embodiments of the present invention are capable of underreaming a borehole to a desired diameter. As a stabilizer, the preferred embodiments of the present invention provide directional control for the assembly 100 , 200 , 300 within the underreamed borehole 25 .
[0073] In summary, the various embodiments of the expandable tool of the present invention may be used as an underreamer to enlarge a borehole below a restriction to a larger diameter. Alternatively, the various embodiments of the expandable tool may be used to stabilize a drilling system in a previously underreamed borehole, or in a borehole that is being underreamed while drilling progresses. The various embodiments of the present invention solve the problems of the prior art and include other features and advantages. Namely, the embodiments of the present expandable tool are stronger and have a higher hydraulic capacity than prior art underreamers. The preferred embodiments of the tool also provide pressure indications at the surface regarding whether the tool is collapsed or expanded. The tool preferably includes a novel assembly for moving the arms to the expanded position. Yet another advantage of the preferred embodiments is that the tool can be used in conjunction with other conventional devices such as a winged reamer or a bi-center bit to ensure that they function properly. The preferred embodiments of the tool further include one or more optimally placed and moveable nozzles for cleaning and cooling the cutting structures. Finally, the preferred embodiments of the present invention allow for adjustable expanded diameters without component changes.
[0074] While preferred embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the system and apparatus are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims. | An expandable downhole tool comprises a tubular body having an axial flowbore extending therethrough, at least one moveable arm, and a selectively actuatable sleeve that prevents or allows the at least one moveable arm to translate between a collapsed position and an expanded position. A method of expanding a downhole tool comprises disposing the downhole tool comprising at least one moveable arm within the wellbore, biasing the at least one moveable arm to a collapsed position corresponding to an initial diameter of the downhole tool, flowing a fluid through an axial flowbore extending through the downhole tool while preventing the fluid from communicating with a different flowpath of the downhole tool, allowing the fluid to communicate with the different flowpath by introducing an actuator into the wellbore, and causing the at least one moveable arm to translate to an expanded position corresponding to an expanded diameter of the downhole tool. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in the manufacture of tantalum solid electrolyte capacitors and is concerned more particularly with the step of the oxidation of the anodes. It is necessary to recall here the principal steps of manufacture of tantalum capacitors as described in the U.S. Pat. No. 3,166,693 to Haring and Taylor.
The anode is essentially produced from tantalum powder of well defined grain size by pressing followed by sintering at temperatures depending upon the performances of the capacitor to be obtained, these temperatures being in the neighbourhood of 1800° C. By means of this metallurgical treatment, it is possible to obtain a porous anodic structure which is thereafter subjected to a surface anodic oxidation for the purpose of forming, over the whole of the surface of the anodic sponge, a layer of tantalum oxide which performs the function of the dielectric of the capacitor. The oxidized anodic structure is thereafter covered by a layer of manganese dioxide obtained by impregnating the porous structure with a manganese salt solution which is decomposable into dioxide by pyrolysis. The pyrolysis operation sometimes causes a deterioration in the oxide layer which must be subsequently reformed. In order to obtain a dioxide layer of sufficient thickness, it is also customary to proceed with a number of successive impregnations followed by pyrolyses and reformations. There then follows the formation of the cathode of the capacitor by deposition of one or more conductive layers upon the anodic structure thus obtained. The capacitor is finished by an encapsulating step.
BRIEF SUMMARY OF THE INVENTION
According to the present invention concerning the steps of the anodic oxidation of the anode, the anodic oxidation and more precisely the first anodic oxidation is carried out in two successive steps separated by a step in which the partially oxidized structures are cleaned in acid medium. A preferred variant of the invention is characterized by the following points:
THE FIRST OXIDATION (OR PRE-OXIDATION) AND THE SUCCEEDING ACID WASHING ARE CARRIED OUT ON THE ANODES IN BATCH;
THE FIRST OXIDATION IS SO CARRIED OUT THAT THE OXIDATION VOLTAGE AND THE OXIDATION CURRENT REACH A VALUE IN THE NEIGHBOURHOOD OF THEIR MAXIMUM VALUES;
THE SECOND OXIDATION IS CARRIED OUT AT A VOLTAGE IN THE NEIGHBOURHOOD OF THE VALUE OF THE MAXIMUM VOLTAGE REACHED IN THE COURSE OF THE FIRST OXIDATION;
A STEP FOR SORTING THE INDIVIDUAL ANODES IS CARRIED OUT BETWEEN THE ACID CLEANING AND THE SECOND OXIDATION.
This anodic oxidizing process carried out in two steps separated by a cleaning phase makes it possible to reduce considerably the leakage currents of the capacitors. Another advantage of the invention resides in a reduction of the leakage current variations as a function of temperature. It is difficult to explain the physical reasons for the improvement in performance which is brought about by the treatment according to the invention. However, it may be assumed that the cleaning in acid medium effects a levelling of the micro roughness present on the surface of the spongy anode. Now, it is known that the thickness of the oxide layer which is formed in the course of an anodic oxidizing operation decreases at protruding points. The levelling of the surface to be oxidized in the course of the oxidation would thus make it possible to obtain an oxide layer of more regular thickness over the whole of the anode. This interpretation is confirmed by the improvements brought about by the invention in the performances of the capacitor.
The two-step oxidation according to the present invention is advantageously utilized in production and does not involve any additional cost if, in accordance with the preferred embodiment, the pre-oxidation and the washing are carried out on the anodes in batch
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be readily understood from the following description and by reference to the accompanying figures which are given by way of non limiting illustration of the invention and in which:
FIGS. 1 and 2 are diagrams illustrating the operations for the production of the anodes of tantalum solid electrolyte capacitors according to the prior art and according to the invention, respectively,
FIG. 3 is a curve illustrating the variations of the oxidation current as a function of time,
FIG. 4 illustrates the leakage current values measured on small series of identical capacitors produced in accordance with the prior art (curve 3) and in accordance with the invention,
FIG. 5 is a curve illustrating the preferred oxidation current and voltage variations in the course of time,
FIG. 6 illustrates characteristics of capacitors produced by application of the invention (curve 5), and
FIGS. 7 and 8 are histograms of the production according to the invention (curve 5) and according to the prior art respectively.
DETAILED DESCRIPTION
FIG. 1 shows the various operating steps in the manufacture of capacitors according to the prior art. There are shown at 1, 2 and 3 respectively the operations of powder weighing and pelletizing and sintering of the anodes. These three operations are carried out on anodes in batch, that is to say, they do not necessitate any individual handling of the anodes by the operators. The sintering phase 3 is followed by an operation 4 in which the individual anodes are sorted so as to be mounted on a belt or any other support (operation 5) for introducing them into the anodic oxidation tanks. The anodes thus mounted are then oxidized (operation 6) and are thereafter impregnated (operation 7) with manganese salt converted into dioxide in the course of the pyrolysis (operation 8). As is well known, operations, 6, 7 and 8 must be repeated a number of times before the anode is ready to receive the conductive coating serving as the cathode. The manufacture is completed by an encapsulating operation.
FIG. 2 sets out the various steps of manufacture of a capacitor according to the present invention, the steps which are identical with steps of the prior art bear the same reference numeral as in FIG. 1. After the sintering 3, a batch of anodes issuing from the furnace is subjected to a pre-oxidizing operation 11 followed by washing in acid medium 12. It is only at this step that the anodes are manually sorted (operation 4) and mounted (operation 5) before being subjected to a second oxidation (operation 13). The impregnation and pyrolysis (stages 7 and 8 respectively) and the other subsequent manufacturing steps are identical with the corresponding steps in the process of manufacture of the prior art. Comparison of FIGS. 1 and 2 clearly shows that the present invention makes it possible to step back the sorting stage 4 in the operating procedure which is a considerable advantage from the industrial viewpoint. Since the sorting of the anodes takes place later, the overall manufacturing output can be improved.
Operation 11 in which the anodes are pre-oxidized in bulk is carried out by dipping the baskets or other receptacles containing the sintered batch into a standard anodic oxidizing bath. This is continued until a uniform colour is obtained on all the anodes. The electrical conductivity between the anodes contained in bulk in the receptacle is ensured by the contact of the anodes with the receptacle on the one hand and the contact between the anodes on the other hand.
The oxidizing conditions of steps 11 and 13 are identical to those which govern the single oxidation step 6 of the prior art. In other words, the electrolyte concentrations, the law of variation of the oxidation current and the temperature and time conditions are those used in the manufacturing procedure according to the prior art for a given type of capacitor. The rate at which the oxide layer grows is a well known phenomenon which is controlled by the oxidizing conditions. As is apparent from FIG. 3, the oxidizing stage 11 is interrupted when the thickness of oxide formed reaches, for example, one half of the total thickness, that is to say, when the voltage levels off after the corresponding duration.
The acid washing operation 12 is carried out by immersing the basket containing the anodes in bulk in the acid bath which is formed of equal volumes of sulphuric and nitric acids to which there are added a half volume of hydrofluoric acid and three volumes of water. The washing is relatively short and its duration does not exceed one minute. By way of example, the capacitors whose characteristics are given in FIG. 4 have undergone an acid cleaning of a duration in the neighbourhood of thirty seconds. After the acid cleaning, it is preferable to subject the anodes to rinsing in water, the bath being at least partially agitated by ultra-sound. The anodes are thereafter carefully washed, first in a slightly alkaline solution intended to neutralize the residual acid traces, and then in a neutral solution, preferably deionized water.
The batch of anodes is thereafter sorted for the purpose of mounting on bars of anodes which have been recognized as good, that is to say, not deformed or faulted in accordance with prior art mode of sorting. The anodes mounted on the bars are thereafter subjected (stage 5) to a further oxidation 13. The capacitors on their bars are therefore reintroduced into the oxidizing bath. As is shown by the curves of FIG. 3, the current applied to the electrolytic cell has the same maximum value as that reached at the end of phase 11. The level stage is maintained for the period necessary for producing an oxide layer of the desired thickness. As is shown by the chain-lined curve, the oxidation voltage does not return immediately on application of the current to the value reached at the end of stage 11. This means that the intermediate cleaning step 12 has in fact modified the oxide layer formed in the course of stage 11.
FIG. 4 illustrates the values of the leakage currents of a set of test capacitors to the left and of a set of capacitors whose anodes have been treated in accordance with the invention to the right, respectively. The leakage current measurements were made at 25° and 85° C. respectively. The capacitors of the two groups are absolutely identical. Since steps 1, 2 and 3 are common, the test capacitors undergo a single oxidation 4 while the capacitors according to the invention undergo oxidation in two steps separated by an acid cleaning (stages 11, 12 and 13). The anodes are then again submitted to the same production steps until the complete capacitors are obtained. It will be seen that the capacitors whose anodes are treated in accordance with the invention have much more closely grouped characteristics then capacitors produced in accordance with the prior art, the leakage currents at 25° C. of the capacitors according to the invention being grouped between 1 . 10 -1 and 3 . 10 -1 μA, while the leakage current range of the capacitors according to the prior art stretches from 1 . 10 -1 to 5 μA. The same grouping is to be found in the case of the leakage currents at 85° C. It will also be observed that the slope of the line joining the value of the leakage current at 25° C. to that of the leakage current at 85° C. is much less steep for the capacitors according to the invention than for the capacitors of the prior art. If the best capacitor is taken from each group, it will be seen that the current variation as a function of temperature in the case of the capacitors according to the invention is from 0.1 μA to 0.3 μA while in the case of the capacitor manufactured in accordance with the prior art the leakage current varies from 0.1 μA to 0.8 μA under the same conditions.
FIG. 5 illustrates as a function of time a preferred law of variation of the oxidation voltage and of the oxidation current in the course of operations 11 and 13. It will be seen that the pre-oxidation (stage 11) is commenced with the maximum value of the current (thick-lined curve), the voltage (chain-lined curve) increasing in proportion as the oxide is formed. Thereafter, the current is reached at constant voltage when the latter has reached the maximum value (±10%), taking into account the maximum current passing through the bath containing the anodes in bulk.
The acid cleaning 12 is carried out in a solution of which the bath consists of a mixture of sulphuric, nitric and hydrofluoric acids, as described in the foregoing. This treatment is continued for a period of about thirty seconds. It is followed by immersion of the basket in a solution of the same composition as the preceding one in a concentration of 1% of the latter. This treatment is continued for one minute in the presence of ultra-sound. As already specified, the batch of anodes is thereafter dipped into an ammoniacal neutralizing bath for one minute in the presence of ultra-sound. The anodes are then washed for four or five minutes in deionized water in the presence of ultra-sound and then dried at 60° C.
The anodes are then sorted and mounted on the oxidation bars.
The oxidation stage (13) commences with the maximum value of the current used in the course of operation 11. The voltage across the terminals of the bath containing anodes mounted on bars is in the neighbourhood of the voltage of the level run reached in the course of the pre-oxidizing stage (at ±10%). The bracket of the voltage values during operation 13 is represented in FIG. 5 by the horizontal double chain line. The absolute values of the voltage and current employed depend upon the type of capacitor produced and more particularly upon the rated voltage.
FIG. 6 comprises four graphic diagrams grouping the results of the measurement of the forward leakage current at 25° C. and 85° C. respectively for two groups of capacitors constructed by the operating procedure of FIG. 5 (case No. 1 and case No. 2) in the case of the left-hand diagrams and for two groups of test capacitors associated with each of the groups (controls Nos. 1 and 2) in the case of the right-hand diagrams. By "test capacitors" are meant capacitors constructed in accordance with the prior art. The steps common to the prior art and to the invention being the same for both groups. It is clearly apparent that the leakage current values of the test capacitors is higher than that of the capacitors produced in accordance with the invention. This difference in behaviour will become more clearly apparent on examination of FIGS. 7 and 8.
FIGS. 7 and 8 are histograms illustrating the distribution of the number of individual capacitors as a function of the forward leakage current for two different groups of capacitors shown in solid lines and in chain lines respectively. FIG. 7 corresponds to capacitors manufactured in accordance with the process shown in FIG. 5 and FIG. 8 to test elements associated with each group as defined in the foregoing. Comparison of these two diagrams makes it abundantly clear that the capacitors produced in accordance with the invention have lower leakage currents than the test capacitors. More than 50% of the test capacitors of one of the groups have leakage currents between 2 and 3 microamperes while no capacitor of either of the two groups produced in accordance with the invention has a leakage current above 2 microamperes. Most capacitors produced in accordance with the invention have leakage currents between 0.1 and 0.2 microampere while no test capacitor has a leakage current lower than 0.3 microampere in the case of one of the groups and 1 microampere in the case of the other. The capacitors whose curves are referred to in the foregoing are low-voltage capacitors whose charge is equal to 2000 microcoulombs for which the maximum leakage current is fixed at about 20 microamperes by the standard CCTU 02 12 B. | The anodization of sintered anodes for tantalum capacitors is carried out in two successive steps separated by a cleaning step in an acid bath. In a preferred variant of the process both the first anodization and the cleaning are performed on batches of anodes which are individually sorted and mounted on current carrying bars before the second anodization step. The direct leakage current of capacitors made from anodes anodized according to the invention is substantially lower than that of capacitors with prior art anodes. The capacitors are also less sensitive to temperature. | 8 |
FIELD OF THE INVENTION
The present invention concerns a process for the regulation of grain growth inhibitors distribution in the production of grain oriented electrical steel strips and, more precisely, concerns a process in which an optimised distribution of said inhibitors is obtained starting from the high temperature heating of the slabs for hot-rolling, avoiding any unevenness due to temperature differences in the slab at the exit from the furnace and highly favouring the subsequent transformation process down to a strip of desired thickness, in which the secondary recrystallization occurs.
STATE OF THE ART
Grain oriented electrical steels are typically produced at industrial level as strips having a thickness comprised between 0.18 and 0.50 mm characterised by magnetic properties depending on the product class, the best product having magnetic permeability values higher than 1.9 T and core losses lower than 1 W/kg. The high quality of the grain oriented silicon steel strips (essentially a Fe—Si alloy) depends on the ability to obtain a very sharp crystallographic texture, which in theory should correspond to the so called Goss texture, in which all the grains have its own {110} crystallographic plane parallel to the strip surface and its own <001> crystallographic axis parallel to the strip rolling direction. This dependance is mainly due to the fact that the <001> axis is the direction of easiest magnetic flux transmission in the body-centered cubic crystals of the Fe—Si alloy; however, in the actual product there always exist some disorientation between 001 axes of adjacent grains, the higher said misorientation the lower the magnetic permeability of the product and the higher the power loss in the electrical machines utilising said product.
In order to obtain an orientation of the steel grains as close as possible to the Goss texture requires a rather complex process, essentially based on the control of a metallurgical phenomenon called “secondary recrystallization”. During the occurence of said phenomenon, which takes place during the final part of the production process, after the annealing for primary recrystallization and before the final box-annealing, the few grains having an orientation close to the Goss one grow at the expenses of the other grains of the primary recrystallised product. To make this phenomenon occurr, non metallic impurities (second phases) are utilised, precipitated as fine and evenly distributed particles at the boundaries of the primary recrystallised grains. Such particles, called grain growth inhibitors, or in short inhibitors, are utilised to slow down the grain boundaries movement, to permit to the grains having an orientation close to the Goss one to acquire such a dimensional advantage that, once the second phases solubilization temperature is reached, they will rapidly grow at the expenses of the other grains.
The most utilised inhibitors are sulphides or selenides (of manganese and/or of copper, for instance) and nitrides in particular of aluminium or of aluminium and other metals, generically called aluminium nitrides; such nitrides allow to obtain the best quality.
The classic mechanism of grain growth inhibition utilises the precipitates formed during the steel solidification, essentially in continuous casting. Such precipitates, however, due to the relatively slow cooling temperature of the steel, are generated as coarse particles unevenly distributed into the metal matrix, and therefore are not able to efficiently inhibit the grain growth. They must, hence, be dissolved during the thermal treatment of the slabs before the hot-rolling, and then reprecipitated in the due form in one or more subsequent process steps. The uniformity of such heating treatment is an essential factor to obtain good results from the subsequent transformation process of the product.
The above is true both for such electrical steel strip production processes in which the precipitates actually able to regulate the secondary recrystallization the grain recrystallization are all present since the hot-rolled strip (for instance described in patents U.S. Pat. Nos. 1,956,559, US 4,225,366, EP 8,385. EP 17,830, EP 202,339, EP 219,181, EP 314,876), and for the processes in which such precipitates are formed, at least in part, after cold rolling or just before the secondary recrystallization (for instance, described in patents U.S. Pat. Nos. 4,225,366, US 4,473,416, 30 US 5,186,762, US 5,266,129, EP 339,474, EP 477,384, EP 391,335).
In the PCT Applications EP/97/04088, EP97/04005, EP97/04007, EP97/04009, EP97/040089, processes are described in which a certain level of inhibition is obtained in the hot-rolled product which, though not sufficient to control the secondary recrystallization, is important in controlling the grain boundaries mobility during the entire first part of the process (hot-rolled strip annealing, decarburization annealing). This definitely reduces the importance of a strict control of the annealing time/temperature parametres of the industrial processes (see PCT/EP/97/04009).
However, processes and plants up to now utilised for the slab heating, during which the coarse precipitates are redissolved (fully or in part, according to the production process), can not ensure a high temperature homogeneity within the slabs. This lack of homogeneity is greatly enhanced in the newest production processes in which the slab heating temperature is relatively low.
In fact, since the dissolution of precipitates is controlled by thermodynamic and kinetic laws exponentially depending on the temperature, it is clear that even temperature differences in the range of 50–1000° C. can result in widely different characteristics.
Moreover, the distribution of the elements necessary to the formation of inhibitors is rather non-homogeneous, also due to other factors (such as the phase transition, at the working temperatures, of some matrix zones from ferrite to austenite structure), thus causingan amplification of the undesirable effects of the low distribution uniformity and of the non-optimal dimensions of the precipitated inhibitors. Moreover other strictly technical factors contribute to render further complex the aspect of the uniformity of temperature in the slab coming out from the healing furnaces. In fact, during the heating process to the desired temperature, thermal gradients are created within the slabs, due to purely practical factors: the support zones of the slabs in the furnaces, both of the pushing and walking beam type, are strongly cooled, thus causing further temperature gradients in the slabs.
Such temperature gradients, particularly the ones due to the walking beams, do also cause mechanical resistance differences between different zones of the slabs, and related thickness variations in the rolled strips up to about a tenth of millimeter, which in turn cause microstructural variations into the final strips, to an extent up to 15% of the strip length.
Such problems are common to all the known electrical silicon steel strip production technologies and induce, particularly fo the high quality products, yield losses even of high level.
The problem remains still unsolved of the formation, during the heat treatment of the slabs before hot-rolling, of the desired quantity of precipitates useful for the inhibition of the grain growth (i.e. of the inhibitors) and the one of the even distribution of such precipitates throughout the whole steel mass, the lack of such conditions rendering more difficult to obtain a final product of high and constant quality.
DESCRIPTION OF THE INVENTION
The present invention aims to eliminate such drawbacks, proposing a treatment permitting to obtain a final product having excellent properties homogeneity, particularly in the case of production technologies for grain oriented electrical steel strips, utilising the strategy of: (i) reducing the slab heating temperatures with respect to conventional technologies, to fully or partially avoid the dissolution of coarse precipitates (second phases) obtained during casting, and (ii) creating after the hot-rolling step the necessary amount of inhibitors able to control the oriented secondary recrystallization.
According to present invention, in a process for the production of grain oriented electrical steel strips, in which a silicon steel is continuously cast, hot-rolled, cold-rolled to obtain a cold-rolled strip which is then subjected to a continuous annealing for primary recrystallization and if necessary for decarburization, and subsequently to a secondary recrystallization annealing at a higher temperature than said primary recrystallization one, the following operative steps are performed in sequence:
slab heating in a plurality of steps, the treating temperature during the last step, of unloading the furnace, being lower than at least one of the preceding treating temperatures; cold-rolling in one or more reduction steps, separated by intermediate annealings, in which in at least one of said steps a reduction higher than 75% is carried out; continuous primary recrystallization annealing of the cold-rolled strip, at a temperature comprised between 800 and 950° C.
In the slab heating, the temperature of the last treatment zones as well as the residence time of the slab into each of said zones are regulated so that a heat transfer is obtained between slab core and slab surface, such that the respective temperatures (of surface and core) equalise before the exit from the last treatment zone at a temperature lower than the maximum temperature reached in the furnace by the slab surface. This allows to carry out the dissolution and diffusion processes of the elements necessary to form the inhibitors during the treatment at higher temperature, while during the last treatment, after uniformation of slab surface and core temperatures, the previous dissolved elements are reprecipitated in form and distribution adequate to the grain growth control.
It is preferable that the slabs pass through the penultimate heat treatment zone in a time interval comprised between 20 and 40 minutes, and through the last zone in a time interval comprised between 15 and 40 minutes. The maximum heating temperature reached is preferably comprised between 1200 and 1400° C., and the temperature of the last treatment zone is preferably comprised between 1100 and 1300° C.
Preferably, the maximum slab heating temperature should be lower than the one for the formation of liquid slag on the slab surface.
Moreover, according to the present invention, between the slab heating zone at the maximum temperature and the last zone at a lower temperature, it is possible to carry out a slab thickness reduction, preferably comprised between 15 and 40%. This thickness reduction permits to homogenize the slab metal matrix as well as to improve the cooling speed control, and thus the slab thermal homogeneity. It must be noted that the above thickness reduction does not correspond to the so called “prerolling”, largely utilized in the hot-rolling of slabs heated to very high temperature; in fact, the pre-rolling is carried out before the slab reaches the maximum treatment temperature,while according to the present invention the thickness reduction is carried out during the slab cooling between the maximum treatment temperature and the lower one of extraction of the slab from the furnace.
If this thickness reduction technique is adopted, it is possible to work either discontinuously, utilising two different furnaces at different temperatures, or continuously utilising, for instance, a tunnel furnace having, before the last treatment zone at a lower temperature, an apparatus for intermediate rolling. This last solution is particularly apt to the treatment of slabs produced utilising thin-slab casting techniques.
The slabs, in which the precipitation of at least part of the grain growth inhibitors already occurred, are hot-rolled and the hot-rolled strips thus obtained are then annealed and cold-rolled to the final thickness; as already said, the cold rolling operation can be carried out in one or more steps, with intermediate annealing, at least one of the rolling steps being preferably carried out with a thickness reduction of at least 75%.
Still according to present invention, a decarburization treatment is carried out during the primary recrystallization annealing, with a heating time up to the primary recrystallization temperature comprised between 1 and 10 s.
In the case of the adoption of a slab heating temperature insufficient to the complete dissolution of the precipitates available, which will afterward form the grain growth inhibitors, such inhibitors will be preferably produced during one of the heat treatmens after cold-rolling and before the start of secondary recrystallization, by reaction between the strip and suitable liquid, solid or gaseous elements, specifically rising the nitrogen content of the strip. Preferably, the nitrogen content of the strip is rised during a continuous annealing of the strip having the final thickness by reaction with undissociated ammonia.
In this last case, it is advisable to strictly control the steel composition with reference to the initial content of the elements useful for the formation of nitrides, such as aluminium, titanium, vanadium, niobium and so on. In particular, the soluble aluminium content in the steel is comprised between 80 and 500 ppm, preferably between 250 and 350 ppm.
As far as nitrogen is concerned, it must be present in the slabs in relatively low concentrations, for example comprised between 50 and 100 ppm.
Once the cold-rolled strip is nitrided, to directly form nitride precipitates of type, amount and distribution apt to inhibit grain growth, the. strip itself undergoes high-temperature continuous annealing, during which annealing the secondary recrystallization is carried out, or at least started.
The equalizing effect of the slab temperature according to present invention is shown in the enclosed drawings, in which:
FIG. 1 represents a conventional schematic slab-heating diagram, in which the extraction temperature from the furnace is the maximum one reached;
FIG. 2 represents a schematic slab-heating diagram according to present invention;
FIG. 3 represents a diagram of the variations along the strip length (abscissa) of the strip thickness (ordinate) after hot-rolling, utilizing a conventional slab heating (each division of the ordinates corresponds to 0.01 mm);
FIG. 4 represents a diagram of the variations along the strip length (abscissa) of the strip thickness (ordinate) after hot-rolling, utilizing a slab heating according to the invention (each division of the ordinates corresponds to 0.01 mm).
In the known technology, as can be seen in FIG. 1 , the continuous temperature variation curve of the slab skin is, during the heating, always higher than the core temperature, shown by the dashed curve, such temperature difference still remaining in the last section of the furnace.
On the contrary, according to present invention ( FIG. 2 ) the slab skin temperature, shown with a continuous line, after reaching a maximum decreases thus approximating the core temperature, shown with a dashed line, and practically coinciding with it in the last section of the furnace.
It is thus possible to obtain a very uniform distribution of the inhibitors-forming elements and, consequently, an excellent distribution of the same inhibitors during the subsequent cooling. Said temperature uniformation concerns, at least partially, also the temperature differences in the slab skin due to the cooled support zones of the furnace; in FIG. 3 and 4 it can be seen that according to the present invention it is possible to reduce the thickness variations in the hot-rolled strip due to cold spots caused by said cooled slab-supporting zones.
The present invention will now be described in the following Examples, not intended to limit its scope and meaning.
EXAMPLE 1
A silicon steel melt from scrap, produced in an electric furnace and comprising at the casting station (weight %) Si 3.15%, C 0.035%, Mn 0.16%, S 0.006%, Al sol 0.030%, N 0.0080%, Cu 0.25% and impurities usual in steelmaking, was continuously cast in 18 t slabs. Eight slabs were selected and submitted, in couples, to experimental industrial hot-rolling programs characterised by different slab-heating cycles in a walking beam furnace. The four experimental cycles were carried out deciding the temperature set of the last two zones of the furnace as shown in Table 1. The transit speed of the slabs through the furnace was selected to guarantee a permanence into the penultimate (pre-equalizing) furnace zone of 35 minutes and into the last (equalizing) zone of 22 minutes.
TABLE 1
Pre-equalizing
Equalizing zone
zone T° C.
T° C.
CONDITION A
1200
1230
COMPARISON
CONDITION B
1150
1180
COMPARISON
CONDITION C
1330
1230
INVENTION
CONDITION D
1330
1180
INVENTION
The as heated slabs were sent via a roller table to a roughing mill in which, in 5 passages, a global thickness reduction of 79% was obtained, and the thus obtained bars were hot-rolled in 7 passages in a continuous finishing mill, down to the final thickness of 2.10 mm.
The so obtained hot-rolled strips were then single-stage (6 passes) cold-rolled at a mean thickness of 0.285 mm. Each cold-rolled strip was divided into two coils weigthing about 8 tons each. Four coils, one for each condition (Table 1), were then conditioned and treated in an experimental continuous decarburization and nitriding line. Each strip was treated with 3 different decarburization and primary recrystallization temperatures; in each case, at the end of this decarburization step the strips were continuously nitrided in a wet Hydrogen-Nitrogen mixture containing ammonia, at a temperature of 930° C., to rise the nitrogen content of the strip by 90–120 ppm. Samples of each strip were coated with MgO and then subjected to a simulation of the final box-annealing usual with those products, with a heating velocity up to 1200° C. of 20° C./h, soaking at 1200° C. for 20 h in dry hydrogen and then cooled in controlled conditions. In Table 2 the obtained magnetic induction values (in Tesla) at 800 A/m are reported.
TABLE 2
Decarb. Temp.
Decarb. Temp.
Decarb. Temp.
830° C.
850° C.
870° C.
CONDITION A
1.83 T
1.89 T
1.87 T
CONDITION B
1.89 T
1.89 T
1.75 T
CONDITION C
1.88 T
1.93 T
1.94 T
CONDITION D
1.92 T
1.94 T
1.89 T
EXAMPLE 2
The four coils remaining of the four different slab heating conditions of Example 1, were treated in an industrial continuous decarburization line at a temperature of 850° C. and continuously nitrided at 930° C., in the same conditions of the experimental line (Example 1) and then transformed down to end-product with industrial box annealing according to the same thermal cycle described in Example 1. The strips were then continuously thermal-flattened and coated with tensioning insulating coating, and then qualified. The mean values of the magnetic characteristics of the four strips are shown in Table 3.
TABLE 3
B800 (TESLA)
P17 (W/kg)
CONDITION A
1.90
1.04
CONDITION B
1.88
1.05
CONDITION C
1.94
0.95
CONDITION D
1.93
0.93
In which B800 is the magnetic induction value measured at 800 A/m, and P17 is the core losses value measured at 1.7 T.
EXAMPLE 3
A silicon steel melt was produced comprising (in weight %) Si 3.10%, C 0.028%, Mn 0.150%, S 0.010%, Al 0.0350%, N 0.007%, Cu 0.250%. This melt was solidified in 18 t slabs 240 mm thick, utilising an industrial continuous casting machine.
Said slabs were then hot-rolled after a heating treatment in a walking beam furnace during about 200 min and reaching a maximum temperature of 1340° C. followed by a transit in the last zone of the furnace, before hot-rolling, at a temperature of 1220° C. for 40 min.
Six of such slabs were then roughened at a thickness of 50 mm and sequence-rolled in a rolling mill to final thicknesses comprised between 3.0 and 1.8 mm. The strips thus produced were subjected to a continuous annealing at a maximum temperature of 1100° C. and cold-rolled to a final thickness of 0.23 mm. In Table 4 the different thicknesses obtained as well as relevant reduction ratio are shown. All the strips were transformed into the end-product utilising the same industrial production cycle (specifically, a decarburization temperature of 865° C. was adopted), continuous annealing nitrided for a nitrogen addition of between 100 and 130 ppm, and then box annealed, utilizing a heating speed up to 1200° C. of 40° C./h. The magnetic characteristics obtained, also shown in Table 4, demonstrate a link between cold-reduction ratio and magnetic characteristics of end product. With the utilised conditions, best results are obtained with cold-rolling reduction comprised between 89% and 91.5%. Must be observed, however, that in the whole cold-reduction field explored, with single stage cold-rolling procedure, products are obtained having magnetic characteristics adequate for the different commercial classes of grain oriented electrical strips.
TABLE 4
Hot-rolled strip
Cold-rolled strip
B800
thickness (mm)
thickness (mm)
Deformation %
(T)
P17 (W/kg)
3
0.23
92.7
1.88
1.03
2.7
0.23
91.5
1.93
0.89
2.5
0.23
90.8
1.91
0.95
2.1
0.23
90.0
1.90
0.97
2.1
0.23
89.0
1.89
1.00
1.8
0.23
87.2
1.87
1.05
EXAMPLE 4
A steel melt containing (weight %) Si 3.180%, C 0.025%, Mn 0.150%, S 0.012%, Cu 0.150%, Al 0.0280%, N 0.008%, was cast in 18 t slabs 240 mm thick, in an industrial continuous casting plant.
Some of said slabs were then heated in a walking beam furnace for about 200 min at a maximum temperature of 1320° C., with a transit of the slabs in the furnace last zone at a temperature of 1150° C. for about 40 min, and then hot-rolled. The slabs were roughened at a thickness of 40 mm and then sequence hot-rolled in a rolling mill to strips having a constant thickness of 2.8 mm. Said strips were then continuous-annealed at a maximum temperature of 1000° C., cold-rolled at intermediate thicknesses comprised between 2.3 and 0.76 mm; all the strips were then continuous-annealed at 900° C. and again cold-rolled at the final thickness of 0.29 mm. Table 5 shows the thicknesses obtained and relevant cold-reduction ratios.
All the strips were then continuoulsy annealed for decarburization and nitriding, coated with an MgO-based annealing separator and box-annealed up to a maximum temperature of 1210° C. to form onto the strip surface a forsterite layer, develop the secondary recrystallization and eliminate S and N from the steel. The final magnetic characteristics reported in Table 5 confirm the dependance on the cold-reduction ratio shown in Example 3, and evidenciate the opportunity to adopt is a final cold-reduction ratio higher than 75%, in order to industrially obtain the commercially required magnetic characteristics.
TABLE 5
Strip
First cold-
Final
thickness (mm)
rolling
Final
cold-rolling
Hot-
First cold-
reduction
thickness
reduction
B800
P17
rolled
rolled
(%)
(mm)
(%)
(T)
(W/kg)
2.8
2.30
17.9
0.29
87.4
1.91
0.96
2.8
2.00
28.6
0.29
85.5
1.89
1.02
2.8
1.70
39.3
0.29
82.9
1.88
1.08
2.8
1.40
50.0
0.29
79.3
1.86
1.15
2.8
1.15
58.9
0.29
74.8
1.83
1.30
2.8
0.90
67.9
0.29
67.8
1.79
1.42
2.8
0.76
72.9
0.29
61.8
1.73
1.61
EXAMPLE 5
A steel composition comprising (weight %) Si 3.30%, C 0.050%, Mn 0.160%, S 0.010%, Al sol 0.029%, N 0.0075%, Sn 0.070%, Cu 0.300%, Cr 0.080%, Mo 0.020%, P 0.010%, Ni 0.080%, B 0.0020%, was continuously cast in thin slabs 60 mm thick. Six of said slabs were then hot-rolled according to the following cycle: heating at 1210° C., subsequent equalization at 1100° C. and direct hot-rolling to 2.3 mm thick strips (cycle A). Six other slabs were hot-rolled to the same thickness, but directly heating at 1100° C., without pre-heating at higher temperature (cycle B).
All the hot-rolled strips were then transformed to final product using the same cycle: pickling, single-stage cold rolling at 0.29 mm, continuous annealing for decarburization and nitriding, coating with MgO-based annealing separator, final box annealing, thermal flattening and coating with insulating coating. Final results, expressed as mean values of the magnetic properties along each strip are shown in Table 6.
TABLE 6
STRIP
No.
Heating cycle
B800 (T)
P17 (W/kg)
1
A
1.92
0.97
Invention
2
A
1.93
0.95
Invention
3
A
1.93
0.96
Invention
4
A
1.92
0.97
Invention
5
A
1.92
0.97
Invention
6
A
1.93
0.96
Invention
7
B
1.87
1.20
Comparison
8
B
1.92
0.98
Comparison
9
B
1.88
1.15
Comparison
10
B
1.87
1.15
Comparison
11
B
1.90
1.03
Comparison
12
B
1.89
1.05
Comparison
It can be seen that utilising a slab heating cycle according to present invention better results can be obtained, particularly with reference to their uniformity. In FIGS. 3 and 4 thickness variations of hot-rolled strips are shown measured at the exit of the hot-rolling mill, respectively on strips 7 and 1 .
EXAMPLE 6
A steel containing (weight %) Si 3.30%, C 0.015%, Mn 0.100%, S 0.010%, Cu 0.200%, Al 0.032%, N 0.007%, was continuously cast in slabs 240 mm thick in an industrial casting machine.
Some slabs were then rolled after the following thermo-mechanical cycle (cycle A):
Heating in a pushing furnace at a maximum temperature of 1360° C.;
Hot thickness reduction from 240 mm to 160 mm in a roughing mill;
Heating in a walking-beam furnace at a maximum temperature of 1220° C.
The other slabs were rolled, for comparison, after heating in a walking-beam furnace at a maximum temperature of 1220° C., without pre-heating and roughening (cycle B).
The thickness of the hot-rolled strips was comprised between 2.1 and 2.3 mm.
The hot -rolled strips were all continuously annealed at a maximum temperature of 1000° C., then single-stage cold-rolled at a mean thickness of 0.29 mm, ensuring that the strips, after the second rolling pass, reached a temperature of 210° C. The cold-rolled strips were then continuous annealed for decarburization and nitriding, to obtain a carbon content comprised between 10 and 30 ppm and a nitrogen content comprised between 100 and 130 ppm.
After coating with MgO, the strips were box annealed for secondary recrystallization and formation of a forsterite surface layer. The obtained magnetic characteristics are shown in Table 7.
TABLE 7
Strip No.
Heating cycle
B800 (T)
P17 (W/kg)
1
A
1.94
0.93
Invention
2
A
1.93
0.92
Invention
3
A
1.94
0.92
Invention
4
A
1.94
0.93
Invention
5
B
1.88
1.03
Comparison
6
B
1.88
1.04
Comparison
7
B
1.87
1.10
Comparison
8
B
1.89
1.02
Comparison
In all the tests made in each of the above Examples, it was observed that working according to present invention better magnetic permeability and core losses values are consistently obtained than those obtained operating according to already known slab heating methods, in which the slab temperature at the exit from the furnace corresponds to the maximum temperature reached by the slabs. Moreover, working according to present invention, the magnetic characteristics variations along the strips are much more limited (by about 50–60%) than those obtainable with traditional slab heating methods.
Accordingly, the maximum variation of permeability and core losses measured every 1 m along the steel strip according to present invention is within 2% and 6%, respectively. | In the production of electrical steel strips, a special islab-reheating treatment before hot rolling is carried out so that the maximum temperature within the furnace is reached by the slab well before its extraction from the furnace. During the heating stage and performance at the highest temperatures of the thermal cycle, second phase particles are dissolved and segregated elements are distributed in the metallic matrix, while during cooling and temperature equalising steps of the slab in the furnace a controlled amount of small second phases particles are more homogeneously re-precipitated from the metallic matrix. Differently from all the conventional processes for the production of electrical steels, the slab reheating furnace become a site in which it is performed the precipitation of a controlled amount of second phases particles for the necessary grain growth control during the successive process steps. | 2 |
FIELD OF THE INVENTION
The present invention relates to a novel pharmaceutical composition for inhibiting xanthine oxidase and a novel compound having xanthine oxidase inhibitory activity which is useful for the active component of the pharmaceutical composition.
BACKGROUND OF THE INVENTION
Uric acid which is a pathogenic substance of gout is synthesized by xanthine oxidase in the human body. Accordingly, inhibition of xanthine oxidase is useful for treatment and prevention of gout. In fact, allopurinol which is known as a therapeutic drug for gout is a useful xanthine oxidase inhibitor.
The present inventors have studied xanthine oxidase inhibitors contained in edible plants, and found that a component having xanthine oxidase inhibitory activity is present in edible plants of Labiatae, Compositae and Liliaceae, and an extract of these plants is useful for treating hyperuricemia. The present inventors have filed a patent application directed to a pharmaceutical composition for improving hyperuricemia comprising as an active component an extract from these plants (Japanese patent application no. 1-213998).
The present inventors have further studied the above active component and have succeeded in isolation and purification of active compounds from plants of Labiatae.
OBJECTS OF THE INVENTION
One object of the invention is to provide a novel pharmaceutical composition for inhibiting xanthine oxidase for treatment or prevention of gout.
Another object of the present invention is to provide a novel compound having xanthine oxidase inhibitor activity.
These objects as well as other objects and advantages of the present invention will become apparent to those skilled in the art from the following description.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a pharmaceutical composition inhibiting xanthine oxidase which comprises as an active component a compound of the formula I: ##STR2## wherein R is 4'-OH or 5'-OH, or a pharmaceutically acceptable salt or an ester thereof.
The compound of the formula [I] wherein R is 5'-OH [I'] is not found in the prior art and is a novel compound. Therefore, the present invention also provides the compound [I'] and its salt.
DETAILED DESCRIPTION OF THE INVENTION
Both active compounds of the formula [I] having xanthine oxidase inhibitory activity used in the present invention have the molecular formula C 17 H 14 O 6 , and they can be named as (Z,E)-2-(3,4-dihydroxyphenyl)ethenylester (abbreviated as XOI-A) or (Z,E)-2-(3,5-dihydroxyphenyl)ethenylester (abbreviated as XOI-B) of 3-(3,4-dihydroxyphenyl)-2-propenoic acid.
These compounds can be isolated and purified from edible plants of Labiatae as a starting material by solvent extraction and chromatography.
Examples of the plants of Labiatae to be used as the starting material include perilla, oregano, thyme, basil, sage and the like. These plants have been cultivated and served as food. In the present invention, all the parts thereof including roots, leaves, stems and the like can be used as the starting material.
For isolation and purification, the starting material is firstly extracted with an alcohol such as methanol, ethanol, n-propanol, iso-propanol or the like, or a solvent such as acetone, ethyl acetate, acetonitrile or the like. Then, the product is purified by passing it through a silica gel column. As an eluent, hexane, benzene, diethyl ether or a mixture thereof can be used. The active fraction thus separated by silica gel column chromatography is further subjected to high performance liquid chromatography to obtain two fractions having xanthine oxidase inhibitory activity. Finally, respective fractions are recrystallized from a mixture of water and ethanol or the like to obtain purified XOI-A and XOI-B.
The active compound XOI-A thus isolated and purified is yellow fine crystals having the melting point of 183° to 185° C. (decomp.). On the other hand, XOI-B is yellow needles having the melting point of 188° to 190° C. Both compounds are readily soluble in methanol, propanol, acetone, ethyl acetate or acetonitrile and slightly soluble in water, chloroform or hexane.
Infrared spectra by KBr method are as follows;
IR (cm -1 ):
XOI-A: 3400 (OH), 1690 (α,β-unsaturated ester), 1625 (phenyl conjugated double bond), 1605 (phenyl ring), 1270, 1150 (ester C-O stretching vibration).
XOI-B: 3380 (OH), 1720 (α,β-unsaturated ester), 1625 (phenyl conjugated double bond), 1600 (phenyl ring), 1280, 1140 (ester C-O stretching vibration).
Both XOI-A and XOI-B have phenolic OH groups, they can form a salt with an alkali metal and the like, or an ester with an organic or inorganic acid. These salts and esters are within the scope of the present invention.
Both compounds have excellent xanthine oxidase inhibitory activity. This xanthine oxidase inhibitory activity can be determined, for example, as follows:
Sample solution: A sample solution is prepared by dispersing the active compound in a suitable amount of water.
Enzyme solution: An enzyme solution is prepared by dissolving 150 μl of xanthine oxidase (15.2 units/ml) in 10 ml of 1/15 M phosphate buffer (pH 7.5).
Substrate solution: A substrate solution is prepared by heating 22.8 mg of xanthine in 1 liter of water to dissolve it.
Determination: 0.1 ml of the enzyme solution and 2.9 ml of phosphate buffer (the same as that described above) are admixed with 1.0 ml of the sample solution and the mixture is incubated at 37° C. for 10 minutes.
Then, 1 ml of the substrate solution preincubated at 37° C. is added to this reaction mixture and, after reaction for 30 minutes, an absorbance at 290 nm (D 1 ) is measured.
Separately, an absorbance at 290 nm (D 2 ) of a reaction mixture obtained by the similar reaction procedure using a heat inactivated enzyme, an absorbance (D 3 ) without addition of the sample solution, and and absorbance (D 4 ) of a reaction mixture obtained by using a heat-inactivated enzyme without addition of the sample solution are measured. By using the values obtained by these measurements, the inhibitory rate of xanthine oxidase is calculated by using the following equation:
Inhibitory Rate (%)={1-(D.sub.1 -D.sub.2)/(D.sub.3 -D.sub.4 }×100
According to this method, concentrations required for realizing a 50% inhibitory rate of XOI-A, XOI-B as well as known xanthine oxidase inhibitors, allopurinol, luteolin and quercetin were measured. The results are shown in Table 1.
TABLE 1______________________________________ Concentration for 50% inhibitory rateCompounds (μg/ml) Relative intensity______________________________________XOI-A 0.021 (1.00)XOI-B 0.124 (0.17)Allopurinol 0.021 (1.00)Luteolin 0.11 (0.19)Quercetin >0.40 (<0.05)______________________________________
As seen from Table 1, the active compound XOI-A of the present invention has an activity comparable to that of allopurinol, and the activity of XOI-B is almost the same as that of luteolin. And, the activities of both XOI-A and B are superior to that of quercetin.
XOI-A and the novel compound XOI-B of the present invention or a pharmaceutically acceptable salt thereof obtained by the conventional method can be formulated into unit dosage forms such as tablets, capsules, pills, powder, granules, powdery packet, cachets, sterile solutions or suspensions, eye drops, elixir, suppository, aerosol, emulsions and the like according to the conventional methods.
For oral administration, they can be formulated into solid or liquid unit dosage forms. For preparing solid compositions, the active compound is mixed with an excipient or carrier such as talc, magnesium stearate, dicalcium phosphate, magnesium aluminum silicate, calcium sulfate, starch, lactose, acacia, methyl cellulose and the like. A capsule is prepared by mixing the active compound with an inert pharmaceutical excipient, filling the mixture into a suitably sized hard gelatin capsule. A soft gelatin capsule is prepared by mechanically encapsulating a slurry of the compound and a suitable vegetable oil, light petrolatum or other inert oil.
For preparing liquid compositions, the active compound is dissolved in an aqueous vehicle together with sugar, an aromatic flavor and a preservative to obtain syrup. An elixir agent is prepared by using an alcoholic vehicle such as ethanol, a sweetener such as sugar or saccharin, and a flavor. A suspension is prepared by using a suspending agent such as acacia, tragacanth, or methyl cellulose, and an aqueous vehicle.
For parenteral administration, a liquid unit dosage form is prepared by using the active compound and a sterile vehicle. The active compound is dissolved or suspended in a vehicle, depending upon the particular vehicle, such as water, Ringer's solution or isotonic sodium chloride solution and a particular concentration to be employed. For preparing solutions, the active compound is dissolved in injectable water, sterilized by filtration, and filled into a suitable vial or ampoule and sealed. Advantageously, an adjuvant such as a local anesthetic, a preservative and a buffer is dissolved in a vehicle. Alternatively, the active compound can be formulated into lyophilized powder which has excellent storage stability. This is reconstituted upon use. A parenteral suspension can be prepared by suspending the active compound according to a similar manner. In this case, the active compound can be sterilized by exposing to ethylene oxide before suspending in a sterilized vehicle. Advantageously, a surfactant or wetting agent is added to facilitate dispersion of the active compound.
In addition, the active compound can be formulated into topical application forms in combination with a suitable carrier for topical application. As examples of the carrier to be used, there are cream, ointment, lotion, paste, jelly, spray, aerosol and the like. Further, the active compound can be formulated into rectal suppository forms useful when no other administration route can be used. As examples of a base to be used, there are cacao butter, polyethylene glycol (carbowax), polyethylene sorbitan monostearate and the like.
The pharmaceutical composition inhibiting xanthine oxidase of the present invention as described above can be administered orally, parenterally, by insufflation, rectally, or topically. Parenteral administration includes subcutaneous, intravenous, intramuscular and intranasal administration as well as infusion. The daily dosage of the active compound is in the range of 0.1 to 200 mg/kg body weight. Usually, the composition is administered once to five times in a day. However, the exact dosage can be selected from the above range in view of particular age, weight and conditions of a patient as well as dosage route.
By administering the active compound in such a dosage, the pharmaceutical composition of the present invention manifests excellent xanthine oxidase inhibitory activity and, therefore, it is useful for improving hyperuricemia and gout.
By the way, the toxicity of the pharmaceutical composition of the present invention must be very low because its active component is derived from edible plants.
The following Examples further illustrate the present invention in detail but are not to be construed to limit the scope thereof.
EXAMPLE 1
Perilla frutescens was used as a starting material. The starting material (3.73 kg, fresh weight) was extracted with ethanol. The resultant ethanolic extract was suspended in water and extracted with ethyl acetate. This extract was purified by passing successively through large, medium and small silica gel columns by using hexane-ethyl acetate (40:60) as an eluent to obtain an active fraction. The eluate was then purified by preparative HPLC to obtain two fractions A and B. Each fraction was recrystallized from water-ethanol (50:50) to obtain 42 mg of XOI-A from the fraction A and 11 mg of XOI-B from the fraction B.
Respective isolation and purification procedures as well as solids content and specific activity (U/mg) at respective steps are summarized in Table 2. In Table 2, 1 U represents the activity required for inhibiting 50% of xanthine oxidase.
TABLE 2______________________________________ Solids Specific Total activity content activitySteps × 10.sup.6 (U) (mg) (μ/mg)______________________________________Extract obtained by 31.80 (100) 151600 210 (1)ethanol extractionEthyl acetate layer 33.30 (105) 53350 624 (3)Silica gel column 15.00 (47) 6000 2500 (12)(large)Silica gel column 13.40 (42) 1780 7520 (36)(medium)Silica gel column 9.17 (29) -- -- (--)(small)Preparative HPLC 5.71 (18) 150 38100 (181)(ODS)Fraction A 1.96 (6) 42 46600 (222)(recrystallization)Fraction B 0.09 (--) 11 8040 (38)(recrystallization)______________________________________
EXAMPLE 2
Tablets containing XOI-A as an active component were prepared by the conventional method according to the following formulation:
______________________________________Ingredient Parts by weight______________________________________XOI-A 10Lactose 60Starch 27Talc 1.5Magnesium stearate 1.5______________________________________ | A pharmaceutical composition inhibiting xanthine oxidase containing as an active component a compound of the formula: ##STR1## wherein R is 4'-OH or 5'-OH, or a pharmaceutically acceptable salt or ester thereof is disclosed. The compound wherein R is 5'-OH is a novel compound. | 2 |
[0001] This patent application follows on from provisional application 60/998,670.
FIELD OF THE INVENTION
[0002] A drainpipe heat exchanger for use on drain- or exhaust pipes for waste heat recovery including from any building's drainpipe. It can be made small enough for use with individual plumbing fixtures such as sinks, or for exhaust pipes of cars and trucks. It can also be used over existing drainpipes and exhaust pipes that cannot have their flow interrupted by their temporary removal/replacement. For example large diameter ones are difficult and expensive to remove and reinstall.
[0003] Heating cold water to make hot water for cleaning and then discarding the heat along with the dirty hot water is expensive, wasteful and environmentally damaging. It is estimated that in North America some $15 billion dollars is spent annually on fuel to heat water. The fuel's exhaust and the discarded heat in the used hot water contribute doubly to global warming and a lower standard of living. Speeding up heating of vehicle occupants using waste exhaust heat is also contemplated.
BACKGROUND OF THE INVENTION
[0004] A shortcoming of traditional drainwater heat recovery (DHR) heat exchangers is their cost effectiveness. This can be partly attributed to the poor use of the expensive heat transfer surface area. Even more so if laid horizontally which is often necessary.
[0005] Copper tubing for cold water coiled around a vertical copper drainpipe makes a simple but expensive DHR heat exchanger. It is based on the long-known Falling Film principle.
[0006] In Falling Film heat exchangers, a liquid is ideally made to overflow into the top of a straight, large bore, vertical tube. The flow is meant to be circumferential, flowing down in an even, falling film clinging to the entire inner vertical tube wall, from top to bottom. (More information on falling film heat exchangers can be found at: The Chemical Educator, Vol. 6, No. 1, published on Web Dec. 15, 2000, 10.1007/s00897000445a, © 2001 Springer-Verlag New York, Inc., and, U.S. Pat. No. 4,619,311 to Vasile which discloses a equal flow Falling Film DHR heat exchanger.)
[0007] The falling film DHR is, in many ways, ideal because it is not blocked by large solids and other matter contained in a building's drainwater. In operation, cold, ground water feeding a water heater first passes through the outer coil of tubing on its way to the heater. At the same time, drainwater is ‘falling’ down the inside tube, transferring heat to the cold water. Thus showering and sink rinsing are the principal appliances/fixtures for such heat exchangers because only then is cold water flowing into the hot water heater exactly while the drain is flowing with the now-dirty used hot water.
[0008] One of the weaknesses of such heat exchangers is the narrow spiral contact patch between the coil's inner surface and the tube's outer wall. Because heat transfer is a direct function of surface area, the less than full contact area reduces performance from high cost materials. Further, the long length of the coil tube (up to 100 feet long) and the fact that it flattens somewhat as it is wound, creates internal resistance to flow and an unwanted drop in water pressure for the heater.
[0009] In the instant invention, instead of tubing, sheet copper is used for the cold water. This dramatically lowers cost, increases contact area, and eliminates pressure drop. For example, in a 5 foot long, 4 inch diameter drainpipe, only ⅔ the weight of copper is needed for the cold water exchanger and, a much higher percentage of that copper surface is used for heat transfer. Further, the instant invention allows for very compact, small diameter DHR (i.e., a 1¼ inch diameter sink drainpipe) for individual fixtures and appliances which is not practical with wrapped tube designs due to the bend radius limitation of suitably sized outer tubing. Thus with the instant invention, DHR is made significantly more cost effective and more widely usable.
SUMMARY OF THE INVENTION
[0010] In one embodiment of the instant heat exchanger invention, sheet copper is formed into a hollow, tubular, sealed chamber or jacket having spaced inner and outer walls forming a cavity and where the inner wall matches the shape or form of the drainpipe to which the exchanger is to be attached. A longitudinal gap, slit or opening is provided where the inner and outer walls converge giving the chamber or jacket a “C” shape. This gap allows contraction of the inner wall tightly onto a circular drain tube when the exterior wall is clamped using band clamps acting on a stiff outer sleeve (for clamp force distribution). Thus an intimate contact between the thermal transfer surfaces, namely, the chamber or jacket inner wall and the drainpipe outer wall is made possible and yet the jacket can be easily slid onto the drainpipe from one end. In addition, normal mains cold water supply pressurizes the inside of the jacket. This pressure adds to the thermal contact force with the drainpipe thereby to maximize thermal conduction and so, the all important rate of heat transfer.
[0011] In one application the jacket is slid over and clamped onto the exterior of an existing drainpipe, in another it is pre-assembled with a drainpipe forming a complete DHR heat exchanger which then replaces a section of existing drainpipe. In a second embodiment, the instant invention is fabricated in two long half-cylindrical jackets (clam-shell like) which are assembled onto a operating drainpipe as described above.
[0012] A third embodiment, for horizontal installation, uses a somewhat flattened (D-shaped) drainpipe. The cold water conduit or chamber is in the form of a bar—a thin, flat, tube, or, in the form of a trough, located under the flat drainpipe and bound to it with clamps applied over a D-shaped shoe or shaped filler piece to even out the clamping force along the whole length. The clamping plus the internal water pressure provide high performance thermal contact therebetween.
[0013] In a fourth embodiment, the flattened, D-shaped drainpipe may be in two parts: an upper hemi-cylindrical plastic support portion bonded to a lower flat metal heat transfer portion, to lower costs.
[0014] In use, a sink or shower may have the heat exchanger lying horizontally beneath it such that cold water is pre-heated before reaching the cold water faucet. In this way less hot water is needed to mix with the now-warm cold water to achieve the desired temperature. Less hot water use saves energy and money and pollution, and, if electrically heated, lowers peak power demand.
[0015] During fabrication, the sheet copper should be slightly creased diagonally where thermal contact will occur to serve as a vent for visible leak detection (a drip path onto the floor). The sheet is then formed into an “outline C shape”, or, double walled hollow tube structure with a longitudinal gap. The outer wall of the jacket is punched to receive soldered-on pipe fittings for the cold water supply and the ends are sealed with “C” shaped rings of copper tubing, rod or twisted wire, dip-soldered into place at each end. Alternatively, the jacket ends may be squeezed-closed and soldered.
[0016] The unique, high-force hydraulic clamping action maximizes heat transfer which increases with contact pressure. For example, if the drainpipe is 3 inches in diameter and the jacket 48 inches long and the cold water is at 50 pounds per square inch pressure, the contact force will be approximately: 3.14(π)×3×48×50=22,000 pounds, or 11 tons of contact force!
[0017] Not only does such an enormous force provide excellent heat transfer but it does so evenly over its entire length. This would be extremely difficult or impossible to achieve by any mechanical clamping method
[0018] Where the instant invention is to be installed on an existing drainpipe already permanently in place, the jacket may be made in two halves (or hinged) with duplicate fittings to connect to the cold water supply. The outer plastic sleeve would also be in two halves (or hinged). In some cases only a lower, half-jacket may be appropriate to reduce cost when using it on a horizontal drainpipe, for example.
[0019] Use of the instant invention is also contemplated on vehicle exhaust pipes. So, for example, a stainless steel model, with a metallic outer retaining sleeve, may be fitted to an exhaust pipe of a car to provide double-walled-safe, hot air to the car interior in cold weather. The internal pressure-clamp feature may be duplicated using compressed air and flow restrictors, or internal fins/spacers to transmit the clamping force onto the inner wall of the jacket and onto the exhaust pipe. The recovered heat can be used to heat the vehicle's interior and/or its motor and/or a heat storage medium. Fresh air blown through the jacket becomes heated air for the vehicle interior.
[0020] In all embodiments, internal baffles, walls, dams (as in a weir) or fins can be incorporated to distribute fluid flow, optimize heat transfer and to distribute the external clamping force.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 shows a partial section end view a middle portion of one embodiment of the drainpipe heat exchanger having an upper conduit for drainwater and a lower conduit for cold water with forced thermal contact all along their flat surfaces;
[0022] FIGS. 2 , 3 , 4 show the same embodiment in a sequence of forming steps to squeeze-close and solder-seal the two end portions of the lower exchanger;
[0023] FIG. 5 shows the same embodiment in side view showing the sealed ends of the cold water heat exchanger, its lower fittings, and, the adapted ends of the upper conduit that connect to regular round drainpipes, and where the right end is shown to have an added adaptor while the left end is shown to have been formed into a short cylindrical shape, in both cases the flow path is flush such that there is no ‘step-up’ to impede drainwater flow in or out;
[0024] FIG. 6 shows an adaptor for the drainwater heat exchanger formed, for example, from a suitable plastic material;
[0025] FIG. 7 shows an end view of another embodiment where the drainwater heat exchanger's end's are formed to rectangular sockets to receive rectangular solder-type plumbing fittings and a plug, and where the excess material is closed off to be sealed by soldering at the same time that the fitting is inserted, and showing an internal fluid distribution tube enclosed therein;
[0026] FIG. 8 shows a copper solder-type fitting having one end formed to a rectangular shape for insertion into the end socket;
[0027] FIG. 9 shows a copper plug to be soldered in unused socket openings;
[0028] FIG. 10 shows a side view of the same embodiment as FIG. 7 showing the end location of the drainwater heat exchanger fittings;
[0029] FIG. 11 shows a top view in section of a cylindrical, jacket-style heat exchanger having a longitudinal gap to allow clamping motion, which would be slid over a drainpipe/exhaust pipe;
[0030] FIG. 12 shows a top section view of a two-piece design for clamping about an in-use drainpipe/exhaust pipe;
[0031] FIG. 13 shows a side view of the embodiment in FIG. 11 showing the outer sleeve and band clamps and showing the fluid fittings and the location of the end sealing members;
[0032] FIG. 14 shows a top view of the sealing ring member made from tube or rod although a stamped sheet design may be more economical in production;
[0033] FIG. 15 show a side view of the sealing member;
[0034] FIG. 16 shows a possible use of the joint flange where it has various notches to distribute the fluid flow evenly over the jacket's inner wall so as to maximize heat transfer by maintaining the best temperature differential;
[0035] FIG. 17 shows a thin, flat cold water (or other fluid) conduit clamped against the flat lower surface of the drainwater conduit;
[0036] FIG. 18 is a cross section of the same embodiment and showing one internal baffle in the cold water exchanger to prevent bulging;
[0037] FIG. 19 is a cross section showing how the drainwater heat exchanger may be a two piece design with the upper, non-heat transfer portion in plastic and the lower heat transfer portion in sheet copper, bonded together along the length, and, with tension walls of sheet copper to transmit the internal pressure in the cold water exchanger to the external clamping member;
[0038] FIG. 20 is a side view of the same embodiment showing how the drainwater flow may be made to enter from the top at the inlet end and to collect in a cross tube outlet arrangement at the exit end;
[0039] FIG. 21 shows a perspective view of the outlet fitting of the embodiment;
[0040] FIG. 22 is a top view looking into the vertical heat exchanger where the cold water is made to flow past a distribution gap formed adjacent an annular ring and the jacket's inner wall so as to sweep the entire surface along its vertical length;
[0041] FIG. 23 is a cross section side view of the same embodiment showing how the cold water inlet is located between the sealing end cap and the annular ring with the single-sided arrows representing the resulting sheet-like flow;
[0042] FIG. 24 is an end view of an embodiment of a upper conduit having a lower surface with a gully-shape along flow path, to resist upward bulging from the force of contact generated by the internal pressure in the shaped cold water jacket below;
[0043] FIG. 25 shows the same embodiment but with an oval shaped lower flow surface.
DETAILED DESCRIPTION OF THE INVENTION
[0044] Two basic embodiments are disclosed, vertical heat exchanger 100 , and horizontal heat exchanger 200 . each has two conduits in thermal contact. One conduit is a straight pipe or tube that typically carries a waste fluid from which heat is to be recovered, and the second conduit is for the second fluid to which heat is to be transferred, although the heat transfer path could be reversed. Generally the conduits are metal and preferably copper if the temperature differential is small and therefore requires fast heat transfer. The two conduits are co-operatively shaped and tightly clamped together so as to provide optimal thermal contact and thus rapid heat transfer. In the horizontal embodiment the waste conduit is normally on top of the second conduit (waste fluid has heat to be recovered), while in the vertical embodiment the waste conduit is encircled by the second conduit.
[0045] One novel feature of the instant invention is the use of the internal water pressure in the colds water conduit to create very high thermal contact force with the drainwater conduit to provide fast heat transfer so as to maximize recovery of waste heat energy.
[0046] In FIG. 1 horizontal heat exchanger 200 has an upper drainwater conduit 60 and a lower cold water conduit 50 held tightly together with clamping bands 12 ( FIGS. 5 and 10 ) around a suitable force distribution sleeve (not shown). Drainwater conduit 60 comprises wall 1 with drainwater A flowing along flattened bottom surface 1 ′ (of wall 1 ) to thereby form a hemicylinder that transfers heat to fluid B which enters and exists cold water conduit 50 via underside fittings 10 , 11 or alternately, via end fittings 80 .
[0047] In FIG. 1-5 , 7 , 10 , cold water conduit 50 is shown being in the shape of a trough made from sheet copper and formed with longitudinal hems 4 that are solder joined to create a generally “C shaped” hemicylindrical conduit with flat surface 5 . Hem 4 also serves as a heat conductive fin and, as a result of the bend curvature 6 , provides a longitudinal vent to the ambient for leak detection.
[0048] In one embodiment, wall 2 of conduit 50 has wings 3 which contact the side of the drainwater conduit 60 to create additional surface for heat transfer. In FIGS. 2 , 3 , 4 cold water conduit 50 is shown having a short end portion of hem 4 folded flat in preparation for sealing the ends. The wings 3 are pinched closed and excess metal is pulled into additional seams 3 ′. In FIG. 4 is shown a dotted line 2 that represents the original cold water conduit 50 shape.
[0049] In FIG. 7 is shown an alternate way of sealing the ends of cold water conduit 50 so as to provide in-line connection sockets 33 ′, 34 ′. The two sockets at each end (4 in total) are formed on each side of hem 4 using an appropriate mandrel about which the remaining wall 3 and wing 2 are squeezed to bring them together as a seam to be soldered. Appropriate surfaces can be ‘tinned’ with solder prior to the forming in preparation for final soldering.
[0050] In FIG. 8 , fluid fitting 80 has rectangular end 33 inserted and soldered into socket 33 ′ or 34 ′ (at each end of cold water conduit 50 ), and has a round end 30 for connecting to standard plumbing. Fitting 80 may also be an end of a longer tube where installation conditions warrant. Alternatively one of the two rectangular shapes 33 ′ and 34 ′ may be blocked with a simple plug 34 as indicated in FIG. 9 . Interior to cold water conduit 50 and inline with the socket 33 ′ and/or 34 ′ is a fluid distribution tube 35 ′ which extends full length and is closed at the far end and has cross apertures at intervals. The purpose of tube 35 ′ is to distribute fluid B (i.e., cold water) to cause a crossflow creating turbulence and evening out flow velocity across the width of cold water conduit 50 .
[0051] In FIG. 5 horizontal heat exchanger 200 is shown having the upper drainwater conduit 60 made from a flattened tube, and lower cold water conduit 50 (for, say, cold water) formed of sheet material bound together by exterior clamping bands 12 . In some uses the upper drainwater conduit 60 may also be formed from sheet to reduce cost. In either case the ends of drainwater conduit 60 can be adapted to connect with existing round drain pipes the right end of the drainwater conduit being shown having a separate, bonded-on adaptor 70 , while the left end 70 ′ is shown as having an integrally formed round end 20 ′. It is important that the drainwater conduit provides a flush flow path especially at the exit end so that solids in the drainwater will not hook and collect at the region of transition from flat to round. This can be achieved by forming a recess in the “D” shaped end of the bonded on adaptor equal to the thickness of the drainwater conduit material. The bonding region is shown at overlap 20 ′.
[0052] FIG. 5 shows fluid B, such as cold water for a water heater, entering fitting 10 at the left to counterflow horizontally under the drainwater water conduit 60 and exit via fitting 11 on the right having absorbed (or given up) heat from warmer (or colder) drainwater. Drainwater A flows horizontally with a first temperature A′ at inlet on right side and a different temperature A″ at outlet on left side.
[0053] FIG. 6 shows adaptor 70 having a “D” shaped first end 20 ′ for bonding to drainwater conduit 60 and a round end 20 for connecting to existing drainpipe. Adaptor 70 may also be made of molded rubber with a shaped shoe 22 (shown in dotted outline) under the flat portion 20 ′ to provide even clamping pressure for sealing.
[0054] In use, by connecting cold water conduit 50 to a pressurized fluid supply, an enormous thermal transfer contact force is created between the flat surfaces of conduits 50 and 60 , restrained by bands 12 (over a stiff sleeve, not shown), to provide exceptional heat transfer therebetween. For example, with a 4 inch wide flat that is 50 inches long and with a pressure of 40 pounds per square inch, the contact force is some 8,000 pounds. This force custom forms typically imperfect flat surfaces 1 ′ and 5 into intimate contact.
[0055] With the instant invention, horizontally flowing drainwater, whose valuable heat energy is normally wasted, can be cooled by heat transfer to the cold water supply of the water heater to thereby shorten the time it takes to fully heat hot water which, in turn, saves energy and money and provides more hot water due to faster recovery. It may also be used to cool a flow of warmer water feeding, for example, an ice cube maker, using colder drainwater from a ice-filled sink.
[0056] In all figures the drainwater flow or exhaust gas inlet flow is indicated as A′ and A″ and the fluid whose temperature is to be changed is B and B′. Heat exchanger 200 may be used to heat or cool fluid B. Although gaps between surfaces are shown in the figures (for clarity) it is understood that there is intimate contact between heat transfer and clamping surfaces.
[0057] In FIGS. 11-13 heat exchanger 100 is a jacket(s) comprising an inner heat transfer wall 5 and outer retaining wall 2 spaced apart for fluid flow therebetween with minimal resistance. This space may be, say, ¼ inch. The walls are contiguous and formed from a single piece of thin sheet metal (copper) using reversing bends 112 and lap joint 5 ′. This leaves a longitudinal opening or gap 111 between bends 112 to accommodate movement from external mechanical clamping forces and internal hydraulic clamping forces. The jacket may also be formed by extrusion in which case finning 115 (representative fins only, shown in FIG. 11 ) and fluid control elements 114 may be easily included on the inner wall 5 and/or outer wall 2 . Outer clamping sleeve 116 with gap 113 closes tightly around and distributes clamping forces from band or hose clamps 12 to prevent expansion or bulging of outer wall 2 from the internal pressure of fluid B such as that from a building's cold water supply. Inner wall 1 is however free to expand every so slightly to provide a tight, intimate thermal contact with drainpipe 1 using that same internal pressure.
[0058] In FIGS. 11 , 12 lap joint 5 ′ is a soldered and may include longitudinal joint flange 110 which can act as a fluid flow distributor and a stabilizer/spacer for aligning the sheet metal during soldering. Inlets(s) 10 and outlet(s) 11 are connections for fluid B (such as cold water) whose temperature is to be changed. Representative fluid control element 114 may be several in number and take various shapes such as mesh, rods, screen, angles, etc., that direct, for example, flow of fluid B over element 114 as indicated by dashed flow arrow 114 ′, to help effect best heat transfer from inner wall 5 by the fluid ‘sweeping’ the surface of the inner thermal contact wall as fully as possible. Element(s) 114 may also be used to create turbulent flow which is known to improve heat transfer. Element 114 may also be shaped and located to deflect fluid B inflow at inlet 10 to avoid erosion corrosion of the small area of the inner wall by the fluid impinging on it perpendicularly at full velocity over long years of daily use.
[0059] FIG. 12 shows the hollow, tubular nature of the heat exchanger 100 as fitted onto a vertical drainpipe 1 . Sealing rings 34 are shown in dotted line and are soldered into the annular space between the inner and outer wall ends at top and bottom. Although a tubular shape is shown, other shapes such as oval are contemplated where, for example, fitting clearance is a concern.
[0060] FIGS. 14 and 15 show the sealing member 34 which can be made from rolled rod, tube or twisted wire bundle to fit snugly into the annular space and have a gap 111 ′ to coordinate with gap 111 . They may be made by winding a long tube onto a mandrel of the correct diameter into the form of a coil spring and then sawing through the coil to free individual rings which are then made planar as in FIG. 15 . Dip soldering is a fast method of construction.
[0061] FIG. 16 shows a method of using the longitudinal joint flange 110 as a flow distributor by providing restriction to flow directly from fitting 10 such that fluid B is forced through spaced vias 120 to travel across inner wall 5 to reach outlet 11 thereby improving heat removal from drainpipe 1 . Flange 110 may also simply be more simply double-tapered (not shown) from full width at the center tapering to nil at each end to even out flow along its length, especially if the fittings 10 and 11 are positioned centrally and opposite one another.
[0062] FIG. 12 shows the cold water conduit in two halves with inlets 10 and outlets 11 on each half. The outer sleeve 116 and clamps 12 of FIG. 11 are not shown. The outer sleeve 112 would of course be in two pieces either separate or hinged for ease of assembly onto the drainpipe in a building while it remains in operation. The sealing rings 34 (not shown in FIG. 12 ) would of course be four in number each being a half ring, one at each of the four ends.
[0063] FIG. 17 shows another embodiment of horizontal heat exchanger 200 where the cold water conduit 2 comprises a sheet copper duct or tube in the form of a flat, rectangular hollow strip. It is sealed at each end and preferably has flow-formers to ensure that the cold water flows as a flat sheet of water across the entire width of the heat transfer surface so as to keep the surface as cool as possible, thereby maximizing delta T for faster heat transfer.
[0064] FIG. 18 shows a cross section of the same embodiment where the drainwater conduit is shown to be a flattened, hemi-cylindrical tube I forced into intimate, conforming thermal contact with cold conduit 2 using shaped pressure distribution shoes 130 , 131 and clamp bands 12 .
[0065] In the embodiments shown in FIGS. 18 and 19 , and all embodiments of the horizontal drainwater heat exchanger, the cold water conduit may have internal baffles 2 ″ comprising one or more flattened tubes soldered between the top and bottom surfaces that will prevent excessive bulging of the conduit in reaction to the water pressure inside. This will help maintain flat drainwater heat exchange surfaces.
[0066] In FIG. 19 drainwater conduit 1 is comprised of a trough-like lower portion in sheet copper through which heat transfer takes place and a U-shaped plastic upper portion bonded 1 b thereto, the two creating a hybrid drainpipe of rounded rectangular or hemicylindrical form. This embodiment is for the lowest cost device. Interior longitudinal supports 1 c act to transmit bulging force from cold water conduit 2 to shoe 130 and bands 12 thereby maintaining a flat profile for the trough. Supports 1 c may be wavy to create a desirable turbulent flow. Supports 1 c also act as fins to extend heat transfer surface area. Supports 1 c may be eliminated and baffles 2 ″ in the cold water exchanger may be used to prevent pressure bulging of the flat surfaces.
[0067] FIG. 20 shows the same embodiment with different drainpipe connection fittings. Inlet 200 ″ is a vertical right angle inlet centered on plastic top 1 a and outlet 200 ′ is a horizontal right angle fitting shown in more detail in FIG. 21 , having an end cap and a slot 201 which matches the shape of the end of heat exchanger 1 , 1 a, 1 b ( FIG. 19 ) and is bonded and sealed thereto. A slight slope to outlet 200 ′ carries away the final drainwater drips to leave drainwater conduit 1 dry.
[0068] In FIG. 22 vertical heat exchanger 100 has an inner wall 5 (heat transfer surface) and ring-shaped flow distributor 110 ′ which provides an even annular gap 120 ′ adjacent wall 5 . End seals 34 ( FIG. 23 ) and flow distributor 110 ′ are spaced apart vertically creating a circular chamber into which flows fluid B, which then must leave the chamber in a full curvilinear sheet flow B′ (half arrows) against inner wall 5 so as to sweep heated (or cooled) fluid towards the outlet, which is similarly configured. This ensures that a maximum temperature differential, or delta T, can be maintained to optimize heat transfer. This annular flow control arrangement may be used to advantage in all the aforementioned heat exchangers including the two-piece embodiment of FIG. 12 . In the case of horizontal heat exchangers 200 the distributor would take the form of a rectangular bridge held a small distance below the heat transfer surface by stand-off elements.
[0069] FIGS. 24 and 25 show variations on the profile of the flow surface 1 ′ of the drainwater conduit 1 with the purpose of stiffening the flow surface 1 ′ to resist upward bulging from the expansive potential of the pressurized cold conduit below. The cold water conduit 2 is shown to be conforming in shape so as to maintain maximum thermal contact. | The present invention is a jacket-type heat exchanger which may, for example, be used to replace or fit over a section of drainpipe to heat fresh cold water using the waste heat in the drainwater. Normal cold water pressure is used to create an internal-expanding force on the inner thermal contact wall of the jacket, which, in turn, creates an enormous heat-transfer clamping force on the drainpipe for fast heat transfer. A longitudinal gap in the jacket (or a two-piece jacket) enables clamping movement. An external sleeve with clamps resists bulging of the outer jacket wall. The heated cold water is plumbed to a faucet or water heater so as to reduce hot water use, which, in turn, reduces energy use and related environmental damage. Double-wall construction and venting for visible leak detection satisfies plumbing code requirements. A horizontal embodiment discloses a two-piece plastic-copper drainwater heat exchanger. Use on vehicular exhaust pipes is also contemplated for providing instant interior heat and/or motor warm-up. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a circuit for distinguishing a detected signal indicating the lifting of the valve element of a fuel injection valve which injects fuel into an internal combustion engine, and more particularly to a circuit for distinguishing a detected valve element lifting signal while removing noise from the detected valve element lifting signal to effect accurate detection of the fuel injection timing of a fuel injection valve.
The lifting of the valve element of a fuel injection valve is detected, for example, by an output signal which is generated by a pressure-sensitive means such as a piezoelectric element in response to the displacement of a member which is movable with the valve element of the fuel injection valve.
Since the pressure-sensitive means such as a piezoelectric element has a high output impedance, however, the output signal thereof is susceptible to noise, and may even pick up noise caused by the vibration of a valve nozzle spring by which the valve element is normally urged against a valve seat. Therefore, the valve element lifting signal is liable to oscillate due to such noise.
In order to distinguish a detected valve element lifting signal, it has been one conventional practice, as shown in FIG. 6 of the accompanying drawings, to count detected pulses (b) each produced upon detection of the top dead center, after a detected valve element lifting signal (a) has been issued, and to mask the signal for a period T up to a detected pulse (b) which is produced immediately before a next detected valve element lifting signal (a) is generated, thus removing noise from the detected valve element lifting signal.
According to another conventional scheme, as shown in FIG. 7, after a detected valve element lifting signal (a) has been produced, noise is masked or removed from the signal by a one-shot multivibrator.
With the former known signal distinguishing circuit, however, noise produced in a period (FIG. 6) after the masked interval cannot be removed.
The latter known circuit arrangement is disadvantageous in that noise in a period (FIG. 7) cannot be eliminated unless the masked interval according to the one-shot multivibrator is increased. However, if the masked interval is increased, it may also mask a next detected valve element lifting signal when the engine rotates at high speed.
The above two arrangements may be combined into a system in which the signal is unmasked at the time whichever masked interval ends first. Even with this system, however, noise cannot be removed from the period of time after the signal is unmasked until a next cycle of fuel injection is started.
There has also been a circuit arrangement in which the frequency of the vibration of the valve nozzle spring is removed by passing the output signal from the piezoelectric element through a low-pass filter. Where the low-pass filter is of an analog filter, it is difficult to provide a sharp decline in its frequency characteristic curve at the cutoff frequency. If the analog low-pass filter is successfully designed with a sharp cutoff decline in the frequency characteristic curve, then the low-pass filter has difficulty in detecting a positive-going edge of the output signal from the piezoelectric element, with the result being that a large detection delay will be produced.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a circuit for distinguishing a detected signal indicating the lifting of the valve element of a fuel injection valve while removing noise from the detected valve element lifting signal to effect accurate detection of the fuel injection timing of a fuel injection valve.
To achieve the above object, there is provided a circuit for distinguishing a detected signal indicating the lifting of the valve element of a fuel injection valve having a valve element lift sensor, the circuit comprising: a waveform shaper for converting a detected valve element lifting signal produced in response to pressure developed by movement of the valve element, into a pulse; a pulse generating means triggerable by the pulse from the waveform shaper for producing a pulse having a pulse duration shorter than a minimum valve element lifting period; and a logic processing means for processing the pulse from the waveform shaper and the pulse from the pulse generating means.
Therefore, the detected valve element lifting signal is converted into a pulse, and the pulse generating means is triggered by the pulse output signal from the waveform shaper to produce a pulse having a pulse duration shorter than the minimum valve element lifting period, and longer than the duration of a pulse issued from the waveform shaper after the supply of fuel to the fuel injection valve has been cut off. The pulse from the waveform shaper and the pulse from the pulse generating means are processed to eliminate any pulses from the waveform shaper which have pulse durations shorter than the pulse duration from the pulse generating means. Thus, any input signal to the waveform shaper which is of a pulse duration shorter than the pulse duration of the pulse from the pulse generating means is fully removed as noise.
The above and other objects, features and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of a distinguishing circuit according to the present invention;
FIG. 2 is a longitudinal cross-sectional view of a fuel injection valve which may be used with the circuit of the present invention;
FIG. 3 is a graph showing a frequency distribution of a detected valve element lifting signal and a resonant frequency of a spring;
FIGS. 4a through 4e, and 5a through 5e are timing charts illustrating operation of the circuit of the present invention;
FIGS. 6 and 7 are diagrams explaining conventional arrangements.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The principles of the present invention are particularly useful when embodied in a circuit for distinguishing a detected signal indicating the lifting of the valve element of a fuel injection valve, incorporated especially in a fuel injection timing measuring device. The circuit as it is employed for the removal of noise produced by a valve nozzle spring will be described by way of example.
First, a fuel injection valve associated with the circuit of the invention will be described below.
FIG. 2 shows in cross section a fuel injection valve 20 having a lift sensor for detecting the lifting of a valve element. The fuel injection valve 20 per se is known in the art from U.S. Pat. No. 4,662,564, for example.
The fuel injection valve 20 includes a nozzle nut 21 to be threaded in an engine head (not shown) and a nozzle body 23 having a valve seat 22 and fitted in the nozzle nut 21. A needle valve 24 serving as a valve element for cooperating with the valve seat 22 in controlling the fuel injection orifice or opening at the valve seat 22 is axially movably fitted in the nozzle body 23. A nozzle holder 25 is threadedly fitted in the nozzle nut 21 for engaging and holding the nozzle body 23 in position axially in the nozzle nut 21.
The needle valve 24 has a rear end over which there is fitted a spring seat 26 extending into a spring chamber 25A defined in the nozzle holder 25. The needle valve 24 is normally urged to close the fuel injection opening at the valve seat 22 by a nozzle spring 27 which is disposed under compression between the spring seat 26 and a spring seat 28 disposed axially remotely from the spring seat 26.
A fuel reservoir 40 is defined between the nozzle body 23 and the needle valve 24 in communication with the fuel injection opening. The fuel reservoir 40 is supplied with fuel from a fuel tank via fuel supply passages 29, 30, 31. When fuel is supplied to the fuel reservoir 40, the pressure of the supplied fuel is applied to the conical taper surface of the needle valve 24 in the fuel reservoir 40 for lifting the needle valve 24 axially against the resiliency of the nozzle spring 27. The fuel injection opening is now opened between the valve seat 22 and the needle valve 24 to inject fuel therethrough into an engine cylinder (not shown). The nozzle nut 21, the nozzle body 23, the needle valve 24, the nozzle holder 25, the spring seats 26, 28, and the nozzle spring 27 are made of an electrically conductive material or materials.
A valve element lift sensor 35 is disposed between the spring seat 28 and the nozzle holder 25 for generating an output signal corresponding to the force applied by the spring seat 28. The output signal from the valve element lift sensor 35 is picked up from a lead-out conductor 36 extending through an insulator 32 sealingly fitted in the nozzle holder 25 and extending to the spring chamber 25A. The valve element lift sensor 35 includes a piezoelectric element 1 made of a ceramic material, for example. The piezoelectric element 1 has one electrode surface held against the nozzle holder 25 through a conductor 38 bonded to the electrode surface by an electrically conductive adhesive. The other electrode surface of the piezoelectric element 1 is held against the spring seat 28 through an insulator 39 bonded to the electrode surface by an adhesive, and is electrically connected to the lead-out conductor 36. The one electrode surface of the piezoelectric element 1 is grounded through the conductor 38 and the nozzle holder 25, whereas the other electrode surface is electrically insulated from the fuel injection valve 20, thus allowing the output signal from the valve element lift sensor 35 to be picked up from the lead-out conductor 36.
When the needle valve 24 is lifted by introducing fuel into the fuel reservoir 40 via the passages 29, 30, 31, the spring seat 26 compresses the nozzle spring 27 to increase the force acting on the piezoelectric element 1 through the spring seat 28. As a result, the piezoelectric element 1 generates a voltage commensurate with the rate of change of the force applied thereto. Therefore, the piezoelectric element 1 produces ah output voltage dependent on the acceleration or deceleration of movement of the needle valve 24.
Referring back to FIG. 1, the output signal from the piezoelement element 1 of the valve element lift sensor 35 is supplied through a bandpass filter 2 to one input terminal of a comparator 3 serving as a waveform shaper means. The comparator 3 is supplied at its other input terminal with a reference voltage produced by dividing a power supply voltage Vcc. The comparator 3 converts the output signal supplied from the piezoelectric element 1 through the bandpass filter 2 into a pulse signal. The comparator 3 generates a positive output signal, for example, when an input signal exceeding the reference voltage is applied thereto. A one-shot multivibrator 5 is triggered by a positive-going edge of the output signal from the comparator 3. A Q output signal from the one-shot multivibrator 5 and the output signal from the comparator 3 are ANDed by an AND gate 6. An output signal from the AND gate 6 is supplied as a clock signal to a D flip-flop 7, from which a Q output signal is supplied to a microcomputer 12 to which an input signal is also applied from an OR gate 8 (described later on). In response to these input signals, the microcomputer 12 calculates an angle (indicated by θ) by which the timing to start fuel injection precedes a top dead sender (T.D.C.)
A reference signal generator 9 generates a reference signal, e.g., a T.D.C. (top dead center) pulse.
The reference signal generator 9 comprises a known sensor for detecting a timing at which piston in the engine reaches a T.D.C., and producing a reference signal (T.D.C. pulse) which is supplied to a zero-crossing detector 10 having hysteresis for detecting a zero-crossing point of the T.D.C. pulse. The zero-crossing detector 10 produces an output signal which resets the flip-flop 7. The Q output signal from the flip-flop 7 and an output signal from a differentiator 11 are ORed by the OR gate 8, which then applies its output signal as an input capture signal to the microcomputer 12.
An output signal produced from the piezoelectric element 1 upon the lifting of the valve element of the fuel injection valve 20 has a frequency distribution A as shown in FIG. 3. An output signal produced from the piezoelectric element 1 when the nozzle spring 27 resonates has a frequency distribution B as shown in FIG. 3. The frequency distribution A of the valve element lifting output signal from the piezoelectric element 1 and the resonant frequency B of the nozzle spring 27 are therefore different from each other. The period in which the fuel injection valve 20 is open is longer than 1/2 of the period of the resonant output signal from the nozzle spring 27. Assuming that the resonant frequency of the nozzle spring 27 is 3 kHz, its half-wave period T 2 (see FIG. 4(b)) is about 160 μs. It is preferable that the pulse duration T 1 see FIG. 4(c)) of the output signal from the one-shot multivibrator 5 be slightly longer than the period T 2 (=160 μs) and shorter than the minimum period of needle valve lifting i.e., the minimum period of time during which the needle valve 24 is being lifted in one lifting cycle thereof, e.g., the period of 200 μs.
When the fuel injection valve 20 is opened, the piezoelectric element 1 produces an output signal as shown in FIG. 4(a). This output signal has a level D because the pressure from the nozzle spring 27 is repeatedly applied to the piezoelectric element 1 so that charges are not completely removed from the piezoelectric element 1. Thus, the output signal is shifted positively by the level D. After the valve element is closed, the output signal from the piezoelectric element 1 due to the resonant frequency of the nozzle spring 27 has damping oscillation. The first negative-going edge E of the output signal after the valve element is closed is steeper than the signal edge when fuel injection is started since the pressure drop in the fuel injection valve 20 is quick after the pressure-feed of the fuel is completed. The following positive-going edge F of the oscillating output signal rises quickly in response to the steep gradient of the negative-going edge E.
In response to the output signal (FIG. 4(a)) from the piezoelectric element 1, the comparator 3 issues an output signal as shown in FIG. 4(b). The one-shot multivibrator 5 is triggered by positive-going edges of the output signal illustrated in FIG. 4(b) to produce output signals as shown in FIGS. 4(c) and 4(d). FIG. 4(c) shows the waveform of the Q output signal from the one-shot multivibrator 5, whereas FIG. 4(d) shows the waveform of the Q output signal from the one-shot multivibrator 5. In FIGS. 4(b) and 4(c), T 1 >T 2 as described above.
The output signal (FIG. 4(b)) from ,the comparator 3 and the Q output signal (FIG. 4(d)) from the one-shot multivibrator 5 are ANDed by the AND gate 6, which produces an output signal as shown in FIG. 4(e). In FIG. 4(e), the pulses having pulse durations T 2 (FIG. 4(b), i.e., noise subsequent to the edge F of FIG. 4(a) is thoroughly removed from the output signal of the AND gate 6. The output signal of FIG. 4(e) indicates fuel injection starting timing because the output signal of the AND gate 6 is a pulse having a pulse duration T 4 , and the period T 3 prior to the positive-going edge thereof is equal to the pulse duration T 1 of the output signal from the one-shot multivibrator 5.
The reference signal generator 9 produces an output signal as shown in FIG. 5(a) which is supplied to the zero-crossing detector 10 that comprises an operational amplifier. The output voltage from the zero-crossing detector 10 is divided and fed back to a noninverting input terminal of the operational amplifier. The zero-crossing detector 10 has a reference level slightly higher than the zero potential when the input signal level increases, and a reference level equal to the zero potential when the input signal level decreases. Therefore, the zero-crossing detector 10 issues an output signal as shown in FIG. 5(b). A point G on the reference output waveform is set to come after the period T 1 is over. The positive-going and negative-going edges of the output signal from the zero-crossing detector 10 are differentiated by the differentiator 11, which produces an output signal as shown in FIG. 5(c). The D flip-flop 7 is reset by the positive-going edges of the output signal from the differentiator 11 to produce an output signal having a pulse duration Tit as shown in FIG. 5(d). The OR gate 8 generates an output siganl as illustrated in FIG. 5(e).
In response to the signal from the OR gate 8, the microcomputer 12 stores a count of output pulses from a free-running oscillator (not shown) during an interval from positive-going to negative-going edges of the applied signal. Upon determination of a fuel injection starting signal based on the signal from the D flit-flop 7, the microcomputer 12 detects an engine rotational speed N (r.p.m.) and a pulse duration Tit based on the stored count. Since the pulse duration Tit is shorter by the period T 3 (=T 1 ), it is corrected into Tit*=Tit+T 1 using the value of T 3 which has been stored in a ROM. Then, the microcomputer 12 calculates an angle (θ) by which the timing to start fuel injection precedes a T.D.C., using the data N,Tit*.
In the above embodiment, the valve element lifting signal is produced by the piezoelectric element. Where the lifting movement of the valve element is converted to an inductance, and a valve element lifting signal is produced from such an inductance, the valve element lifting signal is also subject to the vibration of the nozzle spring. The illustrated embodiment of the invention is also effective to remove noise from such valve element lifting signal.
While the present invention has been described as removing noise produced by the nozzle spring, the circuit of the present invention can also be employed to remove other noise.
With the present invention, as described above, the detected valve element lifting signal is supplied to the waveform shaper means and converted thereby into a pulse, and the pulse generating means for generating a pulse shorter than the minimum valve element lifting period is triggered by an output signal from the waveform shaper means. The output signal from the pulse generating means and the output signal from the waveform shaping means are processed in a logical operation to produce a signal which continues for an interval longer than the pulse duration of the output signal from the pulse generating means, the signal being substantially idential to the detected valve element lifting signal. Any input signal applied to the waveform shaper means, which has a pulse duration shorter than the above signal interval, is completely removed as noise.
Although a certain preferred embodiment has been shown and described, it should be understood that many changes and modifications may be made therein without departing from the scope of the appended claims. | A fuel injection valve for injecting fuel into an internal combustion engine has a valve element lift sensor for producing an output signal in response to pressure developed by movement of a valve element. A detected valve element lifting signal produced from the valve element lift sensor is shaped into a waveform, and employed to generate a pulse having a pulse duration shorter than a minimum valve element lifting period and longer than the duration of a pulse issued from a waveform shaper after the supply of fuel to the fuel injection valve has been cut off. The generated pulse and the shaped valve element lifting signal are ANDed to remove noise from the output signal of the valve element lift sensor. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/448,165 entitled Quality Maintaining Pizza/Food Take-out Box which was filed on May 30, 2003 and which is incorporated herein as is fully set forth.
STATEMENT REGARDING FEDEDRALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] N/A
REFERENCE TO A SEQUENCE LISTING
[0003] N/A
BACKGROUND OF THE INVENTION
[0004] The present invention relates generally to boxes and more particularly to improved pizza (or a similar hot food item) take-out boxes, which minimize the surface area of the box that contacts the pizza.
[0005] Pizza take-out boxes are typically formed from a single panel of fiberboard, liner board, corrugated fiberboard, or micro-flute, which is folded by pizza restaurant personnel to form a box having a lid and a tray portion. There are also pizza take-out boxes that are formed from separate lid and tray portions, but they are not as popular. There are pizza boxes of various shapes and sizes such as circles, squares with cut off corners, octagons, etc, boxes for whole pies single slices, etc. Regardless of the shape or how many parts the boxes have, there are certain common goals; to keep the food hot while retaining the desirable characteristics and quality, such as, in the case of pizza, a crispy crust. While this may seem like an easy task, it is not.
[0006] Hot pizza produces stream, which condenses and absorbs into the box. Since the pizza rests on the conventional box bottom, the condensation also absorbs into the crust of the pizza. This absorption results in a loss of both crispness (e.g., the pizza crust will become soggy) and product quality (the crust absorbs the taste of the cardboard with the condensation). While cutting vents or holes into the box releases some of the steam and lessens the condensation problem it does not entirely eliminate the problem does nothing for the grease and oil problem and it also causes another; temperature loss. With vents in the box, the pizza crust remains slightly crispier but the pizza now arrives at its destination cold.
[0007] In addition to the condensation problem, pizzas that have toppings, such as pepperoni, drip grease which collects in the tray portion of the box resulting in the pizza crust sitting in this grease. This is also not desirable as it causes the pizza crust to become greasy wet and soggy. Venting the box has no effect on this problem.
[0008] Conventional pizza boxes have been designed with relatively expensive moisture absorbing materials, variations in the shape of the box and in the number and size of the vents, etc. in an attempt to resolve this issue. Some of the two-piece boxes also employ permanent projections formed in the tray portions in an attempt to raise the crust off of the bottom of the tray. However, these projections are not employed in the one-piece cartons since the permanent projections prevent the boxes from being stacked flat. Other conventional attempts to resolve this issue include relatively expensive metal or plastic trays with permanent projections, etc. There is at least one conventional one-piece pizza box (U.S. Pat. No. 5,052,559), which employs a combination of discrete support strips, which may be individually elevated, and vents which are used to secure the support strips in an elevated position. However, this design requires too many operations to be practical, requires the pizza to be cut before it is placed into the box and requires too many vents, which causes the heat loss problem discussed above. Each of the conventional pizza box designs are either too expensive, too complicated or address one problem while creating an equally unacceptable problem.
[0009] Another problem faced by a majority of the conventional pizza boxes is that they are difficult to carry from the bottom due to the fact that the bottom of the box gets very hot from the hot pizza resting on the bottom.
[0010] Accordingly there exists a need for an improved pizza take-out box which is relatively inexpensive, maintains a large surface area of the food off of the box, maintains a cool box surface for carrying, can be stored relatively flat and sets up in relatively few steps.
BRIEF SUMMARY OF THE INVENTION
[0011] It has been discovered that various advantages may be realized by the present pizza box having a pizza support. The invention includes a box for transporting hot food. The box includes a top, a bottom an inside and an outside, and is adapted to house the hot food while maintaining a portion off of the bottom of the box. The box includes multiple ribs secured to multiple bases. At least 1 of the bases is adhered to the bottom of the box. The ribs are selectively moveable between a storage position and a support position. The storage position is substantially flat relative to the bottom and the support position is substantially perpendicular relative to the bottom. By substantially it is meant somewhere between 45 degrees and 135 degrees. The box also includes a connector connected to the ribs and configured to extend from the inside of the box to the outside of the box. The connector is also configured to simultaneously move the ribs between the storage position and the support position and to prevent the ribs from moving back to the storage position by mating with the box.
[0012] In an embodiment, the invention may include a method of supporting a pizza in a pizza box. The method includes connecting multiple ribs to a bottom of the box. The ribs are connected to a common connector. The method also includes simultaneously moving the ribs with the common connector from a substantially flat position relative to the bottom to a substantially perpendicular position relative to said bottom. The method also includes pulling the common connector to an outside portion of the box and locking the common connector against an outside of the box.
[0013] In another embodiment, the invention includes an apparatus for supporting hot food in a delivery box having a top a bottom and a plurality of walls. The apparatus includes a blank of material, configured to be adhered to the bottom of the box, having multiple horizontal and vertical cuts therein. The horizontal cuts form a multiple rib/base pairs and the vertical cuts form a pull tab connected to the rib/base pairs only by the ribs. At least two of the horizontal cuts partially separate at least two of the ribs from at least two of the bases. The pull tab is configured to mate with the box after it is pulled; and, to simultaneously rotate at least two of the ribs from a substantially flat position to a substantially perpendicular position.
[0014] The invention will next be described in connection with certain illustrated embodiments; however, it should be clear to those skilled in the art that various modifications, additions and subtractions can be made without departing from the spirit or scope of the claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0015] For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description and accompanying drawings, in which:
[0016] [0016]FIG. 1 depicts a top plan view of an embodiment of the invention in a relatively flat storage configuration showing a pizza support;
[0017] [0017]FIG. 2 depicts a perspective view of the embodiment of FIG. 1 showing a box assembled and the pizza support connected to the box and locked in a support configuration;
[0018] [0018]FIG. 3 depicts a bottom plan view of the pizza support used in the embodiment of FIG. 1 in a substantially flat storage configuration illustrating potential adhesive placement;
[0019] [0019]FIG. 4; depicts a sectional view taken along line A-A of FIG. 2 with the cover of the box closed and a pizza being supported on the pizza support;
[0020] [0020]FIG. 5 depicts a sectional view taken along line A-A of FIG. 2 with the cover of the box closed and a pizza being supported on the pizza support and substituting an alternate embodiment of the pizza support;
[0021] [0021]FIG. 6 depicts a top plan view of an alternate embodiment of the invention in a relatively flat storage configuration showing a pizza support adhered to a box;
[0022] [0022]FIG. 7 depicts a top plan view of another alternate embodiment of the invention in a relatively flat storage configuration showing a pizza support adhered to a box;
[0023] [0023]FIG. 8 depicts a top plan view of still another alternate embodiment of the invention in a relatively flat storage configuration showing a pizza support adhered to a box;
[0024] [0024]FIG. 9 depicts a top plan view of an alternate embodiment of the invention in a relatively flat storage configuration showing a pizza support having an alternate embodiment of a stop tab that prevents the actuator from being pulled too far;
[0025] [0025]FIG. 10 depicts a top plan view of another alternate embodiment of a pizza support in a substantially flat storage configuration illustrating side slats connecting the bases together;
[0026] [0026]FIG. 11 depicts a top plan view of another alternate embodiment of a pizza support in a substantially flat storage configuration illustrating side slats connecting the bases together and a rear slat connecting the side slats together;
[0027] [0027]FIG. 12 depicts a top plan view of another alternate embodiment of a pizza support in a substantially flat storage configuration illustrating side slats connecting the ribs together and a front slat acting as a stop tab;
[0028] [0028]FIG. 13 depicts a top plan view of another alternate embodiment of a pizza support in a substantially flat storage configuration illustrating side slats connecting the ribs together, a front slat acting as a stop tab, and a rear tab connecting the side tabs together;
[0029] [0029]FIG. 14 depicts a top plan view of the invention illustrating that the cuts between the ribs and bases need not be straight lines;
[0030] [0030]FIG. 15 depicts a top plan view of an embodiment of the invention illustrating another possible shape for the cuts between the ribs and the bases and a stress relieving cut between a rib from one set and a base of another set.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Referring to the drawings in detail, wherein like reference numbers identify like elements throughout the various figures, there is illustrated in FIGS. 1-15 a box for supporting heated food in accordance with the invention. All conventional pizza boxes (whether one-piece or two) have at least a cover portion a bottom portion and walls. The invention provides apparatus and methods for supporting a pizza in a pizza take-out box (while the following description will only discuss pizza, those skilled in the art will recognize that the invention could also be used to transport other foods).
[0032] FIGS. 1 illustrates a preferred embodiment of the invention, although by no means the only embodiment. The embodiment illustrated in FIG. 1 includes a support 20 for use with a box 10 to raise a pizza 80 (or any other hot, greasy food) off of the bottom of the box 10 . The support 20 is preferably constructed from a single piece of coated paperboard, such as 0.014 Custom Kote® manufactured by MeadWestVaco. While this particular brand and caliper of coated board is disclosed, those skilled in the art will recognize that other coated or non-coated materials could also be employed as well as other coated materials from other manufacturers. Additionally thicker or thinner materials could be employed which need not be paperboard. They must only be strong enough and flexible enough and resistant enough to heat and/or grease and/or moisture to perform as discussed herein. The support 20 of FIG. 1 is envisioned for use with smaller boxes 10 while larger boxes (such as 18″ and larger are expected, although not required, to be slightly different). By way of example only, for a 14 inch square box, the dimensions of the support could be as follows: the overall length and width of the support 20 , not including the portion of pull tab 50 extending beyond the ribs is 13½inches by 13½ inches. Each rib 30 is approximately ⅜″ long, each base 40 is approximately ⅜″ long and each stress relieving cutout 240 is approximately {fraction (1/16)}″ long. The width of the pull tab 50 is approximately 1″ and the length of the pull tab 50 extending beyond the ribs 30 is approximately 2″. The triangular portion 70 has a lower base, which is approximately ⅛″ on each sides and the stop tab 230 has a substantially similar dimension. The distance between the lower base of the triangular portion 70 and stop tab 230 depends on the thickness of the box 10 (i.e. it should preferably be at least as large as the thickness of the box 10 ). The portion of the pull tab 50 beyond the triangular portion 70 is preferably ¼″ narrower than the remainder of the pull tab 50 to enable the triangular portion to lock with the box 10 after it is pulled therethrough. The vertical cuts 260 are approximately {fraction (11/16)}″ long thus leaving approximately {fraction (1/16)}″ connection between the ribs 30 and the pull tab 50 . Those skilled in the art will recognize that, as shown in FIG. 5, the connection between the pull tab 50 and the ribs 30 could be below the top to bring the pull tab 50 out of contact with the pizza 80 . Further, either the pull tab 50 and/or the ribs 30 could include holes to increase hot air flow and/or grease dripping away from the food 80 . In the preferred embodiment, the ribs 30 are separated from the bases 40 by a cut 90 except in two locations; the location closest to the pull tab 50 and the location farthest from the pull tab 50 . At these locations, the ribs 30 are preferably connected to the bases 40 by {fraction (1/16)}″ wide connection. The support 20 is connected to a box 10 by connecting the bases 40 to the bottom of the box 10 . As illustrated in FIG. 3, this may be realized by placing drops of glue 250 (or any other sufficient adhesive) at various points on the underside of the bases 40 . Those skilled in the art will recognize that the adhesive 250 could be placed at various locations on the bases or on the entire underside of the bases 40 . Those skilled in the art will recognize that currently the adhesive 250 and the support 20 must be made from FDA approved materials in the United States. As illustrated in FIGS. 6-8, the support 20 may be oriented in any direction within the box 10 . Preferably, as illustrated in FIGS. 6-8 the tabs on the lid portion of the box should include a cutout portion so as not to interfere with the pull tab 50 when the box is closed. Although those skilled in the art will recognize that the pull tab 50 could be configured in such a way that the tabs need not be cut, such as if the pull tab 50 is pulled through the bottom or top of the box 10 or near the bottom of a side of the box 10 . Another potential benefit of the invention is that it can be used as a security device. If the pull tab 50 is configured to be pulled through and locked to the top of the box then the customer will be able to tell if the pizza box was opened as opening the box will destroy the pull tab.
[0033] For larger boxes 10 (greater than 18″) it is preferable to have almost all dimensions the same as discussed above with the following exceptions: the overall dimensions for an 18″ box should be approximately 16½″ by 16½″ and the connections between the ribs 30 and the bases 40 should be placed at the location closest to the pull tab 50 and at a location approximately 2″ in from the opposite end of the ribs/bases 30 / 40 .
[0034] In operation, the support 20 is cut (preferably die cut although not required to be) and connected to the box 10 . Either during manufacture of during assembly of the box, the pull tab is placed through slit 60 , which is cut in the box 10 to be narrower than triangular portion 70 . Once this is done and the box 10 is assembled, the pizza salesperson has two options. The first option is to pull the pull tab 50 to rotate the ribs 30 into a supporting position such that the triangular portion 70 gets pulled through the box 10 far enough so that it can not easily be pulled back through the box 10 , but not so far as to pull the ribs 30 too far past perpendicular, thus locking the support 20 in a supporting position. At this point the hot, greasy food may be placed on the support 20 and the box closed. The second option is to place the hot greasy food in the box while the support 20 is in a storage position then either close the box and pull the pull tab 50 as discussed above or pull the pull tab 50 as described above while the box is open to watch the food rise from the bottom of the box 10 . To this end it may be desirable to employ the invention with a conventional windowed pizza box 10 (not shown).
[0035] While preferred embodiments of the invention have been described to this point, there are many changes that can be made without departing from the scope of the invention. For example, those skilled in the art will recognize that the measurements have been provided solely as exemplary and are in no way intended to be limiting. For example the overall dimensions may be enlarged for better support or made smaller to save money and materials, or one or more of the individual measurements may be changed to suit the design needs of the manufacturer. For instance the ribs 30 and bases 40 could be different sizes to allow for more or fewer ribs 30 also the widths of various rib/base pairs could be varied to form various shapes other than squares. Additionally, the following description will illustrate further possible changes that may be applied to the invention without departing from the scope.
[0036] As illustrated in FIG. 9, the stop tab 230 could be located at the rear of the support 20 and configured to be inserted through the opposite end of the box as the pull tab 50 .
[0037] As illustrated in FIG. 10, each of the bases 40 on a side of the support 10 may be connected by a side tab to the other bases 40 on that side of the support 10 . The side tabs may extend beyond the front of the support 10 to form a stop tab 230 . As illustrated in FIG. 11, the side tabs may be connected together by a rear tab.
[0038] As illustrated in FIGS. 12-13, the ribs 30 may be connected together including a front tab which acts as the stop tab 230 .
[0039] [0039]FIGS. 14-15 illustrate that the cuts 90 that separate the ribs 30 from the bases 40 may be various shapes and sizes. The purpose of making larger cuts 90 in the bases 40 is to lessen the stress between the ribs 30 and the bases 40 when attempting to raise the ribs 30 from the storage position to the supporting position. Making larger cuts 90 in the ribs 30 lessens the stress between the ribs 30 and the bases 40 when attempting to raise the ribs 30 from the storage position to the supporting position. It also increase the air circulation under the pizza 80 .
[0040] It will be recognized by those skilled in the art that each embodiment of the invention could be revised in various ways without departing from the scope of the invention. For example, each embodiment could include one or more of the features from another embodiment. The ribs 30 could be varied to form pizza supports 20 of various shapes such as circles, triangles, rectangles, squares, hexagons, pentagons, octagons or some other useful shape. The ribs 30 could be the same size as the bases 40 , larger or smaller and the triangular mating tabs 70 could be various shapes such as arrow shaped, semi-circular, semi-octagonal, etc. Additionally, the support 20 could be configured to be diagonal relative to the box 10 . Further the ribs could be smaller than ⅜″ or larger so long as when the pizza 80 is raised it does not contact the top of the box.
[0041] Since pizza boxes 10 vary in size for small, medium and large pizzas 80 , the present invention can vary in size as well.
[0042] From a manufacturing point of view, the preferred way to manufacture the invention is from a single blank of material. Those of ordinary skill will recognize that it could be made from multiple separate pieces, but that would probably add to the cost and manufacturing complexity. The blank, which varies in size depending upon the embodiment, is cut in different locations (preferably with a single die-cut) to form one of the embodiments. Once the pizza support 20 is formed it is adhered to the bottom of the box 10 . At this point it can be packaged, shipped and stored as pizza boxes are currently packaged, shipped and stored.
[0043] It will thus be seen that the invention provides a method and apparatus for providing a pizza box having a pizza support. Those skilled in the art will appreciate that the invention is depicted in FIGS. 1-15.
[0044] It will be understood that changes may be made in the above construction and in the foregoing sequences of operation without departing from the scope of the invention. It is accordingly intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative rather than in a limiting sense.
[0045] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention as described herein, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. | A pizza box having a plurality of ribs, which are selectively moveable between a first stored position and a second upright position is provided. The ribs are coupled to at least one actuating strip, which enables the ribs to be simultaneously shifted from the first stored position to the second upright position. The ribs and the actuating strip are formed from the same piece of material. The actuating strip may be configured to interlock with the box to maintain the ribs in the second upright position. There is also a stop tab configured to prevent the actuating strip from moving the ribs beyond a predetermine point. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electron-beam exposure apparatus for exposing a printed substrate and the like by the use of an electron-beam. More particularly, the invention relates to an electron-beam exposure apparatus provided with a correction device for correcting deflection distortion which is capable of being constructed economically using a memory device of relatively small capacity.
2. Description of Prior Art
FIG. 1 is a schematic diagram showing a correction device for correcting deflection distortion occurring in conventional electron-beam exposure apparatuses, as disclosed in Japanese Kokai No. 113168/1977. In FIG. 1, reference numeral 10 designates a correction data storing unit for storing data necessary to correct the deflection distortion, and reference numerals 11 and 12 designate data lines for data representing beam positions in the X-axis and Y-axis directions, respectively. The data lines 11 and 12 are connected to either a pattern data storing unit or a pattern data generating unit (not shown). The correction data storing unit 10 is coupled to the X-data line 11 and Y-data line 12 through data lines 13 and 14 for X-address bits and Y-address bits, respectively. The correction data storing unit 10 is also coupled to an X-adder 17 and a Y-adder 18 through an X-correction data output line 15 and a Y-correction data output line 16. In the X-adder 17, the X-correction data is added to the beam position data in the X-axis direction. On the other hand, the Y-correction data is added to the beam position data in the Y-axis direction in the Y-adder 18. The digital outputs of the X-adder 17 and the Y-adder 18 are applied to D/A converters 19 and 20, respectively, to be converted into analog data. A main deflection coil 12 deflects the electron-beam in the X-axis direction according to the output of the D/A converter 19, whereas a main deflection coil 22 deflects the electron-beam in the Y-axis direction according to the output of the D/A converter 20.
The operation of the conventional apparatus will be described with reference to FIG. 1 and FIG. 3(A).
The beam position data which are supplied through the data lines 11 and 12 from either the pattern data storing unit or the pattern data generating unit (not shown), have an accuracy of N-bits in each of the X-axis and Y-axis directions. A deflection area is equally divided by 2 n (n is positive integer satisfying n<N) in both the X and Y directions to thereby obtain lattice pattern points of (2 n +1)×(2 n +1) as shown in FIG. 3(A). The correction data are measured at these correction data measurement (lattice pattern) points and then correction data of 2 n ×2 n is obtained by deleting one column and one line in each of the X and Y directions, voluntarily. The correction data 2 n ×2 n are stored in the correction data storing unit 10. In deflecting the electron-beam, the correction data which have been stored in the correction data storing unit 10 are applied through the data output lines 15 and 16 to the X-adder 17 and the Y-adder 18, respectively, where the X-correction and Y-correction data are added to the X and Y position data to carry out digital correction. The outputs of the X-adder 17 and Y-adder 18 are subjected to D/A conversion in the D/A converters 19 and 20. Thereafter, the thus obtained analog outputs are applied to the main deflection coils 21 and 22 so as to correct the actual position of the electron-beam. In this case, in order to improve the correction accuracy, it has been proposed to increase the number of correction data measurement (lattice pattern) points in the deflection area, i.e., increase the above described "n" to thereby make the division rate finer.
To make it easy to understand the correction operation, a concrete example is where n=3, that is the division rate is 2 3 =8, the division rate being relatively rough, is shown in FIG. 3(A). The left part of FIG. 3(A) illustrates a square electron-beam pattern that is affected by deflection distortion. As shown in FIG. 3(A), the square electron-beam pattern is distorted at the center of each edge like a bobbin. The distortion is measured at the measurement points to be applied to the respective adders 17 and 18 so that the correction is accomplished by subtracting a value corresponding to the distortion from data representing a reference square pattern not distorted. The corrected pattern is as shown in the right part of FIG. 3(A). The corrected pattern is obtained by subjecting the data for each of the measurement points to correction based on the X-correction data and Y-correction data, and therefore the deflection distortion between the adjacent measurement points remains without correction.
With such a conventional apparatus as constructed above, all of correction data are stored in the correction data storing unit 10, and an actual pattern including deflection distortion is subjected to correction in a digital mode. It should be noted that the bobbin-shaped deflection distortion as shown in FIG. 3(A) occurs most frequently, and such a bobbin-shaped figure can be expressed as a cubic function. Accordingly, it is unnecessary to store the correction data for the bobbin-shaped distortion in the correction data storing unit in advance. In other words, while the provision of a cubic-function processing function enables the apparatus to prepare the correction signals with respect to distortions that can be expressed by a cubic function, without the data having to be provisionally stored in the storing unit the memory capacity is nevertheless increased. However, as mentioned above, all of data including the correction data for the bobbin-shaped distortion for instance are stored in the storing unit. To this end, in the case of exposing a printed substance in which deflections having large amplitudes may occur, the correction values becomes larger than those in exposing an ordinary wafer by the use of the conventional apparatus. Accordingly, in order to maintain accuracy in the exposure, it is indispensable to increase the number of measurement points for the correction data, as a result of which the apparatus is made complicated and the manufacturing cost is thus increased.
SUMMARY OF THE INVENTION
In view of the above, the present invention is accomplished to eliminate drawbacks accompanying the conventional apparatus, and thus an object of the present invention is to provide an electron-beam exposure apparatus in which digital correction with respect to beam-position data is combined with analog correction with respect to beam-position data after being subjected to digital-to-analog conversion, thereby resulting in decreasing the number of measuring points so as to reduce the storage capacity of a correction data storing unit and to make the apparatus simple in construction.
The above, and other objects of the present invention are accomplished by the provision of an electron-beam exposure apparatus which comprises a correction data storing unit for storing correction data other than data that can be expressed by a cubic function, an adding unit for adding the correction data from the storing unit to beam position data in both the X- and Y-axis directions; a digital-to-analog converting unit for subjecting output signals from the adder unit to digital-to-analog conversion; and an analog arithmetic operation unit for subjecting outputs from the digital-to-analog converting unit to analog correction according to either a deflection correction control signal or a cubic-function processing function provided to the arithmetic unit.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a schematic diagram showing an example of a deflection distortion correction device in a conventional electron-beam exposure apparatus;
FIG. 2 is a schematic diagram showing an example of a deflection distortion correction device in an electron-beam exposure apparatus according to the present invention; and
FIG. 3(A) is a diagram showing correction results obtained by the conventional apparatus and FIG. 3(B) is also a diagram showing correction results obtained by an apparatus according to the present invention.
DESCRIPTION OF PREFERRED EMBODIMENT
An embodiment of the present invention will be described with reference to FIG. 2 which is a schematic diagram showing an example of a correction device for correcting deflection distortion occurring in an electron-beam exposure apparatus according to the present invention. In FIG. 2, the same circuit components or elements as those in FIG. 1 bear the same reference numeral. Reference numerals 33 designates a digital arithmetic unit disposed on both the X-beam position data line 11 and the Y-beam position data line 12. The digital arithmetic unit 33 is adapted to have a cubic-function processing function, so that the beam position data in the X-axis direction and Y-axis direction are corrected based on either the cubic-function or an external control signal 34. The digital arithmetic unit 33 is provided in order to avoid unnecessary storage of correction data which can be expressed by the above described cubic function. An analog arithmetic unit 35 operates to subject the outputs of the D/A converters 19 and 20 to analog corrections based on either an external control signal 36 or a preset cubic-function processing function provided thereto. Further, reference numerals 37 and 38 designate power amplifiers for amplifying the outputs of the analog arithmetic unit 35 to drive the main deflection coils 21 and 22.
The operation of the embodiment shown in FIG. 2 will be described.
The beam position data which are supplied through the data lines 11 and 12 from either the pattern data storing unit or the pattern data generating unit (not shown), have an accuracy of N-bits in each of the X-axis and Y-axis directions. A deflection area is equally divided by 2 n (n is positive integer satisfying n<N) in both the X and Y directions to thereby obtain lattice pattern points of (2 n +1)×(2 n +1) as shown in FIG. 3(B). The correction data are measured at these correction data measurement (lattice pattern) points and then correction data of 2 n ×2 n is obtained by deleting one column and one line in each of the X and Y directions, voluntarily. The correction data are then subjected to selection in the digital arithmetic unit 33 so as to remove the correction data that can be expressed by a cubic function therefrom. Thereafter, the remaining correction data are stored in the correction data storing unit 10. Upon an occurrence of beam deflection, the correction data is read out from the correction data storing unit 10, and then the correction data are supplied through the data output lines 15 and 16 to the X-adder 17 and the Y-adder 18, respectively, where the X-correction and Y-correction data are added to the X and Y position data to carry out the digital corrections. The outputs of the X-adder 17 and the Y-adder 18 are subjected to D/A conversion in the D/A converters 19 and 20 to be applied to the following analog arithmetic unit 35. In the analog arithmetic unit 35, analog signals are then subjected to the analog conversion based on either the external control signal 36 with respect to the deflection corrections or the preset cubic-function processing function.
In order to clarify the correction operation, concrete examples of a pattern after the analog correction and after the digital correction are illustrated in FIG. 3(B). While the order of the corrections is reversed in FIG. 3(B), the final or net result of the corrections is that obtained by the device constructed as shown in FIG. 2. The left part of FIG. 3(B) illustrates a square pattern having deflection distortion, that is a bobbin-shaped pattern, the middle part thereof illustrating an example of the pattern after the analog corrections and the right part thereof illustrating an example of the pattern after subjecting the analog-corrected pattern to digital correction. The pattern shown in the middle portion of FIG. 3(B) is obtained by subjecting the bobbin-shaped pattern to correction with respect to distortion that can be expressed by a cubic function. The pattern shown in the right part thereof is obtained by subjecting the pattern shown in the middle portion thereof to the digital correction.
As shown in the middle part of FIG. 3(B), there still remains distortion in the pattern. In this case, however, since the three-dimensional distortions which occupy the most part of the distortion have been corrected the occurrence of the distortions is suppressed for the most part. The correction pattern is then further subjected to the digital corrections as fine corrections. Consequently, the pattern shown in the right portion of FIG. 3(B) is obtained.
As is apparent from a comparison of FIGS. 3(A) and 3(B), according to the present invention, each of the edges of the square pattern is corrected smoothly.
With such a correction device as described above according to the present invention, where the deflection distortion is corrected by both the digital correction with a cubic-function processing and analog correction, assuming that the maximum in the correction amount of distortion that cannot be corrected based on the cubic-function could be reduced to 1/m of the maximum in the correction amount thereof in the conventional apparatus, it becomes possible to reduce the capacity of the correction data storing unit to 1/m 2 of that in the conventional one without degrading the correction accuracy. Although the above described apparatus employs a single analog arithmetic unit 35, a plurality of arithmetic units having a variety of arithmetic functions may be employed in order to improve the correction accuracy.
According to the present invention, the correction operation of distortion which can be expressed by the cubic function and which occupies for the most part of the distortion, is shared to the analog arithmetic unit, and the remaining fine distortion is only measured actually to be stored in the correction data storing unit for the purpose of the digital fine correction. As a result, it is realized to make the correction data storing unit compact with maintaining the correction accuracy required. | An electron-beam exposure apparatus having a correction function for correcting deflection distortion. The correction function is carried out by the provision of a correcting device including an analog correction unit 35 and a digital correction unit having a memory unit 10 for storing correction data other than data that can be expressed by a cubic function. The capacity of such a memory unit can be made smaller than that of conventional apparatuses. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from provisional application No. 60/628,311, filed Nov. 15, 2004, and 60/662,469, filed Mar. 30, 2005, the contents of both of which are herewith incorporated by reference.
BACKGROUND
[0002] Technolines LLC has been granted a number of patents, including U.S. Pat. No. 5,990,444 and others, which describe lasers being used to write graphic images and patterns on substrates. The lasers may write graphic images on fabric substrates such as cotton, polyester, suede, leather, and the like. The laser should write with an output power or energy “density” per unit time, or EDPUT, that makes a mark on the fabric, without undesirable damage to the fabric.
SUMMARY
[0003] The present application describes a technique of treating fabrics prior to and/or after marking them with a laser. The treatment allows the laser to make a better sustainable mark on the fabric (specifically after repeated washes or wear).
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIGS. 1 and 2 show embodiments of the system with a pretreatment, and laser marking part.
DETAILED DESCRIPTION
[0005] The general structure and techniques, and more specific embodiments which can be used to effect different ways of carrying out the more general goals are described herein.
[0006] A basic embodiment is shown in FIG. 1 . FIG. 1 shows the operation along a conveyor 100 , however, it should be understood that the operation can be carried out in one place, or as part of any other kind of workstation. A workpiece, e.g., a fabric item, or clothing part, shown as 99 , is exposed to the output of a laser 105 . A controller 110 controls the laser. The controller may be internal to the laser 105 or may be completely separate. The controller causes the laser to output a beam which has an energy amount that causes a change to the look of the fabric. The energy amount may be set as an energy density per unit time, which may avoid undesirable damage to the fabric and may alter the fabric chemistry. The controller, for example, may be a computer that is controlled according to a prestored program. The program may include an image of a design to be scribed. The design may be image portions representing words, or may be image portions representing an actual image, such as a logo. The computers described herein may be any kind of computer, either general purpose, or some specific purpose computer such as a workstation. The computer may be a Pentium class computer, running Windows XP or Linux, or may be a Macintosh computer. The programs may be written in C, or Java, or any other programming language. The programs may be resident on a storage medium, e.g., magnetic or optical, e.g. the computer hard drive, a removable disk or other removable medium. The programs may also be run over a network. FIG. 2 illustrates the incorporation of the invention in a typical screen printing carousel operation. For those skilled in the art, it is apparent that the traditional multiple arms which apply different colored paints to the fabric via individual screen printing, can be situated anywhere along the carousel shown in FIG. 2 .
[0007] It has been observed that most textile substrates are very responsive to the laser writing process. After the textile is processed by the laser, it is desirable that the image that was written during the operation should be seen immediately, and that the image is also seen later—e.g., after wearing or washing. However, on certain garments, and specifically on some cotton materials, the graphic has been observed to disappear or reduce in contrast after washing. The kinds of materials, and the reasons why this happens are unknown. The materials and results have not been easily susceptible of prediction.
[0008] For example, this problem could exist on one specific dyed cotton material. However, the problem might not exist on a similar dyed cotton material of the same color. Some colors tend to produce better laser-scribed graphics than others. There has been minimal consistency between the processes. For example, scribed graphics on blue and red cottons have tended to look better after washing then the same graphics lazed on black or pink cottons.
[0009] It is postulated that variations in the yarn, weaving, dyes, retention techniques or other material variation might be responsible for the inconsistent problem. However, this problem prevented laser scribed graphics from being used on all dyed fabrics; while also withstanding repeated washing.
[0010] The inventor believed that there must be some spray or surface treatment which could change the characteristics of the material, here cotton, to allow the scribed graphics to withstand repeated washings. A variety of different surface treatments were investigated. A specific product called PermaFresh was found from a chemical company called Omnova. The PermaFresh product is a total fabric treatment for stain and wrinkle resistance. This treatment is meant to remain bound to the fabric for the life of the fabric, and to withstand washing.
[0011] Permafresh surprisingly proved to essentially eliminate the post wash characteristic problem when processing laser scribed graphics on many different dyed materials and colors. Other analogous materials may also be used, which will have similar results.
[0012] The PermaFresh compound is applied, and heat cured, to alter the surface chemistry of the material in some way. Element 120 illustrates the fabric pretreatment process, where the sprayer 120 sprays the material 125 on to the workpiece 99 prior to laser scribing. The heat curing may be a totally separate step along the conveyor, or may rely on the heat produced by the laser 105 itself. This allows the laser-written graphics to appear crisp and clean even after repeated washings. This also made it possible, and also facilitates the laser writing of the graphics on certain cotton colors such as black and pink. Laser writing on black and pink has historically been difficult or impossible prior to this pretreatment technique.
[0013] A post treatment step 130 applies a post treatment material on to the workpiece. The post treatment may simply be for example from the heat flow, or may be either another wrinkle resistance material or the same wrinkle resistance material. Heat may serve to further fix the wrinkle resistant material in place. Typically the heat application is applied after the spaying operation and before the lazing operation. An additional post treatment as in step 180 in FIG. 2 could actually cool the spayed and heated material.
[0014] The conveyor may also include a washing station shown as 140 . Washing station 140 may apply soap, using brushes as shown, and may vacuum away the soap residue, and/or may also provide a rinse operation to the material after the soap has been applied or may only provide a rinse function. Alternatively, a more conventional washing machine can be used, instead of doing this along the conveyor. The washing operation would be carried out after all laser marking and heating steps are complete.
[0015] While PermaFresh has been described as the one pretreatment material, it should be understood that any treatment process that remains bound to the fabric for the life of the garment may be able to be similarly used. More specifically, any such treatment product which provides stain and/or wrinkle resistance and/or other kind of treatment to the material which changes the characteristic of the material, may be used. It may be postulated that the stain protection somehow chemically alters the surface to allow it to retain the laser formed image after washing. The pretreatment that is used should preferably be liquid, it should preferably remain bound to the fabric for either the life of the fabric or at least for a number of washing cycles of the fabric, and it should at least in one embodiment, have the function of at least one of wrinkle and/or stain resistance.
[0016] Although only a few embodiments have been disclosed in detail above, other embodiments are possible and the inventor (s) intend these to be encompassed within this specification. The specification describes specific examples to accomplish a more general goal that may be accomplished in another way. This disclosure is intended to be exemplary, and the claims are intended to cover any modification or alternative which might be predictable to a person having ordinary skill in the art. For example, other materials, that is, other than Permafresh may be used. An important part of the material is that it alters the characteristic of the fabric, and in a specific way. The fabric's characteristic should be altered in a way that makes it more resistant. Wrinkle resistance and stain resistance are two exemplary ways in which the characteristic should be altered.
[0017] Also, the inventor(s) intend that only those claims which use the words “means for” are intended to be interpreted under 35 USC 112, sixth paragraph. Moreover, no limitations from the specification are intended to be read into any claims, unless those limitations are expressly included in the claims. | Pretreatment of a fabric using a material that binds to the fabric and changes some characteristic of the fabric. In an embodiment, the characteristic that is changed can be at least one of stain and flash for wrinkle resistance. The material can be Permafresh material. The material can bind to the fabric, and intends to be maintained within the fabric for the life of the fabric. After pretreatment, the pretreated material is processed by a laser which intends to change the look of the material without undesirably damaging the material. The treatment may make the treatment by lasers more consistent and allow the lazed graphic to maintain its quality after repeated washings and wearing. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
This is a divisional of application Ser. No. 08/193,263, filed Feb. 8, 1994 now U.S. Pat. No. 5,504,222, which is a continuation-in-part of application Ser. No. 08/110,095, filed Aug. 20, 1993 now U.S. Pat. No. 5,440,057 whose disclosures are incorporated herein by reference.
FIELD OF INVENTION
The invention relates to taxol and to the synthesis of taxol analogs. More particularly, the invention relates to processes and key intermediates for synthesizing taxol analogs.
BACKGROUND
Taxol is a natural product with anti-cancer activity. Because natural sources of taxol are limited, synthetic methods for producing taxol have been developed, e.g., K. C. Nicolaou et al., J. Chem. Soc., Chem. Commun. 1992, 1117-1118, J. Chem. Soc., Chem. Commun. 1992, 1118-1120, and J. Chem. Soc., Chem. Commun. 1993, 1024-1026. Several synthetic taxol analogs have also been developed and have been found to have altered chemical and biological activity as compared to natural taxol, e.g., K. C. Nicolaou et al., Nature, 1993, 364, 464-466. There is considerable interest in the design and production of further taxol analogs. However, progress with respect to the synthesis of such taxol analogs has been blocked by a lack of information regarding certain key synthetic methods and key intermediates essential for the production of a wide range of taxol analogs.
What is needed is the identification of key synthetic methods and key intermediates for producing taxol analogs having altered activities.
SUMMARY
One aspect of the invention is directed to a method for esterifying taxoid intermediates having an ABCD ring skeleton structure with ring carbons C1-C15 and C20 represented by the following structure: ##STR1## wherein the C13 carbon is a deoxy carbon. The method employs includes at least three steps. In the first step, the deoxy C13 of the taxoid molecule is oxygenated to form a C13 ketone. Pyridinium chlorochromate is a preferred oxidant for performing this process. In the second step, the C13 ketone produced in the first step is reduced to form a C13 alcohol. Sodium borohydrate is a preferred reductant to form an alcohol from the C13 ketone. In the third step, C13 alcohol formed in the second step is esterified. A preferred method of esterification employs a β-lactam intermediate as taught by Ojima (Ojima, I. et al., Tetrahedron 1992, 48, 6985 and Tetrahedron Lett. 1993, 34, 4149) and by Holton, R. (European Patent Application No. EP 400,971 (1990) and Chem Abstracts 1990, 114, 164568q).
An alternative aspect of this invention is directed to an improved taxoid intermediate having an ABCD ring skeleton structure with ring carbons C1-C15 and C20 as indicated above wherein the C1 and C2 carbons are incorporated within a cycle carbonate ester. An example of such an improved taxoid intermediate is indicated below: ##STR2## wherein R is selected from the group consisting of H and a protective group for hydroxyls.
A further aspect of the invention is directed to an improved taxoid intermediate having an ABCD ring skeleton structure with ring carbons C1-C15 and C20 the C13 carbon is a deoxy carbon. Examples of a C13 deoxy taxoid intermediate is provided below: ##STR3## wherein R is selected from the group consisting of H and a protective group for hydroxyls.
Another alternative aspect of this invention is directed an improved taxoid intermediate having an ABCD ring skeleton structure wherein the C13 carbon includes a ketone substitution and forms an enone with the C12-C11 bridgehead double bond. An example of this aspect of the invention is illustrated by the following structure: ##STR4## wherein R is a protective group for hydroxyls, preferably SiEt 3 .
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates degradative and synthetic plans for producing taxoid intermediates from naturally occurring 10-deacetyl baccatin III (2) and for converting such taxoid intermediates to taxol (1).
DETAILED DESCRIPTION
Chemistry is disclosed which defines chemical pathways via which taxol 1 and 10-deacetyl baccatin III 2 (Indena Company, Italy) can be converted to a variety of intermediates including compounds 4-6 and 12-15, all of which can then be converted back to taxol 1. These reactions can be employed in the preparation of taxol analogs and in the total synthesis of taxol.
Initially, a C1-C2 vicinal diol was prepared in order to study the introduction of protecting groups at the C2 position and their conversion to the C1 hydroxy-C2 benzoate. To this end, 7-SiEt 3 baccatin III (3) was prepared from 10-deacetyl baccatin III (2) according to the methods of Magri et al (Journal of Organic Chemistry 1986, 51, p. 3239) and of Denis et al. (Journal of the American Chemical Society 1988, 110, p. 5917), as shown in FIG. 1. All attempts to selectively deprotect the C2 and C10 hydroxyl groups, including basic hydrolysis and metal hydride reductions, produced only low yields of the desired triol. It was then postulated that oxidation of the C13 hydroxyl group would remove a possible hydrogen bond between that hydroxyl and the C4 acetate, thus rendering the C4 acetate less susceptible to hydrolysis or intramolecular attack from the C2 hydroxyl group. Indeed, TPAP oxidation of compound 3, according to the method of Griffith (Aldrichim. Acta, 1990, 23, 13), provided the corresponding C13 ketone, in 98% yield. This was readily hydrolyzed under basic conditions to provide the corresponding C1-C2-vicinal diol with an 81% yield.
Modeling studies (Nicolaou et al., J. Chemical Society, Chem. Communications, 1992, p. 1118) suggest the benefit of using a cyclic protecting group for the C1-C2 diol in order to preorganize the molecular skeleton prior to ring closure to form the 8-membered ring. Furthermore, with the goal of selectively introducing the C2 benzoyl group in the synthetic direction, we found that it is possible to directly convert a C1-C2 carbonate ester into a C2 benzoate by addition of a nucleophilic reagent carrying a phenyl group. Treatment of the triol resulting from the oxidation/hydrolysis of 3 with a phosgene in pyridine, did indeed provide the desired carbonate 4 with a yield of 65%. The acetate 5 was then prepared from 4 using standard acetylation conditions. This intermediate (5) served admirably as a precursor of taxol (1) as described below.
Treatment of carbonate 5 with excess PhLi at -78° C. for 10 minutes resulted in the regioselective formation of the benzoate 6 with a yield, according to chromatographic and spectroscopic analysis, of 70%. A small amount (approximately 1-%) of the 10-deacetyl product resulting from PhLi attack on the C10 acetate group was also observed, although treatment of the crude reaction mixture with Ac 2 O in the presence of DMAP provided 6 as a single product, raising the yield of the 5 to 6 step to 80%. This chemistry provided a convenient protecting device for the C1-C2 diol group and opened directed access to the C1 hydroxyl/C2 benzoate system of taxol. The use of other nucleophilic reagents carrying other than phenyl groups to selectively open this carbonate ring should provide a variety of C2 ester, a class of derivatives which is otherwise difficult to obtain from naturally occurring taxoids. The remarkable resistance of the other four carbonyl functionalities in compound 5 towards PhLi is presumably due to steric shielding of these sites. Conversion of enone 6 back to taxol (1) was then demonstrated by the following sequence. Regio- and stereoselectlive reduction of the C13 carbonyl group was achieved with NaBh 4 , resulting in the formation of 7-TES (SiEt 3 ) baccatin III (3) in 83% yield, according to the method of Kingston, (Pharmac. Ther. 1991, 52, p. 1). Attachment of the side chain onto intermediate 3 was then accomplished using Ojima's method, i.e., Ojima, et al., Tetrahedron 1992, 48, 6985 and Tetrahedron Lett. 1993, 34, 4149 and Holton, R., European Patent Application No. EP 400,971, filed 1990 and Chem Abstracts 1990, 114, 164568q. Thus optically active β-lactams 7 and 8 were coupled with 3 using NaN(SiMe 3 ) 2 , to provide 2',7-diprotected taxol intermediates 9 and 10 respectively. Deprotection of either of these compounds (9 or 10) using standard conditions provided taxol 1 with a overall yield from 3 of approximately 70%.
Anther possible step in a potential total synthesis of taxol 1 is the oxidation of the C13 methylene to a ketone group. To test this hypothesis, the C13 deoxy compound 12 was prepared from 3, via the thionoimidozolide 11, using Barton's deoxygenation procedure, i.e., thiocarbonyldiimidazole-DMAP, heat, 86%, followed by Bu n 3 SnH-AIBN, heat, 40%. (Barton, J. Chem. Soc., Perkin I 1975, p. 1574 and Hartwig, Tetrahedron 1983, 39, p. 2609.) A substantial amount, approximately 25%, of the corresponding C12-C13 alkene was also isolated in this deoxygenation reaction. Enone 6 was then prepared from 12, with a yield of 75%, using pyridinium chlorochromate (PCC) in refluxing benzene. In order to penetrate further into the projected synthetic scheme, the 7-hydroxy compound 13 was prepared from 12 by desilylation (HF.pyr, 65%). Conversion of compound 13 back to 12 was accomplished using Et 3 SiCl in pyridine, with a yield of 85%.
Compound 12 was also converted to carbonate 14 using similar chemistry as described for the synthesis of 4, i.e., K 2 CO 3 in MeOH/H 2 O/THF, 85% based on 55% conversion followed by phosgene in pyridine, 95%. Desilylation of 14 (HF.pyr, 88%) led to the 7-hydroxy compound 15 which was converted back to 14 by silylation under standard conditions, i.e., Et 3 SiCl-pyr, 85%. Nucleophilic addition of PhLi to the carbonate 14 as described above provided the benzoate 12 with a yield of 80%.
REAGENTS AND CONDITIONS
The reagents and conditions for the reactions indicated in FIG. 1 are provided below:
(i) To 10-deacetyl baccatin III 2 is added 20 equivalents of Et 3 SiCl in pyridine at 25° C. for 20 hours to produce the TES (SiEt 3 ) intermediate with a yield of 89%.
(ii) To the TES product of (i) is added 5 equivalents of AcCl in pyridine at 0° C. for 48 hours to produce 7-TES baccatin III 3 with a yield of 90%.
(iii) To the product of (iii) is added 0.05 equivalents of (Pr n ) 4 NRuO 4 , 1.5 equivalents of 4-morpholine N-oxide, 4 Å molecular sieves in acetonitrile for 30 minutes with a yield of 98%.
(iv) To the product of (iii) is added K 2 CO 3 cat., in MeOH, H 2 O at 0° C. for 9 hours with a yield of 81%.
(v) To the product of (iv) is added 10 equivalents of phosgene in pyridine at 25° C. for 30 minutes to produce compound 4 with a yield of 65%.
(vi) To compound 4 is added 10 equivalents of Ac 2 O and 20 equivalents of 4-dimethylaminopyridine in Ch 2 Cl 2 for 30 minutes to produce compound 5 with a yield of 95%.
(vii) To compound 5 is added 5 equivalents of PhLi in TNF at -78° C. for 10 minutes to produce compound 6 with a yield of 70% plus 10% 10-deacetyl 6.
(viii) To compound 6 is added 10 equivalents of NaBH 4 in MeOH at 25° C. for 5 hours to produce compound 3 with a yield of 83%.
(ix) To compound 3 is added 3.5 equivalents of 7 or 8 and 3 equivalents of NaN(SiMe 3 ) 2 in THF at 0° C. for 30 minutes to produce compounds 9 or 10 respectively with a yield of 87% based upon 90% conversion.
(x) To compound 9 is added HF.pyridine in THF at 25° C. for 1.25 hours to produce compound 1 with a yield of 80%. To compound 10 is added EtOh, 0.5% HCl at 0° C. for 72 hours to produce compound 1 with a yield of 80%.
(xi) To compound 3 is added 20 equivalents of thiocarbonyldiimidazole and 30 equivalents of 4-dimethylaminopyridine in THF in sealed tubes at 75° C. for 18 hours to produce compound 11 with a yield of 86%.
(xii) To compound 11 is added 20 equivalents of Bu n 3 SnH, AIBN cat., in toluene at 65° C. to produce compound 12 with a yield of 40%, plus 25% of C12-C13 alkene.
(xiii) To compound 12 is added 30 equivalents of pyridiniumchlorochromate, NaOAc, Cellite in refluxing benzene to produce compound 6 with a yield of 75%.
(xiv) To compound 12 or 14 is added HF.pyridine in THF at 25° C. for 1 hour to produce compound 13 with a yield of 65% or to produce compound 15 with a yield of 88%.
(xv) To compound 13 is added 20 equivalents of Et 3 SiCl in pyridine at 25° C. for 20 hours to produce compound 12 with a yield of 85%.
(xvi) To compound 12 is added K 2 CO 3 cat. in MeOH/H 2 O/THF at 0° C. for 9 hours with a yield of 85% based on 55% conversion.
(xvii) To the product of (xvi) is added 10 equivalents of phosgene in pyridine at 25° C. for 30 minutes to produce 14 with a yield of 95%.
(xviii) To compound 14 is added 5 equivalents of PhLi in THF at -78° C. for 10 minutes to produce 12 with a yield of 80%.
Definitions: TES=SiEt 3 ; Bz=COC 6 H 5 ; Ac=COCH 3 ; EE=ethoxyethyl.
PHYSICAL CHARACTERIZATION
All new compounds exhibited satisfactory spectral and analytical and/or exact mass data. Yields refer to chromatographically and spectroscopically homogeneous materials. Selected physical data is presented as follows:
4: Rf=0.31 (silica, 25% EtOAc in light petroleum); IR (film)=v max /cm -1 2926, 1822, 1754, 1732, 1689; 1 H NMR (500 MHZ, CDCI 3 ): δ 6.52 (s, 1 H, 10-H), 4.89 (d, J 9 Hz, 1 H, 5-H), 4.60 (d, J 9 Hz, 1 H, 20a-H), 4.48 (d, J 5.5 Hz, 1 H, 2-H), 4.45 (d, J 9 Hz, 1 H, 20b-H), 4.42 (m, 1 H, 7-H), 3.49 (d, J 5.5 Hz, 1 H, 3-H), 2.90 (d, J 20 Hz, 1 H, 14a-H), 2.79 (d, J 20 Hz, 1 H, 14b-H), 2.56 (m, 1 H, 6a-H), 2.19 (s, 3 H, OAc), 2.16 (s, 3 H, oAc), 2.07 (s, 3 H, 18-CH 3 ), 1.87 (m, 1 H, 6b-H), 1.71 (s, 3 H, 19-CH 3 ), 1.28 (s, 3 H, 16-CH 3 ), 1.26 (s, 3 H, 17-CH 3 ), 0.89 (t, J 8 Hz, 9 H SiEt 3 ), 0.55 (m, 6 H, SiEt 3 ); 13 C NMR (125 MHZ, CDCI 3 ) 200.2, 195.7, 170.5, 168.7, 152.0, 150.4, 142.5, 88.2, 83.9, 79.8, 76.6, 75.7, 71.5, 61.0, 43.1, 41.6, 39.8, 37.7, 31.6, 29.7, 21.5, 20.7, 18.4, 14.4, 9.7, 6.7, 5.1; HRMS (FAB) Calcd. for C 31 H 44 O 11 Si (M+H-): 621.2731; found 621.2745.
6: Rf=0.5 (silica, 50% EtOAc in light petroleum); IR (film)=v max /cm -1 3499, 2956, 1758, 1732, 1673, 1657, 1604; 1 H NMR (500 MHZ, CDCI 3 ) δ 8.05 (d, J 7.3 Hz, 2 H, OBz), 7.61 (t, J 7.5 Hz, 1 H, OBz), 7.47 (t, J 7.8 Hz, 2 H, OBz), 6.57 (s, 1 H, 10-H), 5.67 (d, J 6.7 Hz, 1 H, 2-H), 4.90 (d, J 8.4 Hz, 1 H, 5-H), 4.46 (dd, J 10.4, 6.8 Hz, 1 H, 7-H), 4.31 (d, J 8.5 Hz, 1 H, 20a-H), 4.09 (d, J 8.5 Hz, 1 H, 20b-H), 3.89 (d, J 6.7 Hz, 1 H, 3-H), 2.92 (d, J 19.9 Hz, 1 H, 14a-H), 2.63 (d, J 19.9 Hz, 1 H, 14b-H), 2.50 (m, 1 H, 6a-H), 2.21 (s, 3 H, OAc), 2.17 (s, 3 H, OAc), 2.16 (s, 3 H, 18-CH 3 ), 1.82 (m, 1 H, 6b-H), 1.65 (s, 3 H, 19-CH 3 ), 1.25 (s, 3 H, 16-H), 1.17 (s, 3 H, 17-H), 0.90 (t, J 7.9 Hz, 9 H, SIEt 3 ), 0.58 (m, 6 H, SIEt 3 ); 13 C NMR (125 MHZ, CDCI 3 ); δ 200.2, 198.3, 170.1, 168.9, 166.8, 153.0, 140.2, 133.9, 130.0, 128.8, 128.7, 83.9, 80.5, 78.4, 76.1, 76.0, 72.8, 72.2, 59.4, 46.2, 43.4 42.4, 37.1, 33.0, 21.7, 21.0, 18.2, 13.5, 9.5, 6.7, 5.1; HRMS (FAB): Calcd for C 37 H 50 O 11 Si (M+H-): 699.3201; found 699.3220.
13: Rf=0.35 (silica, 50% EtOAc in light petroleum); IR (film)=v max /cm -1 3503, 2924, 2853, 1728, 1713; 1 H NMR (500 MHZ, CDCI 3 ); δ 8.06 (d, J 7.3 Hz, 2 H, OBz), 7.58 (t, J 7.5 Hz, 1 H, OBz), 7.45 (t, J 10 Hz, 2 H, OBz), 6.31 (s, 1 H, 10-H), 5.58 (d, J 6.5 Hz, 1 H, 2-H), 4.98 (d J 7.5 Hz, 1 H, 5-H), 4.44 (dd, J 11.0, 7.0 Hz, 1 H, 7-H), 4.30 (d, J 8.0 Hz, 1 H, 20a-H), 4.14 (d J 8.0 Hz, 1 H, 20b-H), 3.76 (d, J 6.5 Hz, 1 H, 3-H), 2.71 (m, 1 H, 13a-H), 2.55 (m, 1 H, 13b-H), 2.29 (s, 3 H, OAc), 2.25 (m, 1 H), 2.23 (s, 3 H, OAc), 1.95 (s, 3 H, 18-CH 3 ), 1.92 (m, 1 H), 1.85 (m, 1 H), 1.69 (m, 1 H), 1.64 (s, 3 H, 19-CH 3 ), 1.11 (s, 3 H, 16-H), 1.09 (s, 3 H, 17-H); 13 C NMR (125 MHZ, CDCI 3 ); 204.4, 171.5, 169.8, 166.9, 144.0, 133.7, 131.3, 130.0, 129.3, 128.6, 84.22, 81.32, 80.97, 76.35, 73.95, 72.39, 65.86, 58.89, 45.89, 42.14, 35.71, 30.19, 29.69, 26.58, 25.30, 22.08, 20.96, 19.61, 15.27, 9.08; HRMS (FAB): Calcd for C 31 H 38 O 10 (M+Na-): 593.2363; found 593.2360.
14: Rf=0.82 (silica, 50% EtOAc in light petroleum); IR film)=v max /cm -1 2924, 1814, 1728, 1461, 1372, 1238; 1 H NMR (500 MHZ, CDCI 3 ); δ 6.40 (s, 1 H, 10-H), 4.95 (d J 9.0 Hz, 1 H, 5-H), 4.60 (d, J 9.0 Hz, 1 H, 20a-H), 4.47 (d, J 9.0 Hz, 1 H, 20b-H), 4.43 (dd, J 10.0, 7.5 Hz, 1 H, 7-H), 4.39 (d, J 5.5 Hz, 1 H, 2-H), 3.36 (d, J 5.5 Hz, 1 H, 3-H), 2.71 (m, 1 H, 13a-H), 2.56 (m, 1 H, 13b-H), 2.17 (s, 3 H, OAc), 2.15 (s, 3 H, OAc), 2.12 (m, 1 H), 2.07 (s 3 H, 18-CH 3 ), 1.97 (m, 1 H), 1.88 (m, 2 H), 1.78 (s, 3 H, 19-CH 3 ), 1.23 (s, 3 H, 16-CH 3 ), 1.17 (s, 3 H, 17-CH 3 ), 0.88 (t J 7.5 Hz, 9 H, OSiEt 3 ), 0.55 (dq, J 8.0, 3.0 Hz, 6 H, --OSiEt 3 ); 13 C NMR (125 MHZ, CDCI 3 ); 202.6, 170.3, 169.2, 153.1, 144.0, 130.7, 92.8, 84.0, 80.3, 80.0, 76.4, 76.1, 60.3, 43.5, 38.0, 29.7, 29.4, 25.5, 23.1, 21.9, 21.1, 19.1, 9.8, 6.7, 5.2; HRMS (FAB) Calcd. for C 31 H 46 O 10 (M+Cs-): 739.1915; found 739.1929. | A method for esterifying C13 deoxy taxoid intermediates employs three steps, i.e., oxygenation of the C13 deoxy taxoid intermediate to produce a C13 enone taxoid intermediate; reduction of the C13 enone to produce an alcohol; followed by esterification of the C13 alcohol. Key intermediates include C13 deoxy taxoids; C13 enone substituted taxoids; and C1-C2 cyclo carbonate esters of taxoids. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to a system for providing a secure and encrypted voicemail repository.
BACKGROUND TO THE INVENTION
[0002] Voicemail facilities are often offered by corporate telephone systems and also mobile telephone systems to enable messages to be taken when a user is unavailable or on another line. Most telephone systems can now offer some form of voicemail. In each case, the voicemail service is typically hosted by a computer system linked to the telephone network being served such that it is able to receive calls to handsets set to forward calls to voicemail or that are unavailable and record messages in a repository.
[0003] In order to offer flexibility to users, current voicemail systems allow users to dial in to the voicemail repository to retrieve their messages. Users can assign a pin number to their mailbox to limit access and many systems have a default pin number if this is not assigned. Some systems will not prompt for a pin number if the caller uses the handset associated with the mailbox (as opposed to dialing in from a different number to retrieve their messages).
[0004] Increasingly, data security is becoming an issue to everyone. The telephone is still considered a more secure method of communication than e-mail for example. As such, confidential messages may be left by voicemail that would not necessarily have been communicated via e-mail.
[0005] However, it is slowly becoming apparent that security surrounding telecommunication systems is insufficient. Security in respect of e-mail systems and the like has increased over the last few years to the extent that strong authentication is often required to access an e-mail mailbox. However, current voicemail systems are very poorly defended and pin numbers can often be guessed or cracked by brute force approaches, allowing anybody access to a user's mailbox. Moreover a voicemail message could be intercepted during retrieval by eavesdropping on the communication.
STATEMENT OF INVENTION
[0006] According to an aspect of the present invention there is provided a secure voicemail repository arranged to receive calls for a handset and record said calls in an encrypted form, wherein the encrypted form is decryptable by a key associated with the handset, the system being arranged, on demand, to provide the encrypted form of the message to the handset.
[0007] Preferably, the voicemail system encrypts each voicemail message as it is received using a public key of a public-private key pair associated with the handset associated with the voicemail mailbox. When a voicemail message is requested, the message in its encrypted form is transmitted to the handset which is then able to use the private key associated with the key pair to decrypt the message and output it to the user.
[0008] Optionally, the voicemail system may check for existence of a secure communication system associated with the handset wishing to leave a voicemail message and establish a secure communication channel with the handset should one exist. In this manner, not only would the voicemail be secure but so would the communication channel used to deposit the voicemail within the voicemail system.
[0009] The voicemail system need not be the default voicemail system assigned by the telecommunication provider. The recipient's handset could be configured to forward voicemail calls to an alternate voicemail provider.
[0010] The repository may be arranged to receive calls in the encrypted form via a secure communication channel and to record said calls in said encrypted form.
[0011] The secure communication channel may be established between a calling system and the recipient system, the recipient system being remote of the repository, the repository being arranged to receive transference of the secure communication channel from the recipient system for receiving said voicemail.
[0012] The repository may be arranged to establish said secure communication channel with said calling system.
[0013] The repository may further comprise at least one encryption key associated with each of a plurality of mailboxes, each of the mailboxes being associated with a recipient system, the repository being arranged to identify the mailbox in dependence on the called recipient system and use said respective at least one key for establishment of said secure communication channel and/or communication with said calling system via said secure communication channel.
[0014] The repository may further comprise at least one encryption key associated with each of a plurality of mailboxes, each of the mailboxes being associated with a recipient system, the repository being arranged to identify the mailbox called in dependence on the called recipient system and to encrypt non-encrypted calls into said encrypted form during or prior to recording using said at least one encryption key.
[0015] The at least one key may comprise a public key of a public-private key pair.
[0016] The system may further comprise a recipient system, wherein the recipient system includes the private key of the public-private key pair and is arranged to obtain said encrypted form of the call from the repository and decrypt the call in dependence on the private key.
[0017] The repository may be arranged, upon completion of recordal of a call, to transmit said encrypted form of said call to the respective recipient system.
[0018] The repository may be arranged to said encrypted form of said call to the respective recipient system during recordal.
[0019] The repository may be remote of any telecommunication provider's network management system and is arranged to receive calls on behalf of recipient systems that operate on different telecommunication networks.
[0020] The system may further comprise a plurality of repositories each arranged to receive calls for a recipient system and to transmit said recorded calls in said encrypted form between themselves upon demand.
[0021] According to another aspect of the present invention, there is provided a method of operating a secure voicemail repository comprising:
[0000] receiving calls for a recipient system;
recording said calls in an encrypted form in the repository; and,
providing, on demand, the encrypted form of the call to the recipient system, wherein the encrypted form is decryptable by a key associated with the handset.
[0022] The receiving step may further comprise receiving calls in a packetised encrypted form and the recording step further comprises recording said calls in said packetised encrypted form.
[0023] The receiving step may comprise receiving calls in the encrypted form via a secure communication channel wherein the secure communication channel is established between a calling system and the recipient system, the recipient system being remote of the repository, the method further comprising receiving transference of the secure communication channel from the recipient system for receiving said voicemail.
[0024] The receiving step may further comprise establishing a secure communication channel with said calling system for receiving the call.
[0025] The method may further comprise:
[0000] storing at least one encryption key associated with each of a plurality of mailboxes, each of the mailboxes being associated with a recipient system;
identifying the mailbox in dependence on the called recipient system; and,
using said respective at least one key for establishment of said secure communication channel and/or communication with said calling system via said secure communication channel.
[0026] The method may further comprise:
[0000] storing at least one encryption key associated with each of a plurality of mailboxes, each of the mailboxes being associated with a recipient system;
identifying the mailbox called in dependence on the called recipient system; and,
encrypting non-encrypted calls into said encrypted form during or prior to recording using said at least one encryption key.
[0027] The method may further comprise, upon completion of recordal of a call, transmitting said encrypted form of said call to the recipient system.
[0028] The method may further comprise transmitting said encrypted form of said call to the respective recipient system during recordal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Examples of the present invention will now be described with reference to the accompanying drawings, in which:
[0030] FIG. 1 is a schematic diagram of a secure voicemail system according to a first aspect of the present invention;
[0031] FIG. 2 is the schematic diagram of FIG. 1 illustrating a preferred manner of operation;
[0032] FIG. 3 is a schematic diagram of a secure voicemail system according to another aspect of the present invention; and
[0033] FIG. 4 is an illustration of a screen display according to another aspect of the present invention.
DETAILED DESCRIPTION
[0034] FIG. 1 is a schematic diagram of a secure voicemail system according to an embodiment of the present invention.
[0035] The secure voicemail system 5 forms part of a mobile telephone network. The mobile telephone network includes a switching station 40 which is connected to a public switched telephone network (PSTN) 30 . A repository 50 is connected via a network 60 to the switching station 40 for storing voicemail messages.
[0036] When a first user wishes to communicate with a second user, the first user uses his or her handset 10 calls the telephone number associated with the handset 20 of the second user. This call is routed via the PSTN 30 to the switching centre 40 . The switching centre 40 determines whether the handset 20 of the second user is in range and available.
[0037] If the handset 20 of the second user is not in range or available (for example if the user was on another call or the handset was set to forward all calls to voicemail), the switching centre 40 initiates a voicemail message capture process that instructs the user at handset 10 to record a voicemail message.
[0038] The recorded voicemail message is stored in the repository 50 . The recorded message is stored in an encrypted form, encryption being performed using a public key from a public-private key pair associated with the second user's handset 20 .
[0039] When the second user wishes to access his or her voicemail, he or she uses the handset 20 to connect to the voicemail system 5 . Upon receiving the request, the voicemail system 5 accesses the messages in the repository 50 and uploads them to the handset 20 . Software on the handset uses the private key from the public-private key pair to decrypt the message so that it can be output to the user via the device 20 .
[0040] FIG. 2 is the schematic diagram of FIG. 1 illustrating preferred operation of the secure voicemail system.
[0000] In this embodiment, the first user's device 15 includes a secure communication system 100 .
[0041] When the switching system 40 connects to the first user's handset 15 , it initiates a query to determine whether a secure communication system exists. In this case, as such a system 120 does exist, the first handset 15 provides a confirmatory response and a secure communication channel 70 is negotiated between the first user's device 15 and the second device 20 . In this manner, communications over the PSTN 30 (or other network as embodiments of the present invention need not operate over a PSTN) are encrypted and also secure.
[0042] In use, when a communication session is being established, the communication system 100 checks to see if the second user's device 20 supports secure communications. In this scenario, the called device 20 includes a compatible secure communication system 110 . During call setup negotiation, the respective secure communications systems 100 , 110 establish a data connection 70 (preferably using an Internet Protocol (IP) based connection), perform key exchange and subsequently intercept voice communications and digitise, packetise and encrypt them before transmitting them over a data connection. Upon receipt, the second user's device 20 performs the steps in reverse and outputs the voice to the remote user.
[0043] Optionally, a direct GSM data connection may be used instead of IP. An HSCSD GSM data connection is used to reduce latency.
[0044] The ITU-T G.722.2 codec is preferably used for voice processing.
[0045] The communications systems 100 , 110 may use redundant encryption systems for session, authentication and/or key exchange. Preferred embodiments use two strong algorithms at the same time in series. The combination preserves security of communication in the event that one algorithm is found to be weak in the future.
[0046] For session encryption: AES and RC4 with 256 bit may be used. For authentication: RSA and DSA with 4096 bit may be used. For key exchange: Diffie-Hellman with 4096 bit may be used.
[0047] Preferably, session keys are deleted from both the initiating and recipient mobile telephones once the communication has been completed. In this way, past communications cannot be decrypted even if the private key material from the mobile phones is extracted. Session keys are only stored on the mobile phone, only in memory and only for the duration of the secure communication.
[0048] Random numbers used for key generation are taken from a secure source if available. As most mobile telephones do not offer such a source, a remote source may be used such as an SMS server 120 for providing a random number seed by SMS 125 . In this way, for each communication session the first seed for a local pseudo random number generator requested through SMS.
[0049] Preferably the communication system is simply installable on a mobile telephone from a remote source. Preferably, installation does not require key management. A ‘first-trust’ key management similar to that in SSH may be used. Making and receiving a phone call will preferably be no different to a traditional phone call in respect of voice quality and latency.
[0050] The identity of a user is bound to the EMSI, IMSI and/or phone number.
[0051] Each GSM packet is preferably encrypted separately. Any GSM packet that does not arrive in time or is lost during transmission is ignored. It is believed that lost GSM packets do not pose a security or quality problem.
[0052] In the case where the second user's device 20 is available to establish the secure communication channel 70 but not available to actually take the call (for example the recipient may be on another call or the device may be set to go straight to voicemail), key exchange and establishment of the secure communication channel 70 happens as above. However, once the channel is established, the second user's device 20 triggers the switching system 40 to divert the call to voicemail.
[0053] The switching system 40 routes the call to the repository 50 where the user's standard or pre-recorded greeting is played to the first user's device 15 . The voicemail message is then received from the first user's device 15 in the packetized, encrypted form. The data is stored at the repository 50 as received. Preferably, the repository captures data on the first user's device and meta data on the call (e.g. identifier/phone number of the first user's device, time of message) and stores this data linked to the stored packets of voicemail data.
[0054] The repository preferably does not hold the key(s) necessary to decrypt the data received over the secure communications channel and therefore has no choice other than to record it in the secure form as received. Therefore, even if the repository is compromised, the data itself is still secure.
[0055] In a preferred embodiment, public/private key encryption is used and the repository holds copies of the second device's public key(s). In this manner, if the second device is not available (for example it was turned off) to establish the secure communication channel 70 , the repository can act as a proxy to the second device and establish the secure communications channel 70 for subsequent use in receiving a voicemail message. Indeed, the repository 50 may act as a proxy even if the second device 20 is available as it may be considered more efficient for the second device to immediately pass voicemail destined connection requests to the repository to be dealt with instead of having to manage the overhead of key exchange etc. Even when the second device 20 does take part in establishing the secure communications channel 70 , it is still preferred that the repository holds copies of the device's public key(s) so that it can encrypt the outgoing voicemail greeting and communicate any options securely to the first device 15 .
[0056] FIG. 3 is a schematic diagram of a secure voicemail system according to another embodiment of the present invention.
[0057] In this embodiment, the second user's handset 20 is configured to forward voicemails to an alternate voicemail system 80 that is not linked or associated with the communication provider's switching centre 40 .
[0058] The alternate voicemail system 80 is sited remotely from the switching centre 40 . When the switching centre 40 attempts to forward the first caller to voicemail, the alternate forwarding address is identified and the first handset 15 is connected (via a secure channel 70 should the handset 15 be capable) to the alternate voicemail system 80 . The secure channel 70 can be established as discussed above (i.e. either by the second device 20 and then redirected or, preferably, direct with the alternate voicemail system 80 using copies of the second device's public encryption keys.
[0059] Preferably, if the alternate voicemail system 80 is remote from the network or systems of the telecommunications operator that serves the second handset 20 , a secure communication channel is established between the second handset 20 and the alternate voicemail system 80 whenever voicemail is transmitted to the handset 20 . In this manner, not only is the voicemail itself is encrypted, so to is the communication traffic providing redundancy and additional security.
[0060] FIG. 4 is an illustration of a screen display according to a further embodiment of the present invention.
[0061] In this embodiment, an interface 100 is provided to the user of the handset 20 associated with the mailbox on the secure voicemail system ( 50 or 80 ). As voicemails are received and stored in the repository 50 , 80 , a notification is pushed out to the handset 20 and displayed on the user interface 100 . Preferably, the telephone number of the caller, time and date and duration of the message are displayed. The interface preferably allows the user to select messages to be downloaded, played, stored or deleted. It will be appreciated that whilst the secure voicemail system of the present invention could work in the same manner as conventional voicemail systems which are accessed and voicemails are output sequentially, by pushing a notification to the user device, random access can be provided to voicemails which should improve the user experience substantially. Additionally, voicemails can be downloaded to the handset 20 to allow the user to listen to them at his or her leisure and the caller and length of voicemail can give the user at the handset 20 an indication of how long it will take to obtain the messages. Optionally, the encrypted messages themselves can be pushed to the handset 20 rather than a notification. In this manner, no wait would be experienced by the user during the downloading process but it would require the handset 20 to have an increased storage capacity.
[0062] As the voicemail messages are encrypted, they could be transported around the Internet as there is a reduced concern in terms of security. One possibility for movement of voicemail messages would be if the user of the second handset 20 was roaming between networks. A voicemail message could be transmitted to a local store on the last known network used by the handset 20 rather than requiring it always to be sent via the user's home network.
[0063] In one embodiment, voicemail repositories may be implemented in some form or hierarchy or peer-to-peer topology and arranged to distribute public keys amongst themselves to provide redundancy, provide roaming and also to enable selection of a closest repository to the caller to reduce network overhead. In such arrangements, a repository may be identified as a home repository for a user device and voicemails received on other repositories may be transferred to, or synchronised with, the home repository. A non-home repository receiving a voicemail may indicate its availability to the home repository and transmit it to the home repository if not requested by the device or home repository within a predetermined amount of time.
[0064] Whilst public/private key pairings are discussed as a preferred implementation for encryption, it will be appreciated that other encryption systems exist which would be equally applicable. For example, the public-private key pairings could be used to negotiate a symmetric session key used only for that message. Preferably, the public/private key pair is generated at the user's handset 20 . It may optionally be linked to a specific parameter of the handset such as the IMEI unique identifier. The public key could be shared among telecommunication providers and those providing the secure encrypted voicemail service without fear of breaching security of the secure voicemail system. Preferably, compatible handsets can download a software application to enable use of an encrypted voicemail system. When the application is first run, the public and private key pairings are created and the public key is then transmitted to the secure voicemail system for use in creating the secure encrypted voicemails. | A system and method are disclosed in which a secure voicemail repository ( 50 ) is arranged to receive calls for a recipient system ( 20 ) and record said calls in an encrypted form. The encrypted form is decryptable by a key associated with the handset. On demand, the encrypted form is provided to the recipient system ( 20 ). | 7 |
This is a division of application U.S. Ser. No. 08/475,887, filed Jun. 7, 1995, now, U.S. Pat. No. 5,750,147.
FIELD OF THE INVENTION
The present invention relates to the preparation of solutions containing imidazole derivatives and to the use of those solutions in the preparation of microspheres. The imidazole derivative containing microspheres are effective in treating fungal infections, particularly in mammals. The microspheres facilitate the oral administration of relatively large amounts of the imidazole derivative, with increased bioavailability.
BACKGROUND OF THE INVENTION
Many present systems for delivering active agents to targets are severely limited by biological, chemical, and physical barriers, which are imposed by the environment through which delivery occurs, the environment of the target itself, or the target itself. Delivery is also limited, in many instances, by the chemical nature of the active agent. For example, oral delivery is generally ineffective with active agents that are poorly water-soluble.
The imidazole derivative family of compounds is particularly effective against a broad range of fungal infections such as those caused by Trichophyton rubrum, Tricophyton mentagrophytes, Epidermophyton floccsum, and Candida albicans, but these compounds are either partially water soluble or insoluble in water. For example, the solubility of itraconazole in water is less than 0.00001 g/ml.
Partially because imidazole derivatives are typically insoluble in water, they are difficult to administer orally. Consequently although imidazole derivatives are frequently prescribed for the treatment of fungal infections, they have been available only in topical preparations or in oral formulations with limited bioavailability.
In recent years, fungal infections, such as those caused by Candida albicans in particular have become more prevalent and intractable due to their appearance in immunocompromised patients, such as those infected with Human Immunodeficiency Virus (HIV) or those suffering from Acquired Immunodeficiency Syndrome (AIDS).
For example, U.S. Pat. No. 3,717,655 discloses imidazole derivatives which have antifungal and antibacterial activity. These compounds are almost insoluble in aqueous solutions such as water and are very poorly soluble in polar solvents such as ethanol.
Das et al., U.S. Pat. No. 4,912,124, disclose a solvent system for imidazole derivatives that include mixtures of a polar solvent, a polyhydric alcohol that acts as a solubilizing agent, a nonionic or amphoteric surfactant, and a cosmetic humectant. Solutions containing at least 1 percent by weight of the imidazole derivatives can be formulated using this solvent system. However, these formulations are suitable for external topical use only.
Accordingly, there is a need for orally deliverable forms of imidazole derivative antifungal agents.
SUMMARY OF THE INVENTION
The present invention provides solutions comprising:
(a) at least about 2.5 parts by weight, based upon 100 parts by weight of solution, of a solute having the formula
wherein R, R 1 , and R 2 are independently hydrogen or lower alkyl;
R 3 is hydrogen, methyl or ethyl;
R 4 is hydrogen or methyl
Ar is phenyl, monohalophenyl, dihalophenyl, trihalophenyl, mono(lower alkyl)phenyl, di(lower alkyl)phenyl, lower alkoxyphenyl, or halothienyl;
Ar 1 is phenyl, monohalophenyl, dihalophenyl, trihalophenyl, mono(lower alkyl)phenyl, di(lower alkyl)phenyl, lower alkoxyphenyl, or cyanophenyl; and
n is 1 or 2; and
(b) a solubilizing effective amount of a solvent comprising at least one volatile organic acid solvent.
Imidazole derivative microspheres are also provided. These microspheres comprise:
(a) an imidazole derivative active agent having the formula ##STR1## wherein R, R 1 , and R 2 are independently hydrogen or lower alkyl;
R 3 is hydrogen, methyl or ethyl;
R 4 is hydrogen or methyl
Ar is phenyl, monohalophenyl, dihalophenyl, trihalophenyl, mono(lower alkyl)phenyl, di(lower alkyl)phenyl, lower alkoxyphenyl, or halothienyl;
Ar 1 is phenyl, monohalophenyl, dihalophenyl, trihalophenyl, mono(lower alkyl)phenyl, di(lower alkyl)phenyl, lower alkoxyphenyl, or cyanophenyl; and
n is 1 or 2; and
(b) a microsphere forming carrier selected from the group consisting of
(i) a proteinoid;
(ii) an acylated amino acid, poly amino acid, or a salt thereof;
(iii) an sulfonated amino acid, poly amino acid, or a salt thereof;
(iv) a protein or a salt thereof;
(v) an enteric coating material; or
(vi) any combination thereof.
Also contemplated by the present invention is a method for preparing these microspheres. The method comprises:
(A) nebulizing a solution comprising
(a) an imidazole active agent having the formula ##STR2## wherein R, R 1 , and R 2 are independently hydrogen or lower alkyl;
R 3 is hydrogen, methyl or ethyl;
R 4 is hydrogen or methyl
Ar is phenyl, monohalophenyl, dihalophenyl, trihalophenyl, mono(lower alkyl)phenyl, di(lower alkyl)phenyl, lower alkoxyphenyl, or halothienyl;
Ar 1 is phenyl, monohalophenyl, dihalophenyl, trihalophenyl, mono(lower alkyl)phenyl, di(lower alkyl)phenyl, lower alkoxyphenyl, or cyanophenyl; and
n is 1 or 2;
(b) an active agent and carrier solubilizing effective amount of a solvent comprising an aqueous solution of at least one volatile organic solvent; and wherein the volume:volume ratio of acid to water in said carrier solution is at least about 3:7, and
(c) microsphere forming a carrier selected from the group consisting of
(i) a proteinoid;
(ii) an acylated amino acid or poly amino acid or a salt thereof;
(iii) an sulfonated amino acid or poly amino acid or a salt thereof;
(iv) a protein or a salt thereof;
(v) an enteric coating material; or
(vi) any combination thereof; and
(B) decreasing said ratio to less than about 3:7, to yield said microspheres. Alternatively, the active agent and the carrier can be solubilized in separate solutions. The separate solutions can be nebulized together and the acid to water ratio then decreased as above.
Methods for the oral administration of imidazole derivatives are also contemplated wherein the microsphere compositions above are orally administered to an animal in need of this treatment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a scanning electron micrograph (SEM) taken at a magnification of 2,000× of microspheres containing itraconazole prepared according to the present invention.
FIG. 1B is a SEM taken at a magnification of 15,000× of microspheres containing itraconazole prepared according to the present invention.
FIG. 1C is a SEM taken a magnification of 20,000× of microspheres containing itraconazole prepared according to the present invention.
FIG. 1D is a SEM taken at a magnification of 20,000× of microspheres containing itraconazole prepared according to the present invention.
FIG. 1E is a SEM taken at a magnification of 20,000× of microspheres containing itraconazole prepared according to the present invention.
FIG. 1F is a SEM taken at a magnification of 20,000× of microspheres containing itraconazole prepared according to the present invention.
FIG. 1G is a SEM taken at a magnification of 2,000× of microspheres containing itraconazole prepared according to the present invention, after being mechanically crushed.
FIG. 1H is a SEM taken at a magnification of 3,500× of microspheres containing itraconazole prepared according to the present invention, after being mechanically crushed.
DETAILED DESCRIPTION OF THE INVENTION
It has now been discovered that water insoluble or partially soluble imidazole derivatives can be solubilized in volatile organic acids. The resultant solutions can be used to prepare imidazole containing microspheres which are suitable for oral administration to animals.
Imidazole Derivatives
The active agents of the present invention are imidazole derivatives having the formula: ##STR3## wherein R, R 1 and R 2 are independently hydrogen or lower alkyl; R 3 is hydrogen, methyl or ethyl;
R 4 is hydrogen or methyl
Ar is phenyl, monohalophenyl, dihalophenyl, trihalophenyl, mono (lower alkyl)phenyl, di(lower alkyl)phenyl, lower alkoxyphenyl, or halothienyl;
Ar 1 is phenyl, monohalophenyl, dihalophenyl, trihalophenyl, mono(lower alkyl)phenyl, di(lower alkyl)phenyl, lower alkoxyphenyl, or cyanophenyl; and
n is 1 or 2.
A preferred imidazole derivative is itraconazole. Itraconazole is a synthetic triazole imidazole derivative 1:1:1:1 racemic mixture of four diastereomers (two enantiomeric pairs), each possessing three chiral centers (Physicians Desk Reference 48th Ed., pg. 1097, 1994).
Imidazole Derivative Solutions
The solutions prepared in accordance with the present invention allow for the solubilization of imidazole derivatives at concentrations suitable for processing into orally administrable forms having acceptable bioavailability.
In accordance with the present invention, imidazole derivatives are solubilized in volatile organic acid solvent(s). Preferred acid solvents for the imidazole derivatives are acetic acid and formic acid. Preferably, the solvent itself is an aqueous solution of the acid. Most preferably the volume:volume ratio of the acid to the total volume of the solvent is 3:7 or greater. It has been found that by using this solvent system up to a 50% solution of imidazole derivative can be prepared.
Dissolution is achieved by simple mixing, with heating if necessary. The more concentrated the acid in the solvent, the greater the amount of active agent that can be incorporated into the solution. If lower concentrations of acid are required for the end use of the solution, the active agent can first be dissolved in a more concentrated acid solution, and the resultant solution then slowly diluted further, preferably with water.
Preferably, the solution comprises from about 3 to about 40 percent by weight of solute and from about 60 to about 97 parts by weight of solvent based upon 100 parts by weight of solution.
The solvent itself, preferably comprises from about 30 to about 80 parts by volume of acid and from about 70 to about 20 parts by volume of water based upon 100 parts by volume of solvent. Most preferably, the solvent comprises from about 40 to about 50 parts by volume of acid and from about 60 to about 50 parts by volume of water based upon 100 parts by volume of solvent.
Microspheres
Microspheres are useful in the delivery of active agents because they protect an active agent cargo until it is delivered to a target. Microspheres are particularly useful in the oral delivery of biologically active agents such as, for example, pharmaceutically active agents.
Microspheres containing an active agent can be generally of the matrix form or the capsule form. In a hollow matrix spheroid form, the center of the sphere is hollow and the cargo or active agent is distributed throughout a carrier matrix. In a solid matrix form, the carrier matrix forms a continuum in which the cargo is distributed. In the microcapsule form, the encapsulated material or cargo can be either in solution or a solid, with the carrier forming a shell around the cargo.
The methods of the present invention are cost-effective for preparing microspheres which contain imidazole derivatives, are simple to perform, and are amenable to industrial scale-up for commercial production.
Carriers
Carriers suitable for use in the present invention are microsphere forming carriers. These carriers include, without limitation, proteinoids; acylated amino acids, poly amino acids or salts thereof; sulfonated amino acids, poly amino acids or salts thereof; proteins or salts thereof, enteric coating materials; or any combination thereof.
Amino acids are the basic materials used to prepare many of the carriers useful in the present invention. Amino acids include any carboxylic acid having at least one free amino group and include naturally occurring and synthetic amino acids. The preferred amino acids for use in the present invention are '-amino acids and, most preferably, are naturally occurring '-amino acids. Many amino acids and amino acid esters are readily available from a number of commercial sources such as Aldrich Chemical Co. (Milwaukee, Wis., USA); Sigma Chemical Co. (St. Louis, Mo., USA); and Fluka Chemical Corp. (Ronkonkoma, N.Y., USA).
Representative, but not limiting, amino acids suitable for use in the present invention are generally of the formula ##STR4## wherein: R 5 is hydrogen, C 1 -C 4 alkyl, or C 2 -C 4 alkenyl;
R 6 is C 1 -C 24 alkyl, C 2 -C 24 alkenyl, C 3 -C 10 cycloalkyl, C 3 -C 10 cycloalkenyl, phenyl, naphthyl, (C 1 -C 10 alkyl) phenyl, (C 2 -C 10 alkenyl) phenyl, (C 1 -C 10 alkyl) naphthyl, (C 2 -C 10 alkenyl) naphthyl, phenyl (C 1 -C 10 alkyl), phenyl (C 2 -C 10 alkenyl), naphthyl (C 1 -C 10 alkyl), or naphthyl (C 2 -C 10 alkenyl);
R 6 being optionally substituted with C 1 -C 4 alkyl, C 2 -C 4 alkenyl, C 1 -C 4 alkoxy, --OH, --SH, --CO 2 R 7 , C 3 -C 10 cycloalkyl, C 3 -C 10 cycloalkenyl, heterocycle having 3-10 ring atoms wherein the hetero atom is one or more of N, O, S, or any combination thereof, aryl, (C 1 -C 10 alk)aryl, ar(C 1 -C 10 alkyl) or any combination thereof;
R 6 being optionally interrupted by oxygen, nitrogen, sulfur, or any combination thereof; and
R 7 is hydrogen, C 1 -C 4 alkyl, or C 2 -C 4 alkenyl.
The preferred naturally occurring amino acids for use in the present invention as amino acids or components of a peptide are alanine, arginine, asparagine, aspartic acid, citrulline cysteine, cystine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, hydroxyproline, β-carboxyglutamic acid, γ-carboxyglutamic acid, phenylglycine, or O-phosphoserine. The most preferred amino acids are arginine, leucine, lysine, phenylalanine, tyrosine, tryptophan, valine, and phenylglycine.
The preferred non-naturally occurring amino acids for use in the present invention are β-alanine, α-amino butyric acid, γ-amino butyric acid, γ-(aminophenyl) butyric acid, α-amino isobutyric acid, ε-amino caproic acid, 7-amino heptanoic acid, β-aspartic acid, aminobenzoic acid, aminophenyl acetic acid, aminophenyl butyric acid, γ-glutamic acid, cysteine (ACM), ε-lysine, methionine sulfone, norleucine, norvaline, ornithine, d-ornithine, p-nitro-phenylalanine, hydroxy proline, 1,2,3,4,-tetrahydroisoquinoline-3-carboxylic acid, and thioproline.
Poly amino acids are either peptides or two or more amino acids linked by a bond formed by other groups which can be linked, e.g., an ester or an anhydride linkage. Special mention is made of non-naturally occurring poly amino acids and particularly non-naturally occurring hetero-poly amino acids, i.e. of mixed amino acids.
Peptides are two or more amino acids joined by a peptide bond. Peptides can vary in length from di-peptides with two amino acids to polypeptides with several hundred amino acids. See, Walker, Chambers Biological Dictionary, Cambridge, England: Chambers Cambridge, 1989, page 215. Special mention is made of non-naturally occurring peptides and particularly non-naturally occurring peptides of mixed amino acids. Special mention is also made of di-peptides tri-peptides, tetra-peptides, and penta-peptides, and particularly, the preferred peptides are di-peptides and tri-peptides. Peptides can be homo- or hetero-peptides and can include natural amino acids, synthetic amino acids, or any combination thereof.
Proteinoids
Proteinoids are artificial polymers of amino acids. Proteinoids preferably are prepared from mixtures of amino acids. Preferred proteinoids are condensation polymers, and most preferably, are thermal condensation polymers. These polymers may be directed or random polymers. Proteinoids can be linear, branched, or cyclical, and certain proteinoids can be units of other linear, branched, or cyclical proteinoids.
Special mention is made of diketopiperazines. Diketopiperazines are six member ring compounds. The ring includes two nitrogen atoms and is substituted at two carbons with two oxygen atoms. Preferably, the carbonyl groups are at the 2 and 5 ring positions. These rings can be optionally, and most often are, further substituted.
Diketopiperazine ring systems may be generated during thermal polymerization or condensation of amino acids or amino acid derivatives. (Gyore, J; Ecet M. Proceedings Fourth ICTA (Thermal Analysis), 1974, 2, 387-394 (1974)). These six membered ring systems were presumably generated by intra-molecular cyclization of the dimer prior to further chain growth or directly from a linear peptide (Reddy, A. V., Int. J. Peptide Protein Res., 40, 472-476 (1992); Mazurov, A. A. et al., Int. J. Peptide Protein Res., 42, 14-19 (1993)).
Diketopiperazines can also be formed by cyclodimerization of amino acid ester derivatives as described by Katchalski et al., J. Amer. Chem. Soc., 68, 879-880 (1946), by cyclization of dipeptide ester derivatives, or by thermal dehydration of amino acid derivatives and high boiling solvents as described by Kopple et al., J. Org. Chem., 33 (2), 862-864 (1968).
Diketopiperazines typically are formed from α-amino acids. Preferably, the α-amino acids of which the diketopiperazines are derived are glutamic acid, aspartic acid, tyrosine, phenylalanine, and optical isomers of any of the foregoing.
Modified Amino Acids and Poly Amino Acids
Modified amino acids, poly amino acids, or peptides are either acylated or sulfonated and include amino acid amides and sulfonamides.
Acylated Amino Acids and Poly Amino Acids
Although any acylated amino acids or poly amino acids are useful in the present invention, special mention is made of acylated amino acids having the formula
Ar.sup.2 --Y--(R.sup.8).sub.n --OH III
wherein Ar 2 is a substituted or unsubstituted phenyl or naphthyl; ##STR5## R 8 has the formula ##STR6## wherein: R 9 is C 1 to C 24 alkyl, C 1 to C 24 alkenyl, phenyl, naphthyl, (C 1 to C 10 alkyl) phenyl, (C 1 to C 10 alkenyl) phenyl, (C 1 to C 10 alkyl) naphthyl, (C 1 to C 10 alkenyl) naphthyl, phenyl (C 1 to C 10 alkyl), phenyl (C 1 to C 10 alkenyl), naphthyl (C 1 to C 10 alkyl) and naphthyl (C 1 to C 10 alkenyl);
R 9 is optionally substituted with C 1 to C 4 alkyl, C 1 to C 4 alkenyl, C 1 to C 4 alkoxy, --OH, --SH and --CO 2 R 11 , cycloalkyl, cycloalkenyl, heterocyclic alkyl, alkaryl, heteroaryl, heteroalkaryl, or any combination thereof;
R 11 is hydrogen, C 1 to C 4 alkyl or C 1 to C 4 alkenyl;
R 9 is optionally interrupted by oxygen, nitrogen, sulfur or any combination thereof; and
R 10 is hydrogen, C 1 to C 4 alkyl or C 1 to C 4 alkenyl.
Special mention is also made of those having the formula ##STR7## wherein: R 12 is (i) C 3 -C 10 cycloalkyl, optionally substituted with C 1 -C 7 alkyl, C 2 -C 7 alkenyl, C 1 -C 7 alkoxy, hydroxy, phenyl, phenoxy or --CO 2 R 15 , wherein R 15 is hydrogen, C 1 -C 4 alkyl, or C 2 -C 4 alkenyl; or
(ii) C 1 -C 6 alkyl substituted with C 3 -C 10 cycloalkyl;
R 13 is hydrogen, C 1 -C 4 alkyl, or C 2 -C 4 alkenyl;
R 14 is C 1 -C 24 alkyl, C 2 -C 24 alkenyl, C 3 -C 10 cycloalkyl, C 3 -C 10 cycloalkenyl, phenyl, naphthyl, (C 1 -C 10 alkyl) phenyl, (C 2 -C 10 alkenyl) phenyl, (C 1 -C 10 alkyl) naphthyl, (C 2 -C 10 alkenyl) naphthyl, phenyl (C l -C 10 alkyl), phenyl (C 2 -C 10 alkenyl), naphthyl (C 1 -C 10 alkyl) or naphthyl (C 2 -C 10 alkenyl);
R 14 being optionally substituted with C 1 -C 4 alkyl, C 2 -C 4 alkenyl, C 1 -C 4 alkoxy, --OH, --SH, --CO 2 R 16 , C 3 -C 10 cycloalkyl, C 3 -C 10 cycloalkenyl, heterocycle having 3-10 ring atoms wherein the hetero atom is one or more of N, O, S or any combination thereof, aryl, (C 1 -C 10 alk)aryl, ar(C 1 -C 10 alkyl), or any combination thereof;
R 14 being optionally interrupted by oxygen, nitrogen, sulfur, or any combination thereof; and
R 16 is hydrogen, C 1 -C 4 alkyl, or C 2 -C 4 alkenyl.
Acylated amino acids may be prepared by reacting single amino acids, mixtures of two or more amino acids, or amino acid esters with an amine modifying agent which reacts with free amino moieties present in the amino acids to form amides.
Suitable, but non-limiting, examples of acylating agents useful in preparing acylated amino acids include
acid chloride acylating agents having the formula ##STR8## wherein: R 17 an appropriate group for the modified amino acid being prepared, such as, but not limited to, alkyl, alkenyl, cycloalkyl, or aromatic, and particularly methyl, ethyl, cyclohexyl, cyclophenyl, phenyl, or benzyl, and X is a leaving group. Typical leaving groups include, but are not limited to, halogens such as chlorine, bromine and iodine.
Examples of the acylating agents include, but are not limited to, acyl halides including, but not limited to, acetyl chloride, propyl chloride, cyclohexanoyl chloride, cyclopentanoyl chloride, and cycloheptanoyl chloride, benzoyl chloride, hippuryl chloride and the like; and anhydrides, such as acetic anhydride, propyl anhydride, cyclohexanoic anhydride, benzoic anhydride, hippuric anhydride and the like. Preferred acylating agents include benzoyl chloride, hippuryl chloride, acetyl chloride, cyclohexanoyl chloride, cyclopentanoyl chloride, and cycloheptanoyl chloride.
The amine groups can also be modified by the reaction of a carboxylic acid with coupling agents such as the carbodiimide derivatives of amino acids, particularly hydrophilic amino acids such as phenylalanine, tryptophan, and tyrosine. Further examples include dicyclohexylcarbodiimide and the like.
If the amino acid is multifunctional, i.e. has more than one --OH, --NH 2 or --SH group, then it may optionally be acylated at one or more functional groups to form, for example, an ester, amide, or thioester linkage.
In acylated poly amino acids, one or more of the amino acids may be modified (acylated). Modified poly amino acids may include one or more acylated amino acid(s). Although linear modified poly amino acids will generally include only one acylated amino acid, other poly amino acid configurations can include more than one acylated amino acid. Poly amino acids can be polymerized with the acylated amino acid(s) or can be acylated after polymerization.
Sulfonated Amino Acids and Poly Amino Acids
Sulfonated amino acids and poly amino acids are modified by sulfonating at least one free amine group with a sulfonating agent which reacts with at least one of the free amine groups present.
Special mention is made of compounds of the formula
Ar.sup.3 --Y--(R.sup.18).sub.n --OH V
wherein Ar 3 is a substituted or unsubstituted phenyl or naphthyl;
Y is --SO 2 --, R 18 has the formula ##STR9## wherein: R 19 is C 1 to C 24 alkyl, C 1 to C 24 alkenyl, phenyl, naphthyl, (C 1 to C 10 alkyl) phenyl, (C 1 to C 10 alkenyl) phenyl, (C 1 to C 10 alkyl) naphthyl, (C 1 to C 10 alkenyl) naphthyl, phenyl (C 1 to C 10 alkyl), phenyl (C 1 to C 10 alkenyl), naphthyl (C 1 to C 10 alkyl) and naphthyl (C 1 to C 10 alkenyl);
R 19 is optionally substituted with C 1 to C 4 alkyl, C 1 to C 4 alkenyl, C 1 to C 4 alkoxy, --OH, --SH and --CO 2 R 21 or any combination thereof;
R 21 is hydrogen, C 1 to C 4 alkyl or C 1 to C 4 alkenyl;
R 19 is optionally interrupted by oxygen, nitrogen, sulfur or any combination thereof; and
R 20 is hydrogen, C 1 to C 4 alkyl or C 1 to C 4 alkenyl.
Suitable, but non-limiting, examples of sulfonating agents useful in preparing sulfonated amino acids include sulfonating agents having the formula R 22 --SO 2 --X wherein R 22 is an appropriate group for the modified amino acid being prepared such as, but not limited to, alkyl, alkenyl, cycloalkyl, or aromatics and X is a leaving group as described above. One example of a sulfonating agent is benzene sulfonyl chloride.
Modified poly amino acids and peptides may include one or more sulfonated amino acid(s). Although linear modified poly amino acids and peptides used generally include only one sulfonated amino acid, other poly amino acid and peptide configurations can include more than one sulfonated amino acid. Poly amino acids and peptides can be polymerized with the sulfonated amino acid(s) or can be sulfonated after polymerization.
Proteins
Proteins are naturally occurring (i.e. not artificial) polymers of amino acids.
Enteric Coating Materials
Enteric coating materials known to those skilled in the art such as, for example, cellulose acetate trimellitate (CAT) and cellulose acetate phthalate (CAP), are suitable for use in the preservation as well.
Formation
These carriers, and particularly proteinoids, acylated amino acids or poly amino acids, sulfonated amino acids or poly amino acids, and proteins are often insoluble or relatively insoluble in neutral or mildly acidic solutions but are also soluble, as are the imidazole derivatives useful in the present invention, in aqueous acid solutions wherein the volume to volume ratio of acid to water is greater than about 3:7. Suitable aqueous acid solvents are as above, i.e. volatile organic acids, such as for example, aqueous acetic acid, aqueous formic acid, and the like. These acids will volatilize upon nebulization or can be diluted in the aqueous solution, thereby decreasing the concentration of the acid and reversing the solubility of the carrier even in the absence of a precipitator. For example, see U.S. patent application No. 08/475,882, filed on Jun. 7, 1995, now, U.S. Pat. No. 5,667,806, (attorney's docket no. 1946/09202) entitled "SPRAY DRYING METHOD AND APPARATUS".
Microsphere formation occurs when the concentration of the acid in the carrier/active agent solution is decreased. As this solution is nebulized, the acid evaporates, decreasing the concentration of the acid in solution to less than 30% by volume. The carrier, then, will self assemble to form microspheres containing any optional active agent. The cargo must be stable in the concentrated acid for the time and conditions necessary to carry out the operation. Alternately, the carrier solution can be diluted, such as with water, whereby the acid concentration is decreased and the carrier precipitates to form microspheres. Preferably, the microspheres are prepared by spray drying.
The microspheres can be pH adapted by using base or acid soluble coatings including, but not limited to, proteinoid coatings, enteric coatings, acylated amino acid coatings, and the like.
Any of the solutions above may optionally contain additives such as stabilizing additives. The presence of such additives promotes the stability and dispersability of the active agent in solution. The stabilizing additives may be employed at a concentration ranging between about 0.1 and 5% (w/v), preferably about 0.5% (w/v). Suitable, but non-limiting examples of stabilizing additives include buffer salts, gum acacia, gelatin, methyl cellulose, polyethylene glycol, and polylysine.
The amount of active agent that may be incorporated in the microsphere is dependent upon a number of factors which include the concentration of active agent in the solution as well as the affinity of the active agent for the carrier. The concentration of the active agent in the final formulation also will vary depending on the required amounts for any particular end use. When necessary, the exact concentration can be determined by, for example, reverse phase HPLC analysis.
The microspheres and, therefore, the solutions described above may also include one or more enzyme inhibitors. Such enzyme inhibitors include, but are not limited to, compounds such as actinonin or epiactinonin and derivatives thereof.
The microspheres are particularly useful for administering itraconazole derivatives to any animals, including but not limited to, birds and mammals, such as primates and particularly humans; and insects. These microsphere systems are particularly advantageous for delivering these active agents as the active agent would otherwise be destroyed or rendered less effective by conditions encountered before the microsphere reaches the active agent target zone (i.e., the area in which the active agent of the delivery composition are to be released) and within the body of the animal to which they are administered. Furthermore, these microspheres can deliver relatively high amounts of the imidazole derivative and retain a high bioavailability.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following examples illustrate the present invention without limitation.
EXAMPLE 1
Solubilization of Itraconazole
Acetic acid solutions were prepared in water to 10%, 20%, 50% and 75% concentrations (expressed as volume glacial acetic acid/total volume of solution ×100). 100 mg itraconazole solute were then mixed independently with 1 ml of each solution and visually monitored for dissolution. If necessary, additional 1 ml aliquots of each acetic acid solution were added until the itraconazole solute was dissolved.
Results are illustrated in Table 1 below. The solubilized material did not precipitate readily.
TABLE 1______________________________________SOLUBILITYConcentration Amount of Solventof Acid 1 ml 1 ml 2 ml 2 ml 3 ml 3 ml 4 ml 4 mlin Solvent Cold Hot Cold Hot Cold Hot Cold Hot______________________________________10% Acetic Ins. Ins. Ins. Ins. Ins. Ins. -- Ins.Acid v:v20% Acetic Ins. Ins. Ins. Ins. Ins. Part -- --Acid v:v Sol.50% Acetic Ins. Ins. Ins. Sol. Ins. -- -- --Acid v:v75% Acetic Sol. -- -- -- -- -- -- --Acid v:v______________________________________
EXAMPLE 2
Solubilization of Itraconazole
100 mg of itraconazole solute were dissolved in 1 ml glacial acetic acid solvent and aqueous acetic acid solvent at various concentrations. Results are illustrated in Table 2 below.
TABLE 2______________________________________ITRACONAZOLE SOLUTE% Acetic Acid (v:v) Dissolved Itraconazole %______________________________________100 >33 (dissolves freely on addition)75 >10 (dissolves freely on addition)40 5 (diss.conc.acid, then dilute)20 2.5 (diss.conc.acid, then dilute)______________________________________
EXAMPLE 3
Preparation of Itraconazole-containing Microspheres One-solution Method
60 grams of itraconazole solute (Janssen Pharmaceutica) were added to 1.43 liters of glacial acetic acid solvent, and the mixture was stirred to dissolve the solute. 1.43 liters of water were then added using a pump at a flow rate of 25 ml/min. Slight clouding of the solution was observed, but cleared upon further stirring. 166 grams of proteinoid (Glu-Asp-Tyr-Phe-Orn) were added and dissolved with further stirring. The final solution was filtered through folded tissue paper.
Using peristaltic pumps, the solution was fed through a Virtis SDO4 spray drying apparatus under the conditions of Table 3 below.
TABLE 3______________________________________SPRAY DRYING CONDITIONSSolution flow rate 7-8 ml/min______________________________________Inlet temperature 175° C.Outlet temperature 116° C.Blower speed fullCompressor pressure full______________________________________
Stable proteinoid microspheres containing itraconazole were formed. Analysis of typical microspheres using RP-HPLC demonstrated that they contained 14-21% itraconazole by weight.
Scanning electron microscopy in FIGS. 1A-1H illustrates that the microspheres were smooth and spherical and had diameters ranging from 0.1 μm to about 5 μm. When mechanically crushed only the larger spheres shattered, while the smaller spheres remained intact. Crushing revealed a solid internal structure. See, FIGS. 1G and 1H.
All patents, applications, publications, and test methods mentioned herein are hereby incorporated by reference in their entirety.
Many variations of the present invention will suggest themselves to those skilled in the art in light of the above-detailed description in which obvious variations are within the full intended scope of the appended claims. | Solutions comprising itraconazole solubilized in a solvent comprising at least one volatile organic acid are provided. Methods for preparing microspheres containing imidazole derivatives are provided. Also provided is the use of imidazole derivatives containing microspheres for treating fungal infections. Oral dosage forms for oral administration are also provided. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to a manually controllable tuning pulse generator adapted to supply a tuning pulse signal to an electronic tuning control device of an electronic tuning type radio receiver.
Known in the art is a radio receiver which comprises a tuning portion and a tuning control portion comprising a pulse generator capable of generating a count up or count down pulse signal depending upon a manual operation and a clock signal, an up/down counter for counting up or count down the clock signal from the pulse generator depending upon the count up or down pulse signal therefrom and a D-A converter responsive to a count output of the counter for supplying an analog channel selection voltage to varactor diodes included in the tuning portion to thereby operate the latter. The manual pulse generator comprises a disc formed along its periphery thereof with a plurality of slits and capable of being rotated manually and a pair of photo-electric devices each comprising a light emitting element and a light receiving element adapted to receive light from the light emitting element through the slits. The photoelectric devices are arranged in parallel with each other to facilitate the detection of the rotating direction of the disc to determine whether the pulse signal is for up counting or down counting of the clock signal. Such an arrangement is disclosed in copending application Ser. No. 915,098.
The tuning pulse generator constructed as above generates the clock pulse signal having a number of pulses which is proportional to a rotation angle of the disc. The tuning pulse generator of this type is advantageous in that the feeling of the operation of the disc is similar to that of the usual variable capacitor and a fine adjustment of the rotation angle is easy. However, when it is desired to select any one among a number of channels, it is troublesome to do so because a wide range of the disc rotation angle is necessary. In addition to this disadvantage, the pulse generator of this type is disadvantageous in space factor due to the mechanical construction thereof.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a manually controllable tuning pulse generator which is fully electronic and facilitates a rapid coarse regulation as well as a rapid fine regulation.
Another object of the present invention is to provide a manually controllable tuning pulse generator of this type in which an on-off switch and a variable resistor ganged therewith are utilized to produce a count direction signal and a control signal for determining the frequency of the tuning pulse signal.
A still further object of the present invention is to provide a manually controllable tuning pulse generator of the type in which a push button switch system is utilized to produce a count up and down signal and the control signal.
Briefly, this is accomplished by providing a first switch having a grounded contact and one at a suitable potential for providing up- and down-count signals and potentiometer with two symmetrical legs so that turning the potentiometer in either direction provides a signal corresponding to the amount and direction of rotation. The outputs at the switch and potentiometer are connected to the U/D terminal and a pulse generator and the output of the latter is connected to the clock input terminal of the counter so that both the direction and speed of counting can be easily controlled. An astable multivibrator may be used to generate the clock pulses.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an embodiment of the present invention;
FIG. 2 is a schematic diagram of an example of the manual control portion of the embodiment in FIG. 1;
FIG. 3 is a schematic diagram of another embodiment of the present invention in which the same components are represented by the same numerals; and
FIG. 4 is a schematic diagram of still another embodiment of the present invention in which the same components are represented by the same numerals.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 which shows an embodiment of the tuning pulse generator according to the present invention, a potentiometer 1 comprises two resistor halves 1a and 1b, one end of each being connected to a voltage source +V and the other end being connected together by a conductor 1d which is grounded. A potential of a slider 1c of the potentiometer is ground potential at a starting position SP where it is in contact with the conductor 1d and increases with the distance along either of the resistor halves from the conductor 1d.
The slider 1c is connected to a voltage-frequency converter 2 which converts the potential into frequency. A frequency output of the voltage-frequency converter 2 appears at a terminal 3 as a tuning pulse signal.
A switch 4 comprises a pair of fixed contact strips 4a and 4b and a movable contact 4c which is ganged with the slider 1c of the potentiometer 1 and is connected to a terminal 5. One end of the contact strip 4b is connected to a suitable voltage source +V and the contact strip 4a is grounded. There is a small gap between the contact halves 4a and 4b.
The length of each of the contact halves 4a and 4b of the switch 4 may be made equal to the length of each of the resistor halves 1a and 1b of the potentiometer 1 so that, when the slider 1c is at the point SP and grounded, the movable contact 4c, i.e. the terminal 5, becomes floating and, when the slider 1c contacts with either the resistor half 1a or 1b, the movable contact 4c is at either ground potential or the source voltage.
FIG. 2 shows an example of the structure of the combination of the potentiometer 1 and the switch 4 in which the latter two are constructed as a rotary type assembly.
In this construction, the ground potential at the terminal 5 is referred to as a count up signal and the source voltage at the terminal 5 is referred to as a count down signal.
In operation, there is no signal applied to an input of the voltage-frequency converter 2 when the switch 4 as well as the potentiometer 1 are in reset states in which the movable contact 4c and the slider 1c are at the center position SP, respectively, because the slider 1c is grounded through the conductor 1d. Therefore, the converter 2 provides no output.
When a shaft 10 of the assembly of the potentiometer 1 and the switch 4 is turned slightly, for example, rightwardly in FIG. 2, the movable contact 4c of the rotary switch 4 contacts with the fixed contact 4a, resulting in a count up signal at the output terminal 5. At the same time, the slider 1c of the potentiometer 1 is also turned slightly along the resistor half 1a and a relatively low voltage corresponding to the amount of rotation of the slider 1c is supplied to the voltage-frequency converter 2. The converter 2 provides a signal having a relatively low frequency corresponding to the low voltage at the output terminal 3. The signal at the terminal 3 is used as the tuning clock pulse signal.
Accordingly, an up/down counter (not shown) of the tuning section counts up the clock pulses supplied from the output terminal 3 according to the count up signal from the output terminal 5, and a channel selection is made according to the counter output.
In this case, since the period of the clock pulse signal is relatively long, the counting operation of the up/down counter is slow correspondingly. This can be effectively utilized to finely tune the selected channel.
When the shaft 10 is further rotated, the movable contact 4c of the rotary switch 4 moves along the contact strip 4a and the count up signal continues to exist at the terminal 5. On the other hand, the slider 1c of the potentiometer 1 moves towards the end of the resistor 1a connected to the voltage source +V and a higher voltage appears at the slider 1c, the value being determined by the rotation angle of the shaft. Therefore, the voltage-frequency converter 2 provides a higher output frequency and thus a higher frequency tuning pulse signal is supplied through the output terminal 3 to the up/down counter, so that the output of the up/down counter increases and thus the receiver is rapidly tuned to the higher receiving signal frequency.
When the shaft 10 is turned leftwardly from the center position SP, the same effect as that obtainable when it is turned rightwardly is obtained. In this case, however, the movable contact 4c of the rotary switch 4 contacts with the fixed contact strip 4b connected to the voltage source +V. Therefore a count down signal is provided at the output terminal 5. The slider 1c of the potentiometer 1 contacts with the resistor half 1b providing a voltage output which causes the voltage-frequency converter 2 to provide a tuning pulse signal, the frequency thereof being determined by the position of the slider 1c on the resistor half 1b. As a result, the up/down counter responds to the down count signal to count down the tuning pulses, so that the tuning is performed toward the lower frequency side at a speed determined by the tuning pulse signal frequency. With the turning amount of the shaft 10 increased, the voltage output at the slider 1c of the potentiometer 1 increases and the output frequency of the voltage-frequency converter 2 increases correspondingly causing a speed up of the downward shift of the tuning frequency.
As mentioned above, with the rightward turning of the shaft 10, the up/down counter counts up the tuning pulses, the frequency of which corresponds to the turning amount of the shaft. The counting speed also corresponds to the turning amount with the leftward turning of the shaft 10 and the up/down counter counts down the tuning pulses, the frequency of which corresponds to the turning amount, and thus the counting speed corresponds to the turning amount.
Therefore, the coarse adjustment can be performed by increasing the turning amount of the shaft 10 in either direction and thereafter the fine adjustment can be performed by returning the shaft 10.
The shaft 10 may be constructed such that it returns to the rest position SP automatically upon completion of the tuning.
FIG. 3 shows another embodiment of the present invention, in which substantially the same assembly of the potentiometer and the rotary switch is used for the mannual control. A difference in structure of the manual control assembly is that the conductor 1d connecting the adjacent ends of the resistor halves 1a and 1b is omitted to make the ends in floating state.
In FIG. 3, a first transistor 10 has a collector connected through a resistor 12 to the voltage source +V, an emitter grounded and a base. A second transistor 13 has a collector connected through a resistor 14 to the voltage source +V, an emitter grounded and a base connected through a capacitor 15 to the collector of the first transistor 10. The base of the latter is connected through a capaciter 16 to the collector of the second transistor 13.
The base of the first transistor is also connected through a resistor 18 to the fixed contact strip 4b of the rotary switch 4 and to the voltage source +V and the base of the second transistor is connected to the slider 1c of the potentiometer 1. As will be clear for those skilled in the art, this circuit construction forms an astable multivibrator.
The manual control assembly is preferably of the auto-return type as mentioned above so that when the manual control is removed the slider 1c of the potentiometer 1 and the movable contact 4c of the rotary switch 4 return to their center positions automatically.
In operation, with the slider 1c and the movable contact 4c at the center position SP, there is substantially no base voltage of the transistor 13 and it is in a non-conduction state. Therefore, the multivibrator does not provide the tuning pulse signal to the output terminal 3.
When the shaft 10 is slightly turned in either direction, for example, rightwardly, the movable contact 4c contacts with the grounded fixed-contact strip 4a and the count up signal appears at the terminal 5.
At the same time, the slider 1c of the potentiometer 1 rides on the resistor half 1a. The resistance value of the potentiometer 1 connected between the voltage source +V and the base of the transistor 13 is proportional to the moving or rotating amount of the slider 1c. Since the oscillation period of the multivibrator is determined by R 1 ·C 15 +R 18 ·C 16 where C 15 and C 16 are capacitance values of the capacitors 15 and 16, respectively, and R 18 is the resistance value of the resistor 18, the larger the resistance value of the potentiometer 1 provides the longer the period.
FIG. 4 is still another embodiment of the present invention which uses an astable multivibration as in the embodiment in FIG. 3. Although in the embodiments in FIGS. 1 and 3, the manual control is performed by a potentiometer and a single pole double throw switch ganged with the potentiometer, a non-lock type push-button switch system is employed in the embodiment in FIG. 4.
In FIG. 4, a fixed resistor 1' is inserted between the voltage source +V and the base of the second transistor 13, as a replacement of the potentiometer 1. The resistor 18 in FIG. 3 is replaced by a resistor 18' and a resistor 18" connected in series with the resistor 18'.
The non-lock type push-button switch system comprises four non-lock type switch buttons 21 to 24 each having three on-off switches. The button 21 is referred to as a high-speed count-up button and has a direction detecting switch 25a, a speed control switch 26a and a tuning pulse switch 27a, all of the switches being ganged.
A low-speed count-up button 22 has a direction detecting switch 25b, a speed control switch 26b and a tuning pulse switch 27b. A low-speed count-down button 23 and a high-speed count-down button 24 have direction detecting switches 25c and 25d, speed control switches 26c and 26d and tuning pulse switches 27c and 27d, respectively.
These switches 25a to 25d, 26a to 26d and 27a to 27d are normally open and, when any button is despressed, the switches associated therewith are closed.
The direction detecting switches 25a and 25b are connected in parallel and one end is connected to the voltage source +V. The other end of the parallel switches is connected to the output terminal 5. The switches 25c and 25d are also connected in parallel, one end being grounded and the other end being connected to the output terminal 5. The speed control switches 26a and 26d are connected in parallel, one end being connected to the voltage source +V and the other end being connected to a junction of the series resistors 18' and 18" of the astable multivibrator.
The tuning pulse switches 27a to 27d are connected in parallel, one end being connected to the output of the multivibrator and the other being connected to the output terminal 3.
In operation, a button for example, the high-speed count-up button 21 is despressed, the switches 25a, 26a and 27a are closed and thus the source voltage appears through the switch 25a at the terminal 5 as a count-up signal H. With the switch 26a closed, the resistor 18' is short-circuited. By this short-circuit of the resistor, the value of the resistor is reduced to that of the resistor 18", resulting in a high frequency oscillation of the multivibrator. The output of the multivibrator appears through the closed switch 27a at the terminal 3. According to the high frequency pulse output at the terminal 3 and the count-up signal at the terminal 5, the up/down counter counts up the output pulses during the depression of the button 21 and thus a high-speed shift in tuning frequency is achieved. The tuning frequency shift thus achieved is maintained after the operation of the button is terminated.
By depressing the low-speed count-up button 22, the switches 25b, 26b and 27b are closed. In this case, the source voltage is also supplied through the switch 25b to the terminal 5 as the count-up signal and the output of the multivibrator is supplied through the switch 27b to the terminal 3. In this case, however, the resistor 18' is not short-circuited and, therefore, the frequency of the output pulses at the therminal 3 is lower than that where the button 21 is operated. Accordingly, the frequency shift to be done by the counter and hence the tuning circuit becomes slow which is suitable to achieve a fine tuning. After the desired frequency shift is achieved, the depression of the button 22 is terminated, so that the output at the terminal 3 disappears and the tuned frequency is fixed.
Depressions of the low-speed count-down button 23 and the high-speed count-down button 24 provide the same effect as that of the buttons 22 and 21, respectively, except that the terminal 5 is grounded and provides a count-down signal.
As described hereinbefore, according to the present invention, it is made possible to facilitate the coarse and fine adjustments of the tuning frequency with a manually controlled freuqency generator. It should be noted, in this connection, that although the manual control of the tuning pulse frequency is performed by the combination of the potentiometer and the rotary switch ganged therewith in the embodiments in FIGS. 1 and 3 and by the non-lock type switch system in the embodiment in FIG. 4, there may be various modifications thereof. Further, the voltage-frequency converter and the astable multivibrator are mere examples of the pulse generators which are controlled manually. | A manual tuning pulse generator for use in an electronic tuning control device of a radio receiver having a tuning circuit, which control device utilizes an up/down counter, is disclosed which comprises a first manual means for selectively producing an up count signal and a down count signal to be supplied to the up/down counter, a second manual means ganged with said first manual means for producing a variable control signal and means responsive to the variable control signal to produce a clock pulse signal having a variable frequency, the pulses of the clock pulse signal being adapted to be counted up or down by the up/down counter the content of which is utilized to shift the tuning frequency. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 08/498,471, filed Jul. 5, 1995 now abandoned.
BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION
The present invention relates to an improved method of treating paper products in order to enhance various properties thereof, and more specifically, including the step of treating the paper with superheated steam.
2. Description of the Prior Art
There are four broad classes of pulps produced today, namely, mechanical, chemimechanical, semichemical, and chemical pulps. Three of these, mechanical, chemical, and semichemical, are of concern to the present invention and are briefly discussed below.
Mechanical pulps such as TMP (thermo-mechanical pulp) and CTMP (chemithermomechanical pulp) are prepared by processes such as refining which convert wood chips into the pulp. Pulp yields are typically 90-95% from dry wood. Virtually all of the wood components, such as lignin, present in the wood, remain in the pulp. The term “ultra-high yield” pulps is sometimes used for these pulps.
Value can be added to mechanical pulps by additional treatments such as bleaching. For example, CTMP subjected to alkaline-peroxide treatment greatly increases the brightness and value of the pulp. BCTMP (bleached chemithermomechanical pulp) is sold on the open market for use in grades such as tissue, toweling, printing and writing papers, and paperboard.
Chemical pulps are prepared in much lower yield as a consequence of the different processing conditions. Kraft pulp is the most important example of a chemical pulp. Chips are soaked for several hours. at elevated temperature and pH in a cooking liquor which dissolves the lignin from the wood chips. These delignified chips are then thoroughly cleaned to provide a pulp consisting of long, conformable fibres.
The Kappa number is commonly used to indicate the degree is delignification of kraft pulps. It can be used with pulps having yields up to about 70%. There is essentially a linear relationship between the Kappa number and Klason lignin (i.e., acid-insoluble lignin). For these pulps, the relationship is (TAPPI Standard T236) Percent Klason lignin=Kappa number ×0.15.
Pulp yields are typically 40-55% based on dry wood for “low yield” kraft pulps. Bleaching of chemical pulps is also done to increase the brightness and commercial value. Unbleached kraft pulp is used extensively in the manufacture of linerboard, one component of containerboard.
Linerboard is typically made commercially using different kinds of pulps for different plies in the same sheet. The bottom liner is frequently made from bottom liner stock of virgin kraft pulp of about 55-60% yield, while the top liner is made from top liner stock of virgin kraft pulp of about 48-50% yield. The higher quality top liner is used to hide the lower quality basesheet and provide a better printing surface. It constitutes about 20-30% of the total linerboard weight (Smook, G. A., “Handbook for Pulp & Paper Technologists”, CPPA/TAPPI, 1989).
Semichemical pulping uses a combination of chemical and mechanical treatment to develop the pulp fibres. Pulp yields vary over the wide range of 55-90% based on dry wood. NSSC (neutral sulfite semichemical) pulp typically has a yield of 75%. It is favoured for the medium, or fluting, in corrugated containers due to its high stiffness.
Recycled pulps are becoming more commonplace. OCC (old corrugated containers) pulp is used commercially to make 100% recycled linerboard. Different pulps are used to make the inner fluting and outer linerboard of a corrugated container, as noted above. OCC for linerboard manufacture can be a mixture of virgin and recycled kraft and semichemical pulps. The composition of OCC and the behavior of paper made from this furnish is further discussed.
Paper is frequently manufactured not just from pulp fibre but from a mixture of pulp fibre and inorganic particles. Such paper grades are generally referred to as “filled” papers. A variety of fillers can be used, but clay is a common example. Adding fillers to paper has a detrimental effect on the strength properties, but can improve the optical properties, of the paper.
Previous work has demonstrated that super-heated steam drying of paper made from pure mechanical pulps, such as TMP and CTMP, significantly improves the dry tensile strength of the paper without substantially increasing sheet density. Paper made from pure chemical pulps such as kraft does not have increased strength after drying in superheated steam (Cui, W.-K., Mujumdar, A. S., and Douglas, W. J. M., “Superheated Steam Drying of Paper: Effects on Physical Strength Properties,” in Drying ′86 [A. S. Mujumdar, Ed.], Hemisphere, N.Y., pp. 575-579 [1986]; Poirier, N. A., “The Effect of Superheated Steam Drying on the Properties of Paper,” Ph.D. thesis, Department of Chemical Engineering, McGill University, 1992; McCall, J. M. and Douglas, W. J. M., “Superheated Steam Drying of Paper from Chemithermomechanical Pulp,” Tappi J., 77 [2]:153-161 [1994]).
The quality requirements of a sheet of paper are becoming increasingly stringent. As paper machine speeds increase, the strength of the wet web must also be adequate to avoid web breakage. Once dried, the paper is subjected to many different end uses, depending on the grade of paper. The relative importance of the various surface and mechanical properties of the paper depends on the end use of the paper. For example, with tissue and toweling and even for some printing papers and paperboard, bulk is very important. For linerboard, the compressive strength and air resistance are two key properties. Printing and writing papers must have adequate resistance to penetration of liquids, and in some cases higher bulk is also an important property.
For many grades of paper and paperboard, a high bulk (apparent specific volume) is an important property. This is especially true for grades such as tissue and toweling for which the pulp properties and processing conditions are carefully selected to provide a final dry sheet having acceptably high bulk. A prime criterion in the choice of drying technique for these grades is the achievement of high bulk. The importance of increasing the bulk of tissue is demonstrated, for example, by the patent issued to the Kimberly Clark Corp. (U.S. Pat. No. 4,994,144, Chen et al, February 1991). Tissue and toweling frequently contain bleached chemithermomechanical pulp (BCTMP) and bleached kraft pulp (BKP) in substantial quantities.
SUMMARY OF THE INVENTION
One aim of the present invention is to provide an improved method of treating paper products in order to enhance various properties thereof, and more specifically, including the step of treating the paper with superheated steam.
Another aim of the present invention is to provide an improvement in a method of treating paper during a paper-making process from wood pulp, the step of drying the paper in superheated steam in order to improve certain physical characteristics.
In one aspect of the present invention a sheet of paper having increased bulk characteristics is provided wherein the sheet of paper is made from a pulp containing between 20% and 100% BCTMP, the pulp having a substantial lignin content, and wherein the sheet of paper has been dried by superheated steam. More specifically, the lignin content includes between 16 and 32% by weight of lignin.
The invention also relates to a method of making paper of superior bulk characteristics comprising the steps of preparing pulp with at least 20% BCTMP content and having a substantial lignin content, and drying the paper with superheated steam.
Another aspect of the present invention provides a linerboard having improved tensile, compressive strength and air resistance values made from a pulp furnish containing from 0 to 100% OCC, wherein the linerboard has been dried by superheated steam.
A method is also provided for making a linerboard sheet including preparing a furnish of 0 to 100% OCC, drying the sheet in a superheated steam environment whereby improved tensile strength, compressive strength, and air resistance values are obtained compared to a similar linerboard sheet dried in air.
A further aspect of the present invention includes a sheet of paper having an inorganic filler content with improved optical and printing properties, wherein the sheet of paper has been dried with superheated steam whereby the breaking length of the paper having 4% filler content or more does not decrease.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Use of special dryers and techniques such as through drying and use of creping or doctor blades to remove the sheet from the drying cylinder are used to impart bulk to paper dried by current technology. Dry creping of tissue has the disadvantage of reducing the tensile strength of the sheet. The development of bulk in tissue or toweling has frequently been described (Back, E. L., “Developments in Drying Technologies,” Pira Reviews of Pulp and Paper Technology, Pira International, Leatherhead, p. 37 [1991]; Oliver, J. F., “Dry-Creping of Tissue Paper—A Review of Basic Factors,” Tappi J., 63 [12], 91-95 [1980]; U.S. Pat. No. 4,994,144; Smith and Chen, 1991, discussed above). Patents concerning through-air drying of tissue have also been granted (U.S. Pat. No. 3,432,936, R. I. Cole, March 1969; 3,303,576, J. B. Sisson, 1967) and are used for the purpose of obtaining high bulk in the product.
The present disclosure reveals that with the specific pulps used for some paperboard and for tissue and toweling, i.e. BCTMP, including blends of BCTMP and BKP, the use of superheated steam as a drying medium can substantially increase the bulk of paper without loss of sheet strength and without the addition of any chemicals.
Key properties of linerboard are its strength and air resistance. The tensile, burst, and short-span compressive strengths, and Gurley porosity are frequently used as measures of these properties. Although the burst strength has traditionally been used as a measure of linerboard strength, the short-span (STFI) compressive strength is becoming the test of choice. Linerboard made from secondary fibres, such as from recycled old corrugated containers (OCC), are often weaker than those made from virgin fibres. As we are in a period of increasing use of recycled fibre, any technique which can regain some of the strength is potentially of even more importance commercially.
Currently linerboard manufacturers using OCC furnish may add additional expensive chemical pulp or change the pulp processing conditions in order to meet product strength specifications. Alternative methods of increasing board strength, such as through press drying, achieve the strength through densification of the sheet. Still other methods increase board strength through the addition of chemicals such as starch.
Conventional contact cylinder drying of paperboard and the effect of cylinder drying conditions on the final properties has been described (Marshall, H. G., “Current Trends in Drying of Paperboard,” Ch. 24 in Drying of Paper and Paperboard [G. Gavelin, Ed.], Lockwood, N.Y., 1972; Bel'skii, A. P, Malysheva, L. V. and Moiseev, Yu. B., “Effect of Temperature During Contact Drying on Board Quality,” Bumazh. Prom., 1981 [7], 25-26; Bulletin of the Institute of Paper Chemistry [ABIPC], 53[1]:355). Contact, convection, radiation, and combinations of two or all three drying methods for paperboard and the effect of drying conditions on the final properties have been compared (Bel'skii, A. P, Malysheva, L. V. and Moiseev, Yu. V., “Effect of Convection Drying Parameters on the Quality of Packaging Board,” Mezhvuz. Sb. Nauch. Tr., Ser. Khim. Tekhnol. Bum. no. 6:83-87 [1978]; Bulletin of the Institute of Paper Chemistry [ABIPC], 54[4]:3725; Bel'skii, A. P., Malysheva, L. V. and Moiseev, Yu. B., “Effect of Convection Drying Conditions on Board Quality Indices,” Sb. Tr. VNIIB, Kompleksnaya Sistema Upravleniya Kachestvom Produktsii na Predpriyatiyakh Tsellyul.-Bumazh. Prom. [Norikov, N. E., et al., eds.], 1980, 62-64; Bulletin of the Institute of Paper Chemistry [ABIPC], 55[9]:9795; Moiseev, Yu. B., Malysheva, L. V., Kuznetsova, E. F. and Bel'skii, A. P., “Influence of Combination Drying on the Physico-Mechanical Properties of Boxboard,” Sb. Tr. VNIIB, Novoe Tekhnol. Proizvod. Bumagi Kartona [Novikov, N. E., et al., eds.], 1981, 27-35; Bulletin of the Institute of Paper Chemistry [ABIPC], 56[1]:476). The degradation of properties with recycling of furnishes used in linerboard manufacture has been described (Putz, H.-J., Török, I., and Göttsching, L., “Making High Quality Board from Low Quality Waste Paper,” Paper Tech. & Ind., 30[6]:14-20 [1989]; Howard, R. C. and Bichard, W., “The Basic Effects of Recycling on Pulp Properties,” J. Pulp and Paper Sci., 18[4]:J151-J159 [1992]; J. Pulp and Paper Sci., 19[2]:J57 [1993]; Nguyen, X. T., Shariff, A., and Jean, M., “Impact of Paper Recycling on the Environment and Quality of Paper and Board Products,” Proc. Recycling Forum, Toronto, 1991, pp. 1-20).
The present disclosure reveals a novel way to improve the strength of linerboard without modifying the furnish composition or densifying the sheet. The technique can be applied to linerboard made from virgin kraft or made from a recycled furnish such as OCC. Specifically, the present disclosure reports that, in order to improve its strength properties, paper made from a commercial recycled linerboard furnish or from virgin kraft linerboard furnish (of about 55-67% yield) needs simply to be dried in an atmosphere of superheated steam instead of, as done universally today, dried in an atmosphere of air.
Value can be added to many grades of paper by the incorporation of inorganic particles. Such grades are commonly referred to as “filled papers”. Many types of inorganic particles can be used in filled papers, one frequently used being kaolin or clay. Incorporation of inorganic particles decreases paper strength but can improve the optical properties of the sheet (Alince, B., “Optimization of Pigment Performance in Paper,” in Fundamentals of Papermaking, Trans. 9th Fund. Res. Symp., Cambridge [Baker, C. F. and Punton, V. W., eds.], Mech. Eng. Publ. Ltd., London, pp. 495-508 [1989]). Papers containing mechanical pulps and fillers are included in the “groundwood specialty” grades. They are often used for newspaper inserts and catalogues, for example. These papers contain mostly mechanical pulps (60-100%) but may also contain chemical pulp (0-40%). Filler contents can be up to about 30% such as in supercalendered (SC) grades (Negele, A. R. and House, L. W., “Use of Kaolin Pigments in Uncoated Groundwood Specialties,” Pulp & Paper Canada, 90[8]:60-66 [1989]). Incorporation of filler into newsprint provides a paper which is brighter, whiter, more opaque, and smoother which leads to improved printability (Koppelman, M. H. and Migliorini, I. K., “Quality Improvement in Standard Newsprint Through Filler Inclusion,” in Preprints of Papers, Tappi Papermakers Conference, 1986, pp. 169-179). The use of clay filler loadings in newsprint furnishes at up to about 7% by weight can provide significant improvements in brightness and opacity, at least a 2 point increase for each property (Koppelman, M. H. and Migliorini, I. K., 1986, see above). In addition to adding value to paper, if a filler is used which is less expensive than fibre, then there is a saving associated with replacing fibre with filler.
The present disclosure teaches that paper made from a typical newsprint furnish to which a given level of clay filler is added is stronger when that sheet is dried in superheated steam rather than dried in air or as is done conventionally, in air on a hot metal surface. It furthermore teaches that the strength of filled paper dried in superheated steam does not continue to decline with increasing filler content at the rate which is found for conventional hot surface drying in air, but rather, above a certain filler content increased filler content leads to little further decrease in tensile strength.
Published work has established that the enhancement of paper properties as a result of drying the paper in superheated steam varies with broad categories of the type of pulp. For example, the earliest publication of properties of superheated steam dried paper (Cui, Mujumdar and Douglas, 1986, see above) reported significant differences in paper properties between the broad categories of paper from mechanical pulps and paper from chemical pulps.
In the enhancement of paper properties by switching to superheated steam drying, and the dependence of such enhancement on the very specific type of paper, the present report of invention takes this distinction much further than previous knowledge. For example, our reported significant enhancement in paper bulk by drying it in superheated steam is very specific to the particular pulp described above. Linerboard has traditionally been made from kraft chemical pulp. Earlier publications established that for kraft paper made from low yield kraft pulp, the switch from drying in air to drying in superheated steam does not produce strength enhancement. The linerboard we tested was made from high yield 100% virgin kraft linerboard furnish or from 100% recycled old corrugated containers (OCC), which is a blend of different chemical pulps. Additional research results are presented for linerboard furnishes made from 100% virgin kraft pulps of higher yield, specifically yields of about 55, 62, and 67%. When paper made from these pulps was dried in air in contact with a hot surface, as is done conventionally, the tensile and compressive strengths of the paper decreased with increasing yield. The opposite trend was found when paper made from these pulps was dried in superheated steam, i.e., strengths tended to increase with increasing pulp yield. The improvement in strength achieved by drying in superheated steam increased with increasing pulp yield. The significant strength enhancement that we report for this switch from drying in air to drying in superheated steam is therefore surprising and would not have been anticipated.
The wet paper webs arriving at the dryer of a paper mill come in endless variety. For paper made from virgin fibre there is the species, age, etc. of the trees, and the type and variables of the pulping, bleaching, wet end chemistry and papermaking processes used. If recycled fibre is used, there is limitless variability possible. And paper is commonly made from blends of recycled and virgin fibres. We have shown that by drying in superheated steam, some commercially important paper properties can be enhanced significantly for some very specific types of paper. Thus we claim to have discovered that one characteristic of the enhancement in paper properties resulting from the switch to drying in superheated steam is that such enhancements can be very sensitive to small changes in the type of paper. For many specific types of paper, superheated steam drying will enhance commercially important properties, while for many other specific types of paper, this drying technique will not lead to enhanced properties.
In summary, we have found that the property enhancement by superheated steam drying can be very specific to the exact type of paper.
For the research reported here, handsheets made from softwood bleached chemithermomechanical pulp, BCTMP, and blends of softwood BCTMP with softwood bleached kraft pulp, BKP, have been dried in 200° C. air and in 200° C. superheated steam. Handsheets made from hardwood BCTMP have also been dried in 150, 200, 250 and 300° C. air and in 150, 200, 250 and 300° C. superheated steam. The thickness (caliper) and other physical and optical properties of each handsheet were measured under standard paper testing conditions. Typically ten handsheets were used, with the caliper measured in five places on each handsheet, and the average of the 50 values used to calculate an average caliper. The ratio of this average caliper to the oven-dry basis weight provides the bulk (cm 3 /g) of the sheet, also known as its apparent specific volume. Tables 1 and 3 summarize the handsheet composition, moisture content at the start of drying (X O , kg water/kg fibre), and moisture content at the end of drying (X f , kg water/kg fibre), and the percentage change in bulk for the various samples. Those bulks marked with an asterisk (*) in Tables 1 and 2 were dried to the indicated X f in the noted drying atmosphere (steam or air) but then removed from the drying chamber and dried in ca. 50° C. air under restraint to an X f of ca. 0.07. In all other cases, the handsheets were dried to the indicated X f solely in the indicated drying conditions. The increase in bulk, (steam-air)/air as % is indicated in the last column.
It is evident that under certain conditions, bulk of steam dried paper can be up to 25% greater than the air dried paper. Tables 2 and 4 show the measured tensile strengths expressed as breaking lengths (km) for the same samples. The increased bulk values found for the steam dried cases occur without loss of tensile strength in most cases. Previous results (McCall and Douglas, 1993, see above) with unbleached softwood CTMP handsheets showed only a small increase in bulk with superheated steam drying. Thus the effect on sheet bulk appears very specific to the pulp used, and our use of exactly the furnish used for tissue and toweling (blends of BCTMP and BKP) is important.
As this is the first study, no publications or patents exist on the effect of superheated steam drying on the bulk of papers or paperboards made from BCTMP or BCTMP/BKP blends. However, generally insignificantly small increases in bulk using superheated steam as a drying medium for paper made from types of pulp other than the above have been reported (Chinese Patent 86102860, Apr. 15, 1987, W. Cui; Cui et al., 1986; McCall and Douglas, 1993; Poirier, 1992; all discussed above. No previous study used BCTMP or BCTMP/KP blends that are used in commercial furnishes for tissue and toweling or for paperboard.
Lightweight grades of paper such as tissue and toweling are currently manufactured by a limited number of techniques. One of the most common is the drying of a paper web on a Yankee cylinder under impinging jets of air and creping the sheet on its removal from the cylinder in order to increase sheet bulk, softness and absorbency (Oliver, 1980, discussed above). Typical initial moisture content after pressing onto the Yankee cylinder is about 1.3-1.6 kg water/kg fibre (Sorrells, F. D., “Drying on Conventional Tissue Machines,” in Tappi Notes, Tissue Runnability Seminar, TAPPI Press, pp. 281-285 [1992]). In the dry creping process, the sheet is removed from the Yankee cylinder using a creping or doctor blade at a moisture content of about 0.02-0.4 kg water/kg fibre (Corboy, W. G., “Yankee Dryers,” Ch. 14 in Pulp and Paper Manufacture, Vol. 7—Paper Machine Operations [B. A. Thorp and M. J. Kocurek, Eds.], Joint Textbook Committee of the Paper Industry of the United States and Canada, Montreal/Atlanta [1991]). Wet creping, which is used with higher basis weight toweling rather than the lower basis weight tissue, removes the sheet at a moisture content of about 0.4-0.8 kg water/kg fibre (Corboy, 1991) with the remaining drying done on cylinder dryers.
Other techniques such as using through-dryers before or after Yankee dryers are used to preserve sheet bulk (Oliver, 1980, discussed above). Through-air drying of tissue before Yankee drying can reduce the moisture content of the web from about 4.0 to about 0.25 kg water/kg fibre (Sisson, J. B. [Procter & Gamble Company], “Apparatus for Drying Porous Paper,” U.S. Pat. No. 3,303,576 [Feb. 14 1967]). Through-air drying of tissue after Yankee drying can reduce the web moisture content from about 1.5 to about 0.03 kg water/kg fibre (Cole, R. I. [Scott Paper Company], “Transpiration Drying and Embossing of Wet Paper Webs,”, U.S. Pat. No. 3,432,936 [Mar. 18, 1969]). The main advantage of through-air drying for tissue is increased bulk and resultant improved softness (Back, 1991, discussed above).
All the above evidence indicates the commercial importance of high bulk for some paper grades. Improving bulk and softness without sacrificing strength have been forecast as future needs for tissue (Linkletter, 1989, discussed above).
Conversion of a conventional Yankee dryer from operating with air to operating with superheated steam has been proposed and analyzed (Thompson, R., Belanger, P., Kerr, R. B., Douglas, W. J. M., “A Superheated Steam Dryer for Tissue Paper,” in Proc. Helsinki Symp. on Alternate Methods of Pulp and Paper Drying, 1991, pp. 357-371). A superheated steam dryer for printing and writing papers or paperboards could be similar to that for lightweight tissue or towel paper except that it could have more than the single cylinder sufficient for lightweight papers. A superheated steam impingement dryer for tissue or towel papers could use similar dryer hoods as used now with air, but modified to allow the use of superheated steam.
TABLE 1
Softwood BCTMP/BKP
PULP
X o
X f
X o
X f
BULK
BCTMP:
STEAM-
STEAM-
AIR-
AIR-
STEAM-
AIR-
CHANGE
BKP
DRIED
DRIED
DRIED
DRIED
DRIED
DRIED
%
100:0
0.72
0.05
0.72
0.05
4.13
3.87
6.7
100:0
0.94
0.07
0.94
0.04
4.43
3.86
14.8
100:0
1.23
0.12
1.22
0.14
5.15*
4.11*
25.3
100:0
1.53
0.19
1.54
0.21
5.16*
5.09*
1.4
100:0
1.40
0
1.56
0
5.11
4.73
8.0
100:0
1.74
0.05
1.61
0.05
4.82
4.12
17.0
100:0
2.02
0.06
2.07
0.05
4.61
4.43
4.1
100:0
4.52
0.03
4.54
0.05
5.07
4.53
11.9
80:20
1.03
0.09
1.10
0.06
3.66
3.24
13.0
80:20
1.11
0.08
1.51
0.04
4.09
4.00
2.3
50:50
1.09
0.07
1.11
0.07
2.90
2.61
11.1
20:80
1.13
0.07
1.19
0.03
2.16
2.00
8.0
Notes to Table 1
X o = moisture content into dryer, kg water/kg oven-dry fiber
X f = moisture content out of dryer, kg water/kg oven-dry fiber
Bulk, cm 3 /g
TABLE 2
Softwood BCTMP/BKP
BREAKING
PULP
BULK
LENGTH
BCTNP:
STEAM-
AIR-
STEAM-
AIR-
BKP
DRIED
DRIED
DRIED
DRIED
100:0
4.13
3.87
4.96
4.50
100:0
4.43
3.86
4.38
4.62
100:0
5.15*
4.11*
3.64
3.86
100:0
5.16*
5.09*
3.69
3.53
100:0
5.11
4.73
3.97
3.74
100:0
4.82
4.12
4.09
4.17
100:0
4.61
4.43
4.15
4.03
100:0
5.07
4.53
4.15
3.73
80:20
3.66
3.24
5.80
5.63
80:20
4.09
4.00
5.56
5.43
50:50
2.90
2.61
7.95
7.82
20:80
2.16
2.00
10.02
10.52
Notes to Table 2
Bulk, cm 3 /g
Breaking length, km
TABLE 3
Hardwood BCTMP
DRYING
FLUID
X o
X f
X o
X f
BULK
TEMP
STEAM-
STEAM-
AIR-
AIR-
STEAM-
AIR-
INCREASE
° C.
DRIED
DRIED
DRIED
DRIED
DRIED
DRIED
%
150
0.99
0.12
1.05
0.04
2.73
2.42
12.8
200
1.10
0.03
1.05
0.09
2.66
2.57
3.5
250
1.16
0.11
0.94
0.02
2.61
2.47
8.5
300
1.24
0.05
0.98
0.07
2.63
2.50
5.2
Notes to Table 3
X o = moisture content into dryer, kg water/kg oven-dry fiber
X f = moisture content out of dryer, kg water/kg oven-dry fiber
Bulk, cm 3 /g
TABLE 4
Hardwood BCTMP
DRYING
FLUID
BULK
BREAKING LENGTH
TEMP.
STEAM-
AIR-
STEAM
AIR-
° C.
DRIED
DRIED
DRIED
DRIED
150
2.73
2.42
4.53
4.30
200
2.66
2.57
4.58
4.38
250
2.68
2.47
4.65
4.50
300
2.63
2.50
4.63
4.44
Notes to Table 4
Bulk, cm 3 /g
Breaking length, km
There are few documented reports of the effect of recycling on the properties of paper made from a commercial furnish derived from OCC. One approach being used in German mills (Putz et al., 1989, discussed above) improves the properties of paper when a low quality recycle furnish was used to manufacture test liner (the term given to linerboard made from OCC) and corrugating medium. They separated the poor quality furnish into its long and short fibre fractions, then refined the long fibre component, and blended it back with the short fibre fraction. The individual fractions can also be used in other applications.
Koning, J. W. and Godshall, W. D., “Repeated Recycling of Corrugated Containers and Its Effect on Strength Properties,” Tappi J., 58(9):146-150 (1975), prepared linerboard from virgin southern pine unbleached kraft pulp and corrugating medium from virgin mixed hardwood neutral sulfite semichemical (NSSC) pulp on a pilot paper machine. Double-face corrugated board was made from these components. The board was then reslushed and linerboard was made from the recycled corrugated board, i.e., from an OCC furnish. The properties of the linerboard made from the virgin fibre were compared with the properties of the linerboard made from the OCC pulp. The linerboard made from 100% OCC was 22% weaker in ring crush, and about 25% weaker in tensile strength.
In laboratory studies of unbleached beaten kraft, the main component by weight of an OCC furnish (Howard and Bichard, 1992, discussed above), demonstrated that after 5 recycles there was a 7% reduction in density, 17% reduction in breaking length, 21% reduction in burst index, and 67% reduction in air resistance.
Corrugated containers are composite structures made from corrugating medium (fluting) between linerboard facers. Semichemical pulp is the furnish of choice for the manufacture of the corrugated medium. Corrugating medium made from 100% OCC is referred to as “bogus” medium and is of low quality. To qualify as “semichemical corrugating medium,” the recycled fibre content must be less than 50%. When compared at the same bulk or density, corrugating medium made with recycled fibres is always weaker than that made from virgin pulps. Equal or improved strength or stiffness of the recycle medium has been achieved only through densification (Nguyen et al., 1991, discussed above).
Laboratory recycling of paper made from 100% thermomechanical pulp (TMP) leads to increased density and tensile strength (Houen, P. J., Helle, T., and Johnsen, P. O., “Effect of Recycling of Thermomechanical Pulp on Some Pulp and Handsheet Properties,” in Proceedings, 18th Intnl. Mechanical Pulping Conf., 1993, 350-372). However, this is due to the generation of fines during the recycling process which leads to sheet densification and thereby higher tensile strengths.
OCC furnish is an example of a pulp mixture. For OCC furnishes, the relative amounts of the components (e.g. kraft pulp for linerboard and semichemical pulp for fluting) are ill-defined because of variable fibre supply, a consequence of the nature of the recycling process. In general, tensile strengths of chemical and mechanical pulps are not linearly additive for the tensile strengths of blends of the components. Both positive and negative deviations from nonlinearity have been reported for chemical-mechanical pulp mixtures (Smook, G. A., “The Role of Chemical Pulp in Newsprint Manufacture,” Pulp & Paper Canada, 80(4):82-87 [1979]; Retulainen, E., “Strength Properties of Mechanical and Chemical Pulp Blends,” Paperi Ja Puu, 74(5):419-426 [1992]).
For the research results reported here, handsheets made from a commercial linerboard furnish consisting of 100% recycled OCC (old corrugated containers) have been dried with complete restraint, under multiple impinging jets, in air and in superheated steam. Basis weights (g/m 2 ), initial (X o ) and final (X f ) moisture contents (kg water/kg fibre) and drying conditions (drying time in seconds, jet temperature in °C., jet Reynolds Number) are shown in Table 5. Physical properties are summarized in Table 6. For the 205 g/m 2 sheets, significant improvements in product quality are reflected in the large increases seen in several properties of the steam dried sheets relative to the air dried sheets, namely STFI compression strength (7%), breaking length (13%), toughness (TEA index, 7%), elastic modulus (19%), zero-span breaking length (21%), and Gurley air resistance (41%). These increases in strengths were accomplished not only without densification of the sheet, but actually with a 4% increase in bulk.
Optical properties (Table 7, brightness, opacity, L*, a*, b*) are reported for the impingement side (wire side) of the sheet. The differences in optical properties between linerboard dried in air and in superheated steam are small and, for linerboard, are generally of no commercial importance. For additional research results reported here, handsheets made from three linerboard furnishes of different yields, but each consisting of 100% virgin kraft pulp, have been dried with complete restraint in a flow of superheated steam at 200° C. passing parallel to the surfaces of the sheet, and dried in air by contact with a hot surface maintained at 150° C. Basis weights (g/m 2 ), initial (X o ), and final (X f ) moisture contents (kg water/kg fibre) and drying conditions (superheated steam or hot surface temperature in ° C.) are shown in Table 8. Physical properties are summarized in Table 9. For the 205 g/m 2 sheets, significant improvements in product quality are reflected in the large increases seen in several properties of the steam dried sheets relative to the air dried sheets, namely STFI compression strength (9-15%), tensile index (1-18%), tensile stiffness index (39-51%), and Gurley resistance (3-42%).
Optical properties (Table 10, brightness, opacity, L*, a*, b*) are reported for the wire side of the sheet. The difference in optical properties between linerboard dried in air and in superheated steam are small and, for linerboard, are generally of no commercial importance.
Handsheets were also made from a commercial thermomechanical pulp (TMP) containing 3.4% of recycled, deinked pulp. These were dried under complete restraint in a flow of air or superheated steam. Basis weights (g/m 2 ), initial (X o ) and final (X f ) moisture contents (kg water/kg fibre) and drying conditions (drying time in seconds, jet temperature in ° C.) are shown in Table 11. Physical properties are summarized in Table 12. Large increases are seen in several properties of the steam dried sheets relative to the air dried sheets, namely STFI compressive index (37%), breaking length (23%), toughness (TEA index, 27%), and specific elastic modulus (7%). These increases in strengths were accomplished without a significant change in the density of the sheet, i.e. without the densification used by some other techniques of strength enhancement.
Optical properties (Table 13, brightness, opacity, L*, a*, b*) are reported for the wire side of the sheet. The differences in optical properties between these high basis weight samples dried in air and in superheated steam are, for linerboard application, of generally no commercial importance.
The publications which cite improvements of properties of other grades of paper using superheated steam as a drying medium (Cui et al., 1986; McCall and Douglas, 1993; Poirier, 1992; discussed above) have not used the furnish we used and have not dried linerboard.
One patent exists on the effect of superheated steam drying on properties of linerboard, but without the finding of improvement in the key property of paperboard strength (Cui, W., “Superheated Steam Drying Methods and Dryers for Paper and Paperboard,” assigned to Zhao, M. and Yu, H., Chinese Patent 86102860 [Apr. 15, 1987]).
Recent, confidential research in the laboratory of Prof. Douglas at McGill University on rates of drying linerboard by impinging jets of superheated steam establish that linerboard can be dried by impinging jets of superheated steam. Thus linerboard could be dried commercially by superheated steam impingement using a modification of the industrial Yankee dryer design currently providing air impingement drying of lightweight grades such as tissue paper and toweling. For heavy basis weight grades such as linerboard, more than the single Yankee cylinder used currently for drying tissue and toweling paper could be required.
Heavy weight grades of paper such as linerboard are currently dried by contact heat transfer in passing over many steam heated cylinders in an atmosphere of air. Use of drying under impinging jets, sometimes referred to as high velocity air caps, can augment such cylinder drying (Marshall, 1972, discussed above). A superheated steam dryer for heavy basis weights could use hoods with high velocity superheated steam jets in place of hoods of impinging air jets in conjunction with cylinder drying. Conversion of a Yankee dryer from use with air to use with superheated steam has been described (Thompson et al., 1991, discussed above).
TABLE 5
DRYING CONDITIONS
Impingement Drying
BASIS
DRYING
DRYING
WEIGHT
MEDIUM
X o
X f
TIME
T j
Re j
207
air
1.00
0.06
50
250
3000
217
steam
1.01
0.05
40-43
250
4700
Notes to Table 5
X o = moisture content into dryer, kg water/kg oven-dry fiber
X f = moisture content out of dryer, kg water/kg oven-dry fiber
Drying time, seconds
T j = jet temperature, ° C.
Re j = jet Reynolds Number
TABLE 6
PHYSICAL PROPERTIES
Impingement Drying
NOMINAL 205 g/m 2
CHANGE
TEST
UNITS
AIR
STEAM
%
Basis
g/m 2
206.7
217.2
Weight
Caliper
μm
487
532
9.2
Sp. Vol.
cm 3 /g
2.36
2.45
3.8
Burst
kpa · m 2 /
2.62
2.68
2.3
Index
g
Breaking
km
3.60
4.08
13.3
Length
Stretch
%
2.29
2.20
−3.9
TEA Index
mJ/g
584
626
7.2
Specific
km
357
425
19.0
Elastic
Modulus
STFI
kN/m
5.01
5.35
6.8
Comp.
Str.
Z-Span
km
7.12
8.60
20.8
Breaking
Length
Scott
J/m 2
148
133
−10.1
Bond
Gurley
s/100
10.9
15.4
41.2
Air Res.
mL
TABLE 7
OPTICAL PROPERTIES
Impingement Drying
NOMINAL 205 g/m 2
TEST
UNITS
AIR
STEAM
Basis
g/m 2
206.7
217.2
Weight
Brightness
%
18.5
17.7
(ISO)
Opacity
%
100
100
(ISO)
L*
61.0
59.8
a*
3.7
3.6
b*
18.9
18.6
TABLE 11
DRYING CONDITIONS
Parallel-Flow Drying
BASIS
DRYING
DRYING
WEIGHT
MEDIUM
X o
X f
TIME
T j
146
air
1.17
0.06
48
200
136
steam
0.94
0.05
53
200
Notes to Table 11
X o = moisture content into dryer, kg water/kg oven-dry fibre
X f = moisture content out of dryer, kg water/kg oven-dry fibre
Drying time, seconds
T j = jet temperature, ° C.
Re j = jet Reynolds Number
TABLE 12
PHYSICAL PROPERTIES
Parallel-Flow Drying
CHANGE
TEST
UNITS
AIR
STEAM
%
Basis
g/m 2
146
136
Weight
Caliper
μm
419
384
−8.4
Sp. Vol.
cm 3 /g
2.87
2.83
−1.4
Burst
kPa · m 2 /g
2.27
2.38
4.8
Index
Breaking
km
4.50
5.54
23.1
Length
Stretch
%
2.1
2.2
4.8
TEA
mJ/g
526
668
27.0
Index
Specific
km
283
304
7.4
Elastic
Modulus
STFI
Nm/g
22.9
31.4
37.1
Comp.
Ind.
TABLE 13
OPTICAL PROPERTIES
Parallel-Flow Drying
TEST
UNITS
AIR
STEAM
Basis
g/m 2
146
136
Weight
Brightness
%
56.7
52.3
(ISO)
Opacity
%
100.0
100.0
(ISO)
L*
86.4
84.6
a*
−0.2
0.0
b*
12.0
13.3
For the work described here, nominally 60 g/m 2 handsheets were prepared from a commercial unbleached TMP containing 3.4% of recycled (deinked) pulp and a commercial clay filler. The filler was incorporated into the handsheets using a commercial retention aid. Control handsheets made in the same manner but without clay filler addition were also prepared. Ashing was done in duplicate at 920° C. for 4 hours and is expressed as weight percent of oven-dry furnish (i.e., filler+fibre). Table 14 summarizes the handsheet composition, moisture content at the start of drying (X o , kg water/kg furnish), and moisture content at the end of drying (X f , kg water/kg furnish). Three drying conditions were used: (1) drying under complete restraint in the plane of the sheet in a flow of superheated steam at 200° C. passing parallel to the surfaces of the sheet, (2) drying similarly except using air at 200° C. as the drying medium, and (3) drying under restraint with the sheet dried by contact with a metal surface maintained at 150° C. The thickness (caliper) and other physical and optical properties of each handsheet were measured under standard paper testing conditions. Typically ten handsheets were used, with the caliper measured in five places on each handsheet, and the average of the 50 values used to calculate an average caliper. The ratio of the oven-dry basis weight to this average caliper provides the apparent density (g/cm 3 ) of the sheet.
Physical properties are summarized in Table 15. As more filler is incorporated in the paper, the strength of the sheet decreases for all of the drying conditions used. The burst index, tensile index, and tensile breaking length show this trend. Toughness, as measured by TEA (tensile energy absorption) Index, and specific elastic modulus are also higher for the steam dried papers. The sheets dried in superheated steam are stronger than the paper dried in air or on the hot surface.
Significantly, the strengths of the steam dried sheets do not further decrease after about 5% filler content, whereas the strengths of the hot surface dried or the air dried sheets continue to decline. Thus, at any particular filler content, not only is paper dried in superheated steam stronger, but the percent improvement in strength over paper dried in air or on the hot surface increases with increasing filler content (Table 16). Thus it appears that the higher the filler content and the lower the strength of the paper dried conventionally in air, the greater is the relative improvement in strength produced by drying in superheated steam.
Optical properties are summarized in Table 17. Increasing the filler content of paper improves the optical (e.g., opacity and brightness) and printing properties, but sharply and steadily decreases the strength (e.g., burst and tensile) properties, of filled papers dried in a conventional manner on cylinder dryers (Negele and House, 1989; Koppelman and Migliorini, 1986; Alince, 1989; all discussed above). The present work shows that filler addition also increases the brightness and opacity of paper dried in superheated steam. However, the breaking length of superheated steam dried paper does not decrease above about 4% filler content, and the brightness and opacity do continue to increase, therefore additional filler can be added to substantially improve the optical properties of the paper without degrading the strength properties as compared to paper dried conventionally by contact with a hot surface.
As this is the first study, no publications or patents exist on the effect of superheated steam drying on the properties of papers containing inorganic particles such as mineral fillers. Publications which cite improvements of properties of other grades of paper using superheated steam as a drying medium have used only pure pulps (Cui et al, 1986; McCall and Douglas, 1993; Poirier, 1992; all discussed above).
Filled papers used in printing and writing are currently dried by contact heat transfer in passing over many steam heated cylinders in an atmosphere of air. However, hygienic papers such as tissue and toweling frequently use recycled pulp from fine papers which contain large amounts of fillers. Thus, it is possible that even these grades contain small amounts of filler. These lightweight grades are currently manufactured by a limited number of techniques. One of the most common is the drying of a paper web on a Yankee cylinder under impinging jets of air and creping the sheet on its removal from the cylinder. Other techniques such as through-drying before or after Yankee drying are also used (Sisson, 1967; Oliver, 1980; discussed above).
Conversion of a conventional Yankee dryer from operating with air to operating with superheated steam has been proposed and analyzed (Thompson et al, 1991, discussed above). A superheated steam dryer for printing and writing papers could be similar to that for lightweight tissue or towel paper except that it could have more than the single cylinder sufficient for lightweight papers. A superheated steam impingement dryer for tissue or towel papers could use similar dryer hoods as used now with air, but modified to allow the use of superheated steam.
While the invention has been described with particular reference to the illustrated embodiment, it will be understood that numerous modifications thereto will appear to those skilled in the art. Accordingly, the above description should be taken as illustrative of the invention and not in a limiting sense.
TABLE 8
DRYING CONDITIONS
Parallel-Flow Drying
KAPPA
BASIS
DRYING
PULP
NUMBER
WEIGHT
MEDIUM
X o
X f
T
A
97.5
206.0
air-contact
1.69
0.06
150
97.5
204.6
steam
1.52
0.07
200
B
130.5
210.2
air-contact
1.52
0.04
200
130.5
200.0
steam
1.46
0.05
150
C
150
208.7
air-contact
1.49
0.05
200
150
200.0
steam
1.58
0.05
150
Notes to Table 8
X o = moisture content into dryer, kg water/kg oven-dry fibre
X f = moisture content out of dryer, kg water/kg oven-dry fibre
T = temperature of hot surface for air-contact drying, jet temperature for drying in superheated steam, ° C.
TABLE 9
PHYSICAL PROPERTIES
Parallel-Flow Drying
DRYING
PULP
PROPERTY
UNITS
CONDITION
A
B
C
Yield
(%)
55.39
62.44
67.21
(screened)
Kappa Number
97.5
130.5
150.0
Est. Klason
%
14.6
19.6
22.5
Lignin
Basis Weight
g/m 2
air-contact
206.0
210.2
208.7
(o.d.)
steam
204.6
200.0
200.0
Tensile Index
Nm/g
air-contact 1
53.0
50.7
49.1
steam
53.6
60.0
54.5
% change
1
18
11
Ten. Stiff.
MNm/kg
air-contact 1
3.29
3.50
3.33
Index
steam
4.97
4.85
4.76
% change
51
39
43
STFI Compr.
Nm/g
air-contact
25.7
25.5
24.9
Index
steam
27.9
29.3
28.0
% change
9
15
12
Gurley Air
s/100 cm 3
air-contact
16.20
27.37
13.92
Resis.
steam
9.43
25.93
14.38
% change
42
5
3
Note to Table 9
1 Basis weights used for pulps A, B, and C were 210.8, 207.9, and 206.2 g/m 2, respectively.
TABLE 10
OPTICAL PROPERTIES
Parallel-Flow Drying
DRYING
PULP
PROPERTY
UNITS
CONDITION
A
B
C
Yield (screened)
%
55.39
62.44
67.21
Kappa Number
97.5
130.5
150
Est. Klason
%
14.6
19.6
22.5
Lignin
Basis Weight
g/m 2
air-contact
206.0
210.2
208.7
(o.d.)
steam
204.6
200.0
200.0
Brightness (ISO)
%
air-contact
15.4
16.4
17.9
steam
15.4
15.6
16.4
Opacity
%
air-contact
99.9
99.8
99.9
steam
99.8
99.9
100.0
L*
air-contact
57.9
60.1
62.3
steam
58.7
59.7
61.3
a*
air-contact
5.8
5.8
5.5
steam
5.2
5.3
5.3
b*
air-contact
20.8
22.5
22.8
steam
22.3
23.4
24.5
TABLE 14
DRYING CONDITIONS
ASH
FILLER
CONTENT
CONTENT
DRYING
(%)
(%)
MEDIUM
X o
X f
0.41
0.00
air
1.94
0.06
0.38
0.00
steam
1.38
0.05
0.53
0.00
contact
1.67
0.01
3.19
2.78
air
1.55
0.04
3.31
2.93
steam
1.47
0.07
3.13
2.60
contact
1.50
0.08
5.61
5.20
air
1.28
0.05
5.96
5.58
Steam
1.33
0.10
6.11
5.58
contact
1.49
0.06
8.96
8.55
air
1.40
0.03
8.46
8.08
steam
1.41
0.08
9.93
9.40
contact
1.34
0.02
Notes to Table 14
X o = moisture content into dryer, kg water/kg oven-dry fibre
X f = moisture content out of dryer, kg water/kg oven-dry fibre
TABLE 15
PHYSICAL PROPERTIES
TEST
UNITS
Filler Content
%
Air
0.00
2.78
5.20
8.55
Steam
0.00
2.93
5.58
8.08
Contact
0.00
2.60
5.58
9.40
Ash Content
%
Air
0.41
3.19
5.61
8.96
Steam
0.38
3.31
5.96
8.46
Contact
0.53
3.13
6.11
9.93
Basis Weight
g/m 2
Air
56.35
57.33
58.58
58.69
Steam
56.46
58.88
58.70
57.82
Contact
58.20
58.23
58.98
57.59
Caliper
μm
Air
201
199
193
188
Steam
202
209
201
196
Contact
203
198
206
196
App. Density
g/cm 3
Air
0.281
0.288
0.303
0.312
Steam
0.280
0.282
0.292
0.296
Contact
0.287
0.295
0.287
0.294
Burst Index
kPa · m 2 /g
Air
2.43
2.08
2.12
1.87
Steam
2.76
2.41
2.33
2.35
Contact
2.52
2.30
2.04
1.88
Breaking Length
km
Air
5.05
4.54
4.21
4.13
Steam
5.54
5.10
4.98
5.03
Contact
4.91
4.57
4.08
3.80
Stretch
%
Air
1.97
1.70
1.83
1.78
Steam
1.71
2.07
2.07
1.88
Contact
2.00
1.81
1.80
1.78
TEA Index
ml/g
Air
599
457
464
442
Steam
625
652
623
569
Contact
590
487
440
415
Specific Elastic
km
Air
416
410
356
357
Modulus
Steam
453
414
395
424
Contact
423
402
345
320
Tensile Index
Nm/g
Air
49.51
44.45
41.20
40.51
Steam
54.25
49.98
48.80
49.25
Contact
48.13
44.74
39.99
37.21
TABLE 16
STRENGTH IMPROVEMENT
Filler Content
Contact
0.00
2.60
5.58
9.40
(%)
Steam
0.00
2.93
5.58
8.08
Breaking Length
Contact
4.91
4.57
4.08
3.80
(km)
Steam
5.54
5.10
4.98
5.03
Change in
(Steam-
13
12
22
32
Breaking Length
Contact)/
(%)
Contact
TABLE 17
OPTICAL PROPERTIES
TEST
UNITS
Filler
%
Air
0.00
2.78
5.20
8.55
Content
Steam
0.00
2.93
5.58
8.08
Contact
0.00
2.60
5.58
9.40
Ash
%
Air
0.41
3.19
5.61
8.96
Content
Steam
0.38
3.31
5.96
9.46
Contact
0.53
3.13
6.11
9.93
Basis
g/m 2
Air
56.35
57.33
58.58
58.69
Weight
Steam
56.46
58.88
58.70
57.82
Contact
58.20
58.23
58.98
57.59
Brightness
%
Air
53.9
57.4
59.3
60.9
(ISO)
Steam
51.3
54.3
57.1
58.1
Contact
55.4
57.4
59.5
61.3
Opacity
%
Air
97.1
97.4
97.8
98.1
(ISO)
Steam
96.1
97.2
97.6
97.6
Contact
96.3
96.7
97.3
97.8
L*
Air
85.5
86.9
87.7
88.2
Steam
84.4
85.7
86.7
87.1
Contact
86.4
87.0
87.8
88.5
a*
Air
−0.1
−0.2
−0.2
−0.3
Steam
0.0
−0.1
−0.1
−0.1
Contact
−0.2
−0.2
−0.3
−0.3
b*
Air
13.2
12.0
11.4
10.9
Steam
13.9
13.1
11.9
11.6
Contact
13.2
12.2
11.5
11.0 | The present invention relates to an improved method of treating paper products in order to enhance various properties thereof, and more specifically, including the step of treating the paper with superheated steam. In a method of treating paper during a papermaking process from wood pulp, the step of drying the paper in superheated steam in order to improve certain physical characteristics. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates to an arrangement for securing an implement to a carrier mounted to lifting arms, particularly those of a front loader boom, where the implement and carrier can be fastened to each other by movable latch rods that can be moved between latched and unlatched positions either manually or by a remotely controlled motor.
BACKGROUND OF THE INVENTION
[0002] A known type of latch arrangement for securing an implement to a carrier mounted to lifting arms of a boom comprises a rod arrangement mounted to the carrier for being shifted laterally between latched and unlatched positions, with the rod arrangement being spring biased to its latched position. The rod arrangement can be either manually or hydraulically moved to the unlatched position, where a secondary latch is engaged by partially rotating the rod by the action of a second spring. The rod arrangement can then be released with the rod arrangement remaining in an arrested unlatched position until an implement coupled to the carrier is rolled back so as to engage the latch rod arrangement causing it to rotate out of its arrested position thereby disengaging the secondary latch permitting the latch rod arrangement to be moved to its latched position by the biasing spring. Such a prior art securing arrangement is disclosed in U.S. Pat. No. 7,001,137.
[0003] Another known type of latch arrangement includes a remotely operable latch rod arrangement which is biased toward a latched position and is selectively moveable to an unlocked position by an extensible and retractable hydraulic cylinder controlled by a solenoid operated valve which is controlled by a circuit including a latching control switch and a height control switch connected in series so that both must be closed to complete a circuit to the control valve so as to prevent unlatching if the height sensing switch senses a height above a preselected safe height for implement detachment. U.S. Pat. No. 7,467,918 discloses such a prior art latch rod control.
[0004] One drawback associated with the patented designs is that a failure of the biasing mechanism when the implement is attached to the boom could result in the latch rod migrating to its unlatched position. Another drawback of the patented designs is that an operator may not be aware if the latching rod arrangement becomes jammed or the like resulting in a partially latched implement. Further, while hydraulic cylinders are effective devices for moving the latching rod arrangements to their unlatched positions, hydraulic fluid leakage is always a problem and the provision of hydraulic hoses and control valves often take up valuable space and require special design considerations resulting in increased cost.
SUMMARY OF THE INVENTION
[0005] According the present invention, there is provided an improved remotely operated latching system for detachably connecting an implement to a carrier mounted to a lifting arm.
[0006] An object of the invention is to provide a remotely operated latching system which is compact and reliable.
[0007] A more specific object of the invention is to provide latching system including a latch rod arrangement which is extendable from a latched position to an unlatched position, with a secondary latch arrangement being provided for rotating the latch rod arrangement into an arrested position once the latch rod arrangement in its extended, unlatched position, with an actuator for extending the latch rod arrangement acting to aid rotation of the latch rod arrangement into its arrested position.
[0008] These and other objects are accomplished by using a linear electric motor for operating the latching rod arrangement, with a microprocessor based digital electronic control for the motor including safety interlocks for preventing unlatching of the implement if the boom is not in a lowered position. The electronic control unit also includes a capability to monitor operating conditions and to apprise the operator of the operating condition, through the means of an LEDs, where a slowly flashing light indicates that the latch rod arrangement is being extended to establish an unlocked condition, a quickly flashing light indicates a jammed condition and full extension being indicated by a steady light. The motor control includes an operating switch which may be placed in a manual over-ride mode whereby the operator may cycle the motor to extend and retract the latch rod arrangement such as to use the latching sections of the rod arrangement to “chip” through frozen material, or the like, blocking the passage of the latching sections to the latching position.
[0009] These and other objects of the invention will be understood by a reading of the ensuing description together with the appended drawings
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a right side elevational view of a loader boom having a rear end mounted to a support frame and a front end coupled to an implement carrier to which an implement is attached.
[0011] FIG. 2 is a right rear perspective view of an implement carrier equipped with a remotely controlled latching mechanism constructed in accordance with the principles of the present invention and showing the latch rod arrangement in a latched condition for securing an implement to the carrier.
[0012] FIG. 3 is a right front perspective view of the implement carrier and latching mechanism shown in FIG. 2 .
[0013] FIG. 4 is an enlarged left bottom perspective view of a right end region of the carrier of FIG. 2 showing the mount and shield assembly for the electric motor.
[0014] FIG. 5 is a top view of the linear electric motor showing its connection to the right end region of the operating rod assembly of the latch rod arrangement FIG. 6 is a rear view of the carrier shown in FIG. 2 , but showing the operating rod in an unlatched position.
[0015] FIG. 7 is a left end view of the carrier shown in FIG. 6 , but showing the lever arm in phantom so as to show the latch rod positioned in the upper region of the guide slot and the secondary latch rod positioned in a lower region of the guide slot.
[0016] FIG. 8 is a view like FIG. 6 , but showing the latch rod arrangement in an unlatched, arrested position.
[0017] FIG. 9 is a left end view of the carrier shown in FIG. 8 , but showing the lever arm in phantom so as to reveal the latch rod arrangement in a lower region of the guide slot and the secondary latch rod below the guide slot, and showing a lower region of the left loader boom arm in dashed lines together with carrier being shown in dashed lines in a rolled back condition wherein an upper surface of the boom arm is in contact with, and holds the latch rod arrangement in a non-arrested position in an upper region of the guide slot, with the secondary latch rod being positioned for re-entry into the guide slot.
[0018] FIG. 10 is a perspective view of a left end region of the implement carrier shown in FIG. 6 , but showing an alternate embodiment featuring a coil spring which acts in compression to resist movement of the latch rod arrangement from its latched position while at the same time acting in torsion to bias the operating rod towards the bottom of the guide slot arrangement.
[0019] FIG. 11 is schematic of the electrical circuit embodying the microprocessor and sensors used for controlling operation of the electric linear motor and giving an operator visual indication of whether or not the latch rod arrangement is operating correctly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] Referring now to FIG. 1 , there is shown a front end loader 10 equipped with an attachment in the form of a bucket 14 . However, it is to be understood that the present invention may be used with other loaders and/or attachments.
[0021] The loader includes a boom 28 comprising left and right, transversely spaced, fore-and-aft extending arms (only right arm 30 being shown) disposed for extending along opposite sides of a tractor (not shown) and each having a rear end pivotally attached, as by a pin 32 , to an upper region of a respective one of a pair of upright masts 34 , the masts 34 , in turn, being fixed to respective upper regions of a pair of upright mounting frames 36 located on opposite sides of, and having lower regions fixed to a frame (not shown) of the tractor. The boom 28 further includes a cross tube (not visible) having opposite ends projecting through, and joining the arms 30 together at a location forwardly of the tractor, with caps 38 being mounted on outer faces of the arms 30 so in closing relationship to opposite open ends of the cross tube.
[0022] Mounted between a lower region of each of the masts 34 and the associated boom arm 30 is an extensible and retractable boom lift cylinder 40 having its rod end coupled to the mast 34 and its barrel end coupled to the arm 30 . An implement carrier 42 is pivotally attached, as at pins 44 to lower front end regions of each of the boom arms 30 , the carrier 42 , in turn, including an upper cross member 46 received within downwardly opening receptacles (not visible) of transversely spaced hooks 48 (only one shown) fixed to an upper region of the a backside of the bucket 14 . The bucket 14 is detachably coupled to a bracket arrangement (not shown) provided on the backside of the bucket 14 , as is described below in further detail. Provided for pivoting the carrier 40 about a horizontal axis defined by the pins 44 are a pair of extensible and retractable bucket tilt cylinders 50 (only one shown), each of which form one link of a leveling linkage 52 coupled, as at a pin 54 , between an upper end of each mast 34 and the implement carrier 42 , with extension of the cylinders 44 effecting clockwise rotation of the carrier 42 and associated bucket 14 about the horizontal axis defined by the pins 44 , while retraction of the cylinders 50 effects counterclockwise rotation of the carrier, and, hence, effects roll back of the associated bucket 14 , such roll back operation being important in the operation of latching the bucket 14 to, and detaching the bucket from, the carrier 42 , as is described below in further detail.
[0023] Referring now to FIGS. 2 and 3 , it can be seen that the cross member 46 at the top of the carrier 42 has right and left end regions to which are attached right and left vertical plate assemblies. Specifically, the right vertical plate assembly includes a pair of transversely spaced outer and inner loader arm mounting plates 56 and 58 , respectively, having upper ends fixed to the right end region of the cross member 46 . Similarly, the left vertical plate assembly includes outer and inner loader arm mounting plates 60 and 62 , respectively, having upper ends fixed to the left end region of the cross member 46 . The right and left vertical plate assemblies 56 , 58 and 60 , 62 each have a fore-and-aft dimension that increases from top to bottom. While not required for carriers of smaller loaders, the carrier 42 further includes right and left, inner strengthening plates 64 and 66 also having upper ends joined to the cross member 46 and having lower ends that terminate forwardly of lower ends of the plates 56 - 62 . The bottoms of the plates 56 , 58 and the right inner plate 64 are joined together by a right rear cross bar 68 , while lower front regions of the plates 56 , 58 and 64 are joined together by a right front cross bar 70 . Extending between and fixed to the front and rear cross bars 68 and 70 at respective locations spaced outwardly from the inner plate 66 is an upwardly projecting locking bar receiving plate 72 . Similarly, the bottoms of the plates 60 , 62 and 66 are joined together by a left rear cross bar 74 having an inner end joined to a bottom rear location of the plate 66 , and being welded within complementary notches provided in the lower edges of the plates 60 , 62 , while a front cross bar 76 extends between and is joined to lower front regions of the plates 60 , 62 and 66 . Extending between and fixed to the left rear and front cross bars 74 and 76 , at locations spaced outwardly from the left inner plate 66 , is an upwardly projecting locking bar receiving plate 78 .
[0024] A right tilt linkage mounting hole arrangement includes a pair of horizontal, axially aligned holes (only hole 80 in the plate 58 being visible) provided at an upper region in the right plate assembly comprising the plates 56 , 58 , while a left tilt linkage mounting hole arrangement includes a pair of horizontal, axially aligned holes (only hole 82 in plate 54 being visible) provided at a mid-height location of the plates 54 , 56 in axial alignment with the holes 74 . Respectively fixed to outer and inner faces of the plates 56 , 58 of the right plate assembly are a pair of short cylindrical tubes 84 that are arranged in axial alignment with the holes 70 . Likewise, a pair of short cylindrical tubes 86 are fixed to the inner and outer surfaces of the left plate assembly comprised by the inner and outer plates 54 and 56 so as to be in axial alignment with the holes 82 . Referring back to FIG. 1 , it can be seen that a pin 88 is received in each of the aligned pairs of holes 80 and 82 and serve to fix one end of a link of the bucket tilt linkage 52 to the right pair of arm mounting plates 56 , 58 of the carrier 42 .
[0025] A right loader boom mounting hole arrangement includes a second pair of axially aligned holes (only hole 90 in plate 58 being visible) provided at lower rear locations of the plates 56 and 58 , and a left loader boom mounting hole arrangement includes a second pair of axially aligned holes (only hole 92 in plate 60 being visible) respectively provided at lower rear locations in the left pair of plates 60 and 62 . Fixed to outer and inner surfaces respectively of the right plate assembly, comprised of the pair of plates 56 and 58 , so as to be in axially alignment with each other and with the holes 90 are short cylindrical tubes 94 . Similarly, fixed to outer and inner surfaces respectively of the left plate assembly comprised of the pair of plates 60 , 62 so as to be in axial alignment with each other and with the holes 92 are short cylindrical tubes 96 . When the carrier 42 is mounted to the loader boom 28 , the right pair of boom arm mounting plates 56 , 58 and the left pair of boom arm mounting plates 60 , 62 respectively straddle lower front regions of the right and left boom arms 30 , with the holes 90 and 92 respectively receiving the pins 44 (see FIG. 1 ).
[0026] Spaced below the pair of hooks 48 on the back side of the bucket 14 (see FIG. 1 ) are right and left, rearwardly projecting mounting lugs (not visible) respectively located for being received between the right strengthening plate 64 and the right latch rod receiving plate 72 , and between the left strengthening plate 66 and the left latch rod receiving plate 78 . Referring now also to FIG. 4 , it can be seen that a latch rod guide 100 is mounted to an inner surface of the right strengthening plate 64 , the guide 80 including a vertical portion 102 extending parallel to, and being spaced inwardly from the plate 64 , with the vertical portion containing a rod-receiving hole 104 disposed in horizontal axial alignment with rod-receiving holes 106 and 108 , respectively provided in the strengthening plate 64 and the rod-receiving plate 72 . On the left side of the carrier 42 , the loader arm mounting plates 60 , 62 , the latch rod-receiving plate 78 and the strengthening plate 66 respectively contain axially aligned holes 110 , 112 , 114 and 116 that are in axial alignment with the holes 84 - 88 and define a latch assembly pivot axis, these holes being brought into alignment with bores in the mounting lugs (not visible) of the bucket 14 for receiving latch rod elements, described below, to secure the bucket 14 to the carrier 42 .
[0027] The present invention relates to a remotely operable latching mechanism 120 including an actuator arrangement 122 and a latch rod arrangement 124 .
[0028] Referring now also to FIGS. 3 and 4 , it can be seen that the actuator arrangement 122 includes a motor mount and shield assembly 125 including a vertical motor mounting plate 126 tightly secured against a left face of the right strengthening plate 64 by a pair of bolt and nut assemblies 128 . As can best be seen in FIG. 4 , the support plate 126 is received within, and is shaped complementary to and is welded to, a right end region of an inverted channel-shaped motor shield 130 , which projects leftward from the strengthening plate 64 . Joined to, and projecting leftward from, a left face of the support plate 126 is a motor mounting clevis defined by upper and lower flanges 132 and 134 , which are disposed in parallel relationship to a top 136 of the shield 130 , the top 136 being inclined downwardly from front to rear. A bolt stem 137 of a motor mounting bolt and nut assembly 138 projects downwardly through the shield top 116 and through the aligned holes provided in the upper and lower flanges 132 and 134 so as to define an upright motor mount pivot axis having a purpose explained below.
[0029] Referring also to FIG. 5 , it can be seen that a linear electric motor 140 comprises a sealed body 142 which is substantially rectangular in cross section. The electric motor 140 has a built in microprocessor (described in more detail below) which continuously monitors the performance of the motor and can be directly interfaced with programmable controllers. An example of a suitable electric motor are those included in the Electrak Pro Series marketed by Danaher Motion located in Radford, Va. Respectively located at front regions of right and left ends of the motor body 142 in approximate transverse alignment with each other are a mounting lug 144 , defined by a rod, and an extensible and retractable output shaft 146 . The mounting lug 144 contains an upright bore 148 in which the stem 137 of the bolt assembly 138 is received when the motor 140 is mounted beneath the top 136 of the motor shield 130 , as shown in FIG. 3 , the mounting lug 144 then being received between the motor mount flanges 132 and 134 .
[0030] Referring back to FIGS. 2 and 3 , it can be seen that the latch rod arrangement 124 includes a horizontal, transverse operating rod assembly 150 including an intermediate coupling rod 152 having a right end loosely received within a left end of a tubular coupler 154 and connected thereto by a bolt and nut assembly 156 wherein the bolt stem is disposed crosswise relative to the motor mounting bolt stem 137 . The motor shaft 146 is loosely received in a right end of the coupler 154 and is connected thereto by a nut and bolt assembly 158 wherein the bolt stem is disposed parallel to the motor mounting bolt stem 137 . A left end region of the coupling rod 152 is tightly received within a right end region of an elongate tubular rod section 160 that is received in an opening 162 provided in the strengthening plate 66 , and in a guide slot arrangement comprising a pair of transversely aligned guide slots 164 respectively provided in the loader boom mounting plates 60 and 62 , with it being noted that slots similar to the slots 164 are provided in the plates 56 and 58 so that during manufacture the plates 56 and 58 are respectively interchangeable with the plates 60 and 62 . As can best be seen in FIG. 3 , the left end of the tubular rod section 160 is welded within an opening provided between opposite ends of a flat lever arm 166 disposed perpendicular to the rod section 160 . A rod is bent to form a handle 168 having an inner end of a horizontal transverse end section fixed to a rear end of the lever arm 166 , and having an outer end joined to a rearwardly extending hand grip portion.
[0031] The latch rod arrangement 124 further includes right and left latch rods 170 and 172 . The right latch rod 170 includes a mounting portion 174 at its left end which is disposed along a lower front portion of the right end region of the tubular rod section 160 , with a pair of nut and bolt assemblies 176 including bolt stems extending through aligned bores provided in the coupling rod 152 and tubular rod section 160 so as to secure the rod 152 within the section 160 while solidly clamping the latch rod mounting portion 174 to the operating rod assembly 150 . Extending parallel to, and being axially offset to, the latch rod mounting portion 174 is a latch rod latching portion 178 , which is joined to the mounting portion by an intermediate portion 180 .
[0032] As can best be seen in FIG. 3 , the left latch rod 172 includes a left end region which projects through a hole (not visible) provided in a forward end of the flat lever arm 166 and into a cylindrical tube 182 welded onto an outer surface of the arm 166 . A nut and bolt assembly 184 secures the latch rod 172 within the cylindrical tube 182 .
[0033] When the latch rod arrangement 124 is in a latched position, as shown in FIGS. 2 and 3 , the latching portion 178 of the right latch rod 170 extends beneath the motor body 142 ( FIG. 3 ) and is received in the axially aligned holes 104 , 106 and 108 respectively provided in the rod guide bracket 100 , strengthening plate 64 and latch rod receptacle plate 72 . The left latch rod 172 is then received in the axially aligned holes 110 , 112 , 114 and 116 respectively provided in the left boom mounting plates 60 and 62 , the latch rod receiving plate 78 and the left strengthening plate 64 .
[0034] Thus, the operating rod assembly 150 forms a leftward extension of the motor output shaft 146 and has a left end region projecting through the guide slot arrangement comprising the pair of transversely aligned guide slots 164 respectively provided in the left pair of plates 60 and 62 . The guide slots 164 are located approximately mid-way between the sets of holes 82 and 92 . As described above, the left latch rod 172 is fixed for movement with the operating rod 132 by the flat lever arm 166 . A secondary latch rod 186 has an outer end welded to a lower middle location of the lever arm 166 and, when the operating rod assembly 150 is in the latched position shown in FIGS. 2 and 3 , the secondary latch rod projects upwardly to the right through a lower region of the guide slot 164 provided in the outer left plate 60 , with the lever arm 166 then being disposed in a raised position flat against the left surface of the plate 60 . The handle 166 is provided for manual operation of the operating rod assembly 150 in the event of a failure of the electric motor 140 .
[0035] Movement of the latch rod arrangement 124 from its latched position shown in FIGS. 2 and 3 to an extended unlatched position, shown in FIG. 6 , is resisted by a coil compression spring 188 received on the operating rod assembly 150 at a region just to the right of the inner boom arm mounting plate 62 and having opposite ends engaged with right and left flat washers 190 and 192 , respectively, with rightward movement of the washer 190 being prevented by a nut and bolt assembly 194 including a bolt stem projecting through the tubular rod section 160 , and with leftward movement of the washer 192 being prevented by the plate 62 . As can be seen in FIG. 6 , a coil tension spring 196 is coupled under tension with a hook at an upper end being engaged with a coil of the compression spring 188 and with a hook at a lower end being received within a hole provided in the strengthening plate 66 , the spring 196 acting to bias the tubular rod section 160 of the operating rod assembly 150 toward the bottom ends of the guide slots 164 for a reason described below.
[0036] The secondary latch rod 186 is provided for retaining the operating rod assembly 150 in an arrested position, as shown in FIGS. 8 and 9 , wherein the operating rod assembly 150 has been shifted to the left a sufficient distance to withdraw the secondary latch rod 186 from the guide slot 164 , thereby permitting the action of the tension spring 196 to rotate the operating rod assembly 150 about the latch rod axis into a bottom region of the guide slots 164 , resulting in the end of the secondary latch rod 186 becoming misaligned relative to the adjacent guide slot 164 so as to retain the operating rod assembly 150 in its extended, unlatched position. As can be seen in FIGS. 7 and 8 , the extended motor output shaft 146 is misaligned relative to the axis of the operating rod assembly 150 which means that the motor housing 142 is rotated downwardly about the upright axis defined by the bolt and nut arrangement 138 , this downward rotation occurring gradually as the output shaft 146 extends with the result that the motor transfers a downward component of force to the operating rod assembly 150 that is added to that exerted by the tension spring 196 so as to aid in moving the operating tubular rod section 160 to the bottoms of the guide slots 164 .
[0037] When the carrier 42 is rolled back, as shown in dashed lines in FIG. 9 , it can be seen that the tubular rod section 160 of the operating rod assembly 150 comes into contact with a forward surface 197 of the left loader arm 30 and lifts the rod section to the top region of the guide slot 164 , with the secondary latch rod 186 then being realigned with the guide slot 164 so as to permit the operating rod assembly 150 to be retracted to its latched position.
[0038] Referring now to FIG. 10 , there is shown an alternate embodiment of the manner of effecting the latching of the secondary latch rod 186 . Specifically, the compression spring 188 of the first-described embodiment is replaced by a combined helically wound compression and torsion spring 188 ′, the latter having a straight left end section 198 that extends upwardly behind an abutment pin 200 that is fixed to, and projects to the right from, the plate 62 at a location adjacent an upper end of the adjacent guide slot 164 . A torsion adjustment nut 202 is secured to a right end of the spring 158 ′ and can be advanced toward the left along a threaded section (not shown) of the operating rod tube section 160 to cause an increase in the torsion pre-load of the spring 188 ′. Thus, the reaction of the force exerted by the spring end 198 on the abutment pin 200 is transferred through the spring to the tubular rod section 160 so as to urge the operating rod assembly 150 toward the bottoms of the guide slots 164 . Accordingly, the tension spring 196 used in the previously described embodiment is no longer needed.
[0039] Starting with the implement carrier 42 mounted to the arms 30 of the loader boom 28 , an implement, such as the bucket 14 can be attached to the carrier 42 by positioning the carrier 42 so as to bring the cross member 46 into engagement with the downwardly opening receptacles of the mounting hooks 48 provided at the backside of the bucket 14 , and then by raising the bucket off the ground far enough that it pivots downwardly against the front of the carrier 42 . The transversely spaced pair of mounting lugs (not shown) at the backside of the bucket 14 will at this time be respectively in fore-and-aft alignment with the space between the right latch rod receiving plate 72 and the right strengthening plate 64 , and with the space between the left latch rod receiving plate 78 and the left strengthening plate 66 . The operator will then operate the bucket tilt cylinders 50 to cause the carrier 42 to roll back about its pivotal connections 44 of the carrier 42 with the boom arms 30 . This will cause the arrested operating rod assembly 150 to come into engagement with the front surface 197 of the left loader arm 30 and to be shifted towards the upper end region end of the guide slots 164 . At this point, the right end of the secondary latch rod 186 will come into register with the guide slot 164 in the plate 60 , while cross bores provided in the bucket mounting lugs will be in axial alignment with the holes respectively provided in the plates 64 , 72 straddling the right bucket lug, and provided in the plates 66 , 78 straddling the left bucket mounting lug. The motor 140 is then operated to cause it to retract thereby simultaneously moving the right latch rod portion 178 through the bore in the right bucket lug and then into the hole 108 provided in the latch rod receiving plate 72 , and moving the left latch rod 172 through the bore in the left bucket lug and then into the hole 116 provided in the left strengthening plate 66 .
[0040] Referring now to FIG. 11 , there is shown a schematic of an electrical control system 210 for remotely controlling the operation of the linear electric motor 140 . Specifically, the electric control system 210 includes an electrical control unit (ECU) 212 connected to the motor 140 by a motor activation output signal line 214 . The ECU 212 preferably, but not necessarily, is a microprocessor which is embodied in the electric motor 140 and continuously monitors the performance of the motor. For purposes indicated below, the motor 140 embodies an electronic load sensor 216 and end of stroke limit switches 218 (extend limit) and 220 (retract limit) here depicted as being respectively connected to the ECU by conductors 222 , 194 and 196 . While not required, the end of stroke positions governed by the limit switches 218 and 220 could be programmable.
[0041] A manually-operated control switch 228 for initiating activation of the motor 140 is located within the cab (not shown) of a tractor and is connected to the ECU 212 by a motor activation input line 230 . The control switch 228 may take various forms including: (1) a momentary “on” rocker switch, (2) a momentary “on” rocker switch with a 1 second delay, (3) a momentary “on” rocker switch with a ½ second delay and a ½ second release window trigger indicated by an LED, (4) a momentary “on” push button switch, (5) a momentary “on” push button switch with a recessed button, and (6) a momentary “on” push button switch with a recessed button with a ½ second delay and a ½ second release window trigger indicated by an LED. Also, instead of a single switch, two momentary toggle switches may be used, with each being toggled in opposite directions. A height sensor 232 , shown mounted on the right mast 34 in FIG. 2 , is connected to the ECU 182 by a height signal input line 234 and is provided for preventing actuation of the electric motor 140 when the carrier 42 is above a predetermined height off the ground. The boom height sensor 234 detects the pivot angle of the lifting boom 28 about the horizontal axis defined by the coupling pins 32 , which secure the boom arms 30 to the masts 34 . The height sensor 234 may be, for example, a potentiometer or an incremental angle transmitter which transmits this signal to the ECU 212 . Angular regions are stored in memory in the ECU 212 , in which an activation of the motor 140 can be prevented at inappropriate positions of the lifting boom 28 , for example, if it is raised beyond a height considered to be an upper height limit for safe disconnection of an implement from the carrier 42 mounted to the boom arms 30 . The angular regions, in which a signal sent by the height sensor 232 is to be ignored, can be permanently programmed or provided as input by the operator with an input key 236 provided in the tractor cab (not shown) and connected to the ECU by an input signal line 238 . The input key 236 can also be used to program the aforementioned travel end limits of the motor output shaft 146 .
[0042] An LED indicator 240 is provided for apprising an operator of the operating condition of the motor 140 and boom 28 as determined by the load sensor 216 , output shaft end limit sensors 218 and 220 , and height sensor 232 . The LED indicator 240 is coupled to the ECU 212 by an output signal line 242 for receiving operation condition signals from the ECU 212 .
[0043] Remote operation of the latching mechanism 120 through remote actuation of the linear electric motor 140 is described below with reference to FIGS. 1 , 2 and 11 . Assuming the implement 14 to be latched to the carrier 42 , as shown in FIG. 1 , and that the tractor 10 is properly located for depositing the implement 14 on the ground, operation to detach the implement 14 from the carrier is commenced by lowering the loader boom 28 so as to place the implement 14 close to the ground. The bucket tilt actuators 50 are then caused to retract to completely roll back the carrier 42 and associated implement, with the weight of the implement 14 thus being relieved from the latch rods 170 and 172 . The normally “off” switch 228 is then momentarily actuated to its “on” position so as to activate the motor 140 to cause extension of the motor shaft 146 and hence extension of the operating rod assembly 150 . Since the carrier 42 has been lowered, the height sensor 232 will not be activated and the signal sent by the switch 228 to the ECU 212 will result in an operating signal being sent to the motor 140 by way of the output line 214 . The motor 140 will then be activated to cause extension of the output shaft 146 and the operating rod assembly 150 . Assuming the latch rod 172 and the latch rod portion 178 are free to move so that no jamming occurs, extension of the latch rod assembly 150 will take place, causing the latch rod 170 and latch rod portion 178 to be fully pulled out of the associated left and right lugs (not shown) provided at the backside of the implement 14 . During extension of the motor output shaft 146 , the retract limit sensor 220 will initially be activated, then cease to be activated as the shaft moves away from its retract limit position, resulting in the LED indicator 212 receiving a signal causing it to blink slowly indicating continuous outward movement of the output shaft 146 . When the output shaft 146 reaches the extend limit position, limit sensor 218 will be activated, sending an input signal to the ECU 212 resulting in the LED indicator receiving a signal causing it to produce a steady light apprising the operator that the unlatch position has been achieved, with the secondary latch pin 186 then being withdrawn from the left guide slot 164 . The tension spring 196 , together with the motor 140 , which is now angled downwardly to the left, will then act to rotate the operating rod assembly 150 to the bottom end of the slots 164 , resulting in the secondary latch pin 186 becoming misaligned with the adjacent slot 164 so that the latch rod arrangement 124 is arrested in the unlatched position. The boom 28 can then be lowered to disengage the cross bar 46 from the hooks 48 at the backside of the implement 14 , thus permitting the tractor 10 to be backed away from the implement 14 .
[0044] The implement 14 can once again be attached to the carrier 42 by a reverse operation. Specifically, the tractor 10 can be driven toward the backside of the implement 14 and the boom 28 and carrier 42 lowered so as to place the cross bar 46 beneath the downwardly opening hooks 48 . The boom 28 is then raised, with gravity causing the implement 14 to pivot downwardly about the axis of the cross bar 46 and rest against the carrier 42 , with left and right lugs at the backside of the implement 14 respectively being received between the right latch rod receiving plate 72 and right strengthening plate 64 , and between the left latch rod receiving plate 78 and the left strengthening plate 66 . To ensure axial alignment of the bores in the bucket lugs with the holes of the receiving plates 72 , 78 and the strengthening plates 64 , 66 , the tilt cylinders 50 are retracted to effect full roll back of the carrier 42 and associated implement 14 . Not only does this result in the desired bore and hole alignment mentioned above, but it also results in the tubular section 160 of the operating rod assembly 150 coming into engagement with the top surface of the left loader boom 30 and being lifted towards the top of the guide slots 164 , this lifting initially resulting in the right end of the secondary latch pin 186 entering the left guide slot 164 . The normally open, motor actuating switch 228 is then manually actuated to send a motor control signal to the ECU 212 . The ECU 212 will then send a motor activating signal causing the motor 140 , at one second intervals, to attempt to retract. If the motor 140 causes the right and left latch rods 170 and 172 to move more than 5 mm., then the motor retracts under full power and the LED indicator 232 blinks slowly. If either one or both of the latch rods 170 and 172 jam, then an overload condition is sensed by the overload sensor 216 which sends a jam signal to the ECU 212 resulting in an output signal being sent to the LED indicator 242 which causes the LED to blink rapidly, with power to the motor 140 via the line 214 being terminated, with the motor 140 going into a latch mode causing the output rod 160 to be retracted. If, instead of a jam occurring, the retract limit of the motor output shaft 146 is reached, the retract limit sensor 220 is activated resulting in the ECU 212 receiving a signal which is processed, the ECU 212 then terminating power to the LED indicator 240 , which shuts off, and with power simultaneously being cut to the motor 140 .
[0045] If jamming happens during latching operation, the operator may use the input key 236 to send an override signal to the ECU 212 , which permits the motor control switch 228 to be intermittently switched “on” and “off” so that the motor 140 is intermittently energized so as to cause the output shaft 146 to extend and retract with the result that the latch rod portion 178 and latch rod 172 are moved back and forth so as to chip away at any material that may be causing an obstruction in the aligned holes provided on the carrier 42 and the lugs (not shown) at the backside of the implement 14 . Upon the material becoming dislodged, the input key 236 can be operated to send a signal to the ECU 212 for resumption of normal operation.
[0046] Thus, it will be appreciated that the electric linear motor 140 makes it possible to remotely effect attachment and detachment of an implement 14 to and from arms 30 of a loader boom 28 , and that the boom height sensor 232 together with the ECU 212 prevents the operator from inadvertently unlatching the implement when the boom 28 is positioned in other than a safe lowered position, while the various motor operation sensors together with the ECU 212 and the LED indicator 240 inform the operator as to whether there is a jam preventing the motor 140 from effecting desired latching or unlatching operations.
[0047] In the event of a failure of the linear electric motor 140 , the motor output shaft 146 can be disconnected from the operating rod assembly 150 by removing one or both of the nut and bolt assemblies 156 and 158 . Operation of the latch rod assembly 124 can then be performed manually. Movement of the operating rod assembly 150 to effect the unlatched arrested position can be accomplished by grasping the handle 168 and pulling outwardly on the operating rod assembly 150 against the bias of the spring 188 until the secondary latch rod 186 is pulled free of the guide slot 164 provided in the left plate 60 . The handle 168 may then be used to pivot the lever arm 166 downwardly so that the operating rod 132 moves to the bottom of the guide slots 164 , with the secondary latch rod 186 then being misaligned relative to the guide slot 164 so as to prevent rightward movement of the operating rod assembly 150 by the compressed spring 188 . The latch rod 172 and latch rod portion 178 are then in respective positions to the left of left and right lugs (not shown) provided at the backside of the implement 14 and disposed between the rod receiving plate 78 and strengthening plate 66 , and between the right receiving plate 72 and strengthening plate 64 .
[0048] Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims. | A remotely operable latching system is provided for securing an implement to a carrier mounted to a forward end of a lifting arm for pivoting about a horizontal tilt axis. The latching system is mounted to the carrier and includes a latching rod arrangement operated by an extensible and retractable linear electric motor between a retracted latching position and an extended unlatching position. A secondary latch arrangement is provided for rotating the latching rod arrangement to an arrested position preventing movement of the rod arrangement to its latching position once the latching rod is extended to its unlatching position. Movement of the rod arrangement to its arrested position is aided by a spring and by the electric motor. Release of the rod arrangement from the arrested position is done by rolling the carrier back towards the lifting arms bringing the latching rod arrangement into contact with the arm so as to pivot the rod arrangement out of its arrested position. A microprocessor based control unit is coupled to the electric motor and acts in response to a boom height input signals to prevent operation of the motor when the boom is above a preset height. Further, an LED indicator light operates in certain modes which apprise the operator of various operating conditions. For example, the LED light blinks slowly when the latching rod arrangement is being extended to its unlatch position, blinks rapidly if the latching rod jams causing an overload condition and gives a steady light when the latching rod arrangement is fully extended. Various timing requirements are also programmed into the control unit. | 4 |
TECHNICAL FIELD
The present invention relates to the deposition of materials onto substrates, and more particularly is a method for depositing rare-earth borides onto the surface of a substrate which is submerged in an organic solution of borane and a rare-earth halide, said deposition being driven by application of electromagnetic radiation.
BACKGROUND
While not limiting, a particularly relevant application of the present invention is in the fabrication of a variety of electron emitting electrodes and gas-discharge plasma display systems which comprise cathode(s) and electrically excitable gas(es). Fabrication of plasma display systems requires that cathode material(s) which can emit electrons be caused to be present in desired patterns on substrates which are situated in close proximity to said electrically excitable gas(es). Preferably said cathode material(s) should have a low work function such that electrons can be easily emitted therefrom in use, and said electrically excitable gas(es) should be capable of providing desired, (eg. visible), electromagnetic wavelengths when electrical discharge is caused to occur therein by application of electric potential to closely situated cathodes.
Approaches to improving gas-discharge plasma displays include:
a. development and use of improved cathode material(s);
b. development and practice of improved cathode material deposition; and
c. development and use of improved electrically excitable gas(es).
While the development and use of improved electrically excitable gas(es) is a very viable and worthy approach to improving operation of gas discharge display systems, the present invention is focused on development and use of improved cathode material(s) and development and practice of improved cathode material(s) deposition onto substrates which can be adapted to comprise plasma discharge displays.
In view of the focus of the present invention, it is noted that various approaches to fabricating substrates which have cathode material(s) present thereon in desired patterns, have been investigated by previous researchers. Such techniques include:
a. screen printing;
b. plasma spray deposition;
c. vacuum deposition by sputtering or evaporation;
d. cluster-assisted deposition;
e. light-induced deposition from solution.
The present invention was arrived at by experimentation in the area of light-induced deposition of cathode material(s) from solution, (preferably organic solvent based), and the present invention is found in practice of a method and the results of the practice thereof.
A search of Patents focused upon gas-discharge plasma displays provided a Patent to Kolwa et al., U.S. Pat. No. 5,159,238, which describes a gas discharge panel with a plurality of electrically conductive oxide cathode electrodes formed from, for instance, lanthanum, chromite, lanthanum calcium chromite, aluminum doped zinc oxide, or antimony-doped tin oxide.
Continuing, and of somewhat more relevance, a Patent to Lafferty, U.S. Pat. No. 2,639,399, and a Patent to Kauer, U.S. Pat. No., 3,399,321 disclose that rare-earth hexaborides have low work functions and are very suitable to application in electron emitter and filament applications. A Patent to Yokono et al., U.S. Pat. No. 4,599,076 describes production of a discharge display involving the cathode forming steps of applying a paste prepared by mixing LaB 6 powder with alkali glass powder in proportion of 20-40% by weight to a base electrode, then burning the paste and then activating the paste by gas discharge with large current after an exhaustion step. A similar process leading to a similar result is also described in U.S. Pat. No. 4,600,397 to Kawakubo et al. A Patent to Kamegaya et al., U.S. Pat. No. 4,393,326 describes a gas discharge panel with an electrode comprised of a metal layer, (eg. Fe and Ni), and a metal compound layer, (eg. alkaline earth metal oxide or sulphide and rare-earth metal hexaboride), which are formed by a plasma spray technique. Another Patent which describes use of a rare-earth hexaboride such as LaB 6 in forming cathodes in a plasma discharge display is U.S. Pat. No. 4,727,287 to Alda et al. Another Patent, U.S. Pat. No. 5,277,932 to Spencer, describes application of chemical vapor deposition techniques to deposit metal boride films onto substrates utilizing metal borane cluster compound as a precursor. While this method is successful, it does not lend itself well to either selective area depositions, or to depositions in large scale area manufacturing where substrates can have dimensions of several inches.
The above Patents show that the use of low work function rare-earth hexaborides to form cathodes in electron emitter, filament and gas plasma displays is not new, and that various techniques exist for forming such rare-earth containing cathodes. However, no known Patent describes the formation of rare-earth containing cathodes by a method comprising light-induced deposition (LISD) from solution. This is even more so where the solution is organic solvent based. It is noted that organic-based solvent based solutions, (eg. those containing methanol, nitriles or amides), as opposed to aqueous solutions, absorb wavelengths in the ultraviolet and are therefore often overlooked in the practice of light-induced deposition from solution.
Additional searching performed with an eye to identifying the application of light-induced deposition (LISD) from solution in formation of rare-earth containing electrodes provided very little. A Patent to Liepins, U.S. Pat. No. 4,464,416 describes a procedure which is purported to be applicable to forming a metallic coating on a polymeric substrate, comprising contacting the polymeric substrate with a fluid containing a metal compound at a temperature below 150 degrees centigrade for a time sufficient for the metal to be sorbed into the substrate, and then subjecting the substrate to a low pressure plasma. A perhaps somewhat more relevant Patent is U.S. Pat. No. 3,484,263 to Kushihashi et al. in which a process for forming a layer of semi-transparent gold on the surface of glass is described as comprising the steps of containing a water-soluable gold salt and a reducing agent in contact with said glass while subjecting said glass to short wave rays in the range of 250 to 500 Nanometers, with the improvement being that the solution is maintained at a temperature of not more than 10 degrees centigrade. Another Patent, U.S. Pat. No. 4,511,595 to Inoue, describes the deposition of a metal to a substrate from a typically flowing solution, wherein a laser beam is directed onto the substrate over a localized area, to activate an interface between said localized area and said solution. A Patent to Braren et al., U.S. Pat. No. 5,260,108 describes deposition of a metal such as palladium onto a substrate such as a polyimide, silicon dioxide, tantalum oxide or polyethylene terephthalate by contacting the substrate surface with a solution of the metal, and then exposing the surface of the substrate to laser radiation characterized by a wavelength absorbable by the substrate and a power density and fluence effective to release electrons to promote deposition of the metal onto the substrate without thermal activation of the substrate or the solution. Finally, a Patent to van der Putten et al., U.S. Pat. No. 5,059,449 describes depositing a nobel metal such as platinum from a salt solution thereof, onto a substrate which can be an insulator, semiconductor or conductor, by use of a laser beam. The solution is described as consisting essentially of a solvent selected from the group consisting of ammonia, a cyclohexanel and an amine, and typical metals which can be deposited are described as Pd, Pt, Rh, Ir, Ru and Ag. Application of the laser through masking to define areas of metal deposition is also described.
Articles of which the inventors are aware include:
A paper which describes the low work function of rare-earth metal borides is titled "Thermionic Emission Properties of LaB 6 and CeB 6 In Connection With Their Surface States, Examination By XPS, Auger Spectroscopy And The Kelvin Method", Berrada et al., Surface Science 72, 177 (1978).
Application of rare-earth metal borides in thermionic emitters is discussed in:
"Microcircuits By Electron Beam", Broers et., Sci. Am. 227, 34 (1972);
"Lanthanum Hexaboride Electron Emitter", Ahmed et al., J. App. Phys. 43, 2185 (1972);
"Electron Beam Fabrication", Miller et al., Solid State Technology, 16, 25 (July 1973);
"Evaluation of a LaB 6 Cathode Electron Gun", Verhoeven et al., J. Phys. E, Scientific Instruments, Vol. 9 (1976);
"Field Emission Pattern Of LaB 6 -Single Crystal Tip", Shimizu et al., J. App. Phys., Vol. 14, No. 7, 1089 (1975);
"Highly Stable Single-Crystal LaB 6 Cathode For Conventional Electron Microprobe Instruments", Shimizu et al., J. Vac. Sci. Technol., 15(3), 922 (1978);
Articles which describe reaction of nido-decaborane and metal chlorides and subsequent chemical vapor deposition (CVD) of gadolinium hexaboride are:
"Chemical Vapor Deposition Of Metal Borides, 4: The Application Of Polyhedral Boron Vapor Deposition Formation Of Gadnolinium Boride Thin-Film Materials", Kher et al., Appl. Organ. Chem., Vol. 10, 197 (1996); and the previously cited Patent, U.S. Pat. No. 5,277,932 to Spencer also discusses this topic.
Similar rare-earth boride deposition, (where gadolinium was not the rare-earth involved), is discussed in:
"The Deposition Of Metallic And Non-Metallic Thin Films Through The Use Of Boron Clusters", Zhang, Kim, Dowben & Spencer, Chemical Perspectives of Microelectronic Materials III, Ed. by C. R. Abernathy et al., Mat. Res. Soc. Symp. Vol. 131, Proc. 282, 185 (1993);
"Metallized Plastics 4: Fundamentals and Applied Aspects", Ed. Mittal et al., Mercel Dekker Inc., New York (1997).
Selective area deposition of copper metal films from solution is described in:
"Laser-Induced Selective Copper Deposition On Polyimides And Semiconductors", Hwang, Kher, Spencer & Dowben, Mat. Res. Symp. Proc., Vol. 282 (1983);
"Material Deposition", Bauerle, Chemical Processing with Lasers", ED. Queisser, Springer Verlag (1986);
"Surface Processing Leading To Carbon Contamination Of Photochemically Deposited Copper Films:, Houle et al., J. Vac. Sci Technol., A 4(6) 2452 (November/December 1986);
"Photochemical Generation And Deposition Of Copper From A Gas Phase Precursor", Jones et al., Appl. Phys. Lett., 46, 97 (January 1985);
"Laser Chemical Vapor Deposition Of Copper", Houle et al., Appl. Phys. Lett., 46(2), 204 (January 1985);
"LCVD Of Copper: Deposition Rates And Deposit Shapes", Moylan et al., Appl. Phys. Lett. A 40, 1 (1986);
"High-Speed Laser Chemical Vapor Deposition Of Copper: A Search For Optimum Conditions", Markwalder et al., J. Appl. Phys., 65(6), 2470 (March 1989);
"Laser Enhanced Electroplating And Maskless Pattern Generation", von Gutfeld et al., Appl. Phys. Lett., 35(9) (1979);
"Laser-Enhanced Jet Plating: A Method Of High-Speed Maskless Patterning", von Gutfeld et al., Appl. Phys. Lett., 43(9), 876, (November 1983);
"High-Speed Electroplating Of Copper Using The Laser-Jet Technique", von Gutfeld et al., Appl. Phys. Lett. 46(10) (May 1985);
"Investigation Of Laser-Enhanced Electroplating Mechanisms", Puippe et al., J. Electrochem. Soc., Vol. 128, No. 12, 2539 (December 1981);
"Laser Induced Copper Plating", Al-Sufi et al., J. Appl. Phys. 54(6), 3629 (June 1983);
"Laser-Induced Decomposition Of Organometallic Compounds", Gerassimov et al., XII International Quantum Electronics Conference, (1982);
"Photoelectrochemical Deposition Of Microscopic Metal Film Patterns On Si and GaAs", Micheels et al., Appl. Phys. Lett., 39(5), 418 (September 1981).
Selective area deposition of complex compound material films from solution is described in:
"Structural And Electrical Properties Of Crystalline (1-x) Ta 2 O 5 - xAl 2 O 3 Thin Films Fabricated By Metalorganic Solution Deposition Technique"et al., Joshi et al., Appl. Phys. Lett. 71(10), 1341 (September 1997);
"Metalorganic Solution Deposition Technique", Joshi et al., Appl. Phys. Lett. 70(9), 1080 (March 1997).
A reference which describes a laser induced solution deposition process which involved copper chloride (Cu 2 Cl 2 ) and nido-decaborane is:
"Solution Deposition And Hetroepitaxial Crystalization Of LaNiO 3 Electrodes For Integrated Ferroelectric Devices", Cho et al., Appl. Phys. Lett. 71(20), 3013 (November 1997);
It is noted that Laser Induced Solution Deposition (LISD) requirements (eg. transparent solvent/solute mixture and solid surface area which acts as a dipole that has a large dielectric response. An article which makes clear that similar requirements apply where selective area chemical vapor deposition is practiced is:
"Designing Of Organometallics For Vapor Phase Metallization Of Plastics", Boag & Dowben, Metallized Plastics 4: Fundamental and Applied Aspects, ED Mittal, Marcel Decker, New York (1997).
Deposition of electrode material (eg. LaNiO 3 ) on substrates to which it does have a good lattice match is described in:
"Effect Of Textured LaNiO 3 Electrode On The Fatigue Improvement Of Pb(Zr 0 .53 Ti 0 .47)O 3 Thin Films", Chen et al., Appl. Phys. Lett. 68(10), 1430 (March 1996);
"Preparation of (100)-Oriented Metallic LaNiO 3 Thin Films On Si Substrates By Radio Frequency Magnetron Sputtering For The Growth Of Textured Pb(Zr 0 .53 Ti 0 .47)O 3 ", Yang et al., Appl. Phys. Lett. 66(20), 2643 (May 1995);
A reference which describes the results of metal deposition which is influenced by nucleation centers is:
"Deposition Of Thin Metal and Metal Silicide Films From The Decomposition Of Organometallic Compounds", Dowben et al., Mat. Sci. Eng. B2, 297 (1989).
A reference which describes vacuum reactor deposition of nickel boride is:
"Chemical Vapor Deposition Precursor Chemistry. 3. Formation And Characterization Of Crystalline Nickel Boride Thin Films From The Cluster-Assisted Deposition Of Polyhedral Borane Compounds", Kher et al., Chem. Mater., 4, 538 (1992);
A reference which describes fabrication of bulk gadolinium borides (an amorphous boron) as a result of thermolysis of a molecular precursor Gd 2 (B 10 H 10 ) 3 is:
"Synthesis Of Cerium And Gadolinium Borides Using Boron Cage Compounds As A Boron Source", Itoh et al., Mat. Res. Bul. 22, 1259 (1987).
Even in view of the large number of references, there remains need for additional, simple and efficient, techniques for selective area laser induced deposition of rare-earth borides onto substrates.
DISCLOSURE OF THE INVENTION
The present invention is primarily a method of depositing rare-earth boride, (eg. hexaboride), onto the surface of a substrate. Typical practice of said method begins with the dissolving borane and at least one rare-earth halide in an organic solvent, followed by providing and placing a substrate into said solution, so that a surface of said substrate is submerged but accessible by electromagnetic radiation. Next, a source of electromagnetic radiation is caused to expose the surface of said substrate to electromagnetic radiation, through said solution of borane and at least one rare-earth halide in said organic solvent. As a result at least one rare-earth halide in the vicinity of said substrate surface is fragmented into free halide and free rare-earth components and said free halide fractures said borane. Components of said fractured borane then combine with the free rare-earth to form rare-earth boride which deposits on said surface of said substrate.
The organic solvent is preferably comprised of at least one selection from the group consisting of: (methanol, THF, hexane, ether, benzene, a nitrile and an amide).
While not limiting, the substrate can be made of sodium glass. It should be appreciated in particular, that a deposited rear-earth boride need not be lattice matched to a substrate to achieve a very good, textured, rear-earth boride film deposition thereupon.
The source of electromagnetic radiation used to expose the surface of said substrate to electromagnetic radiation can be a laser, or a source of essentially white light which is passed through filtering means to provide favored wavelengths, which are in the visible range where hv=2.4 eV. It is noted that use of wavelengths in the visible range greatly diminishes problem of wavelength absorbtion, which can be very significant where organic solvents are utilized. It is also noted that a favored source of electromagnetic radiation in the experimental work performed by the inventors to date is an Argon Ion Laser (I-90 Coherent).
Favored practice is to deposit rare-earth boride onto the surface of a substrate in patterns which are effected by exposing the surface of said substrate to electromagnetic radiation through an electromagnetic masking means placed between said source of electromagnetic radiation and the surface of said substrate.
While most experimental work to date has been done utilizing Gadolinium (Gd), essentially any rare-earth halide can be utilized in practice of the present invention, (eg. Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), and a preferred, but not limiting halide is chloride. In addition, it is noted that a preferred end result is deposition of rare-earth hexaboride on the surface of a substrate.
An exemplary method of depositing GdB x onto the surface of a substrate comprising the steps of:
a. disolving B 10 H 14 and said GdCl 3 in an organic solvent comprising methanol;
b. providing and placing a substrate in said solution of B 10 H 14 and said GdCl 3 in said organic solvent comprising methanol, so that a surface of said substrate is submerged, but accessible by electromagnetic radiation through said solution of B 10 H 14 and said GdCl 3 in said organic solvent which includes at least one selection from the group consisting of: (methanol, THF, hexane, ether, benzene, nitrile and amine);
c. providing a source of electromagnetic radiation and exposing the surface of said substrate to electromagnetic radiation through said solution of B 10 H 14 and said GdCl 3 in said organic solvent comprising methanol, from said provided source of electromagnetic radiation;
such that said GdCl 3 in the vicinity of said substrate surface is fragmented into free chloride and free Gd components, with the result being that said free chlorine fractures said B 10 H 14 , with the further result being that components of said fractured B 10 H 14 combine with Gd to form GdB x +(B 10-x H y Cl+yHCl), which GdB x deposits on said surface of said substrate.
The present invention will be better understood by reference to the Detailed Description Section of this Disclosure in conjunction with appropriate reference to the Drawings.
SUMMARY OF THE INVENTION
It is therefore a primary purpose of the present invention to teach a method for depositing rare-earth boride onto the surface of a substrate which is submerged in an organic solution of borane and a rare-earth halide, via application of electromagnetic radiation to the surface of the submerged substrate.
It is another purpose of the present invention to describe a product which results from practice of the method of the present invention.
It is yet another purpose of the present invention to identify at least one selection from the group consisting of: (methanol, THF, hexane, ether, benzene, nitrile and amine) as an appropriate organic solvent for use in practicing the method of the present invention.
It is still yet another purpose of the present invention to identify sodium glass as an appropriate substrate for use in practicing the method of the present invention.
It is another purpose yet of the present invention to identify appropriate sources of electromagnetic radiation used to expose the surface of said substrate to electromagnetic radiation can be a laser, or a source of essentially white light which is passed through filtering means to provide favored wavelengths, which are in the visible range where hv=2.4 ev.
It is another purpose of the present invention to disclose that favored practice is to deposit rare-earth boride onto the surface of a substrate in patterns which are effected by exposing the surface of said substrate to electromagnetic radiation through an electromagnetic masking means placed between said source of electromagnetic radiation and the surface of said substrate.
It is another purpose of the present invention to disclose that the method of the present invention can be practiced with any of the rare-earths: (Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu).
It is yet another purpose of the present invention to disclose that a preferred halide for use in practice of the present invention is chloride.
It is another purpose yet of the present invention to disclose that hexaboride is the preferred boride for deposition on the surface of a substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 demonstrates a system for practicing the present invention.
FIG. 2 demonstrates interaction between electromagnetic radiation (EM) and a rare-earth halide in the vicinity of said substrate surface (SS) is fragmented into free halide and free rare-earth (FRE) components, with the result being that said free halide fractures said borane, with the further result being that components of said fractured borane (FB) combine with free rare earth (FRE) to form rare-earth boride (REB) which deposits on said surface (SS) of said substrate.
FIG. 3a shows X-ray Diffraction Patterns from Gadolinium Hexaboride (GdB 6 ) deposited onto a glass substrate.
FIG. 3b shows X-ray Diffraction Patterns from Gadolinium sub-borides (GdB 4 ) and (GdB 2 ) on a glass substrate, along with the similar result from the glass substrate prior to deposition.
DETAILED DESCRIPTION
Turning now to the drawings, FIG. 1 demonstrates a system for practicing the present invention. In particular a reservoir of chemicals (RES) with a substrate surface (SS) therein is shown with a source of electromagnetic radiation (EM) positioned to provide "light" through a Mask. Means for entering and recovering waste materials for reuse are demonstrated.
FIG. 2 demonstrates interaction between electromagnetic radiation (EM) and a rare-earth halide in the vicinity of said substrate surface (SS) is fragmented into free halide and free rare-earth (FRE) components, with the result being that said free halide fractures said borane, with the further result being that components of said fractured borane (FB) combine with free rare earth (FRE) to form rare-earth boride (REB) which will deposit on said substrate surface (SS).
Experimental depositions performed to date by the inventors utilized solutions containing various mixtures of methanol, hexane, tetrahydrofuran (THF), ether, benzene, nitrile and amine, and electromagnetic radiation was provided from an Argon Ion Laser (I-90 Coherent) source. Electromagnetic radiation from the Argon Laser provided wavelengths in the ultraviolet, (eg. 300-400 mW, 333 nm-363 nm) and in the visible (5-7 W, 514 nm).
FIG. 3a shows X-ray Diffraction Patterns from Gadolinium Hexaboride (GdB 6 ) deposited onto a glass substrate. The investigated Gadolinium Hexaboride (GdB 6 ) was deposited utilizing gadolinium chloride and decaborane as precursors in a solvent consisting of 10-120 mmol THF (36-48%), 10-100 mmol hexane (36-48%), 2-25 mmol ether (3-28%) and 3-15 mmol (<1%) methanol). The electromagnetic radiation was in the visible range (ie. hv=2.4 ev). XES measurements show no chlorine in the deposited films and the Diffraction Patterns are clearly associated with the presence of Gadolinium Hexaboride (GdB 6 ). The prominence of the <111> diffraction line, as seen in FIG. 3a, clearly indicates that the films grown from solution are textured. It is noted that films of Gadolinium Hexaboride (GdB 6 ) grown in a vacuum reactor typically show far less texturing. It is believed that textured films provide improved electrode fatigue properties. The Gadolinium Hexaboride (GdB 6 ) films were grown on non-crystaline sodium glass, such as used in DC plasma discharge display systems and it is emphasized that no lattice matching between said Gadolinium Hexaboride (GdB 6 ) and the sodium glass was present.
FIG. 3b shows X-ray Diffraction Patterns from Gadolinium sub-borides (GdB 4 ) and (GdB 2 ) on a glass substrate, along with the similar results from the glass substrate prior to deposition. These films showed trace amounts of chlorine present which is consistent with the presence of the identified Gadolinium sub-borides. Similar Lanthanum borides have also been fabricated.
It is again noted that (LISD) deposited films which are deposited utilizing visible range wavelength electromagnetic radiation are typically more uniform that films deposited utilizing more conventional precesses, (eg. CVD).
Additional films were deposited utilizing electromagnetic radiation in the ultraviolet. Where this was done the methanol content of the solution was reduced to less than 1%. The resulting films showed characteristics of nucleation sites. (It is noted that methanol is a necessary solvent component for the dissolution of gadolinium chloride, and that the content of methanol must be reduced where ultraviolet wavelengths are utilized as methanol absorbs uv wavelengths).
The results of the present laser initiated deposition from solution procedure suggests that the deposition chemistry is similar to that associated with use of high temperature vacuum reactor. It is believed that the chemical reaction for the gadolinium borides during deposition from solution can be written as:
GdCl.sub.3 +B.sub.10 H.sub.14 →GdB.sub.x +B.sub.10-x H.sub.y Cl+yHCl.
It is believed that a key chemical intermediate is of the form:
RE.sub.2 (B.sub.10 H.sub.10).sub.3
(where "RE"=Rare Earth), and is a part of the thin film deposition process. The fabrication of the bulk gadolinium borides (and amorphous boron), has been undertaken from the thermolysis of said molecular Gd 2 (B 10 H 10 ) 3 precursor. The dominant gadolinium borides in this pyrolysis reaction are GdB 4 and GdB 6 , as is also the case in the solution deposition reported here.
Laser-induced deposition of gadolinium borides from solution has been shown to be effective and simple. The mechanism of Laser Induced Solution Deposition (LISD) clearly resembles that of Chemical Vapor Deposition (CVD) in the gas phase. However, unlike gas phase deposition, (eg. CVD and PECVD), deposition from solution is compatible with thin film formation on thermally sensitive substrates because of the large thermal sink of the solvent/solute mixture.
It is noted that the mechanism of inducing deposition material reducing electrons at the surface of a substrate onto which a rare-earth boride is to be deposited, such as described in the previously referenced Patent to Inoue, (U.S. Pat. No. 4,511,595), which describes the deposition of a metal onto a substrate from a typically flowing solution, wherein a laser beam is directed onto the substrate over a localized area, to activate an interface between said localized area and said solution, might play a role similar to that in the case where a metal is reduced onto the surface of a substrate.
It should also be appreciated that the (LISD) technique permits one undertake recovery of unused metals and source compounds, and volatility, toxicity and safety issues, common to (CVD) processes, are diminished. Further, the fact that present invention rare-earth boride film deposition occurs best where visible range wavelengths are utilized in the deposition process, means that the present invention process for deposition of rare-earth hexaborides onto substrates can more easily be adapted to industrial scale environments where conventional visible light sources are commonly available.
Having hereby disclosed the subject matter of the present invention, it should be obvious that many modifications, substitutions, and variations of the present invention are possible in view of the teachings. It is therefore to be understood that the invention may be practiced other than as specifically described, and should be limited in its breadth and scope only by the Claims. | Disclosed is a method for depositing rare-earth boride onto the surface of a substrate which is submerged in an organic solution of borane and a rare-earth halide. Application of electromagnetic radiation, preferably in the visible wavelength range, near the surface of the submerged substrate drives the formation and deposition of rare-earth boride onto a substrate. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is related to and claims priority to U.S. patent application Ser. No. 60/231,910, filed Sep. 11, 2000, entitled MOVEABLE SWIMMING POOL FLOOR, the entirety of which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] n/a
FIELD OF THE INVENTION
[0003] This invention relates to an apparatus for swimming pools, namely, a vertically moveable swimming pool floor.
BACKGROUND OF THE INVENTION
[0004] Swimming pools present serious dangers to small children, the elderly, the disabled, and others who do not have the ability to swim. Because most pools are configured to accommodate both diving and swimming, the depth of a pool must be adequate to safely allow users to dive into the pool. Yet, even very shallow water can be deadly to those incapable of swimming.
[0005] Pools often provide a shallow, wading depth at one end, safe enough for non-swimmers, and provide a deeper swimming and diving depth at the opposite end. This requires greater time, effort and expense in laying out and constructing the swimming pool floor, as a sloped floor is inherently more difficult to construct than a flat one.
[0006] Nevertheless, the swimming pool presents a serious drowning hazard to small children or the disabled who may accidentally fall into the pool. Another hazard exists when the pool itself is emptied of water for cleaning or maintenance, presenting a dangerous structural cavity or pit.
[0007] It is desirable therefore, to provide a device which may effectively vary the depth of a swimming pool, without requiring the construction of a curved, sloped, or otherwise complex swimming pool shell, and which may effectively minimize the depth of a pool when such pool is emptied of water.
[0008] Furthermore, the planform area of a swimming pool may significantly decrease the usable area of a yard or other space where the pool is located. For personal and home applications, this decrease in usable planform area can be significant. Conventional devices and methods for covering a swimming pool generally use flexible thin covers such as tarpaulins. Unless a sufficiently rigid device is used to cover the pool, the planform area of the swimming pool is not effectively usable for any other purpose than as a swimming pool.
[0009] It is desirable therefore to provide a device which may render the planform area of a swimming pool usable for a purpose other than swimming or diving, where the pool is covered by a rigid medium suitable for walking, sitting, or playing thereupon.
SUMMARY OF THE INVENTION
[0010] A vertically moveable swimming pool floor apparatus includes a rigid planar platform configured to fit the panform area of a swimming pool, and a plurality of hydraulically powered hoists coupled to the platform to raise and lower the platform. A number of depth indicators are attached to the platform. A control system is coupled to the hoists to monitor and control the movement and position of the platform.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
[0012] [0012]FIG. 1 is a diagram of the moveable swimming pool floor apparatus system;
[0013] [0013]FIG. 2 is a perspective view of the apparatus inside a swimming pool;
[0014] [0014]FIGS. 3A, 3B, and 3 C are cross-sectional views of the apparatus with the platform at varying depths; and
[0015] [0015]FIG. 4 is a cutaway perspective view of a hydraulic hoist assembly.
DETAILED DESCRIPTION OF THE INVENTION
[0016] [0016]FIG. 1 illustrates the moveable swimming pool floor apparatus as integrated with a power and control system, labeled generally as 10 . The moveable swimming pool floor apparatus and system includes a platform 100 , a plurality of hoists or hoist assemblies 105 , a hydraulic power unit 110 , a control unit 115 , a user panel 120 , a depth sensor 125 , communications media 130 , and a number of hydraulic power lines 135 .
[0017] The platform 100 is coupled to a number of hoists 105 . In FIG. 1, four such hoists 105 are positioned around a rectangular platform 100 . The platform 100 may be of any shape suitable to conform to the particular planform area of the swimming pool into which the apparatus is to be installed. The hoists 105 are hydraulically powered rotary hoists, configured to generate torque to power a strap or other mechanical pulling medium (not shown) coupled to the platform. The platform 100 is configured to be moved by the action of the hoists 105 in a direction into and out of the plane of platform 100 .
[0018] The hoists 105 are coupled via power lines 135 to the hydraulic power unit 110 . The power unit 110 is any suitable hydraulic or pneumatic power assembly, capable of providing sufficient hydraulic power through lines 135 to meet the loads presented.
[0019] The hydraulic power unit 110 is in turn coupled via communications medium 130 to the control unit 115 , which may also be coupled to a depth sensor 125 via another, separate communications medium. The communications media 130 are any device capable of sending or receiving data in electronic form, either analog or digital, wired or wireless, suitable to allow control system 115 to send and receive electronic commands and responses from the power unit 110 or depth sensor 125 .
[0020] The hoist assemblies 105 also comprise an automatic braking system (not shown) configured to detect undesired movements of the platform 100 , or individual hoists 105 , such that the actuation of one or all of the hoists 105 , and hence the movement of platform 100 , is arrested in response to the detection of an undesired movement characteristic of the platform 100 . This undesired movement characteristic may be predetermined based on any number of criteria, such as excessive movement speed of the platform 100 when it is being raised or lowered by the hoists 105 , or the detection of an obstruction or hazard around the apparatus.
[0021] The user panel 120 contains a number of switches, gauges, and indicators to allow a user to independently control and monitor each or all of the hoists 105 , as well as to monitor the relative depth of the platform 100 as measured and communicated by depth sensor 125 . The user panel 120 is connected to the control unit 115 , which receives commands and input from the user panel 120 to relay to the power unit 110 . The control unit has mechanical, electrical, or electromechanical components capable of controlling (i) the starting and stopping of each of the individual hoists 105 ; (ii) the speed at which each of the individual hoists 105 are actuated, such that the platform 100 is movable at a nominal speed of about one foot per minute; (iii) additional air-powered shut-off devices located in the apparatus, capable of arresting the action of an individual hoist 105 , platform 100 , or both, when the platform is positioned at a predetermined point, such as near the very top of its range of motion near the top or coping of the swimming pool, or near the very bottom of its range of motion near the floor of the swimming pool.
[0022] [0022]FIG. 2 illustrates the apparatus 10 as installed in a swimming pool of characteristic size and shape. In addition to the platform 100 , FIG. 2 shows the layout and positioning of a number of elements incorporated into the apparatus 10 , namely, a number of depth indicators 140 , each including an elongate member or pole 145 topped with a warning sign 150 and coupled to each of the four corners of the platform 100 , and a number of hoist assembly covers 155 , each covering a hydraulic hoist 105 (not shown). The hoists 105 are positioned opposite each other at two lateral lines across the shorter side of the platform 100 . Coping 160 circumscribes the platform and pool cavity (not shown).
[0023] The platform 100 is shown in FIG. 2 at its uppermost position, wherein it may effectively function as a swimming pool cover and may be usable floor space for a number of applications. The platform is moved up in the direction U and down in the direction L, as shown in FIG. 2. The platform is constructed of lightweight materials having a high modulus of elasticity, having a normal compressive strength that is sufficient to withstand the load of several people as well as commonly used objects such as tables, lawn chairs, barbeques, and the like. The platform 100 may be constructed of any materials suitable and robust enough to meet the foregoing criteria, such as PVC, structural aluminum, stainless steel, carbon fiber, or other rigid, workable material.
[0024] The depth indicators 140 are constructed with at least one elongate pole 145 , having a number of markings affixed longitudinally thereon to show linear dimension in the directions U and L. A sign 150 having a suitable warning message is fixed to the top of each pole 145 . The poles 145 are detachably fixed to the platform 100 in the corners as shown, and may be rigid or semi-rigid. As the platform 100 is actuated up or down in the directions U or L, respectively, the depth indicators 140 move with the platform 100 in such direction. An observer may ascertain the depth at which the platform 100 is lowered into the pool cavity relative to a reference level by viewing the position of such reference level next to the dimensional markings affixed on any of the poles 140 . The reference level may be the pool coping 160 , or any other reference height chosen by the user so generally correspond with the maximum height of the water level in the swimming pool.
[0025] In the alternative, the pole 145 may be a telescoping pole, such that the signs 150 are configured to be indicator gauges, coupled to a depth sensor disposed inside of the poles 145 . The signs 150 are then fixed at a reference height relative to the pool, and do not move as the platform 100 is moved. Instead, as the platform 100 is lowered into the pool, the poles 145 telescope downwards with the platform 100 and relay a depth indication to the signs 150 , which are then observed to ascertain pool depth.
[0026] [0026]FIGS. 3A, 3B, and 3 C show the platform 100 in its uppermost, intermediate, and lowermost stages, respectively, as it descends into a swimming pool cavity 200 . At its upper most stage, the platform 100 is at a depth D 1 above the swimming pool floor 210 , as shown in FIG. 3A. At such a position, a nominal clearance C exists between the platform 100 surface and the very top of the coping 160 . FIG. 3A shows the platform 100 at its uppermost position when the device is used as a pool cover or usable floor space, and no water is in the pool cavity 200 .
[0027] As the platform is lowered in the direction L, it reaches an intermediate position D 2 above the floor 210 , as shown in FIG. 3C. Here the water level 220 is shown at a level corresponding to a height D 1 above the floor 210 , such that the effective depth of water (and hence the usable swimming pool) is: (D 1 -D 2 ). The vertical position of platform 100 is continuously variable by the action of the hoists 105 and control unit 115 as indicated in FIG. 1, such that the effective swimming pool depth (D 1 -D 2 ) is continuously variable.
[0028] When the platform 100 is lowered the maximum amount into cavity 200 , the top surface of platform 100 rests at a small clearance D 3 above the floor 210 (including the thickness of the platform 100 itself), such that the effective swimming pool depth is at its maximum amount: (D 1 -D 3 ).
[0029] A flexible, resilient seal (not shown), made of a material such as rubber, is disposed around the platform 100 , in the plane of the platform 100 , and mates the edges of the platform 100 with the sides 230 of pool cavity 220 . The platform 100 itself is also constructed to have a number of fluid-permeable joints and seals (not shown), such that water can easily travel through such joints and seals to allow the platform 100 to be moved without encountering excessive compressive, expansive, or drag resistance from the water 220 as the platform 100 moves therethrough.
[0030] Not shown in FIGS. 3A, 3B, and 3 C are the hydraulically actuated shutoff mechanisms positioned near the top and bottom of the pool cavity 200 , such that each mechanism is activated when the platform 100 is in its uppermost position, as in FIG. 3A, and its lowermost position, as in FIG. 3C. In such cases, when the platform 100 has been moved to such a position, the action of the hoists 105 , and hence the platform 100 , is halted for safety and efficiency considerations.
[0031] [0031]FIG. 4 shows a cut-away view of a hoist assembly 105 , with the hoist assembly cover 155 cut-away to show detail. The hoist assembly 105 includes an actuation unit 310 , coupled to the hydraulic power lines 135 , and engaged to a rotary spindle 320 , which houses and wraps a strap 330 , connected at its distal end to the platform 100 . The entire hoist assembly 105 and cover 155 are fixedly attached to the coping 160 , wherein the strap 330 is positioned to run vertically very near to the edge of the swimming pool sides 230 . The hoist assembly 105 is hydraulically powered via power lines 135 , such that when the actuator unit 310 engages the spindle to rotate in the direction R shown in FIG. 4, the platform 100 , moves up in the direction U. The mere force of gravity, coupled with a possible resistive drag from the actuation of the hoist 105 and spindle 320 in the direction opposite R, allows the platform 100 to be lowered in the direction L at a safe, controlled speed.
[0032] 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 herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims. | A vertically moveable swimming pool floor apparatus includes a rigid planar platform configured to fit the planform area of a swimming pool, and a plurality of hydraulically powered hoists coupled to the platform to raise and lower the platform. The hoists are controlled by a control system operated by the user. The hoists controllably actuate the platform into and out of a swimming pool cavity, such that effective depth of the swimming pool is variable in a continuous range. The platform is equipped with depth indicators to allow users to observe the effective depth of the pool. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vehicle power steering system for controlling an assist force, which supplementally supports the steering operation, by adjusting a current fed from a car-carried battery to a motor in accordance with a vehicle speed derived from a speed sensor and an angle of the steering wheel from a steering-wheel angle sensor.
2. Discussion of the Related Art
A motor drive power steering system (MDPS) having a basic construction as shown in FIG. 1, is known as this type of the power steering system. In the figure, reference numeral 1 designates a car-carried battery; 2, an alternator; 3, an engine; 4, a speed sensor; 5, a steering-wheel angle sensor; 6, a power steering unit; 7, a motor driven pump; 8, an ignition switch; 9, a signal controller; and 10, a power controller.
In the MDPS thus constructed, a vehicle speed derived from the speed sensor 4 and an angle of the steering wheel from the steering-wheel angle sensor 5 are transferred to the signal controller 9. The signal controller 9 processes these signals received from the sensors 4 and 5 to generate a motor drive signal. The motor drive signal is applied to the power controller 10. The power controller 10 adjusts the current fed from the car-carried battery 1 to the motor driven pump 7 in accordance with the motor drive signal from the signal controller 9.
An oil pressure in a fluid path connecting to the power steering unit 6 is controlled by the adjusted current in the following manner.
When the vehicle runs at low speed, the assist force is increased to reduce the force for steering, viz., to provide a light steering feel. When it runs at medium and high speed, the assist force is decreased to increase the force for steering, viz., to provide a heavy steering feel.
In the MDPS, the battery voltage (DC 12 V) is directly applied to the motor driven pump 7, from the car-carried battery 1. The motor specified for DC 12 V is used for the motor driven pump 7-1.
Thus, a large current is fed to the motor driven pump 7-1, to thereby produce a large torque. This leads to an inevitable increase of the size of the motor 7-1, the increased thickness of the wires for their electrical connection, and an increase of the costs of the overall system.
The battery voltage of the car-carried battery 1 varies depending on the magnitude of a load of the battery. A variation of the battery voltage, caused by the load variation, affects an influence on the motor driven pump 7-1, and hence the assist force for the steering wheel operation. To be more specific, the battery voltage is low, that is, 12 V, and the low battery voltage is directly applied to the motor driven pump 7-1. Because of this, a little variation of the battery voltage causes a great variation of the torque generated by the motor driven pump 7-1. As a result, an accuracy of the control of the assist force is deteriorated.
The description of the power steering system thus far concerns the motor vehicle driven by an internal combustion engine. The same thing is correspondingly applied to the power steering system assembled into an electrically driven vehicle (EV). In the case of the EV, the main voltage supply source consists of only the battery. As a result, the voltage variation is great.
The same problem arises not only in the MDPS but also in a full electric power steering system (FEPS) in which the motor controls the assist force of the power steering unit directly, not by way of the oil path.
SUMMARY OF THE INVENTION
The present invention has been made to solve the above problems, and has an object to provide a vehicle power steering system which realizes the reduction of the motor size and the thinning of wires for electric connection and hence the reduction of costs of the overall system, is little influenced by the battery voltage variation, is capable of accurately controlling the assist force, and eliminates a wasteful energy consumption, thereby securing the energy saving.
To achieve the above object, according to a first aspect of the invention, there is provided a vehicle power steering system, which includes a boosting circuit, inserted in a current feed path to the motor, for boosting a battery voltage of the car-carried battery and applying the boosted one to the motor.
In the vehicle power steering system, the boosting circuit may apply the boosted one as a boosted voltage Vout to the motor, and the vehicle power steering system may further include boosted-voltage stabilizing means for controlling the boosted voltage Vout to a fixed value of voltage through an operation of monitoring the boosted voltage Vout.
The vehicle power steering system may further include boosted-voltage decreasing means for decreasing the boosted voltage Vout at the current decreasing rate of the battery voltage when the boosted-voltage decreasing means detects that the boosted voltage goes below a first preset voltage value V1, through the operation of monitoring a battery voltage of the car-carried battery.
The vehicle power steering system may further include fail-safe means for decreasing the boosted voltage Vout at a preset gradient when the fail-safe means detects that a state of the boosted voltage being below a first preset voltage value V1, continues for a time duration Δt or longer, through the operation of monitoring a battery voltage of the car-carried battery.
The fail-safe means may decrease the boosted voltage Vout at a preset gradient when the fail-safe means detects that the battery voltage goes below a second preset voltage value V2, through the operation of monitoring a battery voltage of the car-carried battery.
In the vehicle power steering system of the first aspect of the invention, the battery voltage is boosted and the boosted one is applied to the motor in the form of the boosted voltage Vout.
Also, in the vehicle power steering system of the invention, the boosted voltage Vout is monitored and controlled to a fixed value of voltage.
Further, in the vehicle power steering system of the invention, when the boosted voltage goes below a first preset voltage value V1, the boosted voltage Vout at the current decreasing rate of the battery voltage.
Still further, in the vehicle power steering system of the invention, when a state of the boosted voltage being below a first preset voltage value V1 continues for a time duration Δt or longer, the boosted voltage Vout gradually decreases at a preset gradient.
Yet still further, in the vehicle power steering system of the invention, when the battery voltage goes below a second preset voltage value V2, the boosted voltage Vout decreases at a preset gradient.
According to a second aspect of the invention, there is provided a vehicle power steering system, which includes a boosting circuit, inserted in a current feed path to the motor, for boosting a battery voltage of the car-carried battery and applying to the motor the boosted one as a boosted voltage Vout, and voltage decreasing means for holding down the boosting operation of the boosting circuit in accordance with a steering condition, to thereby decrease the boosted voltage Vout.
The voltage decreasing means may hold down the boosting operation of the boosting circuit in accordance with a running condition, to thereby decrease the boosted voltage Vout.
The voltage decreasing means may hold down the boosting operation of the boosting circuit in accordance with steering and running conditions, to thereby decrease the boosted voltage Vout.
In the vehicle power steering system of the second aspect of the invention, a battery voltage is boosted and applied to the motor. When a state of no steering operation continues for a preset time duration, the boosting operation of the boosting circuit is held down to reduce the boosted voltage Vout. In this case, the boosting operation may be stopped, if necessary.
Also, a battery voltage is boosted and applied to the motor. When the vehicle speed exceeds a preset value of speed, the boosting operation of the boosting circuit is held down to reduce the boosted voltage Vout. In this case, the boosting operation may be stopped, if necessary.
Further, a battery voltage is boosted and applied to the motor. When a state of no steering operation continues for a preset time duration or the vehicle speed exceeds a preset value of speed, the boosting operation of the boosting circuit is held down to reduce the boosted voltage Vout. In this case, the boosting operation may be stopped, if necessary.
According to a third aspect of the invention, there is provided a vehicle power steering system, which includes a boosting circuit inserted in a current feed path to the motor, for boosting a battery voltage of the car-carried battery to apply to the motor the boosted one as a boosted voltage Vout, and voltage increasing means which monitors a load of the motor for increasing the boosted voltage Vout when the load of the motor is equal to or exceeds a preset value I1.
When the load of the motor is smaller than a preset value I1 for a preset time period Δt, the voltage increasing means may decreases the boosted voltage Vout.
The voltage increasing means may vary the boosted voltage Vout in accordance with the load monitored.
In the vehicle power steering system of the third aspect of the invention, when the load of the motor exceeds a preset value I1, the boosted voltage Vout applied to the motor is increased. In a specific example, when the current fed to the motor exceeds a preset value I1, the boosted voltage Vout is increased from 12 V (the minimum value=battery voltage) to 100 V (the maximum value).
Also, when the load of the motor is indicated by a value above a preset value I1, the boosted voltage Vout is increased. When a state that the load of the motor, indicated by a value below a preset value I1, continues for a preset time period Δt, the boosted voltage Vout is decreased. In a specific example, when the current fed to the motor exceeds a preset value I1, the boosted voltage Vout is increased from 12 V (the minimum value=battery voltage) to 100 V (the maximum value). When a state that the load of the motor is indicated by a value below a preset value I1 continues for a preset time period Δt, the boosted voltage Vout is decreased from 100 V to 12 V.
Further, the boosted voltage Vout varies in accordance with a load of the motor. For example, the boosted voltage Vout is increased as the current fed to the motor increases. It is deceased as the current decreases.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram in block and schematic form the concept of a conventional MDPS;
FIG. 2 is a circuit diagram showing a major portion of an MDPS according to an embodiment of the present invention;
FIG. 3, is a flowchart showing a flow of a process carried out by a microcomputer shown in FIG. 2 according to a first embodiment;
FIGS. 4A and 4B are graphs showing variations of a battery voltage Vin and a boosted voltage Vout, respectively;
FIG. 5 is a circuit diagram showing a major portion of another MDPS in which a DC brushless motor is used in place of a DC brush motor, which is used in the MDPS of FIG. 2;
FIG. 6 is a flowchart showing a flow of a process carried out by the microcomputer shown in FIG. 2, according to a second embodiment;
FIGS. 7A to 7C are graphs showing variations of a steering signal, a vehicle speed signal, and a boosted voltage Vout, respectively;
FIG. 8 is a flowchart showing a flow of a process carried out by a microcomputer shown in FIG. 2, according to a third embodiment; and
FIGS. 9A and 9B are graphs showing variations of a motor drive current I and a boosted voltage Vout, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 2 is a circuit diagram showing a key portion of an MDPS (motor drive power steering system) according to an embodiment of the present invention. In the figure, reference numeral 4 designates a speed sensor 4 ; 5, a wheel angle sensor; 7-1', a motor for a pump; 11, a microcomputer; 12, a boosting circuit; 13, a drive circuit; Tr1, a power transistor; D1 to D4, diodes; and R1 to R4, resistors.
The boosting circuit 12 is inserted in a current supply route from a car-carried battery to the motor 7-1'. More exactly, it is connected between a point P1 for receiving a battery voltage Vin (DC 12 V) from the car-carried battery and another point P2 for applying a voltage to the motor 7-1'. The boosting circuit 12 is made up of capacitors C1 and C2, a coil L1, a diode D5, a switching transistor Tr2, and an oscillator circuit 12-1.
The microcomputer 11 includes terminals A to K. The microcomputer 11 receives at the terminal A a divided voltage Va formed by resistors R1 and R2, and at the terminal E a divided voltage Vb formed by resistors R3 and R4. The microcomputer 11 detects a battery voltage Vin that is received at the voltage receiving point P1, from the divided voltage Va, and detects a boosted voltage Vout appearing at the voltage applying point P2 from the divided voltage Vb. In a third embodiment which will be described later, when the battery voltage Vin drops to below a preset value of voltage, the microcomputer decreases the boosted voltage Vout or controls it to the battery voltage Vin. Further, the microcomputer turns on a warning lamp (not shown) to give warning to a driver.
The microcomputer 11 receives at the terminal I a signal representative of an angle of the steering wheel from the wheel angle sensor 5, and receives at the terminal K a signal representative of a speed of the vehicle from the speed sensor 4. The microcomputer 11 generates a motor drive signal on the basis of the speed signal and the wheel angle signal from the speed sensor 4 and the wheel angle 5, and outputs the motor drive signal from the terminal F to the drive circuit 13.
The microcomputer 11 receives at the terminal C information of temperature of the transistor Tr2, and at the terminal D information of current flowing through the transistor Tr2. The microcomputer 11 receives at the terminal G information of temperature of the transistor Tr1, and at the terminal H information of current flowing through the transistor Tr1. The microcomputer 11 receives at the terminal J information of a motor rotational speed of the motor 7-1'.
The microcomputer 11 sends a signal indicative of a duty ratio from the terminal B thereof to the oscillator circuit 12-1 of the boosting circuit 12. The duty ratio signal determines a duty ratio of a pulse wave outputted from the oscillator circuit 12-1 to the transistor Tr2. In the present invention, an oscillation frequency of the oscillator circuit 12-1 is 20 kHz.
(Basic Operation of the Boosting Circuit 12)
The basic operation of the boosting circuit 12 will be described. A storage and discharge of energy by the coil L1 is repeated through a switching operation of the transistor Tr2 that is caused by a pulse signal from the oscillator circuit 12-1. A high voltage appears at the cathode of the diode D5 when the coil discharges energy.
To be more specific, when the transistor Tr2 is turned on, current flows into the coil L1. When it is turned off, the current flowing through the coil L1 is stopped. At this time, a high voltage is generated so as to impede a change of magnetic flux caused by the stopping of the current flow, and appears at the cathode of the diode D5. This process is repeated, so that a high voltage repetitively appears at the cathode of the diode D5. The high voltage is smoothed by the capacitor C2, and the resultant appears, a boosted voltage Vout, at the point P2.
The boosted voltage Vout, generated by the boosting circuit 12, varies in accordance with a duty ratio command value issued from the microcomputer 11 through the terminal B thereof. The boosted voltage Vout is increased when the boosting circuit receives a large duty ratio command value from the microcomputer. It is decreased when the boosting circuit receives a small duty ratio command value. In other words, a large duty ratio of the pulse signal, which is outputted from the oscillator circuit 12-1 to the transistor Tr2, will provide a large boosted voltage Vout, while a small duty ratio thereof will provide a small boosted voltage Vout.
In the present embodiment, the boosted voltage Vout is set at 100 V. Accordingly, the motor 7-1'is a motor (DC brush motor), designed to be operable at 100 V, not 12 V. The present embodiment uses a high voltage type motor, designed to produce a large torque by small current for the motor 7-1'.
By using this type of the motor, size reduction of the motor 7-1' is realized and use of thinned wires is allowed, so that the cost of the overall system is reduced. Since the boosted voltage Vout is set at 100 V, inexpensive, home use components may be used. In the present embodiment, the boosted voltage Vout varies little when the battery voltage Vin varies. Accordingly, the assist force can accurately be controlled while being little influenced by a variation of the battery voltage Vin.
In recent marked progress of this field, the transistors of high power but low loss are commercially available at low cost. Because of this, the boosting circuit 12 using such a transistor can be manufactured at low cost. An increase of the cost, caused by using the boosting circuit 12, can readily be canceled out by the cost reduction which results from the size reduction of the motor 7-1' and the use of thinned wires. Accordingly, the total cost of the overall system is reduced.
The oscillation frequency of the oscillator circuit 12-1, which is 20 kHz in the embodiment, may further be increased. If so done, a small coil can be used for the coil L1. Use of the small coil leads to the size and cost reduction, as a matter of course. The upper limit of the oscillation frequency of the oscillator circuit 12-1 is determined in connection with the switching speed of the transistor Tr2. Where a transistor of high switching speed is used for the transistor Tr2, the oscillation frequency may be increased.
In the present embodiment, the oscillator circuit 12-1 is contained in the boosting circuit 12. It may be omitted, if required. In this case, the microcomputer 11 outputs a pulse signal of an adjusted duty ratio from the terminal B thereof and applies it to the power transistor Tr1.
(Operation of the Microcomputer 11 according to a First Embodiment)
The operation and some functions of the microcomputer 11 in accordance with a first embodiment of the invention will be described with reference to FIG. 3.
The microcomputer 11 receives a divided voltage Vb at the terminal E, and detects a boosted voltage Vout to be applied to the motor 7-1', from the divided voltage Vb. The microcomputer 11 compares the boosted voltage Vout with a set value V ST (V ST =100 V) (step S101 in FIG. 3). If the boosted voltage Vout is not smaller than the set value V ST , the microcomputer 11 confirms that Vout≧V ST (step S102), and decreases a duty ratio command value to be outputted from the terminal B thereof so that the boosted voltage Vout is equal to the set value V ST (step S103).
In the step S101, if the boosted voltage Vout is smaller than the set value V ST , the microcomputer 11 advances to a step S104. In this step, the microcomputer 11 detects a battery voltage Vin from a divided voltage Va, which receives at the terminal A, and checks whether or not the battery voltage Vin is smaller than a first preset voltage value V1 (e.g., V1=9.5 V). If the battery voltage Vin is larger than the first preset voltage value V1, the microcomputer 11 increases a duty ratio command value to be outputted from the terminal B thereof so that the boosted voltage Vout is equal to the set value V ST (step S105).
Through the operations of the steps S101 to S105, the boosted voltage Vout applied to the motor 7-1' is monitored, and the boosted voltage Vout is kept at the set value V ST on the basis of the result of the monitoring operation. Thus, the boosted voltage Vout is controlled to be equal in level to the set value V ST when the battery voltage Vin is larger than the first preset voltage value V1. Accordingly, the assist force can accurately be controlled while being little influenced by a variation of the battery voltage Vin.
If the battery voltage Vin is smaller than the first preset voltage value V1 in the step S104, the microcomputer 11 causes a warning lamp (not shown) to blink (step S106), and goes to a step S107. In the step S107, the microcomputer 11 checks if a state that the battery voltage Vin is smaller than the first preset voltage value V1 has continued for a time duration Δt or longer. If the answer is NO, the microcomputer 11 advances to a step S108.
In the step S108, the microcomputer 11 checks if the battery voltage Vin is smaller than a second preset voltage value V2 (e.g., V2=8.5 V), which is smaller than the first preset voltage value V1. If the battery voltage Vin is larger than the second preset voltage value V2, the microcomputer 11 decreases a duty ratio command value that will be outputted from the terminal B, in accordance with a decreasing rate of the battery voltage Vin, to thereby decrease the boosted voltage Vout (step S109). This leads to the lessening of the load to the car-carried battery, possibly quickening the restoration of the battery voltage Vin to its normal level of voltage.
In the step S107, if the state of Vin<V1 continues for Δt or more, viz., the battery voltage Vin has been continued for the preset time duration Δt or longer, and drops below the first preset voltage value V1, the microcomputer 11 judges that something is wrong with a system including the battery, and on this judgement, gradually decreases the boosted voltage Vout at a preset gradient (step S110). With progression of the decrease of the boosted voltage Vout, it eventually drops to below the battery voltage Vin. In this way, a fail-safe function can be secured while naturally decreasing the assist force, viz., without abruptly decreasing the assist force.
After executing the process of the step S110 to decrease the boosted voltage Vout at a preset gradient, the microcomputer 11 switches a light furnishing mode of the warning lamp from a blinking mode to a continuous mode (step S111). If the battery voltage Vin is smaller than the second preset voltage value V2, the microcomputer 11 judges that the battery system is abnormal, and advances to the step S110. In this step, the microcomputer 11 gradually decreases the boosted voltage Vout at a given gradient. And when the boosted voltage Vout decreases to be below the battery voltage Vin, the fail-safe function is immediately operated.
FIG. 4A shows a variation of the battery voltage Vin, and FIG. 4B, a variation of the boosted voltage Vout.
If, at time t1, the battery voltage Vin starts to decrease, and the boosted voltage Vout also starts to decrease as indicated by a broken line with respect to the set value V ST , the microcomputer 11 increases a duty ratio command value, which is to be delivered to the oscillator circuit 12-1, thereby keeping the boosted voltage Vout at the set value V ST . If, at time t1, the battery voltage Vin starts to increase, and the boosted voltage Vout also starts to increase as indicated by a broken line with respect to the set value V ST , the microcomputer 11 decreases a duty ratio command value, thereby keeping the boosted voltage Vout at the set value V ST .
When the battery voltage Vin drops below the first preset voltage value V1 at time t2, the microcomputer 11 causes the warning lamp to blink, and decreases the duty ratio command value in accordance with the current decreasing rate of the battery voltage Vin, to thereby decrease the boosted voltage Vout. As the result of decreasing the duty ratio command value, if the battery voltage Vin increases to its original voltage level as indicated by a dotted line, the boosted voltage Vout also returns to its original voltage level.
If the state of Vin<V1 continues for Δt or longer, the microcomputer 11 judges that the battery system is abnormal, and on this judgement, decreases the boosted voltage Vout at a preset gradient while at the same time switches the light furnishing mode of the warning lamp to a continuous mode. With the decrease of the boosted voltage Vout at a preset gradient, the boosted voltage Vout becomes equal to the battery voltage Vin.
At time t4, if the battery voltage Vin increases above the first preset voltage value V1, the microcomputer 11 judges that the battery system is restored to its normal state, and increases the boosted voltage Vout at a preset gradient. The threshold value as a criterion in judging that the battery system is restored to the normal state may be a third preset voltage value V3, higher than the first preset voltage value V1. Where the third preset voltage value V3 is used, the judgement that the battery system is restored to the normal state is made at time t4', and the boosted voltage Vout increases at a given gradient as indicated by a broken line.
A hysteresis may be used for the criterion of the judgement that the battery system is restored to the normal state. Provision of the hysteresis brings about various advantages. The frequency of a large variation of the assist force is reduced. An unnatural feeling is eliminated in the steering operation. The MDPS operation may proceed in a state that the battery voltage Vin is satisfactorily restored. Further, the annoying blinking of the warning lamp can also be minimized.
At time t5, the battery voltage Vin drops below the first preset voltage value V1. Then, as in the operation at time t2, the microcomputer 11 causes the warning lamp to blink, and decreases the duty ratio command value in accordance with a decreasing rate of the battery voltage Vin, to thereby decrease the boosted voltage Vout. Then, if the battery voltage Vin drops below the second preset voltage value V2 before the time period Δt terminates, the microcomputer 11 determines that the battery system is abnormal, and decreases the boosted voltage Vout at a given gradient, while at the same time causes the warning lamp to switch its light furnishing mode to a continuous mode. With the decrease of the boosted voltage Vout at a given gradient, the boosted voltage Vout reaches to the battery voltage Vin.
In the first embodiment, the blinking mode of the warning lamp starts at time t2 (t6), and the continuous mode starts at time t3 (t5). In other words, the warning lamp is lit on in stepwise manner. Alternatively, the warning lamp may be placed to the continuous mode.
(Operation of the microcomputer 11 according to a Second Embodiment)
An operation of the microcomputer 11 according to a second embodiment will be described with reference to FIG. 6. The microcomputer 11 controls the boosting operation of the boosting circuit 12 to decrease the boosted voltage Vout in accordance with steering conditions and vehicle running conditions. Specifically, when a high boosted voltage Vout is not required for the motor 7-1', viz., a large assist force is not required, the microcomputer 11 controls the boosting operation of the boosting circuit 12 to decrease the boosted voltage Vout.
The microcomputer 11 checks whether or not an angle of the operated steering wheel is present, on the basis of a signal representative of an angle of the operated steering wheel, which is produced by the steering-wheel angle sensor 5 (step S1101). If the steering wheel is operated, the microcomputer 11 checks whether or not a vehicle speed, derived from the speed sensor 4, is above a first preset speed value S1 (S1=20 km/h in this embodiment) (step S1102). If the vehicle speed is lower than the first preset speed value S1, the microcomputer 11 controls the boosted voltage Vout to a fourth preset value V4 of voltage (V4=100 V in the embodiment) (step S1103). If the vehicle speed is higher than the first preset speed value S1, the microcomputer 11 checks whether or not it is higher than a second preset value S2 of speed (S2=80 km/h in the embodiment), higher than the first preset speed value S1 (step S1104).
If the vehicle speed is lower than the second preset speed value S2, the microcomputer 11 checks if the present boosted voltage Vout is higher than a third preset value V3 (V3=70 V in this embodiment) of voltage (step S1105). If the boosted voltage Vout is higher than the third preset voltage value V3, the microcomputer 11 decreases the boosted voltage Vout by a quantity of a preset voltage value at a preset gradient (step S1106). Thus, the boosted voltage Vout decreases at a given gradient under the conditions that the vehicle speed is higher than the first preset speed value S1 but lower than the second preset speed value S2, and the boosted voltage Vout is higher than the third preset voltage value V3. If the boosted voltage Vout is lower than the third preset voltage value V3, viz., the answer to the step S1105 is NO, the microcomputer 11 advances to a step S1107 where it controls the boosted voltage Vout to the third preset voltage value V3.
If the vehicle speed is higher than the second preset speed value S2, the microcomputer 11 checks if the present boosted voltage Vout is higher than the first preset voltage value V1 (V1=12 V in this embodiment) (step S1108). If it is higher than the first preset voltage value V1, the microcomputer 11 decreases the boosted voltage Vout by a quantity of a preset voltage value at a preset gradient (step S1109). Thus, the boosted voltage Vout decreases at a preset gradient under the conditions that the vehicle speed is higher than the second preset speed value S2 and the boosted voltage Vout is higher than the first preset voltage value V1. When the boosted voltage Vout goes below the first preset voltage value V1, viz., the answer to the step S1108 is NO, the microcomputer 11 controls the boosted voltage Vout to the first preset voltage value V1.
If the steering wheel is not operated in the step S1101, the microcomputer 11 checks if a given time Δt elapses after the operation of the steering wheel is completed (step S1111). If it has not elapsed, the microcomputer 11 goes to the step S1102. If the time Δt elapses, the microcomputer 11 checks the vehicle speed (step S1112). If the vehicle speed is higher than the second preset speed value S2, the microcomputer 11 controls the boosted voltage Vout to the first preset voltage value V1 (step S113). If the vehicle speed is lower than the second preset speed value S2, the microcomputer 11 controls the boosted voltage Vout to the second preset value V2 (V2=20 V in this embodiment) (step S1114).
The boosted voltage Vout is adjusted dependent on a duty ratio command value outputted from the terminal B of the microcomputer 11, as a matter of course. If the duty ratio command value is reduced, the boosting operation of the boosting circuit 12 is held down. The boosted voltage Vout drops. Consequently, the consumption of energy in the boosting circuit 12 becomes small. When the duty ratio command value is set at 0, the boosting operation of the boosting circuit 12 stops. The boosted voltage Vout becomes equal to the battery voltage Vin. In the present embodiment, V1=Vin.
FIGS. 7A to 7C show variations of a steering signal (FIG. 7A), a vehicle speed signal (FIG. 7B), and a boosted voltage Vout (FIG. 7C). During a period of time from time t1 to t2, the steering wheel is not operated and the vehicle speed is 0. Then, the boosted voltage Vout is set at the second preset value V2 (=20 V). Under this condition, the boosted voltage Vout may be set at the first preset voltage value V1 (12 V). In this embodiment, V2 (second preset value), somewhat higher than V1 (first preset voltage value), is applied to the motor 7-1', in order to improve the response at the start of the steering operation.
At time t1, the steering wheel is operated. In response to the steering operation, the boosted voltage Vout rises to V4 (fourth preset voltage value) (100 V). This is because a large assist force is needed since the vehicle speed is 0 at this time. The vehicle speed increases and exceeds S1 (first preset speed value) (20 km/h) at time t2. The boosted voltage Vout drops at a preset gradient to V3 (third preset voltage value) (70 V). At this time, the vehicle is in a running state. The assist force which is smaller than that when the vehicle is standstill is required.
At time t3, the steering operation stops. At time t3' after the time duration Δt from the stop of the steering operation, the boosted voltage Vout drops to V2. The boosted voltage Vout is kept at V3 during a period of Δt after the steering operation terminates. Keeping of the boosted voltage Vout at V3 eliminates an unnatural feeling of the steering operation when the steering wheel is operated again at an early time immediately after the stop of the steering operation.
At time t4, the steering operation starts again. At this time, the vehicle speed is higher than S1. Then, the boosted voltage Vout is controlled to V3. When the vehicle speed decreases to below S1, the boosted voltage Vout is controlled to V4. At time t6, the steering operation stops. At time t6' after the time duration Δt from the stop of the steering operation, the boosted voltage Vout drops to V2.
The steering wheel is operated during a period between time t7 and t8. The boosted voltage Vout is kept at V4 during a period from t7 to t8' since the vehicle speed is lower than S1. At time t9, the steering operation starts again. The boosted voltage Vout is controlled to V3 since the vehicle speed is higher than S1 at this time t9. At time t10 the steering operation stops. At time t11 before a time duration Δt elapses from the time t10, the steering wheel is operated again. The boosted voltage Vout is kept at V3, while not dropping.
At time t12, the vehicle speed exceeds S2 (second preset speed value) (80 km/h). The boosted voltage Vout drops at a preset gradient to V1 (12 V). At this time, the vehicle speed is high, in excess of S2. The assist force may be controlled to zero, in order to secure a good vehicle stability. In this case, V1 is not always controlled et at 12 V, but it may be controlled in accordance with S2.
As described above, the vehicle power steering system of the present invention operates in the following manner. When a state of no steering operation continues for the time duration Δt, the boosted voltage Vout is reduced so long as a satisfactory response is secured. When the vehicle speed reaches S1 or S2, the boosted voltage Vout is decreased in accordance with the current vehicle speed. Accordingly, the boosting operation of the boosting circuit 12 is held down. The energy consumption by the boosting circuit 12 is controlled to the tolerable minimum, thereby realizing the energy saving.
In the above-mentioned embodiment, the presence or absence of the steering operation, and the vehicle speed are used for holding down the boosting operation of the boosting circuit 12. Examples of other suitable variables that may be used for the same purpose are steering wheel operating speed, steering wheel angle, vehicle yawing rate, lateral gravity acceleration, and such a steering condition as running mode.
Where any of those enumerated variables is used, the boosted voltage Vout is reduced when the steering wheel operating speed is slow, the steering wheel angle is small, the vehicle yawing rate is small, the lateral gravity acceleration is small, or a sport mode is set up.
(Operation of the microcomputer 11 according to a Third Embodiment)
The operation of the microcomputer 11 according to a third embodiment will be described in connection with some functions thereof.
The microcomputer 11 operates such that the computer increases the boosted voltage Vout as the current I (motor drive current) fed to the motor 7-1' increases, and decreases the boosted voltage Vout when the current I decreases. When a load of the motor 7-1' is small, viz., a large assist force is not required, the microcomputer holds down the boosting operation of the boosting circuit 12 to decrease the boosted voltage Vout. When the load of the motor 7-1' is increased, viz., a large assist force is required, the microcomputer 11 increases the boosted voltage Vout.
A process carried out by the microcomputer 11 of the third embodiment will be described with reference to a flowchart shown in FIG. 8.
The microcomputer 11 checks a motor drive current I received at the terminal H (step S2101). If the motor drive current I is above a preset value I1, the microcomputer 11 controls the boosted voltage Vout to a second preset value V2 (V2=100 V in this embodiment) (step S2102).
In the step S2101, if the motor drive current I is below the preset value I1, the microcomputer 11 checks if a state that the motor drive current I is below a preset value I1 continues for a preset time period Δt, viz., the motor drive current I of the preset value I1 or smaller continues for the time duration Δt or longer (step S2103). If the answer is NO, the microcomputer 11 goes to a step S2102. If the answer is YES, the microcomputer 11 decreases the boosted voltage Vout to the battery voltage Vin (step S2104).
The boosted voltage Vout is adjusted dependent on a duty ratio command value outputted from the terminal B of the microcomputer 11, as a matter of course. If the duty ratio command value is reduced, the boosting operation of the boosting circuit 12 is held down. The boosted voltage Vout drops. Consequently, the consumption of energy in the boosting circuit 12 becomes small. When the duty ratio command value is set at 0, the boosting operation of the boosting circuit 12 stops. The boosted voltage Vout becomes equal to the battery voltage Vin.
FIGS. 9A and 9B show a variation of the motor drive current I and a variation of the boosted voltage Vout, respectively.
During a period from time t0 to t1, no steering operation is performed, and the motor drive current I is below the preset value I1 Accordingly, the boosted voltage Vout is controlled to the battery voltage Vin.
Upon the start of the steering operation, the motor drive current I increases. When it exceeds the preset value I1 (at time t1), the boosted voltage Vout is increased to V2 (second preset value) (=100 V).
Upon the completion of the steering operation, the motor drive current I decreases to below the preset value I1 (at time t2). This state continues for the time duration Δt (time t2') or longer, and the boosted voltage Vout is reduced to the battery voltage Vin. In other words, after the motor drive current I decreases to below the preset value I1, the boosted voltage Vout is kept for the time duration Δt. With the thus timed operation, in the steering operation that is commenced again at an early time immediately after the previous steering operation ends, a natural feeling is secured in the steering operation.
The steering operation is commenced again and the motor drive current I increases to above the preset value I1 (at time t3). At this time, the boosted voltage Vout is increased to V2 (second preset value) as in the operation at time t1. Upon the completion of the steering operation, the motor drive current I decreases to below the preset value I1 (time t4). Before the time duration Δt elapses from time t4, the steering wheel is turned again. In other words, if the motor drive current I takes a value of I1 or larger during a period (Δt) from time t4 to time t4', the boosted voltage Vout does not decrease and is kept at V2.
Upon the completion of the steering operation, the motor drive current I decreases to below the preset value I1 (at time t5). This state continues for the time duration Δt (time t5') or longer, and the boosted voltage Vout is reduced to the battery voltage Vin.
As described above, in the vehicle power steering system of the present embodiment, if the motor drive current I continues for the time duration Δt or longer and increases to exceed I1 (preset value), the boosted voltage Vout is decreased to the battery voltage Vin. Accordingly, a wasteful consumption of energy in the boosting circuit 12 is minimized, thereby securing the energy saving.
In the above-mentioned embodiment, the motor drive current I is used for monitoring the load of the motor 7-1'. A motor rotational speed of the motor 7-1' or any other suitable variable may be used for the same purpose.
When the motor drive current I decreases to the preset value I1, the boosted voltage Vout is reduced to the battery voltage Vin in the above-mentioned embodiment. It may be reduced to another value of voltage, as a matter of course.
A single value, the preset value I1, is used for the reference value for the judgement of decreasing (increasing) the boosted voltage Vout in the embodiment. Alternatively, a plural number of reference values are used. In this case, the boosted voltage Vout is stepwise decreased (increased).
Further, such a modification that the boosted voltage Vout is increased as the motor drive current I increases and it is decreased as the current I decreases, is allowed.
In the above-mentioned embodments, the boosting circuit 12 using the coil L1 may be substituted by a boosting circuit using a transformer. In other words, the boosting circuit is not limited to the circuit arrangement of the boosting circuit 12 of the embodiment, but may be realized in any of other suitable circuits if it can set the boosted voltage at a desired value.
In the above-mentioned embodiments, the motor 7-1' is the DC brush motor. If required, a DC brushless motor may be used in place of the DC brush motor. A key portion of a circuit diagram of the MDPS when the DC brushless motor is used for the motor 7-1' is shown in FIG. 5. The MDPS uses a motor drive system which includes a motor drive circuit 13', and a transistor circuit 14 containing power transistors Tr11 to Tr16 and diodes D6 to D11. The motor drive system adjusts the current fed to a DC brushless motor 7-1". Where the DC brushless motor is used, there is no need of the replacement of the brush of the motor (the brush is replaced with a new one at the interval of the run of 2000 to 3000 km in a continuous operating condition). Accordingly, a long life of the motor is ensured with a high stability.
While the present invention has been described using the MDPS, the invention may be applied to the FEPS, as a matter of course. Further, the invention may be used irrespective of the type of motor vehicle, such as a motor vehicle driven by an internal combustion engine and an electric vehicle, and the type of the battery voltage, such as a 12 V battery and a 24 V battery.
In a case where the MDPS is assembled into the electric vehicle, a high voltage source as a vehicle drive source will be used for the motor for driving the pump. In this case, the technical idea of the present invention may be applied to the circuit for decreasing the voltage of the high voltage source, whereby the stabilization of the decreased voltage, the fail-safe function, and the energy saving are also realized as in the above-mentioned embodiments.
As seen from the foregoing description, in the invention, the battery voltage is increased, and a large motor torque can be produced using a small current. The size reduction of the motor specified for high voltage (e.g., 100 V) is realized, and the wires for electric connection are thinned. As a result, the cost of the overall system is reduced. The boosted voltage is little varied when the battery voltage varies. The assist force of the battery is insensitive to a variation of the battery voltage. A high accuracy control of the assist force is secured.
Also, in the first aspect of the invention, the boosted voltage Vout is kept at a fixed value of voltage, and it is little influenced by a variation of the battery voltage.
Further, in the first aspect of the invention, when the boosted voltage goes below a first preset voltage value V1, the boosted voltage Vout is decreased at the current decreasing rate of the battery voltage. As a result, a load to the battery is reduced, possibly quickening the restoration of the battery voltage to its normal level of voltage.
Still further, in the first aspect of the invention, when a state of the boosted voltage being below a first preset voltage value V1 continues for a time duration Δt or longer, the boosted voltage Vout decreases at a preset gradient. The assist force is naturally reduced without abrupt decrease thereof, thereby to secure the fail-safe.
Yet still further, in the first aspect of the invention, when the battery voltage goes below a second preset voltage value V2, the boosted voltage Vout decreases at a preset gradient. Accordingly, as the battery voltage drops below the second preset voltage value V2, the assist force is naturally reduced, thereby securing the fail-safe.
In the second aspect of the invention, when a state of no steering operation continues for a preset time duration, the boosting operation of the boosting circuit is held down to reduce the boosted voltage Vout. In this case, the boosting operation may be stopped, if necessary.
Also, in the second aspect of the invention, when the vehicle speed exceeds a preset value of speed, the boosting operation of the boosting circuit is held down to reduce the boosted voltage Vout. In this case, the boosting operation may be stopped, if necessary.
Further, in the second aspect of the invention, when a state of no steering operation continues for a preset time duration or the vehicle speed exceeds a preset value of speed, the boosting operation of the boosting circuit is held down to reduce the boosted voltage Vout. In this case, the boosting operation may be stopped, if necessary.
In the third aspect of the invention, when the load of the motor is indicated by a value above a preset value I1, the boosted voltage Vout applied to the motor is increased. When a load of the motor, indicated by a value below a preset value I1, continues for a preset time period Δt, the boosted voltage Vout is decreased. Also, the boosted voltage Vout varies in accordance with a load of the motor. When the load of the motor is small, viz., a large assist force is not required, the boosted voltage Vout is reduced. Accordingly, a wasteful consumption of energy in the boosting circuit is minimized, thereby securing the energy saving. | A vehicle power steering system for controlling an assist force which supplementally supports the steering operation, includes a motor for producing the assist force, a battery for supplying a current to the motor, a speed sensor for detecting a vehicle speed, a steering-wheel angle sensor for detecting an angle of a steering wheel, a circuit for adjusting the current fed from the battery to the motor according to the vehicle speed detected by the speed sensor and the angle of the steering-wheel detected by the steering-wheel angle sensor, a booster inserted in a current feed path to the motor for boosting a battery voltage of the battery to apply a boosted voltage to the motor. The vehicle power steering system further may include a boosted-voltage stabilizer for controlling the boosted voltage to a predetermined value through an operation of monitoring the boosted voltage. The vehicle power steering system further may include a boosted-voltage decreasing unit for decreasing the boosted voltage according to the drop rate of the battery voltage when the boosted-voltage decreasing unit detects that the boosted voltage is smaller than a first predetermined value through the operation of monitoring the voltage of the battery. | 1 |
PRIORITY APPLICATION
The present application is a continuation of U.S. patent application Ser. No. 10/839,368 filed on May 5, 2004, which is a continuation of U.S. patent application Ser. No. 09/863,286 filed on May 24, 2001, which is a continuation of U.S. patent application Ser. No. 08/888,014 filed on Jul. 3, 1997 (now U.S. Pat. No. 6,266,419 issued on Jul. 24, 2001) which is related to an application Ser. No. 08/888,009 entitled “Quality Degradation Through Compression/Decompression” by Jack B. Lacy and James H. Snyder, the contents of which are incorporated herein in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of computing. More particularly, the present invention relates to a method for protecting encoded media content for network distribution.
2. Discussion of Related Art
Recent technological advances involving digital data compression, network bandwidth improvement and mass storage have made networked distribution of media content more feasible. That is, media content, such as digitized music, can be conveniently distributed over the Internet. To protect the intellectual property rights associated with a particular piece of media content, it is desirable to obscure the media content to prevent pirating of the content.
Consequently, what is needed is a way for compressing media content for convenient network distribution, while also securing the compressed media content against unauthorized use.
SUMMARY OF THE INVENTION
The present invention provides a method for compressing media content for convenient public distribution, such as over a computer network, while also securing the media content for controlling distribution of the media content and for preventing unauthorized use of the media content. The advantages of the present invention are provided by a method of compressing media content in which a first predetermined portion of a media content is compressed using a first data-based compression algorithm and inserted into a first portion of a data frame. A second predetermined portion of the media content is compressed using a second data-based compression algorithm and is inserted into a second portion of the data frame. The second predetermined portion of the media content is different from the first predetermined portion of the media content, and the second data-based compression algorithm is different from the first data-based compression algorithm. Preferably, at least one of the first and second data-based compression algorithms is a private data-based compression algorithm. The first and second portions of the data frame are separated by a predetermined header code, or can be separated by relative positions of the first and second predetermined portions of compressed media content within the data frame.
The present invention also provides a method for inserting a data stream not associated with the media content into a compressed media content bit stream. The inserted data stream is carried by at least one symbol in at least one initial data set associated with the DBCA. A preferential implementation uses designated symbols in one or more Huffman codebooks for embedding a watermark in the compressed bit stream. The value of the watermark bits recovered from the bit stream depend upon either the values associated with the symbols or alternatively the position of the symbol in the compressed bit stream.
According to the invention, a plurality of data frames are generated and are made available for distribution, for example, by transmission over a computer network, such as the Internet. Alternatively, the data frames can be made publicly available for storage in a memory device, such as a CD ROM.
A plurality of predetermined portions of the media content can be compressed using data-based compression algorithms and grouped into a respectively different portion of the data frame. Each respective predetermined portion of the media content is different from the first and the second predetermined portions of the media content. Similarly, the data-based compression algorithm used to compress a respective portion of the media content is different from the first and the second data-based compression algorithms. Preferably, at least one of the data-based compression algorithms is a private data-based compression algorithm.
Initial data associated with each private data-based compression algorithm is encrypted and made publicly available when the data frames are made available. The encrypted initial data is grouped into a data envelope within a data frame that is preferably available no later than a first data frame containing media content compressed using the private data-based compression algorithm with which the encrypted initial data is associated, but can be made available during a later data frame. Examples of initial data associated with at least one private data-based compression algorithm include a Huffman code-book and/or a vector quantization code-book.
According to the invention, the media content can include audio content, such as music and/or speech, images, video content, graphics and/or textual content.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not limitation in the accompanying figures in which like reference numerals indicate similar elements and in which:
FIG. 1 shows a flow diagram for a media content compression process according to the present invention;
FIG. 2 shows an arrangement of data in a data frame according to the present invention; and
FIG. 3 shows a flow diagram for inserting a data stream not associated with the media content into a compressed media content bit stream according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a method for compressing media content for convenient distribution, such as over a computer network, while also securing the media content for controlling distribution of the media content and for preventing pirating of the media content. Compression algorithm, as used herein, is an algorithm that accepts an input data stream and produces a corresponding output data stream having substantially fewer bits. A data-based compression algorithm (DBCA) is an algorithm that is a subset of compression algorithms in general. The action of a DBCA, together with associated data, depends on a number of initial data values that have been determined before the compression operation begins (that is, without any knowledge of the particular input data sequence to be compressed). The initial data values may represent parametric values or may be used as lookup tables (i.e., as code-books) by the algorithm. Typical DBCAs are noiseless compression (e.g., Huffman) algorithms and vector quantization (VQ) algorithms. The initial data values may be static, i.e., the initial data values do not change, or dynamic, i.e., the initial data values adapt to the input data stream during the course of compression. Two DBCAs are different if the initial data values are different, whether the algorithms are different.
FIG. 1 shows a flow diagram of a media content compression-decompression process 10 according to the present invention. At step 11 , a media content, such as audio signals, are sampled using well-known analog-to-digital techniques, or the input may be a digital representation of an analog signal. At step 12 , the time-domain samples obtained in step 11 are converted to frequency-domain samples using well-known Fourier transform techniques.
At step 13 , a selected portion of the frequency-domain samples of the media content are compressed in a well-known manner using a publicly available DBCA, such as a DBCA having a public Huffman code-book as initial data. Each binary character code or token of the public DBCA represents at least one different quantized representation of the frequency-domain samples. When the media content is music, the selected portion of the frequency-domain samples that are compressed using the public DBCA corresponds to a selected frequency band of the audio content frequency spectrum, for example, 300 Hz to 3 kHz. In video transform coding, DC coefficients would be encoded with the standard table, while the AC coefficients would be encoded with the custom (private) table. The selected portion of the media content, according to the invention, may be null.
At step 14 , the remaining frequency-domain samples corresponding to the remainder of the audio content frequency spectrum are similarly compressed in a well-known manner using a private DBCA, that is, a DBCA in which the initial data is not publicly available. Examples of initial data for private DBCA include private Huffman code-books and private VQ code-books. Alternatively, the compression performed in steps 13 and 14 can be done by any well-known greedy-type algorithm that converts data into tokens or character codes, such as a VQ algorithm, as long as at least one of the two compression steps is performed by a private greedy-type algorithm. Of course, the present invention provides that the data compression of each step 13 and 14 can be performed by a private DBCA.
At step 15 , the tokens for the frequency-domain samples that were compressed using the public DBCA are inserted into a first predetermined portion 31 of a data frame 30 , shown in FIG. 2 . A data frame, as used herein, is an encapsulation of related data, for example, data associated with a given time period, frequency bandwidth, spatial domain or cepstral domain. A data envelope, as used herein, is an encapsulation of a subset of the data within a given data frame. For example, a data frame in a perceptual audio coder might contain a compressed representation of 1024 consecutive samples of audio data. A data envelope within that particular data frame might contain a representation of the frequency interval DC to 300 Hz. Encapsulation, as used here, may be explicit or implicit. An example of an explicit encapsulation is use of a predetermined character code or a header. An implicit encapsulation, that is, an encapsulation without a header, can be defined by relative positions of the encapsulated data within the data frame.
At step 16 , the tokens for the frequency-domain samples that were compressed using the private DBCA are inserted into a second portion 32 of data frame 30 . According to the invention, second portion 32 can be explicitly or implicitly encapsulated within data frame 30 . When second portion 32 is explicitly encapsulated within data frame, a header 33 formed by a predetermined character code or predetermined sequence of character codes containing information relating to the private DBCA, such as escape characters and/or the number of characters contained in second portion 32 .
At step 17 , the data frames are made publicly available, such as available for distribution by transmission in a well-known manner over a computer network, such as the Internet, or by storage in a user-owned storage device, such as a CD-ROM, at a point-of-sale device. In one embodiment of the present invention, the initial information associated with each private DBCA that is used is encrypted in a well-known manner using a secure encryption algorithm and is encapsulated in the data frames preferably no later than the first data frame containing media content compressed using the private DBCA with which the encrypted initial data is associated, but can be encapsulated during a later data frame. In another embodiment, the initial data for the public DBCA is made available with the encrypted initial data of the private DBCA. In yet another alternative embodiment, both the initial data for the public and the private DBCAs are available at the recipient of publicly available data frames 30 and are not distributed when the data frames 30 are distributed. Of course, for this embodiment, the encrypted initial data of the private DBCA is secure and is not accessible to unauthorized individuals. At step 18 , the data frames and any initial data are received by the intended recipient.
At step 19 , the tokens corresponding to the public DBCA in the first portion 31 of each data frame are decompressed using the public DBCA. At step 20 , the character codes corresponding to the private DBCA in the second portion 32 of each data frame are decompressed using the private DBCA. When the first portion 31 of each data frame has been compressed by a private DBCA, portion 31 of each data frame is decompressed accordingly. When encrypted initial information is encapsulated in the data frames, the initial information is decrypted prior to decompression using the private DBCA. At step 21 , the frequency-domain samples resulting from the decompression steps 19 and 20 are reassembled to form frequency-domain samples of the frequency spectrum of the media signal represented by each data frame. At step 22 , the frequency-domain samples are transformed to time-domain samples using well-known inverse Fourier transform techniques. At step 23 , the time-domain samples are converted to the media content using well-known digital-to-analog techniques.
When the initial data for the private DBCA is not known at step 20 , steps 21 - 23 operate on only the portion of the media content that was contained in the first portion 31 of the data frames. In this way, a limited version of the media content is generated that may entice the recipient to purchase the entire media content because the fidelity of the media content is not satisfying.
FIG. 3 shows a functional block diagram 40 of a system for inserting a data stream not associated with the media content into a compressed media content bit stream. Such a system may include a computing device that has the necessary hardware and software components or modules to carry out the functions identified in the functional blocks. A system, computing device or apparatus embodiment disclosure does not encompass software per se but includes the hardware components controlled thereby. Thus, a module or block that can be configured to perform a certain function in a system will include software and the controlled hardware component such as a processor, hard drive, display (if necessary, input capability, etc.). In block 41 , analog media content is quantized using well-known digital-to-analog quantizing techniques to for digitized media content. Alternatively, the input may already be a digital representation of an analog signal. In block 42 , the digitized media content is transformed from time-domain samples to frequency-domain samples using well-known Fourier transform and windowing techniques. In block 43 , the floating point frequency-domain samples are converted into integer values in a well-known manner. The quantizer output is applied to a custom, or private, DBCA at block 44 . A plurality of symbols are output to a bit stream formatter at block 45 which outputs a bitstream of compressed media content.
Functional blocks 41 - 45 correspond to steps of 11 - 16 of method 10 shown in FIG. 1 . Block 47 contains a data sequence as a string of bits that preferably represents watermark data, but can represent any information that is not associated with the media content. Block 48 contains control logic for selecting a watermark data site and sequencing watermark data bits into custom DBCA 44 , which emits symbols to the bitstream formatter 45 . According to the invention, private DBCA 44 can contain either a single data set (e.g., a single Huffman or VQ codebook) or a plurality of data sets (e.g., multiple Huffman or VQ codebooks). Control and timing 48 can be implemented in many ways. For example, if the bit rate coming out of bit stream formatter 45 is N bits/sec, and M watermark bits per second are desired to be inserted, and 1 bit per watermark site is inserted (without loss of generality), then timing and control 48 must insert a watermark bit on average every N/M bits coming out of bit stream formatter 45 . (Hence, the path connecting the output of bitstream formatter 45 to control and timing 48 .) In this case, timing and control 48 can be implemented as a reloadable downcounter that indicates an insertion when the downcounter reloads. In a more secure implementation, randomness can be incorporated into control and timing 48 using a pseudo-random number generator that causes an insertion on average every N/M bits.
More generally, private DBCA 44 may have a plurality of distinct Huffman codes devoted to watermarking, for example, k is equal to 2′ characters. Then, up to K watermark bits can be inserted per special Huffman symbol. For purposes of security, more than one Huffman symbol devoted to the same bit sequence might be chosen. In the case of K watermark bits per insertion, control and timing 48 causes an insertion on average every (N/M)*K bits. Alternatively, custom DBCA 44 may use one or more otherwise unused codebook indices for watermark insertion. For example, when control and timing 48 indicates an insertion, bitstream formatter 45 may put a watermark index and some predetermined number of bits into the bitstream.
In this case, the watermark index appears to indicate an unused codebook. Similarly, the position of the watermark index may be used to indicate the value of the watermark data, for example, if the index occurs in an odd-numbered section in the bitstream, a “1” bit would be indicated, whereas appearance of the index in an even-numbered section indicates a “0” bit.
While the present invention has been described in connection with media having an audio content, such as music and/or speech, it will be appreciated and understood that the present invention is applicable to media having audio and/or image and/or video and/or graph and/or textual content, and that modifications may be made without departing from the true spirit and scope of the invention. | An apparatus for compressing media content is disclosed. The apparatus divides the media content into at least three predetermined portions, compresses each of the at least three portions using one of at least three different compression algorithms and makes the at least three compressed predetermined portions publicly available. Making the portions publicly available includes, for example, transmitting the portions over a computer network such as the Internet. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This is a divisional of co-pending application Ser. No. 07/059,009 filed on Jun. 8, 1987, now U.S. Pat. No. 4,832,587.
FIELD OF THE INVENTION
The invention relates to a method and device for manufacturing bricks with smooth side surfaces.
DESCRIPTION OF THE RELATED ART
The mechanical manufacture of bricks with smooth side surfaces, so-called "Wasserstrichsteine" is not possible with the existing methods and on existing belt moulding-mould container machines. The problem is the discharging of the green brick out of the mould container. Since the side surfaces have to be smooth no releasing material can be used here for this purpose.
SUMMARY OF THE INVENTION
The invention has for its object to obviate this drawback and to enable the manufacture of said bricks on existing belt moulding systems. In accordance with the present invention the mould container is provided with a movable bottom. The mould container is washed, a layer of releasing material is placed in the container, and the container is filled with clay and trimmed off. In particular, only the bottom of the mould container is provided with the releasing material and the bottom is then moved so that it is virtually outside of the mould container. The device includes a circulating conveyor for supplying mould containers, a holder for releasing material, a holder for clay, means for carrying clay out of the holder and into the mould container, means for pressing the clay and trimming the mould container, and means for placing a drying plate onto the filled mould container. This device also includes a mechanism for displacing the bottom of the mould container and a mechanism for throwing up releasing material.
Since the bottom of the mould container is moved so as to be virtually outside the mould container, it is sufficient to have releasing material only on the bottom of the mould container. The friction force occurring between the walls of the mould container and the green brick are overcome by the outward pressure force applied to the bottom. Sand or sawdust, for example, can be used as releasing material.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is elucidated with reference to the annexed drawings of an embodiment.
In the drawings:
FIG. 1 shows a side view in diagrammatic form of the device for use with the method according to the invention,
FIGS. 2 and 3 show the pressing out of the bottom in the device as in FIG. 1,
FIG. 4 is a view on a larger scale of the part IV from FIG. 1,
FIG. 5 shows an alternative embodiment, and
FIG. 6 is detail VI from FIG. 5 on a larger scale.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The device according to the invention comprises a conveyor 1 which transports mould containers 4 in a circulating path consisting of an upper part 2 and a lower part 3. Using the press-on and trimming member 5 clay 6 is carried from holder 7 into the mould container. A gripper device 8 places a carrying plate 9 onto the filled mould container. Using the press-out mechanism 10 and the base shaft 11 attached to bottom 12, the bottom 12 is pressed outside mould container 4. As a result the green brick, carried by carrying plate 9, comes onto a support member 13 which then transfers the green brick to the conveyor 14.
Care should be taken in performing the method that only the bottom of the mould container is provided with releasing material, for example sand or sawdust. Present for this purpose is a control mechanism in the form of a circulating belt 15, which moves the base shaft 11 and therefore the bottom 12 outward in the proximity of the throw-up mechanism 16. At this location (FIG. 4) the bottom 12 is virtually flush with the upper surface of mould container 4. Arranged close to throw-up mechanism 16 are two guide plates 17 and 18. The throw-up mechanism consists of a pair of rotating arms 19 and 20 which move through the supply of releasing material 21 in container 22. As a result of the rotation movement the releasing material is thrown upward and, guided by guide plates 17 and 18, carried onto only the bottom 12. Because the mould container is first washed with water, the releasing material remains adhered to the bottom. The walls of the mould container are very moist as excessive water is used to rinse the mould container.
It is noted that two throw-up arms 16 and 23, which function in identical manner, are drawn in FIG. 4.
Since according to the invention the walls of the mould container are kept very moist there results a green brick with smooth side walls when pressing out takes place, the green brick releasing easily from the bottom as a result of the presence of releasing material on the bottom of the mould container.
FIG. 5 shows a second embodiment of the invention. By means of the dosing device 24 releasing material from a reservoir 25 is placed on the bottom of the mould container. A dosing device consists of a roller 27 rotating in the close proximity of the wall 26 of reservoir 25, the roller being provided on its surface with ribs 28 positioned at an interval from one another. The releasing material falls in a narrow band onto the bottom of the mould container while the latter moves beneath the slit-like opening between wall 26 and roller 27. Setting a dosing device into operation at the right moment by driving the roller 27 for rotation from the driving disc 29 ensures that the releasing material is applied only to the bottom of the mould container, while the walls of the mould container remain unaffected.
More particularly, the flow of releasing material from reservoir 25 of dosing device 24 is synchronized with the movement of the mould container therebelow, so that the releasing material falls in a narrow band onto the bottom of the mould container while the latter moves beneath the slit-like opening. By synchronizing the operation of the dosing device and the movement of the mould container, releasing material is prevented from reaching the side walls of the mould container. | A brick making device wherein clay is dispensed into moulds having sidewalls and a bottom movable relative to the sidewalls. A releasing material such as sand is dispensed by a rotating roller which intermittently forms a dispensing slit so that the releasing material is only applied to the mould bottom. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to coal feed locks and more particularly to apparatus for supplying coal to high pressure gas producers.
2. Description of the Prior Art
Typically, conventional coal feed locks for delivering coal to high pressure gas producers or gasifiers employ sealable transfer chambers. In operation, the coal is dropped or otherwise loaded into the transfer chamber and the chamber is then sealed from the atmosphere. The chamber is then placed in communication with the high pressure gas producer and the coal is allowed to flow into the gas producer.
Conventional coal feed locks of the type described suffer a number of important disadvantages which greatly limit their usefulness. Perhaps the most important disadvantage is that such locks permit large volumes of high pressure gas to escape to the atmosphere. The high pressure gas can escape in several ways. For example, gas may simply leak through the various seals of the lock. More importantly, each time a measured amount of coal is transferred to the gas producer, the transfer chamber fills with high pressure gas. This gas is released to the atmosphere prior to or during the refilling of the transfer chamber with coal and thus is lost.
Additionally, prior art coal locks require large amounts of head room. Further, since very high pressures are involved, the moving parts of these coal locks tend to become unbalanced, causing excessive wear and resulting in increased high pressure gas loss and increased maintenance costs.
A number of prior art devices exist that can deliver metered portions of a material from a bulk supply of the material. Examples of such prior art devices can be found in the following U.S. Pat. Nos. 2,893,609; 2,914,223; 3,172,578; 3,394,850; 3,794,234.
SUMMARY OF THE INVENTION
In accordance with a preferred embodiment of the invention, a coal feed lock for transferring coal to a high pressure gas producer is provided. The coal feed lock includes a housing having a coal charging port and a coal discharging port. Rotatably mounted within the housing is a rotor member which has a bore therethrough. The bore is rotatable from a coal charging position in coaxial alignment with the charging port to a coal discharging position in coaxial alignment with the coal discharging port. A piston element, confined by and slidable within the bore, and activated by a source of high pressure water, discharges coal through the discharge port.
According to the present invention, a coal feed lock is provided that overcomes the disadvantages associated with the prior art systems described above. The coal feed lock of the invention is provided with shallow grooving surrounding the discharge port to the coal gasifier. A source of water that is maintained at a higher pressure than the gas in the gasifier is connected to the shallow grooving. Consequently, any leaks about the discharge port will be water and not gas leaks.
The coal feed lock of the invention prevents high pressure gas from escaping after each load of coal is delivered to the gasifier. As the piston pushes the coal in the bore into the gasifier, the piston simultaneously decreases the volume of the bore exposed to the high pressure gas. Thus, little or no high pressure gas is trapped in the bore as the bore is brought out of communication with the gasifier. When the bore is realigned with the charging port, the trapped gas, if any, escapes to the atmosphere.
The coal feed lock of the invention requires less head room than conventional devices. Consequently, the gasifier and coal feed lock combination can be used where height restrictions would prevent use of conventional systems.
A further advantage of the invention is that the coal feed lock has only two moving parts. Thus, maintenance requirements due to part wear is reduced. A further fact reducing maintenance requirement is the static balance system that is provided. This static balance system uses high pressure water to counteract the forces placed on the coal feed lock by the high pressure gas.
Additional features and advantages of the invention will be set forth in, or apparent from, the detailed description of the preferred embodiments of the invention found hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view illustrating the loading mode of the coal feed lock in accordance with the invention;
FIG. 2 is a cross-sectional view taken generally along line 2--2 of FIG. 1; and
FIG. 3 is a cross-sectional view illustrating the discharge mode of the coal feed lock of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is depicted the preferred embodiment of coal feed lock 10. Coal feed lock 10 includes a housing 12 having a generally cylindrical shape, as depicted in FIGS. 1 and 2 in composite. Housing 12 has a plurality of ports. These include a coal charging port 22 and a coal discharging port 24.
Housing 12 also includes a high pressure water intake port 26 and a water discharge port 28. Intake port 26 extends through the cylindrical wall of housing 12 at a location which is diametrically opposite coal discharge port 24. High pressure water intake port 26 is attachable to a source of high pressure water (not shown) that is generally maintained at a pressure of about 10psi above the gas pressure in the gasifier.
Water discharge port 28 extends through the cylindrical wall of housing 12 and is diametrically opposite coal charging port 22. Port 28 is adapted to be connected to a water sump or alternatively to a vacuum source in combination with a water sump.
Housing 12 includes a plurality of shallow grooves 30 that surround coal discharging port 24. These shallow grooves can form concentric circles (FIG. 1) about discharging port 24 or alternatively can extend radially from discharging port 24. Further, a combination of concentric and radial grooves can be used. These grooves are connectable to the high pressure water source described hereinabove.
Further, housing 12 is provided with a plurality of support legs 32. As depicted in FIG. 1, support legs 32 extend downwardly from housing 12 in the vicinity of water discharge port 28. However, depending on the geometry of the gasifier and coal storage bins, support legs can be positioned at various locations on housing 12.
Housing 12 can be formed of cast metal. Alternatively, housing 12 can be formed of metal plates that are welded or bolted together. Further, other techniques used to design and make pressure vessels, such as various metal or fiber spinning techniques, can be employed.
Rotor member 16 is rotatably mounted in housing 12. Member 16 is generally circular in cross section and includes a bore 18 therethrough. As depicted in FIG. 2, rotor member 16 can be I-shaped in diametrical cross-section with bore 18 formed along a diameter of member 16. This I-shape construction reduces the overall weight of member 16, making member 16 easier to rotate. Alternatively, rotor member 16 can have a generally right circular cylindrical shape with bore 18 therethrough. It is noted that generally the same construction techniques employed in constructing housing 12 are employed to fabricate rotatable member 16.
Located inside bore 18 is a shaft 34 that extends the entire length thereof. As depicted in FIG. 1, shaft 34 is dependent from a plate 40 placed at end 36 of bore 18. Plate 40 has apertures 42. A piston 20 is slidably mounted on shaft 34 so that piston 20 can slide from end 36 to end 38 of bore 18. Piston 20 preferably comprises a disc-like construction including a central hub 21 which rides on shaft 34 and an outer annular wall engaging flange 23.
Further, rotor member 16 has a plurality of drive pins 44 extending therefrom. A drive motor (not shown) for rotating member 16 engages member 16 by means of drive pins 44.
The operation of coal feed lock 10 in combination with a source of coal, a source of high pressure water and a high pressure gas producer or gasifier is as follows. Rotor member 16 is rotated until end 38 of bore 18 is in coaxial alignment with coal charging port 22. A measured amount of coal from the supply of coal is allowed to pass through coal charging port 22 into bore 18. The coal fills bore 18 and pushes piston 20 to a position adjacent the opposite end 36 of bore 18. When bore 18 has been filled with coal, rotor member 16 is rotated until end 38 of bore 18 moves into coaxial alignment with coal discharging port 24 and end 36 of bore 18 moves into fluid communication with high pressure water port 26. As has been previously noted, the source of high pressure water is preferably pressurized to at least 10 psi above the gas pressure in the gasifier. Thus, water flows through apertures 42 in disc 40, forcing piston 20 toward end 38 (FIG. 3) and the coal in bore 18 through coal discharging port 24 into the gasifier. Piston 20 stops adjacent end 38 of bore 18.
Next, rotor member 18 is rotated back into coaxial alignment with coal charging port 22. The minimal amount of high pressure gas trapped in bore 18 is released to the atmosphere. It can be appreciated, however, that a small amount of gas trapped in bore 18 is desirable. This small amount of high pressure gas expands to a volume equal to that of the incoming coal when the gas escapes through coal charging port 22. This expansion purges air from the coal so that little or no oxygen is introduced into the high pressure gasifier.
As end 38 of bore 18 registers with coal charging port 22, end 36 of bore 18 comes into fluid communication with water discharge or suction port 28, which drains water from bore 18.
It should be noted that high pressure water port 26 performs an additional function of statically balancing rotor member 16 in housing 12. The pressure exerted on rotor member 16 counteracts and approximately balances the pressure exerted on member 16 through coal discharging port 24 from the gasifier. This balancing prevents excessive wear of member 16.
The water behind piston 20 prevents high pressure gas from leaking between piston 20 and bore 18. It is also noted that since the aforementioned shallow grooves 30 that surround coal discharging port 24 are also connected to the source of high pressure water, any leakage between housing 12 and rotor member 16 will be water and not gas. It is possible that some small amounts of water can be forced into the gasifier, but this would not detrimentally affect the operation of the gasifier. On the other hand, the escape of gas to the atmosphere reduces the operational efficiency of the gasifier.
It is comtemplated that four coal feed locks 10 can be driven by the same variable speed motor. The drive linkage can be arranged so that feed locks 10 can cycle in sequence. Thus, the various flow of materials such as the coal and the high pressure water would virtually be continuous.
Although the present invention has been described relative to the exemplary embodiment thereof, it will be understood by those skilled in the art that variations and modifications can be effected in these embodiments without departing from the scope and spirit of the invention. | A coal feed lock is provided for dispensing coal to a high pressure gas producer with nominal loss of high pressure gas. The coal feed lock comprises a rotor member with a diametral bore therethrough. A hydraulically activated piston is slidably mounted in the bore. With the feed lock in a charging position, coal is delivered to the bore and then the rotor member is rotated to a discharging position so as to communicate with the gas producer. The piston pushes the coal into the gas producer. The rotor member is then rotated to the charging position to receive the next load of coal. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to a method for manufacturing an aromatic polyester resin.
2. Description of the Related Art:
Aromatic polyester resins have extensively been used as industrial materials because of their excellent heat-resistance, high strength, and high modulus. A known manufacturing method thereof is polycondensation of a combination of, for example, an aromatic diol and an aromatic dicarboxylic chloride; an aromatic diol and an aromatic dicarboxylic ester; acetate esters of an aromatic diol and an aromatic dicarboxylic acid, and the like in an organic solvent.
This method has the advantages of difficulty in handling of unstable aromatic dicarboxylic chloride, high cost of the polyester resins resulting from the expensive starting materials, and the high temperature necessary for the transesterification.
SUMMARY OF THE INVENTION
The present inventors have comprehensively investigated methods for manufacturing an aromatic polyester resin starting from stable, easy-to-handle, and inexpensive starting materials, and have accomplished the present invention.
The present invention provides a method for manufacturing an aromatic polyester resin represented of the general formula: ##STR2## wherein Ar 1 is a bivalent aromatic radical which may be, for example, one selected from the group of ##STR3## provided that X is ##STR4## or X may be absent (single bond);
Ar 2 is a bivalent aromatic radical which may be, for example, one selected from the group of ##STR5## provided that X is --CH 2 -- or --O--; and n is an integer of 10 to 100, comprising a reaction of an aromatic diol represented by the general formula:
HO--Ar.sup.1 --OH (II)
wherein Ar 1 is a bivalent aromatic radical which may be, for example, one selected from the group of ##STR6## provided that X is ##STR7## or X may be absent;
with an aromatic dibromide represented by the general formula:
Br--Ar.sup.2 --Br (III)
wherein Ar 2 is a bivalent radical which may be, for example, one selected from the group of ##STR8## provided that X is --CH 2 --, or --O--; and
carbon monoxide in the presence of a palladium catalyst and an organic base in an organic solvent.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is described below in more detail. The typical aromatic diols represented by the above general formula (II) include resorcinol, hydroquinone, 9,9-bis(4-hydroxyphenyl)fluorene, 2,2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl) ether, bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl) sulfone, 3-(4-hydroxyphenyl)-1,1,3-trimethyl-5-indanol, 1,4-naphthalenediol, 1,5-naphthalenediol, 2,6-naphthalenediol, 4,4'-dihydroxybiphenyl, etc. Other aromatic diols and diol mixtures, however, may also be used.
The typical aromatic dibromides represented by the above general formula (III) include m-dibromobenzene, p-dibromobenzene, bis(3-bromophenyl)methane, bis(4-bromophenyl)methane, 1-bromo-3-(4-bromobenzyl)benzene, bis(3-bromophenyl) ether, bis-(4-bromophenyl) ether, 1-bromo-3-(4-bromophenoxy)benzene, 2,5-dibromothiophene, 2,5-bis(4-bromophenyl)-3,4-diphenylthiophene, etc. Other aromatic dibromides and dibromide mixtures, however, may also be used. Although an aromatic diiodide may be used in place of an aromatic dibromide, the aromatic diiodides are expensive, so that their use is not profitable from an economical point of view.
The organic bases include aprotic amine bases, for example imines and tertiary amines, such as tributylamine, 4-dimethylaminopyridine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene, 1,4-diazabicyclo [2.2.2]octane, and the like.
The aromatic polyester resin represented by the general formula (I) is manufactured through the reaction of an aromatic diol of the general formula (II), an aromatic dibromide of the general formula (III), and carbon monoxide in the presence of a palladium catalyst and an organic base in an organic solvent. The specific examples of the organic solvents employed are amide type solvents such as dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, tetramethylurea, and hexamethylphosphoramide; aromatic solvents such as benzene, toluene, xylene, nitrobenzene, benzonitrile, and chlorobenzene; ether type solvents such as dibutyl ether, tetrahydrofuran, dioxane, and di(methoxyethyl) ether; and dimethyl sulfoxide, pyridine, etc.
The palladium catalysts employed in the present invention are exemplified by halides, organic acid salts, and inorganic acid salts of palladium. Specifically, the examples are palladium acetate, palladium chloride, palladium bromide, palladium iodide, palladium sulfate, and complexes of these palladium componds with phosphine compounds such as dichlorobis(triphenylphosphine)palladium, dibromobis(triphenylphosphine)palladium, diiodobis(triphenylphosphine)palladium, dichlorobis(tritolylphosphine)palladium, dibromobis(tritolylphosphine)palladium, diiodobis(tritolylphosphine)palladium, chlorophenylbis(triphenylphosphine)palladium, bromophenylbis(triphenylphosphine)palladium, and tetrakis(triphenylphosphine) palladium.
The amount of the palladium catalyst to be used is in the range of from 0.01 mole % to 10 mole %, preferably from 0.1 mole % to 5 mole % based on the aromatic diol and the aromatic dibromide. Combined use of triphenylphosphine with the palladium catalyst frequently gives favorable results. Triphenylphosphine is generally used in amounts of about 1 to 10 moles, preferably 2 to 5 moles per mole of catalyst used.
The amount of carbon monoxide to be used in the present invention is twice that of aromatic diol and the aromatic dibromide in molar ratio, but a larger amount is generally employed.
The aromatic polyester resin represented by the above general formula (I) is manufactured by reacting an aromatic diol of the general formula (II), an aromatic dibromide of the general formula (III), and carbon monoxide in the presence of a palladium catalyst and an organic base in an organic solvent. Specifically, an aromatic diol, an aromatic dibromide, a palladium catalyst, and an organic base are first dissolved in an organic solvent. The solution is made to react by agitating in an atmosphere of carbon monoxide at a temperature from about 50° C. to about 250° C., preferably 80° C. to 200° C. As the reaction proceeds, the viscosity of the reaction mixture increases. The agitation is continued usually for 3 hours to 24 hours; in some case, the reaction goes to completion within an hour. The reaction mixture is treated with methanol, acetone, water or the like to separate the aromatic polyester resin after the completion of the reaction.
The polymerization degree n is limited to be within the range of from 10 to 100 in the above formula (I) because with n of 10 or less, the polymer does not exhibit satisfactory properties while with n of 100 or more the polymer has disadvantages in solubility and other properties.
Other features of the invention will become apparent in the course of the following descriptions of exemplary embodiments which are given for illustration of the invention and are not intended to be limiting thereof.
EXAMPLES
EXAMPLE 1
In 10 ml of chlorobenzene, 0.8200 g (2.5 mmol) of bis(4-bromophenyl) ether, 0.5707 g (2.5 mmol) of 2,2-bis(4-hydroxyphenyl)propane, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.5 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 1.1163 g (99%)
Reduced Viscosity: 0.51 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
Elemental analysis
Calculated: C: 77.32%, H: 4.92%;
Found: C: 75.44%, H: 4.79%.
EXAMPLE 2
In 10 ml of chlorobenzene, 0.5898 g (2.5 mmol) of 1,4-dibromobenzene, 0.5707 g (2.5 mmol) of 2,2-bis(4-hydroxyphenyl)propane, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.5 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.8928 g (100%)
Reduced Viscosity: 0.32 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 3
In 10 ml of chlorobenzene, 0.5898 g (2.5 mmol) of 1,3-dibromobenzene, 0.5707 g (2.5 mmol) of 2,2-bis(4-hydroxyphenyl)propane, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.5 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.8062 g (90%)
Reduced Viscosity: 0.20 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 4
In 10 ml of chlorobenzene, 1.3658 g (2.5 mmol) of 2,5-bis(4-bromophenyl)-3,4-diphenylthiophene, 0.5707 g (2.5 mmol) of 2,2-bis(4-hydroxyphenyl)propane, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.7 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 1.6553 g (99%)
Reduced Viscosity: 0.50 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 5
In 10 ml of chlorobenzene, 0.2949 g (1.25 mmol) of 1,3-dibromobenzene, 0.2949 g (1.25 mmol) of 1,4-dibromobenzene, 0.5707 g (2.5 mmol) of 2,2-bis(4-hydroxyphenyl)propane, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 2.1 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.7305 g (82%)
Reduced Viscosity: 0.30 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 6
In 10 ml of chlorobenzene, 0.6049 g (2.5 mmol) of 2,5-dibromothiophene, 0.5707 g (2.5 mmol) of 2,2-bis(4-hydroxyphenyl)propane, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 17.5 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.5512 g (61%)
Reduced Viscosity: 0.18 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 7
In 10 ml of chlorobenzene, 0.8200 g (2.5 mmol) of bis(4-bromophenyl) ether, 0.2753 g (2.5 mmol) of resorcinol, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.5 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.7878 g (95%)
Reduced Viscosity: 0.35 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 8
In 10 ml of chlorobenzene, 0.5898 g (2.5 mmol) of 1,3-dibromobenzene, 0.2753 g (2.5 mmol) of resorcinol, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 2.6 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.4807 g (80%)
The polymer thus obtained was insoluble in solvents, and its reduced viscosity could not be determined.
EXAMPLE 9
In 10 ml of chlorobenzene, 0.5898 g (2.5 mmol) of 1,4-dibromobenzene, 0.2753 g (2.5 mmol) of resorcinol, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 2.6 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.4242 g (71%)
The polymer thus obtained was insoluble in solvents, and its reduced viscosity could not be determined.
EXAMPLE 10
In 10 ml of chlorobenzene, 0.2949 g (1.25 mmol) of 1,3-dibromobenzene, 0.2949 g (1.25 mmol) of 1,4-dibromobenzene, 0.2753 g (2.5 mmol) of resorcinol, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 2.6 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.4668 g (78%)
Reduced Viscosity: 0.17 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 11
In 10 ml of chlorobenzene, 1.3658 g (2.5 mmol) of 2,5-bis(4-bromophenyl)-3,4-diphenylthiophene, 0.2753 g (2.5 mmol) of resorcinol, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.5 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 1.3628 g (99%)
Reduced Viscosity: 0.39 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 12
In 10 ml of chlorobenzene, 0.8200 g (2.5 mmol) of bis(4-bromophenyl) ether, 0.8760 g (2.5 mmol) of 9,9-bis(4-hydroxyphenyl)fluorene, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.9 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 1.4172 g (99%)
Reduced Viscosity: 0.42 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 13
In 10 ml of chlorobenzene, 0.5898 g (2.5 mmol) of 1,3-dibromobenzene, 0.8760 g (2.5 mmol) of 9,9-bis(4-hydroxyphenyl)fluorene, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.8 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 1.0981 g (91%)
Reduced Viscosity: 0.18 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
Example 14
In 10 ml of chlorobenzene, 0.5898 g (2.5 mmol) of 1,4-dibromobenzene, 0.8760 g (2.5 mmol) of 9,9-bis(4-hydroxyphenyl)fluorene, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.8 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 1.1431 g (95%)
Reduced Viscosity: 0.27 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 15
In 10 ml of chlorobenzene, 0.2949 g (1.25 mmol) of 1,3-dibromobenzene, 0.2949 g (1.25 mmol) of 1,4-dibromobenzene, 0.8760 g (2.5 mmol) of 9,9-bis(4-hydroxyphenyl)fluorene, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 2.0 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 1.1118 g (93%)
Reduced Viscosity: 0.23 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 16
In 10 ml of chlorobenzene, 1.3658 g (2.5 mmol) of 2,5-bis(4-bromophenyl)-3,4-diphenylthiophene, 0.8760 g (2.5 mmol) of 9,9-bis(4-hydroxyphenyl)fluorene, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.9 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 1.9576 g (99%)
Reduced Viscosity: 0.54 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 17
In 10 ml of chlorobenzene, 0.8200 g (2.5 mmol) of bis(4-bromophenyl) ether, 0.6709 g (2.5 mmol) of 1,1,3-trimethyl-3-(4-hydroxyphenyl)-5-indanol, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.6 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 1.1770 g (96%)
Reduced Viscosity: 0.34 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
Example 18
In 10 ml of chlorobenzene, 0.5898 g (2.5 mmol) of 1,3-dibromobenzene, 0.6709 g (2.5 mmol) of 1,1,3-trimethyl-3-(4-hydroxyphenyl)-5-indanol, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.8 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.7593 g (76%)
Reduced Viscosity: 0.19 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
Example 19
In 10 ml of chlorobenzene, 0.5898 g (2.5 mmol) of 1,4-dibromobenzene, 0.6709 g (2.5 mmol) of 1,1,3-trimethyl-3-(4-hydroxyphenyl)-5-indanol, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.3 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.8353 g (84%)
Reduced Viscosity: 0.23 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
Example 20
In 10 ml of chlorobenzene, 0.2949 g (1.25 mmol) of 1,3-dibromobenzene, 0.2949 g (1.25 mmol) of 1,4-dibromobenzene, 0.6709 g (2.5 mmol) of 1,1,3-trimethyl3-(4-hydroxyphenyl)-5-indanol, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 2.3 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.8678 g (87%)
Reduced Viscosity: 0.21 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 21
In 10 ml of chlorobenzene, 1.3658 g (2.5 mmol) of 2,5-bis(4-bromophenyl)-3,4-diphenylthiophene, 0.6709 g (2.5 mmol) of 1,1,3-trimethyl-3-(4-hydroxyphenyl)-5-indanol, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.3 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 1.7448 g (98%]
Reduced Viscosity: 0.34 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 22
In 10 ml of chlorobenzene, 0.8200 g (2.5 mmol) of bis(4-bromophenyl)ether, 0.5055 g (2.5 mmol) of bis(4-hydroxyphenyl)ether, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.8 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 1.0368 g (98%)
Reduced Viscosity: 0.08 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
EXAMPLE 23
In 10 ml of chlorobenzene, 0.5898 g (2.5 mmol) of 1,3-dibromobenzene, 0.5055 g (2.5 mmol) of bis(4-hydroxyphenyl)ether, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.7 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.8129 g (98%)
The resulting polymer was insoluble in solvents, and thus the reduced viscosity of the polymer could not be determined.
EXAMPLE 24
In 10 ml of chlorobenzene, 0.5898 g (2.5 mmol) of 1,4-dibromobenzene, 0.5055 g (2.5 mmol) of bis(4-hydroxyphenyl)ether, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 2.3 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.7190 g (87%)
The resulting polymer was insoluble in solvents, and thus the reduced viscosity of the polymer could not be determined.
EXAMPLE 25
In 10 ml of chlorobenzene, 0.2949 g (1.25 mmol) of 1,3-dibromobenzene, 0.2949 g (1.25 mmol) of 1,4-dibromobenzene, 0.5055 g (2.5 mmol) of bis(4-hydroxyphenyl) ether, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 2.9 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 0.7326 g (88%)
The resulting polymer was insoluble in solvents, and thus the reduced viscosity of the polymer could not be determined.
EXAMPLE 26
In 10 ml of chlorobenzene, 1.3658 g (2.5 mmol) of 2,5-bis(4-bromophenyl)-3,4-diphenylthiophene, 0.5055 g (2.5 mmol) of bis(4-hydroxyphenyl)ether, 0.8373 g (5.5 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, 0.0702 g (0.10 mmol) of dichlorobis(triphenylphosphine)palladium, and 0.0525 g (0.20 mmol) of triphenylphosphine were dissolved, and were agitated in an atmosphere of carbon monoxide at a pressure of 1 atmosphere at 115° C. for 1.3 hours. The resulting solution was diluted with 40 ml of chlorobenzene, and was poured into 450 ml of methanol to obtain a polyester which was washed with hot methanol.
Yield: 1.5908 g (99 %)
Reduced Viscosity: 0.69 dl/g (in o-chlorophenol at a concentration of 0.5 g/dl at 30° C.)
The process of the present invention is highly useful because the aromatic dibromides employed instead of the conventional aromatic dicarboxylic chlorides are stable and easily handled which facilitate the operations in purification of the starting materials and practice of the polymerization, and enables the economical manufacture of polyester resins.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | A process for manufacturing an aromatic polyester resin represented by the general formula: ##STR1## wherein Ar 1 and Ar 2 represent a bivalent aromatic radical and n is an integer of 10 to 100, comprising reacting an aromatic diol represented by the general formula:
HO-Ar.sup.1 -OH
wherein Ar 1 is a bivalent aromatic radical with a bivalent dibromide represented by the general formula:
Br-Ar.sup.2 -Br
where Ar 2 is a bivalent radical and with carbon monoxide in the presence of a palladium catalyst and an organic base in an organic solvent. | 2 |
This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/EP01/04576 which has an International filing date of Apr. 23, 2001, which designated the United States of America and which claims priority on European Patent Application number 001 09 543.9 filed May 4, 2000, the entire contents of which are hereby incorporated herein by reference.
FIELD OF THE INVENTION
The present invention generally relates to an arrangement for a fluid-flow machine. In particular, the present invention generally relates to a steam turbine, for sealing a gap between a movable component and a stationary component, of which one carries a grazing layer on a surface flanking the gap.
BACKGROUND OF THE INVENTION
In machines for treating and processing flowing, liquid and/or gaseous media, gaps between movable and stationary components are often to be sealed off from the flowing medium. This also applies in particular to turbines to which steam is admitted, in which a gap is sealed off between a rotor and a casing surrounding the latter in order to block the path of the steam past blade rings. The quality of these seals has a considerable effect on the efficiency of these machines, thus in particular also in the case of steam turbines.
Sealing strips arranged axially one behind the other—also called labyrinth seals—are normally used for this purpose in steam turbine construction. These seals are characterized by sealing strips which are arranged transversely to the flow and which virtually completely close a gap which is usually several millimeters wide. In this case, it is accepted that the sealing strips sometimes graze the component opposite them during transient processes and become slightly worn themselves at the same time. Such labyrinth seals are used in turbine construction both at blading and as piston and shaft seals.
A special form of these seals which has the same effect is a honeycomb seal. This seal, on one side of the gap, usually on the side fixed to the casing, has a structure which reproduces a honeycomb and on whose open surface a leakage flow is prevented by a multiplicity of small vortices in chambers formed by the honeycomb structure. A flow resistance produced as a result prevents a free flow in the passage defined by the honeycomb-like structure on one side.
U.S. Pat. No. 4,177,004 discloses a turbine in which a gap between a turbine blade and a ring enclosing the latter in the circumferential direction and suspended in a casing is to be sealed off. This arrangement is designed in such a way that the turbine blade itself occasionally grazes the ring enclosing it. In order to avoid impending damage in this case, the ring is coated with a material which causes no wear on the turbine blade.
However, both in the known labyrinth seals and in the arrangement according to U.S. Pat. No. 4,177,004, contact between the surfaces of the components moving along one another occurs only very rarely. This is because the components involved are at such a large distance from one another that contact actually takes place only occasionally during extremely transient states. On the other hand, the result of this is that—apart from the rare moments of the contact between the components—there is a gap through which a proportion of a working medium, which proportion is not to be disregarded, flows past the turbine blade without being utilized.
SUMMARY OF THE INVENTION
An object of an embodiment of the present invention is to reduce the quantity of working medium flowing past the turbine blade without being utilized for example steam—without the need for special apparatus and without impairing the operating reliability.
An object of an embodiment of the present invention is achieved according to the present invention in that a component flanking a gap to be scaled, in the region of the gap, carries a grazing layer which is designed as a porous coating which can be at least partly abraded from the component opposite it. By the use of a porous grazing layer in combination with sealing strips opposite it, the favorable properties of a labyrinth seal and of a honeycomb seal are combined with one another. Due to the penetration of the scaling strips, which is possible without risk, into the coating opposite it, the effectiveness of the sealing arrangement is substantially enhanced. As a result, a marked improvement in the sealing capacity is achieved in a surprisingly simple and efficient manner.
A further advantage of an embodiment of the present invention relates to thermoshock resistance. The thermoshock resistance is increased by the porosity and which, with increasing proportion of cavities, is in addition accompanied by increasing flexibility of the coating.
In an embodiment of the present invention, the surface opposite the coating has at least one sealing lip, which is arranged parallel to the direction of movement of the movable component. The at least one sealing lip closes the gap, projects like a cutting edge and includes a sealing strip which penetrates slightly into the coating during movement of the component and partly abrades the coating in the process. The thickness of the coating is equal to 0.5 to 0.1 times the width of the gap flanked by it.
According to an embodiment of the present invention, the coating is applied by spraying together with a bonding agent and is made of a foamed, preferably metallic, material. As one alternative to this, the coating contains a mixture of a mineral and a metallic component and/or a gasifiable or vaporizable component. According to another composition of the coating, it contains granular material proportions, after the at least partial removal of which from the coating the latter has recesses on its surface.
Irrespective of its respective specific embodiment, the coating may be arranged on the stationary component flanking the gap. It is sometimes also expedient to fit both sides of the gap with sealing strips and to provide both sides of the gap—that is both that of the stationary component and that of the moving component—with a coating and with sealing lips.
An additional manner of realizing an embodiment of the present invention includes configuring these surfaces in a steplike manner in the radial direction on one side or on both sides on surfaces flanking the gap.
To avoid damage when the sealing strips are penetrating into the coating opposite them in each case, the sealing strips may be narrowed at their free ends. One example is narrowing the sealing strips at their free ends down to 0.2 to 0.5 mm.
The combination of features according to an embodiment of the present invention can advantageously be used without restriction, optimum gap sealing being achieved while operating reliability is ensured at the same time.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 illustrates a sectional representation on an enlarged scale through a sealing strip in engagement with a layer according to an embodiment of the present invention;
FIGS. 2 , 3 and 4 illustrate an arrangement of an embodiment of the present invention with a gap between a casing and a shaft;
FIG. 5 illustrates an arrangement of an embodiment of the present invention with a gap between a guide blade ring and a shaft; and
FIG. 6 illustrates an arrangement of an embodiment of the present invention with a gap between a casing and a moving blade ring.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Parts corresponding to one another are provided with the same designations in all the figures.
In FIG. 1 , two components 1 and 2 of a steam turbine (not shown in any more detail) form a gap 3 up to several millimeters wide, which is sealed off from a steam flow. The component 1 is preferably a rotor part movable in the operating state and has a groove 4 for accommodating a sealing strip 5 serving as sealing lip. The sealing strip 5 is L-shaped in cross section and rests with its leg, which is shorter in cross section, on the base of the groove 4 . The sealing strip 5 includes one or more sections complementing one another in the circumferential direction to form a ring and is secured in the groove 4 by a calking wire 6 .
The component 2 opposite the component 1 on the other side of the gap 3 is preferably stationary in the operating state and has a coating designed as a grazing layer 7 . The coating may have a thickness corresponding to 0.5 to 0.1 times the width of the gap 3 and is made of a porous or foamy material, for example a foamed metal or a mixture of a mineral and a metallic component and/or contains a gasifiable or vaporizable component.
According to a further possible embodiment of the present invention, the coating may include a mixture which contains a granular component which can be removed from the surface of the coating, so that its surface is then formed by a multiplicity of recesses adjoining one another.
All of these embodiments for the coating may be expediently applied together with a bonding agent to the component 1 and/or 2 carrying them, the most expedient method often being to spray the coating on.
A leg 8 , facing the coating, of the scaling strip 5 of L-shaped cross section grazes the coating and is narrowed at its end plunging slightly into the coating. As a result, the energy demand during grazing or penetration of the sealing strip 5 into the coating is restricted to a very low value. In its narrowed region, the thickness of the scaling strip 5 is about 0.2 mm and is approximately of the order of magnitude of the width of a passage 9 which is formed between the sealing strip 5 and the grazing layer 7 represented by the coating and through which a leakage flow 10 of steam flows.
In this case, the flow resistance for the leakage flow 10 in the passage 9 is not simply determined only by its length and its cross section, but is significantly increased by the unevenness in the surface of the coating. This is achieved by virtue of the fact that, even inside the short passage 9 and despite its comparatively narrow cross section, a multiplicity of small and very small vortices are forced inside the leakage flow in this region. This is a result in particular of an embodiment according to the present invention of the coating applied as grazing layer 7 .
At larger pressure differences between the start and the end of the gap 3 , a multiplicity of sealing strips 5 and thus passages 9 are connected one behind the other in this gap 3 , so that a sufficiently small and reliably controllable pressure drop is allotted to each of the individual passages 9 . Some exemplary embodiments for this are shown in FIGS. 2 to 6 .
FIGS. 2 to 4 show various solutions for the sealing of the gap 3 between the stationary component 2 of a turbine casing (not shown in any more detail) and a turbine shaft as rotating, thus moving, component 1 . Here, in these three examples, the casing-side, stationary component 2 is provided with a coating as grazing layer 7 . In the example according to FIG. 4 , the moving surface of the shaft, as moving component 1 , also carries a coating.
In the solution according to FIG. 3 , sealing strips 5 are anchored solely in the shaft, as the moving component 1 , these sealing strips 5 penetrating slightly into the opposite grazing layer 7 . Since the passages 9 formed between the sealing strips 5 and the grazing layer 7 lie one behind the other on a straight line in this embodiment, this arrangement is also designated as a see-through seal.
The arrangements according to FIGS. 2 and 4 have sealing strips 5 in both the component 1 and the component 2 , each of these sealing strips 5 extending in the gap 3 between the two adjacent components 1 , 2 in the direction of the respectively opposite component 1 or 2 . However, since only the component 2 is provided with a grazing layer 7 in the solution in accordance with FIG. 2 , the effect according to an embodiment of the present invention is only achieved for the sealing strips 5 in the opposite component 1 . On the other hand, in the solution in accordance with FIG. 4 , each of the sealing strips on both sides of the gap 3 interacts with a porous coating as grazing layer 7 .
FIG. 5 shows a seal between a turbine shaft as moving part 1 and a shroud band 11 , the shroud band 11 supporting ends of guide blades 12 . In this case, that side of the shroud band 11 which faces the gap 3 is designed to be stepped and carries a coating as grazing layer 7 on its sectional surfaces oriented parallel to the axis. At least one sealing strip 5 is opposite each step of the shroud band 11 . The shroud band 11 is composed of segments which together produce a complete ring in the circumferential direction of the turbine shaft.
FIG. 6 shows a seal between a casing part as stationary component 2 and a shroud band 13 which supports the ends of moving blades 14 against one another. That side of the shroud band 13 which faces the component 2 is designed to be stepped and each of the axially parallel step surfaces is provided with a coating as grazing layer 7 . A sealing strip 5 is again opposite each strip, formed as a result, of the grazing layer 7 . The shroud band 13 is also composed of segments which complement one another to form a complete ring.
All the grazing layers 7 interact with their opposite sealing strips 5 in the manner described for FIG. 1 .
Although coatings configured according to the invention and used as grazing layer 7 especially suitable for use in steam turbines, they may also be advantageously used in the same way in all other fluid-flow machines.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | In fluid machines frequently gaps between movable and stationary structural parts have been sealed off. Frequently so-called labyrinth packings are used, whereby sealing strips brush against the opposite structural part. To this end, a brush layer is configured as a porous coating that can be detached from the opposite structural part. The inventive system can be advantageously used in virtually any fluid machines. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 098143955 filed in Taiwan, Republic of China on Dec. 21, 2009, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The invention relates to a pointing device.
[0004] 2. Related Art
[0005] In the information era, computers have become indispensible articles for daily use. In practice, the keyboard and mouse are commonly used to serve as the human-machine interfaces for communicating the user and computer.
[0006] The present mouse includes a sensor disposed at the bottom side of the mouse, so that when the user slides the mouse on a plane, the cursor displayed on the screen can be moved correspondingly. Accordingly, the user can control the movement of the cursor by moving the mouse, for example, to point an icon, and click the button of the mouse to execute one of various programs of the computer corresponding to the icon.
[0007] However, the user needs to hold the mouse and slide it on a plane to make the sensor at the bottom side of the mouse sense the sliding direction and distance so that the cursor on the screen can move correspondingly. So, when the user operates the mouse, a plane of a certain area is necessary for allowing the mouse to slide thereon, which may cause restriction on usage.
[0008] On the other hand, the touch control feature is easier for operation and more intuitive for users. Besides, with the progress of touch technology, more and more electronic apparatuses are equipped with touch control interface as the human-machine interface.
SUMMARY OF THE INVENTION
[0009] In view of the foregoing, an object of the invention is to provide a pointing device that contains touch control feature, so that it is not necessary to provide a plane of a certain area for operating the pointing device, so as to improve the application convenience thereof.
[0010] To achieve the above object, a pointing device according to the invention includes a covering material and a touch sensing unit. The covering material is at least made of a flexible material. The touch sensing unit is buried in the covering material and has two touch sensing surfaces.
[0011] In an aspect of the invention, the covering material is sealed.
[0012] In an aspect of the invention, the touch sensing unit is of a capacitance type or a resistive type.
[0013] In an aspect of the invention, the touch sensing surfaces are located at different planes.
[0014] In an aspect of the invention, the pointing device further comprises a feedback unit. When the covering material is touched or pressed to enable the touch sensing unit to generate a touch sensing signal, the feedback unit generates a feedback signal.
[0015] In an aspect of the invention, the pointing device further comprises a proximity sensing unit disposed between the touch sensing surfaces. When the covering material is pressed to change the interval between the touch sensing surfaces, the proximity sensing unit correspondingly generates a sensing signal.
[0016] As mentioned above, in the pointing device of the invention, the covering material covers the touch sensing unit and is at least made of a flexible material, and the touch sensing unit is buried in the covering material and has two touch sensing surfaces. Thus, the user can hold the pointing device and touch or press it to execute functions of, for example, moving the cursor, clicking the button, dragging the page, turning the page, etc. Therefore, the user just holds the pointing device to operate it. In other words, the pointing device can control the movement of the cursor without the operation of sliding on a plane of a certain area, so that the user can use the pointing device more conveniently. In addition, in some embodiments, the touch sensing surfaces of the pointing device are configured to enable different functions. For example, one of the touch sensing surfaces can enable the function of clicking button, and the other can enable the functions of moving the cursor, dragging, and turning the page. Hence, the pointing device of the invention can make more fun for usage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention will become more fully understood from the detailed description and accompanying drawings, which are given for illustration only, and thus are not limitative of the present invention, and wherein:
[0018] FIG. 1A is a schematic view of a pointing device according to a preferred embodiment of the invention, and FIG. 1B is a schematic view showing an enlargement of a portion of the pointing device;
[0019] FIGS. 2A and 2B are schematic views of the touch sensing circuit of the pointing device of the preferred embodiment of the invention;
[0020] FIG. 3 is a schematic diagram showing the situation of using the pointing device of the preferred embodiment of the invention; and
[0021] FIGS. 4 to 6 are schematic diagrams of the pointing devices of various aspects according to the preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
First Embodiment
[0023] FIG. 1A is a schematic view of a pointing device 1 according to a preferred embodiment of the invention, and FIG. 1B is a schematic view showing an enlargement of a portion of the pointing device 1 . In the embodiment, the pointing device 1 means the device serving as a human-machine interface, and for example, it can replace the mouse. The pointing device 1 includes a covering material 11 and a touch sensing unit 12 .
[0024] The covering material 11 is at least made of a flexible material. The covering material 11 of the embodiment is shaped like a plate for example, and it can be bent to any desired angle. Otherwise, the covering material 11 can be made like other shapes.
[0025] The touch sensing unit 12 is buried in the covering material 11 and has two touch sensing surfaces 121 and 122 . The touch sensing unit 12 can also be made of a flexible material. In this embodiment, the covering material 11 is sealed. The covering material 11 can be combined with the touch sensing unit 12 by injection molding or insert molding, so that the covering material 11 can tightly cover the touch sensing unit 12 . That is, the covering material 11 can directly contact the touch sensing surfaces 121 and 122 . The distance D from the exterior surface 112 of the covering material 11 to the touch sensing surfaces 121 or 122 can be smaller than 5 mm. Because the covering material 11 is very thin, the operation of the touch sensing surfaces 121 and 122 will not be hindered. Otherwise, the covering material 11 and the touch sensing unit 12 can be separately manufactured and then assembled with each other. In another aspect, the covering material 11 can be unsealed. The touch sensing unit 12 of this embodiment can be of a capacitance type or a resistive type.
[0026] The touch sensing unit 12 can further include a flexible circuit board 123 , and the touch sensing surfaces 121 and 122 are disposed at two opposite sides of the flexible circuit board 123 respectively. To be noted, the touch sensing unit 12 can have a plurality of flexible circuit boards 123 , and the touch sensing surfaces 121 and 122 are disposed on the flexible circuit boards 123 respectively. Each of the touch sensing surfaces 121 and 122 can have at least a touch sensing circuit, and the touch sensing circuit can be, for example, a single-layer circuit (see FIG. 2A ) or a double-layer circuit. Besides, the touch sensing circuit can also be a matrix double-layer circuit (see FIG. 2B ).
[0027] When the covering material 11 is touched or pressed, the touch sensing unit 12 can correspondingly generate a touch signal, which can be transmitted through a wired transmission or a wireless transmission. Here the touch signal is transmitted through a wireless transmission for example. Otherwise, the pointing device 1 can transmit the touch signal through a wire (not shown).
[0028] Accordingly, as shown in FIGS. 1A and 3 , when the user holds the pointing device 1 (for example, the thumb of the user is located at the side of the touch sensing surface 121 , and the other fingers are located at the side of the touch sensing surface 122 ), the user can control the thumb to touch or press the touch sensing surface 121 . Then, the touch sensing surface 121 senses the clicking and moving of the thumb and thus the cursor displayed on the screen can move correspondingly, so that the computer can execute the function through the operation of the user. As for the touch sensing surface 122 , it can sense the clicking and moving of the fingers as the same way of the touch sensing surface 121 when the user touches or presses the touch sensing surface 122 with the finger(s). Therefore, during the operation of the pointing device 1 , the user just holds it. In other words, the pointing device 1 can control the movement of the cursor without the operation of sliding on a plane of a certain area, so that the usage of the pointing device 1 can be more convenient.
[0029] Furthermore, the touch sensing surfaces 121 and 122 can be defined to enable different functions. For example, the touch sensing surface 121 operated by the thumb can be defined to enable the movement of the cursor; the touch sensing surface 122 operated by the other fingers can be defined to enable the clicking of the button (when the finger clicks or presses it), the dragging or turning of the page (when the finger slides). To be noted, the functions of the touch sensing surfaces 121 and 122 can be changed. For example, the touch sensing surface 121 may control the function of clicking the button, dragging the page or turning the page, and the touch sensing surface 122 may control the function of moving the cursor. Besides, the functions corresponding to the touch sensing surfaces 121 and 122 can be preset in the pointing device 1 , or updated or changed through the firmware.
[0030] Besides, the pointing device 1 can further include a feedback unit (not shown). When the covering material 11 is touched or pressed to enable the touch sensing unit 12 to generate a touch sensing signal, the feedback unit generates a feedback signal. The feedback signal can be an optic feedback signal (e.g. the variation of the brightness or color displayed by the pointing device 1 ), a vibrational feedback signal (e.g. the vibration generated at the pressed location or that generated on the pointing device 1 ), or an acoustic feedback signal (e.g. the various sounds outputted by the pointing device 1 or the sound device of the computer to indicate the operation of clicking or sliding by the user).
[0031] FIG. 4 is a schematic diagram of the pointing device 1 a of another aspect. As shown in FIG. 4 , the covering material 11 a of the pointing device 1 a can have at least a bending portion 111 . In the embodiment, the covering material 11 a is illustrated to have two bending portions 111 , and thus the cross-section of the pointing device 1 a in FIG. 4 is similar to U shape. Of course, the cross-section of the pointing device 1 a can have different shapes.
[0032] Because the flexible circuit board 123 a is flexible, the touch sensing surfaces 121 and 122 can be disposed at two opposite sides of the pointing device 1 a , and that is, the touch sensing surfaces 121 and 122 are disposed at different planes. Besides, the touch sensing circuit is usually not disposed at the bending portions 111 that connect the planes, so that the touch sensing circuit just exists at an upper side and a lower side of the flexible circuit board 123 a. Otherwise, the touch sensing surfaces 121 and 122 can be disposed on different flexible circuit boards or inflexible printed circuit boards (PCB). In this case, the touch sensing surfaces 121 and 122 can be connected with each other by an electric connection element.
[0033] FIG. 5 is a schematic diagram of the pointing device 1 b of another aspect. As shown in FIG. 5 , the covering material 11 b of the pointing device 1 b has a single bending portion 111 b, and thus the cross-section of the pointing device 1 b is similar to C shape. Similarly, the touch sensing unit 12 b is buried in the covering material 11 b , and the covering material 11 b forms a chamber C. Besides, the pointing device 1 b here can transmit the touch signal through a wire L. To be noted, those skilled in the art can design various different structures according to the above-mentioned pointing devices 1 a and 1 b.
[0034] FIG. 6 is a schematic diagram of the pointing device 1 c of another aspect. As shown in FIG. 6 , the covering material 11 c of the pointing device 1 c is solid and the touch sensing unit 12 c is also buried in the covering material 11 c. Besides, the pointing device 1 c can further include a proximity sensing unit 13 which is disposed between the touch sensing surfaces 121 and 122 . That means, the proximity sensing unit 13 can be disposed on one surface of the flexible circuit board 123 c away from the touch sensing surfaces 121 and 122 , or disposed inside the covering material 11 c and located between the touch sensing surfaces 121 and 122 . The proximity sensing unit 13 can be of a capacitance type or an inductive type.
[0035] Thus, when the covering material 11 c is pressed by the finger or the palm of the user to change the interval between the touch sensing surfaces 121 and 122 , the proximity sensing unit 13 correspondingly generates a sensing signal which can be transmitted through a wired transmission or a wireless transmission. Accordingly, the user can operate the pointing device 1 c through the action of pressing. Therefore, the functions of the pointing device 1 c can be increased and the user can have more operation methods.
[0036] In summary, in the pointing device of the invention, the covering material covers the touch sensing unit and is at least made of a flexible material, and the touch sensing unit is buried in the covering material and has two touch sensing surfaces. Thus, the user can hold the pointing device and touch or press it to execute functions of, for example, moving the cursor, clicking the button, dragging the page, turning the page, etc. Therefore, the user just holds the pointing device to operate it. In other words, the pointing device can control the movement of the cursor without the operation of sliding on a plane of a certain area, so that the user can use the pointing device more conveniently. In addition, in some embodiments, the touch sensing surfaces of the pointing device are configured to enable different functions. For example, one of the touch sensing surfaces can enable the function of clicking button, and the other can enable the functions of moving the cursor, dragging, and turning the page. Hence, the pointing device of the invention can make more fun for usage.
[0037] Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention. | A pointing device includes a covering material and a touch sensing unit. The covering material is at least made of a flexible material. The touch sensing unit is buried in the covering material and has two touch sensing surfaces. The pointing device contains the touch control feature, so that it is not necessary to provide a plane of a certain area for operating the pointing device, so as to improve the application convenience thereof. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Indian provisional application No. 1473/MUM/2006, filed on Sep. 15, 2006, the disclosure of which is incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to an improved process for the production of gibberellic acid by fermentation techniques. The present invention in particular relates to the production and optimization of gibberellic acid with strains of Fusarium moniliforme by submerged or solid state fermentation.
BACKGROUND OF THE INVENTION
[0003] Gibberellic acid (GA 3 ) is the most important gibberellin, a class of diterpenoid acids that function as plant growth regulators (Jefferys, E. G., Adv. Appl. Biol. 13:283-316 (1970)). GA 3 affects stem elongation, elimination of dormancy, flowering, sex expression, enzyme induction and leaf and fruit senescence. GA 3 is a high-value, industrially-important, biochemical with various applications in agriculture (L. M. Pastrana et al., “Interactions affecting gibberellic acid production in solid-state culture: A factorial study”; Enzyme and Microbial Technology 17:784-790 (1995), citing to Kumar, P. K. R., and Lonsane, B. K., Appl. Microbiol. Biotechnol. 34:145-148 (1990)). However, its high cost has restricted its use to premium crops (Jefferys, E. G., Adv. Appl. Biol. 13:283-316 (1970)).
[0004] GA 3 has been obtained by chemical synthesis, extraction from plants and by microbial fermentation. Stereospecific chemical synthesis involves multiple steps and the use of expensive reagents. To date, chemical synthesis is not economically competitive with fermentation techniques. Direct extraction of GAs from higher plants is not economically feasible due to extremely low concentration of GAs in plant tissue. A large number of bacteria, actinomycetes and yeast cultures have been reported to produce GA 3 or GA 3 -like substances, but most do not produce GA 3 at commercially-feasible levels. Today, GA 3 is produced by fermentation, mostly from fungi.
[0000] Fermentation Methods
[0005] GA 3 production in fungal culture includes liquid surface fermentation, submerged fermentation, and solid state fermentation.
[0000] Liquid Surface Fermentation (LSF)
[0006] Liquid surface fermentation (LSF), often referred to as surface fermentation, was employed in earlier years for the production of GA 3 but suffered from low yield (e.g. 3.3-9.2 g of crude powdered GA 3 from 130 liters of medium) problems with scalability, contamination and more, and was discontinued (P. K. R. Kumar and B. K. Lonsane, “Microbial production of Gibberellins: state of the art” in Advances in Applied Microbiology. 34: 29-140 (1989)).
[0000] Submerged Fermentation (SmF)
[0007] Currently, GA 3 is largely produced by submerged fermentation (SmF) of the fungus Gibberella fujikuroi . The fungus known as Fusarium moniliforme is also used; F. moniliforme is the anamorph (asexual stage) of Gibberella fujikuroi . GA 3 is also synthesized from several bacteria such as Azotobacter , and Azospirillium in culture medium and from wild strains of fungi such as Sphaceloma sp., Phaeosphaeria sp., and Neurospora sp.
[0008] The initial pH values generally employed by various workers are within the range 3.5-5.8, especially around pH 5.5. Id. pH was not usually controlled during fermentation and thus resulted in a final pH differing from the starting pH, with reports of the final pH of 3.9-5.2, 1.8-1.9, or even slight alkalinization. Id.
[0009] The effect of temperature on the production of GA 3 is dependent on the strain employed. The optimal temperatures reported for the production of GA 3 using G. fujikuroi or F. moniliforme include 25° C.; 28.5-29.5° C.; 30° C.; 34° C.; 29 ± 0.5° C.; 27° C.; and 28° C. (See Id.)
[0010] Different workers have used a variety of carbon sources for the production of GAs, as reported by different authors. A combination of readily and slowly metabolizable carbon sources gave a higher yield of GA 3 . Id. Use of molasses led to decreased but economically useful yields. Id. There was a 49% decrease in the yield of GAs with stearic acid as compared to sucrose. Use of dairy waste as carbon source resulted in 0.75 g GA 3 /liter in 12 days. The production was completely inhibited by 1 ppm geraniol due to total inhibition of cell growth. A direct proportional relationship has been shown between the initial concentration of nitrogen supplied in the medium and the rate of product formation as well as the amount of metabolite produced. Id. See also Jefferys, E. G., Adv. Appl. Biol. 13:283-316 (1970)
[0011] Trace elements such as Fe, Cu, Mn, Zn, Al and Ca are required in the fermentative production of GAs. Id. Trace elements may be expressly added in excess or in combination, as in Raulin-Thom medium, or sufficient trace elements may be present as impurities in other ingredients of the fermentation medium. Id.
[0012] Other growth factors such as vitamins or Yeast extract may improve yield; while other heavy metals or the use of lines steel or stainless steel fermentation tanks can decrease yield. Id.
[0013] Various processes for production of GA 3 are described in U.S. Pat. Nos. 2,842,051, 2,865,812, 2,906,671, 2,906,673 and 3,021,261. U.S. Pat. No. 2,865,812 reported a yield of 630 mg/L in 664 hrs. Eleazar et al. (“Optimization of gibberellic acid production by immobilized Gibberella fujikuroi mycelium in fluidized bioreactors”, Journal of Biotechnology, 76, 147-155 (2000)) reported yields by submerged fermentation as high as 2.862 g/L.
[0000] Solid Substrate Fermentation (SSF)
[0014] SSF (Solid Substrate Fermentation) is defined as any fermentation process performed on a non-soluble material that acts both as physical support and source of nutrients, in the absence of free flowing liquid. No free-moving water is present, but there is enough moisture present for the growth and metabolism of the microorganism. The low moisture content means that fermentation can only be carried out by a limited number of microorganisms, mainly yeasts and fungi, although some bacteria have been used. Work on the production of GAs using SSF technique was initiated in the early 1980s and the initial studies gave variable yields. No information was available on the economics of the process until early 1987. Three cases were examined wherein the yield of GA 3 under the SSF technique were 0.825, 1.05 and 1.54 g/kg of Dry Mouldy Bran. The yield of GA 3 in the fed-batch SSF Process was 1.54 g/kg of Dry Mouldy Bran as compared to 1.05 g/kg of Dry Mouldy Bran in the batch SSF process. Id. One group reported a yield of 3 g/kg by SSF (Bandelier, S., Renaud, R., and Durand, A., “Production of Gibberellic acid by Fed-batch solid state fermentation in an aseptic pilot-scale reactor”, Process Biochemistry, 32:141-145 (1997)). B. Tudzynski (“Biosynthesis of gibberellins in Gibberella fujikuroi : biomolecular aspects”; Appl. Microbiol Biotechnol (1999) 52:298-310) reported that German Patent Number DD252000 also described processes for GA 3 by submerged fermentation, and reported yields of 8 g/kg.
[0000] Art-Known Fermentation Techniques Remain Expensive
[0015] Despite advances in fermentation technology, the cost of production of GA 3 has been a deterrent to its widespread use. Additional cost considerations include problems in the downstream processing and, given the potency of GA 3 to plants, removal and disposal of contaminated wastewater.
SUMMARY OF THE INVENTION
[0016] The inventors of the present invention have developed a process to manufacture GA 3 with Fusarium moniliforme by submerged and solid state fermentation and have been successful in obtaining yields over 15 g/L in submerged fermentation, and over 200 g/kg in solid state fermentation.
[0017] In one embodiment of the present invention, GA 3 is produced by solid state fermentation using various substrates such as wheat bran and Jatropha seed cake, to which mineral salts are added under high moisture content. The mixture is further inoculated with F. moniliforme and incubated for 10 days and the content of the mixture is analyzed for GA 3 . GA 3 is isolated by adjusting the aqueous dilution of the mixture to acidic pH, and extracting using an organic solvent. The organic solvent is distilled and the GA 3 obtained is dissolved in ethanol.
[0018] In another embodiment of the present invention, GA 3 is produced by submerged fermentation by culturing F. moniliforme in Czapek-Dox media containing a carbon source, and incubating for 10 days.
[0019] The present invention has provided industrially-viable processes for the manufacture of GA 3 by fermentation processes such as solid-state fermentation or submerged fermentation. The present invention has in particular provided an improved, cost-effective process for the manufacture of GA 3 , as the process has a surprisingly high yield of product, achieves the maximal yield in shorter time than other techniques, consumes less energy, and works with very inexpensive substrates. In all the manufacturing costs are significantly reduced.
[0020] In one embodiment, the present invention has focused on production and optimization of gibberellic acid by Fusarium moniliforme using various fermentation techniques.
[0021] The present disclosure provides GA 3 produced either by submerged or solid-state fermentation (SSF) technique. In certain embodiments, the submerged fermentation is carried out in reconstituted Czapek-Dox broth whereas solid-state fermentation is done on a humid solid matrix.
[0022] In another embodiment, the present invention relates to the use of microorganism belonging to the genus Gibberella , including Gibberella fujikuroi or Fusarium moniliforme.
[0023] Production of GA 3 is influenced by cultural conditions. In certain embodiments, high yields of GA 3 are obtained by varying factors, such as pH, temperature, incubation time, and other conditions such as optimization of the fermentation media.
[0024] In another embodiment, the present invention may use humid solid matrices substrates such as wheat bran or Jatropha seed cake.
[0025] In another embodiment, the production process of GA 3 by submerged fermentation involves incubating the fungi in liquid media containing various minerals, sodium nitrate as the nitrogen source, and sucrose as the carbon source.
[0026] In another embodiment, the present invention has optimized the pH conditions for submerged fermentation. The process of the present invention provides an optimal pH in the range of 5-8. In one embodiment, the pH is pH 7.0
[0027] In another embodiment, the present invention has optimized the temperature conditions for submerged fermentation. The present invention provides an optimal temperature ranging between 25° C. (room temperature) to 37° C. In one embodiment, the temperature is 30° C.
[0028] In another embodiment, the present invention has optimized the carbon source for submerged fermentation. In one embodiment, the carbon source is sucrose or glucose.
[0029] In another embodiment, the present invention has optimized the media for submerged fermentation. In one embodiment, the medium is reconstituted Czapek-Dox medium.
[0030] In still another embodiment, the present invention provides a process for production of GA 3 by solid-state fermentation. In one embodiment, this involves growing fungi on wheat bran supplemented with a mineral salts solution.
[0031] In the case of GA 3 production in SSF, factors that affect yield include temperature, pH, moisture, substrate particle size, light, autoclave timing, incubation period, amount and age of inoculum.
[0032] GA 3 was produced by submerged or solid-state fermentation (by free or immobilized cells, respectively). We observed that the yield from solid-state fermentation was as high as 39 g/kg using wheat bran as a substrate, and 237.2 g/kg, when using of Jatropha seed cake as substrate. To the best knowledge of the inventors, the GA 3 yields of the present invention are higher than any reported, by any mode of fermentation. For example, only one previous report provides a yield as high as 19.3 g/kg of GA 3 , which was obtained using starch (corn flour) as substrate (Gelmi et al. (“Solid substrate cultivation of Gibberella fujikuroi on an inert support”; Process Biochemistry. 35: 1227-1233 (2000), citing to Qian et al., ( World J. Microbiol Biotechnol. 10:93-98, (1994))).
[0033] A comparison of the present invention with conventional methods was performed. GA 3 produced by the present invention by submerged is greater than 3-fold higher than the highest yield reported in the literature; and by solid-state fermentation greater than 10-fold higher. The present process has demonstrated a yield greater than 15 g/L by submerged fermentation, and greater than 225 g/kg by solid state fermentation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present disclosure, the inventions of which can be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.
[0035] FIG. 1 : Production of GA 3 production (g/kg) by F. moniliforme in SSF using Jatropha seed cake as the substrate.
[0036] FIG. 2 : Illustrates GA 3 production in g/L and biomass, as determined by OD at 600 nm, for Fusarium moniliforme grown by submerged fermentation in commercial Czapek-Dox broth.
[0037] FIG. 3 : Illustrates the effect of pH on GA 3 production (g/L) and biomass (OD at 600 nm) by F. moniliforme in submerged fermentation in commercial Czapek-Dox broth.
[0038] FIG. 4 : Illustrates the effect of temperature on GA 3 production by F. moniliforme in submerged fermentation in Czapek-Dox broth.
[0039] FIG. 5 : Illustrates the effect of carbon source on GA 3 production by F. moniliforme in submerged fermentation in Czapek-Dox broth. No growth was observed when acetic acid was used as the carbon source.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0040] As used herein the term GA 3 or gibberellic acid refers to gibberellic acid with the molecular weight of 346.38 g/mol.
[0041] As used herein the term “solid state fermentation (SSF)” includes a process wherein the microbial growth and formation of product on and inside a humid solid matrix is in the absence of free water. This is also known as “solid substrate fermentation.
[0042] As used herein the term “submerged fermentation” includes a process wherein microbe is grown in a liquid medium and the product is secreted into the media.
[0043] The mineral salts solution used in the present invention comprises copper sulphate, ferric chloride and zinc sulphate.
[0044] Czapek-Dox (Himedia-M076) media contains the following components (per liter)
sucrose—30 g sodium nitrate—3 g dipotassium phosphate—1 g magnesium sulphate—0.5 g potassium chloride—0.5 g ferrous sulphate—0.01 g distilled water—1000 ml
[0052] In one embodiment, the Czapek-Dox media is reconstituted rather than commercially purchased. Reconstituted Czapek-Dox media is prepared by adding all components individually in water at the same concentrations as that of commercially available media.
[0053] One substrate used in the present invention is Jatropha seed cake. Jatropha is grown for its oil, which is extracted after crushing the seeds. Typically, seeds are ground to uniform sized particles and oil is extracted by Soxhlet extraction using Hexane as a solvent. Jatropha seed cake “with oil” means that the seeds have been crushed, but before the oil has been extracted. Seed cake “without oil” refers to seed cake left over after oil extraction, from which more than about 95% of the oil has been removed.
[0000] Solid State Fermentation
[0054] The present disclosure provides an improved process for the production of GA 3 either by submerged fermentation or solid state fermentation.
[0055] In one embodiment, GA 3 production via solid state fermentation comprises the following steps:
[0056] a) Preparation of solid substrate mixture;
[0057] b) Inoculation with F. moniliforme culture;
[0058] c) Incubation;
[0059] d) Extraction of GA 3 ; and
[0060] e) Purification.
[0061] In certain embodiments, the solid-state substrate used in the present invention is wheat bran (50 g) or Jatropha seed cake (5 g) to which is added mineral salt solutions (30 ml and 8 ml, respectively) under high moisture content and then autoclaved in the flasks. In one embodiment, autoclaved substrate is inoculated with F. moniliforme culture in Czapek-Dox broth.
[0062] In one embodiment, incubation of the substrate is done at temperatures ranging between 25-37° C. and analyzed for GA 3 content, at periodic intervals, using a spectrophotometric method (Berrios et al. (Spectrophotometric method for determining Gibberellic acid in fermentation broths. Biotechnology Letters, 26: 67-70 (2004)), high-pressure liquid chromatography (HPLC) and/or thin-layer chromatography (TLC). In TLC the culture filtrate obtained after fermentation was subjected to extraction and purification as described above. The residue obtained was dissolved in ethanol and separated by thin layer chromatography using isopropanol-ammonia-water (10:1:1, v/v/v) as mobile phase. The plates were sprayed with 3% sulphuric acid in methanol containing 50 mg ferric chloride and heated in an oven at 80° C. for 10 min. GAs fluoresce and appear as greenish spot under UV light, allowing their detection. (D. Puchooa and R. Ramburn; “A study on the use of carrot juice in the tissue culture of Daucus carota : African Journal of Biotechnology, Vol. 3(4), pp. 248-252, April-2004).
[0063] The inventors of the present invention extracted GA 3 by diluting the above mixture with water, and acidification with concentrated HCl, to pH 2.5. To 5 ml of broth, 60 ml of methanol:chloroform:2 N ammonium hydroxide in the ratio of 12:5:3 and 25 ml of distilled water was added. The mixture was shaken well in a separating funnel. The bottom chloroform layer was removed and methanol in the upper aqueous layer was evaporated. After adjusting the pH of the remaining solution to 2.5, the solution was extracted thrice with 15 ml of ethyl acetate each time. The ethyl acetate phase was collected and evaporated to dryness. The dried material was dissolved in 5 ml of ethanol and the amount of GA 3 was determined. To a 1 ml aliquot of the sample in ethanol, 8 ml of 3.75N HCl was added and O.D. was measured at 254 nm after 2 min., following the protocol of Berrios et al. (2004).
[0064] Various substrates have been used for solid state fermentation in the literature. Machado et al. reported a yield of 0.925 g of GA 3 /kg of biomass using coffee husk or cassava bagasse as a medium (Machado, C. M. M., Oishi, B. O., Pandey, A., and Soccol, C. R., Biotechnol. Prog. 20:449-1453 (2004)). Gelmi et al. (“Solid substrate cultivation of Gibberella fujikuroi on an inert support”; Process Biochemistry. 35: 1227-1233 (2000)) reported that Qian et al., ( World J. Microbiol. Biotechnol. 10:93-98, (1994)) achieved a yield of 19.3 g GA 3 /kg of dry fermented substrate after 18 days of cultivation using corn flour as a substrate (although Gelmi suggested that the yield was actually less, when taking into account degradation of the substrate).
[0065] Gelmi, ibid. also reported that other workers achieved yields of 3.8 g GA 3 /kg vermiculite and of 6.8 g GA 3 /kg initial dry mass over 190 h, using a wheat bran culture medium. A yield of 8 g/kg of GA 3 was obtained on rice as a substrate (German Patent Number DD 252000). Prema et al., Indian J. Microbiol. 28:1-2 (1988)) reported very low yields of GA 3 (1.14 g/kg) and Kumar, P. K. R., and Lonsane, B. K., Appl. Microbiol. Biotechnol. 34:145-148 (1990), reported 1.2 g/kg of GA 3 using wheat bran as a medium.
[0066] The present invention has obtained GA 3 using wheat bran, and using Jatropha seed cake with oil and without oil. The present invention has found that the GA 3 yields were as high as 237.2 g/kg using Jatropha seed cake with oil on the 6 th day, which is more than ten fold higher than the previously reported possible yield of 19.3 g/kg (Gelmi, ibid.). The GA 3 yield obtained by using Jatropha seed cake as a substrate was also five fold higher than that obtained by wheat bran under the present optimized conditions (see Examples).
[0067] In certain embodiments, the yield of GA 3 in the present invention is further improved by having a higher initial moisture level of 60% and a lower incubation temperature of 23° C. as compared to moisture level of 50% at 28° C. or 30° C., as reported in Prema et al., Indian J. Microbiol. 28:1-2 (1988), or Pastrana et al., Enzyme and Microbial Technology, 17:784-790, 1995 (1995). There does exist one report wherein the temperature was decreased from 28° C. to 22° C. as the fermentation progressed. However, the yield of GA 3 was only 3 g/kg (Bandelier et al., Process Bioche . Vol. 32 2:141-145 (1997)).
[0000] Submerged Fermentation
[0068] In one embodiment, the present invention provides a process for submerged fermentation which comprises the following steps:
[0069] 1. Preparation of the inoculum;
[0070] 2. Incubation in medium containing sugars;
[0071] 3. Extraction of GA 3 ; and
[0072] 4. Purification.
[0073] In one embodiment, the inoculum is prepared by culturing and maintaining F. moniliforme in Czapek-Dox broth medium, in the presence of a carbon source, such as sucrose or glucose.
[0074] In the present invention, various conditions such as pH, temperature, carbon source, and the media may be optimized for high yield.
[0075] One group has previously reported a yield of GA 3 of 5 g/L by submerged fermentation, using a fed-batch cultivation mode under conditions of nitrogen limitation using genetically improved strains (P. K. R. Kumar and B. K. Lonsane, “Microbial production of Gibberellins: state of the art” in Advances in Applied Microbiology. 34: 29-140 (1989)).
[0000] General Comments
[0076] The following examples are included to demonstrate certain exemplary embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent techniques discovered by the inventor to function well in the practice of the invention, and thus can be considered to constitute exemplary 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 the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.
EXAMPLES
Example 1
Organism
[0077] Fusarium moniliforme NCIM 1100 was obtained from National Collection of Industrial Microorganisms, Pune, India. The strain was cultured and maintained on sterile potato dextrose agar (PDA) slants. Unless otherwise indicated, the media used for production of gibberellic acid was Czapek-Dox (Himedia-M076) and the culture was incubated at 30° C. for 10 days on as shaker incubator at 150 rpm.
Example 2
Solid Substrate Fermentation with Wheat Bran
[0078] To 50 g wheat bran, 30 ml of a mineral salts solution (copper sulphate, 0.007 g; ferric chloride, 0.007 g; and zinc sulphate, 0.007 g, dissolved in 1 liter of 0.2N HCl) was added and mixed well. The mixture was then distributed equally into five flasks and sterilized at 15 PSI for 30 min. The autoclaved wheat bran in each flask was inoculated with 10 ml of 6 days old F. moniliforme culture from Czapek-Dox broth, mixed thoroughly and were incubated at 30° C. for 10 days at a 45° angle. Yield was determined by the method of Berrios et al., as described below.
Yield of GA 3 from wheat bran under SSF, over time. GA 3 concentration (g/kg) Days of in solid substrate incubation fermentation (wheat bran) 5 29 6 32 7 33 8 34 9 39 10 39.4
Example 3
Analytical Procedures
[0079] GA 3 was determined spectrophotometrically by the method described by Berrios et al. (Biotechnology Letters 26: 67-70, (2004)) at 254 nm. GA 3 was also determined by HPLC at 206 nm using a C18 column with methanol:water (3:1) as the mobile phase at 1 ml/min flow rate, as described by Sharma et al. (Biotechnol. Appl. Biochem., 39, 83-88 (2004)). The retention time of GA 3 is 3 minutes under these conditions.
[0080] GA 3 was also detected by TLC as described by Puchooa et al. (African Journal of Biotechnology, 3(4): 248-252 (2004)). The culture filtrate obtained after fermentation was subjected to extraction and purification as described below. The obtained residue was dissolved in ethanol and separated by TLC using isopropanol-ammonia-water (10:1:1, v/v/v) as mobile phase. The plates were sprayed with 3% sulphuric acid in methanol containing 50 mg ferric chloride and heated in an oven at 80° C. for 10 min. GA 3 fluoresce and appear as a greenish spot under UV light.
Example 4
Extraction of GA 3 from the Wheat Bran Solid Substrate
[0081] GA 3 was extracted from the solid substrate by adding 100 ml of distilled water to moldy bran in each flask and were kept on shaking incubator at 150 rpm for 2 hrs. The slurry from each flask was filtered through muslin cloth and the volume of the filtrate was made to 100 ml. Filtrate was centrifuged at 10000 rpm for 10 min at 28° C. Supernatant was collected and analyzed for GA 3 concentration spectrophotometrically.
Example 5
Purification of GA 3
[0082] Isolation of GA 3 from the solid substrate extract was done by the method described in Ergun et al. (Turk J. Bot., 26: 13-18 (2002)). Briefly, to 5 ml of the water extract from the solid substrate, 60 ml of methanol:chloroform:2 N ammonium hydroxide in the ratio of 12:5:3 and 25 ml of distilled water was added. The mixture was shaken well in a separating funnel. The bottom, chloroform, layer was removed and methanol in the upper aqueous layer was evaporated. After adjusting the pH of the remaining solution to 2.5 with concentrated HCl the solution was extracted thrice with 15 ml of ethyl acetate. The ethyl acetate phase was collected and evaporated to dryness. The dried material was dissolved in 5 ml of ethanol and GA 3 was determined, using the protocol of Berrios et al. This method of purification may also be adapted to GA 3 from submerged fermentation.
Example 6
Solid Substrate Fermentation with Jatropha Seed Cake
[0083] Jatropha seed cake, one of cheapest substrates available, was employed as the substrate for the production of GA 3 Production of gibberellic acid using Jatropha as the substrate has never been previously reported. Both Jatropha seed cake with oil and without oil were used as the substrate. Five flasks (5 g of Jatropha, 8 ml of MSS (copper sulphate 0.007 g; ferric chloride 0.007 g; zinc sulphate: 0.007 g; dissolved in 1 liter of 0.2N HCl) and 3.5 ml of inoculum)) were inoculated with 3.5 ml of four day old inoculum of F. moniliforme , and were incubated at room temperature. Growth was observed within 24 hours of inoculation. Maximum yield was obtained on the 6 th day of incubation and the yield was found to decrease on the 8 th and 10 th day.
[0084] As depicted in FIG. 1 , the maximum yield of GA 3 obtained was 237.2 g/kg by SSF. This is so far the best-reported yield of GA 3 obtained by SSF. The GA 3 extracted from the SSF migrated on TLC as a single spot similar to the standard and showed an R f value of 0.74, consistent with GA 3 .
Example 7
Production of GA 3 in Jatropha Seed Cake without Oil
[0085] The production of gibberellic acid was determined every 48 hours. Five flasks (5 g of Jatropha seed cake without oil, 8 ml of mineral salts solution MSS and 3.5 ml of inoculum) were inoculated with 3.5 ml of four day old inoculum ( F. moniliforme ) and was incubated at room temperature. Maximum yield was obtained on the 6 th day of incubation and the yield was found to decrease on the 8 th and 10 th day.
Days of GA 3 Concentration incubation g/kg 2 122 4 136 6 213 8 145 10 159
Example 8
Comparison of Yield from Jatropha Seed Cake with Oil and without Oil
[0086] Gibberellic acid was produced by using Jatropha seed cake with oil and without oil as the substrates. A very slight difference was observed in the yield, however yield from Jatropha seed cake with oil (149.72 g/kg) was found to be slightly higher than the yield obtained from Jatropha seed cake without oil (140.22 g/kg) on day 10 after inoculation.
Example 9
Submerged Fermentation
[0087] Fusarium moniliforme culture was inoculated from PDA slants into 250 ml of commercial Czapek-Dox broth at an initial pH of 7.0, and incubated at 30° C. for 10 days on a shaking incubator at 150 rpm. Cell growth was monitored by collecting 1 ml of culture from fermented broth every 24 h, and centrifuged at 13200 rpm for 10 min. The supernatant was used for GA 3 estimation, and the pellet, washed thrice with saline, was used for determining cell growth. The growth and GA 3 production patterns of F. moniliforme culture in Czapek-Dox broth is shown in FIG. 2 .
[0088] After an initial lag, there was an exponential increase in growth. This log phase continued up to 5 days before reaching a plateau indicating the commencement of stationary phase. Production of GA was found to start increasing during the late exponential phase (5 days) and extending well into the stationary phase before reaching a plateau ( FIG. 2 ). Under these conditions, the yield of GA 3 reached the highest on the 8 th day.
Days of F. moniliforme inoculum Incubation GA 3 (g/L) Biomass 1 0.09 1.50 2 — — 3 1.92 14.70 4 2.76 19.44 5 3.29 23.84 6 3.35 24.36 7 3.71 27.20 8 4.21 22.24 9 — — 10 4.02 24.56
Example 10
Optimization of pH in Submerged Fermentation
[0089] Optimization studies were carried out to increase the yield of GA 3 . To determine the optimal pH for the growth and production of gibberellic acid, Fusarium moniliforme culture was inoculated into 100 ml of broth in 250 ml flasks, with flasks having different initial pH values (5, 7 and 8). The cultures were incubated at 30° C. for 10 days on a shaking incubator at 150 rpm. Sampling of 1 ml of broth was done every 24 h throughout the incubation period, to determine cell growth and GA 3 concentration. Initial pH did not have any significant effect on the GA 3 yield ( FIG. 3 ) although the highest yield (6.5 g/L) was obtained at an initial pH of 7.0.
Days of pH 5 pH 7 pH 8 Incubation GA 3 (g/L) GA 3 (g/L) GA 3 (g/L) 1 0.10 0.14 0.11 2 — — — 3 1.15 1.32 1.24 4 2.43 2.99 2.57 5 3.59 4.45 3.48 6 4.25 4.86 3.79 7 4.50 5.31 4.22 8 5.10 6.50 4.73 9 — — — 10 5.46 5.87 5.02
Example 11
Optimization of Temperature in Submerged Fermentation
[0090] The optimal temperature for the growth and production of gibberellic acid by Fusarium moniliforme was evaluated. The F. moniliforme culture was inoculated into four different Czapek-Dox broth flasks, which were incubated at different temperatures (25° C., 30° C., 37° C., and room temperature of 23-25° C.) for 10 days on a shaking incubator at 150 rpm. Sampling was done after every 24 hrs for determination of cell growth and GA 3 concentration. Incubation at 30° C. was the optimal condition for maximizing the production of GA 3 ( FIG. 4 ).
Days of 25° C. 30° C. 37° C. 23° C. Incubation GA 3 (g/L) GA 3 (g/L) GA 3 (g/L) GA 3 (g/L) 1 0.10 0.11 0.024 0.10 2 — — — — 3 1.14 1.32 0.092 1.21 4 2.33 2.97 0.10 2.73 5 3.0 4.06 0.29 3.33 6 3.10 4.34 0.33 3.86 7 3.34 4.76 0.32 4.57 8 3.88 5.77 0.23 5.01 9 — — — — 10 3.65 5.42 0.2 1.92
Example 12
Optimization of Carbon Source in Submerged Fermentation
[0091] To determine the carbon source, which gives optimal yield of GA 3 production, the following carbon sources were used: sucrose, glucose, galactose, xylose, glacial acetic acid and methanol. Fusarium culture was inoculated into reconstituted Czapek-Dox medium containing the aforementioned carbon sources and incubated at 30° C. for 10 days on a shaking incubator at 150 rpm. Sampling was done every 24 hrs throughout the incubation period for determining the cell growth and the GA 3 concentration. Sucrose and glucose were found to be the best source of carbon giving a yield of over 15 g/L ( FIG. 5 ). Galactose and xylose also gave yields higher than 8 g/L.
GA 3 (g/L) Glacial Days of Acetic Incubation Glucose Galactose Xylose Methanol acid Sucrose 1 0.28 0.23 0.64 0.026 No 0.43 Growth 2 1.12 0.89 0.66 0.028 No 1.72 Growth 3 3.07 2.57 1.61 0.018 No 5.57 Growth 4 5.63 4.89 3.51 0.015 No 7.69 Growth 6 12.14 10.93 7.81 0.014 No 13.85 Growth 7 14.02 12.17 9.25 0.001 No 14.6 Growth 8 13.82 12.35 11.08 0.0 No 14.76 Growth 9 15.07 12.64 11.58 0.023 No 15.37 Growth 10 15.28 13.3 12.45 0.018 No 15.91 Growth
Example 13
Optimization of Submerged Fermentation
[0092] A Fusarium moniliforme culture was inoculated into reconstituted Czapek-Dox medium, followed by incubation at 30° C. at an initial pH of 7.0, using sucrose as the carbon source, and was incubated for 10 days on a shaking incubator maintained at 150 rpm. Sampling was done every 24 h throughout the incubation period for determining the cell growth and the GA 3 concentration. As shown in the following table, the yield reached 15.9 g/L at 10 days.
Days of incubation GA 3 (g/L) 1 0.43 2 1.72 3 5.57 4 7.70 5 — 6 13.85 7 14.60 8 14.76 9 15.37 10 15.91
Discussion: Yield from Submerged Fermentation and Solid Substrate Fermentation.
[0093] The GA 3 yield was determined in both submerged fermentation and solid substrate fermentation. The yield obtained from solid substrate fermentation reached as high as 237.2 g/kg when using Jatropha seed cake as a substrate, and as high as 39.4 g/kg when using wheat bran as a substrate. The yield obtained from submerged fermentation reached as high as 15.9 g/L.
[0094] All of the compositions and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and/or methods and in the steps or in the sequence of steps of the methods described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents that are chemically or physiologically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims. | The present invention provides an improved process for the production of gibberellic acid (GA 3 ), achieving a yield over 225 g/kg of GA 3 with solid substrate fermentation, and over 15 g/L by submerged fermentation. The method also provides novel substrates, including the use of Jatropha seed cake. The present invention has in particular provided an improved, cost-effective process for the manufacture of GA 3 , as the process has a surprisingly high yield of product, achieves the maximal yield in shorter time than other techniques, consumes less energy, and works with very inexpensive substrates. In all, the manufacturing costs are significantly reduced. | 2 |
REFERENCE TO RELATED APPLICATION
This application claims priority of U.S. provisional patent application Ser. No. 60/060,377, filed Sep. 29, 1997, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
As set forth in commonly assigned U.S. Pat. Nos. 5,245,337, 5,293,164, and 5,592,667, a multi-dimensional approach has been developed for transforming an unstructured information system into a structured information system. This approach addresses the unique properties of multiple information source systems, including database systems, from an information point of view. In particular, this new methodology attempts to unify the two fields of information theory and database by combining the encoding compression theory and the database theory for general data manipulations into a general information manipulation theory with respect to multi-dimensional information space.
Broadly, multiple information sources are described by different information variables, each corresponding to one information source or information stream. Information manipulations are primarily index manipulations which are, in general, more efficient than non-index manipulations of the same number. The only non-index manipulations are carried out at leaf nodes where unique data values are stored. Therefore, the non-index manipulations are minimized. As a further aspect of this approach, a structured information system or database is built by taking into account information relations between different sets of data in the database. Such relations between neighboring nodes are easily analyzed and presented on-line because they are built into the structure. Relations between nodes that are not neighbors are not explicitly built into the existing structure. On-line analysis on these relations requires efficient information manipulations in main memory.
However, only a limited amount of such statistical information is explicitly built into the structured database information system. For example, information about double patterns made up of two leaf nodes of single patterns is easily shown in the case of two neighboring leaf nodes which have a common parent node of double patterns in an existing tree structure. Analyzing pattern statistics between any two leaf nodes that do not have a common double-pattern parent node in the existing tree structure could be difficult because the statistics is not explicitly stored at any node in the existing structure. Such analysis would be greatly simplified if one could build a double-pattern node in main memory, that has the exact same properties as if it were built from the raw data. In order to build this node efficiently, no data values should be involved, that is, using only manipulations of the memory tokens.
SUMMARY OF THE INVENTION
The subject invention extends the approach outlined above by providing a method of building a virtual node or tree structure for general and systematic on-line analytical processing (OLAP) and other data mining analysis in an associative memory database (AMDB). The invention provides a novel structured database used to store useful statistical information about the data behind the AMDB.
In essence, the invention transforms an existing tree structure into a different tree structure which may be used to readily reveal and analyze statistical relations between any two leaf nodes, or any number of leaf nodes, in the input structure. From an information view point, the new structure makes possible the analysis of mutual relations between any two single information sources in a structured multiple source information system.
The tree structure that is built from an existing tree structure is called a virtual structure or a virtual information system, and contains no original data. The virtual tree is built from a plurality of virtual nodes, each node being representative of a virtual information source in that it takes no disk space and exists only in main memory, while having all the properties of a real node or information source.
A virtual node can be built from any two real leaf or internal nodes in an existing tree structure. A virtual node built from two AMDB tables or two multiple source information systems connected by two referential nodes or two single information sources is quite similar to the so-called "cross-table node" in existing data mining techniques. However, a virtual node is built from unique non-data information values, whereas a cross-table node is built from two sets of data values which may have high information redundancy. The resulting virtual tree structure is equivalent to a virtual relational table or a virtual information system in which there is no raw data values.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE illustrates important steps according to a method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In proceeding with the method of the invention, the general approach is to build a virtual tree structure by building a number of unstructured virtual information sources at a given memory node in an existing memory tree structure. The unstructured virtual information sources are information streams of memory tokens or indices of some leaf nodes in the existing structure. A virtual structure is then built from the unstructured virtual sources.
In practice, it is noted that all the memory tokens or indices of the involved leaf nodes at the memory information source of the closest common ancestor node in an existing tree structure. As such, the leaf node tokens may be propagated to the closest common ancestor node. Here, the memory indices of the leaf nodes are the memory addresses of the unique data values of the corresponding dictionaries. A memory information source at a given node is an information stream of information values of its children nodes, with the number of information events being equal to the cardinality of the node.
The above recalling or propagating procedure is equivalent to building a sub-database of indices of a size of record number equal to the cardinality of the ancestor node. A tree structure is then built from these recalled or propagated multiple information sources. However, this method does not make full use of statistical information already built into the existing tree structure. In particular, the most useful virtual structure of a single virtual node can be built more efficiently after taking into account of the relations that are already stored explicitly in the existing structure. Note that the above general procedure involves only index manipulations. That is, no data values are needed to build a virtual node since the dictionaries of the leaf nodes that are children nodes of the virtual node are already stored in the existing structure. It is also important to note that the information entropy of the virtual information system for building the virtual structure is minimized.
With regard to more specific steps, we start with a single virtual node since it is the easiest one to build and is the most useful one for on-line analytical processing (see Figure ). The first step in building a virtual node is to find the closest common ancestor node for a given two nodes in an existing tree structure, from which the virtual node is going to be built. Let us assume that the two nodes are "a " and "b " and are, for example, two leaf nodes on the existing tree built on disks. The common ancestor node is n a . By definition, the closest common ancestor node has a child node that is an ancestor node of only one node of the two nodes a and b. Similarly, the other child node of the common ancestor node n a is an ancestor node of the other one of the two nodes a and b. For simplicity, assume the left child node n, of the common ancestor node n a is an ancestor node of a, but not b. By the same token, the right child node n r of the node n a is an ancestor node of b, but not a.
Next, we recall the memory tokens (which are the memory addresses of unique data values) of node a at the memory of node n 1 or propagate the a tokens to node n 1 . This replaces the original tokens stored at the n 1 memory with the recalled tokens of node a using look-up tables. Similarly, we recall the tokens of node b at the memory of node n r or propagate the b tokens to node n r .
If node n a has memory structure in some sort of hashing, the virtual node may be built more easily. For example, consider the left hashing structure which stores a set of lists. Each list is indexed by a memory token of the left child node n 1 and stores a number of tokens of the right child node n r . The right child tokens in each list pairs with the same left child token. After recalling the leaf node tokens and replacing the n 1 memory tokens with the a tokens and replacing the n r tokens with the b tokens, the list indices contain duplicates and the list elements in each list may also have repetitions. Therefore, we reduce the redundancy of the list indices by combining all the lists that have the same list index.
After reduction of redundant list indices, all the new lists have unique indices. Then, we reduce redundant list elements by eliminating them and keeping a count of the repeats in each new list. Once this is done, we obtain a virtual node memory structure identical to a real node as if it were built from the output streams of two leaf nodes a and b.
The single virtual node is very useful in on-line analysis. For example, double patterns of the field values of a and b exist in rows or records. They can be easily presented on the virtual node by replacing the memory tokens in pairs by the corresponding field values after recalling dictionaries. The patterns are shown with counts. Patterns existing in columns can also be presented. For example, patterns in the leaf node b associated with each data value in node a may be easily presented by printing out a list of data values of node b pairing with the same list index representing the corresponding data value in node a. Similarly, patterns in node a associated with a given data value in node b can be presented easily from the right hashing memory structure.
EXAMPLE
Assume two fields a and b in a database of 32844 records have 28 and 17 unique data values. The double-pattern node built from these two fields has cardinality of 476 or 476 unique double patterns. Although a real node of cardinality 476 could be built from the two fields a and b in raw data., assume we do not have raw data. Instead, we have a tree structure on disks, in which leaf nodes a and b have an closest common ancestor node which happens to be the root node of the existing tree. The cardinal root node has cardinality of 32844, and has left child node n, and right child node nr. The left child node has cardinality of 5000, and is an ancestor node of a, but not b. The right child node has cardinality of 1000, and is an ancestor node of b, but not a.
With this introduction, the method of building a virtual node according to the invention proceeds as follows. Recall tokens of node a at node n 1 or propagate the a tokens to node n 1 which is equivalent to replacing the tokens of node n 1 by tokens of node a. Recall tokens of node b and replace tokens of node n r by the recalled tokens or propagate the tokens of node b to node n r . Note that before the recall, the list indices in a left hashing memory structure are unique tokens of the left child node n 1 , from 0 to 4999. After the recall, 5000 unique tokens are replaced by 28 different tokens of node a since there were numerous repetitions. Similarly, the unique tokens of node n, stored in each list, are replaced by 17 tokens of node b.
Although redundant tokens in a given list are expected, they can be eliminated in each list while keeping the counts of the repeats. We may then combine those lists which have an identical list index or the same token of node a, such that after the combination, we have 28 lists each corresponds to unique new list index. Once again, we have eliminated the redundant list elements arising from combined lists while keeping track of the repeats. Finally, we obtain a virtual node memory structure made up of 28 lists each of which has 17 unique elements, reproducing a real node as if it were built from raw data.
Printing out 476 pairs of data values of fields a and b shows a double patterns in rows. Printing out a given list of 17 data values after recalling the dictionary is equivalent to presenting 17 field values in field b, that pair with the same field value in field a. If a right hashing table is used in building the memory structure, we would have 17 lists each of which has 28 unique elements.
For a tree of two virtual nodes, it could become more difficult to build the tree depending on the structure. Here are two scenarios: First, the two fields that make the double-pattern virtual node have an closest common ancestor node that is different from the closest common ancestor node of the three leaves that make the whole triplet virtual tree; or second, the common ancestor node of the two fields that build the double-pattern virtual node is the same ancestor node of the three leaves. In the second case, we have to use the general method to recall the tokens of all three leaf nodes at their common ancestor node memory information source or propagate the leaf tokens to their common ancestor node. We may then build a double-pattern virtual node and a triple-pattern virtual node.
In the first scenario, we recall the tokens of the two leaf nodes that make the double-pattern virtual node at their closest common ancestor node and build the double-pattern virtual node there. We recall the tokens of the double-pattern virtual node at the corresponding child node of the triplet ancestor node and recall the tokens of the third leaf node at the other child node of the triplet ancestor node. The triplet virtual node is built using the scheme for building double-pattern virtual node described above.
For a tree with more virtual nodes, one always can use the general method to build the virtual tree. Simplification is possible whenever the common ancestor node of a subpattern is different from the common ancestor node of a parent pattern. In such cases, one may build the sub-pattern virtual node at the sub-pattern common ancestor node and build the parent-pattern virtual node at the parent-pattern common ancestor node, instead of building all virtual nodes at the same parent-pattern ancestor node.
An interesting problem is how to build a virtual node across two tables connected by two referential nodes. Here, we illustrate a procedure for building a cross-table virtual node. Assume two tables t 1 and t 2 are connected by two referential nodes n 1 in t 1 and n 2 in t 2 . Assume n 1 is a primary node and n 2 stores a sub-set of tokens in the n 1 memory. Suppose we want to build a virtual node from two leaf nodes, l 1 in t 1 , and l 2 in t 2 .
First, we build a virtual node in t 1 from n 1 and l 1 and build a virtual node in t 2 from n 2 and l 2 , using the scheme presented earlier. Assume we use left hashing lists in which the left child tokens are list indices and right child tokens are list elements. Suppose we build a cross-table virtual node of the left hashing virtual memory in which tokens of l 2 are the list indices and tokens of l 1 are the list elements. For the virtual node in t 1 , the memory tokens of the referential node n 1 are the hashing list indices and the memory tokens of leaf node l 1 are the list elements.
For the virtual node in t 2 , the memory tokens of the referential node n 2 are the list elements and tokens of l 2 are the list indices. Now we replace every token of n 2 in the virtual node memory lists in t 2 by the corresponding list of tokens of l 1 in the virtual node memory in t 1 , which has the list index identical to the n 2 token. Then we eliminate redundant list elements and keep counts of repeats. Thus, a cross-table virtual node is built in the left hashing form in which the l 2 tokens are the list indices and the l 1 tokens are the list elements.
This invention builds upon the approach identified above by providing a method for building a virtual memory tree structure. The general scheme is to find an closest common ancestor node, in an existing tree, of all leaf nodes that will be involved in the virtual tree, and to recall all the leaf tokens at the memory structure of the common ancestor node or propagate the leaf tokens to the common ancestor node, generating an information stream of the recalled tokens for each leaf node. In other words, by considering each stream of recalled tokens as a single information source which has the number of information events, equal to the cardinality of the common ancestor node, the invention is used to build a virtual tree from the recalled multiple information sources.
In many cases, the method may be simplified whenever the closest common ancestor node for a given pattern structure is different from the closest common ancestor node for its sub-pattern. In particular, a double-pattern virtual node may be built more efficiently by finding the closest common ancestor node of two given leaves in an existing structure; recalling tokens of the two leaves at two child nodes of the common ancestor node and replace the tokens of the two child nodes by the recalled leaf tokens in the hashing memory structure; reducing redundant indices of the hashing lists by combining the hash lists that have the identical hashing index; eliminating redundant elements in each hashing list and keep the counts of repeats; and sorting the remaining unique elements.
A virtual node or virtual tree provides a virtual structured information system for general information manipulations and general pattern demonstration in a given structure, such as on-line analytical processing (OLAP) and other user-initiative data mining manipulations. | A virtual structured information system or a virtual database is developed and presented in the framework of an information theory for multiple source information systems such as databases. A virtual tree structure is built from virtual nodes in main memory which contain no raw data. The virtual nodes and virtual trees provide general non-data virtual structure, like cross-table nodes, for systematic information manipulations such as on-line analytical processing in a structured information system. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to herbicidal agents and more specifically it relates to a herbicidal agent based on DEET (N,N-diethyl-m-toluamide) for killing and controlling undesirable plant growth without damaging desirable plant growth such as grasses, shrubs and trees. The present invention particularly relates to the killing and controlling of leafy spurge.
Conventional herbicides, such as Tordon or 2-4-D, are effective in killing and controlling undesirable plant growth such as leafy spurge, however, conventional herbicides are also kill desirable plant growth. With conventional herbicides, great care must be executed by the spray operator to prevent tree rows, crops, shrubs and grasses from becoming in contact with the conventional herbicides. The operator must always compensate for the direction and strength of the wind. If the conventional herbicides come in contact with the desirable plants, often the desirable plants will be severely damaged or completely killed.
When spraying for undesirable plant growth, such as leafy spurge, the undesirable plant growth is within trees and shrubs, or near water. Convention herbicides will kill or severely damage the desirable plant growth. Also, conventional herbicides usually cannot be applied to environmentally sensitive areas, such as near water, where herbicide use is restricted. Hence, there is a need for a herbicide which can be applied to undesirable plant growth without severely damaging desirable plant growth.
2. Description of the Prior Art
Formulations containing DEET have been previously described by other patents. For example, U.S. Pat. No. 4,272,282 to Hansen et al, U.S. Pat. No. 5,575,988 to Knowles, Jr. et al; U.S. Pat. No. 5,610,194 to Polefka et al; U.S. Pat. No. 4,612,327 to Matukuma et al; U.S. Pat. No. 4,956,129 to Scher et al; U.S. Pat. No. 5,466,460 to McMahon et al; U.S. Pat. No. 5,332,584 to Scher et al; U.S. Pat. No. 5,292,533 to McMahon et al; U.S. Pat. No. 5,160,529 to Scher et al; U.S. Pat. No. 5,120,542 to Scher et al; U.S. Pat. No. 5,621,013 to Beldock et al; U.S. Pat. No. 4,157,983 to Golden; U.S. Pat. No. 4,933,167 to Scher et al; U.S. Pat. No. 5,221,535 to Domball are illustrative of such prior art.
Hansen et al (U.S. Pat. No. 4,272,282) discloses a herbicidal mixture containing a herbicidal substituted anilide and substituted dichloroacetamide as antidote therefor. Hansen et al does not disclose the use of DEET for controlling various types of undesirable plants.
Knowles, Jr. et al (U.S. Pat. No. 5,575,988) discloses a combination sunscreen and insect repellent comprised of an inorganic micronized inorganic substance and DEET. However, Knowles does not disclose the use of DEET for controlling various types of undesirable plants.
Polefka et al (U.S. Pat. No. 5,610,194) discloses an insect repellent comprising an amount of DEET and an amount of N-methyl neodecanamide (MNDA) However, Polefka does not disclose the use of DEET for controlling various types of undesirable plants.
While conventional herbicides may be suitable for the particular purpose to which they address, they are not as suitable for killing and controlling undesirable plant growth without damaging desirable plant growth such as grasses, shrubs and trees. Conventional herbicides severely damage or kill desirable plant growth when placed in contact. Also, conventional herbicides severely damage or kill crops when sprayed near a cultivated field.
In these respects, the herbicidal agent based on DEET according to the present invention substantially departs from the conventional methods of use and compositions of the prior art, and in so doing provides a composition and a method of using the composition primarily developed for the purpose of killing and controlling undesirable plant growth without damaging desirable plant growth such as grasses, shrubs and trees.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a herbicidal agent based on DEET and a method of using the same that will overcome the shortcomings of the prior art.
Another object is to provide a herbicidal agent based on DEET and a method of using the same that kills and controls undesirable plant growth such as leafy spurge, dandy lions, milkweed, spotted napweed, Canadian thistle and various other weeds.
An additional object is to provide a herbicidal agent based on DEET and a method of using the same that does not severely damage desirable plant growth such as grasses, shrubs, trees, conventional crops and various other desirable plants.
A further object is to provide a herbicidal agent based on DEET and a method of using the same that has an application cost approximately the same as conventional herbicides.
Another object is to provide a herbicidal agent based on DEET and a method of using the same that does not harm the environment such as environmentally sensitive wetlands.
Another object is to provide a herbicidal agent based on DEET and a method of using the same that is relatively safe for humans and livestock to come in contact with.
Further objects of the invention will appear as the description proceeds.
DESCRIPTION OF THE PREFERRED EMBODIMENT
DEET (N,N-diethyl-m-toluamide) is readily commercially available, for example, from Morflex Chemical, Inc. The amount of DEET which may be included in the compositions of the invention is from about 5% by weight to about 95% by weight. Preferably, the amount of DEET will be in the range of from about 10% by weight to about 35% by weight. A concentration of from about 20% by weight to about 30% by weight is most preferred. Applications of the herbicide may be accomplished by aerial or ground spraying utilizing conventional spray equipment.
DEET is most commonly utilized in household products such as insect repellents (an example is Deep Woods Off brand insect repellent). Since DEET is directly applied to human skin, extensive research has been conducted on the health affects of DEET. DEET has been noted to cause only moderate irritation of the eyes. DEET has little reaction with the skin of humans, other than mucous membranes and abraded skin. As with most chemicals, ingestion and inhalation may result in serious health affects if in high dosages. Also, none of the components in DEET is a known carcinogen.
The herbicide composition preferably comprises an amount of DEET and an amount of water mixed together. The amount of DEET is preferably from 10% by weight to about 35% by weight for maximum effectiveness when applied to the undesirable plant growth. In addition, an amount of oil is preferably combined with the DEET-water composition to increase the amount of DEET contacting the surface of the undesirable plants and remaining there without dripping off.
In use, an amount of DEET is combined with a fluid such as water to form the herbicide composition. Preferably, the amount of DEET is combined with an oil-in-water emulsion, or a water-in-oil emulsion for improving application to the undesirable plants. The herbicide composition containing DEET is thereafter directly applied to the undesirable plant growth, even if near desirable plant growth. After approximately one day, a noticeable difference in the structure of the undesirable plants occurs, with little noticeable difference in the structure of the desirable plants. After seven days, the leaves, flowers and the main stem of the undesirable plants are dying. After 30 days, kill rates of up to 95% can be achieved with a mixture of approximately 25% DEET by weight.
The present composition and method of using same provides an effective herbicide for undesirable plant growth while not severely harming desirable plant growth. The resulting material is stable over time and relatively harmless to humans and animals.
The invention further is illustrated by the following examples, which are not intended to be limiting in any way. The measurements for the following examples were conducted utilizing conventional measuring methods common in the industry to ensure accuracy.
EXAMPLE #1
A herbicide composition comprising approximately 28% DEET by weight was applied to leafy spurge during the early stage of its growth. The weather conditions and the leafy spurge kill rates are as follow:
__________________________________________________________________________Weather Percentage of Affects OnConditions Percentage Leafy Spurge Killed Percentage Re-Growth Rate Desirable PlantsTemp. (F.)Sky 24 HRs 5 Days 10 Days 30 Days 5 Days 20 Days 30 Days Grasses Shrubs Trees Crops__________________________________________________________________________65 PC 12% 55% 73% 79% 0% 10% 25% <10% <5% N.A. N.A.63 PS 15% 65% 79% 88% 0% 15% 20% <10% N.A. N.A. N.A.65 PS 12% 67% 76% 90% 0% 10% 22% <10% N.A. N.A. N.A.74 OC * 45% 78% 58% 0% 5% 11% <5% N.A. N.A. N.A.72 OC * 52% 80% 86% 0% 0% 10% <7% N.A. N.A. N.A.__________________________________________________________________________ PC* Partly Cloudy; PS Partly Sunny; OC Overcast; S Sunny *1/2 inch of rain was received immediately after applying the herbicide.
EXAMPLE #2
A herbicide composition comprising approximately 6% DEET by weight was applied to leafy spurge during the early stage of its growth. The weather conditions and the leafy spurge kill rates are as follow:
__________________________________________________________________________Weather Percentage of Affects OnConditions Percentage Leafy Spurge Killed Percentage Re-Growth Rate Desirable PlantsTemp. (F.)Sky 24 HRs 5 Days 10 Days 30 Days 5 Days 20 Days 30 Days Grasses Shrubs Trees Crops__________________________________________________________________________78 S 2% 5% 10% 30% 0% 23% 62% 0% 0% 0% N.A.79 S 3% 6% 12% 31% 0% 21% 60% 0% 0% 0% N.A.__________________________________________________________________________ PC Partly Cloudy; PS Partly Sunny; OC Overcast; S Sunny
EXAMPLE #3
A herbicide composition comprising approximately 12% DEET by weight was applied to leafy spurge during the middle stage of its growth. The weather conditions and the leafy spurge kill rates are as follow:
__________________________________________________________________________Weather Percentage of Affects OnConditions Percentage Leafy Spurge Killed Percentage Re-Growth Rate Desirable PlantsTemp. (F.)Sky 24 HRs 5 Days 10 Days 30 Days 5 Days 20 Days 30 Days Grasses Shrubs Trees Crops__________________________________________________________________________76 S 7% 13% 20% 27% 0% 15% 42% 0% 0% 0% N.A.80 S 10% 15% 19% 30% 0% 14% 39% 0% 0% 0% N.A.__________________________________________________________________________ PC Partly Cloudy; PS Partly Sunny; OC Overcast; S Sunny
EXAMPLE #4
A herbicide composition comprising approximately 14% DEET by weight was applied to leafy spurge during the middle stage of its growth. The weather conditions and the leaf spurge kill rates are as follow:
__________________________________________________________________________Weather Percentage of Affects OnConditions Percentage Leafy Spurge Killed Percentage Re-Growth Rate Desirable PlantsTemp. (F.)Sky 24 HRs 5 Days 10 Days 30 Days 5 Days 20 Days 30 Days Grasses Shrubs Trees Crops__________________________________________________________________________84 S 12% 18% 29% 44% 0% 6% 31% 4% 4% 9% N.A.84 S 10% 20% 31% 47% 0% 5% 30% 4% 6% 9% N.A.__________________________________________________________________________ PC Partly Cloudy; PS Partly Sunny; OC Overcast; S Sunny
EXAMPLE #5
A herbicide composition comprising approximately 17% DEET by weight was applied to leafy spurge during the late stage of its growth. The amount of DEET was combined with a water-in-oil emulsion. The weather conditions and the leafy spurge kill rates are as follow:
__________________________________________________________________________Weather Percentage of Affects OnConditions Percentage Leafy Spurge Killed Percentage Re-Growth Rate Desirable PlantsTemp. (F.)Sky 24 HRs 5 Days 10 Days 30 Days 5 Days 20 Days 30 Days Grasses Shrubs Trees Crops__________________________________________________________________________82 PS 10% 18% 28% 47% 0% 7% 26% 4% 10% 10% N.A.82 PS 8% 21% 31% 48% 0% 5% 23% 4% 8% 10% N.A.__________________________________________________________________________ PC Partly Cloudy; PS Partly Sunny; OC Overcast; S Sunny
EXAMPLE #6
A herbicide composition comprising approximately 30% DEET by weight was applied to leafy spurge during the late stage of its growth. The amount of DEET was combined with a water-in-oil emulsion. The weather conditions and the leafy spurge kill rates are as follow:
__________________________________________________________________________Weather Percentage of Affects OnConditions Percentage Leafy Spurge Killed Percentage Re-Growth Rate Desirable PlantsTemp. (F.)Sky 24 HRs 5 Days 10 Days 30 Days 5 Days 20 Days 30 Days Grasses Shrubs Trees Crops__________________________________________________________________________77 S 10% 30% 57% 90% 0% 2% 10% 4% 10% 10% N.A.78 S 12% 32% 61% 92% 0% 1% 9% 4% 12% 12% N.A.74 S 10% 34% 66% 91% 0% 2% 9% 5% 8% 6% N.A.75 S 8% 29% 62% 87% 0% 1% 9% 4% 10% 5% N.A.__________________________________________________________________________ PC Partly Cloudy; PS Partly Sunny; OC Overcast; S Sunny
It should be noted that the percentage of desirable plant growth affected represents only plants which received discoloration or the end of the leaves were burnt off. None of the desirable plants were pruned or killed as a result of the application of the herbicide thereto. The desirable plants fully recovered within a relatively short period of time. It should also be noted that the herbicide killed and controlled the undesirable plants in the vicinity of the leafy spurge.
Observing the applications of the herbicide in the early and late stages of growth of leafy spurge disclosed some interesting information. When the herbicide was applied during the late stages of growth, the re-growth rate was less than 50% than when applied during the early stages of growth. Even though it is expected that early stage re-growth will be higher than the late stage re-growth, the substantial difference between the two applications was never expected when compared to conventional herbicides.
As to a further discussion of the manner of usage and composition of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage will be provided.
With respect to the above description then, it is to be realized that the optimum relationships for the components of the invention, to include variations in proportions and manner of use are deemed readily apparent and obvious to one skilled in the art.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact composition and use shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A herbicidal agent based on DEET (N,N-diethyl-m-toluamide) and method of using same for killing and controlling undesirable plant growth, such as leafy spurge, without significantly affecting desirable plant growth such as trees and grasses. The composition contains a carrier fluid and DEET. The preferred concentration of DEET is in the range of from about 10% to 35% by weight of the composition. The composition can be successfully applied to various families of weeds to kill and control their growth. | 0 |
ORIGIN OF THE INVENTION
The invention described herein was made in the performance of official duties by an employee of the Department of the Navy and may be manufactured, used, licensed by or for the Government for any governmental purpose without payment of any royalties thereon.
FIELD OF THE INVENTION
The invention relates generally to underwater reconnaissance, and more particularly to an unmanned underwater reconnaissance system capable of sensing the presence of nuclear materials in the water, on a vessel or in a harbor, and then relaying the sensed information back to a remote location.
BACKGROUND OF THE INVENTION
The examination or reconnaissance of underwater sites for the purposes of determining the presence of nuclear materials is necessary in a variety of military and civilian situations. For example, military situations include intelligence gathering regarding underwater vessels or harbors. Civilian situations include examination of waters surrounding a damaged or sunken vessel that is powered by or carries nuclear material, and reconnaissance of, for example, the water near a nuclear power plant. Typically, such nuclear material underwater reconnaissance is carried out by divers equipped with various underwater sensors, lights, cameras, etc., to examine an area of interest. However, this approach places divers in jeopardy of detection in the case of covert operations, exposure to nuclear radiation, and the general perils associated with deep sea diving.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a system for performing underwater reconnaissance with the goal of detecting the presence of nuclear material.
Another object of the present invention is to provide a nuclear material underwater reconnaissance system that is unmanned.
Still another object of the present invention is to provide an unmanned nuclear material underwater reconnaissance system that can be operated from a safe stand off distance.
Other objects and advantages of the present invention will become more obvious hereinafter in the specification and drawings.
In accordance with the present invention, an underwater nuclear material reconnaissance system utilizes a controllable underwater vehicle having a body and a plurality of propulsion pods distributed about and coupled to the body. Each propulsion pod has its own power source coupled to a propulsor. The underwater vehicle minimally incorporates nuclear material sensors for generating sensor data indicative of the presence of nuclear material, a tunnel thruster for providing vertical thrust for the underwater vehicle, and a bi-directional communications cable deployable from the underwater vehicle. A remotely-located communications base station coupled to the bi-directional communications cable transmits control commands to the underwater vehicle and receives sensor data transmitted from the underwater vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will become apparent upon reference to the following description of the preferred embodiments and to the drawings, wherein corresponding reference characters indicate corresponding parts throughout the several views of the drawings and wherein:
FIG. 1 is a schematic side view of the underwater vehicle used in the underwater nuclear material underwater reconnaissance system in accordance with the present invention;
FIG. 2 is a front view of the underwater vehicle taken along line 2 — 2 in FIG. 1;
FIG. 3 is an isolated view of one of the underwater vehicle's self-contained propulsion pods; and
FIG. 4 is a schematic side view of the underwater nuclear material underwater reconnaissance system according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and more particularly to FIG. 1, an unmanned underwater vehicle equipped for use in the present invention's underwater nuclear material reconnaissance system is shown and referenced generally by numeral 10 . Underwater vehicle 10 can be used in both military and civilian reconnaissance applications in which an underwater area of interest is to be examined for the presence of nuclear material.
Underwater vehicle 10 includes a main body portion 12 extending from fore to aft and a number of self-contained propulsion pods 14 coupled to main body portion 12 . Main body portion 12 can comprise an exterior housing for supporting a plurality functional modules to be described below. Alternatively, main body portion 12 can be formed by the plurality of functional modules, each of which could include a portion of an exterior housing such that main body portion 12 is formed when the modules are joined together.
Self-contained propulsion pods 14 are typically distributed symmetrically about main body portion 12 as illustrated in FIG. 2 where four such propulsion pods 14 are shown. As illustrated in FIG. 3, each of propulsion pods 14 includes an external waterproof housing 140 and a plurality of batteries 142 that power a propulsion system 144 to include a propeller 146 . The number and type of batteries used is not a limitation of the present invention.
The advantages of using multiple propulsion pods 14 in an underwater nuclear material reconnaissance system include the general advantage of making underwater vehicle 10 highly maneuverable as the speed of each propulsion pod can be individually controlled. For purposes of the present invention, this means that the nuclear material sensors (contained in module 22 ) can be optimally positioned at all times thereby minimizing the number of sensing “passes” required and minimizing the amount of time that underwater vehicle 10 must be on a site that is either potentially dangerous or hostile.
As mentioned above, main body portion 12 incorporates a number of functional modules for carrying out a nuclear material reconnaissance mission. A guidance and control module 20 would typically include a sonar system (not shown) and use sonar data to assist in the route guidance of vehicle 10 . The route guidance commands can be supplied manually/remotely or stored internally as will be explained further below. Nuclear material sensor(s) module 22 is provided to detect the presence of nuclear material which is typically in the water or onboard a vessel in the water. Further, in the case of extremely sensitive sensors or large amounts of nuclear material, sensor module 22 might also be able to detect the presence of nuclear material on dry land in a harbor. Such nuclear material sensors are well known in the art and will not be described further herein. A vertical thruster module 24 is provided in the central area of main body portion 12 so that underwater vehicle 10 can hover and quickly adjust its vertical position in the water. Typically, vertical thruster module 24 is a tunnel thruster, the particular design of which is not a limitation of the present invention. Various electronic systems and power supporting the modules in main body portion 12 are contained in an internal electronics and power module 26 . A fin/control surface assembly module 28 provide the necessary fins/control surfaces 28 A needed to manipulate underwater vehicle 10 as it is propelled through the water. A communication cable spool assembly module 30 houses a communications cable 30 A that is paid out during deployment of underwater vehicle 10 . Cable 30 A should be capable of bi-directional communication and is typically a fiber optic cable.
For improved navigation and/or intelligence gathering, underwater vehicle 10 can be equipped with additional systems. For example, one of propulsion pods 14 can incorporate imaging capability. More specifically, one of propulsion pods 14 can have an extension arm 40 coupled thereto. Arm 40 should extend radially out from main body portion 12 such that underwater vehicle 10 can run in the water while the outboard end of arm 40 extends out of the water. Mounted on the end of arm 40 is a video camera 42 so that underwater vehicle 10 can generate an above-water video image. A GPS antenna 44 can also be attached to arm 40 and provide GPS signals to guidance and control module 20 .
Another system that can be included as part of underwater vehicle 10 is a low-light condition imaging system. More specifically, one of propulsion pods 14 can incorporate an invisible light source/camera 46 capable of illuminating a low-light or no-light area of interest with invisible light and then imaging the area with a camera sensitive to the same invisible light. Although shown associated with the same propulsion pod 14 as video camera 42 , this need not be the case.
The complete underwater nuclear material reconnaissance system according to the present invention will now be explained with the aid of FIG. 4 where the system is referenced generally by numeral 100 . System 100 includes underwater vehicle 10 described above and a remotely-located operation control base station 50 which is typically located onboard a vessel or other platform (not shown) that launches/deploys underwater vehicle 10 . Base station 50 is manned/operated by personnel controlling and/or using underwater vehicle 10 . Accordingly, base station 50 includes a number of displays such as tactical display 52 , sonar display 54 and video display(s) 56 . Control commands for underwater vehicle 10 are input using a command input device 58 (e.g., keyboard, touch screen, voice activated controls, etc.)
In operation, underwater vehicle 10 is launched from a vessel/platform and directed to an underwater destination. As mentioned above, route guidance implemented by guidance and control module 20 can be pre-programmed, controlled manually from base station 50 , or be implemented by a combination of pre-programmed and manual maneuvers. For example, a pre-programmed route guidance could be used until vehicle 10 covered a certain distance (or was out for a specified time), at which point manual control of vehicle 10 could be used. For both pre-programmed and manual route guidance, guidance and control module 20 issues control commands to propulsion systems 144 , vertical thruster module 24 and fin/control surface assembly module 28 . While in route, GPS data and image data from cameras 42 and 46 can be transmitted over cable 30 A to base station 50 . More specifically, vehicle attitude/location and target location are displayed on tactical display 52 while sonar data can be displayed on sonar display 54 . Image data can be displayed on video display(s) 56 . Once in position for performing nuclear material reconnaissance, nuclear material sensor(s) module 22 is activated and underwater vehicle 10 is moved to inspect an area of interest. Sensor data gathered by module 22 is transmitted over cable 30 A to base station 50 .
The advantages of the present invention are numerous. The unmanned underwater nuclear material reconnaissance system will allow a dangerous underwater environment to be inspected from a safe stand off distance. The system can be used in covert military operations as well as civilian operations. The use of multiple propulsion pods allows the use of smaller batteries which are drawn down at a slower rate than larger batteries used in conventional underwater propulsion systems. Thus, the present invention can be used in longer missions and at greater stand off ranges than conventional underwater vehicles.
Although the invention has been described relative to a specific embodiment thereof, there are numerous variations and modifications that will be readily apparent to those skilled in the art 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 other than as specifically described. | An underwater nuclear material reconnaissance system includes an underwater vehicle propelled/steered by a plurality of propulsion pods distributed thereabout. The underwater vehicle includes nuclear material sensors for generating sensor data indicative of the presence of nuclear material, a tunnel thruster for providing vertical thrust for the underwater vehicle, and a bi-directional communications cable deployable from the underwater vehicle. A remotely-located communications base station coupled to the bi-directional communications cable transmits control commands to the underwater vehicle and receives sensor data transmitted from the underwater vehicle. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to apparatus and methods used for processing single-stream commingled recyclable materials, and more particularly, how to separate marketable fractions of recycled material by-product.
BACKGROUND OF THE INVENTION
[0002] Material recycling has become an important industry in recent years due to decreasing landfill capacity, environmental concerns and dwindling natural resources. Many industries and communities have adopted voluntary and mandatory recycling programs for reusable materials. Until recently, most trash collection efforts delivered waste materials, separated at the source, e.g. by the home owner, to the Material Recovery Facilities (MRF). In an effort to improve the economies of collecting garbage for recycling, many municipalities have changed from curbside source-separated to commingled recycling methods. Solid waste and trash that are collected from homes, apartments or companies now are combined in one container. When brought to a waste processing center, or MRF, the recyclable materials are frequently mixed together in a heterogeneous mass of material. These mixed recyclable materials include newspaper, magazines, mixed paper, cardboard, aluminum cans, plastic bottles, glass bottles and other materials that may be recycled. Changes in MRF design were required to handle the new commingled material.
[0003] U.S. Application #20030062294 (1) is an example of equipment developed to separate what is termed “single-stream” waste into fractions which have economic value. The single most valuable recyclable waste product is newspaper and other paper based product. The products of CP Manufacturing, as exemplified in the above application and also in U.S. Pat. No. 6,460,706 (2), are focused primarily on recovering paper, plastic containers and metal cans. These items may represent 70 to 90% of the economic value in recyclable waste as it is constituted today.
[0004] The advent of this equipment, by the nature of its operation, created its own waste by-product which is typically sent to a landfill. This material is referred to as “−4 inch news screens fines” (NSF). It is aggregates of compressed waste which fall through the first operation of the conventional disc screening method; based on the separation of the discs it is less than 4 inches in at least two dimensions; these dimensions vary somewhat with the particular equipment and operator. This material is a combination of glass, paper, metallic objects and general refuse, including food wastes. Historically, no equipment or process has been available to process this trash for sufficient residual value and hence the disposition to a landfill. There is an environmental need to reduce the amount of waste going to landfills and a need to compensate the MRF operator for this service.
SUMMARY OF THE INVENTION
[0005] The invention separates sub-four inch news screen fines, NSF, into fractions with economic value. The NSF Separation System recovers sufficient material of value to provide a return on investment to the purchaser in less than one year. The economic return is based on credits to MRF's from unredeemed funds for glass or metal containers in curbside recycling systems in states or countries which charge a deposit on those containers. The NSF system classifies fractions of materials through a combination of vibratory screening, conveying, and air movement apparatus to separate the waste and recover a high percentage of the portions that can meet the locale's recycling requirements.
[0006] The NSF Separation System can be configured as an addition to a conventional single stream processing system or stand by itself or be configured as a portable system. As a portable system, it can be used to provide audits of the composition of the sub four inch portion of a waste stream. The invented system may be modified to handle waste material with dimensions larger than four inches if desired; the invention has several optional configurations as one knowledgeable in the art will appreciate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a flow diagram of the steps for the first two classifications carried out by the NSF Separation System.
[0008] FIG. 2 is a side elevation of the screening system (S 1 ) of the present invention.
[0009] FIG. 3 is a top view of the screening system (S 1 ) of the present invention.
[0010] FIG. 4 is a side elevation of the screening system (S 2 ) of the present invention with positive and negative air separation portion.
[0011] FIG. 5 is a top view of the screening system (S 2 ) of the present invention with positive and negative air separation portion.
[0012] FIG. 6 is a side elevation view of the final air separation portion of the present invention with cyclone and drop box with rotary airlock.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] The sequence of operations is part of the novelty of the invention. As detailed in FIG. 1 the waste stream is segregated by size. The initial classification of the sub 4 inch material is for the less than 2.5 inch fraction to be separated by falling through the screen, FIG. 1 , step ( 105 ), the beginning of the invented portion of the NSF Separation System. Since the “sub four inch material” is the first fallout of a disc-based operation the actual dimensions of the compressed material may vary from somewhat less than four inches to somewhat more than six inches. The initial screen size, herein set at 2.5 inches, may be somewhat smaller or larger depending on the characteristics of the particular machine producing the compressed waste. The larger fraction, Fraction 2, continues past the screen and returns to the beginning of the NSF system for further processing or, optionally, is discarded, FIG. 1 , step ( 106 - 108 ). Historically it has been found that the material of value is primarily the high density material in the smaller dimensions, such as below three inches. In addition, it is important that a vibratory screen be used as opposed to a disc based system; the vibratory screen helps separate the compressed material. Current disc systems have difficulty processing small dimension waste, particularly glass.
[0014] The material stream, Fraction 1, continues through the NSF Separation System FIG. 1 , step ( 112 ). In this section an unusually small screen is used; 0.25 inch is preferred. Sizes as large as one inch may be used depending on the nature of the material stream. The nature of the conveyor and vibratory action of the screen spread the material across the screen which is preferably about a 48 inches wide screen which is fed by about a 24 inch conveyor. The material dimensioned smaller than the screen size of 0.25 in. falls through, FIG. 1 , step ( 113 ) and is separated from the larger material. The larger material now proceeds to flow under a pneumatic separator, FIG. 1 , step ( 130 ). The embodiment of the invention as a portable apparatus for auditing curbside streams is substantially the same except all dimensions of the frames and conveyors are reduced; the classification sequence and screen sizes stay the same.
[0015] By removing material smaller than one quarter inch first, pneumatic separation of the larger dimensioned material is facilitated. In removing the {fraction (1/4)} inch portion via a shaker screen, the larger material is further separated across a 4 foot screen ensuring separation of high density material from light density material. Upon reaching the end of the screen, the material, across the complete length of the screen, falls into an air chamber, a pneumatic separator. The pneumatic separator has a novel design; using positive pressure air being pushed from below as well as air being extracted from above, the waste stream enters the air chamber, or pneumatic chute, and is classified as “light” or “heavy”. The absence of the smaller fines reduces the load on the pneumatic separator and subsequently the cost of operation. The chute design into the pneumatic separator ensures an even distribution of material already pre-separated by the shaker screen. In this step the “light fraction” passes up the pneumatic chute and the “heavy” fraction falls down. By having two independent streams of air a level of control over what material is removed, up, and what material goes down is achieved. This level of control can be adjusted by increasing or decreasing the air pressure on both the positive and negative air blowers using a variable speed drive. Adjustments to air are necessary given the material stream changes from season to season based on weather, holidays and seasonal variations. This pneumatic separator removes a very large fraction of the low density, paper and light waste products, portion of the stream by sending it up the chute and out of the main stream, FIG. 1 , step ( 132 ).
[0016] Using this novel sequence of steps, starting with about 4 inch material, a first classification, followed by a second classification for the small material, for instance less than one inch, achieved by using a shaker screen which further separates material prior to entering the air chamber followed by the pneumatic separation, high throughputs can be achieved. Conventional equipment which does not remove the small fraction in the second classification achieves processing rates of about two tons per hour. A prototype of the invention has achieved 16 tons per hour
[0017] The smaller fraction, FIG. 1 , step ( 114 ) falls to another conveying system or bin. This smaller fraction usually meets a minimum 50% glass content requirement which has sufficient economic value to avoid landfill disposal. This sub-quarter inch stream is typically about 10% of the total sub-four inch stream. The removal of this sub-quarter inch portion substantially reduces the cost of processing the glass and metal content of the remaining stream, Fraction 3+Fraction 5, as well as increasing overall separation efficiency of the NSF Separation System.
[0018] Typically, the “heavy” portion, Fraction 3, of the “+0.25 in. and −2.5 in.” fraction has value and is sent to be further classified by additional metal and air separation apparatus or other classification options, FIG. 1 , step ( 133 ) and beyond, not shown. Additional classification options include crossbelt magnet for metallic content and its removal, ceramic detection equipment and/or color separation creating a flint fraction and a colored fraction of glass. This heavy portion is classified to several portions, one of which is not less than 90% glass resulting in an economic return for material recovery facilities in bottle bill states where redemption or CRV is reimbursable for curbside operations. The metal and plastic portion have economic value and are recovered.
[0019] FIG. 2 is a side elevation view, figuratively, of the preferred embodiment of the present recycling invention comprising a vibrating screen system ( 202 ), and supporting delivery ( 201 ) and removal conveyors ( 206 and 205 ). The screening system is designed to classify the −4 inch news screen fines (NSF) compressed recyclable material into a less than 2.5 inch fraction (Fraction 1) present at ( 205 ) and greater than 2.5 inch fraction (Fraction 2) on to conveyer ( 206 ) corresponding to step 106 of FIG. 1 . Depending on the material stream, preferred separation screen sizes for screen 1 (S 1 ) may range between 2.5 inches and about 4 inches.
[0020] FIG. 3 is a top view of the same equipment as FIG. 2 . Material enters a recycling apparatus by a conveyor ( 301 ) as in step 101 of FIG. 1 ; is deposited on the uppermost region of the screen ( 302 ); is spread uniformly over the screen using a v-shaped metal separator welded onto the screen 12 inches from the deposit location. Separation occurs as the material moves longitudinally across the vibrating mesh screen surface which has been set at a size of 2.5 inches. The angle of the system design is optional and depends on design flow rate. Fraction 1, the less than 2.5 inch portion, is carried to the second classification by a conveyor ( 305 ). Fraction 2, the greater than 2.5 inch portion, is returned to a single stream sorting system or discarded by conveyor ( 306 ) and (C 4 ) of step ( 107 ), not shown.
[0021] FIG. 4 is a side elevation, figuratively, of the second classification occurring on a second vibrating screen system ( 412 ) as in step 112 . The screening system is designed to classify the less than 2.5 inch (NSF) compressed recyclable material, designated Fraction 1, into a qualifying fraction of sub-0.25 inch NSF Glass, Fraction 4, and a qualifying fraction of +0.25 inch to 2.5 inch portion requiring further classification, Fraction 3. The material enters the invention by a conveyor ( 410 ); is deposited on the uppermost region of the screen ( 412 ) and spread uniformly over the screen using a v-shaped metal separator welded onto the screen 12 inches from the deposit location as in step ( 111 ). Separation occurs as the material moves longitudinally across the vibrating mesh screen surface ( 412 ). The angle of the system design is optional and depends on design flow rate. Fraction 4, sub-0.25 inch NSF, is deposited in a bin or carried to a bin by an optional conveyor ( 414 ).
[0022] FIG. 5 is a top view, figuratively, of the second classification occurring on a second vibrating screen system ( 512 ) as in step 112 . Step ( 131 ), occurring at point ( 531 ), is a point of novelty in using an adjustable positive pressure air separation means from below and an adjustable “negative” pressure air from above to separate a light portion ( 530 ) from a heavy portion ( 533 ).
[0023] FIG. 6 shows schematically, a second pneumatic separation system performing step ( 132 ). The system ( 600 ) is designed to separate lightweight, non-glass material from the +{fraction (1/4)} inch to −2.5 inch stream at the lowermost position of the second screen ( 532 ) feeding into ( 632 ). Light, typically paper and waste material is pushed upward off the screening system by positive air pressure and then removed by suction created by a cyclone ( 642 ), drop box and rotary airlock air system ( 640 ). The heavier portion, having some value, is conveyed ( 645 ) to a bin for additional classification or is discarded. The lighter portion ( 650 ) is conveyed to the waste area. The lighter portion is typically waste and Styrofoam packing material and small bits of paper; the heavier “light fraction” is typically plastic caps and larger pieces of paper. The unusual combination of the cyclone and drop box facilitates the separation of the waste portion from the marketable portion; this separation is enabled by the first pneumatic separation done at the previous step.
[0024] The invention, being a specific sequence of steps and classification processes, enables between 50 and 85% of the initial sub four inch material to be recycled and not added to landfills. The invented apparatus has utility for the waste recycler and benefit to the environment. Previous workers in the field have not understood the advantages of using shaker screens and methodically arranging the sequence of classification to enable economic recovery.
[0025] Foregoing described embodiments of the invention are provided as illustrations and descriptions. They are not intended to limit the invention to a precise form as described. In particular, it is contemplated that functional implementation of invention described herein may be implemented equivalently in hardware and/or other available functional components or building blocks. Other variations and embodiments are possible in light of above teachings, and it is thus intended that the scope of invention not be limited by this Detailed Description, but rather by claims following. | A screening system designed to provide separation of multiple fractions of New Screens Fines. News Screens Fines (“NSF”) contain a mix of compressed, unmarketable recyclables that are generally less than four inches in size created as a by-product of current Material Recovery Facility (MRF) plant designs used to process single-stream recyclables. The NSF separation system uses a series of primary and secondary classification apparatus to separate materials into marketable products that meet legislative requirements. A series of screens, conveyors and air moving systems are designed to separate waste from fractions of glass, plastic and ferrous metals that can be sold. | 8 |
TECHNICAL FIELD
This invention relates to the nondestructive testing of manufactured parts in general, and in particular, to apparatus and methods for the nondestructive, in-situ verification of the minimum tensile elongation specification of metal castings, forgings, and premium mill products such as plate, bar and extrusion, and molded parts and the like.
BACKGROUND
Specifications for metal castings, forgings and premium mill products such as plate, bar and extrusion, frequently include tensile elongation minima among their lot acceptance requirements. Elongations are measured using tensile test specimens, e.g., “coupons,” made from specially cast bars (“prolongs”), or material that is excised from the manufactured parts themselves, which are stretched in specialized tensile testing machines. In addition to the cost of the materials consumed in these tests, there are also significant costs associated with the machining and testing of the specimens. Furthermore, the specimens may not adequately represent the true bulk material properties of the parts being evaluated, which can lead to erroneous test results.
A long-felt but as yet unsatisfied need therefore exists in the manufacturing industry for reliable, low-cost, apparatus and methods for the nondestructive verification of the minimum tensile elongation specification of a manufactured part that can be effected on the part itself, thereby eliminating the need for expensive tensile test coupons and equipment, and any question whether such coupons accurately represent the true bulk material properties of the manufactured part.
BRIEF SUMMARY
In accordance with an embodiment of the present invention, simple yet reliable, low-cost apparatus and methods are provided for the nondestructive, in-situ verification of the minimum tensile elongation specification of a manufactured part that eliminate the need for tensile coupons, and any question whether such coupons accurately represent the actual bulk properties of the manufactured part. Since the non-destructive elongation measurements are made within the parts themselves, material pedigree is no longer an issue. Advantageously, the novel method also applies stresses to a greater amount of the material of the part, and can easily sample different areas of the part, thereby enabling a closer, more thorough evaluation of the part's material bulk properties.
In an exemplary embodiment thereof, the apparatus of the invention includes a simple, disposable, elongated mandrel having opposite first and second ends. A small, first cylindrical portion is disposed adjacent to the first end of the mandrel to define a pilot end portion thereof. A larger second cylindrical portion is disposed adjacent to the second end of the mandrel to define a hole-expanding end portion thereof. A first axial taper extends between the first and second portions. A second axial taper may extend between the first end of the mandrel and the first portion thereof, and a third axial taper may extend between the second portion and the second end thereof. Advantageously, the second, or pushing end of the mandrel may be rounded to form a spherical bearing surface. In one possible embodiment, the mandrel is made of a hard, structural ceramic, such as silicon nitride or a tool steel. An exterior surface of the mandrel may be coated with a hard, low-friction coating, e.g., a baked-on, thin-film lubricant.
In accordance with an exemplary embodiment of the method of the invention, the mandrel functions in cooperation with a pre-lubricated through-hole having a specific diameter H that is formed in the manufactured part, e.g., a casting or a forging, having a minimum tensile elongation specification “e,” expressed as a percentage, which is to be tested. The second, hole-expanding portion of the mandrel has a diameter D that is related to the tensile elongation specification e and the diameter H of the test through-hole by the relationship,
D = ( e 100 + 1 ) · H ,
and is thereby adapted to expand the diameter of the hole to the minimum elongation e required in the specification when the mandrel is pressed into the hole. Thus, the pilot end of the mandrel is inserted into a first, or front, end of the test hole, and the mandrel is then pressed fully into the hole, e.g., with a benchtop press ram, until the second end of the mandrel is about flush, or coplanar with, the first end of the hole. After the mandrel has been pressed into the hole, the region of the part adjacent to the first end of the hole is inspected, e.g., visually, or by fluorescent dye penetrant, for radial cracks. The presence of radial cracks in the part adjacent to the hole indicates that the manufactured part does not meet the specification, and the absence of such cracks indicates that it does.
For parts that are relatively thick, the mandrel may be pressed further into the hole, until the second portion of the mandrel is disposed at a second, or back end of the hole, and the back of the part adjacent to the second end of the hole may also be inspected for radial cracks. For parts that are relatively thin, the front and back surface inspections may be performed concurrently, without further insertion of the mandrel into the test hole. When the test is complete, the mandrel is expelled from the test hole and discarded.
A better understanding of the above and many other features and advantages of the invention may be obtained from a consideration of the detailed description thereof below, particularly if such consideration is made conjointly with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of an exemplary embodiment of an expansion mandrel in accordance with the present invention;
FIG. 2 is a partial cross-sectional elevation view of the exemplary mandrel being pressed into a first end of a test hole of a manufactured part;
FIG. 3 is a partial cross-sectional elevation view of the mandrel after being pressed into the test hole of the part;
FIG. 4 is a partial cross-sectional elevation view of a region of the part adjacent to the first end of the hole being inspected for radial cracks;
FIG. 5 is a partial cross-sectional elevation view of the mandrel being pressed further into the test hole of the part;
FIG. 6 is a partial cross-sectional elevation view of a region of the part adjacent to a second end of the test hole being inspected for radial cracks; and,
FIG. 7 is a partial cross-sectional elevation view of the mandrel being pressed out of the part.
DETAILED DESCRIPTION
In accordance with an exemplary embodiment of the present invention, an inexpensive, disposable mandrel 10 and a few simple bench tool accessories are used in conjunction with a method to radially expand a test hole formed in a casting, forging, or other manufactured part by a prescribed amount to effect a circumferential strain at the edge of the hole matching minimum required elongation, or target strain, of the part. After the test hole has been radially expanded, the area in the vicinity of the test hole is inspected for radial cracks, which indicate that the part does not meet the elongation minima requirements. The apparatus and method can be used either to complement or completely replace existing standard tensile tests.
As illustrated in FIG. 1 , the apparatus of the invention comprises an elongated, tapered mandrel 10 that is used to radially expand a pre-lubricated test hole that has been formed in the part to be tested. The mandrel has opposite, respective first and second ends 12 and 14 . A small, first cylindrical portion 16 is disposed adjacent to the first end of the mandrel, and defines a “pilot” end portion thereof. A larger second cylindrical portion 18 is disposed adjacent to the second end of the mandrel, and defines a hole-expanding end portion thereof. A first axial taper 20 extends between the first and second portions. Advantageously, a second axial taper 22 may extend between the first end of the mandrel and the first portion thereof, and a third axial taper 24 may extend between the second portion and the second end thereof. Optionally, the second end 14 of the mandrel may be rounded to form a spherical-segment bearing surface thereat.
In accordance with one embodiment of the method of this invention, a test hole 26 , as illustrated in FIG. 2 , is located in a region of the part 28 where a tensile strain (i.e., elongation) measurement is desired. Radial cold expansion of a hole can be accomplished using a variety of techniques, the most common of which are (a) pull-type, sleeve-assisted expansion, (b) pull-type split-mandrel expansion, (c) pull-type solid-mandrel expansion, and (d) push-mandrel expansion. A problem with cold expansion of a hole using a standard “sleeve” process is that the hole, sleeve and mandrel dimensional tolerances compound to prevent obtaining a consistent strain around the hole. On the other hand, with sleeveless expansion of holes in, e.g., titanium, mandrel forces tend to be relatively large, and accordingly, a significant amount of galling and material pick up can occur on the mandrel as it traverses the hole, which precludes both the use of a pull-type solid mandrel or a split mandrel, and a re-use of either. Accordingly, this invention incorporates a sleeveless, “push-only” process, in which the expansion mandrel is used only once, to better control forces and strains and minimize the chances of the mandrel being jammed in the hole or scoring it, and varying the hole size prior to expansion as required to attain the desired target strain. Mandrel costs can be controlled by specifying only one, or at most, two standard mandrel sizes (e.g., one basic size and one larger size for re-test or rework) and adjusting the hole size prior to expansion as required to attain the desired target strain.
As illustrated in FIG. 2 , the first step of the exemplary method comprises drilling and reaming a test through-hole 26 at the desired location in the manufactured part 28 to a standard hole size, e.g., 0.3750, +0.0000/−0.0020 inch. The hole is preferably located in an area of the part that will not be highly loaded in service, and away from other stress concentrations. After the hole has been drilled and reamed, the hole is deburred at a first, or front, mandrel entry end 30 , and the hole is lubricated internally, e.g., with molybdenum disulfide grease.
The mandrel 10 is preferably made of a strong, hard material, such as a structural ceramic (e.g., silicon nitride) or a suitable tool steel with a hard, low-friction coating. With reference to FIG. 1 , the diameter B of the first end portion 16 of the mandrel is designed to serve as a pilot, and is therefore made slightly smaller than the test hole 26 initial diameter H. The diameter of the second, hole-expanding portion 18 of the mandrel is related to the initial test hole diameter H by the relationship,
D = ( e 100 + 1 ) · H ,
where e is the minimum percent elongation, or acceptable target strain, in the specification of the part 28 (e.g., 6.0 percent for certain titanium alloy castings), and H is the diameter of the test hole.
The mandrel 10 is then lubricated, and the pilot end portion 16 is inserted in the first, entry end 30 of the test hole 26 , as illustrated in FIG. 2 . Alternatively, the mandrel may be furnished with a baked-on, or otherwise applied, thin-film lubricant to avoid the need for lubricating it prior to the test. A reusable stop 32 made from a high-strength material may be used to control the amount of mandrel travel, but is not required if the process is performed slowly and can be easily halted as the mandrel reaches its maximum amount of engagement near the entry end 30 of the test hole, i.e., when the second end 14 of the mandrel is about flush, or coplanar with, the entry end of the test hole. It may be noted that the mandrel may advantageously incorporate a bearing surface comprising a spherical segment at the second end thereof to define a point contact with the stop 32 , to compensate for any misalignment of the mandrel with the test hole, as well as to facilitate expanding test holes that are not precisely normal to the mandrel entry end of the hole.
As illustrated in FIG. 2 , an annular support element 34 having an internal diameter larger than H may be disposed against a back surface of the part 28 and aligned coaxially with the test hole 26 to react against the pushing force of the mandrel 10 and thereby minimize any deflections in the part when the mandrel is pressed into the test hole. The support element may comprise either a suitably strong hollow cylinder, as illustrated in FIG. 2 , or simply a thick plate with a hole that is larger than and disposed concentrically with the test hole. Of importance, it should be noted that the thickness of the part should be equal to or greater than the test hole diameter H, to minimize permanent axial deformation of the part near the test hole.
The mandrel 10 and the optional stop 32 are pushed slowly toward the part 28 by a benchtop press ram 36 in the direction of the broad arrow 38 in FIG. 2 , until the stop is disposed against the surface of the part and the second end 14 of the mandrel is about coplanar with the first end 30 of the test hole 26 , as illustrated in FIG. 3 , which corresponds approximately to the point of maximum mandrel engagement of the hole near the mandrel entry end 30 thereof. At this point, the ram and stop are pulled away from the mandrel, and the surface of the part adjacent to the first end of the expanded hole is inspected for radial cracks caused by the tensile expansion, or elongation, of the hole, as illustrated in FIG. 4 . The inspection may be performed visually, using conventional light and optical magnifiers, or, e.g., by use of a fluorescent dye penetrant. It may be noted that, by performing the inspection at the maximum expansion of the hole, any radial cracks present will be open and notorious, and therefore more easily detected. As the circumferential strain at the edge of the enlarged test hole has been set by design to match the minimum elongation requirement e in the specification of the part, the presence of detectable radial cracks indicates that the casting does not meet the specification, i.e., the part failed the test, and the absence of such cracks indicates that it passed.
If no radial cracks are found in the part 28 adjacent to the first end 30 of the test hole 26 , the test is continued at the back side of the part, and the procedure followed with respect thereto depends on the local thickness of the part. For test holes that are relatively shallow, i.e., those in which the second, expanding portion 18 of the mandrel 10 is disposed adjacent to a second, or mandrel exit end 40 of the test hole after the mandrel is initially pressed in, both the front and back surface inspections may be conducted concurrently, by simply turning the part over and inspecting the part adjacent to the second end of the expanded test hole for radial cracks.
However, for relatively deep test holes 26 , i.e., those in which the second, expanding portion 18 of the mandrel 10 is spaced apart from the second end 40 of the test hole after the mandrel is initially pressed in, as illustrated in FIG. 4 , it is desirable to press the mandrel further into the hole, until the second portion of the mandrel is disposed at about the second end of the test hole, so that the hole is fully expanded throughout it entire length, before performing an inspection for radial cracks at the second end thereof.
As illustrated in FIG. 5 , this may be effected using a short insert 42 disposed on the optional stop 32 . The length of the insert 42 is selected such that the second portion 18 of the mandrel 10 is disposed adjacent to the second, or mandrel exit end 40 of the test hole 26 , as illustrated in FIGS. 5 and 6 , and the diameter of the insert is, of course, selected to be less than the diameter H of the test hole, so that the insert fits in the hole without interference. As illustrated in FIG. 6 , after the test hole has been fully expanded by this second pressing of the mandrel, the back side of the part 28 may be inspected adjacent to the second end 40 of the test hole for radial cracks in a manner similar to that conducted on the front side.
The test process is completed by expelling the mandrel 10 completely from the test hole 26 , as illustrated in FIG. 7 . This may be effected by pressing against the second end 14 of the mandrel with the press ram 36 and a second insert 44 of an appropriate length. Preferably, the mandrel is then discarded, as it may have been rendered unsuitable for re-use, either by damage or by the accretion of a coating of material from the inspected part 28 as a result of its having been pressed through the test hole. After the mandrel has been ejected from the part, the test hole may be cleaned and inspected for signs of scoring or gouges, and can either be further processed (e.g., reamed) and filled with a fastener, or simply left as an open hole. The part may then be tagged for appropriate subsequent disposition, i.e., rejection, reworking, or further processing. It should be noted that, since the method and apparatus of the invention functions to cold-work the test hole, the possible detrimental effect of the test hole on fatigue performance of the tested part is substantially mitigated.
By now, those of skill in this art will appreciate that many modifications, substitutions and variations can be made in and to the materials, apparatus, configurations and methods of implementation of the present invention without departing from its spirit and scope. Accordingly, the scope of the present invention should not be limited to the particular embodiments illustrated and described herein, as they are merely exemplary in nature, but rather, should be fully commensurate with that of the claims appended hereafter and their functional equivalents. | The minimum tensile elongation specification of a manufactured part, such as metal castings, forgings and premium mill products, is verified in-situ using a simple, inexpensive, nondestructive apparatus and method in which a through-hole is formed in the part to be tested. A disposable mandrel having a diameter adapted to expand the hole to the minimum elongation required in the part's specification is pressed into the hole. The presence of radial cracks in the part adjacent to the hole after the mandrel has been pressed in indicates that the part does not meet the specification, and the absence of such cracks indicates that it does. Since the test is performed on the part itself, the cost of the manufacture and testing of tensile test coupons is eliminated, and different areas of the part may be sampled easily, thereby enabling a closer, more thorough evaluation of part's material bulk properties. | 6 |
REFERENCE TO RELATED APPLICATION
The present application claims priority benefit under 35 U.S.C. §119(e) from U.S. Provisional Application No. 60/586,821, filed Jul. 9, 2004, entitled “Cyanotic Infant Sensor,” which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Cyanosis is a congenital condition in which blood pumped to the body contains less than normal amounts of oxygen, resulting in a blue discoloration of the skin. The most common cyanotic condition is tetralogy of Fallot, which is characterized by an abnormal opening, or ventricular septal defect, that allows blood to pass from the right ventricle to the left ventricle without going through the lungs; a narrowing, or stenosis, proximate the pulmonary valve, which partially blocks the flow of blood from the right side of the heart to the lungs; a right ventricle that is abnormally muscular; and an aorta that lies directly over the ventricular septal defect. Another cyanotic condition is tricuspid atresia, characterized by a lack of a tricuspid valve and resulting in a lack of blood flow from the right atrium to the right ventricle. Yet another cyanotic condition is transposition of the great arteries, i.e. the aorta originates from the right ventricle, and the pulmonary artery originates from the left ventricle. Hence, most of the blood returning to the heart from the body is pumped back out without first going to the lungs, and most of the blood returning from the lungs goes back to the lungs.
Pulse oximetry is a useful tool for diagnosing and evaluating cyanotic conditions. A pulse oximeter performs a spectral analysis of the pulsatile component of arterial blood so as to measure oxygen saturation, the relative concentration of oxygenated hemoglobin, along with pulse rate. FIG. 1 illustrates a pulse oximetry system 100 having a sensor 110 and a monitor 140 . The sensor 110 has emitters 120 and a detector 130 and is attached to a patient at a selected fleshy tissue site, such as a thumb or toe. The emitters 120 project light through the blood vessels and capillaries of the tissue site. The detector 130 is positioned so as to detect the emitted light as it emerges from the tissue site. A pulse oximetry sensor is described in U.S. Pat. No. 6,088,607 entitled “Low Noise Optical Probe,” which is assigned to Masimo Corporation, Irvine, Calif. and incorporated by reference herein.
Also shown in FIG. 1 , the monitor 140 has drivers 150 , a controller 160 , a front-end 170 , a signal processor 180 , a display 190 . The drivers 150 alternately activate the emitters 120 as determined by the controller 160 . The front-end 170 conditions and digitizes the resulting current generated by the detector 130 , which is proportional to the intensity of the detected light. The signal processor 180 inputs the conditioned detector signal and determines oxygen saturation, as described below, along with pulse rate. The display 190 provides a numerical readout of a patient's oxygen saturation and pulse rate. A pulse oximetry monitor is described in U.S. Pat. No. 5,482,036 entitled “Signal Processing Apparatus and Method,” which is assigned to Masimo Corporation, Irvine, Calif. and incorporated by reference herein.
SUMMARY OF THE INVENTION
The Beer-Lambert law provides a simple model that describes a tissue site response to pulse oximetry measurements. The Beer-Lambert law states that the concentration c i of an absorbent in solution can be determined by the intensity of light transmitted through the solution, knowing the mean pathlength, mpl λ , the intensity of the incident light, I 0,λ , and the extinction coefficient, ε i,λ , at a particular wavelength λ. In generalized form, the Beer-Lambert law is expressed as:
I λ =I 0,λ e −mpl λ ·μ a,λ (1)
μ a , λ = ∑ i = 1 n ɛ i , λ · c i ( 2 )
where μ a,λ , is the bulk absorption coefficient and represents the probability of absorption per unit length. For conventional pulse oximetry, it is assumed that there are only two significant absorbers, oxygenated hemoglobin (HbO 2 ) and reduced hemoglobin (Hb). Thus, two discrete wavelengths are required to solve EQS. 1-2, e.g. red (RD) and infrared (IR).
FIG. 2 shows a graph 200 depicting the relationship between RD/IR 202 and oxygen saturation (SpO 2 ) 201 , where RD/IR denotes the ratio of the DC normalized, AC detector responses to red and infrared wavelengths, as is well-known in the art and sometimes referred to as the “ratio-of-ratios.” This relationship can be approximated from Beer-Lambert's Law, described above. However, it is most accurately determined by statistical regression of experimental measurements obtained from human volunteers and calibrated measurements of oxygen saturation. The result can be depicted as a curve 210 , with measured values of RD/IR shown on an x-axis 202 and corresponding saturation values shown on a y-axis 201 . In a pulse oximeter device, this empirical relationship can be stored in a read-only memory (ROM) for use as a look-up table so that SpO 2 can be directly read-out from an input RD/IR measurement. For example, an RD/IR value of 1.0 corresponding to a point 212 on the calibration curve 210 indicates a resulting SpO 2 value of approximately 85%.
Accurate and consistent pulse oximetry measurements on cyanotic infants have been difficult to obtain. An assumption inherent in the calibration curve 210 ( FIG. 2 ) is that the mean pathlength ratio for RD and IR is constant across the patient population. That is:
mpl RD /mpl IR =C (3)
However, EQ. 3 may not be valid when cyanotic infants are included in that population. The reason may lie in what has been observed as abnormal tissue tone or lack of firmness associated with cyanotic defects, perhaps due to reduced tissue fiber. Such differences in tissue structure may alter the mean pathlength ratio as compared with normal infants. A cyanotic infant sensor addresses these problems by limiting variations in the RD over IR mean pathlength ratio and/or by providing a mean pathlength ratio measure so as to compensate for such variations. Alone or combined, these sensor apparatus and algorithms increase the accuracy and consistency of pulse oximetry measurements for cyanotic infants.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a prior art pulse oximetry system;
FIG. 2 is an exemplar graph of a conventional calibration curve;
FIGS. 3A-B are a perspective and an exploded perspective views, respectively, of a cyanotic infant sensor embodiment;
FIGS. 4-5 depict cross-sectional views of a tissue site and an attached pulse oximeter sensor, respectively;
FIG. 6 depicts a cross-sectional view of a tissue site and an attached cyanotic infant sensor;
FIGS. 7A-B are plan and cross-sectional sensor head views of a conventional pulse oximeter sensor;
FIGS. 8-9 are plan and cross-sectional sensor head views of cyanotic infant sensor embodiments; and
FIG. 10 is an exemplar graph of a calibration surface incorporating a mean pathlength ratio measure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 3A-B illustrate one embodiment of a cyanotic infant sensor. The sensor has a light absorbing surface, as described with respect to FIGS. 4-6 , below. The sensor also has a detector window configured to limit the detector field-of-view (FOV), as described with respect to FIGS. 7-9 , below. Advantageously, these features limit mean pathlength ratio variations that are particularly manifest in cyanotic patients.
The sensor emitters and detector are also matched so as to limit variations in the detector red over IR DC response, i.e. RD DC /IR DC , that are not attributed to variations in the mean pathlength ratio (EQ. 3). Such matching advantageously allows for measurement and calibration of the mean pathlength ratio, as described with respect to FIG. 10 , below. In one embodiment, cyanotic infant sensors 300 are constructed so that:
λ RD ≈c 1 ; λ IR ≈c 2 (4)
I 0,RD /I 0,IR ≈c 3 ; for i DC (RD), i DC (IR) (5)
RD DC /IR DC ≈c 4 (6)
That is, sensors 300 are constructed from red LEDs and IR LEDs that are each matched as to wavelength (EQ. 4). The LEDs are further matched as to red over IR intensity for given DC drive currents (EQ. 5). In addition, the sensors 300 are constructed from detectors that are matched as to red over IR DC response (EQ. 6). In an embodiment, at least one detector is selected from a plurality of matched detectors each having a first wavelength response over a second wavelength response ratio for at least one predetermined DC incident intensity.
As shown in FIG. 3A , the sensor 300 has a body 310 physically connecting and providing electrical communication between a sensor head 320 and a connector 330 . The sensor head 320 houses the emitters and detector and attaches to a patient tissue site. The connector mates with a patient cable so as to electrically communicate with a monitor. In one embodiment, a sensor head surface 324 is constructed of light absorbing material.
As shown in FIG. 3B , the sensor 300 has a face tape 330 , a flex circuit 340 and a base tape 360 , with the flex circuit 340 disposed between the face tape 330 and the base tape 360 . The flex circuit 340 has a detector 342 , an emitter 344 with at least two light emitting diodes (LEDs), an information element 346 , and contacts 348 disposed on a connector tab 349 . Neonatal sensors having a detector, LEDs, an information element, contacts and connector tab are described in U.S. Pat. No. 6,256,523 entitled “Low-Noise Optical Probes,” which is assigned to Masimo Corporation, Irvine, Calif. and incorporated by reference herein. In one embodiment, the face tape 350 and base tape 360 are constructed of Betham tape having attached polyethylene head tapes 351 , 361 . In a particular embodiment, the base head tape 361 is made of black polyethylene, and the face head tape 351 is made of white polyethylene. In one embodiment, a clear tape layer is disposed on the base head tape 361 tissue side over the detector window 362 . The base head tape 361 has a detector window 362 and an emitter window 364 each allowing light to pass through the base head tape 361 . In one embodiment, the base head tape 361 has a 4 mil thickness and the flex circuit has a 10 mil thickness. The combined 14 mil material thickness functions to limit the detector FOV, as described with respect to FIGS. 6 and 8 , below.
FIGS. 4-6 illustrate some of the pathlength control aspects of a cyanotic infant sensor 300 . FIG. 4 depicts a fleshy tissue site 10 for sensor attachment, such as a finger or thumb 400 . The tissue 10 has an epidermis 12 , a dermis 14 , subcutaneous and other soft tissue 16 and bone 18 .
FIG. 5 depicts a conventional pulse oximetry sensor 20 having a detector 22 , an emitter 24 and a tape 26 attached to the fleshy tissue 10 . Transmitted light 30 propagating from the emitter 24 to the detector 22 that results in a significant contribution to pulse oximetry measurements passes through and is absorbed by the pulsatile blood in the dermis 14 . A portion of the transmitted light 30 is scattered out of the epidermis 12 and reflected by the tape 26 back into the fleshy tissue 10 . The detector field-of-view (FOV) 40 is relatively wide and, as a result, the detector responds to transmitted light 30 that has propagated, at least in part, outside of the fleshy tissue 10 .
FIG. 6 depicts a cyanotic infant sensor 300 that is configured to limit variations in the mean pathlength ratio. In particular, the sensor 300 has a light absorbing tape inner surface 324 that reduces transmitted light reflection back into the tissue site 10 , as described with respect to FIGS. 3A-B , above. Further, the detector 342 has a limited FOV 50 so as to reduce the detection of transmitted light that has propagated outside of the tissue site 10 , as described in detail with respect to FIGS. 7-9 , below.
FIGS. 8-9 illustrate cyanotic infant sensor embodiments having a limited detector field-of-view (FOV). FIGS. 7A-B illustrate a conventional sensor 700 having a tape portion 760 , a detector window 762 and a detector 742 having a relatively wide FOV 701 . In particular, the window thickness does little to restrict the FOV. FIGS. 8A-B illustrate one embodiment of a cyanotic infant sensor 300 having a material portion 360 , a detector window 362 and a detector 342 having a restricted FOV 801 . In particular, the material thickness 360 functions to define the FOV 801 . In one embodiment, the material thickness 360 comprises a flex circuit thickness and a base head tape thickness, as described with respect to FIG. 3B , above. FIGS. 9A-B illustrate another embodiment of a cyanotic infant sensor 900 having a material portion 960 , a detector window 962 and a detector 942 having a restricted FOV 901 . In particular, an O-ring 980 deposed around the window 962 defines the FOV 901 .
FIG. 10 depicts an exemplar calibration surface 1000 for a cyanotic infant sensor 300 ( FIGS. 3A-B ) calculated along a DC response ratio axis 1001 , a ratio-of-ratios axis 1003 and a resulting oxygen saturation axis 1005 . Matching the emitters and detectors, as described with respect to FIG. 3A , above, allows for pathlength calibration. In particular, variations in the detector DC response ratio (RD dc /IR dc ) are attributed to variations in the mean pathlength ratio (EQ. 3). As such, a calibration surface is determined by statistical regression of experimental measurements obtained from human volunteers and calibrated measurements of oxygen saturation, as is done for a conventional calibration curve ( FIG. 2 ). A calculated DC response ratio 1001 in combination with a conventionally calculated ratio-of-ratios 1003 is then used to derive an oxygen saturation 1005 for the calibration surface 1000 .
A cyanotic infant sensor has been disclosed in detail in connection with various embodiments. These embodiments are disclosed by way of examples only and are not to limit the scope of the claims that follow. One of ordinary skill in art will appreciate many variations and modifications. | A pulse oximetry sensor comprises emitters configured to transmit light having a plurality of wavelengths into a fleshy medium. A detector is responsive to the emitted light after absorption by constituents of pulsatile blood flowing within the medium so as to generate intensity signals. A sensor head has a light absorbing surface adapted to be disposed proximate the medium. The emitters and the detector are disposed proximate the sensor head. A detector window is defined by the sensor head and configured so as to limit the field-of-view of the detector. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
The present application is based on and claims priority from Japanese Patent Application: 2005-351667, filed Dec. 6, 2005, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rotation angle detecting device that employs Hall elements, whose temperature characteristic can be corrected.
2. Description of the Related Art
A well-known rotation angle detecting device employs one or more Hall elements, which are disposed in a magnetic field formed by a permanent magnet. The Hall elements are arranged to rotate relative to the permanent magnet as a rotating object rotates, so that the output voltage of the Hall elements is generated in response to change in magnetic flux density. The rotation angle of the rotating object is calculated based on the output voltage of the Hall elements. JP-A 2001-124511 or U.S. Pat. No. 6,498,479 B1, which is a counterpart U.S. patent, discloses a rotation angle detecting device in which temperature characteristic of the output voltage of the Hall elements is corrected.
Assuming that: the ambient temperature of the rotation angle detecting device is t; the output voltage of the Hall element under the ambient temperature t is V out (t); the offset voltage of the Hall element when the magnetic flux density is zero is V off (t); and the inclination of the output voltage to the magnetic flux density (herein after referred to as sensitivity) is S(t), the output voltage of the Hall element V out (t) can be expressed as follows.
V out ( t )= V off ( t )+ B×S ( t ) (1)
Usually, temperature characteristic is corrected by setting the sensitivity S(t), which is set at a specific magnetic flux density.
However, it is difficult to accurately correct the temperature characteristic of the Hall element disposed in the magnetic field of a magnetic flux density that is different from the specific magnetic flux density.
SUMMARY OF THE INVENTION
Therefore, an object of the invention is to provide a method of correcting the temperature characteristic of the Hall element of a rotation angle detecting device.
According to a feature of the invention, a method of correcting temperature characteristic of a rotation angle detecting device that includes field forming means, a Hall element that rotates relative to the field forming means when a rotating object rotates to provide an output signal. The method is comprised of a step of setting temperature correction values for correcting a temperature characteristic of the rotation angle detecting device according to magnetic flux density.
In the above method: the magnetic flux density is preferably divided into a plurality of grade ranges, and the temperature correction values are respectively set for the grade ranges; and the temperature correction value α(t) is defined as follows: α(t)=V sen-off (t 0 )/V sen-off (t) wherein the ambient temperature of the rotation angle detecting device is t, the output voltage of the Hall element under the ambient temperature t is V out (t), the offset voltage of the Hall element when the magnetic flux density is zero is V off (t), the inclination of the output voltage to the magnetic flux density is S(t), a basic offset voltage under the ambient temperature of t 0 is V 0 , a difference between the basic offset voltage V 0 and a current offset voltage V off (t) is ΔV off , V sen-off (t) is defined as V out (t)−V 0 =ΔV off (t)+B×S(t).
Another object of the invention is to provide an improved rotation angle detecting device that can accurately correct the temperature characteristic of the Hall element at every magnetic flux density.
According to another feature of the invention, a rotation angle detecting device for detecting a rotation angle of a rotating object includes magnet field forming means for forming a magnetic field, a Hall element, disposed in the magnetic field to rotate relative to the magnetic field when the rotating object rotates, for outputting voltage according to magnetic flux density of the magnetic field, setting means for setting a temperature characteristic correction value α i (t) at a temperature (t) for each one of a plurality of grade ranges of the magnetic flux density, a memory for storing the temperature characteristic correction value α i (t) for each one of a plurality of grade ranges of the magnetic flux density, correction means for correcting the temperature characteristic of the Hall element by the temperature characteristic correction value α i (t) that corresponds to a magnetic flux density to detect.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and characteristics of the present invention as well as the functions of related parts of the present invention will become clear from a study of the following detailed description, the appended claims and the drawings. In the drawings:
FIG. 1 is a schematic diagram illustrating a rotation angle detecting device according to a preferred embodiment of the invention;
FIG. 2 is a cross-sectional side view of the rotation angle detecting device according to the preferred embodiment;
FIG. 3 is a block diagram of a Hall IC chip of the rotation angle detecting device according to the preferred embodiment;
FIG. 4 is a flow diagram of a method of correcting temperature characteristic of a Hall element of the Hall IC chip;
FIG. 5 is a flow diagram for setting a temperature characteristic correction value;
FIG. 6 is a graph showing temperature characteristic curves of offset voltage;
FIGS. 7A , 7 B and 7 C are graphs showing characteristic curves for calculating the temperature characteristic correction value; and
FIG. 8 is a table showing temperature characteristic correction values that are set for plural grade ranges of magnetic flux density.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A rotation angle detecting device 10 according to a preferred embodiment of the invention will be described with reference to the appended drawings.
As shown in FIGS. 1 and 2 , the rotation angle detecting device 10 according to a preferred embodiment of the invention includes a cylindrical rotor core 12 , a pair of permanent magnets 14 , a cylindrical stator core 20 and a pair of Hall IC chips 30 . The rotor core 12 and the permanent magnets 14 are fixed to an end of a throttle shaft 2 of a throttle device so that they can rotate together with the throttle shaft 2 . The permanent magnets 14 are respectively fixed to radially opposite sides of the rotor core 12 , thereby forming a magnetic field. The stator core 20 is disposed inside the cylindrical rotor core 12 . The Hall IC chips 30 are mounted on the stator core 20 to line up with a diametrical line of the stator core 20 so that one of the Hall IC chips 30 can serve even if the other fails. As shown in FIG. 3 , each Hall IC chip 30 includes a Hall element 32 , an A/D converter 34 , a digital signal processor (DSP) 36 , an EEPROM 38 and a D/A converter 40 .
The Hall element 32 outputs a voltage signal that corresponds to a component of a magnetic flux density perpendicular to the detecting surface of the Hall element 32 . The DSP 36 corrects the temperature characteristic of the digitalized voltage signal of the Hall element 32 according to a temperature characteristic correction valueS(e.g. α(t)) stored in the EEPROM 38 . The D/A converter 40 converts the corrected digitalized voltage signal into an analog voltage signal.
Assuming that: a basic offset voltage of the Hall element (when the magnetic flux density is zero and the ambient temperature is t 0 ) is V 0 ; and a difference between the basic offset voltage V 0 and other offset voltage V off (t) is ΔV off , the other offset voltage V off (t) of the Hall element (when the magnetic flux density is zero and the ambient temperature is t) can be expressed as follows.
V off ( t )= V 0 +ΔV off ( t ) (2)
Accordingly, the expression (1) can be changed as follows.
V out ( t )= V 0 +ΔV off ( t )+ B×S ( t ) (3)
The above expression (3) can be also expressed as follows.
V out ( t )− V 0 =ΔV off ( t )+ B×S ( t )= V sen-off (4),
where V sen-off includes the temperature characteristics of both offset voltage and the sensitivity.
The basic offset voltage V 0 is a constant value and can be measured by a test.
A temperature characteristic correction value α(t) can be expressed in the following approximation.
α( t )=1+ a ( t−t 0 )+ b ( t−t 0 ) 2 (5)
wherein a and b are set to be 0 before a correction is made.
The temperature characteristic correction value α(t) is set for each grade range of the magnetic flux density, as shown in FIG. 8 . As shown in FIG. 4 , the temperature characteristic correction values are set as follows. At the first step S 200 , the basic voltage V 0 and the sensitivity S (t 0 ) at each grade range of the magnetic flux density from −200 mT up to 200 mT are measured and stored into one of 20 grade ranges of the EEPROM 38 . At S 202 , temperature characteristic correction values α(t) for each one of a plurality of grade ranges of magnetic flux density is set. At S 204 , each set temperature correction value α(t) is stored into the EEPROM 38 . At S 206 , the voltage signal V out (t) of the Hall element 32 is measured to examine whether the voltage signal V out (t) is corrected based on the temperature characteristic correction value α(t) or not.
The temperature characteristic correction value α(t) is set according to flow diagram shown in FIG. 5 .
At step 210 , the output voltage V off (t) of the Hall IC 30 under the magnetic flux density of 0 is measured while the ambient temperature changes from −40 degrees C. up to 120 degrees C. Since the offset voltage V 0 at temperature to has been measured at S 200 , ΔV off can be obtained from the expression (2).
At S 212 , a magnetic field of a certain magnetic flux density B k in one of the grade ranges of the magnetic flux density is given to the Hall IC chip 30 to measure the output voltage V out (t) of the Hall IC ship 30 .
Thereafter, the magnetic flux density B k is calculated from the following expression that is introduced from the expression (1).
B k =( V out ( t )− V 0 )/ S ( t 0 ) (6)
Incidentally, V out (t), V 0 and S(t 0 ) are measured beforehand.
At the next step S 216 , a temperature characteristic correction value at the magnetic flux density of B k is set in the following manner.
Firstly, V sen (t) when the magnetic flux density is B k as shown in FIG. 7A is calculated by the expression (4). Secondly, a variable ratio V sen-off (t)/V sen-off (t 0 ), as shown in FIG. 7B , is calculated. Thirdly, the reciprocal of the variable ratio, which is V sen-off (t 0 )/V sen-off (t) at the magnetic flux density of B k is set as the temperature characteristic correction value α k (t), as shown in FIG. 7C , to obtain the coefficients a and b from the expression (5).
Then, a temperature characteristic correction value α i (t) in a grade range other than the grade range that includes the magnetic flux density B k is obtained.
The following expression can be introduced from the expression (1): V out (t)−V off (t)=B×S(t).
Therefore, (V out (t)−V off (t)) at the magnetic flux density of Bi can be expressed as follows.
( V out ( t )− V off ( t )) B=Bi =( V out ( t )− V off ( t )) B=Bk ×B i /B k (7)
Accordingly, V sen-off (t) under the magnetic flux density of Bi can be obtained by the following expression.
V sen-off ( t )= V out ( t )− V 0 =( V out ( t )− V off ( t )) B=Bk ×B i /B k +ΔV off ( t ) (8)
Accordingly, the coefficients a and b of the temperature characteristic correction value α i (t) in a grade range other than the grade range that includes the magnetic flux density B k can be obtained from the expression (5), as shown in FIG. 8 .
Incidentally, the DSP 36 , which is integrated into the Hall IC chip 30 , can be separated from the Hall IC chip 30 .
In the foregoing description of the present invention, the invention has been disclosed with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made to the specific embodiments of the present invention without departing from the scope of the invention as set forth in the appended claims. Accordingly, the description of the present invention is to be regarded in an illustrative, rather than a restrictive, sense. | A method of correcting temperature characteristic of a rotation angle detecting device that includes a permanent magnet, a magnetic core, a Hall element that rotates relative to the permanent magnet when a rotating object rotates to provide an output signal. The method includes a step of setting temperature correction values for correcting a temperature characteristic of the rotation angle detecting device according to magnetic flux density. The magnetic flux density is divided into a plurality of grade ranges and the temperature correction values are respectively set for the grade ranges. | 6 |
FIELD OF THE INVENTION
[0001] This invention relates to food-drying device with drive mechanism, and the related drive mechanism, particularly those for converting reciprocating movement of a user to rotation motion of the object to be driven.
BACKGROUND OF THE INVENTION
[0002] In many cases, it is desirable to dry washed food, for example to avoid making watery salad, and such food-drying devices or salad spinners are known. Typically, such device has a container, in which a drying assembly having a plurality of bores, for example a basket, is disposed. The drying assembly can be rotated relative to the container. A drive mechanism for rotating the drying assembly relative to the container is provided, while the drive mechanism is usually integrated with the cover of the container. The drive mechanism is typically actuated by a handle.
[0003] Salad spinners in U.S. Pat. No. 5,865,109 and U.S. Pat. No. 7,621,213 have a drive mechanism that includes a reciprocating handle movable along a path, and a conversion mechanism for converting reciprocating movement of the reciprocating handle to rotary motion of the drying assembly. However, the drive mechanism in these salad spinners only allow movement of the reciprocating handle in one direction to be converted to rotary motion of the drying assembly. That is, force applied by the user in another direction of the reciprocating movement of the reciprocating handle is wasted as such is not converted to rotary motion of the drying assembly.
[0004] Although the drive mechanism of the salad spinners of U.S. Pat. No. 5,992,309 is able to convert reciprocating movement of the handle to rotary motion of the drying assembly, in fact the user can apply force in one direction of the reciprocating movement. Movement of the handle in another direction of the reciprocating movement only occurs when force is no longer applied. Therefore, the user can only apply force in one direction of the reciprocating movement of the reciprocating handle for conversion to rotary motion of the drying assembly
[0005] Therefore, there is a need to devise cleverer drive mechanism that can more effectively convert force applied by a user during reciprocating movement of the handle to rotary motion of the drying assembly.
OBJECTS OF THE INVENTION
[0006] Therefore, it is an object of this invention to resolve at least one or more of the problems as set forth in the prior art. Particularly, it is an object of the current invention to provide food-drying devices that can more effectively covert force applied by a user during reciprocating movement of the handle to rotary motion of the drying assembly. As a minimum, it is an object of this invention to provide the public with a useful choice.
SUMMARY OF THE INVENTION
[0007] Accordingly, this invention provides a food-drying device including a container; a drying assembly having a plurality of bores, said drying assembly disposed in the container and capable of being rotated relative to the container; and a drive mechanism for rotating the drying assembly relative to the container. The drive mechanism includes a reciprocating handle movable between a first position and a second position along a path, and a conversion mechanism for converting reciprocating movement of the reciprocating handle to rotary motion of the drying assembly from force supplied by a user to actuate the reciprocating handle moving from the first position to the second position, and from force supplied by the user to actuate the reciprocating handle moving from the second position to the first position. The conversion mechanism includes a slot assembly having ratchet teeth along two edges defining a slot, said slot assembly being coupled to the reciprocating handle, and said slot having a first end corresponding to the first position, and a second end corresponding to the second position.
[0008] Preferably, the conversion mechanism includes an output gear being coupled to the drying assembly; a drive gear meshing with the ratchet teeth such that said slot assembly rotates the drive gear between the first end and the second end; and a clutch gear meshing with the drive gear, said clutch gear engaging the output gear when the drive gear is between the first end and the second end, and disengaging the output gear when the drive gear is at the first end or the second end. The ratchet teeth and the drive gear are arranged such that when the reciprocating handle changes direction of movement when the drive gear reaches the first end or the second end, the ratchet teeth can continue to rotate the drive gear, preferably in the same direction.
[0009] More preferably, at least a portion of the ratchet teeth along the two edges is movable when the drive gear reaches the first end or the second end and is biased to engage the drive gear. Alternatively, the drive gear have flexible gears that mesh with the ratchet teeth, said flexible gears are movable when the drive gear reaches the first end or the second end and are biased to engage the ratchet teeth.
[0010] Even more preferably, the at least a portion of the ratchet teeth along the two edges is positioned at diagonally opposing ends of the two edges, and the ratchet teeth at other diagonally opposing ends of the two edges have reduced pitch. Alternatively, entire portion of the ratchet teeth along the two edges is movable and is biased to engage the drive gear as two movable racks, said movable racks having respective pivotal points being positioned diagonally opposing each other along the slot, and the ratchet teeth at other diagonally opposing ends of the two edges have reduced pitch.
[0011] Optionally, the drying assembly has an open end opposing a closed end, and the closed end has at least one additional rim to increase weight of the closed end.
[0012] It is another aspect of this invention to provide a drive mechanism for driving a device, that includes a reciprocating handle movable between a first position and a second position along a path, and a conversion mechanism for converting reciprocating movement of the reciprocating handle to rotary motion from force supplied by a user to actuate the reciprocating handle moving from the first position to the second position, and from force supplied by the user to actuate the reciprocating handle moving from the second position to the first position. The conversion mechanism includes
an output gear; a slot assembly having ratchet teeth along two edges defining a slot, said slot assembly being coupled to the reciprocating handle, and said slot having a first end corresponding to the first position, and a second end corresponding to the second position; a drive gear meshing with the ratchet teeth such that said slot assembly rotates the drive gear between the first end and the second end; and a clutch gear meshing with the drive gear, said clutch gear engaging the output gear when the drive gear is between the first end and the second end, and disengaging the output gear when the drive gear is at the first end or the second end
wherein at least a portion of the ratchet teeth along the two edges is movable when the drive gear reaches the first end or the second end and is biased to engage the drive gear.
[0017] It is another aspect of this invention to provide a drive mechanism for driving a device that includes a reciprocating handle movable between a first position and a second position along a path, and a conversion mechanism for converting reciprocating movement of the reciprocating handle to rotary motion from force supplied by a user to actuate the reciprocating handle moving from the first position to the second position, and from force supplied by the user to actuate the reciprocating handle moving from the second position to the first position. The conversion mechanism includes
an output gear; a slot assembly having ratchet teeth along two edges defining a slot, said slot assembly being coupled to the reciprocating handle, and said slot having a first end corresponding to the first position, and a second end corresponding to the second position; a drive gear meshing with the ratchet teeth such that said slot assembly rotates the drive gear between the first end and the second end; a clutch gear meshing with the drive gear, said clutch gear engaging the output gear when the drive gear is between the first end and the second end, and disengaging the output gear when the drive gear is at the first end or the second end
wherein the drive gear have flexible gears that mesh with the ratchet teeth, said flexible gears are movable when the drive gear reaches the first end or the second end and are biased to engage the ratchet teeth.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Preferred embodiments of the present invention will now be explained by way of example and with reference to the accompanying drawings in which:
[0023] FIG. 1 shows an exploded view of an exemplary food-drying device of this invention;
[0024] FIG. 2 shows the enlarged view of the drive mechanism of the food-drying device of FIG. 1 ;
[0025] FIG. 3 shows yet another exploded view of the drive mechanism of the food-drying device of FIG. 1 without showing the reciprocating handle;
[0026] FIG. 4 shows the arrangement of the slot assembly and the drive gear of the drive mechanism of the food-drying device of FIG. 1 ;
[0027] FIG. 5 shows the connection of the drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of this invention;
[0028] FIGS. 6 a and 6 b show the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of FIG. 1 when the slot assembly is at one end point;
[0029] FIGS. 7 a and 7 b show the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of FIG. 1 when the slot assembly is moving out of the end point in FIG. 6 ;
[0030] FIG. 8 shows the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of FIG. 1 when the slot assembly is approaching the other end point in FIG. 6 ;
[0031] FIG. 9 shows the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of FIG. 1 when the slot assembly is about to reach the other end point in FIG. 6 ;
[0032] FIG. 10 shows the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of FIG. 1 when the slot assembly enters the other end point in FIG. 6 ;
[0033] FIGS. 11 a and 11 b show the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of FIG. 1 when the slot assembly reaches the other end point in FIG. 6 ;
[0034] FIG. 12 shows the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of FIG. 1 when the slot assembly is moving out of the other end point in FIG. 6 ;
[0035] FIG. 13 shows the exploded view of the drive mechanism of another embodiment of this invention;
[0036] FIG. 14 shows the exploded view of the drive mechanism of yet another embodiment of this invention;
[0037] FIG. 15 shows yet another exploded view of the drive mechanism of FIG. 14 only showing the slot assembly and the drive gear;
[0038] FIGS. 16 a and 16 b show the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of FIGS. 14 and 15 when the slot assembly is at one end point;
[0039] FIGS. 17 a and 17 b show the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of FIGS. 14 and 15 when the slot assembly is moving out of the end point in FIG. 16 ;
[0040] FIG. 18 shows the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of FIGS. 14 and 15 when the slot assembly enters the other end point in FIG. 16 ;
[0041] FIG. 19 shows the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of FIGS. 14 and 15 when the slot assembly is moving out of the other end point in FIG. 16 ;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] This invention is now described by way of examples with reference to the figures in the following paragraphs. Objects, features, and aspects of the present invention are disclosed in or are apparent from the following description. It is to be understood by one of ordinary skilled in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions. List 1 is a list showing the parts and respective reference numerals in the figures.
[0000]
List 1
Reference numeral
Part name
100
Food-drying device
200
Drive mechanism
201
Top cover
202
Reciprocating handle
204
Fixed frame
206
Slot assembly
207
Slot
208
Ratchet teeth
208a
Ratchet teeth with reduced pitch
210
Movable pitch module
211
Elastic spring plate
212
Pivot point
220
Drive gear
230
Clutch gear
232
Clutch gear swing slot
240
Output gear
270
Drive mechanism bottom cover
280
Drying assembly connecting plate
300
Drying assembly
400
Container
506
Slot assembly
508
Movable ratchet teeth rack
508a
Ratchet teeth with reduced pitch
511
Coil spring
512
Pivot point
606
Slot assembly
608
Ratchet teeth
620
Drive gear
622
Drive gear flexible gear
624
Drive gear elastic spring plate
626
Flexible gear swing slot
628
Flexible gear pivot point
[0043] The exploded view of a first exemplary food-drying device 100 of the current invention is shown in FIG. 1 . The food-drying device 100 has a drive mechanism 200 for rotating the drying assembly 300 , which is in the form of a basket having a plurality of bores in this particular embodiment. The drying assembly 300 is contained in a container 400 . The drive mechanism 200 , the drying assembly 300 , and the container 400 can be in any desire shape, for example the general quadrate shape as shown in FIG. 1 , or general cylindrical shape. Naturally, the drive mechanism 200 , the drying assembly 300 , and the container 400 should match each other or at least be able to accommodate each other.
[0044] The reciprocating handle 202 in the exemplary food-drying device 100 in FIGS. 1 and 2 is able move between a first position and a second position along a path, in this particular example being a linear path. However, this path can be curved as in U.S. Pat. No. 5,865,109 and U.S. Pat. No. 7,621,213 if desired. The design of the reciprocating handle 202 is not important as long as it can be moved linear in a reciprocating manner. The first position and the second position correspond to the two end points of the aperture of the top cover 201 . The reciprocating handle 202 is coupled to a slot assembly 206 , which is actuated by the reciprocating handle 202 . The slot assembly 206 can be actuated to move in the same direction when a user actuates the reciprocating handle 202 , or in the opposite direction if desired, subject to how the slot assembly 206 is coupled to the reciprocating handle 202 . An optional fixed frame 204 is provided in the exemplary food-drying device 100 to limit the slot assembly 206 to move along the path.
[0045] As shown in FIGS. 2 and 3 , the slot assembly 206 has ratchet teeth 208 along two edges that define a slot 207 . The slot 207 has a first end that corresponds to the first position, and a second end that corresponds to the second position of the reciprocating handle 202 . As shown in FIG. 4 , a drive gear 220 meshes with the ratchet teeth 208 in the slot 207 such that when the slot assembly is actuated as the reciprocating handle 202 is actuated, the drive gear 220 is rotated. As shown in FIG. 5 , a clutch gear 230 meshes with the drive gear 220 , the clutch gear 230 engaging an output gear 240 when the drive gear 220 is between the first end and the second end, and disengaging the output gear 240 when the drive gear 220 is at the first end or the second end by means of the clutch gear swing slot 232 (shown in FIG. 3 ), as in other clutch mechanisms for converting reciprocating motion to rotatory motion. The output gear 240 is coupled to the drying assembly 300 through the drying assembly connecting plate 280 for rotating the drying assembly 300 . For the convenience of assembly, all components can be assembled on an optional drive mechanism bottom cover 270 .
[0046] The ratchet teeth 208 and the drive gear 220 are arranged such that when the reciprocating handle 202 changes direction of movement when the drive gear 220 reaches the first end or the second end, the ratchet teeth 208 can continue to rotate the drive gear 220 . Otherwise, the drive gear 220 will be jammed when reaching the first end or the second end during the reciprocating movement. The detail of various arrangements to achieve this will be discussed below.
[0047] FIG. 4 shows one of such arrangements, in which at least a portion of the ratchet teeth 208 along the two edges is movable when the drive gear 220 reaches the first end or the second end, and is biased to engage the drive gear 220 . In this specific embodiment, the movable portion of the ratchet teeth is in the form of a movable pitch module 210 , which is biased to engage the drive gear 220 by respective elastic spring plates 211 (as shown in FIG. 3 ), which can be replaced by any suitable biasing means like spring. More specifically, the movable portion of the ratchet teeth 208 along the two edges is positioned at diagonally opposing ends of the two edges, and the ratchet teeth at other diagonally opposing ends of the two edges have reduced pitch 208 a . It was found that if only ratchet teeth with reduced pitch are provided at the first end or the second end, then drive gear 220 may not be able to be driven by the ratchet teeth smoothly after reaching the first end or the second end during the linear reciprocating movement.
[0048] FIGS. 6 to 12 show how the arrangement in FIG. 4 works, in which the relationship between the slot assembly 206 , drive gear 220 , clutch gear 230 , and output gear 240 of the drive mechanism 200 of the food-drying device 100 is shown. In FIGS. 6 a and 6 b , the slot assembly 206 is at an upper end point, which can be viewed as the initial position in the sequence in FIGS. 6 to 12 . As shown in FIG. 6 b , the clutch gear 230 and output gear 240 are disengaged. In FIGS. 7 a and 7 b , when the reciprocating handle 201 is actuated by a user, the slot assembly 206 is caused to be moved out of the end point in FIG. 6 in a downward direction, and the drive gear 220 is rotated clockwise accordingly. This causes the clutch gear 230 to move about the clutch gear swing slot 232 in a clockwise direction to engage the output gear 240 , such that when the drive gear 220 is rotated, the output gear 240 is also rotated through the clutch gear 230 . In FIG. 8 , the slot assembly 206 is moved further downward to approach the lower end point, and the slot assembly 206 is about to reach the lower end point in FIG. 9 . In FIG. 10 , the slot assembly 206 enters the lower end point in FIG. 6 , in which the movable pitch module 210 “concedes” or is moved when the drive gear 220 presses against this movable pitch module 210 . This movable pitch module 210 is arranged to pivot such that it only concedes when the drive gear 220 approaches the movable pitch module 210 from a forward direction when the drive gear 220 approaches the first or second end of the slot 207 . On the other hand, when the drive gear 220 approaches the movable pitch module 210 from a backward direction such that when the drive gear 220 is leaving the first or second end of the slot 207 , this movable pitch module 210 remains stationary. More specifically, the movable pitch module 210 pivots about a pivot point 212 (as shown in FIG. 3 ) that is distant from the first or second end of the slot 207 and in proximity to the slot 207 . In FIGS. 11 a and 11 b , the slot assembly 206 reaches the lower end point, in which the movable pitch module 210 “retracts” or returns to its normal position as the drive gear 220 approaches the end of the slot 207 . As shown in FIG. 11 b , the clutch gear 230 and output gear 240 are disengaged as the clutch gear 230 is moved in an anti-clockwise direction by the output gear 240 as the drive gear 220 does not drive at this end point. In FIG. 12 , the slot assembly 206 is moving out of the lower end point by changing the direction of the linear motion. The cycle in FIGS. 6 to 12 then repeats in a reversed direction.
[0049] The drive gear 220 does not have full set of teeth to mesh with the slot assembly 206 , but only half set of teeth. This allows the teeth of the drive gear 220 to engage with one of the racks in the slot 207 except at the first end and the second end.
[0050] It will be noted in FIGS. 6 to 12 that the movable pitch module 210 is biased to engage the drive gear 220 at all times.
[0051] FIG. 13 shows another arrangement alternative to that shown in FIGS. 4 to 12 . The components in FIG. 13 that are the same as those in FIGS. 4 to 12 are indicated by the same reference numbers. In this embodiment, entire portion of the ratchet teeth along the two edges of the slot assembly 506 is movable and is biased to engage the drive gear as two movable racks 508 . The movable racks 508 having respective pivotal points 512 being positioned diagonally opposing each other along the slot 207 , and the ratchet teeth at other diagonally opposing ends of the two edges have reduced pitch 508 a . In the particular example in FIG. 13 , the movable racks 508 are biased by coil springs 511 positioned at the other end of the pivot point 512 . This alternative embodiment works in a manner similar to that shown in FIGS. 4 to 12 .
[0052] FIGS. 14 and 15 show yet another arrangement alternative to those shown in FIGS. 4 to 13 . The components in FIGS. 14 and 15 that are the same as those in FIGS. 4 to 13 are indicated by the same reference numbers. In this embodiment, the ratchet teeth 608 along the two edges of the slot 607 of the slot assembly 606 are not movable, and have no ratchet teeth with reduced pitch. Instead, the drive gear 620 has flexible gears, in this example being two sets of flexible gears 622 that mesh with the ratchet teeth 608 . The two sets of flexible gears 622 are movable when the drive gear 620 reaches the first end or the second end, and are biased to engage the ratchet teeth 608 by drive gear elastic spring plate 624 . The flexible gears 622 pivot about flexible gear pivot points 628 and within the flexible gear swing slots 626 . The flexible gear pivot point 628 and the flexible gear swing slot 626 of each set of one set of flexible gears 622 are positioned diagonally opposing the other respective flexible gear pivot point 628 and the flexible gear swing slot 626 of the other set of flexible gears 622 .
[0053] FIGS. 16 to 18 show how the arrangement in FIGS. 14 and 15 works, in which the relationship between the slot assembly 606 , drive gear 620 , clutch gear 230 , and output gear 240 is shown. In FIGS. 16 a and 16 b , the slot assembly 206 is at one upper end point, which can be viewed as the initial position in the sequence in FIGS. 16 to 18 . As shown in FIG. 16 b , the clutch gear 230 and output gear 240 are disengaged. In FIGS. 17 a and 17 b , when the reciprocating handle 201 is actuated by a user, the slot assembly 606 is caused to be moved out of the end point in FIG. 16 in a downward direction, and the drive gear 620 is rotated clockwise accordingly. This causes the clutch gear 230 to move about the clutch gear swing slot 232 in a clockwise direction to engage the output gear 240 , such that when the drive gear 220 is rotated, the output gear 240 is also rotated through the clutch gear 230 . In FIG. 17 a , the slot assembly 606 is about to leave the upper end point and is going to move downward, the flexible gears 622 “concede” or are moved when the ratchet teeth 608 presses against the flexible gears 622 . The flexible gears 622 are arranged to pivot such that they always face the end of the slot 607 that they will be approaching. In FIG. 18 , the slot assembly 606 is about to reach the lower end point, in which the flexible gears 622 again “concede” or are moved when the ratchet teeth 608 presses against the flexible gears 622 . In FIG. 19 , the slot assembly 606 reaches the lower end point when the direction of the motion along the linear path is about to be changed. The cycle in FIGS. 16 to 19 then repeats in a reversed direction.
[0054] As shown above, various arrangements of the current invention effectively convert force applied by a user in both directions of the reciprocating motion of the handle to rotation motion of the drying assembly, thereby enhancing the conversion efficiency and the performance of the food-drying device.
[0055] Further, salad spinners give little or no consideration to the design of the drying assembly. It was found that adding extra mass round the rim at the bottom of the drying assembly can enhance the stability of the operation. That is, the closed end of the drying assembly prefers to have at least one additional rim to increase weight of the closed end to enhance performance of the salad spinners.
[0056] While the preferred embodiment of the present invention has been described in detail by the examples, it is apparent that modifications and adaptations of the present invention will occur to those skilled in the art. Furthermore, the embodiments of the present invention shall not be interpreted to be restricted by the examples or figures only. It is to be expressly understood, however, that such modifications and adaptations are within the scope of the present invention, as set forth in the following claims. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the claims and their equivalents. | The current invention discloses a food-drying device that includes a container, a drying assembly having a plurality of bores, and a drive mechanism. The drying assembly is disposed in the container and is capable of being rotated relative to the container. The drive mechanism rotates the drying assembly relative to the container. The drive mechanism includes a reciprocating handle movable between a first position and a second position along a linear direction, and a conversion mechanism for converting reciprocating movement of the reciprocating handle to rotary motion of the drying assembly from force supplied by a user to actuate the reciprocating handle moving from the first position to the second position, and from force supplied by the user to actuate the reciprocating handle moving from the second position to the first position. | 8 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to the field of marine seismic data acquisition systems and methods of using same. More specifically, the invention relates to systems and methods for active steering of marine seismic sources to maintain inline position of the seismic sources.
2. Related Art
The performance of a marine seismic acquisition survey typically involves one or more vessels towing at least one seismic streamer through a body of water believed to overlie one or more hydrocarbon-bearing formations. In order to perform a 3-D marine seismic acquisition survey, an array of marine seismic streamers, each typically several thousand meters long and containing a large number of hydrophones and associated electronic equipment distributed along its length, is towed at about 5 knots behind a seismic survey vessel. The vessel also tows one or more seismic sources suitable for use in water, typically air guns. Acoustic signals, or “shots,” produced by the seismic sources are directed down through the water into the earth beneath, where they are reflected from the various strata. The reflected signals are received by the hydrophones, or receivers, carried in the streamers, digitized, and then transmitted to the seismic survey vessel where the digitized signals are recorded and at least partially processed with the ultimate aim of building up a representation of the earth strata in the area being surveyed. Often two or more sets of seismic data signals are obtained from the same subsurface area. These sets of seismic data signals may be obtained, for instance, by conducting two or more seismic surveys over the same subsurface area at different times, typically with time lapses between the seismic surveys varying between a few months and a few years. In some cases, the seismic data signals will be acquired to monitor changes in subsurface reservoirs caused by the production of hydrocarbons. The acquisition and processing of time-lapsed three dimensional seismic data signals over a particular subsurface area (commonly referred to in the industry as “4-D” seismic data) has emerged in the last decade or so as an important new seismic prospecting methodology. When conducting repeated surveys, ideally one wants to repeat all source and receiver positions from the base or previous survey. In practice, this is hard to achieve for the entire survey area due to the different environmental conditions encountered in different surveys. Varying currents, both spatially and in time, are the main environmental contributor.
When conducting surveys today, a reference point at the vessel is steered automatically to be at a certain cross line distance from a given pre-plot track. A controller may be used for this, and it controls the autopilot mechanism to achieve its goal. The operator sets manually how far the vessel is to be cross-line from the pre-plot line. Conventionally, seismic source arrays are deployed so that fixed distances are maintained from the towing vessel and from the center of the first seismic recording group of the streamers. During the course of an acquisition line, these distances may change due to several factors including crossline current that introduces an angle to the relation between the line from the towing cable/rope and the seismic line direction, often called feather angle when used to describe the same relation but for streamers. In addition to crossline feather, changes in the inline component of the current may alter the tension on the towing ropes for individual source arrays, which may then stretch or contract, changing the distances from the vessel to the to the source arrays, and from the source arrays to the center of the first seismic recording group.
While adjustments may be made during line change, no mechanism is currently employed to control these separation distances in real time during the course of a marine seismic data acquisition run. This lack of control may result in inline differences between the source coordinates from a base and monitor 4D survey.
SUMMARY OF THE INVENTION
In accordance with the present invention, systems and methods are described for inline positioning of one or more acoustic centers of marine seismic sources using control of one or more source deployment components on a vessel. Systems and methods of the invention may be used during seismic data collection, including 3-D and 4-D seismic surveying. The inventive systems and methods may also use inline, as well as crossline control to reform a multi-string source shape in real time or near-real time, and/or for time recording with time and space source firing. In another use of the invention, the ability to move the source into position using both control of the vessel speed and inline source control makes it possible to conduct an undershoot without the source vessel receiving the aim point message. Data transfer that is not time critical can be achieved with the limited bandwidth available from satellite communications eliminating the need and cost for a dedicated line of sight radio effort. Normally, in an undershoot project, the line of sight is needed for transmitting the aim point message from the recording vessel to the source vessel. Instead the vessels shoot on time, with highly synchronized and precise clocks.
The systems and methods of the present invention may include a software module that has knowledge of the inline source positions in relation to target coordinates from a previous survey and an ongoing acquisition. One objective of the software is to control one or more source deployment components that can change the position of one or more sources in relation to the towing vessel in a way that will drive the difference between these two inline coordinates to zero. The software may also have knowledge of a target distance between the center first group (CFG) of a streamer spread and the center of the source (COS) and/or the center of one or more source arrays (COSA) and control the physical mechanism to achieve that target distance. This of course requires that the positions of both the CFG and the COS or COSA, as the case may be, are known.
The systems and methods of the invention may include one or more source deployment components controlled by the software module. Acting in concert, the software module and source deployment components control the inline distances of the COSA of each array in relation to a target coordinate, which may be either reference mentioned above, (i.e., the base survey source coordinates or the distance between a COS of a source array and CFG of a streamer spread). One useful source deployment component is the so-called gun cable winch. A gun cable winch winds and unwinds a pneumatically pressurized cable from the source towing vessel to the source array (gun cables) in or out, changing the distance from the winch to the source array. Gun cable winches are not typically designed to change the length of gun cable dynamically during acquisition when the cables are pressurized.
A first aspect of the invention are systems comprising:
(a) a marine seismic spread comprising a towing vessel and a seismic source, the seismic source comprising one or more source arrays each having a center of source array, each source array having one or more source strings; (b) a seismic source deployment sub-system on the towing vessel, the sub-system controlled by a controller including a software module, the software module and the deployment sub-system adapted to control an inline distance between one of the centers of source array and a target coordinate.
Systems of the invention include those wherein optionally one or more seismic streamers are towed by the towing vessel, or a separate towing vessel may tow one or more streamers. The seismic source deployment sub-system may comprise one or more winches, capstans, or the like, for example a port side winch and a starboard side winch, controlled by the controller software module. In these embodiments, the individual source strings in a source array are actuated pneumatically or electronically through individual active cables wound or unwound from winches. The port winch may be wound a substantially similar amount as the starboard side winch is unwound, or vice versa. Alternatively, the source deployment sub-system may comprise both active source cables and passive steering cables. In one embodiment, the length of active source cables are not controlled but are allowed to move inline, while a set of separate passive cables are connected either to the active cables or the sources themselves. The passive cables do not actuate the sources, but their inline lengths are controlled by separate deployment systems, for example winches, to control an inline distance between one of the centers of source array and a target coordinate. In certain embodiments, the seismic source deployment sub-system may be load-balanced, wherein for example port and starboard winches are controlled to move oppositely. In certain embodiments, the source deployment sub-system may comprise movable winches, wherein the winch does not wind or unwind per se, but rides on a movable platform. Combinations of these may also be employed, in other words, the controller and software module may control both the movable platform and the winding and unwinding of the winches. In yet other embodiments, heave compensators may be employed, whereby the length of either active source cables or passive steering cables are adjusted by exerting a force on the cable out of line of the cable, as explained further herein. Load-balancing may be employed in any of the various embodiments of the invention, which may reduce energy consumption.
The controller and software module may be physically a part of the seismic source deployment sub-system or located separately from the seismic source deployment sub-system, and may use some or all available information, including, but not limited to, source and vessel positions, vessel gyroscope reading, vessel compass reading, vessel speed log, streamer front end positions (if streamers are present), and historical, real-time, and future current and wind information and predictions when calculating a difference between a target position and actual position, and thus these may taken into consideration in the calculation of optimum source cable and/or steering cable position by the seismic source deployment sub-system. The phrase “seismic source deployment sub-system” is defined herein and may differ among the various embodiments of the invention, as explained in the definition. The controller and software module may include logic selected from PI controllers, PID controllers (including any known or reasonably foreseeable variations of these), and computes a residual equal to a difference between a target point 3D coordinate COSA position and an actual COSA position, optionally together with current and wind measurements, to produce one or more inputs to cable deployment actuator, which may be electric motors, used by the seismic source deployment sub-system to control the source inline positions using winches, motorized capstans, and the like. The controller may compute the residual continuously or non-continuously. Other possible implementations of the invention are those wherein the controller comprises more specialized control strategies, such as strategies selected from feed forward, cascade control, internal feedback loops, model predictive control, neural networks, and Kalman filtering techniques.
Systems of the invention may include a seismic spread comprising one or more vessels such as towing vessels, a chase vessel, a work vessel, one or more a seismic sources, and optionally one or more seismic streamers towed by towing vessels. The streamers and sources may be separately towed or towed by the same vessel. If towed by separate vessels, two controllers may be employed and two residuals computed. In general, the controller may compute the residual based on what the position measurement system reports as the 3D coordinate position of the tracking point. Although there may be some degree of error in the reported 3D coordinate position due to a variety of error sources, including instrument measurement error, even with the errors the tracking point may be better controlled by steering the vessel the majority of the time.
Systems and methods of the invention may optionally be used in conjunction with other systems and methods. For example, if the center of source is the tracking point, its 3D coordinate position may be determined from acoustic ranging networks, GPS, and other position sensors, and since the seismic team knows the path the tracking point is supposed to follow based on the survey specifications, the controller may use at least that information to calculate a residual, and a set point based on the residual, for the steering algorithm, either to steer the vessel back to the survey-specified path, or ensure that the survey-specified path is adhered to.
Another aspect of the invention comprises methods of automatically controlling an inline position of a center of a marine seismic source, comprising:
(a) measuring a position of a center of a marine seismic source in a marine seismic spread; (b) computing a residual difference between the measured position and a target position of the center of source; and (c) steering the source using a seismic source deployment sub-system comprising one or more cables attached to the source, the cable adjusted based on the residual difference.
Methods of the invention include those wherein the computing includes use of a PI or PID controller alone or in conjunction with other controllers, and may comprise towing a seismic spread comprising a towing vessel, a seismic source, and one or more seismic streamers, which may be towed in side-by-side configuration, over/under configuration, “V” configuration, “W” configuration, or some other configuration. Other methods of the invention rely not on controlling position or steering of the sources, but in timing their firing to compensate for inline skew caused by environmental and/or other factors.
Another aspect of the invention comprises adjusting firing times of the source strings to distribute evenly any inline error due to un-even shot spacing in time or distance, rather than using mechanical actuators and controllers to correct for inline skew. One method comprises:
(a) deploying a marine seismic spread comprising a towing vessel and a seismic source, the seismic source comprising one or more source arrays each having a center of source array, each source array having one or more source strings; and (b) adjusting firing times of the source strings to distribute evenly any inline error due to un-even shot spacing in time.
Systems and methods of the invention will become more apparent upon review of the brief description of the drawings, the detailed description, and the claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
The manner in which the objectives of the invention and other desirable characteristics can be obtained is explained in the following description and attached drawings in which:
FIGS. 1 and 2 are plan or overhead views of a system useful in describing ideal conditions, and problems addressed by the systems and methods of the invention;
FIGS. 3 , 4 , and 5 are schematic block diagrams of three embodiments of systems and methods of the invention;
FIGS. 6A and 6B are schematic diagrams of a feature of the inventive systems and methods, where FIG. 6A is partially in phantom;
FIGS. 7 , 8 , 9 , and 10 are schematic block diagrams of four other embodiments of systems and methods of the invention;
FIG. 11 illustrates schematically another method of the invention; and
FIG. 12 illustrates is an image from an analysis of an actual seismic data survey, showing all the shots from that particular survey as dots, and illustrating the influence from external forces (e.g. currents) on inline skew.
It is to be noted, however, that the appended drawings are not to scale and illustrate only typical embodiments of this invention, and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
DETAILED DESCRIPTION
In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible. For example, in the discussion herein, aspects of the invention are developed within the general context of controlled positioning of seismic spread elements, which may employ computer-executable instructions, such as software program modules, being executed by one or more conventional computers. Generally, software program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the invention may be practiced in whole or in part with other computer system configurations, including hand-held devices, personal digital assistants, multiprocessor systems, microprocessor-based or programmable electronics, network PCs, minicomputers, mainframe computers, and the like. In a distributed computer environment, software program modules may be located in both local and remote memory storage devices. It is noted, however, that modification to the systems and methods described herein may well be made without deviating from the scope of the present invention. Moreover, although developed within the general context of automatically controlling position of seismic spread elements, those skilled in the art will appreciate, from the discussion to follow, that the principles of the invention may well be applied to other aspects of seismic data acquisition. Thus, the systems and method described below are but illustrative implementations of a broader inventive concept.
All phrases, derivations, collocations and multiword expressions used herein, in particular in the claims that follow, are expressly not limited to nouns and verbs. It is apparent that meanings are not just expressed by nouns and verbs or single words. Languages use a variety of ways to express content. The existence of inventive concepts and the ways in which these are expressed varies in language-cultures. For example, many lexicalized compounds in Germanic languages are often expressed as adjective-noun combinations, noun-preposition-noun combinations or derivations in Romanic languages. The possibility to include phrases, derivations and collocations in the claims is essential for high-quality patents, making it possible to reduce expressions to their conceptual content, and all possible conceptual combinations of words that are compatible with such content (either within a language or across languages) are intended to be included in the used phrases.
The present invention relates to various systems and methods for controlling position of seismic sources in a marine seismic spread primarily by steering the sources using a controller and source deployment components, the latter being a vessel that tows the seismic sources. One aspect of the present invention relates to systems including a seismic source deployment sub-system on the towing vessel, the sub-system controlled by a controller including a software module, the software module and the deployment sub-system adapted to control an inline distance between one of the centers of source array and a target coordinate. Another aspect of the invention comprises methods of using a system of the invention to control the inline position of seismic sources. An alternative method of the invention comprises timing the firing of seismic sources to compensate for inline skew.
As used herein a marine seismic “source” is a collection of air-guns or other acoustic devices designed to produce acoustic signals, or “shots,” which are directed down through the water into the earth beneath, where they are reflected from the various strata.
The phrase “center of source”, sometimes referred to herein as COS, means the 3D coordinate position of the center of a plurality of acoustic devices making up a source. The COS may be the 3D coordinate position of a single source array or multiple source arrays.
A “source array”, as used herein, refers to a plurality of acoustic signal-producing devices arranged generally in a rectangular grid and towed by a vessel using one or more towing members, which may be active or passive. In the case of active towing members, the towing members also function to communicate pneumatic, hydraulic, or electronic signals to the individual acoustic devices in the source arrays to produce an acoustic shot. When speaking of “dual sources”, typically a port source array and a starboard source array are used, and each source array has a “center of source array.” Each source array may have one or a plurality of source strings, such as gun strings, and each source string may have a plurality of individual acoustic devices. Each source string may have its own towing member, but the invention is not so limited.
The phrase “center of source array”, or COSA, is distinguished from COS only when there are two or more source arrays, and means the 3D coordinate position of the center of a plurality of acoustic devices making up a source array.
The phrase “streamer front end center”, sometimes referred to herein as SFC, means the 3D coordinate position of a plurality of streamer front ends determined from the individual 3D coordinate positions of each streamer front end, that is, the streamer ends closest to the towing vessel.
The phrase “seismic source deployment sub-system” means any device or collection of components that are capable of functioning to position or steer source arrays in order that the COSA of each source array may be substantially aligned in a crossline generally perpendicular to a “preplot” line, or target vessel path. Seismic source deployment sub-systems useful in the invention they may include components that generate commands to elements, such as electric motors, winches, capstans, and other actuators, to accomplish the intended movements of the seismic sources. In some embodiments of the invention the seismic source deployment sub-system may include one or more software program modules, controllers, computers and the like, which may interact with vessel tracking and autopilots. In other embodiments of the invention the sub-system may not interact with conventional vessel tracking and autopilot functions, and may be simply one or more winches or capstans and associated controllers. In yet other embodiments of the invention, all of these components (tracking computer, autopilot, rudder controller, and thruster controllers) may be employed.
The term “spread” and the phrase “seismic spread” are used interchangeably herein and mean the total number of components, including vessels, vehicles, and towed objects including cables, sources and receivers, that are used together to conduct a marine seismic data acquisition survey.
The term “control”, used as a transitive verb, means to verify or regulate by comparing with a standard or desired value. Control may be closed loop, feedback, feed-forward, cascade, model predictive, adaptive, heuristic and combinations thereof.
The term “controller” means a device at least capable of accepting input from sensors and meters in real time or near-real time, and sending commands directly to mechanical components, actuators, and the like, of a seismic source deployment sub-system, and optionally to spread control elements, and/or to local devices associated with spread control elements able to accept commands. A controller may also be capable of accepting input from human operators; accessing databases, such as relational databases; sending data to and accessing data in databases, data warehouses or data marts; and sending information to and accepting input from a display device readable by a human. A controller may also interface with or have integrated therewith one or more software application modules, and may supervise interaction between databases and one or more software application modules.
The phrase “PID controller” means a controller using proportional, integral, and derivative features, as further explained herein. In some cases the derivative mode may not be used or its influence reduced significantly so that the controller may be deemed a PI controller. It will also be recognized by those of skill in the control art that there are existing variations of PI and PID controllers, depending on how the discretization is performed. These known and foreseeable variations of PI, PID and other controllers are considered within the invention.
The phrase “spread control element” means a spread component that is controllable and is capable of causing a spread component to change coordinates, either vertically, horizontally, or both, and may or may not be remotely controlled.
The terms “control position”, “position controllable”, “remotely controlling position” and “steering” are generally used interchangeably herein, although it will be recognized by those of skill in the art that “steering” usually refers to following a defined path, while “control position”, “position controllable”, and “remotely controlling position” could mean steering, but also could mean merely maintaining position. In the context of the present invention, “control inline position” means using at least measured position of the COS or COSA and compare it to a pre-plot path in order to give commands to the seismic source deployment sub-system.
“Real-time” means dataflow that occurs without any delay added beyond the minimum required for generation of the dataflow components. It implies that there is no major gap between the storage of information in the dataflow and the retrieval of that information. There may be a further requirement that the dataflow components are generated sufficiently rapidly to allow control decisions using them to be made sufficiently early to be effective. “Near-real-time” means dataflow that has been delayed in some way, such as to allow the calculation of results using symmetrical filters. Typically, decisions made with this type of dataflow are for the enhancement of real-time decisions. Both real-time and near-real-time dataflows are used immediately after the next process in the decision line receives them.
The term “position”, when used as a noun, is broader than “depth” or lateral (horizontal) movement alone, and is intended to be synonymous with “spatial relation.” Thus “vertical position” includes depth, but also distance from the seabed or distance above or below a submerged or semi-submerged object, or an object having portions submerged. When used as a verb, “position” means cause to be in a desired place, state, or spatial relation. The term may also include orientation, such as rotational orientation, pitch, yaw, and the like.
As previously discussed herein, when conducting time-lapse and other marine seismic surveys using towed streamers and sources, conventionally, seismic source arrays are deployed so that fixed distances are maintained from the towing vessel and from the center of the first seismic recording group of the streamers. During the course of a marine data acquisition run, these distances may change due to several factors including crossline current that introduces an angle to the relation between the line from the towing cable/rope and the seismic line direction, often called feather angle when used to describe the same relation but for streamers. In addition to crossline feather, changes in the inline component of the current may alter the tension on the towing ropes for individual source arrays, which may then stretch or contract, changing the distances from the vessel to the to the source arrays, and from the source arrays to the center of the first seismic recording group. While adjustments may be made during line change, no mechanism is currently employed to control these separation distances in real time during the course of a marine seismic data acquisition run. This lack of control may result in inline differences between the source coordinates from a base and monitor 4D survey.
FIGS. 1 and 2 schematically illustrate a system and method useful for describing problems addressed by the inventive systems and methods. Illustrated in schematic plan view is a vessel 2 following a preplot line 4 . The pre-plot line might be straight or have certain curvature. Vessel 2 is illustrated pulling two source arrays 6 and 8 , each having three source strings. Source arrays 6 and 8 each have a center of source array, or COSA, indicated by a star at 10 and 12 , respectively. Source array 6 is towed behind vessel 2 by a series of tow members 13 , while source array 8 is towed by a series of tow members 14 . Streamer front end deflectors 16 and 18 help pull streamers 20 and 22 outward from preplot line 4 , with the help of tow members 24 and 26 , respectively, as well as separation ropes 28 and 30 . Deflectors 16 and 18 may be of the type known under the trade designation MONOWING™, available from WesternGeco, LLC, Houston, Tex., or other type of streamer deflector. Those knowledgeable in the marine seismic industry will recognize many variations on the number of sources and streamers, configuration of streamers and tow members, and so on, and this is only one of many possible foreseeable configurations which may benefit from the teachings of the inventive systems and methods. In the arrangements illustrated, it is understood that sources and seismic streamers are towed at some depth below the water surface. Sources are typically towed at depths ranging from 0 to 10 meters, while seismic streamers may be towed at multiple depths, but are typically at depths ranging from 3 to 50 meters, depending on the survey specifications.
Referring now to FIG. 2 , the system of FIG. 1 is now exposed to an ocean current, wind, and/or waves represented by arrow 32 . The same numerals are used throughout to designate same components unless otherwise mentioned. Vessel 2 must turn into the environmental conditions in order to maintain a path close to preplot line 4 . However, this action by vessel 2 results in inline skewing of the spread, and specifically inline skew of COSAs 10 and 12 as represented by double-headed arrow 34 . In 4D seismic data acquisition scenarios, this presents a problem, specifically that some percentage of the seismic data will not be useful.
Prior to the systems and methods of the invention, the operator viewed the source arrays and streamers, and perhaps took into consideration wind, wave and current data, in steering the vessel in an effort to keep the streamers and the center of source on their respective track lines, while also minimizing inline skew. Systems and methods have been devised to automate the steering feedback loop, by introducing an automatic controller that controls vessel position in such a way that the source is on or close to the desired preplot line; however, these systems do not account for inline skew as depicted schematically in FIG. 2 . Thus even if the source and streamers are on their respective preplot tracks, the COSAs may be experiencing inline skew. Systems and methods of the invention are meant to correct for this inline skew. The systems and methods of the invention may also utilize measurements of environmental conditions, including but not limited to wind magnitude and direction, and current magnitude and direction. Other options include using a feed-forward technique, where a separate controller may be added that takes these environmental conditions into account and performs a proactive reaction so as to minimize the environmental effect on the zero inline slew objective. If other factors are found to impact the zero inline skew objective, feed-forward control aspects from these factors may also be included. By performing these functions automatically, an optimally tuned PID and optionally a feed forward, or other controller strategy will command an algorithm within the seismic source deployment sub-system so that deviations from the inline skew objective is corrected rapidly and in a stable way.
FIGS. 3 , 4 , and 5 are schematic block diagrams of three non-limiting embodiments of systems and methods of the invention for controlling inline position of COSAs 10 and 12 in dashed line 40 . FIG. 3 illustrates a system and method 300 for compensating for inline skew by dynamically actuating otherwise existing actuators, where three actuators 36 may be independently and dynamically actuated, one for each of three port tow members 13 , while three other actuators 38 may also be independently and dynamically actuated for three starboard tow members 14 . It will be understood that more or less than three actuator/tow member combinations may be employed. In this embodiment the actuators, which may be winches or equivalent actuators, such as capstans, do not move in relation to vessel 2 other than to dynamically reel in and reel out the tow members, and operation of one actuator does not interact with the other actuators. Operation of these types of actuators in marine seismic data acquisition, other than the real time or near real time dynamic features of the invention, is well-known and requires no further explanation to the skilled artisan. In certain embodiments, the dynamic reeling in and out of actuators 36 and 38 are automatically controlled in incremental fashion by one or more controllers, each of which may comprise one or more software program modules. The controller may comprise a simple PI or PID feedback loop. For example, a PID controller would compare a set point inline skew of COSAs 10 and 12 with measured 3D coordinate positions of the COSAs, and calculate a difference, referred to herein as a residual or residual difference, and generate a command to actuators 36 and 38 as the case may be to incrementally reel in or reel out the tow members 13 and 14 . It will be understood that in certain embodiments, rather than the controllers sending commands directly to actuators 36 and 38 , the controllers may send commands to a vessel autopilot, vessel tracking device, or both the tracking device and autopilot, and command the vessel rudder and/or vessel thrusters. However, in other embodiments, the response time of the actuators 36 and 38 may be faster when the controllers send commands directly to the actuators to incrementally reel in and out the tow members, and correct for inline skew of COSAs 10 and 12 . In either case the result should be better control of COSAs 10 and 12 inline as depicted in dashed line 40 .
FIG. 4 illustrates another system and method 400 for compensating for inline skew by dynamically actuating three actuators 36 , one for each of three port tow members 13 , while three other actuators 38 are dynamically actuated for three starboard tow members 14 . In this embodiment the actuators again do not move in relation to vessel 2 other than to dynamically reel in and reel out the tow members. However, in embodiment 400 , actuators 36 and 38 are modified so that port and starboard sides are synchronized. In other words, as actuators 36 incrementally reel in tow members 13 because of environmental conditions 32 , a synchronizing connection 42 ensures that actuators 38 incrementally reel out tow members 14 . If environmental conditions 32 were in the opposing direction, then as actuators 36 incrementally reel out tow members 13 , synchronizing connection 42 ensures that actuators 38 incrementally reel in tow members 14 . Embodiment 400 allows load balancing through the synchronizing connection. Load balancing may be used in any of the embodiments of the invention, except embodiment 300 of FIG. 3 which is a non-synchronized, non-balanced embodiment. Load balancing is primarily used to decrease energy requirements and/or increase energy efficiency.
FIG. 5 illustrates another system and method embodiment 500 of the invention in schematic block diagram fashion. System and method embodiment 500 illustrated in FIG. 5 includes certain features not present in embodiments 300 and 400 . In embodiment 500 , actuators 36 and 38 may once again be three port and three starboard winches, respectively, but each actuator 36 and 38 is movable forward and aft on a movable platform (not shown) controlled by one or more controllers commanding movements of a mechanism 44 . Mechanism 44 as illustrated in FIG. 5 may comprise a motorized capstan or other suitable arrangement having a connection to each movable platform associated with actuators 36 and 38 . In certain embodiments, one movable platform is employed for three winches, and in embodiment 500 , two movable platforms are thus utilized, although the invention is not so limited. Alternatively, each actuator 36 and 38 may be controlled by its own motorized capstan. As depicted in FIG. 5 , mechanism 44 allows load balancing as discussed herein, although this is optional. Actuators 36 and 38 may travel on tracks or rails, for example, as discussed in U.S. Pat. No. 5,284,323 with regard to laterally movable reels for streamer deployment. Although this patent discusses tracks for laterally moving reels for streamers, some of the principles are applicable to the inventive systems and methods. Actuators 36 and 38 may be winches movably attached to and capable of traversing forward and aft in separate tracks on the deck of vessel 2 . Separate traversing motors and chains may provide one means known to those skilled in the art to effect the traversal of actuators 36 and 38 over these tracks. Traversing motors may cause chains to rotate over a course along the length of each track, while the winches or reels may ride on a frame (not shown) mounted on wheels that engage the tracks. The frame may be connected to an element of chain such that as the chain circles, winch 36 or 38 as the case may be is carried forward and aft by means of the rolling of the frame wheels over the track. Other equivalent means for effecting the traversal of an actuator over a track will be well known and recognized by those skilled in the art. For instance, a rod with left and right spiral grooves could be caused to rotate. The frame could be attached to an element that rides within the grooves of the rod such that when the rod is rotated, the element causes the winch to be urged forward or aft.
FIGS. 6A and 6B are schematic diagrams of a feature of the inventive systems and methods which may be used with any of the various embodiments. Inline compensation may be supplemented by adding optional port and starboard heave compensators. A starboard compensator is illustrated schematically in side elevation, partially in phantom, in FIG. 6A , employing a first, stationary wheel 46 and a second, slack take up wheel 48 . As tow member 14 is reeled in and out, or even when in a static position, the heaving up and down of vessel 2 by wave action, wind, or other environmental factors, may cause tow member 14 to experience slack, which can adversely result in inline skew of COSAs 10 and 12 . A pivot 50 and mounted pivot arm 52 allows slack take up wheel 48 to pivot as indicated by the double-headed arrow. The phantom position of pivot arm 52 and wheel 48 illustrates a situation when there is relatively no heave. FIG. 6B illustrates schematically how gears 54 and 56 may be employed in conjunction with a starboard pivot 50 and a port pivot 58 for rotation in opposite directions and load balancing.
FIG. 7 illustrates schematically another embodiment 700 where in addition to actuators for tow members 13 and 14 , separate extra actuators 60 and 62 are provided. In certain embodiments, one extra actuator is provided for each tow member 13 and each tow member 14 . In embodiment 700 illustrated schematically in FIG. 7 , six extra actuators (winches, capstans, or the like) are provided, along with three extra tow members 64 and three extra tow members 66 . Extra tow members 64 terminate at and are attached to, in this embodiment, the lead end of each acoustic string in sub-array 6 . Similarly, extra tow members 66 terminate at and are attached to, in this embodiment, the lead end of each acoustic string in sub-array 8 .
Embodiment 800 of FIG. 8 combines features of embodiment 700 of FIG. 7 with embodiment 500 of FIG. 5 . In embodiment 800 , extra actuators 68 and 70 may once again be three port and three starboard winches, respectively, but each extra actuator 68 and 70 is movable forward and aft on a movable platform (not shown) controlled by one or more controllers commanding movements of a mechanism 72 . Mechanism 72 as illustrated in FIG. 8 may comprise a motorized capstan or other suitable arrangement having a connection to each movable platform associated with extra actuators 68 and 70 . In certain embodiments, one movable platform is employed for three winches, and in embodiment 800 , two movable platforms are thus utilized, although the invention is not so limited. Alternatively, each extra actuator 68 and 70 may be controlled by its own motorized capstan. As depicted in FIG. 8 , mechanism 72 allows load balancing as discussed herein, although this is optional. Extra actuators 68 and 70 may travel on tracks or rails, for example, as discussed in embodiment 500 , or any other suitable arrangement. The result is better control of inline skew of COSAs 10 and 12 in the dashed line designated 40 .
FIG. 9 illustrates another embodiment 900 of systems and methods of the invention. In embodiment 900 , all twelve actuators (three port acoustic source string actuators (not shown), three starboard source string actuators (not shown), three extra port actuators 62 for tow members 66 , and three extra starboard actuators 60 for tow members 64 ) are synchronized. Port and starboard extra actuators 60 and 62 are operated so that one side gives out while the other side takes in their respective tow members 64 and 66 .
FIG. 10 illustrates yet another system and method embodiment 1000 , which is identical to embodiment 700 of FIG. 7 except for the terminal connection point of tow members 64 and 66 . In embodiment 1000 tow members 64 and 66 are connected near midpoints of respective tow members 13 and 14 , but this location of connection may vary, depending on the degree of control required, the forces required, the expected environmental conditions, the physical characteristics of tow members 64 and 66 (such as strength, elasticity, and the like), and other factors.
Controllers useful in the invention may be Model Predictive (MP) controllers rather than PID controllers. The characteristics of each are discussed herein below. MP controllers may be mono-variable or multivariable MP controllers, and may use a pre-existing mathematical model of the system in conjunction with measured disturbances on the system, such as wind, currents, and the like, to calculate residuals and generate commands. Modification of set points by a feed-forward controller may optionally feed historical, real time or near-real time, or future predictions of data regarding current and/or wind as a modification to set points. In either embodiment, steering of source strings will then influence the inline skew in a more controlled and stable fashion using an MP controller and feed-forward controller, rather than an MP controller alone, or a human operator.
As should now be evident, using the systems and methods of the invention the operator does not have to perform manual control, and this may result in:
an objective reaction not dependent on operator skill level and alertness; control reaction with little or no delay; proactive response to current and other environmental factors with feed forward options; and more frequent update rates.
The systems of the invention may be used in conjunction with conventional crossline spread control devices. These devices include source steering devices and streamer steering devices. Such devices are often part of the spread and towed by the vessel.
Controllers useful in the systems and methods of the invention may vary in their details. One PID controller useful in the invention may be expressed mathematically as in Equation 1:
u ( t )= K p [e ( t )+1 /T i ·∫e ( t ) dt+T d −è ( t )] (1)
wherein:
∫ means integrate; è(t) means the time derivative; u(t) is controller output to an actuator, typically measured in meters of inline skew; e(t) means difference between wanted (planned, reference) inline position and measured (current position) inline value; T d is a constant for describing the derivative part of the algorithm (the derivative part may be filtered to avoid deriving high frequencies); T i is a constant for describing the integrating part of the algorithm; and K p is a proportional gain constant.
In the s-plane (Laplace), the PID controller may be expressed as (Equation 2):
H r ( s )= K p [1+1 /T i s+T d s /(1 +T f s )] (2)
wherein:
is the variable in the s-plane; and T f is a constant describing the filtering part of the derivative part of the algorithm.
For discretization, a variety of transforms may be employed, and some constants may or may not be useful. For example, the T f constant may not be necessary in some instances, but may be especially useful in other scenarios. As one discretization example, the z-transform may be used, meaning that the integral part of the algorithm may be approximated by using a trapezoid model of the form (Equation 3):
s =(1 −z −1 )/ T (3)
while the derivative part may be approximated using an Euler model (Equation 4):
s= 2 /T ·(1 −z −1 )/(1 +z −1 ) (4)
wherein T is the sampling time.
The resulting discrete model may then be used directly in the steering algorithm. Other discrete models, derived using other transforms, are useful in the invention, and will be apparent to control technicians or control engineers of ordinary skill.
Model Predictive Control (MPC) is an advanced multivariable control method for use in multiple input/multiple output (MIMO) systems. An overview of industrial Model Predictive Control can be found at: www.che.utexas.edu/˜qin/cpcv/cpcv14.html. MPC computes a sequence of manipulated variable adjustments in order to optimise the future behavior of the process in question. At each control time k, MPC solves a dynamic optimization problem using a model of the controlled system, so as to optimize future behavior (at time k+1, k+2 . . . k+n) over a prediction horizon n. This is again performed at time k+1, k+2 . . . MPC may use any derived objective function, such as Quadratic Performance Objective, and the like, including weighting functions of manipulated variables and measurements. Dynamics of the process and/or system to be controlled are described in an explicit model of the process and/or system, which may be obtained for example by mathematical modeling, or estimated from test data of the real process and/or system. Some techniques to determine some of the dynamics of the system and/or process to be controlled include step response models, impulse response models, and other linear or non-linear models. Often an accurate model is not necessary. Input and output constraints may be included in the problem formulation so that future constraint violations are anticipated and prevented, such as hard constraints, soft constraints, set point constraints, funnel constraints, return on capital constraints, and the like. It may be difficult to explicitly state stability of an MPC control scheme, and in certain embodiments of the present invention it may be necessary to use nonlinear MPC. In so-called advance spread control of marine seismic spreads, PID control may be used on strong mono-variable loops with few or nonproblematic interactions, while one or more networks of MPC might be used, or other multivariable control structures, for strong interconnected loops. Furthermore, computing time considerations may be a limiting factor. Some embodiments may employ nonlinear MPC. Mono-variable or multivariable model predictive controllers could substitute for one or more of the PID controllers in various embodiments.
Feed forward algorithms, if used, will in the most general sense be task specific, meaning that they will be specially designed to the task it is designed to solve. This specific design might be difficult to design, but a lot is gained by using a more general algorithm, such as a first or second order filter with a given gain and time constants.
All embodiments of the invention may include a modification of the set point signal by a feed-forward controller, which may optionally feed historical, real time or near-real time, or future predictions of data regarding currents, wind, and other environmental conditions or information regarding obstructions in the designated survey area, and the like.
FIG. 11 illustrates another method of the invention, comprising adjusting firing times of the source strings to distribute evenly any inline error due to un-even shot spacing in time or distance, rather than using mechanical actuators and controllers to correct for inline skew. FIG. 11 illustrates the point of un-even shot spacing in time or distance, showing two sources 10 and 12 at three different times t 1 , t 2 , and t 3 . The center of vessel 2 is indicated at 3 . For repeat surveys that aim to repeat the source positions from the base survey, this is of course also a major problem, as it will be very difficult to match the inline component of the source positions if the source feathering of the subsequent survey does not match the source feathering experienced in the base survey. Another factor to consider is that the chance of overlapping shots (two shots fired into the same shot record) is reduced if the shot interval (in time) is increased. This could be done by adjusting the vessel speed in order to:
1. maximize efficiency (i.e. vessel moves as fast as possible, around ˜5 knots, or 2.5 m/s); and 2. avoid overlapping shots.
FIG. 12 is an image from an analysis of an actual seismic data survey. It shows all the shots from that particular survey as dots. If there had been no influence from external forces (e.g. currents) and the vessel had been steering straight, all the dots would have been found on point (0,−175), as the source was towed 175 m behind the vessel for this particular survey. As can be seen, however, due to currents pushing the source array to the sides (mostly to port side), the inline error was increased (exceeding 40 m in the extreme cases). If there are no crossline currents causing source feather, the vessel speed could be adjusted to maximize efficiency of data collection. In a dual source arrangement, as soon as crossline current starts to affect the inline distance between the center of the two sources, the shot controller may be programmed to try to compensate by adjusting the firing times. As long as there is no shot overlap, the vessel speed may remain constant. If the source feather increases to a point where there is a chance of overlapping shot records, the system decides whether to slow the vessel down, or to freeze the triggering times (i.e. no further adjustment) to avoid overlapping shots. (The decision on which to choose may vary from survey to survey).
Un-even shot spacing in time or distance may be partially fixed by adjusting firing times, and using the geometric mid-point between the sources to distribute the error evenly, as depicted in FIG. 11 . Although none of these techniques can fully compensate for inline skew, the technique illustrated in FIG. 11 has been implemented in an existing shot controller. The implementation is, however, not straightforward. FIG. 11 illustrates an example with a record shot length of 6.0 seconds, a nominal shot spacing of 18.75 m; a vessel speed of 5 knots, or 2.5 m/s; source layback of 300 m; and a source feather of 5°. For these conditions, it can be shown that the inline skew is about 4.35 m. It was found that if the shot time period was held constant at 7.5 seconds, and the shot spacing distance was varied as 14.4 m-23.1 m-14.4 m -23.1 m, the inline skew could be reduced without significant shot overlap. If, rather than varying the shot spacing distance, the shot spacing distance remained constant at 18.75 m, and the shot time period varied in time as follows, 5.75 s-9.25 s-5.75 s-9.25 s, an unacceptable amount of shot overlap was found.
The systems and methods of the invention may be used in many spread embodiments. For example, for obtaining deghosted seismic data, it may be possible to provide one or more seismic streamers with a companion seismic streamer where the companions are towed in over/under fashion. The vertical distance between seismic streamers in an over/under seismic streamer pair may range from 1 meter to 50 meters, and may be about 5 meters. A selected number of hydrophones, either mounted within the seismic streamer or in/on equipment mounted onto the seismic streamer, may be used as receivers in an acoustic ranging system and thereby provide knowledge of the horizontal, vertical and inline position of COSAs as well as seismic streamers.
In use, systems and methods of the invention are particularly adept for 3D and so-called 4D marine seismic data acquisition surveys. More specifically, the systems and methods of the invention may be integrated into the seismic towing vessel steering strategy, and may be integrated into positioning strategies for spread elements other than seismic sources. In time-lapse or so-called 4D seismic, the source and receivers may be positioned to within a few meters of a baseline survey in order to gather a good picture of the evolution of a reservoir over time. The geophysical requirement for the accuracy of the repositioning varies with the geological structure and the expected time-difference signal, but generally a 10 meter positioning discrepancy is allowed, and often a bigger mismatch is allowed due to practicalities regarding the historical repositioning abilities. It is desired to position the source to within 5 meters, and the streamers to within about 10 meters of their previous tracks. Computing a residual difference between the 3D coordinate position and a pre-plot 3D coordinate position of a COS or COSA point may be helpful in order to meet these targets as it allows for corrective actions to be taken before it is too late. One use of systems and methods of the invention is to make approximate inline positioning of COSAs by using controllable actuators, and to fine tune by use of compensation devices such as those described in reference to FIGS. 6A and 6B .
Systems and methods of the invention may interact with any number of spread control elements, which may include one or more orientation members, a device capable of movements that may result in any one or multiple straight line or curved path movements of a spread element in 3-dimensions, such as lateral, vertical up, vertical down, horizontal, and combinations thereof. The terms and phrases “bird”, “cable controller”, “streamer control device”, and like terms and phrases are used interchangeably herein and refer to orientation members having one or more control surfaces attached thereto or a part thereof. A “steerable front-end deflector” (or simply “deflector”) such as typically positioned at the front end of selected streamers, such as 16 and 18 in the figures, and other deflecting members, such as those that may be employed at the front end of seismic sources or source arrays, may function somewhat to influence inline skew, although their purpose is primarily to correct for crossline and depth positions. Orientation members are primarily used to pull streamers and steer sources laterally with respect to direction of movement of a tow vessel. Horizontal separation between individual source strings may range from about 10 to about 100 meters, and the horizontal or crossline source string separation may be consistent between one source string and its nearest neighbors. Horizontal and/or vertical control of streamers may be provided by orientation members which may be of any type as explained herein, such as small hydrofoils or steerable birds that can provide forces in the vertical and/or horizontal planes. One suitable orientation member is the device known under the trade designation Q-FIN™, available from WesternGeco LLC, Houston, Tex., and described in U.S. Pat. No. 6,671,223, describing a steerable bird that is designed to be electrically and mechanically connected in series with a streamer; another suitable device is that known under the trade designation DigiBIRD™, available from Input/Output, Inc., Stafford, Tex. Other streamer positioning devices, such as the devices described in U.S. Pat. Nos. 3,774,570; 3,560,912; 5,443,027; 3,605,674; 4,404,664; 6,525,992 and EP patent publication no. EP 0613025, may be employed.
Systems of the invention may communicate with the outside world, for example another vessel or vehicle, a satellite, a hand-held device, a land-based device, and the like. The way this may be accomplished varies in accordance with the amount of energy the system requires and the amount of energy the system is able to store locally in terms of batteries, fuel cells, and the like. Batteries, fuel cells, and the like may be employed, and wireless communication may be sufficient. Alternatively, or in addition, there may be a hard-wire power connection and a hard wire communications connection to another device, this other device able to communicate via wireless transmission.
Certain systems and methods of the invention may work in feed-forwarded fashion with existing control apparatus and methods to position not only the seismic sources, but streamers as well. Sources and streamers may be actively controlled by using GPS data or other position detector sensing the position of the COSA or streamer (e.g. underwater acoustic network), or other means may sense the orientation of one or more COSAs or individual streamers (e.g. compass) and feed this data to navigation and control systems. While gross positioning and local movement of center of source and/or streamer front end center may be controlled via controlling the actuators and controllers herein described, fine control may be accomplished on some other vessel, locally, or indeed a remote location. By using a communication system, either hardwire or wireless, environmental information ahead of the vessel may be sent to one or more local controllers, as well as the controllers of systems of the invention. The local controllers may in turn be operatively connected to spread control elements comprising motors or other motive power means, and actuators and couplers connected to the orientation members (flaps), and, if present, steerable birds, which function to move the spread components as desired. This in turn may adjust the position of a spread element or COSA, causing it to move as desired. Feedback control may be achieved using local sensors positioned as appropriate depending on the specific embodiment used, which may inform the local and remote controllers of the position of one or more COSAs, crossline distance between source arrays and streamers, a position of an actuator, the status of a motor or hydraulic cylinder, the status of a steerable bird, and the like. A computer or human operator can thus access information and control the entire positioning effort, and thus obtain much better control over the seismic data acquisition process.
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, no clauses are intended to be in the means-plus-function format allowed by 35 U.S.C. §112, paragraph 6 unless “means for” is explicitly recited together with an associated function. “Means for” clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although electronic and hydraulic motion platforms may not be structural equivalents in that an electronic motion platform employs one type of actuator, whereas a hydraulic motion platform employs a different type of actuator, in the environment of movable platforms, electronic and hydraulically actuated movable platforms may be equivalent structures. | Systems and methods for automatic steering of marine seismic sources are described. One system comprises a marine seismic spread comprising a towing vessel and a seismic source, the seismic source comprising one or more source arrays each having a center of source array, each source array having one or more source strings; a seismic source deployment sub-system on the towing vessel, the sub-system controlled by a controller including a software module, the software module and the deployment sub-system adapted to control an inline distance between one of the centers of source array and a target coordinate. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, allowing a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. | 1 |
BACKGROUND OF THE INVENTION
This invention relates generally to gas turbine engines and more particularly, to valve assemblies used to regulate fluid flow for a gas turbine engine.
Gas turbine engines typically include an engine casing that extends circumferentially around a compressor, and a turbine including a rotor assembly and a stator assembly. Within at least some known engines, a plurality of ducting and valves coupled to an exterior surface of the casing are used to channel fluid flow from one area of the engine for use within another area of the engine. For example, such ducting and valves may form a portion of an environmental control system (ECS).
At least some known valve assemblies are used to control fluid flow that is at a high temperature and/or high pressure. Such valve assemblies include a substantially cylindrical valve body that is coupled between adjacent sections of ducting. The valve body includes a valve sealing mechanism that is selectively positionable to control fluid flow through the valve. More specifically, at least some known valves includes a piston/cylinder arrangement that is positioned external to the valve body and is coupled to the valve sealing mechanism to provide the motive force necessary to selectively position the valve sealing mechanism.
Because the piston/cylinder arrangement is offset from the main valve body, a center of gravity of the valve assembly is typically displaced a distance from a centerline axis of the valve body. Such an eccentric center of gravity may induce bending stresses into the valve assembly, adjoining tubing, and supporting brackets during engine operation. Depending on the application, the physical size and weight of the piston/cylinder arrangement may also present difficulties during the duct routing phase of the engine design.
BRIEF SUMMARY OF THE INVENTION
In one aspect, a method for operating a gas turbine engine is provided. The method comprises directing fluid flow from a source into an inlet of a valve, channeling the fluid flow entering an inlet portion of the valve towards an outlet portion of the valve such that a direction of the fluid flow is changed within the inlet portion, and controlling the amount of fluid flow entering the outlet portion of the valve by selectively positioning a valve disk coupled within the inlet portion of the valve by a valve disk axle. The method also comprises channeling the fluid flow from the inlet portion of the valve through the outlet portion of the valve and into a fluid supply pipe, wherein the valve outlet portion has a substantially right cylindrical shape such that a direction of fluid entering the body outlet portion remains substantially constant therethrough.
In another aspect of the invention, a valve for use with a gas turbine engine is provided. The valve comprises a valve body including a valve inlet portion and an outlet portion. The inlet portion extends from an inlet to the body outlet portion. The body outlet portion forms a substantially right cylinder that extends from the inlet portion to a valve outlet, such that a direction of fluid flowing within the body outlet portion remains substantially unchanged between the body inlet portion and the valve outlet. The inlet portion includes a valve disk and at least one bend formed between the body outlet portion and the valve inlet such that a direction of fluid entering the valve body through the valve inlet is changed prior to entering the body outlet portion. The valve disk is pivotally coupled within the inlet portion for controlling fluid flow through the valve.
In a further aspect, a gas turbine engine is provided. The engine includes a fluid supply pipe a valve configured to regulate an amount of fluid flow entering the fluid supply pipe. The valve includes a valve body comprising an inlet, an outlet, an inlet portion, and an outlet portion. The inlet portion extends between the inlet and the outlet. The outlet portion extends between the inlet portion and the outlet. The outlet portion has a substantially right cylindrical shape such that a direction of fluid entering the body outlet portion remains substantially constant therethrough. The inlet portion includes a valve disk and at least one bend formed between the inlet and the body outlet portion, such that a direction of fluid flowing through the body inlet portion is changed prior to entering the outlet portion. The valve disk is used to control fluid flow through the valve into the fluid supply pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a gas turbine engine including a plurality of ducting coupled together by a plurality of valve assemblies;
FIG. 2 is a cross-sectional view of one of the valve assemblies shown in FIG. 1 ;
FIG. 3 is an exploded perspective view of the valve assembly shown in FIG. 2 ;
FIG. 4 is a perspective view of an alternative embodiment of a valve assembly that may be used with the gas turbine engine shown in FIG. 1 ; and
FIG. 5 is a side view of the valve assembly shown in FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a side view of a gas turbine engine 10 including a plurality of ducting 12 coupled together by a plurality of valve assemblies 14 . Engine 10 includes a high-pressure compressor assembly 16 , a combustor 18 , and a turbine assembly 20 . In one embodiment, compressor 16 is a high-pressure compressor. Engine 10 also includes a low-pressure turbine (not shown) and a fan assembly (not shown). In one embodiment, engine 10 is a CF34 engine commercially available from General Electric Company, Cincinnati, Ohio.
In the exemplary embodiment, ducting 12 and valve assemblies 14 form a portion of an engine build up (EBU) 30 . More specifically, ducting 12 and valve assemblies 14 facilitate channeling and controlling, respectively, fluid flow at a high temperature, and/or at a high pressure, from one area of engine 10 for use in another area. For example, in one embodiment, fluid flowing through ducting 12 and valve assemblies 14 has an operating temperature that is greater than 1000° F. and/or an operating pressure of greater than 300 psi.
In the exemplary embodiment, ducting 12 includes a Y-duct 32 that facilitates splitting EBU 30 into a pair of inlet duct assemblies 34 and 36 that are coupled to an engine casing 40 by a plurality of mounting bracket assemblies 42 . More specifically, inlet duct assemblies 34 and 36 are coupled in flow communication to compressor 18 for routing bleed air from compressor 18 for use in other areas, such as an environmental control system.
FIG. 2 is a cross-sectional view a valve assembly 14 . FIG. 3 is an exploded perspective view of valve assembly 14 . Valve assembly 14 includes a valve body 50 having a first body portion 52 and an integrally-formed second body portion 54 . In the exemplary embodiment, first body portion 52 is an inlet body portion, and second body portion 54 is an outlet body portion, and both will be described herein as such. In an alternative embodiment, first body portion 52 is an outlet body portion, and second body portion 54 is an inlet body portion. Inlet portion 52 extends from an assembly first end 56 to outlet portion 54 , and outlet portion 54 extends from inlet portion 52 to an assembly second end 60 . In the exemplary embodiment, assembly first end 56 is an assembly inlet, and assembly second end 60 is an outlet, and both will be described herein as such. In an alternative embodiment, assembly first end 56 is an assembly outlet for discharging fluids therefrom, and assembly second end 60 is an assembly inlet for receiving fluids therein. Valve assembly 14 is hollow and includes a bore 64 that extends between assembly inlet 56 and assembly outlet 60 . Valve assembly 14 also includes an exterior surface 66 that extends over inlet and outlet portions 52 and 54 , respectively.
Valve assembly outlet portion 54 includes an interior surface 70 and a centerline 72 . Interior surface 70 extends through outlet portion 54 to outlet 60 and defines a portion of assembly bore 64 . Because outlet portion 54 is a right cylinder, assembly outlet 60 is substantially perpendicular to outlet portion centerline 72 .
Outlet portion 54 also includes an integrally-formed mounting flange 76 , an inner shoulder 78 , and a pair of actuator system connector link mounts 80 . Flange 76 extends circumferentially from outlet portion exterior surface 66 around assembly outlet 60 , and includes a plurality of openings 84 . Openings 84 are each sized to receive a fastener 86 therethrough for coupling outlet portion 54 to a valve-inner cylinder 90 .
Outlet portion shoulder 78 is positioned between flange 76 and actuator system mounts 80 . More specifically, a diameter d 1 of bore 64 within outlet portion 54 , defined by surface 70 , is substantially constant between assembly outlet 60 and shoulder 78 , and is larger than a diameter d 2 of outlet portion bore 64 extending between shoulder 78 and inlet portion 52 .
Valve-inner cylinder 90 is a substantially right hollow cylinder that that extends from an inlet edge 94 to an outlet edge 96 , and includes an exterior surface 98 and an interior surface 100 . Exterior and interior surfaces 98 and 100 , respectively, define respective external and internal diameters d 3 and d 4 for cylinder 90 . Diameters d 3 and d 4 are substantially constant along cylinder 90 between edges 94 and 96 , and both diameters d 3 and d 4 are smaller than outlet portion bore diameter d 2 . Accordingly, valve-inner cylinder 90 is sized to be received within outlet portion 54 , such that cylinder 90 is substantially concentrically aligned with respect to outlet portion 54 .
A mounting flange 106 extends radially outwardly and circumferentially from cylinder outlet edge 96 . Flange 106 is aligned substantially perpendicular to a centerline axis 108 extending through cylinder 90 , and includes a plurality of fastener openings 110 that are each sized to receive fastener 86 therethrough. More specifically, when valve-inner cylinder 90 is positioned within outlet portion 54 , cylinder fastener openings 110 are each substantially concentrically aligned with respect to each respective outlet portion flange fastener opening 84 , such that fasteners 86 extending through openings 110 and 84 secure valve-inner cylinder 90 in alignment within outlet portion 54 .
A valve piston 120 is slidably coupled between valve-inner cylinder 90 and outlet portion 54 . More specifically, valve piston 120 is a substantially right hollow cylinder that that extends from an inlet edge 124 to an outlet edge 126 , and includes an exterior surface 128 and an interior surface 130 . Exterior and interior surfaces 126 and 130 , respectively, define respective external and internal diameters d 5 and d 6 for piston 120 . In the exemplary embodiment, diameters d 5 and d 6 are substantially constant between piston edges 124 and 126 , and both diameters d 5 and d 6 are larger than valve-inner cylinder external diameter d 3 . In an alternative embodiment, an inlet side of piston 120 has a smaller diameter than an outlet side of piston 120 , which as described in more detail below, facilitates piston 120 being double acting. Additionally, piston external diameter d 5 is slightly smaller than outlet portion bore diameter d 2 , such that when piston 120 is received within outlet portion 54 , piston external surface 128 is slidably coupled against outlet portion interior surface 70 between outlet portion shoulder 78 and inlet portion 52 .
A seal assembly 131 extends circumferentially around piston outlet edge 126 to facilitate minimizing leakage of actuation air past piston outlet edge 126 . Seal assembly 131 is substantially perpendicular to a centerline axis 132 extending through cylinder 120 , and has an outer diameter d 7 that is slightly smaller than outlet portion bore diameter d 1 .
Piston internal diameter d 6 is larger than valve-inner cylinder external diameters d 3 such that a gap 140 is defined between piston interior surface 130 and valve-inner cylinder external surface 98 . More specifically, gap 140 extends between seal assembly 131 and piston inlet edge 124 . A valve spring 150 extends circumferentially within gap 140 between valve-inner cylinder 90 and valve piston 120 , and as described in more detail below, is used to regulate operation of valve assembly 14 .
Valve piston 120 also includes a pair of openings 154 that are extends diametrically aligned with respect to valve piston 120 and extend partially between exterior surface 128 and interior surface 130 . Openings 154 are each sized to receive a connecting rod 155 that enables valve piston 120 to be coupled to an actuator system connector link 156 .
Valve inlet portion 52 includes an interior surface 160 that extends through inlet portion 52 to assembly inlet 56 and defines a portion of assembly bore 64 . In the exemplary embodiment, a diameter d 8 of inlet portion 52 remains substantially constant through inlet portion 52 between outlet portion 54 and assembly inlet 56 , and through an integrally formed bend 164 that is positioned between valve outlet portion 54 and assembly inlet 56 . In the exemplary embodiment, inlet portion 52 has a generally Z-shaped bend 164 such that assembly inlet 56 is substantially parallel to assembly outlet 60 . In an alternative embodiment, interior surface 160 is oriented substantially parallel to formed bend 164 to facilitate a smooth transition between adjoining ducting 12 . In a further alternative embodiment, valve assembly 14 includes piston 120 , but valve inlet portion 52 does not include bend 164 . Rather, in this alternative embodiment, valve inlet portion 52 is a substantially right cylinder.
Valve inlet portion 52 includes a centerline 170 that extends between assembly inlet 56 and outlet portion 54 . More specifically, in the exemplary embodiment, between inlet 56 and bend 164 , centerline 170 is substantially parallel to outlet portion centerline 72 , and between bend 164 and outlet portion 54 , centerline 170 is substantially co-linear with outlet portion centerline 72 . Accordingly, within bend 164 , centerline 170 extends obliquely with respect to outlet portion centerline 72 . More specifically, within bend 164 , centerline 170 is obliquely offset an angle θ from outlet portion centerline 72 . In one embodiment, angle θ is equal between approximately six and twenty degrees. In the exemplary embodiment, angle θ is approximately equal thirteen degrees.
Inlet portion diameter d 8 is smaller than bore diameter d 2 extending between outlet portion shoulder 78 and inlet portion 52 . Accordingly, a shoulder 182 is defined at the union of inlet and outlet portions 52 and 54 , respectively. Shoulder 182 provides a biasing contact for valve spring 150 , and includes an annular seal 184 has a diameter d 9 that is slightly smaller than valve inner cylinder external diameter d 3 , and as such facilitates positioning valve-inner cylinder 90 with respect to valve body 50 .
Inlet portion 52 includes an opening 186 that extends diametrically through inlet portion 52 between inlet portion exterior surface 66 and interior surface 160 . In the exemplary embodiment, opening 186 is substantially parallel valve piston opening 154 and is sized to receive an actuator system axle 190 therethrough. More specifically, and as described in more detail below, each opening 186 extends through an actuator system inlet mount 188 that is integrally formed with inlet portion 52 .
An actuator system 200 is coupled to valve body 50 to facilitate controlling fluid flow through valve assembly 14 . Specifically, actuator system 200 is coupled to valve inlet and outlet portions 52 and 54 , respectively, by connector link 156 . More specifically, an inlet side 202 of connector link 156 is coupled to axle 190 for controlling rotation of a sealing mechanism or sealing plate 206 .
Sealing plate 206 has a substantially circular outer perimeter 208 and a substantially arcuate cross-sectional profile. In the exemplary embodiment, sealing plate 206 is formed with a constant radius such that plate 206 has a truncated spherical cross-sectional profile. Sealing plate 206 includes a front side 210 and an opposing rear side 212 . Plate 206 includes a centerline axis 214 extending therethrough, and a shaft bore 216 that extends therethrough and is sized to receive axle 190 therein. More specifically, axle 190 extends through shaft bore 216 and pivotally couples plate 206 within valve body 50 .
Each plate side 210 and 212 defines a portion of shaft bore 216 . More specifically, bore 216 is not concentrically aligned with respect to plate centerline axis 214 , but rather extends obliquely through plate 206 with respect to centerline axis 214 . Accordingly, each side 210 and 212 includes a raised area 218 that extends outwardly from an outer surface 220 of plate 206 in a frusto-conical cross-section to define a portion of shaft bore 216 .
Plate raised areas 218 enable axle 190 to extend through plate 206 within inlet portion bend 164 . More specifically, axle 190 is aligned substantially perpendicularly with respect to outlet portion centerline 72 , and is therefore aligned obliquely at angle θ with respect to bend centerline 170 . Accordingly, when plate 206 is in a fully open position, as shown in FIGS. 2 and 3 , plate 206 is obliquely offset with respect to inlet portion bend 164 . However, because axle 190 is offset from plate centerline axis 214 , when plate 206 is rotated to a fully closed position, plate 206 is aligned substantially perpendicularly with respect to bend centerline 170 such that plate outer perimeter 208 circumferentially contacts inlet portion interior surface 160 in sealing contact, as described in more detail below. In one embodiment, valve assembly 14 includes a sensor to sense a position of plate 206 with respect to valve assembly, such as but not limited to an LVDT displacement transducer. Valve axle 190 is inclined at angle θ with respect to bend centerline 170 and with respect to plate centerline axis 214 to facilitate providing a continuous and substantially round sealing contact between plate outer perimeter 208 and interior surface 160 . More specifically, bend 164 enables plate 206 to be aligned substantially perpendicularly to interior surface 160 when plate 206 is fully closed, and causes axle 190 to be aligned substantially perpendicularly to the motion of piston 120 .
Axle 190 is rotatably coupled to connector link inlet side 202 at each actuator system inlet mount 188 by a pair of bearings 230 , a valve lock 232 , and a pair of cranks 234 . More specifically, bearings 230 are rotatably coupled to axle 190 within each mount 188 , and are secured in position by seal members 236 . A seal member 236 nearest valve lock 232 are coupled to inlet portion 52 by a plurality of fasteners 240 that extend through seal member openings 242 and into integrally formed inlet mount openings 244 and into integrally formed inlet mount openings 244 . A seal member 236 opposite valve lock 232 are coupled to inlet portion 52 by an arcuate snap ring 245 . Seal members 236 facilitate preventing fluid leakage through inlet portion opening 186 and around axle 190 .
Axle 190 is then inserted through each valve lock 232 prior to being coupled to connector link inlet side 202 by each respective crank 234 . Valve lock 232 facilitates maintaining axle 190 in rotational position, such that plate 206 may be maintained in an orientation, such as fully open or fully closed, with respect to valve body 50 .
An outlet side 25 of each connector link 156 is coupled to valve piston 120 by connecting rod 155 through connector link mounts 80 . More specifically, each connector link mount 80 includes an integrally formed slot 252 that extends substantially parallel to outlet portion centerline 72 . Each slot 252 is sized to receive a slider 254 therein in slidable contact, and includes a slotted opening 256 that extends through slot 252 . Each connecting rod 155 is couple to valve piston 120 and extends radially outward through slotted openings 256 and through sliders 254 to couple through a threaded nut 258 to connector link outlet side 250 . More specifically, a cover plate 260 is aligned with respect to slot 252 by a plurality of dowel pins 262 that extend through cover plate openings 266 .
During operation, fluid enters valve assembly 14 through assembly inlet 56 and into valve body inlet portion 52 . Inlet portion bend 164 causes a direction fluid flowing within inlet portion 52 to be changed within inlet portion 52 . More specifically, fluid flow is turned through angle θ in the vicinity of plate 206 . Bend 164 enables axle 190 to be coupled substantially perpendicularly to movement of piston 120 which, as described in more detail below, facilitates converting rectilinear motion of piston 120 into rotary motion of sealing plate 206 . Accordingly, if plate 206 is in a fully closed position, plate 206 is substantially perpendicular to a direction of fluid flow within bend 164 . As such, plate outer perimeter 208 forms a substantially continuous seal circumferentially within inlet portion 52 , which facilitates preventing fluid flow through valve assembly 14 . More specifically, when plate 206 is rotated to the closed position, actuator or supply fluid is turned off and spring 150 biases sealing plate 206 through actuator system 200 in the fully closed position.
Main actuation fluid enters valve piston 120 through a port 277 and operates against valve piston outlet face 126 . Additional actuation fluid operates on valve piston 120 in a gap 279 that is partially defined between valve piston inlet edge 124 and shoulder 182 . Accordingly, piston 120 is double actuated by the actuation fluid. More specifically, when plate 206 is desired to be rotated into a partially opened or modulated position, main pressurized actuator fluid is supplied to outlet portion 54 through port 277 into a gap 280 defined between valve piston seal assembly 131 and valve-inner cylinder mounting flange 106 . The fluid pressure of the actuator fluid forces piston 120 to translate, which in turn causes connectors links 156 to translate through slots 252 . The translational motion of links 156 causes subsequent rotational motion of valve cranks 234 . Rotation of cranks 234 causes rotation of axle 190 which causes plate 206 to rotate from the closed position, such that fluid flows past sealing mechanism 206 and downstream from valve assembly 14 .
Annular seat 184 allows for axial thermal growth differences between valve-inner cylinder 90 and valve body 50 . Seat 184 also permits flid that has flowed downstream from seat 206 to enter gap 140 . Fluid pressure within gap 140 acts in opposition to the force induced by actuation fluid, which in conjunction with spring force induced by spring 150 causes plate 206 to self-regulate the flow of fluid. More specifically, if the downstream pressure decreases, the opposing force also decreases, which allows pressurized actuation fluid to force sealing mechanism 206 to open more fully to restore the regulated fluid flow at a predetermined pressure.
Despite the offset of inlet portion 52 with respect to outlet portion 54 , a center of gravity 290 of valve assembly 14 is located substantially along outlet portion centerline 72 . Accordingly, ending stresses induced to valve assembly 14 during the operation of actuator system 200 are facilitated to be reduced in comparison to other known valves which have offset centers of gravity. As such, valve body 50 facilitates extending a useful life of valve assembly 14 . Furthermore, because center of gravity 290 is positioned along outlet portion centerline 72 eccentricity induced bending stresses of adjoining ducting 12 are also facilitated to be reduced, which facilitates the use of mounting bracket assemblies 42 fabricated from lighter weight materials. In addition, valve assembly 14 requires less physical space envelopes than other known valve assemblies used for the same applications.
FIG. 4 is a perspective view of an alternative embodiment of a valve assembly 300 that may be used with gas turbine engine 10 (shown in FIG. 1 ). FIG. 5 is a side view of valve assembly 300 . Valve assembly 300 is substantially similar to valve assembly 14 (shown in FIGS. 2 and 3 ) and components of assembly 14 that are identical to components of valve assembly 300 are identified in FIGS. 4 and 5 using the same reference numerals used in FIGS. 2 and 3 . Accordingly, valve assembly 300 includes valve body 50 , inlet portion 52 , and outlet portion 54 . Additionally valve assembly 300 includes valve-inner cylinder 90 , valve piston 120 , and an actuator system 302 . Actuator system 302 is substantially similar to actuator system 200 and includes a pair of pivot links 303 coupled to sealing plate 206 by a wishbone link 304 .
More specifically, each wishbone link 304 includes a pair of outlet ends and a connector actuator coupler 12 . Each wishbone link outlet end is coupled to outlet portion 54 by connecting rods 155 extending through mounts 80 . More specifically, each wishbone link mount 80 include slot 252 and slider 254 . Each connecting rod 155 is coupled to valve piston 120 and extends radially outward through slotted openings 256 and through sliders 254 to couple through bushing 258 to pivot link outlet side 250 . More specifically, cover plate 260 is coupled to each pivot link mount 80 by fasteners 262 that extend through cover plate openings 266 into openings 268 formed integrally within each link mount 80 .
Each pivot links 303 is pivotally coupled to wishbone link 304 between wishbone link outlet end 156 and wishbone connector actuator coupler 312 . Pivot links 303 provide additional support to wishbone link 304 and facilitate maintaining wishbone link 304 in alignment with respect to valve assembly 300 .
Wishbone link 304 extends partially circumferentially to couple together with an actuator rod 320 that extends laterally upstream towards an inlet actuator mount 188 . Within valve assembly 300 , inlet portion 52 includes only one actuator mount 188 , but also includes an integrally-formed axle seat 322 that is described in more detail below. Each wishbone link 304 is also pivotally coupled by a hinge pin 324 that is positioned between wishbone link outlet end 156 and wishbone connector actuator coupler 312 .
Actuator rod 320 is coupled to actuator mount 188 with an axle 190 that is rotatably coupled to actuator rod 320 by a bearing 230 , a valve lock 232 , a crank 234 , and a yoke 330 . More specifically, bearing 230 is rotatably coupled to axle 190 within mount 188 , and is secured in position by seal member 236 . Axle 190 is also inserted through valve lock 232 prior to being inserted through yoke 330 and coupled to actuator rod 320 by crank 234 . Yoke 330 provides addition support to actuator system 302 .
Axle 190 does not extend diametrically through inlet portion 52 , but rather, an inner end 340 of axle 190 is rotatably coupled within a bearing assembly 342 . More specifically, bearing assembly 342 is seated within axle seat 322 . Accordingly, because valve assembly 300 includes only one opening 186 within inlet portion 52 , valve assembly 300 facilitates reducing blow-by leakage that may occur through openings 186 .
The above-described valve assembly is cost-effective and highly reliable. The valve assembly includes a valve body that includes an integrally formed inlet and outlet portion. Because the portions are only offset by a minimal angle, the center of gravity of the assembly is located within the valve assembly and along a centerline of the outlet portion. As such, vibrational induced bending moments and eccentricity induced stresses to the valve body are facilitated to be reduced. As a result, the valve body facilitates extending a useful life of the valve assembly in a cost-effective and reliable manner.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims. | A method enables a gas turbine engine to be operated. The method includes directing fluid flow from a source into an inlet of a valve, channeling the fluid flow entering an inlet portion of the valve towards an outlet portion of the valve such that a direction of the fluid flow is changed within the inlet portion, and controlling the amount of fluid flow entering the outlet portion of the valve by selectively positioning a valve disk coupled within the inlet portion of the valve by a valve disk axle. The method also comprises channeling the fluid flow from the inlet portion of the valve through the outlet portion of the valve and into a fluid supply pipe, wherein the valve outlet portion has a substantially right cylindrical shape such that a direction of fluid entering the body outlet portion remains substantially constant therethrough. | 5 |
This application is a continuation of application Ser. No. 07/649,447, filed Feb. 1, 1991, now abandoned.
FIELD OF THE INVENTION
This invention relates to an instrument for extracting samples of tissue from humans and other animals and more particularly to an instrument for automatically performing a biopsy of a tissue mass in an accurate, expeditious manner with a minimum of discomfort to the patient.
BACKGROUND OF THE INVENTION
It is often desirable and frequently absolutely necessary to sample or test a portion of tissue from humans and even other animals, particularly in the diagnosis and treatment of patients with cancerous tumors, pre-malignant conditions and other diseases or disorders. Typically in the case of cancer, when the physician establishes by means of procedures such as palpitation, x-ray or ultra sound imaging that suspicious circumstances exist, a very important process is to establish whether the cells are cancerous by doing a biopsy. Biopsy may be done by an open or closed technique. Open biopsy removes the entire mass (excision biopsy) or a part of the mass (incision biopsy). Closed biopsy on the other hand is usually done with a needle-like instrument and may be either an aspiration or a core biopsy. In needle aspiration biopsy, individual cells or clusters of cells are obtained for cytologic examination and may be prepared such as in a Papanicolaou smear. In core biopsy, as the term suggests, a core or fragment of tissue is obtained for histologic examination which may be done via a frozen section or paraffin section.
The type of biopsy depends in large part in circumstances present with respect to the patient and no single procedure is ideal for all cases. However, core biopsy is extremely useful in a number of conditions and is being used more frequently by the medical profession.
A variety of biopsy needles and devices have been described and used for obtaining specimens of tissue. For example, reference is made to U.S. Pat. Nos. 4,651,752; 4,702,260; and 4,243,048 which show biopsy needles of varying types. Additionally, a number of very specialized devices for extracting samples of tissue have been described such as the biopsy device in U.S. Pat. No. 4,461,305, which device is designed specifically for removing a sample of tissue from the female uterine cervix. Other devices have been disclosed which relate to surgical cutting instruments. For example, U.S. Pat. No. 4,589,414 discloses an instrument which is particularly designed to operate in the area of the knee to withdraw tissue chips. Also available are so-called biopsy guns for removing a core of tissue which customarily are spring powered devices and must be cocked with considerable force. When actuated such guns produce a loud snapping noise, combined with a jerking action. Such a biopsy gun may employ a needle set consisting of an inner stylet and an outer tube called a cannula. The stylet is a needle like device with a notched cut-out at its distal end. The cannula in effect is a hollow needle with an angled cutting surface at its distal end which slides over the stylet. When the stylet is forced into tissue, the tissue is pierced and relaxes into the notched cut-out of the stylet. When the cannula is then slid forward, the tissue in the notch of the stylet is sliced off and retained in the notch until the cannula is withdrawn. Examples of such devices are shown in U.S. Pat. Nos. 4,600,014 and 4,699,154. Although such spring powered biopsy guns will remove a core or sample of tissue, they have rather serious disadvantages. For one, they must be manually cocked with a plunger bar. Such "cocking" of the gun requires considerable force and the gun must be cocked for each biopsy cut. A further disadvantage is that the springs provided in the gun accelerate the needles until a mechanical stop position is reached, creating a loud snapping noise and jerking motion which is a problem both to the physician and the patient. This noise and jerking action can cause the patient to jump and in some cases even prevents the physician from striking the intended tissue target. Another disadvantage is that the force and velocity delivered to the stylet and cannula rapidly diminishes when traveling from a retracted to a fully extended position resulting in tissue samples of lower quality.
U.S. Pat. No. 4,940,061 discloses a biopsy instrument which represents a substantial improvement over the aforementioned devices, substantially eliminating the loud snapping noise and jerking motion associated with spring-powered biopsy guns, for example. In the instrument of Pat. No. 4,940,061, an electric motor drives a rotary cam assembly which converts rotary motion to linear motion to sequentially extend and retract a stylet and cannula, and employs electrically actuated stops to control the extension and retraction of the stylet and cannula. Details of the construction and operation of the biopsy instrument are disclosed in U.S. Pat. No. 4,940,061, which is hereby incorporated by reference. Although well suited for many applications, that instrument suffers certain drawbacks, one of them being mechanical wear associated with a limit switch assembly and a toggle assembly which both include stationary wiper plates and spring finger contacts which slide against each other during normal operation.
Accordingly it is a principal object of this invention to provide an instrument for obtaining samples of tissue from tissue masses.
It is another object of this invention to provide an instrument for automatically performing a biopsy of a tissue mass in an accurate and expeditious manner with a maximum of accuracy and a minimum amount of discomfort to the patient.
It is a still further object of this invention to provide an instrument for performing tissue mass biopsies by removing a core or sample of tissue, which instrument eliminates the need for springs and mechanical stops, which is silent in operation and has the ability to effectively penetrate even small tissue masses.
It is another object of this invention to provide an instrument for obtaining tissue samples from tissue masses which instrument requires no manual setting or cocking and which may be "fired" multiple times without any abrupt starts or stops.
It is still another object of this invention to provide a biopsy instrument which includes means to convert rotary motion to sequential, linear motion of substantially constant force and velocity to the means for penetrating and severing a tissue sample from a tissue mass.
These and other objects of the invention will be apparent from the following description and claims.
SUMMARY OF THE INVENTION
Based on the prior art instruments for biopsy samples from tissue masses, and the actual present state of this art, there then exists a need for an instrument which is capable of automatically removing a tissue sample or core sample of predetermined size where the process is done very rapidly, is easily repeated if required, is accurate, is relatively simple for the physician to use, is virtually noiseless, and in use results in minimal discomfort to the patient.
Accordingly, I have invented an instrument for removing tissue samples from a tissue mass which instrument automatically penetrates, severs, and removes the tissue portion for examination. The instrument is motor powered, preferably by self-contained rechargeable batteries, and employs electrically actuated stops instead of mechanical stops to control the action of penetration and retraction from the tissue mass. The portion of the instrument which penetrates the tissue mass and severs a portion thereof, the tissue penetrating and severing means, includes an inner stylet which penetrates the tissue mass and a hollow outer tube or cannula which surrounds the stylet and serves to sever a sample of tissue. In a preferred form the tissue penetrating end of the stylet is notched so that when the stylet penetrates the tissue mass, a portion of the tissue relaxes in the notched area. After tissue penetration by the stylet, the cannula, having a cutting surface at its distal end, penetrates the tissue and cuts off the tissue portion residing in the notched area of the stylet. The tissue penetrating and severing means are operably connected to a special motor powered rotary cam assembly by means of cam followers and it is a feature of this invention that the rotary motion of the cam is converted to sequential, linear motion in the tissue penetrating and severing means, the linear motion being of substantially constant force and velocity.
In operation, the physician or technician actuates the instrument by pressing a button causing the stylet to move forward in a rapid, precise manner and penetrate the tissue mass followed with penetration of the mass by the cannula, resulting in a portion or core of tissue being severed and retained in the notched portion of the stylet. Further actuation by the physician causes the cannula to retract exposing the tissue sample in the stylet for easy removal. An additional actuation causes retraction of the stylet and a resetting of the cannula/stylet assembly for further use.
BRIEF DESCRIPTION OF THE DRAWINGS
The above noted advantages and other characteristic features of the present invention will be in part apparent from the accompanying drawings, and in part pointed out in the following detailed description of the preferred embodiment of the invention in which reference will be made to the accompanying drawings wherein like reference numerals designate corresponding parts and wherein:
FIG. 1 is a perspective view of the biopsy instrument of this invention.
FIG. 2 is a side elevational view taken on the line 2--2 of FIG. 1.
FIG. 3 is an exploded view of the major component parts of the instrument shown in FIG. 2.
FIG. 4 is an exploded perspective view of the biopsy instrument further illustrating the major component parts thereof.
FIG. 5 is a plan view of the outer surface of the rotary cam illustrating the cam profile as a function of angular position about the full circumference of the cam.
FIG. 6 is an electrical schematic of a control circuit according to the preferred embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to described the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
Considering now the drawings in detail, FIG. 1 illustrates a perspective view of one embodiment of the inventive biopsy instrument which is shown generally at 10 with the tissue piercing and removing means shown generally at 12. The tissue piercing and removing means comprises a stylet 14 and cannula 13. Referring to FIG. 2 which is a sectional view through the instrument shown in FIG. 1, and FIGS. 3 and 4, which are exploded views of a number of the components of the instrument, the instrument 10 is shown as having an outer housing 15 provided with a motor 18 mounted in one end thereof. Motor 18 is reversible and preferably of the DC type and preferably powered by rechargeable batteries 16 contained within the housing. Suitable contacts 17 are provided to recharge the batteries. Motor 18 is operably engaged with planetary gear assembly 20 by means of shaft 19 which shaft engages central gear 21. Central gear 21 in turn meshes with planetary gears 22 which in turn engage with annulus gear 23. In a preferred embodiment the DC motor operates at about 10,000 rpm with the gearing being about a 6:1 ratio. Drive shaft 25 is secured at its end 26 in the D-shaped opening 35 of the planetary gear set by means of a set screw or other suitable fastening means.
The components of the instrument which guide the stylet/cannula assembly 12 will now be detailed. A physician or technician actuates the instrument causing the stylet 14 to move forward in a rapid and precise manner to penetrate the tissue mass followed by penetration of the mass by the cannula 13, resulting in a portion or core of tissue being severed and retained in the notched portion of the stylet. Further actuation causes the cannula to retract exposing the tissue sample in the notched portion at the distal end of the stylet for easy removal. An additional actuation causes retraction of the stylet and a resetting of the cannula/stylet assembly for further use. The penetration and retraction of the stylet and cannula assembly is controlled in part by hollow rotary cam 55, one embodiment of which is illustrated in FIG. 4. As will be described later, the cam preferably has a cam profile as illustrated in FIG. 5. Cam 55 is provided with a continuous groove 56 which is made up of three sections. A first groove section 56a is positioned substantially parallel to one end of cam 55 and extends about a portion of the circumference of the cam. A second groove section 56b is positioned substantially parallel to the other end of the cam and also extends about a portion of the circumference of the cam. Section 56c connects section 56a and 56b in a generally diagonal manner in the embodiment of FIG. 4. Cam 55 is rotated by means of drive shaft 25, which is secured at its forward end 26 into the opening 63 of the end wall 59 of cam 55. Thus rotation of shaft 25 in a clockwise or counterclockwise direction causes identical rotation of the cam.
As previously described, stylet 14 moves within and is surrounded by cannula 13. The non-penetrating end of stylet 14 is mounted in stylet block 74. Correspondingly, the non-penetrating end of cannula 13 is mounted into cannula block 75. As shown in FIG. 4, stylet block 74 is provided with extension 76 which is in alignment with and moves through opening 77 of the cannula block 75 to aid in proper alignment of the stylet and cannula blocks and therefore the stylet/cannula assembly. An alternative construction of the stylet/cannula assembly is disclosed in U.S. Pat. No. 5,146,921, which is hereby incorporated by reference.
Mounted in the ends of each of the cannula and stylet blocks are drive rods 62 which are in turn secured to drive arms 61. Each of drive arms 61 is provided with a cam follower 60 which rides in the continuous groove 56 of cam 55. Thus, rotation of cam 55 will result in sequential linear movement of the stylet and cannula.
Although a generally diagonal central groove section 56c is useful with an optoelectronic sensor as shown in FIG. 4, the cam profile is preferably as illustrated in FIG. 5, which is a scale drawing of the outer surface of the cam, with the front edge of the cam appearing at the top of the drawing. The groove has a flat rear section 156a beginning at one end point A and extending approximately 235° counterclockwise (CCW) around the cam, as viewed from the rear, followed by a an S-curve or sinusoidal section which includes sections 156c, 156d and 156e extending approximately 68°, 9° and 68° CCW, respectively, around the cam, followed by a flat front section 156b extending approximately 199° CCW around the cam, to the other end point B.
Fixed within the housing is a printed circuit board 120 on which is mounted all of the motor driver and control electronics for the instrument, as will be explained in detail in connection with FIG. 6. The board is provided with a central hole through which drive shaft 25 passes, as shown in FIG. 2. A slotted disc 121 is affixed to the drive shaft, preferably by means of a D-shaped opening mating with a D-shaped section on the shaft as in the case of the connection to the cam 55. The disc is positioned so as to pass through the openings in two optoisolators referred to herein as sensor 1 and sensor 2 and labeled #1 and #2, respectively, in FIG. 3. The slot in the disc is 50° wide, and the disc is fixedly mounted on the drive shaft such that edge 122 of the slot is angularly offset 9°-10° with respect to the endpoint A of the groove in the cam, as shown in FIG. 4. It will be appreciated by those skilled in the art that, although FIG. 4 shows cam followers 60 at the same axial position, this is for illustration purposes only in the exploded view, and that, in operation, the angular position of the cam in FIG. 4 corresponds to the stylet in a partially extended position.
Operation of the instrument begins with stylet 14 and cannula 13 in a retracted position and with the exposed tip of stylet 14 immediately adjacent the tissue mass 11. Initial rotation of cam 55 results in forward movement of stylet block 74 and its attached stylet to penetrate the tissue mass where a portion of the tissue is caught in notch 14a. Continued rotation of the cam results in forward movement of the cannula block 75 and its attached cannula into the tissue mass severing the portion of the tissue within notch 14a from the tissue mass. The instrument is then withdrawn from the patient. Rotation of cam 55 is then reversed thus causing retraction of the cannula exposing the tissue sample in notch 14a for easy removal by the technician. Further rotation of cam 55 will result in retraction of the stylet and, thus, a return to the initial ready-to-fire condition.
Because of the need for precise movement of stylet and cannula, guide means shown generally at 64 are used to further embodiment shown in FIG. 4, guide means 64 includes a generally cylindrical shaped housing 68 having a rectangular opening 69 approximately sized to accommodate the stylet and cannula blocks 74 and 75. Thus the stylet and cannula blocks move laterally within the interior of housing 68 and bear on the interior walls of the housing aiding proper alignment. In addition, guide means 64 also includes a cylindrical shaped guide 65 and bulkhead 70, the latter separating guide 64 and housing 68. Guide 65 is a solid cylinder provided with vertical channels 66 through which drive rods 62 operate. Guide 65 is constructed with a separator between channels 66 to assist in maintaining proper spacing and alighment of the drive rods.
In the preferred embodiment, the instrument has three actuators or buttons which set into motion the action of the stylet/cannula assembly. As shown in FIG. 1, the instrument includes retract button set 80 and a fire button 83, which are preferably provided with a rubber seal. The retract button set is located on the underside of the instrument and mechanically connected to two pairs of contacts 81 in a switch frame 89 which also includes a microswitch 85 mechanically connected to fire button 83. The retract button set includes separate buttons for the cannula and stylet, preferably positioned side by side. Thus, the instrument has three separate pushbutton switches: (1) a fire switch, (2) a cannula retract switch, and (3) a stylet retract switch. Actuation of the fire button, when enabled, causes initial penetration of the stylet into the tissue mass followed by penetration of the cannula. Actuation of the cannula retract button, when enabled, causes retraction of the cannula exposing the sample of tissue. Actuation of the stylet retract button, when enabled, retracts the stylet whereupon the instrument is ready for further use.
Referring now to FIG. 6, which is an electrical schematic for the preferred embodiment of the motor driver and control electronics according to this invention, the primary components of the circuitry are three JK flip-flops, four AND gates, two complementary pairs of MOSFETs, and two optoisolators which return mechanical position data. U2 and U3/B operate in conjunction with each other to dictate which operator button is enabled via U3/A, U1/C and U1/D. Another function of U3/B is to dictate which sensor output is enabled via U1/A and U1/B. U3/A is primarily a latching circuit for the fire button.
In the ready-to-fire position, which is the proper initial position for operation of the device, the stylet and cannula are both retracted and the circuit is in a reset or standby mode. In this mode the outputs (Q1) of all three JK flip-flops are low (logic "0"), thus disabling sensor 1, enabling sensor 2 and enabling the fire button and fire latch U3/A.
Once the fire button is pressed, the output of U3/A goes high (logic "1"), turning on the LEDs in sensors 1 and 2 through transistor Q5 and forward biasing MOSFET Q4, thereby connecting one terminal of the drive motor to ground. U1/C and U1/D are both held low at this time by the low levels on the Q outputs of JK flip-flops U2 and U3/A. Thus, MOSFET Q2 is on, enabling motor drive current to flow from VCC through Q2, the motor, and Q4 to ground.
Therefore, in response to actuation of the fire button, the drive motor begins turning and, through the planetary gear box, causes the drive shaft to rotate clockwise (CW) as viewed from the rear of the instrument. This causes the slotted disc to rotate clockwise from its initial position, in which the slot is adjacent to sensor 1 which is located directly below the drive shaft. Sensor 2, located 120° counterclockwise from sensor 1 as viewed from the rear of the instrument, detects the passage of the slot after approximately 230° of clockwise shaft rotation, and, in response, generates an output pulse which passes through U1/B, enabled at this time by a high state output on the Q output of U3/B, and clocks U3/B, thereby disabling sensor 2 and enabling sensor 1. The motor continues to drive the rotary cam and slotted disc clockwise until the slot returns to a point adjacent sensor 1, which responds by clocking U2 through U1/A. U2 goes high in response, resetting U3/A and thereby stopping the motor. The low output from U3/A not only turns off Q4 and thereby deenergizes the motor, but also turns on Q1 to connect both terminals of the motor to VCC, thereby providing dynamic braking. The motor stops with the stylet and cannula in their extended positions.
The high output from U2 is also supplied to one contact of each of the stylet and cannula retract switches as an enabling signal. With U3/B reset at this time, only the cannula retract switch is actually enabled, because the low Q output of U3/B prevents any pulse from the stylet retract switch from passing through U1/D. When the cannula retract button is pressed, the output of U1/C goes high, turning on transistor Q3 and completing a circuit from VCC through Q1, the motor and Q3 to ground, whereby the motor reverses direction and causes the rotary cam and slotted disc to rotate counterclockwise. It should be noted, perhaps, that both optoelectronic sensors are disabled whenever the motor is deenergized. Once cannula retraction begins, however, both sensor LEDs are again turned on through Q5, although only sensor 2 is enabled because U1/A is disabled at this time. Thus, sensor 2 is the first sensor to respond to the passage of the slot in the slotted disc, and it responds by clocking U3/B, thereby disabling sensor 2 and the cannula retract button and enabling sensor 1 and the stylet retract button. The motor stops in response to the resulting low state at the output of U1/C.
The final step in the cycle is actuation of the stylet retract button. Pressing this button with U1/D enabled re-enables the drive, causing the cam and slotted disc to resume counterclockwise rotation and resulting in sensor 1 clocking U2 and resetting U3/B through U1/A. This disables the stylet retract button and re-enables the fire latch, thereby completing the full cycle.
The instrument's response time is short enough that movement from any one of the predefined extended or retracted positions is completed before any of the control buttons can be released in normal operation.
The presently preferred components are specified as follows:
______________________________________Device Device Type______________________________________U1 CD 4081BU2, U3 CD 4027BQ1, Q2 ECG 2382Q3, Q4 ECG 2383Sensors 1, 2 EE-SX 1067______________________________________
The invention is described above in terms of optoisolators and a slotted disc as the preferred position sensor construction, primarily because of superior speed of response. However, the present invention, more broadly, contemplates the elimination of spring fingers or other wiper elements and wiper plates of the type disclosed in U.S. Pat. No. 4,940,061. The term "wiperless position sensor" is used in this patent to mean any type of limit switch or other position sensor which does not have such a wiper assembly, and is intended to include optoelectronic devices, electromagnetic devices, Hall effect devices, capacitive devices, and microswitches, among others.
The present invention has a number of advantages over all other forms of biopsy instruments including that disclosed in U.S. Pat. No. 4,940,061. In addition to greater reliability as a result of a wiperless position sensor, the instrument has improved action because of the new cam profile, as shown in FIG. 5. The curved section of the cam extends less than 145° around the cam circumference, without abrupt transitions, and begins approximately 55° from the fully retracted position of the cam follower for the stylet. One advantage of this construction is a large increase in the amount of time the motor spends in a no-load condition upon starting, thus allowing the motor to accelerate and reach a motor speed above the loaded rating prior to hitting the ramp in the cam. This increase in speed directly results in desired higher needle velocities. The reduction in ramp length results in greater forward movement per degree of rotation, further increasing the maximum needle velocity during the stroke. Another desirable feature is a small delay between the time the stylet finishes its stroke and the time the cannula begins its stroke. This allows more tissue to fall into the slotted stylet, and thereby results in improved core samples.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. | An instrument for removing tissue samples from a tissue mass which automatically penetrates, severs, and removes a tissue portion for examination. The instrument is motor powered, preferably by self-contained rechargeable batteries, and employs electrically actuated stops to control the action of penetration into and retraction from the tissue mass. The tissue penetrating means and severing means includes an inner stylet which penetrates the tissue mass and a hollow outer tube or cannula which surrounds the stylet and serves to sever a sample of tissue. In a preferred form the tissue penetrating end of the stylet is notched so that when the stylet penetrates the tissue mass, a portion of the tissue relaxes in the notched area. After tissue penetration by the stylet, the cannula, having a cutting surface at its distal end, penetrates the tissue and cuts off the tissue portion residing in the notched area of the stylet. The tissue penetrating and severing means are operably connected to a motor powered rotary cam assembly by means of cam followers and the rotary motion of the cam is converted to sequential, linear motion in the tissue penetrating means and severing means. The angular position of a cam is monitored with a pair of optoelectronic sensors, thereby providing position feedback without mechanical wear on the position sensor assembly. Improved action is provided by a cam having an S-curve profile. | 0 |
This application is a continuation of U.S. application Ser. No. 07/732,100 filed Jul. 18, 1991 now abandoned.
This invention relates to a reactive hot-melt elastic sealant composition, more particularly, to a one-part part moisture-curing type, reactive hot-melt elastic adhesive sealant composition containing a polyurethane prepolymer and a thermoplastic urethane multi-block copolymer resin which has excellent durability, particularly excellent cold resistance (i.e. it shows rubber elasticity even at -30° to -40° C.) and further initial adhesive force and maintenance of adhesive force for a long period of time.
PRIOR ART
In the industry of automobile, it has recently been progressed to fix various parts surrounding windows and other parts by an adhesive, and the materials to be adhered have been changed from the conventional glass products and coated steel plates to plastic materials. The adhesive sealant, particularly for automobiles, requires to have excellent properties such as adhesion strength, durability which are not affected by the atmospheric temperature, that is being stable both at high temperature and under cold conditions (e.g. -30° to -40° C.) and further requires to have excellent initial adhesive force in order to avoid use of a specific means for temporary fixing. The adhesive sealant used for automobiles requires also to have excellent rubber elasticity for absorbing the vibrational energy during driving of automobiles.
The conventional hot-melt sealants comprising a thermoplastic resin as the main component are excellent in the initial adhesive force and worability, but they have some problems in less durability at high temperature because it softens at high temperature to result in lowering adhesive force and further in cold resistance because it becomes plastic-like under cold condition (e.g. at -30° to -40° C.) to lose the rubber elasticity. On the other hand, the conventional reactive sealants have excellent durability at a high temperature and also excellent cold resistance, but it has less initial adhesive force, that is, it requires disadvantageously a much longer time until the desired temporary adhesion is obtained. From this viewpoint, it has been studied to develope a sealant having both properties of the hot-melt sealant and those of the reactive sealant and also excellent temporary adhesive force, but it is very difficult to obtain a sealant having well balanced properties of initial adhesive force and elasticity. Particularly, in order to use the sealant under a cold condition (e.g. at -30° to -40° C.), it is very difficult to keep the elastomeric properties (rubber elasticity).
BRIEF DESCRIPTION OF THE INVENTION
Under the circumstances, the present inventors have intensively studied to obtain a reactive hot-melt elastic sealant having the desired initial adhesive force and the rubber elasticity even under cold condition as well as other required properties, and have found that the desired sealant can be obtained by combining a polyurethane prepolymer obtained by reacting a high molecular weight polyether polyol and an excess amount of polyisocyanate compound and a specific thermoplastic resin which is compatible with the polyurethane prepolymer and that the sealant satisfies the desired initial adhesive force, durability, particularly excellent rubber elasticity together with cold resistance at -30° to -40° C. in addition to the other desired properties as a hot melt sealant.
An object of the invention is to provide an improved reactive hot-melt sealant having excellent initial adhesive force and durability and further rubber elasticity even under cold condition. Another object of the invention is to provide a one part moisture-curing type, hot-melt adhesive sealant suitable for adhesive seal of parts in automobiles and other industrial fields, particularly for adhesive seal of parts surrounding windows of automobiles in cold district. These and other objects and advantages of the invention will be apparent to those skilled in the art from the following description.
DETAILED DESCRIPTION OF THE INVENTION
The reactive hot-melt elastic sealant composition of the invention comprises as the main components (A) a polyurethane prepolymer which is prepared by reacting a polyether polyol having a hydroxyl group at the terminus and having a weight average molecular weight of 6,000 to 40,000 (hereinafter occasionally referred to as "very high molecular weight polyether polyol") and an excess amount of a polyisocyanate compound, and (B) a thermoplastic urethane multi-block copolymer resin.
The very high molecular weight polyether polyol used in the present invention includes polyoxyalkylene ether polyols of the formula: ##STR1## wherein R is a residue of a hydrocarbon group having 2 to 6 carbon atoms, particularly a straight chain or branched chain alkylene having 2 to 6 carbon atoms, n is an integer of 13 to 350, m is an integer of 0 to 440, and α is an integer of 2 to 8, preferably 2 to 4. Suitable examples of the polyether polyol are, for example, polyoxypropylenediol, polyoxypropylene-ethylenediol, polyoxypropylene triol, polyoxypropylene-ethylene triol, polyoxypropylenetetraol, polyoxypropylene-ethylenetetraol, and the like. Among these, preferred compounds have a weight average molecular weight of 6,000 to 40,000, more preferably 10,000 to 30,000, in view of the properties of the sealant product and workability thereof.
The above polyoxyalkylene ether polyols can be prepared by subjecting propylene oxide or propylene oxide-ethylene oxide to a ring opening polymerization in the presence of one or more of a polyhydroxyl compound of the formula:
R-(OH).sub.α
wherein R and α are as defined above, and also in the presence of a conventional catalyst (e.g. a metallic catalyst).
The polyhydroxyl compound includes, for example, in case of α=2: ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, or 1,6-hexanediol; in case of α=3: trimethylolpropane, triethylene triol, or 1,2,6-hexane-triol; in case of α=4: pentaerythritol; in case of α=6: sorbitol; in case of α=8: sucrose.
In the above reaction, butylene oxide may be used instead of propylene oxide (PO) or ethylene oxide (EO).
When the polyether polyol has a weight average molecular weight of less than 6,000, the sealant obtained therefrom has disadvantageously inferior elongation under cold condition (e.g. -30° to -40° C.) and has too high hardness, and on the other hand, the polyether polyol having a weight average weight average molecular weight of more than 40,000 is hardly obtainable by the available technique because too much by-products are produced, while the pure product has satisfactory properties. The very high molecular weight polyether polyol contains the funcitonal groups (OH value, i.e. the number of α) of 2 to 4, more preferably 2 to 3.
These very high molecular weight polyether polyols have a very low glass transition temperature (Tg) such as -70° to -60° C., and hence, when they are cured with a polyisocyanate compound, they can give the desired elastomeric properties under cold condition to the sealant. Polyols having a comparatively lower Tg, such as polybutadiene polyol or hydrogenated polybutadiene polyol are not practically used because they have inferior compatibility to the thermoplastic urethane multi-block copolymer resin.
The polyisocyanate compound used in the present invention includes any compounds used for the preparation of conventional urethane resins, for example, 2,4- or 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 1,3- or 1,4-xylylene diisocyanate, 1,5-naphthalene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, and trimethylol-propane adducts of the above polyisocyanate compounds, and the like, which are used alone or in combination of two or more thereof. In view of the moisture-curing rate, safety and cost, and the like, MDI is preferable.
The reaction of the very high molecular weight polyether polyol with an excess amount of the polyisocyanate compound is carried out under usual coniditions, for example, by heating at a temperature of 70° to 90° C. for 0.5 to 5 hours. The reaction components are used in an equivalent ratio of an isocyanate group/hydroxyl group (NCO/OH) of 1.5 to 3.5, preferably 2 to 3. When the ratio is less than 1.5, the polyurethane prepolymer thus prepared has significantly increased viscosity and extremely low heat stability at 70° to 80° C., and on the other hand, when the ratio is over 3.5, the polyurethane prepolymer tends to have significant foaming due to CO 2 generated during the moisture-curing while it has a good stability at 70° to 80° C.
The thermoplastic urethane multi-block copolymer resin used in the present invention is prepared by reacting a polyfunctional ring-containing and active hydrogen-containing compound, a diol or triol compound and an excess amount of a polyisocyanate compound. The polyfunctional ring-containing and active hydrogen-containing compound has usually a weight average molecular weight of 100 to 4,000, preferably 400 to 2,000, and includes, for example, bisphenol resins, terpene resins, coumarone resins, xylene resins, rosin ester resins, styrene resins, phenol resins, terpene phenol resins, rosin resins, polyester resins, and the like. The diol compound includes, for example, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, polycarbonate diol, polytetramethylene glycol, hydrogenated butadienediol, polyacryldiol, polyoxyalkylene ether diol, polyoxyalkylene-adduct bisphenol, and other active hydrogen-containing compounds. The triol compound includes, for example, trimethylolpropane, glycerin, triethylene triol, polyoxyalkylene ether triol, and the like. The polyisocyanate compound includes all the above-mentioned compounds, but in view of increasing the aggregation energy of urethane and particularly safety and cost, MDI is the most preferable.
The thermoplastic urethane multi-block copolymer resins thus prepared are commercially available, for example, "Thermoplastic Resin Toyo Ace U-B" manufactured by K. K. Toyo Chemical Research Institute, which has a melting point of 70° to 100° C.
The thermoplastic urethane multi-block copolymer resin is effective for exhibiting the initial adhesive force of the sealant. Besides, the copolymer has urethane bond and ring compound residue in the molecule, by which the aggregation energy is exhibited and can show theromplastic properties. Moreover, since it has a polarity due to the ring compound residue and urethane bond, it can show good compatibility with the above polyurethane prepolymer.
The reactive hot-melt elastic sealant composition of the present invention is characteristic in that the above-mentioned polyurethane prepolymer and thermoplastic urethane multi-block copolymer resins are contained as the main components, but it can contain other conventional components in an appropriate amount. Preferable examples of the sealant composition of the present invention comprise 20 to 60% by weight, more preferably 30 to 50% by weight, of a polyurethane prepolymer; 5 to 30% by weight, more preferably 10 to 20% by weight, of the thermoplastic urethane multi-block copolymer resin; not more than 50%, more preferably 20 to 40% by weight, of a filler; and optionally not more than 20% by weight of a plasticizer and not more than 10% by weight of other additives.
When the content of the polyurethane prepolymer is less than 20% by weight, the product does not show the desired properties under cold condition (less elongation and too high hardness), and on the other hand, when the content is over 60% by weight, the product tends to have inferior workability. Besides, when the content of the thermoplastic urethane multi-block copolymer resin is less than 5% by weight, the product does not show the desired initial adhesive force, and on the other hand, when it over 30% by weight, the product tends to be not satisfactory in the properties under cold condition.
The filler includes silicic acid derivatives, talc, metal powders, calcium carbonate, clay, carbon black, and the like. When the filler is used in an amount of more than 50% by weight, the product has too high viscosity which is not suitable for use as a sealant and tends to have inferior adhesion and physical properties.
The plasticizer includes dibutyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, diisooctyl phthalate, diisodecyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, trioctyl phosphate, epoxy resin plasticizers, toluenesulfonamide, chloroparaffin, adipic acid esters, castor oil derivatives, and the like. When the plasticizer is used in an amount of more than 20% by weight, the product tends to have inferior adhesion and initial strength.
The other additives include solvents for adjusting the viscosity, curing catalysts, thixotropic agents (e.g. bentone, silicic anhydride, silicic derivatives, urea derivatives, etc.), dyes and pigments, ultraviolet absorbents, tackifiers, flame-retardants, silane compounds, dehydrating agents, and the like. When the other additives are used in an amount of more than 10% by weight, the product tends to be inferior in characteristics and physical properties as required for a sealant.
The composition of the present invention may be prepared, for example, by the following procedure.
Firstly, a thermoplastic urethane multi-block copolymer resin is molten at a temperature of 80° to 100° C. and the molten resin is charged into a nitrogen-replaceable vessel kept at about 90° C. To the vessel a polyurethane prepolymer is added under nitrogen atmosphere, and the mixture is stirred, and then a filler and optional plasticizer are added, and the mixture is defoamed with stirring under vacuum. Thereafter, other additives such as a viscosity-adjusting solvent and a curing catalyst are further added, and the mixture is further defoamed with stirring under vacuum to give the desired composition.
The sealant composition of the present invention can be used for application at temperature of not higher than 80° C., preferably not higher than 70° C. Besides, in order to apply automatically (for example, by using a robot), it may be done by using a hot-melt applicator.
The present invention is illustrated by the following Example and Reference Example but should not be construed to be limited thereto.
EXAMPLE 1
(1) Preparation of Polyurethane Prepolymer
A polyoxypropylene-ethylene triol having a weight average molecular weight of 12,500 (X-8805, manufactured by Asahi Glass Co., Ltd., trifunctional, EO content 12% by weight, OH value 13.8) (2,000 g) is charged into a reaction vessel wherein air is replaced by nitrogen gas, and it is dried under vacuum (lower than 10 mmHg). After detecting and confirming that the moisture becomes lower than 0.05% by weight, 4,4'-diphenylmethane diisocyanate (MDI) (158 g) is added thereto (in the ratio of NCO/OH=2.61), and the mixture is reacted at 80°±5° C. for one hour. Thereafter, a 1% solution of dibutyl tin dilaurate (DBTDL) in xylene (1 g) is added to the mixture, and the mixture is reacted at the same temperature for 2 hours to give a polyurethane prepolymer having a free NCO content of 1.48% by weight, a viscosity of 24,000 cps/80° C. and 380,000 cps/20° C.
(2) Preparation of Sealant
To the polyurethane prepolymer obtained above (1) (400 g) is charged into a vessel with stirrer wherein air is replaced by nitrogen gas, and the temperature of the vessel is adjusted to 80°±10° C. Thereto is added a thermoplastic urethane multi-block copolymer resin (Thermoplastic resin Toyo Ace U-B, manufactured by K. K. Toyo Chemical Institute) (100 g), and the mixture is stirred at the same temperature for 20 to 30 minutes to dissolve the mixture. To the mixture are added carbon black (350 g) and calcium carbonate (100 g) which are previously dried, and the mixture is stirred for 30 minutes under vacuum (10 mmHg), and thereto are further added xylene (for adjusting the viscosity, 50 g) and a curing catalyst (a 1% solution of DBTDL in xylene, 0.3 g), and then the mixture is stirred to defoam under vacuum for 30 minutes. The reaction product is taken in a sealed aluminum-made cartridge. The sealant composition thus obtained is designated as "Sealant A-1".
In the same manner as described above (2) except that the thermoplastic urethane multi-block copolymer resin is used in an amount of 200 g (instead of 100 g), there is prepared a sealant composition which is designated as "Sealant A-2".
In the following examples, two kinds of sealant compositions are prepared likewise.
EXAMPLE 2
(1) Preparation of Polyurethane Prepolymer
A polyoxypropylene triol having a weight average molecular weight of 15,000 (X-8702, manufactured by Asahi Glass Co., Ltd., trifunctional, only PO, OH value 11) (2,000 g) and a polyoxypropylene-ethylene triol having a weight average molecular weight of 10,000 (X-8202D, difunctional, EO content 8% by weight, OH value 11) (1,000 g) are charged into a reaction vessel wherein air is replaced by nitrogen gas, and it is dried under vacuum (lower than 10 mmHg). After detecting and confirming that the moisture becomes lower than 0.05% by weight, MDI (200 g) is added thereto (in the ratio of NCO/OH=2.65), and the mixture is reacted at 80°±5° C. for one hour. Thereafter, a 1% solution of DBTDL in xylene (1 g) is added to the mixture, and the mixture is reacted at the same temperature for 2 hours to give a polyurethane prepolymer having a free NCO content of 1.28% by weight, a viscosity of 38,000 cps/80° C. and 460,000 cps/20° C.
(2) Preparation of Sealant
In the same manner and components as described above Example 1-(2) except that the polyurethane prepolymer obtained above (1) is used to give two sealant compositions "Sealant B-1" and "Sealant B-2".
EXAMPLE 3
(1) Preparation of Polyurethane Prepolymer
A polyoxypropylene triol having a weight average molecular weight of 30,000 (X-8705, manufactured by Asahi Glass Co., Ltd., trifunctional, only PO, OH value 6.1) (2,000 g) is charged into a reaction vessel wherein air is replaced by nitrogen gas, and it is dried under vacuum (lower than 10 mmHg). After detecting and confirming that the moisture becomes lower than 0.05% by weight, MDI (170 g) is added thereto (in the ratio of NCO/OH=2.75), and the mixture is reacted at 80°±5° C. for one hour. Thereafter, a 1% solution of DBTDL in xylene (1 g) is added to the mixture, and the mixture is reacted at the same temperature for 2 hours to give a polyurethane prepolymer having a free NCO content of 0.85% by weight, a viscosity of 21,000 cps/80° C. and 130,000 cps/20° C.
(2) Preparation of Sealant
In the same manner and components as described above Example 1-(2) except that the polyurethane prepolymer obtained above (1) is used to give two sealant compositions "Sealant C-1" and "Sealant C-2".
REFERENCE EXAMPLE 1
(1) Preparation of Polyurethane Prepolymer
A polyoxypropylene triol having a weight average molecular weight of 5,000 (X-5030, manufactured by Asahi Glass Co., Ltd., trifunctional) (3,000 g) is charged into a reaction vessel wherein air is replaced by nitrogen gas, and it is dried under vacuum (lower than 10 mmHg). After detecting and confirming that the moisture becomes lower than 0.05% by weight, MDI (546.5 g) is added thereto (in the ratio of NCO/OH=2.41), and the mixture is reacted at 80°±5° C. for one hour. Thereafter, a 1% solution of DBTDL in xylene (1 g) is added to the mixture, and the mixture is reacted at the same temperature for 2 hours to give a polyurethane prepolymer having a free NCO content of 3.01% by weight, a viscosity of 11,000 cps/80° C. and 31,000 cps/20° C.
(2) Preparation of Sealant
In the same manner and components as described above Example 1-(2) except that the polyurethane prepolymer obtained above (1) is used to give a sealant composition "Sealant D-1".
The polyurethane prepolymer obtained above (1) (500 g) is charged into a reaction vessel with stirrer wherein air is replaced by nitrogen gas, and thereto is added a dehydrated dioctyl phthalate (200 g), and the mixture is stirred for 10 minutes to dissolve it. To the mixture are added carbon black (400 g) and calcium carbonate (200 g) which are previously dried, and the mixture is defoamed with stirring for 30 minutes under vacuum (10 mmHg), and thereto are further added xylene (for adjusting the viscosity, 50 g) and a curing catalyst (a 1% solution of DBTDL in xylene, 0.3 g), and then the mixture is stirred to defoam under vacuum for 30 minutes. The reaction product is taken in a sealed aluminum-made cartridge. The sealant composition thus obtained is designated as "Sealant D-2".
REFERENCE EXAMPLE 2
(1) Preparation of Polyurethane Prepolymer
A polyoxypropylene triol having a weight average molecular weight of 5,000 (trifunctional) (2,000 g) and a polyoxypropylene glycol having a molecular weight of 2,000 (difunctional) (1,000 g) are charged into a reaction vessel wherein air is replaced by nitrogen gas, and it is dried under vacuum (lower than 10 mmHg). After detecting and confirming that the moisture becomes lower than 0.05% by weight, MDI-(608 g) is added thereto (in the ratio of NCO/OH =2.19), and the mixture is reacted at 80°±5° C. for one hour. Thereafter, a 1% solution of DBTDL in xylene (1 g) is added to the mixture, and the mixture is reacted at the same temperature for 2 hours to give a polyurethane prepolymer having a free NCO content of 3.1% by weight, a viscosity of 18,000 cps/80° C. and 45,000 cps/20° C.
(2) Preparation of Sealant
In the same manner and components as described in the above Example 1-(2) except that the polyurethane prepolymer obtained above (1) is used to give a sealant composition "Sealant E-1".
In the same manner and components as described in the above Reference Example 1-(2) except that the polyurethane prepolymer obtained above (1), there is prepared a sealant composition "Sealant E-2".
TEST OF ADHESION
Each sealant composition obtained in Examples 1 to 3 and Reference Examples 1 to 2 were subjected to the following tests, and the results are shown in Table 1.
(1) Test of Initial Adhesion Strength (Shear Strength)
The sealant to be tested (molten at 80° C) was applied to a steel panel (width 25 mm, length 100 mm, thickness 0.8 mm) in an area of 10 mm from the tip of the panel in a thickness of 5 mm under the condition of 20° C., 65% relative humidity (RH), and thereon a glass plate (width 25 mm, length 50 In, thickness 5 m) was pilad, and after keeping the test piece for 10 minutes, the adhesion strength (kg/cm 2 ) was measured at a pulling rate of 50 mm/min. or 200 mm/min. The results are shown in Table 1-1.
(2) Test of Elastomeric Properties
Th sealant composition to be tested (molten at 80° C.) was applied to a release paper in a thickness of 2 mm, and then cured at 20° C. under 65% RH for 168 hours.
The test was carried out in the same manner as defined in JIS K 6301, Dumbbell test, there were measured the elongation (%), tensile strength (T.S) (kg/cm 2 ) and hardness (Shore A) under various atmospheric conditions such as ordinary state (20° C., 65% RH), under cold condition (-30° C.) or with heating (80° C). The results are shown in Table 1--1.
(3) Adhesion Strength at Cured State (Shear Strength)
In the same manner as in the above test (1), a steel panel and a glass plate was adhered under the atmosphere of 20° C., 65% RH [wherein the glass plate was previously coated with a primer (Primer #435-40, manufactured by Sunstar Giken K. K.), and the steel panel was previously coated with a primer (Primer #435-95, manufactured by Sunstar Giken K. K.)]. The resulting test piece was kept at room temperature for 7 days to complete the moisture-curing, and then there was measured the shear strength (kg/cm 2 ) at a pulling rate of 50 mm/min. under the same atmospheric conditions as in the above test (2). The results are shown in Table 1-2, wherein CF means cohesive failure of the sealant and AF means adhesive failure between the primer and sealant.
TABLE 1-1__________________________________________________________________________ (2) Elastromeric properties(1) Initial adhesion (2) Elastromeric properties at under cold temperaturestrength (kg/cm.sup.2) ordinary state (20° C., 65% RH) (-30° C.) with heating (80° C.) 50 200 Elongation T.S Elongation T.S Elongation T.S Hard-Examples mm/min. mm/min. (%) (kg/cm.sup.2) Hardness (%) (kg/cm.sup.2) Hardness (%) (kg/cm.sup.2) ness__________________________________________________________________________Example 1:Sealant A-1 0.37 0.58 700 64.0 56Sealant A-2 0.49 0.87 650 68.5 58 350 71.8 68 725 46.9 47Example 2: 300 76.9 72 700 44.8 44Sealant B-1 0.36 0.54 700 61.8 55Sealant B-2 0.43 0.85 600 65.4 57 350 69.8 65 750 47.7 48Example 3: 325 75.4 70 675 46.7 45Sealant C-1 0.31 0.49 800 57.0 54Sealant C-2 0.42 0.74 750 59.5 56 400 65.4 64 800 48.1 45Ref.Example 1: 375 69.8 68 725 47.1 42Sealant D-1 0.31 0.52 300 68.0 63Sealant D-2 0.06 0.09 600 51.5 50 150 85.0 84 400 44.1 45Ref.Example 2: 325 69.9 71 600 41.1 41Sealant E-1 0.34 0.57 350 65.0 61Sealant E-2 0.04 0.08 700 54.8 51 150 82.8 88 350 47.1 44__________________________________________________________________________
TABLE 1-2______________________________________ (3) Shear strength (kg/cm.sup.2) at ordinary Under cold state (20° C., condition with heatingExamples 65% RH) (-30° C.) (80° C.)______________________________________Example 1:Sealant A-1 61.8 CF 68.9 CF 45.8 CFSealant A-2 65.4 CF 71.9 CF 41.4 CFExample 2:Sealant B-1 62.8 CF 69.1 CF 46.9 CFSealant B-2 63.9 CF 73.2 CF 43.8 CFExample 3:Sealant C-1 59.1 CF 64.1 CF 43.4 CFSealant C-2 61.1 CF 66.9 CF 41.1 CFRef. Example 1:Sealant D-1 71.1 CF 84.0 AF 49.4 CFSealant D-2 56.4 CF 68.8 CF 43.1 CFRef. Example 2:Sealant E-1 70.8 CF 81.9 AF 46.9 CFSealant E-2 55.8 CF 67.8 CF 44.8 CF______________________________________ | A reactive hot-melt elastic sealant composition which comprises as the main components (A) a polyurethane prepolymer which is prepared by reacting a polyether polyol having a hydroxyl group at the terminus and having a weight average molecular weight of 6,000 to 40,000 and an excess amount of a polyisocyanate compound, and (B) a themoplastic urethane multi-block copolymer resin, in admixture with conventional additives, which has excellent durability, cold resistance, initial adhesive force and maintenance of adhesive force for a long period of time and is useful particularly for adhesive seal of parts in automobiles. | 2 |
FIELD OF THE INVENTION
The present invention generally relates to slide mechanisms for drawers slidable in articles of furniture. The invention specifically relates to a three-part heavy-duty miniature ball bearing drawer slide mechanism with offset outer channel members and a progression roller which assists closure and detent of the slide.
BACKGROUND OF THE INVENTION
To reduce friction and enable a drawer to withstand a heavy load, drawer slides for furniture in file cabinets and other furniture employ bearings to reduce wear, Professional furniture for medical, industrial, and engineering applications often requires thin drawers and thin drawer slides. Such applications also require a heavy-duty slide. Four sets of ball bearings are usually required to bear a typical load when full extension is required. However, the use of four separate sets of ball bearings poses obstacles to miniaturization of the slide. Furniture designers desire the cross-section profile of the slide to be thin in the horizontal direction, thereby enabling a drawer to be as wide as possible compared to the opening in which it slides. Moreover, designers want slides which are shallow in the vertical direction to keep the slide unobtrusive, and enable use with short drawers.
In most drawer slides of the prior art, the four separate ball bearing assemblies are aligned in pairs on two spaced-apart vertical axes. To make a drawer slide thin in the horizontal direction, designers have focused on making the relative vertical separation of one pair of bearings narrower than the other. This enables the vertical axes of the bearing pairs to become nearly collinear, resulting in a thin slide.
For example, U.S. Pat. No. 5,022,768 (Baxter) discloses, in FIG. 1, a prior art slide mechanism in which the ball bearing pairs are on nearly collinear vertical axes. FIGS. 3, 4, and 7 of U.S. Pat. No. 4,469,384 (Fler et al.) discloses a similar collinear axis slide. However, the cross-section profile of the resulting slide is not symmetrical, requiring the separate fabrication of a fixed cabinet member and a moving drawer member, each having a different cross-section. This increases manufacturing costs and increases the height profile of the slide.
Thus, designers of drawer slides desire to provide a slide which is horizontally thin and vertically short to enable unobtrusive installation in a variety of furniture mounting arrangements. Designers of drawer slides also desire to provide a slide in which the central slide member is structurally stable.
Another goal of slide design is smooth control of extension of the slide. U.S. Pat. No. 4,662,761 discloses a multi-part slide with a roller 18. This slide requires four outside channel members and separate plates 57, 58 to join the channels together. The bearings are arranged on a vertical collinear axis. The roller 18 has a horizontal axis of rotation and provides sequential motion rather than smooth progressive movement.
U.S. Pat. No. 3,966,273 shows a slide with progressive movement control of a ball retainer using bands of material which impose friction. U.S. Pat. No. 3,901,564 shows a slide with a progression roller 38 having a horizontal axis of rotation. The roller imposes friction on the outer channel members of the slide.
U.S. Pat. No. 3,857,618 shows control of a ball retainer using a rack and pinion arrangement best seen in FIG. 11. The pinion gear has a horizontal axis of rotation but requires clearance space at the bottom of the slide channel members, thereby increasing the overall height of the slide. Punched holes are required in the slide.
U.S. Pat. No. 3,679,275 shows a drawer slide with four outer channel members and a roller 66 mounted on a vertical shaft 68. The roller has a knurled outer surface which imposes friction on the inside faces of outer plates 16, 36 which hold the four channel members together. This requires special preparation of the slide member surfaces, which leads to higher manufacturing costs and greater complexity of design. Also, the '275 patent requires two separate sets of sliding components.
Thus, the prior art fails to provide a drawer slide which is horizontally thin and vertically shallow or short, and also incorporates a progression roller system. The prior art also fails to provide a slide with a progression roller which can facilitate closure of the slide, act as a detent, and also release pressure on the roller when the slide is closed. A particular disadvantage of prior art slides with progression rollers is that when closed, the roller is in constant compression within the slide. This results in permanent flattening or deformation of the roller over time. This causes undesirable bumpy movement of the slide.
SUMMARY OF INVENTION
Accordingly, the present invention provides a thin profile drawer slide apparatus for slidably supporting a heavy drawer in an article of furniture, comprising symmetrical, identical fixed cabinet and moving members or channels for slidably attaching the apparatus to a drawer and an article of furniture, a plurality of bearings slidably retained in the channels by bearing retainers, and by an intermediate retaining means. The intermediate retaining means preferably comprises an intermediate slide member which is the unitarily formed combination of a generally vertical central wall, a first bearing raceway joined to an end of the central wall, and a second bearing raceway joined to an arcuate wall extending angularly outwardly from the first bearing raceway, whereby the first and second bearing raceways are vertically and angularly separated or offset.
The central wall of the inner retaining means comprises a generally rectangular window with a progression roller mounted therein on a vertical axis of rotation. The roller exerts friction on the inner faces of the channels by compression against the interior faces when the roller is moved. The edges of the window act as a detent on the roller and also urge the slide closed when the slide is brought to rest with the roller against one of the edges. The window provides means for releasing compression tension on the roller when the slide is fully closed.
Thus, the invention provides a horizontally thin, vertically short three-part slide with ball bearings arranged in four nearly collinear, slightly offset sets. Use of a single central member with raceways for four separate sets of bearings enables construction of a thin, strong drawer slide for carrying heavy loads.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a cross-section view of a first embodiment of a three-part drawer slide with progression roller according to the invention;
FIG. 2 is a cross-section view of a second embodiment of a drawer slide, with double-thickness intermediate member raceways, having no bearing retainers and showing fasteners for securing the slide;
FIG. 3 is a cross-section view of a third embodiment of a drawer slide having no progression roller;
FIG. 4 is a cross-section view of a fourth embodiment of a drawer slide according to the invention;
FIG. 5 is a partial elevation view of a drawer assembly showing the slide of FIG. 1 secured to a drawer and an article of furniture;
FIG. 6 is an elevation view of the drawer slide of FIG. 1, showing the slide in a fully closed position;
FIG. 7 is a section view of the slide of FIGS. 1 and 6 taken on line 7--7 of FIG. 6;
FIG. 8 is an elevation view of the drawer slide of FIG. 1, showing the slide in an open position;
FIG. 9 is a section view of the slide of FIGS. 1 and 8 taken on line 9--9 of FIG. 8 with an exaggerated representation of a roller;
FIG. 10 is a partial cross-section view of the slide of FIG. 1 in a nearly closed position; and
FIG. 11 is a partial schematic view of the slide of FIG. 10 showing rotational stress on the roller.
DETAILED DESCRIPTION
In the following detailed description of the preferred embodiments, specific terminology is used for the sake of clarity. However, the invention is not limited to the specific terms selected, but includes all technical equivalents functioning in a substantially similar manner to achieve a substantially similar result.
General construction details of three part drawer slides are well known in the art. Relevant disclosures, showing typical prior art slides, ball bearing retainers, channel members and stop mechanisms include U.S. Pat. Nos. 4,537,450 (Baxter); 4,991,981 (Baxter); and the patent references discussed above in the section entitled "Background of the Invention." The reader is directed to these references for general construction details and configurations of three part drawer slides.
FIG. 1 shows a cross-section view of a drawer slide 10 according to the invention. FIGS. 6 to 11 show elevation and plan views of the slide of FIG. 1. The drawer slide comprises an outer slide member or outer channel member 20 which in a first of two alternate orientations is affixed to an interior wall of a stationary article of furniture; an intermediate slide member 30 which is slidable in the outer member 20; and an inner slide or channel member 40 which can be affixed to an outer surface of a side wall of a movable drawer. A second alternate orientation is shown in FIG. 5 and described below. A first set of ball bearings 70 enable outer slide member 40 to telescope in and out of the intermediate slide member 30. Likewise, a second set of ball bearings 72 mounted between intermediate member 30 and outer member 20 enable the intermediate member to slide through the outer member. To be retained in the channel members the bearings are rotatably or rollably mounted in bearing retainers or ball spacers 74. The retainers axially retain the bearings so as to keep each set together, while the channel members and intermediate slide member retain the bearings. A stop (not shown) can be provided to prevent the drawer from being pulled entirely out of the article of furniture.
The channel members 20, 40 preferably are symmetrically identical. The slide is mounted to the drawer and article of furniture via the channel members. The discussion below relates to details of the outer channel member 20 in FIG. 1, but the same parts are provided in symmetrically opposite locations on the inner channel member 40. The inner and outer channel members can be manufactured in identical form and assembled in opposite orientation and are elongated to any desired slide length. The channel members are preferably formed with a vertically elongated "C" shaped cross section using cold-rolled steel or other suitable material, and comprise a generally vertical or flat outer wall 22, upper and lower inwardly angled walls 26, and arcuate top and bottom walls 28. In this description, "inwardly" means toward a center axis of the intermediate slide member 30. The inner surfaces 29 of top and bottom walls 28 form raceways or trackways for the ball bearings 70, 72.
The intermediate slide member 30 preferably is formed in a single piece of steel or other suitable material. The intermediate member can be roll-formed or solid extruded metal. The unitary construction adds structural stability and reduces manufacturing costs of the entire apparatus. Moreover, the central member is symmetrical and may be inverted or reversed without affecting the operation of the mechanism. For clarity, details of the intermediate member 30 of FIG. 1 are identified by reference numerals on FIG. 3. One of ordinary skill in the art will readily understand that the intermediate members of FIGS. 1 and 3 are identical, except that the intermediate member of FIG. 1 additionally comprises a progression roller as discussed below.
As indicated in FIG. 3, the intermediate slide member 30 comprises a central vertical wall 32 unitarily formed with upper and lower short horizontal walls 34A, 34B. Preferably, the horizontal walls are joined at an approximately right angle to the central wall. Using a sharp or hair pin bend, the walls 34A, 34B are joined to upper and lower parallel arcuate raceway members 36A, 36B. Preferably, each of the raceway members includes an arcuate raceway surface 38A, 38B. The raceways provide a second trackway or bearing surface for ball bearings 70, 72.
Thus, in operation, when the outer or inner channel members are moved axially in or out, the ball bearings 70, 72 will simultaneously rotate on the trackways formed by the inside face 29 of the outer and inner channel members and on the outward-facing raceways 38A, 38B on the intermediate slide member.
Preferably, a central vertical axis of the central wall 32 forms a center of gravity of the slide, so that a downward-bearing load placed on the top of channel member 20 is directed down into the central wall.
The intermediate member 30 further comprises angled arms 80A, 80B joined at one end to raceway members 36A, 36B. The opposite end of the angled arms 80A, 80B is joined to short vertical walls 82A, 82B. These vertical walls are joined at their upper ends to arcuate upper and lower raceways 84A, 84B. These upper and lower raceways provide a ball bearing trackway or raceway directly opposite raceways 29. This combination of elements provides an intermediate member enabling four sets of ball bearings to be arranged on nearly collinear axes, minimizing the horizontal thickness and the vertical height of the slide.
The structure of the intermediate member also enables greater "wrap" around the ball bearings 70, 72. As is known in the art, "wrap" refers to the amount of perimeter surface of the bearing which is covered or guided by a raceway. A large amount of wrap is desirable to prevent lateral disembodiment (pulling apart) of the slide. As shown in FIGS. 1 and 3, the ball bearings 70, 72 are nearly encircled completely by raceways 29, 84A and arcuate member 28 and raceway 38A, 38B.
The slide of FIG. 1 also comprises a progression roller 80 which can rotate on a vertical axis on axles 82, 84. Preferably the roller comprises a resilient material such as soft rubber with a steel core. The axles are formed in a window or cutout 86 of central wall 32 of intermediate member 30. When the slide is opened or closed, as discussed below, the perimeter surface 89 of the roller rolls against the interior faces 24, 44 of the channel members 20, 40. Friction caused by contact of the rubber roller with the metal channel members enables smooth, controlled, progressive opening and closing of the slide. Unlike the prior art, the central mounting location of the roller enables use of a progression roller in a horizontally thin and vertically short slide.
Unlike two-part drawer slides, three-part drawer slides permit full outward extension of a drawer from a cabinet. The progression roller enables smooth and controlled extension of the slide without hitting noise. Three-part slides without progression rollers produce several "clicks" caused by the drawer slide members hitting together as the slide extends. Typically, when a drawer with a prior art slide is pulled out, the movable inner member first extends to its entire length. Inwardly protruding end tabs on the inner member strike the end of the intermediate member, causing "pick up noise" (a "click") and pulling the intermediate member out. When the slide reaches full extension there is another "click" as end tabs on the intermediate member strike stop tabs on the stationary outer member. This phenomenon is well known in the art. It is also possible for the intermediate member to extend first, followed by the movable inner member, but the double click effect is the same.
In contrast, in a slide of the present invention, when a drawer is pulled out of an article of furniture, the inner member extends and the intermediate slide member is also carried forward by the progression roller. As a result, both the movable inner member and the intermediate member extend from the stationary outer member at the same rate, preventing hitting noise or "clicks."
Operation of the progression roller in the slide of FIG. 1 is shown in FIGS. 6 to 11. FIGS. 6 and 7 show elevation and section views, respectively, of the slide of FIG. 1 in the closed position. At least one clearance window 120 is provided in the outer channel member 20. The window 120 preferably comprises a generally rectangular cutout in the outer channel member. The window has a leading edge 122 and a trailing edge 124. When the slide is closed, the roller 80 protrudes through the window, as shown in FIG. 7, and the perimeter surface of the roller rests against the leading and trailing edges 122, 124, 142, 144. Inner channel member 40 has a corresponding window or cutout 140 with a leading edge 142 and a trailing edge 144. When the slide is closed, the windows 120, 140 are opposite one another. In this closed position, the edges of the window act as a detent on the roller. Slight side-to-side pressure on the slide will not cause the slide to move since the protruding roller is abutted against edges 122, 124, 142, 144.
However, firm pressure on the slidable members of the slide will cause the roller to compress inside the slide, moving under edges 124, 142 and assuming the deformed shape shown in exaggerated form in FIGS. 8 and 9. As shown in FIG. 8, when the slide is opened, the roller moves past the window 120 and is compressed between the interior surfaces 24, 44 of outer member 20 and inner member 40. The compression of the roller 80 exerts friction on the channel members, insuring that the slide parts extend smoothly and at a proportional rate. This eliminates the hitting phenomenon found in prior art slides. The progression roller feature also balances the load on the slide, thereby increasing life of the slide.
The window 120 also acts as a decompression mechanism for the roller. In prior art slides with a roller located between outer and inner channel members of a slide, the roller is compressed even when the slide is completely closed. As a result, over time, constant compression of the roller can cause the roller to assume a distorted shape, or lose its compressive tension entirely. This is known in the art as "taking a set" and results in a malfunction of the roller. In the present invention, the windows 120, 140 enable the roller to release compressive tension when the slide and drawer are completely closed. The window prevents flat spots from forming on the roller when it is in continuous compression. This extends the life of the roller and improves its performance.
The roller also provides a self-closing effect, as illustrated in FIGS. 10 and 11. FIG. 10 provides a section view of the slide of FIGS. 7 and 9, in which the slide channel members are almost closed. In this position, the windows 120, 140 are slightly offset, and the roller assumes an oval shape. Part of the perimeter surface of the roller extends into the windows 120, 140, and a portion of the roller remains compressed in the slide. In this position, rotational tension develops in the roller as indicated by arrows 200, 210 in FIG. 11. This tension urges the roller to rotate, thereby causing the slide to close completely. Thus, if the slide is closed part way, such as by a user pushing a drawer with insufficient pressure to close the drawer completely, the roller will tend to urge the slide (and the drawer) closed. This prevents slides and drawers from stopping in a slightly open position.
In an alternative embodiment, the leading and trailing edges of the windows can be formed at an angle, or can be beveled, so as to enhance or retard detent action of the window.
The roller additionally prevents "creep" of the slide. The friction exerted on the outer and inner channel members by the roller under compression increases the force required to move the slide. This causes the slide to remain in a desired position until sufficient force is exerted on the slide to overcome the friction exerted by the roller.
In an alternate contemplated embodiment, the outer and inner channel members can be provided with multiple windows, thereby enabling use of the windows as detents or multiple stop positions for the slide. The roller can comprise any resilient material and can be synthetic.
Referring to FIG. 2, an alternate embodiment slide is shown. Symmetrically identical left and right (outer and inner) channel members or channel means 20, 40 are provided for slidably attaching the slide to an article of furniture and a drawer. One or more holes 48 can be provided in the vertical wall to enable securement of the slide apparatus to a drawer or an article of furniture using a threaded fastener 50. Preferably, a #6 pan head screw is used for fastening the slide to furniture. 0f course, any suitable type of fastener can be used. The fasteners must be flush with the channel or member surface so as to ensure that the roller does not roll over or against the heads of the fasteners. The fasteners could comprise flat head counter sunk threaded screws or bayonets.
Also, in the embodiment of FIG. 2, the raceway members 84A, 84B are joined by an additional hairpin bend to secondary raceway members 86A, 86B. These members provide double-thickness raceways for the intermediate member, thereby increasing the load which the slide can carry.
In the embodiment of FIG. 3, the ball bearings 70 are retained in left and right bridge-type bearing retainers 60L, 60R. The ball bearing retainers are symmetrically identical, thereby reducing manufacturing costs by enabling a single type of retainer to be used on both sides of the apparatus. As is known in the art, each bridge type bearing retainer holds two sets of ball bearings to cause both sets to move synchronously. Both left and right retainers 60L, 60R include corresponding parts in a like arrangement. The left ball bearing retainer 60L includes a central vertical wall 62. The vertical wall 62 is joined using upper and lower angled walls 64A, 64B. Each angled wall has a plurality of spaced-apart holes or pockets (not shown) in which the ball bearings rotate. The general construction of ball bearing retainers is well-known in the art. For example, the ball bearing retainer disclosed in U.S. Pat. No. 4,991,981 (Baxter) is suitable for incorporation in the mechanism disclosed herein.
Another alternate embodiment is shown in FIG. 4. In this embodiment, the intermediate member 30 does not comprise a vertical central wall 32. Instead, the intermediate member comprises a generally horizontal central wall 33 joined by a sharp bend to one end of two short vertical walls 35A, 35B. The opposite end of these walls is joined to the raceway members 36A, 36B. Use of a horizontal central wall 33 in place of the vertical central wall 32 enables the embodiment of FIG. 4 to be vertically shorter than the embodiments of FIGS. 1, 2, and 3. Preferably, the overall height of a side of FIG. 4 is approximately 32 millimeters, and its overall width is about 13 millimeters. The embodiment of FIG. 4 provides a high-strength, heavy-duty miniature drawer slide in which four sets of bearings are provided in a vertically and horizontally compact arrangement.
As shown in FIG. 5, the offset positioning of the channel members facilitates attachment of a slide to a drawer and an article of furniture with the slide in the aforementioned second orientation. In the prior art, slide attachment brackets (not shown) are required to enable attachment of a drawer slide in the arrangement of FIG. 5. The offset channel arrangement of the present invention enables the top surface of the movable channel member 20 to act as a load-bearing member for the drawer.
In this arrangement, a "U"-shaped bracket 90 is provided and secured to the channel member 40 using welding or with a suitable fastener, or using bayonets provided on the exterior surface of the channel member 40. The bracket can comprise a generally vertical wall 92, a horizontal bottom wall 94 joined at a right angle to the vertical wall, and an inner vertical wall 96 which can be joined to the slide. Preferably channel member 40 is welded to the vertical wall 96 or secured thereto using a fastener 105. The bracket can be affixed to an article of furniture using suitable fasteners such as screws 91.
The drawer 100 comprises top and bottom walls 110, 108 which are spaced apart by an inner vertical wall 104. Storage space 106 is provided in the drawer. An inner vertical wall 102 is provided in spaced-apart relation to the vertical wall 104. Preferably channel member or drawer member 20 is fixed to the wall 102 using brackets or other fastening means (not shown).
The drawer also comprises a load-bearing wall 114 which can be mounted directly on the arcuate wall 28 of the slide. This enables the outer channel member 20 to transfer load from the drawer to the intermediate member, thereby reducing shear load on whatever fastening means is used. A fascia panel 120 can be provided, to prevent the drawer slide from being visible when the drawer is open.
The ball bearings may be constructed of steel, plastic, ceramic, or any suitable material, and the slide members can comprise steel, stainless steel, plastic, aluminum, or any similar suitable material.
As indicated above, the present invention provides a novel and unique apparatus for facilitating support and smooth sliding of drawers in articles of furniture. A unitarily-formed central or intermediate slide member provides a plurality of raceways for four separate sets of ball bearings, with reduced manufacturing costs and simpler construction than the prior art. Drawer slides according to the invention may be used in a variety of nondrawer applications such as extendable writing surfaces of desks and other applications known in the art.
The invention may be practiced in many ways other than as specifically disclosed herein. For example, the drawings are not rendered to scale and the size of the walls can be modified. In one contemplated embodiment, elongated plastic strips are affixed to the interior faces of the channel members, thereby increasing friction exerted by the progression roller. The plastic strip can be smooth or knurled. Positive progression can be provided by forming the strips as a rack and using a pinion gear instead of a smooth roller. Bayonet mounting tabs can be formed in the channel members to facilitate mounting the slide on metal furniture. Bayonets are preferred for the embodiment of FIG. 1 and FIG. 4 since use of fasteners protruding through the channel members is impractical with these embodiments.
Thus, the scope of the invention should be determined from the appended claims. | A thin profile drawer slide apparatus for slidably supporting a heavy drawer in furniture, comprising symmetrical, identical channel members for slidably attaching the apparatus to a drawer and an article of furniture, a plurality of bearings slidably retained in the channel members by bearing retainers, and by an intermediate slide member. The intermediate slide member comprises the unitarily formed combination of a generally vertical central wall, a first bearing raceway joined to an end of the central wall, and a second bearing raceway joined to an arcuate wall extending angularly outwardly from the first bearing raceway, whereby the first and second bearing raceways are vertically and angularly separated. The ball bearings are arranged in four linear, slightly offset sets. Use of a single intermediate slide member with raceways for four separate sets of bearings provides a thin, strong drawer slide for carrying heavy loads. In an alternate embodiment, the central wall of the intermediate slide member comprises a generally rectangular window with a progression roller mounted therein on a vertical axis of rotation. The roller exerts friction on the inner faces of the channel members by compression against the inner faces when the roller is moved. Edges of window act as a detent on the roller and also urge the slide closed when the slide is brought to rest with the roller against one of the edges. The windows relieve compression of the roller when the slide is fully closed. | 0 |
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to a quick connect fluid coupling between mateable plug and socket fluid connectors and, more particularly, to a pressure confining blocking valve arrangement that is operable to prevent fluid flow when in a first position and the connectors are uncoupled, and seals the male portion as the connection is mated, then as this male is latched into the female of the connectors opens thereby to pass fluid therebetween.
"Quick Connect Fluid Couplings" U.S. Pat. No. 4,819,908, issued Apr. 11, 1989 discloses a socket connector provided with a valve member and a plug connector that is manually inserted into the socket in order to establish fluid communication therebetween. Upon insertion, the plug engages and moves the valve member from a closed to an open position. Simultaneously therewith a locking mechanism and a seal assembly associated with the socket, respectively, locks the connectors together and seals the mated connectors against leakage.
However, the seal assembly can still have fluid leakage, such as upon the separation of the plug from the socket. For example, as noted by U.S. Pat. No. 4,819,908, only the socket is provided with a shut-off valve to prevent fluid loss when the plug member is detached from the socket member. The plug is not fitted with a flow preventing shut-off valve. A disadvantage of a design that uses only one valve is that a great amount of the fluid medium which is confined by the piping system can be lost upon the separation of the members. Also, air and other material may be introduced into a system which does not utilize dual shut-off valves.
Accordingly, a primary object of the present invention is to provide a quick connect fluid coupling assembly with a fluid shut-off valve arrangement to prevent the release of the fluid medium operable when the individual fluid connector members are disconnected and when the connector members are connected.
It is another object of the present invention to provide connectable plug and socket conduits of a quick connect fluid coupling with separate fluid blocking valves which operate to prevent fluid flow when disconnected and open upon the connection of the plug to the socket to permit flow.
In addition, it is an object of the present invention to provide a fluid connector assembly which inhibits the entry of foreign objects, such as dirt, into the fluid connection system. An object of the invention is to provide a blocking valve that avoids having a spring force applied in a manner which will squeeze a seal in a manner that would cause the seal material to creep and have a smaller diameter inside diameter.
Another object of the present invention is to provide a fluid connector assembly which requires only a one-step snapping connection to open the dual blocking valves.
It is yet another object of the present invention to provide an improved seal retainer means which operates both to secure the blocking valve of the socket within the axial bore of the socket housing, and to retain the bushings, sealing rings and female blocking valve means within the axial bore of the female housing.
To achieve the foregoing objects, the present invention provides a quick connect fluid connector assembly comprising a pair of fluid conduits adapted to be releasably connected and disposed in fluid communication with one another. According to this invention, a socket fluid conduit is sized to receive the forward end portion of a plug fluid conduit inserted longitudinally inwardly of the socket. The plug and socket fluid conduits generally comprise respective tubular housings, each receiving a respective blocking valve which normally operates to prevent fluid flow from the housing until the conduits are in a fully sealed connection. The plug and socket valves open during mating of the conduits with the plug conduit operating to open the socket blocking valve and the socket valve operating to open the plug valve when a predetermined portion of the plug has been received in the socket.
With respect to the plug, the blocking valve comprises an annular disk having an outer periphery and flange portion, and flow by vanes, respectively, in sealed and abutted relation to the forward opening and a frusto-conical shoulder of the plug. In the plug, a spring seats against a fixed retention member and biases the disk forwardly into the sealed relation. The socket comprises a chamber sized to receive a series of nested parts for positioning seals relative to the socket housing, a valve member movable relative to the seals, and a spring for normally biasing the socket valve forwardly and into sealed relation.
The seal holding part arrangement is used to contain the socket blocking valve, bushings, and elastomeric seals within the axial bore of the socket housing upon the removal of the plug.
Advantageously, provision of separate shut-off valves on individual connector members blocks the release of fluid media from each of the individual members until the members are sealed, even though the members are not retained to each other.
Advantageously, provision of the sealing means in the socket acts to prevent fluid leakage when the plug and socket conduits are connected and retained and the fluid begins to flow. Although the sealing means remains in the socket conduit upon the separation of the conduits, the sealing means can be easily removed from the socket for inspection or replacement by the use of a means to retain the parts in the socket housing.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional objects, advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a side elevation view, partially in section, of a pair of fluid conduits positioned for mating;
FIG. 2 is a side elevation view, partially in section, showing the fluid conduits of FIG. 2 when partially mated;
FIG. 3 is a side elevation view, partially in section, showing the fluid conduits of FIG. 1 when fully mated. The means of retaining the two members together is not shown;
FIG. 4 is a side elevation view, partially in section, of an alternate embodiment of a plug fluid conduit; and
FIG. 5 is a side elevation view, partially in section, showing a portion of a socket and alternate retention of the internal parts, and means of retaining the two members together.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1-5 illustrate various preferred exemplary embodiments of the present invention in a quick connect fitting assembly for sealing a pair of cylindrical fluid conduits to one another and in fluid communication therebetween. As will become apparent to one skilled in the art from the following discussion, the principles of the present invention illustrated by the exemplary embodiments depicted in the drawings are equally applicable to fluid systems, fluid conduits, and fluid fitting or coupling assemblies of shapes, configurations or types other than those shown for the purposes of illustration in the drawings.
Referring primarily to FIGS. 1, 2 and 3, in accordance with one preferred embodiment of the present invention, a quick connect fluid coupling assembly 10 is provided for releasably sealing a socket fluid conduit 12 and a plug fluid conduit 14 to one another to establish fluid communication therebetween. The plug conduit 14 is axially aligned with and longitudinally inserted into the socket conduit 12 to be retained therewithin. While not shown, upon insertion, a retention element would operate to releasably lock the -conduits together as well as allow rotation of the plug relative to the socket. For example, the retention element could be located in an enlarged forward end portion of the socket housing and be provided with resilient fingers that engage the plug. These retention systems are known by those skilled in the art.
The socket fluid conduit assembly 12 includes a housing member 16 having an interior chamber 18 to receive the plug conduit, a seal retainer portion 20 and a blocking valve 22. The housing member 16 includes an elongated cylindrical wall 24 that extends longitudinally from an inlet 26 at one end, and an end wall 28 at the other end, the end wall having an opening 42 to pass fluid outwardly of the chamber at 30. In FIGS. 2 and 3, the elongated part is shown as 24/48. The chamber 18 is dimensioned to receive and position the seal retainer portion 20 and blocking valve 22 in partially nested tandem relation.
The housing member 16 includes a mounting area for seals 60, 68 and 70. Bushing part 66 is nested in housing member 16, and separates seals 68 and 70. Housing member 16 also receives snap-in washer 48 or extended member 24/48 which acts as a stop for seal 68 and as a stop for part 78. At the most interior end of housing member 16 is an area 50 that is heat staked or is configured to snap-in part 32 which carries moving valve body 72. The stem of part 38, which causes valve 118 to open as the plug and socket are mated, is also sealed to moving socket valve 72 by means of seal 90. Stem part 38 includes a radially outward flange 40 with at least one opening 42 therethrough. Flange 40 is positioned by area 50 at the inner most end of housing member 16 by step or end area 28.
Housing member 16, and its associated elements 24, 28 slips into a housing shown by housing wall 61 and is retained position by a housing wall innermost stopping wall 30, and an installable clip 62, which is installed through housing wall 61 at openings 64. Fluid passes out of the socket area through the interior of 30.
The socket shown in FIG. 1 is in the closed to fluid flow position. The outer surface of sliding valve body 72 is sealed by seal 68 and to stem part 38 by seal 90. Seal 90 is inwardly positioned by washer 92 which is snapped into moving valve body 72, and washer 92 also acts to restrict the expansion of spring 102 which is restricted from expanding by flange 40 which is a part of stem part 38. Fins 104 function to maintain spring 102 coaxial of the assembly, and fins 78, which are a part of moving valve body 72, limit outward travel of valve body 72 by impinging on washer 48. The frontal area of moving valve body 72 is shown by the number 80, and the exterior of area 80 is positioned in seal 70 to maintain the inside diameter of seal 70 during times when the plug 14 and socket 12 are not mated.
The plug portion 15 of the plug 14 and socket 12 combination 10, is composed of an outer surface 108 that is adapted to open the sliding valve body 72 in the socket portion 12, and to also be sealed by seals 68 and 70 in the socket portion 12. The end of surface 108 denoted by number 110 is rounded or chamfered to facilitate entry into socket 12 and seals 68 and 70. Also shown on surface 108 is expanded diameter 112 to facilitate retaining plug 14 and socket 12 in a mated relationship. The end 110 of plug 14 pushes on end 80 of moving valve body 72 thereby opening the socket 12 valve. The end 44 of stem 38 pushes on plug 14 valve body 118 thereby opening the plug 14 valve.
The interior of plug 14 is hollow and has interior surface 130. Interior surface 130 consists of surface 114 at the end which is sealed by seal 126, opening up in diameter to chamfered surface 116, which acts as a lead-in for seal 126, and stops the outward movement of fins 128 which are part of plug moving seal body 118. Interior surface 130 provides a guide for fins 128, and the more interior of surface 130 provides a stopping larger inside diameter to provide wall 124. Wall 124 prevents movement of part 132 toward the end of plug 14, and is prevented from movement in the other direction by the end of a hose that is not shown in the view.
Spring 120 is compressed between part 132 and chamfered surface 116 and fins 128, which are adapted for fluid flow therethrough, and urges moving seal body 118 toward the open end of plug 14.
FIG. 2 shows a partial insertion of plug 14 into socket 12. The end 110 of plug 14 has contacted front surface 80 of socket moving valve body 72, and partially opened the valve in the socket. Note that seal 70 has sealed the end of plug 14 in socket 12, but stem 38 has not contacted plug 14 moving valve body 118.
At this point the valve in the socket 12 is not opened because seal 68 is still sealing moving socket 12 valve body 72, and the end of stem 38 part at 44 has not yet opened the plug 14 valve body 118.
There is a small bubble of air now trapped between the sealed end of plug 14 and the interior open end area of socket 12 moving valve body 72. When the mated, socket 12 and plug 14 will have open interior valves, and the small amount of air is "digested" by the fluid system, which is not shown. When the assembly 10 is disconnected, the bubble of air will have been replaced by fluid, and that small amount of fluid will wet the interior open end of socket 12.
FIG. 3 shows full insertion of plug 14 into socket 12. Plug 14 is now sealed to socket 12 by both of seals 68 and 70. Stem part 38 end 44 has now contacted valve body 118 and caused it to move to the open position. The end of the plug has moved valve body 72 to an open position now the path for the fluid flow, F is open to allow flow F from the plug 14 through the socket 12.
The flow F is shown from the plug 14 through the socket 12. The flow F enters plug 14 through the openings of part 132, continues between fins 128, continues by the opening created in the interior of plug 12 when stem 38 end 44 pushed against surface 122 which is the end portion of plug 14 valve body 118, compressing spring 120. The flow F through the sealing bore defined by surface 114, into the interior area of socket moving valve body 72, and through openings 84 in valve body 72 into the interior of the socket 12 that was created when the end of plug 14 moved valve body 72, and then between fins 78 of valve body 72, and out of socket 12 through openings 42 in flange 40 of stem 38.
Fins 78 prevent over opening of the socket 12 by being stopped by surface 100 of fins 78 and flange 40 of stem 38.
FIG. 4 illustrates a second preferred embodiment of a plug fluid conduit in accordance with this invention. Plug fluid conduit 133 comprises inner and outer housings 134 and 136 telescoped together, each housing being generally cylindrical, and the assembly being open at its opposite ends for passing fluid. The outer housing 136 includes an inwardly extending annular forming 138 for securing the two housings in relative position and preventing axial rearward movement of the outer housing relative to the inner housing 134 by being formed on each side of bead 150 of housing 134. An outwardly extending annular bead 140 which provides a means of attachment between the plug and socket, such as shown in FIG. 5. Additional stabilization of 136 may be gained by squeezing sections 170 of 136 around 134. Notched out sections 172 allow this squeezing. The outer housing 136 is configured for insertion into the socket 200 with the forward end portion of the housing wall 136 being formed to include a decreased radial diameter portion 142 which is configured for entering the socket member, a cylindrical portion 144, and a frusto-conical portion 146 toward housing 134, away from portion 142.
The inner housing 134 is formed to include a reduced diameter portion 148, and an annular bead 150 to engage the formings 138. The inner housing 134 also is stabilized and sealed to the outer housing 136 by an annular seal 152 and by a pair of annular bushings 154 and 156. The bushings and seal are located between the inner and outer housings to prevent the flow of fluid therebetween and the bushings are located on each adjacent side of the seal to prevent movement of the seal in the axial direction.
A blocking valve body 158, similar to that described above for the plug conduit 14, is disposed in abutted relation against the portion 164 by fins 162 of blocking valve body 158. The blocking valve body 158 mounts seal 160, which seals the interior of housing 136, and includes fin like structures 162. Fin structures 162 act to restrain body 158 from being urged outward of housing 136 by contacting the interior 164 of frusto-conical wall 146.
A coil spring 166 is located between the inner and outer housing walls to provide a means of biasing the blocking valve into a forward position thus sealing housing member 136. The spring coils are disposed between the inner and outer conduits with one end of the spring engaging an end face 168 of the fin structures 162 and the other end engaging the bushing 154.
The operation will now be described briefly and particularly in connection to the fluid connector assembly of FIGS. 1-3. In FIG. 1, the plug conduit 14 is spaced from the socket conduit 12. The blocking valve bodies 72 and 118 are both in their first and closed position. No fluid will pass.
In FIG. 2, the plug is partially longitudinally inserted within the socket housing whereupon the seal 70 is radially compressed against the outer periphery of the plug. The front end of the plug is engaging the front axial face 80 of the moving valve body 72, and partially opening the socket 12 which is still sealed to flow. Further, the end face 44 of stem part 38 of the socket valve enters the recess formed on the front face of the plug valve body 118, but does not yet cause opening to flow of plug 14. No fluid will pass, but plug 14 is sealed into socket 12, but not retained.
As shown in FIG. 3, the plug is driven further into the socket, the end face 44 of stem part 38 urges the plug moving seal body 118 to the right in FIG. 3, thereby causing the plug spring 120 to compress. When this happens the seal 126 that is mounted on body 118 is driven inwardly and removed from its sealing engagement with the inner surface 114 of the plug. Simultaneously, the front end 110 of the plug drives the collar 80, and thus the body 72 of the socket valve, axially towards the left and in a direction inward of the housing thus opening the socket 12 to flow. Seal 90 always seals moving body 72 to stem 34. The spring 102 becomes compressed between against the flange 40 of the stem part 38 and the washer 92. In addition, the spring 120 which abuts valve body 118 becomes more compressed and the valve opens. When both the male and female blocking valves open, fluid can flow from the male member, through passage 82 and 84, and into the female member.
FIG. 5 shows the socket portion 12 of the connection disposed within a connector housing 206. Housing 206 is adapted to be attached to a tubular member (not shown) at 210. Housing wall 24' is similar to wall 24 in FIG. 1. The inner housing surface 212 is adapted to receive the socket 12 inner parts, and to prevent a cam closing line in the mold, the front outer section of housing 20 has been adapted to receive a ring-like part 208. The operation of the socket 12 is the same as described above. The connector housing 200 interior is also shaped to provide surfaces 214,216 and 218. The 214, 216 and 218 interior surfaces receive a retaining member 220 for retaining the internal socket 12 parts in connector housing 206, and a second retainer 230 for locking the plug 14 into engagement with socket 12. Retaining member 220 abuts surface 218 of housing 206 with portions 224 and area 222 and ring 208, and holes 226 assist in the removal of retaining member 220. Retaining member 230 also abuts housing 206 surface 218 at 232, and is formed with a portion or portions 234 which spring open to accept the larger diameter 112 in FIGS. 1-3, and 140 in FIG. 4. After passing by the end of portion 234, portion or portions 234 spring back behind raised diameters 112 or 140 to retain the plug in the socket.
The seals in the above discussion are made from elastomeric material, and all of the other parts may be made of an appropriate metal or plastic material. | A connection 10 for a piping system where non-threaded means are utilized for securing a male portion 14 to a female portion 12, and where sealing of the male portion to the female portion is accomplished by a seal 68,70 which seals the outside surface of the male portion to the inside of the female portion, a blocking valve 22, 72 in each the male and female portion which is operated by means 38 associated with the female portion blocking valve 72, whereby when the connection is separated, also seals the male portion, and wherein the male portion is also sealed within the female portion before the blocking valves 22, 27 in each the male and female portion open to permit flow through the connection 10. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 09/565,251, filed on May 5, 2000 and issued as U.S. Pat. No. 6,443,031, which claims priority on Korean Patent Application 99-48813, filed on Nov. 5, 1999.
BACKGROUND OF THE INVENTION
The present invention relates to a shift lever assembly for an automatic transmission, and in particular, to a slide cover unit of a dual mode shift lever assembly for covering a guide groove formed on an indicator panel.
Typically, a shift lever assembly for an automatic transmission includes an indicator panel having a guide groove, a shift lever passing through the guide groove so as to move along the guide groove, and a slide cover provided in the lower surface of the indicator panel for covering the guide groove such that the interior of the shift lever assembly cannot be seen.
One example of a prior slide cover unit for a shift lever assembly is schematically illustrated in FIG. 7 . As shown in FIG. 7, the slide cover comprises a first cover plate 50 , located under the indicator panel (not shown), which slides forward and rearward with respect to the direction of travel of a vehicle, and a second cover plate 53 which is guided by a pair of guide rails 51 and 51 ′ formed on a lower surface of the first cover plate 50 so as to slide in left and right directions with respect to the direction of travel of the vehicle. An elongated hole 52 is formed in an approximate center of the first cover plate 50 , the elongated hole 52 provided in the widthwise direction thereof. The second cover plate 53 is supported by the L-shaped guide rails 51 and 51 ′ of the first cover plate 50 and is provided with a round hole 54 through which a select lever passes.
Accordingly, the guide groove can be covered by the first cover plate 50 and the second cover plate 53 , regardless of the location of the shift lever.
However, when the second cover plate is operated, the second cover plate rubs the lower surface of the first cover plate so as to cause friction noise, and it also generates particulates.
SUMMARY OF THE INVENTION
The present invention has been made in an effort to solve the above problems of the prior art.
It is an object of the present invention to provide a slide cover unit of a shift lever assembly for an automatic transmission that minimizes friction between first and second cover plate plates so as to prevent friction noise and drag from being generated.
To achieve the above object, a slide cover unit of a dual mode shift lever assembly for covering a guide groove formed in an indicator panel in order to isolate an interior of a housing regardless of movement direction of the shift lever comprises a first cover plate slidably mounted under the indicator panel for covering the guide groove, a pivot pin fixed on a lower surface of the first cover plate, and a second cover plate pivotally mounted on the pivot pin as an auxiliary cover for the guide groove.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and together with the description, serve to explain the principles of the invention:
FIG. 1 is a perspective view showing a dual mode shift lever assembly according to a preferred embodiment of the present invention;
FIG. 2 is an exploded view of a slide cover unit of the dual mode shift lever assembly of FIG. 1;
FIG. 3 is a perspective view of the slide cover unit of FIG. 2 as assembled;
FIG. 4 is a top plane view showing the slide cover unit of FIG. 2;
FIG. 5 is a front cross-sectional view taken along a longitudinal axis of an alternative second cover plate according to a second preferred embodiment of the present invention;
FIG. 6 is a perspective view showing a bottom surface of a first cover plate plate according to the second preferred embodiment of the present invention; and
FIG. 7 is a perspective view showing a prior art slide cover unit.
DETAILED DESCRIPTION
A preferred embodiment of the present invention will be described hereinafter with reference to the accompanying drawings.
As shown in FIG. 1, a shift lever assembly 100 comprises a body 1 , an indicator panel 2 mounted on a top portion of the body 1 , the indicator panel 2 having guide groove 3 , and a shift lever 20 pivotally fixed in the body 1 and extended outward through the guide groove 3 .
The guide groove 3 comprises an auto mode portion and manual mode portion formed in a longitudinal direction with respect to the direction of travel of the vehicle, and the two mode portions are connected to each other by a channel formed in the transverse direction with respect to the direction of travel of the vehicle such that the shift lever can move to the front, rear, left, and right directions of the vehicle along the guide groove. The channel connecting the auto mode portion and the manual mode portion of the guide groove 3 if formed in a portion indicating a D range on the indicator panel 2 .
The guide groove 3 is covered by a slide cover unit 4 . As shown in FIG. 2, the slide cover unit 4 comprises a first cover plate 5 slidably mounted under the indicator panel 2 , and a second cover plate 8 pivotally mounted on the lower surface of the first cover plate 5 .
The first cover plate 5 is rectangular with the longer side oriented in a front and rear direction of the vehicle, and it has an elongated mode conversion hole 6 in the approximate center thereof, the elongation being in a widthwise direction of the first cover plate 5 . On the lower surface of the first cover plate 5 , a pivot pin 7 is fixed at a portion remote from the mode conversion hole 6 along the longitudinal centerline 101 . The pivot pin 7 is provided with a bulbous pin head 7 ′ at its free end and split in longitudinal direction such that the pivot pin 7 is inserted in a hole of which the diameter is smaller than that of the bulbous portion of the pivot pin 7 .
The second cover plate 8 is formed with a shape of a spatula and provided with a lever receiving hole 10 and a pin hole 9 at a narrow end portion of the second cover plate 8 . The pin hole 9 is elongated in a longitudinal direction of the first cover plate 5 such that the second cover plate 8 can move a small amount in a frontward and rearward direction on the first cover plate 5 after the second cover plate 8 is mounted to the first cover plate 5 .
As shown in FIG. 3, the second cover plate 8 is pivotally mounted on the lower surface of the first cover plate 5 so as to remain attached thereto, by inserting the pivot pin 7 of the first cover plate into the pin hole 9 of the second cover plate 8 . The bulbous pin head 7 ′ of the pivot pin 7 prevents the second cover plate 8 from releasing from the first cover plate 5 .
The lower surface of the first cover plate 5 is corrugated having corrugations 12 in a longitudinal direction, except for an approximate central area 13 thereof, for enhancing its sliding movement. The non-corrugated area 13 is defined by the pivoting rotation of the second cover plate 8 on the pivot pin 7 such that movement of the second cover plate 8 is not interfered with by the corrugated surface. Furthermore, a rotation ring 14 (see FIG. 2) is interposed between the first and second cover plates 5 and 8 for reducing rotational friction when the pivot pin 7 is inserted into the pin hole 9 . The second cover plate 8 rotates on the pin 7 of the first cover plate 5 according to a movement of the shift lever 20 .
The shift lever 20 passes through the mode conversion hole 6 of the first cover plate 5 and the lever receiving hole 10 of the second cover plate 8 such that the slide cover unit 4 moves to the front, rear, left, and right directions according to the shift lever manipulation.
To enhance a detent quality when converting from one mode to the other, a detent projection 11 can be formed on a wall of the mode conversion hole 6 (see FIG. 2 ).
The operation of the slide cover unit of the shift lever assembly according to a preferred embodiment of the present invention will be described hereinafter.
Shifting operations are made by moving the shift lever 20 along the guide groove 3 . When the shift lever 20 moves in the longitudinal direction of the vehicle, the first cover plate 5 is moved together with the second cover plate 8 in the same direction. On the other hand, when the shift lever 20 moves in the transverse direction of the vehicle for changing shift mode, the shift lever 20 moves in the longitudinal direction of the elongated mode conversion hole 6 and the second cover plate 8 rotates on the axis of the pivot pin 7 and moves in the same direction of the shift lever 20 . Accordingly, the guide groove 3 is covered by the slide cover unit 4 under the indicator panel 2 regardless of movements of the shift lever.
FIG. 5 is a front cross-sectional view showing a second cover plate according to a second preferred embodiment of the present invention.
As shown in FIG. 5, a guide projection 22 is formed upward around the pin hole 10 such that the guide projection 22 is inserted into the mode conversion hole 6 of the first cover plate 5 . The guide projection 22 has a flange around the edge of the upper end thereof and a rotation ring 14 ′ for reducing friction between the first and second cover plates 5 and 8 , and it is provided around the guide projection 22 .
FIG. 6 is a perspective view showing a bottom surface of a first cover plate according to the second preferred embodiment of the present invention.
As shown in FIG. 6, in addition to the first cover plate unit, the first cover plate further comprises a support rail 21 formed on the lower surface of the first cover plate 5 for supporting the second cover plate 8 .
The operation of the slide cover unit of the shift lever assembly according to the second preferred embodiment of the present invention is the same as that of the first preferred embodiment.
As described above, the second cover plate is formed with a spatula shape small enough not to project out from under the first cover plate and is pivotally mounted on the lower surface of the first cover plate such that the friction area between the first and second cover plates is minimized, and so the second cover plate does not interfere with any operation of other parts of the shift lever assembly. Also, the minimization of the friction area between the first and second cover plates reduces friction noise and generation of particulates. | A slide cover unit of a dual mode shift lever assembly is provided to cover a guide groove formed in an indicator panel in order to isolate an interior of a housing regardless of movement direction of the shift lever. The slide cover includes a first cover plate slidably mounted under the indicator panel for covering the guide groove, a pivot pin fixed on a lower surface of the first cover plate, and a second cover plate pivotally mounted on the pivot pin as an auxiliary cover for the guide groove. | 8 |
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to holsters for handguns, and particularly to holsters in which the length and the width of the holster may be adjusted.
2. Description of the Prior Art
Holsters for law enforcement officers are found in many styles and designs to fit the desires of all sizes and shapes of individuals and their preferences for where their handguns are to be carried on their bodies. In many instances these guns are carried under the outer layer of clothing so as to be hidden from view. Such inside holsters tend to be reduced to their bare essentials so as to be less bulky and lighter in weight.
A particularly pertinent holster of the inside type is that described and claimed in U.S. Pat. No. 5,358,160 granted Oct. 25, 1994 to John E. Bianchi. Improvements have now been made upon the holster of such U.S. Patent.
It is an object of the invention to provide a novel holster for a pistol for use with a shoulder harness. Another object is to provide a holster that can be adjusted for different types and sizes of pistols in length and in width and adapted for use with a shoulder harness. Still other objects will become apparent from the more detailed description which follows.
BRIEF SUMMARY OF THE INVENTION
This invention relates to an underarm handgun holster having two opposing barrel support members adapted to lie along the two opposite sides of the pistol barrel from the muzzle to the trigger guard. Each support member has a forward portion and a rearward portion joined together by a fastener passing through aligned passageways in the two portions, so as to permit adjustment of the length of the barrel support members. One support member includes a muzzle stop extending transversely across the muzzle end of the forward portions. An elongated coil spring is attached at each of its ends to the two member rearward portions, respectively, and is adapted to urge the pistol forward against the muzzle stop. Upwardly extending eyes on both of the rearward portions are attached to a strap connecting the holster to a body harness.
In one of the preferred embodiments of the invention the coil spring, which assists in retaining the handgun in the holster, is restricted in the amount it can stretch by reason of a wire loop placed inside the coil spring. Also, a non-marring sheath is located about the coil spring to protect the handgun. In another preferred embodiment the holster is adjustable with respect to the girth of the handgun at its muzzle. Also, external muzzle supports improve the holster capability of easy withdrawal of the handgun yet a firm gripping of the muzzle while holstered and self centering thereof. In still another embodiment of the invention the holster has eyes on the lower portions of the holster for fastening it to a waist belt when the holster is in an underarm position.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a side elevational view of the holster of this invention, a handgun being shown in broken lines;
FIG. 2 is a top plan view of the holster of FIG. 1;
FIG. 3 is a front elevational view of the holster of FIG. 1;
FIG. 4 is a partial cross-sectional view taken along line 4--4 of FIG. 1;
FIG. 5 is a partial cross-sectional view taken along line 5--5 of FIG. 1;
FIG. 6 is a schematic perspective view of an individual wearing a shoulder harness and the holster of this invention in an underarm position;
FIG. 7 is an enlarged cross-sectional partial view taken along line 7--7 of FIG. 3; and
FIG. 8A is an enlarged perspective view of the coil spring of this invention, partially broken away for clarity; and FIG. 8B is another enlargement at the broken line position B of FIG. 8A.
DETAILED DESCRIPTION OF THE INVENTION
The features and advantages of this invention are best understood by reference to the attached drawing with numeral references to various components.
The adjustable holster of this invention is specifically preferred for carrying a handgun in an underarm location covered by an outer garment, such as a jacket, coat, blouse, shirt, or the like. In FIGS. 1-5 and 7, the structure of the holster is shown, and in FIG. 6, there is shown the way in which the holster and its pistol are worn on the body.
In FIGS. 1-3 there may be seen two barrel support members 10 and 11, which lie along the inside and outside of the barrel of pistol 35 (shown in broken lines in FIG. 1). The terms "inside" and "outside" are intended to refer, respectively to facing the body and facing away from the body of the wearer. In the drawings the wearer is assumed to be right-handed, but it is to be understood that the holster of this invention is equally usable by left-handed as well as right-handed wearers. The forward end of the holster includes a muzzle stop 20 which joins inside barrel support member 10 to outside barrel support member 11. The rearward end of the holster is a length of a coil spring 21 fastened at each of its ends, respectively, to a rivet 39 at the rearward ends of inside barrel support member 10 and outside barrel support member 11. With spring 21 looped around the butt of handgun 35 and the muzzle of the gun pressed against muzzle stop 20, it may be seen that pistol 35 is securely contained in the holster. The two barrel support members are substantially mirror images of each other.
At the forward end of the holster, which preferably is made of a molded tough plastic material, the barrel support members 10 and 11 are curved to form muzzle supports 40 that partially encircle the muzzle of the pistol. Each muzzle support 40 includes a shoulder 46 or 47 (see FIG. 7), that are bent toward each other at right angles to their respective muzzle supports 40, and overlap each other to form muzzle stop 20. One shoulder (47 in FIG. 7) is punctured by a horizontal slot 48 while the other shoulder (46 in FIG. 7) is punctured by a hole 45' through which the shank of a releasable connector in the form of a screw 19 extends to a square nut 45 which is countersunk into shoulder 46. The square nut 45 includes a round sleeve 50' which extends through the hole 45' and terminates between the inner and outer surfaces of shoulder 47. This arrangement permits the contraction or the enlargement of the internal space between muzzle supports 40 by use of a screwdriver on screw 19. As shown more specifically in FIG. 7, the outer face of shoulder 46 contains a plurality of spaced protrusions 53 which surround hole 45' and extend generally vertically, i.e., parallel to a vertical plane extending through the longitudinal centerline between the support members 10 and 11. Complemental grooves 52 (seen also in FIG. 2) are provided in the face of shoulder 47 and extend vertically throughout the area represented by broken lines 52' of FIG. 3 and surrounding slot 48. The protrusions 53 and grooves 52 are generally V-shaped, i.e., a cross-sectional shape of a triangle and are complemental. As seen in FIG. 7, the outer face of shoulder 46 is juxtaposed to inner face of shoulder 47 when the protrusions 53 and grooves 52 intermesh. Therefore, when a user adjusts the width between the support members 10 and 11, the protrusions 53 and grooves 52 maintain the support members 10 and 11 parallel to the grooves 52 and protrusions 53 and substantially parallel to each other. This adjustment allows the muzzle of the holster to expand or contract to provide a more exacting fit onto the different types and configurations of pistol muzzles and also a close fit or a loose fit around the muzzle of a pistol in the holster. Shoulder 47 also contains eye 29 (see FIG. 3) which functions as an attachment for a keeper strap to connect the muzzle end of the holster to a shoulder harness 37 by a loop or snap hook 37' (see FIG. 6). Also, by having two muzzle supports 40 each having two spaced shoulders 40' and 40", the shoulders provide a self-centering capability to the muzzle of the handgun while it is being holstered.
In order to provide an adjustment capability to accommodate guns of different length, each barrel supporting member 10 and 11 is divided into forward and rearward portions joined by releasable fastener 16. Barrel supporting member 10 and 11 have respective forward portions 12 and 14 and rearward portions 13 and 15. Fasteners 16 (one for each barrel supporting members 10 and 11) preferably comprise a bolt 16 and a nut 50 on the outside and inside surfaces respectively, of each barrel supporting member 10 and 11. In order to prevent scratching or marring of the gun surfaces the nut 50 is countersunk in a groove 30 in the inside surfaces of barrel supporting members 10 and 11.
In order to keep forward portions 12 and 14 aligned with respective rearward portions 13 and 15 throughout the length adjustment of barrel supporting members 10 and 11, the forward and rearward portions 12, 13, 14 and 15 are provided with a tongue-and-groove engagement. This may best be seen in FIGS. 1,4, and 5. The rearward portions 13 and 15 of each barrel supporting member 10 and 11 are fashioned with a lengthwise tongue 31 on the outside surface. The forward portions 12 and 14 of each barrel supporting member 10 and 11 is provided with a longitudinal groove 32 to fit snugly with tongue 31. Tongue 31 is also provided with a plurality of closely spaced holes or passageways 18, while groove 32 has one such hole or passageway 18' shown in FIG. 4, through which bolt 16 extends its threaded shank within round sleeve to the internal square nut 50 caged by and recessed within groove 32. This combination of holes or passageways 18 with bolt 16 provides the capability of lengthening or shortening the overall length of the holster.
Each rearward portion 13 and 15 also preferably includes an eye 22 or 23 adapted to provide an attachment position for a strap 44 to extend to a waistbelt of the wearer 36 as shown in FIG. 6. It is, of course, contemplated that the lower connection of strap 44 might be a suspender clip to be attached to the top of the pants instead of a waist belt. Only one of eyes 22 and 23 is expected to be used at any one time, that being the eye of the rearward portion 13 or 15, which is next to the body of the wearer. This provides for both right-handed and left-handed wearers.
Attached to the top of rear portions 13 and 15 is a length of flexible strap 25, preferably leather or a leather substitute fastened at each of its ends, respectively, to rear portions 13 and 15 to button rivets 24. The connection between rivets 24 and rearward portions 13 and 15 is sufficiently loose to permit strap 25 to pivot about rivets 24. Strap 25 is attached to any convenient coupling that can be attached to a shoulder harness. A preferred coupling is a quick release bayonet coupling 26 having a female portion 26' and a male portion 26", having an eye 27 to allow strap 25 to pass through, and an eye 28 to permit attachment to a shoulder harness. (See U.S. Pat. Nos. 4,150,464 and 4,171,555 for such a coupling 26) The sliding connection between coupling 26 and strap 25 as well as the pivotal connection of strap 25 to rear portion 13 or 15 allows the holster to automatically position itself to any body wearing a shoulder harness.
The coil spring 21 is a feature of this invention and is shown in FIGS. 1, 2 and more specifically in FIGS. 8A and 8B. The spring 21 restrains the pistol from falling out of the holster without need for a strap or flap on the holster. Spring 21 is a length (perhaps 3-4 inches) of a tightly coiled spring fastened at each end to rearward portions 13 and 15, respectively, by way of a rivet 39, or other equivalent fastener. Spring 21 is expected to loop around the butt of pistol 35 (see FIG. 1) at the top of the hand grips where there is a curved projection 49 that fits between the thumb and index finger of the hand. Spring 21 is of a size to provide a bias to the pistol urging it forward into the holster against muzzle stop 20. Because a metal-to-metal contact of the bare metal spring 21 against the rear of the gun might produce undesirable scratching or marring, spring 21 is preferably covered with a plastic sheath 41 (see FIG. 7). Another preferred feature is to include a restraint to prevent extension of spring 21 beyond a selected amount. This feature is preferred because it is a safeguard against a deforming overstretching of the spring beyond its ability to return to its non-stretched condition. This restraint can be provided by including a predetermined length of wire inside the coil 21 and connected to the same terminal rivets 39. An especially desirable arrangement is to employ two long loops of wire 33, each tied to respective rivets 39, and with the two loops 33 being interconnected as at 34. The ends of each wire 33 may be connected by a crimping connector 51, for example.
While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention. | The holster includes two opposing barrel support strips adjustable in length and joined together at their forward ends through two over-lapping right angle legs adjustable in width and joined together by a selectively releasable connector to form a muzzle stop, and joined together at their rearward ends by a length of a sheath enclosed coil spring adapted to encircle the hand grip and to bias the barrel toward the muzzle stop. The two barrel support strips each have a forward portion and a rearward portion joined together by selectively releasable connectors and adjustable in length through a plurality of aligned holes on at least one portion. The holster includes a plurality of eyes to facilitate attachment to a shoulder harness. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to Provisional Application Serial No. 60/110,712 filed Dec. 3, 1998 and incorporated herein by reference.
GOVERNMENTAL INFORMATION
The U.S. Government has a license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms of grant number HG01487 awarded by the National Institute of Health (NIH).
TECHNICAL FIELD
The present invention relates to a method and apparatus for DNA electrophoresis and detection.
BACKGROUND
Electrophoretic lanes are widely used for separating multi-component samples ranging from small inorganic ions to large biological molecules. DNA electrophoresis is commonly performed with polyacrylamide gel placed between two glass plates. In recent years, the method of capillary electrophoresis has been developed, which alleviates the dissipation of Joule heat and permits the application of higher voltage, thus speeding up the electrophoresis separation process. In capillary electrophoresis, a buffer-filled capillary is suspended between two reservoirs filled with a buffer liquid. An electric field is applied between the two ends of the capillary. The potential difference that generates the electric field is in the range of kilovolts. Multi-component samples are typically injected under the influence of an electrical field. The samples migrate under the influence of electric field, with components of the sample being electrophoretically separated. After the separation, the components are detected by a detector.
One of the important applications of electrophoretic separation is for DNA sequencing. The use of capillary electrophoresis has improved DNA sequencing rates. Part of the improvement in speed, however, was initially offset by the loss of the ability (inherent in slab gels) to accommodate multiple lanes in a single run. Highly multiplexed capillary electrophoresis, by making possible hundreds or even thousands of parallel sequencing runs, offers an attractive approach to overcoming the current throughput limitations of DNA sequencing instrumentation. Typically, an array of capillaries is held in a guide and the intake (cathode) ends of the capillaries are dipped into vials that contain samples. After the samples are taken in by the capillaries, the ends of the capillaries are removed from the sample vials and submerged in a buffer which can be in a common container or in separate vials.
The currently used multichannel electrophoretic arrays typically represent a coplanar arrangement of capillaries. This geometry has been chosen because of its convenience for detection, which is typically performed with the help of fluorescent tags (fluorophores) attached to the DNA fragments migrating along the electrophoretic lanes. The detection is typically effected by illuminating the lanes within a specially provided translucent portion near their anode end (the observation region) with a laser source that excites fluorescence. One of the common reasons for the conventional planar arrangement of the capillaries has been that it offers a straightforward way of positioning the photoreceiving matrix that detects the fluorescence from all lanes in parallel. Another common reason for the parallel arrangement of capillaries is due to the need for color resolution of different fluorescent markers, which is typically performed by spatially dispersing the emitted fluorescent radiation in the longitudinal (along the lanes) direction. The spatially dispersed radiation from all observation regions is then imaged onto a two-dimensional photoreceiving matrix, such as CCD or CMOS, using a high-aperture projection objective. Still another common reason for the parallel arrangement of capillaries is associated with the desire to illuminate all lanes at once with a laser beam, which propagates in the plane of the capillaries and at the same time transverse to their axes.
In recent years, several authors disclosed such multicapillary systems, see e.g., Quesada et al., “Multiple capillary DNA sequencer that uses fiber-optic illumination and detection”, Electrophoresis , vol. 17, pp. 1841-1851 (1996). Moreover, multicapillary systems have been disclosed in which the capillaries themselves serve as light-guiding elements for the illumination beam, see, e.g., Yeung et al., “Multiplexed capillary electrophoresis system”, U.S. Pat. No. 5,582,70 (1996) and Quesada et al., “Multi-capillary optical waveguides for DNA sequencing”, Electrophoresis , vol. 19, pp. 1415-1427 (1998).
Therefore, a need exists for a non-planar arrangement of multiple capillary electrophoretic lanes which provide miniaturization of the electrophoretic carrier and which will significantly reduce the cost of multiple-lane DNA sequencing machines. A further need exists for a method for manufacturing monolithic cassettes, including multiple capillary lanes and a method and apparatus for parallel detection of fluorescent markers passing through the observation regions in a non-planar arrangement of multiple electrophoretic lanes.
SUMMARY
The present disclosure describes a non-planar arrangement of multiple capillary electrophoretic lanes, a technique for manufacturing monolithic cassettes, comprising such multiple capillary lanes and a method and apparatus for parallel detection of fluorescent markers passing through the observation regions in a non-planar arrangement of multiple electrophoretic lanes. The need for non-planar arrangement arises from the desire to miniaturize the electrophoretic carrier, which will significantly reduce the cost of multiple-lane DNA sequencing machines.
The present disclosure offers inventive solutions that circumvent all of the above-cited common reasons for choosing co-planar geometry of a multilane assembly. In the simplest embodiment, the photoreceiving matrix is arranged in a first plane inclined at an angle relative to the capillary axes, while the observation regions of different capillaries are arranged in a second plane which is also inclined at an angle relative to the capillary axes. For example, the first and second planes are parallel to each other inclined at 45 degrees relative to the capillary axes. The simultaneous illumination of multiple capillary lanes is effected by an array of modulated laser sources whose beams have a specially chosen spatial arrangement and direction relative to the capillary axes and to said first and second planes. Next, the need for spatial dispersion of fluorescent radiation into components corresponding to different fluorescent wavelengths is eliminated in accordance with the method for multicolor fluorescent detection recently disclosed by Gorfinkel et al., “Method and apparatus for identifying fluorophores”, U.S. Pat. No. 5,784,157 (1998). Further, the need for waveguiding the incident radiation in the inventive method is substantially eliminated by using tightly packed capillaries of small cross-section. In a preferred embodiment, the capillaries have a rectangular or square cross-section of less than about 100 μm on the side. For example, a rectangular array of 96 such capillaries has an overall cross-section of less than 1 mm 2 . As many as one thousand capillary lanes can be accommodated in a monolithic array of square cross-section about 3×3 mm. The present invention further discloses techniques for fabricating such multicapillary arrays. These techniques employ drawing a glass preform that has a pre-fabricated set of holes of desired shape (e.g., rectangular) and is similar to drawing hollow optical fibers or glass ferrules, see, e.g., MacChesney et al., “Materials development of optical fiber”, Journal of the American Ceramic Society , vol. 73, pp. 3537-3556 (1990) and Anderson et al., “Optical fiber connector comprising a glass ferrule, and method of making same”, U.S. Pat. No. 5,598,496 (1997). In one preferred embodiment, the preform is prepared with multiple holes to draw a monolithic multicapillary structure. In another preferred embodiment, a multicapillary bundle is fabricated by gluing or soldering together a multiplicity of single capillaries.
Still another aspect of the present invention pertains to loading tightly packed monolithic capillaries. In one of the preferred embodiments, this is provided by matching the capillary array cross-section with a similar array of charging pins on a silicon chip. In another preferred embodiment, the capillary assembly, which is monolithic in the observation region near the anode, is made loose like a brush near the cathode end. A special fixture holder is further provided that fixes the loose cathode ends of capillaries in a desired pattern. In a preferred embodiment, the loose cathode ends of the capillaries are arranged in a pattern that matches the common 96 well plate widely used in the preparation of biological samples.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the general structure of a multicapillary cassette;
FIG. 2 illustrates the cross-section of the capillary assembly near the observation region;
FIG. 3 illustrates the cross-section of the capillary assembly near the loading region;
FIGS. 4 a-c illustrate the spatial configuration of the capillary assembly, the illuminator and the photoreceiver in the observation region. FIG. 4 a : side view; FIG. 4 b : top view; FIG. 4 c : fluorescent image projected onto a photoreceiving matrix;
FIG. 5 illustrates a preferred structure of the illumination source;
FIG. 6 illustrates an array of independently modulated optical sources and coupling of their radiation outputs into a single optical fiber;
FIG. 7 illustrates the structure of a fiber-optic illumination system to provide independently modulated and reconfigurable optical beams;
FIG. 8 illustrates the structure of a fiber-optic illumination system with a multiple independent light sources;
FIG. 9 illustrates illumination of capillaries with the help of an optical line generator;
FIGS. 10 a-b illustrate exemplary spatial arrangements of the capillaries, the optical source and the photoreceivers;
FIG. 11 illustrates the reception of fluorescent signal by a two-dimensional photoreceiving matrix;
FIG. 12 illustrates the reception of fluorescent signal by a linear photoreceiving array; and
FIG. 13 illustrates the reception of fluorescent signal by a wide area photoreceiver.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The multicapillary bundle may be implemented either as a monolithic or quasi-monolithic structure or a loose assembly of individual capillaries. Monolithic structures may be obtained by drawing on a preform. Quasi-monolithic structures may also be obtained by a tight packing together of individual capillaries or smaller monolithic multicapillary units. We also envision intermediate structures, which may be monolithic or quasi-monolithic in one region and loose in another.
Various versions of the multicapillary bundle can be characterized by the geometry of their cross-section at different positions along the capillary lanes, cf. FIG. 1 . The geometry of the bundle is important in that it affect the way the operations of fluorescent detection and sample loading are performed. In every preferred embodiment, the cross-section of the multicapillary bundle in the region of detection is monolithic or quasi-monolithic and is characterized by a definite known pattern of capillaries of a desirable shape. For example said pattern may be periodic in two dimensions as illustrated in FIG. 2 . The desirable shape of the cross-section of the individual capillary lanes in the detection region is determined primarily by the convenience of external illumination and collection of the fluorescent response. For example, said shape is rectangular or oval but it may also be hexagonal or some other polygonal shape. The shape of the bundle cross-section and that of individual capillaries need not be the same in other regions of the bundle as determined by the convenience of loading, efficiency of electrophoresis and facility of manufacturing.
In one preferred embodiment, the entire bundle is monolithic or quasi-monolithic. The loading end surface of the bundle may represent a flat surface perpendicular or inclined to the capillary axis. The surface may also be processed, e.g., mechanically or chemically, resulting in non-flat surface. In this embodiment the bundle cross-section may be constant or variable along the length of the bundle.
In another preferred embodiment, the bundle is monolithic or quasi-monolithic in the detection region while loose in the loading region, as illustrated in FIG. 3 . Loose capillary ends are fixed in a pattern determined by a specially provided fixture plate. In a preferred embodiment, this pattern matches the common 96-well plate containing DNA samples. Holes in the fixture plate are of desired shape, e.g., cylindrical, conical, or pyramidal, designed to tightly hold the capillaries. Fixation of the capillaries in the fixture plate can be done in a variety of ways, e.g., by gluing or soldering.
Loading Device
Loading of the DNA samples into the multicapillary bundle can be done by using a variety of known techniques employed for the injection of DNA samples into single capillary lanes. These techniques include, e.g., the mechanical transfer and electro-kinetic injection. The inventive techniques disclosed here relate to specific configurations that facilitate loading into a bundle of capillaries. Firstly, the loading device must be adapted to the cross-sectional dimensions of the bundle in the loading region. The preferred geometry of the loading device comprises one or more adapters that have a similar pattern as the bundle cross-section. Said adapters may be attached to the source of DNA samples, such as a multi-well plate or a micro-fluidic chip. Said adapters may also be attached to the capillary bundle in a removable or permanent fashion. The adapter may comprise a pattern of holes or protuberances that fit the capillary pattern. Connection between the adapter and the capillary pattern may be either male-to-female or female-to-male. Alternatively, the adapter may be elastic and have a flat surface with holes so that a tight connection is established simply by pressing the edge of the capillary bundle on the adapter.
The loading device may provide means for electrokinetic injection. To this end, it must be outfitted with one or more electrodes. The controlling voltage may be applied to different electrodes individually, so that different voltages are applied to different electrodes.
Referring to FIG. 1, spatial arrangement of elements of a preferred embodiment of the multicapillary cassette for DNA sequencing includes:
housing 11 ; multicapillary bundle 12 ; observation region 13 ; and loading region 14 .
In FIG. 1, it is assumed that the anode and the cathode are placed outside the housing 11 so that capillaries continue beyond regions 13 and 14 . The housing volume may be filled with a heat conducting fluid or other means for thermal control of the capillaries.
Referring to FIG. 2, a cross-section of the capillary assembly near the observation region is shown. The M×N array comprises rectangular capillaries arranged in M columns and N rows. The shape of capillaries can be rectangular, square, elliptic, or any other selected for the convenience of illumination and collection of fluorescence. The capillary assembly in this region is a tightly packed bundle. In a preferred embodiment the assembly is monolithic obtained by drawing a preform with multiple holes of desired shape. In another preferred embodiment the assembly is made up of single, for example, rectangular capillaries, soldered or glued together using solder or glue of properly matched refractive index.
Referring to FIG. 3, a cross-section of the capillary assembly near the loading region is shown. Loose capillary ends are fixed in a pattern determined by the fixture plate. In a preferred embodiment, this pattern matches the common 96-well plate containing DNA samples. Holes in the fixture plate are of desired shape, e.g., cylindrical, conical, or pyramidal, designed to tightly hold the capillaries. Fixation of the capillaries in the fixture plate can be done in a variety of ways, e.g., by gluing or soldering. A thermal process based on the thermal expansion and contraction of the holes can also be used. In another preferred embodiment the capillary ends are not loose but are monolithic, for example, obtained by drawing on a preform. In such embodiments it is contemplated that the well plate from which samples are injected into capillaries is implemented as a microchip or a micro-assembly to match the miniature cross-section pattern of a monolithic multicapillary structure.
The arrangement of capillaries in a cross-section of the capillary assembly near the loading region may be organized in a different way from that near the observation region. While the total number of capillaries is obviously the same in both cross-sections their row x column pattern may be quite different. For example, one may still have a matrix of dimensions P×Q=M×N, where M and N refer to FIG. 2, but the factors P,Q are different from M,N.
To facilitate precise manipulation of the capillary bundle and its alignment relative to the loading device, special set of alignment marks may be provided, that is clearly visible or detectable in a cross-section of the bundle in the loading region. These marks may employ an optical or some other physical effect. In one preferred embodiment, the desired set of alignment marks is obtained by filling a reserved group of capillaries in the bundle with some easily detectable material. For example, said group of capillaries may be filled with some conducting or magnetic fluid, or some distinguishable optically contrast fluid, such as containing color luminescent or fluorescent species.
Referring to FIGS. 4 a-c , an illustration of the spatial configuration of the capillary assembly, the illuminator and the photoreceiver in the observation region, is shown. FIG. 4 a shows a side view of the relevant portion of the apparatus. FIG. 4 b shows a top view of the relevant portion of the apparatus. FIG. 4 c shows a planar view of the fluorescent image projected onto the target screen of the photoreceiving system. FIGS. 4 a-c include: assembly (bundle) of capillaries 41 ; focal plane of the optical receiving system 42 ; one of the capillaries of the assembly 43 ; fluorescent zone 44 in one of the capillaries 43 of the assembly; optical receiving system 45 , such as projection optics; photoreceiving system 46 , such as CCD or CMOS, or PMT matrix; image of the fluorescent zones 47 on the target screen of the photoreceiving system 46 ; optical axis 48 of the optical receiving system with the angle between said optical axis and the capillary axes denoted by α, for example, α=45°; one of the optical paths 49 , including projection optics, carrying the excitation beam from illumination sources.
The illumination sources are arranged so that the optical excitation beams they emit propagate in the focal plane 42 of the optical receiving system 45 . Said excitation beams need not be parallel to each other but may be parallel. In a preferred embodiment, illustrated in FIG. 4 a , the optical excitation beams propagate perpendicular to a plane containing a row of capillaries, i.e., perpendicular to the cross-section of the assembly displayed in the plane of FIG. 4 a . In FIG. 4 b the direction of illumination beams lies in the plane of the drawing and in the direction of sources 49 . The image 47 on the target of the photoreceiver 46 is shown in FIG. 4 c as a plane view.
To facilitate the spatial alignment of the capillary assembly, the illuminator and the photoreceiver in the observation region, the capillary bundle may be outfitted with alignment marks clearly visible or detectable in a cross-section of the bundle in the observation region, such as plane 42 . For example, said set of markers may be obtained by reserving several capillaries in the bundle to be filled with some distinguishable fluorescent fluid or fluids.
Referring to FIG. 5, an illustration of the spatial arrangement of elements of the illumination system are shown and may include: an optical channel 51 delivering the desired combination of modulated spectral components from the optical source and a narrow excitation beam 52 directed onto the capillary assembly.
FIG. 5 displays separately a portion of FIG. 4 c to illustrate the possibility of implementing the illumination system as a group of independent, not necessarily parallel, optical systems, each comprising a modulated source. In another preferred embodiment, illustrated in FIG. 7, the illumination is obtained from a single multiplexed optical source. In general, the number of independent optical sources can be smaller than, equal to or large than the number of illumination channels 52 .
Referring to FIG. 6, an illustration of an array of independently modulated optical sources coupled into a single optical path, for example, an optical fiber and may include: an optical coupler 61 ; optical channels 62 , e.g., fibers, delivering modulated narrow-band optical spectral component to coupler 61 ; modulated narrow-band light source 63 , e.g., diode laser, LED, or a gas or solid-state laser with an external modulator; electrical signals 64 modulating light sources 63 , for example, at distinct radio frequencies f i ; the source of modulating signals 65 , e.g., a modulated current driver for laser diode.
The narrow-band optical spectral components (λ 1 , . . . , λ 4 ) independently modulated at distinguishable radio frequencies (f 1 , . . . , f 4 ) are delivered to the inputs of the optical coupler 61 which combines these components into a single optical path 51 , for example an optical fiber.
Referring to FIG. 7, an illustration of a fiber-optical illumination system delivering a multiple independently modulated and reconfigurable optical beams may include: an optical demultiplexer or beam splitter 71 ; modulating electrical signals 72 at distinct radio frequencies; optical modulators 73 , e.g., choppers, controlled by signal 72 . Optical beam 51 containing multiple spectral components coupled into a single optical path is delivered to the input of a beam splitter 71 which provides at its multiple outputs a number of optical beams. These beams may or may not be similar in intensity or polarization. Each beam is modulated independently by modulators 73 controlled by electrical signals 72 .
Referring to FIG. 8, an illustration of a fiber-optic illumination system with a multiple independent light sources is shown. Each of the narrow optical excitation beams 52 directed onto the capillary assembly comprise multiple modulated optical spectral components taken from the optical channel 51 which delivers the desired combination of modulated spectral components from the optical coupler 61 . As illustrate in FIG. 6, said optical coupler 61 gathers multiple spectral components from a set of modulated light sources 63 and couples them into a single optical channel 1 , for example an optical fiber.
Referring to FIG. 9, an illustration of capillary bundle illumination with the help of an optical line generator is shown which includes: an optical line generator 91 ; a divergent asymmetric beam of light 92 ; an asymmetric beam collimator 93 ; and a collimated laterally extended optical illumination beam 94 . Optical line generator is inserted in the beam path before the capillary assembly. The narrow optical excitation beam 52 is transformed by the optical line generator 91 into a divergent asymmetric beam 92 . The asymmetry of the beam means that the beam cross-section is highly asymmetric, e.g. elliptic rather than circular. In the plane where the divergent beam reaches collimator 93 , said beam is extended in one direction so as to illuminate the full section of the multi-capillary assembly. In the other direction the beam remains as narrow as possible, preferably close to the original width of beam 52 . The purpose of the collimator 93 is to transform the divergent beam 92 into a parallel (collimated) beam 94 .
Another preferred embodiment of an optical line generator is to provides means for scanning the beam 52 laterally over the full section of the multi-capillary assembly. In contrast to the conventional beam scanners which scan by changing the angular direction of a pencil beam, the scanned beam according to present invention is obtained by parallel transfer of a pencil beam, retaining the same angular orientation. Such scanning means are well known to those skilled in the art.
Referring to FIGS. 10 a-b , an illustration of exemplary spatial arrangements of the capillary bundle relative to the optical source and the photoreceiver are shown and include: a direction along an electrophoretic lane 101 indicating the average motion of labeled DNA fragments. FIG. 10 a shows an arrangement similar to FIG. 4 a except that the narrow optical excitation beam 52 is incident on the capillary assembly 41 at an oblique angle. The beam 52 and optical paths 49 represent a whole plane of beams 52 and paths 49 which in the drawing 10 a is perpendicular to the plane of the drawing. Similar representation is assumed in FIG. 10 b which shows the same elements as FIG. 10 a but arranged at still another relative orientation. In FIG. 10 b the plane of beams 52 and paths 49 is perpendicular to capillary axes (direction 101 ). The projection optics 4 is oriented so that the photoreceiving system 46 receives the image of a plane perpendicular to direction 101 .
Referring to FIG. 11, reception of the fluorescent signal by a two-dimensional photoreceiving matrix is shown and includes: one pixel of a two-dimensional photoreceiving matrix 111 . The electric output of each pixel represents a set of amplitudes A j (f j ) of received optical signal at radio frequencies of modulation.
Referring to FIG. 12, reception of the fluorescent signal by a linear photoreceiving array includes one pixel of the linear photoreceiving array 121 and a projection of a single fluorescent spot 122 from a single capillary element of one the N capillary columns (see FIG. 2 ).
Referring to FIG. 13, reception of fluorescent signals by a wide area photoreceiver includes a target 131 of wide area photoreceiver and a projection 132 of a single fluorescent spot from a single capillary element of the M×N capillary bundle (FIG. 2 ).
Commonly assigned provisional applications U.S. application Ser. No. 60/110,714 and 60/110,720 are incorporated herein by reference.
Having described preferred embodiments of a system and method of the invention (which are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments of the invention disclosed which are within the scope and spirit of the invention as outlined by the appended claims. Having thus described the invention with the details and particularity required by the patent laws, what is claimed and desired protected by Letters Patent is set forth in the appended claims. | A multichannel electrophoretic cassette structure is disclosed comprising distinct regions for loading and detection with different spacing between channels. A method and an apparatus are further disclosed enabling multicolor fluorescent detection from a non-coplanar bundle of multiple channels. A method for fabricating monolithic multichannel cassettes for electrophoresis and fluorescent detection is also described. | 6 |
[0001] This application is a national stage filing under 35 U.S.C. 371 of PCT/US2015/031766, filed May 20, 2015, which claims the benefit of United Kingdom Application No.1409095.5, filed May 22, 2014, the disclosure of which is incorporated by reference in its/their entirety herein.
[0002] The present invention relates to methods of making components for medicinal delivery devices, to components for medicinal delivery devices and to medicinal delivery devices. In particular, the present invention relates to methods of making components for medicinal inhalation devices, such components and such devices.
[0003] Medicinal delivery devices, including medicinal inhalation devices such as pressurized inhalers, e.g. metered dose pressurized inhalers (MDIs), and dry powder inhalers (DPIs), are widely used for delivering medicaments.
[0004] Medicinal delivery devices typically comprise a plurality of hardware components, (which in the case of a MDI can include gasket seals; metered dose valves (including their individual components, such as ferrules, valve bodies, valve stems, tanks, springs, retaining cups and seals); containers; and actuators) as well as a number of internal surfaces which may be in contact with the medicinal formulation during storage or come in contact with the medicinal formulation during delivery. In medicinal delivery devices, variability in dosing (i.e. from dose to dose) variability in dosing between units (i.e. device to device) is undesirable. Attention is paid to the design of medicinal delivery devices to reduce variability in particular by ensuring that dose volume, concentration and (if necessary) pressure are consistent dose to dose and unit to unit.
[0005] Often a desirable material for a particular component is found to be unsuitable in regard to its surface properties, e.g. surface energy, and/or its interaction with the medicinal formulation. Potentially undesirable interactions between a component and the medicinal formulation may include enhanced medicament degradation or permeation of a formulation constituent or extraction of chemicals from materials. For DPIs often permeation and adsorption of ambient water pose issues. Also the use of materials having relatively high surface energy for certain components (e.g. metered dose valves and/or individual components thereof), may have undesirable effects for the operation of movable components of a medicinal delivery device.
[0006] Various improvements have been proposed in for example, WO-A-2005/026236, WO-A-2005/061572, WO-A-2002/30848, U.S. Pat. No. -B-3,810,874, WO-A-2009/061891, WO-A-2009/061902, WO-A-2009/061907, WO-A-2010/129783 and WO-A-2010/129758.
[0007] Although a number of different improvements have been proposed, there is an ongoing need for medicinal delivery devices and components having desirable surface properties (e.g. low surface energy) as well as methods of providing such medicinal delivery devices and components.
[0008] The present invention accordingly provides, in a first aspect, a method of making a component for a medicinal delivery device, the method comprising
[0009] a) providing a component of a medicinal delivery device,
[0010] b) providing a primer composition comprising a silane having two or more reactive silane groups separated by an organic linker group,
[0011] c) providing a coating composition comprising an at least partially fluorinated compound,
[0012] d) applying the primer composition to at least a portion of the surface of the component,
[0013] e) applying the coating composition to the portion of the surface of the component after application of the primer composition.
[0014] Previously, it was thought that aspects relating to the design or structure of medicinal delivery devices and not surface properties of medicinal delivery devices were the most important contributors to dose to dose and unit to unit variability, for example in e.g. MDI, differences in dose to dose delivery volume or concentration and unit to unit tolerances in formulation, pressure, or volume.
[0015] However, surprisingly, the inventors have discovered that methods according to the present invention provide components which, when assembled and in use, significantly reduce dose to dose variability of medicinal delivery devices. Additionally, such methods provide components which, when assembled and in use, provide reduced unit to unit variability.
[0016] The at least partially fluorinated compound will usually comprise one or more reactive functional groups, with the or each one reactive functional group usually being a reactive silane group, for example a hydrolysable silane group or a hydroxysilane group. Such reactive silane groups allow reaction of the partially fluorinated compound with one or more of the reactive silane groups of the primer. Often such reaction will be a condensation reaction.
[0017] The reactive silane group may be of formula —Si(R 0 ) n X 3-n , wherein R 0 is a substantially non-hydrolysable group, X is a hydrolysable or hydroxy group and n is 0, 1 or 2.
[0018] Thus, in many embodiments the silane having two or more reactive silane groups is of formula
[0000] X 3-m (R 1 ) m Si-Q-Si(R 2 ) k X 3-k
[0000] wherein R 1 and R 2 are independently selected univalent groups such as C1-C4 alkyl, X is a hydrolysable or hydroxy group, m and k are independently 0, 1, or 2 and Q is a divalent organic linking group.
[0019] Usually, Q will comprise a 1 to 12 atom chain, more usually a substituted or unsubstituted C 2 to C 12 hydrocarbyl chain. Preferably, Q comprises a substituted or unsubstituted C 2 to C 12 alkyl chain.
[0020] Useful examples of silanes having two or more reactive silane groups include one or a mixture of two or more of 1,2-bis(trialkoxysilyl) ethane, 1,6-bis(trialkoxysilyl) hexane, 1,8-bis(trialkoxysilyl) octane, 1,4-bis(trialkoxysilylethyl)benzene, bis(trialkoxysilyl)itaconate, and 4,4′-bis(trialkoxysilyl)-1,1′-diphenyl, wherein any trialkoxy group may be independently trimethoxy or triethoxy.
[0021] Q may comprise a chain substituted by one or more atoms of N, O, and/or S. Thus, further examples of the silane having two or more reactive silane groups include one or a mixture of two or more of bis(trialkoxysilylpropyl)amine; bis (3-trialkoxysilylpropyl) ethylenediamine; bis (3-trialkoxysilylpropyl) n-methylamine; bis[3-(trialkoxysilyl)propyl]fumarate and N, N-bis (3-trialkoxysilylmethyl) allylamine, wherein any trialkoxy group may be independently trimethoxy or triethoxy.
[0022] In preferred embodiments, the silane is such that Q may be of formula —(CH 2 ) i -A-(CH 2 ) j —wherein A is NR n , O, or S; i and j are independently 0, 1, 2, 3 or 4 and wherein R n is H or C 1 to C 4 alkyl. Even more preferably, Q may be of formula —(CH 2 ) i —NH—(CH 2 ) j — and i and j are each independently 1, 2, 3 or 4. Most preferably i and j are each 3.
[0023] The coating solvent usually comprises an alcohol or a hydrofluoroether.
[0024] If the coating solvent is an alcohol, preferred alcohols are C 1 to C 4 alcohols, in particular, an alcohol selected from ethanol, n-propanol, or iso-propanol or a mixture of two or more of these alcohols.
[0025] If the coating solvent is an hydrofluoroether, it is preferred if the coating solvent comprises a C 4 to C 10 hydrofluoroether. Generally, the hydrofluoroether will be of formula
[0000] C g F 2g+1 OC h H 2h+1
[0000] wherein g is 2, 3, 4, 5, or 6 and h is 1, 2, 3 or 4. Examples of suitable hydrofluoroethers include those selected from the group consisting of methyl heptafluoropropylether, ethyl heptafluoropropylether, methyl nonafluorobutylether, ethyl nonafluorobutylether and mixtures thereof.
[0026] The at least partially fluorinated compound may contain a polyfluoroether moiety, in particular a polyfluoropolyether moiety. More particularly, the polyfluoroether moiety may be a perfluorinated polyfluoroether moiety, even more particularly the polyfluoroether moiety may be a perfluorinated polyfluoropolyether moiety.
[0027] The polyfluoropolyether silane may be of formula
[0000] R f Q 1 v [Q 2 w —[C(R 4 ) 2 —Si(X) 3-x (R 5 ) x ] y ] z
[0000] wherein:
[0028] R f is a polyfluoropolyether moiety;
[0029] Q 1 is a trivalent linking group;
[0030] each Q 2 is an independently selected organic divalent or trivalent linking group;
[0031] each R 4 is independently hydrogen or a C 1-4 alkyl group;
[0032] each X is independently a hydrolysable or hydroxyl group;
[0033] R 5 is a C 1-8 alkyl or phenyl group;
[0034] v and w are independently 0 or 1, x is 0 or 1 or 2; y is 1 or 2; and z is 2, 3, or 4.
[0035] The polyfluoropolyether moiety R f may comprise perfluorinated repeating units selected from the group consisting of —(C n F 2n O)—,—(CF(Z)O)—, —(CF(Z)C n F 2n O)—, —(C n F 2n CF(Z)O)—, —(CF 2 CF(Z)O)—, and combinations thereof; wherein n is an integer from 1 to 6 and Z is a perfluoroalkyl group, an oxygen-containing perfluoroalkyl group, a perfluoroalkoxy group, or an oxygen-substituted perfluoroalkoxy group, each of which can be linear, branched, or cyclic, and have 1 to 5 carbon atoms and up to 4 oxygen atoms when oxygen-containing or oxygen-substituted and wherein for repeating units including Z the number of carbon atoms in sequence is at most 6. In particular, n may be an integer from 1 to 4, more particularly from 1 to 3. For repeating units including Z the number of carbon atoms in sequence may be at most four, more particularly at most 3. Usually, n is 1 or 2 and Z is an —CF 3 group, more wherein z is 2, and R f is selected from the group consisting of —CF 2 O(CF 2 O) m (C 2 F 4 O) p CF 2 —, —CF(CF 3 )O(CF(CF 3 (CF 2 O) p CF(CF 3 )—, —CF 2 O(C 2 F 4 O) p CF 2 —, —(CF 2 ) 3 O(C 4 F 8 O) p (CF 2 ) 3 —, —CF(CF 3 )—(OCF 2 CF(CF 3 )) p O—C t F 2t —O(CF(CF 3 )CF 2 O) p CF(CF 3 )—, wherein t is 2, 3 or 4 and wherein m is 1 to 50, and p is 3 to 40.
[0036] The composition may further comprise a cross-linking agent. The cross-linking agent may comprise a compound selected from group consisting of tetramethoxysilane; tetraethoxysilane; tetrapropoxysilane; tetrabutoxysilane; methyl triethoxysilane; dimethyldiethoxysilane; octadecyltriethoxysilane; 3-glycidoxy-propyltrimethoxysilane; 3-glycidoxy-propyltriethoxysilane; 3-aminopropyl-trimethoxysilane; 3-aminopropyl-triethoxysilane; bis (3-trimethoxysilylpropyl) amine; 3-aminopropyl tri(methoxyethoxyethoxy) silane; N (2-aminoethyl)3-aminopropyltrimethoxysilane; bis (3-trimethoxysilylpropyl) ethylenediamine; 3-mercaptopropyltrimethoxysilane; 3-mercaptopropyltriethoxysilane; 3-trimethoxysilyl-propylmethacrylate; 3-triethoxysilypropylmethacrylate; bis (trimethoxysilyl) itaconate; allyltriethoxysilane; allyltrimethoxysilane; 3-(N-allylamino)propyltrimethoxysilane; vinyltrimethoxysilane; vinyltriethoxysilane; and mixtures thereof.
[0037] Usually, the method may include a pre-treatment step prior to the step of applying the primer composition, said pre-treatment step in particular may comprise cleaning the surface with a solvent comprising a hydrofluoroether, e.g. HFE72DE an azeotropic mixture of about 70%w/w trans-dichloroethylene; 30% w/w of a mixture of methyl and ethyl nonafluorobutyl and nonafluoroisobutyl ethers.
[0038] Thus, in a second aspect, the present invention provides, a method of making a component for a medicinal delivery device, the method comprising
[0039] a) providing a component of a medicinal delivery device,
[0040] b) providing a coating composition comprising an at least partially fluorinated compound,
[0041] d) cleaning at least a portion of the surface of the component using a solvent comprising hydrofluoroether of formula
[0000] C g F 2g+1 OC h H 2h+1 wherein g is 2, 3, 4, 5, or 6 and h is 1, 2, 3 or 4
[0043] e) applying the coating composition to the portion of the surface of the component after cleaning with the solvent.
[0044] The hydrofluoroether for the cleaning step in the first or second aspect may be selected from the group consisting of methyl heptafluoropropylether; ethyl heptafluoropropylether; methyl nonafluorobutylether; ethyl nonafluorobutylether and mixtures thereof.
[0045] In the method, the primer composition and/or the coating composition may be, independently of the application step used for the other, applied by spraying, dipping, rolling, brushing, spreading or flow coating, in particular by spraying or dipping.
[0046] In the method, after the step of applying either the primer composition or after the step of applying the coating composition, the method may further comprise a step of curing. The curing step may be carried out at an elevated temperature in the range from about 40° C. to about 300° C.
[0047] The primer may be cured by evaporating the solvent in a moist environment, as water is responsible for the curing, and may be aided by heat or elevated humidity. If heat is applied to the primer coating, it is preferable to allow the prime-coated component to cool to room temperature before applying the top coating.
[0048] Typically, a lower curing temperature is used than for coating polymers than for coating metals, to avoid deformation of the polymer. However, it has been found that it is not essential to ensure that the primer is cured before applying the top coating, as a final curing can be effectively done to both layers simultaneously, thereby simplifying the manufacturing process. Hence, the primer coat may be allowed to set on the surface such that it is not washed off by the subsequent top coating, by allowing (e.g. by leaving to stand) or causing (e.g. by blowing in a current of air) most of the primer solution solvent to be dispersed.
[0049] Coatings applied to valve components, such as plastic stems, metal stems or elastomeric seals, in which the at least partially fluorinated compound is a perfluoropolyether silane according to formula Ia in which R f comprises from 20 to 40 linked repeating units confer additional lubricity compared to those with fewer repeating units, and when these are assembled with other component to make up valves, the valves have lower actuation forces.
[0050] Formula Ia is:
[0000] R f [Q 1 -[C(R) 2 —Si(Y) 3-x (R 1a ) x ] y ] z Ia
[0051] wherein:
[0052] R f is a monovalent or multivalent polyfluoropolyether moiety;
[0053] Q 1 is an organic divalent or trivalent linking group;
[0054] each R is independently hydrogen or a C1-4 alkyl group;
[0055] each Y is independently a hydrolysable group;
[0056] R 1a is a C1-8 alkyl or phenyl group;
[0057] x is 0 or 1 or 2;
[0058] y is 1 or 2; and
[0059] z is 1, 2, 3, or 4.
[0060] In either the first or the second aspect, the surface may be a metal surface, in particular a surface of an aluminium alloy, an iron alloy, or a steel alloy.
[0061] In the first aspect, the surface may be a polymer surface. The polymer may be a thermoplastic or thermoset material.
[0062] The types of plastics that can thus be coated includes polyalkylenes, polyesters, polyoxymethylene, poly(acrylonitrile-butadiene-styrene) (ABS) or other copolymers comprising monomers of acrylonitrile, butadiene and styrene, such as methylmethacrylate-acrylonitrile-butadiene-styrene (MABS), polycarbonate and nylon, e.g. nylon 6,6 or nylon 6,12. Examples of polyalkylenes are polypropylene and polyethylenes such as low density polyethylene (LDPE), ultra-high molecular weight polyethylene (UHMPE). Polyesters include polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) and copolyester.
[0063] Thermosets that may be usefully coated include nitrile elastomer, neoprene elastomer, EPDM and co-vulcanisates of elastomeric polymers with thermoplastic polymers.
[0064] Medicinal delivery devices may include inhalers, or other dispensers in which accurate dosing depends on not leaving medicament behind on the device. Examples include a pressurized metered dose inhaler (pMDI), a nebulizer and a dry powder inhaler (DPI). When the device is a pMDI, examples of components include an actuator, an aerosol container, a ferrule, a valve body, a valve stem and a compression spring. For DPIs, examples of components include a powder container, a component used to open sealed powder container, a component that defines at least in part a deagglomeration chamber, a component of a deagglomeration system, a component that defines at least in part a flow channel, a dose-transporting component, a component that defines at least in part a mixing chamber, a component that defines at least in part an actuation chamber, a mouthpiece and a nosepiece.
[0065] Components to be coated may be made from one of the above materials, or from assemblies or co mouldings of more than one material including at least one of the above material types. Alternatively, plastics coatings on components may provide a surface amenable to further coating.
[0066] It has been found that the deposition of drug on plastics or thermoset components can be reduced when the component is coated by applying a primer coat of a silane having two or more reactive silane groups separated by an organic linker, followed by a top coating of an at least partially fluorinated compound.
[0067] The primer preferably comprises a linking group with a chain of one to twelve atoms. This may have at least one carbon atom either side of a heteroatom, such as nitrogen, oxygen or sulphur. Particularly useful primers include at least one amine group in the linking group.
[0068] It has surprisingly been found that deposition of drug on medicinal delivery device component surfaces is eliminated when the organic linker comprises one or more amine groups and the at least partially fluorinated compound is a perfluoropolyether silane according to formula Ia in which y=z=1.
[0069] In either the first or the second aspect, the surface of the device or the surface of the component of the device, as applicable, is preferably a surface that is or is intended to come in contact with a medicament or a medicinal formulation during storage or delivery from the medicinal delivery device.
[0070] The medicament may comprise or the medicinal formulation may comprise a medicament that may be a drug, vaccine, DNA fragment, hormone or other treatment. Suitable drugs include those for the treatment of respiratory disorders, e.g., bronchodilators, anti-inflammatories (e.g., corticosteroids), anti-allergics, anti-asthmatics, anti-histamines, and anti-cholinergic agents. Therapeutic proteins and peptides may also be employed for delivery by inhalation. Thus the medicament may be selected from the an exemplary group consisting of albuterol, terbutaline, ipratropium, oxitropium, tiotropium, TD-4208, beclomethasone, flunisolide, budesonide, mometasone, ciclesonide, cromolyn sodium, nedocromil sodium, ketotifen, azelastine, ergotamine, cyclosporine, aclidinium, umeclidinium, glycopyrrolate, salmeterol, fluticasone, formoterol, procaterol, indacaterol, TA2005, milveterol, olodaterol, vilanterol, abediterol, omalizumab, zileuton, insulin, pentamidine, calcitonin, leuprolide, alpha-1-antitrypsin, interferon, triamcinolone, salbutamol, pharmaceutically acceptable salts and esters of any of the listed medicaments and mixtures of any of the listed medicaments, their pharmaceutically acceptable salts and esters. For fluticasone, the preferred esters are propionate or furoate; for mometasone, the preferred ester is furoate.
[0071] In either the first or the second aspect, the medicinal delivery device is preferably a metered dose inhaler or a dry powder inhaler. Thus, preferably, the component (preferably comprising metal) is a component of a metered dose inhaler and the component is selected from the group consisting of an actuator, an aerosol container, a ferrule, a valve body (that defines a metering chamber), a bottle emptier, a valve stem and a compression spring.
[0072] An aerosol formulation used in a metered dose inhaler typically comprises a medicament or a combination of medicaments (as discussed above) and liquefied propellant selected from the group consisting of HFA 134a, HFA 227 and mixtures thereof.
[0073] Aerosol formulations may, as desired or needed, comprise other excipients, such as surfactant, a co-solvent (e.g., ethanol), CO 2 , or a particulate bulking agent. Medicament may be provided in particulate form (e.g. particles generally having a median diameter in the range of 1 to 10 microns) suspended (i.e. dispersed) in the liquefied propellant. Alternatively medicament may be in solution (i.e. dissolved) in the formulation. In the event a combination of two or more medicaments is used, all the medicaments may be suspended or in solution or alternatively one or more medicaments may be suspended, while one or more medicaments may be in solution.
[0074] The amount of medicament may be determined by the required dose per puff and available valve sizes, which for MDIs are typically 25, 50 or 63 microlitres, or 100 microlitres.
[0075] Pressurized metered dose inhalers including e.g., aerosol containers (in particular metal aerosol containers) whose interior surfaces are coated in accordance the invention are particularly advantageous for containing and delivering medicinal aerosol formulations comprising a medicament that is dispersed in said formulation.
[0076] In addition embodiments in accordance with the present invention are particularly useful in regard to metered dose inhalers including a medicinal aerosol formulation that includes low amounts of surfactant (0.005 wt % with respect to the formulation); or is substantially free (less than 0.0001 wt % with respect to drug) or free of a surfactant. Alternatively or additionally, embodiments, are particularly useful in metered dose inhalers including a medicinal aerosol formulation that contains low amounts of ethanol (less than 5 wt % with respect to the formulation), or is substantially free (less than 0.1 wt % with respect to the formulation) or free of ethanol.
[0077] In a third aspect, the present invention provides a coated component for a medicinal delivery device comprising a component and a fluorine-containing coating, wherein the fluorine-containing coating comprises two layers, a first polyfluoropolyether-containing layer comprising polyfluoropolyether silane entities of the following Formula Ib:
[0000] R f [Q 1 -[C(R) 2 —Si(O—) 3-x (R 1a ) x ] y ] z Ib
[0000] which shares at least one covalent bond with a second non-fluorinated layer comprising entities of the following Formula IIb:
[0000] (—O) 3-m-n (X) n (R 1 ) m Si-Q-Si(R 2 ) k (X) 1 (O—) 3-k-l IIb
[0000] which in turn shares at least one covalent bond with the component; and wherein:
[0078] R f is a monovalent or multivalent polyfluoropolyether segment;
[0079] Q 1 is an organic divalent or trivalent linking group;
[0080] each R is independently hydrogen or a C1-4 alkyl group;
[0081] R 1a is a C1-8 alkyl or phenyl group;
[0082] k, 1, m and n are independently 0, 1 or 2, but with the priviso that m+n and k+1 are at most 2;
[0083] x is 0 or 1 or 2; y is 1 or 2; and z is 1, 2, 3, or 4; wherein R 1 and R 2 are independently selected univalent groups, X is a hydrolysable or hydroxy group, m and k are independently 0, 1, or 2 and Q is a divalent organic linking group, comprising a substituted C 2 to C 12 hydrocarbyl chain and one or more amine groups. Coated components with more specific surface structural features may be determined by the skilled person in respect of more specific process steps described earlier by taking into account the covalent bonding chemistry of this third aspect of the invention.
[0084] The invention, in its various combinations, either in method or apparatus form, may also be characterized by the following listing of items:
Items
[0000]
1. A method of making a component for a medicinal delivery device, the method comprising
[0086] a) providing a component of a medicinal delivery device,
[0087] b) providing a primer composition comprising a silane having two or more reactive silane groups separated by an organic linker group,
[0088] c) providing a coating composition comprising an at least partially fluorinated compound,
[0089] d) applying the primer composition to at least a portion of the surface of the component,
[0090] e) applying the coating composition to the portion of the surface of the component after application of the primer composition.
2. A method as referred to in item 1, wherein the at least partially fluorinated compound comprises one or more reactive silane groups. 3. A method as referred to in either item for item 2, wherein at least one of the reactive silane groups is a hydrolysable silane group or a hydroxysilane group. 4. A method as referred to in item 3, wherein the or each reactive silane group is of formula —Si(R 0 ) n X 3-n , wherein R 0 is a substantially non-hydrolysable group, X is a hydrolysable or hydroxy group and n is 0, 1 or 2. 5. A method as referred to in any one of the preceding items, wherein the silane having two or more reactive silane groups is of formula
[0000] X 3-m (R 1 ) m Si-Q-Si(R 2 ) k X 3-k
[0000] wherein R 1 and R 2 are independently selected univalent groups, X is a hydrolysable or hydroxy group, m and k are independently 0, 1, or 2 and Q is a divalent organic linking group.
6. A method as referred to in item 5, wherein Q comprises a 1 to 12 atom chain. 7. A method as referred to in item 6, wherein Q comprises a substituted or unsubstituted C2 to Ci2 hydrocarbyl chain. 8. A method as referred to in item 7, wherein the silane having two or more reactive silane groups is selected from 1,2-bis(trialkoxysilyl) ethane, 1,6-bis(trialkoxysilyl) hexane, 1,8-bis(trialkoxysilyl) octane, 1,4-bis(trialkoxysilylethyl)benzene, bis(trialkoxysilyl)itaconate, and 4,4′-bis(trialkoxysilyl)-1,1′-diphenyl, and combinations thereof, wherein any trialkoxy group may be trimethoxy or triethoxy. 9. A method as referred to in item 7, wherein Q comprises a substituted or unsubstituted C 2 to C 12 alkyl chain. 10. A method as referred to in either item 7 or item 8, wherein the chain is substituted by one or more atoms of N, O, and/or S. 11. A method as referred to in item 9, wherein the silane having two or more reactive silane groups is selected from bis(trialkoxysilylpropyl)amine; bis (3-trialkoxysilylpropyl) ethylenediamine; bis (3-trialkoxysilylpropyl) n-methylamine; bis[3-(trialkoxysilyl)propyl]fumarate and N, N-bis (3-trialkoxysilylmethyl) allylamine, and combinations thereof, wherein any trialkoxy group may be trimethoxy or triethoxy. 12. A method as referred to in item 10, wherein Q is of formula —(CH 2 ) i -A-(CH 2 ) j — wherein A is NR n , O, or S; i and j are independently 0, 1, 2, 3 or 4 and wherein R n is H or C 1 to C 4 alkyl. 13. A method as referred to in item 12, wherein Q is of formula —(CH 2 ) i NH (CH 2 ) j — and i and j are each independently 1, 2, 3 or 4. 14. A method as referred to in any one of items 4 to 13, wherein each X is OR 3 , each R 3 being independently hydrogen, phenyl or C 1 to C 4 alkyl. 15. A method as referred to in item 14, wherein each R 3 is independently methyl, ethyl or propyl. 16. A method as referred to in any one of the preceding items, wherein the coating composition further comprises a coating solvent. 17. A method as referred to in item 16, wherein the coating solvent comprises an alcohol or a hydrofluoroether. 18. A method as referred to in item 17, wherein the alcohol is a C 1 to C 4 alcohol, in particular, an alcohol selected from ethanol, n-propanol, or iso-propanol. 19. A method as referred to in either item 16 or item 17, wherein the hydrofluoroether is a C 4 to C 10 hydrofluoroether. 20. A method as referred to in item 19, wherein the hydrofluoroether is of formula
[0000] C g F 2g+1 OC h H 2h+1
[0000] wherein g is 2, 3, 4, 5, or 6 and h is 1, 2, 3 or 4.
21. A method as referred to in item 20, wherein the hydrofluoroether is selected from the group consisting of methyl heptafluoropropylether, methyl nonafluorobutylether, ethyl nonafluorobutylether and mixtures thereof. 22. A method as referred to in item 20, wherein the hydrofluoroether comprises ethyl nonafluorobutyl ether. 23. A method as referred to in any one of the preceding items wherein the at least partially fluorinated compound contains a polyfluoroether moiety, in particular a polyfluoropolyether moiety. 24. A method as referred to in item 23, wherein the polyfluoroether moiety is a perfluorinated polyfluoroether moiety, in particular a perfluorinated polyfluoropolyether moiety. 25. A method as referred to in either item 23 or item 24, wherein the polyfluoropolyether moiety is not linked to the functional silane groups via a functionality that includes nitrogen-silicon bond or a sulfur-silicon bond. 26. A method as referred to in any one of items 23 to 25, wherein the polyfluoropolyether moiety is linked to the functional silane groups via a functionality that includes a carbon-silicon bond. 27. A method as referred to in any one of items 23 to 26, wherein in the repeating units of the polyfluoropolyether moiety, the number of carbon atoms in sequence is at most 6. 28. A method as referred to in item 27, wherein in the repeating units of the polyfluoropolyether moiety the number of carbon atoms in sequence is 4 or fewer, more particularly 3 or fewer. 29. A method as referred to in any one of items 23 to 28, wherein the polyfluoropolyether silane is of formula
[0000] R f Q 1 v [Q 2 w -[C(R 4 ) 2 —Si(X) 3-x (R 5 ) x ] y ] x
[0000] wherein:
[0119] R f is a polyfluoropolyether moiety;
[0120] Q 1 is a trivalent linking group;
[0121] each Q 2 is an independently selected organic divalent or trivalent linking group;
[0122] each R 4 is independently hydrogen or a C 1-4 alkyl group;
[0123] each X is independently a hydrolysable or hydroxyl group;
[0124] 5 R is a C 1-8 alkyl or phenyl group;
[0125] v and w are independently 0 or 1, x is 0 or 1 or 2; y is 1 or 2; and z is 2, 3, or 4.
30. A method as referred to in item 29, wherein the polyfluoropolyether moiety R f comprises perfluorinated repeating units selected from the group consisting of —(C n F 2n O)—, —(CF(Z)O)—, —(CF(Z)C n F 2n O)—, —(C n F 2n CF(Z)O)—, —(CF 2 CF(Z)O)—, and combinations thereof; wherein n is an integer from 1 to 6 and Z is a perfluoroalkyl group, an oxygen-containing perfluoroalkyl group, a perfluoroalkoxy group, or an oxygen-substituted perfluoroalkoxy group, each of which can be linear, branched, or cyclic, and have 1 to 5 carbon atoms and up to 4 oxygen atoms when oxygen-containing or oxygen-substituted and wherein for repeating units including Z the number of carbon atoms in sequence is at most 6. 31. A method as referred to in item 30, wherein n is an integer from 1 to 4 and wherein for repeating units including Z the number of carbon atoms in sequence is at most four. 32. A method as referred to in either item 30 or item 31, wherein n is an integer from 1 to 3 and wherein for repeating units including Z the number of carbon atoms in sequence is at most three. 33. A method as referred to in any one of items 30 to 32, wherein n is 1 or 2 and Z is an —CF 3 group. 34. A method as referred to in any one of items 29 to 33, wherein z is 2, and R f is selected from the group consisting of —CF 2 O(CF 2 O) m (C 2 F 4 O) p CF 2 —, −CF(CF 3 )O(CF(CF 3 )CF 2 O) p CF(CF 3 )—, —CF 2 O(C 2 F 4 O) p CF 2 —, —(CF 2 ) 3 O(C 4 F 8 O) p (CF 2 ) 3 —, —CF(CF 3 )—(OCF 2 CF(CF 3 )) p O—C t F 2t —O(CF(CF 3 )CF 2 O) p CF(CF 3 )—, wherein t is 2, 3 or 4 and wherein m is 1 to 50, and p is 3 to 40. 35. A method as referred to in item 34, wherein R f is selected from the group consisting of —CF 2 O(CF 2 O) m (C 2 F 4 O) p CF 2 —, —CF 2 O(C 2 F 4 O) p CF 2 —, and —CF(CF 3 )—(OCF 2 CF(CF 3 )) p O—(C t F 2t )—O(CF(CF 3 )CF 2 O) p CF(CF 3 )—, and wherein t is 2, 3, or 4, and wherein the average value of m+p or p+p or p is from about 4 to about 24. 36. A method as referred to in any one of items 29 to 35, wherein Q 1 and Q 2 are independently selected from the group consisting of —C(O)N(R 3 )—(CH 2 ) a —, —S(O) 2 N(R 3 )—(CH 2 ) a , —(CH 2 ) a —, —CH 2 O—(CH 2 ) a —, —C(O)S—(CH 2 ) a —, —CH 2 OC(O)N(R 3 )—(CH 2 ) a —, and wherein R 3 is hydrogen or C 14 alkyl, and a is 1 to about 25. 37. A method as referred to in any one of items 23 to 36, wherein the weight average molecular weight of the polyfluoropolyether moiety is about 1000 or higher, in particular about 1800 or higher. 38. A method as referred to in any one of the preceding items, wherein the composition further comprises a cross-linking agent. 39. A method as referred to in item 38, wherein the cross-linking agent comprises a compound selected from the group consisting of tetramethoxysilane; tetraethoxysilane; tetrapropoxysilane; tetrabutoxysilane; methyl triethoxysilane; dimethyldiethoxysilane; octadecyltriethoxysilane; 3-glycidoxy-propyltrimethoxysilane; 3-glycidoxy-propyltriethoxysilane; 3-aminopropyl-trimethoxyilane; 3 -aminopropyl-triethoxysilane; bis (3-trimethoxysilylpropyl) amine; 3-aminopropyl tri(methoxyethoxyethoxy) silane; N (2-aminoethyl)3-aminopropyltrimethoxysilane; bis (3-trimethoxysilylpropyl) ethylenediamine; 3-mercaptopropyltrimethoxysilane; 3-mercaptopropyltriethoxy silane ; 3-trimethoxysilyl-propylmethacryl ate; 3-triethoxysilypropylmethacrylate; bis (trimethoxysilyl) itaconate; allyltriethoxysilane; allyltrimethoxysilane; 3-(N-allylamino)propyltrimethoxysilane; vinyltrimethoxysilane; vinyltriethoxysilane; and mixtures thereof. 40. A method as referred to in any one of the preceding items, wherein the method includes a pre-treatment step prior to the step of applying the primer composition, said pre-treatment step comprising cleaning the surface with a solvent comprising a hydrofluoroether. 41. A method of making a component for a medicinal delivery device, the method comprising
[0138] a) providing a component of a medicinal delivery device,
[0139] b) providing a coating composition comprising an at least partially fluorinated compound,
[0140] d) cleaning at least a portion of the surface of the component using a solvent comprising a hydrofluoroether of formula
[0000] C g F 2g+1 OC h H 2h+1 wherein g is 2, 3, 4, 5, or 6 and h is 1, 2, 3 or 4
[0142] e) applying the coating composition to the portion of the surface of the component after cleaning with the solvent.
42. A method as referred to in either item 40 or item 41, wherein the hydrofluoroether is selected from the group consisting of methyl heptafluoropropylether; ethyl heptafluoropropylether ; methyl nonafluorobutylether; ethyl nonafluorobutylether and mixtures thereof. 43. A method as referred to in any one of the preceding items, wherein said surface is a metal surface, in particular a surface of an aluminium alloy, an iron alloy, or a steel alloy. 44. A method as referred to in any one of the preceding items, wherein independently the primer composition and/or the coating composition are applied by spraying, dipping, rolling, brushing, spreading or flow coating, in particular by spraying or dipping. 45. A method as referred to in any one of the preceding items, wherein after applying the composition, the method further comprises a step of curing. 46. A method as referred to in item 45, wherein the curing is carried out at an elevated temperature in the range from about 40° C. to about 300° C. 47. A method as referred to in any one of the preceding items, where said surface of the device or said surface of the component of the device, as applicable, is a surface that is or will come in contact with a medicament or a medicinal formulation during storage or delivery from the medicinal delivery device. 48. A method as referred to in item 47, wherein the medicament comprises or the medicinal formulation comprises a medicament selected from the group consisting of albuterol, terbutaline, ipratropium, oxitropium, tiotropium, beclomethasone, flunisolide, budesonide, mometasone, ciclesonide, cromolyn sodium, nedocromil sodium, ketotifen, azelastine, ergotamine, cyclosporine, salmeterol, fluticasone, formoterol, procaterol, indacaterol, TA2005, omalizumab, zileuton, insulin, pentamidine, calcitonin, leuprolide, alpha-1-antitrypsin, interferon, triamcinolone, salbutamol and pharmaceutically acceptable salts and esters thereof and mixtures thereof. 49. A method as referred to in any one of the preceding items, where said medicinal delivery device is a metered dose inhaler or a dry powder inhaler. 50. A method as referred to in any one of the preceding items, wherein the component is a component of a metered dose inhaler and the component is selected from the group consisting of an actuator, an aerosol container, a ferrule, a valve body, a valve stem and a compression spring. 51. A medicinal delivery device assembled from at least one component made as referred to in any one of the preceding items. 52. A method as referred in any one of items 30 to 50, wherein the number of linked perfluorinated repeating units is in the range 20 to 40. 53. A method as referred to in any one of items 1 to 39, 44 to 50 and 52, wherein said portion of surface is a polymer surface. 54. A method as referred to in item 53 wherein the component is at least partly made of said polymer. 55. A method as referred to in any one of items 53 and 54, wherein the silane having two or more reactive silane groups is of formula
[0000] X 3m (R 1 ) m Si-Q-Si(R 2 ) k X 3-k
[0000] wherein R 1 and R 2 are independently selected univalent groups, X is a hydrolysable or hydroxy group, m and k are independently 0, 1, or 2 and Q is a divalent organic linking group, comprising a substituted C 2 to C 12 hydrocarbyl chain and one or more amine groups.
56. A method as referred to in any one of items 53 to 55, wherein the at least partially fluorinated compound is polyfluoropolyether silane of the Formula Ia:
[0000] R f [Q 1 -[C(R) 2 —Si(Y) 3-x (R 1a ) x ] y ] x Ia
[0158] wherein:
[0159] R f is a monovalent or multivalent polyfluoropolyether moiety;
[0160] Q 1 is an organic divalent or trivalent linking group;
[0161] each R is independently hydrogen or a C1-4 alkyl group;
[0162] each Y is independently a hydrolysable group;
[0163] R 1a is a C1-8 alkyl or phenyl group;
[0164] x is 0 or 1 or 2;
[0165] y is 1 or 2; and
[0166] z is 1, 2, 3, or 4.
57. A method as referred to in item 56, wherein the polyfluoropolyether moiety R f comprises perfluorinated repeating units selected from the group consisting of —(C n F 2n O)—, —(CF(Z)O)—, —(CF(Z)C n F 2n O)—, —(C n F 2n CF(Z)O)—, −(CF 2 CF(Z)O)—, and combinations thereof; wherein n is an integer from 1 to 6 and Z is a perfluoroalkyl group, an oxygen-containing perfluoroalkyl group, a perfluoroalkoxy group, or an oxygen-substituted perfluoroalkoxy group, each of which can be linear, branched, or cyclic, and have 1 to 5 carbon atoms and up to 4 oxygen atoms when oxygen-containing or oxygen-substituted and wherein for repeating units including Z the number of carbon atoms in sequence is at most 6. 58. A method as referred to in item 57, wherein the number of linked perfluorinated repeating units is in the range 3 to 50. 59. A method as referred to in item 58, wherein the number of linked perfluorinated repeating units is in the range 20 to 40. 60. A method as referred to in any one of items 56 to 59, wherein the polyfluoropolyether moiety R f is terminated with a group selected from the group consisting of C n F 2n+1 —, C n F 2n+1 O—, HC n F 2n O—. 61. A method as referred to in item 60, wherein n=1,2,3,4,5 or 6. 62. A method as referred to in item 61, wherein the average structure of the polyfluoropolyether moiety R f is selected from: C 3 F 7 O(CF(CF 3 )CF 2 O) p CF(CF 3 )—, CF 3 O(C 2 F 4 O) p CF 2 —, C 3 F 7 O(CF(CF 3 )CF 2 O) p CF 2 CF 2 —, C 3 F 7 O(CF 2 CF 2 CF 2 O) p CF 2 CF 2 —, or C 3 F 7 O(CF 2 CF 2 CF 2 O) p CF(CF 3 )—, or CF 3 O(CF 2 CF(CF 3 )O) p (CF 2 O)G-(wherein G is CF 2 , C 2 F 4 —, C 3 F 6 — C 4 F 8 —), and wherein the average value of p is in the range 3 to 50. 63. A method as referred to in item 62, wherein the polyfluoropolyether moiety R f is C 3 F 7 O(CF(CF 3 (CF 3 )CF 2 O) p CF(CF 3 )— 64. A method as referred to in any one of items 56to 63, wherein z=1. 65. A method as referred to in any one of items 56 to 64, wherein y=1. 66. A method as referred to in any one of items 56 to 65, wherein Q 1 contains one or more heteroatoms selected from the group consisting of sulfur, oxygen, and nitrogen. 67. A method as referred to in item 66 wherein Q 1 contains one or more functional groups selected from the group consisting of esters, amides, sulfonamides, carbonyl, carbonates, ureylenes, and carbamates. 68. A method as referred to in item 67 wherein Q 1 comprises from 2 to 25 linearly arranged carbon atoms, optionally interrupted by one or more heteroatoms. 69. A method as referred to in item 68 wherein Q 1 is substantially stable against hydrolysis and other chemical transformations, such as nucleophilic attack. 70. A method as referred to in item 69 wherein Q 1 includes one or more organic linking groups selected from: —C(O)N(R)—(CH2) k —, —S(O) 2 N(R)—(CH2) k —, —(CH2) k —, —CH 2 O—(CH 2 ) k —, —C(O)S—(CH 2 ) k —, —CH 2 OC(O)N(R)—(CH 2 ) k —, —CH 2 OCH2CH(OC (O)NH(CH 2 ) 3 —)CH 2 OC(O)NH(CH 2 ) 3 —, —C(O)NHCH 2 CH[OC(O)NH—]CH 2 OC(O)NH—, wherein R is hydrogen or C1-4 alkyl, and k is 2 to about 25, preferably k is 2 to about 15, more preferably k is 2 to about 10. 71. A method as referred to in any one of items 53 to 70, wherein the polymer is a thermoplastic. 72. A method as referred to in item 71, wherein the thermoplastic material is selected from the group consisting of polyolefines, polyesters, polyoxymethylene, nylons, and copolymers comprising acrylonitrile, butadiene and styrene. 73. A method as referred to in item 7. wherein the polyolefine is polyethylene or polypropylene. 74. A method as referred to in any one of items 53 to 70 wherein the polymer is a thermoset material. 75. A coated component for a medicinal delivery device comprising a component and a fluorine-containing coating, wherein the fluorine-containing coating comprises two layers, a first polyfluoropolyether-containing layer comprising polyfluoropolyether silane entities of the following Formula Ib:
[0000] R f [Q 1 -[C(R) 2 —Si(O—) 3-x (R 1a ) x ] y ] z Ib
[0000] which shares at least one covalent bond with a second non-fluorinated layer comprising entities of the following Formula IIb:
[0000] (—O) 3-m-n X n (R 1 ) m Si-Q-Si(R 2 ) k (X) t (O—) 3-k-l IIb
[0000] which in turn shares at least one covalent bond with the component; and wherein:
[0186] R f is a monovalent or multivalent polyfluoropolyether segment;
[0187] Q 1 is an organic divalent or trivalent linking group;
[0188] each R is independently hydrogen or a C1-4 alkyl group;
[0189] R 1a is a C1-8 alkyl or phenyl group;
[0190] k, 1, m and n are independently 0, 1 or 2, but with the priviso that m+n and k+l are at most 2;
[0191] x is 0 or 1 or 2;
[0192] y is 1 or 2; and
[0193] z is 1, 2, 3, or 4;
[0000] R 1 and R 2 are independently selected univalent groups, X is a hydrolysable or hydroxy group, m and k are independently 0, 1, or 2 and Q is a divalent organic linking group, comprising a substituted C 2 to C 12 hydrocarbyl chain and one or more amine groups.
76. A coated component for a medicinal delivery device as referred to in item 75, wherein the polyfluoropolyether moiety R f comprises perfluorinated repeating units selected from the group consisting of —(C n F 2n O)—, —(CF(Z(O)—, —(CF(Z)C n F 2n O)—, —(C n F 2n CF(Z)O)—, —(CF 2 CF(Z)O)—, and combinations thereof; wherein n is an integer from 1 to 6 and Z is a perfluoroalkyl group, an oxygen-containing perfluoroalkyl group, a perfluoroalkoxy group, or an oxygen-substituted perfluoroalkoxy group, each of which can be linear, branched, or cyclic, and have 1 to 5 carbon atoms and up to 4 oxygen atoms when oxygen-containing or oxygen-substituted and wherein for repeating units including Z the number of carbon atoms in sequence is at most 6. 77. A coated component for a medicinal delivery device as referred to in item 76, wherein the polyfluoropolyether moiety R f is C 3 F 7 O(CF(CF 3 )CF 2 O) p CF(CF 3 )—, wherein the average value of p is in the range 3 to 50. 78. A coated component for a medicinal delivery device as referred to in any one of items 75 to 77, wherein z=1. 79. A coated component for a medicinal delivery device as referred to in any one of items 75 to 78, wherein y=1. 80. A coated component for a medicinal delivery device as referred to in item 79, wherein the entity of Formula IIb shares a covalent bond with a polymer surface of the component. 81. A coated component for a medicinal delivery device as referred to in any one of items 79 or 80, wherein Q 1 includes one or more organic linking groups selected from —C(O)N(R)—(CH2) k —, —S(O) 2 N(R)—(CH2) k —, —(CH2) k —, —CH 2 O—(CH 2 ) k —, —C(O)S—(CH 2 ) k —, —CH 2 OC(O)N(R)—(CH 2 ) k —, wherein R is hydrogen or C1-4 alkyl, and k is 2 to about 25, preferably k is 2 to about 15, more preferably k is 2 to about 10. 82. A coated component for a medicinal delivery device as referred to in any one of items 75 to 78, wherein y=2. 83. A coated component for a medicinal delivery device as referred to in item 82, wherein the entity of Formula IIb shares a covalent bond with a metal surface of the component, in particular a surface of an aluminium alloy, an iron alloy, or a steel alloy. 84. A coated component for a medicinal delivery device as referred to in any one of items 82 or 83, wherein Q 1 includes as organic linking groups: —CH 2 OCH 2 CH(OC(O)NH(CH 2 ) 3 —)CH 2 OC(O)NH(CH 2 )3—or —C(O)NHCH 2 CH[OC(O)NH—]CH 2 OC(O)NH—. 85. A coated component for a medicinal delivery device as referred in any one of items 75 to 84 wherein the component is a component of a metered dose inhaler. 86. A coated component as referred to in item 85, wherein the component is selected from the group consisting of an actuator, an aerosol container, a ferrule, a valve body, a valve stem and a compression spring. 87. A medicinal delivery device assembled from at least one coated component as referred to in any one of items 75 to 86.
[0206] Throughout this specification, the word “inhaler” means a device for delivery of a medicament in fluid (or powder) and does not imply that the device requires inhalation on the part of the patient during delivery. It is known that a medicament may be delivered successfully to the nasal passages by an inhaler without the need for the patient to inhale.
[0207] So that the present specification may be more completely understood, reference is made to the accompanying drawings in which:
[0208] FIG. 1 a represents a schematic cross-sectional view of a pressurized metered dose inhaler known in the art and
[0209] FIG. 1 b represents an enlarged view of a portion of the inhaler.
[0210] FIGS. 2 a and 2 b show the results of Example 3.
[0211] FIG. 3 represents a schematic cross-sectional view of a metered dose valve.
DETAILED DESCRIPTION
[0212] FIG. 1 a shows a metered dose inhaler 100 , including an aerosol container 1 fitted with a metered dose valve 10 (shown in its resting position). The valve is typically affixed, i.e., crimped, onto the container via a cap or ferrule 11 (typically made of aluminium or an aluminium alloy) which is generally provided as part of the valve assembly. Between the container and the ferrule there may be one or more seals. In the embodiments shown in FIGS. 1 a and 1 b between the container 1 and the ferrule 11 there are two seals including e.g., an O-ring seal and the gasket seal.
[0213] As shown in FIG. 1 a, the container/valve dispenser is typically provided with an actuator 5 including an appropriate patient port 6 , such as a mouthpiece. For administration to the nasal cavities the patient port is generally provided in an appropriate form (e.g., smaller diameter tube, often sloping upwardly) for delivery through the nose. Actuators are generally made of a plastics material, for example polypropylene or polyethylene. As can be seen from FIG. 1 a, the inner walls 2 of the container and the outer walls 101 of the portion(s) of the metered dose valve located within the container define a formulation chamber 3 in which aerosol formulation 4 is contained.
[0214] The valve shown in FIG. 1 a, and FIG. 1 b, includes a metering chamber 12 , defined in part by an inner valve body 13 , through which a valve stem 14 passes. The valve stem 14 , which is biased outwardly by a compression spring 15 , is in sliding sealing engagement with an inner tank seal 16 and an outer diaphragm seal 17 . The valve also includes a second valve body 20 in the form of a bottle emptier. The inner valve body (also referred to as the “primary” valve body) defines in part the metering chamber. The second valve body (also referred to as the “secondary” valve body) defines in part a pre-metering region or chamber besides serving as a bottle emptier.
[0215] Referring to FIG. 1 b, aerosol formulation 4 can pass from the formulation chamber into a pre-metering chamber 22 provided between the secondary valve body 20 and the primary valve body 13 through an annular space 21 between the flange 23 of the secondary valve body 20 and the primary valve body 13 . To actuate (fire) the valve, the valve stem 14 is pushed inwardly relative to the container from its resting position shown in FIGS. 1 a and b, allowing formulation to pass from the metering chamber through a side hole 19 in the valve stem and through a stem outlet 24 to an actuator nozzle 7 then out to the patient. When the valve stem 14 is released, formulation enters into the valve, in particular into the pre-metering chamber 22 , through the annular space 21 and thence from the pre-metering chamber through a groove 18 in the valve stem past the tank seal 16 into the metering chamber 12 .
[0216] FIG. 3 shows a metered dose aerosol valve different to the one shown in FIGS. 1 a, 1 b in its rest position. The valve has a metering chamber 112 defined in part by a metering tank 113 through which a stem 114 is biased outwardly by spring 115 . The stem 114 is made in two parts that are push fit together before being assembled into the valve. The stem 114 has an inner seal 116 and an outer seal 117 disposed about it and forming sealing contact with the metering tank 113 . A valve body 120 crimped into a ferrule 111 retains the aforementioned components in the valve. In use, formulation enters the metering chamber via orifices 121 , 118 . It's outward path from the metering chamber 112 when a dose is dispensed is via orifice 119 .
[0217] Depending on the particular metered dose valve and/or filling system, aerosol formulation may be filled into the container either by cold-filling (in which chilled formulation (chilled to temperatures of about −50 to -55° C. for propellant HFA 134a-based formulations) is filled into the container and subsequently the metered dose valve is crimped onto the container) or by pressure filling (in which the metered dose valve is crimped onto the container and then formulation is pressure filled through the valve into the container).
[0218] The present invention is further illustrated by the following Examples. In this specification, ENFBE refers to solvent ethyl nonafluorobutyl ether, MNFBE refers to methyl nonafluorobutyl ether. The polyfluoropolyethersilane that is referred to as fluorosilane A is a fluorosilane of formula:
[0000] (MeO) 3 Si(CH 2 ) 3 NHC(O)OCH 2 CH[O(O)CHN(CH 2 ) 3 Si(OMe) 3 ]CH 2 NHCOR f2
[0000] where R f2 is a moiety of formula CF(CF 3 )(OCF 2 CF(CF 3 )) k O(CF 2 ) 2 CF 3 , k is approximately 5 to 6, but may be in the range 3 to 50, usually 3 to 20, more usually 4 to 10. Fluorosilane B is a fluorosilane of formula:
[0000] (MeO) 3 Si(CH 2 ) 3 NHC(O)R f2
[0000] Fluorosilane C is a fluorosilane of formula:
[0000] (MeO) 3 Si(CH 2 ) 3 OCH 2 R f2 , in which k is approximately 34. BTMSPA refers to bis(trimethoxysilylpropyl)amine. APTMS (ex Sigma) Amino-n-propyltrimethoxysilane APTES (ex Sigma) Amino-n-propyltriethoxysilane Primer A is bis(3-trimethoxysilylpropyl) ethylene diamine, Primer B is bis(triethoxysilyl)ethane, Primer C is bis(3-triethoxysilylpropyl)amine, Primer D is bis(3-trimethoxysilylpropyl) N-methyl amine, Primer E is bis(methyldiethoxysilylpropyl)amine
EXAMPLES
Deposition Test on Cans
[0227] In the Examples the salbutamol sulphate deposition screening test employed a salbutamol dispersion micronised non-amorphous salbutamol sulphate ultrasonically dispersed in decafluoropentane (1 g in 400 g). The test was run by employing an Eppendorf pipette to place a 0.3 ml aliquot of the salbutamol dispersion into each can. The cans were then immediately placed on a horizontal rolling mixer (Stuart Scientific model SRT2 operating to rotate cans at 35 rpm) for 3 minutes to allow the dispersion to dry to the surface. The cans were then placed in an air drying oven for 5 minutes at 65° C. to fully dry. The cans were then rinsed with 2 aliquots of decafluoropentane (5 ml) using a 5 inversion shaking regime with one shake cycle per second.
[0228] Controls were uncoated cans to which salbutamol sulphate dispersion had been added and dried but which had not undergone a subsequent rinse step and hence these cans had a deposit level that represented the maximum level possible in the test. Other cans had undergone a subsequent rinse step and hence cans which showed a low level of salbutamol deposition in this test were showing that the deposited salbutamol could be easily washed away and were therefore deemed to have good release/non-stick performance.
[0229] The residual deposited salbutamol was quantitatively transferred and assayed by u.v. spectrophotometry. For each sample, the amount assayed was divided by the corresponding amount for the controls and expressed as a percentage. Unless otherwise stated, 3 samples were taken for each determination.
Example 1
Method
Washing of Cans
[0230] Cans were immersed in HFE72DE at its boiling temperature (43° C.) for 7 minutes. They were allowed to drain for 2 minutes, and then re-immersed for 3 minutes with ultrasonic agitation. These were allowed to drain for a further 4 minutes then dried at ambient conditions for 7 minutes.
Preparation of Primed and Unprimed Cans
[0231] Washed aluminium cans were fill and drain coated with primer solution (BTMSPA 0.2 g in isopropanol (109.5 g)) by transfer filling brimful into a first can in a first row of 10 cans, allowing 60 s solution contact time, then transferring and topping up from primer solution similarly to the subsequent cans in the row. Meanwhile primer solution was transfer filled into a first can of a second row of 10 cans, and the process repeated as for the first row of cans. Altogether 6 rows of cans were treated, giving a total of 60 cans. The cans were placed inverted to drain on a laboratory wipe, each was shaken and blown dry with compressed air and then placed in an oven for 30 minutes at 60° C.
[0232] A similar quantity of washed cans was not primed.
[0000] Coating of Cans with Fluorosilane A Solution for Spray Coating
[0233] A reservoir bottle of 1% w/w fluorosilane A (13.5 g) in ENFBE (1355 g) was prepared.
[0234] An automated spray coater was employed to spray a sequence of cans. The primed and unprimed cans were presented to the sprayer alternately to eliminate any possible systematic trend in the coating efficiency.
[0235] In the automated spray coater, spraying liquid was pumped from a reservoir bottle through a spray nozzle mounted to spray vertically upwards for a programmed duration at a spraying station. Each can to be sprayed was delivered inverted to the spraying station, then allowed to drain. By suitable adjustment of the spraying pressure and duration, the optimum coating was achieved when the cans were delivered with a maximum load that did not drip excess coating solution upon draining. 8 cans for each experimental condition were coated. Results are reported to include samples from either side of the optimum. Furthermore, runs were included with 2 passes of the sprayer, allowing 60 s draining between passes, and a run with 3 short duration sprays adding up to the optimum duration for a single spray.
[0236] After completion of all coating runs, with draining complete, the cans were placed inverted into a single stainless steel coating tray and placed into the centre of the coating oven at 120° C. for 30 minutes. The cans were then removed, left to cool down and then placed into a large polythene bag for storage.
Testing
[0237] Each can was subjected to the deposition test for cans.
Results
[0238] Certain of the deposition cans were tested using the deposition test for cans. Results are reported in Table 1.
[0000]
TABLE 1
Salbutamol
Sulphate
Spray
deposition
No. of
No. of
duration
observation
test result (%
Primed
passes
sprays
(ms)
of draining
of control)
Yes
1
1
350
Single drip
3
from every
can
Yes
1
1
250
No dripping
4
Yes
2
1
350
Occasional
3
dripping
Yes
2
1
250
No dripping
3
Yes
1
1
300
Only one drip
4
seen in total
Yes
1
3
3 times
No dripping
3
100
No
1
1
350
Single drip
5
from every
can
No
1
1
250
No dripping
5
[0239] With reference to Table 1, the data show that all fluorosilane The spray coated cans both with and without the primer show very low deposition values. The primed cans show marginally better deposition performance than the unprimed cans in this study. The uniformly low deposition data across the study indicate that the spray coating process is robust within the coating variable ranges tested.
Example 2 and Comparative Example 2A
[0240] Example 2 involved coating and performance testing of stainless steel valve components.
Components Used
[0241] Metering tanks, springs, bottle emptiers, inner and outer seals, valve stems and ferrules were assembled for making valves as shown in FIG. 1 a, 1 b with a metering volume of 63 μl.
Washing the Components
[0242] 1000 metering tanks were placed in a stainless steel vessel with lid and ENFBE (1 litre) was added. The components were agitated and then left with the lid on for 30 minutes. After 30 minutes the components were strained using a stainless steel strainer and placed back in the vessel to which a further 1 litre of fresh ENFBE was added. Once more the components were agitated and then left to stand for 30 minutes. The components were then strained and then left in the vessel for the final residues of the ENFBE to evaporate. The components were then placed in a polythene bag for storage.
[0243] The same procedure as above was applied to 1000 springs with 500 ml ENFBE used in place of the 1 litre quantity. The washed springs were then placed in a polythene bag for storage.
Coating of the Washed Components
[0244] 100 washed springs and 100 washed tanks were placed into a glass 250 ml beaker.
[0000] Priming with BTMSPA
[0245] BTMSPA (0.3 g) was weighed into a 500 ml beaker and isopropanol (164 g) was added and the solution mixed. The latter solution was then added to the beaker of components and the components mixed with a spatula then left to stand for 30 seconds. The fluid and components were then poured back into the 500 ml beaker via a stainless steel sieve thereby collecting the coated components in the sieve. The components were then poured out on to a laboratory wipe and were dried off using a hot air blower. The components were returned to the glass beaker and were then placed in an air drying oven at 60° C. for 15 minutes.
Fluorosilane Coating
[0246] The primed components were left to cool down and equilibrate with ambient air for 1 hour.
[0247] ENFBE (300 g) was added to fluorosilane A (3.0 g) in a 500 ml beaker and the solution was mixed. The solution was the poured into the beaker of primed components and the components were stirred with a spatula. The components were then left to sit for 30 seconds in the solution after which time they were drained via a stainless steel sieve back into the 500 ml beaker hence collecting the components in the sieve. The components were then transferred to a glass beaker and placed into an oven at 120° C. for 30 minutes to cure the fluorosilane. The coated components were assembled into inhaler valves as shown in FIGS. 1 a, 1 b.
[0248] Similarly, the uncoated components (Comparative Example 2A) were also assembled into inhaler valves as a control.
Product Filling
[0249] The coated test valves and control valves were incorporated into metered dose inhaler and used to deliver a formulation of micronised salbutamol sulphate suspended in HFA134a. The target dose of the product was 100ug per actuation and the cold filling technique was employed for the filling process.
Product Testing
[0250] Both the coated (Example 2) and the uncoated (Comparative Example 2A) valve product lots were actuated through life to shot number 120, after which point the test inhalers were chilled down, the valves removed and the valve components disassembled and assayed for salbutamol sulphate residue. The assay was done by uv spectrophotometry of quantitative washings from each component made up to a suitable volume with washing solvent. The assay results are shown in table 2, below.
[0000] TABLE 2 Mass of salbutamol sulphate deposited on component at end of life (mg) Uncoated Comparative Component Coated Example 2 Example 2A Stem and seal 0.25 0.47 Spring 0.09 0.38 Tank 0.11 0.25 Bottle emptier 0.03 0.11
The data in Table 2 show that the valves incorporating stainless steel springs and stainless steel tanks coated with BTMSPA followed by fluorosilane A in Example 2 show a very large reduction in component salbutamol sulphate deposition levels compared to the uncoated controls in Comparative Example 2A. Although only the springs and the tanks were coated, coating appears to have had a further beneficial effect in terms of lowered deposition also on the stem and seal and the bottle emptier components of the coated valves. This effect is likely due to reduced deposition at the interface points between uncoated and coated components compared to that seen at the interface points between components that are all uncoated.
Example 3
Preparation
Coating of the Washed Components
[0251] 400 washed springs were placed into a 500 ml beaker and 400 washed 63 μl metering tanks were placed into a second 500 ml beaker. The washing procedure was as for example 2.
Priming
[0252] BTMSPA (0.4 g) was weighed into a 500 ml beaker and isopropanol (219 g) was added and the solution mixed. The latter solution was then added to the beaker of springs and mixed well with a stainless steel spatula and left to stand for 30 seconds. The fluid and components were then poured out into the beaker containing the metering tanks and the latter were then mixed well and left to stand for 30 seconds. The metering tanks and fluid contents were then poured through a sieve into a third beaker. The still wet metering tanks and springs were separated out onto two separate laboratory wipes and left in the fume cupboard with fast air flow for 10 minutes until all the isopropanol had evaporated. The components were then transferred into dry 500 ml glass beakers and placed into the air drying oven for 15 minutes at a temperature of 60° C.
Fluorosilane Coating
[0253] The primed metering tanks and springs were removed from the air drying oven and poured out onto laboratory wipe in the fume cupboard to allow to cool and to equilibrate with atmospheric moisture for 30 minutes.
[0254] ENFBE (400 g) was added to fluorosilane A (4.0 g) in a 500 ml beaker and the solution was mixed. The latter solution was then poured into the beaker of primed springs components and the components were stirred with a spatula. The components were then left to sit for 30 seconds in the solution after which time they were drained via a stainless steel sieve back into the 500 ml beaker containing the metering tanks. After 30 seconds the metering tanks were sieved to isolate them and each beaker of components was air dried on a laboratory wipe with the aid of a hot air blower, then placed into the oven at 120° C. for 30 minutes to cure the fluorosilane.
[0255] Valves as shown in FIGS. 1 a, 1 b were assembled from the above metering tanks and springs, by incorporating seals, a bottle emptier and a ferrule for each set and crimping. Valves as shown in FIGS. 1 a, 1 b were prepared for comparison as above, with the exception that the priming and fluorosilane coating steps were omitted.
[0256] A suspension formulation of fluticasone propionate was made up in propellant (1%w/w ethanol+99%w/w HFA134a). Aluminium cans were filled to deliver 120 shots via 63 μl valve, by cold transferring aliquots of the suspension, and valves prepared as above were crimped on to provide aerosol units.
Testing
[0257] Each aerosol unit to be tested was placed into a plastic actuator (the discharge actuator). The aerosol unit was shaken with a gentle rocking action through 180° inversion for at least 10 s and a shot was fired to waste. The valve was immediately released, and these steps repeated, once using the discharge actuator and again twice using a fresh plastic actuator (the test actuator).
[0258] An USCA (Unit Spray Sample Collection) apparatus as described in US Pharmacopoeia vol. 29 (2006) section <601> was set up. An aerosol unit which had been through firing shots to waste as described above was immediately attached and a pair of shots fired into an USCA Medication Delivery collection tube with a filter (USCA tube), according to the procedure for the apparatus. Each pair of shots from the unit was fired into a separate USCA tube. The drug was quantitatively transferred from each USCA tube for analysis by hplc.
[0259] The test regimen, following on from the firing to waste described above and carried out on 5 units for each of the 2 valve types, was as follows:
[0260] 3 pairs of shots representing the start of unit life through the test actuator (referred to by their sample number as start 1, start 2 and start 3 in FIGS. 2 a , 2 b )
[0261] 48 shots fired to waste through the discharge actuator
[0262] 2 shots fired to waste through the test actuator
[0263] 4 pairs of shots representing the middle of unit life through the test actuator (referred to as middle 1, middle 2, middle 3 and middle 4 in FIGS. 2 a , 2 b )
[0264] 48 shots fired to waste through the discharge actuator
[0265] 2 shots fired to waste through the test actuator
[0266] 3 pairs of shots representing the end of unit life through the test actuator (referred to as end 1, end 2 and end 3 in FIGS. 2 a , 2 b )
Results
[0267]
[0000] TABLE 3 Units with coated Units with uncoated springs and springs and metering tanks metering tanks Start shots mean 38.0 μg 34.9 μg Middle shots mean 38.3 μg 34.5 μg End shots mean 37.2 μg 34.7 μg Start shots relative standard 2.0% 6.5% deviation Middle shots relative standard 2.8% 6.3% deviation End shots relative standard 2.9% 7.7% deviation Overall mean and relative 37.9 μg ± 2.8% 34.7 μg ± 6.7% standard deviation
A graph of μg fluticasone released per shot is shown in FIG. 2 a as a function of through life position and sample number for Example 3, showing a high level of consistency using the valve assembled with coated components. For comparison FIG. 2 b shows the corresponding results for the valve with uncoated components. The results indicate that coating according to the invention is highly advantageous because it results in less dose to dose variability of the medicament, and less unit to unit variability.
Example 4
Preparation
[0268] 19 ml aluminium cans were washed with HFE72DE as in Example 1.
[0269] 4A—BMSTPA (0.05 g) was dissolved in isopropanol (27.4 g). The solution was transferred sequentially brimful into 6 aluminium cans, allowing a solution contact time of 60 s per can. The cans were then drained and placed in an oven at 60° C. for 2 hours, to complete priming. fluorosilane A (0.5 g) was weighed into a plastic beaker and made up to 50 g with MNFBE. The solution was transferred sequentially brimful into 3 primed aluminium cans, allowing a solution contact time of 30 s per can. These cans were drained and placed in an oven at 120° C. for 15 minutes, to effect curing.
[0270] 4B—BMSTPA (0.05 g) and fluorosilane A (0.5 g) were dissolved in ethanol (27.4 g) in a plastic beaker. The solution was transferred sequentially brimful into 3 cleaned aluminium cans, allowing a solution contact time of 60 s per can. These cans were drained and placed in an oven at 120° C. for 15 minutes, to effect curing.
[0271] 4C—BMSTPA (0.05 g) was dissolved in ethanol (27.4 g). The solution was transferred sequentially brimful into 3 aluminium cans, allowing a solution contact time of 5 s per can. The cans were then drained and placed in an oven at 120° C. for 15 minutes, to complete priming. fluorosilane A (0.5 g) was dissolved in ethanol (27.4 g). The solution was transferred sequentially brimful into 3 primed aluminium cans, allowing a solution contact time of 60 s per can. These cans were drained and placed in an oven at 120° C. for 15 minutes, to effect curing and complete the coating.
[0272] 4D—fluorosilane A (0.5 g) was dissolved in ethanol (27.4 g). The solution was transferred sequentially brimful into 3 cleaned aluminium cans, allowing a solution contact time of 60 s per can. These cans were drained and placed in an oven at 120° C. for 15 minutes, to effect curing and complete the coating.
Testing
[0273] The deposition test for cans described earlier was carried out.
Results
[0274]
[0000]
TABLE 4
%
Sample
Description
deposition
4A
HFE72DE cleaned + BTMSPA primed +
1
fluorosilane A coated
4B
HFE72DE cleaned + (fluorosilane A coated +
7
BTMSPA crosslinked)
4C
HFE72DE cleaned + BTMSPA fast primed +
3
fluorosilane A coated
4D
HFE72DE cleaned + fluorosilane A coated
5
Example 5
Preparation
[0275] 10 ml Stainless steel cans were washed with ENFBE as follows. 65 cans were periodically agitated in ENFBE (2 liters) with a contact time of 1 hour, then drained and allowed to dry at ambient conditions.
[0276] Priming, where used, was carried out by taking 20 washed cans and contacting with a solution of BTMSPA (0.1 g) in isopropanol (54.8 g) for 30 s, allowing to drain, then placing in an oven at 60° C. for 1 hour.
[0277] Fluorosilane coating, where used, was carried out by taking 6 cans a filling with fluorosilane A (0.5 g) in MNFBE (50 g) for 30 s, allowing to drain, then placing in an oven at 120° C. for 15 minutes.
Testing
[0278] 6 cans of each test condition were subjected to the Deposition test for cans as follows:
[0279] 5A—washed only
[0280] 5B—washed and primed
[0281] 5C—washed, primed and coated
[0282] 5D—washed and coated
Results
[0283]
[0000]
TABLE 5
Sample
% deposition
5A
84
5B
88
5C
2
5D
5
[0284] The results indicate that the effect of coating was improved by a previous priming, while priming alone was ineffective.
[0285] It is to be understood that the specification is not limited to the embodiments described above and that various modifications can be made without departing from the principles or concepts of the specification.
[0286] Actuators and inhalers as claimed in the specification may include any feature described herein separately or in combination with any other feature(s), if necessary with appropriate modification of other features, as would be readily apparent to the skilled person.
Example 6
[0287] Coatings were applied to the internal surfaces of PET vials and their effectiveness assessed by the deposition test referred to earlier.
Method
[0288] BTMSPA, APTMS and APTES were each prepared individually as solutions of 0.1 g in ethanol (50 g). Each primer solution was then used to prime 3 PET vials using the fill and drain technique with 30 seconds contact time and then draining the vials upside down for 2 minutes then placing upright for 30 minutes to equilibrate then curing at 55° C. for 30 minutes in an oven with a wet lab wipe to boost the moisture level. Each of the 3 samples above was then left to equilibrate with room temperature and humidity for 4 hours prior to ECC7000 coating.
[0289] Each vial was then fill and drain coated with a solution of Fluorocarbon B (10% solution) (1.0 g) in MNFBE (99 g). The vials were left to equilibrate with ambient air for 30 minutes and then cured at 55° C. for 30 minutes in an oven with a wet lab wipe to boost the moisture level.
Results
[0290] The details of any primer and the top coat are given in Table 6 along with the results of the deposition test.
[0000]
TABLE 6
Sample
designation
Primer
Top coat
% deposition
6A
BTMSPA
Fluorosilane B
0, 0, 0
6B
APTMS
Fluorosilane B
21, 28, 25
6C
APTES
Fluorosilane B
28, 26, 30
6D
none
Fluorosilane B
55, 64, 55
Uncoated PET
none
none
80, 82, 81
vials
Example 7
[0291] Further examples of coatings applied to the internal surfaces of PET vials were assessed by the deposition test.
Method
[0292] A top coating solution of Fluorosilane B (10%w/w) was prepared from Fluorosilane B (2 g) in MNFBE (18 g).
[0293] A top coating solution of Fluorosilane C (8%w/w) was prepared from a Fluorosilane C 20%w/w solution (13.5g) in MNFBE (20.2g).
Priming the PET Vials
[0294] PET vials (27) were fill and drain coated in a solution of BTMSPA (0.2 g) in dehydrated ethanol (99.8 g). The vials were then placed open end down onto lab wipe for 5 minutes, to drain excess coating solution, before being placed upright to equilibrate with ambient air (22° C. 34% RH) for 30 minutes. The vials were then cured in an oven at 60° C. for 30 minutes.
Top Coating of PET Vials
[0295] The 27 BTMSPA primed PET vials were separated into 9 sets of 3 vials and were coated as shown in the table below employing the fill and drain approach with a 30 seconds contact time. All vials were placed open end down for 5 minutes to drain the coating solution, before being stored open end up for 30 minutes to equilibrate at ambient temperature and humidity (22° C. 34% RH). The vials were then oven cured at 55° C. for 30 minutes.
[0296] A comparative experiment was performed at the same time in which a primer solution and top coat solution were mixed together and applied as a single coating. Another comparative experiment compared top coating without primer coating.
[0000]
TABLE 7a
Sample
designation
Description of top coating solution
% deposition
7A
Fluorosilane A 10% solution (0.5 g)
19, 19, 22
in MNFBE (99.5 g)
7B
Fluorosilane A 10% solution (1.0 g)
21, 18, 23
in MNFBE (99.0 g)
7C
Fluorosilane A 10% solution (2.0 g)
12, 15, 19
in MNFBE (98.0 g)
7D
Fluorosilane B 10% solution (0.5 g)
0, 0, 0
in MNFBE (99.5 g)
7E
Fluorosilane B 10% solution (1.0 g)
0, 0, 0
in MNFBE (99.0 g)
7F
Fluorosilane B 10% solution (2.0 g)
0, 0, 1
in MNFBE (98.0 g)
7G
Fluorosilane C 8% solution (0.62 g)
1, 2, 2
in MNFBE (99.4 g)
7H
Fluorosilane C 8% solution (1.25 g)
0, 0, 1
in MNFBE (98.75 g)
7I
Fluorosilane C 8% solution (2.5 g)
0, 0, 1
in MNFBE (97.5 g)
Uncoated
none
80, 82, 81
PET vials
[0000]
TABLE7b
Sample
designation
Description of coating
% deposition
7J
As for 7F, but as single coat of mixed
53, 57, 58
primer and top coat solutions
7K
As for 7E, but with no priming coat
59, 62, 58
Results
[0297] The details of top coat for examples are given in Table 7a along with results of the deposition test, and a comparison where no coating was applied. Table 7b gives some further comparative tests with alternative coatings and deposition test results. The vials with BTMSPA prime and Fluorosilane A top coat showed acceptably low deposition. Those with BTMSPA prime and Fluorosilane B or C top coat showed virtually no deposition at all.
Example 8
[0298] Further examples of coatings applied to the internal surfaces of PET vials were assessed by the deposition test.
Method
[0299] Each primer (A to E and also BTMSPA) (0.1 g) was separately dissolved in isopropanol (50 g).
[0300] PET vials (n=3, for each sample designation) were then fill and drain coated with each primer solution using a 30 seconds contact time. The vials were then oven cured at 60° C. for 30 minutes. The primed vials were then left overnight.
[0301] Fluorosilane B (1.0 g) was dissolved in MNFBE (9 g) to make a 10%w/w solution. 10%w/w solution (1.0 g) was then dissolved in MNFBE (99 g). All vials were fill and drain coated for 30 seconds and then oven cured for 30 minutes at 60° C.
[0302] Details of the coatings applied and results of the salbutamol sulphate deposition test are tabulated in Table 8.
[0000]
TABLE 8
Sample
designation
Primer
Top coat
% deposition
8A
Primer A
Fluorosilane B
1.4, 0.4, 0.7
8B
Primer B
Fluorosilane B
56.6, 54.8, 61.8
8C
Primer C
Fluorosilane B
0.3, 0.3, 0.4
8D
Primer D
Fluorosilane B
0.7, 0.3, 0.3
8E
Primer E
Fluorosilane B
2.2, 4.2, 2.4
8F
BTMSPA
Fluorosilane B
0.1, 0.3, 0.3
8G
none
Fluorosilane B
58.4, 50.7, 57.9
Results
[0303] Very low depositions similar to those seen in the previous example were repeated here when other primers were used, except where the primer had an unsubstituted alkyl linking group (Primer B).
Example 9
[0304] A modified coating process for applying coatings to the internal surfaces of PET vials was assessed by the deposition test.
Methods
[0305] Priming solution was prepared from BTMSPA (0.2 g) dissolved in ethanol and made up to 99.8 g.
[0306] Fluorosilane B 10%w/w solution (1.0 g) was added to MNFBE (99 g) to prepare a top coating solution.
[0000] The following samples were prepared:
[0307] 9A—PET vials (3) were fill and drain coated in priming solution. The vials were then placed open end down onto lab wipe for 5 minutes, to drain excess coating solution, before being placed upright to equilibrate with ambient air (22° C. 34% RH) for 30 minutes. The vials were then cured in an oven at 60° C. for 30 minutes. Top coating solution was applied by filling and draining with a 30 seconds contact time. All vials were placed open end down for 5 minutes to drain the coating solution, before being stored open end up for 30 minutes to equilibrate at ambient temperature and humidity (22° C. 34% RH). The vials were then oven cured at 60° C. for 30 minutes.
[0308] 9B—PET vials (3) were fill and drain coated in priming solution. The vials were then quickly air-dried. Top coating solution was applied by filling and draining with a 30 seconds contact time. All vials were placed open end down for 5 minutes to drain the coating solution, before being stored open end up for 30 minutes to equilibrate at ambient temperature and humidity (22° C. 34% RH). The vials were then oven cured at 60° C. for 30 minutes.
[0309] 9C—No primer was used. Top coating solution was applied by filling and draining with a 30 seconds contact time. All vials were placed open end down for 5 minutes to drain the coating solution, before being stored open end up for 30 minutes to equilibrate at ambient temperature and humidity (22° C. 34% RH). The vials were then oven cured at 60° C. for 30 minutes.
Results
[0310]
[0000] TABLE 9 Sample designation Primer Top coat % deposition 9A BTMSPA Fluorosilane B Prime coat 0, 1, 0, heat-cured 9B BTMSPA Fluorosilane B Prime coat 2, 1, 1, air-dried 9C none Fluorosilane B No prime coat 51, 46, 53
Details of the primer and top coat used and any method variations are provided in table 9, along with the results of the deposition test. The prime and top coating may be cured in a single curing step.
Example 10
[0311] Metering valves as shown in FIGS. 1 a and 1 b were assembled with various coatings, and inhalers were prepared in which the metering valves were crimped onto cans containing a suspension formulation in an HFA propellant system. After dispensing the contents, the deposition levels of a medicament on components of the valves were assayed.
Methods
Priming of Metal Springs and Tanks
[0312] A priming solution of BTMSPA (0.2 g) dissolved in HFE72DE (168 g) was prepared. 120 springs and 120 tanks, which had previously been washed as in Example 2, were dip coated in the coating solution and then oven cured at 120° C. for 30 minutes.
Priming of Plastic Stems
[0313] 80 PBT plastic stems were washed in ENFBE as in Example 2.
[0314] A priming solution of BTMSPA (0.1 g) dissolved in dehydrated ethanol (50 g) was prepared. 80 washed PBT plastic stems were dip coated in the coating solution and then oven cured at 55° C. for 30 minutes.
[0000] Top Coating of Primed Springs and Tanks with Fluorosilane A
[0315] A top coating solution of Fluorosilane A (2.0 g) dissolved in HFE72DE (168 g) was prepared. 80 primed tanks and 80 primed springs were dip coated for 30 seconds in the solution. The components were then oven cured at 120° C. for 30 minutes.
[0000] Top Coating of Primed Springs and Tanks with Fluorosilane B
[0316] A top coating solution of Fluorosilane B (10%) (1.0 g) dissolved in MNFBE (84 g) was prepared. 40 primed tanks and 40 primed springs were dip coated for 30 seconds in the solution. The components were then oven cured at 120° C. for 30 minutes.
Top Coating of Primed Plastic Stems
[0317] A top coating solution of Fluorosilane A (1.0 g) dissolved in MNFBE (99 g) was prepared.
[0318] A top coating solution of Fluorosilane B (10%) (1.0 g) dissolved in MNFBE (99 g) was prepared.
[0319] 40 of the BTMSPA-primed plastic stems were dip coated in each solution above as specified in Table 10a. The coated stems were then dried on lab wipe and then oven cured at 55° C. for 30 minutes.
Preparation of Test Samples
[0320] Valves were constructed as in Table 10a below. For each valve lot 10A-10F, five valves were constructed and tested in inhaler canisters (n=5). The springs and tanks of the test samples and the controls were coated, while the bottle emptiers were left uncoated. Use of talc or Magnesium Stearate on the seals (inner tank seal and diaphragm seal) and/or silicone oil lubrication of the stem and seals sub-assembly during valve assembly was done to ensure that the valves functioned reliably when sealed onto inhaler canisters. Nevertheless, controls with and without the seal lubrication and silicone oil lubrication were performed. The assembled valves were then placed on inhaler canisters containing medicament suspended in an HFA propellant formulation.
[0321] The inhalers were actuated repeatedly to exhaust the contents through the valves, then the valves were removed and carefully dismantled. The medicament deposits on the separate components were assayed by washing them off in a suitable solvent and sampling to an hplc.
[0000] TABLE 10a Valve Springs Tanks Plastic stems lot Description Top coating Top coating Top coating 10A Uncoated stem, Fluorosilane A Fluorosilane A Uncoated control with talc and silicone oil 10B Uncoated stem, Fluorosilane A Fluorosilane A Uncoated control valve without talc and silicone oil 10C Coated stem, test A Fluorosilane A Fluorosilane A Fluorosilane A stem with talc and silicone 10D Coated stem, test A Fluorosilane A Fluorosilane A Fluorosilane A stem with Magnesium Stearate dusting of seals 10E Coated stem, test B Fluorosilane B Fluorosilane B Fluorosilane B stem with talc 10F Coated stem, test B Fluorosilane B Fluorosilane B Fluorosilane B stem with Magnesium Stearate dusting of seals
Magnesium Stearate dusting was carried out as disclosed in WO2012/173971 (Experiment 2 dry coating): about 2½ mg Magnesium stearate per gram of seals was used for the inner tank seals; about 1 mg Magnesium stearate per gram of seals was used for the diaphragm seals.
Results
[0322] The levels of deposited medicament on each of the components following exhaustion of the contents of the inhalers is shown in Table 10b. The average cumulative deposition for 3 components (spring, tank and plastic stem) is presented alongside the individual values for the components.
[0000] TABLE 10b Medicament Medicament Medicament Medicament deposition deposition deposition deposition (mg) 3 Valve (mg) per (mg) per (mg) per component lot spring tank plastic stem average 10A 157, 122, 121, 93, 123, 102, 139, 185, 145, 410.8 186, 148 122, 100 155, 156 10B 149, 180, 123, 81, 85, 88, 73, 152, 144, 135, 370.8 145, 111 97 144, 147 10C 49, 46, 41, 41, 64, 106, 104, 80, 83, 58, 67, 199.2 42 85, 79 51 10D 50, 45, 63, 43, 59, 92, 86, 82, 65, 95, 60, 61, 199.0 55 89 50 10E 24, 22, 56, 18, 37, 64, 76, 41, 77, 61, 73, 75, 151.2 25 48 59 10F 24, 54, 35, 48, 61, 55, 54, 50, 63, 64, 43, 90, 166.0 46 58 85
The 3 component average medicament deposition was improved by coating the plastic stem relative to both controls (10A and 10B), as was the medicament deposition on the plastic stem itself
[0323] Even though the stems and springs were coated using primer and fluorosilane in both test and control runs, medicament deposition on the spring and tank was still generally improved by coating the plastic stem.
Example 11
[0324] Valves as shown in FIG. 3 were assembled using components that had been coated. The coated components were made from polybutylene terephthalate (PBT). The valves were crimped onto cans containing a suspension formulation, and tested for drug deposition after dispensing the doses.
Components Used
[0325] Metering tanks, springs, valve bodies, inner and outer seals, valve stems and ferrules were gathered for making valves as shown in FIG. 3 with a metering volume of 50 μl.
[0000] Priming of Metering Tanks, Stems, Springs and Valve Bodies with BTMSPA
[0326] 20 metering tanks, stems, springs, valve bodies were immersed with agitation for 30 seconds in a primer solution comprising BTMSPA (0.2 g) in dehydrated ethanol (100 g). The components were strained out then air dried and then placed in an air drying oven for 30 minutes at 60° C. to cure the priming coating.
Fluorosilane Coating
[0327] The primed components were left to cool down and equilibrate with ambient air overnight.
[0328] 10 sets of metering tanks, stems, springs, valve bodies were each coated with one of each of 2 fluorosilanes as follows:
[0329] A top coating solution of Fluorosilane B (10%) (1.0 g) dissolved in MNFBE (99 g) was prepared for use in Example 11B.
[0330] A top coating solution of Fluorosilane C (0.2%) in MNFBE was prepared for use in Example 11C.
[0331] The above components sets were placed into individual 250 ml glass reagent bottles and contacted for 3 minutes with occasional agitation with the appropriate fluorosilane solution. The components were then strained out air dried and then cured at 60° C. for 16 hours.
[0332] The coated components were assembled into inhaler valves as shown in FIG. 3 .
[0333] Similarly, the uncoated components were also assembled into inhaler valves as controls.
Product Filling
[0334] The coated test valves and control valves were incorporated into metered dose inhaler and used to deliver a formulation of micronised salbutamol sulphate suspended in HFA134a. The target dose of the product was 100 μg per actuation and the cold filling technique was employed for the filling process.
Product Testing
[0335] Both the coated (Examples 11B and 11C) and the uncoated (Comparative Example 11A) valve product lots were actuated through life to shot number 120, after which point the test inhalers were chilled down, the valves removed and the valve components disassembled and assayed for salbutamol sulphate residue (n=5 for each valve lot).
[0336] The assay was done by uv spectrophotometry of quantitative washings from each component made up to a suitable volume with washing solvent. The assay results are shown in table 11.
[0000]
TABLE 11
Treatment
Valve
of
Residual drug deposition (mg)
lot
components
Tank
Stem
body
11A
Uncoated
0.218 0.161
0.182 0.199
0.129 0.146
and
0.197
0.192
0.144
unwashed
0.211
0.146
0.122
components
0.262
0.153
0.213
Average ±
0.210 ± 0.037
0.174 ± 0.024
0.151 ± 0.036
Std
deviation
11B
Coated with
0.163 0.137
0.149 0.166
0.139 0.060
BTMSPA +
0.142
0.136
0.077
Fluorosilane
0.233
0.173
0.082
B
0.144
0.146
0.125
Average ±
0.164 ± 0.040
0.154 ± 0.015
0.097 ± 0.034
Std
deviation
11C
Coated with
0.070 0.099
0.111 0.151
0.069 0.067
BTMSPA +
0.110
0.163
0.067
Fluorosilane
0.137
0.110
0.075
C
0.136
0.137
0.098
Average ±
0.110 ± 0.028
0.134 ± 0.024
0.075 ± 0.013
Std
deviation | Methods of making components for a medicinal delivery device are described, in which a primer composition comprising a silane having two or more reactive silane groups separated by an organic linker group is applied to a surface of a component, then a coating composition comprising an at least partially fluorinated compound is applied to the primed surface. The surface may be a polymer surface. Corresponding coated components and a medicinal delivery device are disclosed. Methods of making metal components are described in which a coating composition comprising an at least partially fluorinated compound is applied to a surface cleaned with a solvent. | 1 |
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