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This is a continuation of application Ser. No. 725,425, filed Apr. 22, 1985, U.S. Pat. No. 4,630,354.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to devices for bending and cutting leads of electrical components such as resistors, capacitors, and the like. More particularly, this invention relates to a new and improved apparatus which will bend and cut the lead of a component with a minimum of mechanical effort through the use of simplified structure.
2. Description of the Prior Art
For the past several years, it has been the practice of the electronics industry to develop tools that permit automatic and semi-automatic assembly of circuit boards and their components. For example, there are devices which will automatically insert the proper component into the holes of a circuit board. Once this insertion has been completed, it may be necessary to trim the leads of the component and further insure that the component will remain fixed in the board. The latter can be achieved by bending the leads so as to cause interference between each lead and the circuit board hole.
One early cutting device comprises a cylinder having a bore containing a solid cutting member which travels in piston-like fashion within the bore. The cylinder has an opening at one end permitting one to insert a component lead into and through the bore, exiting the cylinder through an orifice on the cylinder wall. When the cutting member moves towards the opening of the bore, it interferes with the component lead, severing it at the orifice and the severed portion falls away from the cylinder. This type of apparatus is disclosed in U.S. Pat. Nos. 3,429,170; 3,593,404; and 4,286,379.
Lead cutters have also been designed to perform the cutting action in a radial direction. Some of these devices use concentric shearing means. These are exemplified by the arrangements shown in U.S. Pat. Nos. 3,414,024 and 4,153,082.
Numerous devices have been designed for bending leads of components after they have been inserted into a circuit board. In the vast majority of such devices, a force is applied in a direction perpendicular to the component lead causing interference between the lead and the circuit board hole through which the lead passes. Devices of these types may also be equipped to bend the portion of the lead extending below the plane of the circuit board. Exemplary devices are illustrated in U.S. Pat. Nos. 2,893,006; 3,141,492; 3,435,857; 3,907,008; 4,125,136; 4,464,829; and 4,485,548.
Although the devices noted above are capable of performing the cutting and bending operations required in electrical assembly, such devices are for the most part mechanically complex and require special driving means. As a result, changing of cutting surfaces or elements requires an involved procedure. Also, in certain configurations, the tool makes physical contact with the circuit board as it moves, possibly scoring the underside of the board. Finally, the devices themselves tend to be somewhat bulky and do not permit flexibility in operation and movement.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an apparatus for lead bending and cutting which is mechanically simple.
It is a further object of the invention to provide an apparatus for lead bending and cutting which is easily assembled.
It is a further object of the invention to provide a lead bending and cutting apparatus which provides for easily changed cutting elements.
It is a further object of the invention to provide a lead bending and cutting apparatus that is compact.
It is a further object of the invention to provide a lead bending and cutting apparatus which requires minimal driving power.
It is a further object of the invention to provide a lead bending and cutting apparatus which provides improved operator safety.
It is a further object of the invention to provide a lead bending and cutting apparatus which has no moving parts that make contact with the printed circuit board.
It is a further object of the invention to provide a lead bending and cutting apparatus where the entire assembly can be moved in all directions to achieve a bending action or operation on the component leads.
These objects as well as others not enumerated are achieved by the invention, one embodiment of which may include a cylindrical housing having a cover with an off-center bore and a shaft rotatably received therein having an off-center bore located the same radial distance from its axis as the bore in the cylindrical housing cover, and adapted to shear a component lead inserted through the first and second bores when the internal shaft is rotated with respect to the cylindrical housing. Both the cylindrical housing and the rotatable internal shaft are provided with complimentary cuts relieving portions of both elements so that the severed portion of the lead may be discarded. Finally, a fiber optic element may be provided in the bore of the internal rotatable shaft for illuminating the hole or holes in the circuit board. This entire assembly is mounted for movement in the x-, y-, and z-direction to achieve bending of a component lead as required.
In operation, a lead is inserted into the first bore of the cylindrical housing and into the second bore of the rotatable internal shaft. The end of the lead extends outwardly from the housing through the relieved portions of the shaft and housing. The internal shaft is rotated, severing the lead at the point where the end of the internal shaft abuts the inside of the cover on the cylindrical housing, which is also the point where the first and second bores meet. When the severing operation occurs, the severed portion of the lead merely falls away from the assembly. Once the severing operation has been completed, the head is moved in a predetermined direction creating interference between the component lead and the circuit board hole through which the lead passes.
BRIEF DESCRIPTION OF THE DRAWING
A more complete understanding of the present invention, will become apparent upon consideration of the following detailed description, especially when considered in light of the accompanying drawings wherein:
FIG. 1 is a modified sectional view of the invention;
FIG. 2 is a plan view of the cylindrical housing;
FIG. 3 is a first end view of the cylindrical housing;
FIG. 4 is a second end view of the cylindrical housing;
FIG. 5 is a plan view of the rotatable internal shaft;
FIG. 6 is an end view of the rotatable internal shaft; and
FIG. 7 is a modified sectional view of an alternative embodiment.
DETAILED DESCRIPTION
As stated above this invention relates to bending and cutting devices. Referring therefore to FIG. 1, two bending and cutting devices structured in accordance with the teachings of the present invention as shown and designated generally by the reference numerals 10 and 11. Devices 10 and 11 are shown in side-by-side operating positions such as to be utilized to bend and cut leads 14 and 16 from opposite ends of a component 18, which leads extend through aperatures 15 and 17 formed in a circuit board 12 to which component 18 is to be operatively attached. Each such device 10, 11 has a three-degree-of-freedom (triplanar) positioning means 23 and 25, respectively. For example, one may use an x-y-z platform as a base for the bending and cutting devices 10, 11 such as are well known in the art. Bending and cutting apparatus 10 is shown generally in cross-section.
Each of bending and cutting devices 10, 11 includes cylindrical housing 20 which is slidably received over a rotatable member 24 and a light source 27 which cooperates with a fiber optic element 30. These component parts are shown in their assembled positions in FIG. 1. However, their structured details are best described with respect to FIGS. 2-5.
Considering initially the structure of cylindrical housing 20, and with particular reference to FIGS. 2 and 3, housing 20 can be seen to comprise a generally cylindrical member having a bore 22 extending axially substantially throughout the entire length of the housing. Thus, bore 22 extends from the base of cylinder 20 to a location short of the insertion end 46 of the cylinder 20. The portion of bore 22 closest to insertion end 46 is tapered to define a frusto-conical surface 52 for cooperating with rotatable element 25 as is discussed below in detail.
Formed in insertion end 46 is a through-bore 36 the longitudinal axis of which is parallel to and radially displaced from the longitudinal axis of bore 22. The outer edge of through-bore 36 is provided with a radius to facilitate entry of a lead during operation of the device.
The outer surface 21 of cylinder 20 is relieved to define an arcuate cut 38, the surface of which is tangent at point 39 to the longitudinal axis of bore 22. Further, the center of generation of cut 38 is on a radius which is perpendicular to the longitudinal axis 41 of bore 22 and which contains point 39. As is discussed below, arcuate cut 38 corresponds to a similar cut formed in rotating element 24.
The outer surface 21 of cylindrical housing 20 is machined adjacent insertion end 46 to define four tapered flat surfaces 49, 50, 51 and 53 (FIG. 4). These tapered flats permit placing a plurality of devices 20 in due proximity for operation.
Formed adjacent the base of cylinder 20 are opposing flats 54 which cooperate to define surfaces suitable tooling or the like. The surface of insertion end 46 of cylinder 20 is provided with two bevels 47 and 48.
As can be seen from FIG. 5, the rotatable element 24 has a shaft portion 25, a drive portion, and a contiguous cutting end 32. The cutting end 32 is machined with a frusto-conical taper 58 which cooperates with the frusto-conical surface 52 in the housing 20.
The shaft 26 has a radially-offset longitudinal bore 26 running throughout its length. As mentioned with regard to the housing 20, the outer surface 55 of rotatable element is relieved to define an arcuate cut 44, the surface of which is tangent at point 39 to the longitudinal axis 60 of the rotatable element 24. The center of generation of cut 44 is on a radius which is perpendicular to the longitudinal axis 60 of the rotatable element 24 and which contains point 45.
The drive portion 28 may be a gear 56 or a smooth surface which accepts a drive belt (not shown). If the gear 56 is chosen for the drive portion 28, there can be provided a rack and pinion arrangement 57 comprising the drive gear 56, a rack 59, and, for example, a drive operator 61 such an electric solenoid or air cylinder may be provided.
The operation of the bending and cutting device 10 can be understood by referring to FIG. 1. Initially, the bending and cutting devices 10 and 11 are positioned by the positioning means 23, 25 beneath the circuit board holes 15 and 17, respectively, such that the light emanating from the fiber optic cables is projected through the circuit board holes 15 and 17. This serves to indicate to the machine operator that the components should be inserted into the holes having illumination. The leads 14 and 16 of the component 18 are then inserted into the circuit board holes 15 and 17 and into the bending and cutting devices 10 and 11, respectively. Once in place, the internal shaft 24 is rotated with respect to the outer cylinder 20, severing the leads 14, 16 at the cutting end of the internal shaft 24. The severed portions of the leads 14, 16, free ends 40, 42, fall away from the bending and cutting device 10 and 11, exiting through the arcuate cut 38, 44. After the leads 14, 16 have been cut, the bending and cutting devices 10 and 11 are moved by the positioning means 23, 25 in accordance with the operator or machine instructions in a direction parallel to the surface of the circuit board 12, creating interference between the component leads 14 and 16 and the circuit board holes 15 and 17, respectively. Each device may be moved independently. Thus, they may move in tandem, towards each other, or apart. Further movement of the bending and cutting devices 10 and 11 causes the leads 14 and 16 to bend.
In an alternative embodiment, bending of the leads is performed by turning the entire assembly as a unit. Thus, the shaft 24 and the cylinder 20 would be rotated in unison. After the bending operation is complete, the shaft 24 is rotated relative to the cylinder 20, severing the lead.
In addition to mounting the bending and cutting assemblies 10 and 11 on independent platforms movable in the x-, y-, and z-directions, it is also anticipated that this type of device could be mounted on a pistol grip, as can be seen in FIG. 7. In this embodiment, the cutting device 62 affixed to a pistol grip 64 which has a trigger 66. The cutting device 62 is provided with a rotatable element 67 having an extended shaft portion 68. Instead of a drive gear 56, the extended shaft portion 68 has a spiral thread 70. Riding the shaft portion 68 is a pin collar 72 having a drive pin 74 which cooperatively engages with the spiral thread 70. The pin collar 72 is stabilized by a guide rod 76 running through the guide rod bore 78 in the collar 72.
As pressure is placed on the trigger 64, the pin collar 72 is forced to move towards the cutting device 62. Because the guide rod 76 prevents the pin collar 72 from rotating about the extended shaft portion 68, the forward movement of the drive pin 74 against the spiral thread 70 forces the shaft portion 68 to rotate. The subsequent operation of the pistol arrangement is identical to that of the cutting devices 10 and 11.
It is important to note the structural simplicity of the lead bending and cutting device. Except for the drive and positioning means, the tool has only one moving part.
While there has been described what is believed to be the preferred embodiment of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such embodiments that fall within the true scope of the invention. | A lead cutting and bending apparatus provided for bending component leads placed through a circuit board. The cutting mechanism of the invention uses concentric components operating in an axial mode. | 8 |
FIELD OF THE INVENTION
[0001] Embodiments of the present invention relate to the design and function of lenses for use in various optical signalling applications, such as railway and airfield signal lights.
BACKGROUND
[0002] On railroad networks, such as the British Rail network, over-ground and underground signal heads are used to notify train drivers of whether a route is clear to continue their journey, or if a track is closed. Different colored signals, such as between two and four “aspects” (coloured light signals) can be used to convey different messages. As an example, red light (the stop aspect) signifies danger, telling the driver to stop, while green light informs a driver that a line is clear. Optionally, one or two yellow lights can also be used to caution drivers that they may need to stop at a signal further down the line.
[0003] Traditionally, coloured light signals have been produced using an incandescent white light source in combination with coloured lenses. The use of such a source has led to at least two problems. At long distances, light transmitted from red and green lenses can blend to give the appearance of white light. This is referred to as “colour blending” or “colour bleeding.” Further, incandescent lamps typically have short lifetimes, requiring replacement every six to twelve months. Failure of the filament results in the lamp instantly turning off Though safety procedures are in place to avoid danger from signal failure, maintenance can cause major disruption to rail services such as diversions, delays and cancellations, often at short notice and with a high associated cost.
[0004] Lighting systems comprising light-emitting diodes (LEDs) emitting at multiple wavelengths have been introduced to overcome the problem of colour blending and the short life-span of incandescent lamps for railway signaling applications. Using red and green LED signal heads, each comprising LEDs emitting across a wavelength gradient, colour blending can be alleviated. However, complex circuitry is required. Further, the cost associated with the manufacture and testing of these LED systems is high.
[0005] LEDs are traditionally made from inorganic semiconductors, which emit at a specific wavelength, e.g. AlGaInP (red), GaP (green), ZnSe (blue). Other forms of solid state LED lighting include organic light-emitting diodes (OLEDs), wherein the emissive layer is a conjugated organic molecule wherein delocalised π electrons are able to conduct through the material, and polymer light emitting diodes (PLEDs), in which the organic molecule is a polymer. Advantages of LEDs over traditional incandescent lighting include superior longevity, lower energy consumption resulting from less energy loss as heat, superior robustness, durability and reliability, and faster switching times. This is advantageous for use in transport networks, where downtime associated with maintenance work can be costly. However, solid-state lighting (SSL) is expensive and it requires different materials to emit at different wavelengths. Further, long-red emission (beyond 660 nm) is difficult to achieve using LEDs. Consequently, signalling systems requiring a range of emission wavelengths to display one colour are unfavourable using LEDs.
[0006] Strategies to tune the emission of a single wavelength of LEDs include the use of phosphors. LEDs emitting in the UV or blue region of the electromagnetic (EM) spectrum, which are generally cheap and readily available, can be combined with one or more phosphorescent materials emitting at a longer wavelength. Examples of phosphors include SrSi:Eu 2 + and SrGaS 4 :Eu 2 + , which emit red and green light, respectively. However, the range of available phosphors limits the emission wavelengths that can be achieved using this method.
[0007] Quantum dot (QD) phosphors have been developed, which overcome some of the limitations of conventional phosphors. QDs, semiconductor nanoparticles of the order of 1-50 nm, can be tuned to emit at any wavelength from the UV to the near-IR region of the EM spectrum by controlling the particle size. Thus, simply manipulating the particle size during synthesis can control the colour of light emitted, even using a single type of QD material. Further, colloidally synthesized QDs are capped with organic ligands that impart solubility, making the materials solution processable. Combined with high fluorescence quantum yields, this means that tiny amounts of QD material are required to cover a large area.
[0008] In patent EP 1 259 412 B1 from Dialight Corporation, an LED lamp is proposed having one or more LEDs in a housing unit. By reverse mounting red and green LEDs, the circuitry can be arranged such that the application of a voltage of one polarity would result in emission from the red LEDs, while the application of the reverse polarity would result in green emission. While the lamp would result in superior longevity compared to incandescent lamps, requiring less frequent maintenance, and lower power consumption, the issue of colour blending is not address. Further, the circuitry required to produce multiple coloured emission would be more complex than that proposed in the present invention, where a single wavelength LED backlight can be used to produce both red and green (or indeed any other desired colour) emission.
[0009] Though LED-based signal heads do not fail as readily as incandescent lamps, one of their drawbacks is that current flow can continue even when an LED fails to emit. Further, failure of one LED typically increases the risk of concurrent failure of any other LEDs in the circuit. Consequently, systems to monitor and control the LED output have been developed. Patent application US 2005/0062481 A1 discloses an LED signal lamp with a data processor to monitor the output of each LED by matching its characteristics to a known diode curve. AlInGaP was proposed as a suitable yellow or red LED material, and InGaN as a green emitter. However, a problem with the system described in that application is that the green and the red/yellow emitting LEDs must be sorted (i.e., binned) to obtain lots that provide color consistency.
[0010] Patent GB 2472694 A from Unipart Rail Limited highlights the risks of using coloured LEDs, including inconsistent light output over the required operating temperature range for signal heads in the UK (−30 to 40° C.). Instead, it is proposed that more consistent light output can be achieved using white LEDs in combination with colour filters. Optionally, the colour filters may be shaped to act as lenses, and can be housed in a hooded signal unit to prevent undesired reflections known as “phantom signals”. However, colour filters absorb wavelengths of light that are not emitted, therefore there is a large amount of energy wastage.
SUMMARY
[0011] A lighting system is disclosed uses single wavelength LED backlights with lenses embedded with QDs to down-convert the emission. Using a range of QDs of different particle size, multiple wavelengths can be emitted using a monochromatic backlight requiring simple circuitry, thus reducing the cost of manufacture and maintenance compared to solid state LED-based transportation signalling devices. Using the present lighting system, colour blending between red and green lenses can be prevented without using an array of LEDs emitting at multiple wavelengths that are costly and require complex circuitry.
[0012] The lighting system uses a UV or blue LED backlight, which are cheap and readily obtained, with a lens embedded with QD material to act as a down-converting phosphor. The lens design incorporates cylindrical wells in the back-face, into which QDs emitting at different wavelengths and/or intensities are deposited; this serves to out-couple the light reduce blending of light. The QD emission wavelength can be altered by changing the particle size, while varying the QD concentration can be used to control the relative emission intensities observed from the LED backlight and the QD phosphor.
[0013] The lens design can further incorporate a reflector, situated over the face of the LED backlight to in-couple the light directly into the QD lens; this serves to reduce the amount of internal reflection within the signal head, focussing the light into one direction. As a result, the required LED output intensity is reduced. Using QDs of differing wavelengths and narrow beam angles, the colours will have a reduced blending effect, i.e. they will not merge to appear white at long distances.
[0014] The emission intensity of such down-converted emission is typically much higher (typically as high as 80-90%, as determined by the photoluminescence quantum yield of the QDs) than with white LEDs using filters. Thus, the signal lights according to the instant disclosure are more energy efficient than those using filtered light. The emission wavelength of QDs is not significantly affected by small changes in temperature, so are relatively stable (within a few nanometres) within the required operating temperature range. Further, the UV or blue LED backlights proposed in the present invention are typically cheaper than white LED, reducing the maintenance cost of the signal head.
[0015] In comparison to incandescent lighting, the failure of QD phosphors with an LED backlight is gradual, rather than instant; this acts an indicator that the backlight and/or the QD-embedded lens need replacing, accommodating scheduled down-time. As a result, this can reduce the cost associated with paying maintenance staff to work unsociable hours to replace bulbs, along with reduced disruption to rail services.
[0016] Using QDs to tune the emission of the LED backlight, the construction cost of signal heads are reduced, since the cost of the UV or blue LED backlight and the QD material are significantly cheaper than producing a range of solid state LEDs emitting at each required wavelength. The QD emission wavelength can be tuned during synthesis by manipulating the nanoparticle size. Long-red emission (>660 nm), which is notoriously difficult to achieve using solid state LEDs, can be easily realised using QDs, which is advantageous to reduce colour blending between different coloured signals. Due to the employment of a monochromatic solid state LED backlight, the present lens design also requires less complex circuitry than signal head designs using multiple colours of LEDs as described in the prior art.
[0017] The optical design of the lens described herein results in an improved light distribution. Further, the energy consumption of the total lighting package could be reduced relative to existing commercially available rail signals, due to the reflector component. The lens design can be easily tailored to suit a variety of signal heads, e.g. with different distances between the centres of the green and the red lens. The lens design is suitable for use in conjunction with a light pipe, enabling light to be distributed to areas where insufficient space is available to accommodate the lens package.
[0018] Applications of the lighting system include, but are not restricted to, signal heads for the rail industry, and landing strips in the aeronautical industry, where existing issues include green lamps appearing blue over time, primarily due to demand and binning problems
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a diagram illustrating the rail lens design, comprising an LED backlight (blue in this example), with a reflector to focus the light in the direction of a lens containing a plurality of cylindrical wells. The wells are impregnated with red or green quantum dots (or other colours, as required), to down-convert the LED emission in order to emit red or green (or any other desired colour of) light.
[0020] FIG. 2 : Diagram illustrating a lens architecture, comprising a glass lens with cylindrical wells into which QD material is embedded, a transparent glass backing, and an aluminium backing to restrict the passage of light to the positions of the QD-embedded wells.
[0021] FIG. 3 : Diagram showing the arrangement of QD-embedded wells in the lens, arranged with a colour gradient to reduce the effects of colour blending between red and green lenses at long distances. The colour gradient can be achieved using QDs emitting at different wavelengths, or by graduating the QD concentration.
DETAILED DESCRIPTION
[0022] An exemplary lamp with a lens architecture for a lighting system having single wavelength LED backlights with lenses embedded with QDs to down-convert the emission is illustrated in FIG. 1 . The lens features a blue or UV LED 101 as a primary light source, mounted within a reflecting body 102 . The lens also features a QD optic 103 with wells 104 for containing phosphors, such as red- or green-emitting quantum dots. The QD phosphors absorb blue or UV light 105 generated by primary light source 101 and emit red or green light 106 , depending on whether a red or green-emitting QDs are used. The entire assembly can be contained within a housing 107 .
[0023] FIG. 2 illustrates an expanded view of an embodiment of the QD optic 103 illustrated in FIG. 1 . The optic includes a shelled lens 201 incorporating a series of cylindrical wells 202 on one side, each of these wells being impregnated with QDs, a barrier 203 , of a material such as a glass, with a sealed edge to protect the QDs from contaminants such as oxygen and moisture. The optic can also include a plate 204 having the same shape as the inner wall of lens 201 . Plate 204 includes opaque sections 205 to prevent primary light from the primary light source from escaping trough the non-QD-impregnated regions 206 of lens 201 .
[0024] In one embodiment, the wells within the lens are impregnated with a single type of QD material emitting at a single wavelength, e.g. 530 nm (green) or 640 nm (red). Colour blending is reduced by varying the concentration of the QDs within the wells, to alter the observed intensity of the red or green emission.
[0025] In another embodiment, the wells within the lens are impregnated with one or more types of QD material emitting at multiple wavelengths within the same colour range of the EM spectrum e.g. 510-550 nm (green) or 620-660 nm (red) as shown in FIG. 3 . It has been found that creating a colour gradient reduces the effects of colour blending between red and green signals. This can be achieved by filling the wells as concentric circles, each emitting at a slightly different wavelength from the adjacent circle(s). For example, for a green light, outer wells 301 may be filled with QDs emitting at wavelengths 540-550 nm, interior wells 302 may be filled with QDs emitting at wavelengths 530-540 nm, and center wells 303 may be filled with QDs emitting at wavelengths 520-530 nm.
[0026] To achieve the same results illustrated in FIG. 3 using LEDs without a QD-or similar phosphor (i.e., by using LEDs that themselves emit red or green), one would have to sort the LEDs into very narrow and specific wavelength bins and arrange LEDs of those bins in the desired pattern. This process is cumbersome and expensive. But the QD-containing optic of the instant disclosure, combined with a blue or UV emitting LED, can easily create such a colour gradient, simply by using QDs that emit at slightly different wavelengths (i.e., QDs that are slightly different in size).
[0027] The QD-containing material is embedded in a lens containing a series of wells. In addition to its lensing properties, the lens acts as a container to accommodate the QDs, and also as a barrier to protect the components of the lighting system from the surrounding environment. Thus, the lens must be constructed from a material that is resistant to a wide range of temperatures (e.g. −30 to 40° C. for use in the UK), pollutants, moisture, sunlight, and physical impact that may result from extreme weather conditions such as strong winds and hail storms. The lens can be constructed from any suitable optically transparent material including, but not restricted to, glass, polycarbonate, unplasticised polyvinyl chloride, etc.
[0028] Nanoparticles. Suitable nanoparticles can include any QD materials emitting in the visible range, such as, but not restricted to II-IV compounds including a first element from group 12 (II) of the periodic table and a second element from group 16 (VI) of the periodic table, as well as ternary and quaternary materials including, but not restricted to: CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe.
[0029] II-V compounds incorporating a first element from group 12 of the periodic table and a second element from group 15 of the periodic table, and also including ternary and quaternary materials and doped materials. Nanoparticle material includes, but is not restricted to: Zn 3 P 2 , Zn 3 As 2 , Cd 3 P 2 , Cd 3 AS 2 , Cd 3 N 2 , Zn 3 N 2 .
[0030] III-V compounds including a first element from group 13 (III) of the periodic table and a second element from group 15 (V) of the periodic table, as well as ternary and quaternary materials. Examples of nanoparticle materials include, but are not restricted to: BP, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AlN, BN, GaNP, GaNAs, InNP, InNAs, GAInPAs, GaAlPAs, GaAlPSb, GaInNSb, InAlNSb, InAlPAs, InAlPSb.
[0031] III-VI compounds including a first element from group 13 of the periodic table and a second element from group 16 of the periodic table and also including ternary and quaternary materials. Nanoparticle material includes, but is not restricted to: Al 2 S 3 , Al 2 Se 3 , Al 2 Te 3 , Ga 2 S 3 , Ga 2 Se 3 , In 2 S 3 , In 2 Se 3 , Ga 2 Te 3 , In 2 Te 3 .
[0032] IV compounds including elements from group 14 (IV): Si, Ge, SiC, SiGe.
[0033] IV-VI compounds including a first element from group 14 (IV) of the periodic table and a second element from group 16 (VI) of the periodic table, as well as ternary and quaternary materials including, but not restricted to: PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbSe, SnPbTe, SnPbSeTe, SnPbSTe.
[0034] Core QDs generally exhibit low photoluminescence quantum yields, therefore more preferably one or more shell layers of a wider band gap material should be grown epitaxially on the core surface to eliminate non-radiative recombination pathways, thus improving the optical properties of the material. The shell layer(s) grown on the nanoparticle core may include any one or more of the following materials:
[0035] IIA-VIB (2-16) material, incorporating a first element from group 2 of the periodic table and a second element from group 16 of the periodic table, and also including ternary and quaternary materials and doped materials. Nanoparticle material includes, but is not restricted to: MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe.
[0036] IIB-VIB (12-16) material incorporating a first element from group 12 of the periodic table and a second element from group 16 of the periodic table, and also including ternary and quaternary materials and doped materials. Nanoparticle material includes, but is not restricted to: ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe.
[0037] II-V material incorporating a first element from group 12 of the periodic table and a second element from group 15 of the periodic table, and also including ternary and quaternary materials and doped materials. Nanoparticle material includes, but is not restricted to: Zn 3 P 2 , Zn 3 AS 2 , Cd 3 P 2 , Cd 3 AS 2 , Cd 3 N 2 , Zn 3 N 2 .
[0038] III-V material incorporating a first element from group 13 of the periodic table and a second element from group 15 of the periodic table, and also including ternary and quaternary materials and doped materials. Nanoparticle material includes, but is not restricted to: BP, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AlN, BN.
[0039] III-IV material incorporating a first element from group 13 of the periodic table and a second element from group 14 of the periodic table, and also including ternary and quaternary materials and doped materials. Nanoparticle material includes, but is not restricted to: B 4 C, Al 4 C 3 , Ga 4 C.
[0040] III-VI material incorporating a first element from group 13 of the periodic table and a second element from group 16 of the periodic table, and also including ternary and quaternary materials. Nanoparticle material includes, but is not restricted to: Al 2 S 3 , Al 2 Se 3 , Al 2 Te 3 , Ga 2 S 3 , Ga 2 Se 3 , In 2 S 3 , In 2 Se 3 , Ga 2 Te 3 , In 2 Te 3 .
[0041] IV-VI material incorporating a first element from group 14 of the periodic table and a second element from group 16 of the periodic table, and also including ternary and quaternary materials and doped materials. Nanoparticle material includes, but is not restricted to: PbS, PbSe, PbTe, Sb 2 Te 3 , SnS, SnSe, SnTe.
[0042] Nanoparticle material incorporating a first element from any group in the d-block of the periodic table, and a second element from group 16 of the periodic table, and also including ternary and quaternary materials and doped materials. Nanoparticle material includes, but is not restricted to: NiS, CrS, CuInS 2 , CuInSe 2 , CuGaS 2 , CuGaSe 2 .
[0043] The use of heavy metals (cadmium, lead, and mercury) in lighting equipment is restricted in the EU under the Restriction of Hazardous Substances Directive (RoHS) 2011/65/EU. Similar legislation exists in the US and Asia. Therefore, the preferred method of the present invention uses heavy metal-free QDs, such as InP/ZnS core/shell nanoparticles.
[0044] Capping. The coordination around the atoms on the surface of any core, core/shell or core/multishell nanoparticle is incomplete and the non-fully coordinated atoms have dangling bonds which make them highly reactive and can lead to particle agglomeration, which is undesirable for solution processing. This problem is overcome by passivating (capping) the “bare” surface atoms with protecting organic groups. The organic ligands can provide solubility, facilitating their processability.
[0045] The outermost layer (capping agent) of organic material or sheath material helps to inhibit particle-particle aggregation, further protecting the nanoparticles from their surrounding electronic and chemical environments. In many cases, the capping agent is the solvent in which the nanoparticle preparation is undertaken, and consists of a Lewis base compound, or a Lewis base compound diluted in an inert solvent such as a hydrocarbon. There is a lone pair of electrons on the Lewis base capping agent that is capable of a donor-type coordination to the surface of the nanoparticle, and includes mono- or multi-dentate ligands such as phosphines (trioctylphosphine, triphenylphosphine, t-butylphosphine, etc.), phosphine oxides (trioctylphosphine oxide, triphenylphosphine oxide, etc.), alkyl phosphonic acids, alkyl-amines (octadecylamine, hexadecylamine, octylamine, etc.), aryl-amines, pyridines, long chain fatty acids (myristic acid, oleic acid, undecylenic acid, etc.) and thiophenes, but is, as one skilled in the art will know, not restricted to these materials.
[0046] The outermost layer (capping agent) of a QD can also consist of a coordinated ligand with additional functional groups that can be used as chemical linkage to other inorganic, organic or biological material, whereby the functional group is pointing away from the QD surface and is available to bond/react/interact with other available molecules, such as amines, alcohols, carboxylic acids, esters, acid chlorides, anhydrides, ethers, alkyl halides, amides, alkenes, alkanes, alkynes, allenes, amino acids, azide groups, etc. but is, as one skilled in the art will know, not limited to these functionalised molecules. The outermost layer (capping agent) of a QD can also consist of a coordinated ligand with a functional group that is polymerisable and can be used to form a polymer layer around the particle.
[0047] The outermost layer (capping agent) can also consist of organic units that are directly bonded to the outermost inorganic layer such as via an S—S bond between the inorganic surface (ZnS) and a thiol capping molecule. These can also possess additional functional group(s), not bonded to the surface of the particle, which can be used to form a polymer around the particle, or for further reaction/interaction/chemical linkage.
[0048] Incorporation into Microbeads. The QD-impregnated lens described herein can be fabricated with “bare” QDs embedded directly into the wells within the lens, or more preferably, they can be incorporated into microbeads prior to their embedment into the lens wells; the QD microbeads exhibit superior robustness and longer lifetimes than bare QDs, and are more stable to the mechanical and thermal processing protocols of the signal head fabrication and assembly. By incorporating the QD material into polymer microbeads, the nanoparticles become more resistant to air, moisture and photo-oxidation, opening up the possibility for processing in air that would vastly reduce the manufacturing cost. The bead size can be tuned from 20 nm to 0.5 mm, enabling control over the ink viscosity without changing the inherent optical properties of the QDs. The viscosity dictates how the QD bead ink flows through a mesh, dries, and adheres to a substrate, so thinners are not required to alter the viscosity, reducing the cost of the ink formulation. By incorporating the QDs into microbeads, the detrimental effect of particle agglomeration on the optical performance of bare encapsulated QDs is eliminated.
[0049] One such method for incorporating QDs into microbeads involves growing the polymer bead around the QDs. A second method incorporates QDs into pre-existing microbeads.
[0050] With regard to the first option, by way of example, hexadecylamine-capped CdSe-based semiconductor nanoparticles can be treated with at least one, more preferably two or more polymerisable ligands (optionally one ligand in excess) resulting in the displacement of at least some of the hexadecylamine capping layer with the polymerisable ligand(s). The displacement of the capping layer with the polymerisable ligand(s) can be accomplished by selecting a polymerisable ligand or ligands with structures similar to that of trioctylphosphine oxide (TOPO), which is a ligand with a known and very high affinity for CdSe-based nanoparticles. It will be appreciated that this basic methodology may be applied to other nanoparticle/ligand pairs to achieve a similar effect. That is, for any particular type of nanoparticle (material and/or size), it is possible to select one or more appropriate polymerisable surface binding ligands by choosing polymerisable ligands comprising a structural motif which is analogous in some way (e.g. has a similar physical and/or chemical structure) to the structure of a known surface binding ligand. Once the nanoparticles have been surface-modified in this way, they can then be added to a monomer component of a number of microscale polymerisation reactions to form a variety of QD-containing resins and beads. Another option is the polymerisation of one or more polymerisable monomers from which the optically transparent medium is to be formed in the presence of at least a portion of the semiconductor nanoparticles to be incorporated into the optically transparent medium. The resulting materials incorporate the QDs covalently and appear highly coloured even after prolonged periods of Soxhlet extraction.
[0051] Examples of polymerisation methods that may be used to construct QD-containing beads include, but are not restricted to, suspension, dispersion, emulsion, living, anionic, cationic, RAFT, ATRP, bulk, ring-closing metathesis and ring-opening metathesis. Initiation of the polymerisation reaction may be induced by any suitable method that causes the monomers to react with one another, such as by the use of free radicals, light, ultrasound, cations, anions, or heat. A preferred method is suspension polymerisation, involving thermal curing of one or more polymerisable monomers from which the optically transparent medium is to be formed. Said polymerisable monomers preferably comprise methyl (meth)acrylate, ethylene glycol dimethacrylate and vinyl acetate. This combination of monomers has been shown to exhibit excellent compatibility with existing commercially available encapsulants and has been used to fabricate a light-emitting device exhibiting significantly improved performance compared to a device prepared using essentially prior art methodology. Other preferred polymerisable monomers are epoxy or polyepoxide monomers, which may be polymerised using any appropriate mechanism, such as curing with ultraviolet irradiation.
[0052] QD-containing microbeads can be produced by dispersing a known population of QDs within a polymer matrix, curing the polymer and then grinding the resulting cured material. This is particularly suitable for use with polymers that become relatively hard and brittle after curing, such as many common epoxy or polyepoxide polymers (e.g. Optocast™ 3553 from Electronic Materials, Inc., USA).
[0053] QD-containing beads may be generated simply by adding QDs to the mixture of reagents used to construct the beads. In some instances, nascent QDs will be used as isolated from the reaction employed for their synthesis, and are thus generally coated with an inert outer organic ligand layer. In an alternative procedure, a ligand exchange process may be carried out prior to the bead-forming reaction. Here, one or more chemically reactive ligands (for example a ligand for the QDs that also contains a polymerisable moiety) are added in excess to a solution of nascent QDs coated in an inert outer organic layer. After an appropriate incubation time the QDs are isolated, for example by precipitation and subsequent centrifugation, washed and then incorporated into the mixture of reagents used in the bead forming reaction/process.
[0054] These QD incorporation strategies will result in statistically random incorporation of the QDs into the beads and thus the polymerisation reaction will result in beads containing statistically similar amounts of the QDs. It will be obvious to one skilled in the art that bead size can be controlled by the choice of polymerisation reaction used in their construction, and additionally once a polymerisation method has been selected the bead size can also be controlled by selecting appropriate reaction conditions, e.g. by stirring the reaction mixture more quickly in a suspension polymerisation reaction to generate smaller beads. Moreover, the shape of the beads can be readily controlled by choice of procedure in conjunction with whether or not the reaction is carried out in a mould. The composition of the beads can be altered by changing the composition of the monomer mixture from which the beads are constructed. Similarly, the beads can also be cross-linked with varying amounts of one or more cross-linking agents (e.g. divinyl benzene). If beads are constructed with a high degree of cross-linking, e.g. greater than 5 mol % cross-linker, it may be desirable to incorporate a porogen (e.g. toluene or cyclohexane) during the bead-forming reaction. The use of a porogen in such a way leaves permanent pores within the matrix constituting each bead. These pores may be sufficiently large to allow the ingress of QDs into the bead.
[0055] QDs can also be incorporated in beads using reverse emulsion-based techniques. The QDs may be mixed with precursor(s) to the optically transparent coating material and then introduced into a stable reverse emulsion containing, for example, an organic solvent and a suitable salt. Following agitation, the precursors form microbeads encompassing the QDs, which can then be collected using any appropriate method, such as centrifugation. If desired, one or more additional surface layers or shells of the same or a different optically transparent material can be added prior to isolation of the QD-containing beads by addition of further quantities of the requisite shell layer precursor material(s).
[0056] In respect of the second option for incorporating QDs into beads, the QDs can be immobilised in polymer beads through physical entrapment. For example, a solution of QDs in a suitable solvent (e.g. an organic solvent) can be incubated with a sample of polymer beads. Removal of the solvent using any appropriate method results in the QDs becoming immobilised within the matrix of the polymer beads. The QDs remain immobilised in the beads unless the sample is resuspended in a solvent (e.g. organic solvent) in which the QDs are freely soluble. Optionally, at this stage the outside of the beads can be sealed. Alternatively, at least a portion of the QDs can be physically attached to prefabricated polymer beads. Said attachment may be achieved by immobilisation of the portion of the semiconductor nanoparticles within the polymer matrix of the prefabricated polymeric beads or by chemical, covalent, ionic, or physical connection between the portion of semiconductor nanoparticles and the prefabricated polymeric beads. Examples of prefabricated polymeric beads comprise polystyrene, polydivinyl benzene and a polythiol.
[0057] QDs can be irreversibly incorporated into prefabricated beads in a number of ways, e.g. chemical, covalent, ionic, physical (e.g. by entrapment) or any other form of interaction. If prefabricated beads are to be used for the incorporation of QDs, the solvent-accessible surfaces of the bead may be chemically inert (e.g. polystyrene) or alternatively they may be chemically reactive/functionalised (e.g. Merrifield's Resin). The chemical functionality may be introduced during the construction of the bead, for example by the incorporation of a chemically functionalised monomer, or alternatively chemical functionality may be introduced in a post-bead construction treatment, for example by conducting a chloromethylation reaction. Additionally, chemical functionality may be introduced by a post-bead construction polymeric graft or other similar process whereby chemically reactive polymer(s) are attached to the outer layers/accessible surfaces of the bead. More than one such post-construction derivation process may be carried out to introduce chemical functionality onto/into the bead.
[0058] As with QD incorporation into beads during the bead forming reaction, i.e. the first option described above, the pre-fabricated beads can be of any shape, size and composition, may have any degree of cross-linker and may contain permanent pores if constructed in the presence of a porogen. QDs may be imbibed into the beads by incubating a solution of QDs in an organic solvent and adding this solvent to the beads. The solvent must be capable of wetting the beads and, in the case of lightly cross-linked beads, preferably 0-10% cross-linked and most preferably 0-2% cross-linked, the solvent should cause the polymer matrix to swell in addition to solvating the QDs. Once the QD-containing solvent has been incubated with the beads, it is removed, for example by heating the mixture and causing the solvent to evaporate, and the QDs become embedded in the polymer matrix constituting the bead or alternatively by the addition of a second solvent in which the QDs are not readily soluble but which mixes with the first solvent causing the QDs to precipitate within the polymer matrix constituting the beads. Immobilisation may be reversible if the bead is not chemically reactive, or else if the bead is chemically reactive the QDs may be held permanently within the polymer matrix by chemical, covalent, ionic, or any other form of interaction.
[0059] Optically transparent media that are sol-gels and glasses, intended to incorporate QDs, may be formed in an analogous fashion to the method used to incorporate QDs into beads during the bead-forming process as described above. For example, a single type of QD (e.g. one emission wavelength) may be added to the reaction mixture used to produce the sol-gel or glass. Alternatively, two or more types of QD (e.g. two or more emission wavelengths) may be added to the reaction mixture used to produce the sol-gel or glass. The sol-gels and glasses produced by these procedures may have any shape, morphology or 3-dimensional structure. For example, the particles may be spherical, disc-like, rod-like, ovoid, cubic, rectangular, or any of many other possible configurations.
[0060] Once the QDs are incorporated into the beads, the formed QD-beads can be further coated with a suitable material to provide each bead with a protective barrier to prevent the passage or diffusion of potentially deleterious species, e.g. oxygen, moisture or free radicals from the external environment, through the bead material to the semiconductor nanoparticles. As a result, the semiconductor nanoparticles are less sensitive to their surrounding environment and the various processing conditions typically required to utilise the nanoparticles in applications such as the fabrication of QD-embedded lenses.
[0061] The coating is preferably a barrier to the passage of oxygen or any type of oxidising agent through the bead material. The coating may be a barrier to the passage of free radical species and/or is preferably a moisture barrier so that moisture in the environment surrounding the beads cannot contact the semiconductor nanoparticles incorporated within the beads.
[0062] The coating may provide a layer of material on a surface of the bead of any desirable thickness, provided it affords the required level of protection. The surface layer coating may be around 1 to 10 nm thick, up to around 400 to 500 nm thick, or more. Preferred layer thicknesses are in the range 1 nm to 200 nm, more preferably around 5 nm to 100 nm.
[0063] The coating can comprise an inorganic material, such as a dielectric (insulator), a metal oxide, a metal nitride or a silica-based material (e.g. a glass).
[0064] The metal oxide may be a single metal oxide (i.e. oxide ions combined with a single type of metal ion, e.g. Al 2 O 3 ), or may be a mixed metal oxide (i.e. oxide ions combined with two or more types of metal ion, e.g. SrTiO 3 ). The metal ion(s) of the (mixed) metal oxide may be selected from any suitable group of the periodic table, such as group 2, 13, 14 or 15, or may be a transition metal, d-block metal, or lanthanide metal.
[0065] Preferred metal oxides are selected from the group consisting of Al 2 O 3 , B 2 O 3 , CO 2 O 3 , Cr 2 O 3 , CuO, Fe 2 O 3 , Ga 2 O 3 , HfO 2 , In 2 O 3 , MgO, Nb 2 O 5 , NiO, SiO 2 , SnO 2 , Ta 2 O 5 , TiO 2 , ZrO 2 , Sc 2 O 3 , Y 2 O 3 , GeO 2 , La 2 O 3 , CeO 2 , PrO x (x=appropriate integer), Nd 2 O 3 , Sm 2 O 3 , EuO y (y=appropriate integer), Gd 2 O 3 , Dy 2 O 3 , Ho 2 O 3 , Er 2 O 3 , Tm 2 O 3 , Yb 2 O 3 , Lu 2 O 3 , SrTiO 3 , BaTiO 3 , PbTiO 3 , PbZrO 3 , Bi m Ti n O (m, n=appropriate integer), Bi a Si b O (a, b=appropriate integer), SrTa 2 O 6 , SrBi 2 Ta 2 O 9 , YScO 3 , LaAlO 3 , NdAlO 3 , GdScO 3 , LaScO 3 , LaLuO 3 , Er 3 Ga 5 O 13 .
[0066] Preferred metal nitrides may be selected from the group consisting of BN, Aln, GaN, InN, Zr 3 N 4 , Cu 2 N, Hf 3 N 4 , SiN e (c=appropriate integer), TiN, Ta 3 N 5 , Ti—Si—N, Ti—Al—N, TaN, NbN, MoN, WN d (d=appropriate integer), WN e C f (e, f=appropriate integer).
[0067] The inorganic coating may comprise silica in any appropriate crystalline form. The coating may incorporate an inorganic material in combination with an organic or polymeric material, e.g. an inorganic/polymer hybrid, such as a silica-acrylate hybrid material. The coating can comprise a polymeric material which may be a saturated or unsaturated hydrocarbon polymer, or may incorporate one or more heteroatoms (e.g. O, S, N, halo) or heteroatom-containing functional groups (e.g. carbonyl, cyano, ether, epoxide, amide, etc.).
[0068] Examples of preferred polymeric coating materials include acrylate polymers (e.g. polymethyl(meth)acrylate, polybutylmethacrylate, polyoctylmethacrylate, alkylcyanoacryaltes, polyethyleneglycol dimethacrylate, polyvinylacetate, etc.), epoxides (e.g. EPOTEK 301 A and B Thermal curing epoxy, EPOTEK OG112-4 single-pot UV curing epoxy, or EX0135 A and B Thermal curing epoxy), polyamides, polyimides, polyesters, polycarbonates, polythioethers, polyacrylonitryls, polydienes, polystyrene polybutadiene copolymers (Kratons), pyrelenes, poly-para-xylylene (parylenes), polyetheretherketone (PEEK), polyvinylidene fluoride (PVDF), polydivinyl benzene, polyethylene, polypropylene, polyethylene terephthalate (PET), polyisobutylene (butyl rubber), polyisoprene, and cellulose derivatives (methyl cellulose, ethyl cellulose, hydroxypropylmethyl cellulose, hydroxypropylmethylcellulose phthalate, nitrocellulose), and combinations thereof.
[0069] Stability Enhancement. By incorporating QDs into beads in the presence of materials that act as stability-enhancing additives, and optionally providing the beads with a protective surface coating, migration of deleterious species, such as moisture, oxygen and/or free radicals, is eliminated or at least reduced, with the result of enhancing the physical, chemical and/or photo-stability of the semiconductor nanoparticles.
[0070] An additive may be combined with “bare” semiconductor nanoparticles and precursors at the initial stages of the production process of the beads. Alternatively, or additionally, an additive may be added after the semiconductor nanoparticles have been entrapped within the beads.
[0071] The additives that may be added singly or in any desirable combination during the bead formation process can be grouped according to their intended function, as follows:
a. mechanical sealing: fumed silica (e.g. Cab-O-Sil™), ZnO, TiO 2 , ZrO, Mg stearate, Zn Stearate, all used as a filler to provide mechanical sealing and/or reduce porosity. b. Capping agents: tetradecyl phosphonic acid (TDPA), oleic acid, stearic acid, polyunsaturated fatty acids, sorbic acid, Zn methacrylate, Mg stearate, Zn stearate, isopropyl myristate. Some of these have multiple functionalities and can act as capping agents, free radical scavengers and/or reducing agents. c. Reducing agents: ascorbic acid palmitate, alpha tocopherol (vitamin E), octane thiol, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), gallate esters (propyl, lauryl, octyl, etc.), a metabisulfite (e.g. the sodium or potassium salt). d. Free radical scavengers: benzophenones. e. Hydride reactive agents: 1,4-butandiol, 2-hydroxyethyl methacrylate, allyl methacrylate, 1,6-heptadiene-4-ol, 1,7-octadiene, and 1,4-butadiene.
[0077] The selection of the additive(s) for a particular application will depend upon the nature of the semiconductor nanoparticle material (e.g. how sensitive the nanoparticle material is to physical, chemical and/or photo-induced degradation), the nature of the primary matrix material (e.g. how porous it is to potentially deleterious species, such as free-radicals, oxygen, moisture, etc.), the intended function of the final material or device which will contain the primary particles (e.g. the operating conditions of the material or device), and the process conditions required to fabricate the said final material or device. With this in mind, one or more appropriate additives can be selected from the above five lists to suit any desirable semiconductor nanoparticle application.
EXAMPLES
[0078] The wells within the lens can be embedded with QD material according to the following procedures:
Example 1
[0079] In one embodiment of the current invention, the wells in the lens are filled with organic-capped QDs mixed in an acrylate resin. In a nitrogen-filled glove box, the lens wells are first covered with a blank silicone resin to protect the lens from any damage from the acrylate resin in which the QDs are embedded. The silicone resin is cured on a hotplate. The lens wells are then filled with the QD-embedded acrylate resin, which is cured under UV light. The lens is then encapsulated using a thin gas-barrier layer, attached using a UV curing epoxy resin (e.g. Optocast™), and cured under UV light.
Example 2
[0080] In another embodiment of the present invention, the wells in the lens are filled with QD beads. Silicone resin is mixed with a small amount of a Pt catalyst, then the QD beads are added and the mixture is transferred to the wells in the lens. The lens is cured under a nitrogen atmosphere, then encapsulated under a thin layer of gas-barrier, attached to a UV curing epoxy resin. The lens is then cured under UV light.
[0081] The invention has been described herein with reference to representative and non-limiting embodiments. Numerous modifications and adaptions are possible without deviating from the scope of the invention. | A lamp for safety signalling is disclosed. The lamp uses quantum dot phosphors to down-convert light from a primary light source and provide red or green light. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. §119(e) of the following co-pending and commonly-assigned U.S. patent applications:
[0002] Provisional Application Serial No. 60/215,739, filed Jun. 29, 2000, by Gregory A. Fish and Larry A. Coldren, entitled “OPEN LOOP CONTROL OF SGDBR LASERS,” attorneys' docket number 122.4-US-P1;
[0003] Provisional Application Serial No. 60/215,170, filed Jun. 29, 2000, by Paul F. Crowder, entitled “POWER AND WAVELENGTH CONTROL OF SGDBR LASERS,” attorneys' docket number 122.5-US-P1, and
[0004] Provisional Application Serial No. 60/215,742, filed Jun. 29, 2000, by Paul F. Crowder and Larry A. Coldren, entitled “GAIN VOLTAGE CONTROL OF SGDBR LASERS,” attorneys' docket number 122.6-US-P1,
[0005] all of which applications are incorporated by reference herein.
[0006] This application is a continuation-in-part patent application of the following co-pending and commonly-assigned U.S. patent applications:
[0007] Utility application Ser. No. 09/848,791, filed May 4, 2001, by Gregory A. Fish and Larry A. Coldren, entitled “IMPROVED MIRROR AND CAVITY DESIGNS FOR SAMPLED GRATING DISTRIBUTED BRAGG REFLECTOR LASERS,” attorneys' docket number 122.1-US-U1, which claims the benefit under 35 U.S.C. §119(e) of Provisional Application Serial No. 60/203,052, filed May 4, 2000, by Gregory A. Fish and Larry A. Coldren, entitled “IMPROVED MIRROR AND CAVITY DESIGNS FOR SGDBR LASERS,” attorneys' docket number 122.1-US-P1;
[0008] Utility application Ser. No. 09/872,438, filed Jun. 1, 2001, by Larry A. Coldren, Gregory A. Fish, and Michael C. Larson, entitled “HIGH-POWER, MANUFACTURABLE SAMPLED GRATING DISTRIBUTED BRAGG REFLECTOR LASERS,” attorneys' docket number 122.2-US-U1, which claims the benefit under 35 U.S.C. §119(e) of Provisional Application Serial No. 60/209,068, filed Jun. 2, 2000, by Larry A. Coldren Gregory A. Fish, and Michael C. Larson, and entitled “HIGH-POWER, MANUFACTURABLE SAMPLED-GRATING DBR LASERS,” attorneys' docket number 122.2-US-P1;
[0009] Utility application Ser. No. ______, filed Jun. 11, 2001, by Gregory A. Fish and Larry A. Coldren, entitled “IMPROVED, MANUFACTURABLE SAMPLED GRATING MIRRORS,” attorneys' docket number 122.3-US-U1, which claims the benefit under 35 U.S.C. §119(e) of Provisional Application Serial No. 60/210,612, filed Jun. 9, 2000, by Gregory A. Fish and Larry A. Coldren, entitled “IMPROVED, MANUFACTURABLE SAMPLED GRATING MIRRORS,” attorneys' docket number 122.3-US-P1;
[0010] Utility application Ser. No. ______, filed on same day herewith, by Gregory A. Fish and Larry A. Coldren, entitled “OPEN LOOP CONTROL OF SGDBR LASERS,” attorneys' docket number 122.4-US-U1, which claims the benefit under 35 U.S.C. §119(e) of Provisional Application Serial No. 60/215,739, filed Jun. 29, 2000, by Gregory A. Fish and Larry A. Coldren, entitled “OPEN LOOP CONTROL OF SGDBR LASERS,” attorneys' docket number 122.4-US-P1; and
[0011] Utility application Ser. No. ______, filed on same day herewith, by Paul F. Crowder, entitled “POWER AND WAVELENGTH CONTROL OF SGDBR LASERS,” attorneys' docket number 122.5-US-U1, which claims the benefit under 35 U.S.C. §119(e) of Provisional Application Serial No. 60/215,170, filed Jun. 29, 2000, by Paul F. Crowder, entitled “POWER AND WAVELENGTH CONTROL OF SGDBR LASERS,” attorneys' docket number 122.5-US-P1,
[0012] all of which applications are incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0013] 1. Field of the Invention
[0014] The present invention relates to gain voltage control for semiconductor lasers, and particularly, gain voltage control for Sampled Grating Distributed Bragg Reflector (SGDBR) semiconductor lasers.
[0015] 2. Description of the Related Art
[0016] Diode lasers ate being used in such applications as optical communications, sensors and computer systems. In such applications, it is very useful to employ lasers that can be easily adjusted to output frequencies across a wide wavelength range. A diode laser which can be operated at selectably variable frequencies covering a wide wavelength range, i.e. a widely tunable laser, is an invaluable tool. The number of separate channels that can utilize a given wavelength range is exceedingly limited without such a laser. Accordingly, the number of individual communications paths that can exist simultaneously in a system employing such range-limited lasers is similarly very limited. Thus, while diode lasers have provided solutions to many problems in communications, sensors and computer system designs, they have not fulfilled their potential based on the available bandwidth afforded by light-based systems. It is important that the number of channels be increased in order for optical systems to be realized for many future applications.
[0017] For a variety of applications, it is necessary to have tunable single-frequency diode lasers which can select any of a wide range of wavelengths. Such applications include sources and local oscillators in coherent lightwave communications systems, sources for other multi-channel lightwave communication systems, and sources for use in frequency modulated sensor systems. Continuous tunability is usually needed over some range of wavelengths. Continuous tuning is important for wavelength locking or stabilization with respect to some other reference, and it is desirable in certain frequency shift keying modulation schemes.
[0018] In addition, widely tunable semiconductor lasers, such as the sampled-grating distributed-Bragg-reflector (SGDBR) laser, the grating-coupled sampled-reflector (GCSR) laser, and vertical-cavity lasers with micro-mechanical moveable mirrors (VCSEL-MEMs) generally must compromise their output power in order to achieve a large tuning range. The basic function and structure of SGDBR lasers is detailed in U.S. Pat. No. 4,896,325, issued Jan. 23, 1990, to Larry A. Coldren, and entitled “MULTI-SECTION TUNABLE LASER WITH DIFFERING MULTI-ELEMENT MIRRORS”, which patent is incorporated by reference herein. Designs that can provide over 40 nm of tuning range have not been able to provide much more than a couple of milliwatts of power out at the extrema of their tuning spectrum. However, current and future optical fiber communication systems as well as spectroscopic applications require output powers in excess of 10 mW over the full tuning band. Current International Telecommunication Union (ITU) bands are about 40 nm wide near 1.55 μm, and it is desired to have a single component that can cover at least this optical bandwidth. Systems that are to operate at higher bit rates will require more than 20 mW over the full ITU bands. Such powers are available from distributed feedback (DFB) lasers, but these can only be tuned by a couple of nanometers by adjusting their temperature. Thus, it is very desirable to have a source with both wide tuning range (>40 nm) and high power (>20 mW) without a significant increase in fabrication complexity over existing widely tunable designs. Furthermore, in addition to control of the output wavelength, control of the optical power output for a tunable laser is an equally important endeavor as optical power determines the potential range for the laser.
[0019] Fundamentally, maximizing the output power, while stabilizing the output wavelength and the maximizing the side mode suppression ratio are very desirable objectives in the control of SGDBR lasers. Thus, there is a need in the art for devices and methods which maximize the power output. The present invention meets these objectives through a novel use of gain voltage control.
SUMMARY OF THE INVENTION
[0020] A gain voltage controller for use with a sampled grating distributed Bragg reflector (SGDBR) laser is presented. The controller for provides separate inputs to the laser including a front mirror current controlling a front mirror and a back mirror current controlling a back mirror to control the laser and a voltage monitor, coupled to a gain section of the laser for monitoring a gain voltage of the gain section and providing input of the gain voltage to the controller. The controller controls the front mirror current and the back mirror current to minimize the voltage monitored from the gain section of the laser.
[0021] The gain voltage control of the present invention uses feedback from the SGDBR Laser gain section, typically a voltage, to keep the mirrors aligned with the cavity mode of the laser. The feedback is used to align each mirror, and thereby minimizing the Laser gain section voltage, since the Laser gain section voltage minimum is where the cavity loss is a minimum. By minimizing the gain section voltage, the optical power output for a given operating point is maximized, the output wavelength is stabilized, and the side mode suppression ratio is increased.
[0022] Gain voltage control is implemented in a Digital Signal Processor (DSP) by using either a numerical minima search, or a least mean squares (LMS) quadratic estimator, or can be done using analog circuits using a phase locker (PL) circuit.
[0023] When gain voltage control is performed using a DSP, the Laser mirror currents are dithered while the laser gain section is monitored. The DSP then uses a numerical algorithm to align the mirrors by locating the minima of the Laser gain section voltage.
[0024] To reduce the effects of noise in the sampled gain voltage signal, a LMS estimator is used to effectively filter the noise by using an array of data points to estimate the gain voltage surface. Use of the LMS promotes faster convergence to the gain voltage minima, as well as providing a smoother transition to the gain voltage minima than a straight minima search using only a minima search algorithm.
[0025] In addition to the strictly digital approach using only a DSP, which are limited by analog-to-digital conversion rate and digital-to-analog conversion rate, along with the signal-to-noise ratio of the DSP circuitry, analog phase locking circuitry can be used to minimize these limitations. An analog phase locker (PL), which is a high speed, analog-locking loop is used in conjunction with the DSP, to dither the mirror current, measure the gain voltage with a tuned, narrowband amplifier, extract the phase difference between the stimulus and the measured signal, and drive an error amplifier to adjust the mirror current to the gain voltage. The PL error amplifier output is then measured by the DSP, which adjusts the mirror current values to reduce the error to zero. The DSP effectively operates as an integrator function.
[0026] Once new currents to the various sections are established by locking to the external wavelength reference for a given channel, the look-up table can be updated so that the system is adapted to small changes in device characteristics as it ages. Also, by using a formula based upon the initial calibration characteristics, the currents for the other desired operating powers and wavelength channels stored in the look-up table can be updated as well. This insures that desired operating channels can always be accessed over the device's lifetime.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
[0028] [0028]FIGS. 1A and 1B depict a typical multiple-section, widely-tunable laser as used in the invention;
[0029] [0029]FIG. 2 is a block diagram of a typical embodiment of the invention;
[0030] [0030]FIG. 3 illustrates an open loop control system of present invention;
[0031] FIGS. 4 A- 4 B are flowcharts of the incremental and mirror reflectivity peak calibration processes;
[0032] [0032]FIG. 5 is a block diagram of the current sources used in the controller;
[0033] [0033]FIG. 6 illustrates a typical current source circuit of the present invention;
[0034] [0034]FIG. 7 illustrates a typical current mirror circuit of the present invention;
[0035] FIGS. 8 A- 8 C illustrate a typical closed loop power and wavelength control system;
[0036] [0036]FIG. 9 illustrates the DSP gain voltage control block diagram;
[0037] [0037]FIG. 10 illustrates the analog gain voltage control block diagram;
[0038] [0038]FIG. 11 illustrates the analog phase lock circuit block diagram; and
[0039] [0039]FIG. 12 illustrates the combined operation of analog gain voltage control circuits to correct the outputs to the two mirrors from the open loop digital controller.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] In the following description, reference is made to the accompanying drawings which form a part hereof, and which is shown, by way of illustration, an embodiment of the present invention. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
[0041] 1. Overview
[0042] [0042]FIGS. 1A and 1B depict a typical multiple-section, widely-tunable laser 100 as used in the invention. A typical SGDBR laser 100 as used in the invention essentially comprises four sections that allow its unique tuning characteristics. The laser 100 is comprised of a gain section 102 , a phase section 104 , a back mirror 106 and a front mirror 108 . Below these sections is a waveguide 110 for guiding and reflecting the light beam, while the entire device is formed on a substrate 112 . In use, bias voltages are connected to the electrodes 114 on the top of the device and a ground is connected to a lower substrate 112 . When a bias voltage on the gain section 102 is above a lasing threshold, a laser output is produced from an active region 116 .
[0043] The front and back mirrors 108 , 106 are typically sampled grating mirrors that respectively include different sampling periods 118 , 120 . The gratings behave as wavelength-selective reflectors such that partial reflections are produced at periodic wavelength spacings of an optical signal carried in the cavity. The front and back sampled grating mirrors 108 , 106 together determine the wavelength with the minimum cavity loss through their effective lengths and grating differential; however, the lasing wavelength can only occur at the longitudinal modes of the optical cavity in the waveguide 110 . Therefore, it is important to adjust the mirrors 106 , 108 and waveguide 110 modes to coincide, thereby achieving the lowest cavity loss possible for the desired wavelength and maximum mode stability. The phase section 104 of the device shown in FIG. 1 is used to adjust the optical length of the cavity in order to position the cavity modes.
[0044] Optional back-side monitor 122 and front-side semiconductor optical amplifier (SOA) and/or optical modulator 124 sections are also indicated. Currents are applied to the various electrodes 114 of the aforementioned sections to provide a desired output optical power and wavelength as discussed in U.S. Pat. No. 4,896,325, issued Jan. 23, 1990, to Larry A. Coldren, and entitled “MULTI-SECTION TUNABLE LASER WITH DIFFERING MULTI-ELEMENT MIRRORS”, which patent is incorporated by reference herein. As described therein, a current to the gain section 102 creates light and provides gain to overcome losses in the laser cavity; currents to the two differing SGDBR wavelength-selective mirrors 106 , 108 are used to tune a net low-loss window across a wide wavelength range to select a given mode; and a current to the phase section 104 provides for a fine tuning of the mode wavelength. It should also be understood that the sections are somewhat interactive, so that currents to one section will have some effect on the parameters primarily controlled by the others.
[0045] Currents and voltages are applied and/or monitored at the optional sections to monitor power or wavelength, or provide amplification or modulation as specified in commonly-assigned and co-pending applications, namely application Ser. No. 09/614,378, filed on Jul. 12, 2000, by Gregory Fish et al., and entitled “OPTOELECTRONIC LASER WITH INTEGRATED MODULATOR,”; application Ser. No. 09/614,377, filed on Jul. 12, 2000, by Larry Coldren, and entitled “INTEGRATED OPTOELECTRONIC WAVELENGTH CONVERTER,”; and application Ser. No. 09/614,375, filed on Jul. 12, 2000, by Beck Mason et al., and entitled “TUNABLE LASER SOURCE WITH INTEGRATED OPTICAL AMPLIFIER,” each of which claims priority to Provisional Application Ser. Nos. 60/152,072, 60/152,049 and 60/152,072, all filed on Sep. 2, 1999; all of which applications are incorporated by reference herein. The current invention operates under the same general principles and techniques as these background inventions.
[0046] [0046]FIG. 2 is a block diagram of a typical control system 200 embodiment of the invention. In general, the controller 202 applies input signals 204 to the various sections of the laser 206 to operate it and produce a laser output 208 at a desired wavelength. Many factors may influence the laser output 208 and the controller 202 optimally stabilizes the laser output 208 over the life of the laser 206 . In closed-loop variants of the control system 200 , the controller 202 may monitor the laser 206 and its output via feedback signals 210 and adjust the various laser inputs 204 accordingly. For example, in one embodiment the laser 206 monitors the feedback signals 210 of the multiple-section, widely tunable laser gain section voltage, temperature, and an external reference 212 , such as a wavelength locket (e.g. a Fabry-Perot Etalon), via respective feedback signals 210 A- 210 C. The controller 202 adjusts the laser section currents and temperature to maintain a fixed optical power and wavelength. The Laser temperature is regulated with a cooling device 214 , such as a thermoelectric cooler (TEC), via a separate control loop. The laser 206 generates continuous optical output power.
[0047] The controller 202 interfaces to the host over a system interface 216 , such as a serial or parallel interface. The host commands the operation of the controller 202 . The controller 202 regulates the laser optical output power and wavelength and may operate in one of the following control modes:
[0048] A. Open loop control using fixed operating points.
[0049] B. Power and wavelength control using open loop control's fixed operating points as initial operating points and regulating the optical power and wavelength to a reference thereafter.
[0050] C. Gain voltage control using open loop control's fixed operating points as initial operating points and regulating the Laser mirror alignment with the cavity mode thereafter.
[0051] D. Regulating power, wavelength, and gain voltage using open loop control's fixed operating points as initial operating points.
[0052] Various embodiments of the control modes are detailed hereafter.
[0053] 2.0 Open Loop Control
[0054] [0054]FIG. 3 illustrates an open loop control system 300 that sets the laser optical output 208 power and wavelength by setting the laser section current inputs 204 from values in an aging model stored in the controller 202 . The current inputs 204 may be applied, for example, to a back mirror (BM), phase (Ph), Gain (Gn), front mirror (FM), and optical amplifier (SOA) sections of the laser 304 . The controller 202 regulates the laser temperature to a fixed value by monitoring a sensor 308 and controlling the cooler 214 accordingly. The current input 204 settings or operating points of the various sections of the laser 304 are generated by a calibration routine. The settings are fixed over the lifetime of the product. The choice of the operating current inputs 204 , the current sources, and temperature regulator guarantees maximum stability of the optical output wavelength and power over operating lifetime and ambient environmental conditions.
[0055] As previously mentioned, the integrated optical amplifier (SOA), like the integrated modulator, is optional and not included on all designs.
[0056] 2.1 Operating Points
[0057] The laser operating points are determined by either an incremental calibration routine or a mirror reflectivity peak calibration routine.
[0058] 2.1.1 Incremental Calibration
[0059] Incremental calibration steps and locks the laser to each channel, such as each ITU wavelength channel using a calibrated wavelength locker as a reference, such as a Fabry-Perot etalon. It steps to the next channel by adjusting the phase current and locking the mirrors to the cavity mode with gain voltage control. Once at the channel, it locks the Laser wavelength to the channel by adjusting the phase current using wavelength control and the laser power to a predetermined set point by adjusting the gain current with power control.
[0060] Incremental calibration starts with the mirrors aligned at mirror reflectivity peak 0 and then searches for the next lower channel. At each cavity mode, it resets the phase current to its initial value and continues the search. At the end of each mirror tuning range, the mirror currents are reset to the next mirror reflectivity peak. Once the wavelength wraps around, the process is repeated at mirror reflectivity peak 0 by searching for the next upper channel.
[0061] [0061]FIG. 4A is a flowchart of the incremental calibration process. The typical process may begin by setting the gain current at a nominal operation current at block 404 . The mirrors are set at the next reflectivity peak in a chosen direction (up or down) at block 406 . If the wavelength wrapped at block 402 , the chosen direction is changed at block 400 and the process begins again. If the wavelength did not wrap, the phase current is set at a minimum operation current at block 410 and the mirrors are locked to the cavity mode at block 412 . If the mirrors have reached the end of their tuning range at block 408 , the process resets to block 406 at the next reflectivity peak. If the tuning range has not been reached, the power and wavelength are locked at the channel and the mirrors are aligned at block 416 . The channel and corresponding input currents are recorded at block 418 and the laser is stepped to the next channel with the mirrors lock to phase at block 420 . If the cavity mode has been passed at block 414 , the process restarts at block 410 to reset the phase current. If the cavity mode has not been passed, power and wavelength are locked again at the new channel as the process resets to block 416 . This process will continue until a change in wavelength is indicated again at block 400 . At this point, the process ends.
[0062] The following pseudo-code also describes the logic of the incremental calibration shown in FIG. 4A.
[0063] For each wavelength direction about mirror reflectivity peak 0
[0064] Until (wavelength wraps)
[0065] Set gain current at nominal operational current
[0066] Set mirrors at next reflectivity peak
[0067] Until (end of mirror tuning range)
[0068] Set phase current at minimum operational current
[0069] Lock mirrors to cavity mode
[0070] Until (passes cavity mode)
[0071] Lock power and wavelength at channel and align mirrors
[0072] Record channel and currents
[0073] Step to next channel with mirrors locked to phase
[0074] 2.1.2 Mirror Reflectivity Peak Calibration
[0075] Mirror reflectivity peak calibration determines the mirror reflectivity peaks, generates the mirror tuning efficiency curves, and uses the curves to set the mirror currents for each channel.
[0076] [0076]FIG. 4B is a flowchart of the mirror reflectivity peak calibration process. The process may begin with sweeping the mirror with the cavity mode aligned to the mirror at block 424 . The gain voltage minima, which correspond to the mirror reflectivity peaks, are located at block 426 . The currents corresponding to the minima are recorded at block 428 . If the wavelength does not cross the 0 peak at block 422 , the process returns to block 424 to continue sweeping the mirror. Otherwise, a mirror tuning efficiency curve is generated from the reflectivity peaks at block 430 . Then at block 434 the mirrors are set to a channel using the mirror tuning efficiency curve. The phase section is aligned to the mirrors at block 436 and the wavelength is locked to the channel using wavelength control at block 438 . Finally, the power is locked to the set point using the power control at block 440 and the channel and input currents are recorded at block 442 . The process ends when the last channel has been located as checked at block 432 .
[0077] The following pseudo-code also describes the logic of the mirror reflectivity peak calibration shown in FIG. 4B.
[0078] Until (wavelength crosses mirror reflectivity peak 0)
[0079] Sweep mirror with cavity mode aligned to mirror
[0080] Locate the gain voltage minima, which is the corresponding mirror reflectivity peak.
[0081] Record the currents
[0082] Generate mirror tuning efficiency curve from reflectivity peaks
[0083] Until (step through all channels)
[0084] Set mirrors to channel using mirror tuning efficiency curve
[0085] Align phase section to the mirrors
[0086] Lock wavelength to channel using wavelength control
[0087] Lock power to set point using power control
[0088] Record the channel and currents
[0089] 2.2 Current Sources
[0090] [0090]FIG. 5 is a block diagram of the current sources 500 used in the controller 202 . The Controller current sources 500 drive the phase, mirror, amplifier, and gain sections of the laser 100 . The current sources are comprised of a voltage reference 504 , individual 16-bit digital to analog converters 506 (DACs), and voltage to current (VI) amplifiers 508 . The DACs 506 connect to the digital signal processor (DSP) synchronous serial port 510 (SSP) through a programmable logic device 512 (PLD). The PLD 512 provides a logic interface between the DSP SSP 510 and the DACs 506 . The VI amplifiers 508 translate the DAC voltage outputs 514 to proportional current inputs 204 that drive the laser sections.
[0091] 2.2.1 Voltage to Current Converter
[0092] [0092]FIG. 6 illustrates a typical current source circuit 600 of the present invention. The voltage to current amplifier is a modified Howland circuit source (MHCS). A current mirror 602 is added to the output stage of the amplifier 604 to increase the drive current beyond that of the amplifier 604 alone. A filter stage 606 is added at the load 608 to reduce noise.
[0093] [0093]FIG. 7 illustrates a typical current mirror circuit 602 of the present invention. The current mirror inverts the output of the amplifier 604 , which requires the source, Vin, at the inverting node of the amplifier 604 of the current source circuit 600 .
[0094] The current mirror operates at a fixed gain that is determined, primarily, by the ratio of the resistors 702 in the emitter leads of the transistors. An RC compensation network 704 is added to insure stability of the amplifier and current mirror. The gain of the current is variable up to a maximum ratio. The maximum ratio is determined by the additional drift introduced by heating of the transistor 706 and sense resistor 708 and the maximum thermal loss that can be sustained by the transistor 706 and sense resistor 708 . If additional gain is required, an additional Qmo and Rmo section can be added to the mirror 602 .
[0095] 3 Power and Wavelength Control
[0096] FIGS. 8 A- 8 C illustrate a typical closed loop power and wavelength control system. FIG. 8A illustrates the control block diagram. Power and wavelength control 800 combines open loop control (as shown in FIG. 3) and feedback 210 A from an external wavelength locker (e.g., a Fabry-Perot Etalon) reference 212 to lock the laser optical output power and wavelength to the reference 212 . Power and wavelength control compensates for drift in the controller current sources 508 and the laser operating points over time and temperature.
[0097] Once new currents to the various sections 304 are established by locking to the external wavelength reference 212 for a given channel, the aging model or lookup table can be updated so that the system is adapted to small changes in device characteristics as it ages. Also, by using a formula based upon the initial calibration characteristics, the currents for the other desired operating powers and wavelength channels stored in the aging model can be adjusted as well. For example, the currents for each section at any other channel are adjusted in proportion to the change in that section current at the operating channel.
dIgain=Igain,change/Igain,calibration [at operating channel]
change=(Igain,calibration+dIgain*Igain,calibration [at any other channel]
[0098] This is done for each section current. This insures that desired operating channels can always be accessed over the device's lifetime.
[0099] The power and wavelength controls may each operate independently or interdependently with other laser inputs.
[0100] 3.1 Independent
[0101] [0101]FIG. 8B is a flow diagram of independent control of the power and wavelength. The least complex control algorithm is where the controls operate independently. Each control algorithm induces changes in one laser input, such as a current or temperature, independent of the other laser inputs. The control algorithms are classical proportional, integral control routines. The laser output is compared to the reference to identify whether a change in optical power and/or optical wavelength is indicated at block 810 . If a change in the optical power is indicated at block 812 , the optical power is adjusted by the gain current (Ign) or by the current to a SOA (if integrated into the Laser) at block 814 . If a change in the optical wavelength is indicated at block 814 , optical wavelength is adjusted by the phase current (Iph) or the submount temperature at block 818 . Of course, the order of the power or wavelength adjustment is unimportant. In addition, the aging model may be updated whenever a change (in power or wavelength) is indicated. Mirror currents are left fixed.
[0102] 3.2 Interdependent
[0103] [0103]FIG. 8C is a flow diagram of interdependent control of the power and wavelength. The independent control algorithm is slow and marginally stable in its response to changes in the optical power output and optical wavelength. The mirrors and cavity mode become misaligned as the control algorithm adjusts the gain and phase currents from their predefined values. The quality of the optical output is reduced (decreased side mode suppression ratio) and the probability of a mode hop is increased (wavelength shift) as the mirrors and cavity mode become misaligned.
[0104] The interdependent control algorithm induces primary changes in one laser input, such as a current or temperature, and corrects for secondary changes in at least one other laser input with an adaptive filter or estimator. This compensates for wavelength shifts or power changes and mirror misalignment induced when the control adjusts its primary variable. Here also, the laser output is compared to the reference to identify whether a change in optical power and/or optical wavelength is indicated at block 820 . If a change in the optical power is indicated at block 822 , the power is adjusted by the gain current (Ign) at block 824 and the wavelength is stabilized by adjusting the phase current (Iph) by an adaptive filter at block 826 . The mirror currents are realigned by a fixed estimator at block 828 . Following this, the aging model is updated at block 836 . If a change in the optical wavelength is indicated at block 830 , wavelength is adjusted by the phase current (Iph) or the carrier temperature at block 832 . The power is stabilized by adjusting the gain current (Ign) by an adaptive filter at block 834 . and the mirror currents are realigned by a fixed estimator at block 828 . Here too, the aging model is updated at block 836 .
[0105] The interdependent controls provide more robust, stable, and faster convergence of the power and wavelength to its reference value.
[0106] As outlined above, the aging model is then updated to reflect the new model coefficients whereby the currents from the aging model or look-up table are adjusted for a given desired wavelength and power. Also, the changes required for this particular channel can be used to estimate the changes required for all other channels.
[0107] 4.0 Gain Voltage Control
[0108] Gain Voltage Control uses feedback from the Laser gain section voltage to keep the mirrors aligned with the cavity mode. It aligns the mirrors by minimizing the Laser gain section voltage. The Laser gain section voltage minimum is where the cavity loss is a minimum. It corresponds to maximum optical power output, wavelength stability, and side mode suppression ratio.
[0109] Gain voltage control is implemented in the DSP using a numerical minima search or a least mean squares (LMS) quadratic estimator or in analog circuitry using a phase locker (PL) circuit.
[0110] 4.1 DSP Gain Voltage Control
[0111] [0111]FIG. 9 illustrates the DSP gain voltage control block diagram. The DSP dithers the Laser mirror currents 902 , 904 and monitors the Laser gain section voltage 906 . It uses a numerical algorithm to align the mirrors by locating the minima of the Laser gain section voltage.
[0112] 4.1.1 DSP Minima Search Algorithm
[0113] The minima search algorithm uses three data points (mirror current, gain voltage) and estimates the slope of the gain voltage curve with respect to the mirror current. The algorithm steps towards the gain voltage minima and calculates the next data point and uses the new data point and the two best points to re-estimate the slope of the gain voltage curve. The algorithm continues the above step process, continually searching for the gain voltage minima.
[0114] 4.1.2 DSP LMS Estimator
[0115] The minima search algorithm is susceptible to wandering around the gain voltage minima due to noise in the sampled gain voltage signal. The wandering is reflected as drift and noise on the optical signal. The LMS estimator reduces the wander and noise by using an array of data points to estimate the gain voltage surface, in effect, filtering the noise. The LMS estimator converges to the gain voltage minima faster and smoother than the minima search.
[0116] For fixed phase and gain section currents, the gain section voltage can be modeled using a causal Volterra series expansion over 2 input signals, the front mirror and back mirror currents. For dithering signals in the sub-100 kHz regime, the analog circuitry and the device itself allow a memoryless model, so a 5-tap adaptive quadratic filter model will suffice.
[0117] The LMS estimator can then be achieved using either of two classic adaptive filter update algorithms, a standard gradient descent adaptation (LMS or block LMS algorithm) or a (faster) recursive least squares adaptation (RLS algorithm—based on Newton's Method).
[0118] The second approach is used to achieve faster convergence of adaptive linear filters when the signals driving the system do not have sufficient spectral flatness to allow a rapid gradient descent. However, in the case of adaptive linear filters, the gradient descent approach converges just as fast as the RLS approach when white noise can be used to drive the system. Recently published results indicate that comparable rates of convergence can be achieved with adaptive quadratic filters if a minor filter structure modification is used and (pseudo) Gaussian white noise can be used to drive the system.
[0119] There are two advantages of this LMS estimator approach. First, an initial tap-vector can be stored along with the 4 drive currents in the laser calibration table in flash memory (resulting in much faster convergence). Second, the adaptation step size can be reduced as the system converges, reducing steady-state misadjustment in the mirror section currents.
[0120] 4.2 Analog Gain Voltage Control
[0121] [0121]FIG. 10 illustrates the analog gain voltage control block diagram. The gain voltage 1002 is connected to analog phase lockers (PL) 1004 A, 1004 B for each mirror section 1006 A, 1006 B. The digital algorithms are limited in speed and accuracy by the analog to digital converters (ADC or A/D) 1008 A, 1008 B and digital to analog converters (DAC or D/A) 1010 A, 1010 B as well as the signal to noise ratio (SNR) of the circuit. The analog phase locker's speed and accuracy is limited by the SNR of the circuit.
[0122] [0122]FIG. 11 illustrates the analog phase lock circuit block diagram 1100 . The analog phase locker is a high speed, analog-locking loop. It is realized by a phase lock loop (PLL) or RF dither locker. The PL works with the open loop control circuit. The output of the PL adds to the output of the open loop control current sources.
[0123] The PL uses a high frequency narrowband stimulus 1102 to dither the mirror current. The gain voltage (Vg) 1104 is measured with a tuned, narrowband amplifier 1106 . The phase difference between stimulus and measured signal is extracted by a phase comparator 1108 and drives an error amplifier that adjusts the mirror 1110 current to the gain voltage minima and is sampled by an ADC 1112 .
[0124] The PL error amplifier output is measured by the DSP. The DSP adjusts the mirror current values in the Open Loop Control aging model to reduce the error to zero. The DSP effectively operates as an integrator function.
[0125] [0125]FIG. 12 illustrates the combined operation of analog gain voltage control circuits to correct the outputs to the two mirrors from the open loop digital controller. The digital memory/DSP 1200 can set a first approximation current and voltage from a table look up. The analog correction circuits 1004 A, 1004 B can provide feedback and correction signals to the device as described previously, and the digital controller then monitors the correction signals 1202 , 1204 and readjusts the currents and voltages to have the feedback currents from the analog correction portions approach zero. The adjusted currents are used by the aging model to update the aging coefficients. This allows for correction of the laser controller over the life of the SGDBR laser, and accounts for changes in operating temperatures and conditions as well as changes in the operation of the SGDBR laser internal components.
[0126] 5 Power, Wavelength, and Gain Voltage Control
[0127] Power, wavelength, and gain voltage control operates the power and wavelength control and gain voltage control simultaneously.
[0128] 6 Conclusion
[0129] The foregoing description of the preferred embodiment 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 not intended that the scope of the invention be limited by this detailed description.
[0130] This concludes the description of the preferred embodiment of the present invention. The foregoing description of the 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. | A gain voltage controller for use with a sampled grating distributed Bragg reflector (SGDBR) laser is presented. The controller for provides separate inputs to the laser including a front mirror current controlling a front mirror and a back mirror current controlling a back mirror to control the laser and a voltage monitor, coupled to a gain section of the laser for monitoring a gain voltage of the gain section and providing input of the gain voltage to the controller. The controller controls the front mirror current and the back mirror current to minimize the voltage monitored from the gain section of the laser. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional App. No. 60/609,201, filed Sep. 10, 2004, and to U.S. patent application Ser. No. 11/225,266, filed Sep. 12, 2005, the entire contents of each of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method and system for managing applications data submission, policy quotation, and policy issuance for insurance applications.
[0004] More specifically, the present invention relates to a method and system providing a real-time, entry, collection and processing of insurance application data. The processing of the data includes the generation of a policy quote together with the means for issuing a subsequent policy. The data management is furthered through the creation of a living folder which can accept or donate data from/to each of the routines, rating engines and report generators under control of the system.
[0005] 2. Description of the Related Art
[0006] The related art involves a plurality of related processes and systems for selected aspects of the insurance business. Selected examples of such related processes and systems fail to include the novel aspects discussed herein, but are supplied below and incorporated fully herein to aid the reader in grasping the overall concepts discussed.
[0007] In a first example, US Pub. No. 2001/0049611 to Peach (hereinafter referred to as “Peach”), the contents of which are fully incorporated herein by reference, provides a system and method for electronically acquiring and distributing insurance policy data to broker offices. As noted in Peach, while selected client data is entered into insurance industry standardized forms, such as those provided by the Association for Cooperative Operations Research (ACORD), such data entry is well known as responding to data inquiry requests, and fails to disclose the unique data-stamp validation and tracking elements discussed herein.
[0008] In an additional example of a related art reference, US Pub. No. 2002/0138310 to Sagalow (hereinafter referred to as “Sagalow”), the contents of which are fully incorporated herein by reference, the inventor provides a process for online sale of internet insurance products in a very brief three-page discussion, but fails to focus on the present invention and instead is customer-focused, allowing a customer to select an insurance desired and to apply for the same. Unfortunately, Sagalow fails to recognize the needs within the insurance management and intermediate underwriting, binding, and tracking management areas.
[0009] In an additional example, US Pub. No. 2004/0078243 to Fisher (hereinafter referred to as “Fisher”), the contents of which are fully incorporated herein by reference, the inventor discusses an automatic insurance processing method wherein an end-insured completes an insurance request form and emails the same for later review and underwriting and return after underwriting. Unfortunately, Fisher fails to address the industry specific needs noted below for an efficient and effective management of a secure underwriting insurance system.
[0010] In another additional example, as noted in US Pub. No. 2002/0120476 to Labelle et al. (hereinafter referred to as “Labelle”), the contents of which are fully incorporated herein by reference, the inventors discuss a system and method of dispensing insurance through a computer network. While Labelle does provide electronic distribution of insurance products, it fails in completing the essential security and management aspects provided herein.
[0011] In a further related example, as noted in US Pub. No. 2002/0194033 to Huff, the contents of which are fully incorporated herein by reference, the inventor discusses an automatic insurance data extraction and quote generating system, and methods therefore.
[0012] In a final related example, provided by “Insurance Noodle”, and noted at http://www.insurancenoodle.com/Products/licensing/index.asp, the contents of which are fully incorporated herein by reference, the inventors provide various data entry, and risk appetite programs for license and also discuss the cross-incorporation of insurance billing and insurance services.
[0013] What is not appreciated by the related art, is the need for an insurance management system providing the improvements enabled by the present disclosure.
[0014] Accordingly, based upon the limited related art and its inability to provide a comprehensive electronic insurance application receipt, tracking, underwriting, binding, and issuing system, there is a need for an improved method and system for insurance applications, underwriting, and management thereof, having at least one of the following benefits:
[0000] (a) a stream-lined system minimizing human administration costs throughout the insurance request, broker, underwriting, binding, and issuance process;
(b) minimize the loss of “unusual” applications and those applications otherwise lost or trapped within an application tracking system or requiring additional information or input;
(c) to minimize the generation of duplicate of ghost applications or preliminary quotations and underwritings within an overall insurance issuance and managing system; and
(d) allow the generation, tracking, and management of “electronic notes” on each underwriting and application page that are created detailing the date and time each task was completed, who performed the task and what was performed, as well as any additional follow-up matters.
[0015] Additionally, there is the need for the provision of a living folder for the acceptance and donation of data relative to one or more applicants and/or insureds and the applications and/or policies related to them.
OBJECTS AND SUMMARY OF THE INVENTION
[0016] An aspect of the present invention is to provide an enabling system providing at least one of the benefits noted above.
[0017] Another aspect of the present invention is to provide a living folder for the acceptance and donation of data relative to one or more applicants and/or insureds and the applications and/or policies related to them.
[0018] The present invention relates to a method and system for data submission management of insurance application data by a host data processing system. The invention comprises authenticating the submission of data relative to an insurance applicant. The authenticated data is matched with a set of data points and merged to create a submission to be matched with a set of price points in a quotation routine to establish a quote. The quote is ultimately accepted or rejected by the applicant outside of the system parameters. If accepted, then the underwriter will issue an order to bind conditionally. A policy is then issued to the applicant in respect of the quote. Subsequently, a set of endorsements may be added to the policy. A policy information routine for matching the insurance application data to a set of data fields is initiated to establish a living folder which can be the source of data for populating other routines, system folders, or report generators.
[0019] According to an embodiment of the present invention there is provided a method and system for data submission management of insurance application data by a data processing system. The method comprises a number of steps which include authenticating, at a remote node, the submission of data to be entered in the system relative to an insurance applicant. The authenticated data is then matched with a set of one more pre-established routines residing in a system memory and corresponding to particular data entry points indicative of the routines to be utilized.
[0020] The authenticated data is merged with the matched routines to create a submission; each submission further comprising a set of data fields.
[0021] The submission is then submitted to a host data processing center to match the data fields with a set of price points in a quotation routine to establish a quote in respect of the submission.
[0022] The quote is then transmitted from the host data processing center to the remote node where it is accepted or rejected by the applicant. If the quote is rejected, then the system user is prompted as whether or not to modify the data to be authenticated; and, if the data is not modified, than terminating the routine. If, however, the quote is accepted, then the applicant is bound conditionally and one or more tasks to be performed in respect of the binding are identified. A policy is then issued to the applicant in respect of the quote. Subsequently, the one or more tasks, such as a facility inspection, repair, or an individual's physical exam, are performed, and a set of one or more endorsements (changes or modifications) to the policy in respect of a result related to the tasks is added to the policy.
[0023] The pre-established routines further comprise the steps of determining a set of one or more options that are available to the applicant for construction of the policy. A set of administrative options, based on the data input, are also made available by the system. Additionally, the pre-established routines further comprise the step of determining the set of one or more tasks to be performed subsequent to the policy being issued. The system can generate a report, relative to a policy, and derived from the data collected by the system.
[0024] The data input is utilized by the host data processing center to re-calculate and re-set one or more data fields, such as price points, resident within the system memory. The pre-established routines are trainable by updating one or more fields with data that is input periodically to reflect market conditions and fluctuations.
[0025] The method further comprises the acceptance of an application for entry into the data processing system. A policy information routine for matching the insurance application data to a set of one or more data fields relevant to the application is initiated to establish a living folder. The living folder can be modified at any time required by the system; and, can be the source of data for populating other routines, system folders or report generators. The living folder further comprises a plurality of sub-folders for storing data relevant to an applicant's application or policy. Each of the sub-folders can be populated with data generated by the plurality of routines and collected from the data processing system. Additionally, the data processing system can query each of the sub-folders and withdraw data from the relevant sub-folder based upon a set of pre-established criteria and needs.
[0026] The authenticated data is then merged with the matched routines to create a quick quote; the quick quote further comprising a set of data fields. The quick quote is then transmitted from the host data processing center to the remote node, where it is accepted or rejected by the applicant. A quick quote differs from the standard quote in that it is using a reduced number of fields to draw data as compared to a full policy quote. The advantage to the applicant is in terms of speed because of the reduced amount of information required of the applicant.
[0027] The system of the present invention, on the other hand, comprises the host data processing center and the set of one or more remote nodes for linking with the host data processing center. At least one of the remote nodes can be co-located with the host. The system includes transmission means for transmitting data between each one of the set of one or more remote nodes and the host data processing center. The transmission means can comprise wireless and/or hard-wired transmission means depending upon the nature of the network utilized. Further, the system can reside in either a wide area network (WAN), a local area network (LAN), or be accessible through the Internet.
[0028] Additionally, there is an insurance policy creation application residing in the data processing system, the application further comprising an input routine residing in the host data processing system wherein the routine accepts data input from at least one of the remote nodes relative to an insurance application. The input routine can be resident at the host data processing center, or at the remote node.
[0029] The system further comprises authentication means for authenticating the data input. The data is then introduced to first matching means for matching the authenticated data with a set of one more pre-established routines residing in a memory of the host data processing center and corresponding to particular data entry points. Merging means then merge the authenticated data with the matched routines to create a submission comprising a set of data fields. Then, second matching means match the set of data fields with a set of price points in a quotation routine of the host data processing center to establish a quote in respect of the match. Matching means then allow the quote to be selected or rejected by the applicant. If the quote is rejected, then it is determined through query whether or not to modify the data to be authenticated; and, if the data is not modified than terminating the routine. However, if the quote is accepted, then the system user creates a binder and one or more tasks to be performed in respect of the binding are identified. The system can then generate a policy to be issued to the applicant in respect of said quote.
[0030] In addition to the routines and hardware previously mentioned, the system further comprises a forms library for providing a pre-determined format for data to be transmitted in the form of the quote, the policy, or any number of reporting formats. There is also provided a rating engine for calculating the set of price points for the quotation routine and printing means for printing a set of reports and/or documents derived from the system.
[0031] An important aspect of the present invention is the creation of a living folder that can accept or donate data relative to each insurance holder's policy or application. The data processing system further comprises a data management routine for directing data to each of the sub-folders in accordance with a pre-established set of criteria associated with each of the sub-folders.
[0032] The living folder further comprises a set of one or more sub-folders. In a preferred embodiment of the present invention, there are a plurality of sub-folders which include a first sub-folder for storing general information about one or more policies associated with the applicant. Additionally, there may be: a second sub-folder for storing insurance broker information; a third sub-folder for storing details of said one or more policies; a fourth sub-folder for storing endorsements associated with said one or more policies; a fifth sub-folder for storing one or more documents associated with said one or more policies; a sixth sub-folder for storing communications in respect of said one or more policies; a seventh sub-folder for storing notes relative to said one or more policies; and an eighth folder for storing task requests relative to said one or more policies.
[0033] The data processing system further comprises a routine for creating notes for entry into a sub-folder (the seventh sub-folder of the exemplar preferred embodiment) of the living folder. The routine further comprises a set of rules for automatically creating notes based on available content; a set of rules for automatically creating notes at specific pre-established date/time points; and, a set of rules for creating notes based upon certain events.
[0034] Each of the sub-folders may be further sub-divided in accordance with the needs of the respective sub-folder. For instance, in a preferred embodiment of the present invention, the first sub-folder further comprises: first data identifying a system user; second data identifying a broker/underwriter; and, third data identifying the status of said policy. The second sub-folder further comprises: a broker name and identifying data; a broker address; and, a set of one or more contact points relative to said broker.
[0035] Additionally, in a preferred embodiment, the third sub-folder further comprises: a set of policy coverages; a set of policy limits; a set of policy costs; a set of bottom line costs associated with said policy; and, a set of locations covered by said policy. The third sub-folder can additionally comprise a set of insured classes or additional coverages associated with the one or more policies.
[0036] Additionally, in a preferred embodiment, the fourth sub-folder further comprises data identifying endorsements pertaining to said policy; and, the fifth sub-folder further comprises documents generated in the course of managing the policy.
[0037] Additionally, in a preferred embodiment, the sixth sub-folder further comprises: a set of electronic copies of communications relative to a policy; and, data descriptive of each communication of the set of electronic communications.
[0038] Additionally, in a preferred embodiment, the seventh sub-folder further comprises a set of notes pertaining to one or more events associated with the relevant policy; and, the eighth sub-folder further comprises a description of each of a set of tasks to be performed relative to the policy.
[0039] In furtherance of the creation of the living folder, the method of the present invention further includes initiating a sweeping routine having pre-set parameters for querying the set of one or more remote nodes, said remote nodes comprising data; identifying data relevant to the pre-set parameters at each one of the queried nodes; and, transmitting a copy of the relevant data to the system for use by the application in populating the living folder.
[0040] The above, and other objects, features and advantages of the present invention, will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1 is an upper level diagram of the system of the present invention showing the host data processing center and exemplary nodes.
[0042] FIG. 2 is a block diagram of the host data processing center.
[0043] FIG. 3 is an upper level flowchart of the method of the present invention.
[0044] FIG. 4 is a flowchart depicting the “authentication” workflow.
[0045] FIG. 5 is a flowchart of the “home/messages” system functionality.
[0046] FIG. 6 is a flowchart of the “create submission” routine workflow.
[0047] FIG. 7 is a flowchart of the “quoting” routine workflow.
[0048] FIG. 8 is a flowchart of the “binding” routine workflow.
[0049] FIG. 9 is a flowchart of the “inspections and tasks” routine workflow.
[0050] FIG. 10 is a flowchart of the “policy issuance” routine workflow.
[0051] FIG. 11 is a flowchart of the “endorsements” routine workflow.
[0052] FIG. 12 is a flowchart of the “Quick Quote” routine workflow.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] Reference will now be made in detail to several embodiments of the invention that are illustrated in the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. For purposes of convenience and clarity only, directional terms, such as top, bottom, up, down, over, above, and below may be used with respect to the drawings. These and similar directional terms should not be construed to limit the scope of the invention in any manner. The words “connect,” “couple,” and similar terms with their inflectional morphemes do not necessarily denote direct and immediate connections, but also include connections through mediate elements or devices.
[0054] FIG. 1 is an upper level diagram of the system of the present invention showing the host data processing center 10 and exemplary nodes.
[0055] The host data processing center 10 has a central processing unit 12 interoperatively linked to: a monitor 14 ; a keyboard 16 ; a printer 18 ; and, a mouse 20 . Additionally, the host data processing center is linked with a database server 22 . It is understood that the listed peripherals could be removed and/or additional peripheral devices could be included with the host data processing center 10 as system or local needs require.
[0056] The host data processing center 10 is linked 50 to one or more remote nodes. It is contemplated that a remote node could be co-located with the host data processing center 10 if local needs require. The linkage 50 can be through wireless or hardwire needs or a combination of both as network needs dictate. The linked data processing center and nodes can be part of a local area network (LAN), a wide area network (WAN), or as part of an internet or intranet network. Each of the nodes will generally have a CPU 30 linked to: a monitor 32 ; a keyboard 34 ; a printer 38 ; and, a mouse 36 . It is understood that the listed peripherals could be removed and/or additional peripheral devices could be included with the remote node as system or local needs require.
[0057] FIG. 2 is a block diagram of the host data processing center 10 having a CPU 60 . The CPU 60 is interoperatively connected to: a policy management application 62 which drives the system flow; a memory 64 ; a monitor 66 ; a printer 68 , a telecomm interface 70 for linking with remote nodes; a data input peripheral 72 such as a mouse or scanner; and, a possible co-located remote node 80 . Memory 64 is further divided to store a living folder 82 in addition to the data bases required for system functionality. The living folder 82 is further subdivided into sub-folders 84 a - n.
[0058] An important aspect of the present invention is the creation of the living folder 82 that can accept or donate data relative to each insurance holder's policy or application. The host data processing center 10 further comprises a data management routine for directing data to each of the sub-folders 84 a - n in accordance with a pre-established set of criteria associated with each of the sub-folders.
[0059] In a preferred embodiment of the present invention, the plurality of subfolders 84 a - n includes a first sub-folder for storing general information about one or more policies associated with the applicant. Additionally, there may be: a second sub-folder for storing insurance broker information; a third sub-folder for storing details of said one or more policies; a fourth sub-folder for storing endorsements associated with said one or more policies; a fifth sub-folder for storing one or more documents associated with said one or more policies; a sixth sub-folder for storing communications in respect of said one or more policies; a seventh sub-folder for storing notes relative to said one or more policies; and an eighth folder for storing task requests relative to said one or more policies.
[0060] FIG. 3 is a top level flowchart of the method of the present invention. Each of the steps listed in this figure are further described in FIGS. 4-12 .
[0061] The flow begins with the authentication routine of step 100 which validates the use of the system by a system user before advancing to the home/messages routine of step 105 . This routine is described in more detail in FIG. 5 . At step 105 , the system will allow the user to select whether or not a “Quick Quote,” as opposed to a detailed policy quote, is required for the policy applicant. If the Quick Quote is selected, then the system advances to step 107 where the quick quote routine is initiated. This routine is further described in detail in FIG. 12 . From the Quick Quote, the system flow advances to step 115 . If, however, the Quick Quote was not selected at step 105 , then the system flow advances to step 110 where the routine for establishing a detailed submission is initiated.
[0062] The detailed submission routine, which is described in more detail in FIG. 6 , is utilized to produce the input necessary for the quoting routine at step 115 . If the policy applicant accepts the quote established at step 115 , then the applicant is bound at step 120 (see FIG. 8 ). From step 120 , the system advances to step 125 where certain inspections and tasks (such as a dwelling inspection, a medical exam, or similar tasks) are set-up. These are later described in more detail in FIG. 9 . The insurance policy is generated at step 130 , and as later described in detail in FIG. 10 . The inspections and tasks are completed and the results of these drive the production of endorsements in step 135 . Endorsements are changes or additions to the issued policy which are unique to the conditions and requirements of a specific insured.
[0063] Turning next to FIG. 4 , there is shown a flowchart depicting the “authentication” workflow of the present invention.
[0064] Access to the re-authentication process begins from the system Sign-In page by advancing to the sign-in routine at step 150 . From step 150 , the system advances to the query at step 152 which asks if the user name and password have been entered. If the response to the query is “NO”, then the system displays a message to the user at step 160 and returns to the sign-in step at 150 . If, however, the response to the query at step 152 is “YES”, then the system advances to the query at step 154 which asks if the user name exists. The system performs a match of the input with the names and passwords of approved users; and, if the name matches, then the system advances to the query at step 156 . However, if the response to the query at step 154 is “NO”, then the system displays a message to the user at step 160 and returns to the sign-in step at 150 .
[0065] Returning to step 156 , if the password matches, then the system advances to the query at step 158 . However, if the response to the query at step 156 is “NO”, then the system displays a message to the user at step 160 and returns to the sign-in step at 150 . At step 158 , the system queries as to whether or not a new user is logging in. If the response to the query is “YES”, then the system advances to step 160 where the appropriate user settings are loaded for advancing at step 162 to the home/messages functionality as is shown in FIG. 4 . If the response to the query at step 158 is “NO”, however, then the system advances to step 164 which displays registration instructions that direct the user to input their credentials at step 166 , their contact information at step 168 , and to complete the registration at step 170 before advancing along path A to re-enter the flow at step 150 .
[0066] Returning to step 150 , if the user does not have a password, or they have forgotten it, they are directed to step 174 where they enter their user name. The name is submitted, and the system queries as to whether or not the user name was entered. If the response to the query is “NO”, then the system displays an appropriate message and returns the user to step 174 . If, however, the response to the query at step 176 is “YES”, then the system advances to the query at step 178 which asks if the user name already exists in the system database. If the response to the query is “NO”, then the system displays an appropriate message and returns the user to step 174 . If the response to the query at step 178 is “YES”, however, then the system advances to step 182 where an identity confirmation question is posed to the system user. The user entry is submitted which advances the user to the query at step 184 .
[0067] At step 184 , the system queries as to whether or not the question posed at step 182 was answered by the user. If the response to the query is “NO”, then the system displays an appropriate message and returns the user to step 182 . If the response to the query at step 184 is “YES”, then the then the system advances to the query at step 186 which asks if the response from the user at step 182 was correct. If the response to the query is “NO”, then the system displays an appropriate message and returns the user to step 182 . If the response to the query at step 186 is “YES”, then the system generates an e-mail message to be sent to the user. The e-mail message includes the password for use by the user. The system then advances to step 192 where a confirmation of the transaction is displayed before the system advances along path A to return to the system flow at step 150 .
[0068] FIG. 5 is a flowchart of the “home/messages” system functionality. Entry to the functionality occurs at step 200 which displays a user screen further divided into subwindows. The subwindows display messages from the system to the logged-in user, listing of recent submissions to the system that are pertinent to the user, current sessions being conducted by the system with other local users and other communication. From step 200 , the flow allows selection of insured/policy information at step 202 . The information displayed at step 202 includes details as to a particular insured, a listing and detail of existing submissions for an insured and related contact information for each entry. From step 202 , the system permits a “quick view” at step 204 of the submission information listed for any selected submission.
[0069] From step 202 , the user can “dig” deeper into the details associated with any account by selecting the insured information flow at step 260 or the policy information flow at step 276 .
[0070] Beginning at step 260 , insured information (details pertaining to the insured client) can be viewed in more detail at step 262 . This detail includes name and contact details, a description of the entity involved, and other pertinent data. The detail can be edited, if required, thus producing an update at step 264 . Also from step 260 , the user can select details concerning certificates of insurance associated with a particular insured. These can be viewed at step 266 and augmented at step 268 by the selection of a particular policy linked with the insured. The policy is reviewed at step 270 as to the certificate holder details; the corresponding certificate can be viewed at step 272 and attached to the insured details at step 274 .
[0071] Returning to step 276 , the general information and details relative to a particular policy can be viewed. General or overview information can be viewed at step 278 ; and, the cancellation or re-instatement of any particular submission can be affected at step 279 where an electronic signature is required for authenticating the action to be taken.
[0072] In addition to the general information to be viewed, policy information step 276 can flow to broker/dealer information at step 280 . Policy details can be viewed at step 282 . These include, but are not limited to: type of coverage; coverage limits; policy costs; locations of insured subject matter, etc. A breakdown of endorsements on a per-policy basis can be reviewed at step 284 , with a further selection of individual document views available at step 286 . Selected or reviewed documents at step 288 can be sent via e-mail or similar vehicle based on selections made at step 290 . The status of communications can be viewed at step 292 and the sending or resending of documents can be affected based on selections made at step 290 . Notes to or from the system can be viewed at step 296 and additional notes created at step 298 . The creation of tasks associated with a particular policy can be viewed at step 300 and new tasks created at step 302 .
[0073] Returning to the system flow at step 200 , the system user, at this point, has the ability to select movement to the Quick Quote routine at step 206 , the create submission routine at step 208 , and the endorsements routine at step 210 . Each of these routines is described in more detail in FIGS. 12 , 6 and 11 respectively. Also from step 200 , the user can access the forms library at step 212 .
[0074] The document library lists all of the forms or templates that can be used for the building of a policy or its supporting paperwork. From entry to the library, specific documents can be viewed at step 214 and communication options for transmitting documents or forms can be selected at step 216 .
[0075] Also available for access from step 200 is the reports detail available at step 218 . By selecting specific criteria at step 220 , customized or standardized reports can be generated and printed at step 222 .
[0076] A settings step 224 is also available from step 200 . This step allows the user to access various parameters associated with other system users. These parameters include the establishment, at step 226 , of “out of office” settings associated with certain individuals; the sharing of work queues at step 228 , the changing of passwords at step 230 and updating of user profiles at step 232 .
[0077] The final step available from step 200 is the administration step 234 . From this step, insurance broker maintenance (updating of file details) can be accomplished at step 236 , with new brokers added at step 238 , or updated information being provided at step 240 . Additionally, from step 234 , instant messaging functionality can be accessed through pop-up windows associated with selected individual recipients. User maintenance can be controlled though step 244 with new users being added at step 246 or activity logs being created and viewed at step 248 . Document management is available at step 250 .
[0078] Next, we turn to FIG. 6 which is a flowchart of the “create submission” routine workflow. The workflow begins at step 310 where the create submission routine can be selected before advancing to step 312 . At step 312 , broker specific details can be accessed by entering a broker's name. Clicking on a “New Broker” icon will allow the user to request creation of a new broker field. From step 312 , the system advances to the query at step 316 which asks if a broker has been found. If the response to the query is “NO”, then the system advances to step 318 which allows the request for a new broker entry to be sent to Broker maintenance for input. If, however, the response to the query at step 316 is “YES”, then the broker is selected and the system advances to step 320 .
[0079] At step 320 , insured details can be accessed to locate a specific insured. If the user cancels the search for the insured, then the system advances via step 322 to the home messages functionality as is further described in FIG. 5 above. From step 320 , the system advances to the query at step 324 which asks if the insured has been found. If the response to the query is “NO”, the system treats the insured's name as a “new” insured and allows appropriate details to be entered into the system at step 326 . If the user chooses not to continue, then the system advances to the home/message functionality via step 328 . However, if the user does continue, then the system advances to the query at step 334 which asks if a match has been found between the newly created insured file, and any existing file.
[0080] If the response to the query at step 334 is “YES”, then the system allows the user to view the matched files at step 336 . If the matched view is cancelled, then the system returns to step 326 ; otherwise, the system advances to step 330 where the insured details are reviewed. If the user cancels the review at step 330 , then the system will return to the home/messages functionality as is shown in FIG. 5 . However, if the user continues, then the system will advance to step 338 where specific policy coverages are selected.
[0081] Returning to the query at step 334 , if a match is not found, then the system will advance to step 338 where specific policy coverages are selected. From step 338 , the selection can be cancelled at step 340 before returning to the home/messages functionality as is shown in FIG. 5 . If the select coverages step is continued, then the system will advance to step 342 where a submission record is created. A copy of the submission letter is generated and transmitted at step 344 after selecting various options at step 345 . These options include: selection of recipients; selection of attachments; selection of pre-defined notes to the file; and, communication content. A communications summary is generated at step 346 , and the system flow returns to enter just prior to step 348 .
[0082] At step 348 , the insurance application is attached to the file. At this point, several alternatives are possible based upon user selection. If the user wishes to bypass the immediate attachment of the application, then an “attachment document” task can be created at step 352 which allows the user to set-up a future application attachment. From step 352 , the system flow would allow access to the quoting routine (as described in more detail in FIG. 7 ) at step 356 . However, if the user, at step 348 , decided to save the application attachment for a later time, without establishing the specific task, then the system would advance to step 350 where the flow would return to the home/message functionality. A third alternative at step 348 allows the user to advance to the query at step 354 which asks if the application is attached. If the response to the query is “NO”, then the flow circles back to step 348 . If the response to the query at step 354 is “YES”, then the flow advances to step 356 as noted above.
[0083] Turning next to FIG. 7 there is shown a flowchart of the “quoting” routine workflow for the present invention.
[0084] The quoting routine begins at step 380 where a particular insurance application submission is selected and transmitted to a rating options step 382 . The rating options are displayed on the appropriate screen with a header that identifies the applicant. The quote data is subdivided by quote type, date, wholesaler or carrier, the cost of each element, and the status of the submission. If the user decides to save the rating options for later, than the user can do so at step 384 before returning to the home/message functionality of FIG. 5 . If, however, the user wishes to add an additional line of business, then the system will duplicate the submission data at step 386 before returning, at step 388 , to the quoting workflow as described in FIG. 6 .
[0085] From step 382 , the system advances to step 390 where the insurance carrier and quote type are selected. From step 390 , the system advances to the query at step 392 which asks what quote has been selected. If the response to the query is “Carrier Request” then the system advances to step 394 where the appropriate communications option is selected for responding to the carrier. From step 394 , the system advances to step 396 where a communications summary is generated before finishing and returning along path A to rejoin the flow at step 382 . If the response to the query at step 392 is “Quote from Outside System”, then the system advances to step 398 where the outside quote is attached to the file. If the response to the query at step 392 is “E-Quote” or “Manual quote”, then the system advances to the query at step 406 .
[0086] At step 398 , there are three routes that the system can follow. If a system quote is to be created, then the system will flow from step 398 to step 412 which described below. Once the quote has been attached at step 398 , a copy is sent to the broker by selecting the appropriate communications vehicle at step 402 . However, if the quote is declined by the potential insured, then the system logs the reason for the declination at step 400 before finishing and returning along path A to step 382 .
[0087] Returning to step 406 , the system queries as to whether or not there is existing data for establishing the quote. If the response to the query is “YES”, then the system advances to step 408 to import the data from the appropriate location. If the data importation at step 408 is canceled, then the system will re-enter the system flow at step 382 . If the data import step is bypassed, then the system flow will advance to step 412 where the quote is assembled by the system. If, however, the import data step is continued, then the system will advance to step 410 where the quote data is duplicated before advancing to the quote preparation of step 412 .
[0088] From step 412 , the system advances to step 414 where the quote data is saved to the system memory before advancing to the query at step 416 . At step 416 , the system queries as to whether or not the quote will be established as an E-quote (electronic quote). If the response to the query is “YES”, then the system advances to the rating engine of step 418 where the quote is determined before advancing to step 420 where the quote data is saved. From step 420 the system advances to step 422 where the quote can be viewed and the individual policy costs detailed. The details include policy costs, taxable and non-taxable fees, and carrier fees.
[0089] Returning to the query at step 416 , if the response to the query is “NO”, then the system advances directly to step 422 . At step 422 , if the user decides to suspend their activity until a later time, then the system advances along path A to re-enter the flow at step 382 . However, if the user continues with the process, then the system advances to the query at step 424 which asks if the policy is being issued by the system. If the response to the query is “YES”, then the system prompts the user to select the appropriate forms at step 426 before continuing to step 402 where the various communications options for transmitting the quote are displayed. After selecting the communication option and sending the quote, a communication summary is produced for the file at step 404 before either returning to step 382 via path A, or completing the rating sequence and advancing, at step 428 , to the binding routine as is shown in FIG. 8 .
[0090] FIG. 8 is a flowchart of the “binding” routine workflow. The routine begins at step 450 where a submission (with a quote sent) is in the system's process queue. A particular submission is selected and then reviewed at step 452 . If additional rating options are added or required, then the system advances to step 456 where the submission's status is changed to “quoting” and then sent back, via step 458 , to the quoting workflow (as is shown in FIG. 7 ) to re-enter at step 382 . If, however, the user decided to suspend action until a later time, then the system advances to step 454 where the system returns to the home/message routine.
[0091] If the user has determined that the coverage detailed in the submission is to be bound, then the system advances to the query at step 460 which asks if a selection is to be made from among multiple quotes. If the response to the query is “YES”, then the quote is selected at step 462 , and can be viewed by the user at step 464 . The bind order is attached to the file at step 466 . If the response to the query at step 460 is “NO”, then the system advances directly to step 466 .
[0092] At step 466 , if the user decides to bypass the attachment sequence of steps 466 and 470 , then the system advances to step 468 where a task is created. Tasks are actions that occur after a policy is bound. Tasks may include real estate or building inspections, requests for missing documents, requests for required data within the living folder, or similar actions whose results will lead to endorsements to be added to the policy. From step 468 , the system advances to step 472 where certain binder options may be selected. These may include such options as terrorism coverage, or the name of the inspection company (for performing certain tasks).
[0093] Returning to step 466 , if the binder order is attached, the system advances to the query at step 470 which asks if the bind order is attached. If the response to the query is “NO”, then the system returns to step 466 . However, if the response to the query at step 470 is “YES”, then the system advances to step 472 where certain binder options may be selected. From step 472 , the user can save their work for later and be returned, via step 474 , to the home/message functionality of FIG. 5 ; or, the user can continue processing by advancing to the query at step 476 .
[0094] At step 476 , the system queries as to whether or not the policy will issue to a corporation. If the response to the query is “NO”, then the system advances to step 478 where the request to bind the policy will be sent to the appropriate insurance carrier via a selected communications option. From step 478 , the request is sent to the carrier and a communications summary is generated at step 480 before moving to an “in process” status at step 482 . The submission is selected and reviewed at step 484 ; the binding confirmed and the confirmation attached to the file at step 486 . The system then moves to the query at step 488 which asks if the confirmation has been attached to the file. If the response to the query is “NO”, then the system returns to step 486 . If, however, the response to the query at step 488 is “YES”, then the flow advances along path B to re-enter the system flow at step 490 .
[0095] Returning to the query at step 476 , if the response to the query is “YES”, then the system advances to step 490 where the policy data is reviewed. From step 490 , the flow advances to step 496 where the policy costs are reviewed and the binder updated if necessary. The user has the option of attaching the binder to the file at step 492 before advancing to the query at step 494 . Step 494 asks if the binder is attached to the file. If the response is “NO”, then the system returns to step 492 to attach the binder. If the response to the query at step 494 is YES”, then the system continues to step 496 where the policy costs are reviewed and the binder updated if necessary.
[0096] From step 496 , the system advances to the query at step 498 which asks if the system will be issuing the policy. If the response to the query is “YES”, then the system advances to step 500 where the appropriate forms are selected before rejoining the flow at step 502 . If the response to the query at step 498 is “NO”, however, then the system advances directly to step 502 where the binder communication options are reviewed and the binder sent. A communications summary is produced at step 504 and the routine is finished at step 506 before advancing to the inspections and task routine as is further described in FIG. 9 .
[0097] Turning then to FIG. 9 , there is shown a flowchart of the “inspections and tasks” routine workflow. The routine begins at step 550 where a submission is selected from the “action required” work queue. The system advances to step 552 where an inspection company is selected to perform an inspection of the insured property or individual as required. From step 552 , the system advances to the query at step 554 which asks if the inspection company is integrated with respect to access to the system for scheduling the services offered (i.e., multiple locations, services for various inspection types, or testing capabilities). If the response to the query is “NO”, then the external site is displayed on the monitor at step 556 before advancing to step 570 where the inspection request documents can be viewed and/or attached to the file. If, however, the response to the query at step 554 is “YES”, then the system advances to the query at step 558 which asks if the inspection company has received the listing of various locations where inspections are to be made. If the response to the query is “YES”, then the system advances directly to step 562 where the location details are entered. If the response to the query at step 558 is “NO”, then the inspection locations are entered at step 560 before advancing to step 562 for the entry of location details.
[0098] From step 562 , the system advances to the query at step 564 which asks if there any additional locations for scheduling. If the response to the query is “YES”, then the system returns to step 562 ; however, if the response to the query at step 564 is “NO”, then the system advances to step 566 where the data is submitted to the inspection company before advancing to step 570 .
[0099] At step 570 , the inspection request documents can be viewed and/or attached to the file before the individual inspection tasks are created at step 572 . The system then queries at step 572 whether or not there are additional tasks to be created. If the response to the query is “YES”, then the system returns to step 572 . If, however, there are no additional tasks to be added, then the system advances to the policy issuance routine via step 576 .
[0100] Turning next to FIG. 10 , there is shown a flowchart of the “policy issuance” routine workflow which begins at step 600 . From step 600 , the system selects a submission and advances to step 602 where the issuance options are displayed. The options generally include selections for: send to policy issuance now; issue the policy now selection; delay the policy issuance; or, update the binder. If “update binder” is selected, then the system returns, via step 604 , to the binding workflow at step 472 . If the “delay” option is chosen, then the submission is delayed at step 606 , and the submission is returned to the queue at step 600 . If either of the other two choices is selected at step 602 , the system advances to the query at step 608 .
[0101] At step 608 , the system queries as to whether or not the user is in the policy issuance department. If the response to the query is “YES”, then the system advances to the query at step 610 which asks if the policy issuance is being down by the system. If the response to the query is “NO”, then the system attaches the policy at step 612 before querying as to whether or not the corporation copy is attached to the file. If the response to the query is “NO”, then the system returns to step 612 to attach the policy. If, however, the response to the query at step 614 is “YES”, then the system advances directly to step 624 where the company communication options can be selected.
[0102] Returning to the query at step 610 , if the response to the query is “YES”, then the system will prepare to issue the policy and advance to step 618 for selection of the appropriate forms.
[0103] Returning to the query at step 608 , if the response to the query is “NO”, then the system advances to the query at step 616 which asks if there are issuance options. If the issuance request is sent to the policy issuance department, the system will advance to the query at step 614 ; otherwise, if the response to the query at step 616 is to issue the policy now, then the system will advance to step 618 to select the appropriate forms for issuing the policy.
[0104] From step 618 , the system advances to step 620 where the policy is reviewed as to details concerning: the insured; the producer; the agent; the company covering the insurance; the forms selection; any binder updates; and, the policy commitment. If the binder is to be updated, then the system returns to the binding routine via step 622 . If the forms selection is to be adjusted, then the system returns to step 618 . After review, the policy is committed and sent to the company, at step 624 , via one of the communication options. The communication summary memorializing the transmission is generated at step 626 .
[0105] Returning to the query at step 638 , the system asks if the corporation will be issuing the policy. If the response to the query is “YES”, then the system advances to step 640 where the binder is sent to invoicing, then to step 642 for receipt by the policy issuance department. From step 642 , the system returns to step 600 . If the response to the query at step 638 is “NO”, then the binder is sent to invoicing at step 644 , but then advances to step 646 where the binder is sent to brokerage processing. A copy of the policy is attached at step 648 before advancing to the query at step 650 . The query at step 650 asks if the corporation version is attached to the file, if the response to the query is “YES”, then the system advances to step 636 where the policy is sent to the printing department. If the response to the query at step 650 is “NO”, then the system returns to step 648 to attach the policy before being sent on to the printing department.
[0106] Returning to step 626 , the system advances to the query at step 628 , which asks if the binder has been sent to invoicing. If the response to the query is “NO”, then the binder is sent to invoicing at step 630 before advancing to step 632 . If the response to the query at step 628 is “YES”, then the system advances directly to step 632 where the various options for sending the policy to the broker are available for selection. The policy is transmitted and the communication summary is generated at step 634 before finishing the policy issuance and turning over the policy for printing at step 636 . From step 636 , the system returns, via step 652 , to the home/messages routine as is shown in FIG. 5 .
[0107] In FIG. 11 , there is shown a flowchart of the “endorsements” routine workflow which begins with the selection of the endorsements routine at step 680 . From step 680 , the system advances to step 682 where the policy is located in the system through the “Find Policy” screen. The system advances to step 684 where the endorsements to the selected policy are created and summarized before the system moves on to step 686 . At step 686 , the insured details are reviewed before advancing to the query at step 688 .
[0108] At step 688 , the system queries as to whether or not the system will be issuing the policy with the relative endorsements. If the response to the query is “NO”, then the system advances to step 690 where ACORD form 175 is created. Client data is collected in insurance industry standard forms such as those provided by the Association for Cooperative Operations Research (ACORD). From step 690 , the system advances to step 692 where ACORD form 175 is attached to the policy before advancing to the query at step 694 . At step 694 , the query asks if the ACORD form is attached to the policy. If the response to the query is “NO”, then the system returns to step 692 ; otherwise, if the response to the query is “YES”, then the system advances to step 696 . At step 696 , the various communications options available to the user are listed. One option is selected and the policy sent to the proper binding authority. The communications summary is generated at step 698 before the system follows path B to return to the system flow at step 738 .
[0109] Returning to the query at step 688 , if the response to the query is “YES”, then the system advances to step 700 where the policy details (policy costs, taxable fees, commissions, etc.) are listed and reviewed before selecting the appropriate policy forms at step 702 . From step 702 , the system advances to step 704 where the submission is reviewed once again. If a rate endorsement is required, then the system advances to the query at step 706 which asks if the quote is an E-quote (electronic quote). If the response to the query is “YES”, then the system advances to the rating engine at step 708 to determine the final quote. The quote data is saved at step 710 before the system makes the quote available for viewing, together with the individual policy costs, at step 712 . If the response to the query at step 706 is “NO”, then the system advances directly to step 712 before utilizing path A to re-enter the system flow at step 704 .
[0110] Returning to step 704 , if the submission review determines that an approval is required, the request is formatted at step 714 in accordance with the communications options available. The transmission is summarized at step 716 . The approval, once granted, is attached to the policy which is verified at step 720 before the system utilizes path A to return to step 704 .
[0111] Again returning to step 704 , if the endorsement is issued, then the system advances to the query at step 722 , which asks if the issue is being done by the system. If the response to the query is “NO”, then the system advances to step 724 where the policy costs are determined before advancing to step 726 where the endorsement text is generated for the policy. If the response to the query at step 722 is “YES”, then the system advances directly to step 726 . From step 726 , the policy is transmitted to the insurance carrier utilizing the communications options available at step 742 . A communication summary is generated at step 744 and the endorsement is sent to invoicing at step 750 before returning the user back to the home/messages routine via step 752 .
[0112] Returning to step 704 once more, if a binder needs to be created, then the system advances to the query at step 728 which asks if the policy will be issued by the system. If the response to the query is “YES”, then the system advances directly to step 732 where the binder text is generated before being sent to the broker. If the response to the query at step 728 is “NO”, then the policy costs are determined at step 730 before the system advances to step 732 .
[0113] From step 732 , the system chooses amongst the various communications options available at step 734 before sending the policy with the associated binder text to the broker. The communications summary is generated at step 736 before the system follows path A to return to the flow at step 704 . At step 704 , the final option available is the attachment of an endorsement which occurs by advancing to step 738 . The system verifies, at step 740 , that the endorsement has been attached to the policy before advancing to the communications options of step 742 .
[0114] FIG. 12 is a flowchart of the “Quick Quote” routine workflow 107 that is shown in FIG. 3 . The routine begins at step 800 where the “quick Quote” routine is selected in relation to select coverages identified in step 802 . If the user desires to terminate the routine, then the system advances to step 804 where the user is returned to the home/messages routine. If the user continues with the quick Quote routine, then the system advances to step 806 where the system queries as to whether or not the user wants to compare rates available from more than one insurance carrier. If the response to the query is “YES”, then the multiple carriers can be selected for review at step 808 before the system advances to step 812 where the quote data must be entered. If the response to the query at step 806 is “NO”, then the system advances to step 810 where a single insurance carrier is selected before the system advances to step 812 .
[0115] From step 812 , the system advances to step 814 where the quote data is saved before utilizing the rating engine of step 816 . The rating engine determines a quote for the data entered relative to a carrier. The quote data is saved at step 820 and the system advances to the query at step 822 which asks if the carrier being quoted is the last carrier. If the response to the query is “NO”, then the system returns to step 814 where the next carrier quote is determined. If the response to the query at step 822 is “YES”, then the system advances to the query at step 824 .
[0116] The system, at step 824 , queries as to whether or not the quote data derived is to be compared. This would only be a factor when multiple carriers have been entered at step 808 . If the response to the query is “YES”, then the system produces a summary at step 826 and allows the user to view a selected quote at step 828 . From step 828 , the system advances to step 832 where a particular insured is sought from the system database. Returning to the query at step 824 , if the response was “NO”, then the single quote and policy costs can be viewed before advancing to step 832 .
[0117] From step 832 , the system verifies that the insured was found before advancing to step 838 . If, however, the insured could not be located, then the system advances to step 836 where an insured file is created before advancing to step 838 where the identified insured's file is reviewed. The system then advances to step 840 where the applicable broker is identified before communications options are selected at step 842 . The quote is transmitted to the applicable broker and the communication summary generated at step 844 before the routine is ended at step 846 and the user directed to the home/message routine.
[0118] In the claims, means, or step-plus-function clauses, are intended to cover the structures described or suggested herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, for example, although a nail, a screw, and a bolt may not be structural equivalents in that a nail relies on friction between a wooden part and a cylindrical surface, a screw's helical surface positively engages the wooden part, and a bolt's head and nut compress opposite sides of a wooden part, in the environment of fastening wooden parts, a nail, a screw, and a bolt may be readily understood by those skilled in the art as equivalent structures.
[0119] Having described at least one of the preferred embodiments of the present invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes, modifications, and adaptations may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. | The present invention is a method and system for data submission management of insurance application data by a host data processing system. The invention comprises authenticating the submission of data relative to an insurance applicant. The authenticated data is matched with a set of data points and merged to create a submission to be matched with a set of price points in a quotation routine to establish a quote. The quote is then accepted or rejected by the applicant. If accepted, then the applicant is bound conditionally. A policy is then issued to the applicant in respect of the quote. Subsequently, a set of endorsements may be added to the policy. A policy information routine for matching the insurance application data to a set of data fields is initiated to establish a living folder which can be the source of data for populating other routines, system folders, or report generators. | 6 |
BACKGROUND OF THE INVENTION
[0001] A. Field of the Invention
[0002] This invention relates to a method and apparatus for a fast heat rise resistor that can be used as a resistive igniter. More particularly, this invention relates to the use of resistive foil and photolithographic production to produce a fast heat rise resistor, the resistor suitable for use as an igniter in autoignition-deployed safety devices.
[0003] B. Problems in the Art
[0004] There are numerous needs for fast heat rise resistors. One such need relates to the use of a resistor as an igniter used to ignite a pyrotechnic or other explosive material. In these resistive igniter applications, it is desirable that the resistive igniter act quickly for rapid ignition. One such application is in vehicle airbag inflators where it is crucial that an igniter act quickly to ignite a gas-generating pyrotechnic in order to ensure that an air bag is deployed in a timely fashion. As the resistor is driven by current, the heat of the resistor increases to a point where other material such as pyrotechnic material can be ignited. There are numerous other applications of resistive igniters, including in other auto-ignition devices such as seatbelt pretensioners, battery cable disconnects, fuel line shut off devices, roll bars, safety devices, and other applications.
[0005] There have been attempts made at a resistive igniter in the prior art. Previous attempts have been made that have used metal wire or film bridges. In metal wire or bridgewire devices, a metal filament also known as a bridgewire is used. Some problems with bridgewire devices involve the difficulties involved in manufacturing bridgewires. In order to predict performance of a bridgewire, there must be uniform thermal and electrical properties. Problems remain in manufacturing bridgewires of the needed uniformity.
[0006] Another problem with bridgewire devices is that the response time is too slow or else too much activation energy is required. This is problematic where a fast response time is needed or else there are limited power resources that can not support large activation energies. One example of a situation where there are limited power resources is in a vehicle where a 12 volt battery is used to activate an igniter.
[0007] Yet another problem with bridgewire devices involves reliability. In bridgewire devices pyrotechnic powder is pressed against the bridgewire. This process can result in detachment of the bridgewire. Thus there are reliability problems with bridgewires as well.
[0008] Other attempts at creating resistive igniters have used metal film bridges that are either thin film or thick film. One problem with a thick film or thin film approach is the increased cost of manufacturing associated with these approaches, and in particular with the thin film approach. Another problem with a metal film approach is that there is contact between the metal film bridge and a substrate. This contact between the metal film bridge and the substrate results in a loss of heat from the metal film bridge to the substrate, resulting in an increase in the amount of time for the metal film bridge to reach a particular temperature or alternatively, an increase in the amount of current required in order for the metal film bridge to reach a particular temperature in a given time.
[0009] Another problem with film bridges relates to their reliability. Pyrotechnic powder is pressed against the bridge, however, this powder may become displaced during handling. Thus, the pressed powder may or may not constantly touch the wire or film. Where a liquid pyrotechnic is used, the same contact problems may also arise, as the liquid pyrotechnic may not be in constant contact with the wire or film. These problems result in an igniter that is not reliable.
[0010] Thus there is a need for a reliable heat rise resistor which has fast response and can be manufactured in a uniform fashion. There is a further need for a heat rise resistor that can be easily packaged and delivered to customers.
[0011] Thus, it is a primary object of the present invention to provide an igniter which improves upon the state of the art.
[0012] Yet another object of the present invention is to provide an igniter with a fast response time.
[0013] Another object of the invention is to provide an igniter that is reliable.
[0014] It is another object of the present invention to provide an igniter that requires decreased activation energy.
[0015] Yet another object of the present invention is to provide an igniter that can be manufactured uniformly.
[0016] Another object of the present invention is to provide an igniter suitable for use in auto-ignition safety devices.
[0017] A still further object of the present invention is to provide an igniter suitable for use in an airbag deployment system.
[0018] Yet another object of the present invention is to provide a fast heat rise resistor that does not lose heat to a substrate.
[0019] It is another object of the present invention to provide a fast heat rise resistor and method of making a fast heat rise resistor that can be easily packaged and distributed.
[0020] A still further object of the present invention is to provide a resistor capable of having all of its sides in contact with a pyrotechnic.
[0021] These and other objectives, features, or advantages of the present invention will become apparent from the specification and claims.
SUMMARY OF THE INVENTION
[0022] This invention describes a method and apparatus for a fast heat rise resistor using resistive foil with photolithographic production. The invention provides for a fast heat rise resistor that results in a fast response and is suitable for use as an igniter to ignite pyrotechnic material.
DESCRIPTION OF THE DRAWINGS
[0023] [0023]FIG. 1 is a cross-sectional diagram of the substrate of the resistor.
[0024] [0024]FIG. 2 is a cross-sectional diagram depicting the substrate with capton layered on top.
[0025] [0025]FIG. 3 is a cross-sectional diagram showing a substrate, capton layer, and copper-plated foil.
[0026] [0026]FIG. 4 is a cross-sectional diagram showing the resistor after the copper-plated foil has been preferentially dissolved away.
[0027] [0027]FIG. 5 is a top view depiction of the resistor after excess foil has been dissolved away.
[0028] [0028]FIG. 6 is a cross-sectional diagram after the excess foil has been dissolved away.
[0029] [0029]FIG. 7 is a cross-sectional diagram after capton has been removed.
[0030] [0030]FIG. 8 is a cross-sectional diagram showing the resistor and pyrotechnic.
[0031] [0031]FIG. 9 is a top view of the step and repeat array of resistors.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] With reference to the drawings, the same reference numerals or letters will indicate the same parts or locations throughout the drawings unless otherwise indicated.
[0033] Method of the Invention
[0034] The steps of creating a fast heat rise resistor according to the present invention are shown in detail in the drawings. FIG. 1 shows a substrate 2 . The substrate may be a polyimide substrate or other substrate such as are well known in the art. The layer of polyimide has a thickness of approximately two mil. The polyimide is preferably fully cured and surface etched. The present invention contemplates that the layer of polyimide may be a sheet of convenient size such as one that is 4 inches by 5 inches, or other standard or convenient size.
[0035] In the next step, as best shown in FIG. 2, a layer of material such as capton 4 , is bonded or otherwise attached to the substrate 2 . The present invention is not limited to capton and contemplates that other types of material such as photoresistive film may be used in place of capton.
[0036] A photoresistive step is then applied to print a pattern on the capton and to then develop the capton so as to leave a series of stripes of capton on the polyimide. The present invention contemplates that stripes of different dimensions may be used. The present invention further contemplates that film can be bonded in stripes as well such that the photoresistive step is not required, even though the photoresistive print and develop step provides a convenient method of obtaining the capton stripes. Stripes of 20 mils can be placed every 60 mils across the long dimension of the polyimide. It is to be appreciated that other configurations and dimensions of stripes can be used and the present invention contemplates these and other variations.
[0037] As shown in FIG. 3, copper plated foil 6 is applied over the layer of capton 4 and the substrate 2 . The copper plated foil has a copper side 8 and a foil side 10 . The foil used may be a Ni/Cr foil or other foil as may be known in the art. The copper plating is of a thickness of 1 mil, or of other thickness as required by the particular application of the resistor. The foil is of a thickness of 0.1 mil. The present invention contemplates other thicknesses of foil and copper plating. The selection of the foil material and of the thickness of the foil should be made so as to reflect the properties desired in the resulting resistor including the activation time and activation energy required. These requirements will be discussed later in the context of an exemplary embodiment of the fast heat rise resistor apparatus.
[0038] A first etching step is then applied to the resistor of FIG. 3. Through a Kodak® photo resistive process (KPR) or other photolithography process, a defined length of foil is printed on the copper side 8 of copper plated foil 6 . The printing on copper plated foil 6 defines a length of the resistors in the array. The length of the resistor path may be 20 mils at this point, although the present invention contemplates other variations. After this printing and developing, the copper is then preferentially etched away, leaving the portion desired. The resistor after the etching step is applied is best shown in FIG. 4. As FIG. 4 shows, the foil 10 is now exposed as the layer of copper on the foil 8 has been preferentially etched away.
[0039] A second print and etching step is then applied. In this step, the foil 10 is printed on to expose a defined width of the resistor trays. The present invention contemplates various widths of the traces but 1 mil is preferable. The high resistivity of foil 10 increases the amount of heat generated when current is passed through trace 10 . The heat generated further increases as the width of foil 10 is reduced. The resulting resistor is shown in FIG. 5. As shown in FIG. 5, the foil trace 12 is still attached to the capton 4 and electrically connected between the copper terminals 14 . FIG. 6 shows a perspective view of the resistor after this step has been completed. The resistive trace 12 of the foil remains attached to the capton and electrically connected between the copper terminals 14 .
[0040] It is to be appreciated that many such resistors of the present invention may be manufactured at the same time. This is shown best in FIG. 9. In FIG. 9, a step and repeat array of resistors is shown prior to singulation. The resistors can then be singulated for shipping to customers. The capton 4 is still a part of the resistor at this point. Capton 4 provides stability to the foil traces 12 . This reduces or eliminates the possibility of foil traces 12 breaking or otherwise being damaged in transit.
[0041] Prior to use, capton 4 can optionally be dissolved or otherwise removed resulting in the resistor best shown in FIG. 7. This removal may be through application of a chemical solvent. The present invention also contemplates that the capton 4 is not removed. The resistor is then mounted onto the squib and connected to posts. This connection may be made by soldering the resistor in place, applying a conductive epoxy, welding the resistor in place, or other means such as are well known in the art.
[0042] In this resistor, foil trace 12 is suspended between the copper terminals on copper plating 8 . Thus, when current is passed through the resistor from terminal to terminal, the foil trace 12 will quickly increase in temperature. This increase in temperature is due to the material used for the foil trace 12 , the width of the foil trace, and the fact that as the foil trace is not in physical contact with substrate 2 , heat is not absorbed by substrate 2 .
[0043] The customer may include the resistor of the present invention in applications where the resistor serves as an igniter. This is shown best in FIG. 8 where the resistor is surrounded by a first pyrotechnic material 16 and a second pyrotechnic material 18 . Because the foil resistor is suspended, the pyrotechnic material can completely surround the foil resistor. As the foil resistive trace 12 is not attached to a substrate, heat is not absorbed by the substrate due to conduction. As resistor 12 heats, pyrotechnic material 16 is ignited. This results in an explosion which can be used to ignite the second pyrotechnic material 18 . One example where this configuration can be used is in an air bag. In an air bag, a current passed through a resistor can be used to ignite a first pyrotechnic 16 which in turn ignites a gas-generating pyrotechnic material 18 which can inflate an air bag. In such application, it is important that the air bag is inflated as quickly as possible thus the fast rising action of resistor 12 is desirable.
[0044] Apparatus of the Invention
[0045] The apparatus of the present invention is best shown in FIG. 7. The fast heat rise resistor includes a polyimide substrate 2 . On top of substrate 2 is capton 4 . The capton is used to secure the resistive trace 12 in place during handling and shipping to a customer. Resistive trace 12 is a foil trace preferably of Ni/Cr, but may be of other types of foil as requirements of the heat rise resistor may require. The foil trace 12 is elevated above the substrate 2 as the foil trace 12 is on top of the capton layer 4 . The resistor also has a top layer 8 of copper plating on the copper plated foil 6 . The underside of the copper plating foil is foil and that portion of the foil that extends across the gap is the resistive trace 12 . The resistor is secured in place onto a circuit board or other structure through soldering with solder 16 onto solder pad 14 . The present invention contemplates that the resistor may be mounted by other methods such as conductive epoxy or welding.
[0046] [0046]FIG. 7 best shows the resistor after the layer of capton 4 has been removed. When the layer of capton 4 is removed, such as by application of a chemical solvent, the foil trace is suspended over substrate 2 . This results in the heat of foil 12 increasing more rapidly as current is passed through the resistor. As the foil trace 12 is not in physical contact with substrate 2 , heat is not absorbed by the substrate 2 which would increase the time that it would take for a given current passed through the resistor to cause foil trace 12 to reach a particular temperature. The apparatus of the present invention is shown in one environment in FIG. 8. In this environment, the resistor is surrounded by pyrotechnic material 16 . Thus, when foil trace 12 reaches a particular temperature, pyrotechnic material 16 is ignited. The ensuing explosion serves to ignite a gas generating pyrotechnic 18 . The amount of time that is needed to ignite is reduced because the foil trace 12 is heated more thickly than in the prior art. The present invention also contemplates that the capton 4 need not be removed. As Capton 4 has thermal diffusivity lower than a ceramic substrate, even with capton 4 in place, improvement in rise time is achieved. When the capton remains in place, pressed powder can surround the resistor.
[0047] Due to the fast rise time and reliability, the present invention contemplates use in a variety of applications, including, without limitation, auto-ignition applications, safety applications, airbags, seat belt pretensioners, battery cable disconnects, fuel line shut off devices, roll bars, and numerous other uses.
[0048] Thus, an apparatus and method for a fast heat rise resistor using resistive foil with photolithographic production has been disclosed which solves problems and deficiencies in the art. It will be readily apparent to those skilled in the art that different types of substrates and types of foil may be used in the foil resistor. It will also be clear to those skilled in the art that different materials, dimensions, and other variations may be used including different types of foil, different thicknesses and widths of foil, different thicknesses of plating, different lengths of foil, different films in place of capton, and other variations as required by particular applications and environments.
[0049] It is therefore seen that this invention will achieve at least all of its stated objectives. | A fast heat rise resistor comprising a substrate, a foil bridge on the surface of the substrate, the foil bridge having an elevated portion and a contact portion, the elevated portion above the substrate, the contact portion in contact with the substrate, a conductive layer attached to the contact portion of said foil bridge. The activation energy and/or response time is reduced as the foil bridge is suspended over the substrate. Another aspect of the invention include a method of manufacturing the foil bridge and application to autoignition vehicle airbags. | 5 |
FIELD OF THE INVENTION
The present invention relates to the field of selective separation of radioisotopes. More particularly, the present invention relates to the selective separation of sodium-22 from an irradiated aluminum target. This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).
BACKGROUND OF THE INVENTION
Sodium-22 is well suited as a radioactive tracer due to its relatively long half life (about 2.6 years) and its strong gamma ray emission (about 1275 KeV) with 99.9 percent abundance. Its uses as a radioactive tracer are principally in biological and geological fields, e.g., as a radioactive tracer for logging data in subterranean formations such as oil wells. Additionally, sodium-22 can be used in intense slow positron beams.
Proton irradiation of targets for radioisotope production is a common process. Often, in the proton irradiation of, e.g., molybdenum or rubidium bromide, the target material is encapsulated in aluminum or an aluminum alloy. The irradiation of the aluminum in such encapsulation material results in the production of sodium-22. However, no convenient separation process has previously been known, especially a separation process from aluminum alloys.
U.S. Pat. No. 4,894,208 describes a distillation process of separating sodium-22 from aluminum, a process which is vastly different from the presently described process. Additionally, it is described that the distillation process requires the use of a graphite cup as molten aluminum forms alloys with metal, e.g., Monel alloy, cups from which sodium does not distill.
It is an object of the present invention to provide a process of separating sodium-22 from an irradiated aluminum target and especially from an irradiated aluminum alloy target.
SUMMARY OF THE INVENTION
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention provides a process for selective separation of sodium-22 from a proton irradiated aluminum target including dissolving a proton irradiated aluminum target to form a first solution including aluminum ions and sodium ions, separating a portion of the aluminum ions from the first solution by crystallization of an aluminum salt, contacting the remaining first solution with an anion exchange resin whereby ions selected from the group consisting of iron and copper are selectively absorbed by the anion exchange resin while aluminum ions and sodium ions remain in solution, contacting the solution with an cation exchange resin whereby aluminum ions and sodium ions are adsorbed by the cation exchange resin, and, contacting the cation exchange resin with an acid solution capable of selectively separating the adsorbed sodium ions from the cation exchange resin while aluminum ions remain adsorbed on the cation exchange resin.
DETAILED DESCRIPTION
The present invention is concerned with the selective separation of sodium-22 from a previously irradiated target, e.g., a proton irradiated aluminum target. Such a process can produce up to curie quantities of sodium-22 for use in the field of nuclear chemistry, e.g., as a radioactive tracer.
As a starting material in the present process, an aluminum target is irradiated by energetic protons having energies sufficient to generate a large number of isotopes by spallation reactions, generally energies greater than about 200 MeV, more preferably from about 600 MeV to about 800 MeV. In order to produce the desired millicurie to curie quantities of the radioisotopes, the aluminum target should have a weight of at least about 100 grams (g).
One method of irradiation is by proton bombardment of the aluminum target. Such proton bombardment can be accomplished by inserting the target into a linear accelerator beam at a suitable location whereby the target is irradiated at an integrated beam intensity of from about 30 milliampere-hours (mA-hr) to about 1000 mA-hr. After the irradiation of the aluminum target, the target is generally allowed to decay for at least from about 7 to about 14 days whereby unwanted short-lived isotopes will be substantially removed.
Aluminum, or more usually an aluminum alloy, has often been used as an encapsulation material for other materials subjected to such a high energy irradiation process. The aluminum or aluminum alloy material used in encapsulating other target materials can be used in the recovery or selective separation of sodium-22 without the need for a separate aluminum target. Aluminum alloys used in encapsulating other target materials often include alloying materials such as copper, zinc, iron, vanadium, zirconium, titanium and the like.
In the selective separation of the present invention, the irradiated aluminum target is initially dissolved into a suitable acid solution, e.g., a hydrochloric acid solution, by either a batch or continuous process. Preferably, the dissolution is by a batch process. The hydrochloric acid solution can be of any convenient concentration, although concentrated solutions, i.e., concentration of greater than about 6 Molar hydrochloric acid are preferred for quicker dissolution.
The resultant solution from the dissolution of the target contains a high concentration of aluminum ions together with smaller concentrations of the ions from the other alloying metals and the sodium-22 and other isotopes generated during the irradiation. Initially, the solution can be concentrated by evaporation of a portion of the water whereupon a solution saturated or supersaturated in an aluminum salt, e.g., aluminum chloride (AlCl 3 ), is eventually generated. The generated crystals of the aluminum salt, e.g., aluminum chloride, can be filtered from the remaining solution and washed with concentrated hydrochloric acid. The filtrate and washings are retained and subjected to further crystallizations of, e.g., aluminum chloride either by further concentration via evaporation or by addition of concentrated hydrochloric acid to increase the concentration of the chloride anions and thus decrease the solubility of the aluminum chloride. By careful repeated crystallizations, a significant portion of the aluminum ions can be removed from the solution while largely excluding the removal of sodium ions from the solution.
The remaining solution is then contacted with an anion exchange resin, preferably by passing the solution through a bed of the anion exchange resin. Generally, prior to contact with the resin, the solution is converted to a strong or highly acidic solution, e.g., by first evaporating to dryness followed by redissolution in, e.g., from about 6 Molar to about 10 Molar hydrochloric acid, preferably about 8 Molar hydrochloric acid. The anion exchange resin can be, e.g., a strongly basic anion exchange resin such as AG-1X8, available from Bio-Rad Laboratories. As the solution is passed through the anion exchange resin, metal complexes of, e.g., iron and copper will be adsorbed by the resin, while the solution will retain the aluminum and sodium ions. The majority of the iron and copper present in the solution can be removed at this stage.
The remaining solution is then contacted with a cation exchange resin, preferably by passing the solution through a bed of the cation exchange resin. The cation exchange resin can be, e.g., a macroporous cation exchange resin such as AG-MP-50, available from Bio-Rad Laboratories. After the solution is passed through the cation exchange resin, the aluminum and sodium as well as additional contaminants such as rubidium, copper, beryllium, and vanadium will be adsorbed by the resin. The resin bed is then washed with successive fractions of an acid solution, preferably a dilute acid solution, to strip or selectively separate the sodium-22 from the cation exchange resin while leaving the remainder of the metal ions upon the resin. Hydrochloric acid is generally preferred as the acid for the stripping step. Generally, the dilute acid solution can be from about 0.1 Molar to about 1.0 Molar hydrochloric acid, preferably from about 0.1 Molar to about 0.5 Molar. If necessary, multiple cation exchange columns can be used where necessary for effective separation.
Optionally, the final solution can then be cleaned up to eliminate any resin throw, i.e., traces of the cation exchange resin, by contacting the remaining solution with another anion exchange resin, preferably by passing the solution through a bed of the anion exchange resin. The anion exchange resin can again be, e.g., a strongly basic anion exchange resin such as AG-1X8.
The present invention is more particularly described in the following example which is intended as illustrative only, since numerous modifications and variations will be apparent to those skilled in the art.
EXAMPLE 1
Portions of an aluminum target encapsulation material which had been irradiated with 600-800 MeV protons at an integrated beam intensity of about 590 mA-hr were cut into small pieces, each piece approximately 50 grams (g). Two 50 g pieces of irradiated aluminum were dissolved, each piece dissolved in steps with minor heating in about 500 milliliters (ml) of concentrated hydrochloric acid (HCl) and about 250 ml of water. The solutions were each filtered and the residue washed with 0.1 Molar (M) HCl, the washings combined with the filtrate. The solutions were then combined and used as the starting material for the separation of sodium-22.
The solution was initially divided into three 650 ml batches. Each solution was evaporated down until the solutions were saturated in aluminum chloride (AlCl 3 ). The solutions were then allowed to cool. The resulting crystals were filtered from the solution, washed with concentrated HCl, and discarded. The washes and filtrates from the three batches were combined and evaporated down so that a second crystallization and filtration were performed. In the same manner, the resulting wash and filtrate were combined and a third crystallization and filtration were performed.
The resulting filtrate and wash were again combined, then evaporated to dryness and then redissolved in 500 ml of 8 M HCl. This solution was passed through a 250 ml anion exchange resin column (AG-1X8) to remove stable copper as well as other alloying agents such as iron and zinc. The column was rinsed with four 50 ml fractions of 8M HCl. The last fractions contained some copper so they were evaporated to dryness, redissolved in 8M HCl and passed through a second 250 ml anion exchange resin column (AG-1X8), followed by three 50 ml washes of 8M HCl. These anion exchange columns removed most of the copper as well as other alloying agents such as iron and zinc.
Subsequent crystallizations were then undertaken. The fractions from the anion exchange column containing measurable sodium-22, as determined by an intrinsic germanium detector, were combined and evaporated to dryness. The resulting solids were admixed with water and the solution or suspension was converted to a 6M HCl solution by addition of concentrated HCl. This acidic solution was evaporated down to about 100 ml and allowed to cool. To this solution 250 ml of chilled concentrated HCl was added whereby a precipitate formed. The resultant crystals were filtered and washed with chilled concentrated HCl. As these crystals contained a measurable amount of sodium-22, they were redissolved in water, more concentrated HCl added and the same crystallization and filtration process performed. At this point, the resultant crystals were discarded, the filtrate and washes combined and three more crystallizations performed. Each time the aluminum chloride crystals were discarded and the filtrate and washes combined for the next crystallization.
The remaining solution was then evaporated to dryness and redissolved in 500 ml of water. This solution was placed onto a one liter macroporous cation exchange resin column (AG MP-50) and washed with fourteen 500 ml fractions of 0.2M HCl. At this step, all of the rubidium and the last of the copper were removed. Fractions 5 through 14 were combined and taken to dryness. The solids were again taken up in 500 ml of water and placed on a one liter macroporous cation exchange column (AG MP-50). The column was then rinsed with twenty-nine 500 ml fractions of 0.5M HCl. Fractions 11 through 26 were combined and evaporated to dryness. At this point the last traces of aluminum, beryllium-7 and vanadium-48 had been removed.
The solids were redissolved in about 25 ml of water and passed through a 12 ml anion exchange column (AG-1X8) followed by 25 ml of 0.1M HCl to remove traces of the cation resin. The resulting solutions were combined, evaporated to dryness and redissolved in about 20 ml of water. This final solution was assayed as the product. The assay showed radiochemical pure sodium-22 with traces of calcium.
Although the present invention has been described with reference to specific details, it is not intended that such details should be regarded as limitations upon the scope of the invention, except as and to the extent that they are included in the accompanying claims. | A process for selective separation of sodium-22 from a proton irradiated minum target including dissolving a proton irradiated aluminum target in hydrochloric acid to form a first solution including aluminum ions and sodium ions, separating a portion of the aluminum ions from the first solution by crystallization of an aluminum salt, contacting the remaining first solution with an anion exchange resin whereby ions selected from the group consisting of iron and copper are selectively absorbed by the anion exchange resin while aluminum ions and sodium ions remain in solution, contacting the solution with an cation exchange resin whereby aluminum ions and sodium ions are adsorbed by the cation exchange resin, and, contacting the cation exchange resin with an acid solution capable of selectively separating the adsorbed sodium ions from the cation exchange resin while aluminum ions remain adsorbed on the cation exchange resin is disclosed. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to power-line-operated electronic ballasts for gas discharge lamps, particularly of a type that comprises a voltage-doubler in combination with a full-bridge inverter having parallel-resonant output circuitry.
2. Description of Prior Art
Power-line-operated electronic inverter-type ballasts having parallel-resonant output circuitry are well known. One such ballast is described in U.S. Pat. No. 4,277,726 to Burke. However, to achieve an adequate degree of safety from electric shock hazard--as is required to permit listing by Underwriters Laboratories--a ballast of this type generally requires the use of an isolation transformer. However, such an isolation transformer adds significantly to the size, weight and cost of the ballast, in addition to substantially reducing efficiency.
SUMMARY OF THE INVENTION
1. Objects of the Invention
An object of the present invention is that of providing a more efficient and cost-effective electronic ballast for gas discharge lamps.
This, as well as other important objects and advantages of the present invention will become apparent from the following description.
2. Brief Description
In its preferred embodiment, subject invention is a full-bridge inverter-type ballast comprising four switching transistors and which is symmetrically powered from a center-tapped DC voltage source through an inductor means having two windings on a single magnetic core--with one winding positioned in each leg of the DC source. This full-bridge inverter has a center-tapped parallel-resonant L-C circuit connected across its output, and is made to self-oscillate by way of two positive feedback current-transformers, each connected in series with the center-tapped L-C circuit and a lamp load connected in parallel therewith.
The outputs from the current-transformers are applied to the control terminals of the four switching transistors, thereby providing load-proportional drive to these transistors.
The center-tapped DC voltage source, the inductor means and the full-bridge inverter circuit with its two feedback current-transformers are connected together in symmetrical fashion; which provides for the center-tap of the inverter output to be at the same potential as the center-tap of the DC voltage source. The DC voltage source consists of a voltage doubler powered directly from the power line--with the grounded side of the power line being directly connected with the center-tap of the DC source. Thus, with the center-tap of the DC source grounded, the center-tap of the inverter's output is grounded as well; which implies that the gas discharge lamp connected at the inverter's output is symmetrically referenced to ground.
The feedback current-transformers are saturable and so designed as to saturate approximately at the time the inverter's output voltage reaches zero magnitude.
A Zener-type voltage-limiting device is connected directly between the inverter's DC power input terminals, thereby to protect the transistors from voltage transients of excessive magnitude.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates the preferred embodiment of the invention.
FIG. 2 shows various voltage waveforms associated with the preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
1. Details of Construction
FIG. 1 shows an AC power supply S, which in reality is an ordinary 120 Volt/60 Hz electric utility power line.
One terminal of power supply S is grounded and also directly connected to a junction J between two energy-storing capacitors C1 and C2. The other terminal of power supply S is connected to the anode of a rectifier R1 and to the cathode of a rectifier R2. Rectifier R1 has its cathode connected to one terminal of C1--the other terminal of C1 being connected to junction J. Rectifier R2 has its anode connected to one terminal of C2--the other terminal of C2 being connected to junction J.
An inductor means IM has two equal but separate windings W1 and W2: W1 is connected between the cathode of rectifier R1 and a junction B+ between the collectors of two transistors Q1a and Q1b; W2 is connected between the anode of R2 and a junction B- between the emitters of two transistors Q2a and Q2b.
A Zener diode Z is connected between junction B+ and junction B-.
Transistor Q1a is connected with its emitter to a junction Ja, as is also the collector of transistor Q2a. Transistor Q1b is connected with its emitter to a junction Jb, as is also the collector of transistor Q2b.
A center-tapped inductor L is connected between inverter output terminal Oa and Ob. Connected in parallel with L is a capacitor C. The center-tap on inductor L is grounded.
Primary winding PW1 of a saturable current-transformer SCT1 is connected between junction Jb and output terminal Ob. Primary winding PW2 of saturable current-transformer SCT2 is connected between junction Ja and output terminal Oa.
One secondary winding SW1a of transformer SCT1 is connected between the base and the emitter of transistor Q1a; another secondary winding SW1b of transformer SCT1 is connected between the base and the emitter of transistor Q1b.
One secondary winding SW2a of transformer SCT2 is connected between the base and the emitter of transistor Q2a; another secondary winding SW2b of transformer SCT2 is connected between the base and the emitter of transistor Q2b.
A series-combination of a ballasting capacitor CB and a gas discharge lamp GDL constitutes a load LD; which load is connected across output terminals Oa and Ob.
2. Description of Operation
The operation of the full-bridge inverter-type ballast circuit of FIG. 1 may be explained as follows.
Source S provides 120 Volt/60 Hz voltage to the voltage-doubling and rectifying/filtering circuit consisting of R1, R2, C1 and C2. A substantially constant DC voltage of about 320 Volt magnitude then results at the output of this circuit, with the positive side of this DC voltage being present at the cathode of R1 and the negative side being present at the anode of R2.
This substantially constant-magnitude DC voltage is applied by way of inducator means IM and its two windings W1 and W2, poled as indicated, to the DC power input terminals B+ and B- of the full-bridge inverter circuit comprising transistors Q1a, Q1b, Q2a and Q2b.
This inverter circuit is made to self-oscillate by way of positive current feedback provided by saturable current-transformers SCT1 and SCT2, poled as indicated. Thus, the magnitude of the current provided to any given transistor's base-emitter junction is proportional to the magnitude of the current flowing between output terminals Oa and Ob.
The frequency of inverter oscillation is determined by a combination of the saturation characteristics of the saturable current-transformers and the natural resonance frequency of the parallel L-C circuit (as combined with the capacitive effect of the lamp loading circuit connected thereacross).
The saturation characteristics of the saturable current-transformers are substantially identical to one another and so chosen that, when there is no load connected across output terminals Oa and Ob, the waveform of the output voltage is as indicated in FIG. 2a; which waveform is made up of sinusoidal half-waves of voltage, indicated by HW1 and HW2, interconnected with periods of zero-magnitude voltage, indicated by ZM1 and ZM2. This waveform is achieved by making the time-length of the saturation-time required for the saturable current-transformers to reach saturation longer than the time-length of one of the sinusoidal half-waves of voltage. The degree to which the time-length of the saturation-time is longer than the time-length of one of the sinusoidal half-waves of voltage corresponds to the time-length of the periods of zero-magnitude voltage.
In FIG. 2a, each of the sinusoidal half-waves of voltage represents the natural interaction between L and C as fed from a substantially constant current source.
In combination, the two separate but equal windings W1 and W2 of inductor means IM provide for a total inductance that is large enough so that the current flowing through the two windings and into the inverter remains substantially constant during a complete time-period of one cycle of the inverter's oscillation. That is, the DC current flowing into the B+ junction and out of the B- junction is substantially constant during the interval between point X and point Y in FIG. 2a. Thus, whenever the L-C parallel circuit is connected between B+ and B---which it is during the complete time-length of each of the sinusoidal half-waves of voltage--it is indeed fed from a substantially constant current source.
When a load impedance having a net component of capacitive reactance (such as does LD) is connected across the inverter's output terminals Oa and Ob, capacitive reactance is in effect added to the L-C parallel circuit; which results in the time-lengthening of the sinusoidal half-waves of voltage--as indicated by FIG. 2b. The more capacitance added this way, the more time-lengthening results.
On the other hand, when a load impedance having a net component of inductive reactance is connected between Oa and Ob, the result would be a time-shortening of the sinusoidal half-waves of voltage.
By having two different load impedances connected between Oa and Ob, and by having these two load impedances be of conjugate nature, there will be no net effect on the length of the period of the sinusoidal half-waves. For instance, by having another gas discharge lamp like GDL connected in series with an inducator having a reactance of the same absolute magnitude as that of CB, and by connecting this series-combination in parallel with load LD, the total net load impedance would be resistive and would cause no net shortening or lengthening of the sinusoidal half-waves of voltage.
By making the time-length of the saturation-time of the saturable current-transformers substantially equal to the time-length of one of the sinusoidal half-waves of voltage, the resulting output voltage will be as illustrated in FIG. 2c; which indicates that the net inversion frequency will now be the same as the natural resonance frequency of the L-C parallel circuit (as combined with the load impedance connected thereacross).
By making the time-length of the saturation-time of the saturable current-transformers shorter than the time-length of one of the sinusoidal half-waves of voltage, the resulting output voltage will be as illustrated in FIG. 2d; which indicates the the net inversion frequency will now be higher then the natural resonance frequency of the L-C circuit (as combined with whatever load impedance might be connected between Oa and Ob).
In subject preferred embodiment for ballasting of gas discharge lamps, the time-length of the saturation time of the saturable current-transformers is chosen to be substantially equal to the time-length of one of the sinusoidal half-waves of voltage under the condition of maximum anticipated lamp loading; which implies that the output voltage then provided as the output of the ballasting circuit of FIG. 1 is substantially sinusoidal--as illustrated in FIG. 2c.
With a substantially sinusoidal output voltage, ballasting of (or current-limiting for) a gas discharge lamp properly be accomplished by way of a simple ballasting capacitor--like BC.
It is important to note that, as long as the time-length of the saturation-time of the saturable current-transformers remains equal to or longer than the time-length of one of the sinusoidal half-waves of voltage, the net inversion frequency will not be affected by the addition or removal of a load impedance, such as LD of FIG. 1, regardless of the magnitude of the net reactive impedance thereby added to or subtracted from the L-C parallel circuit.
It is noted that inductor L is center-tapped; which, in effect, provides for a center-tap between the inverter's output terminals Oa and Ob. Because of the symmetrical arrangement of the full-bridge inverter, the electrical potential at this output center-tap is essentially the same as that at the center-tap of the DC source; which therefore permits the grounding of the center-tap of the ballast output--recognizing that the power line is connected with the DC source in such a way that the grounded side of the power line is connected with the center-tap of the DC source.
Since the inverter/ballast output is center-tapped, and since this center-tap is grounded, the voltage between ground and output terminal Oa will be equal in magnitude to the voltage between ground and output terminal Ob. Thus, the chances of receiving an electric shock when servicing the gas discharge lamp can be lessened as compared to the situation where the voltage between ground and one of the output terminals is higher in magnitude than the voltage between ground and the other output terminal--assuming that the magnitude of the voltage between the two terminals is the same in both situations.
In fact, as long as it takes more than half of the full magnitude of the voltage existing between the two output terminals to cause the gas discharge lamp to ignite, it is not going to be possible for a ground-connected person to get an electric shock by making contact with one of the output terminals by way of the gas discharge lamp--as may commonly occur when installing a new lamp.
The magnitude of the Zener voltage of Zener diode Z is chosen such as to be somewhat higher than the maximum magnitude of the peak voltage of the sinusoidal half-waves of voltage present across the inverter's output terminals Oa and Ob. That way, the Zener diode will not interfere with normal operation of the inverter; yet, it will prevent the magnitude of the peak voltages of the sinusoidal half-waves from substantially exceeding the normally occurring maximum magnitudes. Without the Zener diode, for various transient reasons (such as due to the sodium removal of a load) the magnitude of the peak voltages of the sinusoidal half-waves would occasionally become larger than the normally occurring maximum magnitudes; and that would either cause transistor destruction, or it would necessitate the use of very special transistors of exceptionally high voltage capabilities.
It is also noted that inductor means IM may consist of two entirely independent inductors--with one inductor located in each leg of the power supply. In fact, it is even acceptable under some circumstances to use but a single inductor in just one leg of the power supply; in which case, however, it would not be possible to connect the output's center-tap with the power supply's center-tap.
The inverter of FIG. 1 must be triggered into oscillation. This triggering may be accomplished by way of providing a special trigger winding on each of the feedback current-transformers, and then to discharge a capacitor through these trigger windings. This may be done automatically by way of a capacitor-resistor combination connected between B+ and B-, and a Diac for discharging the capacitor through the trigger windings.
Finally, it is noted that the average absolute magnitude of the AC voltage appearing between inverter output terminals Oa and Ob must be substantially equal to the magnitude of the DC voltage provided from across the two series-connected energy-storing capacitors C1 and C2.
Or, stated differently, in the circuit of FIG. 1, if the inverter's AC output voltage as provided between terminals Oa and Ob were to be rectified in a full-wave rectifier, the average magnitude of the DC voltage obtained from this full-wave rectifer would have to be substantially equal to the magnitude of the DC voltage supplied from the DC output of the rectifier/filter combination consisting of R1, R2, C1 and C2.
This relationship would have to exist substantially regardless of the nature of the load connected between the inverter's output terminals.
Although the full-bridge inverter circuit of FIG. 1 may be designed to invert at any one of a wide range of frequencies, in the preferred embodiment the inversion frequency is approximately 30 kHz. Thus, the time-length of the interval between point X and point Y of FIG. 2a is about 33 micro-seconds.
It is believed that the present invention and its several attendant advantages and features will be understood from the preceeding description. However, without departing from the spirit of the invention, changes may be made in its form and in the construction and interrelationships of its component parts, the form herein presented merely representing the presently preferred embodiment. | Center-tapped DC power to a self-oscillating full-bridge inverter-type fluorescent lamp ballast is obtained from a regular power line by way of a voltage doubler. The DC power is supplied to the inverter through an inductor means having two separate windings on a common magnetic core--with one winding being positioned in each leg of the DC power supply. The full-bridge inverter, which comprises four switching transistors connected in usual full-bridge fashion, comprises a center-tapped parallel-tuned L-C circuit connected across its AC output, thereby providing a center-tapped sinusoidal voltage to its load, which consists of a fluorescent lamp connected in series with a current-limiting capacitor. Due to the effect of the inductor means, the current provided to the bridge is substantially constant during a complete period of the inverter's oscillation. The arrangement is symmetrical and provides for the center-tap of the DC voltage source to be at the same potential as the center-tap of the inverter's AC output; which means that the center-tap of this inverter or ballast output may be grounded without the need for using an isolation transformer. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non-Provisional of U.S. patent application Ser. No. 60/738,271 filed on Nov. 19, 2006, the disclosure of which is incorporated herein by reference.
COPYRIGHT AUTHORIZATION
[0002] A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
REFERENCE TO COMPUTER LISTING APPENDIX
[0003] A computer program listing appendix is stored on each of two duplicate compact disks which accompany this specification. Each disk contains computer program listings which illustrate implementations of the invention. The listings are recorded as ASCII text in IBM PC/MS DOS compatible files which have the names, sizes (in bytes) and creation dates listed below:
File Name Bytes Created animatronics_control_software.txt 134,866 Nov. 04, 2006 conversational_agent_software.txt 29,745 Nov. 04, 2006 conversation_finder_firmware.txt 36,134 Nov. 04, 2006 finger_ring_firmware.txt 13,425 Nov. 13, 2006 issue_detection_scripts.txt 36,453 Nov. 13, 2006 sensor_node_control_software.txt 126,807 Nov. 04, 2006
FIELD OF THE INVENTION
[0004] This invention relates to electronic communications systems for managing incoming telephone calls in accordance with the preferences of callers, called parties, and persons located near to the called parties.
BACKGROUND OF THE INVENTION
[0005] People use mobile communication devices everywhere, all the time. Quite often, they do so even if they are not alone, and therefore, the desire to telecommunicate and to communicate with co-located people simultaneously clashes. Over a long period of time, the human species has developed efficient ways of regulating and maintaining conversations with co-located people, using a variety of verbal and non-verbal cues. However, our current mobile telecommunication devices are insensitive to these cues and often disrupt human conversations.
[0006] Our mobile communication devices not only lack the capabilities to interact with us in a social manner, but also don't help us to integrate the two facets of communication, communication with co-located people and telecommunication with remote people using mobile devices. Instead, mobile calls interrupt us at inappropriate times, such as during public performances, during important conversations with our superiors, etc.
SUMMARY OF THE INVENTION
[0007] The following summary provides a simplified introduction to some aspects of the invention as a prelude to the more detailed description that is presented later, but is not intended to define or delineate the scope of the invention.
[0008] Today's cell phones are passive communication portals. They are neither aware of our conversational settings, nor of the relationship between caller and callee, and often interrupt us at inappropriate times. The present invention adds elements of human style social intelligence to our communication devices in order to make them more socially acceptable to both a user and others who are near to and perhaps conversing with the user.
[0009] Preferred embodiments of the present invention actively mediate between a caller, callee, and others who are located near the callee. In order to behave in a socially appropriate way, the Intermediary interrupts with non-verbal cues and attempts to harvest residual social intelligence from the calling party, the called person, the people close by, and its current location.
[0010] For example, the Intermediary obtains the user's conversational status from a decentralized network of autonomous body-worn sensor nodes. These nodes detect conversational groupings in real time, and provide the Intermediary with the user's conversation size and talk-to-listen ratio.
[0011] The Intermediary can ‘poll’ all participants of a face-to-face conversation about the appropriateness of a possible interruption by slightly vibrating their wirelessly actuated finger rings. Although the alerted people do not know if it is their own cell phone that is about to interrupt, each of them can veto the interruption anonymously by touching his/her ring. If no one vetoes, the Intermediary may interrupt. A user study showed significantly more vetoes during a collaborative group-focused setting than during a less group oriented setting.
[0012] A preferred embodiment of the invention takes the form of apparatus for handling an incoming telephone call that includes a call processor coupled to a wired or wireless telephone network for receiving an incoming telephone call directed to a called person, a conversation detector for determining whether a conversation is currently taking place between the called person and one or more other persons who are near to the called person, and a call inhibitor for terminating or rerouting the incoming call if the conversation detector determines that a conversation is taking place.
[0013] The call inhibitor delivers an audible, visible or tactile notification signal to each participant in a conversation that is taking place with the called person and thereafter terminates or reroutes the incoming call in response to a veto command received from any of the participants in the conversation. The call inhibitor may respond to a veto command by transferring the incoming call to a voice mail or voice messaging system.
[0014] The call inhibitor may first issue a notification signal to each person in a conversation with the called person, the notification signal preferably being produced by a vibratory transducer for applying a tactile notification signal to the body of each participant in the conversation. The participant may respond by operating a manually manipulatable switching device to issue the veto command. Both the vibratory transducer and the switching device may be worn on the hand or wrist of each participant.
[0015] The system may further include a message receiver for storing a spoken message from the person placing the incoming call, a speech-to-text converter for translating the spoken message into a data file containing recognized words, and a content analyzer for comparing the recognized words with a database of words known to be of interest to the called person, thereby determining if the spoken message is of probable interest to the called person. If the spoken message is found to be of sufficient probable interest, an alert generator may be employed to notify the called person of incoming call or recorded message.
[0016] The Intermediary is implemented as both a conversational agent and an animatronic device. The animatronics is a small wireless robotic stuffed animal in the form of a squirrel, bunny, or parrot. The purpose of the embodiment is to employ intuitive non-verbal cues such as gaze and gestures to attract attention, instead of ringing or vibration. Evidence suggests that such subtle yet public alerting by animatronics evokes significantly different reactions than ordinary telephones and are seen as less invasive by others present when we receive phone calls.
[0017] The Intermediary is also a dual conversational agent that can whisper and listen to the user, and converse with a caller, mediating between them in real time. The Intermediary modifies its conversational script depending on caller identity, caller and user choices, others who are located near the user, and the conversational status of the user. It interrupts and communicates with the user when it is socially appropriate, and may break down a synchronous phone call into chunks of voice instant messages.
[0018] These and other objects, features and advantages of the invention may be better understood by considering the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the detailed description which follows, frequent reference will be made to the attached drawings, in which:
[0020] FIG. 1 is an architecture overview of an interactive autonomous intermediary system that embodies the invention;
[0021] FIG. 2 is a block diagram illustrating the communication subsystem;
[0022] FIGS. 3-6 are flowcharts which illustrate the call tree processing employed by the conversational agent program;
[0023] FIG. 7 is a diagram of the software architecture employed in the conversational agent program;
[0024] FIG. 8 illustrates the behavior of an on-the-shoulder animatronic animal that acts as user agent;
[0025] FIG. 9 illustrates the behavior of an on-the-shoulder upright animatronic bird that acts as user agent;
[0026] FIG. 10 illustrates the behavior of an in-the-vest-pocket animatronic animal that acts as user agent;
[0027] FIG. 11 illustrates the behavior of a hand-held or on-a-table animatronic bunny that acts as user agent;
[0028] FIG. 12 is a diagram depicting the Bluetooth® communications pathway used to couple a PC to an animatronic squirrel;
[0029] FIG. 13 is a block diagram of the principal hardware components mounted within the animatronic squirrel;
[0030] FIG. 14 shows the screen display of a manual servo control used to create motion primitives which drive the servomotors of an animatronic creature;
[0031] FIG. 15 shows the screen display of a movement pattern sequencer used to create motion primitives which drive the servomotors of an animatronic creature; and
[0032] FIG. 16 shows the screen display of the combined controls, including a movement pattern library listing and listing of the primitive files that are combined to form sequences of primitives which drive the servomotors of an animatronic creature.
DETAILED DESCRIPTION
[0033] Implementation
[0034] The preferred embodiment of the invention described below is an Autonomous Interactive Intermediary that consists of a combination of computer hardware (PC level, microcontroller level, other electronics), software (see the accompanying computer program listing appendix), a variety of radio transceivers (433 Mhz, 2.4 GHz), and animatronic parts (servos, sensors).
[0035] System Overview
[0036] The preferred embodiment of the invention operates as an “Intermediary” that helps manage communications between the “user” of the Intermediary and remote persons (via one or more communications networks) as well as between the user and nearby persons with whom the user may be conversing. Ideally, an Intermediary is a completely autonomous, self-contained entity, preferably a small animatronic “creature,” that is meant to be a permanent companion of the user: wherever she goes, the Intermediary is with her. An Intermediary can be carried or worn, but in order not to bother the user, it should not be larger than the size of a cellphone.
[0037] As described below, the Intermediary's computationally intensive processes run on a desktop computer. The actual agent software runs on this computer and communicates with the Intermediary via a wireless audio and data link. This approach is commonly referred to as “remote brain robotics,” and was chosen to test paradigms and implement functionality that cannot be implemented using the limited resources commonly available with conventional cellphones. However, the ultimate goal is to run all agent processes on the user's phone or a telephone base station and control the Intermediary via short-range wireless link, or alternatively to integrate phone and Intermediary into one device altogether.
[0038] But even when cellphone and animatronics can be integrated and miniaturized into one tiny device, the Intermediary still relies on a sensor network that cannot be part of the cellphone itself. Ultimately, each person may wear one or several tiny sensor nodes, either in the shape of jewelry (including wrist bracelets, belt buckles, rings, etc.), or sewn directly into the clothes. These nodes will form an adhoc and completely decentralized sensor network that will serve as a shared resource for all Intermediaries in proximity.
[0039] The Intermediary consists of the following main subsystems as seen in FIG. 1 :
(a) Remote computer seen at 101 : located within range of audio and data transceiver; runs all high-level control processes; has a landline phone interface; runs speech recognition server; access to wireless data transceivers (for animatronics and sensor network) (b) Animatronics 103 : to be carried or worn by user; sensors and actuators controlled locally by microprocessors; wireless duplex audio and data link to PC for audio functionality (cellphone) and to relay actuator and sensor data (c) Conversation Finder nodes seen at 105 : to be worn close to the neck; overall size less than 40 mm (d) Finger Ring nodes seen at 107 : to be worn on finger
[0044] System Components
[0045] The remote PC seen at 101 that includes a telephone interface (a Dialogic card) seen at 111 that provides landline call control and a Bluetooth transceiver seen at 113 that provides an audio and data link with the animatronic unit 103 , and a serial data transceiver 115 that communicates with the local sensors, including the Conversation Finder nodes 105 and the Finger Ring nodes 107 .
[0046] The remote PC 101 executes programs including a conversational agent that interacts simultaneously with the caller (seen at 120 ) on a remote telephone, and the user via the animatronic unit 103 . The remote PC includes a speech recognition system for interpreting user commands. The PC 101 further acts as an animatronics control server, sending commands to the animatronic unit 103 via the Bluetooth link, and as a sensor network bridge server for receiving sensor data vial the serial port 115 .
[0047] The PC 101 may be further connected to other servers which can perform other functions of use to the system.
[0048] The PC 101 includes an animatronic control server which receives high level messages from a conversational agent and sends servo-command signals to one or more different animatronic units 103 . As described later, the animatronic unit 103 may take a variety of forms, such as a parrot, squirrel or bunny. The overall size of the creatures is between 11 cm and 30 cm.
[0049] Actuated degrees of freedom of an animatronic unit 103 include eyes opening/closing (bunny, squirrel), looking up (bending neck back) or uncurling (from curled position to straight back), turning head, and wing movements (parrot). The animatronics control server software, running on a remote PC, receives high-level messages from the conversational agent and sends servo signals to the animatronic device 103 via Bluetooth wireless serial data link 113 .
[0050] The Bluetooth transceiver provides a wireless duplex audio and data connection between the animatronics unit 103 and the PC 101 . The animatronics unit includes an audio section 106 with a speaker (for sending voice and other audible prompts to the user) and a microphone for receiving voice responses and commands from the user. The PC 101 sends speech and audio prompts to the user via the animatronic unit, and receives and recognizes spoken responses from the user. The PC's audio input and output capabilities are thus extended to the user via the animatronic device, and to the remote caller via the phone hookup. The Bluetooth transceiver also provides a duplex data channel. Via this serial channel, the animatronics receives high-level servo control signals from the animatronics server, and simultaneously sends back the animatronics' unit's sensor data.
[0051] Animatronics Controllers
[0052] The animatronics unit includes two microcontrollers (PIC 16F84A): the first one reads the switches in the animal's extremities, and sends back the status of each switch via Bluetooth channel. The second controller receives the serial servo data from the Animatronics control server, and generates the pulse width modulated (PWM) signals for the actuator servos that cause the animatronic animal (parrot, squirrel or bunny) to move in characteristic ways.
[0053] There are three switches in the extremities of the animatronics. They are generally used as Yes, No, and Connect/Disconnect buttons, but their functionality varies slightly depending on the status of the animatronics. In earlier Intermediaries (bunny), there was an additional switch in the creature's ear, which was used as a push-to-talk button.
[0054] Conversation Finder Nodes
[0055] The conversation finder nodes 105 worn at the neck of each user consists of two microcontrollers, a microphone and microphone preamplifier, a radio transceiver for exchanging data with the remote PC 101 and other nodes in proximity, and a battery.
[0056] Each user owns his or her Conversation Finder node, worn close to the neck. It functions as binary speech detector and communicates asynchronously with other nodes on a single radio channel. Each node sends out frequent heartbeat messages over RF, as well as specific messages when the user is talking, and receives messages from the nodes in proximity (approx. 10 meters). Each node independently comes to a decision about who is in the user's current conversation by looking at alignment and non-alignment of the speaking parties. At any time, the Intermediary can query the user's node wirelessly for this continuously updated list of people, as well as for other information concerning the user's conversational status.
[0057] Finger Ring Nodes
[0058] The actuated ring 107 consists of a tiny vibration motor (pager motor with an eccentric weight), a 20 mAh lithium polymer battery, a micro switch, a Radiometrix Bim2 transceiver (433 MHz), and a 16F877 microcontroller. The Finger Ring's transceiver receives messages from its user's Conversation Finder node indicating when the ring is to vibrate. If the user touches the micro switch located under the ring, the transceiver broadcasts an anonymous veto message to the Intermediary. Alternatively, the node may take the form of a vibratory transducer, a transceiver and a microswitch worn on the wrist.
[0059] Room Memory Nodes
[0060] Room Memory nodes seen at 125 are implemented as virtual nodes in software, and use the sensor network base station with Radiometrix Bim2 transceivers.
[0061] System Communications
[0062] The main system components communicate with each other as described below. These communications take place in one of two system states
[0063] (a) Upon system startup, and
[0064] (b) Upon incoming call
[0065] Upon system startup, several connections are established in sequence. As seen in FIG. 2 , the sensor controller 301 on the animatronics goes through a sequence of serial commands to set the Bluetooth transceiver 303 into duplex audio and duplex data mode. The Bluetooth transceiver attempts a Master-Slave connection to the Bluetooth dongle 305 on the remote PC. After this sequence, the sensor controller 301 starts to read the positions of all switches and generates serial signals that it sends to the Bluetooth transceiver 303 which sends this data to the animatronics control server 306 via the wireless link. As soon as the animatronics server 306 reads sensor signals from the serial port, it sends a socket message to the conversational agent software 307 that a connection to the animatronics has been established. The conversational agent 307 receives this message, and sends back its first high-level command “System Stand by” as seen at 310 .
[0066] The animatronics server 306 looks up the primitive behaviors associated with “System Stand by” and starts generating the basic PWM (pulse width modulation) serial signals for the servos via the Bluetooth data link to the Bluetooth transceiver 303 in the animatronic unit. The servo controller board seen at 320 reads these serial signals and generates continuous control signals for each servo. At this point, the system is up and running.
[0067] The communication protocols between the subsystems will be described in greater detail in later sections.
[0068] Upon Incoming Call
[0069] When the Intermediatry receives a phone call via the Dialogic board seen at 111 in FIG. 1 , it-first contacts the sensor network to establish the conversational setting of the user via the Conversation Finder nodes. In a second step, if necessary, it polls all conversational participants for their input via the Finger Ring nodes.
[0070] The following scenario illustrates the communication between conversational agent and the sensor nodes. Suppose three people, Albert, Ben and Claudia are in the same room. Albert is in a face-to-face conversation with Ben. While they are in the same room as Claudia, she is not part of their conversation. All three wear Conversation Finder nodes as well as Finger Ring nodes. Albert is holding his Intermediary, a squirrel, in his hand.
[0071] A fourth person, Dana, who is at a remote location, places a phone call to Albert which arrives at the Dialogic board of the PC. The conversational agent, running on the PC, registers the incoming call for Albert. The Conversational Agent running on the PC first determines Albert's conversational status by sending a message to Albert's conversation finder node 105 which is worn at Albert's neck, asking how many people are in his conversation, and how much he has been talking recently. Albert's node sends back the requested information.
[0072] Next, the Conversational agent on the PC agent polls the conversational partners of Albert by broadcasting a message to all Conversation Finder nodes in range: If the Conversation Finder of each person in range thinks that person is engaged in a conversation with Albert, those agents are asked to notify their users of the upcoming call! All three Conversation Finder nodes (Albert, Ben, Claudia) receive this message.
[0073] However, only the nodes of Ben and Albert think they are in a conversation with Albert. Claudia's node does not think so, since it registered her talking at the same time as Albert for several seconds. Ben and Albert's nodes accordingly send messages to their respective finger rings 107 , causing them to vibrate briefly.
[0074] Ben notices the pre-alert, and thinks it is inappropriate to get an interruption right now, so he touches his ring slightly. The ring broadcasts an anonymous veto message, saying that it vetoes to the interruption by Albert's agent. Albert's conversational agent receives the veto, and takes it into account when deciding if it wants to interrupt Albert.
[0075] Conversational Agent
[0076] The previous section briefly explained the interaction of the conversational agent with the sensor nodes. This section will describe in detail the workings of the conversational agent.
[0077] From the perspective of the human user, the Intermediary consists of two types of ‘agency’:
(1) Conversational agent: for the owner and the calling party (2) Embodied agent: for the owner and co-located people
[0080] For a caller, the conversational agent may appear first as an ordinary answering machine or voice mail system: it picks up the call instead of the user. Indeed, the Intermediary makes conventional answering machines and voicemail obsolete and is perfectly able to ‘emulate’ such systems. However, the Intermediary transcends the capabilities of an answering machine in several ways. For example, it has the capability to mediate between caller and user in real time, being able to converse with both parties at the same time. It is also superior to a voicemail system because it takes into account the current conversational status of the user.
[0081] Call Tree
[0082] The conversational agent, implemented as a finite state machine, follows a decision tree with branches that depend on external data and sensors, as well as caller and user choices detected via speech recognition and tactile feedback. The operation of the conversational agent is illustrated by the flowcharts, FIGS. 3-6 . The following are the main factors influencing state changes:
a. Distinction between known and unknown callers via caller ID and a list of known caller b. Caller and user choices: using speech recognition, both caller and user may choose between different modalities including voice mail and voice instant messages, or may choose to ignore the partner c. Knowing if the recipient of the call is engaged in a conversation d. Getting input from others in the co-located conversation e. Knowing how other people in this location have responded to incoming calls
[0088] As shown in FIG. 3 , when a call comes in, the Intermediary first polls the user's conversational size and determines how often she spoke recently. If the user is in a conversation with somebody, or has talked for more than 25% during the last 15 minutes, the Intermediary assumes that the user is busy. If the user is not busy, however, the conversational agent plays a ringing tone and connects the caller directly to the user, which results in a full-duplex audio connection between caller and user.
[0089] If the user is busy (as defined above), the Intermediary polls all participants of the co-located conversation by asking their conversation finder nodes to vibrate their finger ring nodes. All participants then have a 10-second window to anonymously veto the incoming call. As seen in FIG. 4 at 401 , if any of the participants vetoes the incoming call, the caller is informed that the user cannot be reached.
[0090] During this window, the Intermediary keeps collecting information, such as caller ID, and compares the ID with a list of known people. Then the Intermediary greets the caller as indicated at 301 , and asks the caller if she wants to leave a voicemail message, or needs an immediate response. If the caller chooses voicemail, the system records the message and terminates the call.
[0091] If the Intermediary recognizes the caller from caller ID as seen in FIG. 5 at 501 , and the caller needs an immediate response, the Intermediary allows the caller to record the message as seen in FIG. 6 at 601 , alerts the user, and plays back the message, waits for a reply, and plays back the reply to the user. However, if the caller is not known, the conversational agent asks the caller for more details about the call as seen at 503 in FIG. 5 and the caller's identity. The caller's answers are recorded and fed into the speech recognition engine, which is loaded with a specific vocabulary that tries to detect certain keywords that might be of interest to the user. The specific vocabulary may be compiled by processing data files on the user's computer, such as the user's outgoing email, the user's to-do list, or web searches recently conducted by the user. Stop words of little interest are removed from these text files, and a the most frequently used “uncommon” words which are indicative of the user's current interests are then compared with the text created by speech-to-text conversion from the incoming message. In this way, messages which may warrant the user's immediate attention may be identified.
[0092] If the caller mentions a certain amount of interesting keywords, the conversational agent moves on and lets the caller record a voice instant message, and follows the path described above.
[0093] At any point in the conversation, the user has the possibility to influence the caller's mode of communication by interacting‘with the animatronic device. If the user presses the front paw of the animatronic device, the caller gets connected directly to the user as seen at 505 , 507 , and 603 regardless of the caller's previous choices. If the user pressed the animatronics' back leg, the caller gets sent to voicemail immediately, regardless of the caller's choices, as illustrated at 511 , 513 and 611 . In each of these cases, a short prompt is played to explain the situation to the caller.
[0094] Similarly, if one of the co-located people vetoes to the call (within a 10-second window) as determined at 401 , the caller gets sent directly to voicemail. There is thus a clear hierarchy among all involved parties in terms of communication mode changes. The hierarchy is as follows:
1. Owner of the Intermediary 2. Co-located people 3. Caller
[0098] The conversational agent first checks the highest priority source, the owner of the Intermediary. The owner (user) can influence the call at any time by interacting with the animatronics. The user's choices are equivalent to “Connect the caller through!” (picks up the phone), and “Do not bother me now!” (unplugs the phone).
[0099] Below the user in the hierarchy are the co-located people. They can influence the call tree by vetoing. If the user does not express any-preferences, the Intermediary checks if it has received valid vetoes from co-located people. If it did, any vetoes are received, the caller is sent to voicemail directly.
[0100] And finally, the conversational agent takes into account the preferences of the caller by evaluation the caller's language choices via speech recognition. Both the owner of the Intermediary, as well as vetoes from co-located people can override the caller's choices, however.
[0101] Although the caller has the lowest priority of all parties and can be ‘overruled’ by either co-located people or the Intermediary's owner, there is a safeguard built into the system for emergencies that allows the caller to make sure that her call still gets through. The conversational agent supports ‘barge-in,’ meaning, the caller can interrupt the agent's prompts at any time. If the caller does so, the currently playing prompt is halted and the conversational agent records the caller's words and sends the recording to the speech recognizer, looking for special ‘emergency’ keywords such as ‘hospital,’ ‘accident,’ and ‘death’ or words or phrases which are indicative of subjects of probable special interest to the user. If a matching word or phrase is identified, the caller is provided with a “barge in” connection to the called party (the Intermediary user).
[0102] Hardware
[0103] The remote PC (seen at 101 in FIGS. 1 and 2 ) may take the form of a conventional PC running the Windows® XP operating system.
[0104] The Dialogic phone card seen at 111 in FIG. 1 provides a communications port for long range communications via the telephone network, and allows programs executing on the PC 101 to receive and dial phone calls. The phone card may be implemented using an Intel(& Dialogic® D/41JCT-LS PCI card which provides four-port, analog communications to support applications such as unified messaging, IVR (interactive voice response control), and contact centers. The D/41JCT-LS supports voice, fax, and software-based speech recognition processing in a single PCI slot, providing four analog telephone interface circuits for direct connection to analog loop start lines. In the illustrative arrangement described here, the Dialogic card utilizes only a single landline, but is built to serve up to four lines, each of which can receive incoming calls directed to a particular user via that user's Intermediary. Thus, a single remote PC may effectively operate as a PBX serving plural connected Intermediaries and their users which are coupled to the PC via a Bluetooth connection as seen in FIG. 2 .
[0105] Software
[0106] The conversational agent is written in C++ and a source language listing is provided in the accompanying computer program listing appendix. The program instantiates six main objects which shown in the object diagram seen in FIG. 7 :
1) DialManager: manages the Dialogic phone card and its low-level hardware features such as line state detection, touch-tone detection, caller ID detection, etc. 2) DialAudio: handles audio playback and recording of the phone card; enables full-duplex conversations, pause detection, barge-in, etc. 3) SpReco_Client: deals with the speech recognition server 4) BT_Client: handles audio to and from the animatronics (via Bluetooth) 5) Animatronics_Client: interacts with the animatronics server 6) Cfinder_Client: interacts with the sensor network hub, which allows communication between conversational agent and Conversation Finder and Finger Ring sensor nodes
[0113] The code that allows for a duplex audio connection between caller (from the Dialogic card 111 ) and animatronics (via Bluetooth connection 113 ) employs a multiple buffering strategy to make sure the audio streams pass in both directions with minimal delay. A delay of 200 ms is acceptable without tying down the computer's processor too much, but still making sure that the delay does not disrupt the conversational partners.
[0114] The main modules rely on sub-modules, such as Socketlnterface.cpp, which enables the multiple socket connections between the clients and servers, and WaveAudio.cpp that deals with all low-level audio functions, including a more convenient pause detection algorithm than the Dialogic's native one.
[0115] Since the agent's processes are multi-threaded, the software creates an extensive log file for later analysis, which includes saving all audio messages that have passed through the system, speech recognition results, etc.
[0116] The conversational agent relies on a speech recognition server based on Microsoft Speech, sending audio buffers and getting back the recognition results. It can dynamically change the recognizer's vocabulary, which is specified as an XML file. Both the audio that was sent as well as the speech recognition output is stored for each session.
[0117] Developing the Intermediary Embodiments
[0118] In accordance with a feature of the present invention, the call handling agents which provide the interface to users and others who are nearby takes the form of an animatronic robotic “animal” such as a squirrel, a parrot or a bunny. The embodied agent's primary function is to interact socially, with both the user and other co-located people. Humans are experts in social interaction, find social interaction enjoyable, and feel empowered and competent when a human-machine interface is based on the same social interaction paradigms that people commonly use. See Reeves, B., Nass, C. I. The media equation: how people treat computers, televisions, and new media like real people and places, Stanford, Calif. New York: CSLI Publications; Cambridge University Press (1996),
[0119] Non-Verbal Cues for Interruption
[0120] How do people interact with and interrupt each other? What kind of non-verbal cues are used? Non-verbal cues are communication signals without the use of verbal codes (words). Such cues can be both intentional and unintentional, and most speakers and listeners are not conscious of these signals. The cues include (but are not limited to): touch, glance, eye contact (gaze), volume, vocal nuance, proximity, gestures, facial expression, pause (silence), intonation, posture, and smell.
[0121] The problem is well studied for dyadic conversations with speakers and listeners taking turns. For example, the paper by Duncan, S., On the structure of speaker - auditor interaction during speaking turns, Language in Society 3: pp 161-180 (1974) shows that turn-taking behavior is a complex multi-step process involving a strict pattern, which, if not followed properly, will result in simultaneous turn taking and confusion. There is a multitude of signals that are used to regulate this behavior. Of particular interest in this context are eye contact and gestures, e.g., a listener raising hand into gesture space as a nonverbal wanting-turn cue (e.g., see McFarlane, D. C., Interruption of People in Human - Computer Interaction: A General Unifying Definition of Human Interruption and Taxonomy, NRL Formal Report NRL/FR/5510-97-9870, Washington: US Naval Research Laboratory (1997).
[0122] However, an Intermediary's task to interrupt is different from signaling turn taking in an ongoing conversation. It is rather comparable to an outside person trying to interrupt an ongoing face-to-face conversation. Experts for these kinds of interruptions are administrative assistants who are professional ‘interruption mediators.’ They make decisions every day about whether to allow interruptions to the person they support. See Dabbish, L. A., and Baker, R. S. Administrative assistants as interruption mediators, In Proceedings of ACM Conference on Human Factors in Computing Systems (CHI'03): Extended abstracts. New York: ACM Press, pp 1020-1021. http://doi.acm.org/10.1145/765891.766127 (2003) which, based on a series of interviews with administrative assistants, suggest a production-rule model of the decision process when deciding whether to deliver interruptions to the person they support.
[0123] Ideally, the Intermediary would learn the ‘mechanics’ of such behavior by imitating interactions between humans, perhaps starting with facial mimicry. See Breazeal, C., Fitzpatrick, P. That Certain Look: Social Amplification of Animate Vision, Proceedings of the AAAI Fall Symposium on Socially Intelligent Agents: The Human in the Loop, November 3-5, North Falmouth, Mass., Technical Report FS-00-04, pp 18-23, http://www.ai.mit.edu/people/paulfitz/pub/AAAIFS00.pdf (2000). Such a capability may well be a significant stepping-stone to developing appropriate social behavior, to predicting other's actions, and ultimately to understanding people as social beings. However, the present invention focuses on the use of human-style cues to alleviate the interruption problem.
[0124] In order for an agent to be understandable by humans, it must have a naturalistic embodiment and interact with its environment like living creatures do by sending out readable social cues that convey its internal state. See Zlatev, J, The Epigenesis of Meaning in Human Beings and Possibly in Robots, Lund University Cognitive Studies, vol.79. http://www.lucs.lu.se/People/Jordan.Zlatev/Papers/Epigenesis.pdf (Zlatev, 1999). It is not implied that the Intermediary's software mimics mental cognitive processes. However, it is-designed to express itself with human-style non-verbal cues such as gaze and gestures to generate certain effects and experiences with the user. The underlying idea is that human-style social cues can improve the affordances and usability of an agent system.
[0125] A conversational agent is given a physical presence, through interactive critters of different shapes and sizes, remotely controlled by a computer. These creatures interact by performing a combination of pet-like and human-like behaviors, such as waking up, waving for attention, or eye contact. These non-verbal cues are intuitive, and therefore may be ideal for unobtrusive interruptions from mobile communication devices. Physical activity of the embodied agent can alert the local others to the communication attempt, allowing the various parties to more gracefully negotiate boundaries between co-located and remote conversations, and forming “subtle but public” cues as described in Hansson, R., Ljungstrand, P., Redström, J. Subtle and Public Notification Cues for Mobile Devices, Proceedings of UbiComp 2001, Atlanta, Ga., USA. Hansson et al. (2001). Furthermore, these cues allow for more expressive alerting schemes by embedding additional contextual information into the alert. For example, the agent may try to get the user's attention with varying degrees of excitement, depending on the importance or timeliness of the interruption.
[0126] The animatronics are also ‘socially evocative’ as they rely on our tendency to anthropomorphize and capitalize on feelings evoked when we nurture, care, or are involved with our “creation.” See Fong, T., Nourbakhsh, I., Dautenhahn, K. (2003). A Survey of Socially Interactive Robots. Robotics and Autonomous Systems, vol. 42(3-4), March 2003. http://www.ri.cmu.edu/pub_files/pub3/fong_terrence_w — 2003 — 4/fong_terrence_w — 2003 — 4.pdf
[0127] The animatronic embodiment of the user agent serves as a social interface by employing human-like cues and communication metaphors. Its behavior is modeled at the interface level, so the current agent is not implemented with social cognition capabilities. Yet, it is ‘socially embedded’ since the agent is partially aware of human interaction paradigms. For example, with its capability to detect speech activity and conversational groupings in real-time, the agent may choose to interrupt the user only when there is no speech activity. See Marti, S., Schmandt, C. Giving the Caller the Finger: Collaborative Responsibility for Cellphone Interruptions, Extended Abstracts of CHI2005, pp 1633-1636. (2005), http://doi.acm.org/10.1145/1056808.1056984
[0128] These animatronic user agents are zoomorphic, but employ anthropomorphic behaviors (gaze, gestures). Although this combination partially violates the ‘life-likeness’ of the creatures, it helps to avoid the ‘uncanny valley,’ an effect where a near-perfect portrayal of a living thing be-comes highly disturbing because of slight behavioral and appearance imperfections.
[0129] Embodying an agent grounds it in our own reality. The structural coupling between system and agent creates a potential for “mutual perturbation.” See Dautenhahn, K., Embodiment and Interaction in Socially Intelligent Life - Like Agents. In C. L. Nehaniv (ed.) Computation for Metaphors, Analogy and Agent, Springer Lecture Notes in Artificial Intelligence, Volume 1562, New York, N.Y.: Springer, pp 102-142. (1999). http://www.springerlink.com/link.asp?id=9m9h2e7eiahq42ur.
[0130] In the current system, the user agent is realized on two levels. First, the degrees of freedom of our animatronics allow the system to ‘perturb’ its environment via physical movements. Second, the dual conversational capability that enables the system to engage in spoken interactions with both user and caller, allows the agent to communicate in the conversational domain, which is equally human accessible. On both levels, the agent can manifest its internal state towards its environment (the caller, the user, and co-located people), and get input from its environment (spoken language, tactile) via its sensors and actuators. For example, the Intermediary changes its movements when there is an incoming call, further differentiating between known and unknown callers using non-verbal signals to ‘act out’ what is going on in the phone domain.
[0131] The current Intermediaries are all based on animals (bunny, squirrel, and parrot), but their respective morphologies are diverse enough so that their appearances create different expectations (and preferences, as user studies show). These expectations influence the behaviors that the user might want to see from the animatronics. Due to the layered software architecture, the same conversational agent can control any of our Intermediaries, without modifications of the state machine. A diversity of Intermediaries is fully intended, since users may have strong individual preferences for their personal animatronics.
[0132] Although the main function of the Intermediary's animatronic device is enhancing communication and alerting, is unlike any conventional stationset equipment, and certainly not just like a cellphone. Rather, the Intermediary should be regarded as a ‘sentient companion’ (although not in the literal sense) that keeps the user's company, much like a pet dog or another small, tamed creature. Such a view suggests some of the ways an Intermediary could be embodied; that is, suggests what it should look like and how it should behave. Since the animatronics part of the Intermediary is a personal companion to the user, the metaphors of a pet like companion has been employed.
[0133] Pirate with Parrot
[0134] One famous pet-like companion is the parrot sitting on the mystical sailor's shoulder. Another one is the snake wound around the handler's neck. Some metaphors are more contemporary, like a small rodent ‘living’ in the shoulder/neck area of a punk rocker. The last two mentioned, however, do not guarantee wide public acceptance, because of the ambivalent connotation of snakes and rats.
[0135] However, there are more ways an Intermediary can be embodied, keeping in mind that one of the most important reasons to embody the Intermediary is to provide a natural and clear focal point of attention for the people around the user. In other words: it has to be clearly visible to the people around the user. One such Intermediary could be a hamster (or similar sized creature) sitting in the user's chest pocket. This location is highly visible to the people around the user, and includes the important option of looking up to the user.
[0136] As mentioned earlier, another important reason to embody the Intermediary is to use socially intuitive cues to interrupt and alert, instead of ringing or vibration. One of the strongest social cues is gaze. Therefore, it is important that an Intermediary can look at people, and at the user specifically, with big eyes. As a contrast, the Intermediary could be asleep when not in use. This can include slight breathing movements to make it still appear ‘alive’ (in a wider sense).
[0137] In general, the most generic mapping between the animatronics behaviors and meaning is as follows:
Behavior Meaning Sleeping, breathing Idle, nothing important going on Waking up, looking around, Get attention from user and seeking eye contact co-located people
In the following description, four different generic types of Intermediaries are presented that differ in their respective functional advantages and disadvantages. Three Intermediaries are described in detail.
[0138] Creature Resting on Shoulder
[0139] A user agent that takes the form of a creature resting on the user's shoulder is seen in FIG. 8 .
Features: Opens and closes its big eyes; touch sensitive nose and ears Advantages: Good visibility to other people; rests easily on shoulder Disadvantages: Only one degree of freedom (only its eyes are animated)
Although having a creature resting on a user's shoulder as illustrated in FIG. 8 is highly visible to co-located people (which is the desired effect), the user himself can‘t see the eyes of the creature if its head is not turning. Therefore, opening its eyes could be accompanied by a very low volume sound, only audible to the user. Such a sound would also mask the sound of the actuators, if they were based on motors and gears. (The masking issue disappears if quiet actuators are used, such as magnetic actuators or actuators based on shape memory alloys.) This instantiation is based on a ‘lazy animal’ resting its (oversized) head on the user's shoulder. It has an extremely oversized nose and head section. The animal has big eyes, which grab attention by just opening its eyes. In addition to that, the animal incorporates all features that seem to influence the ‘cuteness’ of a creature: big eyes, high forehead, big head compared to body, short arms and legs. Cuteness may be important to increase the social acceptance of an Intermediary. In addition, it is often associated with young creatures, like puppies, which are given more freedom in case of misbehavior, since the creature is still in its infancy, and just doesn't know any better. Therefore, people are more forgiving with interruptions from creatures obviously still “in training.”
[0143] Bird Standing on Shoulder
[0144] A second Intermediary, a bird on the user's shoulder, is illustrated in FIG. 9 .
Features: Moving head up/down, or eyes opening/closing;
wings flapping; touch sensitive wings; head turning towards user
Advantages: Very good visibility on shoulder, can talk directly into user's ear Disadvantages: Difficult to mount/balance on shoulder
Although balancing a bird on one's shoulders is non-trivial, sitting on the user's shoulders has the obvious advantage of being very close to the user's mouth as well as one of his ears. Because the microphone is close to the user's mouth, his voice is picked up well even if talking in a low volume; and because the speaker is close to the user's ear, especially when the user turns towards the Intermediary, playback volume can be very low and still acceptable for the user.
[0150] Creature in Chest Pocket
[0151] A third Intermediary, a creature in the user's chest pocket, is illustrated in FIG. 10 .
Features: Moves in and out of chest pocket (vertically), turns upwards towards user Advantages: Convenient to carry; small Disadvantages: Difficult to integrate all elements into a chest pocket sized animal; not as visible as the other instantiations
This instantiation is inspired by a hamster that sits in the user's shirt pocket, usually asleep, but wakes up when it has to alert, peeks out and looks up to the user when it wants his attention. A possible version would be a Beanie Baby® sized doll, or a custom made stuffed animal
[0155] Creature in Hand and on Table
[0156] A third Intermediary, a creature in the user's hand or on a table, is illustrated in FIG. 10 .
Features: Moving head up/down (big ears covering eyes);
touch sensitive ears
Advantages: Doesn't have to be worn, can sit on desk by itself Disadvantages: Has to be carried around
As mentioned above, making the creature appear cute is important to increase its social acceptance for co-located people. This creature in the hand or on a table profits from the very cute movement of a small rabbit baby being curled in during sleep, almost spherical in shape, and then stretching its back when waking up. When asleep, its eyes are covered by its floppy ears, but are uncovered in a very cute way when waking up. This is a typical example of a “cute” movement, which can be as important as “cute” static features. Such movements are slow, never abrupt or fast, and may exhibit non-linear acceleration and deceleration to more realistically mimic such “cute” movements.
[0161] Since cuteness does not have to coincide with ‘life-likeness,’ it is possible to explore non-lifelike entities as Intermediaries that become attractive and socially acceptable through their mere movements. The movement of “unfolding” seems a promising candidate. A good example it the so-called robotic calculator that unfolds and stands up, which is an amazingly cute feature since the spring is damped heavily to allow for a very smooth and slow unfolding process. Another possibly cute movement could be a creature coming out of its nest or ‘house’, like a hermit crab or a turtle peeking out of its shell.
[0162] Other possible locations for the Intermediary include:
1) Hanging in front of chest, with necklace 2) Wrapped around neck, as a scarf (octopus, snake) 3) Wrapped around upper or lower arm 4) On user's back or over shoulder: e.g., a monkey disguised as a backpack or shoulder bag. Advantage: enough space for adding sub-systems; can “hold” or “hug” the user naturally Disadvantage: much larger than cellphone 5) Finger mounted, fingertip mounted (thimble), thumb nail mounted. Disadvantage: difficult to incorporate all necessary subsystems on such a small form factor.
[0168] Other possible degrees of freedom for the Intermediary may include:
a) Opening/closing pupils (making big eyes) b) Tilting head sideways (may increase perceived cuteness) c) Wiggling ears or tail d) Raising eyebrows e) Crawling up and down the user's sleeve (attached to lower arm) f) Shrinking shoulders g) Waiving with paws (if sitting in chest pocket) h) Nose movement (sniffing, like Ocha-Ken™) i) Slightly breathing (chest movements) j) Blowing up cheeks (like hamster) k) Moving and glowing up whiskers l) Rattling (snake) m) Moving eyes on eyestalks
[0182] Clearly there is a design and fashion aspect to an Intermediary. Cell phones are becoming fashion statements, a trend that will soon become the main reason to buy new communication devices. Although it will be very difficult to keep up with the quickly changing fashion trends, there are things that would increase the acceptance of an Intermediary to fashion conscious users, e.g., can if it can be worn in more than one location.
[0183] Animatronics
[0184] The following section describes different Intermediary embodiments. These embodiments include “stuffed animals” that were heavily “enhanced” so that each contained some or all of the following subsystems:
A. Actuators and sensors B. Wireless transceiver (i.e., Bluetooth for duplex audio and data) C. Audio (audio amplifier, speaker, microphone) D. Animatronics control (converting actuator and sensor signals) E. Batteries and power conditioning F. Skeleton and skin
Three generations of animatronics were employed in a parrot, a bunny and a squirrel. Each has different capabilities, for example, different degrees of freedom and different audio/data links.
[0191] Actuation
[0192] The parrot has four degrees of freedom: two for the neck (up-down, left-right), and both wings separately. This allows the bird to look up, look around, express different patterns of excitement and frustration with its wings, etc.
[0193] Both bunny and squirrel have also four DOF: two for the neck and spine, and both eyelids. The initial posture is curled up; they wake up with an ‘unfolding’ movement. They then can look around, and together with fine eyelid control express surprise, sleepiness, excitement, etc.
[0194] In order to create a realistic eye opening and closing expression, both bunny and squirrel are able to move both upper and lower lids, using small rubber bands as lids that are pulled back simultaneously by a micro servo via thin threads.
[0195] All actuators are independent channels that are fully proportional with a resolution of 100 steps from one extreme to the other.
[0196] The animatronics do not try to express emotions per se. Since they mainly use gestures and gaze, they do not employ complex facial expressions other than moving eyelids, and have no need for mobility (i.e., no walking).
[0197] Wireless Link
[0198] Although the animatronics may be controlled directly by the user's cellphone, or the animatronics will contain the cellphone, the animatronics devices described here are implemented with a ‘remote brain’ approach; that is, they are computer-remote controlled, but completely wireless and self-contained devices.
[0199] The three generations of Intermediaries differ in their wireless links: the parrot has a simplex data link and no audio capabilities. The bunny sports a simplex data link as well as half-duplex audio. And the final generation, the squirrel, has both full duplex audio and data link.
[0200] The parrot and the bunny are controlled via radio control (“R/C”) gear that is used by hobbyists to control airplanes and boats. This channel is simplex, with a range up to 100 meters indoors. The most advanced Intermediary, the squirrel, sports a fully digital link for both audio and data. On the desktop computer side, a Bluetooth class 1 transceiver is used with modified antenna to achieve a range of 40 meters indoors. On the animatronic Intermediary side, a Bluetooth class 1 module with a ceramic antenna is used. This Bluetooth link allows simultaneous duplex audio and duplex data transmission, and replaces the bulky RIC transmitter and half-duplex radio of our earlier prototypes. The duplex audio capability enables not only asynchronous voice instant messages between caller and user, but also a full duplex phone conversation. The duplex data channel allows sending back sensor data from the Intermediary to the animatronics control software.
[0201] A variety of conventional techniques may be used to control the movement of an animatronic creature in order to implement the present invention.
[0202] For example, U.S. Pat. No. 6,012,961 issued on Jan. 11, 2000 to H.D. Sharpe et al., the disclosure of which is incorporated herein by reference, describes an electronic toy that includes a user reprogrammable data storage device, such as recordable tape media, or digital memory, whereby a user can selectively download program information into the data storage device to change the independent operating characteristics of the toy. The program information is generated by a personal computer. The disclosed toy consists of an animatronic teddy bear having a reprogrammable digital memory. The program information, which may include audio data for speech and control data for movement of animatronic body parts under the control of servomechanisms, with the movements being synchronized with the toys audio output. The toy can be operated directly from output generated in real-time by the computer while connected to the computer, or by remote computer connected to the local personal computer.
[0203] U.S. Pat. No. 6,230,078 issued on May 8, 2001 to John D. Ruff, the disclosure of which is incorporated herein by reference, describes a simplified animatronic system using a computer to control the speed and direction of multiple stepper motors, so that a script for a sequence of operations of the motors can be prepared and edited, stored on disk, and played back to control the motors to control the motors to perform the sequence of operations. Each letter of the alphabet can identify a different motor speed, and each line of the script contains one letter for each motor being controlled.
[0204] The specific embodiments of the invention having the characteristics needed to act as an intermediary between calling parties and called parties and nearby people included a parrot that sat on the shoulder of the user and that moved in four degrees of freedom: two for the neck (up-down, left-right), and both wings separately. This allows the bird to look up, look around, and express different patterns of excitement and frustration with its wings. The neck consists of a servo that can turn the head sideways. This servo is attached to the spine with a ‘nodding’ joint. A second servo moves the whole first servo forward and backward (nodding motion) via pushrod and devises. The wing servos are attached on the side of the spine, and a square plastic tube extends the servo horns into the wings so that they can be moved on command.
[0205] The Bunny, chosen specifically for its cuteness, but also because of its size, fits perfectly into a hand, but has enough space inside to accommodate all electronics and mechanics. As a stuffed animal, its basic posture is curled up, almost spherical in shape. In this position, the floppy ears tend to cover the eyes. If the bunny raises its head, the ears uncover the eyes. The bunny's neck consists of two servos (Cirrus CS-6.2) connected head to head with an angular offset of 90 degrees. This neck construction allows the bunny to look left and right with a 90-degree angle, and independently raise its head with about the same angle. Instead of actuating the paws, it was decided to make the eyes open and close. Two micro servos (Cirrus CS-4.4) that fit in the bunny's head move the upper and lower eye lids using small rubber bands. The lids are pulied back by the micro servo via thin threads, providing a very life-like movement of the eyelids. On the bunny side, a transceiver accepted commands from an external push-to-talk button (momentary switch) in the right ear of the bunny, allowing the user to grab the bunny's ear when she wants to talk (“squeeze-ear-to-talk” metaphor). An additional momentary switch hidden in the right foot of the bunny allowed the user to turn on and off the transceiver without opening the animatronics. Whenever the user squeezes the talk button by squeezing the ear of the bunny, and then releases this button, a short noise burst is produced that is interpreted as positive confirmation signal (or another kind of signal depending on the context), allowing the user to signal the main agent software as needed.
[0206] The squirrel is the most advanced animatronics implementation of the three generations with its Bluetooth duplex audio and data connection. The mechanics of the squirrel are the same as in the bunny, and it uses the same skeleton and servos, but the communications take place over the Bluetooth link as illustrated in FIG. 12 . The Bluetooth transceiver indicated at 1201 permits the squirrel to be up to 30 to 40 meters from the PC which sends audio and servo command data to squirrel (and hence to the user and those near the user), and transmits user signals back to the PC. On the desktop computer side, a Bluetooth class 1 transceiver (Linksys© USBBT100) seen at 1203 is used with modified antenna (2.4 GHz Range Extender) to achieve a range of 40 meters indoors.
[0207] On the Intermediary side, a Bluetooth class 1 module with a ceramic antenna is used. This Bluetooth link 1201 allows simultaneous duplex audio and duplex data transmission, and replaces the bulky R/C transmitter and half-duplex radio of our earlier prototypes. The duplex audio capability enables to not only pass asynchronous voice instant messages between caller and user, but also switch to a full duplex phone conversation. The duplex data channel allows sending back sensor data from the Intermediary to the animatronics control software.
[0208] FIG. 13 illustrates the hardware components used to implement the squirrel. A Bluetooth board seen at 1301 includes an onboard audio codec and RS232 UART seen at 1303 . Two PIC microcontrollers (16F87A), one each for the servo control and one for the sensor control are employed as seen at 1306 and 1308 respectively. An audio amplifier (1 watt) seen at 1310 delivers amplified audio signals to drive a speaker 1312 which delivers audible sound to the user and to those nearby. Four servo motors indicated at 1330 are controlled by the Servo PIC microcontroller 1306 to move the squirrel's head and eyelids as described above for the bunny. A 9V NiMH rechargeable battery seen at 1340 powers the Bluetooth board 1301 and the microprocessors 1306 and 1308 via a voltage regulator seen at 1350 . A 3.7 V lithium polymer battery 1360 powers the servos 1330 .
[0209] Since the squirrel has four degrees of freedom, two for the neck and spine, and two for the two eyelids, the four servos at 1330 can be driven to make the squirrel wake up with an ‘unfolding’ movement, and look around. These movements, couple with fine eyelid control can be used to express surprise, sleepiness, excitement, etc.
[0210] The Bluetooth board 1301 is a commercially available board (a BlueRadios© BR-EC11A) made for evaluating Bluetooth modules, and comes with a codec, connectors for microphone and line out, UART and RS232 connectors, programmable status LEDs, a stable power supply, and as well a host of other connectors. The board is configured and controlled through simple ASCII strings over the Bluetooth RF link or directly through the hardware serial UART.
[0211] The first microcontroller 1306 generates the servo signals from the serial signals it gets via Bluetooth board 1301 . The second microcontroller 1308 reads the position of three switches seen at 1370 and sends back serial signals via Bluetooth board 1301 . The servo microcontroller 1306 can generate PWM signals for 12 servos in parallel with a resolution of 240 steps over 90 degrees rotation. The commands are 2 bytes per servo, one for the ID of the servo, one for the desired position. The sensor microcontroller reads the switch positions and sends back serial signals over the Bluetooth connection to the animatronics server. At initialization time, the sensor microcontroller also produces a sequence of precisely timed commands that it sends to the Bluetooth board and then starts reading the position of the switches and sends serial signals via the Bluetooth link to the remote PC.
[0212] Microphone, Speaker and Amplifier
[0213] Although the Bluetooth board 1301 has an onboard codec and features a headset output, its audio signal is not strong enough to power a speaker. Therefore, the line out signal is fed into a small 1-watt audio amplifier 1310 to drive a tiny speaker conveniently located in the bushy tail of the squirrel. A microphone 1380 is connected to the Bluetooth board to pickup speech from the user and return it to the remote PC using the audio channel of the Bluetooth link.
[0214] Animatronics Server and Sequencer
[0215] All of the animatronic creatures described above are controlled remotely by the animatronics control program which executes on the remote PC. The accompanying computer program list appendix contains the source code for this program which serves both as an authoring tool to create low and high-level behaviors, as well as the hub that translates high-level commands from the conversational agent program described earlier to low-level control signals for the creature's movement servos, and transmits sensor signals from the switches in the creature back to the conversational agent. It will be understood that the hub conversion functions may be performed locally in the creature's electronics with the authoring functions to be described next performed by the developer using a PC.
[0216] The animatronics server and sequencer program performs the following functions:
1) Record and modify behavior primitives in loops 2) Compose primitives into behavior sequences 3) Map behavior sequences to agent state changes
[0220] Creating Behavior Primitives
[0221] The program provides the character designer who develops movements for a given animatronic creature with a Manual Servo Control whose screen display is seen in FIG. 14 , which allows the character designer to manipulate each DOF separately via sliders. As seen in FIG. 14 , each of six vertical slider controls may be moved with a mouse and, as it is moved, the position of the servo associated with the slider (channel) moves as well. The instantaneous position of the slider is shown in the display box at the bottom of the slider. In order to find the center, an additional Center button is provided per channel.
[0222] Manual Servo Control
[0223] The sliders in the manual servo control seen in FIG. 14 are initially moved by the character designer and recorded in a data file which can then be played back to repeat the movement. As noted above, PWM signals can move each servo with a resolution of 240 steps over 90 degrees rotation. The speed of the movement mimics the speed at which the developer moved the slider as the movement date was recorded.
[0224] Manipulation of manual servo control is used during repeated playbacks of movement primitives under the control of the Movement Pattern Sequencer which produces the screen display seen in FIG. 15 , where behavior primitives are created and modified. The standard mode for recording primitives is a loop of 8 seconds, with a sample rate of 40 Hz. The character designer modifies the position of the servos via the sliders in real-time. All changes are recorded automatically “on the fly,” and played back during the next loop. If a change is not satisfying, the designer can easily undo it by “over-writing” the change during the next loop. This recording metaphor is similar to the “audio dubbing” method used in movie making, where the actor watches a short scene in a loop, and can keep recording and adjusting the dubs a satisfactory result is achieved.
[0225] Movement Pattern Sequencer
[0226] Creating primitives in a simultaneous playback/recording loop has proven to be a fast and efficient method. The creature designer teaches the system the desired behavior (by manipulating the sliders), and in a tight loop gets feedback of the system's performance by seeing both the sliders repeat what the character designer just did, as well as seeing how the creature behaves given those slider movements. In addition to direct manipulation via sliders, the character-designer has access to each individual data point by text-editing the resulting data file, which guarantees maximum control over the behavior design process.
[0227] Once the combination of servo movements which make up a given movement primitive have been produces, the movements can be fine-tuned by reducing (or increasing) the speed of the loop recording and playback, allowing for finer control during the recording process. Furthermore, a primitive might start out as a 8-second loop, but can easily be pruned to a sub-section of the whole sequence by modifying the start and end points of the pattern, The “pruning” is done in a non-destructive way, with the “deleted parts” saved, and can be restored and modified at any time. Once a primitive is built and modified to the designer's satisfaction, it can be stored as a named data file in the Movement Pattern Library, and recalled at any time. To this end, the name of the primitive is entered into the text box seen at the lower right in the Movement Pattern Sequencer control seen in FIG. 15 , and the “Save” button is pressed. Note that a saved primitive can be modified and saved under a different name, making it easy to create new primitives which are modified versions of previously created primitives.
[0228] Composing Complex Behaviors
[0229] On the next level, the behavior primitives that are stored in the library can be composed into behavior sequences. Essentially, a behavior sequence consists of a linearly arranged sequence of primitives.
[0230] The entire screen display for the Animatronics server and sequencer program is seen in FIG. 16 and includes a movement pattern library listing at 1601 which identifies and permits the selection of previously named primitive files created using the Movement pattern sequences control seen in FIG. 15 . The software allows rapid creation of such sequences by simply dragging and dropping primitives from the pattern library listing at 1601 into one of the lists of other behaviors seen at 1603 . Such a composited behavior sequence is stored, and can be played back in three modes:
1) Play back whole sequence once, and then stop 2) Play back all, and then repeat the last primitive 3) Repeat whole sequence until the next behavior command is issued
[0234] Mapping Behaviors to Agent States
[0235] Each state change of the conversational agent may trigger behaviors of the animatronics. The cues are high-level descriptions of the agent state, such as “call received”, or “caller finished recording a voice instant message,” and are mapped to composite behaviors designed by the character designer. For each different animatronic device, the high level cues from the conversational agent are implemented according to its affordances (degrees of freedom, etc). This architecture allows an abstraction of the high level states of the conversation from the implementation of the respective behaviors in the animatronics. Therefore, animatronics with different affordances can get plugged into the same conversational system without the need to adjust the decision tree. This means that-a user can choose which Intermediary fits his/her mood, social setting, etc., without having to modify the conversational agent state machine, and lends new meaning to the phrase interface “skins.”
[0236] The animatronics' behaviors are generated in real-time, depending on the agent-caller interaction. Therefore, factors such as the length of a voice instant message influence the animatronics behavior dynamically.
[0237] To create such dynamic behaviors, the conversational agent sends short messages to the animatronics server requesting certain behavior sequences when state changes occur. In addition, the agent can also specify the mode (‘play sequence once’, ‘repeat all’, ‘repeat last primitive’), and the overall speed for the behavior. If a sequence is requested in ‘repeat all’ or ‘repeat last primitive’ mode, the animatronics repeats the behaviors until it receives a new command so the animatronics does not ‘freeze’ at the end of a sequence.
[0238] Interaction Example
[0239] The example below shows the relationship between state transitions, the intended animatronics' behavior, and the low-level physical gestures. Although the example is fictitious, the current system works as described.
[0240] Joe is in a meeting. His animatronics, a palm-sized bunny with soft furry skin, is sleeping quietly. It is completely curled up, head tucked between its legs, eyes closed firmly and covered by its floppy ears. Every now and then it sighs (moves head twice up and down, 10% of actuator travel) in order to let its owner know that every-thing is ok, it's just asleep. A call comes in, and the bunny twitches slightly in its sleep, as if it had a dream (two sharp head movements, left-right-left-right to 20%, eyes opening 10% then closing again), but is still asleep. The Intermediary then recognizes the caller from caller ID: it's Joe's friend Clara. The bunny sighs, and slowly wakes up (slow head movement up and 30% to the left; at the same time, its eyes start to open slowly to 50%, close again, open twice for 20%; the head shakes slightly left-right-left, then the eyes open, a bit faster now, to 70%.
[0241] The agent asks Clara if she wants to leave a voice mail or voice instant message. Clara leaves a voice instant message. During that time, the bunny sits still, looks up as if it would listen to something only it can hear, slowly turning its head from left to right, blinking once in a while. As soon as she is done leaving the message, the bunny gets excited and looks around pro-actively (rapid full movements of the head from one side to another). Joe notices it, and turns his attention towards it. The bunny whispers in his ear and tells him who is on the phone, then plays back the short message it took from Clara. The animatronics is now fully awake and attentive (eyes completely open, head straight). Joe touches the bunny's right ear (which triggers the recording mode) to leave a reply. The bunny sits still, listening (head tilted slightly upwards, blinking fast and of-ten). As soon as Joe is done, it confirms by nodding (medium fast head movement down and then back to middle, followed by single blink). When the message has been delivered to Clara, the bunny looks back at Joe and winks at him, to confirm the delivery (head straight, one eye blinks twice). Then it stretches (head slowly upwards to 100%, then medium fast back to middle), and gets sleepy again (eyes close to 50%, and slowly closing and opening again, twice; at the same time, the head goes slowly down to its belly, halting 2 times in the movement), eventually assuming the same curled up posture it had before the call.
[0242] Conversation Finder
[0243] The purpose of the Conversation Finger subsystem is to provide the Intermediary with information about the conversational status of the user. This is achieved by utilizing a decentralized network of autonomous body-worn sensor nodes. These nodes detect conversational groupings in real time, and offer the Intermediary information about how many people participate in the user's conversation, as well as if the user is mainly talking or listening.
[0244] Each user owns his or her Conversation Finder node, worn close to the neck. It functions as binary speech detector and communicates asynchronously with other nodes on a single radio channel. Each node sends out frequent heartbeat messages over RF, as well as a message when the user is talking, and receives messages from the nodes that are close by. The nodes independently come to a conclusion about who is in the user's current conversation by looking at alignment and non-alignment of the speaking parties. At any time, the Intermediary can query the user's node wirelessly for this continuously updated list of people.
[0245] Each node consists of two microcontrollers, a microphone, a transceiver, a microphone preamplifier, and a battery.
[0246] Conversational Groupings
[0247] In order to detect conversational groupings, the Conversation Finder nodes assume that if two people are in a conversation with each other, their speaking does not overlap for a significant amount of time. A “significant amount of time” may be a culturally biased parameter, but an overlap of 3 seconds has proven to be a useful value in informal tests.
[0248] The Conversation Finder can use a messaging protocol that is simple yet efficient. Each message consists of one byte (repeated for error checking purposes). The first nibble is the message ID; the second nibble is the node ID. Each node sends out a HEARTBEAT message every 3000 ms. When the wearer of a node is talking, the node sends out TALK messages continuously, 6 every 200 ms. A 4 bit message space and 4 bit ID space allows for 16 different kinds of commands, as well as 16 different node IDs.
[0249] Conversation Finder Hardware
[0250] A Conversation Finder node consists of two main elements: an audio part with a microphone, amplifier and a microcontroller to analyze the microphone signal, and a transceiver part with the radio module and yet another microcontroller. The audio part amplifies the microphone signal, then the controller digitizes it with 10 bits, integrating the result over time and providing the transceiver part with a single bit of information specifying whether the user is talking or not. The transceivers in the nodes are Radiometrix© BiM2, which operate in the free 433 MHz spectrum, and have an output of 10 dBm (10 mW) nominal that gives them a range of about 20 meters indoors.
[0251] Conversation Finding Software
[0252] There are two microcontrollers per node. The audio microcontroller's code is identical for all nodes. In a loop, it adds up one thousand 10 bit samples (which takes 183 ms, resulting in a sampling rate of 5.45 kHz). It then calculates the average value, and raises the talk line in case it is above a certain threshold. In addition to this software threshold, each audio board also contains a potentiometer to adjust the analog amplification level of the microphone preamp. The Transceiver node microcontrollers contain identical code as well, except for that each has a unique node ID.
[0253] The transceiver microcontroller runs a main program that consists of a loop that lasts about 200 ms, and contains the following steps:
a. Listen for incoming messages for about 200 ms b. If the user is talking, send out a TALK message c. Update internal data structure d. Keep track of the user's “talk-to-listen” ratios e. Send out a HEARTBEAT message (every 3000 ms)
[0259] The logic of the transceiver node in terms of its internal data structure is as follows: Each node listens for incoming radio messages from nearby nodes. Upon receiving a ‘heartbeat,’ the other node is classified as Listener. Detecting a ‘talk’ message will upgrade its status to a Talker. Each node continuously determines if the detected nodes might be part of its owner's conversation or not. If the node's microphone determines that its user is talking, and simultaneously receives ‘talk’ messages from another node for more than a three-second window, it excludes the other node for a 30-second period by tagging it as Excluded. If a node classified as a Talker stops sending ‘talk’ messages, it will get re-classified to a Listener after a period of time. Similarly, if a node fails to send out ‘heartbeat’ messages, it will get tagged as Absent by the other nodes. This continuous process of classifying all other nodes is done in each sensor node independently, and during informal tests with a set of six prototype nodes, this logic demonstrated to be a reliable and fault tolerant source of conversational status information.
[0260] The transceiver node also continuously calculates how much the user is talking, versus being quiet or listening. It does so for three different time periods (rolling windows): the last 3.2 seconds, the last 51.2 seconds, and the last 819.2 seconds. The Intermediary can poll these values, providing it with important information about the user's conversational status.
[0261] Calculated are these “talk-to-listen” ratios from three hierarchical levels of circular audio buffering. Each buffer's overall result is piped into the next higher buffer's basic slot:
1) First-level buffer: 16 slots (bits), each representing 0.2 seconds. If there was talk activity during the last 200 ms segment, a bit of the first-level buffer is set to high. This first-level buffer covers the last 3.2 seconds. 2) Second-level buffer: 16 slots, each representing 3.2 seconds. If the last first-level buffer (3.2 seconds) contained any talk activity (any of the 16 bits set to high), a bit of the second-level buffer is set to high. This second-level buffer covers the last 51.2 seconds. 3) Third-level buffer: 16 slots, each representing 51.2 seconds. If the last second-level buffer (51.2 seconds) contains more than 50% talk activity (more than 8 of the 16 bits set to high), a bit of the third- level buffer is set to high. This third-level buffer covers the last 13 minutes 39.2 seconds.
[0265] Finger Ring
[0266] The actuated ring consists of a tiny vibration motor (pager motor with excenter), a 20 mAh lithium polymer battery, a micro switch, Radiometrix Bim2 transceiver (operating in the 433 MHz spectrum), and a PIC 16F877 microcontroller.
[0267] The Finger Ring's transceiver receives messages from its user's Conversation Finder node indicating that it has to alert the ring wearer, upon which it vibrates slightly. If the user touches the micro switch located under the ring, the transceiver broadcasts a veto message to the Intermediary.
[0268] Messaging Protocol
[0269] Although the Finger Ring nodes are part of the Intermediary's sensor network and use the same transceivers as the Conversation Finder nodes, each Finger Ring node only looks for one message type: a message from its Conversation Finder node asking it to vibrate.
[0270] This message contains a target ID. If the node receives such a message, it compares the target ID with its own ID. If there is a match, the microcontroller turns on the vibration motor for 1000 ms. This value has been proven to be subtle enough not to interrupt, but still perceivable by the wearer.
[0271] After the reception of a valid CONTRACT message, a 10-second window opens. If the user decides to veto to the upcoming interruption, she has ten seconds to press the micro switch attached to the under side of the ring. If she decides to veto, the ring broadcasts a VETO message. This message is anonymous, but contains as a payload the ID of the interrupting agent. This allows for several polling processes at the same time. Therefore, the requesting agent can see if an incoming VETO message is meant for it, but does not know its origin.
[0272] If a user presses the micro switch on the ring outside this 10-second window (before or after), a different message (VETO_OWN) is sent out which is addressed specifically to the Finger Ring's own Intermediary. This is done so that the user can use the finger ring for other purposes, like to influence the animatronics, or to pick up an incoming call. To the Intermediary, it is perceived as a button press, similar to the switches in the extremities of the animatronics.
[0273] The Finger Ring microcontroller code runs as a loop with the following elements:
1) Listen for incoming messages for 200 ms, and keep track of the user's button presses 2) Send out a veto message if the user has pressed the button 3) Send out a HEARTBEAT message (every 3000 ms)
[0277] Sensor Network Hub
[0278] All nodes of the sensor network are perfectly able to function on their own, since they are conceived as an adhoc, decentralized network. They are built to interact mainly with each other. However, the Intermediary software is running on a remote PC and needs to communicate with its sensor network somehow. For this purpose, a sensor network hub was build that connects to the serial port of a PC and can interact with the nodes of the sensor network.
[0279] Hardware
[0280] The hardware involved for the sensor network hub is a BiM2 transceiver connected to a desktop computer. It consists of a small PCB board that houses the transceiver, as well as an RS232 cable (serial) for communication, and a USB cable for power. This transceiver is identical to the transceivers used for the Conversation Finder nodes as well as for the Finger Ring nodes. The main function, though, is to relay socket messages from the Intermediary to the sensor network nodes.
[0281] Issue Detection
[0282] This section describes the implementation of a specific sub-system of the Intermediary, the Issue detection infrastructure. One part of the Issue Detection infrastructure is a set of PERL scripts that continuously (every hour) captures bags of words from data files which contain text data that is indicative of the user's current interests and work subject matter. These data file preferably include sent mail (separately for message body, quoted text, subject lines, to lines) that have gone through the user's ‘MAP sent-mail folder as a robotic mail client). In addition, the data files may include the user's To-Do list (web based), and the user's Google web search strings (via modified API).
[0283] The system also harvests once a day a bag of words from the user's home pages, for capturing long-term interests. During all harvesting processes, a stop list (a list of commonly used words that are typically not of interest for indexing purposes; such as the most commonly used 10,000 words in the English language).
[0284] In addition to the speech recognition server, another piece of software matches the bags of words with the speech recognition output, and returns what it thinks this call is about, and how important this is to the user, by showing the importance levels of the matches it found. Importance for To-Do list entries decay the further down they are in the list. Web searches and sent email message have decaying importance: the further in the past the events are, the less importance they get assigned (subject lines decays slower than message body, though, since they are more concise).
[0285] In order to go beyond simple literal word matching, a more sophisticated mapping may be used needed, such as ‘fuzzy inferences’ between what the caller says and the bags of words.
[0286] One option may be to expand the existing bags of words with synonyms, so that “dinner” will match “supper,” etc. The right sense of a word could be guessed from the words of the context.
[0287] All these fuzzy inference mechanisms would go beyond what CLUES filtering is capable of. (See Marx, M., Schmandt, C. (1996). CLUES: Dynamic Personalized Message Filtering. Proceedings of CSCW '96, November 1996, pp 113-121. http://www.media.mit.edu/speech/papers/1996/marx_CSCW96_clues.pdf.) At the same time, they also increase the bags of words. The speech recognition engine is provided with the bags of words as a dynamic vocabulary (XML file), so that it is more likely to recognize them if they would occur during the conversation. The resulting percentages are then added up, so the Intermediary doesn't look at just one word, but the compound ‘relevance’ of the recognized words.
[0288] As shown in FIG. 3 , a message receiver, such as a voice mail system or a voice messaging system, may be employed to record the response of a caller in response to the prompt issued at 301 . A speech-to-text converter is for translating the recorded spoken message into a data file containing recognized words, a content analyzer is employed for comparing the recognized words with a database of words known to be of interest to said called person, and an alert generator may then be employed to immediately alert the called person the incoming call if said spoken message is determined to be of probable interest. In this way, a caller with a potentially important message may be permitted to “barge in” to a conversation even though one of the participants has issued a veto which would otherwise prevent the conversation from being interrupted. As noted above, the database of database may consist of words known to be of interest to the called party that is created by collecting words from computer files created by said called person, or the words may be collected from a set of trigger words that are likely to be used in an “emergency” call.
[0289] Conclusion
[0290] It is to be understood that the methods and apparatus which have been described above are merely illustrative applications of the principles of the invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention. | Apparatus for handling an incoming telephone call including a call processor coupled to a wired or wireless telephone network for receiving an incoming telephone call directed to a called person, a conversation detector for determining whether a conversation is currently taking place between said called person and one or more other persons who are near to said called person, and a call inhibitor for inhibiting the delivery of, delaying or rerouting said incoming call if said conversation detector determines that a conversation is taking place. Each participant in the conversation is provided with a speech detector, and vibrator for producing a tactile alert when incoming calls directed to a participant arrive, and a manually operated control for issuing a veto command that inhibits the delivery of, delays, or reroutes the incoming call so that the conversation is not interrupted. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. application Ser. No. 11/855,082, entitled “AD-HOC Network Power Save System and Method,” filed on Sep. 13, 2007, now U.S. Pat. No. 8,315,193, which claims the benefit of U.S. Provisional Patent Application No. 60/825,611, filed Sep. 14, 2006. All of the above-referenced applications are hereby incorporated by reference herein in their entireties.
FIELD OF THE DISCLOSURE
The invention relates generally to a power save system in a network and, more particularly to a periodic power save system in an ad-hoc wireless network.
BACKGROUND
A wireless network (e.g., Wi-Fi based on IEEE 802.11 standards) may be characterized as an infrastructure mode network or an ad-hoc mode network depending on whether the stations within the wireless network can directly communicate with other stations in the network. FIG. 1(A) illustrates an example of an infrastructure mode wireless network, which may typically comprise an access point 2 and stations 4 , 6 and 8 . In the infrastructure mode network, the stations 4 , 6 and 8 are not configured to directly communicate with each other, and any communication between the stations 4 , 6 and 8 must be channeled through the access point 2 .
In contrast, an ad-hoc mode network allows each station to communicate directly with each other, as illustrated in FIG. 1(B) . Thus, in the ad-hoc mode wireless network, there is no central access point controlling communication among the stations 4 , 6 and 8 . Ad-hoc devices are configured to communicate only with other ad-hoc devices, and they are not able to communicate with any infrastructure devices or any other devices connected to a wired network.
Considering that a significant portion of the Wi-Fi devices are portable devices (e.g., cellular phones, portable gaming devices, wireless headsets, wireless headphones, wireless speakers and the like), power consumption has become an important issue for the Wi-Fi devices. This has led the IEEE to standardize the infrastructure mode network power save protocol. However, due to the decentralized nature of ad-hoc mode networks, it is much more difficult and complicated to implement power save algorithms when there is no central access point that dictates all the decisions related to power consumption in the network.
SUMMARY OF THE DISCLOSURE
The invention allows ad-hoc network devices to enter a power save mode. The invention also provides for power consumption decisions to be made in an ad-hoc network to improve implementation of power save algorithms. Other advantages and benefits of the invention are apparent from the discussion herein.
Accordingly, in one aspect of the invention, a method for saving power in an ad-hoc network including first and second stations each having a wireless capability to directly communicate with each other includes issuing a request to the second station to buffer data traffic intended for the first station for a first predetermined period, granting the request to buffer data traffic, causing the first station to enter a first power save mode for the first predetermined period, and enabling the second station to buffer data traffic intended for the first station for the first predetermined period.
The method may further include causing the first station to exit the first power save mode after the first predetermined period elapses, and sending the buffered data traffic to the first station. Sending the buffered data traffic may include sending the buffered data traffic from the second station to the first station. The method may further include causing the first and second stations to simultaneously enter a second power save mode for a second period time. The method may further include advertising a master capability of the second station to buffer data traffic intended for the first station. The method may further include causing the second station to exit the second power save mode before the first station exits the second power save mode. The ad-hoc network may be a wireless network using protocol selected from the group consisting of IEEE 802.11 standards and Bluetooth standards. The method may further include determining whether the second station has a capability to buffer data traffic intended for the first station. The method may further include issuing a request to the first station to buffer data traffic intended for the second station for a second predetermined period, granting the request to buffer data traffic intended for the second station, causing the second station to enter a second power save mode for the second predetermined period, and enabling the first station to buffer the data traffic intended for the second station for the second predetermined period. The method may further include causing the second station to exit the second power save mode after the second predetermined period elapses, and sending the buffered data traffic to the second station. Sending the buffered data traffic to the second station may include sending the buffered data traffic from the first station to the second station. The method may further include determining whether the first station has a capability to buffer data traffic intended for the second station. The method may further include preventing the first station from entering the first power save mode if the second station requests the first station to buffer the data traffic intended for the second station, and preventing the second station from entering the second power save mode if the first station requests the second station to buffer the data traffic intended for the first station. The method may further include preventing the first station from entering the first power save mode occurs if the request is received within a predetermined period of time from when the first station sends such a request, and preventing the second station from entering the second power save mode occurs if the request is received within a predetermined period of time from when the second station sends such a request. The method may further include causing the slave station to exit the power save mode after the predetermined period elapses, and causing the master station to send the buffered data traffic to the slave station. The method may further include advertising a master capability of the master station to buffer data traffic intended for any of the plurality of stations in the ad-hoc network, and determining if the master station has the master capability to buffer data traffic intended for one of the plurality of stations. The ad-hoc network may be a wireless network using a protocol selected from the group consisting of IEEE 802.11 standards and Bluetooth standards.
According to another aspect of the invention, a method for saving power in an ad-hoc network including a plurality of stations, the plurality of stations including a master station and at least one slave station incapable of buffering traffic for other stations, each station having a wireless capability to directly communicate with other stations, includes issuing a request to the master station to buffer data traffic intended for the slave station for a predetermined period, granting the request to buffer data traffic, causing the slave station to enter a power save mode for the predetermined period, and enabling the master station to buffer data traffic intended for the slave station for the predetermined period.
The first station has a master capability to buffer data traffic intended for other stations in the ad-hoc network for a second predetermined period and may be configured to grant a request from the second station to allow the second station to enter a second power save mode, and wherein the second station may be configured to determine if there may be any station having the master capability in the ad-hoc network. The second station may enter the second power save mode for the second predetermined period when the first station grants the request from the second station, and the first station sends the buffered data traffic to the second station after the second predetermined period elapses. The first station may be configured not to enter the first power save mode if the second station requests the first station to buffer the data traffic intended for the second station, and the second station may be configured not to enter the second power save mode if the first station requests the second station to buffer the data traffic intended for the first station. The first station may not enter the first power save mode if the request is received within a predetermined period of time from when the first station sends such a request, and wherein the second station may not enter the first power save mode if the request is received within a predetermined period of time from when the second station sends such a request. The master and slave stations may be configured to simultaneously enter a second power save mode for a second period time. The master station may be configured to exit the second power save mode before the slave station exits the second power save mode. The ad-hoc network may be a wireless network using a protocol selected from the group consisting of IEEE 802.11 standards and Bluetooth standards.
In yet another aspect of the invention, an ad-hoc network includes a first station having wireless communication capabilities and configured to determine if there is any station in the ad-hoc network having a master capability to buffer data traffic intended for other stations in the ad-hoc network for a first predetermined period, the second station having wireless communication capabilities and the master capability and configured to grant a request from said first station to allow said first station to enter a first power save mode, and wherein the first station enters the first power save mode for the first predetermined period when the second station grants the request and the second station sends the buffered data traffic to the first station after the first predetermined period elapses A system for saving power in an ad-hoc network including first and second stations each having a wireless capability to directly communicate with each other, the system further includes means for issuing a request to the second station to buffer data traffic intended for the first station for a first predetermined period, means for granting the request to buffer data traffic, means for causing the first station to enter a first power save mode for the first predetermined period, and means for enabling the second station to buffer data traffic intended for the first station for the first predetermined period.
A machine-readable medium including stored instructions, which, when executed by a processor cause the processor to implement power saving in an ad-hoc network having a plurality of stations, the instructions including instructions for determining whether a first one of the stations has a capability to buffer data traffic intended for a second station, instructions for requesting the at least one station to buffer data traffic intended for the second station for a first predetermined period, instructions for granting a request to buffer data traffic intended for the second station, instructions for causing the second station to enter a first power save mode for the first predetermined period, and instructions for enabling the first one station to buffer data traffic intended for the second station for a second predetermined period, instructions for causing the second station to exit the first power save mode after the first predetermined period elapses, and instructions for sending the buffered data traffic to the second station.
Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the detailed description serve to explain the principles of the invention. No attempt is made to show structural details of the invention in more detail than may be necessary for a fundamental understanding of the invention and the various ways in which it may be practiced. In the drawings:
FIGS. 1(A) and 1(B) illustrate an example of an infrastructure mode network and ad-hoc mode network, respectively;
FIGS. 2(A) and 2(B) illustrate examples of a symmetrical ad-hoc network;
FIGS. 3(A) , 3 (B) and 3 (C) illustrate examples of a asymmetrical ad-hoc network;
FIG. 4(A) is a flow chart for a power save scheme in a symmetrical ad-hoc network constructed according to the principles of the invention; and
FIG. 4(B) is a flow chart for a power save scheme in an asymmetrical ad-hoc network constructed according to the principles of the invention.
FIGS. 5-12 show various exemplary implementations of the invention.
DETAILED DESCRIPTION
The embodiments of the invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be omitted so as to not unnecessarily obscure the embodiments of the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those of skill in the art to practice the embodiments of the invention. For example, the invention is described in terms of Wi-Fi network based on IEEE 802.11 standard, but it will be understood that the invention is not so limited. The invention may be broadly applicable to any ad-hoc mode wireless network and other types of wireless networks that have appropriate features and characteristics. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the invention, which is defined solely by the appended claims and applicable law. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings.
The invention relates to periodic power save protocols for ad-hoc networks. Different devices within the ad-hoc network can take on the role of a master while the other slave devices enter a power save mode. The master device receives data for the other devices and sends the buffered data when those slave devices wake up. This protocol allows for power savings among the devices. Various aspects of the invention will now be described in greater detail below.
FIGS. 2(A) , 2 (B), 3 (A), 3 (B) and 3 (C) illustrate examples of an ad-hoc mode network configuration. Depending on similarity of capabilities among the devices (i.e., stations, nodes or the like) in the network, the ad-hoc mode network may be characterized as a symmetrical ad-hoc mode network or an asymmetrical ad-hoc mode network. FIGS. 2(A) and 2(B) illustrate examples of the symmetrical ad-hoc mode network, in which the devices may have similar capabilities, such as, for example, processing power, memory, battery life or the like. In particular, FIG. 2(A) illustrates two walkie-talkies or cellular phones 12 and 14 with identical or substantially the same capabilities connected via an ad-hoc mode network. This connection allows real-time multi-user voice communication via the ad-hoc mode network. When the devices 12 and 14 are not in use, it may be necessary to turn off one or both devices to save power. Since there is no central access point to carry out a power save mode, a power save protocol may be carried out on all devices in the network without overburdening any particular device. For example, each of the devices 12 and 14 may alternatively take charge by acting as a master device that carries out power save algorithms in the network.
Similarly, FIG. 2(B) illustrates two identical portable gaming devices 16 and 18 (e.g., Sony™ PSP™ or the like) connected to each other via an ad-hoc mode network. This connection may provide real-time multi-player gaming experiences for those using the portable gaming devices 16 and 18 . When the devices 16 and 18 are not being used, the devices 16 and 18 may communicate with each other to decide which device will take charge as a “master” to carry out a power save protocol for the network. The “master” device may allow other devices (i.e., slaves) in the network to enter a power save mode and buffer data traffic for the slave devices, which will be also described below in detail. It should be understood that walkie-talkies, cell phones and gaming devices are merely illustrative of the type of devices that may be connected in a symmetrical, ad-hoc network.
FIGS. 3(A) , 3 (B) and 3 (B) illustrate examples of the asymmetrical ad-hoc mode network configuration, in which the ad-hoc devices have different capabilities. For example, FIG. 3(A) illustrates an asymmetrical ad-hoc mode network including a cellular phone 20 and a wireless headset 22 . Typically, the wireless headset 22 is provided with significantly less capabilities than the cellular phone 20 and may not be able to carry out the power save algorithms for the ad-hoc network. In this case, the power save protocol may exploit the capabilities of the cellular phone 20 , which may permanently take charge as a master while the headset 22 permanently operates as a slave in this situation. Similarly, FIG. 3(B) illustrates a PC 24 and a wireless headphone 26 connected to each other via an ad-hoc mod network, wherein the PC 24 operates as the master while the wireless headphone 26 operates as the slave in carrying out the power save mode. In FIG. 3(C) , an audio device 30 with more capabilities may carry out the power save mode as a permanent master to wireless speakers 32 . Again, these examples are merely illustrative of the type of devices that may be connected in an asymmetrical, ad-hoc network.
FIG. 4(A) illustrates a flow chart for a power save scheme in a symmetrical ad-hoc network constructed according to the principles of the invention. As mentioned above, in a symmetrical ad-hoc mode network, each device may have capabilities to carry out power save algorithms in the network as a master. Thus, it is assumed that stations A and B (e.g., walkie-talkies 12 and 14 in FIG. 2(A) , respectively) are both equally capable of carrying out the power save algorithms without overburdening the other one. As shown in steps 40 and 42 , stations 12 and 14 both advertise their master capabilities to other stations in the network. The master capabilities may include an ability to buffer data designated for other stations in the network that are in a sleep (power save) mode. After confirming that station B has master capabilities, station A may send a power save enter request to station B, as shown in step 44 . The power save enter request may be included in an uplink IEEE action management frame of station A's beacon that is sent to station B. The frame may include information about the sleep period of station A. The power save enter request may be included in an uplink IEEE action management frame sent from slave to master. The capability to implement this protocol may be advertised in the station beacons and probe responses. The power save enter request/response may be sent using IEEE Action Management frames. Further, the power save enter request may include information about the slave station's frequency of wake-ups (referred to as sleep period), while the power save enter response may include information about a number of service periods the master may buffer traffic for slave.
It is possible that both stations A and B send their respective power save enter requests to each other. To avoid the conflict, each station may be configured to stay in a full power mode when the request is received from other stations. Each station may then compute a random back-off and re-attempt to enter the power save mode when the back-off expires or stay in full power mode as the master if other station's back-off expires earlier.
Upon accepting the request from station A, station B becomes the master and station A becomes the slave. As shown in step 46 , station B may send a power save enter response to station A. The power save enter response may be included in an IEEE action management frame. The power save enter response may contain the maximum number of service periods during which the master station B will buffer data traffic for slave station A. According to an embodiment of the invention, a service period may be defined as the period between receiving an uplink trigger from slave station A to the point where master station B sends an end of service period (EOSP) indication. Each uplink frame with a trigger bit set from slave station A may be counted as one service period by master station B. For Wi-Fi multi-media (WMM) applications, for example, the WMM EOSP bit in the quality of service (QOS) information field may be used as the trigger bit by slave station in the uplink direction. For non-WMM applications, for example, the “more-data” bit in the IEEE 802.11 frame control field may be used as the trigger bit.
In step 46 , after receiving the power save enter response from master station B, slave station A may enter power save mode as shown in step 48 . Master station B may start buffering data traffic for slave station A, as shown in step 50 . While in the power save mode, slave station A may not beacon and advertise its capability as a master. Every time slave station A wakes up, it may send an uplink trigger frame to master station B with the trigger bit “set.” Slave station A may send exactly one trigger frame in every wake-up period. If slave station A has more than one frame in every wake-up period, slave station A may transmit subsequent frames with trigger bit “unset.” If slave station A has no uplink data to send, it may send a “null” uplink trigger frame with trigger bit set. Also, all uplink frames from slave station A may have the power management bit set to “1” in the IEEE 802.11 frame control field. Master station B, in turn, may respond to the trigger frame with downlink data buffered for slave station A. The last downlink frame from master station B may the EOSP bit set. For WMM applications, the WMM EOSP bit in the QOS information field may be used by master station B in the downlink direction to mark EOSP. For non-WMM applications, the “more-data” bit in the IEEE 802.11 frame control field may be used as the EOSP indication. If no downlink data has been buffered for slave station A, master station B may send a null data frame with the EOSP bit set. Also, in one example, the system may be configured so that the uplink frames sent from slave station A with the trigger bit unset may not cause master station B to empty a power save queue for the respective slave station.
After the maximum number of service periods permitted by master station B is reached, master station B may stop buffering data traffic for slave station A. Slave station A may end power save mode in step 52 . The data is buffered by master station B and forwarded to slave station A in step 54 . Slave station A and master station B may enter the full power mode by resuming beaconing and advertising their capability as a master station, as shown in steps 56 and 58 . Both stations A and B then may compute a random back-off and attempt to become slaves on back-off expiry. The steps shown in FIG. 4(A) may be repeated. Since each station may rotate through the role of a slave or master, power consumption issues on all stations in the network may be greatly improved without overburdening a particular station. For example, assuming that each station spends equal time in the master and slave roles, the power save protocol may reduce the power consumption for the slave stations up to about 75%. Further, the protocol may reduce the power consumption for both master and slave stations up to about 38% compared to the full power mode. The power saving may increase as the number of slave stations increases.
FIG. 4(B) illustrates a flow chart for a power save scheme in an asymmetrical ad-hoc network constructed according to the principles of the invention. For example, the asymmetrical ad-hoc network may include the cellular phone 20 as the master and the wireless headset 22 illustrated in FIG. 3(A) . As mentioned above, in the asymmetrical ad-hoc network, only one station may have the master capabilities. Thus, step 60 of advertising the master capabilities and the master/slave power save enter request/response steps 62 and 64 (i.e., master/slave handshake) are implemented. For example, the master station may return 0xFFFF in the maximum service period field as the “master indefinite” indication. Some implementations with pre-provisioned master/slave configurations may bypass the master/slave handshake among the stations as their roles may have been already decided at the production stage. Other than those differences, the power save protocol illustrated in FIG. 4(B) may perform steps similar to the steps performed for the symmetrical ad-hoc power save mode shown in FIG. 4(A) . For example, after executing the master/slave handshake shown in steps 62 and 64 , the slave station 22 may enter the power save mode at step 66 while the master station 20 may buffer the data traffic for the slave station 22 at step 68 . When the slave station 22 wakes up from the power save mode at step 70 , the master station 20 may send the buffered data traffic to the slave station 20 at step 72 . If the slave station 22 is not frequently used, power save may be greatly increased by allowing the slave station 22 to enter the power save mode.
In order to further improve power saving, the master station 20 may use the sleep period of the slave station 22 to enter the power save mode after sending a downlink frame with the EOSP bit set. For example, upon receiving an uplink frame from the slave station 22 with the trigger bit set, the master station 20 may start a sleep clock timer with a timeout set to expire at a certain point before the slave station 22 wakes up. The sleep clock timer may include an offset that may account for any timing errors in the sleep clock to ensure the master station 20 wakes up before the next slave wakeup. The master station 20 may exchange data with the EOSP bit set in the last downlink frame to the slave station 22 . After sending the frame with the EOSP bit set, the master and slave stations both may enter the power save mode. The slave station 22 may be required not to transmit any frames after receiving the downlink with the EOSP bit set. In this case, if both the master and slave stations have 75% power savings in the power save mode, the overall system may be able to save power up to 75%.
Referring now to FIGS. 5 , 6 , 7 , 8 , 9 , 10 , 11 and 12 , various exemplary applications of the invention are shown. Referring to FIG. 5 , the invention may be embodied in a hard disk drive 500 . The invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 5 at 502 . In some implementations, signal processing and/or control circuit 502 and/or other circuits (not shown) in HDD 500 may process data, perform coding and/or encryption, perform calculations, and/or format data that is output to and/or received from a magnetic storage medium 506 .
HDD 500 may communicate with a host device (not shown) such as a computer, mobile computing devices such as personal digital assistants, cellular phones, media or MP3 players and the like, and/or other devices via one or more wired or wireless communication links 508 . HDD 500 may be connected to memory 509 , such as random access memory (RAM), a low latency nonvolatile memory such as flash memory, read only memory (ROM) and/or other suitable electronic data storage.
Referring first to FIG. 6 , the invention may be embodied in a digital versatile disc (DVD) drive 511 . The invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 6 at 512 , and/or mass data storage 518 of the DVD drive 511 . Signal processing and/or control circuit 513 and/or other circuits (not shown) in the DVD 511 may process data, perform coding and/or encryption, perform calculations, and/or format data that is read from and/or data written to an optical storage medium 516 . In some implementations, signal processing and/or control circuit 512 and/or other circuits (not shown) in DVD 511 can also perform other functions such as encoding and/or decoding and/or any other signal processing functions associated with a DVD drive.
DVD drive 511 may communicate with an output device (not shown) such as a computer, television or other device via one or more wired or wireless communication links 517 . DVD 511 may communicate with mass data storage 518 that stores data in a nonvolatile manner. DVD 511 may be connected to memory 519 , such as RAM, ROM, low latency nonvolatile memory such as flash memory, and/or other suitable electronic data storage.
Referring now to FIG. 7 , the invention may be embodied in a high definition television (HDTV) 520 . The invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 7 at 522 , a WLAN interface and/or mass data storage of the HDTV 520 . HDTV 520 receives HDTV input signals in either a wired or wireless format and generates HDTV output signals for a display 526 . In some implementations, the signal processing circuit and/or control circuit 522 and/or other circuits (not shown) of HDTV 520 may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other type of HDTV processing that may be required.
HDTV 520 may communicate with a mass data storage 527 that stores data in a nonvolatile manner such as optical and/or magnetic storage devices. At least one DVD may have the configuration shown in FIG. 6 . HDTV 520 may be connected to a memory 528 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. HDTV 520 also may support connections with a WLAN via a WLAN network interface 529 .
Referring now to FIG. 8 , the invention may be implemented in a control system of a vehicle 530 , a WLAN interface and/or mass data storage of the vehicle control system. In some implementations, the invention implements a powertrain control system 532 that receives inputs from one or more sensors 536 such as temperature sensors, pressure sensors, rotational sensors, airflow sensors and/or any other suitable sensors and/or that generates one or more output control signals from an output 538 such as engine operating parameters, transmission operating parameters, and/or other control signals.
The invention may also be embodied in other control systems 540 of vehicle 530 . Control system 540 may likewise receive signals from input sensors 542 and/or output control signals to one or more output devices 544 . In some implementations, control system 540 may be part of an anti-lock braking system (ABS), a navigation system, a telematics system, a vehicle telematics system, a lane departure system, an adaptive cruise control system, a vehicle entertainment system such as a stereo, DVD, compact disc and the like. Still other implementations are contemplated.
Powertrain control system 532 may communicate with mass data storage 546 that stores data in a nonvolatile manner. Mass data storage 546 may include optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. At least one DVD may have the configuration shown in FIG. 6 . Powertrain control system 532 may be connected to memory 547 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. Powertrain control system 532 also may support connections with a WLAN via a WLAN network interface 548 . The control system 540 may also include mass data storage, memory and/or a WLAN interface (all not shown).
Referring now to FIG. 9 , the invention may be embodied in a cellular phone 550 that may include a cellular antenna 551 . The invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 9 at 552 , a WLAN interface and/or mass data storage of the cellular phone 550 . In some implementations, cellular phone 550 includes a microphone 556 , an audio output 558 such as a speaker and/or audio output jack, a display 560 and/or an input device 562 such as a keypad, pointing device, voice actuation and/or other input device. Signal processing and/or control circuits 552 and/or other circuits (not shown) in cellular phone 550 may process data, perform coding and/or encryption, perform calculations, format data and/or perform other cellular phone functions.
Cellular phone 550 may communicate with a mass data storage 564 that stores data in a nonvolatile manner such as optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. At least one DVD may have the configuration shown in FIG. 6 . Cellular phone 550 may be connected to a memory 566 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. Cellular phone 550 also may support connections with a WLAN via a WLAN network interface 568 .
Referring now to FIG. 10 , the invention may be embodied in a set top box 580 . The invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 10 at 584 , a WLAN interface and/or mass data storage of the set top box 580 . Set top box 580 receives signals from a source such as a broadband source and outputs standard and/or high definition audio/video signals suitable for a display 588 such as a television and/or monitor and/or other video and/or audio output devices. Signal processing and/or control circuits 584 and/or other circuits (not shown) of the set top box 580 may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other set top box function.
Set top box 580 may communicate with mass data storage 590 that stores data in a nonvolatile manner. Mass data storage 590 may include optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. At least one DVD may have the configuration shown in FIG. 6 . Set top box 580 may be connected to memory 594 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. Set top box 580 also may support connections with a WLAN via a WLAN network interface 596 .
Referring now to FIG. 11 , the invention may be embodied in a media player 600 . The invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 11 at 604 , a WLAN interface and/or mass data storage of the media player 600 . In some implementations, media player 600 includes a display 607 and/or a user input 608 such as a keypad, touchpad and the like. In some implementations, media player 600 may employ a graphical user interface (GUI) that typically employs menus, drop down menus, icons and/or a point-and-click interface via display 607 and/or user input 608 . Media player 600 further includes an audio output 609 such as a speaker and/or audio output jack. Signal processing and/or control circuits 604 and/or other circuits (not shown) of media player 600 may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other media player function.
Media player 600 may communicate with mass data storage 610 that stores data such as compressed audio and/or video content in a nonvolatile manner. In some implementations, the compressed audio files include files that are compliant with MP3 format or other suitable compressed audio and/or video formats. The mass data storage may include optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. At least one DVD may have the configuration shown in FIG. 6 . Media player 600 may be connected to memory 614 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. Media player 600 also may support connections with a WLAN via a WLAN network interface 616 .
Referring to FIG. 12 , the invention may be embodied in a Voice over Internet Protocol (VoIP) phone 650 that may include an antenna 618 . The invention may implement either or both signal processing and/or control circuits, which are generally identified in FIG. 12 at 604 , a wireless interface and/or mass data storage of the VoIP phone 650 . In some implementations, the VoIP phone 650 includes, in part, a microphone 610 , an audio output 612 such as a speaker and/or audio output jack, a display monitor 614 , an input device 616 such as a keypad, pointing device, voice actuation and/or other input devices, and a Wireless Fidelity (Wi-Fi) communication module 608 . Signal processing and/or control circuits 604 and/or other circuits (not shown) in VoIP phone 650 may process data, perform coding and/or encryption, perform calculations, format data and/or perform other VoIP phone functions.
VoIP phone 650 may communicate with mass data storage 602 that stores data in a nonvolatile manner such as optical and/or magnetic storage devices, for example hard disk drives HDD and/or DVDs. At least one DVD may have the configuration shown in FIG. 6 . The VoIP phone 650 may be connected to memory 606 , which may be a RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The VoIP phone 650 may be configured to establish communications link with a VoIP network (not shown) via Wi-Fi communication module 608 . Still other implementations in addition to those described above are contemplated.
In accordance with various embodiments of the invention, the methods described herein are intended for operation with dedicated hardware implementations including, but not limited to, semiconductors, application specific integrated circuits, programmable logic arrays, and other hardware devices constructed to implement the methods and modules described herein. Moreover, various embodiments of the invention described herein are intended for operation with as software programs running on a computer processor. Furthermore, alternative software implementations including, but not limited to, distributed processing or component/object distributed processing, parallel processing, virtual machine processing, any future enhancements, or any future protocol can also be used to implement the methods described herein.
It should also be noted that the software implementations of the invention as described herein are optionally stored on a tangible storage medium, such as: a magnetic medium such as a disk or tape; a magneto-optical or optical medium such as a disk; or a solid state medium such as a memory card or other package that houses one or more read-only (non-volatile) memories, random access memories, or other re-writable (volatile) memories. A digital file attachment to email or other self-contained information archive or set of archives is considered a distribution medium equivalent to a tangible storage medium. Accordingly, the invention is considered to include a tangible storage medium or distribution medium, as listed herein and including art-recognized equivalents and successor media, in which the software implementations herein are stored.
While the invention has been described in terms of exemplary embodiments, those skilled in the art will recognize that the invention can be practiced with modifications in the spirit and scope of the appended claims. By way of example, the stations of the inventions may be any device capable of wireless communication and standards other than the IEEE 802.11 standard may be used to implement the invention, such as Bluetooth and similar standards. These examples given above are merely illustrative and are not meant to be an exhaustive list of all possible designs, embodiments, applications or modifications of the invention. | Symmetrical and asymmetrical ad-hoc, wireless networks and a method for saving power in the same may include causing a first station to determine whether a second station has a master capability to buffer data traffic for the first station. A first station requests the second station to buffer the data traffic intended for the first station for a first predetermined period. The first station enters a first power save mode, and the second station buffers the data traffic for the first station for the first predetermined period. The first station exits the first power save mode after the first predetermined period and the second station sends the buffered data traffic to the first station. Both the first and second stations may have master capabilities, or only one of the first and second stations may have a master capability. | 8 |
RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional application 61 / 461 , 112 , filed Jan. 12, 2011
FEDERALLY SPONSORED RESEARCH
[0002] N/A
BACKGROUND OF THE INVENTION
[0003] This invention relates to methods for measuring bacterial growth and antibiotic resistance, and particularly to such measurements using a Suspended Microchannel Resonator (SMR) and measuring the mass of multiple bacteria over time and in changing fluidic environments.
[0004] Precision measurements of nanometer- and micrometer-scale particles, including living cells and multicellular entities such as bacteria, have wide application in pharmaceuticals/drug delivery and disease studies, as well as in other major industries and fields of research. This need is growing due to the need to better understand and treat diseases and develop and maintain effective treatments and drugs.
[0005] A variety of particle sizing and counting techniques, such as light scattering, Coulter Counters and others are known in the art. These techniques are embodied in commercial instruments and are used in industrial, medical, and research applications. Although such techniques have proven utility, they have limitations that limit their applicability. Relatively recently, particle detection and measurement based on the use of SMR's has been developed, and shows promise of going beyond some of the limitations of conventional techniques. The SMR uses a fluidic microchannel embedded in a resonant structure, typically in the form of a cantilever or torsional structure. Fluids, possibly containing target particles, are flowed through the sensor, and the contribution of the particles to the total mass within the sensor causes the resonance frequency of the sensor to change in a measurable fashion. SMR's are typically microfabricated MEMS devices. The use of microfabricated resonant mass sensors to measure fluid density has been known in the literature for some time [P. Enoksson, G. Stemme, E. Stemme, “Silicon tube structures for a fluid-density sensor”, Sensors and Actuators A 54 (1996) 558-562]. However, the practical use of resonant mass sensors to measure properties of individual particles and other entities suspended in fluid is relatively recent, as earlier fluid density sensors were not designed to measure individual particles at the micron and submicron scale.
[0006] In a body of work including work by the inventors of this application, miniaturization and improvement of several orders of magnitude in mass resolution has been demonstrated. Development in the microfabrication recipes, the fluidics design, and measurement techniques are described in a number of co-pending patent applications and scientific publications. In particular U.S. patent application Ser. Nos. 11/620,320, 12/087,495, and 12/305,733 are particularly relevant and are incorporated by reference in their entirety. Also of relevance is a publication by others including the current inventors, [T. P. Burg, M. Godin, S. M. Knudsen et al., “Weighing of biomolecules, single cells and single nanoparticles in fluid,” Nature 446 (7139), 1066-1069 (2007)] By using the microfabrication techniques described in the references, SMR sensors have been fabricated with mass resolution of less than 1 femtogram (10 −15 g). This resolution is sufficient to detect and measure the mass of individual particles in the range of −100 nanometers up to many microns in size, including living cells.
[0007] Improvements in SMR based measurement techniques have been disclosed, which allow for a particle to be held in the measurement portion of the SMR for extended periods of time. Although the disclosed techniques have the advantage of improving signal to noise, they also provide for the ability to measure particle properties which may change over time. Of particular interest is the possibility of measuring cell or bacterial growth. High precision measurements of the mass of living cells or small multi-cellular organisms such as bacteria have not been possible previously.
[0008] Given the mass resolution of current SMR's cell mass measurements may be accomplished with resolution approximately 1% of the mass of a typical bacterium, which is sufficient to measure mass change due to growth and/or mitosis. With such resolution it is possible to detect bacterial growth by measuring change in mass over time, and potentially even more importantly to measure bacterial response to changes in the chemical or environmental properties of the bacteria's liquid environment. Such measurements would have applicability in drug resistance/susceptibility studies, and general environmental toxicity studies. More than 100,000 deaths per year in the US result from bacterial infections, behind only cancer and heart disease. Moreover the rising resistance of bacteria to existing antibiotics coupled with the difficulty in developing new antibiotics is negatively impacting effective treatment of bacterial infections. One of the leading roadblocks to analysis of bacterial resistance to existing drugs and the effectiveness of new drugs is the slowness of existing bacterial assay techniques, such as disk diffusion/dilution assays, which commonly take days to produce results. Therefore it is the object of this invention to provide faster, accurate bacterial assays based on the application of SMR's.
SUMMARY OF THE INVENTION
[0009] The invention, in one embodiment, is a Method for measuring bacterial growth using an SMR with a particle trap, including introducing at least two bacteria into the SMR in a fluid medium, trapping the bacteria in the particle trap, controlling the trapping time and fluid environment to which the bacteria are exposed, and measuring the mass and growth rate of the bacteria during the period when bacteria are trapped.
[0010] In some embodiments the method includes changing the properties of the fluid, including, chemical and environmental properties, during the period the bacteria are trapped in the SMR.
[0011] In another embodiment, the method of includes measuring the change in growth rate over time in response to the change in fluid properties. From these measurements drug resistance and drug susceptibility can be determined. In a particular embodiment the method includes changing the fluid environment in a sequence of collection, growth and antibiotic exposure steps.
[0012] In a preferred embodiment, the growth step includes exposure to nutrient in the fluid and the antibiotic exposure step includes exposure to a series of different antibiotics to determine which ones are effective at inhibiting bacteria growth. In addition changes in mass due to nutrient efficiency as well as gas absorption may be measured.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention will be better understood by referring to the following figures:
[0014] FIG. 1 is a schematic illustration of a Suspended Microchannel Resonator configured with a particle trap particularly suitable to the invention.
[0015] FIG. 2 depicts the trapping of multiple bacteria in an SMR trap.
[0016] FIG. 3 is a schematic illustration of a preferred embodiment of the invention.
[0017] FIG. 4 is a schematic illustration of an array of Suspended Microchannel Resonators configured for rapid bacterial assay.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The embodiments described herein are improved methods that can be implemented using the microfabrication techniques, fluidics, and control electronics disclosed in the documents referenced and other publications available at the time the invention was made. Since those aspects of the invention do not contribute to the novelty, they are not described in detail. For instance novel versions of the SMR's may be produced with mask changes in the microfabrication process. Similarly the fluidics, data acquisition, and data processing steps can be accomplished with implementations derived from set-ups previously disclosed. The novelty of the current invention lies in the arranging of the physical SMR geometries, fluid control schemes and measurement steps to achieve significantly improved results. Also the term particle is interchangeably used in this application to mean any particulate substance, including cells and bacteria and particularly live cells or bacteria in a suitable fluid medium. Also it is to be understood that fixed end cantilever SMR's are shown by way of example, but the techniques disclosed are not restricted to any particular SMR geometry.
[0019] Techniques for trapping of particles in SMR's and measuring changes in the particle characteristics over time in response to changes in the carrier fluid medium are discussed in detail in co-pending Application U.S. Ser. No. 12/661,772, whose contents are incorporated in their entirety by reference. In particular, microfabricated SMR's configured with particle traps sized to trap cellular dimensioned particles are disclosed. Fluidic systems suitable for injecting fluids carrying cellular sized objects into the SMR fluidics channels and varying the fluid composition over time are also discussed. However the disclosure of the '772 application was primarily directed toward the trapping and characterization of single particles such as human cells.
[0020] A single bacterium may be trapped using trapping geometries within the design rules of current SMT fabrication. However, the growth and/or mitosis rate of single cells is slow so measurable changes in a single bacterium may require long measurement times.
[0021] To speed up characterization times of trapped bacteria, multiple bacteria may be trapped at one time, so the cumulative growth rate becomes measurable on much shorter time scales. Although many of the trap geometries disclosed in the '772 application would work, as well as others which will occur to those skilled in the art, the inventors have found that the trap geometry shown in FIG. 1 is particular suitable for trapping multiple bacteria. FIG. 1 shows a typical single channel 2 , two port cantilever SMR 1 with fluid inlet PORT 1 and outlet PORT 2 . In this embodiment the trap consists of one or more posts or sieves spanning a dimension of channel 2 , preferably at the free end of the lever, which is the most sensitive measurement location. Using MEMS techniques, posts can be fabricated to have spacings 500 nanometers or less, which is sufficiently small to prevent the passage of particles or cells, while still allowing the suspending fluid to flow freely by the posts and any trapped particles.
[0022] FIG. 2 depicts the application of a trapping SMR to bacteria characterization. A fluid containing a fixed amount of target bacteria 3 is injected onto channel 2 . The entry of a bacterium into the trap region 4 will increase the mass of the SMR and cause a downward step in the resonant frequency. By counting the number of downward steps in the frequency signal the number of trapped bacteria will be known, and any desired number of bacteria can be captured. Once the desired number are trapped, the source solution can be switched to a pure fluid containing no bacteria. This fluid may include nutrient, and growth and/or mitosis of the trapped bacteria will commence. If a sufficiently large number of bacteria are trapped, the change in bacterial mass vs. time will be observable as a rapid decrease in the resonant frequency. This decrease occurs as the trapped bacteria extract nutrient material from the environment and add it to their mass, and also as they increase their numbers as they undergo mitosis. Experiments by the authors have shown that with 10-100 bacteria the growth rate can be measured within a few seconds. Of course these steps do not have to be cleanly delineated. For instance the nutrient could be present from the beginning if the collection is rapid.
[0023] FIG. 3 depicts the system of FIG. 2 set-up and operating to do a true bacterial assay of a type that provides similar information to existing assay techniques, albeit at very much reduced time. A desired number of bacteria are collected at the trap in the load phase. Once collection is stabilized a growth phase may be induced to witness mass change under benign conditions, to characterize normal growth. Then a series of antibiotics may be introduced sequentially or in treatment “cocktails” to compare the effect of the antibiotics on growth compared to the normal growth observed in the growth phase. Both antibiotics that are known or suspected to have reduced effectiveness, as well as ones believed to be effective, may be introduced in sequence leading to complete information for clinicians and researchers. Thus bacterial resistance and susceptibility may be observed. A system flush step may also be used between measurement cycles to expel the bacteria and sterilize the SMR.
[0024] The inventors have observed load, growth, and antibiotic exposure times of less than 10 minutes total. In some real-world drug susceptibility applications, the total time for a sequence such as that shown in FIG. 3 may take about an hour. This is far faster than conventional methods such as broth cultures or disk diffusion techniques, which require a culture to mature for many hours or even a day or more to produce results.
[0025] Times could be even further reduced by fabricating arrays of SMR's, as shown in FIG. 4 , allowing for simultaneous exposure to multiple antibiotics and/or nutrients at once.
[0026] With minor variations the invention can also be used in other applications which require precise measurement of cell growth. For example, cell and bacteria cultures are widely employed to manufacture quantities of target proteins to be used in drug formulations. These “drug factory” cultures are precisely engineered to optimize the growth rate of the cell culture so as to maximize yield of the protein product. Using the invention, the cell growth rate could be measured as a function of changes in nutrient content or concentration, or as a function of changes to other environmental parameters such as absorbed oxygen. In this way the optimal culture growth parameters could be determined and monitored.
[0027] The foregoing description of the embodiments of the present invention has shown, described and pointed out the fundamental novel features of the invention. It will be understood that various omissions, substitutions, and changes in the form of the detail of the systems and methods as illustrated as well as the uses thereof, may be made by those skilled in the art, without departing from the spirit of the invention. Consequently, the scope of the invention should not be limited to the foregoing discussions, but should be defined by appended claims. | Methods for improving measurements of bacterial growth, such as mass, in Suspended Microchannel Resonators (SMR's). Methods include techniques to provide for bacterial growth over time in response to changing fluid environment to aid in determining parameters such as drug resistance and drug susceptibility. In particular the methods include trapping multiple bacteria in the SMR for a time period and varying the fluid to include sequences of nutrients and antibiotics, and measuring the rate of mass change of the bacteria in response to the changes in fluid composition. | 6 |
BACKGROUND OF THE INVENTION
This invention relates generally to seekers and more particularly to gyroscopic, spin stabilized missile seekers.
As is known in the art, seekers of the gyroscopic, spin stabilized type have been used successfully in many applications. One such system is described in U.S. Pat. No. 3,872,308 issued Mar. 18, 1975, inventors James E. Hopson and Gordon G. MacKenzie, assigned to the same assignee as the present invention. As is known, in one type of such system, a missile seeker includes a catadioptric arrangement made up of a spherical primary mirror and flat secondary mirror arranged to focus infrared energy received from an object. The primary and secondary mirrors are fixed to one another. The housing of the primary mirror is a magnet. The magnet reacts with a magnetic flux produced by adjacent, missile body mounted, motor coils, to cause the primary mirror and the attached secondary mirror to rotate as a single unit about an axis of rotation. The catadioptric arrangement is also gimballed in pitch and yaw within the missile body. The rotating catadioptric arrangement acts as a two degree of freedom gyroscope. By forming the catadioptric arrangement as a gyroscope the mass formed by the primary and secondary mirrors will maintain the axis of rotation in inertial space decoupled from the missile's body unless acted upon by a gimbal section responding to tracking boresight error signals produced by a processor.
As is also known, one missile seeker of such type includes a precession coil and a cage coil. The field produced by the precession coil drives the gimballed catadioptric arrangement in pitch and yaw within the body of the missile. More particularly, the precession coil is fixed to the body of the missile and is wrapped circumferentially about the missile's center line. The precession coil encircles, but is spaced from, the magnetic housing of the primary mirror. A sinusoidal precession coil current, having a period equal to the period of rotation of the housing about the axis of rotation, is fed to the precession coil from the processor. The precession coil current is produced to enable the gimballed catadioptric arrangement to maintain track of the target. More particularly, in response to the precession coil current, a magnetic field component perpendicular to the magnetic field of the rotating primary mirror housing, is produced by the precession coil which reacts with the rotating magnetic field produced by the permanent magnet housing to produce a torque on the housing. In response to such torque the position of the axis of rotation, in inertial space, changes. The magnitude of the rate of change in the angular position of the axis of rotation in inertial space is proportional to the magnitude of the current passed to the precession coil by the processor. Such current produced by the processor being proportional to the boresight error (i.e., the deviation between the line of sight to the target (i.e., the boresight axis) and the axis of rotation).
Also included in such seeker is a cage coil used to sense the angular deviation of the axis of rotation from the missile body's center line. The cage coil is fixed to the body of the missile and is also wrapped circumferentially about the missile body's center line in a manner similar to the precession coil so that it also encircles the permanent magnet housing of the primary mirror. The cage coil is disposed laterally along the missile body's center line and is placed adjacent to the precession coil. As the permanent magnet housing rotates about the axis of rotation, a component of the associated rotating magnetic field produced by such housing induces a sinusoidal voltage in the cage coil with a magnitude related to the magnetic flux linking to the cage coil. The magnitude of the induced voltage is proportional to the magnitude of the angular deviation of the axis of rotation from the missile body's center line. The phase of the voltage induced in the cage coil, relative to the phase of a voltage induced to a body mounted reference coil, is proportional to the angular direction of the angular deviation of the axis of rotation from a yaw axis of the missile's body. It is noted that in changing the magnitude of the current fed to the precession coil, because of the proximity of the cage coil, an unwanted voltage is induced in the adjacent cage coil. This cage coil induced voltage is proportional to the time rate of change in the precession coil current. Further, as noted above, a desired voltage is induced in the cage coil proportional to the angular deviation of the axis of rotation from the missile body's center line. The cage coil thus has induced in it a desired voltage (the voltage indicating the angular deviation of the axis of rotation from the missile body's center line) and an undesired voltage (the voltage induced in it in response to a change in the current fed to the adjacent precession coil). This undesired induced voltage thus corrupts the accuracy of the voltage induced in the cage coil.
One solution to this problem is to use a third circular coil, sometimes referred to as a caging cancellation coil, arranged to cancel the magnetic coupling from the precession coil. Achieving cancellation in this manner however, not only increases the complexity of the coil designs but also reduces the caging coil induced voltage and seriously degrades the linearity of the signal amplitude verses the angle between the axis of rotation and the missile body's longitudinal axis due to the back electromotive force (EMF) also generated in the cancellation coil.
SUMMARY OF THE INVENTION
With this background of the invention in mind it is therefore an object of this invention to provide an improved seeker system.
It is another object of the invention to provide an improved gyroscopic, spin stabilized missile seeker of the type having adjacently mounted cage and precession coils.
These and other objects of the invention are attained generally by providing a seeker having a gyroscopic spin stabilized optical arrangement adapted to gimbal relative to a missile body in response to a current fed to a precession coil, gimballing action of such optical arrangement being measured by a voltage induced in a cage coil, such precession coil and cage coils being mounted adjacent each other, such seeker including a cage coil compensator comprising: a differentiator means, fed by a measure of the current in the precession coil, for producing a voltage related to the rate of change of the current in the precession coil; and, differencing means fed by: (i) the voltage induced in the cage coil, such induced voltage having a desired component related to the motion of the optical arrangement relative to the missile body, and an undesired component related to the rate of change of the current in the precession coil; and, (ii) the voltage produced by the differentiator means, for cancelling the undesired component of the voltage induced in the cage coil.
In a preferred embodiment of the invention, the differentiator means includes: a resistor fed by current in the precession coil for producing a voltage related to the current in the precession coil; and, a capacitor and wherein the differencing means includes a differential amplifier having a first input coupled to the cage coil and wherein the capacitor is coupled between the resistor and a second input of the differential amplifier.
With such arrangement, cancellation of the undesired voltage induced in the cage coil is provided by an electronic circuit thereby eliminating the requirement of an additional caging cancellation coil.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned and other features of the invention will become more apparent by reference to the following description taken together in connection with the accompanying drawings in which:
FIG. 1 is a simplified isometric sketch of the frontal portion of a missile incorporating an optical system according to the invention as the seeker thereof;
FIG. 2 is the diagram of the array of detectors used in the seeker of FIG. 1, such array being disposed in a detector plane;
FIG. 3 is a sketch showing the focal plane of a gimballed scanning and focusing system used in the seeker of FIG. 1 and the detector plane of FIG. 2 having disposed therein an array of detectors used in such seeker when the planes are in a skewed condition;
FIGS. 4A-4C show the orientation of three sets of detectors in the array of FIG. 2 and the relationship of such sets to six sectoral regions of the detector array;
FIG. 5 is a cross-sectional sketch, greatly simplified, of the seeker of FIG. 1 with the gimballed axis of rotation of the optical system aligned with the longitudinal center line, of the missile, the upper half of such cross-section being taken along a yaw axis of the body of the missile and the bottom half being taken along the pitch axis of the missile;
FIG. 6 is a diagrammatical sketch showing the relationship between motor coils used in a gimbal control section of the seeker of FIG. 1 to the pitch and yaw axis of the missile's body, and to a rotating permanent magnet housing for a primary mirror used in the optical system;
FIGS. 7A-7B are sketches of the path traced by a focused spot, S, on a focal plane as a scanning and focusing system of the optical system rotates about an axis of rotation; FIG. 7A showing such path traced by the focused spot, S, when a target is orientated along the axis of rotation, and FIG. 7B showing the path traced by such spot, S, when the target is orientated at an angle φ with respect to a reference axis of the missile's body and displaced in angle from the axis of rotation an amount proportional to R T ;
FIG. 8 is a diagrammatical sketch showing the relationship of a pair of reference coils used in the gimbal control section to the missile's body;
FIGS. 9A and 9B are diagrammatical sketches. FIG. 9A is a frontal view showing the orientation of a cage coil located in the gimbal control section relative to the primary mirror housing and the pitch and yaw axis of the missiles, and FIG. 9B is a cross-section diagrammatical sketch taken along the missile body's yaw axis showing the orientation of the cage coil of FIG. 9A, and an adjacent precession coil used in the gimbal control section, relative to the housing of the primary mirror and the pitch and yaw axis of the missile;
FIGS. 10A-10D are time histories of voltages induced in one of the pair of reference coils and cage coil after compensation under different gimbal angle conditions; FIG. 10A showing the time history of the voltage induced in one of the pair of reference coils; and FIGS. 10B-10D showing the time history of voltages induced in the cage coil after compensation for three correspondingly different skew angular orientations between the detector plane and the focal plane; and
FIG. 11 is a block diagram of a quadrature combining circuit within the processor for combining voltages induced in the pair of reference coils to develop the current required for the precession coil for target tracking.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a guided missile 10 is shown to carry within its frontal portion an optical system, here a missile seeker 16, such missile seeker 16 being responsive to that portion of the infrared energy radiated from an object, here a target (not shown) and entering the frontal portion of the missile 10. The seeker 16 includes a gimballed scanning and focusing system 18, a detector section 20, a processing section 22, a gimbal control section 24, and a gimbal section 25. The gimballed scanning and focusing system 18 focuses a portion of the radiant energy passing through the frontal portion of the missile 10 onto a spot in a focal plane 26 (shown in phantom in FIG. 1) and rotates about an axis of rotation 37 to scan such focused spot in a circular path on the focal plane 26. The detector section 20 includes a plurality of, here 10, detectors 42 1 -42 10 arranged in an array 28 disposed in a detector plane 30, as shown in detail in FIG. 2. The detector plane 30 is fixed to the body of missile 10. As will be described hereinafter, if the scanning and focusing system 18 is gimballed in pitch and/or yaw relative to the body of missile 10 (as indicated by arrows 32, 34) by magnetically coupled forces generated by the gimbal control section 24 and/or if the missile's body pitches and/or yaws and/or rolls in space, the focal plane 26 of the scanning and focusing system 18 may be skewed with respect to the detector plane 30, as shown in FIG. 3. Hence, when in a skewed condition, while one portion of the array 28 of detectors will be out of focus, the portion of the array 28 on, or adjacent to, the line 49 (FIG. 3) formed by the intersection of the skewed detector and focal planes 30, 26, will be in, or substantially in, focus. Referring again to FIG. 1, the processing section 22 includes a selector section 40 for identifying and, then coupling, the portion of the detectors 42 1 -42 10 of array 28 disposed in, or adjacent to line 49, and hence in, or substantially in, focus to processor 41. The processor 41, in response to the signals produced by the identified and coupled portion of the detectors 42 1 -42 10 produces, inter alia, a signal representative of the deviation of the line of sight to the target (hereinafter referred to as the boresight error axis 36 from the axis of rotation 37 (i.e., a signal representative of boresight error). This boresight error signal is used to guide the missile 10 toward the target and is also fed from processor 41 gimbal control section 24, via line 86, to move the scanning and focusing system 18 to maintain track of the target.
The detector section 20, as mentioned above, includes a plurality of detectors, here 10 detectors 42 1 -42 10 , arranged as shown in FIG. 2, in array 28 disposed in the detector plane 30. The detector plane 30 is fixed to the body of missile 10 and is normal to the longitudinal center line 38 of the missile 10. As shown, detector 42 1 is positioned at the center 27 of the array 28. The center 27 is along the missile's center line 38. Detectors 42 2 , 42 3 , 42 4 , 42 5 , 42 6 and 42 7 , are regularly angularly spaced along the outer, circumferential, periphery of the array 28 about the centrally positioned detector 42 1 . Detector 42 2 is positioned along the missile body's yaw axis 43. Thus, detector 42 2 is disposed at 0°, and detectors 42 3 , 42 4 , 42 5 , 42 6 and 42 7 , are positioned at 60°, 120°, 180°, 240° and 300°, respectively, from the missile's yaw axis 43. Disposed along the circumference of a circle concentric with the outer circumferential periphery and having a radius intermediate the radius of the outer periphery are detectors 42 8 , 42 9 , and 42 10 . Detector 42 8 is positioned between detector 42 3 and 42 4 and hence is positioned 90° from detector 42 2 (i.e., along the missile's pitch axis 45). Likewise, detector 42 9 is positioned 210° from detector 42 1 and detector 42 10 is positioned 330° from detector 42 2 . It is further noted that detectors 42 1 to 42 10 are arranged in 3 sets 44 1 , 44 2 and 44 3 . Detectors 42 2 , 42 10 , 42 1 , 42 9 and 42 5 are in set 44 1 . Detectors 42 4 , 42 8 , 42 1 , 42 9 and 42 6 are in set 44 2 . Likewise detectors 42 3 , 42 8 , 42 1 , 42 10 and 42 7 are in set 44 3 . Each one of the three sets 44 1 -44 3 is disposed along a corresponding one of three different, partially overlaping regions 46 1 -46 3 extending radially from the center 27 of the array 28 along directions 0°, 60° and 120° from the missile's yaw axis 43, respectively. Thus set 44 1 is directed along the 0° (and 180°) or missile body's yaw axis 43. Set 44 2 is directed along a line 60° (and 240°) from the missile body's yaw axis 43. Set 44 3 is directed along a line 120° (and 300°) from the missile body's yaw axis 43.
The array 28 of detectors 42 1 -42 10 is mounted to a Dewar flask and a cryogenic chamber included within the detector section 20 (FIG. 1), and fixed to the body of missile 10, for enabling a suitable cyrogenic substance to cool the array 28 of detectors 42 1 -42 10 . The mechanical pivot point of the gimballed scanning and focusing system 18 is in the detector plane 30 at the intersection of the axis of rotation 37 and the missile's center line 38. Thus, the mechanical pivot point is at the center 27 of the array 28 of detectors 42 1 -42 10 , (i.e., it is coincident with detector 42 1 ). It should also be noted that the axis of rotation 37 intersects the detector plane 30 at the center 27, or pivot point, regardless of the pitch, yaw, or roll angular excursion of the scanning and focusing system 18 which excursion may be produced by the gimbal control section 24 acting on the gimbal section 25 and/or by the motion of the missile 10 in space, acting signals produced by processor 41, as noted above.
As further noted above, the scanning and focusing system 18 focuses infrared energy from the target passing through the frontal portion of the missile 10 onto the focal plane 26 (shown in phantom in FIG. 1). When the gimballed scanning and focusing system 18 is directed along the longitudinal center line 38 of the missile 10, the detector plane 30 is co-planar with the focal plane 26 and the image formed by the focusing system 18 will be in focus with all of the detectors 44 1 -44 10 in the array 28. However, as mentioned above, if the scanning and focusing system 18 moves in pitch and yaw relative to the missile's body by the gimbal control section 24 acting on gimbal section 25, as when tracking a target, and/or if the missile's body pitches and/or yaws and/or rolls in space, the focal plane 26 and the detector plane 30 will become skewed as shown in FIGS. 2 and 4. Thus, in this skewed condition the image formed by the scanning and focusing system 18 will not be in focus with all of the detectors 44 1 -44 10 in the detector plane 30. It is noted however, that the image will be in focus along the line 49 (FIG. 3) formed by the intersection of the skewed focal and detector planes 26, 30. It is noted that the line 49 of intersection is the line, in the detector plane 30, which is perpendicular (i.e., 90°) to the projection 50 of the axis of rotation 37 onto the detector plane 30. The projection 50 of the axis of rotation 37 is shown at an angle α from the missile's yaw axis 43. Thus, the angular deviation, θ, of the line 49 of intersection from a reference axis fixed to the body, such as the missile yaw axis 43 or pitch axis 45, here the yaw axis 43, is equal to (α+90°). As will be described, the angle α is quantized to a selected one of six values and is obtained from signals produced by gimbal control section 24 in a manner to be described. Suffice it to say here, however, that in response to the signals produced by gimbal control section 24 (FIG. 1) the processing section 22 enables selection of the one of the three sets 44 1 -44 2 of detectors (FIG. 2) disposed along, or adjacent to line 49, and hence in, or substantially in, focus by the gimballed scanning and focusing system 18. More specifically, an output, to be described, produced by the gimbal control section 24 is fed to the processing section 22. Processing section 22 includes a phase detector 75 which, in response to the signals produced by the gimbal control section 24 in a manner to be described, produces a signal representative of the quantized angular deviation α. This signal is used as a control signal for the selector section 40 included within the processing section 22. The selector section 40 is fed by the outputs of the 10 detectors 42 1 -42 10 on lines 55 1 -55 10 , respectively. In response to the control signal provided by the phase detector 75 the outputs of 5 of the 10 detectors 42 1 -42 10 in the selected one of the three sets 44 1 -44 3 of detectors which are well focused are selectively coupled to a processor 41 via lines 56 1 -56 5 while the remaining, unselected 5 detectors (i.e., the detectors in the unselected 2 sets 44 1 -44 3 of detectors) are inhibited from passing to the processor 41.
More specifically, as shown in FIG. 4A, the array 28 of detectors 42 1 -42 10 is quantized into a plurality of, here 6, equal angular sectors 60 1 to 60 6 . Thus, the intersectors of the sectors 60 1 to 60 6 are disposed at angles 0°, 60°, 120°, 180°, 240° and 300°, respectively, from the missile body's yaw axis 43. Thus, as noted above, and as will be described, the gimbal control section 24 produces signals which enable determination of the quantized angular deviation, α, of the projection 50 of the axis of rotation 37 (FIG. 3) onto the detector plane 30, from the missile body's yaw axis 43 to within one of the six sectors 60 1 -60 6 . Further, as described above in connection with FIG. 3, the line 49 of intersection of the skewed focal and detector planes 26, 30, is at an angle θ=α+90° from the missile's yaw axis 43. Thus, referring also to FIGS. 4A-4C, if the signals produced by the gimbal control section 24 indicates that α (which is perpendicular to the line 49 of intersection) is between 60° and 120° (i.e., in sector 60 2 ), or between 240° and 300°, (i.e., in sector 60 5 ), the detectors 42 2 , 42 10 , 42 1 , 42 9 and 42 5 in set 44 1 are selectively coupled to the processor 41 by selector section 40. If α is between 0° and 60°, or between 180° and 240°, (FIG. 4C), the detectors 42 7 , 42 10 , 42 1 , 42 8 and 42 4 , in set 44 3 are selectively coupled to the processor 41. Likewise, if α is between 120° and 180°, or between 300° and 360°, (or 0°) (FIG. 4B) the detectors 42 3 , 42 8 , 42 1 , 42 9 and 42 6 , in set 44 2 are selectively coupled to the processor 41. This arrangement thus provides that five detectors from the total of 10, 42 1 -42 10 in the one of the three sets 44 1 -44 3 aligned along, or adjacent to line 49 (and hence, which are in, or are substantially in focus) pass to the processor 41. The energy impinging on the selected one of the three sets 44 1 -44 3 of detectors in the detector array 28 is processed by the processing section 22 (FIG. 1), to produce electrical signals for the wing control section (not shown) of the missile 10 and via line 86 for the gimbal control section 24. As will be described, the gimbal section 25, in response to gimbal section 24, is used to gimbal the scanning and focusing system 18 within the missile 10 so as to cause the optical system 16 to track the target independent of missile pitch, yaw or roll motion. More specifically to gimbal the scanning and focusing system 18 within the missile to drive the boresight error axis 36, here, preferably, towards the center of the array 28 of detectors 42 1 -42 10 , i.e., towards detector 42 1 . Such arrangement prevents boresight error transients when switching between detector sets while tracking targets in pitch or yaw and when the missile rolls.
Referring now to FIG. 5, the scanning and focusing system 18 is here shown with the boresight error axis 36 aligned with the axis of rotation 37 and the center line 38 of the missile. The upper half of FIG. 5 is a cross section taken along the missile body's yaw axis 43 and the cross section of the bottom half of FIG. 5 is taken along the missile body's pitch axis 45. The focusing system 18 includes a catadioptric optical arrangement which here includes a spherical primary mirror 60 and an attached flat secondary mirror 58, and attached focusing lens 56, here silicon, disposed symetrically about an axis of rotation 37. The flat secondary mirror 58, is disposed in a plane tilted at an angle γ with respect to a plane normal to the axis of rotation 37. Thus, the optic axis is displaced from the axis of rotation 37 by 2 γ. More specifically, the plane of the tilted secondary mirror 58 intersects the focal plane 26 and at the angle γ. The flat secondary mirror 58, lens 56, and the primary mirror 60 are fixedly attached to one another by supports 70a and 70b. The catadioptric optical arrangement focuses a portion of the infrared energy from the target passing through the missile's frontal portion into a small spot on the focal plane 26. The frontal portion of the missile 10 is a conventional IR dome 69 rigidly mounted to the missile 10. The IR dome 69 is optically designed to reduce spherical aberration introduced by the spherical primary mirror 60. The flat secondary mirror 58 is used to fold and displace the path of infrared energy within the scanning and focusing system 18, as shown by the dotted line 63. The primary mirror 60 and attached tilted, flat, secondary mirror 58, and lens 56 (which has its instantaneous optic axis 36A displaced by the 2 γ from the axis of rotation 37), are adapted to rotate, as one unit, with respect to the body of missile 10, about the axis of rotation 37 of the scanning and focusing system 18, here by forming the primary mirror 60 as the rotor of an electrical motor. In particular, the housing 61 of the primary mirror 60 is a permanent magnet having north and south poles, the north pole indicated by N (shown in FIG. 5) and is here aligned with the missile body's yaw axis 43. As will be described, a primary purpose of the rotating housing 61 is to form a gyroscope such that the primary mirror 60 will maintain the axis of rotation 37 in inertial space, uncoupled from the body of the missile unless acted on by the gimbal control section 24 in response to signals fed through from processor 41 via line 86. It should be noted that, because the housing 61 is attached to the tilted mirror 58, the north/south axis 74 of the housing 61 intersects the plane of the tilted mirror 58 at the angle γ even as the housing rotates about the axis of rotation 37.
The housing 61 is adapted to rotate about the axis of rotation 37 by means of bearings 59 coupled between support structure 70a of the housing 61 and a hollow support member 67. The stator of such motor includes two pairs of motor coils 62a, 62b (FIG. 6) fixed to the body of the missile 10 in the gimbal control section 24. The motor coil pair 62a includes two serially connected coil sections, each wrapped around an axis 45° with respect to the missile body's yaw axis 43, as shown, on opposing sides of the permanent magnet housing 61. Likewise, motor coil pair 62b includes two serially connected coil sections, each wrapped around an axis -45° with respect to the missile body's yaw axis 43 on opposing sides of housing 61. A sinusoidal current, I, fed through motor coil pair 62a is 90° out of phase with the sinusoidal current, I, fed across motor coil pair 62b. The spatial orientation of the coil pair 62a, 62b and the phase of the currents applied to such coil pairs 62a, 62b establishes a magnetic field perpendicular to the missile's center line 38 which reacts with the magnetic field produced by permanent magnet housing 61, to produce a rotational torque about the axis of rotation 37. A pair of reference coils 66a, 66b (which will be described in detail hereinafter) is included in the gimbal control section 24 (FIG. 1). One of the pair of reference coil 66a, 66b, here reference coil 66a, produces a sinusoidal voltage on line 66'a; i.e., a reference signal indicating the rotational position of the north/south axis 74 relative to the body yaw axis 43 as well as the rotational rate (ω) of the housing 61. This reference signal on line 66'a from reference coil 66a is fed, inter alia, to a rotation rate, or speed controller 65. The rotation speed controller 65 adjusts the sinusoidal current (both magnitude and phase) to the motor coil pairs 62a, 62b in response to the rotational rate signal produced by the reference coil 66a to cause a constant angular rate of rotation (ω) of the primary mirror 60 about the axis of rotation 37, as indicated by arrows 57 in FIG. 6, in a conventional feedback system manner.
Referring again to FIG. 5, the hollow support member 67 (and hence the attached primary and secondary mirrors 60, 58, and lens 56) is mechanically coupled to the body of the missile 10 through a two-degree of freedom gimbal system made up of: a support 76a, fixed to the missile body; an outer gimbal ring 76b, pivotally coupled to the support 76a by a gimbal section bearing 71; and, an inner gimbal ring 76c, integrally formed with hollow support member 67 and pivotally coupled to outer gimbal ring 76b by bearing 73. The rotation axis of bearings 71, 73 are orthogonal to each other and both pass through pivot point 27, detector plane 30, and focal plane 26.
In operation, then, infrared energy from the target passing through the frontal portion of the missile 10 is scanned and focused to a small spot in the focal plane 26 by the catadioptric focusing arrangement. The secondary mirror 58 is tilted, as described, so that it nutates the spot along the instantaneous optic axis 36A about the axis of rotation 37 when tracking a target with no boresight error; i.e., the boresight error axis 36 is coincident with the axis of rotation 37. As the scanning and focusing system 18 rotates about the axis of rotation 37, the optic axis of the catadioptric arrangement will trace a circle in the focal plane 26. Thus, the spot, which is at the intersection of the focal plane 26 and the optic axis, will scan, or trace a circular path on the focal plane 26. The center of the circle formed by the instantaneous optic axis 36A during a rotation of lens 56, secondary mirror 58 and primary mirror 60 will be along the boresight error axis 36. The boresight error is thus a function of the position of the center, 36, of the circle relative to the point of intersection of the axis of rotation 37 and the focal plane 26. Thus, for example, if the target were orientated along the axis of rotation 37, the energy from such would be focused to a spot, S, along the instantaneous optic axis 36A on the focal plane 26, as shown in FIG. 7A, translated from the center 27 of focal plane 26 by an amount R related to the tilt angle, γ, of the secondary mirror 58. Further, if the axis of rotation 37 were aligned with the missile's center line 38 and if the north/south axis 74 of the housing 61 were aligned with the missile body's yaw axis 43, the spot would lie on the body's yaw axis 43 as shown in FIG. 7A at point S 1 , at one instant in time and as the housing 61, and attached secondary mirror 58, rotate about the axis of rotation 37, the spot, S, would trace a circle of radius R centered at the axis of rotation 37. If, however, the boresight error axis 36 was angularly offset from the axis of rotation 37, the spot, S, would be displaced from the axis of rotation 37 here an amount R T and as the tilted mirror 58 rotates about the axis of rotation 37, the spot, S, would again trace a circle of radius R. However, as shown in FIG. 7B, the center of such circle would now lie along an axis 51 on the focal plane 26, displaced by the angular deviation φ of axis 51 from the missile body's yaw axis 43. The angular deviation φ combined with the displacement of the center of the circle from the axis of rotation 37, R T , provide the polar coordinates of the boresight error tracking signal produced by the processor 41 on line 86 to enable tracking of the target. (The tilted mirror 58, in effect, may be viewed as causing each of the detectors 42 1 -42 10 to sense and trace an independent circular region of object space as focused by the primary mirror 60. The independent circle center locations are determined by the location of each of the detectors 42 1 -42 10 . The combined coverage of the five circles from the selectd one of the sets 44 1 -44 3 determines the field of view over which a target may be tracked or a boresight error signal generated). As noted above, if the axis of rotation 37 and the missile's center line 38 were not aligned, the focal and detector planes 26, 30 would be skewed and would intersect at an acute angle. Therefore, the axis of rotation 37 deviates from the missile's center line 38. In this skewed condition, the spot traced in the detector plane 30 will not be a circle, but rather will be an ellipse. However, because the ellipse crosses the detectors selected at the same place as the circle, no error is introduced. As noted above, the processor 41 responds only to detectors disposed in, or substantially in, both the detector plane 30 and the focal plane 26, the computation of the translation R T center of the circle traced in the focal plane 26 and the angular deviation φ of the axis 51 from the missile body's yaw axis 43 enables the processor 41 to produce a proper target tracking boresight error signal on line 86 to drive the gimballed scanning focusing system 18 via gimbal control section 24 and gimbal section 25 to maintain track of the target.
The pair of reference coils 66a, 66b are shown in FIG. 8, and sense the spin, or angular, orientation of the gimballed scanning and focusing system 18, relative to the missile's body. More particularly, the reference coil 66a is used to determine the rotational position of primary mirror housing 61 (more particularly the north/south axis 74), about the axis of rotation 37, relative to the yaw axis 43 and reference coil 66b is used similarly relative to the pitch axis 45. The reference coil 66a shown in FIG. 8 to be made up of two serially connected coil sections fixed to the body of missile 10 and wrapped around the missile's yaw axis 43 on opposite sides of permanent magnetic housing 61 and reference coil 66b is made up of two serially connected coil sections fixed to the body of the missile 10 and wrapped around the missile's pitch axis 45 on opposite sides of housing 61. As the permanent magnetic housing 61 of the primary mirror rotates about the axis of rotation 37, the magnetic field produced by such housing 61 rotates about the axis of rotation 37. A component of such magnetic field rotation occurs about the missile's center line 38. The accompanying time rate of change in magnetic field induces a sinusoidal voltage on line 66'a of the reference coil 66a. The phase of the induced sinusoidal voltage on line 66'a relates to the angular orientation of the housing 61 relative to the missile body's yaw axis 43. More particularly, the sinusoidal voltage induced in reference coil 66a reaches a maximum (or minimum) when the north/south axis 74 is perpendicular to the missile body's yaw axis 43. Likewise, the sinusoidal voltage induced in reference coil 66b reaches a maximum (or minimum) when the north/south axis is perpendicular to the missile body's pitch axis 45. Therefore, when the reference coil 66a induced voltage on line 66'a reaches a maximum, an indication is provided that the north/south axis 74 is perpendicular to the missile body's yaw axis 43. Likewise, when the reference coil 66b induced voltage on line 66'b reaches a maximum, an indication is provided that the north/south axis 74 is perpendicular to the missile's pitch axis 45. Thus, the induced voltage on line 66'a of reference coil 66a provides a reference signal which indicates the rotational angular orientation of the primary mirror 60 (and hence, the tilt of the tilted secondary mirror 58) relative to the missile body's yaw axis 43 and the induced voltage in line 66'b of reference coil 66a provides a reference signal which indicates the rotational angular orientation of the tilted secondary mirror 58 relative to pitch axis 45.
The gimbal control section 24 also includes a precession coil 64 (FIGS. 9A and 9B) for driving the gimballed scanning and focusing system 18 about the gimbal system bearing 73 and the orthogonal gimbal system bearing 71 (FIG. 5) indicated by arrows 32, 34 as mentioned above in connection with FIG. 1. More particularly, the precession coil 64 is fixed to the body of missile 10 and is wrapped circumferentially about the missille's center line 38. As shown in FIGS. 9A and 9B, the precession coil 64 encircles the housing 61 of the primary mirror 60. A sinusoidal precession coil current, having a period equal to the period of rotation of the housing 61 about the axis of rotation 37, is fed to the precession coil 64 from processor 41 (FIG. 1) via line 86 in a manner to be described. The precession coil current is produced to enable the gimballed scanning and focusing system 18 to maintain track of target (FIG. 1). More particularly, in response to the precession coil current a magnetic field component perpendicular to magnetic field 74 (produced by the housing 61 of the primary mirror 60) is produced by the precession coil 64 which reacts with the rotating magnetic field 74 produced by permanent magnetic housing 61 to produce a torque on the housing 61. In response to such torque the position of the axis of rotation 37, in inertial space, changes about pivot point 27. The magnitude of the rate of change in the angular position of the axis of rotation 37 in inertial space is proportional to the magnitude of the current passed to the precession coil 64 by processor 41 via line 86 and is proportional to the magnitude R T of the boresight error. The angular direction of such rate of change in angular position of the axis of rotation 37 in inertial space is related to the phase of the boresight error φ and proportional to the phase of the sinusoidal current in the precession coil 64. A precession coil current is generated on line 86 from the quadrature sinusoidal voltages induced in the pair of reference coils 66a and 66b which pair of voltages are algebraically added proportional to the boresight error in the yaw and pitch planes, respectively, in quadrature combining circuitry 100 within processor 41 (to be described hereinafter in detail in connection with FIG. 11). Suffice it to say here, however, that the resultant current produced by the quadrature combining circuit 100 is fed, via line 86, to the precession coil 64. Futher, the angular direction of the change in the axis of rotation 37 in inertial space is related to the phase between the sinusoidal current fed to precession coil 64 (via line 86) and the orientation of the magnetic housing 61 north/south magnetic field. The precession coil 64 current (on line 86) is, as will be discussed in detail in connection with the combining circuit 100 (FIG. 11), derived from the boresight error and the reference coils 66a, 66b voltages induced on lines 66'a, 66'b respectively. The magnitude of the boresight error controls the magnitude of the current fed to the precession coil 64 via line 86.
Finally, the gimbal control section system 24 includes a cage coil 68, shown in FIG. 9B, to sense the angular deviation of the axis of rotation 37 from the missile body's center line 38. Cage coil 68 is fixed to the body of missile 10 and is wrapped circumferentially about the missile body's center line 38 in a manner similar to precession coil 64 to encircle the permanent magnetic housing 61 of primary mirror 60. The cage coil 68 is disposed laterally along the missile body's center line 38 adjacent to the precession coil 64. As permanent magnet housing 61 rotates about the missile body's center line 38 a component of the associated rotating magnetic field produced by such housing 61 induces a sinusoidal voltage in the cage coil 68 with a magnitude related to the rate of change of the magnetic flux linking to the cage coil 68. The magnitude of the induced voltage is proportional to the magnitude of the angular deviation of the axis of rotation 37 from the missile's center line 38. The magnitude of the cage coil 68 voltage in phase with the induced voltage in the reference coil 66a on line 66'a is proportional to the magnitude of the angular deviation of the axis of rotation 37 from the missile's yaw axis 43 (and similarly for the pitch axis 45 when using the reference coil 66b). When the gimballed scanning and focusing system 18 is driven to rotate about the axis of rotation 37 by the motor coils 62a, 62b the focusing system 18 acts like a two degree of freedom gyroscopic and unless driven to move in pitch and or/yaw relative to an inertial angle by activation using the precession coil 64, the gyroscopic effect of the spinning housing 61 will maintain the axis of rotation 37 pointed in a particular direction in inertial space regardless of pitch and/or yaw and/or roll motion of the body of the missile 10 in inertial space. While, the focal plane 26 and the detector plane 30 may become skewed because either the body of the missile 10 pitches and/or yaws and/or rolls in space, the precession coil 64 will drive the gimballed scanning and focusing system 18 in response to target angular motion only the angular rates need not be resolved into pitch and/or yaw rate relative to the body of the missile 10; or both for the control of the missile's trajectory since, as will be described in connection with FIG. 11, they are developed separately by the quadrature combining circuit 100 within processor 41 as pitch and yaw error signals.
As noted above, a sinusoidal voltage is induced in the reference coil 66a because the rotation of the permanent magnetic housing 61 produces a phase reference signal which provides an indication of the rotational orientation of the housing 61 relative to the missile's yaw axis 43. Further, as noted above, a sinusoidal voltage is induced in the cage coil 68 having a magnitude proportional to the angular deviation of the axis of rotation 37 from the missile center line 38, and a phase proportional to the difference between the axis of rotation 37 and yaw axis 43. The phase difference between the sinusoidal voltage developed by cage coil compensator 80 (in a manner to be described hereinafter) and the sinusoidal voltage induced in the reference coil 66a is equal to angular deviation α of the projection 50 (FIG. 3) of the axis of rotation 37 onto the detector plane 30 from the missile body's yaw axis 43. The time history of the voltage induced in the reference coil 66a after compensation by compensator 80 is shown in FIG. 10A. As noted also, the induced voltage reaches a maximum (positive or negative) amplitude when the north/south axis 74 of housing 61 passes through the missile body's pitch axis 45. The time history of the voltage induced in the cage coil 68 is shown in FIG. 10B after compensation for an angular deviation α (which is perpendicular to the line 49 of intersection of the detector and focal planes) from the missile body's yaw axis 43, which is between 0° and 60° (and 180° and 240°). FIG. 10C shows the time history of the voltage induced in the cage coil 68 after compensation as a function of time for an angular deviation α which is between 60° and 120° (and 240° and 300°). Likewise, FIG. 10D shows the time history of the voltage induced in the cage coil 68 as a function of time for an angular deviation α which is between 210° and 180° (30° and 360°).
A phase detector 75 (FIG. 1) is fed by the voltages induced in the reference coil 66a (on line 66'a) and the cage coil 68, after passing through a cage coil compensator 80, (to be described), to produce an output signal representative of the angular deviation α (which is perpendicular to the line 49 of intersection of the focal and detector planes). The output signal representative of α is fed to a quantizer 82. Quantizer 82 produces a 2-bit digital word representative of the 6 quantized angular sectors 60 1 -60 6 (FIG. 4A-4C) organized as three pairs and covered by arrays 44 1 and 44 3 . Thus, if α is between 0° and 60°, (or between 180° and 240°) the 2-bit word is (00) 2 ; if α is between 60° and 120° (or between 240° and 300°), the 2-bit word is (01) 2 ; and if α is between 120° and 180° (or between 300° and 360°) the 2-bit word is (11) 2 . The 2-bit word produced by quantizer 82 is fed as the control signal for selector 87. The outputs of detectors 42 1 -42 10 are fed to the selector 87 on line 55 1 -55 10 , as noted above. In response to the 2-bit control word produced by quantizer 82, 5 of the 10 outputs of detectors 42 1 -42 10 are fed to processor 41, such 5 being, as discussed above, those in best focus and coupled to the detectors 42 1 -42 10 in one of the three sets 44 1 -44 3 in, or substantially in, focus by the scanning and focusing system 18. (That is, the set in, or adjacent to, the line 49 of intersection of the focal plane 26 and the skewed detector plane 30). Also fed to the processor 41 is the output voltage induced in the reference coil 66a. Thus, if the 2-bit word is (00) 2 only detectors 42 2 , 42 10 , 42 1 , 42 9 , 42 5 are identified and passed to processor 41. If the 2-bit word is (01) 2 only detectors 42 3 , 42 8 , 42 1 , 42 9 , 42 6 are identified and passed to processor 41. If the 2-bit word is (10) 2 only detectors 42 4 , 42 8 , 42 1 , 42 10 , 42 7 are identified and passed to processor 41.
The processor 41 produces a sinusoidal current on line 86 which is fed to the precession coil 64 as will be described in detail hereinafter in connection with FIG. 11. Suffice it to say here however that the magnitude of the current on line 86 is proportional to the desired rate change in inertial space, of the axis of rotation 37. The phase of such current, relative to the sinusoidal reference coils 66a, 66b induced voltages, is proportional to the angular direction of such rate relative to the yaw axis 43 and the pitch axis 45. The phase and magnitude of the sinusoidal output current on line 86, are fed to the precession coil 64 to drive the scanning focusing system 18 so that the boresight error axis 36 is driven towards the central detector 42 1 as it maintains track of the target.
More particularly, the five detectors in the one of the three sets 44 1 -44 3 thereof in, or substantially in focus are fed to processor 41 through selector section 40. Also fed to processor 41 are the voltages induced in reference coils 66a, 66b (on lines 66'a, 66'b). Thus assume, as described above in connection with in FIG. 7B, the spot, S, in the focal plane 26 traces the circle shown in FIG. 7B, having a center along axis 51, (such axis 51 being at an angle φ with respect to the missile body yaw axis 43) and translated from the axis of rotation 37 an amount equal to R T . The processor 41, in response to the outputs of the five detectors in focus with the focal plane 26 (and hence in common with the detector plane 30) and identified and fed thereto via selector 87, determines the amount of translation R T of the center of the circle from axis of rotation 37 and the angle φ to produce a signal representative of R T and φ. For example, let it be assumed, as discussed above in connection with FIG. 7B, that the set 44 3 of detectors is in focus and that the detectors in such set 3 (and hence in focus) indicate that the circle traces through detector 42 7 . The position of the center 27 of the detector plane 30 (i.e., the center detector 42 1 and the axis of rotation 37) relative to the positions of each of the detectors 42 1 -42 10 are known, a priori. These relative positions (both magnitude R D and angle Δ (relative to the yaw axis 43)) are stored in a read only memory (ROM), not shown, included in processor 41. Thus, detector 42 7 is at a known distance R D7 from the center detector 42 1 (and the axis of rotation 37) and a known angle Δ 7 , as shown in FIG. 7B (here Δ 7 =300°=-60°). If the spot, S, traces a circular arc β between the time the tilted mirror 58 places the optic axis through yaw axis 43 and the time of detection of such spot by detector 42 7 (i.e., a difference in time Δ T) then, in the general case, the magnitude of the boresight error R T is: ##EQU1## and the angle φ of such boresight error is:
φ=tan.sup.-1 {[R.sub.D cos Δ-R cos β]/[R.sub.D sin Δ-R sin β]} eq (2)
The angle β is determined by a timer (not shown) included in processor 41. The timer is initiated by a signal produced from the reference coil 66a induced voltage and is stopped when there is an indication that one of the five detectors fed to processor 41 by selector 87 (i.e., the signal on one of the lines 56 1 -56 5 ) has detected the circularly travelling spot S. The contents of the counter contains the time Δ T. Since the rotational rate of the secondary mirror 58 about the axis of rotation 37 is controlled to ω as described above, β=ω(ΔT) may be determined by the processor 41. A quadrature combining circuit 100 shown in FIG. 11 is included in processor 41. The voltages induced in reference coils 66a, 66b, are fed via lines 66'a, 66'b, respectively, to a summing amplifier 102 through multipliers 104a, 104b, and resistors R 6 , R 7 , respectively, as shown. Multiplier 104a is also fed by a signal produced within processor 41 by conventional microprocessor (not shown) from eq (1) and (2) equal to R T sin φ. Likewise, multiplier 104b is also fed by a signal produced by the microprocessor (not shown) from eq (1) and (2) equal to R T cos φ. The products produced by multiplier 104a, 104b, are summed by resistors R 6 , R 7 , at the (-) input of amplifier 102. The (-) input of amplifier 102 is also coupled to the precession coil 64 through resistor R 8 via lines 84, 85 for boresight error gain control. The (+) input of amplifier 102 is coupled to ground. The amplifier 102 combines the summed voltages into a total, resulting current which is fed to the precession coil 64 via line 86 which causes the scanning and focusing system 18 to track a target simultaneously in both pitch and yaw using a combined control signal. The resulting sinusoidal current produced on line 86 (FIG. 1) has a magnitude proportional to R T and the desired rate of change in inertial space of the axis of rotation 37, and a phase proportional to the angular direction φ of such rate from the missile body's yaw axis 43. As noted above, the signal on line 86 is used to drive the scanning and focusing system 18 to track the target and here, preferably, to drive the axis of rotation 37 towards the target and maintain the center of the spot's path centered on center detector 42 1 .
It is noted that in changing the magnitude of the sinusoidal current fed to the precession coil 64 a sinusoidal voltage is induced in the adjacent cage coil 68 (FIG. 9B). This cage coil 68 induced voltage is proportional to the rate of change in the precession coil 64 current (here a sinusoidal voltage in cage coil 68 induced by a sinusoidal current fed to precession coil 64. Further, as noted above, a sinusoidal voltage is also induced in the cage coil 68 proportional to the angular deviation of axis of rotation 37 from the missile's body center line 38. The cage coil 68 thus has induced in it a desired sinusoidal voltage (the voltage indicating the angular deviations of the axis of rotation 37 and from the missile body's center line 38) and an undesired sinusoidal voltage (the voltage induced in it in response to a sinusoidal current fed to the adjacent precession coil 64). To compensate for this undesired induced voltage in the cage coil 68, the cage coil compensator 80, as shown in FIG. 1, is provided. The cage coil compensator 80 is a differentiating and subtraction network and includes a differential amplifier 90 and an inverting buffer amplifier 94. The non-inverting (+) input of the differential amplifier 90 is connected to ground. The inverting (-) input of amplifier 90 is coupled to capacitor C, and resistor R 2 . Resistor R 3 completes the circuit and adjusts gain through feedback. The precession coil current from the processor 41 fed via line 86 is returned via line 85 and develops a voltage across resistor R 1 . The developed sinusoidal voltage is differentiated by the capacitor C which inputs to amplifier 90 a current equal to the derivative (i.e., time rate of change) of the developed sinusoidal voltage fed thereto on line 85, as shown in FIG. 1. Thus, current is fed to one end of the precession coil 64 by processor 41 via line 86, and the other end (i.e., line 85) of precession coil 64 is connected to ground through resistor R 1 and to the inverting (-) input of the amplifier 90 through the capacitor C. The output of the cage coil 68 is coupled, through the inverter buffer amplifier 94, and the second resistor R 2 , to the inverting (-) input of amplifier 90, as shown. A third resistor R 3 provides a feedback resistor between the output and the inverting (-) input of the amplifier 90, as shown, to produce an output voltage proportional to the difference between the differentiated voltage and the induced voltage. Thus, resistor R 1 produces a voltage proportional to the current fed to the precession coil 64. The capacitor C produces a current proportional to the time rate of change in the current fed to precession coil 64 without adding any unwanted phase shift over a wide band of frequencies. As noted above, this change in the current fed to precession coil 64 induces an undesired voltage in the adjacent cage coil 68. The undesired portion of the voltage induced in cage coil 68 (that induced by the time rate of change in current fed to the precession coil 64) is subtracted from the total voltage induced in cage coil 68. In particular, a current proportional to the undesired portion of the cage coil 68 voltage is produced at the output of capacitor C and is subtracted from the current in resistor R 2 proportional to the total induced voltage in the cage coil 68 by the inverting buffer amplifier 94 so that the output of amplifier 90 (on line 91) represents the desired voltage induced in cage coil 68 (i.e., the voltage attributed to the position of the permanent magnet 61, FIG. 8B, from missile's center line 38). That is, the magnitude of the voltage produced by amplifier 90 is equal to the voltage induced in the cage coil 68 because of the magnitude of the angular deviation of the axis of rotation 37 relative to the missile's center line 38 and also, has a phase angle, relative to the voltage induced in the reference coil 66a, which, when phase detected, provides and angle α.
Finally, it should be noted that each one of the detectors 42 1 -42 10 covers a different portion of the field of view of the seeker system 16. The field of view is proportional to the sum of twice the scan circle radius R and the distance between any two opposite detectors, twice R D in each set 44 1 , 44 2 , 44 3 .
Having described a preferred embodiment of the invention, other embodiments incorporating these concepts will now become evident to one of skill in the art. For example, the number of detectors may be different from the 10 detectors described herein. Therefore, it is felt that the invention should not be restricted to its disclosed embodiment but rather, should limited only by the spirit and scope of the appended claims. | A seeker having a gyroscopic spin stabilized optical arrangement adapted to gimbal relative to a body in response to a current fed to a precession coil by a processor. Gimballing action of such optical arrangement within the body is measured by a voltage induced in a cage coil. The precession coil and cage coil are mounted adjacent to each other. The seeker includes a cage coil compensator comprising a differencing network and a differentiator. Changes in the current fed to the precession coil induces unwanted voltage in the adjacent cage coil. The differentiator is fed by the current in the precession coil to produce a voltage related to the rate of change in the current in the precession coil and hence, related to the undesired voltage induced in the cage coil. The differencing network is fed by the voltage produced by the differentiator and the total voltage induced in the cage coil to subtract from such total voltage the undesired portion thereof induced therein by the adjacent precession coil. With such arrangement, cancellation of the undesired voltage induced in the cage coil is provided by an electronic circuit thereby eliminating the requirement of an additional caging cancellation coil. | 5 |
BACKGROUND OF THE INVENVTION
[0001] 1. Field of the Invention
[0002] Embodiments of the invention relate generally to photographic lighting systems, and more specifically to systems and methods for controlling color balance for a photographic illuminator.
[0003] 2. Description of the Related Art
[0004] Photographic recording conventionally involves projecting a scene image through a lens assembly onto a sampling surface. The scene image represents a section of a scene, as projected and focused by the lens assembly. The sampling surface may be a frame of photographic film or an electronic image sensor configured to sample the scene image for electronic storage. The scene image may be stored as a two-dimensional field of chemical state in the frame of photographic film or as electronic state in a digital memory subsystem. The process of sampling ultimately produces a photographic image representing the scene image. Sampling period (shutter speed), lens aperture, and sampling sensitivity (conventionally referred in terms of an “ISO” index of sensitivity) determine overall image exposure. Proper exposure for the photographic image is based on attempting to emulate natural human visual perception, which is highly adaptive over a large dynamic range. Human visual perception is highly efficient at maximizing perceived tonal balance, and therefore a properly exposed photographic image exhibits good tonal balance. Modern digital cameras can generally achieve good tonal balance and proper exposure in recording photographic images.
[0005] In certain scenarios, ambient lighting within a scene is inadequate to produce a properly exposed photographic image of the scene or certain subject matter within the scene. In certain other scenarios, an additional light source from one or more directions may aesthetically improve or highlight certain aspects of a subject being photographed within the scene. In one example scenario, a photographer may wish to photograph a person (subject) at night in a setting that is inadequately illuminated by incandescent or fluorescent lamps. A photographic strobe may be used to beneficially provide additional light on the subject to achieve a desired exposure, however the color balance (ratios of red, green, and blue light) of the strobe will not match that of the ambient incandescent or fluorescent lighting.
[0006] Human visual perception also dynamically adapts to ambient illumination color to enable proper perception of color despite off-white ambient illumination. For example, a white sheet of paper is commonly perceived as being white regardless of whether the paper is illuminated by inherently white sunlight or inherently orange candlelight. A modern digital camera is typically configured to be able to compensate for ambient illumination color in order to reproduce overall correct colors for the scene. In this way, the camera attempts to emulate human visual perception with respect to white balance. Alternatively, white balance of a digital photograph may be achieved via post processing. Persons skilled in the art will recognize that color balance for a photographic image is conventionally accomplished by modifying channel gain for each one of red, green, and blue color channels over the entire photographic image to compensate for overall scene color.
[0007] One challenge of color photography is that a given scene may have multiple different light sources, each characterized by different color balances. In such a scene, achieving white balance that appears correct can be quite difficult. For example, an incandescent lamp is characterized as emitting significantly more red light than blue light, while a conventional Xenon photographic strobe emits a relatively even mix of red, green, and blue light. If the digital camera uses a color balance based on ambient incandescent or sunset lighting, then objects predominantly illuminated by the ambient lighting will be properly color balanced, while objects that are predominantly illuminated by the strobe will appear overly blue. Alternatively, if the camera assumes a color balance corresponding to the strobe color balance, then objects that are predominantly illuminated by ambient lighting will appear overly red. Because the Xenon photographic strobe produces an inherently different balance of light compared to the ambient light, achieving a realistic white balance is oftentimes impractical while photographing such scenes.
[0008] As the foregoing illustrates, what is needed in the art is a technique for properly illuminating a scene according to existing ambient color balance.
SUMMARY OF THE INVENTION
[0009] One embodiment of the present invention sets forth a method for generating color illumination having a target color balance, the method comprising the steps of determining the target color balance, generating a transmission factor for each color channel of a plurality of color channels within an active color filter based on the target color balance and color characteristics of an illumination source, and activating each color channel of a plurality of color channels based on the corresponding transmission factor to transmit illumination having the target color balance.
[0010] Another embodiment of the present invention sets forth a system for generating color illumination having a target color balance, the system comprising an active color filter, configured to selectively transmit different color components of source illumination based on corresponding transmission factors, and a controller. The controller is configured to determine the target color balance, generate a transmission factor for each color channel of a plurality of color channels within the active color filter based on the target color balance and color characteristics of the source illumination, and to activate the active color filter using a control signal representing the transmission factors.
[0011] A further embodiment of the present invention sets forth a portable photographic system, the system comprising a digital camera subsystem configured to sample and store photographic images, a multi-spectral light source, configured to provide the source illumination when triggered by the digital camera subsystem, an active color filter, configured to selectively transmit different color components of the multi-spectral light source based on corresponding transmission factors, and a controller. The controller is configured to determine the target color balance, generate a transmission factor for each color channel of a plurality of color channels within the active color filter based on the target color balance and color characteristics of the multi-spectral light source, and to activate the active color filter using a control signal representing the transmission factors.
[0012] The present invention enables photographers to advantageously illuminate photographic scenes with appropriately color balanced light, resulting in higher quality, more natural looking photographs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0014] FIG. 1A illustrates a color compensated flash unit, according to one or more aspects of the present invention;
[0015] FIG. 1B illustrates a functional diagram of the color compensated flash unit of FIG. 1A , according to one embodiment of the present invention;
[0016] FIG. 2A illustrates a color compensation unit configured to attach to a separate flash unit, according to one embodiment of the present invention;
[0017] FIG. 2B illustrates the color compensation unit attached to the separate flash unit, according to one embodiment of the present invention;
[0018] FIG. 2C illustrates a filter unit and control unit coupled to the separate flash unit, according to one embodiment of the present invention;
[0019] FIG. 2D illustrates a functional diagram of the color compensation unit, according to one embodiment of the present invention;
[0020] FIG. 3A illustrates a digital camera configured to implement one or more aspects of the present invention;
[0021] FIG. 3B illustrates a side detail of the digital camera, according to one embodiment of the present invention;
[0022] FIG. 3C illustrates a functional diagram of a color compensated flash module within the digital camera, according to one embodiment of the present invention;
[0023] FIG. 3D illustrates a front view of a mobile wireless device configured to implement one or more aspects of the present invention;
[0024] FIG. 3E illustrates a functional diagram of the mobile wireless device, according to one embodiment of the present invention;
[0025] FIG. 4A illustrates a detailed view of an active color filter, according to one embodiment of the present invention;
[0026] FIG. 4B depicts a side view of a pixel array, according to one embodiment of the present invention;
[0027] FIG. 4C depicts a response curve of light transmission as a function of applied voltage for a cell within the pixel array, according to one embodiment of the present invention;
[0028] FIG. 5A illustrates the pixel array configured to include color filters for red, green, and blue, according to one embodiment of the present invention;
[0029] FIG. 5B illustrates the pixel array configured to include color filters for red, green, blue, cyan, magenta, and yellow according to one embodiment of the present invention;
[0030] FIG. 5C illustrates the pixel array configured to include color filters for red, green, blue, cyan, magenta, and yellow according to an alternative embodiment of the present invention;
[0031] FIG. 5D illustrates the pixel array configured to include color filters for cyan, magenta, yellow, and white according to one embodiment of the present invention
[0032] FIG. 5E depicts an ideal band pass color filter as a function of wavelength (λ), and centered at λ 0 ;
[0033] FIG. 5F depicts a typical physical realization of a band pass color filter as a function of wavelength (λ), and centered at λ 0 ;
[0034] FIG. 6 illustrates a technique for controlling multiple levels of transmission within the active color filter, according to one embodiment of the present invention;
[0035] FIG. 7 is a conceptual diagram of a color compensated flash unit comprising functional blocks for measuring ambient color balance and filtering a multi-spectral light signal to generate a controlled illumination signal based on ambient color balance, according to one embodiment of the present invention;
[0036] FIG. 8A is a flow diagram of method steps for generating controlled illumination based on measured ambient color, according to one embodiment of the present invention;
[0037] FIG. 8B is a flow diagram of method steps for generating controlled illumination based on a specified color balance, according to one embodiment of the present invention.
DETAILED DESCRIPTION
[0038] FIG. 1A illustrates a color compensated flash unit 100 , according to one embodiment of the present invention. The color compensated flash unit 100 comprises an active color filter 120 , an emitter lens 122 , a light source 166 , an ambient sampling lens 138 , and an attachment module 170 .
[0039] The active color filter 120 is configured to selectively pass different wavelengths of visible light, based on a set of one or more electronic control signals. The active color filter 120 is disposed between the light source 166 and the emitter lens 122 . Light emitted by the light source 166 passes through the active color filter 120 and then through the emitter lens 122 to be emitted as controlled illumination 123 . A reflector 168 may be configured to direct light emitted from the light source 166 towards the active color filter 120 .
[0040] The ambient sampling lens 138 is configured to receive and diffuse ambient light to yield an optical signal that is representative of ambient lighting for a particular setting. Ambient light may be represented as ratios among red, green, and blue ambient light intensity. Ambient light may also be represented as having a color temperature, according to the industry standard color temperature Kelvin scale. The optical signal is sampled by a color measurement apparatus, described in greater detail below.
[0041] The attachment module 170 is configured to mechanically couple the color compensated flash unit 100 to a host device, such as a camera, a stand apparatus such as a tripod, or any other device or base. The attachment module 170 is also configured to transmit signals between the color compensated flash unit 100 and the host device. In one embodiment, the transmitted signals comprise electrical signals. In an alternative embodiment, the transmitted signals comprise electromagnetic signals. In another alternative embodiment, the transmitted signals comprise magnetic signals. In yet another alternative embodiment, the transmitted signals comprise mechanical signals. Certain of the signals may be configured to transmit commands, such as a strobe trigger command, a target strobe intensity, or a target strobe color. Persons skilled in the art will recognize that certain commands, such as a strobe trigger, are transmitted from a prior art camera to a prior art flash unit. However, prior art flash systems are not configured to receive target strobe color information. In one embodiment of the present invention, a target strobe color is transmitted to the color compensated flash unit 100 . In an alternative embodiment, a measured ambient color is sampled by the color compensated flash unit 100 and transmitted to the host device.
[0042] In one embodiment, the attachment module 170 comprises a strobe “hot shoe,” the light source 166 comprises a Xenon flash tube, and the active color filter 120 comprises a liquid crystal array manufactured to include a plurality of color cells with individual light transmission characteristics controlled by the one or more electronic control signals. The emitter lens 122 comprises a Fresnel lens configured to control dispersal of the controlled illumination 123 .
[0043] FIG. 1B is a functional diagram of the color compensated flash unit 100 of FIG. 1A , according to one embodiment of the present invention. Functional elements of the color compensated flash unit 100 comprise the emitter lens 122 of FIG. 1A , the active color filter 120 , the light source 166 , a light source driver 164 , a flash controller 160 , a filter driver 114 , and a color controller 110 . In certain embodiments, the color compensated flash unit 100 further comprises the ambient sampling lens 138 , an ambient color sensor 136 , a color receiver 130 , user input/output (I/O) circuitry 140 , a battery 152 , and a power controller 150 .
[0044] The light source 166 is configured to generate multi-spectral visible light, including component wavelengths of red, green and blue light. Persons skilled in the art will understand that visible light is descriptive of a range of light wavelengths spanning approximately 700 nm to 380 nm, with each color of light approximately correlated to human perception of color. Humans perceive light color according to a perception of red, green, and blue components, with a perceptive peak of red at approximately 580-620 nm, a perceptive peak of green at 535-565 nm, and a perceptive peak of blue at approximately 440-460 nm. Some individuals may perceive color slightly differently than others, however there are standard color models in the art and the meaning of red, green, and blue components is commonly accepted.
[0045] The active color filter 120 is configured to selectively pass different component colors of light generated by the light source 166 , based on transmission factors transmitted in a filter control signal 116 . Each transmission factor characterizes a ratio of light passed through an element of the active color filter 120 versus an amount of light made available to the element. Each color component is optically transmitted through the active color filter 120 , according to a corresponding transmission factor. The active color filter 120 includes a plurality of color filter elements, each configured to respond to an associated transmission factor. The color filter elements are described in greater detail below in FIGS. 4-6 . Each color filter element is configured to pass one or more color components of light. For example, one color filter element may be configured to primarily pass red light, with significant attenuation of green and blue light. A second color filter element may be configured to primarily pass green light, with significant attenuation of red and green light. A third color filter element may be configured to primarily pass yellow light, with significant attenuation of blue light, and so forth.
[0046] The active color filter 120 may employ any technically feasible technique for implementing a transmission factor for associated color components. In one embodiment, a three color (red, green, blue), multi-level liquid crystal array of pixels implements the active color filter 120 . Each red, green, and blue pixel is driven to an appropriate value for a transmission factor to produce an overall light color that is suitable for a particular setting. The overall light color may be selected based on an ambient light color measurement for the setting.
[0047] The emitter lens 122 may be configured to produce a specific dispersal pattern for the controlled illumination 123 . In one embodiment, the active color filter 120 is configured to be an integral component of the color compensated flash unit 100 . In this embodiment, the active color filter 120 is fixed in position relative to the light source 166 . In another embodiment, the active color filter 120 is configured to be movably disposed relative to the light source 166 . In this embodiment, the active color filter 120 may be removed from or inserted into an optical path from the light source 166 to the controlled illumination 123 . For example, the active color filter 120 may be mounted on a movable slide bearing, allowing the active color filter 120 to be positioned either in the optical path or not in the optical path. In yet another embodiment, the active color filter 120 may be detached from and reattached to the body of the color compensated flash unit 100 ; the emitter lens 122 may also be detached and reattached as part of a module comprising the active color filter 120 and the emitter lens 122 .
[0048] The light source driver 164 generates electrical signals used to activate the light source 166 . In one embodiment, the light source 166 is a Xenon flash tube, and the light source driver 164 is configured to generate a drive voltage and a trigger voltage for the Xenon flash tube. The drive voltage is typically over two hundred volts and the trigger voltage is typically in a range of several thousand volts. The drive voltage is typically supplied by a capacitor and is applied at each end of the Xenon flash tube prior to activation. A trigger voltage is applied at an offset from one end, causing the tube to be activated and to generate light. The Xenon flash tube may be extinguished by turning off the drive voltage. Activating and extinguishing the Xenon flash tube each typically take less than a millisecond. In an alternative embodiment, the light source 166 comprises at least one multi-spectral light emitting diode (LED), such as a phosphor-based white LED, and the light source driver 164 is configured to generate a driver current to activate the at least one LED. Removing the drive current extinguishes the at least one LED.
[0049] The flash controller 160 is configured to receive a host flash control signal 173 and to generate a light source control signal 162 . The host flash control signal 173 may include any number of individual electrical or optical signals and may carry any technically feasible flash control protocol without departing the scope and spirit of the present invention. A simple, exemplary hot-shoe flash control protocol includes three electrical wires corresponding to a neutral (ground), a flash trigger, and a flash extinguish signal. When the flash trigger signal is driven by a host camera, the flash controller 160 causes the light source driver 164 to activate the light source 166 . When the flash extinguish signal is driven by the host camera, the flash controller 160 causes the light source driver 164 to extinguish the light source 166 . The flash trigger signal is driven in response to a shutter release event within the camera, and the extinguish signal is driven separately upon accumulation of sufficient light exposure. Conventional flash control protocols presently implement bidirectional communication between a flash unit and a camera, and enable sophisticated flash features beyond simply triggering and extinguishing the flash. In one embodiment, the host flash control signal 173 implements a conventional hot-shoe flash control protocol and the flash controller 160 is configured to communicate with the host device via the flash control protocol. The flash controller 160 may also transmit flash status information via internal flash control signal 113 and receive flash commands from the color controller 110 via internal flash control signal 113 . The status information may include flash readiness. The internal flash control signal 113 may transmit flash commands including flash trigger and flash extinguish commands.
[0050] Ambient light 139 enters the ambient sampling lens 138 and is therein filtered to produce a representative color for the ambient light 139 . The representative color is optically transmitted to the ambient color sensor 136 . The ambient color sensor 136 is configured to generate an electrical ambient color signal 132 corresponding to the representative color. The electrical ambient color signal 132 includes a color component value for each color component sensed by the ambient color sensor 136 . Any technically feasible technique may be used to represent each color component value without departing the scope and spirit of the present invention. For example, an analog voltage or current value may be used to represent a color component value. Furthermore, the analog voltage or current may comprise a linear representation, a logarithmic representation, or any other technically feasible representation. Alternatively, each color component value may be represented by a corresponding digital signal. In one embodiment, the ambient color sensor 136 is configured to sense red, green and blue color components and to generate the electrical ambient color signal 132 comprising independent color component values for red, green, and blue.
[0051] The color receiver 130 is configured to receive the electrical ambient color signal 132 and to generate a corresponding digital ambient color signal 134 . For embodiments implementing an analog representation of the electrical ambient color signal 132 , the color receiver 130 may provide amplification, current to voltage conversion, voltage to current conversion, linear to logarithmic conversion, logarithmic to linear conversion, analog-to-digital (AD) conversion, or any technically feasible combinMion thereof to generate the digital ambient color signal 134 . Furthermore, the color receiver 130 may be configured to implement any non-linearity or mapping function. Any technically feasible technique may be used to implement the digital ambient color signal 134 .
[0052] The color controller 110 is configured to receive the digital ambient color signal 134 , a host control signal 175 , or any combination thereof, and to generate a color control signal 112 . The filter driver 114 receives the color control signal 112 and generates the filter control signal 116 . In one embodiment, the filter driver 114 comprises a voltage translation amplifier for driving liquid crystal cells, and the active color filter 120 comprises a liquid crystal array with a plurality of independently controlled color cells. The color controller 110 computes the color control signal 112 based on the digital ambient color signal 134 . In certain embodiments, the color controller 110 accounts for spectral emission characteristics of the light source 166 and transmission characteristics of the active color filter 120 . For example, the light source 166 may generate a certain magnitude of light for red, green, and blue light, and the active color filter 120 is characterized as having an independent transmission factor for each of red, green, and blue light based on corresponding color control signals 112 . In this example, the color controller 110 can generate color control signals 112 to produce a ratio of red, green, and blue light within the controlled illumination 123 that preserves the ratio of red, green, and blue ambient light sensed by the ambient color sensor 136 .
[0053] In one embodiment, an N-bit binary integer is used to represent each transmission factor, with integer value 0 indicating minimum transmission, and an integer value of 2̂N−1 indicating maximum transmission. For an 8-bit value, N is equal to 8 and 2̂N−1 is equal to 255. Persons skilled in the art will understand that any technique for encoding and transmitting a transmission factor may be implemented without departing the scope and spirit of the present invention.
[0054] In one embodiment, the color controller 110 implements an index table for each of red, green, and blue to map an ambient light level of each color component to a corresponding component of the color control signal 112 . For example, if the digital ambient color signal 134 comprises eight bits per color component (red, green, blue), and the color control signal 112 comprises eight bits per color component, then the color controller 110 would implement three index tables that each map eight bits to eight bits. The three index tables can be configured to account for arbitrary nonlinearities within the ambient sampling lens 138 , ambient color sensor 136 , color receiver 130 , filter driver 114 , active color filter 120 , as well as color balance variations in the light source 166 . In this way, the entire system may be calibrated based on three tables. The tables may additionally account for temperature effects, which may impact system components in varying amounts. Furthermore, the tables may additionally account for component colors being transmitted through other color filters. For example, a table configured to determine a red transmission factor for the active color filter 120 may be primarily based on relative red ambient intensity, but the table may also account for red transmission through green and blue filters by including at least a portion of the ambient components for green and blue as index values for the table.
[0055] In certain embodiments, the color receiver 130 implements sensor calibration tables or calibration parameters to map the analog representation of the electrical ambient color signal 132 to a standard set of intensity values represented in the digital ambient color signal 134 . The sensor calibration tables (or parameters) are configured to map the analog representation of the electrical ambient color signal 132 to an appropriately calibrated value for the digital ambient color signal 134 . The sensor calibration tables (or parameters) account for nonlinearities within the ambient sampling lens 138 , ambient color sensor 136 , and analog portions of the color receiver 130 . The color controller 110 implements a separate set of emission calibration tables for generating the color control signal 112 , comprising a color channel for each color component. In such embodiments, each color channel is processed via two tables, and the digital ambient color signal 134 represents a standard color representation that relates sensed ambient color balance to target color balance for the controlled illumination 123 . Any self-consistent standard color representation may be used without departing the scope and spirit of the present invention. In certain embodiments or modes of operation, the host control signal 175 transmits a target color balance for the controlled illumination 123 , in accordance with the standard color representation associated with the digital ambient color signal 134 . In such embodiments, a host device, such as a digital camera, performs an ambient color balance measurement and transmits results of the ambient color balance measurement to the color controller 110 via the host control signal 175 . Alternatively, the host control signal 175 is configured to transmit an ambient color balance measurement performed by the color compensated flash unit 100 to the host device. The host device may then use or record the ambient color balance measurement.
[0056] In one embodiment, user I/O circuitry 140 provides user input devices such as buttons and user output devices such as light-emitting diode (LED) indicators, an LCD display, and the like. In particular, the user I/O circuitry 140 may provide an on/off control, means for setting color temperature on the standard Kelvin scale, means for setting ratios of red to green to blue component intensities, or any combination thereof to produce a corresponding controlled illumination 123 . Furthermore, the user I/O circuitry 140 may be configured to display measured ambient color temperature, measured ambient intensities or ratios of red, green, and blue color components, or any combination thereof.
[0057] The battery 152 may comprise a replaceable rechargeable battery, a fixed rechargeable battery, or replaceable primary battery. Any battery chemistry may be implemented without departing the scope of the present invention. Alternatively, a super capacitor may implemented in place of or in combination with the battery 152 . Power controller 150 provides charging circuitry, as well as power management and voltage conversion and regulation functions, according to specific implementation requirements. Persons skilled in the art will understand that the power controller 150 may implement various power management techniques, according to requirements for a specific embodiment. Power signals 171 may be used to transmit power from the power controller 150 to an external device, or receive power from an external device. Power signals 171 may also convey power status between devices.
[0058] FIG. 2A illustrates a color compensation unit 200 configured to attach to a separate flash unit, according to one embodiment of the present invention. The color compensation unit 200 includes active color filter 120 of FIG. 1B , a mechanical opening 210 , and a coupling 212 . The color compensation unit 200 may also include emitter lens 122 . The mechanical opening 210 is configured to encompass an optical output port of the separate flash unit. The coupling 212 may comprise a mechanical latch, a friction fitting, a magnetic latch, a magnetic signal connector, an optical signal connector, an electrical signal connector, a mechanical signal connector, or any combination thereof.
[0059] The separate flash unit (not shown) emits strobe illumination 211 , which passes through the mechanical opening 210 . The strobe illumination 211 is subsequently filtered by the active color filter 120 to yield controlled illumination 123 . In one embodiment, the controlled illumination 123 is passed through emitter lens 122 .
[0060] FIG. 2B illustrates the color compensation unit 200 of FIG. 2A attached to separate flash unit 202 , according to one embodiment of the present invention. The mechanical opening 210 is configured to receive strobe illumination 211 generated by the flash unit 202 and transmit the strobe illumination 211 to the active color filter 120 . The active color filter 120 filters the strobe illumination 211 to generate controlled illumination 123 . Coupling 212 (shown in FIG. 2A ) is configured to attach the color compensation unit 200 to the flash unit 202 . The coupling 212 may attach using friction, magnetic attraction, a mechanical structure such as a latch, or any other technically feasible attachment means. The color compensation unit 200 may also include emitter lens 122 .
[0061] The flash unit 202 may include an attachment module 170 , configured to mechanically couple the flash 202 unit to a host device, such as a camera, a stand apparatus such as a tripod, or any other appropriately configured device or base. The attachment module 170 may be configured to transmit signals to the flash unit 202 , for example, to trigger the flash unit 202 to generate the strobe illumination 211 . The attachment module 170 may also be configured to transmit signals to the color compensation unit 200 via the flash unit 202 . For example, a camera, coupled to the attachment module 170 , may transmit an activation signal to the color compensation unit 200 via the attachment module 170 and flash unit 202 . Any technically feasible signal may be used as an activation signal, including signals comprising electrical, electromagnetic, magnetic, or mechanical energy.
[0062] In one embodiment, the color compensation unit 200 is configured to measure ambient color and transmit results of the ambient color measurement via the coupling 212 to the flash unit 202 , which further transmits the results via the attachment module 170 . An attached camera or related device may receive the ambient color measurement. The ambient color measurement includes red, green, and blue color components. The ambient color measurement may be taken through ambient sampling lens 138 (not shown), using ambient color circuitry described in FIG. 1B and comprising ambient color sensor 136 and color receiver 130 .
[0063] In one embodiment, color compensation unit 200 includes an electrical power source, such as a battery. In an alternative embodiment, the color compensation unit 200 draws electrical power from the flash unit 202 , for example via an electrical connector within the coupling 212 .
[0064] FIG. 2C illustrates a filter unit 203 and control unit 204 coupled to the separate flash unit 202 , according to one embodiment of the present invention. The filter unit 203 and control unit 204 collectively implement color compensation unit 200 of FIG. 2B . Specifically, the filter unit 203 includes active color filter 120 and mechanical opening 210 , and control unit 204 implements control and measurement functions of color compensation unit 200 .
[0065] In one embodiment, control signals are transmitted from the control unit 204 to the filter unit 203 via control cable 205 . Control cable 205 may include at least one connector (not shown) used to couple the control cable 205 to the control unit 204 , the filter unit 203 , or both units. In one alternative embodiment, control signals are transmitted from the control unit 204 to the filter unit 203 via a signal path within the flash unit 202 . In another alternative embodiment, control signals are transmitted from the control unit 204 to the filter unit 203 via electromagnetic signaling, such as a radio-frequency signal or an optical signal path. Control unit 204 may include ambient sampling lens 138 and an ambient color measurement circuit comprising ambient color sensor 136 and color receiver 130 , as described previously in FIG. 1B .
[0066] In one embodiment, the ambient color measurement circuit transmits ambient color measurement results via attachment module 170 to an attached host device, such as a camera. In alternative embodiments, the ambient color measurement circuit transmits results to a host device via a radio signal, infra-red signal, or any other technically feasible data carrying signal. The ambient color measurement circuit may also transmit ambient color measurement results to control units 204 coupled to other flash units 202 .
[0067] FIG. 2D is a functional diagram of the color compensation unit 200 , according to one embodiment of the present invention. As shown, the color compensation unit 200 comprises a filter unit 203 and a control unit 204 . The filter unit 203 comprises active color filter 120 and mechanical opening 210 . The filter unit 203 may include filter driver 114 , input lens 124 , and emitter lens 122 . As shown, strobe illumination 211 enters the mechanical opening 210 and is filtered by the active color filter 120 to generate controlled illumination 123 . Strobe illumination 211 may also pass through input lens 124 . Controlled illumination 123 may also pass through emitter lens 122 .
[0068] In one embodiment, color control signal 112 is transmitted via control cable 205 to the filter driver 114 . The filter driver 114 generates filter control signal 116 , which activates active color filter 120 to filter strobe illumination 211 into controlled illumination 123 . In an alternative embodiment, filter driver 114 is disposed within the control unit 204 .
[0069] Control unit 204 includes color controller 110 , which is configured to generate color control signal 112 based on a target ambient color balance. Control unit 204 may also include ambient color sensor 136 , color receiver 130 , user I/O circuitry 140 , described previously. In one embodiment, control unit 204 also includes battery 152 and power controller 150 , configured to receive electrical energy from battery 152 and to generate one or more voltage supplies for the control unit 204 . The power controller 150 may also generate voltage supplies for the filter unit 203 . In one embodiment, power controller 150 is configured to report battery charge level associated with battery 152 to a host device via attachment module 170 .
[0070] In one embodiment, color controller 110 transmits ambient color information, such as color balance measured for ambient light 139 via ambient sampling lens 138 and ambient color sensor 136 , to the host device via attachment module 170 . Battery charge level may be transmitted via a battery charge signal 271 , while ambient color information may be transmitted via a color signal 277 . Similarly, the host device may transmit color control information to the color controller 110 via color signal 277 . Persons skilled in the art will understand that different techniques may be used to transmit color information from the color controller 110 to the host device, and from the host device to the color controller 110 . Furthermore, the host device may be a digital camera, or any other device configured to be coupled to attachment module 170 .
[0071] FIG. 3A illustrates a digital camera 300 configured to implement one or more aspects of the present invention. The digital camera 300 includes an image lens 366 , a shutter release button 364 , an image sensor (not shown) disposed behind the image lens 366 , a light source (not shown), and image processing and storage circuitry (not shown). The digital camera 300 includes active color filter 120 of FIG. 1B disposed in front of the light source, as illustrated in greater detail below in FIG. 3B . The digital camera 300 may also include emitter lens 122 . In one embodiment, the digital camera 300 includes an image lens cover 368 configured to cover and protect the image lens 366 , for example when the digital camera 300 is turned off. The image lens cover 368 is also configured to uncover the image lens 366 when a user wishes to take a photograph with the digital camera 300 .
[0072] FIG. 3B illustrates a side detail of the digital camera 300 , according to one embodiment of the present invention. Light source 166 of FIG. 1B generates strobe illumination, which is filtered by active color filter 120 to generate controlled illumination 123 . The controlled illumination 123 may be used to illuminate a photographic subject or enhance illumination for the photographic subject. Reflector 168 directs light from the light source 166 to the active color filter 120 .
[0073] In one embodiment, the active color filter 120 is mounted in a fixed position between the light source 166 and a photographic subject (via emitter lens 122 ). In an alternative embodiment, the active color filter 120 is movably mounted so that it may be substantially removed from optical paths leading from the light source 166 to the photographic subject. For example, the active color filter 120 may be slid out of the optical paths, allowing unfiltered light from the light source 166 to be used to illuminate the photographic subject. The emitter lens 122 may remain in the optical paths between the light source 166 and the photographic subject.
[0074] In one embodiment, the digital camera 300 is configured to generate a photograph and to display the photograph on a display module 350 , such as a liquid crystal display (LCD) screen. The camera may also present user interface objects on the display module 350 . Importantly, the digital camera 300 generates a strobe of controlled illumination 123 that is filtered via active color filter 120 to conform to a color balance of ambient scene illumination for the photograph. In this way, the photograph is sampled with consistently colored illumination for a realistic, consistent appearance.
[0075] FIG. 3C illustrates a functional diagram of a color compensated flash module 302 within the digital camera 300 , according to one embodiment of the present invention. The digital camera 300 comprises the color compensated flash module 302 and a digital image module 304 .
[0076] The color compensated flash module 302 comprises system elements, including active color filter 120 of FIG. 1B , light source 166 , light source driver 164 , flash controller 160 , color controller 110 , and filter driver 114 , each described previously in FIG. 1B . The color compensated flash module 302 may further comprise reflector 168 and emitter lens 122 . As described previously in FIG. 1B , the system elements are configured to generate controlled illumination 123 , characterized as having red, green, and blue color components having a color balance determined by a target color balance. The target color balance may be determined by measuring ambient color balance.
[0077] In one embodiment, the target color (white) balance is determined by digital image module 304 using any technically feasible technique and transmitted to the color controller 110 via host control signal 175 . The color controller 110 generates color control signal 112 from the target color balance. In an alternative embodiment, the ambient sampling lens 138 , ambient color sensor 136 , and color receiver 130 of FIG. 1B are also included within the digital camera 300 and are configured to sample ambient color balance for a scene being photographed by the digital camera 300 . The target color balance for the color compensated flash module 302 is computed from the sampled ambient color balance by color controller 110 , which may also transmit the target color balance to the digital image module 304 .
[0078] The digital image module 304 includes an electro-optical module 330 , a processing unit 320 , data storage unit 340 , a display module 350 , and input devices 344 . The electro-optical module 330 comprises image lens 366 , and image sensor 332 . The electro-optical module 330 may also comprise focusing apparatus for focusing the image lens 366 with respect to the image sensor 332 . The electro-optical module 330 may also include an iris mechanism for controlling an optical aperture for the image lens 366 . The image lens cover 368 is configured to cover and protect the image lens 366 in one mechanical position, and uncover and expose the image lens cover 368 in a second mechanical position.
[0079] Optical scene information 331 is focused by the image lens 366 onto image sensor 332 , which converts focused optical scene information comprising a focused image into an electrical representation of the focused image. The image sensor 332 is configured via image sensor interconnect 334 . The focused image is sampled according to certain parameters, such as sensor gain and sample timing. The electrical representation of the focused image is transmitted via image sensor interconnect 334 to the processing unit 320 , which formats the electrical representation of the focused image into a digital photograph for storage within data storage unit 340 . Persons skilled in the art will recognize that different digital image storage formats may be used for storing the digital photograph. An electro-optical control interconnect 338 is configured to control mechanical focus and aperture actuators within the electro-optical module 330 .
[0080] The processing unit 320 is configured to process and store image data from the image sensor 332 . The processing unit 320 is configured to transmit image data for a given digital photograph to the data storage unit 340 via storage interconnect 342 . The processing unit 320 is also configured to retrieve image data from the data storage unit 340 via the storage interconnect 342 for display on the display module 350 . The processing unit 320 is configured to transmit display data to the display module 350 via display interconnect 352 . The processing unit 320 is also configured to receive user commands from input devices 344 via input device signals 346 . The commands may include, for example, user interface inputs, shutter release button events, and the like.
[0081] The digital camera 300 includes a power management unit 356 and a battery 354 . The battery may be a fixed battery or a replaceable battery. The replaceable battery may be a primary battery or a rechargeable battery. In one embodiment, the battery 354 comprises a set of replaceable industry standard “AA” primary or rechargeable cells. The power management unit 356 is configured to receive electrical energy from the battery 354 and to generate voltage supplies for use by the digital image module 304 and the color compensated flash module 302 .
[0082] In one embodiment, the target color balance is computed from the electrical representation of the focused image. The optical scene information 331 is focused by the image lens 366 onto image sensor 332 , which generates the focused image having a particular red, green, and blue white balance. The focused image represents a specific region of a corresponding scene being photographed, and does not necessarily represent overall color balance for the scene.
[0083] In another embodiment, the image lens cover 368 is manufactured to be optically neutral and translucent. The image lens cover 368 is configured to transmit at least one sixteenth of all incident light comprising the optical scene information 331 . The image lens cover 368 is configured to receive and diffuse ambient light to yield an optical signal that is representative of ambient color balance for a particular setting. The optical signal is sampled by the image sensor 332 as an unfocused substantially even two-dimensional signal that is representative of the overall color balance for the scene. In this embodiment, the image lens cover 368 and image lens 366 collectively function as ambient sampling lens 138 of FIG. 1B . The image sensor 332 functions as ambient color sensor 136 and color receiver 130 . To sample color balance in a given scene, the digital camera 300 closes the image lens cover 368 so that only a diffuse, single color representation of the optical scene information 331 is transmitted to the image sensor 332 . The image sensor 332 then samples the single color representation to determine an overall color balance for a corresponding scene. This overall color balance corresponds to the target color balance transmitted to the color compensated flash module 302 . After the image sensor 332 samples the color balance of the scene, the image lens cover 368 is opened by the digital camera 300 to allow the optical scene information 331 to be focused on the image sensor 332 .
[0084] Several techniques have been described herein to sample an ambient color balance, however any technically feasible technique may be used to determine and represent the ambient color balance of a scene. Importantly, the ambient color balance determines the target color balance. As described previously, the color compensated flash module 302 is configured to generate controlled illumination 123 based on the target color balance.
[0085] FIG. 3D illustrates a front view of a mobile wireless device 370 configured to implement one or more aspects of the present invention. The mobile wireless device 370 includes a digital image module, such as digital image module 304 of FIG. 3C having image lens 366 . The mobile wireless device 370 also includes a color compensated flash module such as color compensated flash module 302 , configured to include light source 166 and active color filter 120 . The color compensated flash module 302 generates controlled illumination 123 . The mobile wireless device 370 may include an emitter lens 122 , configured to direct controlled illumination 123 to a photographic subject. The mobile wireless device 370 may comprise a cellular phone, an application platform, a music player, or any other computational or communications functionality.
[0086] FIG. 3E is a functional diagram of the mobile wireless device 370 , according to one embodiment of the present invention. As shown, the mobile wireless device 370 includes a wireless communications subsystem 372 , an application subsystem 374 , a digital image module 304 , a color compensated flash module 302 , a battery 376 , and a power management unit 378 .
[0087] As described previously in FIG. 3C , the digital image module 304 is configured to receive, focus, and sample optical information and to generate a digital photograph from the optical information. Color compensated flash module 302 is configured to generate controlled illumination 123 . The battery 376 may be a fixed battery or a replaceable battery. The replaceable battery may be a primary battery or a rechargeable battery. The power management unit 378 is configured to receive electrical energy from the battery 376 and to generate voltage supplies for use by the mobile wireless device 370 .
[0088] In one embodiment, the wireless communications subsystem 372 comprises a digital cellular telephone subsystem. The application subsystem 374 comprises a central processing unit, data storage, an operating system configured to facilitate execution of applications, and one or more applications configured to execute on the operating system.
[0089] During normal operation of the mobile wireless device 370 , a user may choose to take a photograph using mobile wireless device 370 . The user activates a camera application to execute on the application subsystem 374 . The camera application directs the digital image module 304 to take a photograph. The color compensated flash module 302 is triggered to generate a strobe comprising controlled illumination 123 . The photograph may be stored within the mobile wireless device 370 . The photograph may also be transmitted via the wireless communications subsystem 372 to an upstream server (not shown) or other users (not shown).
[0090] FIG. 4A illustrates a detailed view of an active color filter 400 , according to one embodiment of the present invention. In one embodiment, at least one instance of active color filter 400 implements active color filter 120 of FIG. 1B . Active color filter 400 includes a pixel array 402 , and pixel driver circuits, such as column drivers 404 and row drivers 406 . The column drivers 404 are controlled according to column data 414 and the row drivers 406 are controlled according to row data 416 . The column data 414 comprises intensity data for driving individual pixels P along a specified row of the pixel array 402 . The row data 416 comprises row selection information to specify a particular row of the pixel array 402 . The active color filter 400 is configured to accept power via VC 412 and GND 410 ports.
[0091] In one embodiment, pixels P include color filters. For example, each row of pixels P may comprise a repeating color filter pattern of red, green, and blue. In this example, pixels P(a,d), P(b,d), and P(c,d) would respectively include color filters of red, green, and blue.
[0092] FIG. 4B depicts a side view of a pixel array 402 , according to one embodiment of the present invention. As shown, the pixel array 402 comprises different structural layers, including a back polarizer 448 , a back substrate 446 , a layer of liquid crystal material 478 , column electrodes 470 - 474 , one or more row electrodes 444 , a front substrate 442 , a front polarizer 440 , and a filter layer 456 . Protective front and back layers (not shown) may also be incorporated to protect the filter layer 456 and back polarizer 448 , respectively.
[0093] In normal operation, randomly polarized light 460 from light source 166 of FIG. 1B passes through back polarizer 448 to yield polarized back light 462 . The polarized back light 462 passes through column electrodes 470 - 474 , the layer of liquid crystal material 478 , the one or more row electrodes 444 , and into the front substrate 442 to yield polarity modulated light 464 . At each intersection of one of the column electrodes 470 - 474 and one of the one or more row electrodes 444 , the layer of liquid crystal material 478 is able to rotate the polarity of traversing light. An electric potential applied between the column electrodes 470 - 474 and the one or more row electrodes 444 causes localized changes in polarization of the traversing light. The polarity modulated light 464 , therefore, comprises a two-dimensional region of light having a polarity corresponding to electric potentials between the column electrodes 470 - 474 and the one or more row electrodes 444 . The front polarizer 440 converts polarity modulated light 464 into intensity modulated light that passes through a set of color filters 450 within the filter layer 456 . The color filters 450 emit intensity modulated color light 466 . A group of color filters 450 -A through 450 -C collectively yield intensity modulated color light 468 , having individually modulated color components 466 -R, 466 -G, 466 -B. The intensity modulated color light 468 includes individually controlled red, green, and blue color intensity. In one embodiment, the intensity modulated color light 468 corresponds to controlled illumination 123 .
[0094] FIG. 4C depicts a response curve 484 of light transmission T 480 as a function of applied voltage Va 482 for a cell within the pixel array 402 of FIG. 4A , according to one embodiment of the present invention. The applied voltage Va 482 corresponds to the electric potential applied between one of the column electrodes 470 - 474 of FIG. 4B and one of the one or more row electrodes 444 . Light transmission T 480 refers to a total amount of light energy passing through a region of the pixel array 402 corresponding to an area of one pixel (intersection of one of the column electrodes 470 - 474 and one of the one or more row electrodes 444 ). As shown, approximately maximum light transmission occurs within a “dead band” 486 , centered about a zero applied voltage Va 482 . Increasing the applied voltage Va 482 decreases light transmission according to response curve 484 , which is typically non-linear. Conventional liquid crystal materials tend to degrade when the applied voltage Va 482 is maintained in consistent polarity. Therefore, polarity of the applied voltage Va 482 should be alternated, to produce positive and negative values of Va 482 .
[0095] Persons skilled in the art will recognize that any controlled transmission technology may be used to implement the pixel array 402 without departing the scope of the present invention. For example, bi-stable materials that can alternate between an opaque and clear state may be employed. Applied voltage Va 482 is then used to set a state that for a given pixel that generally persists until being set to a different state.
[0096] Different techniques may be used to generate different color components within the controlled illumination 123 . For example, applied voltage Va 482 may be used to select an overall light transmission factor for each color filter within the pixel array 402 . Alternatively, each pixel within pixel array 402 may be turned completely on or off independently to generate patterns for red, green, and blue pixels that, in aggregate, represent a target light transmission factor for each respective color. This concept is illustrated in greater detail below in FIG. 6 .
[0097] In an alternative embodiment, intensity modulation is implemented using selective reflection rather than polarization modulation converted to intensity modulation by a polarizer. For example, a micro-machine reflector array is used to selectively direct light through plural color filters to generate the controlled illumination 123 .
[0098] FIG. 5A illustrates the pixel array 510 configured to include color filters for red, green, and blue, according to one embodiment of the present invention. A pixel group 512 comprises one red cell (RED 3,1), one green cell (GREEN 4,1), and one blue cell (BLUE 5,1). In one embodiment, pixel array 510 corresponds to pixel array 402 of FIG. 4A , and each cell corresponds to one intersection of one of the column electrodes 470 - 474 of FIG. 4B , and one of the one or more row electrodes 444 .
[0099] FIG. 5B illustrates the pixel array 520 configured to include color filters for red, green, blue, cyan, magenta, and yellow according to one embodiment of the present invention. A pixel group 522 comprises one red cell (RED 0,1), one green cell (GREEN 1,1), one blue cell (BLUE 2,1), one cyan cell (CYAN 3,1), one magenta cell (MAGENTA 4,1), and one yellow cell (YELLOW 5,1). In one embodiment, pixel array 520 corresponds to pixel array 402 of FIG. 4A , and each cell corresponds to one intersection of one of the column electrodes 470 - 474 of FIG. 4B , and one of the one or more row electrodes 444 .
[0100] FIG. 5C illustrates the pixel array 530 configured to include color filters for red, green, blue, cyan, magenta, and yellow according to an alternative embodiment of the present invention. A pixel group 532 comprises one red cell (RED 0,0), one green cell (GREEN 1,0), one blue cell (BLUE 2,0), one cyan cell (CYAN 0,1), one magenta cell (MAGENTA 1,1), and one yellow cell (YELLOW 2,1). In one embodiment, pixel array 530 corresponds to pixel array 402 of FIG. 4A , and each cell corresponds to one intersection of one of the column electrodes 470 - 474 of FIG. 4B , and one of the one or more row electrodes 444 .
[0101] FIG. 5D illustrates the pixel array 540 configured to include color filters for cyan, magenta, yellow, and white according to one embodiment of the present invention. A pixel group 542 comprises one cyan cell (CYAN 0,0), one magenta cell (MAGENTA 1,0), one yellow cell (YELLOW 2,0), and one white cell (WHITE 3,0). In one embodiment, pixel array 540 corresponds to pixel array 402 of FIG. 4A , and each cell corresponds to one intersection of one of the column electrodes 470 - 474 of FIG. 4B , and one of the one or more row electrodes 444 .
[0102] FIGS. 5A-5D illustrate different techniques for organizing different color filters, with a goal of filtering multi-spectral light, such as from light source 166 of FIG. 1B and to generate controlled illumination 123 , having a specific color balance. FIGS. 5A-5D illustrate four examples of organizing color filters, however, persons skilled in the art will recognize that any organization of color filters structured to implement active color filter 120 is within the scope and spirit of the present invention.
[0103] FIG. 5E depicts an ideal band pass color filter as a function of wavelength (λ) 552 , and centered at λ 0 . As shown, light transmission 550 within window λ w is 1.0 (full transmission), while light transmission 550 outside the window λ w , is 0.0 (no transmission). In practice, however, a color filter exhibits non-ideal characteristics, as illustrated below in FIG. 5F .
[0104] FIG. 5F depicts a typical physical realization of a band pass color filter as a function of wavelength (λ) 552 , and centered at λ 0 . As shown, light transmission 550 within window λ w is greater than light transmission 550 outside the window λ w . For example, a physical implementation of a “red” color filter will actually have imperfect transmission of red light and have non-zero transmission for green and blue light.
[0105] While practical color filters do not exhibit ideal band pass characteristics, persons skilled in the art will recognize that such filters can implement satisfactory color filtering characteristics for the purpose of implementing active color filter 120 of FIG. 1B .
[0106] FIG. 6 illustrates a technique for controlling multiple levels of transmission within an active color filter, according to one embodiment of the present invention. A pixel set 610 includes a plurality of individual pixels having substantially identical color filters. Shaded pixels represent low light transmission, while light pixels represent high light transmission. By selecting which pixels are turned on or off, an aggregate light transmission can be achieved. This technique is advantageously not sensitive to particulars of non-linear response curves, such as response curve 484 of FIG. 4C . As shown, a binary code of [00000] yields minimal light transmission, while binary code [111111] yields maximum light transmission.
[0107] The pixel set 610 may be interleaved with similar pixel sets of other colors. For example, red, green, and blue pixels may be adjacently disposed, with the red pixels belonging to a red pixel set, the green pixels belonging to a green pixel set, and so forth. The pixel set 610 may also be contiguously disposed (as shown) to create a region of the same color having controlled intensity. A plurality of such regions may comprise active color filter 120 .
[0108] FIG. 7 is a conceptual diagram of a color compensated flash unit 700 comprising functional blocks for measuring ambient color balance and filtering a multi-spectral light signal 732 (D) to generate a controlled illumination signal 742 (E) based on ambient color balance, according to one embodiment of the present invention. The color compensated flash unit 700 comprises an ambient color measurement circuit 710 , a filter controller 720 , a light source 730 , and an active color filter 740 .
[0109] The ambient color measurement circuit 710 is configured to measure ambient light color balance from ambient light signal 712 (A) and to generate a digital ambient color signal 714 (B) based on the ambient light signal 712 (A) and a mapping function M AB . The ambient light signal 712 (A) represents an optical signal (A) comprising different color components, including red, green, and blue color components (A={A red , A green , A blue }). The digital ambient color signal 714 (B) is an electrical representation of the ambient light signal 712 (A). The digital ambient color signal 714 (B) may represent color components of the ambient light signal 712 (A) using any technically feasible technique. For example, one binary integer may be used to represent an intensity value for each color component, with a total of three binary integers used to represent red, green, and blue color components for the ambient light signal 712 (A). This may be expressed as B={B red , B green , B blue }, where each component B red , B green , B blue comprises one binary integer. In one embodiment, the components of B are normalized against a maximum component value (MAX{B red , B green , B blue }).
[0110] The mapping function M AB represents an abstraction of the operation of the ambient color measurement circuit 710 . The mapping function M AB may implement any technically feasible linear or nonlinear mapping from optical intensity to binary representation for the digital ambient color signal 714 (B). Persons skilled in the art will understand that any technique for measuring and representing ambient color may be implemented without departing the scope and spirit of the present invention.
[0111] In one embodiment, the ambient color measurement circuit 710 comprises ambient sampling lens 138 of FIG. 1B , ambient color sensor 136 , and color receiver 130 . Furthermore, ambient light signal 712 (A) corresponds to ambient light 139 , digital ambient color signal 714 (B) corresponds to digital ambient color signal 134 .
[0112] The filter controller 720 is configured to receive the digital ambient color signal 714 (B) and to generate filter control signal 722 (C). Any technically feasible mapping from the digital ambient color signal 714 (B) to the filter control signal 722 (C) may be implemented without departing the scope of the present invention. In one embodiment, the filter control signal 722 (C) comprises electrical signals, such as voltage or current signals, configured to control transmission of optical color components through the active color filter 740 . For example, the filter control signal 722 (C) may comprise voltage signals for driving a liquid crystal array, which selectively transmits red, green, and blue color components based on the filter control signal 722 (C). The filter controller 720 performs a mapping function M BC from digital ambient color signal 714 (B) to filter control signal 722 (C). The mapping function M BC is an abstraction of the operation of the filter controller 720 . The mapping function M BC may be configured to compensate for non-linear transmission characteristics associated with the active color filter 740 .
[0113] In one embodiment, the filter controller 720 corresponds to a combination of the color controller 110 and the filter driver 114 , and the filter control signal 722 (C) corresponds to filter control signal 116 .
[0114] The light source 730 may implement any technically feasible technology for generating multi-spectral light. For example, the light source 730 may comprise a gas discharge chamber, such as a Xenon flash tube. Alternatively, the light source may comprise a white light emitting diode (LED), such as a white phosphor LED. In one embodiment, the light source corresponds to light source 166 . The multi-spectral light is characterized by multi-spectral light signal 732 (D), comprising plural color components. In one embodiment, the multi-spectral optical signal 732 (D) is characterized as having red, green, and blue color components (D={D red , D green , D blue }).
[0115] The active color filter 740 filters multi-spectral light signal 732 (D) to generate controlled illumination signal 742 (E) in response to filter control signal 722 (C). The active color filter 740 may implement selective transmission filters, such as commonly associated with a liquid crystal display (LCD). The active color filter 740 may also implement selective reflection filters, such as commonly associated with micro-electro-mechanical system (MEMS) based arrays used for projection displays. In one embodiment, active color filter 740 corresponds to active color filter 120 , and color components of the controlled illumination signal 742 (E) comprise red, green, and blue colors (E={E red , E green , E blue }).
[0116] The active color filter 740 may implement a set of individual color filters, based on any technically feasible set of individual colors and purity of color for each filter. A narrow (high purity) color filter has a relatively narrow wavelength transmission window λ w , as illustrated in FIG. 5F . A narrow color filter will generally pass less overall light, and will appear to have a very distinct, saturated color. A wide (low purity) color filter has a relatively wide wavelength transmission window λ w . A wide color filter may pass a relatively large portion of other color components. For example, a wide color filter for green predominantly passes green light, but may also pass red and blue light. A very wide color filter will generally pass more overall light, and may appear to be unsaturated or tinted rendering of a principle color.
[0117] The active color filter 740 is characterized as an optical transmission function (T DE ), comprising plural, independent transmission components. In one embodiment, the transmission components comprise red, green, and blue components T DE ={T red , T green , T blue }). In alternative embodiments, different transmission components (e.g., cyan, magenta, and yellow) are implemented to generate a net transmission for red, green, and blue. While different variations of the active color filter 740 have been disclosed herein, persons skilled in the art will recognize that any active optical filter technology may be implemented without departing the scope and spirit of the present invention.
[0118] The color compensated flash unit 700 measures ambient light signal 712 (A) and generates controlled illumination signal 742 (E), where E≈A * k. Controlled illumination signal 742 (E) is related to ambient light signal 712 (A) by scalar coefficient k, meaning that ratios among color components are preserved between controlled illumination signal 742 (E) and ambient light signal 712 (A), although corresponding component values may be different by a constant factor of k. This overall operation is described by Equation 1, below:
[0000] E≈D·T DE ( M BC ( M AB ( A )))* k (Equation 1)
[0119] Persons skilled in the art will recognize that the active color filter 740 will typically transmit a given color component as a sum of net transmission of the color component through all color component filters. For example, if the active color filter 740 includes red, green and blue components and associated color component filters, then net transmission for the green component is actually a sum of the green transmission associated with the physically implemented red filter, the green transmission associated with the physically implemented green filter, and the green transmission associated with the physically implemented blue filter. This is expressed below in Equation 2:
[0000] T green =t gr ( C red )+ t gg ( C green )+ t gb ( C blue ) (Equation 2)
[0120] In Equation 2, T green represents net transmission of green light through the active color filter 740 , where t gr represents the net transmission of green light through the physically implemented red filter as a function of the red component of the filter control signal 722 (C red ), t gg represents the net transmission of green light through the physically implemented green filter as a function of Cgreen, and t gb represents net transmission of green light through the physically implemented blue filter as a function of C blue . An active color filter 740 that implements perfect, independent color filtering of each color component would have the corresponding coefficient values for green transmission: t gr =0, t gg =1, and t gb =0. However, practical values of t gr , t gg , and t gb should generally range from greater than zero to less than one.
[0121] Larger values for the coefficients t gr and t gb indicate a wider window λ w shown in FIG. 5F . In certain implementations, higher coefficient values for t gr and t gb may be desirable because higher coefficient values indicate greater net transmission, which implies greater overall system efficiency.
[0122] Mapping functions M AB and M BC may comprise any technically feasible linear or non-linear transform or transforms that collectively solve Equation 1 for E≈A * k. In one embodiment, mapping function M BC comprises an iterative function for solving Equation 1. For example, the mapping function M BC may comprise a method that first assigns a dominant color component, based on MAX{B red , B green , B blue }, for one component of components T red , T green , T blue . In one implementation, the dominant color component may be set equal to a maximum value (e.g., 1.0 on a scale from 0.0 to 1.0). The mapping function M BC may then assign a second to dominant color component while preserving a ratio between the dominant and second to dominant color components for both B and T. The mapping function M BC may then assign a least dominant color component while preserving ratios between the dominant color component, second to dominant component, and least dominant color components for B and T. At each stage, the mapping function may iterate to maintain proper ratios for components in T.
[0123] An example mapping function M BC may receive B={B red , B green , B blue }, where MAX{B red , B green , B blue } is B green , followed by B red and B blue . If components in C and T are normalized to a range of 0.0 to 1.0, then C green is set to 1.0, resulting in a green transmission value T green of 1.0. Next, B red is set to a value that results in a value of T red that preserves the ratio B green /B red green =T green /T red . And so forth. Importantly, the red filter associated with T red may contribute to net green light transmission. The transmission contributions for each color filter to each color may be known in advance, allowing the mapping function M BC to generate an appropriate filter control signal 722 (C). In one embodiment, a direct lookup table implements mapping function M BC , with components for B comprising table inputs, and components for filter control signal 722 (C) comprising table outputs. Persons skilled in the art will recognize that different techniques for solving Equation 1 may be implemented without departing the scope of the present invention.
[0124] In an alternative embodiment, digital ambient color signal 714 (B) is processed to yield a single scalar value that is descriptive of ambient color balance. A color temperature is one common scalar description of color balance. Hue is another scalar description of color. While a scalar description of ambient color balance represents a narrow gamut of possible color, this approach is broadly useful and accepted in the art. Generating the filter control signal 722 (C) from a scalar value for color balance comprises directly mapping the scalar value to each component of the filter control signal 722 (C) via a set of lookup tables or an appropriate mapping function. Such a direct mapping can account for net transmission of each component for each filter for each value of the scalar value color value.
[0125] FIG. 8A is a flow diagram of method steps 800 for generating controlled illumination based on measured ambient color, according to one embodiment of the present invention. Although the method steps are described in conjunction with system FIGS. 1 B- 4 B, 5 A- 5 D, and 7 , persons skilled in the art will understand that any system configured to perform the method steps, in any order, is within the scope of the invention.
[0126] The method begins in step 810 , where the color compensated flash unit 100 of FIG. 1B receives a start signal. The start signal indicates that the color compensated flash unit 100 should prepare for a strobe trigger by appropriately driving the active color filter 120 to match ambient color balance. If, in step 812 , the color compensated flash unit 100 is directed to measure ambient color balance, then the method proceeds to step 814 . The color compensated flash unit 100 may be directed to measure an ambient color balance via a user input setting from a physical control such as a button or switch, via a software user interface, or via any technically feasible input means. In step 814 , the color compensated flash unit 100 measures ambient color balance to generate a measured ambient color signal.
[0127] In step 820 , the color compensated flash unit 100 computes filter control values comprising a filter control signal based on the measured ambient color signal. In one embodiment, the color compensated flash unit 100 solves Equation 1 of FIG. 7 for E≈A * k . In an alternative embodiment, the color compensated flash unit 100 computes filter control values to match an ambient color temperature (scalar) value derived from the measured ambient color signal.
[0128] In step 822 , the color compensated flash unit 100 drives an active color filter, such as active color filter 120 , using the filter control values. In step 824 , the color compensated flash unit 100 triggers a light source, such as light source 166 , in response to receiving a trigger signal from a host device, such as a camera.
[0129] If, in step 826 , ambient color balance was measured by the color compensated flash unit 100 , then the method proceeds to step 830 , where the color compensated flash unit 100 transmits a measured ambient color signal back to the host device. The method terminates in step 832 .
[0130] Returning to step 826 , if the ambient color balance was not measured by the color compensated flash unit 100 , then the method terminates in step 832 .
[0131] Returning to step 812 , if the color compensated flash unit 100 is not directed to measure ambient color balance, then the method proceeds to step 816 , where the color compensated flash unit 100 receives a color balance. The color balance may comprise color components (such as red, green, and blue), a color temperature value, or any other technically feasible color description. The color balance may be received from a host device, such as a camera, a physical input device, such as a button, a software user interface, or any other technically feasible means for conveying a color balance.
[0132] Although the method steps 800 are described with respect to color compensated flash unit 100 , any other color filtering system having an active color filter, such as color compensation flash module 302 of FIGS. 3C and 3E , is within the scope of the present invention.
[0133] FIG. 8B is a flow diagram of method steps 802 for generating controlled illumination based on a specified color balance, according to one embodiment of the present invention. Although the method steps are described in conjunction with system FIGS. 1B-4B , 5 A- 5 D, and 7 , persons skilled in the art will understand that any system configured to perform the method steps, in any order, is within the scope of the invention.
[0134] The method begins in step 850 , where the color compensation unit 200 of FIG. 2A receives a start signal. The start signal indicates that the color compensation unit 200 should begin appropriately driving the active color filter 120 to match ambient color balance. If, in step 852 , the color compensation unit 200 is directed to measure ambient color balance, then the method proceeds to step 854 . The color compensation unit 200 may be directed to measure an ambient color balance via a user input setting from a physical control such as a button or switch, via a software user interface, or via any other technically feasible input means. In step 854 , the color compensation unit 200 measures ambient color balance to generate a measured ambient color signal.
[0135] In step 860 , the color compensation unit 200 computes filter control values comprising a filter control signal based on the measured ambient color signal. In one embodiment, the color compensation unit 200 solves Equation 1 of FIG. 7 for E≈A * k . In an alternative embodiment, the color compensation unit 200 computes the filter control values to match an ambient color temperature (scalar) value derived from the measured ambient color signal.
[0136] In step 862 , the color compensation unit 200 drives an active color filter, such as active color filter 120 , using the filter control values. If, in step 866 , ambient color balance was measured by the color compensation unit 200 , then the method proceeds to step 870 , where color compensation unit 200 transmits a measured ambient color signal back to a host device, such as a camera. The method terminates in step 872 .
[0137] Returning to step 866 , if the ambient color balance was not measured by the color compensation unit 200 , then the method terminates in step 872 .
[0138] Returning to step 852 , if the color compensation unit 200 is not directed to measure ambient color balance, then the method proceeds to step 856 , where the color compensation unit 200 receives a color balance. The color balance may comprise color components (such as red, green, and blue), a color temperature value, or any other technically feasible color description. The color balance may be received from a host device, such as a camera, a physical input device, such as a button, a software user interface, or any other technically feasible means for conveying a color balance.
[0139] Although the method steps 800 are described with respect to color compensation unit 200 , any other color filtering system having an active color filter is within the scope of the present invention.
[0140] While the forgoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | A system and method for generating controlled illumination having a color balance that corresponds to prevailing ambient color balance. A multi-spectral light source having a given spectral characteristic is filtered through an active color filter to produce multi-spectral light conforming to the prevailing ambient color balance. Embodiments of the present invention advantageously enable photographic capture of images without introducing color balance inconsistencies seen in prior art illumination solutions. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
The present invention is related to co-pending application Ser. No. 805,645, titled "In-Circuit Testing of Control Turn-Off Semiconductors" which was filed on even date herewith and which is assigned to the assignee of the present invention.
BACKGROUND OF THE INVENTION
The present invention relates to apparatus and method for determining the conductive state of a control turn-off semiconductor and to such method and apparatus as applied to an electric power converter employing series connected control turn-off semiconductors between direct current (dc) buses to prevent the rendering a one of the semiconductors in the series connection conductive before the other has become non-conductive.
There are a number of situations in which the conductive state of a semiconductor device is required to be known. It may, for example, be required to know the state of conduction for alarm or total shutdown purposes of a system. More commonly, in many power converters, there are included two semiconductors connected in a series arrangement in what is commonly referred to as a "leg" between the buses of a dc source. These semiconductors serve to control the electric power supplied to a load. A common converter of this type is a three-phase converter having three legs connected in mutual parallel between positive and negative dc buses. The semiconductors of the legs are rendered conductive in a predetermined order or sequence in order to control the electrical power delivered from the dc buses to the load. If both semiconductors of any one leg become simultaneously conductive, it is apparent that there will exist between the two dc buses a short circuit which, if allowed to continue may have disastrous results to the load, the power source and/or to the semiconductors themselves. If the semiconductor devices are of the type which require signals to a control electrode in order to render the device selectively conductive and non-conductive, the problem becomes more acute since devices of this nature, as presently known, are very limited in the amount of current which they can interrupt or turn-off. Devices of this nature common in today's discipline are referred to as gate turn-off thyristors and power transistors. Collectively, such devices are referred to in this application as "control turn-off semiconductors".
There are several methods and apparatus for determining the conductive capabilities of a control turn-off semiconductor. For example, the recently invented scheme described in the aforementioned patent application Ser. No. 805,645, which is cross referenced to this application, employs current transformers and determines the general operational capability of the control turn-off semiconductor prior to application of full power to the device. This scheme is not, however, well suited to the detection of the conductive state of the device during full operation.
One method of attempting to avoid the earlier referenced dc short circuit between the buses is to simply provide a delay between the gate pulses turning one of the devices of a leg off and the gate pulses turning the other device on. So long as the delay is longer than the time it takes to turn the semiconductor off, a short is usually prevented. This system has the disadvantage in that it is not positive in its action; i.e., there is no positive indication that the first device has actually turned off. Additionally, it is not well adapted to high performance systems since the delay must be sufficient to permit the first semiconductor to turn off under all operating circumstances.
Another system is what is referred to as the anode sensing method. This system monitors current direction and the semiconductor anode to cathode voltage. If the current polarity is positive, then the turn-off of that semiconductor will be indicated by the appearance of a positive voltage from the anode to cathode. Thus, by delaying the gating of the second semiconductor of the leg until the voltage appears across the first, a short circuit of the dc source can be prevented. This system, however, does not work if the current is negative; that is, being carried by the diode which is normally connected in antiparallel in these types of systems. In this case, because the diode is conducting, the voltage sensed will stay very small. If the second control turnoff device is gated on before the first is actually turned off, or when the first has failed in a shorted mode then a short circuit will exist.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide improved method and apparatus for failure testing of a control turn-off semiconductor.
It is another object to provide for the sensing of an improper operating state of a control turn-off semiconductor through sensing the voltage at the control electrode of the semiconductor.
It is a further object to provide method and apparatus for preventing a short circuit between dc buses of a power converter of the type having series connected control turn-off semiconductors.
It is an additional object to provide method and apparatus for preventing a short circuit, between the dc buses of a power converter of the type having series connected control turn-off semiconductors, through sensing of the voltage of the control electrode to thereby develop inhibit signals to prevent the inappropriate firing in time of the semiconductors of a given leg.
The foregoing and other objects are achieved in accordance with the present invention, by determining the operational state of a control turn-off semiconductor of the type having anode, cathode and control electrodes. Appropriate signals are applied to the control electrode to govern the conductive state thereof and the extant voltage at that electrode is used to determine to actual conductive state. The present invention also utilizes a first signal representing the desired operational state of the semiconductor in conjunction with a second signal representing the actual operation of the state of the semiconductor. The second signal is that developed as a function of the extant voltage at its control electrode. The first and second signals developed are appropriately combined to generate a fault indication when the second signal indicates a conductive state of the semiconductor and the first signal indicates a desired nonconductive state. In an embodiment of the invention employed in a series connection of two such control turn-off semiconductors forming a leg between a pair of dc buses, the second signal representing the extant state of a one of the semiconductors in a leg is combined (cross-coupled) with the desired control signal of the first semiconductor to inhibit the rendering of that first semiconductor conductive when the second semiconductor is still in its conductive state.
In a still further embodiment of the present invention, the cross-coupled system just described is further combined with an anode sensing system to provide a further improved, more positive system of preventing the dc short. This embodiment provides the anode system sensing output signal as a further input to the combination of the cross-coupled second signal and signal representing desired conduction.
In an additional refinement applicable to either of the cross-coupled emodiments, a latch (e.g. flip-flop) circuit is used to maintain a semiconductor in its conducting state for its intended conduction period to prevent spurious turn-off operation.
BRIEF DESCRIPTION OF THE DRAWING
While the present invention is defined in particularity in the claims annexed to and forming a part of this specification, a better understanding thereof can be had by reference to the following description taken in conjunction with the accompanying drawing in which:
FIG. 1 is a high level schematic diagram of a typical three-phase power converter for supplying power to a load, useful as a typical background and environment for understanding the present invention;
FIG. 2 is a schematic diagram illustrating the present invention in its preferred and basic form and further illustrating the present invention as applied to a power converter to prevent a short circuit across the dc buses of a converter;
FIGS. 3, 4 and 5 are waveforms helpful in understanding the present invention;
FIG. 6 is a schematic diagram illustrating a further embodiment of the present invention; and
FIG. 7 is a schematic diagram of a possible modification to the embodiments of FIGS. 2 and 6.
DETAILED DESCRIPTION
Referencing first FIG. 1, there is shown a typical three-phase voltage source inverter for supplying power to a load from a dc source. Such an inverter provides a suitable environment for the present invention although it is not limited thereto. This invention is applicable to current source converters as well although the utilization of the fault signal could be different. As shown, the converter 10 is comprised of three legs including control turn-off semiconductor devices G1 through G6 having corresponding antiparallel connected diodes D1 through D6. A first leg is defined by the series connection of semiconductors G1 and G2 with their respective diodes D1 and D2. Semiconductors G3 and G4 with their respective diodes form the second leg while semiconductors G5 and G6 with diodes D5 and D6 form the third leg. A source of dc power, indicated generally at 12 and which may be, for example, a full wave rectification bridge connected to an alternating current (ac) source, is connected by way of positive bus 16 and negative bus 18 to the converter 10. A load 14 which may be of any suitable type, for example an alternating current motor, is connected to the output of converter 10 by leads 22, 23 and 25. Each of the control turn-off semiconductors includes an anode, a cathode and a control electrode in accordance with standard depiction. As is customary in the art, under the action of a suitable control 20, the various control turn-off semiconductors G1 through G6 are rendered conductive and nonconductive at appropriate times by the application of suitable signals to the control electrodes to thereby control the power which is supplied from the source 12 to the load 14.
From the depiction in FIG. 1, it is seen that if both control turn-off semiconductors of a single leg (e.g., G1 and G2) are on at any one time, a short circuit will exist between the buses 16 and 18 which can result in damage to the semiconductors, the power supply and/or load.
Reference is now made to FIG. 2 which illustrates the apparatus and method of the present invention both in its basic form to determine the operational state of a control turn-off semiconductor and the use of that basic invention to prevent the simultaneous conduction of two semiconductors connected in series across a bus, such as described earlier with respect to FIG. 1. FIG. 2 shows buses 16 and 18 between which devices G1 and G2 are connected in series. Diodes D1 and D2 are included in their customary antiparallel relationships.
In the ensuing discussion, binary connotations of "1" and "0" will be used. This is a form of convenience in discussing the logic and not an indication that only digital implementations are contemplated. The equivalency of digital and analog logic is well recognized.
The anode of semiconductor G1 is connected to bus 16 and the cathode is connected to a node 21 from which emanates line 22, connected to the load. Node 21 is also connected to anode of semiconductor G2 the cathode of which is connected to the negative bus 18. The gate or control electrodes of the two semiconductors G1 and G2, electrodes 24 and 26, are connected respectively to the inverting inputs of a pair of comparators 30 and 32. Comparator 30 has a non-inverting input connected to node 21 by way of a suitable voltage reference 34 such that there will appear at the output of the comparator 30 (node 35) a binary 1 signal when the gate electrode 24 is sufficiently negative to indicate that control turn-off semiconductor G1 is in its non-conductive state. In a similar manner, comparator 32 has its inverting input connected to control electrode 26 of device G2 and its non-inverting input connected to a suitable negative voltage reference 36. The output of comparator 32, at node 39, will be a binary 1 when the gate 27 of device G2 is sufficiently negative to indicate that it is not conductive.
The output of comparator 30 at node 35 is first applied to an inverting input of an AND gate 42 which has a second inverting input connected to line 46. The signal on line 46 (G1 ON) would emanate from suitable control means, (e.g., control 20 in FIG. 1) and would normally be a pulse continuing for the length of time that the control desired or commands the semiconductor G1 to be in the conducting state. AND gate 42 will thus have as its output on line 49 a signal which is a binary 1 only during those periods when there is a binary 0 at node 35 indicating that device G1 is conducting and the absence of a signal on line 46. This situation exists when device G1 is conducting when it should not be.
The signal on line 49 is applied to a low pass filter (which may be of analog or digital form) the output of which on line 52 will be a fault signal indicating that the device G1 is conducting at a time when it should not be. This signal may be used for any desired purpose such as activating a visual or audio alarm or it may, if desired, be employed for remedial action such as to remove input power from the semiconductor devices. It is noted that the sole function of the low pass filter 50 is to remove spurious or transient signals of a positive nature which may occur as, for example, during switching operations, to prevent nuisance indications.
In a similar manner, the output of comparator 32, at node 39, is applied to an inverting input of an AND gate 44 having as its second input the signals on line 48 indicating a desired conduction mode of device G2. The output of AND gate 44 is applied to a low pass filter 54 the output of which is a fault signal on line 56 representing a conduction of device G2 at a time when it is supposed to be non-conducting. Thus, it is seen there is provided a relatively simple way of providing an indication of improper conduction of devices G1 and G2.
The aspect of the invention related to the preventing of the simultaneous conduction of the two control turn-off semiconductors within the leg of a system such as the bridge of FIG. 1 also employs the outputs of the two comparators 30 and 32 and the signals on lines 46 and 48 but in a cross coupling arrangement. In accordance with the convention here being used, binary 1 signals on lines 46 and 48 designate, respectively, a desired conducting state for the respective semiconductor devices. It will also be remembered that the output of each of the comparators 30 and 32 is a binary 1 when the respective control turn-off semiconductor is nonconductive and a binary 0 when it is conductive. As seen in FIG. 2, the signal at node 35 is applied as one input to an AND gate 60 (by way, if required, of a suitable isolation circuit 61) the other input of which is the signal on line 48. Thus, it is seen that when comparator 30 provides an output signal which is a binary 1, indicating that device G1 is not conductive, gate 60 is free to pass the signals on 48 to a suitable gate driving circuit 28 which provides a signal of suitable magnitude to the control electrode 26 of semiconductor device G2, thus permitting that device to be turned on. If, however, the output of comparator 30 is a binary 0, indicating that semiconductor G1 is conducting, the signal applied therefrom to AND gate 60 will be of an inhibiting nature preventing the passing of the signals on line 48. Thus the driver circuit 28 will not be permitted to provide enabling signals to the device G2.
Node 59 at the output of comparator 32 is cross coupled and applied via an isolation circuit 59 (again, if required) to one input of an AND gate 62. The other input of gate 62 is the gating signals for semiconductor G1 on line 46. The output of AND gate 62 is applied to a driver circuit 26 the output of which, as was described earlier, is the signal enabling the conduction of device G1. If device G2 is conducting the binary 0 signal from comparator 32 will inhibit gate 62 and the passing of the signals on line 46. Thus, the rendering conductive of device G1 will be prevented. It is seen that by this cross coupling arrangement, rendering a one of the two control turn-off semiconductors in the leg between the two buses 16 and 18 conductive will be inhibited so long as the other semiconductor is in a conducting state.
FIG. 3 shows, in its several traces, typical operational waveforms applicable to a gate turn-off (GTO) thyristor used as the control turn-off semiconductor in the circuit of FIG. 2. The waveforms of FIG. 3 are to the same time base, are taken with the cathode as a reference, and show the time of a turn-off with forward current, that is, current from anode to cathode of a device.
Turn-off of the device is initiated at time t 0 by the beginning of the rise of negative gate (control electrode) current I G . (See bottom trace in FIG. 3.). There is no change in the anode voltage or current until time t 1 when I G reaches a value sufficient to initiate voltage blocking in the control turn-off semiconductor. At time t 1 , anode current I A begins to fall and the anode voltage V A begins to rise. Gate voltage rises to the gate-cathode junction avalanche voltage at time t 1 when reverse gate current can no longer be drawn from the junction. The time of blocking, t 1 , can be determined by sensing this rise of voltage on the gate. Time t 1 is the time that the control voltage V G exceeds the reference voltage V 1 .
If the current in the leg is negative, that is, in the diode rather than in the control turn-off semiconductor, the anode voltage will never rise due to a turn-off pulse to the GTO. Thus, only the gate sensing method herein disclosed of FIG. 3 is effective. The waveforms in this case are shown in FIG. 4. The anode voltage and current are not shown because they are not affected by the turn-off signal. The gate current in this case can flow in reverse direction for only a brief time (t 0 to t 1 ) because it has only to sweep out the carriers resulting from the immediately previous "on current" to the gate. The gate to cathode voltage V G steps to larger than V 1 at time t 1 to indicate that the GTO is in the blocking state even though there is no anode voltage to prove it. This is a major advantage of the method of the present invention. By waiting a brief time after t 1 , the control can apply a turn-on pulse to the other series control turn-off semiconductor with confidence that the first has been given a turn-off pulse which will block voltage when the antiparallel diode recovers. As earlier indicated, the waveforms of FIGS. 3-5 are for a GTO. Waveforms for bi-polar transistors would be very similar while other types of devices would be characterized by somewhat similar waveforms.
FIG. 5 shows the case when the control turn-off semiconductor being turned off has failed (has lost its ability to block forward voltage) or has failed for some reason to turn off. In this case, gate voltage is always small, never exceeding V 1 , such that the control is inhibited from turning on the other series connected semiconductor device. It can be shown that a failed gate turn-off thyristor which is shorted anode to cathode will always be shorted anode to gate. The effect of the disclosed invention in the case of a total failure of the device to turn off is that the inverter stops producing output, but there is no fault on the dc bus, and thus there is no damaging current requiring the more drastic action such as blowing of circuit breakers or fuses. In a case of a failure of a control turn-off device to turn-off temporarily (for example due to over temperature), the device may be saved from permanent damage by the present invention which prevents a damaging current level from following the failure. The inverter may be, therefore, restarted after a short cooling down period without having to replace fuses or other parts.
The advantages of a further modification of the present invention will be described with respect to FIG. 6. In the FIG. 2 embodiment, if the sensing of turn-off had been by the anode sensing method, as was previously described in the background of the invention, and if the threshhold voltage of the sensor were set at value V 2 (top trace in FIG. 3), then the time of blocking would have been sensed at time t 2 . This represents a potentially better time for sensing that turn-off has occurred. It is better to turn on the other control turn-off semiconductor as the voltage across it approaches zero. The time of this zero voltage is better represented by time t 2 rather than time t 1 . If time t 1 only were used, a fixed delay would be desired in the gating of the other control turn-off semiconductor. By utilizing time t 2 , the delay may be eliminated and gating of the other device may proceed as soon as possible. Thus, the embodiment of FIG. 6 employs both methods, that is, the control electrode sensing method described with respect to FIG. 3 in combination with the anode sensing method to provide the best turn time for the other device.
Referencing FIG. 6, it is seen that that portion of the drawing to the left of the devices G1 and G2 (and diodes D1 and D2) is the same as described with respect to FIG. 2 with two exceptions. First of all, AND gates 42 and 44, low pass filters 50 and 54 and output lines 52 and 56 have been omitted since they play no part in this portion of the invention. In addition, the two input AND gates 60 and 62 have been replaced, respectively, by three input AND gates 60' and 62' to accommodate additional enabling/inhibit signals to these gates from the rest of the depiction as shown in FIG. 6.
Looking now to the upper portion of FIG. 6, it is seen within the dashed line block 80 there is provided a first comparator 82 which has its inverting input connected to the anode of device G1. A second (noninverting) input is connected by way of a suitable voltage reference 84 to the cathode of device G1. Thus, comparator 82 will provide a binary 1 signal only when the anode voltage is below a predetermined value, for example, that shown at V 2 in the upper trace of FIG. 3. As a current sensing function, a second comparator 90 is provided with an input representing the voltage at node 21 and a second input from a suitable current sensing device such as a current transformer 88. Thus, comparator 90 provides a binary 1 output when current is flowing in line 22 in the direction towards load. The two comparators 82 and 90 provide inputs to an AND gate 86 which, because of the inverted output, will provide a binary 0 on line 91 when the anode voltage is below the prescribe value (V 2 ) and the current is in the forward direction. AND gate 86 provides a binary 1 at all other times. This output is applied (via an isolating circuit 92 if desired) in a cross coupled manner as the third input of the AND gate 60'. Thus AND gate 60' will be disabled when the current is positive and the anode voltage is below V 2 (FIG. 3). In a similar manner, although not shown in detail, a block 80' provides an output signal via an isolating circuit 94 to a third input of AND gate 62'. The only difference in this situation would be that the comparator within block 80' which receives the signal from the current transformer 88 would be applied by way of inverting input indicating that current in line 22 is in the opposite direction, that is, flowing from the load and through diode D1.
FIG. 7 shows a modification which may be made to either of the embodiments of FIG. 2 or FIG. 6. In FIG. 7, control turn-off semiconductor G and diode D represent any of the similarly designed devices of the earlier figures. In a like manner, drive 100 represents either of the drives 26 and 28 of the earlier showings and AND gate 102 represents any of the AND gates 60 and 62 of FIG. 2 and 60' and 62' of FIG. 6. AND gate 102 receives an "ON" signal via line 106 as in the previous instances and lead 108 represents the application of the additional enabling/inhibit signal or signals.
The difference between the earlier embodiments and the present is the inclusion of a latch circuit or flip-flop 110 which is interposed between the AND gate and the drive. In this embodiment a logic 1 signal from AND gate 102 will place flip-flop 110 in its set state to enable drive 100 until the flip-flop is reset. Resetting flip-flop 110 is achieved by the application of an appropriate signal to its R input via inverter 112 connected to line 106. Thus flip-flop 110 will reset when the signal on line 106 calls for non-conduction of device G.
The latching feature is desirable if the control turn-off semiconductors are not capable of turning off instantaneously when commanded to do so. It is also very beneficial to have in the situation in which a control turn-off semiconductor fails while it is in the non-conducting or blocking state. In this latter case, failure will result in the immediate establishment of a short circuit which the control turn-off semiconductor may be incapable of correcting. By way of example using the FIG. 2 embodiment, assume device G2 is properly conducting and although commanded to be in the off condition, device G1 fails and begins to conduct. In this situation, comparator 30 would immediately provide an output signal which would disable AND gate 60 to cause semiconductor G2 to turn-off and interrupt the short circuit. This is a desirable response where the control turn-off semiconductor G2 has a turn-off time sufficiently short with respect to the rise time of the fault current so that this current can be interrupted before it exceeds the turn-off rating of the good device (G2 in this example). In the case, however, where the device is slow to turn off or the source inductance is small, the good control turn-off semiconductor may be unable to turn off until after the fault current has exceeded its maximum turn-off rating resulting in destruction of the good device.
The interposed flip-flop 110 of FIG. 7 prevents the above from occurring. The cross-coupled signals can inhibit the turning on of a semiconductor but cannot cause an interruption of the "on" signal to a conducting device once it is conducting. In addition to the above, it will be recognized that the interposing of the flip-flop in the manner indicated will reduce erratic turn-off action as from spurious signals, etc.
While there have been described what are presently believed to be the preferred embodiments of the present invention, modifications thereto will readily occur to those skilled in the art. It is not desired, therefore, that the present invention be limited to the specific embodiments shown and described and it is intended to encompass within the claims all such modifications that fall within the true spirit and scope of the invention. | A scheme for determining the operational state of a control turn-off semiconductor, of the type having an anode, a cathode and control electrode to which signals are applied to control the conductive state of the semiconductor, utilizes the extant voltage at the control electrode to determine the actual conductive state of the semiconductor. A first signal representing the desired operational state of the semiconductor and a second signal representing the actual operation of the state of the semiconductor and appropriately combined in one embodiment to generate an indication of the operational state of the control turn-off semiconductor. A further embodiment, employed in a series connection of two such control turn-off semiconductors beteen dc buses, uses the second signals in a cross-coupled arrangement between the two semiconductors to inhibit the application of control signals to a first semiconductor if the second semiconductor is conductive.
In a still further embodiment, the cross-coupled system just described is further combined with an anode sensing system to provide an improved, more positive system of preventing the dc short by providing the anode system sensing output system as a further input to the combination of the cross-coupled second signal and signal representing desired conduction.
In an additional modification a latch function serves, in the cross-coupled embodiments, to render the cross-coupling inhibiting ineffective, once a semiconductor has been rendered conductive, for the commanded period of conduction. | 7 |
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention refers to an improved method for the detection of at least one analyte in a sample.
BACKGROUND ART
[0002] It is well-known to purify antibodies and/or antigens from a sample in a conventional analysis plate, e.g. an ELISA plate, containing microparticles or beads, with ligands bound thereto located in the bottom of the wells on the analysis plate. Antibodies and/or antigens present in the sample added are specifically bound to the ligands present on the microparticles or on the beads. Thereafter, non-bound sample components still present in the wells are washed out from the wells by the addition of a wash liquid. Thereafter, the antibodies/proteins or antigens are eluated from the ligands by the addition of a buffer, and separated purified antibodies, proteins and/or antigens are collected and analyzed.
[0003] It is also known to detect specific analytes, e.g. proteins, in a sample by use of an ELISA plate having a porous filter in the bottom of each well and a layer of microparticle or porous beads located above said porous filter. The microparticles or porous beads contain a covalently bound ligand, which is able to bind to the analyte. When a sample is added to the well of the ELISA plate, the analyte is specifically bound to the ligand. Non-bound analyte components still present in the well are washed out from the plate through the porous filter by the addition of a wash liquid. For detection and quantification of the bound analyte, different techniques are used. The microparticles or beads can be removed and analyzed by for example flow cytometry. Alternatively, the analyte can be eluted from the microparticles by adding a buffer for elution and eluting the analyte through the filter and thereafter determining the quantity of the analyte by for example sodium dodecyl sulfate polyacrylamide gel electrophoresis, or by traditional ELISA techniques. If the analyte is radiolabelled or reacted with a radiolabelled substance, the analyte is determined using scintillation counting. As another alternative, a scintillation liquid is added to the wells and the scintillation is measured.
[0004] Several different pathogenic bacteria and virus bind to specific carbohydrate receptors in humans where the carbohydrate acts like an anchor point for the bacteria, virus or bacterial toxin. EHEC, enterohemorrhagic Escherichia coli , is one of several examples of micro-organisms which either itself or via toxins binds to carbohydrate receptors in human beings. EHEC produces a toxin called Shiga toxin, which also may be produced by several other types of infectious bacteria, e.g. Shigella . The Shiga toxin binds to Gb3 (globotriaosylceramide) structures, in which the disaccharide unit in Gb3, i.e. Galα1-4Gal, is regarded to be smallest saccharide structure to which the Shiga toxin binds. Gal means D-galactose, and α1-4 means the glycosidic bond between the two galactose units. The Galα1-4Gal structure is also of importance for example in urinary tract infections caused by the binding of Galα1-4Gal specific E. coli . Several other carbohydrate structures such as structures containing one or several of for example Man (D-mannose), Fuc (L-fucose), sialic acid (for example N-acetylneuraminic acid), Glc (D-glucose), GIcNAc (N-acetyl-D-glucosamine) and/or GalNAc (D-N-acetyl-galactosamine) for example, have been implicated in bacterial and viral infections.
[0005] Carbohydrate structures of importance in connection with various forms of human cancer (for example Galili-antigens) have been identified, as well as antibodies specific for such structures. Also blood group structures have been implicated in bacterial and viral infections. Human antibodies specific for blood group A and B structures are important for example in blood group incompatible transplantation, in blood group incompatible blood transfusions and in immunoglobulin preparations for injection (IVIG).
[0006] With a view to treating viral and bacterial infections, such as HUS, hemolytic uremic syndrome, antibiotic treatments, in some cases together with repeated blood transfusions and in some cases together with repeated plasma exchanges, are applied. However, these measures are not specifically acting on the toxin and may lead to side-effects and/or a non-desired treatment effect. Instead, a more specific treatment is desired. Further, it is of interest with an access to better detection methods, e.g. for screening of the toxin(s) and bacteria involved with a view to diagnosing and properly treating the disease condition in question.
[0007] Antibodies are of interest in a range of conditions. Several autoimmune diseases involve autoantibodies, for example anti-GM1 antibodies. In blood group incompatible transplantation, for example, it is important to determine the levels of recipient antibodies specific for the donor blood group antigens, pre- and posttransplant. The present methods for determination blood group specific antibodies rely on red blood cells as obtained from human blood, or modified such cells, and using for example gel cards or expensive flow cytometry for their determination. For the HLA sensitized transplant recipient, the levels of different HLA antibodies are important.
[0008] The above examples of analytes of interest are mentioned as examples and are not intended to limit the scope of the invention.
[0009] The known detection and purification methods based on various types of beads or suspensions have different problems. Various methods for detection have been developed, but often involve expensive equipment, and/or are time consuming, or involve radioactive labels for detection. Traditional ELISA with ligands/primary antibodies non-covalently or covalently bound to the plastic surfaces of the wells in the ELISA plates, requires relatively long incubation times for the binding reactions. Also, the surfaces used for binding of the ligand/primary antibody often introduce non-specific adsorption effects, especially for smaller ligands. For larger ligands such as proteins there is a risk that the structure of the protein is more or less impaired. Also, the surface of the wells is limited, resulting in limited sensitivity, a problem when the analyte is present in a relatively low concentration in the sample.
[0010] Thus, there is a need of an improved method for the detection of analytes in a sample when using an analysis plate technique.
SUMMARY OF THE INVENTION
[0011] The object of the present invention is to reduce the above-mentioned problems associated with known products and methods used for detection and quantification. This object is achieved by the method according to the present invention.
[0012] In one embodiment the present invention relates to a method for the detection of at least one analyte in a sample, wherein it comprises the steps of:
a) providing a layer comprising a porous matrix having at least one ligand bound thereto above a porous filter constituting the bottom of at least one well of an assay plate, wherein said filter does not allow passage of said porous matrix having a ligand bound thereto, b) adding a sample containing said at least one analyte to be detected, said at least one analyte having the ability to specifically bind to said at least one ligand, c) adding a wash solution with a view to washing out non-bound sample components from the assay plate through the filter, d) adding enzyme-linked antibodies or antigens having the ability to specifically bind to said at least one analyte, e) adding a wash solution with a view to washing out non-bound enzyme-linked antibodies or antigens from the analysis plate through the filter, f) adding a substrate specific for the enzyme, wherein a product is formed by a reaction between the enzyme and the substrate, g) determining the quantity of said at least one analyte by measuring a signal related to the amount of product formed.
[0020] The measurement of the product produced by the enzyme is proportional to the amount of the analyte bound to the beads in each well. The measurement of the product can for example be made with a conventional ELISA plate reader, either by direct spectrophotometric measurement of the absorption of the wells in the plate, wherein steps a)-f) above are performed, or by allowing the product formed in the enzyme reaction f) above to pass through the filter in each well of the ELISA plate down to corresponding wells of a second ELISA plate and measurement of the absorbance of the wells of this second plate.
[0021] In one embodiment the present invention also relates to a product kit, said kit comprising one or more of the following components:
1) a layer comprising a porous matrix having at least one ligand bound thereto, situated above a porous filter constituting the bottom of at least one well of an assay plate, wherein said filter does not allow passage of said porous matrix having a ligand bound thereto, 2) the ligand in a) above having the ability to specifically bind at least one analyte in the sample, 3) at least one enzyme-linked antibody, or enzyme-linked antigen, having the ability to specifically bind to said at least one analyte, 4) at least one wash solution with a view to washing out non-bound enzyme-linked antibodies, or enzyme-linked antigens, from the analysis plate through the filter, 5) at least one substrate specific for the enzyme which is converted to at least one product by the enzyme, the product being able to be detected spectrophotometrically or by other method, 6) optionally a second plate, having the same number of wells as the first plate, but not having a filter in the bottom of the wells. The wells of this second plate can be placed below the corresponding wells of the plate in 1) above, allowing the product in 5) above to pass down through the filter of the first plate down to the corresponding wells of the second plate. The absorption of the product, now in the corresponding wells of the second plate, is read spectrophotometrically in an ELISA plate reader.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0028] The present invention relates to an improved method for detection of a least one analyte in a sample, e.g. antibodies, proteins, peptides, and bacterial toxins as exemplified above.
[0029] A porous matrix having a ligand bound thereto is used.
[0030] Examples of a preferred matrix is an agarose based matrix, e.g. cross-linked agarose which normally is in the form of beaded gel particles. The agarose matrix is known to be porous or macroporous, thus containing pores which allow entrance of proteins or antibodies up to at least one million Daltons into said pores, where a large part of ligand is bound. Further non-limiting examples of agarose are commercially available, for example so called CL-Sepharose 2B, 4B or 6B, or similar so called Fast Flow variants and other similar variants. The matrix can be chosen by the expert in the field.
[0031] There are other matrixes based on e.g. cellulose, cross-linked cellulose, and plastic porous polymers and porous filter materials used in e.g. hemofiltration and plasma exchange.
[0032] The linkage between the ligand and the matrix is preferentially covalently stable, and examples thereof are an amide, an N—C or an O—C linkage.
[0033] The former linkage is preferentially formed by reacting an activated carboxyl group (activated with a carbodiimide and/or an N-hydroxysuccinimide) on a ligand, or a matrix, with an amino group on a matrix, or a ligand. The pH, solvent, temperature, concentrations of reagents, matrix and ligand, reaction temperature, and washing procedures, so called coupling procedures, are selected by the expert in the field an do not limit the scope of the invention.
[0034] If plasma is to be analyzed, a smaller matrix bead size may be chosen e.g. in the range of 20 to 200 μm or a more narrow range within that range. If whole blood is to be analyzed, the size of matrix beads may be chosen in the range 100-300 μm or a more narrow range within said range.
[0035] The analysis plate used in the method and the kit according to the present invention is chosen by the expert in the field and this does not limit the scope of the invention. There are several different types of assay plates available having wells with a porous filter in the bottom of each well, allowing liquid to pass through, but not matrix beads or particles. Plates are available having for example 96 wells per plate, and plates having more wells are available, for example plates with 386 wells per plate. The larger number of wells can for example allow more samples to be determined or more different analytes to be determined, by using different matrix beads with different coupled ligands, than the plates with fewer wells. This can be determined by the expert in the field. Each well of said analysis plate has been provided with a porous matrix having one or more specific ligands bound thereto above the filter.
[0036] Preferably the matrix, to which one or more ligands are bound, has the form of porous gel particles. Further, the ligands are bound to the porous matrix both on the surface of the matrix and inside the pores of the matrix, thereby providing a larger surface available for binding. Alternatively, the matrix may have the form of a porous layer covering the whole or a part of the cross-section of each well and is in such a case located above the filter.
[0037] The pores in the porous matrix should preferably have such a porosity that also larger proteins, such as IgG, IgM (Immunoglobulin M) and toxins are allowed to enter into the pores and bind to the ligand, as well as enzyme-linked antibodies or enzyme-linked antigens should be able to enter the pores and bind to the analyte bound to the ligand within the pores.
[0038] The exact parameters for the matrix are chosen by the skilled person in the art, e.g. in view of the size of the beads and the volume of the beads applied in the wells. Typically a value of from 5 to 50 μl of beads with covalently bound ligand can be used per well. The expert in the field can determine the volume of matrix-ligand to be applied for the specific analysis to be performed.
[0039] Normally, when a beaded (e.g. in the form of gel particles) matrix is used, the matrix gel particle diameter lies in the interval of 20-300 μm, preferably 30-150 μm, but smaller smaller or larger particles can be chosen and also a more narrow interval of particle size distribution. Smaller particles will give a higher flow resistance than larger beads at the same bead volume. The pore size of the matrix, the volume of the bead layer, as well as the thickness of the gel bead layer, which shall allow a desired flow of liquid and/or sample through the filter in the bottom of the wells, can also be determined by a person skilled in the art.
[0040] The skilled person in the art can also determine the sample volume, the sample dilution for each well, the choice of ligand, choice of plate with filter and number and volume of the wells in the plate, the type of wash buffer, for example PA buffer, the amount of wash buffer, the type of enzyme-antibody or the type of enzyme-linked antigen, substrate, contact time for each step, flow rate through the filter and whether vacuum or centrifugation should be applied to speed up the flow of sample, wash buffer and other solutions through the beads and the filter for each step, as well as the time for the enzyme reaction to convert substrate to product.
[0041] Further, the skilled person in the art can also choose to apply a second mechanical filter applied above the matrix gel bead layer in each well with a view to reducing the problem with undesired agitation of the gel layer during the addition of the sample, the wash buffer, and the labelled antibody, e.g. enzyme-linked antibody, and substrate.
[0042] The skilled person in the art can also choose the amount of the gel beads of matrix-ligand, the amount of ligand to bind per volume of matrix, any dilution of the matrix-ligand with (not derivatized) matrix, the type and concentration of antibody label, the type of enzyme, the wash buffer, the type and concentration of substrate, the concentrations of other applied different reagents which according to the person skilled in the art can be used with the product and the method according to the invention.
[0043] In one embodiment of the detection method according to the present invention, the ligand is a saccharide and the matrix having a saccharide ligand bound thereto is used in an assay performed in an ELISA (Enzyme-Linked Immunosorbent Assay) plate. In the analysis device used in this embodiment the bottom in each well of the plate has been replaced with a mechanical filter having a predetermined pore diameter which allows passage of fluid but not of the matrix.
[0044] Below the filter in the bottom of each well of the plate, the analysis plate is in one embodiment designed as a downwards narrowing funnel starting from just below the filter of the well, with a view to leading/directing the liquid flow out through the filter below each well of the plate allowing the liquid to pass to the respective wells of a second plate placed below the analysis plate.
[0045] In this embodiment the ligand may also be a peptide or a protein covalently bound to the matrix.
[0046] In one embodiment the detection of the analyte is made with the basis of the reaction between an enzyme-linked antibody and a substrate, wherein the absorption of the reaction product is measured, either outside (the second plate mentioned above) or within the wells of the analysis plate. In one embodiment the ligand and the the antibody (or the antigen) labelled with an enzyme may be identical. In one embodiment, eluated reaction product is collected and measured in a container, e.g. an ELISA plate, or column arranged under the analysis plate.
[0047] To conclude, the method according to the present invention allows a substantially larger surface for the binding of the ligand and analyte compared to conventional ELISA. Also the method also allows for a higher volume of sample to be applied to each well than in ordinary ELISA, since the bead layer in each well act as a small affinity column allowing passage of one or several well volumes of sample through each well with matrix-ligand. This is important especially when determining low concentration of analyte in a sample. The sample is better contacted with the ligand compared to conventional ELISA since the analyte passes through narrow pores (for example with an average pore diameter in the size range of approximately 0.1 μm) with covalently bound ligand, thereby promoting binding between analyte and ligand. This in turn speeds up the binding of analyte compared to conventional ELISA. The sample volume applied is determined by the expert in the field. It also contributes to a reduction of the problem with non-specific binding.
[0048] In another embodiment of the invention the analysis plate with porous beads with covalently bound ligand as described and exemplified above, when the ligand is a saccharide, and is used in a kit for separation of analytes where the analyte is a saccharide binding biomolecule, for example a protein, an antibody, an other protein, such as for example a lectin or toxins, from a sample.
[0049] In this embodiment of the invention, the bound analyte can be eluted, after application of sample, binding and washing as described above, from the wells by for example addition of a buffer of higher pH (for example a pH of between 9 and 11) or lower pH (for example of a pH between 3 and 5), allowing the eluate to pass through the beads and the filter as described above, and collecting the eluted analyte, as described above. Alternatively, the analyte can be eluted by addition of a specific saccharide binding to the analyte, thus specifically eluting the analyte. In this way, for example a multiple purification of different analytes can be achieved, or the analyte can be purified from a range of samples. The analyte can then be used for different applications and/or for different types of analyses.
[0050] According to one embodiment the present invention relates to a method for the diagnosis of peptides and proteins, for example of antibodies specific for carbohydrate structures. Several such antibodies are known specific for e.g. blood group antigens, for example blood group A, B, H, their different subtypes (for example blood group tetrasaccharides belonging to subtype 1, 2, 3 and 4), other blood group saccharides (such as blood group P and Pk), galiliantigens, TF-antigens and related antigens (for example Galβ1-3GalNAc structures), antibodies specific for other antigens of importance for example in autoimmune disorders, such as ganglioside carbohydrate structures (for example carbohydrate structures of GM1), for diagnosis of virus, bacteria, and toxins which have the ability to bind to carbohydrates as exemplified above, or to peptide receptors, antibodies specific for protein or peptide antigens, for example detection of antibodies specific for different HLA antigens. The method can also be used for example in determining the relative quantities of immunoglobulins IgG1, IgG2 and IgG3, IgA, and IgM which are specific for a certain antigen, for example blood group A and its subtypes, by using enzyme-labelled antibodies which are specific for the different types of human antibodies.
[0051] According to one embodiment of the present invention the saccharide is bound to the matrix via an aglycon. Non-limiting examples of the aglycon may e.g. be a monomeric aglycon glycosidically bound to the saccharide via —O— on the C1 position of the saccharide (i.e. the reducing end of the saccharide): —OPhNH—, OEtPhNH—, and O(CH)2-NH— are non-limiting examples of aglycons which may be chosen by the expert in the field, wherein the NH group is bound to the matrix, or bound to the matrix via a mono-, di-, oligo-, or polymer structure, e.g. a —(CH)n-O—CH2-matrix, wherein n is an integer, preferably 1, 2, 3, 4, 5, or 6.
[0052] Further non-limiting examples of the above-mentioned carbohydrates and carbohydrate derivatives according to the present invention, are one or several of blood group A-, blood group B-, blood group H- and or GM1, α-sialo-GM1, containing carbohydrates found in glycoproteins, glycopeptides, or glycolipids, mono-, di-, tri-, tetravalent and higher oligomers of above mentioned A-, B-, H- and or GM1 and or α-sialo-GM1-oligosaccharides, derivatives of said saccharides e.g. containing O-, N-, or S-glycosides of these substances, wherein the aglycon comprises e.g. an aliphatic or aromatic part and e.g. the aglycon containing a terminal sulfhydryl-, hydroxyl-, amino- or carboxyl group for covalent binding to the matrix, e.g. the polymer particle, bead or filter as described above, or in which said carbohydrate derivatives contains at least one biotin, avidin or streptavidin molecule for non-covalent binding to an avidine, streptavidine or biotin-matrix.
[0053] The choice of the aglycon and its binding to saccharide or peptide and its binding to the matrix is determined by the expert in field and does not limit the scope of the invention.
[0054] A di-, tri-, tetra-, or oligomeric aglycon can be constructed by the expert in the field to be able to be linked O-, N- or S-glycosidically, or via another aglycon in between the carbohydrate and the —(CH 2 ) n —O— units, to one or serveral carbohydrates or carbohydrate derivatives, thereby forming a dimeric, trimeric, tetrameric, or oligomeric carbohydrate derivative, which in turn is linked to matrix.
[0055] The di-, tri-, tetra- or oligomeric ligand can be chosen by the expert to obtain a stronger binding to the product of the antibody or protein to be analysed and/or minimize the size of the product for the specific application/use of the product. The exact structure of the aglycon is made by the expert in the field. The aglycon can also contain a peptide or protein.
[0056] The quantity of ligand in the matrix-ligand is typically chosen to contain 0.1, 0.5, 1.0, 2.0, 10, or 20 mg ligand per mL volume of matrix-ligand or is any value between these values. The exact value is chosen by the expert in the field.
[0057] At least the final stages of the production of the matrix-ligand and also the application of matrix-ligand in the wells can optionally be performed in clean rooms, and the reagents and clean room(s) used are preferentially certified according to international standards and/or requirements for the product application.
[0058] Alternatively, the matrix-ligand is end-sterilized with steam and or autoclaving to ensure a sterile matrix-ligand product before use.
[0059] The pores in the matrix should preferably have such a porosity that also larger proteins, such as IgM (Immunoglobulin M) and toxins are allowed to enter into the pores, as well as enzyme-linked antibodies.
[0060] The enzyme and the conjugate enzyme-antibody or enzyme-antigen, as well as the concentration and quantity of the conjugate per weill, are chosen by the expert in the field and do not limit the scope of the invention. For example, if a human antibody is to be determined by the method according to the invention, a conjugate between the enzyme and the anti-human antibody is used, wherein the anti-human antibody is produced in for example a rabbit or mouse. The enzyme-antibody conjugate can, also according to the present invention, be a conjugate between an enzyme and a fragment of an antibody which is able to bind the analyte.
[0061] The enzyme can for example be a peroxidase or an alkaline phosphatase. The substrate, its concentration, the buffer solution with substrate and its volume per well, as well as the choice of enzyme is made by the expert in the field and does not limit the scope of the invention.
[0062] For example, when determining the quantity of blood group specific antibodies in a plasma sample, the following components can be chosen:
[0063] A known volume of matrix-ligand, e.g. a beaded agarose with covalently bound blood group A saccharide, for binding of the blood group A specific antibody in the plasma, is added to each well. Plasma samples, each one of the same volume but of different dilutions, are added to the wells, and binding is allowed to take place. Non-bound plasma components are washed with wash buffer and are allowed to pass through the beads and the filter in the bottom of each well. The wash procedure is repeated, typically one to three times, with a view to removing practically all non-bound components. A diluted conjugate of peroxidase-labelled anti-human IgG is added to each well. After binding of the conjugate for a predetermined time, a wash solution is added to each well, and non-bond conjugates follow the wash solution through the filter in each well. This is repeated, typically one to three times, to remove practically all non-bound conjugates. The same volume and concentration of peroxidase substrate solution, OPD, is added to each well. The enzyme raction is allowed to take place. A second plate with corresponding wells is placed under the respective wells of the above-mentioned assay plate. Centrifugation or vacuum are applied to allow the product solution to pass through the gel and the filter of the assay plate down to the corresponding wells of the second plate. An ELISA reader is used to read the absorption (e.g. at 492 nm) of each well.
[0064] Curves (absorption against dilution) for the dilution series of each type of sample of plasma applied is obtained and the quantity of antibody is determined (for example using results for a known quantity of purified human antibody specific for the same ligand).
[0065] A good correlation with the anti-A titers (obtained by titration against red blood cells) in different pooled or non-pooled plasma samples of higher or lower titers from different blood donors was obtained using the product and method above. Samples with higher titers gave higher absorption values (more product formation) than samples of lower titers. As matrix-ligand, i.e. blood group A-Sepharose was used, that is cross-linked agarose with covalently bound blood group A determinant. Samples (used as a control) which had passed the A-Sepharose gave low or no binding.
[0066] One of the advantages with the method according to the present invention is for example that a more absolute measure of the specific antibody is obtained than with conventional red blood cell titrations. Moreover, plasma samples from several blood donors or from several patients can be screened on the same plate. Also, by using matrix with covalently bound A-trisaccharide and matrixes with covalently bound A-tetrasaccharide of the different blood group A subtypes, more information about the quantity and specificity of the blood group specific antibodies in the sample can be obtained than by using conventional red blood cell titration.
[0067] Moreover, by using peroxidase conjugated to anti-human IgG1, peroxidase conjugated to anti-human IgG2, and peroxidase conjugated to anti-human IgG3, the content of for example IgG1, IgG2 and IgG3 specific for the blood group A saccharides mentioned above, or specific for other saccharides, peptides or proteins (used as ligands in the assay), can be determined for a range of blood group subtypes, as well as for other ligands, in one or a few assay plates.
[0068] The concentrations, dilutions and volumes of reagents above, as well as contact times for binding, washing and enzyme reactions, and other parameters, are determined by the person skilled in the art.
[0069] Typically, 10 μl or 50 μl or a value between these values, of matrix-ligand in each well and a few minutes of binding (typically between 2 and 10 minutes or a value between these values, for example 5 minutes) and washing has been shown to be sufficient for each one of the steps above, except for the binding of the enzyme-antibody conjugate, or for the enzyme-antigen conjugate, and for the enzyme reaction, which normally requires a longer time, typically 10 minutes or 15 minutes, or a value between these values. All steps can optionally be performed at room temperature.
[0070] As a further example may be mentioned that by using matrix with different bound ligands, in each well or in different lines of wells, multiple analytes can be determined, for example for screening of antibodies of different specificities towards, for example, but not limited to, different carbohydrate antigens, towards different HLA antigens, or towards different toxins.
EXAMPLE
[0071] In the following a non-limiting example of an embodiment of the present invention is disclosed. After the application of a sample containing an analyte to be determined to at least one well of an ELISA plate containing matrix-ligand, non-bound material is washed away by the addition of a wash buffer, e.g. a PA buffer, which is allowed to pour down through the porous matrix and the filter. Thereafter, a solution containing enzyme-linked antibody is added, wherein said antibody has the ability to bind to the analyte. This is followed by a washing step with a wash buffer with a view to washing away non-bound enzyme-labelled antibody, and a substrate is then added to each well. The product formed in each well is measured spectrophotometrically by an ELISA plate reader, either directly or after suction of the product solution in each well to the corresponding wells of an ELISA plate. | A method for the detection of at least one analyte in a sample is disclosed, wherein it comprises the steps of: a) providing a layer comprising a porous matrix having at least one ligand bound thereto above a filter constituting the bottom of at least one well of an assay plate, wherein said filter does not allow passage of said porous matrix having a ligand bound thereto, b) adding a sample containing said at least one analyte to be detected, said at least one analyte having the ability to specifically bind to said at least one ligand, c) adding a wash solution with a view to washing out non-bound sample components from the assay plate through the filter, d) adding enzyme-linked antibodies or antigens having the ability to specifically bind to said at least one analyte, e) adding a wash solution with a view to washing out non-bound enzyme-linked antibodies or antigens from the analysis plate through the filter, f) adding a substrate specific for the enzyme, wherein a product is formed by a reaction between the enzyme and the substrate, determining the quantity of said at least one analyte by measuring a signal related to the product, as well as method for the diagnosis of an EHEC (enterohemorrhagic Escherichia coli ) infection or HUS (hemolytic uremic syndrome), wherein a body sample from a patient is added as the sample and the analyte is detected using the above disclosed method, wherein the saccharide in the ligand is Galα1-Gal or Galα1-4Galβ1-4Glc. | 6 |
BACKGROUND OF THE INVENTION
This application claims priority under 35 USC § 119 to Korean Patent Application No. 2004-44515, filed on Jun. 16, 2004, the contents of which are herein incorporated by reference in their entirety for all purposes.
1. Field of the Invention
The present invention relates generally to wireless receivers, and in particular to a quadrature voltage controlled oscillator used within a wireless receiver for generating oscillation signals with automated phase control.
2. Description of the Related Art
FIG. 1 shows a conventional wireless receiver as disclosed in U.S. Pat. No. 6,462,626 entitled “Quadrature Output Oscillator Device”. Referring to FIG. 1 , the conventional receiver includes an antenna 12 for receiving an RF (radio frequency) signal. The RF signal is filtered by a filter 14 and amplified by an amplifier 16 .
The filtered and amplified RF signal is then applied to a first mixer 18 and a second mixer 20 of a first mixing stage 21 . The first mixer 18 uses an in-phase oscillation signal Ia generated by a first quadrature voltage controlled oscillator 22 . The second mixer 20 uses a quadrature-phase oscillation signal Qa generated by the first quadrature voltage controlled oscillator 22 .
An output of the first mixer 18 is provided to a third mixer 24 and a fourth mixer 26 of a second mixing stage 27 . The third mixer 24 uses an in-phase oscillation signal Ib generated by a second quadrature voltage controlled oscillator 29 , and the fourth mixer 26 uses a quadrature-phase oscillation signal Qb generated by the second quadrature voltage controlled oscillator 29 .
The second mixer 20 generates an output provided to a fifth mixer 28 and a sixth mixer 30 . The fifth mixer 28 uses the in-phase oscillation signal Ib, and the sixth mixer 30 uses the quadrature-phase oscillation signal Qb. Outputs of the third and sixth mixers 24 and 30 are provided to a selector 32 that generates an in-phase representation IFI of the RF signal. Outputs of the fourth and fifth mixers 26 and 28 are provided to a selector 34 that generates a quadrature-phase representation IFQ of the RF signal. Depending on the phases of the oscillation signals applied to the various mixers, a desired down-converted signal is obtained with the selector 32 acting as an adder and the selector 34 acting as a subtractor, or vice versa, with the selector 32 acting as a subtractor and the selector 34 acting as an adder.
The second quadrature voltage controlled oscillator 29 generates oscillation signals at a much lower frequency, compared to the first quadrature voltage controlled oscillator 22 . For example, the frequency of the RF signal received at the antenna 12 is around 1.9 GHz. The frequency of the oscillation signals generated by the first quadrature voltage controlled oscillator 22 is in a range from about 1.5 to about 1.7 GHz. The second quadrature voltage controlled oscillator 29 generates oscillation signals with a difference frequency between the frequency of the RF signal received at the antenna 12 and the frequency of oscillation signals generated by the first quadrature voltage controlled oscillator 22 . For example, the difference frequency is in a range from about 200 MHz to about 400 MHz.
The mixers within the receiver of FIG. 1 are used to down-convert the frequency of the RF signal received at the antenna 12 to an intermediate frequency. An image signal has a frequency lower than the oscillation frequency. The image signal is down-converted to the same intermediate frequency as the received radio signal. The down-converted image signal may interfere with the desired down-converted radio signal and degrade the receiver's performance.
To reject the image signal, extra image-rejection filters may be used before the mixers. However, integration of such extra filters on to the same circuit as the receiver in FIG. 1 is difficult. Therefore, the mixers within the receiver are used here to eliminate the down-converted image signal. The quality of the mixers is determined by a quadrature phase relationship between oscillation signals generated by the first quadrature voltage controlled oscillator 22 . For example, the down-converted image signal may not be completely eliminated without a precise quadrature relationship between the in-phase component I and the quadrature phase component Q generated by the first quadrature voltage controlled oscillator 22 .
FIG. 2 shows a block diagram of a quadrature voltage controlled oscillator as disclosed in U.S. Pat. No. 6,456,167 entitled “Quadrature Oscillator”. Referring to FIG. 2 , the conventional quadrature voltage controlled oscillator includes a first oscillation circuit 100 , a second oscillation circuit 200 , and current sources I 1 and I 2 . In-phase components IP and IN output from the first oscillation circuit 100 are applied to input terminals of the second oscillation circuit 200 . Quadrature components QP and QN output from the second oscillation circuit 200 are applied to input terminals of the first oscillation circuit 100 , respectively. The in-phase components IP and IN and quadrature components QP and QN are applied to mixers 18 and 20 in the receiver of FIG. 1 for example.
However, the in-phase components of the voltage controlled oscillator may not have an ideal quadrature relationship with the quadrature-phase components. That is, a phase difference between the in-phase components and the quadrature-phase components may be 90°+ERR, with ERR being an error component. Such an error in the phase difference is mainly due to device mismatch in the voltage controlled oscillator. With such an error, a passive filter may be used to reject the resulting image signal from the received radio frequency in a receiver. However, such a passive filter within the receiver complicates the design and increases the chip size of the receiver.
Therefore, the quadrature voltage controlled oscillator needs to be precisely controlled so that the in-phase signal and the quadrature-phase signal have the proper quadrature relationship for desired receiver performance. U.S. Pat. No. 6,462,626 discloses a quadrature oscillator device that controls a gain of an amplifier.
In U.S. Pat. No. 6,462,626, an amplifying ratio of the amplifier in the quadrature oscillator device is controlled for a precise quadrature relationship between an in-phase signal component I and a quadrature phase signal component Q. However, such a gain adjustment may be manual after measurement of the in-phase and quadrature signal components I and Q. Such manual adjustment may be time-consuming and prone to error. Thus, an efficient and accurate mechanism for automatically controlling the quadrature relationship between the in-phase and quadrature signal components I and Q is desired.
SUMMARY OF THE INVENTION
Accordingly, the present invention automatically controls the quadrature phase relationship between oscillation signals generated by a quadrature voltage controlled oscillator within a receiver.
In an aspect of the present invention, a quadrature voltage controlled oscillator includes oscillation circuits for generating at least one in-phase oscillation signal and at least one quadrature-phase oscillation signal that are used to generate an in-phase output signal and a quadrature-phase output signal. In addition, a compensation circuit adjusts biasing in the oscillation circuits depending on a phase relationship between the in-phase and quadrature-phase output signals.
The quadrature voltage controlled oscillator may be used to particular advantage within a wireless receiver that mixes the in-phase and quadrature-phase oscillation signals with an RF (radio frequency) signal to generate the in-phase and quadrature-phase output signals.
In an exemplary embodiment of the present invention, the biasing in the oscillation circuits is adjusted by the compensation circuit to set a phase difference between the in-phase and quadrature-phase output signals to be substantially 90°.
In another exemplary embodiment of the present invention, the oscillation circuits include a first oscillation circuit for generating differential in-phase oscillation signals and a second oscillation circuit for generating differential quadrature-phase oscillation signals.
In a further exemplary embodiment of the present invention, the quadrature voltage controlled oscillator further includes a first current source that generates a first bias current for the first oscillation circuit and a second current source that generates a second bias current for the second oscillation circuit. In that case, the compensation circuit adjusts the first and second bias currents. For example, the first and second bias currents are adjusted complimentarily.
In yet another exemplary embodiment of the present invention, the compensation circuit includes a phase mismatch detector that determines a phase difference between the in-phase and quadrature-phase output signals. The first and second bias currents are adjusted complimentarily until the phase difference between the in-phase and quadrature-phase output signals is substantially 90°.
In this manner, the phase relationship between the oscillation signals generated by the oscillation circuits is automatically controlled by monitoring the phase relationship between the resulting in-phase and quadrature-phase output signals.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of the present invention will become more apparent when described in detailed exemplary embodiments thereof with reference to the attached drawings in which:
FIG. 1 shows a wireless receiver of the prior art;
FIG. 2 shows a block diagram of a conventional quadrature voltage controlled oscillator of the prior art;
FIG. 3 shows a block diagram of a quadrature voltage controlled oscillator according to an exemplary embodiment of the present invention;
FIG. 4 shows a circuit diagram of the quadrature voltage controlled oscillator according to an exemplary embodiment of the present invention;
FIG. 5 shows a block diagram of a wireless receiver having the quadrature voltage controlled oscillator of FIG. 3 according to an exemplary embodiment of the present invention;
FIG. 6 shows a graph of a simulation result for phase variation of a quadrature-phase oscillation signal of the quadrature voltage controlled oscillator of FIG. 4 ; and
FIG. 7 shows a graph of simulation results for in-phase and quadrature-phase oscillation signals of the quadrature voltage controlled oscillator of FIG. 4 .
The figures referred to herein are drawn for clarity of illustration and are not necessarily drawn to scale. Elements having the same reference number in FIGS. 1 , 2 , 3 , 4 , 5 , 6 , and 7 refer to elements having similar structure and/or function.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3 shows a block diagram of a quadrature voltage controlled oscillator according to an exemplary embodiment of the present invention. Referring to FIG. 3 , the quadrature voltage controlled oscillator includes a phase compensation circuit 300 , a first oscillation circuit 100 , a first current source 410 , a second oscillation circuit 200 , and a second current source 420 .
The phase compensation circuit 300 receives an in-phase output signal IFI and a quadrature-phase output signal IFQ to detect a level of deviation from a desired phase difference (such as 90° for example) between the in-phase and quadrature-phase output signals IFI and IFQ. Additionally, the phase compensation circuit 300 generates first and second compensation signals −IC and +IC based on the phase deviation for complementarily controlling first and second bias currents I 1 and I 2 .
The first oscillation circuit 100 receives quadrature-phase oscillation signals QP and QN from the second oscillation circuit 200 to generate in-phase oscillation signals IP and IN. The first current source 410 provides the first bias current I 1 to the first oscillation circuit 100 in response to the first compensation signal −IC. The second oscillation circuit receives the in-phase oscillation signals IP and IN from the first oscillation circuit 100 to generate the quadrature-phase oscillation signals QP and QN. The second current source 420 provides the second bias current 12 to the second oscillation circuit 200 in response to the second compensation signal +IC.
The in-phase and quadrature-phase output signals IFI and IFQ are generated by mixing the in-phase and quadrature phase oscillation signals IP, IN, QP, and QN with an RF (radio frequency) signal such as within a wireless RF receiver for example. The in-phase oscillation signals IP and IN are generated as differential signals in the first oscillation circuit 100 , and the quadrature-phase oscillation signals QP and QN are generated as differential signals in the second oscillation circuit 200 .
FIG. 4 shows a circuit diagram of the quadrature voltage controlled oscillator of FIG. 3 according to an exemplary embodiment of the present invention. Referring to FIG. 4 , the quadrature voltage controlled oscillator includes a local oscillator 530 and a phase compensation circuit 300 . The local oscillator 530 includes the first oscillation circuit 100 , the second oscillation circuit 200 , a current source IS, a first NMOSFET (N-channel metal oxide semiconductor field effect transistor) MN 9 , a second NMOSFET MN 10 , and a third NMOSFET MN 11 .
The second NMOSFET MN 10 forms the first current source providing the first bias current I 1 for biasing the first oscillation circuit 100 . Similarly, the third NMOSFET MN 11 forms the second current source providing the second bias current 12 for biasing the second oscillation circuit 200 .
The first oscillation circuit 100 includes PMOSFETs (P-channel metal oxide semiconductor field effect transistors) MP 1 and MP 2 , an inductor L 1 , a capacitor C 1 , and NMOSFETs MN 1 , MN 2 , MN 3 and MN 4 . The in-phase oscillation signals IP and IN are generated as differential signals at first and second in-phase output lines LI 01 and LI 02 , respectively.
The PMOSFET MP 1 has a source coupled to a high supply voltage VDD, a drain coupled to the first in-phase output line LI 01 , and a gate coupled to the second in-phase output line LI 02 . The PMOSFET MP 2 has a source coupled to the high supply voltage VDD, a drain coupled to the second in-phase output line LI 02 , and a gate coupled to the first in-phase output line LI 01 . The inductor L 1 and the capacitor C 1 are coupled in parallel between the first and second in-phase output lines LI 01 and LI 02 .
The NMOSFET MN 1 has a drain coupled to the first in-phase output line LI 01 , a source coupled to a first node N 1 , and a gate coupled to the second in-phase output line LI 02 . The NMOSFET MN 2 has a drain coupled to the second in-phase output line LI 02 , a source coupled to the first node N 1 , and a gate coupled to the first in-phase output line LI 01 . The NMOSFET MN 3 has a drain coupled to the first in-phase output line LI 01 , a source coupled to the first node N 1 , and a gate receiving a quadrature-phase oscillation signal QP. The NMOSFET MN 4 has a drain coupled to the second in-phase output line LI 02 , a source coupled to the first node N 1 , and a gate receiving a quadrature-phase oscillation signal QN.
The second oscillation circuit 200 includes PMOSFETs MP 3 and MP 4 , an inductor L 2 , a capacitor C 2 , and NMOSFETs MN 5 , MN 6 , MN 7 and MN 8 . The quadrature-phase oscillation signals QN and QP are generated as differential signals at first and second quadrature-phase output lines LQ 01 and LQ 02 , respectively.
The PMOSFET MP 3 has a source coupled to the high supply voltage VDD, a drain coupled to the first quadrature-phase output line LQ 01 , and a gate coupled to the second quadrature-phase output line LQ 02 . The PMOSFET MP 4 has a source coupled to the high supply voltage VDD, a drain coupled to the second quadrature-phase output line LQ 02 , and a gate coupled to the first quadrature-phase output line LQ 01 . The inductor L 2 and the capacitor C 2 are coupled in parallel between the first and second quadrature-phase output lines LQ 01 and LQ 02 .
The NMOSFET MN 5 has a drain coupled to the first quadrature-phase output line LQ 01 , a source coupled to a second node N 2 , and a gate coupled to the second quadrature-phase output line LQ 02 . The NMOSFET MN 6 has a drain coupled to the second quadrature-phase output line LQ 02 , a source coupled to the second node N 2 , and a gate coupled to the first quadrature-phase output line LQ 01 . The NMOSFET MN 7 has a drain coupled to the first quadrature-phase output line LQ 01 , a source coupled to the second node N 2 , and a gate receiving an in-phase signal IP. The NMOSFET MN 8 has a drain coupled to the second quadrature-phase output line LQ 02 , a source coupled to the second node N 2 , and a gate receiving an in-phase signal IN.
The second NMOSFET MN 10 has a drain coupled to the first node N 1 and a source coupled to a low supply voltage VSS. The supply voltage VSS may be a negative voltage or a ground voltage. The third NMOSFET MN 11 has a drain coupled to the second node N 2 and a source coupled to the low supply voltage VSS. A first resistor R 1 is connected between a gate of the second NMOSFET MN 10 and a third node N 3 , and a second resistor R 2 is connected between a gate of the third NMOSFET MN 11 and the third node N 3 .
The current source IS and the first NMOSFET MN 9 that is diode-connected partially bias the second and third NMOSFETs MN 10 and MN 11 . The third node N 3 is coupled to the diode connection of the first NMOSFET MN 9 . The current source IS is connected between the high supply voltage VDD and the third node N 3 . The diode-connected first NMOSFET MN 9 is connected between the third node N 3 and the low supply voltage VSS.
The phase compensation circuit 300 receives the in-phase and quadrature-phase output signals IFI and IFQ to detect a level of deviation from a desired phase difference (such as 90° for example) between the phases of the in-phase and quadrature-phase output signals IFI and IFQ. In addition, the phase compensation circuit 300 produces first and second compensation signals −IC and +IC in response to the phase deviation. The first and second compensation signals −IC and +IC are differential signals for complementarily adjusting the first and second bias currents I 1 and I 2 . A first control current +IC is applied to a gate of the third NMOSFET MN 11 and a second control current −IC is applied to a gate of the second NMOSFET MN 10 .
The operation of the quadrature voltage controlled oscillator of FIGS. 3 and 4 is now described. The first oscillation circuit 100 receives quadrature-phase oscillation signals QP and QN through the gates of the NMOSFETs MN 3 and MN 4 . The inductor L 1 and the capacitor C 1 form a resonant tank causing the first oscillation circuit 100 to resonate. As a result, the first in-phase oscillation signal IP is outputted from the first in-phase output line LI 01 , and the second in-phase oscillation signal IN is outputted from the second in-phase output line LI 02 .
The second oscillation circuit 200 receives the in-phase oscillation signals IP and IN through the gates of the NMOSFETs MN 7 and MN 8 . The inductor L 2 and the capacitor C 2 form a resonant tank causing the second oscillation circuit 200 to resonate. As a result, a first quadrature-phase oscillation signal QN is outputted from the first quadrature-phase output line LQ 01 , and a second quadrature-phase oscillation signal QP is outputted from the second quadrature-phase output line LQ 02 .
FIG. 5 shows a block diagram of a wireless receiver having the quadrature voltage controlled oscillator of FIGS. 3 and 4 according to an exemplary embodiment of the present invention. Referring to FIG. 5 , the wireless receiver includes a down converter 510 , a phase compensation circuit 300 , and a local oscillator 530 . The down converter 510 receives an RF (radio frequency) signal and generates an intermediate in-phase output signal IFI and an intermediate quadrature-phase output signal IFQ by mixing the received RF signal and oscillation frequencies LOI and LOQ from the local oscillator 530 . The oscillation frequency LOI includes the first and second in-phase oscillation signals IP and IN, and the oscillation frequency LOQ includes the first and second quadrature-phase oscillation signals QN and QP.
The phase compensation circuit 300 detects a level of deviation from a desired phase difference (such as 90° for example) between the phases of the in-phase and quadrature-phase output signals IFI and IFQ to generate the complementary compensation signals +IC and −IC. The local oscillator 530 generates the in-phase and quadrature-phase frequencies in response to the complementary compensation signals +IC and −IC. The phase compensation circuit 300 includes a phase mismatch detector 321 , an analog-to-digital (A/D) converter 323 , and a digital-to-analog (D/A) converter 325 .
The operation of the wireless receiver of FIG. 5 is now described. The down converter 510 receives the RF signal and generates the intermediate in-phase output signal IFI and the intermediate quadrature-phase output signal IFQ by mixing the received RF signal and the oscillation frequencies LOI and LOQ from the local oscillator 530 . The phase mismatch detector 321 compares a phase of the intermediate in-phase output signal IFI with a phase of the intermediate quadrature-phase output signal IFQ. The phase mismatch detector 321 generates a detection signal DETO that indicates the level of deviation from a desired phase difference (such as 90° for example) between the phases of the in-phase and quadrature-phase output signals IFI and IFQ.
The analog-to-digital converter 323 converts the detection signal DETO to a digital control signal CNT having a digital value. The digital-to-analog converter 325 generates a first current −IC and a second current +IC based on the digital control signal CNT and transmits the first and second currents −IC and +IC to the local oscillator 530 . In one embodiment of the present invention, the first and second currents −IC and +IC are differential currents such that the current +IC is sourced to the local oscillator 530 via a first terminal and the current −IC is sunk from the local oscillator 530 via a second terminal.
FIG. 6 shows a simulated graph of a phase variation of a quadrature-phase output signal of the quadrature voltage controlled oscillator of FIG. 4 versus the magnitude of the compensation current IC. Referring to FIG. 6 , the phase of the quadrature-phase output signal QP (or QN) varies substantially linearly with the compensation current IC. Thus, the compensation current IC from the D/A converter 325 in the phase compensation circuit 300 of FIG. 5 is adjusted to vary the phase difference between the quadrature-phase oscillation signals QP and QN of the voltage controlled oscillator.
FIG. 7 shows a simulated graph of the in-phase and quadrature-phase oscillation signals of the quadrature voltage controlled oscillator of FIG. 4 . Referring to FIG. 7 , the phases of the quadrature-phase oscillation signals QP-QN are precisely adjusted while the amplitude is maintained to be constant.
In this manner, the phase relationship of the oscillation signals generated by the quadrature voltage controlled oscillator of FIG. 4 is automatically adjusted precisely by monitoring the phase relationship between the resulting in-phase and quadrature-phase output signals IFI and IFQ. With such precise adjustment, the phase relationship between the in-phase and quadrature-phase oscillation signals and in turn between the in-phase and quadrature-phase output signals is maintained to be substantially 90°. With such a quadrature phase relationship, the receiver using such oscillation signals has the image signals effectively eliminated.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. | A quadrature voltage controlled oscillator includes oscillation circuits for generating in-phase and quadrature-phase oscillation signals that are used to generate in-phase and quadrature-phase output signals. A compensation circuit adjusts biasing in the oscillation circuits depending on a phase relationship between the in-phase and quadrature-phase output signals to automatically control the phase relationship between the oscillation signals. | 7 |
BACKGROUND OF THE INVENTION
This invention is directed to an improvement in a wheelchair wherein the wheelchair can be powered by the occupant therein by the occupant pushing a lever away from the occupant. Movement of the lever transfers power to the appropriate driving wheel of the wheelchair to propel the wheelchair. When the lever is in a neutral position, however, the wheelchair is capable of being moved by more conventional methods such as using the push rims normally attached to the wheels of the wheelchair, or by pushing by an assisting person in the normal manner.
Many wheelchairs augmented with devices wherein the occupant of the wheelchair can propel himself have been developed. Typical of such wheelchairs are those in U.S. Pat. Nos. 3,994,509; 3,309,110; 3,877,725; 3,666,292 and 4,274,651. In the U.S. Pat. No. 3,994,509 an extensive discussion is directed to certain of the negative aspects of many of the prior known wheelchairs which have been augmented with devices for self-propulsion. Others of the patents listed in this paragraph also have such discussions.
One thing which can be gleaned by reviewing the patents which have issued in this art area is that there is a lot of disagreement as to what is advantageous and what is disadvantageous in devices of this type. Certain inventors have deemed it disadvantageous to only get power from one of a forward or reverse stroke of devices utilizing levers capable of being pushed back and forth. To this end, U.S. Pat. Nos. 3,994,509 and 3,666,292 have developed systems wherein the power of both the forward and reverse stroke is utilized. U.S. Pat. No. 4,274,651 skirts the problem entirely by sustituting rotating cranks instead of levers which can be moved back and forward.
U.S. Pat. No. 3,309,110 develops its power stroke in returning the lever back toward the occupant of the chair and teaches the use of a "Y" shaped apparatus which enables the lever to be gripped with something other than a fist, such as positioning the wrist within the "Y" shaped apparatus.
U.S. Pat. No. 3,877,725 teaches utilizing the forward motion of the lever as the power stroke in a normal instance, and the adaptation of the mechanism such that, to go backwards, a rearward stroke of the lever can be utilized.
While all of the above noted patents certainly have their individual, unique advantages, it is deemed that all of them also suffer with certain defects.
As U.S. Pat. No. 3,309,110 notes, many of the persons confined to wheelchairs and the like do not have use of their fists sufficiently such that they can grip a lever or a crank and hold on to the same while pushing or rotating. This patent, as noted above, attempted to solve this problem by utilizing a "Y" shaped member which can be cocked around the wrist. If a person confined to a wheelchair suffers from arthritis or the like, deformities of the hands and wrists are quite frequent. Because of the pain associated with the joint, even the use of the "Y" shaped member of U.S. Pat. No. 3,309,110 could be precluded. Further, any wheelchair having propulsion levers, cranks, or the like, which require the pulling of the lever back toward the occupant during all of or a portion of the power stroke, continually direct a force on to the occupant, sliding the occupant forward on the seat in response to the pulling of the lever backward by the occupant. While this does not constitute a problem in those individuals who are fairly heavy, in the handicapped person who carries little body weight, the constant tugging of this perkson's lighter body forward, in attempts to pull back on the lever in a power stroke, can lead to failure of acceptance of use of the device by such a person.
It could then be summed up that, with regard to the direction of stroke of a lever, crank or the like, because of gripping problems and because of body weight problems, it is considered advantageous to utilize as a power stroke a movement away from the body of the occupant of the chair. Because of this factor, many of the known prior devices in this art area are thus excluded.
Additionally, many of the wheelchairs equipped with self-propelling devices do not allow for disattachment of these devices from the driving wheels or, if the devices can be disattached from the driving wheels, detachment is inconvenient and sometimes impractical. U.S. Pat. No. 3,994,509 provides a simple push button for detaching the interconnection between its driving levers and the driving wheels. Unfortunately, if a hand is occupied in depressing the push button, that same hand cannot be utilized to move the wheels in the more conventional manner by pushing on the push rims normally attached to the side of the wheels of the wheelchair. U.S. Pat. No. 3,666,292 provides no means for disattaching levers, such that whenever the wheelchair is moving, the levers are continually oscillating back and forth, which can serve as a hazard. Many times, the occupant of the wheelchair wishes to utilize the push rims on the individual wheels for moving short distances, turning in circles or, at other times, the occupant of the wheelchair simply lets another person push him around utilizing the gripping means normally found on the upper back of the wheelchair.
In those instances when the occupant of the wheelchair wishes either someone else to push him, or wishes to push himself, or move himself via the push rims on the wheels, placement of any levers or the like which continually oscillate, such as those in U.S. Pat. No. 3,666,292, or which are in the way of use of the push rims such as those seen in U.S. Pat. No. 3,309,110, is considered disadvantageous.
In view of all of the problems discussed above, it is considered that while many approaches have been taken toward providing a wheelchair which is conveniently used by the occupant therein to propel himself, each of the known devices suffer from one or several defects which has prevented wide acceptance and use of these type of devices.
BRIEF DESCRIPTION OF THE INVENTION
In view of the above, it is therefore a broad object of this invention to provide a wheelchair which can be freely pushed by another person in both a backward and forward diection without the disengagement of any parts, components or the like. It is a further object to provide a wheelchair that is capable of being utilized in a normal manner by the occupant therein in propelling the occupant backward or forward utilizing arm and hand movement on the push rims formed on the outboard side of the driving wheels. It is a further object of this invention to provide a wheelchair which has means thereon wherein the occupant of the wheelchair can propel himself by pushing with his arms away from his body against a lever or the like in a power stroke. It is a further object of this invention to provide a wheelchair wherein the drive wheels are completely free wheeling in a forward direction with regard to the driving mechanism such that the forward speed of the wheelchair is not inhibited by the back and forth speed of the driving mechanism but, in fact, the wheelchair is capable of being accelerated to a fairly rapid velocity by users thereof when participating in sporting events devoted strictly to the users of wheelchairs such as marathons, sprints, use on the backetball court or the tennis court. It is a further object to provide a wheelchair which, while being propelled in a forward manner by the propelling device, is inhibited from moving backwards such that the chair can be safely negotiated up a ramp or the like, utilizing the propelling device without fear of the chair rolling backwards. Additionally, it is an object to provide a wheelchair which is capable of being braked to inhibit or stop all forward velocity.
Furthermore, it is considered that it is advantageous to provide a device which is capable of being attached to existing wheelchairs manufactured utilizing certain standard techniques, or can be built into new designs of wheelchairs wherein the device is an inherent part of the wheelchair. Furthermore, because of the continued daily use of the chair and the device, any such device must be so engineered so as to be capable of a long and useful lifetime.
These and other objects, as will become evident from the remainder of this specification are achieved in an occupant propellable device which comprises: a frame capable of supporting said occupant; a plurality of wheels rotatably mounted on said frame; at least one of said wheels comprising a driving wheel; at least one movable means mounted on said frame, at least a portion of said movable means reciprocally movable back and forth away from and towards the occupant from a neutral position towards said occupant to a displaced position away from said occupant, said movable means movable in a power stroke wherein said movable means moves in a direction away from said neutral position and said occupant towards said displaced position and said movable means movable in a return stroke wherein said movable means moves in the direction from said displaced position back towards said neutral position and said occupant; at least one transfer means rotatably mounted on said frame in association with said driving wheel and said movable means; said transfer means including a first and a second ratchet means; said first ratchet means operatively associated with said driving wheel, said first ratchet means allowing said driving wheel to free wheel in the forward direction of movement of said device; said second ratchet means operatively associated with said first ratchet means and said movable means, said second ratchet means allowing said driving wheel to free wheel in both said forward direction and the reverse direction when said movable means is in said neutral position and said second ratchet means acting through said first ratchet means by engaging with said first ratchet means rotating said driving wheel in said forward direction in response to said movable means moving in said power stroke and said second ratchet means disengaging with said first ratchet means when said movable means moves in said return stroke.
Preferredly, the device of the invention would have both a first and second driving wheel with both a movable means a transfer means associated with each of the driving wheels respectively. Preferredly, the device would comprise a wheelchair with independent first and second main axles with the first and second driving wheels independently rotably mounted on said axles, allowing for convenient folding of the chair or the like.
In the preferred embodiment of the invention each of the movable means would comprise a lever means pivotably mounted to the frame of the wheel chair, with the upper portion of each of the lever means being positioned to be comfortably gripped by the occupant and to be moved reciprocally back and forth in an arc toward and away from the occupant with movement away from the occupant constituting the power stroke. Preferredly, each of the transfer means would further include a member rotatably mounted about one of the respective axle means in association with the respective driving wheel also rotatably mounted on the axle.
Preferredly, the first ratchet means would include one of the member or the driving wheel having a first set of ratchet teeth means located thereon, and having a ratchet engagement means associated with the other of the member or the driving wheel which is capable of engaging the first set of ratchet teeth means in a first instance, and disengaging in a second instance. Preferredly, the second ratchet means would include each of the members having a second set of ratchet teeth means located thereon. A connecting means would attach to the lever means and would be associated with the member with the connecting means including a second engaging means capable of engaging the second set of ratchet teeth means when the lever moves in the power stroke whereby the member is rotated. The second engaging means would disassociate with the second set of ratchet teeth means when the lever would be in the neutral position.
In addition to the preferred embodiments noted above, a brake means could be operatively associated with each of the lever means and would be capable of engaging against the outside periphery of the driving wheels upon movement of the respective lever means backward toward the occupant, away from the respective neutral position. As such, then, the power stroke would be from the neutral position away from the occupant whereas movement of the lever means from the neutral position back to the occupant would engage the brake means against the wheels.
Preferredly, the connecting means would include a flexible connector having ends, with one of the ends attaching to the lever means and the other of the ends having a biasing means which is interspaced between that end and the frame. The flexible connector would engage the member by slidably contacting the member and the second engagement means would include a contact member located on the flexible connector. The contact member would be positioned on the flexible connector such that it disengages from the second set of ratchet teeth means when the lever is in the neutral position and engages with the second set of ratchet teeth means when the lever moves in its power stroke.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention described in this specification will be better understood when taken in conjunction with the drawings wherein:
FIG. 1 shows, in side elevation, a wheelchair having this invention attached thereto;
FIG. 2 is a side elevational view in a larger scale of certain portions of FIG. 1;
FIG. 3 is a side elevational view similar to FIG. 2 with the exception that certain of the components therein are positioned in a different spatial relationship;
FIG. 4 is an end elevational view in partial section about the line 4--4 of FIG. 2;
FIG. 5 is a side elevational view in section about the line 5--5 of FIG. 4;
FIG. 6 is a side elevational view similar to FIG. 5 with certain of the components located in a different spatial relationship from that seen in FIG. 5; and
FIG. 7 is a view similar to FIGS. 5 and 6 with these components located in even a further spatial configuration.
This invention utilizes certain principles and/or concepts as are set forth in the claims appended to this specification. Those skilled in the art to which this art pertains will realize that these principles and/or concepts are capable of being utilized in a variety of different embodiments differing from the exact illustrative embodiment utilized herein to illustrate the invention. For this reason, this invention is not to be construed as being limited to the exact illustrative embodiment, but is to be construed only in light of the claims.
DETAILED DESCRIPTION OF THE INVENTION
Prior to a total review of all mechanical components of this invention, it is believed that, by briefly describing certain of the components, and illustrating the manner in which the invention is utilized to propel a wheelchair, a further understanding of the totality of the components will be facilitated.
In FIG. 1, there is illustrated a wheelchair 10 of the common type having rear driving wheels, collectively identified by the numeral 12, and front supporting wheels, collectively identified by the numeral 14. These components are attached to respective frame members, not individually identified at this time.
As seen in FIG. 1, the wheelchair 10 includes a left side lever 16 and a right side lever 18. The levers 16 and 18, as well as other components of the invention are identical with each other and only differ in their placement on the respective sides of the wheelchair 10. A cable 20 leads from lever 16 around the back axle spool 22 (identified in greater detail later) and terminates at spring 24. Spring 24 is attached to a portion of the frame and biases the cable taut. A brake 26 is located on the lever 16 and can contact the tread 28 of the driving wheel 12.
The right side lever 18 also includes a cable, axle, spool, spring, brake, etc., as per the left side. For the operation of the wheelchair 10 discussed below, reference will be made to the right lever 18, however, detailed reference to the parts attached thereto will not be made, insofar as their operation is exactly the same as the operation of those parts attached to lever 16.
In FIG. 1, the orientation of lever 16 and 18 with respect to one another are not that which they would assume if the wheelchair 10 was unoccupied as shown in FIG. 1. Both of the levers would be oriented as per lever 16 because of the bias of spring 24. The right side lever 18 is oriented differently to show its placement on the other side of the wheelchair 10.
When the wheelchair 10 is occupied by an occupant and the levers 16 and 18 are in the position as occupied by the lever 16 in FIG. 1, the occupant of the wheelchair 10 can freely move the wheelchair 10 by the push rims 30 formed on the exposed side of the driving wheels 12 in a typical manner common to most wheelchairs. When the levers 16 and 18 are positioned as is lever 16 in FIG. 1, the wheelchair 10 is free to go backward and forward, or spin in circles with one wheel going backward and the other wheel going forward, as is typical for all common wheelchairs, by manipulation of the push rims 30 by the occupant of the chair. Additionally, the handles 32 can be gripped by an auxiliary person to push the chair 10 and the occupant therein, if it is so occupied, backward, forward, up stairs, and the like in the normal manner.
The occupant of the chair can propel himself forward by pushing the levers 16 and 18 away from his body toward the forward end of the chair to cause movement of the cable 20 around the axle spool 22, elongating the spring 24. The movement away from the occupant constitutes the power stroke for the levers 16 and 18. This power stroke need not be a full stroke, but can be a partial stroke, and can be a partial stroke in the area from the occupant to about mid point in the movement of the levers, or from the mid point to the far reach of the levers, or any other portion of the full movement of the levers 16 and 18 from their position toward the occupant to their position distal from the occupant. The lever 16 in FIG. 1 is seen in what can be constituted as a neutral position. At this point, the driving wheels 12 are free to rotate as noted above. As soon as the lever 16 is moved slightly forward from this neutral position, the power stroke starts, and any further forward movement is movement in the power stroke to drive the driving wheels 12 counterclockwise, as seen in FIG. 1, to propel the chair 10 to the left, as seen in FIG. 1.
The individual levers 16 and 18 can be moved in unison, backward and forward together to drive the wheelchair 10 in a straight direction, or one or the other of the levers can be moved in the power stroke while the other is held stationary to cause the driving wheel 12 associated with the particular lever, whether it be lever 16 or 18, to rotate while the other remains static, or free wheels. This causes turning of the wheelchair 10. Additionally, one of the levers 16 or 18 could be utilized and the other driving wheel 12 could be held fast by gripping of the hand rail 30 by the occupant of the wheelchair 10 or even rotated in the reverse direction, to cause a very tight rotation of the wheelchair 10 about that driving wheel 12 which is gripped by its hand rail 30 by the occupant of the wheelchair 10.
As the occupant of the wheelchair 10 utilizes the levers 16 and 18 to propel the wheelchair 10 forward, the occupant at any time can simply hold the levers 16 or 18 fixed in their position whether it be their neutral position or a position pushed forward from the neutral position toward the front of the wheelchair 10 and the wheelchair 10 will continue to move forward by free wheeling of the driving wheels 12 with respect to their mounting on the wheelchair 10.
The free wheeling of the driving wheels 10 irrespective of the position of the levers 16 and 18 allows for use of the wheelchair 10 in competitive situations, which are becoming more and more common among those individuals confined to wheelchairs. Thus, an occupant confined to a wheelchair could utilize the wheelchair 10 in a sports event, such as a race or the like, or in a team sport, such as basketball or the like. Because of the ability to propel the wheelchair 10 at a fairly rapid velocity, and then coast after once achieving this velocity, the occupant of the wheelchair 10 can rest in between power strokes without having to return the levers 16 and 18 to the neutral position or having the stopping of the movement of the levers 16 and 18 concurrently cause a braking or stopping effect on the driving wheels 12.
If the occupant of the wheelchair 10 wishes to decrease the velocity of the wheelchair 10, or to brake it or hold it in a fixed position, the right and left levers 16 and 18 can be pulled backwards from the neutral position such that the brake 26 contacts the outside perimeter of the driving wheels 12 and fixedly holds them in position. Either of the levers 16 or 18 can be pulled backward to independently contact its appropriate brake 26 against its appropriate driving wheel 12 to slow up or fix that particular driving wheel. This allows for steering of the wheelchair 10 as well as for stopping and holding it in a fixed position.
Referring now to FIGS. 4 and 5, an axle 34 is mounted to an upright frame member 35 of the chair 10 by appropriately attaching the axle 34 with a nut 36 which appropriately threads on to threads formed on the axle 34. A collar 38 having a bearing race 40 formed on its end is fed over axle 34. A wheel hub 42 having a sleeve 44 located therein fits onto the axle 34 next to the collar 38. A bearing race 46 fits next to the sleeve 44 and the totality of the unit is secured to the axle 34 via a washer 48 and an outside nut 50.
The wheel hub 42 is appropriately suspended on the bearing races 40 and 46 via bearing races 52 and 54 by the insertion of appropriate bearings collectively identified by the numeral 56 between the respective bearing races. An inside snap ring 58 and an outside snap ring 60 maintain the bearings 56 and bearing races 54 and 52 appropriately positioned within the wheel hub 42. Spokes collectively identified by the numeral 62 project from the wheel hub 42 in the normal manner to support the rim (not numbered or seen) and tread 28 of the driving wheels 12.
A flanged boss 64 abutts against the inside edge of the wheel hub 42 over the area occupied by the collar 38. The flange boss 64 is held in position by a second flange boss 66 having threads on its inside surface which thread against a portion of the hub 42. This positions the flange boss 64 in a coaxial arrangement with the axle 34. Because of the presence of the threaded flange boss 66 the flange boss 64 is fixedly held against the hub 42 and rotated in conjunction therewith. Because of the shape of the flange boss 64 an annular cavity 68 is formed between the inside surface of the flange portion of the flange boss 64 and a portion of the hub 42.
Two pawls 70 and 72 fit within the annular cavity 68 by fitting within small grooves 74 formed in the flanged boss 64. Each of the pawls 70 and 72 include a flat surface collectively identified by the numeral 76. A spring ring 78 fits within the annular cavity 68 over the top of both the pawls 70 and 72 against the flat surface 76. This biases the pawls outward by the pressure of the spring ring 78 on the flat surfaces 76. If the pawls are rotated, as seen in FIG. 5, such that the end of the top pawl goes down and the end of the bottom pawl goes up, the flat surfaces 76 push against the spring ring 78 which biases the pawls back into their position as they are seen in FIG. 5. In FIG. 7, both the pawls 70 and 72 have had their outside ends pushed inwardly such that their flat surfaces 76 are pushing against the bias of the spring ring 78. As can be seen with regard to the pawl 70 in FIG. 4, the pawls 70 and 72 are bifurcated such that their flat surface 76 is between the bifurcations, such that the spring ring 78 is capabale of fitting between the bifurcations, maintaining it in position over the pawls 70 and 72 and holding the pawls 70 and 72 within the grooves 74.
An annular member 80 fits around the flanged boss 64 and is rotatably movable about the flanged boss 64 and the hub 42 via ball bearings collectively identified by the numeral 82. The annular member 80 carries a first set of ratchet teeth 84 on its inside surface which are positioned such that they interact with the pawls 70 and 72. The annular member 80 contains a second set of ratchet teeth 86 which are bifurcated such that they are located in pairs along the outside of the annular member 80. A space 88 is thus formed between each of the sets of individual teeth of the second ratchet teeth 86. The space 88 accepts the cable 20 between the individual members of a set of the second ratchet teeth 86. The bifurcation of the second ratchet teeth 86 fixedly positions the cable 20 in relation to these second ratchet teeth 86 and does not allow it to slip off one way or the other of the annular member 80.
As referred to above, the cable 20 is attached to one of the levers 16 or 18, in an analagous manner for both, at one of its ends, and attach to the spring 24 at its other end. Referring now to FIGS. 2 and 3, it can be seen that the spring 24 is connected to frame member 90 at one of its ends. The other end of the spring 24 is connected to the cable 20. The spring 24 is a tension spring, and when stretched tends to revert back to its original shape. In FIG. 3, the lever 16 is in its neutral position. The cable 20 can be seen wrapping around the annular member 80 with the second ratchet teeth 86 exposed.
The cable 20 includes a sleeve 92 which is swaged to the cable 20 to hold it in its position on the cable. When the lever, be it lever 16 or 18, is in the neutral position, the sleeve 92 is positioned at the bottom of and to the left of the annular member 80 and does not contact the second ratchet teeth 86. The force of the spring 24 is such that the cable 20 is simply held against the surface of the annular member 80. The annular member 80 is capable of sliding with respect to the cable 20, there being only a slight frictional contact between the two formed by the tension of the spring 24. The tension of the spring 24, however, is sufficient to keep cable 20 located within the annular space 88 between the bifurcated individual teeth of the second ratchet teeth 86.
When the lever 16 or 18 is in the neutral position, the driving wheels 12 are free to free wheel either clockwise or counterclockwise as follows. If they free wheel clockwise, the interaction of the pawls 70 and 72 with the first ratchet teeth 84 is such that the pawls 70 and 72 can slip with respect to the ratchet teeth, allowing the flange boss 64 to which they are attached to rotate independently of the annular member 80. For FIGS. 5, 6 and 7, this would be free rotation of the flange boss 64 in a counterclockwise direction with respect to the annular member 80.
Additionally, the annular member 80 is free to rotate either clockwise or counterclockwise with respect to the cable 20 because of the light frictional fit between these two components. This allows the wheelchair 10 to be moved freely either forward or backward by either the occupant of the chair utilizing the push rims formed as a part of the driving wheels 12 or by an auxiliary person pushing on the handles 32.
When the left or right levers 16 or 18 are pushed forward, the cable 20 is moved with respect to the annular member 80, stretching the spring 24. At a point as is illustrated in FIG. 6, the sleeve 92 engages against the second ratchet teeth 86 and becomes fixed between two adjacent sets of teeth. This then fixes the cable 20 with respect to the annular member 80. Further movement of the levers 16 or 18 continues the movement of the cable 20 and, in FIGS. 5, 6 and 7, results in a counterclockwise torque applied to the annular member 80. This rotates the annular member 80 counterclockwise.
The counterclockwise rotation of the annular member 80 such as that seen in FIG. 6 is communicated via the first ratchet teeth 84 and the pawls 70 and 72 to the flanged boss 64, which in turn, because it is fixedly tightened against the wheel hub 42, rotates the wheel hub 42 and the driving wheel 12 attached thereto. Thus, the forward movement of the lever 16 or 18 in the power stroke, away from the body of the occupant of the wheelchair 10 results in movement of the driving wheels 12 in a direction pushing the wheelchair 10 forward, to the left in FIG. 1. This rotation of the annular member 80 by interlocking of the sleeve 92 with the second ratchet teeth 86 is seen in FIG. 2, and is depicted as movement from the phantom line for the lever 16 to movement of the lever 16 to its position shown in solid line.
When the lever 16 or 18 is released, the cable 20 and the lever 16 or 18 are returned to their original position by the bias created in the spring 24. This movement is depicted in FIG. 3. Additionally, at this time, as depicted in FIG. 7, the annular member 80 is rotating clockwise with respect to the flanged boss 64, which, it will be remembered, is fixed to the driving wheel 12 and the annular member 80 slips with respect to flanged boss 64 by sliding of the first ratchet teeth 84 with respect to the pawls 70 and 72 as the pawls 70 and 72 are flexed inward against the bias of the spring ring 78.
If the driving wheel 12 and the flanged boss 64 attached thereto are rotating faster in a counterclockwise direction, as seen in the Figs. (a forward direction for the wheelchair 10) at a faster rate than the annular member 80 is turned counterclockwise during a power stroke of one of the levers 16 or 18, the faster rotation of the driving wheel 12 and therefore the flanged boss 64 will allow the flanged boss 64 to move counterclockwise with respect to the annular member 80 at a faster rate of counterclockwise movement because of the allowed slippage of the pawls 70 and 72 with respect to the first ratchet teeth 84. Thus, if the wheelchair 10 is already in motion, an inefficient or slow power stroke will not result in loss of momentum of the chair, but simply will result in slippage of the annular member 80 with respect to the flanged boss 64 by slippage of the pawls 70 and 72 with respect to the first ratchet teeth 84.
It is only when the annular member 80 is driven faster in the same direction with respect to the flanged boss 64 that power is communicated from the annular member 80 to the flanged boss 64 via the interaction of the pawls 70 and 72 with the first ratchet teeth 84.
Because the annular member 80 can move in the opposite direction with respect to the flanged boss 64 by the slippage of the pawls 70 and 72 with respect to the first ratchet teeth 84, it is not necessary to return all the way back to the neutral position in a return stroke before initiating a further power stroke. Even a partial return toward the neutral position of one of the levers 16 or 18 will allow for repositioning of the pawls 70 and 72 in different sets of teeth of the first ratchet teeth 84 and then when movement of the levers 16 or 18 is resumed in the direction of the power stroke, further power is then transferred to the flanged boss 64 by the annular member 80 by gripping of the pawls 70 and 72 against the first ratchet teeth 84.
In summary then, it can be seen that the driving wheels 12 are free to spin both forward and backward when the lever 16 or 18 with which the individual driving wheel is associated is in its neutral position. Further, the driving wheel 12 is free to maintain a forward spin even if the levers 16 or 18 are not in their neutral position, because of slippage of the annular member 80 and the flanged boss 64 by the pawls 70 and 72 slipping against the first ratchet teeth 84. This also allows for movement in the reverse direction of the annular member 80 with respect to the flanged boss 64 which happens when the levers 16 and 18 move back toward the occupant of the chair 10 toward the neutral position.
A very important feature of the invention resides in being able to utilize the levers 16 and 18 in partial power strokes while propelling the chair up a ramp, hill, or other inclined surface. As long as the levers 16 and 18 are not returned all the way back to their neutral position during the return stroke, the sleeve 92 will remain engaged with the second ratchet teeth 86 on the annular member 80. This results in preventing free wheeling of the driving wheels 12 in a reverse direction such that the wheel chair 10 will not roll backwards.
The occupant of the wheel chair 10 simply propels himself up a ramp, inclined plane or the like by simply always maintaining the levers 16 and 18 somewhat away from his body, thus out of the neutral position, and makes a successive number of power and return strokes while maintaining the sleeve 92 at all times in operative engagement with the second ratchet teeth 86. | A wheelchair having a frame capable of supporting the occupant includes a plurality of wheels including two driving wheels. Left and right side levers are mounted on the wheelchair such that the tops of the levers can be moved back and forth reciprocally toward and away from the occupant of the wheelchair. When the levers are in a position towards the occupant of the wheelchair, they are in a neutral position and by pushing away from the occupant from the neutral position to a displaced position, a power stroke is performed. Movement of the levers in the reverse direction back toward the occupant constitutes a return stroke of the same. A power transfer mechanism includes a first and second ratchet operatively associated with each of the driving wheels. The first ratchet allows the driving wheel to free wheel at all times in a forward direction. The second ratchet allows the driving wheel to free wheel in both a forward and reverse direction whenever the lever associated with that wheel is in the neutral position, and as the lever is moved in the power stroke away from the occupant, the second ratchet transfers this movement through the first ratchet to rotate the driving wheel in the forward direction. The second ratchet transfers no movement to the first ratchet as the lever moves back toward the occupant in the return stroke. | 8 |
CLAIM OF PRIORITY
[0001] This application claims the benefit of priority under 35 U.S.C. 119 to Hebbert et al., U.S. Provisional Patent Application No., 61/803,942, entitled, “GEAR FLOW DIVIDER FOR AGRICULTURAL PRODUCT INJECTION,” filed Mar. 21, 2013, which is hereby incorporated by reference herein in its entirety.
OVERVIEW
[0002] This application discusses, among other things, agricultural equipment and more particularly agricultural chemical applicators. In an example, an agricultural sprayer system can include a first boom section configured to receive a carrier material and a chemical material and to provide an agricultural chemical mixture, the boom section having a plurality of nozzles for spraying the chemical mixture; and a first rod insert coupled to an end cap of the boom section, the rod insert configured to reduce the volume of the boom section and to provide increased flow velocity of the chemical mixture to each of the plurality of nozzles.
[0003] This overview is intended to provide a general overview of subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about the present patent application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.
[0005] FIG. 1 illustrates general an example sprayer system.
DETAILED DESCRIPTION
[0006] The present inventors have recognized apparatus and methods for improving chemical injection for sprayer applications, such as chemical injection for agricultural sprayers and sprayer systems. In certain examples, more precise application of injection chemicals can be achieved using the apparatus and methods discussed below. In some examples, an apparatus can include a gear flow divider and multiple injector locations for the injection chemicals, including injector locations at or near the sprayer nozzles. In some examples, an apparatus can include a rod insert that can be inserted in a boom and can decrease boom volume. Decreased boom volume can allow an increase in flow velocity and, therefore, a decrease in chemical injection latency and application latency.
[0007] FIG. 1 illustrates general an example sprayer system 100 including multiple sections, or boom sections 102 , a flow divider 103 , recirculation circuit 104 and multiple injectors 105 . In certain examples, an injector 105 can be associated with a boom section 102 that includes one or more nozzles (not shown) for releasing or spraying a carrier material and an injection chemical. In certain examples, the sprayer system 100 can include a reservoir 101 , such as a tank, to hold a supply of the injection chemical. In certain examples, the sprayer system 100 can include a pump 106 to draw the injection chemical from the reservoir 101 to the flow divider 103 . The flow divider 103 can distribute an aggregate flow of the injection chemical to a number of injectors 105 . In certain examples, the flow divider 103 can include a gear flow divider that can provide a continuous supply of the injection chemical to each injector 105 with little if any flow ripple. In some examples, the gear flow divider can include a stackable architecture to allow the sprayer system 100 to be reconfigured for more or less injectors or injector locations. In certain examples, the gear flow divider can include gear sizes having gear diameter and gear width dimensions that are configured to reduce wear while providing a wide range of flow without a ripple effect. In certain examples, the reduced wear can be achieved using gears designed to operate at low speeds.
[0008] In certain examples, portions of the spray system 100 , such as individual sections or boom sections 102 , can be enabled and disabled, for example, to minimize overlapping and wasting spray materials. In certain examples, the spray system 100 can include a recirculation valve 107 in each output circuit of the flow divider 103 . In certain examples, when a boom section 102 is disabled, the recirculation valve 107 can be used to isolate the boom section 102 from the flow of the injection chemical and can simultaneously recirculate an injection chemical flow back to the input of the flow divider 103 . In certain examples, the recirculation circuit 104 can include a check valve 108 to mitigate injection chemical flow bypassing the flow divider 103 through the recirculation circuit 104 . In certain examples, a controller 113 can control the injection pump 106 and the recirculation valves 107 . In some examples, each recirculation valve 107 can operate in conjunction with a section control valve 114 configured to enable and disable one or more boom sections 102 of the sprayer system 100 . In certain examples, a recirculation valve 107 can include, but is not limited to, a 2-way, 3-port valve. In certain examples, the controller can adjust the speed of the injection pump 106 such that as boom sections 102 are enabled and disabled, the speed of the injection pump 106 can be adjusted to provide a proper aggregate flow of the injection chemical.
[0009] At or near each boom section 102 , an injection flow line 109 can be coupled to a carrier flow line 110 , at an injector 105 or an injector junction, to allow the injection chemical to be introduced with the flow of the carrier material. In certain examples, each boom section 102 can include a mixer, such as an inline mixer 111 , after the injector 105 to mix the injector chemical and the carrier material prior to being released or sprayed at a nozzle of the boom section 102 . In certain examples, a frame can include the sprayer system 100 . In some examples, the frame can be configured to be towed over a field. In certain examples, the frame can include a drive train for moving the sprayer system 100 over a field. In some examples, the frame can include the sprayer system 100 and the carrier material distribution system (not shown). In some examples, the controller can receive application information such as an application map and position, speed and heading information of the sprayer system to control the sprayer system 100 according to application rates dictated by the application map.
[0010] In certain examples, a section or a section boom 102 can include a rod insert 112 . A rod insert 112 can be configured to reduce injection latency by reducing the volume of a boom section 102 or a portion of a boom section 102 . With reduced volume, flow of the carrier material and the injection chemical can be increased and thus reduce the time for the injection chemical to pass through the sprayer system 100 . Such a reduction can assist in allowing the system to more precisely control the application of the injector chemical. In certain examples, use of injectors 105 located at the boom sections 102 and use of the rod inserts 112 can reduce injection latency up to about 75%.
Additional Notes and Examples
[0011] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as “examples.” All publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference(s) should be considered supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls.
[0012] In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.
[0013] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. | This application discusses, among other things, agricultural equipment and more particularly agricultural chemical applicators. In an example, an agricultural sprayer system can include a first boom section configured to receive a carrier material and a chemical material and to provide an agricultural chemical mixture, the boom section having a plurality of nozzles for spraying the chemical mixture; and a first rod insert coupled to an end cap of the boom section, the rod insert configured to reduce the volume of the boom section and to provide increased flow velocity of the chemical mixture to each of the plurality of nozzles. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to U.S. Provisional Patent Applications Ser. Nos. 61/009,208 entitled, “A LIGHTING SYSTEM”, by Scott A. Jones et al., filed Dec. 27, 2007 and 61/075,534 entitled, “A LIGHTING SYSTEM”, by Scott A. Jones et al., filed Jun. 25, 2008 in the United States Patent and Trademark Office, the disclosures of which are incorporated herein in their entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is related to a method, system and apparatus, in particular, a lighting system and method of controlling the lighting system, comprising a computer readable medium and a programmable device capable of controlling and manipulating individually addressable lights to realize a visual display at a pixel level.
[0004] 2. Description of the Related Art
[0005] In general, the lighting industry has expanded into the area of decorative lighting, and more specifically, into the area of holiday decorations. Representative holiday lighting systems may contain controllers that are capable of controlling individual strands of lights. Thus, a light controlling device is often limited to controlling an entire strand of incandescent and/or LED lights in unison. The controlling device is often a commercially available controller limited to manipulating an entire strand of lights in performing simple functions. In particular, light controllers on holiday light systems may allow a user to turn a light strand on or off. Other light controllers may allow manipulation of an entire light strand to displaying various colors, and/or perform various actions such as intermittent display, or streaming display. However, this method of controlling an entire strand in unity confines the manipulation of light displays to large scale manipulation. To display arbitrary images and/or other media at the pixel level using commercially available controllers and light strands is impossible. Alternatively, other controllable lighting systems may use a light display panel, such as an LED display panel. An LED display panel is capable of integrating individual LEDs together to display an image. While these types of LED display panels may display images on a pixel level, the panels are limited to the manufacturer determined position of lights on the panel. Lights on such panels are unable to be manipulated into varying positions, images, shapes and/or integrated into other non-pre-determined displays as the spatial positioning of individual lights may not be determined. A method of positioning and manipulating individual lights is desired, particularly, a system comprised of randomly distributed individual lights that can be monitored, programmed, and utilized is desired to achieve a level of control of individual lights of random positions.
SUMMARY OF THE INVENTION
[0006] A lighting system is provided whereby the system comprises apparatus capable of controlling, and lighting apparatus that is capable of being controlled to display images, video and text utilizing lighting technology. Control of the lighting apparatus may be facilitated through computer readable medium. The computer readable medium may be provided as computer software to be used in detecting, analyzing and programming the lighting apparatus. The lighting apparatus may include a plurality of individual LEDs and/or any other lights combined on lighting strands and/or other structures or fixtures. The controlling apparatus may be comprised of a multimedia or other recording device and/or a lighting controller. The recording device may be provided as a video recorder capable of capturing a position(s) of any lights associated with a lighting apparatus. The lighting controller may be provided as a control box. The control box may include components capable of manipulating the lighting apparatus or structure to display static graphics, animated sequences, scrolling marquees, text and/or videos utilizing any combination of available lights.
[0007] These together with other aspects and advantages which will be subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a diagram of a system embodiment.
[0009] FIG. 2 illustrates a flow diagram of a system process.
[0010] FIG. 3 is a diagram of an exemplary lighting apparatus design.
[0011] FIG. 4 is diagram of an exemplary strand control circuit.
[0012] FIG. 5A is a diagram of an exemplary light control circuit.
[0013] FIG. 5B is a diagram of an exemplary light control circuit.
[0014] FIGS. 6A-6D illustrate an exemplary system controller.
[0015] FIGS. 7A-7C illustrate a flow diagram of a system process.
[0016] FIG. 8 illustrates a flow diagram of software program code logic.
[0017] FIG. 9 illustrates a graphical user interface (GUI).
[0018] FIG. 10 illustrates a GUI.
[0019] FIG. 11 illustrates a GUI.
[0020] FIG. 12 illustrates a GUI.
[0021] FIG. 13 illustrates a GUI.
[0022] FIG. 14 illustrates a GUI.
[0023] FIG. 15 illustrates a GUI.
[0024] FIG. 16 illustrates a GUI.
[0025] FIG. 17 illustrates a GUI.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Reference will now be made in detail to the present embodiments discussed herein, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the disclosed system and method by referring to the figures. It will nevertheless be understood that no limitation of the scope is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles as illustrated therein being contemplated as would normally occur to one skilled in the art to which the embodiments relate.
[0027] A user may be able to place a lighting strand(s) on an object or surface and connect a strand(s) to a controller which may be embodied as a control box. A plurality of strands may be connected together to implement a larger display. A control box may be a single component or multiple controllers may be networked for desired scalability. A user may obtain recorded information of a lighting strand(s) as they are functioning by utilizing any recording device that may be provided internally or externally to the lighting system. The recorded information may include a video capture or other visual record of the lighting strands performing in a predetermined sequence. The video capture may be obtained through open loop and/or closed loop video capture technology. The recorded information may alternatively be information that is not visual, for example, a recording may be taken of ultraviolet, infrared and/or other detectable emissions.
[0028] In an alternative embodiment, a user may implement the method of the lighting system by creating and/or using a desired large-scale display by, for example using existing display panels such as LCD display panels, televisions screens or any other units, etc., and detecting the positions of these units. The positions of individual pixels may be obtained by combining the positions of units with predetermined pixel positions or other known positions into the lighting system representative units. A parallel algorithm may be used to identify the position of individual lights in the lighting system. In particular, a first position(s) of a plurality of lights may be identified and a second position(s) of other groups, subgroups and/or other plurality of individual lights may be detected in parallel based on the first position(s).
[0029] A computer readable medium is provided which may be embodied as computer software containing a program(s), one of which may implement a graphical user interface for a user to transfer visual information from a recording device to a user system. A program of the computer readable medium may convert the visual information into any known format that is capable of being manipulated on a singular frame level. The visual information may be analyzed by a program of the computer readable medium and 2D and/or 3D positioning of a plurality of individual lights may be determined. A program of the computer readable medium may output a graphical representation of the analyzed video information.
[0030] Utilizing the system software, a user is able to select and/or design animated sequences or video, static images, scrolling images and text, and/or other display media or information. The display media may be transferred to a portable memory storage device that is capable of being input into the lighting controller. Alternatively, the display information may be transferred directly to the controller through network cables, port cables, or other wired and/or wireless technology. The controller may be capable of storing various amounts of display information.
[0031] The controller or control box may include serial or parallel control circuitry. The controller may be capable of synchronization of an internal timing mechanism with an incoming stream of display information. The controller may capture the incoming stream of display information and process the information for lighting control. The control box may be manipulated or networked to any number of other control boxes and/or other devices with compatible networking capabilities. Compatible devices may be used to activate and/or manipulate any control box components.
[0032] In FIG. 1 , a system 100 is disclosed. The system 100 includes a lighting system 105 , a recording system 110 and a user system 115 . A lighting system 105 is provided which may include a lighting fixture apparatus, light or lighting controller apparatus, and computer readable medium. In at least one embodiment, the lighting fixture apparatus is comprised of a plurality of individual LEDs combined to form a single strand of lights. However, the lighting fixture may be a grouping of LED display panels, television or other illuminated panels or screens, a plurality of incandescent lights or any other lights combined as a lighting strand, a lighting rod and/or incorporated as any other fixture or structure. The lighting fixture apparatus may be flexible as to be able to be placed in any desired location such as attached to any object or location commonly utilized for lighting decoration, for example, a tree, a fence, etc. The lighting fixture apparatus may be a singular fixture or may be a connection of a plurality of fixtures, such as a series of lighting strands connected together. As illustrated in FIG. 3 , and discussed further herein, in at least one embodiment, the lighting fixture apparatus is controllable by implementing microcontrollers that may be manipulated to control a subset of individual lights. For example, as shown in FIG. 3 , a microcontroller may be placed every third light in a series of lights.
[0033] The lighting system 105 may also contain a light controller apparatus. A light controller apparatus may be embodied as control box as further illustrated in FIGS. 6A-6D . A light controller is provided to manipulate the lighting fixture apparatus. In at least one embodiment, the lighting fixture apparatus may be connected to the controller by means of a wired connection. The connection may be an electrical cord, and/or may be any wired and/or wireless connection capable of facilitating communication between the controller and the lighting fixture. In a preferred embodiment, the lighting fixture apparatus and the controller are two separate components of the lighting system; however, the lighting fixture and the controller may be coupled together into one component, or may alternatively be any number of separate components.
[0034] The lighting fixture apparatus may be manipulated by the lighting controller by utilizing a computer readable medium provided in the lighting system 105 as computer software. The computer software may be implemented as a program on the user system 115 . In at least one embodiment, the computer software may be provided to a user as a series of graphical user interfaces (GUIs). Utilizing such interfaces, a user may be able to select and/or design an animated sequence, static image, scrolling image or text, and/or other display information. The computer readable medium as implemented on the user system 115 may be capable of utilizing input information from the recording system 110 and/or providing output information based on the selected and/or designed display information. The output information can be transferred to and/or utilized by the light controller apparatus. The output information may be transferred to a portable memory storage device, or any other device that is capable of being associated with the light controller. Alternatively, the output information may be transferred directly or indirectly to the light controller through network cables, port cables, or other wired and/or wireless technology.
[0035] The light controller may be capable of reading, analyzing, manipulating and/or storing various forms of display information. The light controller may include several components, such as a serial or parallel control circuit, an internal timing mechanism, a port(s), means for connecting to the lighting fixture apparatus, means for connecting to an external power or energy source, an internal energy source, and/or various internal or external controls. The light controller may be capable of synchronization of an internal timing mechanism with an incoming stream of display information as provided by utilizing the computer software. The light controller may capture an incoming stream of display information and process the information for lighting control of the light fixture apparatus. The light controller may be manipulated by and/or networked to any number of other controllers and/or other devices with compatible wired and/or wireless network capabilities. For example, other compatible devices, such as a remote control may be used to activate and/or manipulate the controller and any of its components.
[0036] A recording system 110 may be provided as part of the system 100 . A recording device may be included in the system 100 as an individual component, or it may be provided internally or externally to any other component of the system. For example, the recording device may be incorporated into another component of the system, such as the lighting controller. The recording device may be a digital camera, video recording device, and/or any other device capable of capturing visual or other detectable information. The visual information may include a video capture of any light(s) of the lighting fixture. For example, the visual information may be a video capture of a plurality of LEDs flashing in a predetermined sequence. The video capture may be obtained through open loop and/or closed loop video capture technology. The visual information may be transferred from the recording device directly or indirectly to the user system 115 . The transfer of visual information from the recording device to the user system may be facilitated by utilizing a portable memory storage device, such as a camera memory card, or any other memory storage device capable of being read by the computer system. Alternatively, the recording device may be connected to a user system via any wired and/or wireless connection capable of facilitating communication and/or data transfer.
[0037] The user system 115 is provided in FIG. 1 . The user system 115 may be any typical desktop or laptop system, such as a PC, a handheld computer such as a personal digital assistant (PDA), or any other device that may allow a user to import, analyze, and/or manipulate any visual information recorded via the recording system 110 . The user system 115 may be any device that is capable of reading the visual information and/or capable of performing analysis of such visual information. The user system 115 may perform an analysis of visual information via any computer readable medium that may be provided as software or any other type of program that may be used in the analysis and/or manipulation of the recorded visual information. The computer readable medium of the lighting system 105 may be implemented on the user system 115 to analyze the position of any lights associated with, and/or resident in the lighting fixture apparatus. The computer readable medium may convert the visual information into any known format that is capable of being manipulated on a singular frame level. The visual information can be analyzed by the computer readable medium, and a 2D and/or 3D positioning of the plurality of individual lights can be determined. Utilizing the computer readable medium, the lighting system 105 may be able to analyze the visual obtained by the recording system 110 and be able to output a graphical representation of the analyzed visual information to the display of the user system 115 .
[0038] In FIG. 2 , a flow diagram of the process 200 is shown. In operation 205 , a user distributes any lighting fixture(s) of the lighting system 105 ( FIG. 1 ) and any associated components, such as any associated lighting controllers, to a desired location(s). For example, a lighting fixture, which may be embodied as a strand including a plurality of lights, may be placed on an object, such as a tree, a house, a fence, or any other object or location capable of supporting the lighting fixture. If the lighting fixture has been distributed as desired, control is passed to operation 210 and process 200 continues.
[0039] In operation 210 , a user associates a lighting fixture(s) with a light controller(s) via a connection. The lighting fixture may be two or more lighting fixtures coupled together, and associated with one or more controllers. The lighting fixture(s) can be connected to the controller(s) via a connection which may be any physical connection, for example, an electrical cord on a lighting fixture embodied as a strand of lights may be connected to a receiving port on the light controller. The connection may be any wired or wireless connection that facilitates communication between the light controller(s) and the lighting fixture(s). The controller may be able to connect to any number of lighting fixtures through any number of connections. In addition, the controller may be coupled with additional controllers and/or other devices for scalability of the system. If operation 210 is complete, control is passed to operation 215 and process 200 continues.
[0040] In operation 215 , a light controller(s) is powered. The powering of a light controller may be achieved through connection to any power source, such as a standard electrical outlet, any stand-alone power source, such as a generator, a battery, etc., or any other source capable of providing power to the controller. The power source may be supplied as AC and/or DC power. Alternatively, the light controller may be provided with an internal power source such as a battery to facilitate operation. If operation 215 is complete, control is passed to operation 220 and process 200 continues.
[0041] In operation 220 , a sequencing event including any lights incorporated in or associated with the lighting fixture apparatus is performed and recorded. The sequencing of lights may be based on a predetermined sequence. For example, program code calling a function for turning lights on and off may be provided to manipulate any microcontrollers associated with individual lights. A resulting intermittent and/or ‘flashing’ lights may be displayed on any lighting fixture(s) resulting from the distribution of lights performed in operation 205 . A sequence of ‘flashing’ lights may include a plurality of lights flashing in unison, individual lights flashing in a predetermined order, a predetermined pattern of individual and/or a plurality of lights flashing at various times, or any other sequence of lit and/or unlit lights. The sequencing event of the lights may serve as a calibration of the lighting system display by utilizing any lights as static reference points. The sequencing event may include any number of synchronization frames to enable the lighting system to overcome the inaccuracy of capturing a frame rate of an associated recording device. Any sequence of flashing lights may vary based on conditions such as size of the lighting fixture(s) and associated lights, for example, a lighting fixture embodied as a light strand with a light count greater than a certain threshold of light nodes may cycle through a different sequence than a light strand with a light node count less than or equal to the threshold.
[0042] In at least one embodiment, a sequencing event may be embodied as a parallel mapping algorithm used for a calibration of the lighting system. For example, to decrease a number of frames required to calculate positions of all lights associated with a lighting system, a parallel sequence display of any number of lights may be performed. Using a method of parallel mapping, a calibration of a lighting position(s) may be scalable. In at least one embodiment, a lighting fixture apparatus embodied as a lighting strand(s) and a plurality of lighting controllers as control boxes may comprise an overall lighting system. Using this embodiment, an illumination of all lights associated with all control box(es) may be a first tier of a parallel mapping algorithm to determine a distribution of all lights, and a second tier may be separate concurrent or parallel illuminations of all lights associated with each of a plurality of control box(es) to determine a distribution of all lights associated with each of the separate control boxes. A third tier of the parallel mapping algorithm may be separate concurrent or parallel illuminations of all lights associated with each of a plurality of individual channels or channel ports associated with the control box(es). A fourth tier of the parallel mapping algorithm may be separate concurrent or parallel illuminations of all lights associated with each of a plurality of individual lighting strands associated with each of the channel ports of each of the control box(es). A fifth tier of the parallel mapping algorithm may be separate concurrent or parallel illuminations of each light associated with each of a plurality of lighting strands associated with each of the channel ports of each of the control box(es).
[0043] Using the exemplary embodiment of the lighting system above, a lighting system may comprise three communicatively coupled control boxes of sixteen channel ports for each control box, three light strands for each channel port and ninety-nine lights for each light strand. In implementing a parallel mapping algorithm, a first step may be illuminating all lights associated with the three control boxes to identify a total light distribution area and/or pattern associated with the overall lighting system. A second step may be separately illuminating all lights associated with each control box to identify a separate light distribution and/or pattern associated with each control box. A third step may be separately illuminating all lights associated with each of the channels, with each of the three control boxes performing this illumination step concurrently. A fourth step may be illuminating all lights associated with each light strand separately, with all sixteen channels for all three control boxes performing this illumination step concurrently. A fifth step may be illuminating each light separately on every light strand, with all light strands performing this illumination step concurrently. Information obtained by performing this parallel mapping algorithm may be combined and used to facilitate determining an indexing or positioning of each light, light strand, channel, and/or control box.
[0044] A predetermined sequencing program code may be resident in the light controller such that the controller is capable of manipulating the lights to run the predetermined sequence. Alternatively, the program code may be transferred directly from a computer system and/or transferred by any commonly known removable or portable memory storage devices. For example, in at least one embodiment, the program code associated with a calibration sequence is written to an SD card capable of being inserted directly into the light controller much like the memory card of a digital camera or other device. The sequencing event may be initiated by a button, switch, or any other control associated directly on or with the light controller, or by a control associated remotely and/or indirectly with the controller, such as a remote control, a control on a computer system, and/or any other device capable of communication with the controller whether by wired, or wireless communication. The sequencing event may be utilized to determine an initial location or position of individual lights. The sequencing event of the lights may be recorded via a recording device associated with the recording system 110 ( FIG. 1 ).
[0045] The recording of the sequence event may be performed via a recording device included in the lighting system, or by any other device capable of providing suitable visual or other information for analysis. The recording of the sequencing event may be performed by open loop capture, such that a user may utilize his or her desired recording device. Alternatively, the recording of the sequencing event may be performed by closed loop capture, such that a recording device is connected to and/or associated with the light controller, thus providing for synchronization of the recording device by the controller. The recording of the sequencing event may be performed to obtain visual information of a 2D and/or 3D position(s) of any lights associated with the lighting fixture(s). A 3D position of any lights may be facilitated by the recording device by performing any recording(s) of the lights from different angles and/or directions. The recording device associated with operation 220 may be arranged at any suggested and/or desired location relative to the lighting fixture(s). The recording device may have a suggested location relative to the location of the lighting fixture. For example, a suggested range for a physical distance between the recording device and any lights may be provided, such as, ‘three to five feet away from the lighting fixture.’ Alternatively, a recording device may be placed at any location relative to the lighting fixture(s) that may provide for a visual representation of the entire distribution of lights desired to be utilized in a display. A user may be instructed to maintain a manual focus on the recording device being used. For example, if an auto-focus or other automatic focus function of a camera or other recording device is used, an overall distortion or ‘blurring’ may occur as the sequencing event occurs. In at least one embodiment, a recording device may be used to obtain only the key frames required for calculating light position(s). For example, a plurality of static images obtained from a camera, such as a digital camera, may be captured at different time(s) and/or locations. Using the above example, the static images may be translated, modified, resized and/or rotated to overcome the problem of position change of camera between different frames. A plurality of key frames may be captured and utilized to obtain the position(s) of any lights associated with a lighting fixture apparatus. Alternatively, a closed loop recording method may be used. If the recording of operation 220 is complete, control is passed to operation 225 and process 200 continues.
[0046] In operation 225 , the visual or other information obtained during the sequencing event is transferred to a computer or other user system capable of reading, analyzing, and/or manipulating the information. The visual information may be transferred from the recording device directly or indirectly to a computer system. The transfer of visual information from the recording device to the computer system may be facilitated by utilizing a portable memory storage device, such as a memory card, or any other memory storage device capable of being read by the computer system. Alternatively, the recording device may by connected to the computer system directly or indirectly via any wired and/or wireless connection capable of facilitating communication and/or data transfer. If operation 225 is complete, control is passed to operation 230 and process 200 continues.
[0047] In operation 230 , a user system that has been provided with program code and any associated data of the computer readable medium of the lighting system may be utilized to initialize the reading and/or analyzing of the visual information obtained during the recording of the sequencing event of operation 220 . The computer readable medium, embodied as computer software, may include a file conversion program, a program to read, analyze, and manipulate the visual information, an interface(s) for user selection of display information, and other data and/or information used in facilitating the output display information that may be transferred to the light controller. In at least one embodiment, a software package is provided that may include a file conversion program, such as any open-source video conversion utility capable of converting the visual information obtained via the recording device to any desired file format. For example, the original visual information transferred to the computer system may be converted to compressed AVI file format via the file conversion program. The file format of the converted visual information may be any format that can allow individual frames of visual information to be extracted from the entire file. Extraction of individual frames may be facilitated by using any software application programming interface, or any other software and/or codec capable of extracting individual frames.
[0048] If the visual information is converted to a file format supported by the software program, the program may read the converted visual information, and process and/or analyze the images obtained. For example, the program may read a first frame of the converted visual information, and thus be capable of reading any dimensions of the visual information, such as dimensions of a video frame, any codec and/or software used to convert and/or compress the visual information, information associated with the recording device, such as frame rate, etc., and/or any other information available. A first frame of the converted visual information may be obtained by bypassing a portion of the visual information. For example, if a sequencing event is initiated, a ‘flashing’ of all lights associated with the lighting fixture(s) may be performed to indicate that the sequencing event has commenced, and such a ‘flashing’ of all associated lights may be bypassed as any initial ‘flashing’ of lights may, for example, interfere with the program reading, analysis and/or processing of the visual information. A bypassing of a portion of visual information may be based on a time period, a frame set, or any other measurement or element.
[0049] If the visual information is read by the computer system, the program may process and/or analyze the images contained in the visual information. An analysis of the visual information may be done on an individual frame basis. An analysis of the visual information may include locating a first frame where a percentage and/or threshold of all lights associated with a lighting fixture are illuminated, locating subsequent frame(s) in which a percentage or threshold, which may be based on a first frame reading of all lights associated with the lighting fixture are illuminated, and/or any other analysis of the visual information. In performing an analysis on light illumination of the visual information, the program may initially set a threshold value. A threshold value may be a certain percentage associated with a total. A threshold value may be used to determine whether a frame of visual information is considered a frame having all of the lights associated with the light fixture illuminated.
[0050] In determining whether a frame of visual information is considered a frame having all of the lights associated with the light fixture illuminated, a frame of visual information may be analyzed based on a portion of the frame, for example, analysis may be initially based on any number of lights. A frame of visual information may be analyzed based on an individual light. In considering whether an individual light is considered by the program code to be illuminated, the visual information associated with the light may be analyzed. For example, a pixel, or any other measurement of the visual information may be analyzed to determine illumination of a light. An analysis of a measurement of the visual information may be based on any component level(s). For example, a pixel may be considered a possibility for illumination of a light if any, or all component level values of a pixel reach a certain threshold. For example, if a red, a green, and/or a blue component associated with a pixel meets, and/or exceeds a certain threshold value, the pixel may be considered an illuminated pixel associated with an illuminated light. A threshold value may be based on a percentage applied toward a total value. For example, a threshold value may be a percentage of a total intensity value associated with a light.
[0051] In determining whether a frame of visual information is considered a frame having all of the lights associated with the light fixture illuminated, an analysis of visual information based on any portion of the frame may be utilized. For example, the information obtained from analysis of an individual pixel(s) of the visual information may be utilized in determining an overall illumination of a frame. A threshold value may be utilized. A threshold value may be based on a percentage applied toward a total value. For example, a threshold value may be a percentage of a total pixel count or dimension of a frame of visual information. A total pixel count or dimension of a frame of visual information may be obtained by various methods. For example, the height may be multiplied by the width of a frame of visual information to determine overall pixel count of a frame of visual information. A threshold value of the total pixel count may be taken. A threshold value may reflect the minimum illumination requirement of a frame that may be utilized to consider a frame of visual information a frame having all of the lights associated with the light fixture illuminated. An illumination requirement may be met by analyzing a portion of a frame of visual information, for example, the analysis of illumination of individual pixels of a frame may facilitate determination of illumination for the entire frame. In determining whether a frame of visual information is considered a frame having all of the lights associated with the light fixture illuminated, any subsequent threshold value(s) may be set based on actual illumination determined in a frame of visual information. For example, if a frame of visual information contains 9000 pixels that are considered illuminated pixels and thus illuminated lights, but the threshold value for considering a frame of visual information a frame having all the lights associated with the light fixture illuminated was initially set to reflect 6000 pixels, then a new threshold value to determine whether a subsequent frame is considered an illuminated frame may be based on the pixel analysis resulting in a count of 9000 pixels.
[0052] The software or program code may continue to analyze any and/or all the visual information associated with the sequencing event in determining the position(s) of lights. The program may continue until all frames associated with the visual information are read and analyzed. The program may determine an average and/or representative frame of the lighting fixture distribution by utilizing any information obtained during the analysis of the visual information. An average frame may be utilized in subsequent analysis of individual lights of the lighting fixture(s). For example, analysis of all frames associated with the visual information may yield individual values that may be totaled and averaged into a representative frame of visual information considered a frame of visual information with all lights associated with the light fixture illuminated. Alternatively, in at least one embodiment, a representation of light positioning may be produced manually or by a coupling of automatic detection utilizing the software code and manual inclusion of light positions using a matrix or sectional system. For example, if in operation 205 , a lighting fixture(s) is distributed in a grid format or other uniform positioning, then an axis positioning of lights may be produced by utilizing a simple graphing program. Whether obtained automatically, manually, and/or by a combination of both methods, the representative frame of visual information may be utilized in determining the positioning of the lights associated with the lighting fixture(s).
[0053] A program may continue to analyze any and/or all the visual information associated with the sequencing event. The program may continue to analyze any frames in determining if a frame is considered to be a frame with potential of any lights associated with the light fixture illuminated. For example, the program may continue to analyze the visual information on a singular frame level, and thus determine whether any pixel associated with a frame meets and/or exceeds a certain threshold value set to determine if a pixel is considered to be associated with an illuminated light. The program may continue to analyze any light potential of any individual pixel, and/or any other portion, or measurement associated with a frame of visual information to determine any and/or all light potential associated with any and/or all frames of visual information. This analysis may be used to determine the location and/or maximum intensity and/or illumination information of any components associated with a pixel, section, sector, and/or frame of visual information. The resulting illumination information may be used to create a histogram and/or any other textual, pictorial, graphical, or any other type of representation of the information. A representation of light illumination information may be any set of coordinates, such as axes coordinates, which may be utilized in facilitating the mapping and/or locating of any lights associated with a light fixture(s). The locating of any lights associated with the light fixture may represent a 2D and/or 3D location(s) or position(s) of individual lights. In locating or detecting position(s) of lights associated with a light fixture(s), the locations may be utilized in designing a display pattern, graphic, animation, and/or any other static or animated visual display utilizing the location determined lights associated with the light fixture(s). If operation 230 is complete, control is passed to operation 235 and process 200 continues.
[0054] In operation 235 , a user is provided with the ability to select and/or design display information. For example, the program code associated with the computer readable medium of the lighting system 105 ( FIG. 1 ) may include a software program that provides a user with the ability to design display features, images, text, graphics, animations, effects and/or any other elements of visual information that may be included in a display, sequence, effect and/or other visual program or display utilizing any lights associated with the light fixture(s). A user may be provided with selections or selectable options via a graphical user interface(s) (GUIs) as further illustrated in FIGS. 9-17 . A user may be provided with the ability to design his or her own display based on any given display features, and/or the ability to design and/or program his or her own features or elements. As discussed further herein, a display(s) utilizing light positions as well as non-positional effects may be designed and displayed. For example, a user may desire to display a chasing effect, a twinkling effect, and/or other commonly known lighting effects that are not dependent on determining the spatial positioning of lights associated with a lighting fixture(s). Alternatively, a user may utilize any existing image, video or other multimedia programs or software to create or generate a video sequence to be used by the software program. If operation 235 is complete, control is passed to operation 240 and process 200 continues.
[0055] In operation 240 , any display information designed and/or selected in operation 235 is output to the lighting controller. The controller may be capable of synchronization of an internal timing mechanism with an incoming stream of display information. The controller may capture the incoming stream of display information and process the information for lighting control. A controller may receive information by any means available, by for example, any display information may be output to a removable memory storage device, such as any MultiMediaCard (MMC), for example an SD card, etc. The controller may manipulate any microcontrollers of the associated lights to display the display information designed and/or selected by the user in operation 235 . Any number of controllers may be used to control any number of lights. For example, in at least one embodiment, a controller may be limited to controlling a certain number of light strands based on the power output capabilities of the controller, and thus for example, several controllers may be coupled together so that a plurality of controllers may be used to control a larger amount of light strands. Operation 240 may continue until a user selects to discontinue display of the lighting system, and/or a user selects to return to a preceding operation to change a distribution of any lighting fixture(s), change any display features, etc.
[0056] FIG. 3 illustrates an exemplary lighting apparatus with microcontroller implementation. As illustrated in FIG. 3 , the lighting fixture apparatus 300 is embodied as a strand of lights including a light emitting diode (LED) 305 , LED lead wires 310 , strand ground wire 315 , strand power wire 320 , and microcontroller 325 .
[0057] The LED 305 may be any type, size or shape LED. For example, the LED 305 may be a monochrome LED, an RGB and/or multi-color light such as any bi-color and/or tri-color LED that may be commonly known. Alternatively, the LED 305 may be any light source such as a liquid crystal display (LCD), an organic light emitting diode (OLED), an incandescent light, or other lamp. As illustrated in FIG. 3 , and in at least one embodiment, a plurality of LEDs is connected in series along a strand. The LED lead wires 310 include an anode and a cathode lead as commonly known and associated with a diode. Utilizing the lead wires 310 , the LED 305 can be connected to a power supply facilitated by the power wire 320 . Additionally, the LED 305 may be connected to the ground wire 320 .
[0058] As illustrated in FIG. 3 , the microcontroller 325 may be any low feature microcontroller capable of performing simple functions or existing light or LED drivers. For example, as shown in FIG. 3 , an 8-bit microcontroller, such as an Atmel ATtiny13 microcontroller with built-in oscillator may be used. As illustrated in FIG. 3 , the microcontroller 325 includes a supply voltage, a ground and a 6-bit bi-directional I/O port with internal pull-up resistors. The microcontroller 325 may be capable of manipulating lights, such as the LED 305 by utilizing pulse-width modulation (PWM) from data received on an asynchronous communication line. The microcontroller 325 may be paired with a decoupling capacitor for use in a DC circuit configuration such as that illustrated in FIG. 5A . Alternatively, the light controller may be embodied in an AC configuration as further discussed herein with respect to the light control circuitry illustrated in FIG. 5B .
[0059] In at least one embodiment, the lighting apparatus 300 of FIG. 3 may include a strand controller. For example, for each lighting apparatus embodied as a strand of lights, a strand controller may be provided to transfer data from the lighting controller or control box of the lighting system 105 ( FIG. 1 ) to each strand of lights and/or from each strand of lights to the lighting controller.
[0060] FIG. 4 illustrates an exemplary light strand microcontroller unit (MCU) and associated strand controller integrated circuit 400 . The strand controller circuit 400 includes a receiving control signal 405 ; positive regulator 410 , MCU 415 , transmitting control signal 420 , ESD 1 425 and ESD 1 - 2 430 .
[0061] A strand controller may be connected at the beginning of a strand of lights. As illustrated in FIG. 4 , a receiving control signal 405 receives data from the lighting system controller or control box. The positive regulator 410 maintains a constant voltage through the strand controller circuit 400 . The receiving control signal 405 may be received by a built-in serial communications interface of the MCU 415 and/or by a software implemented interface or GUIs. Alternatively, communication protocols, such as TCP/IP, inter-integrated circuit control (I 2 C) and/or other multidirectional, 1-wire, 2-wire and/or any other communication protocols may be utilized for communication among the lighting controller or control box and the strand controller. The MCU 415 may be any microcontroller capable of sending and receiving data for each light strand. As illustrated in FIG. 4 , the MCU 415 is a commonly available 8-bit microcontroller unit. The transmitting control signal 420 transmits data from the MCU 415 to the light controller, such as the light controller 500 ( FIG. 5A ). The strand controller circuit 400 also contains electrostatic discharge controls ESD 1 425 and ESD 1 - 2 430 to dissipate electrostatic charge(s).
[0062] To control individual lights of a lighting fixture(s), the transmitting control signal 420 ( FIG. 4 ) from the strand controller circuit 400 may be transferred to the light controller, such as the light controller illustrated in FIG. 5A . FIG. 5A illustrates an exemplary light controller circuit 500 . The light controller circuit 500 includes LED 1 505 , LED 2 510 , LED 3 515 , a light control positive regulator 520 and a light control MCU 525 . The light controller circuit 500 illustrates the process of receiving a transmitted signal from the strand controller to facilitate the individual control of a plurality of LEDs. As illustrated in FIG. 5A , the light controller 500 contains LED 1 505 , LED 2 510 , and LED 3 515 connected in series along the circuit. FIG. 5A illustrates a light controller capable of controlling three LEDs, however additional embodiments may have a light controller that controls any number of lights or LEDs. In at least one embodiment, a light strand includes ninety-nine monochrome LEDs connected in series, therefore, each MCU controlling three lights each may be addressed from a numerical range, such as, for example, the range 1-33.
[0063] The light control positive regulator 520 maintains a constant voltage through the light controller circuit 500 . The light control MCU may be any microcontroller capable of sending and receiving data. As illustrated in FIG. 5A , the MCU 525 is an inexpensive low-pin count 8-bit microcontroller with a built-in 8-bit modulo timer. The MCU 525 may be any commonly known microcontroller with an internal clock source for running the light controller program code and/or modulo timer used to maintain current intensities of the LEDs during any periods of idle control signal. The central component of the modulo timer is the 8-bit counter with a timer overflow interrupt that can be enabled to generate periodic interrupts for time-based software loops.
[0064] FIG. 5B illustrates an exemplary RGB light controller circuit 550 utilizing an AC power source. The RGB light controller circuit 550 includes LED 1 555 , LED 2 560 , LED 3 565 , power line 570 , data line 575 , and light controller MCU 580 . The RGB light controller circuit 550 includes a red LED 1 555 , a blue LED 2 560 and a green LED 3 565 . The power line 570 is the power source for the circuit 550 and the data line 575 is used to transmit a signal from the strand controller, such as the strand controller 400 ( FIG. 4 ) or a previous light controller if the light controller 550 ( FIG. 5B ) is at least a second light controller in a series. The MCU 580 may be any microcontroller capable of sending and receiving data. As illustrated in FIG. 5B , the MCU 580 is an 8-bit microcontroller with direct-drive PWM output. While the exemplary embodiment utilizes PWM communication, any other communication method, such as power line communication (PLC) and/or any other system of communication for carrying data on a conductor or otherwise may be implemented.
[0065] The exemplary light controller circuits of FIGS. 5A and 5B are only two such embodiments of a light controller of a lighting fixture apparatus of the lighting system 105 ( FIG. 1 ). Other embodiments may exist that are commonly known.
[0066] FIGS. 6A-6D illustrate an exemplary lighting controller of the lighting system 105 ( FIG. 1 ). FIG. 6A illustrates a top view of the enclosure of a lighting controller embodied as a control box 600 . In at least one embodiment, the control box 600 is a durable and/or weatherproof enclosure capable of entirely containing the lighting controller components. FIG. 6B is a bottom view of the control box 600 . As shown in FIG. 6B , a bottom portion of the control box 600 may contain a plurality of openings 605 . The openings 605 may be sized as to accept a nail, a screw or any other securing or anchoring means. For example, a user may desire to mount or secure the control box 600 to an object or location by means of threading a screw through the openings 605 into, for example, a post, a wall, etc.
[0067] FIG. 6C illustrates an exemplary rear and front view of the control box 600 . As illustrated in FIG. 6C , the front of the control box 600 contains the signal cord port 610 , the power cord port 615 , the output fan 620 , the intake fan 625 and the network connection port 630 . The signal cord port 610 may accept any standard electrical cord and/or other cord or cable to serve as a signal input to the lighting controller of the control box 600 . For example, an electrical cord leading out from the signal cord port 610 may be connected to other control boxes, a third party controller and/or other devices. By utilizing the signal cord port 610 , a user may connect the control box 600 to a signaling device that may signal or trigger the microcontroller unit of the lighting controller of the control box 600 to read, process, integrate and/or synchronize received information. The power cord port 615 may accept any standard electrical cord and/or other cord or cable to serve as a connection between the power source and the control box 600 . For example, an electrical cord leading out from the power cord port 615 may be connected to a standard wall outlet to provide power to the control box 600 .
[0068] As illustrated in FIG. 6C , the output fan 620 and the intake fan 625 may be included in the control box 600 . The output fan 620 may output heated air from inside the control box 600 that may be a result of a prolonged and/or continuous use of the control box 600 . The output fan 620 and the intake fan 625 may cycle continuously or they may be triggered to initiate performance upon an internal temperature sensor, a timing clock, etc. The intake fan 625 may input cooled air into the control box 600 that may be used to cool down any components inside the control box 600 that may need to maintain a certain lower temperature for proper functioning and control. The network connection port 630 may accept any standard Ethernet and/or any other network cable to serve as a network connection from the control box 600 to another device. For example, a network cable leading from the network connection port 630 may be connected to other control boxes, a third party controller and/or other devices. In this way, more than one control box may be networked together to provide scalability of the lighting system and/or synchronization of any number of displays controlled by any number of control boxes. For example, as further illustrated in FIG. 6D , in at least one embodiment of the control box 600 , the lighting controller may control up to sixteen channels. However, if networked, a control box may share timing and other data and information with another control box(es) to synchronize visual displays as separate components or displays and/or as part(s) a singular entire display.
[0069] FIG. 6D illustrates the right and left lateral views of the control box 600 . The left lateral view depicts the control box 600 as having two latches to ensure proper closure of a lid or top of the control box 600 . While latches are provided in the embodiment illustrated in FIG. 6D , any such enclosure means may be used to secure the lid of the enclosure in a closed position. The right lateral view of the control box 600 illustrates the channel ports 635 . As illustrated in FIG. 6D , in at least one embodiment, the control box 600 contains sixteen channel ports. In at least one embodiment, the channel ports are three-pin female end receivers that accept a three-pin male end input. For example, the channel ports 635 may accept a three-pin male end connector of a light strand such as the exemplary lighting fixture apparatus 300 ( FIG. 3 ). The control box 600 may be limited in the number of channel ports it may contain by any power requirements of the lighting controller and/or the lighting fixture apparatus, and/or any lights or LEDs associated with the lighting fixture(s). While the illustrated embodiment contains sixteen channel ports, the design illustrated is based on a total load capacity of lighting fixtures that may be connected to the control box 600 . For example, the control box 600 is designed to control sixteen channels with each channel port allowing the connection of three light strands, with each light strand containing ninety-nine monochrome LEDs connected together in series for a maximum controlling capacity of 4,752 LEDs. In an alternative implementation of the control box 600 , a maximum control of 1,600 RGB LEDs is achieved through connection of sixteen one-hundred-light RGB light strands, one strand connected to each channel port on the control box 600 .
[0070] The light controllers, such as those illustrated in FIGS. 5A and 5B execute the light controller program code. The light controller program facilitates synchronization, data capture, counter control and light control of the lighting system. A light controller's internal clock may be synchronized with the incoming data bit stream. If an incoming data bit stream is detected and/or synchronized, it can be captured, processed and/or stored by the light controller. Utilizing program code, the light controller may utilize any data to control illumination of any lights on the light fixture apparatus. The process 700 of FIGS. 7A-7C illustrates the process of executing the light controller program code of the lighting system.
[0071] FIG. 7A illustrates the program code start of the light controller program code execution. In ate least one embodiment, data may be sent using a one-way asynchronous communication protocol utilizing 5-bit binary words. The light controller program length spans the time for a microcontroller to read a 5-bit word of data. In at least one embodiment, the word 0b11111 serves as a packet header containing addressing and other information. Data can be captured and stored for processing during a subsequent word transmission. A series of 5-bit PWM values can be sent to control the state of each light. In operation 705 , the program code is executed. If operation 705 is complete, control is passed to operation 710 and process 700 continues
[0072] In operation 710 , hardware and data variables are detected. An external hardware interrupt can detect a low-high transition which corresponds to a stop-start bit transition. This detection may be utilized at the start of a data word transmission to enable the light controller program to start at the external interrupt vector's address. Utilizing the transition allows cycle losses associated with a relative jump to be avoided. The external interrupt may only be enabled at the end of the initialization of the light controller program for prevention of a data low-high from triggering the interrupt. If operation 710 is complete, control is passed to operation 715 and process 700 continues.
[0073] In operation 715 , a determination is made as to whether an external interrupt is detected from a signal pin. If an external interrupt is detected, control is passed to operation 720 and process 700 continues. If an external interrupt is not detected, control is passed to operation 710 and process 700 continues.
[0074] In operation 720 , a clearing of the state of all lights is performed by the light controller program code and all lights of the lighting fixture apparatus are set to the ‘off’ or unlit state or position. A light controller microcontroller may not be addressed by assigning a particular serial number. Alternatively, the microcontroller may count the number of PWM ‘words’ transmitted and/or update any lights the microcontroller controls when the PWM value(s) of the lights is received. If operation 720 is complete, control is passed to operation 725 and process 700 continues.
[0075] In operation 725 , a determination is made as to whether the intensity or illumination of a first in a plurality of lights meets a certain threshold PWM value. If the certain threshold PWM value is met or exceeded, control is passed to operation 727 and process 700 continues. If the certain threshold PWM value is not met or exceeded, control is passed to operation 730 and process 700 continues. The determination of operation 725 may be made by comparing an individual PWM light value to a PWM system value. For example, in an exemplary light controller program code, a value of ‘PWMCount’ is defined as a PWM system value. In the above example, ‘PWMCount’ may be incremented in value by a numerical value of ‘1’ if the program completes an entire cycle. The incremented value of ‘PWMCount’ may be cleared and/or reset if ‘PWMCount’ reaches a certain maximum value that may, for example, correspond to the number of microcontrollers resident in a lighting fixture apparatus.
[0076] In operation 727 , a light state of a first in a plurality of lights is modified. If in operation 725 , the detected PWM of a first light meets or exceeds a certain threshold value then in operation 727 the light is illuminated or turned on. If operation 727 is complete, control is passed to operation 730 and process 700 continues.
[0077] In operation 730 , a determination is made as to whether the intensity or illumination of a second in a plurality of lights meets a certain threshold PWM value. If the certain threshold PWM value is met or exceeded, control is passed to operation 735 and process 700 continues. If the certain threshold PWM value is not met or exceeded, control is passed to operation 740 and process 700 continues. The determination of operation 730 may be made by comparing an individual PWM light value to a PWM system value. For example, in an exemplary light controller program code, a value of ‘PWMCount’ is defined as a PWM system value. In the above example, ‘PWMCount’ may be incremented in value by a value of ‘1’ if the program completes an entire cycle. The incremented value of ‘PWMCount’ may be cleared and/or reset if ‘PWMCount’ reaches a certain maximum value that may correspond to the number of microcontrollers resident in a lighting fixture apparatus.
[0078] In operation 735 a light state of a second in a plurality of lights is modified. If in operation 730 , the detected PWM value of a second light meets or exceeds a certain threshold value then in operation 735 the light is illuminated or turned on. If operation 735 is complete, control is passed to operation 740 and process 700 continues.
[0079] In operation 740 , a determination is made as to whether the intensity or illumination of a third in a plurality of lights meets a certain threshold PWM value. If the certain threshold PWM value is met or exceeded, control is passed to operation 745 and process 700 continues. If the certain threshold PWM value is not met or exceeded, control is passed to operation 755 ( FIG. 7B ) and process 700 continues. The determination of operation 740 may be made by comparing an individual PWM light value to a PWM system value. For example, in an exemplary light controller program code, a value of an exemplary variable, such as ‘PWMCount’, is assigned as a PWM system value. In the above example, ‘PWMCount’ may be incremented in value by a value of ‘1’ if the program completes an entire cycle. The incremented value of ‘PWMCount’ may be cleared and/or reset if ‘PWMCount’ reaches a certain maximum value that may correspond to the number of microcontrollers resident in a lighting fixture apparatus.
[0080] In operation 745 a light state of a third in a plurality of lights is modified. If in operation 740 , the detected PWM value of a third light meets or exceeds a certain threshold value then in operation 745 the light is illuminated or turned on. If operation 745 is complete, control is passed to operation 755 ( FIG. 7B ) and process 700 continues.
[0081] In operation 755 , a first of a plurality of data bits is captured. The data capture occurs through a series of lines of program code. The program code may contain a carry flag for data bit capture. Upon execution of the program code, the carry flag may be cleared to enable capture of a first data bit. In operation 755 , a first data bit is captured and stored into the carry flag. To enable proper capture of data bits, program code may be placed in the center of each data bit as an MCU receiver clock of a light strand controller may drift high or low. If a data bit is captured in operation 755 , the carry flag may be rotated into a new data variable which may be placed into a subsequent data variable for processing during a next program cycle. If operation 755 is complete, control is passed to operation 760 and process 700 continues.
[0082] In operation 760 , a determination is made as to whether a microcontroller counter transmitted signal data value equals a value of a microcontroller serial number or unique identification. If in operation 760 , the microcontroller transmitted signal data value equals the value of a microcontroller serial number, control is passed to operation 761 and process 700 continues. If in operation 760 , the microcontroller transmitted signal data value does not equal the value of a microcontroller serial number, control is passed to operation 765 and process 700 continues.
[0083] The determination in operation 760 is made to detect whether data transmitted to a microcontroller is intended for the microcontroller. The determination of operation 760 may be based on any microcontroller counter and/or serial number counter values. For example, in the lighting controller program code, a variable such as ‘LEDCount’ may be defined to correspond to a targeted LED and a variable ‘ChipCount’ may be defined to correspond to a targeted microcontroller. The variable ‘LEDCount’ may be set to begin, for example, at the numerical value of ‘3’. The ‘LEDCount’ variable may be decremented by a value of ‘1’ if a program cycle is completed. In the above example, the value of ‘3’ is representative of the light strand embodiment of FIG. 3 in which three LEDs are controlled by each microcontroller or MCU. If ‘LEDCount’ is decremented by a value of ‘1’ until it reaches the value of ‘0’, the variable may be restored to an initial value of ‘3’ and/or the variable ‘ChipCount’ may be incremented by a value of ‘1’.
[0084] Using the above exemplary program code, in operation 760 , the value of the variable of ‘ChipCount’ may be compared to the value of the variable(s) assigned to the serial number(s) to each microcontroller of the lighting fixture apparatus. For example, in at least one embodiment, a microcontroller is placed every third LED on a light strand of ninety-nine lights for a total of thirty-three microcontrollers per light strand. Using the above example, each of the thirty-three microcontrollers may be assigned or may have a serial number or other unique identification detected and defined as a variable, such as the variable ‘SerialNum’. In operation 760 , the value of the variable ‘SerialNum’ may be compared to the value of the variable ‘ChipCount’ to determine if the data transmitted to the microcontroller is intended for that microcontroller.
[0085] In operation 761 , a PWM updating subroutine is executed by the lighting controller program code. If operation 761 is complete, control is passed to operation 762 and process 700 continues.
[0086] In operation 762 , a second of a plurality of data bits is captured. The data capture occurs through a series of lines of program code operating under the initializing of the PWM updating subroutine. The program code may contain a carry flag for data bit capture. In operation 762 a second data bit is captured and stored into the carry flag. To enable proper capture of data bits, program code may be placed in the center of each data bit as an MCU receiver clock of a light strand controller may drift high or low. If a data bit is captured in operation 762 , the carry flag may be rotated into a new data variable which may be placed into a subsequent data variable for processing during a next program cycle. If operation 762 is complete, control is passed to operation 763 and process 700 continues.
[0087] If in operation 760 a microcontroller transmitted signal data value equals the value of a microcontroller serial number or unique identification, the updating subroutine of operation 761 is bypassed and control is passed to operation 765 .
[0088] If the targeted microcontroller is not determined in operation 760 , operation 765 and process 700 continues to capture data bits without execution of the PWM updating subroutine. In operation 765 , a second of a plurality of data bits is captured. The data capture occurs through a series of lines of the main program code. The program code may contain a carry flag for data bit capture. In operation 765 a second data bit is captured and stored into the carry flag. To enable proper capture of data bits, program code may be placed in the center of each data bit as an MCU receiver clock of a light strand controller may drift high or low. If a data bit is captured in operation 765 , the carry flag may be rotated into a new data variable which may be placed into a subsequent data variable for processing during a next program cycle. If operation 765 is complete, control is passed to operation 770 and process 700 continues.
[0089] In operation 770 , a determination is made as to whether the targeted microcontroller value has reached or exceeded a threshold value. For example, in operation 770 , the targeted microcontroller value, continuing to be defined as the exemplary program code variable ‘ChipCount’, may be compared to a threshold value. If the microcontroller counter variable ‘ChipCount’ reaches or exceeds a threshold value, then the microcontroller counter may overflow. The overflow may be a result of a packet header data value failing to be transmitted and/or skipped or missed. In order to prevent the microcontroller counter from overflowing, the determination of operation 770 is made by the lighting controller program code. If the microcontroller value has reached a threshold value, control is passed to operation 771 and process 700 continues. If the microcontroller value has not reached or exceeded a threshold value, control is passed to operation 772 and process 700 continues.
[0090] In operation 771 , the microcontroller counter value is decremented. For example, using the exemplary variable ‘ChipCount’, the value of ‘ChipCount’ may be decremented by a value of ‘1’ to return the ‘ChipCount’ value to a value below the defined threshold value. If operation 771 is complete, control is passed to operation 772 and process 700 continues.
[0091] If the targeted microcontroller is determined in operation 760 , operation 761 executes the PWM updating subroutine, process 700 continues to capture data bits, and a determination is made for targeting lights. In operation 763 , a determination is made as to whether a first of a plurality of lights is targeted for PWM. If it is determined that a first of a plurality of lights is targeted for PWM, control is passed to operation 764 and process 700 continues. If it is determined that a first of a plurality of lights is not targeted for PWM, control is passed to operation 765 and process 700 continues.
[0092] In operation 764 the light state of a first of a plurality of lights is modified. For example, if in operation 763 , it is determined that light ‘one’ is targeted by a transmitted stream of data, then by PWM the light intensity or luminance is updated in response to the incoming stream of data. The light luminance modification or update may include turning a light or LED ‘on’, turning a light or LED ‘off’, changing a light or LED color, effect, intensity, or any other manipulation allowable by the light controller or MCU.
[0093] In operation 765 , a determination is made as to whether a second of a plurality of lights is targeted for PWM. If it is determined that a second of a plurality of lights is targeted for PWM, control is passed to operation 766 and process 700 continues. If it is determined that a second of a plurality of lights is not targeted for PWM, control is passed to operation 767 and process 700 continues.
[0094] In operation 766 the light state of a second of a plurality of lights is modified. For example, if in operation 765 , it is determined that light ‘two’ is targeted by a transmitted stream of data, then by PWM the light intensity or luminance is updated in response to the incoming stream of data. The light luminance modification or update may include turning a light or LED ‘on’, turning a light or LED ‘off’, changing a light or LED color, effect, intensity, or any other manipulation allowable by the light controller or MCU.
[0095] In operation 767 , a third of a plurality of data bits is captured. The data capture occurs through a series of lines of program code operating under the branch of the program code initializing the PWM updating subroutine. The program code may contain a carry flag for data bit capture. In operation 767 , a third data bit is captured and stored into the carry flag. To enable proper capture of data bits, program code may be placed in the center of each data bit as an MCU receiver clock of a light strand controller may drift high or low. If a data bit is captured in operation 767 , the carry flag may be rotated into a new data variable which may be placed into a subsequent data variable for processing during a next program cycle. If operation 767 is complete, control is passed to operation 768 and process 700 continues.
[0096] In operation 768 , a determination is made as to whether a third of a plurality of lights is targeted for PWM. If it is determined that a third of a plurality of lights is targeted for PWM, control is passed to operation 769 and process 700 continues. If it is determined that a third of a plurality of lights is not targeted for PWM, control is passed to operation 773 and process 700 continues.
[0097] In operation 769 , the light state of a third of a plurality of lights is modified. For example, if in operation 769 , it is determined that light ‘three’ is targeted by a transmitted stream of data, then by PWM the light intensity or luminance is updated in response to the incoming stream of data. The light luminance modification or update may include turning a light or LED ‘on’, turning a light or LED ‘off’, changing a light or LED color, effect, intensity, or any other manipulation allowable by the light controller or MCU.
[0098] In operation 772 a third of a plurality of data bits is captured. The data capture of operation 772 occurs through a series of lines of program code operating under the branch of the main program bypassing the PWM updating subroutine. The program code may contain a carry flag for data bit capture. In operation 772 a third data bit is captured and stored into the carry flag. To enable proper capture of data bits, program code may be placed in the center of each data bit as an MCU receiver clock of a light strand controller may drift high or low. If a data bit is captured in operation 772 , the carry flag may be rotated into a new data variable which may be placed into a subsequent data variable for processing during a next program cycle. If operation 772 is complete, control is passed to operation 773 and process 700 continues.
[0099] In operation 773 , any I/O ports of the microcontroller of the light controller are updated. If operation 773 is complete, control is passed to operation 774 and process 700 continues.
[0100] In operation 774 , a second synchronization occurs by polling the data line value in the serial communications start bit. If operation 774 is complete, control is passed to operation 775 and process 700 continues.
[0101] In operation 775 , the value of the PWM counter of the microcontroller is updated. For example, using the exemplary light controller program code, a value of an exemplary variable, such as ‘PWMCount’, is assigned as a PWM system counter value. In the above example, ‘PWMCount’ may be updated by incremented in value by a value of ‘1’ if the program code completes an entire cycle. If operation 775 is complete, control is passed to operation 776 and process 700 continues.
[0102] In operation 776 , a determination is made as to whether the PWM counter has met or exceeded a certain threshold value. If it is determined that a PWM counter has met or exceeded a certain threshold value, control is passed to operation 777 and process 700 continues. If it is determined that a PWM counter has not met or exceeded a certain threshold value, control is passed to operation 780 ( FIG. 7C ) and process 700 continues. The determination in operation 776 may be facilitated by a simple comparison of program code values. For example, using the exemplary light controller program code, a value of an exemplary variable, such as ‘PWMCount’, is assigned as a PWM system counter value. In the above example, ‘PWMCount’ may be compared against a maximum threshold numerical value to determine if the PWM counter has met or exceeded a maximum value.
[0103] In operation 777 , the incremented value of the PWM counter may be reset or cleared. For example, using the exemplary light controller program code, the variable ‘PWMCount’ may be cleared and/or reset if ‘PWMCount’ reaches a certain maximum value that may correspond to the number of microcontrollers resident in a lighting fixture apparatus.
[0104] In operation 780 , a determination is made as to whether header data is read by the lighting controller. If it is determined that header data is read by the lighting controller, control is passed to operation 782 and process 700 continues. If it is determined that header data is not read by the lighting controller, control is passed to operation 784 and process 700 continues.
[0105] In operation 782 , a microcontroller counter is reset or cleared. For example, using the exemplary light controller program code with the variable ‘ChipCount’, the value of ‘ChipCount’ may be reset to a numeric value of ‘0’ to clear the ‘ChipCount’ value. If operation 782 is complete, control is passed to operation 783 and process 700 continues.
[0106] In operation 783 , a light or LED counter is reset or cleared. For example, in the lighting controller program code, a variable such as ‘LEDCount’ may be defined to correspond to a targeted LED and a variable. Using the exemplary light controller program code with the variable ‘LEDCount’, the value of ‘LEDCount’ may be reset to a numeric value of ‘0’ to clear the ‘LEDCount’ value. If operation 783 is complete, control is passed to operation 784 and process 700 continues.
[0107] In operation 784 , a fourth of a plurality of data bits is captured. The data capture of operation 784 occurs through a series of lines of program code operating under the branch of the main program code. The program code may contain a carry flag for data bit capture. In operation 784 , a fourth data bit is captured and stored into the carry flag. To enable proper capture of data bits, program code may be placed in the center of each data bit as an MCU receiver clock of a light strand controller may drift high or low. If a data bit is captured in operation 784 , the carry flag may be rotated into a new data variable which may be placed into a subsequent data variable for processing during a next program cycle. If operation 784 is complete, control is passed to operation 785 and process 700 continues.
[0108] In operation 785 , a light counter is decremented. For example, in the lighting controller program code, a variable such as ‘LEDCount’ may be defined to correspond to a targeted LED. The variable ‘LEDCount’ may be set to begin at the value of ‘3’. Using the above example, in operation 785 , the ‘LEDCount’ variable may be decremented by a numeric value of ‘1’. If operation 785 is complete, control is passed to operation 786 and process 700 continues.
[0109] In operation 786 , a determination is made as to whether a light or LED counter value equals the numeric value of ‘0’. Using the exemplary light controller program code with the variable ‘LEDCount’, the value of ‘LEDCount’ may be decremented by a value of ‘1’ after a data bit capture until ‘LEDCount’ reaches the value of ‘0’. If it is determined that the LED counter value reaches the numeric value of ‘0’, control is passed to operation 787 and process 700 continues. If it is determined that the LED counter value has not reached the numeric value of ‘0’, control is passed to operation 788 and process 700 continues.
[0110] In operation 787 , a light counter is decremented. For example, in the lighting controller program code, a variable such as ‘LEDCount’ may be defined to correspond to a targeted LED. Using the above example, in operation 787 , the ‘LEDCount’ variable may be decremented by a numeric value of ‘1’ If operation 787 is complete, control is passed to operation 788 and process 700 continues.
[0111] In operation 788 , a determination is made as to whether a microcontroller has accounted for all lights or LEDs associated with the microcontroller. If it is determined that the microcontroller has accounted for all light or LEDs associated with the microcontroller, control is passed to operation 789 and process 700 continues. If it is determined that the microcontroller has not accounted for all lights or LEDs associated with the microcontroller, control is passed to operation 790 and process 700 continues.
[0112] In operation 789 , the microcontroller counter value is decremented. For example, using the exemplary variable ‘ChipCount’, the value of ‘ChipCount’ may be incremented by a value of ‘1’. If operation 789 is complete, control is passed to operation 790 and process 700 continues.
[0113] In operation 790 , a fifth of a plurality of data bits is captured. The data capture of operation 790 occurs through a series of lines of program code operating under the branch of the main program code. The program code may contain a carry flag for data bit capture. In operation 790 , a fifth data bit is captured and stored into the carry flag. To enable proper capture of data bits, program code may be placed in the center of each data bit as an MCU receiver clock of a light strand controller may drift high or low. If a data bit is captured in operation 790 , the carry flag may be rotated into a new data variable which may be placed into a subsequent data variable for processing during a next program cycle. If operation 790 is complete, control is passed to operation 791 and process 700 continues.
[0114] In operation 791 , data is stored for processing. If operation 791 is complete, control is passed to operation 792 and process 700 continues.
[0115] In operation 792 , a data register of received data is cleared. If operation 792 is complete, control is passed to operation 793 and process 700 continues.
[0116] In operation 793 , any external hardware interrupt flags created by the lighting controller program code may be cleared and re-enabled for program restart. If operation 793 is complete, control is passed to operation 794 and process 700 continues.
[0117] In operation 794 , a determination is made as to whether an external interrupt is detected from a signal pin. An external interrupt can detect a low-high transition which corresponds to a stop-start bit transition. If an external interrupt is detected, control is passed to operation 795 and process 700 continues. If an external interrupt is not detected, control remains at operation 794 and process 700 continues.
[0118] In operation 795 , the external interrupt detection is utilized at the start of a data word transmission to enable the light controller program to navigate to the external interrupt vector address. If operation 795 is complete, control is passed to operation 720 ( FIG. 7A ) and process 700 continues.
[0119] FIG. 8 illustrates a flowchart depicting the overall logic structure 800 of the computer software associated with the lighting system 105 ( FIG. 1 ). As previously discussed according to the system process 200 ( FIG. 2 ), computer readable medium, embodied as computer software, may include a file conversion program, a software program to read, analyze, process and/or manipulate visual information or data, an interface(s) for user selection of display information, and other data and/or information used in facilitating the output display information that may be transferred to the light controller.
[0120] In operation 805 , video or other visual or other information obtained during a recording process of the lighting apparatus is loaded into a software program. Visual information may be loaded into the software program by, for example, utilizing a GUI such as the GUI 900 illustrated in FIG. 9 . If operation 805 is complete, control is passed to operation 810 and process 800 continues.
[0121] In operation 810 , a video or any other portion of visual information is converted into individual frames. In at least one embodiment of the lighting system 105 ( FIG. 1 ), a software package is provided that may include a file conversion program, such as any commonly available open-source video conversion utility capable of converting the visual information obtained via a recording device to any desired file format. For example, the original visual information transferred to the software program in operation 805 may be converted to a compressed AVI file format via the file conversion program. The file format of the converted visual information may be any format that can allow individual frames of visual information to be extracted from the entire file. Extraction of individual frames may be facilitated by using any software application programming interface, or any other software and/or codec capable of extracting individual frames. If operation 810 is complete, control is passed to operation 815 and process 815 continues.
[0122] In operation 815 , the software program may read the converted visual information, and process and/or analyze any images or frames of such visual information for determining light detection. For example, the software program may read a first frame of the converted visual information, and thus be capable of detecting any metadata, for example, any dimensions of the visual information, such as frame dimensions of a video frame, any codec and/or software used to convert and/or compress the visual information, information associated with the recording device, such as frame rate, etc., and/or any other information, parameters and/or data available. Alternatively, a user may be able to define any parameters associated with visual information. For example, a user may be presented with a parameter interface, such as the GUI 1000 ( FIG. 10 ), in which a user may be able to define frame dimensions, pre-determined or pre-defined light position(s), lighting apparatus quantity, type, size, shape, etc., and/or any other data or information that may be used in defining an exemplary light image or map of the lighting fixture apparatus and associated lights. If operation 815 is complete, control is passed to operation 820 and process 800 continues.
[0123] In operation 820 , any frames associated with the visual frame information may be read, processed, analyzed, compared and/or grouped according to an index of light detection. A first frame of the converted visual information may be obtained by bypassing a portion of the visual information. For example, if a sequencing event is initiated, such as the calibration sequencing event of the lighting apparatus discussed in operation 220 of process 200 ( FIG. 2 ), a ‘flashing’ of all lights associated with the lighting fixture(s) may be performed to indicate that the sequencing event has commenced, and such a ‘flashing’ of all associated lights may be bypassed as any initial ‘flashing’ of lights may, for example, interfere with the software program reading, analysis and/or processing of the visual information. A bypassing of a portion of visual information may be based on a time period, a frame set, or any other measurement.
[0124] The processing of operation 820 may be done on an individual frame basis. An analysis of the visual information may include locating or detecting a first frame where a percentage and/or threshold value of all lights of a frame of visual information associated with a lighting fixture are illuminated, locating subsequent frame(s) in which a percentage or threshold, which may be based on a first frame reading of all lights associated with the lighting fixture are illuminated, and/or any other analysis of the visual information. In performing an analysis on light illumination of the visual information, the program may initially set a threshold value for light illumination. Alternatively, a user may be provided with an interface, such as the GUI 1000 ( FIG. 10 ), in which a user may be able to define an initial pixel intensity threshold value which may be a numeric value. A threshold value may be a certain percentage associated with a total.
[0125] The analysis of operation 820 may be based on any component level(s). For example, a pixel, or any other measurement of the visual information may be analyzed to determine illumination of a light. A pixel may be considered a possibility for illumination of a light if any, or all component level values of a pixel reach a certain threshold. For example, if a red, a green, and/or a blue component associated with a pixel meets, and/or exceeds a certain threshold value, the pixel may be considered an illuminated pixel associated with an illuminated light. The information obtained from analysis of an individual pixel(s) of the visual information may be utilized in determining and/or assigning an overall illumination value or index of a frame.
[0126] The comparing or grouping of operation 820 may be based on a threshold value(s) and/or an average multiplier, etc. The software program may define or determine an average multiplier and/or threshold value(s) to be utilized in determining an average or representative frame of the lighting fixture apparatus. Alternatively, a user may be provided with an interface, such as the GUI 1000 ( FIG. 10 ), in which a user may be able to define a pixel difference threshold value and/or pixel average multiplier, etc. An average frame may be utilized in comparing or grouping frame(s). For example, analysis of all frames associated with the visual information may yield individual values that may be totaled and averaged into a representative frame of visual information considered a frame of visual information with all lights associated with the lighting fixture apparatus illuminated.
[0127] The software program may continue through operation 820 until all frames associated with the visual information are read, analyzed, and compared. Alternatively, in at least one embodiment, a representation of light positioning may be produced manually or by a coupling of automatic detection utilizing the software code and manual inclusion of light positions using a matrix or sectional system. For example, if the lighting fixture(s) is distributed in a grid format or other pre-defined and/or uniform positioning, then an axis positioning of lights may be produced by utilizing a graphing or matrix program. Whether obtained automatically, manually, and/or by a combination of both methods, the representative frame or image or light map of visual information is utilized in determining the positioning of the lights associated with the lighting fixture(s). If operation 820 is complete, control is passed to operation 825 and process 800 continues.
[0128] In operation 825 , the resulting image or light map created in operation 820 may be converted from a 2D image to a 3D representation. The 2D positioning information obtained in operation 820 may be used to create a set of coordinates, a histogram, and/or any other textual, pictorial, graphical, or any other type of representation of the information. The 2D representation of light illumination information may be any set of coordinates, such as axes coordinates, for example, Cartesian coordinates utilizing an x-axis and a y-axis. The 2D coordinates of each light position of the representative image or light map may in turn be utilized in rendering a 3D image based on an image based rendering algorithm. For example, a lighting apparatus with identification (ID) tags or labels associated with each light may be distributed as desired. The tags or label IDs of a plurality of lights representative of a 3D space may be determined and/or input into the software program. For example, lighting fixture apparatus may be distributed on a three-dimensional object, such as a tree, and ID tags of a sampling of lights from a top four corners and a bottom four corners may be determined and input as coordinates or otherwise into the software program. The program may use the ID tags or coordinates to render a 3D image.
[0129] Alternatively, sensors, such as infrared, radio frequency and/or other devices may be installed in or applied to any lights associated with a lighting fixture apparatus. For example, an infrared sensor may be installed on each LED of an exemplary light strand such as the light strand 300 ( FIG. 3 ). An infrared sensor(s) associated with a first light or LED may detect an infrared sensor(s) associated with a second light and thus detection of a relative position(s) of any lights associated with a lighting apparatus may be obtained. The relative position(s) may be input into the software program to render a 3D positioning or image of the lights associated with the lighting fixture apparatus.
[0130] Another alternative to obtain a 3D image is by utilizing spatial positioning of a recording device. For example, during a recording of a calibration sequence, such as in operation 220 of process 200 ( FIG. 2 ), a camera or other recording device may be placed at a pre-determined or fixed position(s) relative to the lighting fixture apparatus. A camera may be placed at a fixed distance(s) relative to a known orientation of a location(s) or object(s) displaying the lighting fixture apparatus. The position of any lights visible to the camera may be determined by utilizing the known positioning of the camera. For example, angles and/or distances may be calculated based on physical measurements taken of a fixed spatial position of a camera relative to a fixed position of a light(s). A plurality of cameras and/or fixed camera positions may be utilized. For example, in at least one embodiment, three cameras set at three separate fixed positions may record a calibration sequence of any lights associated with a lighting fixture apparatus. Using the above example, the position(s) of the lights associated with the lighting fixture apparatus may be calculated from the three fixed camera positions and the three camera angles.
[0131] Another alternative of 3D image rendering utilizes calculations based on matrices and linear equations. For example, the spatial position and orientation of a recording device may be represented by six variables. Using the above example, the variables (x n , y n , z n ) may represent the position of a camera in space, the variables (r n , r n , r n ) may represent the orientation of the camera, and the variables (x m , y m , z m ) may represent the position of individual lights. In the example, the variable ‘n’ is the number of cameras or camera positions and the variable ‘m’ is the number of lights associated with the lighting fixture apparatus. The exemplary variables can translate into parameters which may be input into matrix form for solving a system of linear equations. Utilizing reference points and distance(s) between these reference points, for example, by comparing these known 3D position(s) or coordinates to relative 2D image(s), the software program may calculate or create a system of linear equations. The software program may use the matrix parameters to solve the linear equations thus determining a 3D positioning of any lights. If operation 825 is complete, control is passed to operation 830 and process 800 continues.
[0132] In operation 830 , the 2D or 3D light positioning determined in operation 825 is utilized by the software program to create or construct an image or light map. An exemplary light map 1305 is shown in GUI 1300 ( FIG. 13 ). If operation 830 is complete, control is passed to operation 835 and process 800 continues.
[0133] In operation 835 , an image or light map is displayed to a user. The image displayed may be represented by light and/or dark areas. For example, the representative light map 1305 ( FIG. 13 ) is shown to contain light circles representing lights or LEDs that have had their positions detected by the software program and a dark background representing unlit areas. The image displayed to a user may be a 2D or 3D representation depending on which method of image rendering was utilized in operation 825 . If operation 835 is complete, control is passed to operation 840 and process 800 continues.
[0134] In operation 840 , the image reconstruction resulting from operation 835 may be modified. A representation of light positioning may be produced manually utilizing the software and/or any manual or user defined inclusion of light positions using matrices and/or a coordinate or sectional system may be utilized. For example, if a lighting fixture(s) is distributed in a grid format or other pre-defined and/or uniform positioning, then coordinates representing a positioning of lights may be produced by utilizing a graphing or matrix algorithm of the software program. If operation 840 is complete, control is passed to operation 845 and process 800 continues.
[0135] In operation 845 , a user is provided with the ability to select and/or design a sequence or display information. For example, the software program may include a front end as illustrated by the GUIs of FIGS. 9-17 . The software program may provide a user with the ability to design display features, graphics, animations, and/or any other static and/or visual information that may be included in a display and/or other visual program utilizing any lights associated with the light fixture(s). A user may be provided with selections or selectable options, and/or provided with the ability to design his or her own display or program based on any given display features. If operation 845 is complete, control is passed to operation 850 and process 800 continues.
[0136] In operation 850 , any sequence or display information designed and/or selected in operation 845 is processed by the software program to enable output to the lighting controller. The program may process information into any file format that may be compatible with a lighting controller. If operation 850 is complete, process 800 completes if a user completes his or her utilization of the software program.
[0137] FIG. 9 illustrates an exemplary GUI 900 which may be presented to a user upon initiation of the software program associated with the lighting system 105 ( FIG. 1 ). The GUI 900 includes window controls 905 , main menu controls 910 , submenu controls 915 , tabs 920 , display bar 925 , time scale bar 927 , selection control 930 , display bar control 935 , zoom controls 937 , video simulation control 940 , export control 945 , sector window 950 , user controls 955 , animation addition control 960 , sector selection control 965 , animation property window 970 , animation selection text box 975 , animation selection browse control 977 , initiation time controls 980 , and duration time controls 985 .
[0138] The window controls 905 may include any commonly known GUI window controls such as a close, minimize, and/or restore or maximize control. The main menu controls 910 may include menu headers associated with the software program. For example, as illustrated in FIG. 9 , the main menu controls 910 include a ‘File’, an ‘Edit’ and a ‘Help’ selectable menu headers. The submenu controls 915 may include additional selectable menu headers that may be used to navigate through portions of the software program.
[0139] The tabs 920 represent the selectable controls that may be used to navigate between the two main interfaces presented in the exemplary software embodiment illustrated by FIGS. 9-17 . The tab 920 a may be used to open the ‘Animation Mode’ interface as illustrated in FIG. 11 . The tab 920 b may be used to open the ‘Display Design’ interface as illustrated in FIG. 9 . The ‘Animation Mode’ window may be utilized for the design and/or selection of a sequence of an image(s), animated image(s), text, video(s), or effect elements, or any individual such element. The ‘Animation Mode’ interface may be utilized independent of the existence of any display or light map. The ‘Display Design’ window may be utilized for an initial creation of a representative light image or map.
[0140] The display bar 925 may display a graphical, textual, or other representation of any images, animations, sequences, etc. designed in the ‘Animation Mode’ interface. The time scale bar 927 represents a relative time scale or duration for any sequence displayed in the display bar 925 . The selection control 930 may be used to select any image, animation and/or sequence or other design element displayed in the display bar 925 . The display bar control 935 may be used to scroll or navigate through the display bar 925 to display additional images, animations, sequences, etc. contained in the display bar 925 , but not visible due to constraints of an available viewing area on a user system computer screen and/or limited by a programmed size of the GUI 900 . The zoom controls 937 may contain a ‘Zoom In’ control 937 a and a ‘Zoom Out’ control 937 b. The zoom controls 937 may be used to display a larger or smaller time scale and/or time increments for ease of viewing animations, images or sequences displayed in the display bar 925 . As illustrated in FIG. 9 , the display bar 925 and selection control 930 may comprise a row, for example, a sector animation design row. A plurality of such rows may be included in GUI 900 that corresponds to the number of sectors or sector grids added to a light map. For example, numerous sector grids may be assigned and/or placed on the light map or rendered image loaded into the software program. While GUI 1500 illustrates an exemplary sector grid 1505 , any number of sector grids may be assigned to a light map contained in the sector window 950 ( FIG. 9 ). For example, if three sectors are assigned to a light map, three display bars 925 ( FIG. 9 ) may be displayed in the GUI 900 .
[0141] The video simulation control 940 may be used to generate a visual simulation output of the display that has been designed utilizing the software program. The export control 945 may be used to export the designed display to a file format that may be compatible with any number of multimedia programs. For example, selection of the export control 945 may result in the software program processing any display information contained in the display bar 925 for output as display sequence file that may be capable of being read by a lighting controller of the lighting system 105 ( FIG. 1 ).
[0142] The sector window 950 may be used to display a light map or image created by the software program during the process 800 ( FIG. 8 ). The sector window may display the relative positioning or location(s) of any lights associated with a lighting fixture apparatus, and/or allow selection of any portions or sectors of the displayed light map. The user controls 955 may be used to create, load, alter, save and/or make selections of a light map associated with the sector window 950 . For example, the ‘Create Light Map from Video’ control 955 a may allow a user to open and/or select a video file contained in any available memory storage device to be used in the creation of a light positioning image or light map by the software program as described in the process 800 ( FIG. 8 ). The ‘Save Light Map’ control 955 b may allow a user to save a light map displayed in the sector window 950 to any available memory storage device. The ‘Load Light Map’ control 955 c may allow a user to load a light map created during a software program process 800 , or any other available light map or position image, such as any light position image stored on an associated memory storage device, into the sector window 950 . The control 955 c may be used to load any light map that has been saved to a file extension associated with light positioning image(s) or light map(s). The ‘Insert New Sector’ control 955 d may allow a user to select a portion or selection of a light map displayed in the sector window 950 . If a user selects the ‘Insert New Sector’ control 955 d, a sector grid, such as the sector grid 1505 of FIG. 15 may be displayed in the sector window 950 ( FIG. 9 ). The ‘Save Sector Layout’ control 955 e may allow a user to save any layout of a sector grid(s) displayed in the sector window 950 . The ‘Load Sector Layout’ control 955 f may allow a user to load any saved sector layout into the sector window 950 .
[0143] The animation addition control 960 may allow a user to add an animation(s), image(s), and/or other design element(s) to a desired sector grid displayed in the sector window 950 . A sector grid may be selected by utilizing the sector selection control 965 . The sector selection control 965 may be embodied as a text box, drop-down menu, and or other control that may allow a user to select a sector grid that corresponds to a numerical value. For example, a first of a plurality of sector grids may be assigned the numerical value of ‘0’. Using this example, a user may add a design element to the sector grid ‘0’ by selecting the number ‘0’ in the sector selection control 965 .
[0144] The animation property window 970 may display any data, information, parameters and/or properties associated with a desired sector as selected by the sector selection control 965 . The animation property window 970 includes the animation selection text box 975 , animation selection browse control 977 , initiation time controls 980 , and duration time controls 985 . The animation selection text box 975 may allow a user to input a file name and/or other identifier associated with design element file or resource. For example, an image contained on any memory storage device, such as an image embodied as a GIF, PNG, or JPG may be input into the text box 975 . Alternatively, the animation selection browse control 977 may allow a user to browse to any location on a memory storage device associated with a user system and/or select a design element to load into the software program. The initiation time controls 980 may allow a user to select and/or view a time that may be embodied as initiation time minutes 980 a and/or initiation time seconds 980 b that corresponds to an initiation or start time for a design element on the time scale bar 925 . The duration time controls 985 may allow a user to select and/or view a time that may be embodied as duration time minutes 985 a and/or duration time seconds 985 b that corresponds to a duration of time for a design element on the time scale bar 925 .
[0145] FIG. 10 illustrates an exemplary GUI 1000 that may allow a user to set light mapping or image rendering parameters as discussed according to process 800 of the software program. The GUI 1000 may be displayed to a user upon a selection of a control enabling the creation or generation of a light map, such as the control ‘Create Light Map from Video’ control 955 a of GUI 900 ( FIG. 9 ). The GUI 1000 may contain a pop-up window 1005 , light mapping parameter controls 1010 , lighting system parameter controls 1015 and parameter user controls 1020 . The pop-up window 1005 may be alternatively displayed to a user as an integrated window of GUI 1000 . The light mapping parameter controls 1010 may allow a user to define parameters to be utilized in the light mapping or image rendering operation(s) as discussed in the explanation of process 800 ( FIG. 8 ). For example, a user may be allowed to select and/or define a pixel difference threshold value, a pixel intensity threshold, a pixel average multiplier and/or a video file seconds per step or any other parameters that may be used in creating a representative image or light map associated with a lighting fixture apparatus.
[0146] The lighting system parameter controls 1015 may include controls to input and/or select a number of lighting controllers or control boxes and/or number of lighting strands or other lighting fixture apparatus associated with the lighting system. The lighting system parameters may be utilized by the software program in calculating and/or determining a percentage or other representative value of lights detected or mapped versus a total value of lights associated with the lighting system. The parameter user controls 1020 may include any commonly known GUI controls such as a ‘Reset to Defaults’ control 1020 a, an ‘OK’ control 1020 b, and a ‘Cancel’ control 1020 c. The ‘Reset to Defaults’ control 1020 a may allow a user to return any parameter controls of the GUI 1005 to their default or system defined values. For example, the default parameter values may be originally set by the software program to be values that may be utilized positively in several different instances. The ‘OK’ control 1020 b may allow a user to accept any parameters contained in the GUI 1005 and apply them to the light mapping operation of the process 800 ( FIG. 8 ). Alternatively, the ‘Cancel’ control 1020 c may allow a user to cancel any changes or modifications to the parameters of the GUI 1005 and/or close or exit out from the window.
[0147] FIG. 11 illustrates an exemplary GUI 1100 which may be presented to a user upon selection of the ‘Animation Mode’ tab 920 a. The GUI 1100 includes window controls 905 , main menu controls 910 , submenu controls 915 , tabs 920 , animation bars 1125 , animation time scale bar 1127 , selection controls 1130 , animation bar control 1135 , zoom controls 1137 , animation bar addition control 1139 , design element legend 1140 , and design element property window 1145 .
[0148] The GUI 1100 may be displayed to a user for the design and/or selection of a display sequence. The animation bars 1125 may include any number of bars or rows in which a design element may be added. A plurality of animation bars 1125 may be included in GUI 1100 that corresponds to the number of individual animation designs that a user may be concurrently designing or selecting, limited, by for example, a user system's resources.
[0149] Design elements may be added to the animation bars 1125 by any available means. For example, by using a mouse, a user may ‘right click’ the area of an animation bar 1125 to be prompted to select a design element to add to the animation bar 1125 . For example, GUI 1200 illustrates a pop-up window 1205 that may allow a user to select a design element from a given list or menu to be added to an animation bar 1125 . If a selection on the window 1205 is made, a user may be prompted to input and/or browse to a memory storage location where a design element file(s) is located. A selected design element may be displayed in an animation bar 1125 according to its corresponding visual representation included in the design element legend 1140 . For example, each design element such as a text element, an image element, an animation element, an effect element, etc. may be represented by a plurality of dissimilarly sized, shaped and/or colored boxes. For example, GUI 1400 illustrates a text design element representation 1435 and a static image element representation 1440 in an animation bar. A user may click on or select any design element representation displayed in the animation bars 1125 to display any properties associated with a design element in the design element property window 1145 .
[0150] The animation time scale bar 1127 represents a relative time scale or duration for any design element displayed in the animation bar 1125 . The selection controls 1130 may be used to select any image, animation, sequence or other design element displayed in the animation bars 1125 . As illustrated in FIG. 11 , the ‘Select All’ control 1130 a may be used to select all design elements of the animation bar 1125 a and the ‘Select All’ control 1130 b may be used to select all design elements of the animation bar 1125 b. A selection of all design elements contained in an animation bar may facilitate a user to save a design configuration of an entire animation or sequence display. The animation bar control 1135 may be used to scroll or navigate through the animation bars 1125 to display additional images, animations, sequences, etc. that may be contained in animation bar 1125 , but not visible due to constraints of an available viewing area on a user system computer screen and/or limited by a programmed size of the GUI 1100 . The zoom controls 1137 may contain a ‘Zoom In’ control 1137 a and a ‘Zoom Out’ control 1137 b. The zoom controls 1137 may be used to display a larger or smaller time scale and/or time increments for ease of viewing animations, images or other design elements displayed in the animation bars 1125 .
[0151] As illustrated in FIG. 11 , the design element property window 1145 contains a resize checkbox 1150 , a design element text box 1155 , a design element selection browse control 1157 , initiation time controls 1160 , duration time controls 1165 , scrolling direction control 1167 , display text control 1170 , save control 1175 , image view 1180 , effect text box 1185 , effect selection browse control 1187 and effect checkbox 1190 .
[0152] The resize checkbox 1150 may be selected by a user to allow the software to resize a design element to fit or correlate with any parameters associated with the representative light map contained in the sector window 950 ( FIG. 9 ). For example, a parameter associated with a size of a defined sector or sector grid may have an effect on a size and/or shape of the design element that may be assigned and/or displayed in the sector. For example, the exemplary sector grid 1505 of GUI 1500 ( FIG. 15 ) represents a small corner portion of the light map 1305 of GUI 1300 ( FIG. 13 ). Alternatively, the exemplary sector grid 1605 of GUI 1600 ( FIG. 16 ) represents a relatively larger portion of the light map 1305 . Therefore, as sector grid may include any or all of a light map, various defined sectors may be limited in the size and/or shape of a design element that may be displayed. As illustrated in the GUI 1300 , a light map, such as the light map 1305 may be larger than the sector window 950 ( FIG. 9 ) such that the scrollable controls 1310 may be used to scroll or navigate through sector window 950 to display additional areas or portions of a representative light map that may be loaded, but not visible due to constraints of an available viewing area on a user system computer screen and/or limited by a programmed size of the GUI.
[0153] A design element text box 1155 may allow a user to view, input, and/or modify a file name and/or other identifier associated with design element file or resource. For example, GUI 1400 ( FIG. 14 ) illustrates a text design element representation 1435 in the animation bar 1125 ( FIG. 11 ). If a user selects to view any properties associated with the text design element 1435 , the design element text box 1155 may be populated with the exemplary data 1405 . For example, in GUI 1400 , the file property data of the text design element 1435 includes the exemplary data 1405 as a file location with a file extension of ‘.txt’. Alternatively, a user may select a design element selection browse control 1157 ( FIG. 11 ). The design element selection browse control 1157 may allow a user to browse to any location on a memory storage device associated with a user system and/or select a design element to load into the software program.
[0154] The initiation time controls 1160 may allow a user to select and/or view a time that may be embodied as initiation time minutes 1160 a and/or initiation time seconds 1160 b that corresponds to an initiation or start time for a selected design element on the animation time scale bar 1127 . The duration time controls 1165 may allow a user to select and/or view a time that may be embodied as duration time minutes 1165 a and/or duration time seconds 1165 b that corresponds to a duration of time for a design element on the animation time scale bar 1127 . For example, the exemplary initiation data 1415 and exemplary duration data 1420 of GUI 1400 ( FIG. 14 ) illustrate that a selected design element, such as the text design element 1435 , is to start its associated effect on the display sequence at ‘0.46 seconds’ on the animation time scale bar 1127 and run or continue for a duration of ‘10.00 seconds’.
[0155] The scrolling direction control 1167 may allow a user to select or assign a spatial direction for creating the effect of ‘scrolling text’. For example, the exemplary scrolling direction data 1425 of GUI 1400 ( FIG. 14 ) illustrates that a selected design element, such as the text design element 1435 , is not to scroll as the data illustrates the text ‘No Scroll’. Alternatively, if a user enters the direction ‘Right’ in the scrolling direction control 1167 ( FIG. 11 ), the selected design element may scroll from the left to right in the associated display sequence.
[0156] The display text control 1170 may allow a user to view and/or enter simple keyboard entry text. For example, the exemplary display text 1430 of GUI 1400 ( FIG. 14 ) illustrates that a selected design element, such as the text design element 1435 , displays the text ‘Welcome to Galaxia’. Alternatively, if a user desires to enter simple text, by for example, bypassing a selection of a .txt or other text file, a user may be able of entering any desired text utilizing the display text control 1170 . A save control 1175 may allow any user entered text displayed in the display text control 1170 to a resource file. For example, if a user desires to input and/or modify any text displayed in the display text control 1170 , a text file, such as a resource file with a ‘.txt’ file extension may be saved to a user system associated memory storage device.
[0157] The image view 1180 may display a thumbnail, icon and/or other visual representation of a selected design element. For example, in the GUI 1400 ( FIG. 14 ), if a user selects to display the properties of the static image element representation 1440 , and the static image design element represented by 1440 is a static image of a cat, then a thumbnail of a cat may be displayed in the image view 1180 . The effect text box 1185 may allow a user to view, input, and/or modify a file name and/or other identifier associated an effect file or resource. For example, the software program may be populated with various non-positional effects such as any commonly known lighting effect, for example, a twinkling effect, a chasing effect and/or a fading effect, etc. The effect selection browse control 1187 may allow a user to browse to any location on a memory storage device associated with a user system and/or select any program or file associated with an effect to load into the software program. The effect checkbox 1190 may allow a user to select and/or deselect any application of an effect contained in the effect text box 1185 for execution during a display sequence.
[0158] If a user has completed the design process associated with the GUIs 9 - 16 , a user may indicate completion by exporting a completed display sequence to a file format that may be compatible with the lighting system controller. For example, a user may select the export control 945 ( FIG. 17 ) to initiate processing of a completed display sequence. As illustrated in GUI 1700 , if a user initiates processing of a display sequence, a progress bar 1710 may be displayed. The progress bar 1710 may indicate the advancement or status of the system program in processing a display sequence. The progress bar 1710 may indicate completion of display sequence processing by, for example, displaying a full or completed progress bar. The file exported as a result of the display sequence processing may be any file type that is compatible with the lighting controller of the lighting system 105 ( FIG. 1 ). For example, any proprietary and/or commonly known multimedia file extension may be used that is able to be read and/or processed by the lighting controller to display a display sequence utilizing any lights associated with the lighting fixture apparatus. | The present invention is related to a method, system and apparatus, in particular, a lighting system and method of controlling the lighting system, comprising a computer readable medium and a programmable device capable of controlling and manipulating individually addressable lights to realize a visual display at a pixel level. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is generally related to a method of fabricating interconnections including a multi-layer metal film stack, particularly, to an improvement in corrosion and heat resistances of interconnections.
2. Description of the Related Art
TFT (thin film transistor) apparatuses, such as LCDs (liquid crystal displays), require low resistivity interconnections with high corrosion and heat resistances. A technique for fabricating such interconnections is disclosed in Japanese Patent Application No. Jp-A-Heisei 8-62628. The disclosed technique involves forming a refractory metal film, oxidizing the surface of the refractory metal film, forming an aluminum film on the oxidized surface, oxidizing the upper surface of the aluminum film, forming another refractory metal film on the oxidized surface of the aluminum film to complete a film stack, patterning the film stack, and oxidizing sides of the film stack. The oxides effectively avoids the aluminum film being corroded by stripping agent for stripping off resist patterns used as a mask.
Japanese Patent Application No. P2000-26335A discloses an interconnections structure composed of an aluminum film sandwiched by a pair of refractory metal films. Oxygen including aluminum films are disposed between the aluminum film and refractory metal films to prevent thermally induced counter diffusion between the aluminum film and refractory metal films.
Japanese Patent Application No. P2002-198360 discloses an etching technique for etching a structure including a silicon layer, and an aluminum layer disposed on the upper surface of the silicon layer. The disclosed etching technique involves etching the aluminum layer with Cl 2 gas and H 2 gas, and etching the silicon layer with SF 6 gas, and HCl gas and He gas. The document also discloses the use of Cl 2 gas in place of the HCl gas.
Japanese Patent Application No. P2002-90774A discloses a LCD fabrication process to reduce deterioration of liquid crystal within cells caused by pollution with material of gate electrodes. The disclosed process involves successively depositing an aluminum layer and a molybdenum layer, partially etching the molybdenum layer in an effective display region of the display panel, and oxidizing the aluminum layer in the effective display region through an anodization technique to complete the gate electrodes.
Japanese Patent Application No. 2000-252473 discloses a TFT structure for achieving low resistivity ohmic contact onto gate electrodes. The disclosed TFT structure is composed of gate electrodes including first through third metal layers, the first metal layer being formed of refractory metal such as Ta, Hf, Nb, and Zr, the second metal layer being formed of low resistivity metal such as Al, Ti, Cu, Cr, W, and Mo, and the third metal layer being formed of refractory metal such as Ta, Hf, Nb, and Zr.
SUMMARY OF THE INVENTION
In summary, the present invention addresses an improvement in corrosion and heat resistances of interconnections, especially those integrated within TFT devices.
In an aspect of the present invention, a method of fabricating a semiconductor device including an interconnection is composed of:
forming a metal film stack to cover a substrate; the film stack including: a lower refractory metal film over the substrate, a lower protective layer of a first compound including metal disposed on an upper surface of the lower refractory metal film, a core metal film of the metal on an upper surface of the lower protective layer, an upper protective layer of a second compound including the metal disposed on an upper surface of the core metal film, and an upper refractory metal film disposed on an upper surface of the upper protective layer; patterning the metal film stack; and forming a side protective layer of a third compound including the metal on a side of the patterned core metal film.
At least one of the first, second, and third compounds may be oxide, nitride, or oxynitride of the metal.
In the event that the metal is selected from among the group consisting of aluminum and aluminum alloy, the first, second, and third compounds are preferably selected from the group consisting of oxide, nitride, and oxynitride of the metal.
For copper, silver, and an alloy thereof, by contrast, the first, second, and third compounds are preferably selected from the group consisting of nitride, and oxynitride of the metal.
The patterning may include:
forming a resist pattern on the metal film stack, and etching the metal film stack using the resist pattern as a mask, the formation of the side protective layer being implemented before the resist pattern is stripped off.
Alternatively, the patterning may include:
forming a resist pattern on the metal film stack, etching the metal film stack using the resist pattern as a mask, and stripping off at least a portion of the resist pattern, the formation of the side protective layer being implemented after the stripping off.
The method may further includes:
forming a semiconductor film stack to cover the substrate; the semiconductor film stack including a semiconductor layer and a heavily doped semiconductor layer disposed on an upper surface of the semiconductor layer, and the metal film stack being patterned so that the patterned metal film stack overlaps the semiconductor film stack; patterning the semiconductor film stack using the patterned film stack as a mask.
When the method includes covering the substrate with a semiconductor film stack including a semiconductor layer and a heavily doped semiconductor layer disposed on an upper surface of the semiconductor layer, and patterning the semiconductor film stack, the patterning the metal film stack may include:
forming a resist pattern on the metal film stack, etching the metal film stack using the resist pattern as a mask so that the patterned metal film stack overlaps the semiconductor film stack, and the patterning the semiconductor film stack may be achieved by using the resist pattern as a mask.
The above-mentioned method is especially effective in the case that the patterning the semiconductor film stack is achieved by using an etchant including fluorine and/or chlorine.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A through 1F are cross sectional views illustrating a fabrication process of an inversely staggered TFT device in an embodiment of the present invention; and
FIGS. 2A through 2G are cross sectional views illustrating a fabrication process in an alternative embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention are described below in detail with reference to the attached drawings.
In one embodiment, as shown in FIG. 1A , a process for fabricating a TFT device begins with forming a gate electrode 2 and a scan line (not shown) on a transparent insulating substrate 1 . In order to form the gate electrode 2 , a core metal film 21 of aluminum is firstly deposited on the substrate 1 , and then the surface of the metal film 21 is covered with a thin protective film 22 . The protective film 22 may be formed through oxidizing, nitriding, or oxinitriding the surface of the core metal film 21 . A refractory metal film 23 of chromium is then deposited on the protective film 22 . The core metal film 21 , the protective film 22 , and the refractory metal film 23 is then patterned. After the patterning, the sides of the patterned core metal film 21 are oxidized, nitrided, or oxinitrided to form thin protective films thereon, which typically have a thickness in the orders of tens or hundreds of nano meters. This completes the gate electrode 2 .
After the gate electrodes 2 are covered with a gate dielectric 5 , as shown in FIG. 1B , a semiconductor film stack 6 of an amorphous silicon film 61 and a heavily doped amorphous silicon film 62 is then formed to cover the gate dielectric 5 .
As shown in FIG. 1C , the semiconductor film stack 6 is then patterned to form a semiconductor film stack 6 .
After patterning the semiconductor film stack 6 , as shown in FIG. 1D , a metal film stack of a lower refractory metal film 91 , a lower protective film 93 a , a core metal film 92 , an upper protective film 93 b , and an upper refractory metal film 94 is then formed to cover the patterned semiconductor film stack 6 .
The refractory metal films 91 and 94 are formed of a material selected from the group of chromium (Cr), titanium (Ti), tantalum (Ta), Niobium (Nb), hafnium (Hf), zirconium (Zr), molybdenum (Mo), tungsten (W), alloys thereof, and conductive nitrides thereof, such as titanium nitride.
The core metal film 92 is formed of a low resistivity metal, such as aluminum, copper, silver, and alloys mainly consisting of these metal, such as AlNd.
The protective films 93 a and 93 b are formed of oxides, nitrides, or oxynitrides of the metal or alloy used as the core metal films 92 . In the event that the core metal film 92 is formed of aluminum, or aluminum alloy, any of the oxides, nitrides, or oxynitrides thereof is suitable for the protective films 93 a and 93 b . For copper, silver, and alloys thereof, by contrast, the use of the oxides as the protective films 93 a and 93 b is not preferable because of the poor corrosion resistivity thereof.
The lower protective film 93 a may be formed through any of three processes described below.
A first process for forming the lower protective film 93 a involves oxidizing the upper surface of the lower refractory metal film 91 through plasma modification or O 2 annealing after cleaning the upper surface, and depositing the core metal film 92 on the oxidized surface. The oxidized surface of the lower refractory metal film 91 provides oxygen for the bottom portion of the core metal film 92 , and thereby completes the lower protective film 93 a of an oxide of the core metal film 92 .
A second process for forming the lower protective film 93 a involves reactive sputtering with a sputtering gas including O 2 , N 2 , or N 2 O gas as well as Ar gas at the initial deposition stage of the core metal film 92 . This achieves deposition of the lower protective film 93 a of an oxide, nitride, or oxynitride of the core metal film 92 . After the completion of the lower protective film 93 a , the sputtering gas is then switched to pure Ar gas to deposit the core metal film 92 .
A third process for forming the lower protective film 93 a involves depositing the metal used as the core metal film 92 , and oxidizing or nitrizing the deposited metal through O 2 plasma treatment, N 2 plasma treatment, or annealing in an oxidizing atmosphere. The oxidizing or nitrizing is followed by deposition of the core metal film 92 .
The upper protective film 93 b may be formed by oxidizing or nitrizing the upper surface portion of the core metal film 92 through O 2 plasma treatment, N 2 plasma treatment, or annealing in an oxidizing atmosphere. Alternatively, the upper protective film 93 b may be formed through reactive sputtering with a sputtering gas including O 2 , N 2 , or N 2 O gas at the final deposition stage of the core metal film 92 .
As shown in FIG. 1E , the metal film stack is then patterned through a photolithography technique using a resist pattern 10 as a mask to form source and drain electrodes 7 , 8 and data lines (not shown) so that the source and drain electrodes 7 , 8 overlap the heavily doped amorphous silicon film 62 . The source electrode 7 includes a lower refractory metal layer 71 , a lower protective layer 73 a , a core metal layer 72 , a upper protective layer 73 b , and an upper refractory metal layer 74 , which are respectively formed from the refractory metal film 91 , the lower protective film 93 a , the core metal film 92 , the upper protective film 93 b , and the upper refractory metal film 94 . Correspondingly, the drain electrode 8 includes a lower refractory metal layer 81 , a lower protective layer 83 a , a core metal layer 82 , a upper protective layer 83 b , and an upper refractory metal layer 84 . The patterning of the metal film stack exposes a portion of the heavily doped amorphous silicon film 62 of the semiconductor film stack 6 .
After patterning the metal film stack, the side surfaces of the core metal layer 72 , and 82 are then oxidized or nitrized through O 2 plasma treatment, N 2 plasma treatment, or annealing in an oxidizing atmosphere to form side protective layers 73 c , and 83 c . The lower, upper, and side protective layers 73 a , 73 b , and 73 c may be collectively referred to as a protective layer 73 . Correspondingly, the lower, upper, and side protective layers 83 a , 83 b , and 83 c may be collectively referred to as a protective layer 83 .
After the resist pattern 10 is stripped off, as shown in FIG. 1F , the exposed portion of the heavily doped amorphous silicon film 62 is dry-etched using the source and drain electrodes 7 , 8 as a mask. It should be noted that the surface portion of the amorphous silicon film 61 may be etched by the dry-etching. This dry-etching forms a channel region 9 to complete an inversely staggered TFT. An etchant used for this dry-etching includes fluorine based chemicals, such as fluorocarbon. The etchant may additionally include chlorine based chemicals.
Alternatively, the exposed portion of the heavily doped amorphous layer 62 may etched using the resist mask 10 as a mask. In this case, the resist mask 10 is stripped off after the etching.
The protective layers 73 , and 83 effectively avoids the corrosion of the core metal films 72 and 82 during and after the dry-etching using fluorine and/or chlorine based chemicals. The use of fluorine and/or chlorine based chemicals potentially causes corrosion of the sides of the core metal films 72 and 82 during dry-etching. Furthermore, subjecting the device structure to the atmosphere may cause undesirable production of hydrofluoric and/or hydrochloric acids through reaction of residual fluorine and/or chlorine based chemicals and moisture of the atmosphere, and the produced acids potentially corrodes the core metal films 72 and 82 . However, the protective layers 73 , and 83 , which is resistive against chemicals, effectively prevent the core metal films 72 , and 83 from being corroded.
In addition, the protective layers 73 , and 83 , which are disposed between the core metal films and the refractory metal films, effectively prevent the undesirable reaction therebetween, and thereby improve the heat resistance of the interconnections. Improvement of the heat resistance is of much importance for implementing the remaining fabrication processes, typically including heat treatment for stabilizing transistor characteristics, passivation using a plasma chemical vapor deposition, and so forth.
In another alternative embodiment, as shown in FIG. 2A , the metal film stack of the refractory metal film 91 , the lower protective film 93 a , the core metal film 92 , the upper protective film 93 b , and the upper refractory metal film 94 are deposited before patterning the semiconductor film stack 6 . As described below, the metal film stack and the semiconductor film stack 6 are then patterned using a single photolithography process. The fabrication process in this embodiment preferably reduces the number of necessary photolithography steps.
In this embodiment, as shown in FIG. 2B , after depositing the metal film stack, the resist pattern 10 is formed thereon through a photolithography technique using a gray tone mask so that the resist pattern 10 has a thinner portion 110 .
The metal stack is then patterned with the resist pattern 10 used as a mask to expose a portion of the semiconductor film stack 6 . After patterning the metal stack, the side surfaces of the core metal film 92 are then oxidized or nitrized through O 2 plasma treatment, N 2 plasma treatment, or annealing in an oxidizing atmosphere to form side protective films 93 c.
After forming the side protective layers 93 c , as shown in FIG. 2C , the semiconductor film stack 6 is then etched with an etchant gas including fluorine based chemicals, such as fluorocarbon, using the resist pattern 10 used as a mask. The etchant may additionally include chlorine based chemicals. As is the case of the protective layers 73 and 83 described before, the protective films 93 a , 93 b , and 93 c effectively avoids corrosion of the core metal film 92 resulting from the fluorine and/or chlorine based chemicals.
After etching the semiconductor film stack 6 , as shown in FIG. 2D , the resist pattern 10 is subjected to ashing to remove the top portion of the resist pattern 10 . This ashing exposes a portion of the upper refractory metal film 94 to form a pair of separated resist patterns 210 .
As shown in FIG. 2E , the metal film stack is then patterned to form the source and drain electrodes 7 , and 8 . This patterning exposes a portion of the heavily doped amorphous silicon film 62 of the semiconductor film stack 6 . After patterning the metal film stack, the side surfaces of the core metal layers 72 and 82 are then oxidized or nitrized through O 2 plasma treatment, N 2 plasma treatment, or annealing in an oxidizing atmosphere to form the protective layers 73 c and 83 c.
The resist patterns 210 is then stripped off as shown in FIG. 2 F.
As shown in FIG. 2G , the exposed portion of the heavily doped amorphous silicon film 62 is dry-etched using the source and drain electrodes 7 , 8 as a mask. The etchant may additionally include chlorine based chemicals. This dry-etching forms a channel region 9 to complete an inversely staggered TFT. It should be noted that the surface portion of the amorphous silicon film 61 may be etched by this etching. An etchant used for this dry-etching includes fluorine based chemicals, such as fluorocarbon. As mentioned above, the protective layers 73 and 83 are effective for avoiding corrosion potentially caused by fluorine and/or chlorine based chemicals.
In concludion, the aforementioned method for fabricating interconnections effectively improves corrosion resistance through forming the protective layers 73 and 83 around the core metal layers 72 and 82 . The protective layers 73 and 83 , which are disposed between the core metal layers 72 , and 82 and the refractory metal layers 71 , 81 , 74 , and 84 , are also effective for improving heat resistance of the interconnections.
Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been changed in the details of construction and the combination and arrangement of parts may be resorted to without departing from the scope of the invention as hereinafter claimed. | A method of fabricating a semiconductor device including an interconnection is provided. The method is composed of covering a substrate with a metal film stack including a lower refractory metal film over the substrate, a lower protective layer of a first compound including metal disposed on an upper surface of the lower refractory metal film, a core metal film of the metal on an upper surface of the lower protective layer, an upper protective layer of a second compound including the metal disposed on an upper surface of the core metal film, and an upper refractory metal film disposed on an upper surface of the upper protective layer, patterning the metal film stack; and forming a side protective layer of a third compound including the metal on a side of the patterned core metal film. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to calendering systems. Such structures of this type, generally, employ the use of hard or soft nips to provide excellent smoothness without gloss mottle.
2. Description of the Related Art
It is well known in calendering systems, particularly heated soft roll calendering systems, to employ a soft roll at high pressures. Exemplary of such prior art is U.S. Pat. No. 4,624,744 ('744) to J. H. Vreeland, entitled "Method of Finishing Paper Utilizing Substrata Thermal Molding". While the '744 patent does achieve calendering, the use of the high nip pressures, namely, pressures above 2000 psi, reduce the bulk of the paper. Consequently, such use of a calendering device is, typically, employed when calendering fine papers. Consequently, a more advantageous calendering system, then, would be employed if calendering could be done at lower nip pressures in order to reduce bulk loss.
It is apparent from the above that there exists a need in the art for a calendering system which is able to calender as well as the known calendering systems, while providing excellent smoothness without gloss mottle (an uneven pattern of gloss or reflectance), but at the same time is able to calender at lower nip pressures.
It is a purpose of this invention to fulfill this and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.
SUMMARY OF THE INVENTION
Generally speaking, this invention fulfills these needs by providing a substantially gloss mottle-free calendered paper with significantly increased smoothness consisting of a coated paper produced by a method comprising, passing the coated paper through a first nip formed between a substantially harder calendering roll and a heated roll means, passing the coated paper through a second nip formed between a substantially softer calendering roll and the heated roll means to produce a substantially gloss mottle-free calendered paper having significantly increased smoothness and operating the method at nip pressures between the first and second nip of substantially less than 2000 psi.
In certain preferred embodiments, the harder calendering roll has a surface hardness of greater than 80 shore D. The heated roll is a polished metallic roll. The softer calendering roll has a surface hardness of less than or equal to 80 shore D. Also, calcium carbonate (CaCO 3 ) is added to the coating placed upon the paper. The coating is applied at a coat weight of approximately 8-24 lbs/3000 ft 2 . The coating contains at least 40% solids and at least 30% CaCO 3 .
In another further preferred embodiment, the use of the harder-softer roll combination allows one to produce a paper which is substantially gloss mottle-free and has a significantly increased smoothness.
The preferred calendering system, according to this invention, offers the following advantages: good stability; good durability; substantially reduced gloss mottle; significantly increased smoothness; reduced operating nip pressures; increased operating capacity; reduced converting problems; and excellent economy. In fact, in many preferred embodiments, these factors of improved gloss mottle, improved smoothness, reduced nip pressures, increased capacity, and reduced converting problems are optimized to an extent that is considerably higher than heretofore achieved in prior, known calendering systems.
BRIEF DESCRIPTION OF THE DRAWING
The above and other features of the present invention, which will become more apparent as the description proceeds, are best understood by considering the following detailed description in conjunction with the accompanying FIGURE, in which the FIGURE is a schematic illustration of a calendering system using hard and soft rolls, according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As discussed earlier, the '744 patent adequately calenders fine papers, but at higher nip pressures. Typically, these nip pressures are greater than 2000 psi as measured by Equation (1) below as set forth by H. L. Schmidt, Rubber Roll Hardness-Another Look, Pulp and Paper, Mar. 18, 1968, pp 30-32. The Equation (1) is: ##EQU1##
m=exponent which is dependent on roll diameter
L=line load (pli)
T=thickness of cover (inches)
D 1 =diameter of harder roll (inches)
D 2 =diameter of softer roll (inches)
E=elastic modulus
However, in today's modern paper manufacturing machines, it is desirable to run at lower nip pressures, i.e., substantially less than 2000 psi. These lower nip pressures reduce bulk loss of the calendered paper and allow paper with greater caliper or thickness to be produced. Using Equation (1), nip pressures in the present invention have been measured from 900 to 1400 psi.
Along with reducing bulk loss, there are several other desired qualities that a paper manufacturer wants the paper to achieve after calendering. From past studies, it has been determined that a Parker Print-Surf (a measurement of surface roughness) of 1.0 or less and a gloss (or reflectance) of greater than or equal to 60 based upon a 75° Hunter gloss are currently acceptable parameters for determining whether or not a paper is calendered to achieve the best results.
With reference first to the FIGURE, there is illustrated an advantageous environment for use of the concepts of the invention. In particular, as shown in the FIGURE, there is illustrated calendering system 2. System 2, includes in part, harder or backing roll 4 having a hard resiliently yieldable surface, conventionally treated, polished metal roll 6, softer or backing roll 8 having a soft resiliently yieldable surface, conventional paper 10, coating 12, and nips 14 and 16. It is to be understood that softer roll 8 may also be located ahead of harder roll 4. Also, roll 6 may be a series of heated rolls such that substrate 10 does not wrap around roll 6 and nips 14 and 16 located in a series.
Harder roll 4, preferably, is any roll constructed of natural or synthetic materials having a surface hardness of greater than 80 shore D measured by conventional techniques. Softer roll 8, preferably, is any suitable roll constructed of natural or synthetic materials having a surface hardness of less than or equal to 80 shore D.
Paper substrate 10 of the present invention is coated by coating 12 on at least one side surface and frequently on both sides. The paper trade characterizes a paper web or sheet that has been coated on one side as C1S and C2S if sheet coated on both sides.
Compositionally, coating 12 is a fluidized blend of coating clay, calcium carbonate (CaCO 3 ), and/or titanium dioxide with binders and additives which is smoothly applied to the traveling web surface. In particular, CaCO 3 is added to the fluidized blend of minerals such that the CaCO 3 comprises greater than 30% by weight of the minerals. Also, the mixture includes at least 40% by weight of solids in order to reduce gloss mottle and increase smoothness.
Coating 12 is applied to paper 10 at a rate of 8-24 lbs/3000 ft 2 by conventional techniques. Preferably, coating 12 is applied by a means of a rod coater, air knife or blade by conventional techniques.
The following test results prove the novelty of the present invention and its application as a desired calendering system.
Using coated basestock with a starting Parker Print-Surf value of 1.9 and a caliper value of 0.012", the following results were achieved as shown below in TABLE 1:
TABLE 1______________________________________ CaliperLoad (pli) Roll Hardness (in) PPS Sheffield Gloss______________________________________348 Softer 11.9 1.4 15 61417/417 Harder/Softer 11.9 1.2 6 68348 Harder 12.0 1.1 8 68______________________________________ ,where PPS = Parker PrintSurf, Softer = Softer roll 8, and Harder = Harde roll 4
The above data demonstrate a more profound effect of the harder polymer roll (88 Shore D) on the larger scale roughness (Sheffield) than on the fine scale roughness (measured by PPS). There was an obvious visual improvement in surface uniformity of the harder/softer roll combination condition as compared to the harder roll only condition.
Using coated basestock with a starting PPS value of 2.4 and a caliper value of 0.11", the following results were achieved as shown below in TABLE 2:
TABLE 2______________________________________ CaliperLoad (pli) Roll Hardness (in) PPS Sheffield Gloss______________________________________348 Harder 10.9 1.9 10 64417/417 Harder/Harder 10.7 1.7 10 71417/417 Harder/Softer 10.8 1.7 13 71______________________________________
Again, the harder/softer roll combination provides reduced PPS values and higher gloss values than a single hard roll. Also, the harder/softer roll combination gives better gloss uniformity than the harder/harder roll combination.
Based upon the favorable results from TABLE 1 and TABLE 2, calendering system 2 was placed on a conventional papermaking machine. The paper was calendered using a harder roll (Shore D hardness of greater than 80), two softer rolls (Shore D hardness of less than or equal to 80) and the harder/softer roll combination of the present invention. The results of the three runs are shown below in TABLE 3:
TABLE 3______________________________________ Shef-Roll Hardness PPS field Gloss Mottle______________________________________Harder 1.2 N/A 62 Unacceptable Gloss UniformitySofter/Softer 1.3 6 56 Acceptable Gloss UniformityHarder/Softer 0.8 4 68 Acceptable Gloss Uniformity______________________________________
Clearly, the use of the harder/softer calendering roll combination creates a paper having a Parker Print-Surf of 1.0 or less, a gloss of greater than or equal to 60, and reduced gloss mottle.
Once given the above disclosure, many other features, modifications or improvements will become apparent to the skilled artisan. Such features, modifications or improvements are, therefore, considered to be a part of this invention, the scope of which is to be determined by the following claims. | This invention relates to calendering systems. Such structures of this type, generally, employ the use of hard and soft nips acting on a heated roll to provide excellent smoothness without gloss mottle. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates to a modular system for transporting wind turbine blades and to a use of the system for providing a suitable spatial arrangement of at least two wind turbine blades for transport. The present invention also relates to a transport system for transporting wind turbine blades in at least two different spatial arrangements.
BACKGROUND OF THE INVENTION
[0002] Wind turbine blades used for horizontal axis wind turbines for generating electrical power from wind can be rather large and may exceed 70 metres in length and 4 metres in width. The blades are typically made from a fibre-reinforced polymer material and comprise an upwind shell part and a downwind shell part. Due to the size and fragility of these large rotor blades, the blades may be damaged during transport as well as during loading and unloading. Such damages may seriously degrade the performance of the blades. Therefore, the blades need to be carefully packaged in order to ensure that they are not damaged.
[0003] However, due to the increasing length of modern wind turbine blades, it is gradually becoming more complicated and expensive to transport the blades. It is not uncommon that the transportation costs amount to 20 percent of the total costs for manufacturing, transporting and mounting the wind turbine blade on the rotor of a wind turbine blade. Also, some blades are transported to the erection site through different modes of transport, such as by truck, train and ship. Some of these modes of transports may have restrictions on large loads, maximum heights, maximum widths, maximum distances between transport frames or supports, for instance dictated by local regulations. Therefore, there exists a logistic problem of providing transport solutions that are suitable for various types of transport.
[0004] Overall, there is a demand for making transport solutions simpler, safer and cheaper. In particular, there is a demand for making such systems more flexible such that adaption to a certain transportation situation is possible. This applies for example for shifting from land transport to sea transport. While height restrictions require lowest possible inter-blade spacings, sea transport may require an increased inter-blade spacing to avoid contact between blades during sea disturbance. The prior art shows various solutions for transporting more than one rotor blade using a single container or other packaging system, which is an obvious way to reduce the transport costs. However, the afore-mentioned restrictions and limits may increase the difficulty of transporting a plurality of blades using the same packaging system.
[0005] WO 2014/064247 describes a transportation and storage system for at least two wind turbine blades. The system is adapted to stack the blades in an alternating root end to tip end arrangement. The tip end of the second wind turbine blade may extend beyond the root end of the first wind turbine blade, and the tip end of the first wind turbine blade may extend beyond the root end of the second wind turbine blade, when the first and the second wind turbine blades are arranged in the packaging system.
[0006] EP1387802 discloses a method and system for transporting two straight wind turbine blades, where the root end of a first blade is arranged in a first package frame, and the tip end of a second, neighbouring blade is arranged in a second package frame that is arranged next to and connected to the first package frame with the effect that the blades are stored compactly alongside each other in a “tip-to-root” arrangement. However, in this transport system the tip end frames support the blades at the very tip of the blades, where they are mechanically most fragile. Further, the package frames are arranged at the root end face and the blade tip. Therefore, the distance between the package frames are approximately equal to the length of the blades. For very long blades of 45 metres or longer, this might not be possible due to local regulations and restrictions on transport.
[0007] It is therefore an object of the invention to obtain a new method and system for storing and transporting a plurality of wind turbine blades, which overcome or ameliorate at least one of the disadvantages of the prior art or which provide a useful alternative.
[0008] Particularly, it is an object of the invention to provide a more flexible transport solution that is able to accommodate for different transport situations and regulatory requirements.
SUMMARY OF THE INVENTION
[0009] In a first aspect, the present invention relates to a modular system for transporting wind turbine blades in at least two different spatial arrangements, each blade having a tip end and a root end, each blade further having a bolt circle diameter D at said root end, the system comprising two or more root end transport frames each having a height H for supporting a root end of a wind turbine blade, wherein H<D, two or more first tip end transport frames each having a height h 1 for supporting a portion of a wind turbine blade towards the tip end of said blade, each first tip end transport frame comprising a base frame and a support bracket provided on top of said base frame for receiving a portion of a wind turbine blade, wherein each first tip end transport frame is stackable on top of a root end transport frame and vice versa, such that the modular system is operable to stack successive wind turbine blades in an alternating root end to tip end arrangement, and wherein the modular system further comprises at least one of parts (i), (ii) and (iii):
(i) two or more second tip end transport frames each having a height h 2 exceeding h 1 for supporting a portion of a wind turbine blade towards the tip end of said blade, each second tip end transport frame comprising a base frame and a support bracket provided on top of said base frame for receiving a portion of a wind turbine blade; wherein each second tip end transport frame is stackable on top of a root end transport frame and vice versa to replace the first tip end transport frames, such that the modular system is operable to stack successive wind turbine blades in an alternating root end to tip end arrangement with two alternative inter-blade spacings resulting from the respective use of either the first or the second tip end transport frames; (ii) two or more tip end distance pieces each attachable on top of or below a first tip end transport frame, wherein the first tip end transport frame and attached tip end distance piece is stackable on top of the root end transport frame and vice versa, such that the modular system is operable to stack successive wind turbine blades in an alternating root end to tip end arrangement with two alternative inter-blade spacings resulting from the respective use of the first tip end transport frames either with or without the tip end distance pieces; and (iii) at least one root end distance piece having a height h 3 and being attachable in between two vertically stacked root end transport frames, wherein (H+h 3 )≧D, such that the modular system is operable to stack successive wind turbine blades in a root end to root end arrangement as alternative to the root end to tip end arrangement by stacking two or more first or second tip end transport frames at one end and two or more root end transport frames with interposed root end distance pieces at the opposing end.
[0013] It has been found that such modular system is inexpensive and offers a high degree of flexibility allowing for transport of two or more wind turbine blades in various spatial arrangements. For example, land transport in a stacked root end to tip end arrangement may be carried out with a minimum inter-blade spacing to minimise height of the overall stack by using the root end transport frames together with a set of first tip end transport frames having a height h 1 . When the freight is reloaded for subsequent sea transport a stacked root end to tip end arrangement with an increased inter-blade spacing and an increased overall stack height may be accomplished by replacing the first tip end transport frames with the second tip end frames of part (i) having a height h 2 which exceeds h 1 . Reducing overall height is not as much of a concern in sea transport as compared to road transport. Instead, sea transport is potentially more turbulent which necessitates higher inter-blade spacings. A similar effect is obtained when using the tip end distance pieces of part (ii).
[0014] Typically, the increased height h 2 will be provided by an increased base frame height of each second tip end transport frame as compared to the first tip end transport frames.
[0015] While the invention has been described as increasing the height by changing to a new tip end frame having an increased height or using tip end distance piece to increase the inter-blade spacing, it is also recognised that a corresponding technical effect may be achieved by instead changing to a tip end frame having a lower height or providing the tip end frame with a removable tip end distance piece.
[0016] In one spatial arrangement a first wind turbine blade may be placed such that the tip end of the first wind turbine blade points in a first direction, and a second wind turbine blade is placed such that the tip end of the second wind turbine blade points in a second direction, which is substantially opposite to the first direction. The tip end of the second wind turbine blade may extend beyond the root end of the first wind turbine blade, and the tip end of the first wind turbine blade may extend beyond the root end of the second wind turbine blade, when the first and the second wind turbine blades are vertically stacked in this arrangement. It is thus apparent that the system is adapted to arranging the first and the second wind turbine blades substantially parallel to each other and pointing tip to root but with an overhang.
[0017] The downside of such an arrangement is the increased overall length of the stack. The modular system of the present invention may also address this problem by providing an alternative spatial arrangement. Using part (iii), a root end to root end stack can be provided by arranging the root end distance piece in between two root end transport frames stacked vertically. Thus, the overall length of the stack is reduced in an efficient and simple manner.
[0018] Typically, the frames are arranged such that a root end transport frame and at least a portion of a successively-stacked tip end transport frame will overlap with the root end diameter of a wind turbine blade supported by the said root end transport frame, and wherein the tip end transport frame is arranged such that a tip end of a supported pre-bent or swept blade will be spaced from the ground.
[0019] Preferably, the modular system comprises part (i). In another embodiment, the modular system comprises part (ii). In yet another embodiment, the modular system comprises part (iii). The modular system may also comprise two of parts (i)-(iii), such as parts (i) and (ii), parts (i) and (iii), or parts (ii) and (iii). In another embodiment, the modular system comprises all three of parts (i), (ii) and (iii).
[0020] Preferably, the wind turbine blades are stacked vertically. In one embodiment (H+h 3 ) is within 0.95 to 1.05 times h 2 ; most preferably (H+h 3 ) equals h 2 . In such embodiments, at root end to root end stack can be provided by using stacked root end transport frames with interposed root end extension pieces at one end and second tip end transport frames at the opposing end without substantially changing the tilt of the wind turbine stack as compared to the root end to tip end stack.
[0021] In a preferred embodiment of the modular system, h 1 is less than 0.9 times h 2 . Advantageously, h 1 is less than 0.8 times, preferably less than 0.7 times, more preferably less than 0.6 times, and most preferably less than 0.5 times h 2 .
[0022] In another embodiment of the modular system, (H+h 3 ) is at least 1.05 times D, such as at least 1.1 times D, at least 1.15 times D, at least 1.2 times D or at least 1.25 times D.
[0023] In another embodiment of the modular system, (0.5 D)<H<(0.9 D), preferably (0.5 D)<H<(0.75 D).
[0024] In another embodiment of the modular system, each root end transport frame has a height, a width, and a depth, wherein the width of said root end transport frame is equal to or greater than the bolt circle diameter of a wind turbine blade to be supported by said root end transport frame.
[0025] In another embodiment of the modular system each root end transport frame has a height, a width, and a depth, wherein the depth of said root end transport frame is equal to or greater than one quarter of the width of the root end transport frame.
[0026] In another embodiment of the modular system each root end transport frame comprises: a frame body and a root end plate coupled to said frame body, said root end plate arranged to couple with a root end of a wind turbine blade, wherein said root end plate is arranged to couple with less than ⅔ of the bolt circle of a root end of a wind turbine blade to support said wind turbine blade on said root end transport frame.
[0027] In another embodiment of the modular system said root end plate comprises a substantially C-shaped body arranged to couple with a portion of the bolt circle of a root end of a wind turbine blade.
[0028] In another embodiment of the modular system each root end transport frame comprises: a frame body and a root end plate for coupling to the root end of a wind turbine blade, wherein said root end plate is hingedly coupled to said frame body.
[0029] In another embodiment of the modular system said root end plate is hingedly coupled to the frame body of said root end transport frame along the horizontal axis.
[0030] In another embodiment of the modular system said root end plate is hingedly coupled to the frame body of said root end transport frame along the vertical axis.
[0031] In another embodiment of the modular system said root end plate is mounted on at least one bracket arm, said at least one arm coupled to said root end transport frame via a hinged joint.
[0032] In another embodiment of the modular system said at least one bracket arm comprises an articulated bracket.
[0033] In another embodiment of the modular system said root end transport frame comprises at least a first and a second bracket arm, wherein said first and second bracket arms are positioned on opposed sides of a notional central longitudinal axis of a wind turbine blade to be mounted to said root end plate.
[0034] In another embodiment of the modular system said first and second tip end transport frames each comprise a frame body, at least one tip end support bracket for supporting a portion of a wind turbine blade towards the tip end of said blade, wherein a first end of said tip end support bracket is hingedly coupled to said tip end transport frame along the horizontal axis, and wherein a leading edge support lip is provided on said bracket, said leading edge support lip arranged to receive a portion of the leading edge of a wind turbine blade supported by said support bracket, such that the wind turbine blade can be pivotably moved about said hinged coupling relative to said tip end transport frame while supported on said bracket.
[0035] In another embodiment of the modular system a second end of said support bracket may be releasably secured to the respective frame bodies of said first and second tip end transport frames when said support bracket is received in said frame body.
[0036] In another embodiment of the modular system said tip end support bracket comprises a flexible strap having a support surface provided on said flexible strap.
[0037] In another embodiment of the modular system the first and second tip end transport frames further comprises a securing strap to be fitted around a wind turbine blade received in said tip end transport frame.
[0038] In another embodiment of the modular system said first and second tip end transport frames are arranged to be positioned at a location toward the tip end of a wind turbine blade to be supported by the modular system, such that a sweep or bend of the wind turbine blade from the location of said tip end transport frame to the tip end of the supported blade is less than respective heights of the base frame of the first and second tip end transport frames.
[0039] In another embodiment of the modular system a wind turbine blade to be supported by the modular system has a longitudinal length L, and wherein the first and second tip end transport frames are arranged to be positioned at a distance F from the root end of said blade, wherein (0.5 L)<F<(0.95 L), preferably (0.6 L)<F<(0.85 L).
[0040] In another aspect, the present invention relates to the use of the modular system of the present invention for providing a suitable spatial arrangement of at least two wind turbine blades for transport, each blade having a tip end and a root end, by selecting among:
a) an alternating root end to tip end stack with a first inter-blade spacing using at least two root end transport frames and at least two first tip end transport frames, such that the tip end of the first wind turbine blade points in a first direction and the tip end of the second wind turbine blade points in the opposite direction; b) an alternating root end to tip end stack with a second inter-blade spacing exceeding the first inter-blade spacing using at least two root end transport frames and at least two second tip end transport frames, such that the tip end of the first wind turbine blade points in a first direction and the tip end of the second wind turbine blade points in the opposite direction; c) an alternating root end to tip end stack using at least two root end transport frames and at least two first tip end transport frames, wherein a tip end distance piece is attached on top of or below each tip end transport frame, such that the tip end of the first wind turbine blade points in a first direction and the tip end of the second wind turbine blade points in the opposite direction; d) a root end to root end stack using at least two root end transport frames and at least two first or second tip end transport frames, wherein a root end distance piece is attached in between two vertically stacked root end transport frames, such that the tip end of the first wind turbine blade points in the same direction as the tip end of the second wind turbine blade.
[0045] Preferably, the first inter-blade spacing is less than 0.9 times the second inter-blade spacing, such as less than 0.8 times or less than 0.7 times the second inter-blade spacing. With a variety of possible shapes, curved surfaces and stacking arrangements, the inter-blade spacing will typically vary over the length of the blades even within a single stack. As used herein, the term “inter-blade spacing” refers to the minimum vertical spacing in between two vertically stacked wind turbine blades.
[0046] In yet another aspect, the present invention relates to a transport system for transporting wind turbine blades in at least two different spatial arrangements, each blade having a tip end and a root end, each blade further having a bolt circle diameter D at said root end, the system comprising: two or more root end transport frames each having a height H for supporting a root end of a wind turbine blade, wherein H<D; two or more extendible tip end transport frames for supporting a portion of a wind turbine blade towards the tip end of said blade, each extendible tip end transport frame comprising a base frame, at least one vertical extension means for extending the height of the tip end transport frame and a support bracket provided on top of said base frame for receiving a portion of a wind turbine blade; wherein each extendible tip end transport frame is stackable on top of a root end transport frame and vice versa, such that the modular system is operable to stack successive wind turbine blades in an alternating root end to tip end arrangement with at least two alternative inter-blade spacings created by varying the height of the extendible tip end transport frames via the vertical extension means.
[0047] Such transport system offers the advantage of providing flexibility in transport situations that require different inter-blade spacings, such as land transport versus sea transport. By extending the height of the tip end transport frames by using the vertical extension means an increased inter-blade spacing can be achieved in an efficient, simple and cost-effective manner.
[0048] Preferably, the vertical extension means are suitable for extending the height of the tip end transport frame stagelessly.
[0049] In a preferred embodiment, the vertical extension means increase the overall height of the tip end transport frames by at least 5%, more preferred at least 10%, and most preferred at least 20%. It will be understood that the vertical extension means is an integral part of the extendible tip end transport frames. Accordingly, the overall height of the frame may be made up of the height of the base frame, the support bracket and the height of the extension means extending beyond the base frame.
[0050] In a preferred embodiment of the transport system, the vertical extension means consists of one or more threaded legs suitable for continuous height adjustment and at least partially received in the base frame of the extendible tip end transport frame.
[0051] Such legs may suitably comprise an outer thread, which is received in a fixture comprising a bore with a matching internal thread within the base frame of the extendible tip end transport frame.
[0052] In other embodiments, the extension means may comprise extendible elements which form part of the base frame, e.g. telescopic posts provided in each corner of the base frame. In these embodiments, the height of the base frame as such may be increased by the vertical extension means.
[0053] Alternatively, a support portion for supporting the tip end of the blade may be movable within the tip end frame, such that the inter-blade spacing may be varied by varying the position of said support portion.
[0054] A typical method for transporting or storing at least two wind turbine blades using the modular system or the transport system of the present invention comprises the steps of: a) placing the first wind turbine blade so that the tip end of the first wind turbine blade points in a first direction, b) placing the second wind turbine blade adjacent and in immediate vicinity to the first wind turbine blade so that the tip end of the second wind turbine blade points in a second direction, which is substantially opposite to the first direction. Typically, the second wind turbine blade is in step b) arranged so that the tip end of the second wind turbine blade extends beyond the root end of the first wind turbine blade. The tip end of the first wind turbine blade may also extend beyond the root end of the second wind turbine blade. This will inevitably be the case, if the first wind turbine blade and the second wind turbine blade are of the same length.
[0055] Thus, two wind turbine blades may be arranged substantially parallel to each other and oriented in opposite directions. Since the thickness of the blades is typically decreasing from the root end towards the tip end, the blades can with the new “tip-to-root” layout be arranged on top of each other via frames having a relatively small combined cross-section.
[0056] According to an advantageous embodiment, the first wind turbine blade and the second wind turbine blade in steps a) and b) are stacked on top of each other, i.e. so that the second wind turbine blade is arranged above the first wind turbine blade. Advantageously, the first wind turbine blade and the second wind turbine blade are arranged so that chordal planes of their respective tip ends are arranged substantially horizontally. By “substantially horizontally” is meant that the chordal plane may vary up to +/−25 degrees to horizontal.
[0057] In a preferred embodiment, the blades are arranged so that an upwind side (or pressure side) of the blade is facing substantially downwards.
[0058] In a stacking system for storing more than two blades, it is also possible to stack the blades both horizontally and vertically, i.e. in a stacked array.
[0059] Typically, the wind turbine blades will have a length of at least 40 metres, or at least 45 metres, or even at least 50 metres. The blades may be prebent so that, when mounted on an upwind configured horizontal wind turbine in a non-loaded state, they will curve forward out of the rotor plane so that the tip to tower clearance is increased.
[0060] The first and the second wind turbine blades may be prebent. Such prebent blades may be arranged in the tip end frames and root end frames so that they are straightened slightly or fully during transport, e.g. as shown in WO05005286 by the present applicant. However, the blades need not forcedly be straightened. Since the blades are supported near the ends and the blades are arranged with the upwind side facing downwards, the own weight of the blade may straighten the blades due to the gravitational forces acting on the middle part of the blade.
[0061] According to a preferred embodiment, the root end of the first wind turbine blade is arranged in a first root end frame, the root end of the second wind turbine blade is arranged in a second root end frame, the tip end of the first wind turbine blade is arranged in a first tip end frame, and the tip end of the second wind turbine blade is arranged in a second tip end frame.
[0062] The tip end frames typically comprise a receptacle for supporting a tip end section. Thus, the first tip end frame comprises a first tip end receptacle, and the second tip end frame comprises a second tip end receptacle. Depending on the particular solution, the receptacle may for instance either support the pressure side of the blade or alternatively the leading edge of the blade. However, in principle the receptacle may also support the suction side of the blade or even the trailing edge of the blade. The frames themselves may be used as lifting tools so that two or more blades may be lifted in one go and without imposing stress to the blades.
[0063] In a typical embodiment of the modular system, one first tip end frame with a height h 1 is connected, optionally detachably connected, to a root end frame, and another first tip end frame with a height h 1 is connected, optionally detachably connected, to another root end frame. After replacing the first tip end frames with the second tip end frames to increase inter-blade spacing, one second tip end frame with a height h 2 is connected, optionally detachably connected, to a root end frame, and another second tip end frame with a height h 2 is connected, optionally detachably connected, to another root end frame.
[0064] In another embodiment of the modular system, one first tip end frame with a height h 1 is connected, optionally detachably connected, to a root end frame, and another first tip end frame with a height h 1 is connected, optionally detachably connected, to another root end frame. Inter-blade spacing may then be increased by attaching the respective tip end distance piece to each first tip end frame.
[0065] In yet another embodiment of the modular system, one first tip end frame with a height h 1 is connected, optionally detachably connected, to a root end frame, and another first tip end frame with a height h 1 is connected, optionally detachably connected, to another root end frame. To decrease stack length both root end frames are attached on top of each other separated by the root end distance piece with a height h 3 . The respective root ends of the blade are received in the respective root end frames. Likewise the two first tip end frames are stacked on top of each other on the opposite side to receive the respective tip ends of the blades.
[0066] Preferably, the connection parts of the root end frames and the tip end frames that connect to or fix the blade in the frame may be hinged to the frame itself. This can for instance for the root be achieved by connecting a plate to the root of the blade that is hingedly connected to the frame. Similarly, this can be achieved by letting a tip end receptacle be hingedly connected to the tip end frame. Such embodiments have the advantage of alleviating loads that would otherwise be introduced to either the frames or blades due to blade deflections or the like during transport.
[0067] In another advantageous embodiment, each root end frame is a root end bracket adapted to be attached to a root end face of a wind turbine blade. This provides a particularly simple solution, where the frame or bracket may be attached to for instance a root end plate of the blade and without having to support the exterior of the blade. Thus, external damages to the outer surface of the blades may more easily be avoided. The tip end frames (with receptacles) may be attached to the brackets, so that the tip end extends beyond the bracket, when the blade is inserted into the tip end frame (and receptacle).
[0068] In yet another advantageous embodiment, the connection between root end and tip end frames is an L-shaped or a T-shaped configuration so that a base of the L- or T-shaped configuration is attached to the root end of the first wind turbine blade, and a transversely extending frame part (or extremity) of the L- or T-shaped configuration supports a longitudinal section of the tip end of the second wind turbine blade. Advantageously, the L- or T-shaped configuration is formed so that the base is a root end face bracket attached to the root end face of the first blade, and the transversely extending frame part supports a tip end section of the second blade.
[0069] Advantageously, the frame connection is arranged so that the base of the L- or T-configuration is arranged vertically. The transversely extending frame part may be arranged to that it extends from the top or the bottom of the base. In this configuration the second wind turbine blade is arranged on top of the first wind turbine blade. The extremity or transversely extending frame part may thus support either a part of the suction side or the pressure side of the blade in an upwardly facing receptacle. Alternatively, the extremity may extend from the side of the base. In such a configuration, the blades are arranged side-by-side, and the extremity or transversely extending frame part may support either a part of the leading edge or the trailing edge of the blade in an upwardly facing receptacle.
[0070] If the blades are arranged so that both blades are facing with the leading edge downwards (in the side-by-side arrangement) or with the upwind shell parts facing downwards (in the vertically stacked arrangement), it is clear that the transversely extending frame parts of the two frame assemblies must be arranged inversely compared to the base frame. Thus, the two frame assemblies have slightly different configurations.
[0071] The L- or T-shaped frame assembly has the advantage that the transversely extending frame supports a larger part of the tip sections, thus better alleviating loads and possibly also minimising the necessary overhang of the tip part that extends beyond the root end frame.
[0072] In one embodiment, the longitudinal extent of the transversely extending frame part is at least 1 meter, advantageously at least 1.5 metres, more advantageously at least 2 metres. The longitudinal section of the tip end of the blade may be supported along the entire section, or it may be supported in a plurality of discrete sections within the extremity of the L- or T-shaped frame assembly.
[0073] As an alternative to the L- or T-shaped frame assembly, the root end frame and the tip end frame may be arranged substantially in the same plane.
[0074] Advantageously, a plurality of first wind turbine blades and second wind turbine blades are placed in an array, and wherein the wind turbine blades each comprise a shoulder defining a maximum chord of the blade, and wherein the blades are arranged so that the maximum chord forms an angle of between 20 and 75 degrees to a horizontal plane, advantageously between 22 and 73 degrees. Even more advantageously, the maximum chord forms an angle of between 15 and 35 degrees to a horizontal plane, advantageously between 20 and 30 degrees. It is clear that this stacking method may be advantageous to any configuration of stacking blades side by side with the root end and tip end arranged in the same direction. In a preferred embodiment, it is the root end of the blade that is turned between 15 and 35 degrees to a horizontal plane, advantageously between 20 and 30 degrees. The angle may for instance be defined by bond lines between an upwind shell part and a downwind shell part at the root end of the blade. In this setup, the blades in a stacked array may be arranged so that they slightly overlap with the shoulder of one blade extending partly over an adjacent blade, so that the upwind side of one blade near the shoulder faces down towards the downwind side near the leading edge of an adjacent blade. Thereby, it is possible to stack the blades in frames having a width corresponding to the diameter of the root or only slightly larger, even though the chord length of the shoulder exceeds this diameter.
[0075] In another embodiment, intermediate protection members are arranged between the first wind turbine blade and the second wind turbine blade. Advantageously, the intermediate protection members are arranged near the tip end frames so as to provide additional support to a tip end section of the wind turbine blade. The protection means prevent the blades from being damaged due to bending or the blades impacting each other. The intermediate protection members are particularly advantageous, when the blades are stacked on top of each other. In such a setup, the intermediate protection members may be used as support for supporting an additional tip end section of one blade and may transfer loads from the tip end of the upper blade to the mechanically stronger root region of the lower blade. Additional protection members may be arranged below the lowermost blade in a stacked array and a support platform or the ground. The additional protection member is advantageously arranged to support an additional tip end section of the lowermost blade, e.g. near the tip end frame of the lowermost blade. This is particular relevant for embodiment, where the inter-blade spacing is low, thus being particular applicable to embodiments for land transport and storage.
[0076] The intermediate protection members may be made of a foamed polymer.
[0077] In another embodiment, a root end face of the first wind turbine blade is arranged within 45 metres of a root end face of the second wind turbine blade, advantageously within 42 metres. Accordingly, root end brackets or frames should also be arranged at maximum 45 metres or 42 metres from each other.
[0078] Typically, one first tip end frame may be connected, optionally detachably connected, to one root end frame, and another first tip end frame may be connected, optionally detachably connected, to another root end frame.
[0079] In one advantageous embodiment, the root end frames are root end brackets adapted to be attached to a root end face of a first wind turbine blade and a second wind turbine blade, respectively. This provides a particularly simple solution, where the frame or bracket may be attached to for instance a root end plate of the blade and without having to support the exterior of the blade. Thus, external damages to the outer surface may more easily be avoided. The first or second tip end frames or the extendible tip end frames (with receptacles) may be attached to the brackets, so that the tip end extends beyond the bracket, when the blade is inserted into the respective tip end frame (and receptacle).
[0080] Typically, the tip end of the first wind turbine blade, when arranged in its tip end frame, extends a first longitudinal extent beyond the tip end frame, and the tip end of the second wind turbine blade, when arranged in its tip end frame, extends a second longitudinal extent beyond the tip end frame. In other words, the tip end frames are adapted to package the tip end of a wind blade at a first distance from the tip. The distances will typically be approximately the same. The first longitudinal extent and the second longitudinal extent may be at least 2 metres, advantageously at least 3.5 metres, and more advantageously, at least 5 metres. The blade tip may even extend at least 6, 7, or 8 metres beyond the tip end frame.
[0081] In a particular advantageous embodiment, the modular system or the transport system is adapted to stack the first and the second wind turbine blade on top of each other. One tip end frame may for instance be attached to a top of one root end frame, and another tip end frame is attached to a bottom of another root end frame. In this setup the blades are arranged so that chord planes of the tip ends of the blades are arranged substantially horizontally. The setup may be adapted to arrange the blades with an upwind shell part substantially downwards.
[0082] In another embodiment, at least a first intermediate protective member is arranged between the first wind turbine blade and the second wind turbine blade. The first intermediate protective member may advantageously be arranged near the tip end of an upper arranged blade of the first wind turbine blade and the second wind turbine blade. Additionally, a second protective member may be arranged below the lower of the two wind turbine blades. In a stacked array, this blade will then also be an intermediate protective member arranged between two blades. Further, a protective member may be arranged below the lowermost blade in the stacked array. The intermediate protective members may be made of a foamed polymer.
[0083] It is clear that some of the provided solution may also be used for other configurations of transporting and storing blades, e.g. without the tip overhang.
[0084] A typical method for transporting or storing at least two wind turbine blades with the modular system or the transport system of the present invention comprises the steps of:
[0085] a) placing the root end of a first wind turbine blade in a root end frame,
[0086] b) placing a tip end section of the first wind turbine blade in a tip end frame,
[0087] c) placing the root end of the second wind turbine blade in another root end frame,
[0088] d) placing a tip end section of the second wind turbine blade in another tip end frame, wherein
[0089] the root end frame of step a) and the tip end frame of step d) as well as the tip end frame of step b) and the root end frame of step c) are connected as L-shaped or T-shaped frame assemblies so that bases of the frame assemblies are attached to the root ends of the first and the second wind turbine blade, and extremities of the frame assemblies support a longitudinal section of the tip ends of the first and the second wind turbine blades.
[0090] Advantageously, the first wind turbine blade and the second wind turbine blade are arranged such that the maximum chord of the blades form angles of between 15 and 35 degrees to a horizontal plane, advantageously between 20 and 30 degrees, more advantageously around 25 degrees.
[0091] It is clear that all the embodiments described with respect to one aspect of the invention also apply to any other aspect of the invention.
[0092] Advantageously, by providing the tip end frame with a base height h on top of which the support bracket is located, this allows the base frame to be stacked on top of a preceding root end frame, such that the vertical height of the root end frame and the base frame of the tip end frame are substantially equal to the root end diameter of the supported blade. The height of the tip end base frame is obviously lower than the entire height of the tip end transport frame h 1 or h 2 .
[0093] Preferably, (0.5 D)<H<(0.9 D).
[0094] There is also provided a root end transport frame for a wind turbine blade, the blade having a tip end and a root end, the transport frame having a height, a width, and a depth, wherein the height of the transport frame is less than the bolt circle diameter of a root end of a wind turbine blade to be supported by said transport frame.
[0095] A reduced-height transport frame allows for relatively easier handling of the transport frame, and reduces transport and handling costs of the frame when not in use supporting a wind turbine blade.
[0096] Preferably, the width of said transport frame is equal to or greater than the bolt circle diameter of a wind turbine blade to be supported by said transport frame.
[0097] Preferably, the depth of said transport frame is equal to or greater than one quarter of the width of the transport frame.
[0098] Providing a transport frame with such dimensions results in a stable structure with a low centre of mass, and which is able to support a wind turbine blade.
[0099] Preferably, the root end transport frame comprises:
[0100] a frame body;
[0101] a root end plate coupled to said frame body, said root end plate arranged to couple with a root end of a wind turbine blade,
[0102] wherein said root end plate is arranged to couple with less than ⅔ of the bolt circle of a root end of a wind turbine blade to support said wind turbine blade on said transport frame.
[0103] As the root end plate is designed to support a wind turbine blade by only coupling with a portion of the root end of the wind turbine blade, accordingly the height of the root end plate relative to the bolt circle diameter of the root end of the wind turbine blade may be reduced, resulting in a reduced total height of the root end transport frame.
[0104] Preferably, said root end plate comprises a substantially C-shaped body arranged to couple with a portion of the bolt circle of a root end of a wind turbine blade.
[0105] There is also provided a root end transport frame for a wind turbine blade, the blade having a tip end and a root end, the transport frame comprising:
[0106] a frame body; and
[0107] a root end plate for coupling to the root end of a wind turbine blade, wherein said root end plate is hingedly coupled to said frame body.
[0108] By providing a hinged root plate, any bending moments due to blade deflection or bending are prevented from being transferred to the frame body. Accordingly, the frame body may be of a relatively lighter construction, as it does not need to bear such relatively large forces.
[0109] Preferably, said root plate is hingedly coupled to said frame body along the horizontal axis.
[0110] As the angle to the vertical made by the root end of a blade may depend on factors, such as the centre of gravity of the blade and the blade bending properties, accordingly the ability for the root plate to hinge along the horizontal axis allows for different angles of the blade root end to be accommodated by the transport frame.
[0111] Additionally or alternatively, said root plate is hingedly coupled to said frame body along the vertical axis.
[0112] The hinging of the root plate around the vertical prevents damage to the transport frame due to misalignment or handling issues.
[0113] Preferably, said root end plate is mounted on at least one bracket arm, said at least one arm coupled to said transport frame via a hinged joint.
[0114] Preferably, said at least one bracket arm comprises an articulated bracket.
[0115] The use of an articulated bracket allows for greater degrees of freedom of manipulation of the root plate, to more easily receive and accommodate the root end of a wind turbine blade on the transport frame.
[0116] Preferably, said transport frame comprises at least a first and a second bracket arm, wherein said first and second bracket arms are positioned on opposed sides of a notional central longitudinal axis of a wind turbine blade to be mounted to said root end plate.
[0117] By positioning the bracket arms on either side of the centre point of the blade root end, the take up of forces from the root end of the blade is balanced in the transport frame.
[0118] There is also provided a first tip end transport frame with a height h 1 for a wind turbine blade, the blade having a tip end and a root end, the transport frame comprising:
[0119] a frame body;
[0120] a tip end support bracket for supporting a portion of a wind turbine blade towards the tip end of said blade, wherein a first end of said tip end support bracket is hingedly coupled to said transport frame along the horizontal axis; and
[0121] wherein a leading edge support lip is provided on said bracket, said leading edge support lip arranged to receive a portion of the leading edge of a wind turbine blade supported by said support bracket, such that the wind turbine blade can be pivotably moved about said hinged coupling relative to said transport frame while supported on said bracket.
[0122] There is also provided a second tip end transport frame with a height h 2 for a wind turbine blade, the blade having a tip end and a root end, the transport frame comprising:
[0123] a frame body;
[0124] a tip end support bracket for supporting a portion of a wind turbine blade towards the tip end of said blade, wherein a first end of said tip end support bracket is hingedly coupled to said transport frame along the horizontal axis; and
[0125] wherein a leading edge support lip is provided on said bracket, said leading edge support lip arranged to receive a portion of the leading edge of a wind turbine blade supported by said support bracket, such that the wind turbine blade can be pivotably moved about said hinged coupling relative to said transport frame while supported on said bracket.
[0126] By providing a hinged coupling for the support bracket, a wind turbine blade may be adjusted relative to the frame body, to allow for correct positioning of the wind turbine in the transport frame. The leading edge support lip provided on the bracket allows for the partial support of the wind turbine blade, preventing unwanted movement of the wind turbine blade during any such pivoting or subsequent transport.
[0127] Preferably, a second end of said support bracket may be releasably secured to said frame body when said support bracket is received in said frame body.
[0128] Preferably, said tip end support bracket comprises a flexible strap having a support surface provided on said flexible strap.
[0129] The use of a flexible strap as part of the bracket allows for minor adjustments or movements of a supported wind turbine blade to be absorbed through appropriate torsion or twisting of the strap, without being transferred to the relatively rigid frame body. Accordingly, the frame body may be of a more lightweight construction compared to prior art systems.
[0130] Preferably, the first and/or the second tip end transport frame further comprises a securing strap to be fitted around a wind turbine blade received in said transport frame.
[0131] Preferably, the tip end transport frame is arranged to be positioned at a location toward the tip end of a wind turbine blade to be supported by the transport system, such that a sweep or bend of the wind turbine blade from the location of said tip end transport frame to the tip end of the supported blade is less than height h of the base frame of the tip end transport frame.
[0132] The transport system is preferably used in the transport of blades having a pre-bend Δy, and/or swept blades. Accordingly, locating the support bracket of the tip end frame above the horizontal surface by a height h allows for such a curved blade to be supported on the ground without the tip end of the blade striking the ground.
[0133] Preferably, the tip end transport frame is arranged to be positioned spaced from the tip end of the blade.
[0134] Preferably, a wind turbine blade to be supported by the transport system has a longitudinal length L, wherein the first or second tip end transport frame is arranged to be positioned at a distance F from the root end of said blade, wherein (0.5 L)<F<(0.95 L), preferably (0.6 L)<F<(0.85 L).
[0135] Supporting the tip portion of the wind turbine blade at such a location in the outboard portion of the blade, spaced from the tip end, provides a balance between effectively structurally supporting the blade, while reducing the minimum effective wheelbase or support surface needed to support the total transport system.
[0136] It will be understood that any of the above-described features may be combined in any embodiment of the transport system as described.
DETAILED DESCRIPTION OF THE INVENTION
[0137] The invention is explained in detail below with reference to embodiments shown in the drawings, in which
[0138] FIG. 1 shows a wind turbine,
[0139] FIG. 2 shows a schematic view of a wind turbine blade according to the invention,
[0140] FIG. 3 shows a schematic view of an airfoil profile,
[0141] FIG. 4 shows a schematic view of the wind turbine blade according to an embodiment of the invention, seen from above and from the side,
[0142] FIG. 5 shows an embodiment of a root end transport frame according to an embodiment of the invention,
[0143] FIG. 6 shows an embodiment of a tip end transport frame according to an embodiment of the invention,
[0144] FIG. 7 shows a side view of an arrangement of wind turbine blades supported by one embodiment of a modular system according to the invention,
[0145] FIG. 8 shows a side view of an arrangement of wind turbine blades supported by another embodiment of a modular system according to the invention,
[0146] FIG. 9 shows a side view of an arrangement of wind turbine blades supported by another embodiment of a modular system according to the invention, and
[0147] FIG. 10 shows a cross-sectional view of an arrangement of wind turbine blades supported by an embodiment of a transport system according to the invention.
[0148] The present invention relates to transport and storage of wind turbine blades for horizontal axis wind turbines (HAWTs).
[0149] FIG. 1 illustrates a conventional modern upwind wind turbine according to the so-called
[0150] “Danish concept” with a tower 4 , a nacelle 6 and a rotor with a substantially horizontal rotor shaft. The rotor includes a hub 8 and three blades 10 extending radially from the hub 8 , each having a blade root 16 nearest the hub and a blade tip 14 furthest from the hub 8 . The rotor has a radius denoted R.
[0151] FIG. 2 shows a schematic view of a first embodiment of a wind turbine blade 10 . The wind turbine blade 10 has the shape of a conventional wind turbine blade and comprises a root region 30 closest to the hub, a profiled or an airfoil region 34 furthest away from the hub and a transition region 32 between the root region 30 and the airfoil region 34 . The blade 10 comprises a leading edge 18 facing the direction of rotation of the blade 10 , when the blade is mounted on the hub, and a trailing edge 20 facing the opposite direction of the leading edge 18 .
[0152] The airfoil region 34 (also called the profiled region) has an ideal or almost ideal blade shape with respect to generating lift, whereas the root region 30 due to structural considerations has a substantially circular or elliptical cross-section, which for instance makes it easier and safer to mount the blade 10 to the hub. The diameter (or the chord) of the root region 30 may be constant along the entire root area 30 . The transition region 32 has a transitional profile gradually changing from the circular or elliptical shape of the root region 30 to the airfoil profile of the airfoil region 34 . The chord length of the transition region 32 typically increases with increasing distance r from the hub. The airfoil region 34 has an airfoil profile with a chord extending between the leading edge 18 and the trailing edge 20 of the blade 10 . The width of the chord decreases with increasing distance r from the hub.
[0153] A shoulder 40 of the blade 10 is defined as the position, where the blade 10 has its largest chord length. The shoulder 40 is typically provided at the boundary between the transition region 32 and the airfoil region 34 .
[0154] It should be noted that the chords of different sections of the blade normally do not lie in a common plane, since the blade may be twisted and/or curved (i.e. pre-bent), thus providing the chord plane with a correspondingly twisted and/or curved course, this being most often the case in order to compensate for the local velocity of the blade being dependent on the radius from the hub.
[0155] The wind turbine blade 10 comprises a shell made of fibre-reinforced polymer and is typically made as a pressure side or upwind shell part 24 and a suction side or downwind shell part 26 that are glued together along bond lines 28 extending along the trailing edge 20 and the leading edge 18 of the blade 10 .
[0156] FIGS. 3 and 4 depict parameters, which are used to explain the geometry of the wind turbine blades to be stored and transported according to the invention.
[0157] FIG. 3 shows a schematic view of an airfoil profile 50 of a typical blade of a wind turbine depicted with the various parameters, which are typically used to define the geometrical shape of an airfoil. The airfoil profile 50 has a pressure side 52 and a suction side 54 , which during use—i.e. during rotation of the rotor—normally face towards the windward (or upwind) side and the leeward (or downwind) side, respectively. The airfoil 50 has a chord 60 with a chord length c extending between a leading edge 56 and a trailing edge 58 of the blade. The airfoil 50 has a thickness t, which is defined as the distance between the pressure side 52 and the suction side 54 . The thickness t of the airfoil varies along the chord 60 . The deviation from a symmetrical profile is given by a camber line 62 , which is a median line through the airfoil profile 50 . The median line can be found by drawing inscribed circles from the leading edge 56 to the trailing edge 58 . The median line follows the centres of these inscribed circles and the deviation or distance from the chord 60 is called the camber f. The asymmetry can also be defined by use of parameters called the upper camber (or suction side camber) and lower camber (or pressure side camber), which are defined as the distances from the chord 60 and the suction side 54 and pressure side 52 , respectively.
[0158] Airfoil profiles are often characterised by the following parameters: the chord length c, the maximum camber f, the position d f of the maximum camber f, the maximum airfoil thickness t, which is the largest diameter of the inscribed circles along the median camber line 62 , the position d t of the maximum thickness t, and a nose radius (not shown). These parameters are typically defined as ratios to the chord length c. Thus, a local relative blade thickness t/c is given as the ratio between the local maximum thickness t and the local chord length c. Further, the position d p of the maximum pressure side camber may be used as a design parameter, and of course also the position of the maximum suction side camber.
[0159] FIG. 4 shows other geometric parameters of the blade. The blade has a total blade length L. As shown in FIG. 3 , the root end is located at position r=0, and the tip end located at r=L. The shoulder 40 of the blade is located at a position r=L w , and has a shoulder width W, which equals the chord length at the shoulder 40 . The diameter of the root is defined as X. Further, the blade is provided with a prebend, which is defined as Δy, which corresponds to the out of plane deflection from a pitch axis 22 of the blade.
[0160] Blades have over the time become longer and longer and may now exceed a length of 70 metres. The length of the blades as well as the shape of the blades with respect to shoulder, twist and prebending makes it increasingly difficult to transport the blades, in particular if a plurality of blades is to be transported and stored together. The shape and size of the blades also puts limitations on how closely the blades can be stored in a stacked array.
[0161] With reference to FIG. 5 , an embodiment of a root end transport frame according to an aspect of the invention is indicated generally at 100. The root end transport frame 100 comprises a frame body 102 and a root end plate 104 coupled to the frame body 102 . FIG. 5( a ) illustrates a front perspective view of the transport frame 100 , FIG. 5( b ) illustrates a plan view of a root end plate 104 of the transport frame, FIG. 5( c ) illustrates a rear perspective view of the transport frame 100 , and FIG. 5( d ) illustrates a rear perspective view of the root end plate of the frame of FIG. 5( c ) .
[0162] The transport frame 100 is arranged to couple with less than the entire circumference of a bolt circle of a wind turbine blade to be supported by the transport frame, as this provides several advantages in terms of stability, and transport and handling issues.
[0163] The transport frame 100 is designed to have a height H less that the bolt circle diameter of the root end of a wind turbine blade to be supported by the transport frame, and preferably to have a width W greater than or equal to said bolt circle diameter. The depth D f of the frame 100 is designed to adequately support the frame 100 , preferably being at least one quarter of the bolt circle diameter distance. Such a construction provides a relatively low centre of mass of the transport frame 100 , and reduced the possibility of the frame 100 being easily overturned, either when supporting a root end of a wind turbine blade or when not supporting a blade.
[0164] The root end plate 104 is hingedly coupled to the frame body 102 , via a pair of projecting bracket arms 106 . In the embodiment of FIG. 5 , the bracket arms 106 are hinged to the frame body 102 about the horizontal axis, but it will be understood that any suitable hinged joint may be provided, and/or articulated brackets may be provided. The use of a hinged connection between the root end plate 104 and the frame body 102 means that the plate 104 can be provided at any suitable angle to the vertical, to accommodate any bending or deflection of the root end of the wind turbine blade, without transferring such bending moments to the frame body 102 . As a result, the frame body 102 may be of a relatively lightweight construction, as it does not have to bear such relatively large bending moments from the blade root end.
[0165] Preferably, at least two bracket arms 106 are provided, with the arms 106 arranged to be spaced around the centre point of the root end of a blade supported by said transport frame 100 , such that the forces associated with said wind turbine blade are evenly transferred to the supporting frame body 102 .
[0166] The root end plate 104 is preferably arranged to couple with a subsection of the bolt circle of a wind turbine blade root end, resulting in a reduced height of the total structure of the transport frame 100 . The embodiment of FIG. 5 shows the end plate 104 having a substantially C-shaped structure, wherein the plate 104 is operable to couple with approximately ⅔ of the bolt circle of a wind turbine blade root end. The shape and coupling of the root end plate 104 is selected so as to adequately support a root end of a wind turbine blade, while keeping the height of the transport frame 100 structure to a minimum.
[0167] It will be understood that any other suitable shape of root end plate 104 may be used, which is arranged to couple with a portion of a bolt circle of a wind turbine blade, e.g. a U-shaped plate, a substantially square plate, etc.
[0168] It will be understood that the root end plate 104 may be provided with a plurality of coupling apertures arranged along separate notional bolt circles on the end plate 104 , to accommodate the coupling of the root end plate 104 to root ends of different wind turbine blades having different bolt circle diameters. This allows the root end transport frame 100 to be interchangeably used with wind turbine blades of different dimensions.
[0169] It will further be understood that the coupling apertures may be shaped to be wider and/or longer than corresponding apertures in the bolt circle of a wind turbine blade, to allow for adjustment of coupling between the root end plate 104 and the blade root end, for example in the event of misalignment, root end ovalisation, etc.
[0170] With reference to FIG. 6( a ) , an embodiment of a tip end transport frame according to an aspect of the invention is indicated generally at 108 . The transport frame 108 comprises a base frame 110 and a support portion 112 provided at the top of the base frame 110 . The support portion 112 comprises at least one tip end support bracket 114 which is hingedly coupled to the transport frame 108 . The support bracket 114 receives a portion of a wind turbine blade (indicated by section 116 ) to be supported by the tip end transport frame 108 , wherein the blade portion is spaced from the tip end of the blade.
[0171] With reference to FIG. 6( b ) , an enlarged view is shown of an example of a tip end support bracket 114 . The bracket 114 comprises first and second ends 118 a , 118 b arranged to couple with the support portion 112 of the tip end transport frame 108 . The bracket 114 further comprises a cushioning or padding material 120 arranged to support the surface of a wind turbine blade. A leading edge support lip 122 is provided on the bracket 114 , preferably projecting from the cushioning or padding material 120 . The leading edge support lip 122 is arranged to receive the leading edge of a wind turbine blade supported on the bracket 114 , to prevent movement of the blade when on the bracket 114 .
[0172] In use, a first end 118 a of the bracket 114 may be attached to the support portion 112 , with the second end 118 b projecting free of the frame. A portion 116 of a wind turbine blade can be placed on the bracket 114 with the leading edge of the blade fitted adjacent to said lip 122 . The bracket may then be pivoted relative to the transport frame body, to position the blade within the transport frame 108 , at which point the second end 118 b of the bracket 114 can be secured to the frame 108 . A secondary support strap 124 may then be positioned over the surface of the blade section 116 opposed the support bracket 114 , and secured to the support portion 112 , to securely retain the wind turbine blade within the transport frame 108 .
[0173] It will be understood that the support bracket 114 may be formed from a relatively flexible strap having a cushioning or padding material 120 and a leading edge support lip 122 moulded onto the strap.
[0174] The base frame 110 of the tip end transport frame 108 has a height h. This ensures that the portion 116 of the wind turbine blade is supported at a distance h from the ground or underlying surface. With reference to FIG. 13 , this configuration of a transport system for a wind turbine blade provides additional advantages when used for the transportation or storage of pre-bent wind turbine blades, where the wind turbine blades are manufactured to have a curve or bend in a substantially upwind direction, as described in European Patent No. EP1019631.
[0175] FIG. 7 is a schematic side view of a first embodiment of a modular system 200 according to the present invention. The modular system comprises two root end transport frames 171 , 271 each having a height H, two first tip end transport frames 172 , 272 each having a height h 1 , and two second tip end transport frames 372 , 472 each having a height h 2 exceeding h 1 . In FIG. 7( a ) , the first tip end transport frame 172 is attached on top of root end transport frame 171 at one end, and root end transport frame 271 is attached on top of the other tip end transport frame 272 at the opposing end. Accordingly, two wind turbine blades 10 are vertically stacked in a root end to tip end arrangement, each being supported by one root end transport frame and one tip end transport frame. Two second tip end transport frames 372 , 472 are also part of the modular system of this embodiment but are not displayed in use in FIG. 7( a ) .
[0176] FIG. 7( b ) shows the same modular system 200 as in FIG. 7( a ) , however, here the second tip end transport frames 372 , 472 are used instead of the first tip end transport frames 172 , 272 to increase the inter-blade spacing during transport.
[0177] The configuration with lower inter-blade spacing may for instance be used during land transport or storage. Further, intermediate support means (not shown) may be arranged between the blades in order to provide a cushion effect and protect the blades. The configuration with larger inter-blade spacing may for instance be used for sea transport, where the frame system and blades may be subject to turbulence from the sea.
[0178] FIG. 8 is a schematic side view of another embodiment of the modular system 200 according to the present invention. The modular system comprises two root end transport frames 171 , 271 each having a height H, two first tip end transport frames 172 , 272 each having a height h 1 , and two tip end extension pieces 201 , 202 . In FIG. 8( a ) , the first tip end transport frame 172 is attached on top of the root end transport frame 171 at one end, while the root end transport frame 271 is attached on top of the other tip end transport frame 272 at the opposing end. In FIG. 8( a ) , the tip end extension pieces are not used. By contrast, in FIG. 8( b ) the extension piece 201 is attached below the first tip end transport frame 172 , and the extension piece 202 is attached below the first tip end transport frame 272 to increase the inter-blade spacing as compared to the arrangement of FIG. 8( a ) .
[0179] While the modular system 200 has been described as a system, where an extension piece 201 , 202 is attached to the tip end transport frame 172 , 272 , it is also recognised that a similar technical effect can be achieved by providing a tip end frame, which has a removable extension piece. This is illustrated in FIGS. 8 c and 8 d , where FIG. 8 c shows a tip end transport frame 172 and a removable extension piece or distance piece 201 (corresponding to the transport or storage shown in FIG. 8 b ), whereas FIG. 8 d shows the tip end transport frame 172 with the removable extension piece 201 removed (corresponding to the transport or storage shown in FIG. 8 a ). The removable extension piece 201 may for instance have a height of 20-40 cm.
[0180] FIG. 9 is a schematic side view of yet another embodiment of the modular system 200 according to the present invention. Again, the modular system 200 comprises two root end transport frames 171 , 271 each having a height H, two first tip end transport frames 172 , 272 each having a height h 1 , and two tip end extension pieces 201 , 202 . In FIG. 9( a ) , the first tip end transport frame 172 is attached on top of the root end transport frame 171 at one end, while the root end transport frame 271 is attached on top of the other tip end transport frame 272 at the opposing end. Also shown in FIG. 9( a ) is a root end extension piece 203 having a height h 3 . In FIG. 9( b ) , the root end extension piece is inserted in the stack by attaching it in between the two vertically stacked root end transport frames 171 , 271 . This enables an alternative spatial arrangement in that the blades 10 can now be stacked in a root end to root end fashion, thus reducing overall stack length and simultaneously minimising the inter-blade spacing.
[0181] FIG. 10 is a cross-sectional view of a transport system 300 according to the present invention. The transport system 300 comprises two root end transport frames 171 , 271 each having a height H and two extendible tip end transport frames 572 , 672 . Two wind turbine blades 10 are supported by the transport frames in a root end to tip end vertical stack. Each extendible tip end transport frame 572 , 672 contain a threaded leg 204 , 205 which is received in bore or a fixture with a matching internal thread within the respective transport frame. In FIG. 10( a ) the legs 204 , 205 are shown in a retracted position for reduced inter-blade spacing. In FIG. 10( b ) , the legs 204 , 205 are shown in an extended position to increase the overall height of the tip end transport frames 572 , 672 , thereby increasing inter-blade spacing, e.g. for sea transport.
[0182] The invention has been described with reference to preferred embodiments. However, the scope of the invention is not limited to the illustrated embodiments, and alterations and modifications can be carried out without deviating from the scope of the invention that is defined by the following claims.
[0183] The invention is not limited to the embodiments described herein, and may be modified or adapted without departing from the scope of the present invention.
LIST OF REFERENCE NUMERALS
[0000]
2 wind turbine
4 tower
6 nacelle
8 hub
10 blade
14 blade tip
15 tip end section
16 blade root
17 root end face
18 leading edge
20 trailing edge
22 pitch axis
24 pressure side shell part/upwind shell part
26 suction side shell part/downwind shell part
28 bond lines
29 horizontal
30 root region
32 transition region
34 airfoil region
50 airfoil profile
52 pressure side/upwind side
54 suction side/downwind side
56 leading edge
58 trailing edge
60 chord
62 camber line/median line
100 root end transport frame
102 frame body
104 root end plate
106 bracket arms
108 tip end transport frame
110 base frame
112 support portion
114 support bracket
116 wind turbine blade portion
118 support bracket end
120 cushioned support material
122 leading edge support lip
124 retaining strap
171 root end transport frame
172 first tip end transport frame
200 modular system
201 tip end extension piece
202 tip end extension piece
203 root end extension piece
204 threaded leg
205 threaded leg
271 root end transport frame
272 first tip end transport frame
300 transport system
372 second tip end transport frame
472 second tip end transport frame
572 extendible tip end transport frame
672 extendible tip end transport frame
c chord length
d t position of maximum thickness
d f position of maximum camber
d p position of maximum pressure side camber
f camber
L blade length
r local radius, radial distance from blade root
t thickness
D blade root diameter
Δy prebend
H root end transport frame height
W root end transport frame width
D f root end transport frame depth
h tip end base frame height
h 1 height of first tip end transport frame
h 2 height of second tip end transport frame
h 3 height of root end distance piece | A modular system for transporting wind turbine blades in at least two different spatial arrangements comprising two or more root end transport frames having a height H for supporting the root end, wherein H<D (D=bolt circle diameter), and two or more first tip end transport frames having a height H 1 for supporting the blade towards the tip end, each first tip end transport frame has a base frame and a support bracket provided on top of the base frame, wherein each first tip end transport frame is stackable on top of a root end transport frame and vice versa, so the system is operable to stack successive blades in an alternating root end to tip end arrangement. The first tip end transport frame is replaceable with a second end transport frame that increase the inter-blade spacing, or with a tip end or a root end distance piece. | 5 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] The present invention relates to calenders in general, and to supercalenders in particular.
[0004] A calender, particularly a supercalender, can increase the value of the paper manufactured on a papermaking machine without increasing the cost of fiber, and with only a small increase in energy cost. By improving the surface finish or other attributes of the paper web, the value of the paper is increased without otherwise modifying the papermaking machinery or process. Because of the large fixed costs and high production rates typically involved in paper manufacture, increasing the value of the paper produced can be a particularly advantageous way to increase revenue produced by a papermaking machine.
[0005] A supercalender is comprised of a stack of rolls, sometimes as many as ten, eleven, or more, which form a plurality of nips through which the paper web is directed. Pressure and often heat are applied to the web as it passes through the nips of the supercalender. A supercalender can impart an improved, or more valuable surface finish, can correct curl, and can improve paper caliper variations.
[0006] Improving the supercalender has involved controlling the nip force between adjacent rolls by supporting each roll independently of the other rolls in the stack of rolls; the use of crown control rolls, and the use of higher roll temperatures. The use of higher roll temperatures requires an ability to rapidly open a calender stack so that the high-temperature rolls do not overheat opposed compliant rolls when a paper break occurs.
[0007] Where a plurality of intermediate rolls are mounted between a fixedly mounted, variable-crown upper roll and a movable variable-crown lower roll, one known technique for controlling inter roll nip loading is to mount the intermediate roll bearings on pivot arms. The pivot arms can be supported by support cylinders as disclosed in U.S. Pat. No. 4,901,637 to Hagel et al.; U.S. Pat. No. 5,438,920 to Koivukunnas et al.; U.S. Pat. No. 5,806,415 to Lipponen et al.; and U.S. application Ser. No. 09/303,587 (PCT/FI98/00392), filed May 7, 1998, claiming priority from U.S. provisional application No. 60/045,871 to Maenpaa et al., which are each incorporated herein by reference. The support cylinders allow control of the nip loading between each of the supercalender rolls.
[0008] A supercalender may employ rolls of varying diameters and of different types. One type of roll has a polymer roll cover. The resilient roll cover provides a wider nip due to compression of the roll at the nip between rolls. Polymer covered rolls have a relatively long life and require only relatively small reductions in diameter due to refinishing the roll surface during the life of the roll. Smooth metal rolls provide a hard smooth surface against which the paper is compressed. Although metal rolls may be refinished, relatively little material is removed over time. Metal rolls may be heated, typically by hot water, steam or induction heating. Another type of known roll is a filled roll which is comprised of a large number of disks of a material like cotton, flax, or paper. Each disk has a central hole and thousands of individual disks or sheets are stacked up on a metal core and compressed axially at very high pressures. The resulting roll is finished by turning the surface of the roll formed by the compressed disks of fabric or paper. The surface of a filled roll has a relatively short service life requiring frequent machining so that a filled roll decreases substantially in diameter over the life of the roll.
[0009] Many existing calenders are of the closed frame, or A-frame type, which means the roll bearings at the ends of the individual calender rolls making up the supercalender are held between pairs of vertical frames, which are joined at the top. In these existing calenders, the rolls have bearings which slide on rails between the vertical frames. Nip loading between rolls making up the calender can be controlled only by loading the uppermost roll, which means each successively lower nip has an increased nip loading as the weight of each successive roll adds to the total nip load.
[0010] A conventional closed calender cannot rapidly open the nips. Rapid nip opening protects polymer and fiber rolls from damage caused by wads of paper passing through the calender nips. Typically photoeye and web tension sensors detect a paper break and instigate rapid nip opening so that wads of paper formed during a break can pass between calender rolls without damaging them. Existing solutions to rebuilding calenders do allow support of individual rolls by hydraulic pistons which extend between a support frame and the roll bearings. Existing systems, however, do not provide sufficient vertical movement of the roll bearings to accommodate a variety of roll diameters, particularly the ability to accommodate the diameter change of filled rolls over time.
[0011] A calender or calender rebuild design is needed which can accommodate a wide variety of calender rolls, and facilitate the use of filled rolls by accommodating the substantial change in roll diameter overtime.
SUMMARY OF THE INVENTION
[0012] The calender of this invention may be based on an existing calender of the closed A-frame type. One half of each A-frame in the machine direction is removed and a weldment is bolted to the track of each remaining frame along which the bearing housings of the calender rolls formally rode. Each weldment rests on the calender foundation and consists of two parallel plates which extend in the machine direction 72 inches away from the remaining frames. The lower portion of each weldment has a vertical rail along which the bearing housings of a bottom roll rides. The bottom roll mounted to the bottom bearing is supported by a bottom cylinder which controls the bottom roll's vertical movement and the opening and closing of the calender roll stack.
[0013] A top calender roll is fixedly mounted between the weldments. A plurality of intermediate calender rolls are mounted by pivot arms to the weldments, so that each intermediate calender roll is supported on each end by two pivoting arms. Each arm has two plates which extend between the roll end bearing, and extend along either side of the weldment to bearing pins located adjacent to the upstream side of the weldment where the weldment is bolted to the track of the existing frames.
[0014] The bearing housings of each roll connect the two plates of each arm to form a single integrated pivot arm. The bearing housings incorporate a stop so that each bearing housing on each pair of pivot arms, when pivoting downwardly comes to rest on resilient pads mounted to weldment stops which extend like teeth from the sides of the weldments. The weldment is substantially open ended, opposite the calender rolls.
[0015] Positioned within the sides of the weldments are pairs of load supporting cylinders which extend between cylinder brackets which span the sides of the weldments and piston mounting brackets which extend from the calender roll bearing housings. The piston mounting brackets are narrower than the weldment and fit within the sides of the weldment and between the weldment stops on which rubber pads are mounted, thus accommodating the stroke of the load supporting cylinders without interference of the supporting weldment.
[0016] The greater length of the pivot arms combined with the greater stroke of the load support cylinders allows the supercalender to accommodate filled rolls which change diameter substantially over their life, as the surface of the rolls is repeatedly turned down to refurbish the roll surface.
[0017] It is an object of the present invention to provide a supercalender which can accommodate calender rolls of varying diameter.
[0018] It is another object of the present invention to provide a supercalender in which greater vertical motion of individual calender rolls is provided for.
[0019] It is a further object of the present invention to provide a supercalender which can control the nip load on intermediate calender rolls.
[0020] It is a still further object of the present invention to provide a supercalender in which intermediate rolls are mounted on pivot arms which minimize lateral displacement of the rolls when they are pivoted on the arms.
[0021] Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 is a side elevational view of the supercalender rebuild of this invention in the closed position.
[0023] FIG. 2 is a side elevational view of the supercalender rebuild of this invention shown in the open position.
[0024] [0024]FIG. 3 is a broken away side elevational view of the supercalender rebuild of FIG. 1.
[0025] [0025]FIG. 4 is an exploded isometric view of the supercalender rebuild of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Referring more particularly to FIGS. 1 - 4 , wherein like numbers refer to similar parts, a calender 20 is shown in FIGS. 1 and 2. The calender 20 has two spaced apart frames 24 to which weldments 38 are bolted. A top roll 28 is mounted on the weldment 38 for rotation. A bottom roll 26 is mounted for vertical motion on hydraulic pistons 72 and is slidably mounted to the weldment 38 . A plurality of intermediate rolls 34 are placed one above another, so that when the top roll 28 , bottom roll 26 and intermediate rolls 34 are brought together they form calender nips 29 therebetween.
[0027] The calender 20 may be constructed as a rebuild where the rolls 26 , 28 , 34 of an existing calender, and portions of the frame 24 of an existing calender are used in the construction of a new calender 20 . Because of the considerable cost of the calender rolls generally, and particularly of the bottom roll 26 and the top roll 28 which will normally be variable-crown rolls, reuse of the calender rolls will save considerable cost. Reuse of the part of the frame 24 saves the cost and time of constructing a new frame and foundation.
[0028] In a supercalender, where a plurality of intermediate calender rolls are positioned between a lower variable-crown roll and a upper variable crown roll, the nip loading uniformity could be controlled by the variable-crown rolls, except for the fact that the rolls extended beyond the paper engaging nip, and relatively heavy roll bearings are cantilevered off the ends of the rolls. In addition, in a conventional supercalender each successive nip must have a higher linear nip load because each roll must support the weight of all the rolls position above it.
[0029] The weight of the bearings and the unsupported portions of the rolls cause a downward deflection of the roll ends. Mounting the roll bearings to arms which are supported by hydraulic loading cylinders allows the weight of the unsupported portion of the rolls plus the bearing housings to be supported. As explained more fully in U.S. patent application Ser. No. 09/303,587 (PCT/FI98/00392), the loading angle which defines the linear loading of intermediate rolls can also be controlled by the use of hydraulic loading cylinders which are mounted to support the arms to which the roll bearings are mounted.
[0030] Referring to FIGS. 1 and 2, the calender 20 provides the benefit of using hydraulic loading cylinders 30 to support the bearing housings 32 of the intermediate rolls 34 which are mounted on the arms 36 . The roll support arms 36 are mounted to a weldment 38 by pivots 39 . The weldment 38 is bolted to an existing calender frame 24 , as shown in FIG. 4. The loading cylinders 30 are arranged so that the extension of the pistons 46 do not interfere with the mounting of the loading cylinder 30 of the next higher intermediate roll 34 , as shown in FIG. 1. The bearing housings 32 of each intermediate roll have piston mounting brackets 42 which extend towards and partly between the sides 44 of the weldment 38 , as shown in FIGS. 3 and 4. Hydraulic loading cylinders 30 is comprised of the piston 46 which is mounted to the piston mounting bracket 42 and a hydraulic cylinder 48 which is mounted between lower support cylinder brackets 50 which are mounted between the two spaced apart vertical walls 44 of the weldment 38 .
[0031] The lower support cylinder brackets 50 are mounted below the piston mounting brackets 42 and spaced inwardly towards the pivots 39 which mount the arms 36 . The position and arrangement of the hydraulic loading cylinders 30 , and the way in which they are substantially contained within the weldment 38 allows greater extension of the hydraulic loading cylinder pistons 46 , without the interference between cylinders inherent in the prior art. The greater extension of the hydraulic loading cylinder pistons 46 allows greater vertical movement of the intermediate rolls 34 . Greater movement of the intermediate rolls 34 allows the supercalender to accommodate fiber rolls which decrease in diameter substantially over their useful life. Greater vertical movement also facilitates substituting different intermediate rolls as may be required by a particular grade of paper.
[0032] Referring to FIGS. 2 and 3, a rebuilt calender 20 is constructed by tearing down an existing closed calender A-frame (not shown) to leave a single frame 24 consisting of the up machine direction portion of the A-frame of the pre-existing calender, on both the front frame 24 and back (not shown) of the pre-existing calender. The front frame 24 has a track 54 along which previously the bearing housings of the intermediate rolls rode. The weldment 38 has a protruding land 56 which fits within the sides 58 of the track 54 . Bolts 60 mount the weldment 38 to the track 54 of the front frame 24 . The weldment 38 extends over the foundation previously occupied by the portion of the A-frame which was removed.
[0033] The weldment has a back 62 and two sides 44 and downstream edges 64 which are thicker than the sides 44 and support one pair of triangular teeth 66 for each intermediate roll 34 . The triangular teeth 66 have upwardly facing surfaces 67 on which are mounted resilient pads 70 and which form stops, which support the intermediate rolls 34 , when the calender 20 is in the open position, as shown in FIG. 2. Corresponding teeth 68 are formed on the bearing housings 32 of the intermediate rolls 34 . As shown in FIG. 2, when the calender 20 stack is opened by moving the bottom roll 26 down by means of the bottom roll support cylinder 72 , the intermediate rolls 34 come to rest on the upwardly facing surfaces 67 and resilient pads 70 of the triangular teeth 66 which engage the bearing housing teeth 68 . As shown in FIG. 3, the bearing housing of the bottom roll 26 slides along a track 74 formed on lower portions 76 of the weldment 38 .
[0034] A gap 78 is formed between the downstream edges 64 , of the weldment 38 . The gap opens into the interior 80 of the weldment 38 . In contradistinction to the prior art, where the hydraulic load cylinders are mounted substantially along the downstream edges of the calender support, the hydraulic loading cylinders 30 of the calender 20 are mounted substantially within the interior 80 of the weldment 38 . The downstream edges 64 of the weldment sides 44 may be tied together for increased stiffness by short bars 81 which extend between the weldment sides 44 . The short bars 81 are positioned to avoid interference with the hydraulic load cylinders 30 . Assembly of the calender 20 is facilitated by access openings 82 which facilitate positioning pairs of opposed bracket parts which form the lower support cylinder brackets 50 which are mounted to the sides 44 of the weldment with bolts 86 .
[0035] The access openings 82 also facilitate positioning the lower portions 88 of the hydraulic cylinders 48 within the grooves 90 in the bracket parts 50 . The bracket parts 50 may also be joined by through bolts (not shown) which tie the weldment sides 44 together. In addition, the lower portions 88 of the hydraulic cylinders 48 may be held within the brackets by keys 93 which prevent the hydraulic cylinders 48 from being inadvertently lifted out of the grooves 90 . The pivotal arms 36 are mounted over the pivots 39 which extend outwardly of the weldment sides 44 , closely spaced from the back 62 of the weldment 38 . Pivot brackets 92 overlie the arms 36 and the pivots 39 to provide stronger support to the pivots 39 . The pivot arms 36 are bolted by bolts 94 to ductile cast iron bearing housings 32 , on which the piston mounting brackets 42 are integrally formed.
[0036] During assembly, the bearing housings 32 with attached hydraulic load cylinders 30 are bolted to the pivot arms 36 . The bottom of the roll support cylinder 72 may then be positioned the lower portions 88 through access openings 82 so the lower portions 88 ride with in the grooves 90 of the bracket parts 50 . The intermediate rolls 34 , as shown in FIG. 3, are mounted by bearings 102 within the bearing housings 32 . Referring to FIGS. 1 and 2, an inside flyroll 104 is mounted to the inside part 99 of the pivot arm 36 . Alternatively, an outboard flyroll 100 is mounted to a bracket on the bearing housing 32 .
[0037] The top roll 28 is fixedly mounted, as shown in FIGS. 1 and 2, to the weldment 38 . All loading of the calender stack is performed by the bottom roll 26 which, as previously described, slides along the track 74 formed on lower portions 76 of the weldment 38 . The calender stack can be rapidly opened, as shown in FIG. 2, by moving the bottom roll 26 downwardly and allowing the pivot arm 36 to come to rest on the upwardly facing surfaces 67 of the teeth 66 . In the open position, gaps of at least about 0.19 inches are formed between each intermediate roll and the preceding roll.
[0038] In combination with a greater stroke of the hydraulic loading cylinders 30 , the pivot arms will have a correspondingly greater swing radius between the axis 106 of the intermediate the rolls 34 , and a pivot axis defined by the pivots 39 . Pivoting the arms 36 results in not only vertical movement of the intermediate rolls, but a small horizontal or machine direction motion so that the individual intermediate rolls may not be positioned precisely above, or precisely below another intermediate roll 34 or the top roll 28 or bottom roll 26 . To the extent any intermediate roll 34 forms a nip which is offset from a calender plane 107 extending between the axis 108 of the top roll 28 and the axis 110 of the bottom roll 26 , lateral forces will be developed in the pivot pins 39 . The lateral forces are related to the amount of lateral offset of the intermediate roll 34 axis 106 . These lateral offsets are minimized by positioning the pivot pins 39 and the stops formed by the upwardly facing surfaces 67 to position each intermediate roll so that the intermediate roll axes 106 are initially positioned to the right as viewed in FIGS. 1 and 2 of the calender plane 107 extending between the axes 108 , 110 of the top and bottom rolls. The pivot arms 36 are arranged so that the intermediate roll axes 106 cross the plane 107 twice, thus reducing the total angular displacement of the intermediate roll axes 106 , away from the calender plane 107 , by a factor of four, and the lateral displacement by more than a factor of ten.
[0039] The calender 20 achieves an ability to accommodate greater vertical movement in a calender where the rolls are mounted to pivot arms, by using the arms which in proportion to the diameter of the intermediate rolls, are substantially longer, so that intermediate roll diameter is about 40 percent or less of the pivot radius defined between the intermediate roll axis 106 , and the pivots 39 , and by placing the hydraulic loading cylinders 30 in the overlapping diagonal arrangement as shown in FIGS. 1 and 2 so that greater extension of the hydraulic loading cylinders 30 is possible without interference between cylinders. In the prior art, hydraulic loading cylinders are positioned substantially in a vertical line, and thus each loading cylinder could only extend until it came into interference with the loading cylinder immediately above.
[0040] The calender 20 , as shown in FIGS. 1 and 2, has a top roll diameter which begins life with a diameter of 34.28 inches, and a bottom roll which begins life with a diameter of 42 inches. The intermediate rolls, depending on roll type, vary between 32 inches for filled rolls, 28.8 in. for polymer rolls, and 24.7 inches for thermal rolls. The rolls will decrease in diameter, in a manner known in the art, due to periodic resurfacing by a turning down of the roll diameters, with the amount of roll diameter reduction being dependent on the roll type. FIG. 2 shows the calender 20 in the open position with maximum diameter rolls, and the rolls resting on stops formed by the surfaces 67 of the triangular teeth 66 . FIG. 1 shows the calender 20 in a closed position with minimum diameter rolls. The total vertical motion of the bottom roll axes is thirty inches between FIG. 1 and FIG. 2. The pivot radius defined between the intermediate roll axes 106 and the center of the pivots 39 is eighty inches. For the lowermost intermediate roll 114 , which has a maximum angular motion of about 17 degrees, and a maximum vertical motion of the roll axes of about twenty-four inches, or about 30 percent of the pivot radius. The roll has a maximum horizontal displacement of the roll axes of about 0.45 inches from the calender plane 107 , which is less than one percent of the pivot radius, with the actual displacement of the nip formed between the lowermost intermediate roll 114 and the bottom roll 26 , or the roll immediately above being displaced about a maximum of 0.41 inches from the calender plane 107 and it is this last displacement which controls the amount of lateral loads developed at the pivot arm 36 pivots 39 .
[0041] The intermediate roll 34 immediately above the lowermost intermediate roll 114 has a smaller vertical motion, approximately twenty-one and one half inches or slightly more than twenty-five percent of the pivot radius and proportionately less horizontal displacement. Less vertical motion is required of the intermediate rolls 34 as the top roll 28 is approached, so that the horizontal motion can be to less than one percent of the pivot radius, without necessarily causing the axis of the intermediate rolls 34 to pass twice through the calender plane 107 . The calender plane 107 could be tilted with respect to the vertical, in which case the horizontal and vertical displacements are measured as parallel and perpendicular to the calender plane.
[0042] It should be understood that the calender rolls 26 , 28 , 34 are supported on either end by mirror image frames, arms, and load support cylinders. The rolls having a typical cross machine direction width which is greater than the width of the paper web being calendered which, for an on-machine calender, may be several hundred inches wide.
[0043] It should be understood that the calender 20 may be constructed as a rebuild calender or as a new calender.
[0044] It should be understood that in the claims the term support frame refers to the structure to which the pivot arms are mounted, whether that is a weldment, a weldment plus an existing frame, or simply a frame, however constructed, which supports the pivot arms.
[0045] It should be understood that in the claims the terms support cylinders includes hydraulic cylinders, pneumatic cylinders, electric actuators, air rides/air bags, and other types of actuator.
[0046] It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms thereof as come within the scope of the following claims. | A supercalender has a top roll, a bottom roll, and a plurality of intermediate rolls. The intermediate rolls are mounted to support frames by pivot arms. The pivot radius defined by the arms is at least about 2½ times the diameter of the largest intermediate roll. Hydraulic load support cylinders are arranged between the intermediate roll bearings and anchor points which are spaced away from the intermediate rolls, to allow greater movement without mechanical interference between hydraulic load support cylinders. The greater length of the pivot arms combined with a greater stroke of the load support cylinders allows the supercalender to accommodate filled rolls which change diameter substantially over their life, as the surface of the rolls is repeatedly turned down to refurbish the roll surface. The calender may be based on an existing calender of the closed A-frame type. One half of each A-frame in the machine direction is removed and a weldment is bolted to the track of each remaining frame along which the bearing housings of the calender rolls formally rode. | 3 |
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to fastener tools, and more particularly to concrete nailers.
Description of the Related Art
[0002] Concrete nailers are quite different from conventional nailers designed simply for nailing wood and metal together. As may be imagined, driving a nail into concrete requires much higher energy and produces greater impacts than driving nails into metal or wood. Driving a nail into concrete requires that the systems of a concrete nailer be made much more robustly, and that those systems be especially configured to deal with the particular challenges presented to a concrete nailer on a job site, which are not encountered by conventional nailers. Also, it has now become imperative that, for maximum flexibility, concrete nailers use magazines which can accommodate nails ranging in length from 1/2 inch to at least 2¼ inches. Furthermore, it is important that when driving nails into a concrete work surface, the nail be oriented as close to 90° as possible to the concrete, so that the concrete does not chip, crack or break away, as is likely to occur if the nail is impacted at an angle relative to the concrete. These requirements present a significant test for a concrete nailer when the concrete nailer is required to nail a deep track to concrete.
[0003] “Tracks” are U-shaped steel channels for holding everything from electrical conduits and piping, to partitions, other structural members, and the like. Tracks have become ubiquitous on a job site, and consequently it would be very desirable to provide a concrete nailer capable of quickly and easily nailing tracks to concrete work surfaces. However, the vast range of sizes of tracks used in construction has presented a challenge to the operator, who will frequently encounter on the same job, tracks having widths ranging from 30 mm to 100 mm, and depths ranging from 20 mm to 70 mm. On the one hand, if the operator encounters a track at the wide and shallow ends of the range (e.g. 100 mm wide×20 mm deep), the operator can position the concrete nailer so that the drive axis of the nail is maintained at 90° relative to the channel and concrete. However, as the track gets narrower and deeper, the ability of the operator to drive a nail perpendicularly into the track becomes increasingly difficult. The operator must now skew the concrete nailer so that the nail magazine, which is often mounted on a lower surface of the nailer housing, clears a vertical wall of the track. But then, as the track width approaches 30 mm and the depth approaches 70 mm (a “deep track”), it becomes almost impossible for an operator using a conventional concrete nailer having a magazine large enough to accommodate both short and long nails to drive a nail perpendicularly to the track. The magazine of such a concrete nailer blocks an operator from having sufficient “reach” into the track so that the nailer contact trip cannot be fully depressed against the base of the track, thereby preventing the nailer from being fired. To accommodate all of the sizes of tracks likely to be available on a job site, the reach should be 60-70 mm, and preferably 70 mm.
[0004] Nail lengths further complicate the concrete nailer arena. Short nails are commonly used to nail track to concrete. There are conventional concrete nailers that use magazines which only accommodate short nails. Short nails enable magazines to be made with relatively short heights, thereby creating sufficient reach for the operator to drive the nails perpendicularly to the base of the track and into the concrete. Conversely, magazines that are tall enough to accommodate long nails will also block conventional concrete nailers from satisfactorily nailing into track. “Long nails”, in this context, are nails which are long enough to nail 2×4's to concrete, which means they must be at least 2¼ inches long. Nailing 2×4's to concrete is another critical job that contractors need to perform. However, switching between a short fastener magazine and a long fastener magazine results in a significant cost, because the contractor must maintain at least two nailers on the job site, one loaded with short nails and another loaded with long nails; or the contractor must provide the nailer with at least two different magazines, one containing short nails and the other containing long nails. However, switching out various magazines takes time, which increases cost.
[0005] An unsuccessful attempt has been made to solve both problems. A concrete nailer using a magazine that accommodates both short and long nails was introduced with an unusually long drive track and contact trip subassembly to artificially create enough reach for the nailer to drive nails into many sizes of tracks, as well as to accommodate 2¼ inch nails. However, generating an unusually long drive track and contact trip subassembly also requires that the rest of the nailer be made taller. The result is a concrete nailer which is heavier, more unwieldy and less able to fit into tight spaces than the other concrete nailers. (The height of the conventional nailer is 18½ inches.) Moreover, making the tool larger inevitably adds cost. However, the maximum reach attained with the conventional concrete nailer is only 50 mm, and consequently it has much less flexibility to accommodate the sizes of tracks likely to be found on the construction site then one having a reach of 70 mm.
[0006] The dilemma faced by conventional concrete nailers is shown in FIGS. 1-3 , which illustrate how a first conventional concrete nailer 100 , 100 ′ is unable to accommodate both short and long nails 40 , 42 and still drive them perpendicularly into a complete range of tracks 44 likely to be encountered on the job site. FIG. 1 shows that a first conventional concrete nailer 100 , having a housing 102 to which is connected a magazine 104 , is able to depress its contact trip 106 against the base 46 of the track 44 , because the height H 1 of the magazine need only accommodate short nails 40 . However, as shown in FIGS. 2 and 3 , when concrete nailer 100 ′ uses a magazine 104 ′ that has a height H 2 for accommodating long nails 42 as well short nails 40 , full actuation of the contact trip 106 becomes geometrically impossible when the drive axis 22 is oriented at an angle A of 90° to the base 46 of track 44 . Thus, concrete nailer 100 ′ is blocked by the conventional magazine 104 ′ so that the contact trip 106 is held above the bottom 46 of track 44 by a distance G, and consequently is unable to fire.
[0007] Referring now to FIGS. 4, 5 and 6 , a second conventional concrete nailer 200 that unsuccessfully attempts to overcome such deficiencies includes a housing 202 and a magazine 204 configured to accommodate both short and long nails 40 , 42 . The magazine 204 is disposed at an unusually large distance above a work surface. The purpose was to artificially create enough reach R so that the second conventional concrete nailer 200 can handle many sizes of track 44 likely to be found on a job site. However, this additional flexibility comes at a price. In order to elevate magazine 204 at such a distance above the track 44 , it is also necessary concomitantly to lengthen the contact trip 206 and drive system 218 . When such components as the contact trip 206 and drive system 218 are elongated, or made taller, the housing 202 and all of the other components disposed therein must also be made taller, as shown in FIGS. 5 and 6 . The resulting overall height H 2 above the work surface 34 of the second concrete nailer 200 must now be 18½ inches.
[0008] Thus, it can be seen that in the demanding field of concrete nailers, the ranges of track dimensions, the length of reach, and the size ranges of nails used in concrete nailer magazines are in fact critical parameters.
[0009] Consequently there has been generated a long-felt need for a concrete nailer that accommodates both short and long nails, that drives nails perpendicularly into the entire range of tracks likely to be available on a construction site, and that also has the flexibility to nail 2×4's to concrete.
SUMMARY OF THE INVENTION
[0010] In an embodiment of the present invention, a cutout is formed in the bottom of a magazine for a concrete nailer. In the concrete nailer, the cutout is proximate the concrete nailer drive track. The cutout is configured to accommodate tracks having dimensions ranging from 30 mm to 200 mm wide and from 20 mm to 70 mm deep. As such, it is possible to press the contact trip of the concrete nailer against the base of the track or channel so that the contact trip can be fully actuated, and nails can be driven perpendicularly to the base of the track and into the concrete, for a variety of track sizes.
[0011] In an embodiment of the present invention, a magazine can be configured to accommodate nails ranging in length from as short as ½ inch to as long as 2¼ inches. Thus, concrete nailers having such a magazine can drive several different sizes of nails perpendicularly into the track and concrete, and have the flexibility to nail 2×4's to concrete.
[0012] In the field of concrete nailers, to a person of ordinary skill in the art, the concrete nailer and magazine of the present invention could not actually accommodate, and satisfactorily drive, nails as short as ½ inch. The prevailing thought was, by disposing the cutout of the magazine proximate the concrete nailer drive track, short nails driven along the drive track were exposed to the cutout and would thereby lose vertical support. Without vertical support, the short nails would face serious problems in maintaining the nail alignment along the drive axis of the concrete nailer, resulting in nails that could be thrown out of alignment and jam the drive system.
[0013] However, it was discovered that by mounting nails into a plastic carrier, and then loading them into the magazine, the magazine interface and the drive track of the concrete nailer of the present invention could be configured to cooperate with the nails and carrier to drive a nail and a portion of the attached carrier along the drive axis while maintaining the desired orientation of the nail.
[0014] Accordingly, one embodiment of the concrete nailer of the present invention includes a housing and a drive system configured for driving a nail. The drive system includes a drive track configured to guide nails along a drive axis. The concrete nailer further includes a magazine connected to the housing and being configured to accept nails having lengths ranging from ½ inch to at least 2¼ inches, the magazine having a bottom portion that defines a cutout disposed proximate the drive track.
[0015] In another embodiment, the cutout is configured to accommodate U-shaped channels having widths ranging from 30 mm to 100 mm and depths ranging from 20 mm to 70 mm, while still enabling the concrete nailer to drive nails along a drive axis oriented perpendicularly to the base of the channels, such that the nails fasten the channels to concrete.
[0016] In still another embodiment, the concrete nailer includes a system configured to maintain an orientation relative to a work surface of nails as short as ½ inch along the drive axis in the drive track, notwithstanding the proximity of the nails to the cutout. The system includes a magazine interface located at one end of the magazine and disposed proximate the concrete nailer drive track, and a plastic carrier carrying a plurality of nails. The magazine interface and drive track are configured to cooperate with a portion of the plastic carrier and nails to maintain the alignment of a nail all along the drive track until the nail is driven into a workpiece.
[0017] In a further embodiment, a magazine is configured to accept nails having lengths ranging from ½ inch to at least 2¼ inches, so that the nails are oriented in the magazine to be parallel to the drive axis of a concrete nailer. The magazine includes a magazine interface configured to be positioned proximate a drive track of the concrete nailer when the magazine is attached to a bottom surface of the concrete nailer. The magazine further includes a lower portion that defines a cutout disposed proximate the magazine interface.
[0018] Yet another embodiment includes a method of nailing a U-shaped channel to concrete using a concrete nailer having a magazine, where the channel has two vertical walls, a horizontal base, and the dimensions of the channel range from 30 mm to 100 mm wide and from 20 mm to 70 mm deep. The method includes positioning a nose of the concrete nailer above the channel so that a cutout formed in the bottom of the magazine clears at least one wall of the channel; engaging the base of the channel so that a contact trip of the nailer is oriented perpendicular to the base of the channel while the cutout still clears the wall; while maintaining the orientation, pressing the contact trip against the base of the channel so that the contact trip is fully actuated; and firing a nail through the base of the channel and into the concrete.
[0019] In another embodiment, a method of maximizing the reach of a concrete nailer having a housing, a nose portion, and a contact trip includes connecting a nail magazine to the housing so that an interface of the magazine is proximate the nose portion and so that, when the contact trip is fully actuated, the distance from a work surface to a portion of the magazine proximate the nose portion lies in the range of from 60 mm to 70 mm; and wherein the nail magazine accommodates nails having lengths ranging from 1/2 inch to at least 2¼ inches.
[0020] In a further embodiment, a method of minimizing the height of the concrete nailer having a housing and a contact trip includes connecting a nail magazine to the housing so that the magazine provides the concrete nailer with a reach of from 60 mm to 70 mm into a U-shaped channel when the contact trip is fully actuated against the bottom of the channel; wherein the magazine accommodates nails having lengths ranging from ½ inch to at least 2¼ inches.
[0021] The present invention accordingly fulfils the long-felt need for a concrete nailer having a magazine that accommodates short and long nails and is still able to nail a complete range of channels or tracks likely to be found on a job site into concrete, as well as having the flexibility to nail 2×4's and boards of similar thicknesses to concrete.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
[0023] FIG. 1 is a partial elevational sectional detail view of a conventional concrete nailer using a magazine loaded with short nails, and driving the nails into a track and concrete.
[0024] FIG. 2 is a view similar to that of FIG. 1 , with long nails shown superimposed over the short nails for contrast.
[0025] FIG. 3 is a view similar to those of FIGS. 1 and 2 , and illustrating the problems encountered by a conventional concrete nailer when attempting to nail a track to concrete using a magazine configured to accept both short and long nails.
[0026] FIG. 4 is a partial elevational detail view of a conventional concrete nailer using a drive system, drive track and contact trip made unusually long to artificially create enough reach to nail many sizes of track to concrete.
[0027] FIG. 5 is a rear perspective view of the conventional nailer of FIG. 4 positioned next to the concrete nailer and magazine of the present invention.
[0028] FIG. 6 is a side-by-side elevational view, taken from the bottom, illustrating the differences in height between the concrete nailers of FIG. 5 .
[0029] FIG. 7 is a perspective view of one embodiment of a concrete nailer and magazine according to the present invention, with the contact trip shown in the extended position.
[0030] FIG. 8 is an enlarged partial elevational detail view of the concrete nailer and magazine of FIG. 7 , with the actuated position of the contact trip shown in phantom, and illustrating short nails loaded in the magazine.
[0031] FIG. 9 is a view similar to FIG. 8 , but showing long nails loaded in the magazine.
[0032] FIG. 10 is an enlarged partial elevational detail view of the concrete nailer and magazine of FIG. 7 , illustrating the contact trip of the concrete nailer oriented along a drive axis and fully actuated against the base of a track to be nailed to concrete.
[0033] FIG. 11 is a view similar to FIG. 10 , but showing the concrete nailer and magazine of FIG. 7 driving long nails into a 2×4 and concrete.
[0034] FIG. 12 is a partial elevational detail view of the contact trip and drive track subassembly of the concrete nailer of FIG. 7 , illustrating what happens when a short nail becomes misaligned along the drive axis.
[0035] FIG. 13 is a side elevational detail view of the magazine of FIG. 7 .
[0036] FIG. 14A is an enlarged elevational detail view of the circled portion of the magazine of FIG. 13 .
[0037] FIG. 14B is an enlarged elevational detail view of the portion of the magazine shown in FIG. 14A positioned proximate the drive track of the concrete nailer of FIG. 7 .
[0038] FIG. 15A is an enlarged elevational detail view of short nails mounted in a carrier of the present invention.
[0039] FIG. 15B is an enlarged perspective detail view of the magazine interface taken along line 15 - 15 of FIG. 14B , and illustrating a nail mounted in a portion of the carrier.
[0040] FIG. 16 is an exploded perspective detail view of the magazine interface of the magazine of FIG. 7 being positioned proximate the drive track of the concrete nailer of FIG. 7 , and showing a system for aligning nails along the drive track of the concrete nailer.
[0041] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the present invention, and such exemplifications are not to be construed as limiting the scope of the present invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
[0042] Referring now to the drawings and particularly to FIG. 7 , a cordless concrete nailer 10 in accordance with an embodiment of the present invention includes a housing 12 , a motor 14 (shown schematically in phantom) disposed in the housing, a battery pack 16 for providing power to the motor, and a drive system 18 (also shown schematically in phantom) configured for driving a nail and operatively associated with the motor. The drive system 18 includes a drive track 20 disposed parallel to a drive axis 22 . The concrete nailer 10 further includes a magazine 24 connected to a bottom surface 25 of the housing 12 . A bottom portion 26 of the magazine 24 in turn defines a cutout 28 which is disposed proximate the drive track 20 when the magazine 24 is connected to the concrete nailer housing 12 . A contact trip 30 extending from a nose 32 of the housing 12 is operatively associated with the drive system 18 , and is coaxial with the drive axis 22 . In operation, nails are fed from the magazine 24 and into engagement with the drive track 20 . When an operator presses the contact trip 30 against a work surface 34 , the contact trip is moved upwards to its actuated position, thus completing an electrical circuit (not shown) which permits the concrete nailer 10 to be fired, thereby driving nails along the drive track 20 , out the bottom of the contact trip 30 , and into the work surface.
[0043] Although the concrete nailer 10 is described as having an electric drive system 18 , the magazine 24 may also be used in conjunction with concrete nailers having other drive systems, including without limitation pneumatic, hydraulic, powder-actuated/explosive, and gas/explosive.
[0044] FIGS. 8 and 9 show the concrete nailer 10 in which the magazine 24 accommodates both short nails 40 ( FIG. 8 ) and long nails 42 ( FIG. 9 ). One embodiment of the magazine 24 accommodates nails ranging in length from a small as ½ inch to at least as long as 21/4 inches, thus providing the concrete nailer 10 with considerable flexibility.
[0045] Still referring to FIGS. 8 and 9 , the unique cooperation of components of the concrete nailer 10 and magazine 24 allows the concrete nailer to have considerable “reach” R when the contact trip 30 is moved from an extended position 36 to an actuated position 38 (shown in phantom). This cooperation enables a contractor to use the concrete nailer 10 in constricted spaces and in connection with workpieces having challenging geometries.
[0046] FIG. 10 illustrates how the concrete nailer 10 easily handles one of the most difficult of workpiece geometries likely to be encountered on a job site, namely, when the concrete nailer is required to nail a U-shaped metal channel or “track” 44 to concrete 50 . The sizes of track which are likely to be found on a job site have widths W at the base 46 ranging from 30 mm to 100 mm, and depths D of walls 48 ranging from 20 mm to 70 mm. As previously noted, where this gets particularly challenging for a concrete nailer is when the track dimensions approach the narrowest but tallest ends of the range, namely, when the track measures 30 mm wide, but is 70 mm deep. That is because, when nailing concrete, it is very important to maintain the angle A of the drive axis 22 as close to 90° relative to the concrete as possible. However, as shown in FIG. 10 , the reach R generated by the concrete nailer 10 is at least 70 mm. Therefore, even though the magazine 24 accommodates both short nails 40 , as shown in FIG. 10 , and long nails 42 (including nails at least as long as 2¼ inches), as shown in FIG. 11 , the path 43 of the tips of the long nails 42 (see FIGS. 10 and 11 ) is still above the walls 48 of track 44 . This enables the concrete nailer 10 using the magazine 24 to maintain the drive axis 22 perpendicular to the concrete 50 , thereby successfully tackling workpiece geometries which, to date, have been difficult, if not impossible, for conventional concrete nailers to successfully handle. (It should be noted that, although the optimum orientation of the drive axis 22 to the work surface 34 is 90°, the concrete nailer 10 is capable of maintaining the orientation of the drive axis at any desired angle relative to the work surface.)
[0047] Returning for the moment to FIGS. 5 and 6 , the height H 1 of the concrete nailer 10 can thus be as short as 16 inches, compared to the height H 2 of the second conventional concrete nailer 200 , which must be 18½ inches, an increase of more than 12%. Thus the design of the second conventional concrete nailer 200 requires more metal and larger components, and is more unwieldy, heavier and more costly than the concrete nailer 10 , and is less able to fit into the constricted space requirements that the concrete nailer 10 easily handles.
[0048] Referring to FIGS. 7, 10 and 11 , the magazine cutout 28 is disposed proximate the drive track 20 . As shown in greater detail in FIGS. 13, 14A and 14B , the magazine 24 includes a magazine interface 52 that is aligned along drive axis 22 when the magazine is attached to the concrete nailer 10 .
[0049] FIG. 14A shows that the cutout 28 of magazine 24 has a length LC and a height HC.
[0050] In one embodiment, the length LC is about 28 mm, and the height HC is about 20 mm. When the magazine 24 is connected to the concrete nailer 10 , as shown in FIG. 14B , the magazine interface 52 of magazine 24 is disposed proximate the drive track 20 of the concrete nailer 10 , so that the drive axis 22 of the magazine interface shown in FIG. 13 is coincident with the drive axis 22 of the concrete nailer 10 . However, at first glance, it is not intuitively apparent how a short nail 40 , in particular, can be maintained in a desired orientation along the drive axis 22 , in that the travel of the nail 40 along the drive track 20 is exposed to the cutout 28 . That is because, as shown in FIG. 12 , without support proximate the cutout 28 , the nail would likely become skewed from the drive axis 22 and jam the mechanism, as shown at 40 ′.
[0051] FIGS. 15A, 15B and 16 show a system 53 of the present invention configured to maintain the desired orientation relative to a work surface 34 of nails as short as ½ inch in the drive track 20 , notwithstanding the proximity of the nails 40 to the cutout 28 .
[0052] As shown in FIGS. 15A and 15B , nails 40 , 42 are mounted vertically in a plastic carrier 54 , which is angled to match the angle N of the magazine 24 . When the concrete nailer 10 is fired, a drive bar (not shown) of the drive system 18 strikes the top of the nail 40 presented to the concrete nailer drive axis 22 by the magazine interface 52 , and separates a portion 56 carrying the nail 40 from the rest of the carrier 54 . Portion 56 carries the nail 40 all the way along the drive track 20 , and moves with the nail even as the nail is driven into a work surface 34 . The orientation system 53 is configured to capitalize on this effect: the magazine interface 52 defines respective guide surfaces 58 and 59 , and the carrier 54 defines guide surfaces 60 that match the configuration of guide surfaces 58 . Furthermore, the drive track 20 of the concrete nailer 10 is also provided with guide surfaces 62 . As shown particularly in FIG. 16 , the respective guide surfaces 58 , 59 , 60 and 62 of the orientation system 53 cooperate to maintain the orientation of the nail 10 along the drive axis 22 during its entire travel along the drive track 20 .
[0053] To nail the track 44 to concrete, the operator positions the nose 32 of the concrete nailer 10 above the track so that the cutout 28 formed in the bottom 26 of the magazine 24 clears at least one wall 48 of the track. The contact trip 30 of the concrete nailer 10 then engages the base 46 of the track 44 so that the contact trip is oriented perpendicular to the base of the track, while the cutout 28 still clears the wall 48 . Then, while maintaining this orientation, the contact trip 30 is pressed against the base 46 of the track 44 so that the contact trip is fully actuated, and the concrete nailer 10 fires a nail 40 , 42 through the base of the track and into the concrete 50 .
[0054] It can now be seen that the concrete nailer 10 and magazine 14 of the present invention fulfill the long-felt need for a concrete nailer having a magazine which accommodates both short and long nails, has the flexibility to nail 2×4's into concrete, and which also satisfactorily nails to concrete the complete range of track presently available on job sites. While the emphasis has been placed on being able to nail 2×4's into concrete, it should be recognized that the concrete nailer 10 , if desired, may nail other sizes of wood with similar thicknesses to concrete as well.
[0055] While the present invention has been described with respect to various embodiments, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the present invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limitations of the appended claims. | A concrete nailer has a cutout defined by a magazine. The cutout is disposed proximate the drive track of the concrete nailer and provides the concrete nailer with sufficient reach to perpendicularly nail a complete range of U-shaped channels or track available to the job site against concrete, even though the magazine accommodates both long and short nails. The concrete nailer has the added ability to nail thick boards like 2×4's to concrete. | 1 |
This application is a Continuation In Part of PCT application No. PCT/IL2004/001161 of Dec. 23, 2004, and claims the benefit of U.S. Provisional Patent Application No. 60/531,985, filed Dec. 24, 2003, the contents of all listed applications being hereby incorporated in their entirety.
FIELD OF THE INVENTION
The present invention concerns an antiviral preparation obtained from a plant extract.
BACKGROUND OF THE INVENTION
Viruses are important pathogens of both humans and animals. Outbreak of a virus infection often results from introduction of a new virus (such as HIV, West Nile Virus, SARS), or from introduction of a new strain of a well known virus to an immunologically naïve population, e.g. influenza.
Despite the importance of the recent outbreaks of West Nile Virus and SARS, influenza is still one of the most prevalent and significant viral infections. Although the availability of formalin-inactivated trivalent vaccines has reduced the impact of influenza epidemics, this virus is still associated with significant morbidity and mortality worldwide. It infects 10-20% of the total population during seasonal epidemics, resulting in between three to five million cases of severe illness and at least 250,000 to 500,000 deaths each year worldwide (World Health Organization, W.H.O., Global Influenza Program, September 2003 and W.H.O. Fact Sheet, March 2003). In the U.S.A. alone, more than 100 million cases are reported each year, causing 20,000 deaths and a consequent strong economic impact, estimated at around 22.9 billion dollars for 1995 (American Lung Association, 2002). W.H.O. has estimated the total burden at around 71-167 billion dollars per year (W.H.O. Fact Sheet, March 2003).
Until recently, amantadine and rimantadine were used for the treatment of influenza infection, but these are now believed to be associated with severe adverse effects (including delirium and seizures which occur mostly in elderly persons on higher doses). When used for prophylaxis of pandemic influenza at lower doses, such adverse events are less apparent. In addition, the virus tends to develop resistance to these drugs (Steinhaur et al., 1991).
A new class of antivirals, the neuraminidase inhibitors, has recently been developed. Such drugs as zanamivir and oseltamivir, which have fewer adverse side effects (although zanamivir may exacerbate asthma or other chronic lung diseases) are nevertheless expensive and currently not available for use in many countries (W.H.O. Fact Sheet, March 2003). Influenza may develop resistance to neuroaminidase inhibitors too (McKimm-Berschkin, 2000; Gubavera, et al. 2002).
Many herbs and spices, among them also cinnamon, have been shown to feature antimicrobial and chemoprotective activities, (Lay and Roy, 2004). Extracts from cinnamon obtained by organic solvents (for example as in Velluti et al, 2004), typically contain the following ingredients: Eugenol (82%), Caryophylene (4.6%), Eugenyl acetate (2.1%), Linalool (1.8%), Cinnamaldehyde (1%), Cinnamyl alcohol acetate (1%), 2-Propyl benzodioxol (1%), and Cubebene (<1%). These extracts, which are in fact essential oils, have shown to exhibit antifungal activity. (Velluti et al., 2003 and Velluti et al, 2004).
Other cinnamon bark essentials oils had antibacterial activity against Bacillus cereus , (Valero and Salmeron, 2003); as well as antibacterial and antifungal activities, (Kalemba and Kunicka, 2003 and Mau et al., 2001).
Cinnamon hydrophobic fractions extracted in organic solvents had antibacterial activity against Helicobacter pylori , (Tabak, M. et al., 1999); antifungal activity for fungi causing respiratory tract mycoses, (Singh, H. B. et al., 1995), and anti HIV-1 activity caused by inhibiting the reverse transcription, (Yamasaki et al., 1998).
Compounds obtained from cinnamon are also used for other indications such as the use of cinnamon powder for reducing serum glucose triglycerides, LDL cholesterol and total cholesterol, (Khan et al, 2003); water extracts of cinnamon were used as antioxidants (Murcia et al, 2004); were shown to prevent insulin resistance, (Qin et al., 2004); and were also shown to inhibit Na + /K + ATPase and Cu 2+ ATPase, (Usta et al., 2003). Essential oil extract obtained from cinnamon were further shown to improve digestion (Hernandez et al., 2004).
SUMMARY OF THE INVENTION
The present invention is based on the surprising finding that a natural aqueous extract from a cinnamon bark ( Cinnamon sp.) has antiviral activity against enveloped viruses including influenza A, Parainfluenza (Sendai) virus and HSV-1 viruses, as well as in vivo activity in inhibition of Influenza A and Parainfluenza viruses in mice.
By a preferred embodiment of the invention, isolated active fraction of cinnamon bark (hereon referred to as CE) having antiviral activity, has in addition one or more of the following chemical properties:
1. It is precipitated by various chloride salts such as KCl, NaCl, MgCl 2 , SrCl 2 , CuCl 2 , or ZnCl 2 . 2. It exhibits absorbance at 280 nm of 15 O.D/mg. cm. 3. It maintains most of its activity after incubation in 0.1M NaOH, or 0.1M HCl, or 0.1M H 2 SO 4 . 4. It can be extracted into an aqueous solution without need for organic solvents in a relatively inexpensive and simple manner. 5. It can be maintained for a long period of time (at least two years) as a stable powder or in solution in a refrigerator or at room temperature; 6. It is heat-stable and can thus be sterilized at temperature up to at least 134° C.
The term “CE ppt” as used hereon refers to the extract isolated fraction obtained by salting out with KCl 0.15M.
As regards the biological activity, the CE of the invention is capable of inhibiting viruses at room temperature, within a few minutes of administration, and at relatively low levels. Thus in addition to the pharmaceutical use, this immediate inhibition, at room temperature and at low levels enables also surface disinfections of suspected contaminated areas or purifying circulating air.
The CE of the present invention are effective against both influenza and Parainfluenza viruses as well as against HSV-1 viruses and may protect infected human erythrocytes and other erythrocyte cells from the activity of viruses pre-absorbed on the erythrocytes. Thus, the CE of the present invention may be considered as effective treatment of cells already pre-absorbed with the virus. Furthermore, pre-absorption of the CE of the invention onto cells has a prophylactic effect in protecting the cells from subsequent viral infection.
By one aspect the present invention concerns a novel aqueous extract of cinnamon bark ( Cinnamon sp) which has an absorbance at 280 nm at between about 15 to 20 O.D. per mg. cm, as shown in FIG. 12( d ) , and which additionally has the above mentioned chemical properties. In one embodiment, the extract has an absorbance at 280 nm at about 15 OD.
The present invention further concerns a CE obtainable by the following process:
(i) grounding cinnamon bark into powder and stirring it into an aqueous buffer to obtain a solution; (ii) centrifuging the solution and separating a supernatant (iii) introducing a salt to obtain a precipitate.
The process may further comprise of the following steps:
(iv) dissolving the precipitate obtained in step (iii) above in water or buffer at an essentially neutral pH; (v) separating the solution on a sepharose or Sephadex column; and (vi) eluting the solution with suitable buffer and varying concentrations of saccharide, preferably galactose to obtain the antiviral fractions of cinnamon sp.
By a preferred embodiment, the present invention concerns a CE obtained by the above process, wherein said salt used to obtain a precipitate is a chloride salt.
By another preferred embodiment, the present invention concerns an extract from cinnamon bark, ( Cinnamon sp.) obtained by the following method:
(i) grounding the bark into powder; (ii) stirring the bark in aqueous phosphate buffer 0.01M or 0.02M, pH 7.0; (iii) separating the supernatant by centrifugation to be used as the crude neutralizing extract; (iv) precipitate the active ingredient in the crude extract by 0.15M KCl or 0.08M MgCl 2 ; (v) dissolving the precipitate in water or 0.01M phosphate buffer at pH 7.0; (vi) loading the solution onto a column of sepharose 4B followed by a stepwise elution with phosphate buffer and various concentrations of galactose; and (vii) eluting the active antiviral material from the column by 0.15M galactose ( FIGS. 12 a, b, c ; fraction b or II).
The present invention also concerns compositions, which may be nutraceutical or pharmaceutical compositions, comprising the CE of the invention together with a pharmaceutically or nutraceutically acceptable carrier. The composition may be in a liquid, solid or semi solid state.
Furthermore, the present invention concerns a pharmaceutical composition or a nutraceutical composition for the treatment of an infection comprising as an active ingredient an effective amount of the CE together with a carrier suitable for pharmaceutical or nutraceutical compositions.
The term “treatment” in the context of the invention refers generally to one of the following: treatment of an established infection to cure it or decrease the viral load, decrease of at least one of the undesirable side effects of a viral disease, shorting the acute phase of the infection, and prevention of an infection before it occurs.
The term “influenza” or “Parainfluenza virus” or “HSV-1 virus” in accordance with a preferred embodiment of the invention refers to all known and newly evolving strains of these viruses, including animal viruses such as avian influenza.
The present invention further concerns a method for the treatment of a subject suffering from viral infection comprising administering to the subject in need of such treatment an effective amount of the extract as described above.
The viral infection is preferably an enveloped virus infection; more preferably a virus of the family Orthomyxoviruses, Paramyxoviruses, Herpesviruses, Retroviruses, Coronaviruses, Hepadnaviruses, Poxviruses, Togaviruses, Flaviviruses, Filoviruses, Rhabdoviruses, or Bunyaviruses.
Most preferably the virus infection is caused by a virus selected from: the avian influenza virus, Influenza virus, Parainfluenza virus (also referred to herein as “the Sendai virus”), NDV virus, HIV viruses or HSV-1 virus.
The subject in need may be a subject already suffering from an established viral infection, thus treatment is provided in order to cure the infection, decrease at least one undesired side effect of the infection or decrease in the duration of the infection, or a subject which is treated in a prophylactic manner in order to avoid subsequent infection by the virus.
The “subject” in accordance with the invention may be a human or an animal subject, and may be mammal or poultry especially farm and pet animals. The subject may also be fish in various aquacultures, bees and other insects of interest in agriculture.
Administration may be by any manner known in the art such as orally, parenterally, rectally, topically, nasally, by application to the eye, ear, nose or mucosal tissue, and the like. Preferably the administration is subcutaneously, intramuscularly, orally or intranasal.
The present invention further concerns a method for disinfecting an area suspected of being contaminated with viruses, comprising applying, for example by spraying, by brush or sponge application, etc., onto a suspected area an affective amount of the extract of the present invention. The surface may be any area in the house or in a medical facility that should be disinfected.
The disinfectant composition may be used to clean and disinfect surfaces such as ceramic tiles, PVC, porcelain, stainless steel, marble, silver and chrome to remove grease, wax, oil, dry paint and mildew and the like. The disinfectant composition may also be used as a laundry additive and may take the form of an aerosol spray, in which case, the composition is mixed with an appropriate propellant such as mist activators and sealed in an aerosol container under pressure.
In one specific embodiment, the composition is absorbed in a towel or a cloth, thus providing a disinfectant towel that may be used as means of applying the composition to the various surfaces or may be used to disinfect the hands and skin of an individual.
By another option the disinfectant composition may be applied onto plants for preventing or treatment plants viral infection. The plants may be, for example, fruit groves, vines, cotton fields, forests, prairies, private or public gardens, grass fields, vegetable fields and the like. The extract may also be used in a pre- or post-harvesting method of treating fruits and vegetables which may have been infected by viruses.
The disinfectant composition of the present invention may generally also include surfactants which are preferably selected from nonionic and cationic surfactants. The nonionic surfactant may, for example, be one or more selected from polyglycol ethers, polyalkylene glycol dialkyl ethers, and the addition products of alcohols with ethylene oxides and propylene oxides.
The cationic surfactant may be selected from various quaternary ammonium salts such as, but not limiting to octyl dimethyl benzyl ammonium chloride, octyl decyl dimethyl ammonium chloride, dioctyl dimethyl ammonium chloride, didecyl dimethyl ammonium chloride and dimethyl ethyl benzyl ammonium chloride, or mixtures thereof such as, but not limiting to, alkyl dimethyl benzyl ammonium chlorides and dialkyl dimethyl ammonium chlorides. In one embodiment, the composition may further comprise dyestuffs, perfumes, builders, chelating agents and corrosion inhibitors.
The composition comprising the extract of the present invention may also be used for the treatment of water reservoirs such as, but not limiting to, water systems, cooling systems, swimming pools, natural and artificial water reservoirs, fisheries, water tanks, aquariums, and any other volume of water.
In one embodiment, the composition is added in a dry form to the water reservoir in an amount sufficient to control the growth of viruses. In another embodiment, the dry composition is added to a water reservoir after being dissolved in an appropriate vehicle.
In another aspect of the present invention there is provided a method for purifying circulating air in airplanes, hospitals, kindergartens, offices, homes etc. by passing the air through appropriate filters containing or absorbed with the extracts of the invention. Within the scope of the present invention, also provided is a filter containing or absorbed with the CE of the invention. Such filter may be manufactured from any material suitable for the specific utility as known to a person skilled in the art. The filter may be a single unit filter or a multi-filter system and may be manufactured as to be adaptable to any existing purification unit, filtering or air-conditioning systems such as those found in clean-rooms, industry, hospitals, homes, offices and other facilities.
The extract of the present invention may be absorbed onto the filter during production of the filter or immediately prior to its use by methods known in the art such as: spraying of the extract onto of the filter at a predetermined flow and concentration, thereafter allowing the carrier to dry; dropping the filter into a solution of the extract for a period of time suitable for the extract to be absorbed onto the surface of the filter, thereafter allowing the solvent to dry; and the like.
All compositions of the present invention may be in a liquid or solid form depending on the specific utility.
By another aspect, the present invention concerns a method for producing a neutralized virus comprising contacting native viruses with an effective amount of the extract of the invention. The neutralized native viruses may be used for subsequent immunization against the viral infection instead of inactivated virus particles used today. Especially the use is for inactivated influenza, Parainfluenza viruses or HSV-1, that can be neutralized to produce a vaccine instead of the formalin inactivated viruses currently used. Thus, there is provided a method of immunization against a viral infection comprising administering to a subject the neutralized virus of the present invention.
The vaccine may be administered by various routes such as oral, intranasal, subcutaneous, intramuscular and others known to a person skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to understand the invention and to see how it may be carried out in practice, some preferred embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:
FIG. 1( a ) shows the in vitro effect of varying concentrations of crude extract of the invention on the hemolytic activity of Influenza A;
FIG. 1( b ) shows the in vitro effect of varying concentrations of crude extract of the invention on the hemolytic activity of Parainfluenza (Sendai);
FIG. 2 shows the antiviral effect of extracts treated by autoclaving or after 4 years maintenance;
FIG. 3 shows the inhibition of Influenza A PR8 by varying concentrations and different fractions of the crude extract of the invention;
FIG. 4( a ) shows the antiviral effect of a fraction of the extract treated with HCl and H 2 SO 4 ;
FIG. 4( b ) shows the antiviral effect of a fraction of the extract treated with NaOH;
FIG. 5 shows the antiviral effect of a fraction extracted treated with dialysis against water;
FIG. 6( a ) shows the antiviral effect of the extract on Influenza A-PR8 after varying incubation periods;
FIG. 6( b ) shows the antiviral effect of the extract on Parainfluenza (Sendai) after varying incubation periods;
FIG. 7 shows inhibition of Influenza A PR8 pre-absorbed onto erythrocytes by varying concentrations of the extract of the invention;
FIG. 8 shows protection against Influenza A PR8 after pre-absorption of CE fractions onto erthrocytes.
FIG. 9 shows in vivo results showing the effect of the extract of the invention on weight of mice infected with Influenza A virus;
FIG. 10 shows in vivo results showing the effect of the extract of the invention on weight of mice infected with Parainfluenza Sendai virus;
FIG. 11( a ) and FIG. 11( b ) show a histogram showing death and relative weight of mice infected with Influenza A PR8 virus incubated with the CE inhibitor;
FIG. 12( a ) shows galactose elution of fraction from sepharose 4B—fraction (II) having antiviral activity;
FIG. 12( b ) shows galactose elution of fraction from sepharose 4B—Fraction (II) having antiviral activity;
FIG. 12( c ) shows galactose elution of fraction from sepharose 4B—Fraction (b) having antiviral activity;
FIG. 12( d ) shows the optical density curve of the cinnamon extract.
FIG. 13( a ) shows the effect of the crude extract of the invention on HSV-1 infected Vero cells;
FIG. 13( b ) shows the effect of varying concentrations of HSV-1 (on Vero cells) in response to a fixed amount of the extract of the invention;
FIG. 13( c ) shows the effect of increasing amounts of the compound of the invention on fixed amounts of HSV-1 Vero infected cells;
FIG. 14( a ) depicts changes in weight after i.n. administration of the inhibitor after viral infection in mice;
FIG. 14( b ) depicts changes in weight after treatment with the inhibitor immediately or an hour after injection with the virus;
FIG. 14( c ) depicts changes in weight of mice immunized i.n. by Sendai virus and the inhibitor before infecting the mice with naïve Sendai virus;
FIG. 14( d ) depicts changes in weight of mice immunized orally or s.c. with Sendai virus and the inhibitor before infecting the mice with naïve Sendai virus;
FIG. 15 ( a - b ) depicts the inhibition of HIV-1 activity tested on MT2 cells in two different experiments;
FIG. 16 depicts the inhibition of avian influenza H9N2 by VNF (CE ppt);
FIG. 17 depicts the inhibition of preabsorbed avian influenza H9N2 by VNF (CE ppt);
FIG. 18 depicts the inhibition of the hemagglutinating activity of NDV by VNF;
FIG. 19 ( a - b ) depicts in vivo neutralization and inhibition of influenza H9N2 by VNF (CE ppt);
FIG. 20 ( a - b ) depicts in vivo inhibition and neutralization of Newcastle Disease Virus (VNF) by VNF (CEppt); and
FIG. 21 shows the development of filters for decreasing influenza activity.
DETAILED DESCRIPTION OF THE INVENTION
a. Preparation of Active Extract
The active material was isolated by three steps as follows: a) the bark was purchased in the market and was ground into powder before it was stirred in aqueous phosphate buffer 0.01M-0.02M, pH 7.0, overnight. The supernatant was separated by centrifugation and was used as the crude neutralizing extract; b) The active material in the crude extract was precipitated by KCl 0.15M or 0.08M MgCl2, and the precipitate was dissolved in water or 0.01M phosphate buffer, pH 7.0 (CE ppt.); c) This solution was submitted onto column of sepharose 4B followed by a stepwise elution with phosphate buffer and various concentrations of galactose. The active antiviral material was eluted from the column by 0.15M galactose ( FIGS. 12 a,b,c , fraction b or II).
B. Determination of Hemagglutinating Unit (HAU) and Hemolytic Activity
Hemagglutinating unit (HAU) was determined by using 0.4% washed human red blood cells. Viral hemolytic activity was tested in vitro in two successive steps: 1) attachment of the free virus onto 1 ml of 4% washed human erythrocytes for 15 minutes at room temperature; 2) incubation of the infected cells in 37° C. for 3 hours followed by centrifugation. The hemolytic activity of the viruses was determined by measuring the absorbance of the supernatant at 540 nm.
C. Elution of Active Fractions
60 ml of crude extract were precipitated by MgCl 2 0.08M or KCl 0.15M. The precipitate was dissolved in water or in 0.01M phosphate buffer and was submitted on 10 ml column of sepharose 4B pre-washed with phosphate buffer 0.01M, pH 7.0. After submission, the column was washed with the buffer followed by stepwise elution of galactose 0.15M, 0.3M, and various concentrations of acetonitrile, as shown in FIGS. 12 a,b,c . The antiviral material was found in fraction b eluted from the column by 0.15M galactose ( FIG. 12( c ) ) or fraction II in FIG. 12 a, b.
EXAMPLE 1
In Vitro Inhibition of Hemolytic Activity by Influenza A by Crude Extract of the Invention
Various amounts of crude extract were incubated with 256 HAU samples of Influenza A PR8 virus to test the inhibitory effect on the hemolytic activity of the virus, as described in the experimental procedure. Virus alone or the crude extract alone was used as controls. The results are shown in FIG. 1( a ) . The hemolytic activity of the virus was totally inhibited by 250 μg of the crude extract.
EXAMPLE 2
In Vitro Inhibition of Hemolytic Activity of Sendai Virus by the Extract of the Invention
Various amounts of crude extract were incubated with 256 HAU samples of Sendai virus to test the inhibitory effect on the hemolytic activity of the virus, as described in the experimental procedure. Virus alone or the crude extract alone was used as controls. The results are shown in FIG. 1( b ) . The hemolytic activity of the virus was totally inhibited by 250 μg of the crude extract.
EXAMPLE 3
Maintenance of Antiviral Activity after Time Period, Refrigeration and Autoclave
The cinnamon extracts (CE) or autoclaved CE was kept at room temperature or in the refrigerator for 4 years before testing their ability to inhibit the hemolytic activity of Sendai Virus (S.V.). 200 μg of CE were mixed with 256 HAU of the virus and hemolysis was tested as described in the experimental procedures. The results are shown in FIG. 2 . As can be seen, the antiviral activity of CE was maintained after all treatments although it lost some activity after autoclaving at 134° C.
EXAMPLE 4
Inhibition of Influenza A PR8 by Various Fractions of the Extract of the Invention, Treated with Various Reagents
Autoclaved CE fractions were incubated with 256 HAU of Influenza A PR8 virus at room temperature for 15 minutes. After application on human erythrocytes, the mixture was transferred to 37° C. for 3 hours. The results are shown in FIG. 3 . 50-100 μg of each CE fractions was sufficient to inhibit the viral hemolytic activity. CE ppt (isolated fraction obtained by salting out with KCl 0.15M) expressed the strongest antiviral activity.
CE ppt was incubated with 0.01M or 0.1M HCl and H 2 SO 4 at room temperature for 3 hours followed by neutralization to pH 7 before examining its ability to neutralize the virus, as described in FIG. 3 . The results after this treatment are shown in FIG. 4( a ) .
CE ppt was incubated with 0.01M or 0.1M NaOH at room temperature for 3 hours, followed by neutralization to pH 7, before examining its ability to inhibit the hemolytic activity of the virus, as described in FIG. 3 . The results are shown in FIG. 4( b ) . The treated material remained partially active. CE ppt is the precipitated fraction obtained by salting out with KCl 0.15M.
CE fractions were dialyzed against water before examining the antiviral activity as described in FIG. 3 . The results are shown in FIG. 5 . The active material in the CE fractions has a molecular weight greater than 10 KDa (the dialysis bag cut-off).
EXAMPLE 5
Inhibition of Influenza A PR8 by the Extract of the Invention after Incubation for Various Time Periods
50-200 μg samples of the CE ppt fraction were incubated with the virus for 1-30 minutes at room temperature, before adding the erythrocytes. Hemolytic activity of the virus was determined as described in FIG. 3 . The results are shown in FIG. 6( a ) . Short incubation (one minute) was sufficient to neutralize the virus.
50-200 μg samples of the CE ppt fraction were incubated with the virus for 1 min. or 20 minutes at room temperature before adding the erythrocytes. Hemolytic activity of the virus was determined as described in FIG. 3 . The results are shown in FIG. 6( b ) . Short incubation (one minute) was sufficient to neutralize the virus.
EXAMPLE 6
Inhibition of Influenza A PR8 Pre-Absorbed onto Erythrocytes
256 HAU of Influenza A PR8 virus were absorbed to human erythrocytes at room temperature before application of various CE fractions, and incubation at 37° C. as described in methods. The results are shown in FIG. 7 . Each of the CE fractions inhibited the hemolytic activity of the virus, although this required at least two-fold amount of each fraction compared to the direct interaction between the free virus and the CE fractions.
Two CE fractions were absorbed onto human erythrocytes, and the excess was washed twice with PBS before application of 256 HAU of Influenza A PR8 virus at room temperature and incubation at 37° C. as described in methods. The results are shown in FIG. 8 . Both the refrigerated crude extract and the isolated fraction CE ppt protected the erythrocytes from the hemolytic activity of the virus, but CE ppt was more effective. The amount needed for the protections was 4-10 times higher than the amount that inhibited the virus by direct interaction.
EXAMPLE 7
In Vivo Effect of Treatment of the Extract of the Invention on Influenza A Infected Mice
3.5 week old mice were injected i.v. (caudal vein) with 250 μl of PBS containing 128 HAU of Influenza A virus alone or Influenza A mixed with 250 μg of the crude extract or the crude extract alone. The mice were weighed at 2-3 day intervals. The results are shown in FIG. 9 . While the mice infected with the virus alone lost weight and most of them died within 7-10 days, the mice injected with a mixture of the virus and the crude extract continued to gain weight almost on a level with those injected with the crude extract alone. Each group included 10 mice.
EXAMPLE 8
In Vivo Effect of the Extract of the Invention on Sendai Virus
3.5 week old mice were allowed to inhale 50 μl of water containing 64 HAU of Sendai virus alone, or virus mixed with 125 μg of the crude extract, or the crude extract alone. The mice were weighed at 2-3 day intervals. The results are shown in FIG. 10 . While the mice infected with the virus alone lost weight and most of them died within 7-10 days, the mice treated internasally with a mixture of the virus and the crude extract recovered and gained weight. Each group included 10 mice.
EXAMPLE 9
In Vivo Effect of the Extract of the Invention on Influenza A PR8 Infection
3.5 weeks old mice were injected into the caudal vein with 128 HAU of Influenza A PR8 pre-incubated with 250 μg of the CE inhibitor for 30 minutes at room temperature. The mice were weighed every 2-3 days for 3 weeks. The results are shown in FIGS. 11( a ) and 11( b ) . Weight loss of over 2 gr. was marked as a weight loss event. No deaths occurred among the mice infected with the virus pre-incubated with the inhibitor. Each group included 10 mice.
EXAMPLE 10
Effect of the Extract of the Invention of HSV-1 Infected Vero Cells
100 PFU aliquots of HSV1 were mixed with 50 μg (B) of autoclaved CE ppt in 100 μl medium M-199 and immediately submitted on Vero cells in 24 wells plate. After 2 hours incubation at 37° C., 5% CO 2 , each well was overlaid with additional one ml medium and the incubation continued 3 days. The cells were washed twice with PBS before fixation with methanol and staining with Giemsa.
The results are shown in FIG. 13( a ) . As can be seen in lane (A), cells with HSV alone were detached and washed from plate. Against this, cells with HSV mixed with 50 μg CE ppt were not affected, indicating that the extracts of the invention protected the Vero cells from HSV-1 infection.
50 μg fixed aliquots of CE ppt were incubated with samples containing 10 2 -10 6 PFU of HSV1 for 1 hour in 100 μl of medium M-199. Each sample was applied on confluent Vero cell monolayer growth in 24 wells plate and the plate was incubated at 37° C., 5% CO 2 for 2 hours. One ml medium was added to each well and incubation continued 3 days. The cells were washed twice with PBS before fixation with methanol and staining with Giemsa.
Results are shown in FIG. 13( b ) . The lanes were as follows: A—10 2 PFU, B—10 3 PFU, C—10 4 PFU (A-C—virus was totally inhibited); D—10 5 PFU—Virus was partially inhibited; E—10 6 PFU—Virus was hardly inhibited; F—10 2 PFU of virus without inhibitor, cells were detached and washed from wells.
Aliquots containing 10 6 PFU of HSV1 were mixed with 50 μg-400 μg of CE ppt in 100 μl medium M-199. Each mixture immediately submitted on confluent Vero cell monolayers in 24 cells plate. After 1 hour incubation at 37° C., 5% CO 2 , the cells from each well were overlaid with one ml M-199 and the incubation continued 3 days. The cells were washed twice with PBS before fixation with methanol and staining with Giemsa.
The results are shown in FIG. 13( c ) . The lanes were as follows: A—10 6 PFU of virus without inhibitor, cells were detached and washed from wells; B—F: 10 6 PFU of virus with various amounts of CE ppt as follows: B—50 μg, C—100 μg, D—200 μg, E—300 μg, F—400 μg. There is direct correlation between inhibition and increasing amounts of the CE ppt.
As can be seen from all these results the extract of the invention was able to protect Vero cells from the damaging effects caused by HSV-1 infection.
EXAMPLE 11
Effects of the Extract of the Invention on the Weight Loss of Mice Infected with Virus
Three and a half week old mice were infected with 32HAU of Sendai virus which was pre-incubated for 20 minutes with 125 μg of the CE ppt inhibitor or treated with the CE ppt immediately after infection with the virus. The mice were then weighed every 2-3 days during a 3-week period. As FIG. 14 a shows, the two groups of mice which had been treated with the inhibitor started to gain weight 8 days post infection (P=0.017). The control group which had not been treated with the inhibitor continued losing weight.
In a different experiment, 3.5-week old mice were infected internasally with 32 HAU of Sendai virus and immediately thereafter treated with 125 μg of the CE ppt inhibitor. A second group of mice was treated with the CE ppt inhibitor one hour post infection. The mice were weighed every 2-3 days for a period of 2.5 weeks. As FIG. 14 b shows, Mice which had been treated with the CE ppt inhibitor continued to gain weight whereas mice in the control group lost weight significantly (P=<0.001).
EXAMPLE 12
Effect of the Extract of the Invention on the Weight Loss of Immunized Mice
In another set of experiments, immunization with the CE ppt inhibitor was tested. 3.5 week old mice were immunized intranasally (i.n). with 32 HAU of Sendai virus mixed with 125 μg of the CE ppt. The controlled group received only water. Three weeks post immunization both groups of mice were infected with 64 HAU of the naïve virus alone. The mice were weighed every 2-3 days over a period of 40 days. As FIG. 14 c shows, the immunized mice were not affected by the subsequent virus infection and kept gaining weight (P=0.013).
Similarly, two groups of mice were immunized 3 times by the Sendai virus mixed with the CE ppt inhibitor via two different routes of administration: oral and subcutaneously (s.c) as shown in FIG. 14 d . Two weeks after the third administration of the virus plus the CE ppt, the mice of both groups were infected with 80 HAU of the naïve virus, as were the mice of the control group. The immunized mice were not affected by the subsequent virus infection and continued gaining weight. Basically, no difference was observed between the mice to which the virus plus the CE ppt were administered orally or the mice which were administered s.c (P=<0.001).
EXAMPLE 13
Inhibition of HIV-1
HIV-1 activity was tested on MT2 cells (CD4+ T-cells) using the model of syncytia formation in cell culture. 20-120 μl aliquots of the VNF (CEppt) fraction, 0.5 mg/ml, were incubated with 50 μl virus for 5 minutes in a final volume of 200 μl RPMI medium at room temperature. 90 μl of each mixture were added onto the cells in duplicates. After 3 days of incubation at 37° C. in a 5% CO 2 humidified incubator, the infectivity was determined by monitoring syncytia formation.
Syncytia were observed in 95-100% of the control wells without CEppt and served as the 100% infectivity to which other wells were compared. As shown in FIGS. 15A and B, 8-10 μg of CEppt in 8-10 μl was sufficient to neutralize the virus completely.
EXAMPLE 14
Inhibition of Avian Influenza H9N2 by VNF (CE ppt)
The inhibition of avian influenza H9N2 by VNF was tested by the in vitro Hemolysis Assay as done previously (Borkow and Ovadia, 1994, 1999). The hemolytic activity of the influenza virus (release of hemoglobin from red blood cells) was examined on human erythrocytes as follows: Human blood was obtained from the Blood Bank and was used fresh. Prior to use, erythrocytes were washed 5 times with Phosphate Buffered Saline (PBS), pH 7 and diluted to a concentration of 4%, with the same buffer. The washed diluted erythrocytes were mixed with the virus alone or with a virus preincubated with the Viral Neutralizing Fraction (VNF) for 20 minutes at room temperature. After the attachment, excess virus was removed by washing with PBS before adding 200 μl of 0.1 M sodium citrate buffer at pH 4.6 for three min., in order to achieve fusion of the virus with the erythrocytes. The mixture was then washed in PBS, centrifuged and incubated in 0.8 ml PBS at 37° C. for 3 hours. Intact erythrocytes were removed by centriftigation and 300 μl aliquot was withdrawn from the supernatant of each sample into wells of an ELISA plate for measurement of the absorbance in an ELISA plate reader at 540 nm. Release of hemoglobin into the measured supernatant indicates viral hemolytic activity.
As FIG. 16 shows, the hemolytic activity of the virus was neutralized by the VNF (CEppt) in a dose dependent manner.
EXAMPLE 15
Inhibition of Preabsorbed Avian Influenza H9N2 by VNF (CEppt)
Influenza H9N2 virus was absorbed onto human erythrocytes at room temperature before application of VNF (CEppt) on the infected cells. The cells were then incubated at 37° C. and the hemolytic activity was determined as described in a previous figure. As FIG. 17 shows, CEppt inhibited the hemolytic activity of the avian influenza virus after it was attached on the infected cells as it did to the free virus.
EXAMPLE 16
Inhibition of NDV Hemagglutinating Activity by VNF
Hemagglutinating activity of the Newcastle Disease virus (NDV) was tested by mixing a drop of chicken blood with a drop of the virus suspended in PBS on a microscope slide (left side of the picture). As shown in FIG. 18 , right hand-side picture, preincubation of the virus (10 8 EID 50 ) with 10 mg of VNF (CEppt) resulted in Hemagglutination Inhibition. No such HI was observed in the absence of the NVF (left hand-side picture).
EXAMPLE 17
In-vivo (In-ova) Neutralization of Avian Influenza H9N2 by VNF
One ml containing 4.5 mg of VNF (CEppt) and 10 7 EID 50 of influenza H9N2 were incubated for 20 minutes at room temperature before preparing 10 fold dilutions from this mixture. 0.1 ml of each dilution was injected into each allantoic cavity of 10 embryonated chicken SPF eggs, 11 days old. Same dilutions of the virus alone or VNF alone were used as controls (10 eggs in each group). The eggs were observed during the following week for vitality and viral hemagglutinating activity. As FIGS. 19A and B demonstrate, VNF decreased the viral infectivity by 5 logs ( FIG. 15B ) and increased the survival of the embryos at the similar rate ( FIG. 19A ).
EXAMPLE 18
In-vivo Neutralization of Newcastle Disease Virus by VNF
This experiment is similar to the previous one carried out with the avian influenza H9N2. One ml containing 5 mg of VNF (CEppt) and 10 8 EID 50 of Newcastle Disease Virus were incubated for 20 minutes at room temperature before preparing 10 fold dilutions from this mixture. 0.1 ml of each dilution was injected into each allantoic cavity of 10 chicken SPF eggs (11 days old). Same dilutions of the virus alone or VNF alone were used as controls (10 eggs in each group). The eggs were observed during the following week for vitality and viral hemagglutinating activity. As FIGS. 20A and B demonstrate, VNF decreased the viral infectivity by 5 logs and increased the survival of the embryos at the similar rate.
EXAMPLE 19
Development of Filters for Decreasing Influenza Activity
0.5 ml containing 2.5 mg of VNF (CEppt) were absorbed onto 250 mg of each three filtering materials (names on the graph) and dried overnight at room temperature. 1 ml of human influenza H1N1 virus containing 1280 HAU was filtered through each one, and the passing fluid was tested for hemolytic activity on washed human erythrocytes as described above. As FIG. 21 demonstrates, the lab filter paper absorbed with the CEppt was most efficient in absorbing the VNF and reduced the hemolytic activity of the filtered virus significantly.
EXAMPLE 20
Serum Titer of Chicks Following Vaccination with NDV+CEppt
Two different approaches of vaccination were used: Vaccination in-ovo was compared with the customary intraocular vaccination of 1-2 day old chicks. In-ovo vaccination of the first group was carried out by injecting 0.1 ml of PBS containing 10 5.3 EID 50 of NDV preincubated with 1 mg of VNF into SPF chicken eggs at day 18 of the embryonic development. Second group was vaccinated 1-2 days after hatching by dripping the same dose into the eyes of the chicks (the customaryintraocular vaccination). Non-vaccinated chicks were used as controls. Blood samples were withdrawn from each chick at days 7, 14, 24 post-vaccination and the serum titer was determined by hemagglutination inhibition assay of serial dilutions of each serum.
The serum titer after in-ovo vaccination was as good as the tedious customary intraocular vaccination of 1-2 day old chicks. In-ovo vaccination was much more comfortable and safe.
TABLE
Serum titer of chicks following vaccination with NDV + CEppt
Average Serum Titer
(Hemagglutination Inhibition)
Group
Day 7
Day 17
Day 24
in-ovo (D18)
7.6 ± 0.5
9.2 ± 0.8
9.0 ± 0.1
NDV + CEppt
intraocular
4.0 ± 1.0
8.1 ± 1.0
8.7 ± 0.7
(D2) NDV only
non-vaccinated
2.0 ± 0.1
1.9 ± 0.2
3.1 ± 0.2±
LIST OF REFERENCES
American Lung Association, Jan. 8, 2002. Flu and Cold: Statistics.
Hernandez et al., (2004). Influence of two plant extracts on broilers performance, digestibility, and digestive organ size, Poult. Sci ., 83(2):169-74.
Kalemba and Kunicka, (2003). Antibacterial and antifungal properties of essential oils, Curr. Med. Chem ., 10(10):813-29.
Khan et al, (2003). Cinnamon improves glucose and lipids of people with type 2 diabetes, Diabetes Care , 26:3215-3218.
Lay nd Roy, (2004). Antimicrobial and chemo-preventive properties of herbs and spices, Curr. Med. Chem ., 11(11):1451-60.
Mau, J. L., et al., (2001). Antimicrobial effect of extracts from Chineese Chive, Cinnamon, and Corni fructus. J. Agric. Food Chem . 49:183-188.
Murcia et al, (2004). Antioxidant evaluation in dessert spices compared with common food additives, influence of irradiation procedure, J. Agric. Food Chem ., 52:1872-1881.
Qin et al., (2004), Cinnamon extract prevents the insulin resistance induced by a high fructose diet, Horm. Metab. Res ., 35:119-125.
Singh, H. B. et al., (1995), cinnamon bark oil, a potent fungitoxicant against fungi causing respiratory tract mycoses. Allergy, 50(12): 995-999.
Steinhaur, D. A., Wharton, S. A., Skehel, J. J., Wiley, D. C. and Hay, A. J. (1991). Amantadine selection of a mutant influenza virus containing an acid stable hemagglutinin glycoprotein: evidence for virus specific regulation of the pH of glycoprotein transport vesicles. Proc. Natl. Acad. Sci. U.S.A., 88: 11525-11529.
Tabak, M. et al., (1999). Cinnamon extracts' inhibitory effect on Helicobacter pylori, J. Ethnopharmacol . 67:269-277.
Usta et al., (2003). Comparative study on the effect of cinnamon and clove extracts and their main components on different types of ATPases, Hum. Exp. Toxicol ., 22(7):355-62.
Valero and Salmeron, (2003). Antibacterial activity of 11 essential oils against Bacillus cereus , in tyndallized carrot broth. Intl. J. of Food Microbiology , 85: 73-81.
Velluti et al., (2004). Impact of essential oils on growth rate, zearalenone and deoxynivalenol production by Fusarium graminearum under different temperature and water activity conditions in maize grain, J. of Applied Microbiology , 96: 716-724.)
Velluti et al., (2003). Inhibitory effect of cinnamon, clove, lemongrass, oregano and palmarose essential oils on growth and fumonisin B1 production by Fusarium proliferatum in maize grain. Intl. J. of Food Microbiology , 89:145-154.
W.H.O. Influenza, Fact Sheet No. 211, March 2003.
W.H.O. Global Influenza Programme, Note for the Press No. 22, September 2003.
W.H.O. Avian influenza, January 2004.
W.H.O. H5N1 avian influenza: a chronology of key events, February 2004.
W.H.O. Avian influenza A (H7) human infections in Canada, April 2004.
W.H.O. Working Group Three: Antivirals—their use and availability, April 2004.
W.H.O. Assessment of risk to human health associated with outbreaks of highly pathogenic H5N1 avian influenza in poultry, May 2004.
Yamasaki et al., (1998), anti-HIV-1 activity of herbs in Labiatae. Biol. Pharm. Bull ., 21:829-8339.
Borkow et al., (1994), Echinibin-1—an inhibitor of Sendai virus isolated from the venom of the snake Echis coloratus . Antiviral Research 23:161-76.
Borkow et al., (1999), Selective lysis of virus infected cells by cobra snake cytotoxins. Biochemical and Biophysical Research Communication, 264:63-8. | The present application provides a natural aqueous extract obtainable from a cinnamon bark ( Cinnamon sp.) which has antiviral activity against enveloped viruses including influenza A, Parainfluenza (Sendai) virus and HSV-1 viruses, as well as in vivo activity in inhibition of Influenza A and Parainfluenza viruses. The present application also concerns a method for the extraction of said cinnamon extract and applications thereof. | 0 |
This is a continuation of co-pending application Ser. No. 07/790,608 filed on Nov. 8, 1991, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a test method and apparatus and more particularly to a test method and apparatus for accelerated reliability testing.
The use of high temperatures and low temperatures as a means to stress electrical and electronic components in order to uncover weaknesses and faults without damaging healthy components is well known. Military standard Mil-Std-785B, Task 301 addresses the use of environmental stress as a method of inducing early failures due to part weaknesses and workmanship defects.
U.S. Pat. No. 3,710,251 issued to Holderfield et al. discloses a fixture for holding an unmounted microelectronic die or wafer and subjecting the microelectronic die or wafer to hot and cold temperatures while performing circuit tests. The hot and cold temperatures are derived from hot and cold liquids respectively and transferred through the holding fixture to the die or wafer. At column 2, lines 29-33 mention that rapid cycling between high and low temperatures is possible if such is required for circuit testing.
U.S. Pat. No. 4,870,355 issued to Kufis et al. discloses a fixture for holding a die or wafer and directly heating or cooling the die or wafer with hot or cold nitrogen gas.
U.S. Pat. No. 4,962,355 issued to Holderfield et al. discloses a fixture for heating or cooling a single electronic device, such as a hybrid semiconductor chip, with an unspecified fluid.
U.S. Pat. No. 4,945,302 issued to Janum discloses a test circuit board for mounting a plurality of microelectronic circuit and then subjecting part of the test circuit board and the microelectronic circuits thereon to elevated temperatures as a burn in procedure. The other part of the circuit board has test support circuits thereon and is not subjected to the elevated temperatures.
These patents all have the short coming that they do not disclose a method or an apparatus for testing a production printed circuit board (PCB), or a PCB assembly that has many electrical and electronic components attached thereto and inter-connected thereby. Yet each PCB assembly represents a considerable investment by the manufacturer, so it is desirable to uncover and repair any fault or weakness on each PCB and on each PCB assembly.
Thus, it is an object of the present invention to provide a test apparatus for mounting a PCB or PCB assembly, testing the operation of the PCB assembly during rapid temperature cycling of the entire circuit board and all the electrical and electronic components thereon.
It is another object of the present invention to provide a test method for testing a PCB or a PCB assembly during rapid temperature cycling in order to uncover weaknesses and faults thereof.
SUMMARY OF THE INVENTION
Briefly stated, in accordance with one aspect of the invention the foregoing objects are achieved by providing a method for testing a PCB or PCB assembly, including a PCB and electrical and electronic components that are connected thereto. The method includes the steps of inserting the PCB assembly in a circuit board connector that is part of a test apparatus; enclosing the PCB assembly and the circuit board connector within a liquid-tight enclosure; filling the enclosure with a first liquid having a first temperature to affect the temperature of the PCB assembly to rapidly move to the first temperature; draining the first liquid from the enclosure such that the PCB assembly is no longer covered; and subsequently filling the enclosure with a second liquid having a second temperature to affect the temperature of the PCB assembly to rapidly move to the second temperature. Operation of the PCB assembly is tested at the first temperature, during the change from the first temperature to the second temperature, and at the second temperature.
In another aspect of the invention, the aforementioned objects may be achieved by providing an apparatus for testing a printed circuit board assembly, including a PCB and at least one electronic component that is connection thereto as a PCB assembly. The apparatus includes a connector for inserting the PCB assembly; a device for enclosing the PCB assembly and the connector, the enclosing device being liquid-tight; a device for filling the enclosing device with a first liquid having a first temperature to affect the temperature of the PCB assembly to rapidly move to the first temperature; a device for draining the first liquid from the enclosing device and subsequently filling the enclosing device with a second liquid having a second temperature to affect the temperature of the PCB assembly to rapidly move to the second temperature. The apparatus also includes a device for testing the operation of the PCB assembly at the first temperature, during the change from the first temperature to the second temperature, and at the second temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with the appended claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention will be better understood from the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a block diagram of a test apparatus according to the invention.
FIG. 2 is a graphic representation of a set of temperature cycles that could be performed by the apparatus shown in FIG. 1.
DETAILED DESCRIPTION
Referring now to FIG. 1, an apparatus 10 for testing electrical or electronic assemblies is shown in block diagram form. The test apparatus 10 has a test enclosure 12. For reasons that will be explained below, the enclosure 12 is liquid-tight. Inside the enclosure 12 is a connector 14 for receiving and connecting to a PCB or PCB assembly to be tested (not shown in FIG. 1). The connector 14 is connected by cable 16 that is made up of N conductors to an operation test set 18. The operation test set controls the supply of power to the PCB or PCB assembly under test, and also samples responses of the PCB or PCB assembly to test stimuli in order to determine proper or improper performance of the PCB or PCB assembly.
The test apparatus 10 is preferably used to locate faults on PCB assemblies, however it also has been used to screen test bare PCBs before assembly to check for printed conductor and via/through-hole faults before the electrical and electronic components are added to make up a PCB assembly. The make up of the operation test set 18 is sufficient to test either bare PCBs or PCB assemblies.
The connector 14 can be a separate connector if the PCB or PCB assembly under test is self sufficient, or it can be a connector of a larger system. If the connector 14 is part of a larger system, then the enclosure 12 may enclose only enough of the larger system to perform the operational test. For reasons that will be explained below, the enclosure 12 is preferably vapor-tight during the performance of the operational tests.
Once the PCB or PCB assembly under test is in the connector 14 and the operation test is started, a liquid 20 is pumped by pump 22 from cold bath 21 through pipes 24, 26 and 28 into the enclosure 12. The liquid 20 is a perfluorinated liquid, such as Fluorinert, which is a registered trademark of 3M Corporation, Minneapolis, Minn. The liquid 20 is approximately twice as dense as water, so it is capable of absorbing large quantities of heat from the PCB or PCB assembly to the colder fluid 20. Since the fluid 20 may cost as much as $400 a gallon, leakage of the fluid 20 or vapors thereof are prevented wherever possible. To this end, a pipe 30 vents the vapor that is displaced from the enclosure 12 as the enclosure 12 is filled by the liquid 20 back into the cold bath 21. At the cold bath 21, any vapor therein is cooled. This cooling causes most of the liquid 20 that is evaporated and contained therein is condensed back into liquid form and becomes part of the liquid 20 again.
A controller 31 starts the filling of the enclosure 12 with the liquid 20 when the operator activates the start cold switch 33. The liquid 20 is subsequently pumped into the enclosure 12 until a float switch 32 by its position afloat in the liquid 20 is activated and indicates that the enclosure 12 is sufficiently full. The float switch 32 by operator action or by action of a simple switching circuit stops further filling.
The liquid 20 is cooled to a low temperature, such as 273 degrees kelvin or lower, and since the liquid 20 has a high density and a high heat capacity it can absorb heat from the PCB or PCB assembly under test very rapidly. Thus, in a short time the PCB or PCB assembly will be cooled down to essentially 273 degrees kelvin. After substantially reaching the first temperature and a short delay, which may be as long as the controller 31 takes to stop the pump 22 and open the valve 36, the liquid 20 is drained through pipes 38, 40 into the cold bath 21. A filter 42 is preferably included between the enclosure 12 and the pipe 38 to filter out water, hydrofloric acid formed by the action of water on perfluorinated liquids, any other liquid contaminates, and particulate matter from the PCB or PCB assembly under test and the apparatus 10.
As the liquid 20 drains into the cold bath 21, vapor from which most of the evaporated perfluorinated liquid has been condensed is both driven and drawn from the cold bath 21 into the enclosure 12.
Once the liquid 20 has been drained, the float switch 32 assumes the full down position, which corresponds substantially to the empty condition of the enclosure 12. At this point, a sensor, such as the float switch 32, turns the empty indicator 43 ON, indicating that the apparatus is prepared to start the cold-to-hot transition portion of the operation test cycle.
To start the cold-to-hot transition, the controller 31 under operator control by actuation of switch 53, or under automatic control if the controller 31 is so designed, energizes pump 48 and pumps liquid 50 out of the hot bath 51. The pump 48 pumps the liquid 50 from the hot bath 51 through pipes 54, 56, 28 to the enclosure 12. The liquid 50 is pumped into the enclosure 12 until the float switch 32 is again actuated, at which time the pumping ceases. As before, the location of the float switch 32 is selected such that the PCB or PCB assembly is completely immersed in the liquid 50.
Preferably, the liquid 50 is chemically the same as the liquid 20, in order to lessen problems of the two liquids mixing. The liquid 50 is heated within the hot bath 51 to a temperature of at least 333 degrees kelvin, and preferably to a temperature of 343 degrees kelvin. The temperature of 343 degrees kelvin, i.e. 70 degree Celsius, is close to the operating maximum of some electronic components. If such components are used, then the temperature of 333 degrees kelvin should be used, otherwise the higher temperature gives the greater temperature transition and hence the greater fault detecting stress on the PCB or PCB assembly under test.
At temperatures of 333 degrees kelvin or more, the liquid 50 will evaporate more readily than at room temperature. This being the case, it is even more important to have the enclosure 12 vapor tight for this portion of the test than during the cold portion of the test. The hot liquid 50 as it is pumped into the enclosure 12 will give off vapors which will be displaced as the enclosure is filled with liquid. To provide another closed venting action, the hot bath 51 is connected to the cold bath 21 by pipe 58. Thus, as vapor is displaced from the enclosure 12, the vapor is routed through the cold bath 21. In the cold bath 21, the vapor has a chance to cool and condense a part of its evaporated Fluorinert before some of it is drawn into the hot bath 51 in order to take the place of the liquid 50 that was pumped into the enclosure 12.
The high density and high heat capacity of the liquid 50 provides the means for transferring heat to the PCB or PCB assembly under test in order to rapidly increase its temperature to at least 333 degree kelvin. The placement of the float switch 32 or a deliberated delay may be inserted in the test if necessary to permit the PCB or PCB assembly under test to warm up to the temperature of the liquid 50. After the PCB or PCB assembly has been tested at the temperature of the liquid 50, the enclosure 12 is drained by opening a valve 60 and allowing the liquid 50 to drain through the filter 42, the pipe 38, the valve 60 and the pipe 62 into the hot bath 51.
As the hot bath 51 is filled by the liquid 50 returning from the enclosure 12, the hot vapor displaced thereby is driven and drawn through the pipe 58 into the cold bath 21 where it is cooled and most of the evaporated liquid therein is condensed therefrom. The enclosure 12 as it drains draws a cooled vapor through the pipe 30 from the cold bath 21 as the liquid 50 drains back to the hot bath 51. In this manner, the cold bath 21 is used also as a condensing means to recover some of the vapor borne Fluorinert that would otherwise escape and be lost to the atmosphere.
When the liquid 50 is substantially drained from the enclosure, the float switch 32 again is activated to indicate that the enclosure 12 is again empty and prepared to be filled. This completes one full temperature cycle.
Referring to FIG. 2, the description above describes a method of testing a PCB or PCB assembly as it is temperature cycled from point A, to point B, to point C, and is cooling down to point D (if the enclosure 12 is not filled again with either the liquid 20 or the liquid 50). As FIG. 2 indicates, a PCB or PCB assembly under test can be subjected to multiple dynamic temperature stresses as a way to uncover faults and defects. Since the test apparatus 10 takes energy to heat the hot bath 51 and to cool the cold bath 21, and since it takes a technician's time to perform the testing, a trade off must be made between the cost of running a longer test versus the savings of uncovering additional faults. As shown in FIG. 2, a test period of approximately 30 minutes has been found previously to be reasonable.
Referring again to FIG. 1, at the conclusion of each test of a PCB or PCB assembly, the enclosure 12 is opened up and the PCB or PCB assembly is removed from the connector 14. There will always be a small quantity of Fluorinert `dragged out` of the enclosure 12 by clinging to various surfaces and collecting in small aperatures of the PCB or PCB assembly, so some Fluorinert is lost with this test method.
To prevent mixing of the hot and cold liquids 50, 20, it may be desirable to have valves 100 and 102 as part of the apparatus 10 to separate and limit such mixing. The valves may be controlled by the controller 31 as shown, or for example, could also be one way check valves. Controlled valves 100, and 102 can be closed for emergency situations to halt flows of liquids 20 and 50 into the enclosure 12. The valves 100, 102 along with valves 36 and 60 could be used to substantially stop all flow of fluid within the apparatus 10. Such a stop could be initiated by the action of either over flow float switch 104 or 106. The expense and trouble of an overflow of Fluorinert at the cold bath 21 or the hot bath 51 warrants the precaution of an emergency stop capability if the flow in the apparatus 10 becomes imbalanced or clogged. Those skilled in the art will recognize that if the valves 100, 102, 60, and 36 are closed for an emergency, the pumps 48 and 22 should stop when the valves 100, 102, 60, and 36 are all closed until the operator can make repairs and safe operation testing can resume.
Thus, it will now be understood that there has been disclosed a method and apparatus for thermally accelerated reliability testing for a PCB or a PCB assembly. While the invention has been particularly illustrated and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form, details, and applications may be made therein. For example, some other inert liquid other than Fluorinert may be used. It is accordingly intended that the appended claims shall cover all such changes in form, details and applications which do not depart from the true spirit and scope of the invention. | A method for rapidly changing temperatures of either an unpopulated printed circuit board or a completed printed circuit board assembly and testing operation thereof. The rapid temperature change nondestructively stresses the printed circuit board or assembly and uncovers many defects that are hard to discover by constant temperature test methods. Each unit under test is alternately bathed with cold perfluorinated liquid and hot perflourinated liquid to rapidly change it temperature from cold (273 degrees kelvin) to hot (333 degrees kelvin). | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This present application is a continuation of PCT Serial No. PCT/EP00/13406, filed Dec. 29, 2000, claiming priority to French Application Serial No. 99/16655, filed Dec. 29, 1999, both of which are incorporated by reference herein.
FIELD OF THE INVENTION
The invention relates to a method of creating pores in a polymer material in sheet form or a polymer layer such as a thin film with a thickness equal to around 100 nanometers, previously deposited on a metallic base. The invention relates more particularly to a method of creating pores of nanometric to micrometric size in a polymer material such as polycarbonate in sheet form or any other equivalent material and to the use of such microporous sheets, notably for producing filtration membranes and/or for connecting filaments to an electronic circuit previously written on a base. The invention also relates to the microporous membranes obtained by the said method, the membranes being able to have porosity areas with a diameter of around 10 μm.
BACKGROUND AND SUMMARY OF THE INVENTION
Various methods of creating pores with a small cross-section in sheets of polymer material are already known in the prior art, for example with a view to producing microporous membranes for the purification or filtering of industrial or biological fluids, or for water treatment. These methods can be grouped together according to three major types:
a first, mechanical, type of method comprising at least one stamping step, as described for example in the document U.S. Pat. No. 4,652,412; a second type of method, comprising at least one irradiation using a CO 2 or NdYAG infrared laser or pulsed laser, as described for example in the documents U.S. Pat. No. 4,923,608, U.S. Pat. No. 3,742,182, WO-A-98 30317; a third type of method, comprising at least one ion irradiation followed by a chemical etching.
The method according to the invention for creating pores in a material such as polycarbonate in sheet form belongs to the third general type presented above. For this type of pore creation method, with a view to producing filtration membranes, reference can be made for example to the following documents: DE-A-4 319 610, U.S. Pat. No. 5,234,538, U.S. Pat. No. 3,713,921. The document U.S. Pat. No. 4,956,219, from the applicant, describes a method of creating pores in a material chosen from amongst the group comprising saturated polyesters such as ethylene polyterephthalate, carbonic acid polyesters such as polycarbonate produced from bis-phenol A (bis(hydroxy-4 phenol)-2,2 propane), aromatic polyethers, polysulphones, polyolefins, cellulose acetates and cellulose nitrates. The material is bombarded by a beam of ions preferably issuing from rare gases such as argon, with an energy of around 2 MeV per nucleon, the density of ions passing through the polymer film being between 10 4 and 10 13 ions per square centimeter. Such beams can be obtained by means of particle accelerators such as cyclotrons with separate sectors. The material is in the form of a strip moving substantially perpendicular to the beam of ions, the thickness of the strip being from around a few microns to 100 microns, the width of the strip being between 5 and 150 centimeters. By magnetic deflection, the beam of ions effects a sinusoidal sweep, each portion of the strip being bombarded on several occasions so that an even density of pores is obtained over the entire strip of material treated. After bombardment, the strip of material is possibly subjected to ultraviolet (UV) radiation. After this UV treatment or directly after ion bombardment, a chemical treatment is effected in a corrosive solution containing an organic solvent. Thus, for example, the strip of material is immersed in a solution of caustic soda containing methanol, ethanol or isopropanol. The ion bombardment and/or the chemical treatment can be carried out continuously, possibly one directly after the other, the strip of material which passed opposite the beam being driven continuously in the corrosive solution. After neutralisation, rinsing and drying, a continuous strip of microporous polymer material is obtained.
The document U.S. Pat. No. 3,852,134 describes a method for the ion bombardment of polycarbonate film with a thickness of less than 20 microns, followed by exposure to radiation with a wavelength of less than 4000 angstroms, under oxygen, before a first chemical etching, after baking and second chemical etching with a view to obtaining pores with diameters of between 1000 and 100,000 angstroms. The preferential etching methods in directions defined by molecular structure defects resulting from an ion bombardment make it possible to produce filtering membranes with a greater quality than the membranes resulting from other methods such as stamping or laser treatment. However, controlling the density, shape and size of the pores obtained is still tricky. Thus for example there is a probability that one or more pores may pass completely through the membrane which, in some applications, may be detrimental. To reduce this risk, a method of bombardment on both faces of the membrane is proposed in the document U.S. Pat. No. 4,855,049. This method does however result in an unfavourable hydromechanical behaviour in some cases, because of the great convolution obtained for the fluid passages. It has also been found that the pores are of variable diameter from the surface towards the heart of the membrane, thus having a “cigar” shape (for polycarbonate membranes, see Schönenberger et al., J. Phys. Chem. B101, p. 5497-5505, 1997). This in particular interferes with a good prediction of the properties of these membranes merely looking at their surface, for example with a scanning electron microscope. The cause of this shape of the pores is still being discussed.
The document U.S. Pat. No. 3,713,921 presents the use of a surfactant added to the etching reagent in order to attenuate these variations in shape and transverse dimension of the pores. Some authors invoke an influence of the thickness of the membrane and imperfect control of the etching conditions in order to explain the “cigar” shape of the pores.
The invention relates to a method of creating pores in a polymer material in sheet form, such as polycarbonate or any other equivalent material, the said method making it possible to obtain porous areas with controllable sizes and shapes, these areas being distributed according to densities and locations which can also be controlled. According to one embodiment, the method also allows, within the said areas, the formation of pores of a cylindrical shape overall, without any depreciable variation in average diameter of these pores in the thickness of the sheets of polymer material treated. The invention also concerns the microporous membranes produced from the said treated sheets of polymer material.
The invention relates, according to a first aspect, to a method for creating pores with a nanometric to micrometric size in a polymer material in a thin sheet which can be supported, comprising an ion bombardment followed by chemical etching, the said method comprising a step of global heat treatment providing partial deactivation of the traces formed in the polymer material by the ion bombardment, and a step of selective irradiation of the polymer film, steps which take place after the ion bombardment and before the chemical etching.
In another embodiment, the global heat treatment and the selective irradiation of the bombarded polymer material are carried out simultaneously. In one embodiment, the selective irradiation is effected after the heat treatment of the bombarded polymer material. In another embodiment, the selective irradiation is effected by means of a UV source and through a mask. In another embodiment, the selective irradiation is effected by means of a UV laser beam. According to one particular embodiment, a step of pre-etching of the polymer material is carried out prior to the ion bombardment, this pre-etching reducing the thickness of the sheet of polymer material.
The polymer material is chosen from the group comprising saturated polyesters such as ethylene polyterephthalate, carbonic acid polyesters such as polycarbonate produced from bis-phenol A (bis(hydroxy-4 phenol)-2,2 propane), aromatic polyethers, polysulphones, polyolefins, cellulose acetates and cellulose nitrates. The sheet of polymer material initially has, and in particular before any pre-etching, a thickness of between a few microns and around a hundred microns. The pre-etching is carried out until the ablation of a thickness of between 0.5 microns and 3 microns approximately on each face of the said sheet. According to a particular embodiment, the polymer material is an amorphous polycarbonate approximately 25 microns thick before pre-etching. According to another particular embodiment, the polymer material is a crystalline polycarbonate with a thickness of approximately 10 microns. The ion bombardment is performed by a beam of ions preferably issuing from rare gases such as argon, with an energy of around 2 MeV per nucleon, the beam having an intensity of between 10 6 and 10 13 ions per second.
In one embodiment, the chemical etching is said to be slow and is carried out in a bath containing 0.5 N caustic soda in aqueous solution, at a temperature of approximately 70° C., for approximately 260 min. In another embodiment, the chemical etching is said to be fast and is carried out in a bath containing 2 N caustic soda, in aqueous solution, at a temperature of approximately 70° C., for approximately 30 min. The chemical etching bath comprises, in one embodiment, an organic solvent chosen from amongst the group comprising methanol, ethanol and isopropanol. The chemical etching is carried out in the presence of a surfactant. The microporous films obtained after chemical etching are washed until the pH is neutralised, rinsed and dried. The washing of the microporous film is carried out in an aqueous solution of acetic acid at approximately 15%, at a temperature of approximately 70° C. for approximately 15 minutes; then in demineralised water, at a temperature of approximately 70° C., for approximately 15 minutes and more, until a neutral pH is obtained.
The method for creating pores described above is carried out continuously. The invention relates, according to a second aspect, to a microporous film of polymer material produced by implementing the method presented above. The microporous film is used as a matrix with a view to producing micrometric filaments of metal or polymer.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will emerge during the following description of embodiments, a description which will be effected with reference to the accompanying drawings, in which:
FIG. 1 is a schematic diagram depicting the successive steps of a method of creating pores in a polymer material in sheet form, according to a first embodiment of the invention;
FIG. 2 is a schematic diagram depicting the successive steps of a method of manufacturing metallic filaments, a manufacturing method using the polymer material in sheet form treated in accordance with the pore creation method as shown schematically in FIG. 1 ;
FIG. 3 is a schematic diagram depicting the successive steps of a method of manufacturing polymer filaments, a manufacturing method using the polymer material in sheet form treated in accordance with the pore creation method as shown schematically in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Reference is made first of all to FIG. 1 . The method of creating pores in an initial polymer film 1 , as shown schematically in FIG. 1 , comprises four successive steps:
an ion bombardment 2 of the film 1 , producing a bombarded film 3 ; a global heat treatment 4 of the bombarded film 3 ; a selective irradiation 5 of the bombarded film 3 producing an irradiated film 6 ; a chemical etching 7 of the irradiated film 6 .
The initial polymer film 1 can be produced from a material chosen from amongst a group comprising saturated polyesters such as ethylene polyterephthalate, carbonic acid polyesters such as polycarbonate produced from bis-phenol A (bis(hydroxy-4 phenol)-2,2 propane), aromatic polyethers, polysulphones, polyolefins, cellulose acetates and cellulose nitrates.
In the remainder of the description, only the results obtained with polycarbonate will be described. Two grades of polycarbonate produced from bis-phenol A will be considered: a crystalline polycarbonate (referred to as PCc hereinafter, for the purpose of simplification) and an amorphous polycarbonate (referred to as PCa hereinafter). As PCc, a 10 micron thick film, sold under the brand name Makrofol™ by Bayer, is used in the following detailed examples. This Makrofol™ film is produced by moulding, crystallisation and longitudinal stretch forming. As PCa, a 25 micron thick film, sold under the brand name Lexan™ by General Electric, is used in the following detailed examples. This Lexan™ film comprises crystallites of size so small that it is of very high transparency in natural light. In certain particular embodiments, a pre-etching of the film is carried out before ion bombardment. The ion bombardment 2 is carried out, in one embodiment, by means of a beam of ions preferably issuing from rare gases such as argon, with an energy of around 2 MeV per nucleon, the beam having an intensity of between 10 6 and 10 13 ions per second. Such beams can be obtained by means of particle accelerators such as cyclotrons with separate sectors. The film to be bombarded, pre-etched or not, is, in one embodiment, in the form of a strip passing substantially perpendicular to the beam of ions, the thickness (e) of the strip being around a few hundreds of a nm at 100 microns, the width of the strip being between 5 and 150 centimeters.
In another embodiment, the polymer film, with a thickness (e) which may vary from a few nanometers to a few hundreds of nanometers, is deposited on a base (not shown). By magnetic deflection or any other equivalent method, the beam of ions performs a sinusoidal sweep, each portion of the strip being irradiated on several occasions so that an even density of pores is obtained over the entire strip of bombarded film. After it has cooled, the bombarded film 3 is subjected to:
a global heat treatment 4 , so that the structural defects or “traces” formed in the polymer film during the ion bombardment are less sensitive to the chemical etching; a selective irradiation 5 of the heat-treated bombarded film 3 reactivates some traces and makes them more sensitive to the subsequent chemical etching 7 ; a chemical etching 7 , performed in a corrosive solution containing an organic solvent.
The heat treatment 4 is carried out at a temperature of between room temperature and approximately 200° C., for a time less than a few tens of minutes. When the polymer film is made from polycarbonate, the heat treatment 4 is carried out at approximately 150° C. The irradiation 5 can be performed for a very short time, using a laser beam, or much longer, around several hours, for a less intense energy source. In one embodiment, the irradiation 5 is performed employing a wavelength of around 360 nm, for a power which may attain around 10 millijoules per square micrometer. Thus, for example, the selectively irradiated film 6 is immersed in a solution of caustic soda containing methanol, ethanol or isopropanol. The steps of ion bombardment 2 , heat treatment 4 , selective irradiation 5 and chemical etching 7 can be carried out continuously, possibly one directly after the other. After neutralisation, rinsing and drying, a continuous film of microporous polymer material 8 is obtained. The non-porous membrane 9 results from the membrane 3 which has undergone the heat treatment 4 and then the chemical etching 7 , but which has not undergone irradiation 5 . In a variant embodiment of the chemical etching 7 , a surfactant is added to the soda solution in order to improve the wetting of the irradiated film 6 during the etching 7 .
As stated above, the conventional implementation of the chemical etching methods 7 for polymer films which have undergone an ion bombardment 2 results in the formation of pores of variable diameter from one edge to the other of these films. The inventors have carried out thorough investigations in order both to propose an explanation for this irregular form of the pores and to propose a method of manufacturing microporous polymer films in which the pores have a cylindrical shape overall.
The experimental results obtained will be presented below with reference to embodiments of the invention. An initial film of PCc of Makrofol™ make, 10 microns thick (e), and an initial film of PCa of Lexan™ make were each subjected to a light pre-etching Preal and an intense pre-etching Preai, so as remove a thickness of 0.5 microns and 2.0 microns on each face of the films respectively. The thicknesses removed were measured by gravimetric analysis. The pretreated films were then subjected to an ion bombardment 2 at the Cyclotron Research Centre at Louvain-la-Neuve. Ar 9+ ions were used, at an acceleration voltage of 5.5 MeV/AMU. The bombarded films 3 were then subjected to a heat treatment 4 (150° C. for 15 min) and to an ultraviolet irradiation 5 through a mask (not shown). The irradiated films 6 were next subjected to a chemical etching according to two modes:
a so-called “slow” chemical etching 7 a , in a bath containing 0.5 N caustic soda in aqueous solution, at a temperature of approximately 70° C. for approximately 260 min; a so-called “fast” chemical etching 7 b , in a bath containing 2 N caustic soda in aqueous solution at a temperature of approximately 70° C. for approximately 30 min.
In the two cases of chemical etching 7 a , 7 b , a surfactant was added to the solution in order to increase the wetting of the irradiated film 6 during the etching. After the chemical etching 7 a , 7 b , the microporous films 8 obtained were washed: in an aqueous solution of acetic acid at approximately 15%, at a temperature of approximately 70° C., for approximately 15 minutes; then in demineralised water at a temperature of approximately 70° C. for approximately 15 minutes and more, until a neutral pH was obtained. The films were then coated with polyvinylpyrrolidone or PVP in order to increase their hydrophilic character, then dried in warm air.
Reference is now made to FIGS. 2 and 3 . The microporous films 8 were then subjected to an electrolysis 10 performed in an electrochemical cell with three electrodes, at room temperature, such as a galvanoplasty cell, with a compartment made from Teflon™ with a counter-electrode made from platinum and a reference electrode made from calomel. A metallic twin layer 13 , serving as electrodes, is applied to one of the faces of the microporous film 8 . This twin layer 13 comprises:
a first adhesion layer 13 b of chromium, 10 to 20 nm thick, directly applied to one of the faces of the microporous film 8 ; a second layer 13 a of gold, 500 nm to 1 micron thick, applied to the first layer 13 b and in direct contact with the atmosphere.
The electrolysis 10 is carried out for example:
with a solution comprising 50 g/l of CoSO 4 and 30 g/l of H 3 BO 3 , at a potential difference of −0.1 V, to produce metallic filaments 12 ; with a solution comprising 0.1 M of pyrrole and 0.1 M of LiClO 4 , at a potential difference of +0.8 V, producing polymer filaments 14 .
At the end of the galvanoplasty, the polycarbonate matrix of the microporous films was dissolved during step 11 in dichloromethane. The filaments 12 or 14 obtained can be filtered by means for example of a silver membrane. The microporous polymer films 8 and the filaments 12 or 14 obtained were observed under a field effect electron microscope (DSM 982 Gemini from the company LEO). Images with a satisfactory resolution were obtained for magnifications ranging up to 200,000, at an acceleration voltage of 400 V, without metallic deposition on the samples to be observed. The following parameters were measured:
mean diameter of the filaments, half-way along (MWD); mean diameter of the pores on the surface of the microporous film 8 (MPS).
A calibration using nanospheres (Calibrated nanospheres™ from Duke Scientific Corp.) with a mean diameter of 30 nm was carried out in advance. By small angle X-ray diffraction (SAXS), a measurement of the distribution of the sizes of pores contained in the microporous membranes 8 was carried out (E. Ferain, R. Legras, Nuclear Instruments and Methods in Physics Research B131, 1997, p. 97). An average pore size value (APS) and a standard deviation in the distribution of the pore diameters were derived from these measurements of intensity of the diffracted beam as a function of the diffraction angle.
The study of the variations in the parameters MWD, MPS and APS specified above, as a function of the chemical etching time, for slow and fast attacks on a PCc film of the Makrofol™ type showed that:
the filaments obtained have MWD diameters greater than the size of the pores on the surface of the microporous films 8 , whether the chemical etching be slow or fast and whatever the etching time in question, the filaments obtained have a toothpick shape; the difference between the diameter values of the MWD filaments and the MPS diameters of the pores on the surface of the microporous film 8 is lower than for the slow chemical etching 7 a and for the fast chemical etching 7 b (approximately 15 nm as against approximately 30 nm); the variations in the MPS and MWD values, as a function of the etching time, are similar, for a given type of etching 7 a , 7 b; the average pore diameter values in the PCc film, after slow etching 7 a , measured by SAXS, are between the values of the diameters of the filaments half-way along MWD and the values of the diameters of the pores on the surface of the film MPS.
The study of the variation in the parameters MWD, MPS, as a function of the etching time, for a fast etching 7 b of a PCa film of the Lexan™ type, for films which have undergone a light pre-etching Preal and for non pre-etched films, showed that:
a light pre-etching Preal reduces the difference between the values of the diameters of the filaments MWD and the values of the diameters MPS of the pores on the surface of the microporous films 8 , compared with a non pre-etched film (approximately 30 nm as against approximately 10 nm); the pre-etching does not modify the rate of variation in MPS or MWD as a function of the etching time.
The study of the variations in the parameters MWD, MPS and APS, as a function of the etching time, for a slow etching 7 a of a PCa film of the Lexan™ type, for films which have undergone an intense pre-etching Preai, showed that the variations in the parameters MWD, MPS and APS are substantially merged, for a given slow etching time range 7 a , so that the pores formed in the film can be considered to be cylindrical.
The polyamide filaments 14 obtained after electrolytic deposition (step 10 ) in the pores of a PCa film which has undergone an intense pre-etching Preai and dissolution (step 11 ) of this polycarbonate film also have a very regular cylindrical shape. The filaments obtained from PCa have a lower roughness than those obtained from PCc. This observation must probably be correlated with the greater size of the crystallites in the Makrofol™ type PCc films than in the Lexan™ type PCa films used here, resulting in irregularities in the chemical etching paths forming the pores.
The pores obtained for PCa films which have undergone an intense pre-etching Preai have distributions of average diameters with standard deviations lower than those obtained for the pores in the PCc films. The losses of thickness measured by gravimetric analysis, for increasing etching times of films of PCa, PCc and PCa strongly pre-etched, not subjected to ion bombardment 2 , are substantially identical for the first two microns of thickness of the films. Consequently there does not appear to exist any surface layer more resistive to chemical etching 7 , unlike the assumptions sometimes adopted in the literature.
Overall, the experimental results presented above made it possible to establish a high positive influence of a pre-etching of the films before ion bombardment 2 , this pre-etching making it possible to obtain pores which are substantially cylindrical rather than in the shape of “toothpicks” or “cigars” as in the prior methods. The precise origin of this influence of the pre-etching remains indeterminate. The geometry of the pores obtained makes it possible to produce nanofilaments or nanotubes of metal or polymer, these filaments being able to have a smooth surface and a cylindrical shape over lengths varying between a few nanometers and several tens of microns. Such nanofilaments or nanotubes are of very great interest for electronic, optical or biomedical applications for example. Moreover, the precise control of the three-dimensional porosity in polymer films makes it possible to produce filters which are very useful in the medical fields or in water treatment.
The method of the invention can also find an application in the field of connector engineering. The placing of a sheet of polymer, for example 100 nanometers thick, on an electronic circuit itself placed on a substrate, and the application of the method described above to the said polymer, allows the connection of the nanofilaments to the said electronic circuit. | The invention relates to a method of creating pores in a polymer material in sheet form or a polymer layer such as a thin film with a thickness equal to around 100 nanometers, previously deposited on a metallic base. The invention further relates to a method of creating pores in a polymer material in sheet form, such as polycarbonate or any other equivalent material, the said method making it possible to obtain porous areas with controllable sizes and shapes, these areas being distributed according to densities and locations which can also be controlled. | 1 |
RELATED APPLICATIONS
This application is a Divisional of U.S. application Ser. No. 13/242,719 filed Sep. 23, 2011, which application is a continuation-in-part of application No. PCT/EP2009055279, filed on Apr. 30, 2009, in Europe and published as WO2010/124737 A1, the disclosures of which are incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to hearing aids. The invention, more specifically, relates to analog-to-digital input signal converters in digital hearing aids. The invention further relates to a method of converting an analog signal to a digital signal in a hearing aid.
An analog-to-digital converter, denoted an A/D converter in the following, converts a varying current or voltage into a digital data format. Several different A/D converter topologies exist, each having benefits and tradeoffs in terms of conversion speed, accuracy, quantization noise, current consumption, word length, linearity and circuit complexity. In contemporary, digital hearing aid designs, the delta-sigma A/D converter type is the preferred converter type due to a number of important factors such as easy aliasing filter implementation, conversion noise being controllable by design, comparatively low power consumption and relatively easy implementation due to a low component count when compared to existing A/D converter designs.
By definition, noise inherent in a signal processing device is unwanted signals introduced by the signal processing device itself. Inherent noise may e.g. originate from inadequate operating conditions, poor design or variations in component values. These circumstances have to be taken into account in designing the signal processing device. In A/D converters, several different types of noise may be observed. Among these are conversion noise, quantization noise, thermal noise, flicker noise, recombination noise, and noise due to various physical limitations in the gain-producing elements. In order to provide a distinction between the sources of these different noise types, the most important noise types will be discussed briefly in the following.
Quantization noise originates from the process of quantifying a continuous input voltage span into a finite set of voltage levels that may be represented by discrete, binary levels according to the expression:
L N =2 n
where L N is the number of discrete levels possible and n is the number of bits used to represent a single sample in the digital domain. Quantization noise may be thought of as the difference between the actual input voltage of a single sample and the discrete voltage used to represent it. This type of noise may thus be minimized, e.g. by increasing the number of bits representing the signal arbitrarily, and will therefore not be discussed further here.
Thermal noise originates from the random Brownian motion of electrons in a resistive medium. Given a resistance, a bandwidth and a temperature, the rms thermal noise V nt is given by:
V nt =√{square root over (4k b TΔfR)}
where k b is Boltzmann's constant, 1,38065*10 −23 J/K, T the absolute temperature in K, Δf the bandwidth of interest in Hz and R the resistance in Ω of the circuit element considered.
Flicker noise, or 1/f noise, is predominant in the noise spectrum at low frequencies. It has been observed in electronic devices since the era of vacuum tubes, and is also present in contemporary semiconductor devices.
Shot noise is the result of stochastic phenomena caused by an electric current crossing a potential barrier, such as the barrier found between P-doped and N-doped material in a semiconductor element. Current shot noise I n is a temperature-independent quantity, and may be described by the expression:
I n =√{square root over (2qI)}
where q is the electron charge, 1,602*10 −19 Coulombs, and I the bias current for the semiconductor element. The unit of the spectral density of shot noise is A/√{square root over (HZ)}.
In order to provide a hearing aid capable of working uninterrupted for several days without a need for replacing the battery, one design goal for the hearing aid is that the current drawn from the battery by the electronic circuit is reduced as much as possible, preferably to a value below 1 mA. A semiconductor element providing amplification in the order of between one hundred times to perhaps a thousand times the signal present at its input uses a considerable percentage of this current as its bias current in order to handle the large gain within its operating limits. From the foregoing it is evident that shot noise is dependent on the current flowing through the semiconductor element, this fact providing further motivation for reducing the bias current for the amplifier in the A/D converter as much as possible.
2. The Prior Art
Delta-sigma A/D converters are well known in the art. Their purpose is to convert a varying, analog input voltage into a binary bit stream for further processing in the digital domain. Delta-sigma A/D converters have significant advantages over other A/D converter designs. They have a relatively low component count, and they feature various signal processing advantages above other A/D converter designs. In order to reduce conversion noise, oversampling is used. By measuring each discrete voltage many times, e.g. 64, errors due to statistical variations in the input signal are leveled out, and the conversion noise spectrum is pushed far beyond the Nyquist limit, thus making conversion noise very easy to filter out from the signal. One drawback is that the converter clock rate in this example has to be 64 times the desired sample clock rate.
In its essence, a delta-sigma A/D converter comprises a delta-sigma modulator and a low-pass filter. This may be made with an integrator, a comparator and a D-flip-flop. The output signal of the flip-flop is fed back through a feedback loop comprising a one-bit D/A converter, and is subtracted from the input signal upstream of the integrator. The subtracted feedback signal provides an error signal to the input of the delta-sigma modulator.
The error signal from the feedback loop of the A/D converter is used to ensure that, on average, the output signal level of the converter is always equal to the input signal level. If no signal is present on the converter input, a symmetric output bit stream of binary ones and zeroes is generated by the A/D converter. When the input signal voltage changes to a more positive voltage, more binary ones will be present in the output bit stream, and when the input signal voltage changes to a more negative voltage, more binary zeroes will be present in the output bit stream. The delta-sigma A/D converter thus converts an analog input signal into a balance between ones and zeroes in the output bit stream.
SUMMARY OF THE INVENTION
The invention, in a first aspect, provides an input converter for a hearing aid, said converter comprising a first voltage transformer and an analog-to-digital converter of the delta-sigma type, the analog-to-digital converter having an input stage and an output stage, a connection from the output of the input stage to the input of the output stage, and a feedback loop between the input of the input stage and the output of the output stage, said input stage comprising an amplifier and an integrator, wherein the first voltage transformer has a transformation ratio such that it provides an output voltage larger than the input voltage and is placed in the input converter upstream of the input stage.
The invention, in a second aspect, provides a method of converting an analog signal into a digital signal in a hearing aid comprising a digital signal processor, a sampling clock generator and a system clock generator, said method comprising the steps of transforming an input signal voltage, amplifying the transformed input signal voltage, integrating the transformed, amplified voltage, digitizing the amplified, integrated voltage, transforming the digitized, integrated voltage into a higher voltage, subtracting the transformed, digitized voltage from the transformed input voltage, and using the digitized, integrated voltage for generating a digital output bit stream representing the input signal voltage to subsequent stages of the digital signal processor in the hearing aid.
In order to overcome the above shortcomings, the input converter according to the invention comprises a first voltage transformer placed in the input converter upstream of the input stage and having a transformation ratio such that it provides an output voltage larger than the input voltage. When the input signal voltage is transformed up prior to being amplified by the amplifier stage, less amplification is needed in order to bring the input signal up to an acceptable level, and the relative amplifier noise contribution to the amplified signal is lower, and the same is the case when the feedback signal voltage is transformed up prior to being presented to the amplifier input.
According to the invention, both the input transformer and the feedback transformer are implemented as voltage transformers. Voltage transformers are easily implemented in synchronized (clock-controlled) digital networks, and may be designed so as to optimize their impedance to the impedance of the amplifier and the subsequent stages of the A/D converter.
Further features and advantages are evident from the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in further detail with respect to the drawings, where
FIG. 1 is a schematic of a prior art delta-sigma A/D converter;
FIG. 2 is a more detailed schematic of the prior art delta-sigma converter in FIG. 1 ;
FIG. 3 is an equivalent schematic illustrating the noise level voltage V n of an amplifier of the delta-sigma converter in FIG. 2 ;
FIG. 4 is a schematic illustrating the principle of equivalent transformation of the input signal to the amplifier in FIG. 3 ;
FIG. 5 is a schematic illustrating a first phase of a prior art sampled capacitor integrator;
FIG. 6 is a schematic illustrating a second phase of a prior art sampled capacitor integrator;
FIG. 7 is a schematic illustrating a first phase of the sampled capacitor integrator according to an embodiment of the invention;
FIG. 8 is a schematic illustrating a second phase of the sampled capacitor integrator according to an embodiment of the invention;
FIG. 9 is a schematic of an implementation of an input transformer in a first phase according to an embodiment of the invention;
FIG. 10 is a schematic of an implementation of an input transformer in a second phase according to an embodiment of the invention;
FIG. 11 is a schematic of a delta-sigma analog-to-digital converter according to an embodiment of the invention;
FIG. 12 is a schematic of a preferred embodiment of a delta-sigma analog-to-digital converter according to an embodiment of the invention; and
FIG. 13 is a schematic of a hearing aid having four delta-sigma converters according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a block schematic of a prior art delta-sigma A/D converter comprising an input terminal IN, a subtraction point 1 , an integrator 2 , a comparator 3 , a D-flip-flop 4 , a 1-bit digital-analog converter 5 , a clock generator 6 , and an output terminal OUT. An analog signal presented to the input terminal IN is fed to the subtraction point 1 where the output signal from the 1-bit D/A converter 5 is subtracted from the input signal, generating an error signal. The difference signal from the subtraction point 1 is fed to the input of the integrator 2 for generating an integral of the difference signal from the subtraction point 1 . The output signal from the integrator 2 is presented to the input of the comparator 3 for generating a logical “one”-level whenever the integral signal exceeds a predetermined threshold limit set by the comparator 3 , and a logical “zero”-level whenever the output signal from the integrator 2 falls below the predetermined threshold. This logical signal then feeds the data input of the flip-flop 4 .
The clock generator 6 controls the flip-flop 4 in such a way that the output signal from the comparator 3 is quantized in time and synchronized to the clock signal, the flip-flop 4 working as a latch, thus creating a bit stream representing the input signal. The bit stream from the output of the flip-flop 4 is split between the output terminal OUT and the input of the 1-bit D/A converter 5 to the subtraction point 1 and subtracted from the input signal. The 1-bit D/A converter 5 converts the logical ones and zeroes in the bit stream into a positive or negative voltage with respect to the input signal for subtraction from the input signal in the subtraction point 1 .
This arrangement, in essence, creates a feedback loop, making the bit stream represent the changes in the input signal over time, i.e. when the input signal level is zero, an equal number of digital ones and zeroes will be present in the bit stream; whenever the input signal goes positive, more ones than zeroes will be present in the bit stream in a proportion to the input signal level; and whenever the signal goes negative, more zeroes than ones will be present in the bit stream in a proportion to the input signal level. The bit stream may then be converted into a suitable, digital format for further processing in the digital domain.
A delta-sigma A/D converter design for a hearing aid should have a small noise figure and a low current consumption. However, if the current consumption of the input amplifier of the A/D converter is decreased without any alterations to the design, the noise figure of the amplifier will increase correspondingly. This problem, and a possible solution, will be explained in further detail in the following.
FIG. 2 shows a more detailed schematic of a prior art delta-sigma A/D converter. The converter comprises an input IN, a first resistor R 1 , a second resistor R 2 , an amplifier A, a capacitor C s a residual loop filter RLF, a D-flip-flop DFF, and a clock generator CLK generating a clock signal. The amplifier A and the capacitor C forms the integrator 2 of the converter topology shown in FIG. 1 , and the residual loop filter RLF comprises subsequent low-pass filter stages present in second- or higher-order delta-sigma converters. The converter receives an analog input signal in the form of a voltage U at the input terminal IN and presents a bit stream representing a digital output signal Y at the output terminal OUT. It should be noted that the signals in the converter are time-continuous until the generation of the bit stream from the output Q of the flip-flop DFF.
The amplifier A and the residual loop filter RLF comprises the loop filter of the converter, and the frequency transfer function of the loop filter, i.e. the frequency transfer function of both A and RLF, determines the converter's ability to suppress frequency-dependent quantization noise. The gain of the amplifier A also suppresses the noise from the filter RLF because the filter RLF is positioned in the feedback loop of the converter. In this discussion, the reason for distinguishing between the amplifier loop filter, respectively, is to isolate the noise contribution from the amplifier A from other noise sources in the feedback loop. All other things being equal, the noise level of the amplifier A thus constitutes the main noise component of the converter apart from quantization noise. This is the reason that the contribution from this particular noise source should be minimized, as mentioned in the foregoing.
If the amplifier A were to have infinite gain, the signal level on the input terminal of the amplifier would be zero. Instead it may be assumed that the total gain of A and RLF combined is sufficiently large throughout the desired frequency bandwidth of the converter for the converter quantization noise to be neglected. Given an input voltage U and a resulting output voltage Y, the transfer function H of the complete converter in FIG. 2 in the ideal case may thus be estimated as:
H
=
Y
U
=
-
R
2
R
1
In order to address the problem of the noise contribution from the input stage of the converter, this particular noise source has to be isolated. This is illustrated in the schematic in FIG. 3 .
In FIG. 3 , an ideal, noise-free amplifier A and a noise voltage source V n is substituting the amplifier A in FIG. 2 , and the configuration of C s R 1 , R 2 and A is sketched out together with the input voltage U, the output voltage Y, and the amplifier noise voltage source V n , while the remaining components from FIG. 2 are left out from the schematic for clarity. If the total amplification from A and RLF (not shown in FIG. 3 ) is assumed to be sufficient for the desired bandwidth of the converter, the noise contribution Y n to the output voltage Y may be written as:
Y
n
=
(
1
+
R
2
R
1
)
·
V
n
The noise voltage contribution U n with reference to the input voltage U may then be calculated by combining the two expressions thus:
U
n
=
Y
n
H
=
-
(
1
+
R
1
R
2
)
·
V
n
This implies that the input noise U n is dependent on the amplifier noise V n . In other words, if it is possible to decrease V n , the input noise U n will decrease, too.
The amplifier noise voltage V n has three primary origins. Noise due to the fact that the amplifier A has finite gain, intermodulation products originating from nonlinearities in the amplifier A, and thermal noise produced by the input stage of the amplifier A. Multi-stage amplifiers with large gain values have traditionally been used in order to minimize thermal noise. Likewise, noise may also be reduced by supplying the semiconductor elements in the amplifier with sufficiently large currents in order to keep the total noise in the output signal at an acceptable level.
However, none of these approaches are especially attractive in a converter design for a hearing aid, where current consumption and component count has to be kept to a minimum in order to prolong battery life. An alternative way of reducing the noise sensitivity of the amplifier in the converter is thus desired.
In theory, the noise voltage V n may be downscaled, e.g. by transforming the input signal U and the output signal Y by placing ideal transformers between the input terminal U and R 1 and between the output terminal and R 2 with a given transformation factor N.
FIG. 4 shows an equivalent schematic of the converter in FIG. 3 as modified by the incorporation of ideal transformers T 1 and T 2 in the input branch and the output branch of the converter, respectively. The input transformer T 1 transforms the input voltage by the ratio 1:N, (i.e. the voltage on the transformer output is N times the voltage on the transformer input), and the feedback transformer T 2 transforms the feedback voltage by the ratio 1:N (i.e. the voltage presented to the amplifier is N times the voltage present at the output node Y). The values of the resistors R 1 and R 2 are each scaled with a factor of N 2 in order to preserve the current load of the input and the output, respectively. Likewise, the value of the integrator capacitor C is scaled by the factor N −2 . It may be shown that the resulting amplifier noise voltage V n is scaled correspondingly by the factor V n /N. In theory, it is possible to scale the noise contribution from the amplifier stage down by an arbitrary amount, providing the amplifier stage is capable of handling the increased input voltage without being saturated. The current demands for the converter are also smaller due to the impedance transformation.
Real transformers are non-ideal and therefore impossible to use in practical hearing aids due to their size, weight, current consumption and power losses. The inventor has realized that the equivalent of an ideal transformer may be applied as a solution to the problem with satisfactory results. Such an equivalent is described in further detail in the following. The starting point of this discussion is a delta-sigma A/D converter utilizing a topology based on sampled capacitors. Sampled-capacitor stages are considered to be well-known in the art, and the working principle of such a sampled-capacitor A/D converter is described in further detail in the following with reference to FIG. 5 and FIG. 6 .
FIG. 5 is a schematic illustrating a first phase of a sampling clock control signal in a prior art sampled-capacitor delta-sigma A/D converter comprising an input terminal U, a first sampling capacitor C s , a first switch S I , a second switch S E , a hold capacitor C h , an amplifier A, a feedback loop capacitor C s ′, a feedback loop terminal Q and an output terminal Y. The feedback loop terminal Q carries the feedback signal from the output of the D-flip-flop (not shown). The switches S I and S E are controlled by a sampling clock (not shown). In a first phase of the sampling clock control signal, shown in FIG. 5 , the sampling capacitor C s is charged by the input voltage presented on the input terminal U during a first, specific period of time, via the switch S I . The second switch S E is open in the first phase.
In a second phase of the sampling clock control signal, shown in the schematic in FIG. 6 , the switch S I disconnects the sampling capacitor C s from the input terminal U and connects it to the input of the amplifier A and the hold capacitor C h , whereby the sampling capacitor C s is discharged for a second, specific period of time via the switch S I , transferring its charge to the hold capacitor C h . The switch S E is closed in the second phase, and connects the feedback loop capacitor C s ′ to the input of the amplifier A. The voltage on the input terminal of the amplifier A is now equal to the voltage on the input terminal U during the first period of time minus the error voltage present on the feedback terminal Q. When the second phase ends, the switches S I and S E are returned to their initial positions shown in FIG. 5 , and the process is repeated periodically.
If the position of the switch S is controlled by a periodical signal having the frequency f s , the impedance Z s of the sample capacitor C s may be described as:
Z
h
=
1
(
C
s
·
f
s
)
Consider the sampling capacitor C s of the sampled-capacitor delta-sigma A/D converter in the first phase shown in FIG. 5 split into two capacitors, each having a capacitance of C s /2. A voltage transformation may then be implemented by changing the sampled-capacitor design to look like the schematic in FIG. 7 and FIG. 8 , respectively. The sampled-capacitor circuit design shown in FIG. 7 and FIG. 8 comprises two controlled switches S I and S E , an amplifier A, a hold capacitor C h , and four capacitors C a and C b , C c and C d , each of the four capacitors having a capacitance of C s /2. In FIG. 7 , the switch S I connects the two capacitors C a and C b to the input terminal IN in parallel in the first phase, in a manner similar to that shown in FIG. 5 , and in FIG. 8 , the switch S I connects the two capacitors C a and C b to the amplifier A in series in the second phase in a manner similar to that shown in FIG. 6 .
Likewise, the feedback capacitors C c and C d are charged in parallel to the voltage present on the feedback loop terminal Q with reference to ground via the switch S E in the first phase in FIG. 7 , and in the second phase, shown in FIG. 8 , the feedback capacitors C c and C d are connected in series between the feedback loop terminal Q and the amplifier A via the switch S E during discharge of the feedback capacitors C c and C d , whereby the voltage drop between the feedback loop terminal Q and the hold capacitor C h is doubled. The voltage present at the input of the amplifier A in the second phase is then V U -V Q , i.e. the doubled input voltage minus the doubled feedback voltage.
The effect of this arrangement is that the input node of the amplifier A is isolated from the input terminal U and the feedback loop terminal Q by the voltage transformers formed by the capacitors C a , C b , C c and C d , respectively. The net result of doubling the input voltage and the feedback loop voltage is that the intrinsic noise level V n of the amplifier A becomes comparatively smaller, and the signal-to-noise ratio thus is improved, while maintaining both the input impedance and the output impedance of the amplifier stage A as seen from outside the circuit shown in FIG. 7 and FIG. 8 , respectively.
With the capacitors C a , C b , C c and C d having values of C s /2, respectively, this configuration is equivalent to a voltage transformation with a transformation factor of 1:2 for the input transformer, respectively 2:1 for the feedback transformer, as the impedance Z s of the hold capacitor C s now becomes:
Z
s
=
4
(
C
s
·
f
s
)
This arrangement thus effectively quadruples the input impedance of the amplifier A. By changing the configuration of the circuit in synchronization with the two phases of the sampling clock frequency f s of the sampled-capacitor delta-sigma A/D converter, by means of the switches S I and S E as shown in FIGS. 7 and 8 , the input voltage U presented to the input terminal of the amplifier A is then doubled to 2U.
Consider the amplifier A having unity gain, and an error signal of 0 V being present on the feedback loop terminal Q. Then the output signal downstream of the second voltage transformer C c and C d is:
2
·
U
+
V
n
2
=
U
+
V
n
2
This is based on the imperative that the capacitors C c and C d are shifted between the parallel configuration in the first phase shown in FIG. 7 and the serial configuration in the second phase shown in FIG. 8 . By isolating the input of the amplifier A of the input stage of the A/D-converter from the rest of the circuitry with first and second voltage transformers in this way, an effective, comparative noise figure of V n /2 may be obtained in a simple and effective manner.
A schematic illustrating a first and a second phase of the function of the input voltage transformer circuit of FIGS. 7 and 8 is described in the following with reference to FIG. 9 and FIG. 10 . In FIG. 9 and FIG. 10 , a voltage transformer circuit comprises an input terminal U, an output terminal V A , five controlled switches S 1 , S 2 , S 3 , S 4 , and S 5 , and two sampling capacitors C a and C b , both having a capacitance of C s /2 with respect to the schematic of the circuit shown in FIGS. 5 and 6 . The output terminal V A of the voltage transformer circuit is to be connected to an amplifier (not shown) as illustrated in FIGS. 7 and 8 .
In the first phase of the voltage transformer, shown in FIG. 9 , the switches S 1 , S 3 , and S 5 are closed, and the switches S 2 and S 4 are open. The two capacitors are thus connected in parallel to the input terminal U in FIG. 9 . A voltage present on the input terminal U will thus charge the capacitors C a and C b to the same voltage.
In the second phase of the voltage transformer, shown in FIG. 10 , the switches S 1 , S 3 , and S 5 are now open, and the switches S 2 and S 4 are now closed. The two capacitors C a and C b are now connected in series, thus doubling their total charge voltage while reducing the total capacitance to CA, and connected to the output terminal V A . The combined charge collected by the capacitors C a and C b is now presented as a voltage to the output terminal V A . This voltage is double the voltage of U due to the altered configuration of the capacitors C a and C b .
Consider the output terminal V A of the input voltage transformer shown in FIG. 9 and FIG. 10 connected to the input stage of an amplifier A in the way shown in FIG. 7 and FIG. 8 . If the amplifier A has an amplification gain β, then the input voltage U is both doubled and multiplied by β, but the noise voltage V n is just multiplied by β. For a given input voltage U, the voltage output V Y from the amplifier A will be:
V Y =2 ·β·U+β·V n V Y =β(2 ·U+V n )
The noise voltage contribution V n to the output voltage V Y is then half the noise voltage contribution of the untransformed input voltage in this case, provided that the amplifier is capable of handling the transformed input voltage of 2U.
The voltage contribution from the feedback loop signal of the delta-sigma A/D converter is doubled in a similar way by the second voltage transformer C c and C d as indicated in FIG. 7 and FIG. 8 .
The principle of voltage transformation is extensible to an arbitrary number N of sampling capacitors each having the capacitance of C s /N, in effect reducing the apparent noise figure of the amplifier equally to V n /N. It is not essential for operation of the invention that the input transformer and the feedback transformer have the same transformation ratio. This principle permits implementation of the input amplifier in a much simpler way due to the reduced demands on its performance with regard to amplification gain, thermal noise, intermodulation noise, and errors due to finite gain of the amplifier.
The amplifier in the input stage of the A/D converter according to the invention may consequently be implemented as a simple, single-stage amplifier comprising one single semiconductor element, such as a BJT, FET, or other amplifying element having sufficient gain. Single-stage amplifiers inherently have a very attractive relationship between thermal voltage noise and current consumption. The voltage transformation further reduces the bias current demands of the amplifier and thus the current consumption of the complete A/D converter, of which the bias current for the input amplifier constitutes a substantial part.
FIG. 11 shows a delta-sigma A/D converter ADC according to the invention. The A/D converter ADC comprises an input terminal IN, an input transformer stage IT, an amplifier stage Q A , a hold capacitor C h , a constant current generator I c , a feedback transformer stage OT, a residual loop filter RLF, a comparator CMP, a flip-flop DFF, and an output terminal OUT. The flip-flop DFF is controlled by a system clock source (not shown). The amplifier stage Q A is fed a constant current from the constant current source I c powered by a connection to the reference voltage source V ref . This current controls the operating point of the amplifier Q A in order for it to be able to provide the desired gain to the input signal.
The input transformer stage IT comprises switching transistors Q 1 , Q 2 , Q 3 , Q 4 , and Q 5 , and capacitors C a and C b . The feedback transformer stage OT comprises switching transistors Q 6 , Q 7 , Q 8 , Q 9 and Q 10 , and capacitors C c and C d . For simplicity, these four capacitors are considered to be of equal capacitance, i.e. C a =C b =C c =C d .
The switching transistors Q 1 , Q 2 , Q 3 , Q 4 and Q 5 of the input transformer stage IT are controlled by a sampling clock generator (not shown) in such a manner that when the signal edge of the sampling clock generator goes positive in a first phase, the switching transistors Q 1 , Q 3 , and Q 5 close (i.e. they allow an electrical current to pass), and Q 2 and Q 4 open (i.e. they block an electrical current). This is illustrated in FIG. 11 by an open or a filled circle, respectively, on the base terminal of the respective switching transistors. In the first phase of the signal edge of the sampling clock generator, a filled circle denotes a closed transistor and an open circle denotes an open transistor.
When the signal edge of the sampling clock generator goes negative in a second phase, the switching transistors Q 1 , Q 3 , and Q 5 of the input transformer IT open, and the switching transistors Q 2 and Q 4 close. In the second phase of the signal edge of the sampling clock generator, an open circle denotes a closed transistor and a filled circle denotes an open transistor. This configuration is equivalent to the schematics shown in FIGS. 9 and 10 , respectively, where the transistors Q 1 , Q 2 , Q 3 , Q 4 , and Q 5 substitute the switches S 1 , S 2 , S 3 , S 4 , and S 5 , respectively, retaining the essential function of the circuit shown in FIGS. 9 and 10 . The clock frequency of the sampling clock generator (not shown) is of the magnitude of 30 kHz, and the clock frequency of the system clock generator (not shown) is of the magnitude 1-2 MHz. This gives an oversampling ratio of the converter of from 30 to 60 times oversampling.
In the first phase, where Q 1 , Q 3 and Q 5 are closed and Q 2 and Q 4 are open, the capacitors C a and C b are connected in parallel to the input terminal IN, and each capacitor is charged to the voltage present on the input terminal IN. In the second phase, where Q 1 , Q 3 and Q 5 are open and Q 2 and Q 4 are closed, the capacitors C a and C b are connected in series to the input of Q A , delivering their combined charge to the input of Q A and the hold capacitor C h . Due to this arrangement, the input voltage fed to the input transformer IT will be doubled at its output, as explained above.
The switching transistors Q 6 , Q 7 , Q 8 , Q 9 and Q 10 of the feedback transformer OT are also controlled by the sampling clock generator (not shown) in such a way that when the signal edge of the sampling clock generator goes positive in the first phase, the switching transistors Q 6 , Q 8 and Q 10 close and Q 7 and Q 9 open. This is also illustrated by an open or a filled circle, respectively, on the base terminal of the respective switching transistors, where a filled circle denotes a closed transistor and an open circle denotes an open transistor. This implies that the capacitors C c and C d are connected in parallel to the input of the amplifier Q A in the first phase, delivering their combined charge to the input of the amplifier Q A .
In the second phase, when the signal edge of the sampling clock generator goes negative, the switching transistors Q 6 , Q 8 and Q 10 open, and Q 7 and Q 9 close. In this case, an open circle on the base terminal of the respective transistor denotes a closed transistor and a filled circle denotes an open transistor. This implies that the capacitors C c and C d are connected in series to the output terminal OUT in the second phase and charged by the error voltage from the flip-flop DFF. The capacitors C c and C d are essentially placed in the feedback loop of the amplifier Q A , doubling the feedback voltage from the output of the flip-flop DFF before presenting the error voltage to the input of the amplifier Q A .
The residual loop filter RLF outputs the integral of the signal from Q A , and the comparator CMP outputs a logical zero value whenever the integral is below a predetermined threshold, and a logical one value whenever the integral is above a predetermined threshold. The flip-flop DFF converts the binary integral signal from the comparator CMP into a bit stream controlled by the clock signal CLK and fed to both the output terminal OUT and the input of the feedback transformer OT as a feedback signal.
By doubling the voltage present at the input of the amplifier Q A with the voltage transformers IT and OT respectively, the input voltage is increased by a factor two, and the relative noise voltage level V n is reduced as a consequence without the need for increasing the supply current to the amplifier Q A .
A preferred embodiment of the A/D converter according to the invention is shown in FIG. 12 . The general configuration of the input terminal IN, the input transformer IT, the feedback transformer OT, the constant current generator I c , the amplifier Q A , the hold capacitor C h , the residual loop filter RLF, the comparator CMP, the flip-flop DFF, and the output terminal OUT is similar to the configuration shown in FIG. 11 , but the topologies of the input transformer IT and the feedback transformer OT differs from the embodiment shown in FIG. 11 .
The input transformer IT comprises switching transistors, Q 1 , Q 2 , Q 3 , Q 4 , and Q 5 , and capacitors C a and C b , and the feedback transformer OT comprises switching transistors, Q 6 , Q 7 , Q 8 , Q 9 , Q 10 , and Q 11 , one capacitor C c , and two AND gates AG 1 and AG 2 . In this preferred embodiment, the feedback transformer OT has one capacitor less than the embodiment shown in FIG. 11 .
All the switching transistors of the input transformer IT and some of the switching transistors of the feedback transformer OT are controlled by a sampling clock generator (not shown) in such a way that when the sampling clock signal goes positive in a first phase, the transistors Q 1 , Q 2 , Q 5 , Q 7 , and Q 10 close, i.e. they allow an electric current to pass, and the transistors Q 3 and Q 4 open, i.e. they block an electric current. When the clock signal goes negative, in a second phase, the transistors Q 1 , Q 2 , Q 5 , Q 7 , and Q 10 open, and the transistors Q 3 and Q 4 close.
The switching transistors Q 6 , Q 8 , Q 9 and Q 11 are controlled by first and second AND gates AG 1 and AG 2 , respectively. The first AND gate AG 1 outputs a logical high level when the logical flip-flop output Q is logically high and the inverted system clock signal CLK is logically high. The second AND gate AG 2 outputs a logically high level when the flip-flop output Q is logically high and the system clock signal CLK is logically high. The logical flip-flop output signals Q and Q are mutually exclusive, and CLK and CLK are also mutually exclusive, so only one of the two AND gates AG 1 and AG 2 may output a logically high level at any one time. When a logical zero is present in the bit stream, AG 1 is logically high on every negative clock pulse, and when a logical one is present in the bit stream, AG 2 is logically high on every positive clock pulse.
When the first AND gate AG 1 outputs a logically high level, the switching transistors Q 6 and Q 8 close, while the switching transistors Q 9 and Q 11 open. This has the effect of the first node of the capacitor C c being connected to ground through Q 8 , and the second node of the capacitor C c being connected to the input of the amplifier Q A , and whatever voltage present on the first node of the capacitor C s is mirrored as a negative voltage at the input of the amplifier Q A . In the first phase of the sampling period, the switching transistors Q 7 and Q 10 are closed. They provide the voltage V ref to the first node of the capacitor C c , and connects the second node of C s to ground, while V ref gets added to the voltage already present on the first node of C c . In the second phase of the sampling period, the switching transistors Q 7 and Q 10 are open. The first node of the capacitor C c is now connected to the output of AG 1 , and the second node of C c is connected to the input of the amplifier Q A .
When the second AND gate AG 2 outputs a logically high level, the switching transistors Q 9 and Q 11 are closed, while the switching transistors Q 6 and Q 8 are open. Consequently, the first node of the capacitor C c is connected to the input of the amplifier Q A , and the second node of the capacitor C c is connected to V ref through Q 8 . In the first phase of the sampling period, the switching transistors Q 7 and Q 10 are closed. They provide the voltage V ref to the first node of the capacitor C c , and connect the second node of C c to ground while V ref gets added to the voltage already present on the first node of C c . In the second phase of the sampling period, the switching transistors Q 7 and Q 10 are open. The first node of the capacitor C c is now connected to the input of the amplifier Q A , and the second node of C c is connected to the output of AG 1 .
The result of this arrangement is that whenever a logical one is present in the bit stream to the output terminal OUT, the voltage contribution from OT is equal to 2V ref , and whenever a logical zero is present in the bit stream, the voltage contribution from OT is equal to −V ref . For a bit stream comprised of an equal number of ones and zeroes, the mean value of the error signal from OT is thus equal to ½V ref .
The delta-sigma A/D converter according to the invention accomplishes two goals at the same time. Firstly, the single-stage input amplifier design implies that the current consumption of the input amplifier may be reduced considerably, and secondly, the signal-to-noise ratio is improved by transforming up the signal level before it reaches the input stage. The application of sample-clock controlled voltage transformers for isolating the input stage from the input and the error feedback loop, respectively, provides the solution to the signal-to-noise ratio problem arising from using a single-stage input amplifier without a significant increase in power consumption. This design is preferred in a battery-powered circuit such as a hearing aid, and as a result, more than one delta-sigma A/D converter may be implemented on the circuit chip comprising the main part of the electronic circuit of a hearing aid.
FIG. 13 is a schematic of a hearing aid 20 comprising a plurality of A/D converters according to the invention. The hearing aid 20 comprises a first microphone 21 , a second microphone 22 , a telecoil 23 , an antenna 24 , a wireless receiver 25 , a first A/D converter 26 , a second A/D converter 27 , a third A/D converter 28 , a fourth A/D converter 29 , a digital signal processor 30 and a loudspeaker 31 . All the components of the hearing aid 20 are fed from a battery cell (not shown) disposed within the hearing aid.
When in use, the first microphone 21 and the second microphone 22 pick up acoustical signals from the surroundings and convert them into continuously varying electrical signals for use by the hearing aid 20 . The continuously varying electrical signal from the first microphone 21 is fed to the first A/D converter 26 , which converts the variations in the electrical signal into a first digital bit stream suitable for being processed by the digital signal processor 30 . In a similar way, the continuously varying electrical signal from the second microphone 22 is fed to the second A/D converter 27 , which converts the variations in the electrical signal into a third digital bit stream suitable for being processed by the digital signal processor 30 . As the first and the second A/D converters 26 and 27 are independent entities, they generate individual bit streams for independent processing by the digital signal processor 30 .
The digital signal processor 30 may combine the individual bit streams from the first and the second A/D converters 26 and 27 , representing the signals from the first and the second microphone 21 and 22 , respectively, in such a way that directional information inherent in the acoustical signals picked up by the microphones is retained for processing in the digital signal processor 30 and subsequent reproduction by the speaker 31 .
In situations where a suitable wireless signal is available, the wireless receiver 25 may be engaged for receiving and demodulating the wireless signal for reproduction by the hearing aid 20 . The wireless signal is received by the antenna 24 , demodulated by the wireless receiver 25 , and presented as a varying electrical signal to the third A/D converter 28 , which converts the variations in the electrical signal into a third digital bit stream suitable for being processed by the digital signal processor 30 . The third A/D converter 28 operates independently of the first A/D converter 26 and the second A/D converter 27 , and the signal from the wireless receiver 25 may thus be selected even if both the first and the second microphone 21 and 22 are engaged simultaneously.
If the hearing aid user is at a location where a telecoil loop system is present, it may be advantageous to use the signal from the telecoil 23 . In this case, signals from the loop system (not shown) is picked up by the telecoil 23 and presented to the input of the fourth A/D converter 29 , which converts the variations in the electrical signal into a fourth digital bit stream suitable for being processed by the digital signal processor 30 . The fourth A/D converter 29 operates independently of the first, the second and the third A/D converters 26 , 27 and 28 , respectively, and the signal may be selected even if both the first microphone 21 , the second microphone 22 , and the wireless receiver 25 are engaged at the same time.
The digital signal processor 30 comprises means (not shown) for selecting up to four individual bit streams from the four A/D converters 26 , 27 , 28 and 29 , respectively. The bit streams are preferably interleaved by the digital signal processor 30 and mutually weighted in order to generate a preferred balance between the signals from the four signal sources feeding the four A/D converters 26 , 27 , 28 and 29 for reproduction to a hearing aid user.
The digital signal processor 30 performs a series of calculations on the individual bit streams in order to process the digital representations of the audio signals according to an individual prescription for the hearing aid user. The balance between the signals from the four signal sources feeding the four A/D converters 26 , 27 , 28 and 29 may be determined when fitting the hearing aid to the user, and subsets of different signal source balances may be stored in the hearing aid as programs for later recall by the user. | In order to minimize noise and current consumption in a hearing aid, an input converter including a first voltage transformer and an analog-to-digital converter of the delta-sigma type for a hearing aid is devised. The analog-to-digital converter of the input converter has an input stage, an output stage, and a feedback loop, and the input stage includes an amplifier (Q A ) and an integrator (RLF). The first voltage transformer (IT) has a transformation ratio such that it provides an output voltage larger than the input voltage and is placed in the input converter upstream of the input stage. A second voltage transformer (OT) having a transformation ratio such that it provides an output voltage larger than the input voltage, is optionally placed in the feedback loop of the converter. The voltage transformers (IT, OT) are switched-capacitor voltage transformers, each transformer (IT, OT) having at least two capacitors (C a , C b , C c , C d ). The invention further provides a method of converting an analog signal. | 7 |
TECHNICAL FIELD
The present invention pertains generally to pond plants, and more particularly to a cage that protects a pond plant growing in a pot from fish or other animals.
BACKGROUND OF THE INVENTION
Pond plants growing in pots are well known in the art. One such plant is the water lily. The pot is placed on the bottom of the pond and the leaves or pads of the water lily float to the surface. The fish in the pond will not eat the stems or leaves but they will dig in the dirt in the pot until they expose the roots that are much tendered that the stems and leaves and will eat the roots. This feeding will eventually kill the plant.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to a cage for protecting a pond plant planted in a pot by preventing fish, turtles, or other animals from digging in the dirt in the pot and eating the roots of the plant. The cage is attached to the top of the pot. It has openings that allow the leaves and stems of the pond plant to pass to the surface. The cage comes in different sizes and shapes to accommodate various pot configurations.
In accordance with one embodiment, the cage includes first and second sections that are removably connectable to each other and to the rim of the pot. The first section has at least one opening that is of a sufficient size to pass the leaf and stem of the pond plant, and the second section also includes at least one opening that is of a sufficient size to pass the leaf and stem of the pond plant.
In accordance with another embodiment, the cage includes a first grid that is supported by a first plurality of legs, and a second grid that is supported by a second plurality of legs.
In accordance with another embodiment, the first and second grids are semi-circular.
In accordance with another embodiment, the first and second grids each have a truncated semi-circular shape, so that when the first and second sections are connected to each other and to the rim of the pot the first and second sections reside in spaced apart relationship.
In accordance with another embodiment, the first section includes a pair of spaced apart first tabs, each of the first tabs having a hole. The second section includes a pair of spaced apart second tabs, each of the second tabs having a hole. The first and second sections are connectable by bolting the pair of spaced apart first tabs to the pair of spaced apart second tabs.
In accordance with another embodiment, the first section includes a first rim-receiving groove, and the second section includes a second rim-receiving groove. The first and second rim-receiving grooves are shaped and dimensioned to receive the rim of the pot.
In accordance with another embodiment, the openings of the first and second sections are of sufficient size to pass a leaf that has been rolled up.
In accordance with another embodiment, the cage does not include two sections but rather comprises a unitary cage that is removably connectable to the rim of the pot. The unitary cage has a plurality of openings that are of sufficient size to pass the leaf and stem of the pond plant. The unitary cage includes a grid that is supported by a plurality of legs. The unitary cage is held on the rim of the pot by bolts passing underneath the rim.
In another embodiment, the cage cooperates with a male fish and a female fish to enhance fish roe fertilization and incubation. When a female koi is sufficiently pregnant, the male koi bumps against her knocking her roe into the water. If the male does not do this, the female can become sick and die. It is difficult for the male to knock the roe out of the female in clear water. He needs to knock the female against something. The pot and cage of the potted pond plant provide objects against which the male koi can knock the female koi. Once the roe is floating in the water, the male fertilizes it with his milt. The fertilized roe gradually settles to the bottom of the pond. But in the process, the koi usually eat all of the roe. The cage and top of the pot then provide an added benefit. If the discharged roe falls through the cage and into the pot, it is protected from being eaten. If some of the roe develops into baby fish, they are protected inside the cage and pot and are small enough to swim through the spaces in the cage out into the pond.
Other embodiments, in addition to the embodiments enumerated above, will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, that illustrate, by way of example, the principles of the cage and method of use.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a reduced top plan view of a prior art pond plant in a pot;
FIG. 2 is a reduced side elevation view of the pond plant in a pot;
FIG. 3 is a top plan view of a cage for protecting the roots of the pond plant in accordance with the present invention;
FIG. 4 is a side elevation view of the cage installed on the top of a pot having a pond plant;
FIG. 5 is a cross sectional view along the line 5 - 5 of FIG. 3 ;
FIG. 6 is a top plan view of first and second sections of the cage;
FIG. 7 is front elevation view of the first and second sections;
FIG. 8 is a side elevation view of the first and second sections;
FIG. 9 is a rear elevation view of the first and second sections;
FIG. 10 is a front perspective view of the first section;
FIG. 11 is a rear perspective view of the second section;
FIG. 12 is a front perspective view of a leaf and stem being passed through an opening in the first section;
FIG. 13 is a front perspective view of the leaf and stem after they are passed through the opening in the first section;
FIG. 14 is a top plan view of a second embodiment of the cage;
FIG. 15 is a top plan view of a third embodiment of the cage;
FIG. 16 is a front elevation view of the third embodiment;
FIG. 17 is an enlarged cross-sectional view along line 17 - 17 of FIG. 15 ; and,
FIG. 18 is a side elevation view of the cage being used by a male and female fish.
DETAILED DESCRIPTION OF THE INVENTION
Referring initially to FIGS. 1 and 2 , there are illustrated reduced prior art views of a top plan and side elevation of a prior art pond plant 500 . Pond plant 500 is planted in a pot 600 that resides on the bottom 702 of a pond 700 . Pond plant 500 has a plurality of stems 502 and each stem has a leaf 504 that floats on the surface of pond 700 . Pond plant 500 also has roots 506 that are planted in the dirt in pot 600 . Pot 600 has an open top and a top rim 602 . As previously described, because the top of pot 600 is open, fish 800 such as koi can dig in the dirt and eat the roots 506 of pond plant 500 thereby killing the plant.
FIGS. 3 and 4 are top plan and side elevation views, respectively, of a cage, generally designated as 20 , for protecting pond plant 500 . FIG. 5 is a cross-sectional view along the line 5 - 5 of FIG. 3 . Cage 20 is installed over the top of pot 600 to prevent fish 800 from gaining access to the roots of the plant. In the shown embodiment, cage 20 includes a first section 22 and a second section 24 . First and second sections 22 , 24 are removably connectable to each other and to the rim 602 of pot 600 (refer to FIG. 5 ). In the shown embodiment, first and second sections 22 , 24 are identical and are installed in the shown opposing relationship around the rim 602 of pot 600 .
First section 22 includes at least one opening 26 that is of sufficient size to pass the rolled up leaf 504 and stem 502 of pond plant 500 (refer to FIGS. 12 and 13 and the associated discussion). Similarly, second section 24 includes at least one opening 28 that is of sufficient size to pass the rolled up leaf 504 and stem 502 of pond plant 500 . When first and second sections 22 , 24 are connected to each other and to the rim 602 of pot 600 , they form cage 20 .
First section 22 includes a first grid 32 having a plurality of openings that is supported by a first plurality of legs 34 . First grid 32 is substantially flat. Second section 24 includes a second grid 36 that is supported by a second plurality of legs 38 . Second grid 36 is substantially flat. In the shown embodiment, first and second grids 32 , 36 are semi-circular. Openings 26 and 28 are squares having 2 inch sides that are small enough to prevent the passage of fish 800 yet large enough to allow passage of leaves 504 and stems 502 of pond plant 500 (also refer to FIGS. 12 and 13 and the associated discussions). It may be appreciated that while square grids are illustrated, other types of opening configurations could also be utilized.
FIG. 5 is a cross-sectional view along line 5 - 5 of FIG. 3 . Only first section 22 is shown. First section 22 includes a first rim-receiving groove 40 created by the space between cage seat 54 and flange 58 . Second section 24 has an identical groove. First rim-receiving groove 40 is shaped and dimensioned to captively receive the rim 602 of pot 600 so that cage 20 can be fixedly connected around rim 602 of pot 600 . First section 22 includes a pair of spaced apart first tabs 44 with each tab 44 having a hole 46 (see also FIGS. 10-11 ). First section 22 is connectable to second section 24 by bolting the pair of spaced apart first tabs 44 to the pair of spaced apart second tabs 50 with bolts 52 as is shown in FIGS. 3 and 4 . It is noted in FIG. 5 that holes 46 and bolts 52 are vertically aligned with flange 58 .
FIG. 6-9 are top plan, front elevation, side elevation, and rear elevation views, respectively, of first and second sections 22 , 24 . First section 22 is identical to second section 24 , and as such the figures and descriptions pertaining to first section 22 also apply to second section 24 . Shown are first and second openings 26 , 28 ; first and second grids 32 , 36 ; first and second legs 34 , 38 ; first and second rim-receiving grooves 40 , 42 ; first and second tabs 44 , 48 ; first and second holes 46 , 50 ; first and second cage seats 54 , 56 ; and first and second flanges 58 , 60 .
FIG. 10 is a front perspective view of first section 22 , and FIG. 11 is a rear perspective view of second section 24 . The two sections are shown in a relative position to be placed around rim 602 of pot 600 as shown in FIGS. 3 and 4 . Shown are first and second grids 32 , 36 , first and second legs 34 , 38 , first and second rim-receiving grooves 40 , 42 , first and second tabs 44 , 48 and first and second holes 46 , 50 .
In an embodiment, cage 20 is fabricated from a polymer. In another embodiment cage 20 is shaped and dimensioned to connect to the rim 602 of a five gallon pot 600 , and has a connected diameter of about twelve inches. It may be appreciated that cage 20 can be combined with plant 500 and pot 600 to form a system for protecting a pond plant.
FIG. 12 is a front perspective view of first section 22 showing rolled up leaf 504 and stem 502 being passed through opening 26 . FIG. 13 is a front perspective view after leaf 504 and stem 502 have been passed through opening 26 . Leaf 504 is rolled up to pass it through the opening because it is too large to otherwise pass through the opening. When pond plants are purchased by a consumer, they are typically full grown with large leaves. When the leaf 504 is released, it opens into its natural shape as indicated by the arrows. A leaf 504 and stem 502 can be similarly passed through opening 28 in second section 24 . In an embodiment, openings 26 and 28 are of sufficient size to pass a six inch diameter (d) leaf 504 that has been rolled up (also refer to FIG. 1 ). A square grid opening of about 2 inches on a side is a useful size for passing such a leaf 504 .
FIG. 14 is a top plan view of a second embodiment of the device, generally designated as 120 . Cage 120 includes first and second grids 132 , 136 that have truncated semicircular shapes. When first and second sections 122 , 124 are bolted together on the rim 602 of pot 600 , first and second sections 122 , 124 reside in spaced apart relationship. Because of the spacing, bolts 152 can exert continuous pressure on first and second sections 122 , 124 to hold them securely together on pot 600 around rim 602 . As defined herein, a truncated semicircular shape has a height H that is less than half of the diameter D of rim 602 of pot 600 .
FIGS. 15 and 16 are top plan and side elevation views, respectively, of a third embodiment of the cage, generally designated as 220 . Cage 220 is similar to cage 20 except that it is made as one piece. Cage 230 has a plurality of openings 226 that are of sufficient size to pass the leaf 504 and stem 502 of the pond plant 500 . Cage 230 includes a grid 232 that is supported by a plurality of legs 234 . FIG. 17 is an enlarged cross sectional view along line 17 - 17 of FIG. 15 . A pair of bolts 252 screw into cage 220 underneath rim 602 to lock cage 220 to rim 602 . It may be appreciated that other methods of connecting cage 220 to rim 602 of pot 600 could also be utilized.
FIG. 18 is a side elevation view of cage 20 being used by a male 800 A and female 800 B fish. The male fish 800 A bangs the female fish 800 B against the side of the pot 600 and cage 20 causing female fish 800 B to discharge roe 802 . Some of the roe 802 floats into cage 20 and into pot 600 as indicated by the broken away area 804 . Some of the milt from the male floats with the roe into the pot where it fertilizes the roe. The fertilized roe is thereby protected by the cage 20 from being eaten by the fish.
In terms of use, a method for protecting a pond plant 500 includes (refer to FIGS. 1-18 ):
(a) providing a pond 700 having a bottom 702 ;
(b) providing a pond plant 500 that is planted in a pot 600 , the pot 600 having a rim 602 , the pond plant 500 having a plurality of stems 502 , each stem 502 having a leaf 504 ,
(c) providing a cage 20 for protecting pond plant 500 including:
a first section 22 ; a second section 24 ; first 22 and second 24 sections removably connectable to each other and to rim 602 of pot 600 ; first section 22 including at least one opening 26 that is of sufficient size to pass leaf 504 and stem 502 of pond plant 500 ; and, second section 24 including at least one opening 28 that is of sufficient size to pass leaf 504 and stem 502 of pond plant 500 ;
(d) upwardly passing a leaf 504 and stem 502 through opening 26 in first section 22 ;
(e) upwardly passing another leaf 504 and stem 502 through opening 28 in second section 24 ;
(f) after (e), connecting first 22 and second 24 sections to each other so that the connected sections connect to rim 602 of pot 600 ; and,
(g) placing pot 600 on bottom 702 of pond 700 .
The method further including:
in (c), first section 22 including a pair of spaced apart first tabs 44 , each tab 44 having a hole 46 ;
in (c), second section 24 including a pair of spaced apart second tabs 48 , each tab 48 having a hole 50 ;
in (c), first and second sections 22 , 24 connectable by bolting the pair of spaced apart first tabs 44 to the pair of spaced apart second tabs 50 ;
providing two bolts 52 ; and,
in (f), using bolts 52 to connect first and second sections 22 , 24 together around rim 602 of pot 600 .
The method further including:
in (c), first section 22 including a first rim-receiving groove 40 ;
in (c), second section 24 including a second rim-receiving groove 42 ; and,
in (f), causing first and second rim-receiving grooves 40 , 42 to captively receive rim 602 of pot 600 .
The method further including:
prior to (d), rolling up leaf 504 ; and,
prior to (e), rolling up the other leaf 504 .
The method further including, cage 20 cooperating with a male fish 800 A and a female fish 800 B:
in (f), when first and second sections 22 , 24 are connected to each other and to rim 602 of pot 600 , first and second sections 22 , 24 forming a cage 30 ; and,
the male fish 800 A urging the female fish 800 B into contact with the pot 500 and cage 20 causing the female fish 800 B to discharges roe 802 .
The method further including:
some of the roe 802 falling through cage 20 and into pot 600 .
The embodiments of the cage and method of use described herein are exemplary and numerous modifications, combinations, variations, and rearrangements can be readily envisioned to achieve an equivalent result, all of that are intended to be embraced within the scope of the appended claims. Further, nothing in the above provided discussions of the cage and method should be construed as limiting the invention to a particular embodiment or combination of embodiments. The scope of the invention is defined by the appended claims. | A cage protects the roots of a pond plant planted in a pot from fish and other animals. If the roots are eaten, the plant will die. The pot has a rim and the pot resides on the bottom of a pond. The pond plant has a plurality of stems and each stem has a leaf. The cage covers the top of the pot so that the fish cannot gain access to the roots. In one embodiment the cage includes two sections that are connected together and to the rim of the pot. In another embodiment the cage is a single piece. In both embodiments the leaves of the pond plant are rolled up and passed upwardly through a grid of the cage. | 0 |
FIELD OF THE DISCLOSURE
[0001] The present disclosure generally relates to a rotor hub, and more particularly, to a tiltrotor aircraft rotor hub having yokes in two or more axially offset planes.
BACKGROUND
[0002] Rotor hubs are used to mount the rotor blades of tiltrotor aircraft in predetermined geometric configurations, and also serve to oppose centrifugal forces acting to pull the spinning blades away from a centerline of rotation. Generally, hubs having a radially compact arrangement about the centerline of rotation experience lower relative loads, as the moment arm between system forces and the center of rotation is reduced. Lower loads allow components and other structure to be leaner, resulting in reduced system weight. Additionally, compact hub designs may have lower drag coefficients due to having smaller profiles. However, the extent of compact radial packaging may be limited by physical interferences between components, especially in systems having multiple spinning elements. In such systems, hub components may be arranged at a radius from the centerline of rotation sufficient to provide circumferential space to physically accommodate each spinning element and its given range of motion in a given plane, thereby limiting the compactness of the design.
[0003] In addition, rotor blade diameter on tiltrotor aircraft often results from a design compromise between desired vehicle performance in “helicopter mode” (primarily vertical takeoff/landing, hover, and low speed flight) and “airplane mode” (primarily high speed forward flight). Generally speaking, larger diameter rotors offer favorable performance in helicopter mode, but may degrade performance in airplane mode, and vice versa. Improvements in rotor efficiency in helicopter mode may provide for a smaller diameter rotor to be used, thereby potentially improving performance in airplane mode, resulting in overall improved vehicle performance.
SUMMARY
[0004] Embodiments of the present disclosure generally provide rotor hubs for tiltrotor aircraft.
[0005] The present disclosure is directed to a rotor hub of a tiltrotor aircraft comprising a first configuration of two or more yokes arranged in a first plane about a mast of the tiltrotor aircraft and having substantially equal angular spacing therebetween, and a second configuration of an equal number of yokes as the first configuration, the equal number of yokes being arranged in a second plane about the mast of the tiltrotor aircraft and having substantially equal angular spacing therebetween, wherein the second plane is substantially parallel to and axially offset from the first plane, and wherein a portion of each yoke in the first configuration overlaps with a portion of each azimuthally adjacent yoke in the second configuration.
[0006] In various embodiments, the second configuration yokes are angularly offset from the first configuration yokes. In an embodiment, the second configuration yokes substantially bisect the angular spaces separating the first configuration yokes.
[0007] In an embodiment, at least some of the yokes of the first configuration and second configuration may undergo flapping motion. In another embodiment, the second plane is axially offset from the first plane by a predetermined distance sufficient to accommodate flapping without interference. In yet another embodiment, the second plane is axially offset from the first plane by a predetermined distance substantially equal to about one or two rotor chord lengths.
[0008] In an embodiment, the hub further comprises a common mounting component coupling each first configuration yoke to at least one azimuthally adjacent second configuration yoke. In an embodiment, at least some of the yokes of the first configuration and the second configuration are substantially stiff in-plane. In yet another embodiment, the first configuration yokes and the second configuration yokes are arranged at a common radius from the mast.
[0009] In an embodiment, the first configuration has two yokes and the second configuration has two yokes. In another embodiment, the first configuration has three yokes and the second configuration has three yokes. In yet another embodiment, the first configuration has four yokes and the second configuration has four yokes.
[0010] In another aspect, the present disclosure is directed to a rotor hub of a tiltrotor aircraft comprising a plurality of blade yokes arranged in a first plane about a central axis, and a plurality of blade yokes arranged in a second plane about the central axis, wherein the second plane is substantially parallel to and axially offset from the first plane, a portion of each yoke in the first plane overlaps with a portion of each azimuthally adjacent yoke in the second plane, and the rotor hub is selectively positionable for operation of the tiltrotor aircraft in helicopter mode, airplane mode, and transition modes there between. In various embodiments, the plurality of blade yokes in each of the first plane and second plane are positioned with substantially equal angular spacing therebetween. In various embodiments, the plurality of blade yokes in the first plane are angularly offset from the plurality of blade yokes in the second plane. In an embodiment, the plurality of blade yokes in the second plane substantially bisect the angular spaces separating the plurality of blade yokes in the first plane.
[0011] In an embodiment, the hub further comprises a common mounting component coupling each yoke in the first plane to the overlapping azimuthally adjacent yoke in the second plane.
[0012] In another aspect, the present disclosure is direct to a rotor hub of a tiltrotor aircraft comprising a plurality of blade yokes configured in a stacked arrangement such that a portion of each yoke in a first axial plane overlaps with a portion of each azimuthally adjacent yoke in a second axial plane, and a plurality of mounting components, each mounting component coupling each yoke in the first axial plane to the overlapping azimuthally adjacent yoke in the second axial plane, wherein the rotor hub is coupled to a mast of the tiltrotor aircraft. In various embodiments, the plurality of blade yokes in each of the first plane and the second plane are positioned with substantially equal angular spacing therebetween. In an embodiment, the plurality of blade yokes in the second plane substantially bisect the angular spaces separating the plurality of blade yokes in the first plane.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For a more complete understanding of this disclosure, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
[0014] FIG. 1 depicts a perspective view of an offset stacked yoke hub coupled to a mast according to an embodiment of the present disclosure;
[0015] FIG. 2 depicts a perspective view of the offset stacked yoke hub of FIG. 1 , schematically representing four yokes undergoing flapping motion according to an embodiment of the present disclosure;
[0016] FIG. 3A depicts a top view of a yoke of an offset stacked yoke hub according to an embodiment of the present disclosure;
[0017] FIG. 3B depicts a side cutaway view of a yoke according to an embodiment of the present disclosure;
[0018] FIG. 3C depicts another side cutaway view of the yoke of FIG. 3B with a blade cuff coupled thereto according to the embodiment of the present disclosure;
[0019] FIG. 4A depicts a top view of an arrangement of yokes in an offset stacked yoke hub according to an embodiment of the present disclosure;
[0020] FIG. 4B depicts a side cutaway view of the arrangement of yokes in an offset stacked yoke hub of FIG. 4A according to an embodiment of the present disclosure;
[0021] FIG. 4C depicts a side cutaway view of the arrangement of yokes in an offset stacked yoke hub of FIG. 4A , shifted 90° about a vertical axis with respect to the side cutaway view of FIG. 4B , according to an embodiment of the present disclosure;
[0022] FIG. 5A depicts a top view of mounting hardware used to secure yokes to a mast according to an embodiment of the present disclosure;
[0023] FIG. 5B depicts a side cutaway view of the mounting hardware used to secure yokes to a mast of FIG. 5A according to an embodiment of the present disclosure;
[0024] FIG. 6A depicts an assembled perspective view of an offset stacked yoke hub having four yokes according to an embodiment of the present disclosure;
[0025] FIG. 6B depicts an exploded perspective view of the offset stacked yoke hub having four yokes of FIG. 6A according to an embodiment of the present disclosure;
[0026] FIG. 7A depicts an assembled perspective view of an offset stacked yoke hub having six yokes according to an embodiment of the present disclosure;
[0027] FIG. 7B depicts an exploded perspective view of the offset stacked yoke hub having six yokes of FIG. 7A according to an embodiment of the present disclosure;
[0028] FIG. 8A depicts an assembled perspective view of an offset stacked yoke hub having eight yokes according to an embodiment of the present disclosure; and
[0029] FIG. 8B depicts an exploded perspective view of the offset stacked yoke hub having eight yokes of FIG. 8A according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0030] Embodiments of the present disclosure generally provide an offset stacked yoke rotor hub for use on a tiltrotor aircraft. As described herein, the rotor hub may package tightly to a rotorcraft mast, thereby reducing weight, drag profile, and loads on the hub and accompanying structure. The rotor hub may also provide for improved aerodynamic rotor performance in axial flow compared to single-plane rotor hubs, resulting in possible production of a comparable thrust/power ratio using a smaller diameter rotor disk. In various embodiments, blade yokes may be arranged in two or more axially offset planes, may partially overlap, and may share common axial retainer bolts.
[0031] FIGS. 1-8B illustrate representative embodiments of offset stacked yoke hubs 100 , 500 , 600 and parts thereof. It should be understood that the components of offset stacked yoke hubs 100 , 500 , 600 and parts thereof shown in FIGS. 1-8B are for illustrative purposes only, and that any other suitable components or subcomponents may be used in conjunction with or in lieu of the components comprising offset stacked yoke hubs 100 , 500 , 600 and the parts of offset stacked yoke hubs 100 , 500 , 600 described herein.
[0032] Offset stacked yoke hubs 100 , 500 , 600 according to the present disclosure may be used to secure rotor blades on tiltrotor aircraft. Hubs 100 , 500 , 600 may support blades or other items attached thereto in a predetermined geometric arrangement and may oppose centrifugal forces acting on those items during rotation of the system. Hubs 100 , 500 , 600 may be configured to provide for yoke flapping and pitching motion. The present disclosure is directed to various embodiments of offset stacked yoke hubs 100 , 500 , 600 that closely package multiple yokes 200 about a central axis 130 , and may thereby reduce weight, drag profile, and loads on the hubs 100 , 500 , 600 and accompanying structure.
[0033] Referring now to FIG. 1 , an offset stacked yoke hub 100 is depicted coupled to a tiltrotor mast 132 . The offset stacked yoke hub 100 may generally comprise a plurality of blade yokes 200 , such as an even number of blade yokes 200 , arranged about a central axis 130 in a predetermined geometric configuration. As described in more detail herein, yokes 200 may be axially offset from one another along the central axis 130 , and yokes 200 may substantially overlap one another (thereby being “stacked”) so as to package tightly with respect to central axis 130 . Offset stacked yoke hub 100 may be coupled to a tiltrotor mast 132 as further described herein and may rotate about central axis 130 . Rotation of hub 100 may be driven by the tiltrotor mast 132 or by other external forces acting on hub 100 or the blades attached thereto.
[0034] In various embodiments, construction of hub 100 may provide for motion of blade yokes 200 , as the flapping motion schematically depicted FIG. 2 .
Yokes
[0035] As depicted in FIG. 1 , offset stacked yoke hub 100 may comprise four or more substantially identical yokes 200 . FIGS. 3A and 3B depict a top view and a side cutaway view, respectively, of a representative yoke 200 having a longitudinal axis 205 and a lateral axis 207 , and FIG. 3C depicts a side cutaway view of the yoke 200 with a blade cuff 246 coupled thereto. The yoke 200 comprises a yoke body 210 extending longitudinally from an inner end 231 to an outer end 235 and having a substantially elongated planform (for example, rectangular, ovular, triangular, or a variant thereof). The yoke body 210 may be constructed of any suitable material able to withstand the forces and moments of the dynamic system including, but not limited to, laminated fiberglass composites, carbon composites, or any combination thereof. Yokes 200 of hubs 100 , 500 , and 600 may be limited to stiff in-plane constructions in order to handle loads associated with strong axial flow in tiltrotor airplane mode. One or more retainer holes 230 may be laterally disposed through the inner end 231 .
[0036] Each yoke 200 may further comprise an inboard beam assembly 240 . In an embodiment, the inboard beam assembly 240 comprises a substantially “C” shaped member constructed of forged metallic material. The inboard beam assembly 240 may be disposed within a cutout 242 in the yoke 200 and may be oriented such that the open part of the “C” faces radially outward with respect to central axis 130 . Inboard beam assembly 240 may be rotationally coupled to yoke 200 about longitudinal axis 205 , providing for possible pitching motion of components coupled thereto. In an embodiment, a blade (or intermediate structure, such as a composite blade grip 246 ) may be coupled to inboard beam assembly 240 via inboard beam attachment holes 244 using any suitable mechanism, such as one or more bolts.
[0037] Each yoke 200 may further comprise coupling means by which a blade (or intermediate structure) may couple thereto and be restrained against centrifugal forces acting to pull the blade away from a centerline of rotation during rotation. In one embodiment, a blade (or intermediate structure, such as a spindle assembly, not shown) may be coupled to yoke 200 via yoke attachment holes 232 using any suitable mechanism, such as one or more bolts.
Arrangement of Yokes in Yoke Planes
[0038] FIG. 4A depicts a top view, and FIGS. 4B and 4C depict side cutaway views offset from one another by 90°, of an arrangement of four yokes 200 of offset stacked yoke hub 100 . The yokes 200 may be arranged in two or more planes 215 , each containing the same number of yokes 200 . In one embodiment, yokes 200 and planes 215 may comprise two groups—those yokes 212 situated in a first plane 210 , and those yokes 222 situated in a second plane 220 . As best shown in FIG. 4A , yokes 212 are arranged about a central axis 130 (possibly defined by a mast 132 ) at a radius 312 , and are equally spaced at planar spacing angles 310 within plane 210 . An equal number of yokes 222 are similarly arranged about the same mast 132 at the same radius 312 , and are equally spaced at planar spacing angles 310 in plane 220 . Such an arrangement provides for balanced mass distribution within the plane 215 to manage dynamic loads and stability in rotating systems, such as rotors.
[0039] Mechanical packaging and load considerations may influence radii 312 . Generally speaking, flapping forces are concentrated at a flapping hinge 314 , and the radius 312 (also known as hinge offset) between the central axis 130 and the flapping hinge 314 defines a moment arm. Therefore, the closer a flapping hinge 314 is situated to a mast 132 , the lower the flapping moment imparted to the mast 132 . This may result in reduced weight by allowing the mast 132 and other components to be leaner, and may result in reduced drag by narrowing the profile of the hub 100 . In embodiments using substantially rigid, stiff in-plane yokes 200 , a flapping hinge 314 may comprise an actual hinge within the yoke body 210 of yoke 200 , or the flapping hinge 314 may instead coincide with the mechanical juncture of the yoke 200 to offset stacked yoke hub 100 . Radius 312 may, however, be conversely influenced by mechanical packaging considerations, such as establishing a minimum radius 312 to physically assemble hub 100 about a mast 132 without interferences. One having ordinary skill in the art will recognize a desirable radius 312 for a given application.
Axial Arrangement of Yoke Planes
[0040] Still referring to FIGS. 4A , 4 B, and 4 C, each yoke plane 215 may be substantially parallel, and may share a common central axis 130 . Each plane 215 may be axially offset from the others at a predetermined axial offset distance 320 , as best shown in FIGS. 4B and 4C . Predetermined axial offset distance 320 may be influenced by design considerations including, but not limited to, flapping angle, weight, and performance characteristics. Predetermined axial offset distance 320 may be of sufficient length to avoid physical interference of yokes 200 in the various planes 210 , 220 and the blades attached thereto when undergoing flapping motion. While larger offset distances 320 may generally provide ample flapping clearance, they may extend the height of hub 100 , which may result in increased weight due to the additional material. Additionally, radial forces acting on a taller hub 100 may result in greater moments thereby driving increased structural weight to handle the loads. Similarly, a taller hub 100 may result in increased drag. However, other aerodynamic performance benefits may drive predetermined offset distance 320 to be greater than that necessary to provide flapping clearance. Offset rotor disks often demonstrate improved aerodynamic efficiency in axial flow conditions. At certain offset distances, the rotor may perform as though it has a larger effective diameter, resulting in increased thrust/power ratio than a similar single-plane rotor. As such, the proper axial offset distance 320 may provide for desired aerodynamic performance to be achieved using a smaller rotor diameter. Accordingly, the rotors may be disposed further inward toward the tiltrotor fuselage, possibly resulting in reduced aircraft weight. In one embodiment, aerodynamic performance improvements are maximized using a predetermined axial offset distance 320 corresponding with one to two rotor blade chord lengths. One having ordinary skill in the art will recognize a desirable predetermined axial offset distance 320 that may balance the considerations described herein for a given application.
[0041] In an embodiment, yokes 212 of plane 210 and yokes 222 of plane 220 are situated about a common central axis 130 (possibly defined by a mast 132 ), and plane 210 is parallel to and axially offset a predetermined distance 320 from plane 220 . In another embodiment, a 3-inch thick yoke 212 in plane 210 may flap at ±12 degrees of flapping angle 316 in each direction. A minimum predetermined axial offset distance 320 between plane 210 and 220 may be set at 6.25 inches to provide clearance between a yoke 212 and an azimuthally adjacent yoke 222 in plane 220 having similar dimensions and flapping characteristics. However, the predetermined axial offset distance 320 of this embodiment may be larger to take advantage of the aerodynamic performance benefits described in the previous paragraph.
Angular Arrangement of Yoke Planes
[0042] Still referring to FIGS. 4A , 4 B, and 4 C, yokes 200 in a given plane 215 may be angularly offset an angular offset angle 330 from yokes 200 in other plane(s) 215 . This may provide for blade flapping clearance, and improved airflow through blades 246 that may be attached to yokes 200 in planes 215 .
[0043] In one embodiment, as best shown in FIG. 4A , yokes 212 of plane 210 may be angularly offset by an angular offset angle 330 from yokes 222 of plane 220 . In another embodiment, yokes 212 of plane 210 substantially bisect the equal angular spacing angles 310 separating yokes 222 in plane 220 , and vice versa.
[0044] One having ordinary skill in the art will recognize that the number of blade yokes 200 , as well as the axial offset distance 320 and the angular offset distance 330 between them, may be determined by a variety of design factors including, but not limited to, performance characteristics; blade flapping and pitching angles; and weight, drag, and load characteristics.
Mechanical Embodiment
[0045] Referring now to FIGS. 5A and 5B , offset stacked yoke hub 100 may include mounting hardware 400 , which may comprise mounting plates 410 and axial mounting bolts 420 . Hub 100 may comprise any number of mounting plates 410 , and mounting plates 410 may be of any suitable material, shape, size, and construction to couple yokes 200 to a mast 132 or similar structure. Mounting plate 410 may comprise a mast cutout 412 forming an aperture of sufficient diameter to allow a mast 132 to pass there through. Each mounting plate 410 may further comprise mounting holes 414 that are sized and arranged to be substantially concentric with the retainer holes 230 disposed through the inner ends 231 of yokes 200 when arranged in a desired configuration about the central axis 130 . In such a configuration, mounting bolts 420 may pass through each set of axially-aligned mounting holes 414 and retainer holes 230 to secure yokes 200 to mounting plates 410 .
[0046] In an embodiment, as best shown in FIG. 5B , hub 100 comprises three mounting plates 411 , 413 , 415 . First mounting plate 411 and second mounting plate 413 may be positioned about the mast 132 on the axially outer sides of planes 210 and 220 , respectively. A third mounting plate 415 may be positioned about the mast 132 axially between yokes 212 and yokes 222 . In this particular embodiment, each of yokes 212 and 222 comprises two retainer holes 230 , and the retainer holes 230 of each yoke 212 in plane 210 substantially axially align with the retainer holes 230 of each azimuthally adjacent yoke 222 in plane 220 . Mounting plates 410 are oriented such that mounting holes 414 substantially align with the aforementioned axially aligned retainer holes 230 of yokes 212 and 222 . A mounting bolt 420 is disposed through each set of axially aligned mounting holes 414 and retainer holes 230 to secure yokes 212 and 222 to the mounting plates 410 , and thereby to mast 132 .
[0047] Referring now to FIGS. 6A and 6B , an offset stacked yoke hub 100 having four yokes 200 is depicted in assembled and exploded views, respectively. Two mounting bolts 420 secure each yoke 200 , and each mounting bolt 420 is shared by two azimuthally adjacent yokes 200 . As such, the number of mounting holes 414 in a mounting plate 410 is equal to the number of yokes 200 in hub 100 . In this embodiment, the four total yokes 200 may be arranged in two axially offset planes 215 , namely two yokes 212 in an upper plane 210 , and two yokes 222 in a lower plane 220 . Each pair of yokes 212 and 222 has equal angular spacing 310 within their respective planes 210 and 220 —that is, yokes 200 in each given plane 215 are spaced 180° apart. The planes 210 and 220 are substantially parallel, share a common central axis 130 , and are angularly offset such that yokes 212 in plane 210 bisect the planar spacing angle 310 between yokes 222 in plane 220 —that is, each yoke 212 is positioned about 90° from each azimuthally adjacent yoke 222 . Yokes 212 and 222 are also “stacked” at an axial offset distance 320 .
[0048] Each yoke 212 and 222 comprises two retainer holes 230 in its base, and yokes 212 and 222 are set at a radius 312 from the central axis 130 such that a retainer hole 230 on any given yoke 212 aligns axially with a retainer hole 230 on an azimuthally adjacent yoke 222 . Mounting holes 414 are arranged to coincide with the axially-aligned retainer holes 230 of the stacked azimuthally adjacent yokes 212 and 222 , and mounting bolts 420 may be disposed therein. By stacking yokes 212 and 222 such that their inner ends 231 partially overlap, offset stacked yoke hub 100 may be packaged tighter to a central axis 130 than if all yokes 212 and 222 were arranged in a single plane 215 , thereby reducing hub loads, weight, and drag. Axial offset distance 320 between yokes 212 and 222 may accommodate flapping motion of the yoke 200 .
[0049] Referring now to FIGS. 7A and 7B , an offset stacked yoke hub 500 having six yokes 200 is depicted in assembled and exploded views, respectively. This embodiment comprises mounting plates 410 having six mounting holes 414 arranged in a hexagonal pattern to coincide with axially-aligned retainer holes 230 of yokes 212 and 222 stacked in a manner similar to that described with respect to offset stacked yoke hub 100 having four yokes 200 . The six total yokes 200 may be arranged in two axially offset planes 215 , namely three yokes 212 in an upper plane 210 , and three yokes 222 in a lower plane 220 . Each set of yokes 212 and 222 has equal angular spacing 310 within their respective planes 210 and 220 —that is, yokes 200 in a given plane 215 are spaced 120° apart. The planes 210 and 220 are substantially parallel, share a common central axis 130 , and are angularly offset such that yokes 212 in plane 210 bisect the planar spacing angle 310 between yokes 222 in plane 220 —that is, each yoke 212 is positioned about 60° from each azimuthally adjacent yoke 222 . Yokes 212 and 222 are also “stacked” at an axial offset distance 320 .
[0050] Each yoke 212 and 222 comprises two retainer holes 230 in its base, and yokes 212 and 222 are set at a radius 312 from the central axis 130 such that a retainer hole 230 on any given yoke 212 aligns axially with a retainer hole 230 on an azimuthally adjacent yoke 222 . Mounting holes 414 are arranged to coincide with the axially-aligned retainer holes 230 of the stacked azimuthally adjacent yokes 212 and 222 , and mounting bolts 420 may be disposed therein. Flapping motion may be similarly accommodated by this embodiment.
[0051] Referring now to FIGS. 8A and 8B , an offset stacked yoke hub 600 having eight yokes 200 is depicted in assembled and exploded views, respectively. This embodiment comprises mounting plates 410 having eight mounting holes 414 arranged in an octagonal pattern to coincide with axially-aligned retainer holes 230 of yokes 212 and 222 stacked in a manner similar to that described with respect to offset stacked yoke hub 100 having four yokes 200 and offset stacked yoke hub 500 having six yokes 200 . The eight total yokes 200 may be arranged in two axially offset planes 215 , namely four yokes 212 in an upper plane 210 , and four yokes 222 in a lower plane 220 . Each set of yokes 212 and 222 has equal angular spacing 310 within their respective planes 210 and 220 —that is, yokes 200 in a given plane 215 are spaced 90° apart. The planes 210 and 220 are substantially parallel, share a common central axis 130 , and are angularly offset such that yokes 212 in plane 210 bisect the planar spacing angle 310 between yokes 222 in plane 220 —that is, each yoke 212 is positioned about 45° from each azimuthally adjacent yoke 222 . Yokes 212 and 222 are also “stacked” at an axial offset distance 320 .
[0052] Each yoke 212 and 222 comprises two retainer holes 230 in its base, and yokes 212 and 222 are set at radius 312 from the central axis 130 such that a retainer hole 230 on any given yoke 212 aligns axially with a retainer hole 230 on an azimuthally adjacent yoke 222 . Mounting holes 414 are arranged to coincide with the axially-aligned retainer holes 230 of the stacked azimuthally adjacent yokes 212 and 222 , and mounting bolts 420 may be disposed therein. Flapping motion may be similarly accommodated by this embodiment.
[0053] It may be advantageous to set forth definitions of certain words and phrases used in this patent document. The term “couple” and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like.
[0054] Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. | A tiltrotor rotor hub comprises first and second configurations of yokes arranged in two parallel and axially offset planes, each having an equal number of two or more yokes substantially equally spaced about a mast, wherein a portion of each yoke overlaps with a portion of each azimuthally adjacent yoke. Another tiltrotor rotor hub is selectively positionable for operation in helicopter/airplane/transition modes and comprises substantially parallel and axially offset first and second planes, each containing a plurality of blade yokes arranged about a central axis and a portion of each yoke overlaps with a portion of each azimuthally adjacent yoke. Another tiltrotor rotor hub is coupled to a tiltrotor mast and comprises a stacked arrangement of blade yokes wherein a portion of each yoke overlaps with a portion of each azimuthally adjacent yoke, and a plurality of mounting components coupling each yoke to the overlapping azimuthally adjacent yoke. | 1 |
FIELD OF THE INVENTION
The present invention relates generally to the field of optical scanners and more particularly to a system and method for obtaining multiple views from one scan window. In particular, this invention provides for mote than one view of sets of scan data to be obtained from a single scan window.
BACKGROUND OF THE INVENTION
Optical scanners are used to capture and digitize images. For example, an optical scanner can be used to capture the image of printed matter on a sheet of paper. The digitized image can then be electronically stored and/or processed with character recognition software to produce ASCII text. Most optical scanners use illumination and optical systems to illuminate the object and focus a small area of the illuminated object, usually referred to as a "scan line," onto the optical photosensor array. The entire object is then scanned by sweeping the illuminated scan line across the entire object, either by moving the object with respect to the illumination and optical assemblies or by moving the illumination and optical assemblies relative to the object.
A typical scanner optical system will include a lens assembly to focus the image of the illuminated scan line onto the surface of the optical photosensor array. Depending on the particular design, the scanner optical system may also include a plurality of mirrors to "fold" the path of the light beam, thus allowing the optical system to be conveniently mounted within a relatively small enclosure.
While various types of photosensor devices may be used in optical scanners, a commonly used sensor is the charge coupled device or CCD. As is well-known, a CCD may comprise a large number of individual cells or "pixels," each of which collects or builds-up an electrical charge in response to exposure to light. Since the size of the accumulated electrical charge in any given cell or pixel is related to the intensity and duration of the light exposure, a CCD may be used to detect light and dark spots on an image focused thereon. In a typical scanner application, the charge built up in each of the CCD cells or pixels is measured and then discharged at regular intervals known as exposure times or sampling intervals, which may be about 5 milliseconds or so for a typical scanner. Since the charges (i.e., image data) are simultaneously collected in the CCD cells during the exposure time, the CCD also includes an analog shift register to convert the simultaneous or parallel data from the CCD cells into a sequential or serial data stream.
A typical analog shift register comprises a plurality of "charge transfer buckets" each of which is connected to an individual cell. At the end of the exposure time, the charges collected by each of the CCD cells are simultaneously transferred to the charge transfer buckets, thus preparing the CCD cells for the next exposure sequence. The charge in each bucket is then transferred from bucket to bucket out of the shift register in a sequential or "bucket brigade" fashion during the time the CCD cells are being exposed to the next scan line. The sequentially arranged charges from the CCD cells may then be converted, one-by-one, into a digital signal by a suitable analog-to-digital converter.
In most optical scanner applications, each of the individual pixels in the CCD are arranged end-to-end, thus forming a linear array. Each pixel in the CCD array thus corresponds to a related pixel portion of the illuminated scan line. The individual pixels in the linear photosensor array are generally aligned in the "cross" direction, i.e., perpendicular to the direction of movement of the illuminated scan line across the object (also known as the "scan direction"). Each pixel of the linear photosensor array thus has a length measured in the cross direction and a width measured in the scan direction. In most CCD arrays the length and width of the pixels are equal, typically being about 8 microns or so in each dimension.
The sampling rate in the cross direction is a function of the number of individual cells in the CCD. For example, a commonly used CCD photosensor array contains a sufficient number of individual cells or pixels to allow a sampling rate in the cross direction of about 600 pixels, or dots, per inch (600 ppi), which is referred to herein as the native sampling rate in the cross direction.
The sampling rate in the scan direction is inversely related to the product of the scan line sweep rate and the CCD exposure time (i.e., the sampling interval). Therefore, the sampling rate in the scan direction may be increased by decreasing the scan line sweep rate, the CCD exposure time, or both. Conversely, the sampling rate in the scan direction may be decreased by increasing the scan line sweep rate, the CCD exposure time, or both. The "minimum sampling rate in the scan direction" for a given exposure time is that sampling rate achieved when scanning at the maximum scan line sweep rate at that exposure time. For example, a maximum scan line sweep rate of about 3.33 inches per second and a maximum exposure time of about 5 milliseconds will result in a minimum sampling rate in the scan direction of about 60 ppi.
Currently, optical character recognition (OCR) requires 300 ppi sampling rates for accurate results. Thus, a 300 ppi 4 bit gray scan (8.5×11), which is high resolution, low bit depth, is approximately 4.2 Megabytes. Color fidelity requires a 24 bit color scan. Thus, a 150 ppi 24 bit color scan (8.5×11), which is low resolution, high bit depth, is approximately 6.3 Megabytes. In order to provide a scan of a document that has both color pictures or drawings and writing requiring OCR, the scan would have to be approximately 300 ppi at 24 bits (8.5×11) which corresponds to 25.24 Megabytes of memory. Accordingly, to scan a document that includes both text and pictures would require quite a bit of memory. Yet, the software on the computer will down sample the color image to approximately 6.3 Megabytes and throw away the color image to obtain the text. This process is extremely slow to perform in software and unnecessarily consumes a great deal of memory. Another alternative is to first scan either the text or the graphics and then perform a scan of the other. Then the document could be regenerated by software. However, this is also a very time consuming method of scanning the document, besides using a lot of memory as well.
Accordingly, it would be desirable to provide a scanner that is able to scan a document containing both text and graphics, and greatly reduce the total amount of data being sent from the scanner to the host computer (which is currently a speed constraint), and reduce the total amount of data being stored and processed by the host computer software.
SUMMARY OF THE INVENTION
The above and other aspects of the present invention are accomplished in a multiple image scanner that performs a single scan of a document containing multiple types of images (e.g., text and graphics) and send multiple renditions of the same document from the scanner to the host computer (e.g., one high resolution gray scale image, and one low resolution high bit depth color image), thus greatly reducing the total amount of data sent to and processed by the host computer, for example, from approximately 25.24 Megabytes to approximately 10.5 Megabytes (a 300 ppi 4 bit gray image 8.5×11! that is 4.2 Megabytes and a 150 ppi 24 bit color 8.5×11! that is 6.3 Megabytes), which is a 2.4 to 1 reduction.
The scanner of the present invention may send the muliple images to the host computer interleaved on a line basis, for example, with two lines of high resolution gray data and then one line of low resolution color data, if the resolution ratio between the images was two. The advantage of the present invention is less information for the host software to process and store, and less information to be sent from the scanner to the host, which is a current limitation on scanner speed.
The present invention may further comprise host computer software that is capable of parsing the data stream of interleaved images into the individual images that are then ready for manipulation and further processing by the host computer.
The present invention may comprise a computer operable method for implementing multiple views from a single scan window following a scanning process of an image scanner, said method comprising the following steps: designating the number of views to be obtained from said single scan window; designating the data type and other parameters for each of the number of designated views to be obtained from said single scan window; designating the number of views to be sent from the image scanner to a host computer; once a window has been scanned one or more times, generating a data signal representative of each of the number of views designated to be obtained from said single scan window; and sending each of the data signals representative of the number of views designated to be send from the image scanner to the host computer for further processing, wherein said computer operable method is implemented in scanner command language.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will be better understood by reading the following more particular description of the invention, presented in conjunction with the following drawings, wherein:
FIG. 1 shows a block diagram of the data path for a multiple image scanner according to the present invention;
FIG. 2 shows a more detailed block diagram of the data path of the image pre-processor for a multiple image scanner according to the present invention;
FIG. 3 shows a more detailed block diagram of the data path of the image post-processor for a multiple image scanner according to the present invention;
FIG. 4 shows a more detailed block diagram of the data path from the multiple image scanner to the host computer according to the present invention; and
FIG. 5 shows a flow chart of a method of parsing a data stream containing more than one set of data according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention provides a scanner that is capable of obtaining two sets of scan data simultaneously from a single scan. While the region of the scan is the same, the data types and resolutions of the two views can vary. For example, when a scan of a document is performed, an image processing unit in the scanner will generate one high resolution gray scale image and one low resolution 24 bit color image of the document scanned and then send both renditions of the scanned document to a host computer interleaved in a data stream, which the host computer will then parse in order to recreate the two views of the scanned document.
FIG. 1 shows a block diagram of the data path for a dual image scanner with dashed line area 100 being scanner functions implemented by an image processeing unit and dashed line area 102 being host computer functions. It should be noted that although the embodiment being described herein is a dual image scanner comprising a black and white and a color image, the concepts are extensible to multiple images. Image processing unit 100 is implemented in an ASIC with functional details described below with respect to FIGS. 2 and 3. When a document is scanned, a CCD array 104 or other known photosensor device outputs a red data signal 106, a blue data signal 108 and a green data signal 110. These three data signals are then converted into a color image data signal 128 and a monochrome image data signal 130 by an image pre-processor 112. The image pre-processor 112 places the color image data signal 128 into a color buffer portion 118 of buffer 114 and the monochrome image data signal 130 into a monochrome buffer portion 116 of buffer 114.
Next the image post-processor 120 uses the image data in the color buffer 118 and the monochrome buffer 116 to generate either 1 or 2 views of the window scanned by the scanner as specified by the host computer. If two views are generated, the image post-processor will send the two views to the host computer in an interleaved data stream 136.
When the host computer receives the two views of the scan window, a data parser 122 will parse the data stream 136 into a color image 124 and a monochrome image 126. The two views are then ready to be manipulated by the host computer. The advantage is less information for the host software to process and store, and less information to be sent from the scanner to the host, which is a current limitation on the speed of scanners.
I. MULTIPLE IMAGE SCANNER
The dual image scanner reduces the data required to be sent from the scanner to the host computer for complete page (text and graphics/image) information with one scan. Currently optical character recognition requires 300 ppi sampling rates for accurate results. For color fidelity, a 24 bit color scan is required. In order to do this, the typical scan would be 300 ppi at 24 bits (8.5×11), which is 25.24 Megabytes. By letting the scanner send two renditions of the same page, one high resolution gray scale image, and one low resolution 24 bit color image, the total amount of data sent to and processed by the host software is greatly reduced. A 300 ppi 4 bit gray (8.5×11) is approximately 4.2 Megabytes and a 150 ppi 24 bit color (8.5×11) is approximately 6.3 Megabytes for a total of 10.5 Megabytes, which is approximately a 2.4 to 1 reduction in data.
The multiple image scanner of the present invention has an image processing unit which performs the above operations very fast. The image processing unit may be implemented in a conventional field programmable gate array, an ASIC or the like, using verilog, for example with the function description provided herein. The image processing unit of the multiple image scanner comprises the image pre-processor 112, buffer 116 and image post-processor 120, which are described in more detail below.
A. Image Pre-Processor
Referring to FIG. 2, the image pre-processor 112 takes the RGB (red 106, green 108 and blue 110) image data from the CCD 104 and places either one or two different representations of that image into the buffer 114. One of the possible representations is a color image and the other is a monochrome image which is generated by selecting only one of the three color channels (red, green, or blue). The two different buffer images have the same y resolution but can have different x resolutions and bit depths. The bit depth of each image can be selected to be either 12-bit or 8-bit and the x resolution can be the CCD resolution divided by any integer factor from 1 to 63. The CCD resolution is the same for both images and can be either 300 ppi or 150 ppi. For example, the image pre-processor 112 can be programmed to put 300 ppi (x) by 300 ppi (y) 8-bit monochrome (green channel) data and 100 ppi (x) by 300 ppi (y) 12-bit color data into the buffer. Note that both images do not need to be generated. The pre-processor can be programmed to generate only the color representation or only the monochrome representation or both.
The four main functions performed by the image preprocessor of the present invention are described in greater detail below and with reference to FIGS. 1 and 2.
1. A/D Converter
The A/D convertor takes the 300 ppi or 150 ppi analog RGB image data from the CCD array and converts either 1 of the 3 or all 3 color values for each pixel to 10-bit digital numbers. These digital values are padded to 12 bits and sent to the dark clamp.
2. Dark Clamp
The dark clamp subtracts the average dark current for the line from each pixel value. Pixels inside the desired scan window are then sent to the compensator.
3. Compensator
The compensator removes pixel variations caused by non-uniform illumination and CCD response. Compensated pixel values are then sent to the prescaler.
4. Prescaler
The prescaler splits the compensated pixel values into a monochrome image and a color image, reduces the x-resolution of each image by a different integer factor, and puts one or both of the resulting images into the buffer. The prescaler splits the image data from the compensator into a monochrome stream and a color stream, reduces the x-resolution of each stream by a different integer factor, and then stores one or both of the resulting streams in the buffer. This is done to minimize the amount of buffer space consumed by each line of image data, especially when 2 views are requested by the host. For example, if no prescaler were provided and the host requested a 300 ppi monochrome view and a 100 ppi color view of an 8.5 inch wide scan window, each line of the image would consume 11.475 Kbytes of buffer space (8.5 inches 300 ppi 3 colors/pixel 1.5 bytes/color). However, with the prescaler each line consumes only 6.375 Kbytes (8.5 inches 300 ppi 1 color/pixel+8.5 inches 100 ppi 3 colors/pixel 1.5 bytes/color).
Note that the prescaler can either place full 12-bit or truncated 8-bit data into the buffer. The data width can be specified independently for each stream. The prescaler reduces the x-resolution of the 2 data streams by averaging adjacent pixels together rather than simply dropping pixels. This effectively lowpass filters the image data before it is resampled at the lower resolution and helps reduce aliasing. The prescaler can reduce x-resolution by any integer factor between 1 and 63.
B. Image Post-Processor
The image post-processor uses the image(s) in the buffer to generate either 1 or 2 views of the scan window specified by the host. Each view is generated from either the color image or the monochrome image. The two views can be generated from the same or different images. For example, one view could be generated from the color image and the other view from the monochrome image OR both views could be generated from the color image OR both views could be generated from the monochrome image. The two views can have different y resolution but the y resolution of each view must be the buffer y resolution divided by an integer factor from 1 to 16. The two views can also have different x resolutions which can be any resolution form 1/4 to 2× the x resolution of the buffer image from which the view is generated. Each view can also have different matrices, tonemaps, data types, etc. (with some restrictions which will be covered in greater detail below).
When two views are enabled, the views will be sent out interleaved on a line basis dependent on the ratio of their y resolutions. For example, if view one's y resolution is 300 and view two's y resolution is 150, then the data would alternate with two lines of view one's image data and then one line of view two's image data (except at the beginning). Other examples of interleaved data as a ratio of y resolution:
(2 to 1 ratio)→output 300 to 150 ratio: 300, 150, 300, 300, 150, 300, 300, 150 . . .
(1 to 2 ratio)→output 150 to 300 ratio: 150, 300, 300, 150, 300, 300, 150, 300 . . .
(3 to 1 ratio)→output 300 to 100 ratio: 300, 300, 100, 300, 300, 300, 100, 300, 300, 300 . . .
(1 to 3 ratio)→output 100 to 300 ratio: 300, 100, 300, 300, 300, 100, 300, 300, 300, 100 . . .
(4 to 1 ratio)→output 300 to 75 ratio: 300, 300, 75, 300, 300, 300, 300, 75, 300, 300 . . .
(1 to 4 ratio)→output 75 to 300 ratio: 300, 75, 300, 300, 300, 300, 75, 300, 300, 300 . . .
(5 to 1 ratio)→output 300 to 60 ratio: 300, 300, 300, 60, 300, 300, 300, 300, 300, 60 . . .
(1 to 5 ratio)→output 60 to 300 ratio: 300, 300, 60, 300, 300, 300, 300, 300, 60, 300 . . .
Note, the above examples are merely exemplary; other possible ratios for the current implementaion go up to 1 to 9.
The six main operations performed by the image post-processor of the present invention are described in greater detail below and with reference to FIGS. 1 and 3.
1. Line Merger
The line merger reads 1 to 9 lines from the appropriate image (color or black and white), optionally averaging some lines together before sending the resulting lines to the matrixer. The line merger essentially interleaves the two or more renditions of the scanned image into a single interleaved data stream to be sent to the host computer. By interleaving the two or more renditions of the scanned image on a line-by-line basis, the scanner does not have to save all of any rendition, as all renditions are generated, interleaved and sent to the host computer real time--that is, on a somewhat line-by-line basis.
The line merger reads 1 to 9 lines of data from either the color image or the black and white image and averages some of the lines together to reduce the number of computations that must be done by the matrixer. In addition, the line merger can provide a simple form of y resolution prescaling by averaging additional adjacent lines together. For example, the line merger can read 9 lines from the buffer, average every 3 adjacent lines to reduce the effective y resolution by a factor of 3, average the two remaining outer lines for kernel symmetry, and then send the resulting 2 lines to the matrixer. Therefore, it has reduced the number of lines that must be processed by the matrixer from 9 to 2.
Any integer number of adjacent lines from 1 to N (where N is the number of lines read from the buffer--up to 9) can be averaged together. However, after adjacent lines have been averaged, the resulting number of lines must be 1, 3, 5, 7, or 9 so that symmetrical lines can be further averaged before being passed on to the matrixer. This means that if no adjacent lines are averaged, we can use either 1, 3, 5, 7, or 9 line kernels. However, if 2 or 3 adjacent lines are averaged, we can only use 1 or 3 line kernels. If 4 through 9 adjacent lines are averaged, we can only use a 1 line kernel.
Lines are averaged by adding the corresponding pixels of each line and dividing by a scale factor of 1, 2, 4, or 8. Therefore, exact averaging is obtained only when averaging together 1, 2, 4, or 8 lines. The line merger will overflow if the number of lines added together divided by the scale factor is greater than 2. Therefore, if 3, 5, 6, 7 or 9 line averaging is desired, the nearest lower scale factor should be used and the matrixer coefficients may need to be reduced to compensate for the extra "gain" introduced in the line merger. The only exception to this rule is when we are reading 9 lines from the buffer, averaging every adjacent 3 lines, and then using a 3 line kernel. In this case, the line merger will end up reducing 9 line to 2. One of these two lines (the one corresponding to the center of the kernel) will be obtained by adding the center 3 lines from the buffer. The other line will be obtained by adding the outer 6 lines from the buffer. However, only one divisor can be selected and must be selected such that no line coming out of the line merger has been multiplied by more than 2. Therefore, in this example, a divisor of 4 must be selected. Since the gain of the line merger is now 3/4, the matrixer coefficients may need to be increased to compensate.
The buffer image to be used (color or monochrome), the number of lines read from that image, the number of adjacent lines averaged, and the scale factor can be specified independently for each view to be generated.
2. Matrixer
The matrixer "mixes" the three colors of each pixel to produce a single color or three new colors before sending the lines on to the tone mapper.
3. Tone Mapper
The tonemapper uses lookup tables and interpolation to adjust image contrast and intensity before sending the data to the formatter. The output pixels are further transformed by the tonemapper which passes them through a lookup table which contains a transfer curve called the tonemap. Tonemaps are used to perform gamma correction, adjust contrast and intensity, enhance shadows, etc.
4. Formater
The formatter optionally thresholds or dithers the data before packing it into the specified data width. This stage can also invert the data, if desired, before sending it to the compression engine.
5. Compression Engine
The compression engine optionally uses the packbits algorithm to compress the line of image data before sending it to the host.
II. MULTIPLE VIEWS FROM ONE SCAN WINDOW
The multiple image scanner of the present invention has the ability to obtain two images from a single scan. The scanner command language (SCL) implementation of multiple image separates the concept of the scan window with the particular view of that window. SCL is the command language used for scanners and is commonly known. It should be noted that any command language could be used. However, in the preferred embodiment, SCL is used to generate multiple views from one scan window. The scan window is the physical area of the page that will be scanned (defined by the x and y position and the extents). The view of that scan window is the data contained inside the physical area (defined by the resolution, data type, mirror, inverse, etc.). There are scanner settings that are window and view independent (i.e., is ADF attached, serial number, etc.). The advantage of separating the view and the window is that it makes the definition of multiple views extensible to multiple window with multiple views. No other scanner has multiple image abilities or an implementation of multiple views. It should be noted that although in the present implementation of multiple views, a single scan is used to obtain multiple views of the same document, it is irrelevant whether one or more scans are used to obtain multiple views of the same document. It does not matter how the data is obtained (from one or more scans), the important point is that the SCL implementation of more than one view allows different data to represent the same space.
In a preferred embodiment, the Hewlett-Packard ScanJet 5p is utilized to allow the acquisition of two views of data simultaneously. However, it should be noted that any color scanner from any manufacturer could be modified to implement the present invention. While the region of the scan is the same, the data types and resolutions of the two views can vary. The limits on the variables set on the two views are described with the SetViewType macro in SCL as follows:
______________________________________INT16 DualScan(INT16 Phase, PUINT8 pBufferView0, INT32 LengthView0, PINT32 pReceivedView0, PUINT8 pBufferView1, INT32 LengthView1, PINT32 pReceivedView1);______________________________________
The parameters are set as indicated below:
Phase--Flag indicating if this is the first transfer in a sequence. Must be one of the following values:
SL -- FIRST or SL -- SCAN, the first buffer in the transfer,
SL -- ADF -- SCAN, the first buffer in an ADF transfer (Currently only supported by HP1750A & HP5110A),
SL -- NEXT, each additional buffer transfer;
PbufferView0--Pointer to view 0 data buffer to receive the data;
LengthView0--Size of the view 0 data buffer in bytes;
pReceivedView0--Pointer to the actual number of bytes received from the scanner for view 0;
pBufferView1--Pointer to view 1 data buffer to receive the data;
LengthView1--Size of the view 1 buffer in bytes;
pReceivedView1--Pointer to the actual number of bytes received from the scanner for view 1.
This function is nearly identical to the Scan() function, which is well known to those familiar with SCL, except that it supports the dual view mode of the scanner.
Some of the default settings for the two views of a scan are shown below in Table 1.
______________________________________Parameter Default: Image One Default: Image Two______________________________________Data Type 0 (b/w threshold) 5 (color)Data width 1 bit/pixel 24 bits/pixelB/W Dither Pattern 0 (coarse fatting) 0 (coarse fatting)Coefficient Matrix 2 (green only) 0 (NTSC color)Tone Map 0 (contrast/intensity) 0Intensity 0 0Contrast 0 0Mirror 0 (off) *Auto Background 0 (off) *Inverse Image 0 (off) 0 (off)X Resolution 300 ppi 100 ppiY Resolution 300 ppi 100 ppiX Scale Factor 100% 100%Y Scale Factor 100% 100%X Location 0 *Y Location 0 *X Extent 2550 (pixels) *Y Extent 3300 (pixels) *Lamp 0 (off) *Scan Bar Position stops where it is *Download Type 0 (b/w dither 0 (b/w dither pattern) pattern)Downloaded 8 × 8 B/W none (old pattern *Dither Pattern is erased)Downloaded 8 bit Tone none (old map *Map is erased)Downloaded Color Matrix none (old matrix * is erased)Downloaded Calibration none (old parameters *Strip Parameter erased)Downloaded 16 × 16 B/W none (old pattern *Dither Pattern is erased)Downloaded B/W Matrix none (old matrix * is erased)Downloaded 10 bit Color none (old parameters *Matrix erased)Downloaded RGB tone none (old parameters *maps erased)Downloaded B/W tone none (old parameters *maps erased)Downloaded RGB gains none (old parameters * erased)Calibration Y-Start -1 (white strip) *Calibration Strip parameters 0 (auto-select) *Calibration Mode 0 (auto--calibration * dependent on data width)Speed Mode 0 (auto) *Compression 0 (off) 0 (off)Select number views 1 NASelected view 1 (off) NACaiibration Strip Lower 0 (calculated) *Max. # Lines per Buffer 0 (use calculated) *______________________________________
In the above table "*" indicates that the parameter is not set independently for the two views. However, this could be modified to allow some or all of these parameters to be independently set for the two views. Also, these parameter settings and SCL commands reflect the implementation used by the inventors and is not intended to be the only possible combination of parameter settings or SCL commands that could enable the multiple views from a single scan concept of the present invention.
The following commands have been added to select the number of views to be sent by the scanner to the host computer:
Command: Select Number of Views
Escape Sequence: Esc*f#A
Inquire ID: 10466
Range: 1-2
Default: 1
Macro: SetNumberofViews(x)
Send Command: SendCommand(SL -- NUM -- OF -- VIEWS,x)
Where x can be either 1 or 2.
This command will select how many views of the window will be sent by the scanner. The default will be one. The present implementation supported values are 1=one view, 2=two views. When two views are enabled, the data for the two views will be sent out interleaved on a line basis dependent on the ration of their Y resolutions. For example, if view one's Y resolution was 300 and view two's Y resolution was 150, then the data would alternate with two lines of view one's image and then one line of view two's image (except at the start; see examples above in the image post-processor section).
The select view command is used to set scanner settings for the view or views you want to work with as follows:
Command: Select view
Escape Sequence: Esc*f#B
Inquire ID: 10467
Range: 0-1
Default: 0
Macro: SetViewType(x)
SendCommand: SendCommand(SL -- VIEW -- TYPE, x)
Where x can be: 0--for view one, or 1--for view two.
The view must be selected prior to choosing the scanner settings. This command selects which view the subsequent SCL commands or inquires refer to. Supported values are: 0(view one) and 1(view two). The default is view one.
III. METHOD FOR PARSING MULTIPLE IMAGE SCAN DATA
Host computer software parses the interleaved multiple image data sent by the scanner. In the present implementation, the software program DualScan and its supporting modules permit a user unfamiliar with the details of the multiple image data format to easily parse multiple image data from the scanner into familiar tiff files, which can then be used with programs such as Photo Shop. DualScan is a software program sold by Hewlett-Packard Co. It is possible that one or both of the images will contain compressed data further complicating the parsing issue. The DualScan software allows use of a scanner with multiple image capability in its hardware by parsing the interleaved data stream received from the scanner. One skilled in the art could readily expand DualScan to include the parsing of multiple views of data, rather than the two views as described in the present implementation.
FIG. 4 is a block diagram of a dual image data stream 136 being sent from the scanner (not shown) and parsed by a data stream parser 122 on the host computer (not shown) into view 1 data (monochrome image) 126 and view 2 data (color image) 124. The operation of the data stream parser will be further explained with reference to FIG. 5, which is a flow chart of the data stream parsing function.
At the initial entry point, the resolution, compression state, and bytes per line for each of the images is imquired by the data parser at 200. Next image ratios for each view are calculated by the data parser at 202. Then interleaved image data is received by the data parser from the scanner at 204. The data parser then copies one line of scan data to the appropriate output buffer, decompressing the data if necessary at 206. The data parser then switches views (210) based on the image ratios calculated at 202. If no errors are detected and the parsing of the data stream is not finished (212), the data parser returns to 204 and receives more interleaved data from the scanner to be parsed. If an error is detected or the parsing of the data stream is completed at 212, the data parser returns this status to the calling function which takes an appropriate action. Error conditions may include: (1) output buffers full, (2) bad response from the scanner, (3) decompression engine out of data and scanner has no more data, or (4) scan completed. The steps in FIG. 5 are also shown in source code in Appendix A.
It should be noted that although the implementation described herein describes a dual scan, dual views, and the parsing of two interleaved data streams, these concepts are readily extensible to multiple scan, multiple views, and the parsing of multiple interleaved data streams.
The foregoing description of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and other modifications and variations may be possible in light of the above teachings. For example, the data stream parser is capable of parsing any interleaved data stream containing more than one set of data. The data stream does not have to be an scanned image data stream. Also, the SCL implementation of multiple views of the same window does not matter how the multiple views were obtained; the implementation is the same whether the views were obtained from one or more scans of the same area. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the appended claims be construed to include other alternative embodiments of the invention except insofar as limited by the prior art.
__________________________________________________________________________APPENDIX A__________________________________________________________________________INT16 FP DualScan(INT16 Phase,PUINT8 pBufferView0, INT32 LengthView0, PINT32 pReceivedView0,PUINT8 pBufferView1, INT32 LengthView1, PINT32 pReceivedView1)/*** Parameters:** Phase Flag indicating if this is the first transfer in** a sequence. Can be one of the following values.** SL.sub.-- FIRST or SL.sub.-- SCAN, the first buffer in the transfer.** SL.sub.-- ADF.sub.-- SCAN, the first buffer in an adf transfer.** SL.sub.-- NEXT, each additional buffer transfer.** pBufferView0 Pointer to view 0 data buffer to receive the data.** LengthView0 Size of the view 0 data buffer in bytes.** pReceivedView0 Pointer to the actual number of bytes** recieved from the scanner for view 0.** pBufferView1 Pointer to view 1 data buffer to receive the data.** LengthView1 Size of the view 1 data buffer in bytes.** pReceivedView1 Pointer to the actual number of bytes** recieved from the scanner for view 1.** Globals: None.** Operation: SL.sub.-- ADF.sub.-- SCAN ONLY SUPPORTED BY HP1750A and Domino |** This procedure is nearly identical to the "Scan()" function** except that it supports the dual view mode of the scanner.** Please refer to the internal documentation for the "Scan()"** function for additional usage information|! This command is** only supported on scanners which supports dual view, such as** "Domino".**** Note, that this routine is also capable of handling compressed** input data.**** Return:** status OKAY, commands sent to scanner successfully.** SL.sub.-- BADACCESS, transfer terminated in error.** SL.sub.-- BADRESPONSE, inquire resulted in incorrect response.** SL.sub.-- NULLRESPONSE, inquire resulted in NULL response.** SL.sub.-- ILLEGALCMD, illegal command sent to scanner (scanner** may not support the SCL command).** SL.sub.-- SCANERROR, compression scan error.*/ INT16status = OKAY; INT16num.sub.-- views, /* Number of views presently active */ INT16active.sub.-- view; /* Active view (0 or 1) on entry to */ /* this routine */ INT32received = -1; /* Amount of data actually received */ /* from the scanner (initialized */ /* -1 to test for.. */ INT16YRes.sub.-- view0, /* Y Resolution for views 0 and 1 */YRes.sub.-- view1; INT16ImageRatio.sub.-- view0, /* Image Ratio for views 0 and 1 */ImageRatio.sub.-- view1; static INT16 Compression.sub.-- view0, /* Scan data compression flag for */Compression.sub.-- view1; /* views 0 and 1 */ static INT16 WidthBytes.sub.-- view0, /* Width of single scan line in */WidthBytes.sub.-- view1; /* bytes for view 0 and 1 */ static INT16 cur.sub.-- view; /* Current view being processed */ static INT16 view.sub.-- count 2!; static INT16 imageratio 2!; static PUINT8 pScanBuffer; /* Pointer to current location in */ /* statically allocated input */ /* scanbuffer */ static INT16 bytes.sub.-- avail; /* Number of bytes used available */ /* (or free) in the input buffer *//* Check to make sure we are processing dual image scan before proceeding*/ if(Phase |= SL.sub.-- NEXT) { status = InquireNumber (SL.sub.-- VIEW.sub.-- TYPE, SL.sub.-- NOM,(PINT16) &active.sub.-- view); if(status |= OKAY) return (SL.sub.-- ILLEGALCMD); /* Get applicable scan state information for view #0 (first view) */ SetViewType (0); if( (status = InquireNumber(SL.sub.-- NUM.sub.-- OF.sub.-- VIEWS,SL.sub.-- NOM, &num.sub.-- views) |= OKAY)∥ (num.sub.-- views |= 2)∥ (status = InquireNumber(SL.sub.-- Y.sub.-- RESOLUTION, SL.sub.-- NOM,&YRes.sub.-- view0) |= OKAY)∥ (status = InquireNumber(SL.sub.-- COMPRESSION, SL.sub.-- NOM,&Compression.sub.-- view0)|= OKAY)∥ (status = InquireNumber(SL.sub.-- BYTES.sub.-- PER.sub.-- LINE,SL.sub.-- NOM, &WidthBytes.sub.-- view0) |= OKAY)) return (SL.sub.-- ILLEGALCMD); /* Now get the same information for view #1 (second view) */ SetViewType (1); if( (status = InquireNumber(SL.sub.-- Y.sub.-- RESOLUTION, SL.sub.--NOM, &YRes.sub.-- view1) |= OKAY)∥ (status = InquireNumber(SL.sub.-- COMPRESSION, SL.sub.-- NOM,&Compression.sub.-- view1)|= OKAY)∥ (status = InquireNumber(SL.sub.-- BYTES.sub.-- PER.sub.-- LINE,SL.sub.-- NOM, &WidthBytes.sub.-- view1) |= OKAY)) return (SL.sub.-- ILLEGALCMD); /* Compute the Y image ratios for each view using the Y Resolutions */ if (YRes.sub.-- view0 <= YRes.sub.-- view1) { ImageRatio.sub.-- view0 = 1; ImageRatio.sub.-- view1 = YRes.sub.-- view1 / YRes.sub.-- view0;#ifndef VORTEX.sub.-- WORKAROUND view.sub.-- count 0! = 0; view.sub.-- count 1! = ((INT16) ((ImageRatio.sub.-- view1 / 2) + 1)) % ImageRatio.sub.-- view1; if(view.sub.-- count 1! == 0) /* Special case: 1:2 ratio */ cur.sub.-- view = 0; /* Set starting view */ else cur.sub.-- view = 1;#endif } else { ImageRatio.sub.-- view0 = YRes.sub.-- view0 / YRes.sub.-- view1; ImageRatio.sub.-- view1 = 1;#ifndef VORTEX.sub.-- WORKAROUND view.sub.-- count 0! = (INT16) (ImageRatio.sub.-- view0 / 2); view.sub.-- count 1! = 0; cur.sub.-- view = 0; /* Set starting view */#endif }#ifdef VORTEX.sub.-- WORKAROUND /* Initialize view output counters (for supporting image ratios) */ view.sub.-- count 0! = 1; /* = ImageRatio.sub.-- view0 - 1; */ /* (for final Vortex release) */ view.sub.-- count 1! = ImageRatio.sub.-- view1; cur.sub.-- view = 0; /* Set starting view */#endif imageratio 0! = ImageRatio.sub.-- view0; imageratio 1! = ImageRatio.sub.-- view1; /* Reset view to initial active view when this routine was entered */ SetViewType (active.sub.-- view); /* Initialize pointer to scan input buffer */ pScanBuffer = (PUINT8) &ScanBuffer; } /* if (Phase |= SL.sub.-- NEXT) *//* Initialize the actual number of bytes received for both views. * * Note: While these 2 function return arguments are initialized within * this routine, they are actually set within another function, * "CopyScanLine()", called by this routine. */ *pReceivedView0 = 0; *pRecievedView1 = 0;/* Make sure the scanner is communicating and clean up the error state*/ if (Phase == SL.sub.-- NEXT ∥((status = InquireOldestError()) |= SL.sub.-- BADACCESS && status |= SL.sub.-- BADRESPONSE && status |= SL.sub.-- NULLRESPONSE2 && (status = SendCommand(Phase, 0)) == OKAY)){ if ((Phase == SL.sub.-- FIRST) ∥ (bytes.sub.-- avail ==SCAN.sub.-- BUFSIZE)) { /* Force buffer to be filled */ bytes.sub.-- avial = SCAN.sub.-- BUFSIZE; status = SCANBUFEMPTY; } while ( (status |= OUTBUFFERFULL) && (status |= SL.sub.-- SCANERROR) && (recieved |= 0) ) { /* Refill scan input buffer if necessary */ if (status == SCANBUFEMPTY) { memmove (ScanBuffer, pScanBuffer, SCAN.sub.-- BUFSIZE - bytes.sub.--avail); pScanBuffer = &ScanBuffer SCAN.sub.-- BUFSIZE - bytes.sub.-- avial!; received = RecFromScanner (pScanBuffer, bytes.sub.-- avail, SL.sub.--ALLCHAR); if (received < 0) /* Error in reading scan data */ { *pReceivedView0 = 0; *pReceivedView1 = 0; return (SL.sub.-- BADACCESS); }#ifdefDEBUG.sub.-- DI if (debug.sub.-- flag) { printf ("bytes.sub.-- avail A1 = %d\n", bytes.sub.--avail); }#endif bytes.sub.-- avail = bytes.sub.-- avail - (INT16) received; /* Reset count of the # bytes available*/#ifdef DEBUG.sub.-- DI if (debug.sub.-- flag) { printf ("bytes.sub.-- avail A2 = %d\n", bytes.sub.-- avail); }#endif pScanBuffer = &ScanBuffer 0!; status = OKAY; } /* if(..) */ if (bytes.sub.-- avail == SCAN.sub.-- BUFSIZE) break; /* Fill appropriate input scan buffer */ if (cur.sub.-- view == 0) { status = CopyScanLine (Compression.sub.-- view0, WidthBytes.sub.--view0, &pScanBuffer, &bytes.sub.-- avail, &pBufferView0` LengthView0, pReceivedView0); } else /* cur.sub.-- view == 1 */ { status = CopyScanLine (Compression.sub.-- view1, WidthBytes.sub.--view1, &pScanBuffer, &bytes.sub.-- avail, &pBufferView1` LengthView1, pReceivedView1); } /* Switch (compute) next image to process (either view 0 or 1) */ if( (status |= SCANBUFEMPTY) && (status |= OUTBUFFERFULL) && (status |= SL.sub.-- SCANERROR)) {#ifdef VORTEX.sub.-- WORKAROUND --view.sub.-- count cur.sub.-- view!; if (view.sub.-- count cur.sub.-- view! == 0) { view.sub.-- count cur.sub.-- view! = imageratio cur.sub.-- view!;#else ++view.sub.-- count cur.sub.-- view!; if (view.sub.-- count cur.sub.-- view! == imageratio cur.sub.-- view!) { view.sub.-- count cur.sub.-- view! = 0;#endif cur.sub.-- view = ((cur.sub.-- view + 1) % 2); } } } /* while () */#ifdef DEBUG.sub.-- DI if (debug.sub.-- flag) printf(" DualScan! status = %d; bytes.sub.-- avail A3= %d\n", status, bytes.sub.-- avail);#endif /* Test if Decompression engine needs more data to finish a */ /* line but the scanner had no data to send */ if ( ((status == SCANBUFEMPTY) && (received == 0)) ∥ (status == SL.sub.-- SCANERROR)) status = SL.sub.-- SCANERROR; else status = OKAY; } /* if(..) */ return status;} /* DualScan */static INT16 FP CopyScanLine (INT16 Compression, INT16 WidthBytes, PUINT8 *ScanBuffer, PINT16 bytes.sub.-- avail, PUINT8 *pBuffer, INT32 Length, PINT32 pReceived)/*** Parameters:** Compression Input scan data compression flag.** WidthBytes Width of single scan line in bytes.** ScanBuffer Pointer to a pointer containing the current byte within** scan input buffer. On exit -- the indirectly referenced** byte pointer is set to the address of the byte immediately** following last byte processed from the input buffer.!** bytes.sub.-- avail Pointer to the number of bytes available (or free)in the** input buffer. (This argument will always be equal to** SCAN.sub.-- BUFSIZE the first time this function is called.)** On exit -- this counter is incremented by the number of** input bytes successfully processed by this routine.!** pBuffer Pointer to a pointer containing the current position** within the output buffer where processed data is to be** stored. On exit -- the indirectly referenced byte** pointer is set to the address of the the next byte to** be added to the output buffer.!** Length Total size (in bytes) of output buffer, `pBuffer`. (Note,** this is the total length of `pBuffer` and NOT the number** of free bytes remaining in the buffer.)** pReceived Pointer to the actual number of bytes found in the output** buffer, pointed to by `pBuffer`. On exit -- this counter** contains the total number of bytes currently found in the** output buffer.!**** Globals: None.** Operation: This private function copies a single scan line of data** from the input buffer, `ScanBuffer`, to the output buffer,`pBuffer`.**** Refer to the internal documentation for the "Scan()" and** "DualScan()" functions for additional usage information|!**** Return:** status OKAY, output buffer successfully filled.** SCANBUFEMPTY, input raw scan buffer is empty (input buffer** does not have enough data for one single** complete scan line).** OUTBUFFERFULL, output scan buffer contained processed** data (unpacked "dual image" and/or** decompressed data) is full (similar to the** above, output buffer does not contain** enough space to hold a new single complete** scan line).*/{ INT16 status = OKAY; /* Return value from this function */ /* (default = OKAY) */ /* * Check if there is enough room in the output buffer to store acomplete * single scan line of data. */ if((*pReceived + WidthBytes) > Length) status = OUTBUFFERFULL; else { /* Output buffer NOT full| */ if(|Compression) { /* UnCompressed data */ /* * Check if the input buffer contains enough raw data for * one full scan line. */ if((SCAN.sub.-- BUFSIZE - *bytes.sub.-- avail) < WidthBytes) status = SCANBUFEMPTY; else { /* Everything OK -- now copy the data */ memmove ((PUINT8) *pBuffer, (PUINT8) *ScanBuffer, WidthBytes); *ScanBuffer += WidthBytes; *bytes.sub.-- avail += WidthBytes; *pBuffer += WidthBytes; } } else { /* Compressed data */ /* Decompress single scan line of raw data */ status = Decomp(ScanBuffer, bytes.sub.-- avail, WidthBytes, pBuffer); } /* if() else */ if (status == OKAY) { *pReceived += WidthBytes; } } return status;} /* CopyScanLine */__________________________________________________________________________ | A computer operable method for implementing multiple views from a single scan window following a scanning process of an image scanner, the method involves designating the number of views to be obtained from the single scan window; designating the data type and other parameters for each of the number of designated views to be obtained from the single scan window; designating the number of views to be sent from the image scanner to a host computer; once a window has been scanned one or more times, generating a data signal representative of each of the number of views designated to be obtained from the single scan window; and sending each of the data signals representative of the number of views designated to be send from the image scanner to the host computer for further processing. The computer operable method may be implemented in scanner command language (SCL). | 7 |
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of copending application Ser. No. 399,253 filed Sept. 20, 1973 now abandoned.
This invention relates to a building structure generally having a domical shape which has a radius at the base greater than the height at the center. It is constructed of four basic structural units, each of which is an isosceles triangle. The basic units are arranged in circular symmetrical tiers. Circular tiers or rows comprise combinations of the basic units in a symmetrical pattern.
Prior art structures constructed as domes usually comprise a number of individual large basic structural units such as hexagons, etc. Because of this, erection of the structure requires that the structural units be exact in their various geometric dimensions in order that all the elements can be fit together properly. Thus, if a unit has incorrect dimensions, difficulty is encountered during construction. Furthermore, prior art dome structures are generally true hemispheres wherein the radius of the base is equal to the height at the center of the dome. A hemispherical dome has two drawbacks in its structure. One is that the volumetric space at the top is generally unusable, and heating and cooling thereof is wasteful. Two, the bottom portion of the dome angles in at a sharp angle from the floor. The area immediately adjacent the bottom wall of a building structure is generally usable as a zone where a person can stand or sit, or for using the wall space for the hanging of decorative items, etc. This zone is a hemispherical dome structure is not easily usable for these purposes because the wall is at an angle to the floor.
SUMMARY OF THE INVENTION
In accordance with this invention, a minimum number of simple basic structural units are required to construct domical structures of varying sizes. The invention provides a domical-type construction wherein only four basic structural units are required. The units are isosceles triangles having predetermined thickness, dimensions, and edge angles on each side, whereby the units are mated together to form the structure.
Generally, the domical structure is constructed by arranging a floor level substantially perpendicular first tier or row of one basic triangular unit wherein the units alternate as upright and inverted units in a circular pattern. Similarly, a second canted tier atop the first tier comprises upright basic units of the first tier alternating with second inverted basic units. Similarly a third canted tier comprises upright second basic units alternating with third inverted basic units. The structure is closed at the top by a fourth tier of canted adjacent upright units arranged in a circular conical pattern and abutting the third tier of inverted units. The various abutting units are secured together along their edges angles. No internal support is required for the domical structure.
The design of the construction of the dome permits domes of varying floor diameters by merely increasing the size of the basic triangular units or by increasing the number of basic units in each tier.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view through the center of a circular dome constructed in accordance with this invention.
FIG. 2 is a schematic top plan view of the dome of FIG. 1; and
FIG. 3 is an exploded elevational view of the four basic structural units and their relationship to each other in the construction of the dome.
FIG. 4 is an inner view of the first structural basic unit labeled A, showing the edge angles and the dimensional lengths of each side thereof;
FIG. 5 is an inner view of the second structural basic unit labeled B, showing the edge angles and the dimensional lengths of each side thereof;
FIG. 6 is an inner view of the third structural basic unit labeled C, showing the edge angles and the dimensional lengths of each side thereof;
FIG. 7 is an inner view of the fourth structural basic unit labeled D, showing the edge angles and the dimensional lengths of each side thereof;
FIG. 8 is a view taken along line 8--8 of FIGS. 4, 5 and 6;
FIG. 9 is a view taken along line 9--9 of FIGS. 6 and 7
FIG. 10 is a view taken along line 10--10 of FIG. 7; and
FIG. 11 is an inner view with portions exposed of a typical basic structural unit showing an insulating core material sandwiched between outer panels.
DETAILED DESCRIPTION OF THE INVENTION
The four basic structural units of the invention used in constructing the domical structure can be designated as A, B, C and D as shown in FIG. 3. Each basic unit is an isosceles triangle having having outer and inner surfaces, a predetermined thickness and predetermined lengths for the equal and third sides. Each side edge of the units is bevelled or angled inwardly from the outer surface and this edge angle is predetermined for each of the basic units, the purpose being that abutting or adjacent units in the upward curving structure of the dome will correctly mate together at the edge interfaces of each unit, whether they are the same basic unit or not.
As shown in FIG. 1, the domincal structure is constructed by erecting a first circular, substantially perpendicular tier or row of angularly abutting alternating upright A and inverted A units. The upright units are secured to a ground level foundation of concrete or the like as will be described hereinafter. Adjacent upright and inverted units are secured together along adjacent equal sides of the units. The alternating upright and inverted A units angle inwardly and outwardly to a small degree around the circular row. A second tier of alternating upright A units and inverted B units are installed with the angled third side of the upright A units of tier two abutting the angled third side of the inverted A units of the first tier. The second tier is therefore canted inwardly from one an amount equal to the edge angle of unit A.
A third tier is similarly installed as the second tier comprising alternating upright B units and inverted C units with the angled third side of the upright B units of the third tier abutting the angled third side of the inverted B units of tier two. The third tier is therefore also canted inwardly from tier two an amount equal to the edge angle of unit B.
The top of the domical structure is enclosed by installing a fourth tier of upright units D all angularly abutting each other along their equal sides to form a conical top with the apexes of each unit meeting at the top of the dome. The angular third sides of units D abut with the angular third sides of upright units C in tier three. The fourth tier is canted inwardly from the third tier by an amount equal to the edge angle of unit D. The cantation can be varied, as desired, by changing the edge angle of the third side of unit D to provide a higher or lower top to the dome.
Dimensional, predetermined interrelationships exist between A, B, C and D units. Units A, B, and C each have the same lengths E on their respective equal sides, however unit A has length F, unit B has length G and unit C has length H on their respective third sides. Both units A and B each have the same edge angle X on all three sides, whereas unit C has edge angle X on the equal sides but edge angle Y on the third side. Unit D has lengths I and edge angle Z on its equal sides, and length H and edge angle Y on the third side. FIGS. 4-10 illustrate typical units A, B, C and D showing their edge angles, and dimensional lengths on their equal and third sides.
The dimensions of the four basic units are determinant on two, not necessarily dependent, factors. One factor is the desired diameter of the base of the structure. The second factor is the desired planar surface size of each of the four basic units. When a dome of a particular base diameter is desired, the four basic units can be manufactured of a larger or smaller planar size. A greater number of smaller planar size units would be required than larger units to construct the first tier of the units. Accordingly, the lengths of the third sides and edge angles of the units would be dependent on the number of units required to form a circle, with each edge angle of each unit providing an increment angle in the circle. It is to be noted, however, that once a set of predetermined calculations are made for a dome having a desired diameter, the base diameter of the dome can be increased or decreased by proportionally reducing the planar size of the triangular units, whereas the edge angles remain constant. In determining the planar size of the basic units in any desired base diameter of the structure, consideration should be given to the dimensions of the first and second tiers of the units. Thus, the invention provides that the first tier be substantially perpendicular with the second tier being canted to the first by a predetermined degree. In this regard, the space and floor area near the first and second tiers should all be substantially usable to the edge of the perimeter. Thus, in predetermining the dimensions of the first and second tiers of triangular units, their combined height should desirably be 7-8 feet, which is the desired height of walls in conventional housing construction. Therefore, in predetermining the edge angles of the basic units, the diameter of the dome and the dimensions of the units are mainly determinant in calculating the edge angles of the units in the first and second tiers, wherein the planar heights of the units are fixed to provide an inner surface wall of 7 or 8 feet high. Thus, a dome of larger floor diameter would require a greater number of basic units with smaller edge angles in the first and second tiers, whereas a smaller floor diameter would require fewer basic units with larger edge angles.
The basic units A, B, C and D of the invention based on the above stated dimensional relationships, are predetermined with respect to each other as follows. With a desired floor diameter of the dome and a first and second tier height about 7 or 8 feet high, the number of upright A units required to form the first tier is obtained by determining the circumference of the dome at its base. From the circumference, the dimension of the third side of A unit is determined to provide a sufficient number of upright A units which will circle the circumference in the first tier. In determining the third sides, consideration is given to the height of the triangle to obtain a structurally strong unit. From the number of upright A units required, the edge angle of the A units is determined as follows: ##EQU1## Accordingly, the dimension of the third side and edge angle of A unit will be determined with the height being preferably about four feet. Since upright A units are used in the second tier, this will provide an inner substantially perpendicular wall of about 8 feet high. The equal sides of the A unit can be calculated from the third side dimension and its height.
The side dimensions and edge angles of the B units can then be determined from the above recited relationship between A and B units. Thus A and B units have the same lengths of equal sides and the edge angles are the same in both. The third side of B unit will be less than the third side of A unit and can be determined by the distance between the apexes of two canted upright A units in tier two.
Similarly, the side dimensions and edge angles of C units can be determined. C units have the same lengths and edge angles on their equal sides as units A. With respect to their third side of C unit, the length is determined by the distance between the apexes of two canted, upright B units in tier three. The edge angle of the third side of C unit is determined by the amount of cantation desired in units D.
The side dimensions and edge angles of units D are determined from the desired cantation of the fourth tier to enclose the dome. The length of the third side of unit D is the same as the third side of unit C. When the desired cantation of tier four is determined, the length of the equal sides of unit D is the distance from the apex of a unit B in tier three to the center top of the dome. The edge angles of the equal sides of unit D are dependent on the cantation and the number of D units in tier four.
The dome-type structure described above is not a true dome, i.e. a hemisphere. Because of the predetermined cantation of the upper tiers of the structure, a stable structure is present and a spherical surface is not necessary as is the case in geodesic-type domes. Accordingly, the unique construction of the invention provides a structure which has a center height which is less than the radius of the circular base. Thus, less space is present in the upper part of the dome of this invention than is present in a true geodesic-type dome. Correspondingly less space reduces the heating and cooling requirements of the dome.
The following is a detailed description of an embodiment of a domical construction according to this invention, having a diameter of 30 feet, wherein four basic triangular units are used having predetermined equal and third sides, and edge angles. The triangular units are constructed from 2×4 plywood strips with the broad side providing the thickness to the unit. Dimensions of the units hereinafter stated, refer to the larger planar surface of each unit. The thickness of the triangular units can vary depending on the materials of construction and the desired thickness needed. Generally, thickness of about several inches up to about a foot are suitable.
Referring to the drawings, the reference numeral 10 designates a skeletal dome structure in FIG. 1 which is constructed using the basic triangular structural units A, B, C and D shown in FIG. 3.
Unit A of tier one comprises equal sides 18 and 20 and third side 22. The unit is strengthened by struts 24 and 26. The equal sides 18 and 20 are 60 inches in length with third side 22 being 74 inches. Each side 18, 20 and 22 has an edge angle 12° with respect to the plane of the triangle. Adjacent upright and inverted A units are mated together at the edge sides in each tier.
In the second circular tier, upright A units alternate with inverted B units. Unit B comprises equal sides 28 and 30, third side 32, and struts 34 and 36. The equal sides 28 and 30 are 60 inches in length with third side 32 being 673/4 inches. The edge angle of all three sides of B unit is 12°.
In the third circular tier, upright B units alternate with inverted C units. Unit C has equal sides 38 and 40, third side 42, and struts 44 and 46. The equal sides 38 and 40 are 60 inches in length with thid side 42 being 531/2 inches. The edge angles of C units are 12° along the equal sides 38 and 40 and 12° for third side 42.
The fourth tier comprises upright D units all arranged in a circular pattern forming a conical structure which encloses the dome at the top. Unit D comprises equal sides 48 and 50, third side 52, and struts 54, 56 and 58. The equal sides 48 and 50 are 11 feet 4 inches with third side 52 being 531/2 inches. The edge angles of D units are 10° along equal sides 48 and 50 and 15° along side 52.
The dome is constructed by installing units A in the first tier. The upright units A are each successively secured to a ground foundation 12 by means of anchor bolts 14 passing through holes in side 22 of unit A and secured by nuts 16. The inverted units A are successively installed between the upright A units to form the circular first tier. The upright units A installed substantially perpendicularly on the foundation with the edge angle of side 22 being adjusted by shims or inserts and the like to assure a substantial perpendicularity to the unit. Alternating upright and inverted units A are secured together by suitable means. Thus the sides 28, 30, and 32 can have holes 60 through which nuts and bolts (not shown) can be inserted. Similar fastening means are employed throughout the structure.
The second tier of alternating upright A and inverted B units are installed with the third side of upright A units angularly abutting the third side of inverted A units in tier one and secured similarly. The second tier, because of the mating edge angles of inverted A units in tier one and upright A units in tier two will be angled or canted inwardly from the perpendicular by 12°. The vertical height of unit A is about four feet and unit B is about four feet, two inches. The combined vertical height of tiers one and two provides a substantially perpendicular wall of about eight feet on the inside surface of the dome, thereby permitting all usable floor space within the circumferential confines of the dome structure.
The third tier of alternating upright B units and inverted C units are installed similarly as the first and second tiers and secured similarly with the third side of upright B units regularly abutting the third side of the inverted B units of tier two. The third tier is also canted inwardly about 12°
Units D in the top tier of the dome are installed with the third sides of D units abutting the third sides of inverted C units in tier three. In this tier, units D angularly abut each other on their respective equal sides 48 and 50 to form a conical top structure. In the construction of the above dome structure, 45 A units, 30 B units, 15 C units, and 15 D units are required.
The completed skeletal structure can be covered with a variety of lightweight materials, for example, canvas, plastic materials, plywood panels, etc., such as is shown at 60 and 62 on a D panel in FIG. 3. Preferably when panels of plastic or plywood are used to cover each outer face of units A, B, C and D, the seams between them can be covered with a weatherproof tape or filling materials to provide a continuous weatherproof outside surface as is shown at 64 in FIG. 1.
Although the above embodiment has been described with the basic structural units comprising a skeletal wood construction, the basic units can be made of triangular panels of wood having an insulating material such as plastic foam therebetween. Furthermore, the basic units can be a suitable solid molded plastic material as shown in FIGS. 4-10 or plastic panels 72 and 74 with an insulating core material 76 such as polyurethane, polystyrene, fiberglass, etc. sandwiched therebetween as shown in FIG. 11. The basic units can also be fabricated of fiberboard, corregated fiberboard, fiberglass, metal such as aluminum or any rigid flat material. In addition, the materials of construction can be constructed as sandwich panels 66 and 68 as shown with a B panel in FIG. 3 having an insulating material 70 therebetween.
In the erection of the dome, the units instead of being bolted together can be welded or bended together, the abutting surfaces can be tongue and grooved, etc.
The above embodiment is illustrative of one size dome that can be constructed from the basic units, i.e. a 30 foot diameter dome having a height of 14 feet, 4 inches. Larger diameter domes can also be constructed by increasing the number of triangles in each tier by increments of two units in each tier, however, in so doing, the edge angle must be decreased a predetermined amount as described heretofore to compensate for the greater number of units in the circumference of each tier. Alternatively, the larger dome can be constructed by increasing the dimensions of each basic unit proportionally.
One particular advantage of the dome construction of this invention is that the height at the center is less than the radius of the circumferential base and is thus not a true spherical structure. The advantage, therefore, is that less unused volume at the top of the dome is present, which would normally require heating or cooling.
The invention provides a strong symmetrical, domical structure having substantially uniform expansion of all the component units. Erection of the structure is simple, wherein one or two men can easily assembly the units in place in a minimum amount of time.
The basic units can be manufactured to provide doors in combinations of units A and B of tiers one and two. Furthermore, skylights can easily be provided in units D and windows in units A, B or C.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usage and conditions. | The invention relates to a dome-type structure constructed from four basic triangular structural units. Each basic unit is an isosceles triangle which has predetermined angular edges. The four units are interrelated in their dimensional sizes and angular edges. The several units are installed in four circular tiers whereby abutting adjacent units fit together properly, and whereby upper tiers are canted inwardly to enclose the structure. The structure requires no internal support members. The radius of the circular base is greater than the height of the structure. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 61/388,006 filed Sep. 30, 2010.
FIELD OF THE INVENTION
[0002] This invention pertains to aromatic transalkylation processes. In particular, the invention relates to processes which transalkylate feed aromatics to produce xylene and convert feed olefins.
DESCRIPTION OF RELATED ART
[0003] The xylenes, para-xylene, meta-xylene and ortho-xylene, are important intermediates which find wide and varied application in chemical syntheses. Para-xylene upon oxidation yields terephthalic acid which is used in the manufacture of synthetic textile fibers and resins. Meta-xylene is used in the manufacture of plasticizers, azo dyes, wood preservers, etc. Ortho-xylene is feedstock for phthalic anhydride production. The distribution of xylene isomers from catalytic reforming and other sources generally does not match that of the sought isomers for chemical intermediates and thus the producer converts feed stocks to generate more of the sought isomers.
[0004] Transalkylation processes are known to convert various aromatic hydrocarbons to xylenes. Transalkylation may be combined with other processes such as isomerization, and xylene isomer separation in various configurations to produce one or more specific isomers of xylene. A prior art aromatics complex flow scheme has been disclosed by Meyers in part 2 of the H ANDBOOK OF P ETROLEUM R EFINING P ROCESSES , Second Edition, 1997, published by McGraw-Hill.
[0005] The feed to an aromatic transalkylation process may be obtained from a variety of sources including the catalytic reforming of naphtha fractions, pyrolysis of hydrocarbons, and other processes in an aromatic complex. In addition to producing desired aromatic feed components, these processes produce other chemical compounds including olefins. Olefins have been generally considered undesirable feed impurities and have been limited to a maximum contaminant level. Various pretreatment steps such as clay treating, hydrotreating, and hydrogenation have been used to remove olefins from the feed before the transalkylation process. US 2009/0036724 A1 discloses catalysts that produce xylenes and remove olefins in a transalkylation process.
[0006] There remains a need in the art for alternate transalkylation processes capable of producing xylenes and removing olefins.
SUMMARY OF THE INVENTION
[0007] Transalkylation processes according to the invention may be part of a xylene production complex, another arrangement of process units, or a stand alone processing unit. In general, the feed to the transalkylation zone comprises aromatic hydrocarbon and olefin compounds and the transalkylation zone produces xylenes and reduces the olefin content of the feed. The invention may be used to minimize or avoid the necessity of feedstock pretreatment such as hydrotreating, hydrogenation, or treating with clay and/or molecular sieves.
[0008] In an embodiment, the invention is a process for transalkylating aromatic hydrocarbons and removing olefins from a feed having a Bromine Index of more than 50 comprising introducing a feed comprising the olefin and aromatic hydrocarbon compounds to a transalkylation zone; contacting the feed with a catalyst in the transalkylation zone under transalkylation conditions; and producing a reaction product stream having an increased concentration of xylenes relative to the feed and at least 60% lower olefins as determined by Bromine Index relative to the feed. The catalyst comprises an aluminosilicate zeolite component having an MOR framework type, an MFI molecular sieve component having a Si/Al 2 molar ratio of less than 80, an inorganic oxide binder, and a metal component comprising a metal consisting essentially of molybdenum.
DETAILED DESCRIPTION
[0009] The aromatic hydrocarbons to be transalkylated by processes of the invention include alkylaromatic hydrocarbons of the general formula C 6 H (6-n) R n , where n is an integer from 0 to 5 and R is CH 3 , C 2 H 5 , C 3 H 7 , or C 4 H 9 , in any combination. Non-limiting examples include: benzene, toluene, ethylbenzene, ethyltoluenes, propylbenzenes, tetramethylbenzenes, ethyl-dimethylbenzenes, diethylbenzenes, methylethylbenzenes, methylpropylbenzenes, ethylpropylbenzenes, triethylbenzenes, trimethylbenzenes, di-isopropylbenzenes, and mixtures thereof. In an embodiment, the feed stream includes up to about 35 mass percent of C 8 aromatics. In another embodiment, the feed stream includes up to about 30 mass percent of C 8 aromatics; the C 8 aromatic content of the feed stream may range from about 5 to about 25 mass percent and the C 8 aromatic content of the feed stream may be less than about 5 mass percent.
[0010] As used herein, the term “transalkylation” encompasses transalkylation between and among alkyl aromatics, between benzene and alkyl aromatics, and it includes dealkylation and disproportionation, e.g., of toluene to benzene and xylene. The aromatic hydrocarbons also may comprise naphthalene and other C 10 and C 11 aromatics. Herein, hydrocarbon molecules may be abbreviated C 1 , C 2 , C 3 , . . . C n , where “n” represents the number of carbon atoms in the hydrocarbon molecule. Such abbreviations followed by a “+” is used to denote that number of carbon atoms or more per molecule, and a “−” is used to denote that number of carbon atoms or less per molecule.
[0011] Polycyclic aromatics having from 2 to 4 rings are permitted in the feed stream of the present invention. Non-limiting examples include: indanes, naphthalenes, tetralins, decalins, biphenyls, diphenyls and fluorenes. Indane is meant to define a nine carbon atom aromatic species with one ring of six carbon atoms and one ring of five carbon atoms wherein two carbon atoms are shared. Naphthalene is meant to define a ten carbon atom aromatic species with two rings of six carbon atoms wherein two carbon atoms are shared.
[0012] The aromatic hydrocarbons to be transalkylated may be introduced to the transalkylation zone in one or more feed streams. As used herein, the term “zone” can refer to one or more equipment items and/or one or more sub-zones. Equipment items may include, for example, one or more vessels, heaters, separators, exchangers, conduits, pumps, compressors, and controllers. Additionally, an equipment item can further include one or more zones or sub-zones. In embodiments having multiple feed streams, the feed streams may be introduced separately to the transalkylation zone, or two or more of the feed streams may be combined in any manner prior to passing them into the transalkylation zone.
[0013] The feed streams may be derived from one or more sources including, without limitation, catalytic reforming, pyrolysis of naphtha, distillates or other hydrocarbons to yield light olefins and heavier aromatics-rich byproducts, and catalytic or thermal cracking of heavy oils to yield products in the gasoline range. Products from pyrolysis or other cracking operations generally will be hydrotreated according to processes well known in the industry before being charged to the transalkylation zone in order to remove sulfur and other compounds which would affect product quality. Light cycle oil also may be beneficially hydrocracked to yield lighter components which can be reformed catalytically to yield the aromatics-rich feed stream. If the feed stream is catalytic reformate, the reformer preferably is operated at high severity for high aromatics yield with a low concentration of non-aromatics in the product. In an embodiment, reformate and other feed streams containing olefins may be processed in the transalkylation zone without pretreatment to remove olefins.
[0014] A feed stream can include a substantially pure alkylaromatic hydrocarbon of from about 6 to about 15 carbon atoms, a mixture of such alkylaromatic hydrocarbons, or a hydrocarbon fraction rich in said alkylaromatics. A feed stream also may contain lesser concentrations of non-aromatics such as pentanes, hexanes, heptanes and heavier paraffins along with paraffins along with methylcyclopentane, cyclohexane and heavier naphthenes; pentanes and lighter paraffins generally will have been removed before processing. The combined transalkylation feed preferably contains no more than about 10 wt % non-aromatics.
[0015] In an embodiment, at least two feed streams are introduced to the transalkylation zone, a light feed stream and a heavy feed stream. The light aromatic feed stream may comprise at least one of benzene and toluene. Preferred components of the heavy aromatic feed are C 9 + aromatics, thereby effecting transalkylation of toluene and C 9 + aromatics to yield additional xylenes. Benzene may also be transalkylated to yield additional toluene. Indane may be present in the heavy aromatics feed stream although it is not a desirable component to effect high yields of xylenes in the transalkylation zone effluent. C 10 + aromatics also may be present, preferably in an amount of 30% or less of the heavy aromatic feed. The heavy aromatic feed stream preferably comprises at least about 90 mass % aromatics, and may be derived from the same or different known refinery and petrochemical processes as the benzene/toluene feed stream and/or may be recycled from the separation of the transalkylation effluent.
[0016] The feed to the transalkylation zone also comprises an olefin. As used herein, the term “olefin” includes alkenes, cyclic alkenes, alkenylbenzenes and other bromine reactive species as determined by UOP304. The olefin content of the feedstock and other streams herein is reported as a Bromine Index, which is a commonly used indicator of the olefin content. The feed according to the invention has a Bromine Index of more than 50. In an embodiment, the feed has a Bromine Index of at least about 100, the feed may have a Bromine Index of more than 600. In an exemplary embodiment, the feed has a Bromine Index of at least about 1000, and the feed may have a Bromine Index of at least about 2000. The Bromine Index is determined in accordance with UOP Method 304, obtainable through ASTM International, 100 Barr Harbor Drive, West Conshohocken, Pa., USA. It should be pointed out that there are other standard test methods for Bromine Index. However, these methods do not necessarily provide the same results as UOP304. Therefore, it is to be understood that the numerical values of Bromine Index herein are as measured by UOP304 only and are reported in units of milligrams of bromine per 100 g of sample.
[0017] When multiple feed streams are introduced to the transalkylation zone, overall or total feed properties such as the above Bromine Index values of the feed are the weighted average Bromine Index of all the feed streams introduced. The aromatic feed to a transalkylation reaction zone is usually first heated by indirect heat exchange against the reaction product stream and then is heated to reaction temperature by exchange with a warmer stream, steam or a furnace. The feed is preferably transalkylated in the vapor phase and in the presence of hydrogen. In an embodiment a hydrogen stream is introduced to the transalkylation zone. The hydrogen stream may comprise other compounds, e.g. C 1 to C 4 hydrocarbons, in addition to hydrogen. Hydrogen and hydrocarbons may be recycled in the process as described below. If present, free hydrogen is associated with the feedstock and recycled hydrocarbons, if any, in an amount from about 0.1 moles per mole of aromatics up to 10 moles per mole of aromatics. This ratio of hydrogen to aromatics is also referred to as hydrogen to hydrocarbon ratio.
[0018] The feed is then passed through one or more reactors containing the transalkylation catalyst to produce a reaction product stream comprising unconverted feed and product hydrocarbons including xylenes. The reaction product stream has a greater amount of xylenes relative to the feed stream on a mass basis, and a reduced amount of olefins relative to the feed as determined by Bromine Index. Benzene may also be produced. This reaction product stream is normally cooled by indirect heat exchange against the aromatic feed stream entering the transalkylation zone and may be further cooled through the use of air or cooling water. The reaction product stream may be separated e.g. in a vapor-liquid separator to produce a vapor phase hydrogen stream and a liquid phase reaction product stream. The vapor phase hydrogen stream includes hydrogen and light hydrocarbons which may be recycled and combined with the feed as described above. The liquid phase reaction product stream may be passed into a stripping column in which substantially all C 5 and lighter hydrocarbons present are concentrated into an overhead stream and removed from the process. As used herein, the term “substantially all” means an amount generally of at least 90%, preferably at least 95%, and optimally at least 99%, by weight, of a compound or class of compounds in a stream. The stripping column also produces a net stripper bottoms stream, which is referred to herein as the transalkylation zone effluent.
[0019] The transalkylation zone effluent may be further separated in a distillation zone comprising at least one distillation column to produce a benzene product stream. Various flow schemes and combinations of distillation columns to separate transalkylation zone effluent via fractional distillation are well known in the art. In addition to the benzene product stream, the distillation zone may produce a toluene product stream, and a C 8 + product stream. See, e.g., U.S. Pat. No. 7,605,295. It is also known that the transalkylation zone stripper column may be designed and operated to produce a benzene product stream. See, e.g., U.S. Pat. No. 6,740,788. Thus, the reaction product stream contains a benzene fraction that may be separated by fractional distillation to produce a benzene product stream.
[0020] In another embodiment, the transalkylation effluent is separated into a light recycle stream, a mixed C 8 aromatics product, and a heavy aromatic product stream in a distillation zone. The mixed C 8 aromatic product may be sent for recovery of para-xylene and/or other isomers. The light recycle stream may be diverted to other uses such as benzene and toluene recovery, but may be recycled, in part, to the transalkylation zone. The heavy recycle stream contains substantially all of the C 9 and heavier aromatics and may be partially or totally recycled to the transalkylation reaction zone.
[0021] In an embodiment, the transalkylation conditions are sufficient to provide a reaction product stream having a higher concentration of xylenes than the transalkylation feed and an olefin content that is at least 60% lower than the olefin content of the feed as determined by Bromine Index. In an embodiment, the olefin content of the product is at least 80% lower than the olefin content of the feed as determined by Bromine Index, and may be at least 90% lower, preferably at least 95% lower than the olefin content of the feed as determined by Bromine Index.
[0022] Contacting the feed with the catalyst can be effected in any conventional or otherwise convenient manner and may occur as a batch or continuous type of operation. In an embodiment, the catalyst is disposed in one or more fixed beds in a reaction zone of a vertical reactor with the aromatic feed charged through the bed in an upflow or downflow manner. Transalkylation conditions may include a temperature in a range of from about 200° C. to about 540° C., preferably between about 200° C. to about 480° C.; a pressure in a range of from about 100 kPa to about 6 MPa absolute; and a weight hourly space velocity (WHSV, i.e., weight of aromatic feed introduced per weight of catalyst per hour) in a range of from about 0.1 to about 20 hr −1 , preferably ranging from about 1 to about 10 hr −1 .
[0023] The transalkylation conditions include the presence of a transalkylation catalyst comprising: an aluminosilicate zeolite having an MOR framework type, an MFI molecular sieve having a Si/Al2 molar ratio of less than 80, a metal component, and an inorganic oxide binder.
[0024] Aluminosilicate zeolite having an MOR framework is described in A TLAS OF Z EOLITE F RAMEWORK T YPES, 6th Revised Edition, C. H. Baerlocher, L. B. McCusker, and D. H. Olson, editors, Elsevier (2007), pp. 218-219. The MOR framework comprises four- and five-membered rings of SiO 4 and AlO 4 tetrahedra to form a crystal lattice comprising 12-ring channels running parallel along a crystal axis to give a tubular configuration. In an embodiment, the aluminosilicate zeolite having an MOR framework comprises mordenite. Where mordenite is a component of the catalyst, the mordenite preferably has a Si/Al 2 molar ratio of less than about 40. The Si/Al 2 molar ratio of mordenite in an embodiment is less than about 25, and in another embodiment the mordenite Si/Al 2 molar ratio is between about 15 and about 25. Mordenite may be synthesized with a Si/Al 2 molar ratio of between about 10 and about 20. Mordenite is preferably at least partially in the hydrogen form and/or may be dealuminated by a variety of techniques, e.g. steaming, and acid extraction of aluminum to increase the Si/Al 2 ratio of the mordenite.
[0025] In another embodiment, the aluminosilicate zeolite having an MOR framework comprises UZM-14. UZM-14 is described in U.S. Pat. No. 7,687,423, which is incorporated herein by reference in its entirety. UZM-14 comprises globular aggregates of crystallites having a MOR framework type comprising 12-ring channels, and one or more of the following distinctive characteristics: a mesopore volume of at least about 0.10 cc/gram, preferably at least about 0.13 cc/gram, more preferably at least about 0.2 cc/gram; a mean crystallite length parallel to the direction of the 12-ring channels of about 60 nm or less, preferably about 50 nm or less; a Si/Al 2 mole ratio of between about 8 and about 50, and preferably is no more than about 30; and at least about 1×1019 12-ring channel openings per gram of UZM-14 material.
[0026] In an embodiment, UZM-14 comprises globular aggregates of crystallites having a MOR framework type comprising 12-ring channels, a silica-alumina mole ratio of from about 8 to no more than about 30, a mesopore volume of at least about 0.10 cc/gram, and a mean crystallite length parallel to the direction of the 12-ring channels of about 60 nm or less.
[0027] UZM-14 has an empirical composition in the as-synthesized form on an anhydrous basis expressed by the empirical formula:
[0000] M m n+ R r p+ Al 1-x Si y O z
[0000] where M is at least one exchangeable cation and is selected from the group consisting of alkali and alkaline earth metals including but not limited to lithium, sodium, potassium, rubidium, cesium, calcium, strontium, barium and mixtures thereof. R is at least one organic cation selected from the group consisting of protonated amines, protonated diamines, quaternary ammonium ions, diquaternary ammonium ions, protonated alkanolamines, and quaternized alkanolammonium ions. Relating the components, “m” is the mole ratio of M to Al and varies from about 0.05 to about 0.95; “r” is the mole ratio of R to Al and has a value of about 0.05 to about 0.95; “n” is the weighted average valence of M and has a value of about 1 to about 2; “p” is the weighted average valence of R and has a value of about 1 to about 2; “y” is the mole ratio of Si to Al and varies from about 3 to about 50; and “z” is the mole ratio of O to Al and has a value determined by the equation: z=(m·n+r·p+3+4y)/2.
[0028] The catalyst also includes an MFI molecular sieve having a Si/Al 2 molar ratio of less than 80. Zeolites having an MFI type framework are described in A TLAS OF Z EOLITE F RAMEWORK T YPES, 6th Revised Edition, C. H. Baerlocher, L. B. McCusker, and D. H. Olson, editors, Elsevier (2007). MFI type zeolites have a 3-dimensional 10-ring channel system: [100] 10-MR 5.1×5.5 Å and [010] 10-MR 5.3×5.6 Å. In an embodiment, MFI molecular sieves used in the catalysts of this invention have a Si/Al 2 molar ratio of less than about 40, preferably less than about 25, for example, between about 15 to about 25. An example of a suitable MFI molecular sieve for inclusion in the catalyst includes, but is not limited to, ZSM-5, which is disclosed in U.S. Pat. No. 3,702,886, incorporated herein, by reference thereto. Suitable MFI molecular sieves are also available, for example, from Zeolyst International of Conschocken, Pa. and Tosoh Corporation of Tokyo, Japan.
[0029] In an embodiment, the MFI molecular sieve has a “Total Acidity” of at least about 0.15, preferably at least about 0.25, and more preferably at least about 0.4, for example, 0.4 to 0.8. Total Acidity is determined by Ammonia Temperature Programmed Desorption (Ammonia TPD). The Total Acidity of the MFI molecular sieve may be that of the MFI to be used in making the catalyst of the invention or may be achieved during the preparation of the catalyst. Typically, the MFI molecular sieve is at least partially in the hydrogen form in the finished catalyst. The Ammonia TPD process involves first heating a sample (about 250 milligrams) of molecular sieve at a rate of about 5° C. per minute to a temperature of about 550° C. in the presence of a 20 volume percent oxygen in helium atmosphere (flow rate of about 100 milliliters per minute). After a hold of about one hour, helium is used to flush the system (about 15 minutes) and the sample is cooled to about 150° C. The sample is then saturated with pulses of ammonia in helium at about 40 milliliters per minute. The total amount of ammonia used is greatly in excess of the amount required to saturate all the acid sites on the sample. The sample is purged with helium (about 40 milliliters per minute) for about 8 hours to remove physically adsorbed ammonia. With the helium purge continuing, the temperature is increased at a rate of about 10° C. per minute to a final temperature of 600° C. The amount of ammonia desorbed is monitored using a calibrated thermal conductivity detector. The total amount of ammonia is found by integration. Dividing the total amount of ammonia by the dry weight of the sample yields the Total Acidity. As used herein, values of Total Acidity are given in units of millimoles of ammonia per gram of dry sample.
[0030] The inorganic oxide binder of the catalyst comprises such materials as alumina, silica, zirconia, titania, thoria, boria, magnesia, chromia, stannic oxide, and the like as well as combinations and composites thereof, for example silica-alumina, alumina-zirconia, alumina-titania, aluminum phosphate, and the like. Alumina is a preferred refractory inorganic oxide binder. As is well known in the art, a precursor of the desired refractory inorganic oxide may be used to form, bind, and/or otherwise prepare the catalyst. Such binder precursors or sources may be converted into a refractory inorganic oxide binder, e.g. by calcination. The alumina may be any of the various aluminum oxides, hydroxides, and gels, including boehmite, pseudo-boehmite, gibbsite, bayerite, and the like, especially transition and gamma aluminas Suitable aluminas are commercially available, e.g. under the trade names CATAPAL B and VERSAL 250.
[0031] In an embodiment, the metal component of the catalyst comprises a metal consisting essentially of molybdenum. In another embodiment, the metal component comprises molybdenum. In an embodiment, the molybdenum content of the catalyst ranges from about 0.5 wt % to about 10.0 wt % as the metal based upon the total weight of the catalyst. In another embodiment, the molybdenum content of the catalyst ranges from about 1 wt % to about 8 wt %, and may range from about 2 wt % to about 7 wt % as the metal based upon the total weight of the catalyst.
[0032] The metal component may be incorporated into the catalyst in any suitable manner such as comulling, coprecipitation or cogellation with the carrier material, ion exchange, or impregnation. The metal component may exist within the final catalyst as a compound such as an oxide, sulfide, halide, or oxyhalide, in chemical combination with one or more of the other ingredients of the composite, or as an elemental metal. One method of preparing the catalyst involves the use of a water-soluble or solvent-soluble, decomposable compound of the metal to impregnate the molecular sieve-containing support. Alternatively, a metal compound may be added at the time of compositing the molecular sieve component and binder.
[0033] The weight ratio of the MFI molecular sieve component to the aluminosilicate zeolite having the MOR framework may range from about 1:10 to 5:1, preferably from about 1:10 to 2:1. In an embodiment, the aluminosilicate zeolite component having the MOR framework comprises from about 20 wt % to about 80 wt % of the catalyst, the MFI molecular sieve component comprises from about 10 wt % to about 70 wt % of the catalyst, and the inorganic oxide binder comprises between about 1 wt % and about 40 wt % of the catalyst.
[0034] The catalyst may optionally include an additional molecular sieve component preferably selected from one or more of MEL, EUO, FER, MFS, MTT, MTW, MWW, MAZ, TON and FAU (IUPAC Commission on Zeolite Nomenclature) and UZM-8 (see U.S. Pat. No. 6,756,030 which is herein incorporated by reference in its entirety). The catalyst may optionally include a fluoride component in an amount ranging from about 0.1 wt % to about 5.0 wt % of fluoride based upon the total weight of the catalyst. The fluoride component may be incorporated into the catalyst by any known technique, e.g. impregnation.
[0035] The techniques used to prepare the catalyst are well known to those of ordinary skill in the art. The catalyst can be formed by combining the aluminosilicate zeolite component having the MOR framework, the MFI molecular sieve component, and the inorganic oxide binder and/or a precursor thereof in any conventional or otherwise convenient manner to form spheres, pills, pellets, granules, extrudates, or other suitable particle shapes. For example, finely divided aluminosilicate zeolite having the MOR framework and MFI molecular sieve particles, and metal salt particles can be dispersed in an alumina sol, and the mixture in turn dispersed as droplets in a hot oil bath whereby gelation occurs with the formation of spheroidal gel particles. A preferred method comprises mixing a finely divided form of the selected aluminosilicate zeolite having the MOR framework, MFI molecular sieve particles, a binder and/or precursor thereof, with a metal salt and, optionally, a lubricant; and compressing the mixture into pills or pellets. Alternatively, and still more preferably, the aluminosilicate zeolite having the MOR framework, MFI molecular sieve particles, binder and/or precursor thereof, and metal salt are combined and admixed with a peptizing agent in a mixer-muller, a dilute nitric acid being one example of the suitable peptizing agent. The resulting dough can be pressured through a die or orifice of predetermined size to form extrudate particles which can be dried and calcined and utilized as such. A multitude of different extrudate shapes are possible, including, but not limited to, cylinders, cloverleaf, dumbbell and symmetrical and asymmetrical polylobes, with a trilobe form being favored. The extrudates also may be formed into spheres by means of a spinning disc or drum. The variously formed particles are then usually dried and/or calcined.
[0036] If the metal component is not included in the above forming steps, the formed particles produced above can be impregnated with a soluble, decomposable compound containing the metal component to form a composite. For example, typical compounds which may be employed include ammonium heptamolybdate, alkali metal molybdates (also peroxo-, di-, tri-, tetra-, hepta-, octa-, or tetradecamolybdate), molybdic acid, phosphomolybdic acid, Mo—P heteropolyanion compounds, acetyl acetonates, Mo(0) metal, Mo oxides, Mo peroxo complexes, and mixtures thereof. The composite is preferably calcined in an air atmosphere at a temperature of from about 425° C. to about 750° C., preferably at a temperature of from about 475° C. to about 600° C., over a period of from about 0.5 to about 10 hours. Typically, the formed particles are also calcined at similar conditions prior to the impregnation step. The catalyst preparation may include various optional steps such as drying and steaming which are well known in the art.
Example 1
[0037] A catalyst was prepared by blending of UZM-14, MFI zeolite, and Catapal C to obtain a 50% UZM-14, 25% MFI zeolite, and 25% Catapal C mixture on a volatile free (VF) weight basis. The mixture also included a solution of ammonium heptamolybdate to obtain 5 wt % molybdenum (VF) in the final catalyst, and a solution of diluted nitric acid as the peptizing agent to form a dough. The dough was extruded as a cylinder and the catalyst was calcined at 580° C. for 20 minutes with 7.5% added steam. The UZM-14 zeolite used in this example was prepared according to Example 1 of U.S. Pat. No. 7,687,423 except the crystallization temperature was 140° C. and commercial scale equipment was used. After synthesis, the UZM-14 material was washed, exchanged with an ammonium sulfate solution and dried. This material had the following properties: a molar SiO 2 /Al 2 O 3 ratio of 18.0, a BET surface area of 440 m 2 /g, a micropore volume of 0.20 cc/gram, and a mesopore volume of 0.22 cc/gram. The MFI zeolite was CBV 2314, a ZSM-5 material with SiO 2 /Al 2 O 3 of 23, obtained from Zeolyst International. Catapal C was purchased from Vista Chemical Company. The finished catalyst had a BET surface area of 360 m 2 /g and a total pore volume of 0.50 cc/g. The piece density was 1.200 g/cc.
Example 2
[0038] The catalyst prepared in example 1 was tested in an aromatics transalkylation test with a feed blend of 50 wt % toluene and 50 wt % a xylene column bottoms stream, i.e. C 9 + aromatics. The feed had nominally the composition in weight percent given in Table 1. Prior to testing, the catalyst was sulfided in-situ as is well known in the art to convert the MoO 3 and/or molybdenum metal of the calcined catalyst, at least partially, to molybdenum sulfide. An objective of catalyst sulfiding is to add a fixed amount of sulfur to the catalyst. This was accomplished by passing excess dimethyl disulfide (DMDS), equivalent to 250 ppm-wt as sulfur in the feed over the catalyst at a temperature ranging from about 280° C. to 360° C., a pressure of 2,758 kPa(g), a weight hourly space velocity of 4, and a hydrogen to hydrocarbon ratio of 2 for 30 hours. This procedure provides a sulfided catalyst with a relatively fixed sulfur content such that longer sulfiding with excess DMDS will not increase the sulfur content of the catalyst further. After the sulfiding procedure was complete, feed without DMDS was introduced to the catalyst and testing conditions of a pressure of 2,758 kPa(g), a weight hourly space velocity of 4, and a hydrogen to hydrocarbon ratio of 2 were established. The reactor temperature was adjusted to obtain 50% overall conversion, calculated as the net disappearance of toluene, C 9 and C 10 aromatics from the feed stream, i.e. (mass of toluene, C 9 and C 10 aromatics in the feed minus mass of toluene, C 9 and C 10 aromatics in the reaction product)/mass of toluene, C 9 and C 10 aromatics in the feed, on a weight percent basis.
[0039] After reaching steady-state at test conditions, two C 9 olefins were added to the feed to determine olefin removal during transalkylation. The modified feed contained 0.42 wt % alpha-methylstyrene and 0.35 wt % indene. The Bromine Index of the modified feed was determined to be 1,067. The liquid product from the transalkylation reactor was analyzed by GC and no alpha-methylstyrene or indene was detected, indicating complete conversion of the olefins. The Bromine Index of the liquid product was determined to be 21. These results demonstrate excellent olefin removal capability of a transalkylation catalyst containing molybdenum as exemplified by example 1.
[0000]
TABLE 1
Toluene
50
Propylbenzene
2.1
Methylethylbenzene
10.5
Trimethylbenzene
24.5
Indane
0.7
Methylpropylbenzene
1.8
Diethylbenzene
0.5
Dimethylethylbenzene
3.5
Tetramethylbenzene
2.1
Other C 10 aromatics
1.6
C 11 + aromatics
2.7 | A process for aromatic transalkylation and olefin reduction of a feed stream is disclosed. Transalkylation conditions produce xylenes and reduced olefins in the feed. The process may be used in a xylene production facility to minimize or avoid the necessity of feedstock pretreatment such as hydrotreating, hydrogenation, or treating with clay and/or molecular sieves. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuing application, under 35 U.S.C. §120, of copending International Application No. PCT/EP2005/000786, filed Jan. 27, 2005, which designated the United States; this application also claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2004 006 620.5, filed Feb. 10, 2004; the prior applications are herewith incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The invention relates to a storage-transport system and to a method for storing and for transporting radioactive waste.
[0003] Following cost-effective use of radioactive materials, the latter have to be disposed of in a suitable manner due to their residual radiation and long half-lives. Considerable quantities of radioactive waste are produced, in particular in the case of energy being generated through the use of nuclear power. In addition to spent fuel elements, those quantities of radioactive waste also include low-level and medium-level radioactive waste, for example contaminated operating equipment. Liquid radioactive waste is often cast, in a cementation installation, into a solid mass which is introduced, for example, into drums.
[0004] Safe storage of the waste has to be ensured due to the very long half-lives. At present, in Germany, the radioactive waste is stored in interim storage facilities over a period of a number of years until being transported, at the end of that period, into a yet-to-be-determined final storage facility.
[0005] It is thus necessary for those containers, into which the radioactive waste has been introduced, to meet requirements with respect to storage both in the interim storage facility and in the final storage facility, as well as requirements with respect to necessary transportation, for example between the interim storage facility and the final storage facility. As a result, the containers have to meet very stringent requirements overall both with respect to providing shielding for radiation of the radioactive waste located in the container and with respect to a sufficiently high level of transportation safety, for example by way of sufficiently high mechanical stability, in order to reliably avoid the leakage of radioactivity in the event of an accident during transportation. Furthermore, the containers have to be constructed so as to be capable of transportation and handling. Those requirements render current transporting and storage containers highly complex and correspondingly expensive.
SUMMARY OF THE INVENTION
[0006] It is accordingly an object of the invention to provide a storage-transport system and a method for storing and for transporting radioactive waste, which overcome the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type and which allow simplified and more cost-effective storage and simplified and more cost-effective transportation, in particular of low-level and medium-level radioactive waste.
[0007] With the foregoing and other objects in view there is provided, in accordance with the invention, a storage-transport system for storing and for transporting radioactive waste. The transport system comprises a storage container for accommodating the radioactive waste. The storage container meets relatively less stringent requirements regarding shielding capacity against radioactive radiation for storage in a storage facility, in particular an interim storage facility, but does not meet relatively more stringent requirements for transportation outside the storage facility. The storage container is configured for placement in a transport container meeting the relatively more stringent transportation requirements for transportation outside the storage facility.
[0008] This configuration is based on the concept of taking into account the different requirements with respect to storage and transportation of the storage and transportation functions of a container for radioactive waste being separated and divided between two containers constructed to meet different requirements. To be precise, a specific storage container which, for transportation, is transported into a suitable transport container is provided. Due to the more low-level requirements with respect to storage in the interim storage facility, this measure allows the storage container to have a considerably more straightforward and, in particular, more cost-effective construction than is possible for the current conventional containers, which are constructed both for storage and for transportation purposes.
[0009] Separating the storage and transportation functions, in addition, makes it possible to select different storage systems for the final storage facility. Since the interim storage facilities are constructed, for example, for a half-life of 30 years, it is thus possible to take into account technical developments and findings for final storage purposes.
[0010] In particular, the containers have to meet requirements, on one hand, with respect to providing shielding for the radioactive radiation and, on the other hand, with respect to mechanical stability. Both requirements are usually considerably less stringent in the interim storage facility since, for example, in comparison with transportation, there is no risk of an accident during storage (mechanical stability). It is also the case that the interim storage facility itself, which is in the form of a dedicated part of a building, for example directly on the grounds of a nuclear plant, provides shielding for the radioactive radiation, whereas during transportation, the container comes into direct contact with the environment and thus has to provide better shielding than in the interim storage facility. The containers in this case have to be constructed in such a way that a maximum admissible radiation-dose output is not exceeded.
[0011] In accordance with another feature of the invention, the storage container is constructed merely for complying with a relatively high maximum admissible radiation-dose output in the interim storage facility, but not for complying with a relatively low maximum admissible radiation-dose output outside the interim storage facility. It is only by placing the storage container in the transport container that the radiation-dose output also drops below the relatively low maximum admissible value outside the interim storage facility.
[0012] In accordance with a further feature of the invention, the storage container is provided for accommodating a plurality of receptacles with radioactive waste, in particular for accommodating drums. This simplifies the handling of the receptacles and allows the latter to be handled together. It is also possible, if required, to provide for additional measures for shielding purposes and for increasing the mechanical stability. Thus, for example, for final storage purposes, the receptacles stored in the storage container are preferably cast in place in the storage container. In an alternatively advantageous configuration, without reverting to the use of receptacles, the storage container is provided for accommodating solid radioactive waste.
[0013] In accordance with an added feature of the invention, in order to ensure accessibility to the individual receptacles, in particular drums, in the storage container, the storage container is closed merely by a loosely or releasably disposed cover. This measure thus makes it possible, at any time, to remove the cover and, for example, automatically inspect and monitor the stored drums. Furthermore, it is also possible to handle the individual receptacles. In particular, the configuration with the loose cover makes it possible, for final storage purposes, for the individual receptacles to be stored in accordance with the most recent technological findings.
[0014] In accordance with an additional feature of the invention, in order to provide storage in the interim storage facility which is as space-saving and stable as possible, the storage container preferably has a stackable construction. For this purpose, the container has, for example, a rectangular cross section and, on its underside, feet and, on the top side, mounts or guides for the feet of a further storage container, as is provided in conventional stacking containers.
[0015] In accordance with yet another feature of the invention, the storage container is constructed in such a way that its side walls and its base are formed of a concrete structure or of steel. The concrete structure may be provided with corresponding reinforcement. The concrete structure makes it possible, straightforwardly and cost-effectively, to achieve both good shielding and sufficient mechanical stability for storage purposes. In this case, however, the wall thicknesses are smaller than in the case of a container constructed for transportation purposes.
[0016] In accordance with yet a further feature of the invention, in order to keep the costs low, the transport container is constructed for repeated transportation of storage containers. Only a small number of transport containers is required by virtue of it being possible to reuse the transport container. Correspondingly, it is possible for the transport container to be very complex and constructed to meet highly stringent safety requirements without this having a marked influence on the costs for the storage-transport system overall. It is expedient, for repeated loading and unloading of the transport container, for the latter to be configured with a container cover which, in particular, can be motor-actuated and closed repeatedly.
[0017] In accordance with yet an added feature of the invention, in order for the storage container to fit as closely, and thus reliably, as possible in the transport container, the internal dimensions of the transport container are adapted to the external dimensions of the storage container. In order for the storage container to be straightforwardly introduced and securely retained, guides which are constructed, in particular, in the manner of profiles or strips are preferably provided, in addition, on the walls of the transport container. These guides allow the storage container to be retained in the transport container, as far as possible, in a play-free manner. The guides preferably have introduction slopes for easy introduction.
[0018] In accordance with yet an additional feature of the invention, the transport container is constructed as a steel container from a suitable steel with a high shielding capacity and high mechanical stability.
[0019] With the objects of the invention in view, there is also provided a method for storing and for transporting radioactive waste. The method comprises providing a storage container meeting relatively less stringent requirements regarding shielding capacity against radioactive radiation for storage in a storage facility, in particular an interim storage facility, but not meeting relatively more stringent requirements for transportation outside the storage facility. The radioactive waste is introduced into the storage container. The storage container is positioned in the storage facility. The storage container is placed in a transport container meeting the relatively more stringent transportation requirements for transportation outside the storage facility.
[0020] The preferred configurations and advantages which have been cited with respect to the storage-transport system can also be applied analogously to the method.
[0021] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0022] Although the invention is illustrated and described herein as embodied in a storage-transport system and a method for storing and for transporting radioactive waste, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0023] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a diagrammatic, partly-sectional, side-elevational view of a storage container according to the invention with a cover provided for loose placement in position;
[0025] FIG. 2 is a further partly-sectional, side-elevational view of the storage container according to FIG. 1 ;
[0026] FIG. 3 is a plan view of the storage container according to FIGS. 1 and 2 , indicating section lines I-I of FIG. 1 and II-II of FIG. 2 ;
[0027] FIG. 4 is a perspective view of a transport container;
[0028] FIG. 5 is a side-elevational view of the transport container according to FIG. 4 , with a diagrammatically illustrated driver's cab of a truck; and
[0029] FIG. 6 is a block diagram demonstrating disposal of radioactive waste.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Referring now to the figures of the drawings in detail and first, particularly, to FIGS. 1-3 thereof, there is seen a storage container 2 which is constructed in such a way that its side walls 4 , together with its base 6 , are formed of a single-piece concrete structure. A cover 8 , which is preferably likewise made of concrete, is provided with a gripping device 9 for the purpose of closing the storage container 2 . The cover 8 is merely placed loosely in position on the side walls 4 for the purpose of closing the storage container 2 . The storage container 2 has a rectangular outline and a stackable construction. For this purpose, feet 10 are disposed at four corner points on the underside of the base 6 . The side walls 4 each carry mounts or guides 12 on their top end side at the four corners. The feet 10 of a further storage container 2 are introduced into these mounts or guides during stacking of this further storage container.
[0031] In the exemplary embodiment, the storage container 2 is provided for accommodating a total of 8 radioactive receptacles in the form of drums 14 . In order to prevent the drums 14 from slipping, the base 6 has a profile construction on its top side and has, in particular, rhomboidal elevations, resulting in the formation of a total of 8 separate accommodating spaces for the drums 14 , as is seen in FIG. 3 .
[0032] A transport container 20 , which can be seen in FIGS. 4 and 5 in particular, is adapted specifically for transportation within the grounds of a power station. In the exemplary embodiment, it is constructed as a steel container and can be closed by a double-wing container cover 22 . Two motors 26 are provided on an outer end side of a side wall 24 of the container for the purpose of reversible opening and closing. These motors 26 are each connected, through an extensible linkage 28 , to a respective wing of the container cover 22 in order for the wing to be reversibly opened and closed.
[0033] Locking and securing devices 30 for the container cover 22 are also disposed on the side wall 24 of the container.
[0034] Guide profiles 32 in the interior of the container are fastened on the side walls 24 of the container. These guide profiles 32 have an introduction slope 34 on their top end side. The internal dimensions of the transport container 20 are such that the storage container 2 , which has been 1 ) described in relation to FIGS. 1-3 , fits as closely as possible between the guide profiles 32 . The introduction slope 34 makes it easier for the storage container 2 to be introduced. This introduction slope, at the same time, also provides for automatic alignment and centering of the storage container 2 .
[0035] The transport container 20 is provided for transportation through the use of a truck 36 , of which the driver's cab is illustrated diagrammatically in FIG. 5 . The transport container 20 in this case is connected to the truck by suitable screw connections or other types of releasable connections or else in a non-releasable manner by welding.
[0036] The storage container 2 and the transport container 20 form part of a common concept for storing and for transporting low-level and medium-level radioactive waste. The important factor in this concept is to be seen in the fact that the storage and transportation functions are divided between two different container combinations. Thus, on one hand, the storage container 2 is constructed merely for storage, in particular in a non-illustrated interim storage facility, whereas the transportation function is performed by the transport container 20 combined with the storage container 2 introduced therein. Different regulations and requirements apply for the storage of radioactive waste in an interim storage facility and for the transportation of radioactive waste, not in the least because of legal requirements. Since a building which forms the interim storage facility also performs a shielding function with respect to the surroundings and, in addition, there is no transportation-related accident risk, the requirements with respect to storage in the interim storage facility are considerably less stringent than the requirements which have to be met by the transport container. Accordingly, the storage container 2 is constructed merely to meet the requirements which apply to the interim storage facility. In comparison with a transport container constructed for transportation purposes, this is manifested by a lower shielding capacity and, in addition, also by a lower level of sealing and mechanical stability. The storage container 2 is thus configured in such a way that, when a radioactive waste with a certain initial level of radioactivity is stored therein, the radiation-dose output drops below the maximum admissible value which applies to the interior of the interim storage facility, but does not drop below the lower, and thus more critical, maximum admissible value outside the interim storage facility.
[0037] The shielding capacity of the storage container 2 is determined substantially by the material selected for the side walls 4 , the base 6 and the cover 8 and by the density of the material and the wall thickness. The configuration of the storage container 2 in order to meet the more low-level requirements within the interim storage facility is manifested, for example, in such a way that, in each case in comparison with a container which also has to meet transportation requirements:
[0000] a) if use is made of the same material, the wall thickness is smaller,
b) if use is made of the same material, the latter may have a lower density, and
c) use can be made, overall, of a more cost-effective material with a lower shielding capacity and/or lower mechanical stability.
[0038] In particular, this gives rise to considerable cost-saving opportunities in comparison with a container which is constructed both as a storage and as a transport container.
[0039] In the exemplary embodiment of FIGS. 1-3 , the storage container 2 is constructed as a concrete container. It is also possible for the storage container 2 to be formed of some other material or material mix and to be constructed, for example, as a steel container.
[0040] The more stringent requirements with respect to transportation are manifested, for example, in the above-mentioned lower maximum admissible radiation-dose output and in the more stringent requirements which have to be met by the mechanical stability in order to take into account the greater risk of an accident during transportation. The more stringent transportation requirements are met by the transport container 20 combined with the storage container 2 inserted therein. It is also possible for the transport container 20 to already be constructed in such a way that it alone meets the transportation requirements so that, in principle, it would also be possible for receptacles containing the radioactive waste to be introduced loosely into the transport container 20 .
[0041] The transport container 20 basically serves for transportation purposes within the power-station grounds. In contrast, in order to transport the storage container 2 outside an interim storage facility 40 , for example for transporting the storage container 2 from an installation for conditioning the radioactive waste, such as a cementation installation 42 , into the interim storage facility 40 , as well as for transporting the storage container from the interim storage facility 40 into a final storage facility 44 , as is diagrammatically illustrated in simplified form in FIG. 6 , or for other transporting trips on public roads, a transport container which meets the requirements stipulated by IAEA is provided. The conditioning installation 42 is illustrated in this case as part of a nuclear plant 46 . The interim storage facility 40 may be a specific building on the grounds of the nuclear plant.
[0042] During operation of the nuclear plant 46 , in particular for generating energy (nuclear power station), both solid and liquid low-level and medium-level radioactive waste is produced and has to be disposed of in a suitable manner. In particular in the case of liquid waste, provision is often made for such waste to be mixed with a suitable cement mass in the cementation installation 42 and introduced into the above-mentioned drums 14 , in which the mass then solidifies. These drums 14 which are filled in the cementation installation 42 are inserted into the storage container 2 , and the storage container 2 is then inserted into the transport container 20 and transported into the interim storage facility 40 , where the storage container 2 is lifted out of the transport container 20 again and positioned in a storage location envisaged therefor. Respectively suitable cranes or lifting apparatuses are provided for handling the drums 14 and the storage container 2 , in the process of which they grip the drums 14 and/or the storage container 2 at suitable locations.
[0043] The cover 8 of the storage container 2 need only be placed in position loosely, not in the least because of the relatively low-level requirements in the interim storage facility 40 . This provides the advantage that, during the storage period in the interim storage facility, it is possible for the cover 8 to be easily removed and for the drums 14 stored therein to be inspected and monitored and exchanged, if required, for example in the event of leakage. The cover 8 has the gripping device 9 on its top side for the purpose of handling the same.
[0044] A further significant advantage of the cover 8 only being loosely or releasably placed in position is that there is no need to decide on the method of conditioning the radioactive waste at the interim storage stage. Rather, the option for the definitive conditioning method remains open until the radioactive waste is moved into the final storage facility 44 . Since the interim storage facility 40 is constructed, for example, for storing waste over a period of 30 years, that is to say a number of decades can elapse before the waste is transported into the final storage facility 44 , this measure makes it possible to take into account future technological developments or findings for definitive conditioning. This is particularly advantageous since the storage container 2 can be used not just for accommodating drums 14 but also for accommodating loose radioactive waste. A comparatively straightforward conditioning method for the final storage facility 44 is that of using a suitable cement mass to fill the storage container 2 , with the drums 14 stored therein. | A storage-transport system includes a storage container and a transport container for respectively storing and transporting weak to intermediate level active nuclear waste. The storage-transport system has different containers for the functions of storage and transport, namely the storage container and the transport container. The storage container only meets the requirements for temporary storage which are less strict than the requirements for the transport container, thereby allowing for a simple and therefore less expensive construction of the storage container. A method for storing and for transporting radioactive waste is also provided. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pharmaceutical composition, and, in particular, to an antitussive agent containing Cynanchi Atrati extract as an active antitussive component and the method for making the same.
2. Description of the Related Art
It should be noted that reference is made herein to concepts and practices well known within the established realm of traditional Chinese herbal remedy. A brief notation regarding the pertinent aspects of the art appears in Appendix A.
Cynanchi Atrati Radix is the root and rhizome of Cynanchum atratum Bunge or C. versicolor Bunge, family Asclepiadaceae, which is known as Bai Wei (rendered herein in accordance with pinyin standards of Chinese Romanization) in traditional Chinese medicine.
Crude drugs of Cynanchi Atrati Radix used in Chinese medicine are generally horse's tail-shaped, 10-15 cm long with rhizome stout, tubercular, transversely growing and circular stem tracing at the upper part with numerous slender roots clustered in the lower regions, The root of Cynanchi Atrati is 0.1-0.2 cm in diameter, grey-yellow and fragile. Crude drugs of Cynanchi Atrati Radix are conventionally prepared as bitter and salty segments, characterized within the parameters of traditional Chinese herbal remedies as being cold in nature and attributive to stomach and liver channels.
In traditional Chinese medicine, Cynanchi Atrati Radix is known as a successful remedy for lower asthenic fever. Specifically, Cynanchi Atrati Radix is regarded as curative for seasonal febrile disease involving depleted yin levels with prolonged fever or high fever at night subsiding in the morning, infantile summer fever, postpartum fever, and so on. Traditional indications for Cynanchi Atrati Radix disperse the disruptive factors from the body surface, for common cold with prolonged fever, especially those with yin-deficiency. Promote diuresis and relieve stranguria of heat type and when complicated by hematuria.
In addition, Cynanchi Atrati Radix is prescribed conventionally in combination with Cortex Lycii Radicts or di gu pi (rendered herein in accordance with pinyin standards of Chinese Romanization) or Herba Artemisiae Annuae in Chinese herbal medicine.
SUMMARY OF THE INVENTION
An object of the invention is to provide an antitussive agent that comprises an extract of Cynanchi Atrati Radix.
The present invention also provides a pharmaceutical composition containing the antitussive agent and a pharmaceutical acceptable carrier and/or excipient.
Another object of the invention is to provide a method for preparing the antitussive agent, and a method for relieving and/or preventing cough in mammals.
In an embodiment, the Cynanchi Atrati extract is prepared by extracting Cynanchi Atrati Radix, such as Cynanchum atratum Bunge or C. versicolor Bunge, with water, ethanol, hexane, ethyl acetate or a combination thereof. Moreover, the crude extract is preferably filtered by an ultrafiltration membrane with a molecular weight cut off 1000 to 3000 daltons to obtain a filtrate as an active component of the antitussive agent.
In addition, the crude extract of Cynanchi Atrati Radix can further be loaded onto a reverse phase column packed with HP20 resin or RP-18 resin and eluted with water and 80-95% ethanol solution sequentially. The ethanol eluate is collected as an active component of the antitussive agent.
In a preferred embodiment, the crude extract of Cynanchi Atrati Radix, with or without filtration using an ultrafiltration membrane, is further loaded onto a reverse phase column and then eluted with water and 80-95% ethanol solution sequentially. The ethanol eluate is collected and concentrated approximately 50 times. Water is added to the concentrated ethanol eluate to give a concentration of 5-20 mg dry basis/ml and then concentrated approximately 10 times. The eluate is then filtered to obtain a filtrate as the extract of Cynanchi Atrati Radix.
DETAILED DESCRIPTION OF THE INVENTION
Evaluation Model
The antitussive activity of various extracts of Cynanchi Atrati Radix is herein evaluated according to the method described by Winter C. A. et al. (J. Pharmacol. Exp. Ther. 112:99, 1954) with modification.
Duncan Hartley derived male and female guinea pigs, weighing 450±50 g, were used. Each guinea pig was placed in a 4-liter sealed chamber equipped with an ultrasonic nebulizer to provide cough-inducing irritant by aerosol. A microphone was set to amplify coughing sounds from the guinea pigs. The animals were exposed to an aerosolized solution of 10% citric acid for 10 seconds and selected if 9-15 coughs ensued in the following 5 minutes. On the next day, solvent, i.e. distilled water, or extracts were administered orally to the animals twice a day (10:00 am and 4:00 pm). The animals were again exposed to aerosolized 10% citric acid 60 minutes after the second dose administration. The inhibition activity of extracts on citric acid-induced cough was evaluated as follows:
Inhibition (%)=[(Number of coughs before administration)−(Number of coughs after administration)]/(number of coughs before administration)×100%
Sample Preparation and Antitussive Assessment Thereof
EXAMPLE 1
The dry rhizome of Cynanchum atratum was used. One kilogram pulverized dry material of Cynanchum atratum was heated to boil and refluxed twice with 10 L of the following solvents: water (Sample 1-1), 50% ethanol (Sample 1-2), 95% ethanol (Sample 1-3), ethyl acetate (EA) (Sample 1-4) and hexane (Sample 1-5), respectively. The extracts were then filtered with 350 mesh sieve and the filtrates were collected, respectively. The filtrates were further centrifuged continuously at 1089×g (Avanti™ J-25I, Beckman) for 3 hr to precipitate microparticles and impurities. The supernatants were further concentrated and freeze-dried. The antitussive assessment of the above extracts is shown in Table 1.
TABLE 1
Inhibition rate*
sample
Dosage (g/kg)
(%)
1-1
1.0
62 ± 8
0.5
49 ± 8
1-2
1.0
78 ± 4
0.5
88 ± 7
1-3
1.0
75 ± 9
0.5
66 ± 5
1-4
1.0
88 ± 4
0.5
41 ± 6
1-5
1.0
74 ± 3
0.5
56 ± 4
*data are presented as means ± s.e. (N = 4)
The results in Table 1 show that water, 50% ethanol, 95% ethanol, ethyl acetate (EA) and hexane extracts of Cynanchum atratum inhibited at least 60% of citric acid-induced coughs in the guinea pigs at 1.0 g/kg dosage.
EXAMPLE 2
120 g of dried Cynanchum atratum was extracted with 50% ethanol as in Example 1. The 50% ethanol extract of Cynanchum atratum was concentrated to 500±100 mL and adjusted to a volume of 2 L with water. The 2 L extract was further filtered by way of an ultrafiltration membrane with molecular weight cut off 1,000 (Amicon LP-1, inlet P=1.5 kg/cm 2 , outlet P=0.5 kg/cm 2 ). 1800 mL of the filtrate was firstly collected and 1800 mL water was added to the retentate to continue the ultrafiltration, repeating the process for 3 times. The retentate (Sample 2-1) with molecular weight greater than 1,000 dalton and the filtrate (Sample 2-2) containing substances with molecular weight less than 1,000 dalton were collected respectively and freeze-dried. The antitussive assessment of the above samples is shown in Table 2.
TABLE 2
Dosage
Inhibition rate*
Sample
(g/kg)
(%)
2-1
0.5
65 ± 8
2-2
0.5
57 ± 11
*data are presented as means ± s.e. (N = 4)
The results in Table 2 show that both of the fractions with molecular weight more and less than 1,000 dalton of the 50% ethanol extract of Cynanchum atratum are active to inhibit citric acid-induced coughs in the guinea pigs at 0.5 g/kg dosage.
EXAMPLE 3
680 g of dried Cynanchum atratum was extracted with water as in Example 1. 12000 g water extract obtained was further filtered by way of an ultrafiltration membrane with molecular weight cut off 1,000 (Amicon LP-1, inlet P=1.5 kg/cm 2 , outlet P=0.5 kg/cm 2 ). 10800 g of the filtrate was firstly collected and 10800 g water was added to the retentate, repeating the process for 3 times. The filtrate containing substances with molecular weight less than 1,000 dalton was concentrated to 0.812 dry base g/mL. The concentrated filtrates containing 38.5 g and 31.5 g dry powder were loaded onto columns packed with 3080 g and 2520 g HP20 (Diaion, Mitsubishi Chemistry inc.) resin, respectively, i.e. in a ratio of 1 g filtrate/80 g HP20 resin. The columns were first eluted with 24640 g and 20160 g water, respectively and then eluted with 50% or 95% ethanol respectively. 24640 g of 50% ethanol eluate and 20160 g of 95% ethanol eluate were collected, respectively (Sample 3-1 and 3-2). The 50% ethanol eluate and the 95% ethanol eluate were concentrated and freeze-dried. The antitussive assessment of the above eluates is shown in Table 3.
TABLE 3
Dosage
Inhibition rate*
Sample
(g/kg)
(%)
3-1
1.0
71 ± 7
0.5
41 ± 9
3-2
1.0
43 ± 9
0.5
38 ± 11
*data are presented as means ± s.e. (N = 4)
The results in Table 3 show that Sample 3-1 is highly active to inhibit citric acid-induced coughs in the guinea pigs at 1.0 g/kg dosage.
EXAMPLE 4
1200 g of dried Cynanchum atratum was extracted with water as in Example 1. The water extract was further concentrated to a concentration of 0.59 g/ml. A concentrated water extract containing 170 g dry powder was further loaded onto a reverse phase column packed with 6800 g HP20 resin, in a ratio of 1 g dry basis of the extract/40 g resin, The column was first eluted with 68000 g water and then eluted with 95% ethanol. The water eluate and 68000 g 95% ethanol eluate were collected respectively (Sample 4-1 and 4-3), concentrated and freeze-dried.
Similarly, 760 g of dried Cynanchum atratum was extracted with water as in Example 1. The water extract was further concentrated to a concentration of 0.811 g/mL. A concentrated water extract containing 120 g dry powder was further loaded onto a reverse phase column packed with 9600 g HP20 resin, in a ratio of 1 g dry basis of the extract/80 g resin. The column was first eluted with 76800 g water and then eluted with 95% ethanol. The water eluate and 76800 g 95% ethanol eluate were collected respectively (Sample 4-2 and 4-4), concentrated and freeze-dried.
The antitussive assessment of the above eluates is shown in Table 4.
TABLE 4
Dosage
Inhibition rate*
Sample
(g/kg)
(%)
4-1
1.0
62 ± 8
4-2
1.0
15 ± 12
4-3
1.0
59 ± 10
4-4
1.0
72 ± 9
*data are presented as means ± s.e. (N = 4)
The results in Table 4 show that the eluates through the reverse phase column (Sample 4-1, 4-3 and 4-4) were active for reducing citric acid-induced coughs at 1.0 g/kg dosage, except for the water eluate of column packaged in the ratio of 1 g extract/80 g HP20 resin (Sample 4-2).
EXAMPLE 5
3000 g of dried Cynanchum atratum was extracted with water as in Example 1. Concentrated water extracts containing 345 g and 250 g dry powder were further loaded onto reverse phase columns packed with 6900 g and 5000 g HP20 resin, respectively, in a ratio of 1 g dry basis of the extract/20 g resin. The columns were first eluted with 75900 g and 60500 g water respectively and then eluted with 70% and 95% ethanol, respectively. The 75900 g 70% ethanol eluate and 60500 g 95% ethanol eluate were collected respectively (Sample 5-1, and 5-2), concentrated and freeze-dried.
Similarly, 1500 g of dried Cynanchum atratum was extracted with water as in Example 1. Concentrated water extracts containing 130 g and 115 g dry powder were further loaded onto reverse phase columns packed with 10400 g and 9200 g HP20 resin, respectively, in a ratio of 1 g dry basis of the extract/80 g resin. The columns were first eluted with 62400 g and 55200 g water, respectively and then eluted with 50% and 95% ethanol, respectively. The water eluate, 62400 g 50% ethanol eluate and 55200 g 95% ethanol eluate were collected respectively (Sample 5-3, 5-4 and 5-5), concentrated and freeze-dried.
Similarly, 3000 g of dried Cynanchum atratum was extracted with water as in Example 1. Concentrated water extracts containing 250 g and 210 g dry powder were further loaded onto reverse phase columns packed with 3750 g and 3150 g HP20 resin, respectively, in a ratio of 1 g dry basis of the extract/15 g resin. The columns were first eluted with 37500 g and 31500 g water, respectively and then eluted with 50% and 95% ethanol, respectively. 37500 g 50% ethanol eluate and 31500 g 95% ethanol eluate were collected respectively (Sample 5-6 and 5-7), concentrated and freeze-dried.
Samples 5-6 and 5-7 were further filtered by way of an ultrafiltration membrane with molecular weight cut off 1,000 (Amicon LP-1, inlet P=1.5 kg/cm 2 , outlet P=0.5 kg/cm 2 ), respectively. 1800 mL of the filtrate was firstly collected and 1800 mL water was added to the retentate to continue the ultrafiltration, repeating the process for 3 times. The retentates containing substances with molecular weight more than 1,000 dalton (Samples 5-8 and 5-10) and the filtrates containing substances with molecular weight less than 1,000 dalton (Samples 5-9 and 5-11) were collected and freeze-dried.
The antitussive assessment of the above samples is shown in Table 5.
TABLE 5
Dosage
Inhibition rate*
Sample
(g/kg)
N
(%)
5-1
1
4
39 ± 9
0.5
4
32 ± 4
0.25
4
25 ± 4
5-2
1
4
89 ± 5
0.5
4
48 ± 3
0.25
4
35 ± 7
5-3
1.0
4
34 ± 7
5-4
1.0
8
41 ± 3
0.5
4
32 ± 12
0.25
4
17 ± 9
5-5
1.0
8
65 ± 5
0.5
4
64 ± 9
0.25
4
27 ± 1
5-6
1.0
4
41 ± 5
5-7
1.0
4
72 ± 8
5-8
1.0
4
42 ± 5
5-9
1.0
4
48 ± 8
0.5
4
44 ± 5
0.25
4
27 ± 3
5-10
1.0
4
55 ± 4
5-11
1
4
60 ± 7
0.5
4
55 ± 5
0.25
4
45 ± 6
*data are presented as means ± s.e. (N = 4 to 8)
The results in Table 5 show that after various processes of the crude extracts of Cynanchum atratum , the fractions, such as Samples 5-2, 5-5, 5-7, 5-9, 5-10 and 5-11, still show efficacy for reducing citric acid-induced coughs.
EXAMPLE 6
1500 g of dried Cynanchum atratum was extracted with water as in Example 1. The water extract containing 285 g dry powder was further loaded onto a reverse phase column packed with 5700 g HP20 resin in a ratio of 1 g dry basis of the extract/20 g resin. The column was first eluted with 45600 g water and then eluted with 95% ethanol. 45600 g 95% ethanol eluate was collected and concentrated approximately 50 times and then had water added to adjust a concentration of 10 mg/ml and then was concentrated 10 times. The concentrated solution was filtered by a filter paper (Whatman No. 2) to obtain the filtrate. The filtrate was then freeze-dried (Sample 6-1). The antitussive assessment of the above samples is shown in Table 6.
TABLE 6
Dosage
Inhibition rate*
Sample
(g/kg)
(%)
6-1
1.0
60 ± 11
0.5
58 ± 4
0.25
42 ± 12
*data are presented as means ± s.e. (N = 4)
The results in Table 6 show Sample 6-1 is active for reducing citric acid-induced coughs, even at 0.25 g/kg dosage.
EXAMPLE 7
2500 g of dried Cynanchum atratum was extracted with water as in Example 1. 40420 g water extract collected was further filtered by way of an ultrafiltration membrane with molecular weight cut off 1,000 (M12, speed: 50%, inlet P=20 psi). 36380 g of the filtrate was firstly collected and 36380 g water was added to the retentate to continue the ultrafiltration, repeating the process for 3 times. The retentate containing substances with molecular weight more than 1,000 dalton was collected, concentrated and freeze-dried as Sample 7-1.
The filtrate containing substances with molecular weight less than 1,000 dalton was collected and concentrated 3 times. The concentrated filtrate containing 420 g dry powder was then loaded onto a reverse phase column packed with 8400 g HP20 resin in a ratio of 1 g dry basis of the extract/20 g resin. The column was first eluted with 67200 g water and then eluted with 95% ethanol. 67200 g 95% ethanol eluate (Sample 7-2) was collected, concentrated and freeze-dried. 40 g dry powder of the ethanol eluate was added in 4000 g water as a concentration of 10 mg/mL. The solution was further partitioned with 4000 mL hexane for 3 times to collect the water fraction. The water fraction was subsequently filtered by a filter paper (Whatman No. 2) and the filtrate was freeze-dried as Sample 7-3.
The antitussive assessment of the above samples is shown in Table 7.
TABLE 7
Dosage
Inhibition rate*
Sample
(g/kg)
(%)
7-1
1.0
38 ± 4
7-2
1.0
71 ± 4
7-3
1.0
78 ± 4
0.5
52 ± 8
0.25
36 ± 6
*data are presented as means ± s.e. (N = 4)
The results in Table 7 show Sample 7-2 and 7-3 are active for reducing citric acid-induced coughs.
While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. | An antitussive agent. A composition for relieving, preventing and/or treating cough includes a sufficient amount of Cynanchi Atrati Radix extract as an active component. The effective Cynanchi Atrati Radix extract is prepared by extracting Cynanchi Atrati Radix with water, ethanol, hexane, ethyl acetate or a combination thereof. The crude extract can be further fractioned by ultrafiltration or reverse phase column. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method of manufacturing cold rolled steel sheets for extra deep drawing with excellent press formability and/or chemical conversion treating property.
2. Description of the Prior Art
In the manufacture of cold rolled steel sheets for use in the extra deep drawing, it has hitherto been adopted to add Ti to an extremely low carbon steel having a carbon content of 0.001-0.02% and perform the hot rolling at a temperature higher than the Ar 3 transformation point as disclosed in Japanese Patent Application Publication No. 44-18,066. However, in such a method, as the carbon content becomes lower, the Ar 3 transformation point rises, so that the hot finishing temperature (FT) must be set at not less than 880° C. Thus, in order to secure this FT, the heating temperature of the cast slab must be raised from about 1,200° C. used in the conventional low carbon steel (C≅0.02-0.04%) to a high temperature of 1,250°-1,350° C., which has the following drawbacks:
(a) The energy consumed in the heating furnace becomes considerably and uneconomically larger;
(b) Since the heating temperature becomes higher, there are caused the increase in the maintenance cost of the heating furnace, the reduction of the yield due to the increase in the amount of scale produced, the increase in the wear-out amount of the rolls, and the like;
(c) In the case that the cast slab is directly subjected to a hot rolling without passing through a reheating furnace, the slab temmperature is apt to lower in the hot rolling, so that it is difficult to maintain the hot finishing temperature of not less than Ar 3 transformation point and to obtain sheets of good quality.
SUMMARY OF THE INVENTION
An object of the present invention is to solve the aforementioned drawbacks of the prior art and to provide a method of economically and advantageously manufacturing cold rolled steel sheets for the extra deep drawing, which can considerably lower the heating temperature of the slab or directly apply the continuously cast slab to a hot rolling without heating.
According to a first aspect of the invention, there is the provision of a method of manufacturing cold rolled steel sheets for extra deep drawing with an excellent press formability, which comprises the steps of:
melting a steel material containing not more than 0.0060% by weight of C, 0.01 to less than 0.10% by weight of Mn, 0.005-0.10% by weight of Al and Ti corresponding to Ti (%) represented by the following equation (1) when an effective Ti amount expressed by Ti* in the equation (1) satisfies the following inequality (2);
continuously casting the resulting molten steel to produce a cast slab;
hot rolling the resulting cast slab immediately or after the slab is heated at a temperature of 900°-1,150° C., during which a hot finishing temperature is made to a temperature of not more than 780° C.;
cold rolling the resulting hot rolled sheet in the usual manner; and
subjecting the resulting cold rolled sheet to a recrystallization annealing at a temperature of not less than the recrystallization temperature but not more than 1,000° C.
Ti*(%)=Ti(%)-(48/14)N(%)-(48/32)S(%) (1)
4.0×C(%)≦Ti*(%)≦0.10 (2)
According to a second aspect of the invention, there is the provision of a method of manufacturing cold rolled steel sheets for extra deep drawing with excellent press formability and chemical conversion treating property, which comprises the steps of:
melting a steel material containing not more than 0.0060% by weight of C, 0.01-0.10% by weight of Mn, 0.005 to less than 0.10% by weight of Al, Ti corresponding to Ti(%) represented by the following equation (1) when an effective Ti amount expressed by Ti* in the equation (1) satisfies the following inequality (2) and 0.05-0.20% by weight in total of at least one element selected from Cu, Ni and Cr;
continuously casting the resulting molten steel to produce a cast slab;
hot rolling the resulting cast slab immediately or after the slab is heated at a temperature of 900°-1,150° C., during which a hot finishing temperature is made to a temperature of not more than 780° C.;
cold rolling the resulting hot rolled sheet in the usual manner; and
subjecting the resulting cold rolled sheet to a recrystallization annealing at a temperature of not less than the recrystallization temperature but not more than 1,000° C.
Ti*(%)=Ti(%)-(48/14)N(%)-(48/32)S(%) (1)
4.0×C(%)≦Ti*(%)≦0.10 (2)
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in detail with reference to the accompanying drawings, wherein:
FIG. 1 is a graph showing the relation between the carbon content of the slab and the r value of the steel sheet product in case of Ti*/C≧4.0;
FIG. 2 is a graph showing an appropriate range in the relation between the carbon content and Ti* of the slab; and
FIG. 3 is a graph showing the relation between the slab heating temperature and the r value of the steel sheet product.
DETAILED DESCRIPTION OF THE INVENTION
The invention will now be described in detail below.
The inventors have made studies in order to overcome the aforementioned problems of the prior art and found that cold rolled steel sheets having an excellent extra deep drawability can be obtained by making the C content as extremely low as not more than 0.0060% and the Mn content as low as 0.01 to less than 0.10% with respect to the composition of the steel material and by adding a small amount of Ti even when the hot finishing temperature is not more than 780° C.
According to the invention, the reason why the ingredients of the steel material are restricted to the above defined ranges is mentioned as follows.
Ti and C
The addition amount of Ti is determined from the standpoint of the intended improvement on the quality and is particularly important for the invention.
In order to obtain a good quality in the titanium-containing steel, it is necessary to add Ti in such an amount that it fixes all the amount of solid solved C in the form of TiC. The order of the production of Ti-base precipitates in the Ti-containing steel is that Ti, N and TiS are first precipitated at a high temperature of not less than 1,400° C., and then the remaining Ti is reacted with C to form TiC precipitate. Therefore, if the addition amount of Ti is too small and a part of C in the molten steel remains in the steel sheet as a solid solved C without being fixed as TiC precipitate, the r value and elongation of the steel sheet are deteriorated. Hence, Ti must be added in an amount required for precipitating all of solid solved C in the form of TiC.
The lower limit of the Ti addition amount is determined as follows.
That is, as defined in the above equation (1), the effective Ti amount for the fixation of C (shown by "Ti*" in the equation (1)) is calculated by subtracting the amount of Ti forming TiN and TiS from the total amount of Ti to be added (shown by "Ti" in the equation (1)). When the thus obtained Ti* is equal to the left-hand side of the inequality (2) or 4 times of the C content, the Ti content in the equation (1) is the lower limit of the Ti content to be added.
As to carbon, it is necessary to restrict the carbon content to not more than 0.0060% in order to provide cold rolled steel sheets with an excellent press formability.
The reason why the contents of Ti and C are restricted as above is described in detail below.
FIG. 1 is a graph showing the influence of the C content in the slab upon the r values of the steel sheet product in case of Ti*/C≧4. That is, FIG. 1 shows the relation between the C content of the slab and the r value of the steel sheet product when a steel material containing 0.0010-0.0080% of C, 0.05-0.09% of Mn, 0.010-0.012% of S, 0.0020-0.0040% of N, 0.030-0.050% of Al and 0.055-0.080% of Ti and satisfying Ti*/C of 4.0-19.5 was melted and cast into a slab, and the resulting slab was hot rolled under such conditions that the slab heating temperature is 1,000° C. and the hot finishing temperature is 750°-775° C., cold rolling at a draft of 78% and continuously annealed at 820° C. for 60 seconds. From this figure, it is understood that in case of Ti*/C≧4.0, when the carbon content is not more than 0.0060%, a very high r value of 1.8-2.4 is obtained even if the hot finishing temperature is not more than 780° C.
In FIG. 2 is shown the relation between the C content and the effective Ti content (Ti*) suitable for obtaining the excellent press formability. In FIG. 2, the shadowed region is an appropriate range in the relation between Ti* and C content.
Moreover, if Ti* exceeds 0.10%, the addition effect is no longer improved, and also the increased amount of Ti leads to increase the production cost. Thus, the upper limit of Ti* is 0.10%.
For the above reason, the C content is limited to not more than 0.0060%, while the Ti content is limited to not less than (4.0×C)% but not more than 0.10% in terms of Ti*.
Mn
Generally, Mn is an element lowering the r value of the steel sheet. Particularly, when the hot finishing temperature is not higher than Ar 3 transformation point, the deterioration of the r value is conspicuous. Accordingly, in order to prevent the deterioration of the r value when the hot finishing temperature is lower than Ar 3 transformation point, it is necessary to limit the C content to not more than 0.0060% and add Ti in an amount of corresponding to not less than four times of C as previously mentioned, and at the same time it is necessary to restrict Mn to less than 0.10%.
Although Mn is usually added in an amount of Mn/S≧10 so as to prevent the hot brittle cracks due to S, the addition of Ti as defined in the invention causes no hot brittle crack because S is fixed in the form of TiS, so that it is not necessary to add Mn at the amount required for the prevention of hot brittle crack in the invention.
That is, the feature that steel sheets having r value required for the provision of the excellent press formability can be produced according to the invention even when the hot finishing temperature is not less than 780° C. is first realized by making the C content of the steel material lower and adding Ti to fix C in the form of TiC and at the same time fix S in the steel material in the form of TiS to thereby restrict the Mn content of the steel material as low as possible.
On the other hand, it is industrially difficult to remove Mn contained as an impurity element in the steel material up to less than 0.01%.
From the above reasons, Mn is restricted to a range of 0.01 to less than 0.10%.
Al
Al is added to deoxidize the steel material, but this element has no direct influence upon the improvement of the properties aimed at by the invention, and therefore its upper limit is set at 0.10% in view of the reduction of the cost. On the other hand, the lower limit is theoretically zero, but it is required to remain in an amount of about 0.005% so as to complete the deoxidation.
Cu, Ni, Cr
The steel sheet for automobile structural use is usually subjected to a treatment with zinc phosphate (chemical conversion treatment) prior to the coating. When the extremely low carbon, titanium-containing, steel sheet is subjected to the chemical conversion treatment, the crystal nuclei of zinc phosphate are scatteringly formed, which may come into problems depending on the chemical conversion treating conditions.
In order to solve such problems, Cu, Ni and Cr are further added alone or in combination according to the invention. Thus, the nuclei of zinc phosphate are densely precipitated onto the surface of the steel sheet to provide an excellent chemical conversion treating property. If the amount in total of Cu, Ni and Cr is smaller than 0.05%, no improvement effect on the chemical conversion treating property is obtained, while if it exceeds 0.2%, the quality of the steel sheet is deteriorated. Therefore, the amount in total of Cu, Ni and Cr is restricted to 0.05-0.20%.
Next, the invention will be described with respect to the hot rolling conditions.
FIG. 3 is a graph showing the influence of the change in the slab heating temperature upon the r value of the steel sheet product. That is, FIG. 3 shows the relation between the slab heating temperature and the r value of the steel sheets product when the slab containing 0.0015-0.0040% of C, 0.08% of Mn, 0.040-0.060% of Al and 0.055-0.065% of Ti and satisfying Ti*/C of 4.0-19.5 is heated in a reheating furnace by varying the slab heating temperature between 1,000°-1,200° C. and then hot rolled under such conditions that the hot finishing temperature (FT) is made to either of two levels of 775° C. and 870° C. and the coiling temperature is 550°-650° C.
As apparent from FIG. 3, when the hot finishing temperature (FT) is as high as 870° C., the improvement of r value is not observed even if the slab heating temperature is lowered from 1,200° C. to 1,000° C., while when FT is 775° C., the r value is remarkably improved if the slab is heated at a temperature of not more than 1,150° C. However, if the slab-heating temperature is less than 900° C., the deformation resistance in the hot rolling becomes higher, so that the hot rolling is impossible.
As mentioned above, when the slab is heated in the reheating furnace in order to increase the r value, the slab heating temperature is restricted to 900˜1,150° C., and also the FT in the hot rolling is set at not more than 780° C.
On the other hand, according to the invention it is possible to directly hot roll the continuously cast slab (CC slab) without being passed through the reheating furnace. In general, when the CC slab is subjected to a direct hot rolling (DR), the temperature of such slab is low in the hot rolling, and hence FT is liable to be low. According to the invention, however, a high r value is obtained even if the FT is not more than 780° C. as mentioned above, so that the invention is most suitable for directly hot rolling the CC slab (i.e. CC-DR process). Thus, even if the invention is applied to CC-DR process without the reheating furnace, the FT is sufficient to be not more than 780° C.
The subsequent cold rolling is not required to take any special conditions and may be carried out in the usual manner.
Referring to the annealing conditions, no sufficient press formability can be obtained unless the annealing is carried out at a temperature higher than the recrystallization temperature, while if the cold rolled sheet is heated to a temperature for the formation of austenite exceeding 1,000° C., the r value of the steel sheet product is adversely affected. Therefore, the annealing is carried at a temperature of not less than the recrystallization temperature but not more than 1,000° C. for not less than 15 seconds.
The following examples are given in illustration of the invention and are not intended as limitations thereof.
EXAMPLE 1
Each of steel materials having a chemical composition as shown in the following Table 1, in which Run Nos. A and B are embodiments of the invention and Run Nos. C-F are comparative examples, was melted and continuously cast into a slab. The thus obtained slab was hot rolled to be 3.2 mm in thickness at hot rolling temperatures as shown in Table 1 and coiled at a coiling temperature of 600° C. Then, the hot rolled sheet was cold rolled to be 0.7 mm in thickness and subjected to a continuous annealing and a skin pass rolling at a rate of 0.4% to obtain a steel sheet product.
The quality of each of the thus obtained steel sheets was examined as follows:
Namely, test pieces of JIS No. 5 were prepared by cutting out each steel sheet at three angles of 0°(L), 45°(D) and 90°(C) with respect to the rolling direction, respectively, and the tensile test was made with respect to these test pieces. Thus, each of the yield strength, tensile strength, elongation, and r value were measured with respect to the test pieces in three directions L, C, D and an average value of (L+C2D)/4 was calculated from the measured values to evaluate the quality of the steel sheet.
Moreover, the unit consumption of fuel in the reheating furnace was also measure. The thus obtained results are shown in the following Table 2.
TABLE 1__________________________________________________________________________ Hot rolling temperature Slab Hot heating finishingRun Chemical composition (wt %) (Ladle analysis) tempera- tempera- AnnealingNo C Si Mn P S Al N Ti Ti* Ti*/C ture ture conditions Remarks__________________________________________________________________________A 0.0033 0.02 0.08 0.011 0.010 0.047 0.0030 0.061 0.036 10.91 1,000° C. 775° C. 30° C. × 40 sec.B 0.0018 " " " " 0.048 0.0020 0.058 " 20.0 " " "C 0.0078 " " 0.012 0.011 0.050 0.0042 0.065 0.034 4.36 " 770° C. " Deviated carbon contentD 0.0035 " 0.35 " " 0.048 0.0029 0.062 0.036 10.3 " " " Deviated Mn upper limitE 0.0045 " 0.08 " 0.012 0.050 0.0030 0.040 0.011 2.6 " " " Deviated Ti* lower limitF 0.003 " " " 0.011 0.051 0.0029 0.062 0.036 11.9 1,250° C. 875° C. " Deviated hot rolling temperature__________________________________________________________________________
TABLE 2__________________________________________________________________________ Yield Tensile Elonga- Unit consumptionRun strength strength tion of fuel inNo. (kgf/mm.sup.2) (kgf/mm.sup.2) (%) -r value reheating furnace Remarks__________________________________________________________________________A 14.0 27.5 51.5 2.41 ⊚B 13.5 27.3 52.3 2.51 ⊚C 20.2 31.5 45.8 1.51 ⊚ Poor qualityD 19.8 31.0 46.2 1.54 ⊚ "E 22.3 32.1 43.3 1.45 ⊚ "F 15.4 29.0 50.0 1.90 x The unit consumption of fuel in the reheating furnace is poor__________________________________________________________________________ ⊚ : Low slab heating temperature and good unit consumption of fuel x: High slab heating temperature and poor unit consumption of fuel
EXAMPLE 2
A continuously cast slab was produced from molten steel having the chemical composition shown in Run No. B of Table 1 and directly hot rolled without being passed through the reheating furnace. As the hot rolling conditions, there were the hot finishing temperature of 725° C. and the coiling temperature of 675° C., and the thickness of the thus hot rolled sheet was 3.2 mm. The hot rolled sheet was cold rolled to be 0.7 mm in thickness, which was then subjected to a continuous annealing at 830° C. for 40 seconds and a skinpass rolling at a rate of 0.4% to obtain a steel sheet product.
The same tensile test as described in Example 1 was made with respect to the thus obtained steel sheet product to obtain results as shown in the following Table 3.
TABLE 3______________________________________Yield Tensilestrength strength Elongation(kgf/mm.sup.2) (kgf/mm.sup.2) (%) -r value______________________________________14.0 27.5 52.3 2.45______________________________________
As seen from the above, according to the invention, it is also possible to adopt the direct hot rolling system without the reheating furnace. Even in this case, it is possible to obtain the steel sheet having the same quality as in the slab-reheating system and also the unit consumption of fuel can be reduced largely.
EXAMPLE 3
A continuously cast slab was produced from molten steel having a chemical composition as shown in the following Table 4, wherein Run No. G is an embodiment of the invention and Run No. H is a comparative example, and then hot rolled to be 3.2 mm in thickness at a hot rolling temperature as shown in Table 4 and coiled at a coiling temperature of 600° C. The hot rolled sheet was cold rolled to be 0.7 mm in thickness and then subjected to a continuous annealing and a skin pass rolling at a rate of 0.4% to obtain a steel sheet product. The same tensile test as described in Example 1 was made with respect to the thus obtained steel sheet to obtain results as shown in the following Table 5.
In addition, the steel sheet was subjected to a chemical conversion treatment with zinc phosphate by spraying to obtain results as shown in Table 5.
TABLE 4__________________________________________________________________________ Hot rolling temperature Slab Hot heating finishingRun Chemical composition (wt %) (Ladle analysis) tempera- tempera-No. C Si Mn P S Al N Ti Ti* Ti*/C Cu Ni Cr ture ture__________________________________________________________________________G 0.0018 0.02 0.08 0.011 0.010 0.048 0.0020 0.058 0.036 20.0 0.08 0.04 0.04 1,000° C. 775° C.H " " " " " 0.050 " " " " 0.01 0.01 0.02 " "__________________________________________________________________________
TABLE 5__________________________________________________________________________ Judgement Amount of on chemical Yield Tensile zinc phosphate conversionRun strength strength Elongation deposited treatingNo. (kgf/mm.sup.2) (kgf/mm.sup.2) (%) -r value (g/m.sup.2) property__________________________________________________________________________G 14.0 27.8 52.1 2.45 2.49 ⊚H 13.5 27.3 52.3 2.51 1.55 o__________________________________________________________________________ ⊚ : Chemical conversion treating property is superior to that of the conventional boxannealed sheet. o: Chemical conversion treating property is equal to that of the conventional boxannealed sheet.
From Table 5, it is understood that the steel sheet obtained from the steel material containing such an amount of Cu, Ni and Ni as defined in the invention has mechanical properties equal to that of the steel sheet obtained from the steel material containing such elements at amounts outside the defined range of the invention and has more excellent chemical conversion treating property. | A method of manufacturing cold rolled steel sheets for extra deep drawing is disclosed, which comprises the steps of:
melting and continuously casting a steel material containing not more than 0.0060% of C, 0.01 to less than 0.10% of Mn, 0.005-0.10% of Al, Ti corresponding to Ti(%) of the following equation (1) when an effective Ti amount expressed by Ti* in the formula (1) satisfies the following inequality (2), and optionally, 0.005˜0.2% in total of at least one of Cu, Ni and Cr to obtain a cast slab;
hot rolling the cast slab immediately or after the slab is heated at a temperature of 900°-1,150° C. during which a hot finishing temperature is made to not more than 780° C.;
cold rolling the hot rolled sheet in the usual manner; and
recrystallization annealing the cold rolled sheet at a temperature of not less than the recrystallization temperature but not more than 1,000° C.
Ti*(%)=Ti(%)-(48/14)N(%)-(48/32)S(%) (1)
4.0×C(%)≦Ti*(%)≦0.10 (2) | 2 |
TECHNICAL FIELD
The present invention relates to a printing drum assembly for a stencil printing device, and in particular to a printing drum assembly for a single-drum rotary stencil printing device.
BACKGROUND OF THE INVENTION
Squeegee type single-drum rotary printing devices are widely used as one type of single-drum rotary stencil printing devices, and comprise a cylindrical printing drum including an ink permeable outer shell on which a stencil master plate is mounted, and a squeegee member consisting of a squeegee roller or a squeegee blade engaging with the inner surface of the outer shell of the printing drum. As the printing drum or, in particular, the outer shell rotates, printing ink is squeezed through or across the ink permeable outer shell by the squeegee member which is stationary.
According to the conventional printing drum structure disclosed in Japanese patent laid-open publication (kokai) No. 3-254985, the two axial ends of the outer shell are closed by end walls, and the outer shell is rotatably supported by a central shaft passed through the central parts of these end walls. The squeegee member is supported by the central shaft.
According to the alternate conventional structure disclosed in Japanese patent laid-open publication (kokai) No. 59-12893, the printing drum having an open end is rotatably supported at its outer circumference adjacent to its open end by a fixed side plate in the manner of a cantilever, and a fixed frame securely attached to the side plate projects into the interior of the printing drum. The squeegee member is mounted on this fixed frame for engagement with the inner surface of the outer shell of the printing drum.
Single-drum rotary stencil printing devices not using any squeegee member are also known, and printing drums having a central shaft for use in such stencil printing drums are disclosed in Japanese patent laid-open publications (kokai) Nos. 56-72987, 62-42873, 59-12893 and 2-164576. According to this group of conventional stencil printing devices, the two ends of the printing drum are closed by end walls, and the central shaft is passed centrally through these end walls.
According to the printing drum having end walls and a central shaft passed through these end walls, because the printing drum is supported at its two axial ends, the printing drum is relatively free from any eccentricity or mis-alignment in the overall structure, and can be supported in a stable fashion. Furthermore, because the interior of the printing drum is entirely enclosed by the end walls, the printing ink is favorably confined within the printing drum, and would not leak out even during transportation of the printing drum. However, the enclosed structure of the printing drum would not allow easy access to the interior of the printing drum, and an ink bottle serving as a source for printing ink cannot be readily replaced. Also, when the squeegee angle and the squeegee pressure are to be adjusted, the printing drum has to be dismantled. Normally, it is not possible to adjust the squeegee angle and the squeegee pressure while the printing drum is mounted on the stencil printing device.
According to the cantilever type printing drum for a stencil printing device, because one of the axial ends of the printing drum is open, an ink bottle placed inside the printing drum can be readily replaced, and the squeegee angle and the squeegee pressure can be adjusted while the printing drum is mounted on the stencil printing drum. On the other hand, due to the nature of the mode of supporting the printing drum, it is not easy to support the printing drum in a stable fashion, and there is an increased possibility of involving eccentricity. If there is an excessive eccentricity in the printing drum, it will cause unevenness in the density of the printed images. Furthermore, there is an increased possibility of causing leakage of printing ink from the interior of the printing ink, in particular when the printing drum is placed vertically with its open end down. Leakage of printing drum should be avoided because it will smear the clothing of the operator and other parts. Furthermore, because the interior of the printing drum consists of a single chamber, and there is no separating wall between the squeegee member assembly and the ink bottle/pump assembly, printing ink which has leaked from the squeegee member assembly may smear the various parts of the ink bottle/pump assembly. Possibility of smearing the clothing of the operator will seriously reduce the acceptability of the stencil printing device for office use.
According to the printing drum for a single-drum stencil printing device not using a squeegee member, the printing drum is substantially enclosed with the two axial ends of the printing drum closed by end walls, and a central shaft is passed through these end walls. However, the printing ink used for such printers has a relatively low viscosity, and tends to seep through the outer shell of the printing drum under the action of gravity. Therefore, according to this type of printing drums, the rest position of the printing drum must be selected such that a non-ink permeable part of the printing drum be located at the bottom end of the printing drum whenever the printing drum is brought to a stop.
BRIEF SUMMARY OF THE INVENTION
In view of such problems of the prior art, a primary object of the present invention is to provide a printing drum assembly for a single drum type rotary stencil printing device which is simple in structure and which can be supported in a stable fashion without reducing the accessibility to the interior of the printing drum.
A second object of the present invention is to provide a printing drum assembly which is free from the seeping out of printing ink even when the printing ink has a relatively low viscosity, and can thus eliminate the need to stop the printing drum always precisely at a predetermined angular position.
According to the present invention, these and other objects can be accomplished by providing a printing drum assembly for a stencil printing device, comprising: a fixed hollow cylindrical member supported by a frame of a stencil printing device; a printing drum rotatably supported by the fixed hollow cylindrical member at two axially spaced positions thereof, the printing drum including an ink permeable outer shell; a printing ink container disposed inside the fixed hollow cylindrical member; and printing ink supplying means for feeding printing ink from the printing ink container to an inner circumferential surface of the printing drum.
Thus, the printing drum is supported at axially spaced positions thereof in a highly stable fashion so that any mis-alignment of the printing drum can be avoided, and the interior of the fixed hollow cylindrical member provides an easily accessible space for accommodating a printing ink container and printing ink supplying means such as pumps and valves. In particular, by using a squeegee blade instead of a squeegee roller, a particularly advantage can be obtained because the diameter of the fixed hollow cylindrical member can be such that an annular chamber defined between the fixed hollow cylindrical member and the inner circumferential surface of the printing drum is barely sufficient to accommodate the squeegee blade in the annular chamber, and the fixed hollow cylindrical member can provide a highly rigid support structure.
In case of a squeegee-less printing drum, the fixed hollow cylindrical member easily allows a highly liquid tight structure which prevents seeping or leaking of printing ink from the printing drum. It is particularly advantageous, if the supplying means is reversed immediately after the printing device is stopped so that the printing ink remaining on the inner circumferential surface of the printing ink may be safely returned to the ink container inside the fixed hollow cylindrical member so as to eliminate any possibility of printing ink leakage.
The fixed hollow cylindrical member may be either fixedly secured to a frame at two axial ends thereof, or fixedly secured to a frame at an axial end thereof in the manner of a cantilever.
BRIEF DESCRIPTION OF THE DRAWINGS
Now the present invention is described in the following with reference to the appended drawings, in which:
FIG. 1 is a longitudinal sectional view of a first embodiment of the printing drum assembly for a stencil printing device according to the present invention;
FIG. 2 is a cross sectional view of the printing drum assembly of FIG. 1;
FIG. 3 is an enlarged sectional view showing a mechanism for adjusting the squeegee angle in the printing drum assembly according to the present invention; and
FIGS. 4 through 6 are views similar to FIG. 1 showing different embodiments of the printing drum assembly for a stencil printing device according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show a first embodiment of the printing drum assembly for a stencil printing device according to the present invention. The printing drum assembly which is generally denoted with numeral 1 comprises a hollow cylindrical member 3 which is fixedly secured to a pair of side plates 2a and 2b at its two axial ends, and a cylindrical printing drum 9 coaxially fitted on the fixed cylindrical member 3 via a pair of roller or ball bearings 5 and 7 at two axial ends of the printing drum 9.
If the printing drum assembly 1 is a permanent type which is not intended for replacement by the user, the hollow cylindrical member 3 may be fixedly secured to a fixed frame of a printing device. If the printing drum 1 is a detachable type which can be axially drawn out for replacement by the user, for instance as disclosed in Japanese patent publication (kokoku) No. 62-28758, the fixed hollow cylindrical member 3 may be fixedly secured to a detachable frame which can be selectively removed from the main frame of the printing device.
The printing drum 9 essentially consists of a cylindrical shell 11 and a pair of annular support members 13 engaged with two axial end portions of the cylindrical shell 11, and is rotatably supported on the cylindrical member 3 in a coaxial relationship via the annular support members 13, and the ball bearings 5 and 7.
A master plate clamp 17 is provided in a flat segment 15 of the printing drum 9, and a master plate sheet is mounted around the outer circumferential surface of the printing drum 9 with an end of the master plate sheet engaged by the master plate clamp 17. The outer shell 11 is provided with an ink permeable structure, for instance consisting of a metallic shell provided with a minute porous structure except for the flat segment 15 and its surrounding region.
A ring gear 19 is fixedly secured to one of the annular support members 13 coaxially with the cylindrical shell 11, and a drive gear 21 rotatively driven by an electric motor not shown in the drawing meshes with the ring gear 19. The drive gear 21 turns in clockwise direction as seen in FIG. 2, and the printing drum 9 therefore turns in counter clockwise direction around its axial center line.
The fixed hollow cylindrical member 3 has an open first end, and a second end which is closed by an end wall 23. The cylindrical member 3 has an outer diameter which is smaller than the inner diameter of the cylindrical shell 9 by the size of the bearings 5 and 7. The printing drum is thus rotatably supported by the fixed cylindrical member 3 via the ball bearings 5 and 7, all in a coaxial relationship. For the purpose of sealing off an annular chamber 25 defined between the fixed cylindrical member 3 and the outer shell 9 of the printing drum 9, the roller bearings 5 and 7 are provided with seals.
The fixed hollow cylindrical member 3 internally defines a cylindrical chamber 29 which is separated from the annular chamber 25, and has an open end 27 at the fixed axial end. The internal cylindrical chamber 29 has a relatively large volume which is determined by the diameter of the fixed hollow cylindrical member 3, and accommodates therein an ink bottle retaining assembly 31 for replaceably holding an ink bottle B introduced into the cylindrical chamber 29 from its open end 27. The ink bottle retaining assembly 31 comprises an ink bottle connection portion 33 which can engage with an ink outlet A of the ink bottle B.
The ink bottle B comprises a cylindrical bottle main body C having the ink outlet A at its one end, and a moveable bottom plate E is axially slidably received in the bottle main body C so as to serve as a piston defining an ink chamber D and displace the printing ink out of the ink outlet A.
The cylindrical chamber 29 further accommodates therein a pair of ink supply pumps 35, and a pair of motors 37 for driving the ink supply pumps 35. The ink supply pumps 35 each have an inlet which is connected to the ink bottle connecting portion 33 via an ink conduit 39. The outlets of the ink supply pumps 35 are connected to ink supply conduits 41 which are passed through the fixed hollow cylindrical member 3, and extend into the annular chamber 25. The free end of each of the ink supply conduits 41 is located in the annular chamber 25.
To the outer circumferential surface of the cylindrical member 3 is secured a squeegee blade mount assembly 45 which carries a squeegee blade 47. The radial dimension necessary to accommodate the squeegee blade 47 is provided by the overall thickness of the two rings of the ball bearings 5 and 7 as seen in the radial direction. In other words, the radial dimension of the annular chamber 25 is selected to be barely sufficient to accommodate the squeegee blade 47 therein.
The squeegee blade 47 is made of rubber or rubber-like material, and engages the inner circumferential surface of the cylindrical shell 11 of the printing drum 9 at a prescribed squeegee angle and a prescribed squeegee pressure. The squeegee blade mount assembly 45 is provided with means for adjusting the squeegee angle and squeegee pressure of the squeegee blade 47 from the end of the cylindrical member 3.
As best shown in FIG. 2, the free end 43 of each of the ink supply conduits 41 is located behind the point of contact between the squeegee blade 47 and the cylindrical shell 11 as seen in the rotational direction of the printing drum 9, and printing ink is expelled from each of the ink supply conduits 41 onto the inner circumferential surface of the cylindrical shell 11 of the printing drum 9 so that a small lump of printing ink or an ink reservoir P is formed in an wedge-like gap defined between the inner circumferential surface of the cylindrical shell 11 of the printing drum 9 and the squeegee blade 47. The amount of printing ink in the ink reservoir P is detected by a pair of electrostatic capacitance type ink amount sensor 51 each comprising an ink amount detecting needle 49, and the operation of the motors 37 is controlled according to the amount of ink detected by the ink amount sensors 51. The ink amount sensors 51 may have a similar structure as that of the one disclosed in Japanese utility model publication (kokoku) No. 3-28342, and the electric circuit for the sensor 51 and the drive circuit from the motor 27 may be disposed in the cylindrical chamber 29 defined inside the fixed cylindrical member 3.
According to this structure, as the drive gear 21 rotates in clockwise direction as seen in FIG. 2, the printing drum 9 rotates in counter-clockwise direction around its axial center line with its two axial ends supported by the fixed hollow cylindrical member 3.
When the amount of ink in the ink reservoir P detected by the ink amount sensors 51 in this condition falls below a prescribed level, the ink supply pumps 35 are driven by the electric motors 37, and the printing ink is drawn from the ink bottle B connected to the ink bottle connecting portion 33 by the ink supply pumps 35, and is metered to the ink reservoir P via the ink supply conduits 41.
In the illustrated embodiment, the ink supply pumps 35, the electric motors 37, the ink supply conduits 41, and the ink amount sensors 51 are arranged in the regions adjacent to the axial ends of the printing drum, and the two sensors individually detect the amount of printing ink in the parts of the ink reservoir P adjacent to the axial ends, and individually control the two motors 37 and hence the two ink supply pumps 35 so that the amount of the printing ink may be made uniform over the entire ink reservoir P. In FIG. 2, numeral 53 denotes a press roll.
Although the two axial ends of the fixed cylindrical member 3 were supported by a fixed frame 2a and 2b in the above described embodiment, it is also possible to support only one axial end of the fixed cylindrical member 3 with a frame 2a in the manner of a cantilever. Because the fixed cylindrical member 3 has a large diameter with various mechanisms for supplying printing ink accommodated therein, it is possible to ensure a sufficient structural rigidity even when it is supported only at one axial end thereof.
FIG. 3 shows an example of the mechanism for adjusting the squeegee angle of the squeegee blade 47. The squeegee blade 47 is mounted on a blade support member 111 which is vertically pivotably mounted on a bracket 113 fixedly secured to the outer circumferential surface of the fixed cylindrical member 3, via a pivot shaft 115. In other words, the squeegee blade 47 is pivotably mounted on the cylindrical member 3 via the blade support member 111 so that the squeegee angle around the pivot shaft 115 along with the squeegee pressure can be adjusted.
For this purpose, an adjust screw support block 117 is fixedly mounted on the inner circumferential surface of the fixed cylindrical member 3 for threadably engaging an adjust screw 119 thereto. The adjust screw 119 is passed through an opening 121 provided in the fixed cylindrical member 3, and is provided with a push rod portion 123 for abutting the blade support member 111 at its free end. The adjust screw 119 may be locked into a position with a lock nut 125 threadably engaged therewith.
According to this adjust mechanism, the push rod portion 123 moves vertically as the adjust screw 119 is threaded into and out of the adjust screw support block 117, and the blade support member 111 is moved by the push rod portion 123 by a corresponding amount so that a desired change in the squeegee angle and squeegee pressure may be accomplished.
FIG. 4 shows a second embodiment of the present invention. In FIG. 4, the parts corresponding to those of the first embodiment are denoted with like numerals.
In this embodiment, the fixed cylindrical member 3 is divided into a pump chamber 63 and an ink bottle chamber 65 by a partition wall 61. The pump chamber 63 accommodates therein an ink supply pump 35, a motor 37 and an ink supply conduit 41. The ink bottle chamber 65 accommodates therein a piston member 67 disposed in an axially slidable manner, thereby defining an ink receiving chamber 69 between the piston member 67 and the partition wall 61. The partition wall 61 is provided with an ink outlet 71 which is connected to an ink conduit 39 leading to the inlet of the ink supply pump 35. According to this embodiment, the fixed cylindrical member 3 itself serves as an ink bottle having a relatively large capacity.
FIGS. 5 and 6 show third and fourth embodiments of the printing drum assembly according to the present invention applied to a squeegee-less printing drum. In FIGS. 5 and 6, the parts corresponding to those of the previous embodiments are denoted with like numerals. According to these embodiments, the fixed hollow cylindrical member 3 is provided with an enclosed structure with its axial ends closed by end walls 81 and 83, internally defining an ink receiving chamber 85. Printing ink can be replenished into the ink receiving chamber 85 from an opening 89 provided in one of the end walls 83 and normally closed by a cap 87.
In the embodiment illustrated in FIG. 5, a pair of ink pump 93 are provided inside the ink receiving chamber 85, and are actuated by corresponding electric motors 91. The inlets 95 of the ink pumps 93 open into the ink receiving chamber 85. The outlets of the ink pumps 93 are connected to ink supply conduits 97 which are passed through the outer wall of the fixed hollow cylindrical member 3 and extends into the annular chamber 25. The free end 99 of each of the ink supply conduits 97 is placed adjacent to the inner circumferential surface of the printing drum 9 in the annular chamber 25.
In the embodiment illustrated in FIG. 5, the ink pumps 93 are selectively actuated by the electric motors 91, and the printing ink in the ink receiving chamber 85 is drawn by the ink pumps 93 and is delivered or metered to the annular chamber 25 or, more specifically, the inner circumferential surface of the printing drum 9, via the ink supply conduits 97. When the printing device is stopped operative, the ink pumps 93 may be reversed by the motors 91 so that the printing ink remaining in the annular chamber 25 may be drawn back to the ink receiving chamber 85.
The recovery of printing ink by the reversing of the pumps can be employed also in a printing drum equipped with a squeegee member by placing the free ends 43 of the ink supply conduits 41 close to the ink reservoir P.
In the embodiment illustrated in FIG. 6, the fixed hollow cylindrical member 3 is provided with an ink outlet 101 which opens into the annular chamber 25, and is adapted to be opened and closed by a solenoid valve 103. The solenoid valve 103 comprises a valve element 107 which can sit on a valve seat 105 and close the ink outlet 101, and a solenoid 109 for actuating the valve element 107.
The solenoid valve 103 may be a simple valve for simply opening and closing the ink outlet 101, but may also be a flow control valve which can control the lift of the valve element 107 by way of the solenoid 109, and can control the opening of the ink outlet 101 through continuous or stepwise control of the solenoid 109. In either case, the amount of ink supply to the inner circumferential surface of the printing drum 9 can be controlled according to the opening and closing or the opening area of the ink outlet 101.
In the embodiments illustrated in FIGS. 5 and 6, a squeegee blade 47 is disposed inside the annular chamber 25 similarly as the embodiments illustrated in FIGS. 1 and 4.
In each of the above described embodiments, the amount of printing ink in the ink reservoir P, or the inner circumferential surface of the printing drum 9 can be detected in a number of ways beside from the method based on the use of an electrostatic capacitance type ink amount sensor 51. For instance, the ink suction type ink amount detecting device disclosed in Japanese patent laid-open publication (kokai) No. 4-195316 can be used.
Thus, according to the printing drum of the present invention, because the printing drum is supported at its two axial ends by a fixed hollow cylindrical member, mis-alignment of the rotational center of the printing drum can be minimized, and the printing drum can be supported in a highly stable manner. Also, a relatively large chamber can be defined inside the fixed hollow cylindrical member, and this chamber can be conveniently used for accommodating a printing ink receiving tank or bottle and means for supplying printing ink. Thus, the present invention allows the printing device to be a highly compact unit. In particular, using the interior of the fixed hollow cylindrical member as an ink receiving tank is highly advantageous.
Because the means for feeding or supplying printing ink and the inner circumferential surface of the cylindrical shell of the printing drum are separated from each other by the wall of the fixed hollow cylindrical member, the various units are safely accommodated in the cylindrical chamber inside the fixed hollow cylindrical member, and are prevented from being smeared by the printing ink. Furthermore, because the annular chamber defined between the fixed hollow cylindrical member and the printing drum is well sealed, leakage of printing ink from the printing drum can be avoided even during transportation. However, easy access to the various units of the printing drum can be ensured through the open end of the fixed hollow cylindrical member, and fine adjustment of the squeegee angle and squeegee pressure can be carried out without dismantling the printing drum.
In case of a squeegee-less printing drum which uses highly fluid printing ink, the printing ink is safely received inside the fixed hollow cylindrical member which is separated from the inner circumferential surface of the printing drum, and is supplied and metered to the inner circumferential surface of the cylindrical shell of the printing drum. Therefore, no substantial amount of printing ink remains on the inner circumferential surface of the cylindrical shell of the printing drum when the printing device is not operative. In particular, the amount of printing ink remaining on the inner circumferential surface can be further reduced by drawing the printing ink back into the cylindrical chamber by reversing the ink supply pump. Thus, seeping of printing ink through the outer shell of the printing drum under the action of gravity can be avoided, and the need for stopping the printing drum at a prescribed angular position for preventing such a seeping of printing ink can be eliminated.
Although the present invention has been described in terms of specific embodiments, it is possible to modify and alter details thereof without departing from the spirit of the present invention. | A printing drum is rotatable supported by a fixed hollow cylindrical member at two axially spaced positions thereof so that the printing drum may be supported in a highly stable fashion and any mis-alignment of the printing drum can be avoided. Also, the interior of the fixed hollow cylindrical member provides an easily accessible space for accommodating a printing ink container and a pump for supplying printing ink. In particular, by using a squeegee blade instead of a squeegee roller, a particularly advantage can be obtained because the diameter of the fixed hollow cylindrical member can be such that an annular chamber defined between the fixed hollow cylindrical member and the inner circumferential surface of the printing drum is barely sufficient to accommodate the squeegee blade in the annular chamber, and the fixed hollow cylindrical member can provide a highly rigid support structure. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional patent application no. 60/632,162, filed on Dec. 1, 2004, under 35 U.S.C. §119(e).
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a non-lethal stun projectile that relies on an electrical impulse to stun the target. More specifically, the present invention relates to a self-contained, non-lethal piezoelectric stun projectile.
[0004] 2. Description of the Prior Art
[0005] Non-lethal neuromuscular disrupter weapons, sometimes referred to as “stun guns”, use a handpiece to deliver a high voltage charge to a human or animal target. The high voltage causes the target's muscles to contract uncontrollably, thereby disabling the target without causing permanent physical damage.
[0006] The most well known type of stun gun is known as the TASER gun. TASER guns look like pistols but use compressed air to fire two darts from a handpiece. The darts trail conductive wires back to the handpiece. When the darts strike their target, a high voltage charge is carried down the wire. A typical discharge is a pulsed discharge at 0.3 joules per pulse.
[0007] Taser guns and other guns of that type (herein referred to as “neuromuscular disrupter guns” or “NDG's”) are useful in situations when a firearm is inappropriate. However, a shortcoming of conventional NDGs is the need for physical connection between the projectile and the source of electrical power, i.e., the handpiece. This requirement limits the range of the NDG to about 20 feet.
[0008] One approach to eliminating the physical connection is to use an ionized air path to the target to create a conductive air path. For example, it might be possible to ionize the air between the handpiece and the target by using high-powered bursts or other air-ionizing techniques. However, this approach unduly complicates an otherwise simple weapon. An example of a NDG that uses conductive air paths to deliver a charge to the target is described in U.S. Pat. No. 5,675,103.
[0009] U.S. Pat. No. 5,698,815 describes a stun bullet that does not require a wired connection to the handpiece and which is designed to penetrate the skin of the target and deliver an electrical charge having a lower voltage and lower energy per pulse than typical stun guns. This stun bullet is provided with a battery or alternatively it may have a capacitor to temporarily store a charge delivered to the bullet just prior to firing. The range of this device is said to be well over 100 yards, but the dual dart electrodes must unwind from the bullet to be deployed, and subsequently penetrate the skin. Thus, these projectiles have some disadvantages resulting from the method of deploying the electrodes.
[0010] Another approach to providing an NDG that does not require an electrical connection between the handpiece and the projectile is described in U.S. Pat. No. 5,962,806. In this device, an electrical charge is generated within the projectile by means of a battery-powered converter housed within the projectile.
[0011] U.S. Patent Nos. 6,679,180; 6,802,261 and 6,802,262 each describe a tetherless neuromuscular disrupter gun employing a liquid-based capacitor projectile. In these patents, the projectile has an outer housing for the liquid and a capacitor is also located within the housing. The gun charges the projectile prior to discharge of the projectile from the gun. Upon impact, the liquid is discharged to deliver a single pulse with sufficient electrical charge to disrupt neuromuscular activity. These projectiles have a limited range of about 60 meters.
[0012] There remains a need in the art for a non-lethal approach to stunning or inhibiting a target that does not require electrical contact between the target and a hand-held apparatus, such as a stun gun. In addition what is needed is a single projectile, non-lethal approach to stunning or inhibiting a target that is not range-limited by wires coupled to darts, such as with a TASER, and that can be easily reloaded if an initial firing is unsuccessful.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a diagram of the piezoelectric stun projectile with an electrical oscillating circuit.
[0014] FIG. 2 is a diagram of the piezoelectric stun projectile with a mechanical oscillating circuit.
[0015] FIG. 3 is a schematic diagram of the experimental setup used to demonstrate the effectiveness of the piezoelectric element of the invention.
[0016] FIG. 4 is a photograph of the experimental device of FIG. 3 .
[0017] FIG. 5 is a graph of the voltage oscillogram for Experiment 1.
[0018] FIG. 6 is a graph of the voltage oscillogram for Experiment 2.
SUMMARY OF THE INVENTION
[0019] The present invention provides a non-lethal projectile for delivering an electric pulse to a target that does not require electrical contact between the projectile and the hand held apparatus.
[0020] According to a first aspect of the invention, a projectile for delivering an electric pulse to a target is disclosed. The projectile has a housing; a piezoelectric element located within the housing; and an electrical oscillating circuit connected to the piezoelectric element.
[0021] According to a second aspect of the invention, a projectile for delivering an electric pulse to a target is disclosed. The projectile has a housing, a piezoelectric element located within said housing; and a stress spring, wherein compression of the stress spring completes a circuit that is connected to the piezeoelectric element.
[0022] These and various other advantages and features of novelty that 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 the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The term “piezoelectric” refers to a class of materials that generate an electrical charge when subjected to an applied force that produces stress or otherwise induces strain in the piezoelectric material. One common type of piezoelectric device is a pressure transducer.
[0024] Piezoelectric pressure transducers typically are exposed to a fluid medium which exerts pressure directly or indirectly upon a diaphragm that is mechanically coupled to the piezoelectric element in a manner that applies a force thereto. The applied force generates a stress and related strain in the piezoelectric material. The piezoelectric element responds to the applied force and strain by generating an electrical charge. The electrical charge is directed to poles of the piezoelectric element which have electrical leads connected thereto. Electrical circuitry detects this generated electric charge and derives an electric signal representative of the pressure within the fluid medium. One attribute of piezoelectric devices is that the amount of electrical charge is typically very low.
[0025] A piezoelectric stun projectile (PESP) is designed to incapacitate a target by generating a powerful electrical output pulse. The principle of operating a PESP is based on the phenomenon of the direct piezoelectric effect. The source of electrical energy is a piezoelectric element, which generates a short electrical pulse upon application of mechanical stress to the piezoelectric element. In the context of the present invention, the short electrical pulse of the piezoelectric element may be applied to an under-damped oscillating circuit, which generates an attenuated periodic signal for about 0.5-1 second. During this time interval, the amplitude of the generated voltage can reach tens of kilovolts.
[0026] In the device of the present invention, the source of the mechanical stress may be the energy of a direct internal controlled explosion in the projectile. The PESP of the present invention is thus able to generate a powerful impulse of electrical energy in the range of 1 to 300 joules, and has a distance-range of up to about 150 meters. To deliver the PESP of the present invention, to the target, conventional sources of mechanical energy could be used, such as pneumatic devices or other devices for delivery of projectiles.
[0027] A diagram of one embodiment of a PESP in accordance with the present invention is presented in FIG. 1 . FIG. 1 depicts a PESP 30 provided with an electrical oscillating circuit. The housing 1 holds the components of the PESP 30 together. The housing 1 may be a single molded piece of high impact plastic or it may be any suitable casing material including a standard shell casing for a shotgun or M203 grenade. The housing 1 has a nose tip 2 made of a material that shields the electrodes 10 , 13 , in this case conductive needles 10 , 13 , prior to discharge of the PESP 30 . Nose tip 2 may be an energy-absorbing foam rubber, but any material may be used to fabricate nose tip 2 , so long as the material can be compressed upon impact to allow the conductive needles 10 , 13 to pierce through nose tip 2 , once nose tip 2 of projectile 30 strikes a target.
[0028] A depression or hole 3 may be provided in the housing 1 for the purpose of assisting in deployment of the projectile 30 by a suitable deployment mechanism. Housing 1 also contains a piezoelectric element 4 , located between a pair of metallic plates 5 , 6 . Explosive material 7 , 8 is positioned adjacent to metallic plates 5 , 6 , such that detonation of explosive material 7 , 8 will apply a force to metallic plates 5 , 6 causing plates 5 , 6 to compress piezoelectric element 4 . Explosive material 7 , 8 may be detonated upon impact of the projectile 30 with a target by electro-detonators 14 .
[0029] When PESP 30 hits a target, the nose tip 2 is compressed and conductive needles, 10 , 13 , penetrate into the target thereby creating an electrical connection between conductive needles 10 , 13 . This electrical connection between conductive needles 10 , 13 , activates electronic device 11 to close switch S, connecting electro-detonators 14 to energy source E. This results in the substantially simultaneous explosion of explosive materials 7 , 8 . Explosion of explosive materials 7 , 8 breaks wires 9 , 12 along the lines A-A and B-B, respectively, thereby breaking the connection between conductive needles 10 , 13 and electronic device 11 . At the same time, the metal plates 5 , 6 apply a force to piezoelectric element 4 to cause piezoelectric element 4 to generate an electric pulse. Also, piezoelectric element 4 is connected in parallel to the electrical oscillating circuit L, C and conductive needles 10 , 13 , via metal plates 5 , 6 , thereby transmitting the high voltage electric pulse from the piezoelectric element 4 to the target via electrical oscillating circuit L, C and conductive needles 10 , 13 .
[0030] Turning now to FIG. 2 , an alternative embodiment of the PESP of the present invention is shown. FIG. 2 shows a PESP 100 wherein a mechanical spring-mass system is used to create a harmonic mechanical stress on piezoelectric element 104 , which will generate the high voltage electrical signal. FIG. 2 shows projectile body or housing 101 , nose tip 102 , hole or recess 103 that may be provided in the housing 101 for the purpose of assisting in deployment of the projectile 100 by a suitable deployment mechanism, piezoelectric element 104 , metal plates 105 , 106 , propellant 107 , flat springs 108 , 115 , electrical wires 109 , 112 , conductive needles or electrodes 110 , 113 , electronic device 111 , electrodetonator 114 , and metal plates 116 , 117 .
[0031] When PESP 100 hits a target, nose tip 102 is compressed and conductive needles, 110 , 113 , penetrate into the target thereby creating an electrical connection between conductive needles 110 , 113 . The impact with the target activates electronic device 111 to close switch S 1 , connecting electro-detonator 114 to energy source El. This results in the explosion of propellant 107 . As a result of the explosion, propellant 107 , applies severe mechanical stress to springs 108 , 115 causing springs 108 , 115 to compress. The compression of stress springs 108 , 115 results in the contact of metal plates 116 , 117 with metal plates 105 and 106 thereby completing a circuit to allow an electric pulse generated by the force applied to piezoelectric element 104 to be transferred to the target via conductive needles 110 , 113 .
[0032] FIG. 3 is a schematic diagram of an experiment conducted to demonstrate the usefulness of the present invention. The diagram shows piezoelectric element 60 with a height h and a diameter d, a holder 62 , metal plates 64 , 66 and an attached oscilloscope 68 . Resisters R 1 and R 2 are shown as well as H, which represents the altitude from which a 5.313 kg object 70 was dropped, generating force F onto plate 64 . In this experimental setup, a 5.313 kg object 70 , was dropped on two circular piezoelectric disks the position of which is represented by piezoelectric element 60 , mounted in a holder 62 between two metal plates 64 and 66 . Each time the object 70 was dropped, the voltage was recorded by the oscilloscope using a voltage divider V and an attenuator V 1 (10:1). The first piezoelectric element had a diameter (d) of 9.56 mm and a height (h) of 1 mm. The second one had a diameter (d) of 6.96 mm and a height (h) of 8.86 mm. FIG. 4 is a photograph showing the experimental apparatus of FIG. 3 : holder 62 and the two metal plates 64 , 66 .
[0033] In the first experiment, the object was dropped from the altitude H of 1.08 m and the voltage divider V was constructed of two resistors, R 1 =100 kΩ and R 2 =3.3 kΩ. In the second experiment, the object was dropped from the altitude H of 1.75 m and the voltage divider V was constructed of two resistors, R 1 =100 kΩ and R 2 =1.5 kΩ. Recorded voltages for both experiments are presented in FIG. 5 (experiment 1 ) and FIG. 6 (experiment 2 ), respectively, as oscillograms.
[0034] As can be seen from FIGS. 5 and 6 , and accounting for the values of the resistors R 1 and R 2 , as well as the attenuation coefficient of the attenuator, the voltage amplitudes in both experiments are 16.7 kV and 44.7 kV, respectively. Thus, this demonstrates that piezoelectric elements can effectively develop sufficient charge to disable a target by electric shock without the need for batteries or trailing wire. | The present invention provides a non-lethal projectile for delivering an electric pulse to a target. In one aspect of the invention, the projectile utilizes a piezoelectric device and an electrical oscillating circuit in order to generate a pulse. In another aspect of the invention, the projectile utilizes a piezoelectric device and a mechanical oscillating circuit in order to generate an electric pulse. Since the projectile of the present invention contains the structure to generate the required electric pulse, it can be employed effectively at distances of up to 150 meters. | 5 |
BACKGROUND
The invention generally relates to gravel packing a well.
When well fluid is produced from a subterranean formation, the fluid typically contains particulates, or “sand.” The production of sand from the well must be controlled in order to extend the life of the well. One technique to accomplish this involves routing the well fluid through a downhole filter formed from gravel that surrounds a sandscreen. More specifically, the sandscreen typically is a cylindrical mesh that is inserted into and is generally concentric with the borehole of the well where well fluid is produced. Gravel is packed between the annular area between the formation and the sandscreen, called the “annulus.” The well fluid being produced passes through the gravel, enters the sandscreen and is communicated uphole via tubing that is connected to the sandscreen.
The gravel that surrounds the sandscreen typically is introduced into the well via a gravel packing operation. In a conventional gravel packing operation, the gravel is communicated downhole via a slurry, which is a mixture of fluid and gravel. A gravel packing system in the well directs the slurry around the sandscreen so that when the fluid in the slurry disperses, gravel remains around the sandscreen.
A potential challenge with a conventional gravel packing operation deals with the possibly that fluid may prematurely leave the slurry. When this occurs, a bridge forms in the slurry flow path, and this bridge forms a barrier that prevents slurry that is upstream of the bridge from being communicated downhole. Thus, the bridge disrupts and possibly prevents the application of gravel around some parts of the sandscreen.
One type of gravel packing operation involves the use of a slurry that contains a high viscosity fluid. Due to the high viscosity of this fluid, the slurry may be communicated downhole at a relatively low velocity without significant fluid loss. However, the high viscosity fluid typically is expensive and may present environmental challenges relating to its use. Another type of gravel packing operation involves the use of a low viscosity fluid, such as a fluid primarily formed from water, in the slurry. The low viscosity fluid typically is less expensive than the high viscosity fluid. This results in a better quality gravel pack (leaves less voids in the gravel pack than high viscosity fluid) and may be less harmful to the environment. However, a potential challenge in using the low viscosity fluid is that the velocity of the slurry must be higher than the velocity of the high viscosity fluid-based slurry in order to prevent fluid from prematurely leaving the slurry.
Thus, there exists a continuing need for an arrangement and/or technique that addresses one or more of the problems that are set forth above as well as possibly addresses one or more problems that are not set forth above.
SUMMARY
In an embodiment of the invention, a technique that is usable with a subterranean well includes communicating a slurry through a shunt flow path and operating a control device to isolate slurry from being communicated to an ancillary flow path.
In another embodiment of the invention, a system that is usable with a subterranean well includes a shunt tube and a diverter. The shunt tube is adapted to communicate a slurry flow within the well to form a gravel pack. The diverter is located in a passageway of the shunt tube to divert at least part of the flow.
In yet another embodiment of the invention, a technique that is usable with a subterranean well includes communicating a slurry through a shunt flow path and operating a control device to isolate the slurry from being communicated to an ancillary flow path.
Advantages and other features of the invention will become apparent from the following description, drawing and claims.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic diagram of a gravel packing system according to an embodiment of the invention.
FIG. 2 is a flow diagram depicting a technique to gravel pack a well in accordance with an embodiment of the invention.
FIGS. 3 and 4 are schematic diagrams showing operation of a leak control device according to an embodiment of the invention.
FIGS. 5 and 6 are schematic diagrams depicting operation of another leak control device according to another embodiment of the invention.
FIG. 7 is a schematic diagram depicting a dampening layer for use with a rupture disk in accordance with an embodiment of the invention.
FIG. 8 is a top view of a dampener of FIG. 7 according to an embodiment of the invention.
FIG. 9 is a schematic diagram of a slurry distribution system according to an embodiment of the invention.
FIG. 10 is a perspective view of a wedge used in the system of FIG. 9 according to an embodiment of the invention.
FIG. 11 is a schematic diagram of a slurry distribution system in accordance with another embodiment of the invention.
FIG. 12 is a cross-sectional view of a well in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
Referring to FIG. 1 , an embodiment 10 of a gravel packing system in accordance with the invention includes a generally cylindrical sandscreen 16 that is inserted into a wellbore of a subterranean well. The sandscreen 16 is constructed to receive well fluid through its sidewall from one or more subterranean formations of the well. As shown in FIG. 1 , the sandscreen 16 may be located inside a well casing 12 of the well. An annulus 20 is formed between the interior surface of the well casing 12 and the components of the system 10 . It is noted that in some embodiments of the invention, the well may be uncased well, and thus, in these embodiments of the invention, the annulus 20 may be located between the components of the system 10 and the uncased wall of the wellbore.
In accordance with some embodiments of the invention, a two-phase gravel packing operation is used to distribute gravel around the sandscreen 16 . The first phase involves gravel packing the well from the bottom up by introducing a gravel slurry flow into the annulus 20 . As the slurry flow travels through the well, the slurry flow loses its fluid through the sandscreen 20 and into the formation. That which enters the sandscreen returns to the surface of the well. During the first phase of the gravel packing operation, one or more bridges may eventually form in the annulus 20 due to the loss of fluid to the formation, thereby precluding further gravel packing via the straight introduction of the slurry flow into the annulus 20 . To circumvent these bridges, the gravel packing enters a second phase in which the slurry flow is routed through alternative slurry flow paths.
More particularly, in some embodiments of the invention, the alternative flow paths are formed at least in part by shunt flow paths that are established by one or more shunt tubes 22 (one shunt tube depicted in FIG. 1 ) that extend along the sandscreen 16 . Therefore, as depicted in FIG. 1 , in some embodiments of the invention, a particular shunt tube 22 may receive a gravel slurry flow 24 for purposes of bypassing one or more bridges that may be formed in the annulus 20 .
More specifically, as depicted in FIG. 1 , each shunt tube 22 may be connected to ancillary flow paths that are established by various packing tubes 30 (packing tubes 30 a , 30 b , 30 c and 30 d , depicted as examples) for purposes of distributing slurry through these tubes into the annulus 20 . As shown, in some embodiments of the invention, each packing tube 30 has an upper end that is connected to a radial opening in the shunt tube 22 ; and the packing tube 30 extends along the shunt tube 22 to a lower outlet end at which the packing tube 30 delivers a slurry flow downstream of the radial opening. In some embodiments of the invention, each packing tube 30 may have several outlets that extend along the length of the packing tube 30 .
As discussed further below, each of the depicted packing tubes 30 a–d may be associated with a particular section of the well to be packed. For example, as depicted in FIG. 1 , the packing tubes 30 a–d may be associated with well sections 44 , 46 , 48 and 50 , respectively. Each section may contain more than one packing tube 30 that is connected to the shunt tube 22 ; and each section may contain more than one shunt tube 22 , depending on the particular embodiment of the invention. Furthermore, as depicted in FIG. 1 , in some embodiments of the invention, the packing tubes 30 of a particular section may be surrounded by an outer shroud 32 that surrounds both the shunt tube(s) 22 , packing tube(s) 30 and sandscreen 16 . Each shroud 32 may include perforations 34 for purposes of receiving the gravel and fluid from the slurry. In this regard, the slurry may flow from the outside of the shroud 32 into the interior of shroud 32 . Ideally, the fluid from the slurry flow 24 enters the screen 16 , returns to the surface, as depicted by the flow 40 , thereby leaving the deposited gravel around the exterior of the sandscreen 16 .
In some embodiments of the invention, the shunt tube(s) 22 may be located outside of the shrouds 32 ; and in some embodiments of the invention, the shunt tubes 22 may be located both inside and outside of the shrouds 32 . Thus, many variations are possible and are within the scope of the claims.
As a more specific example of the two phase gravel packing operation, FIG. 2 depicts a technique 60 that may be used to gravel pack the well using the system 10 . In accordance with the technique 60 , gravel packing initially proceeds from the bottom of the well to the top of the well. Thus, in this initial phase, the gravel slurry is introduced into the annulus 20 of the well. The gravel slurry enters the annulus 20 and proceeds with packing the annulus 20 with gravel from the bottom of the well up. This gravel packing from the bottom up (block 62 ) continues until one or more bridges are formed (diamond 64 ) that significantly impede the flow of slurry through the annulus 20 . As described further below, this bridge increases a pressure in the slurry to activate the second phase of the gravel packing operation in which sections of the well are packed from top to bottom using alternative flow paths.
More specifically, using FIG. 1 as an example, at the onset of the second phase of the gravel packing operation, the upper section 44 is packed first, then the section 46 , then the section 48 , which is followed by the section 50 , etc. The packing in a particular section continues until the bridge(s) that form in the annulus 20 and/or packing tubes 30 of that section significantly impede the flow of the slurry. Thus, in accordance with the technique 60 , gravel packing for a particular section continues (block 68 of FIG. 2 ) until bridge(s) are formed (diamond 70 ) in the section that significantly impede the flow of slurry into that section. For example, for the section 44 , a bridge may form in the packing tube 30 a and/or other packing tubes 30 (not shown) to impede flow of the slurry enough to trigger a transition to the next section.
In some embodiments of the invention, the technique 60 includes preventing the communication through the shunt tube(s) between a particular section being packed and the adjacent section until the flow of slurry has been significantly impeded.
The significance of the blockage of the slurry flow affects the pressure of the slurry flow. Therefore, in some embodiments of the invention, the pressure increase initiates mechanisms (described below) that shut off packing in the current section and route the slurry flow to one or more alternate flow paths in the next section to be gravel packed. More particularly, when the bridge(s) cause the pressure of the slurry to reach a predetermined threshold (in accordance with some embodiments of the invention), communication to the next section to be packed is opened (block 72 ). Thus, slurry flows through the shunt tube(s) to the next section to be packed. Gravel packing thus proceeds to the next adjacent section, as depicted in block 68 .
In some embodiments of the invention, one or more devices are operated to close off communication through the packing tube or tubes of the section at the conclusion of packing in that section, as described below. By isolating all packing tubes of previously packed sections, fluid loss is prevented from these sections, thereby ensuring that a higher velocity for the slurry may be maintained. This higher velocity, in turn, prevents the formation of bridges, ensures a better distribution of gravel around the sandscreen 16 and permits the use of a low viscosity fluid in the slurry (a fluid having a viscosity less than 30 approximately centipoises, in some embodiments of the invention).
FIG. 3 depicts a slurry distribution system 100 (in accordance with some embodiments of the invention) that may be used in a particular well section to control slurry flow through alternative flow paths. In accordance with some embodiments of the invention, the system 100 may be located in the vicinity of the union of a shunt tube 22 and a particular packing tube 30 .
The system 100 includes a plug 112 that is initially partially inserted into a radial opening 125 of the packing tube 30 . In this state, the plug 112 does not impede a slurry flow 102 through the passageway of the packing tube 30 . A spring 116 is located between the plug 112 and a sleeve 120 . The sleeve 120 , in some embodiments of the invention, is coaxial with the shunt tube 22 , is closely circumscribed by the shunt tube 22 and is constructed to slide over a portion of the shunt tube 22 between the position depicted in FIG. 3 and a lower position that is set by an annular stop 136 . In other embodiments of the invention, the sleeve 120 may be located outside and closely circumscribe the shunt tube 22 . O-rings 130 form a fluid seal between the sleeve 120 and the shunt tube 22 . As an example, for embodiments in which the sleeve 120 is located inside the shunt tube 22 , the O-rings 130 may reside in annular grooves that are formed in the exterior of the sleeve 120 .
Initially, a shear screw 114 holds the spring 116 in a compressed state and holds the sleeve in the position depicted in FIG. 3 . The shear screw 114 is attached to the sleeve 120 and extends through the shunt tube 22 and the interior of the spring 116 to the plug 112 . Therefore, in its initial unsheared state, the screw 120 keeps the plug 112 from completely entering the radial opening 125 and obstructing the passageway of the packing tube 30 .
A lower end 139 of the sleeve 120 contains a rupture disk 134 that controls communication through the end 139 . Initially, the rupture disk 134 blocks the slurry flow 24 from passing through the shunt tube 22 . Thus, the slurry flow 24 exerts a downward force on the sliding sleeve 120 via the contact of the slurry 24 and the rupture disk 134 . When the flow of slurry through the section being gravel packed becomes impeded, the pressure of the slurry 24 acting on the rupture disk 134 increases. The impeded flow may be due to the formation of one or more bridges in the annulus and/or packing tube(s), of the section, such as the exemplary bridge 109 that is shown as being formed in the packing tube 30 of FIG. 3 . When the slurry flow into the section becomes sufficiently impeded by the bridge(s), the pressure on the rupture disk 134 increases to the point that the sliding sleeve 120 , shears the screw 114 , moves downhole and rests against the stop 134 . A further restriction of slurry flow by the bridging eventually causes the rupture disk 134 to rupture.
This subsequent state of the system 100 is depicted in FIG. 4 . As shown, after the shear screw 114 shears, the spring 116 is free to expand and exerts a radial force on the plug 112 , thereby forcing the plug 112 fully into the passageway of the packing tube 30 to seal off the passageway. Thus, entry of the plug 112 into the passageway of the packing tube 30 prevents any further fluid flow through the packing tube 30 . This sealing off of the packing tube 30 serves to further increase the pressure on the rupture disk 134 to facilitate its rupture. As depicted in FIG. 4 , the rupture of the rupture disk 134 opens communication through the shunt tube 22 .
An alternative slurry distribution system 160 is depicted in FIG. 5 . The system 160 includes a sliding sleeve 166 that is concentric with and slides inside the shunt tube 22 , in some embodiments of the invention. Alternatively, the sleeve 166 circumscribes and slides outside of the shunt tube 22 , in other embodiments of the invention. The system 160 includes O-rings 170 that are located between the sleeve 166 and shunt tube 22 to form a fluid seal.
As depicted in FIG. 5 , the sleeve 166 includes a radial opening 168 that is initially aligned with the opening between the packing tube 30 and the shunt tube 22 . Furthermore, a lower end 191 of the sliding sleeve 166 includes a rupture disk 190 , thereby initially preventing flow through the shunt tube 22 below the rupture disk 190 . Thus, initially, the slurry flow 24 is routed entirely through the packing tube 30 .
The sleeve 166 is constructed to move between the position depicted in FIG. 5 and a position in which the lower end of the sleeve 166 rests on an annular stop 182 that is located below the sleeve 166 inside the shunt tube 22 . However, the sleeve 166 is initially confined to the position depicted in FIG. 5 by a shear screw 162 that, it its unsheared state, attaches the sleeve 166 to the shunt tube 22 .
Over time, bridges, such as an exemplary bridge 183 shown in the packing tube 30 , may form to impede the flow of the slurry. The resultant pressure increase in the slurry flow, in turn, creates a downward force on the sleeve 166 . After the flow has been sufficiently impeded, the force on the sleeve 166 shears the shear screw 162 and causes the sleeve 166 to slide to the position in which the bottom end of the sleeve 166 rests against the stop 182 . In this position, the radial opening 168 is misaligned with the opening to the packing tube 30 ; and thus, communication between the shunt tube 22 and packing tube 30 is blocked. This blockage along with any additional bridging increases pressure on the rupture disk 190 so that the rupture disk 190 ruptures.
This state of the system 160 is in FIG. 6 . As can be seen, in this state, the slurry flow 24 is isolated from the packing tube 30 and is routed by the system 160 through the shunt 22 to the next section to be packed.
In some embodiments of the invention, a dampening layer may be included below a particular rupture disk in the shunt tube 22 , such as the rupture disks 134 ( FIGS. 3 and 4 ) and 190 ( FIGS. 5 and 6 ). This dampening layer tends to, as its name implies, dampen a pressure spike that might otherwise propagate through the opening of the rupture disk when the rupture disk ruptures. Such a pressure spike may inadvertently rupture a downstream rupture disk inside the shunt tube 22 .
An exemplary dampening layer 199 , in accordance with some embodiments of the invention, is depicted in FIG. 7 . As shown, the dampening layer 199 may be formed from a generally circular disk 204 (see also FIG. 8 ) that is positioned across the cross-section of the shunt tube 22 and includes several openings 206 for purposes of allowing the slurry to flow therethrough. However, the disk 204 is not entirely open, thereby functioning to dampen a pressure spike, if present, when an upstream rupture disk 203 ruptures. In some embodiments of the invention, a cylindrical spacer 200 may be located between the disk 204 and the rupture disk 203 . Furthermore, in accordance with some embodiments of the invention, the rupture disk 203 may be attached to the end of a sliding sleeve 207 (such as the sleeve 120 ( FIG. 3 ) or 166 ( FIG. 5 ), for example). In some embodiments of the invention, the rupture disks 203 and disk 204 may have shapes other than the circular shapes that are depicted in the figures.
FIG. 9 depicts another slurry distribution system 300 , in accordance with some embodiments of the invention. The system 300 includes a deflector 304 that may be used to deflect a slurry flow 24 from directly contacting a particular rupture disk 320 . The rupture disk 320 is located inside and initially blocks communication through an outlet of a manifold, or crossover 310 . A shunt tube 321 is connected to this outlet. Therefore, until the rupture disk 320 ruptures, the rupture disk 320 block communication of slurry into the shunt tube 321 . As shown, the crossover 310 includes an inlet that is connected to a shunt tube 22 to receive a slurry flow 24 . The crossover 310 includes two additional outlets that are connected to two packing tubes 30 . Thus, when the rupture disk 320 is intact, the crossover 310 distributes the incoming slurry flow to both packing tubes 30 and does not deliver any slurry to the shunt tube 321 .
The central passageway of the shunt tube 22 may be generally aligned with the passageway of the lower shunt tube 321 . Therefore, due to inertia, the main flow path along which the slurry flow 24 propagates may generally be directed toward the central passageway of the lower shunt tube 310 and thus, toward the rupture disk 320 . The deflector 304 , however, deflects the slurry flow 24 away from the rupture disk 320 and toward the corresponding packing tubes 30 . As depicted in FIG. 9 , in some embodiments of the invention, the deflector 304 may include at least two inclined (relative to the direction of the slurry flow 24 ) deflecting surfaces 305 for purposes of dividing the slurry flow 24 into two corresponding flows that enter the packing tubes 30 . More specifically, in some embodiments of the invention, the deflector 304 may generally be a wedge ( FIG. 10 ), with the side surfaces of the wedge forming the deflecting surfaces 305 .
One function of the deflector 304 is to deflect a potential pressure spike that may be caused by the rupture of an upstream rupture disk. Thus, the deflector 304 may prevent premature rupturing of the rupture disk 320 . Another potential advantage of the use of the deflector 304 is to prevent erosion of the rupture disk 320 . More specifically, in some embodiments of the invention, the rupture disk 320 might erode due to particulates in the slurry 24 . Over time, this erosion may affect the rupture threshold of the rupture disk 320 . Therefore, without such a deflector 304 , the rupture disk 320 may rupture at a lower pressure than desired.
The third function, which may be the major function of the deflector (in some embodiments of the invention), is to divert the gravel to the packing tube, after the rupture disk burst, in order to seal the packing tubes hydraulically.
In some embodiments of the invention, the slurry flow 24 gradually erodes the deflector 302 to minimize any local flow restriction. However, this erosion occurs well after the desired rupturing of the rupture disk 320 .
FIG. 11 depicts another slurry distribution system 350 in accordance with some embodiments of the invention. The system 350 includes two deflectors 354 (wedge-shaped deflectors, for example) that are located inside a crossover 361 . The crossover 361 includes two inlets that each receives a shunt tube 22 . The crossover 361 has two outlets that are connected to two corresponding packing tubes 30 ; and the crossover 361 has a third outlet that is connected to a lower shunt tube 380 . The crossover 361 includes a rupture disk 370 that initially blocks communication of slurry to the lower shunt tube 380 . As shown, the lower shunt tube 380 may be coaxial with the crossover 361 .
As depicted in FIG. 11 , the two deflectors 354 divert corresponding slurry flows 24 from the shunt tubes 22 into the corresponding packing tubes 30 . As shown, in some embodiments of the invention, a gap 360 exists between the deflectors 354 . In some embodiments of the invention, each of the deflectors 354 may be a wedge. As a more specific example, each wedge 354 may have an inclined (relative to the deflected flow) deflecting surface 358 for purposes of deflecting the associated slurry flow 24 into the associated packing tube 30 . Furthermore, another surface 356 of each deflector 354 may be generally aligned with the longitudinal axis of the shunt tubes 22 for purposes of permitting flow between the deflectors 354 . However, the flow between the deflectors 354 is not aligned with either slurry flow 24 to prevent the erosion and premature bursting of the rupture disk 370 , as described above in connection the deflector 304 (see FIG. 9 ).
Referring to FIG. 12 , in some embodiments of the invention, alternative flow paths may be provided by structures other than shunt tubes and packing tubes. In this manner, in some embodiments of the invention, an alternative flow path may be provided by an annular space 501 that exists between the outer surface of a sandscreen 502 and the inner surface of an outer circumscribing shroud 504 . Thus, in accordance with some embodiments of the invention, a rupture disk or other flow control device may be located in the annular area 501 . Furthermore, deflectors may be also located in the annulus 501 for purposes of performing the function of the deflectors described above. Additionally, in some embodiments of the invention, the radial paths from the outer shroud 504 may be sealed off for purposes of preventing fluid loss, similar to the arrangements depicted in FIGS. 3–6 above. Furthermore, structures other than tubes may provide ancillary flow paths. Therefore, the language “flow path” is not restricted to a flow in a particular tube, as the term “flow path” may apply to flow paths outside of tubes, between tubes, other types of flow paths, etc. in some embodiments of the invention.
Although rupture disks have been described above, it is noted that other flow control devices, such as valves, for example, may be used in place of these rupture disks and are within the scope of the claims.
Orientational terms, such as “up,” “down,” “radial,” “lateral,” etc. may be used for purposes of convenience to describe the gravel packing systems and techniques as well as the slurry distribution systems and techniques. However, embodiments of the invention are not limited to these particular orientations. For example, the system depicted in FIG. 1 (and the variations discussed herein) may be used in a lateral wellbore or highly deviated wellbore, for example. Other variations are possible.
While the present invention has been described with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention. | A technique that is usable with a subterranean well includes communicating a slurry through a shunt flow path and operating a control device to isolate slurry from being communicated to an ancillary flow path. The system may include a shunt tube and a diverter. The shunt tube is adapted to communicate a slurry flow within the well to form a gravel pack. The diverter is located in a passageway of the shunt tube to divert at least part of the flow. A slurry may be communicated through the shunt flow path, and a control device may be operated to isolate the slurry from being communicated to the ancillary flow path. | 4 |
This application claims priority benefits from French Patent Application No. FR 06 11368 filed Dec. 26, 2006, the disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The invention relates to a method for setting a safety threshold that triggers the sending, by an acceleration or movement sensor device, of a safety signal that causes a safety movement of a motorized screen used as a closure or as a sunshade or for privacy. The invention also relates to an acceleration or movement sensor device for implementing such a method.
DESCRIPTION OF THE PRIOR ART
It is known practice to use a vibration sensor comprising, for example, an accelerometer, to detect movements caused by the wind on a mobile structure such as an awning. The sensor is mounted on the mobile structure at a point where the wind effects are particularly important. It also includes a device that analyzes the signals produced by the accelerometer and a radio transmitter to send to a motor control unit a command to wind the awning up when the vibration level exceeds a predetermined threshold.
Such a device is known for example from application FR 2 811 431.
Document EP 1 659 256 describes a similar sensor for detecting the presence of wind and controlling a sunshade installation accordingly.
One problem with this type of sensor is how to set adjustment thresholds (to adjust the degree of sensitivity of the sensor), because it is important that the sensor should have a completely watertight housing since the mobile structure, which is sensitive to wind action, is also exposed to weather, moisture and salt fogs. The means for setting the threshold or thresholds can only be got at after the housing has been disassembled, which usually means removing the sensor from the structure.
Furthermore, setting a preset potentiometer contained in a closed housing is a difficult task. But on the other hand, making the control of the potentiometer accessible from the outside significantly increases the cost, because of the need for water tightness.
It is an object of the invention to provide a method for setting a sensor device that overcomes the drawbacks cited above and improves the known setting methods of the prior art. In particular, the invention proposes a simple setting method that limits the work on the sensor device. The invention further relates to a sensor device for implementing such a setting method.
SUMMARY OF THE INVENTION
The setting method according to the invention is defined in claim 1 .
Various embodiments of the setting method are defined in claims 2 - 7 .
The sensor device according to the invention is defined in claim 8 .
DESCRIPTION OF THE DRAWINGS
The appended drawing shows, by way of example, an embodiment of a sensor device according to the invention and a way of carrying out a method of setting a sensor device according to the invention.
FIG. 1 is a diagram of an installation comprising a sensor device according to the invention.
FIG. 2 is an exploded diagram of a sensor device according to the invention.
FIG. 3 is an electrical diagram of a sensor device according to the invention.
FIG. 4 is a flow chart showing one way of carrying out a method for setting a sensor device according to the invention.
FIG. 5 is a flow chart showing one way of carrying out the first step of the setting method.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an installation 10 comprising a motorized awning in which the fabric 11 is attached by a fixing 12 to a load bar 13 . The fabric is wound onto a motorized tube 18 . When the motor winds the fabric onto the winding tube, the fabric moves the load bar 13 in direction X 1 , and, to a lesser extent, in direction Y 2 . A plurality of spring-loaded hinged arms 14 apply a force to the load bar 13 in direction X 2 and, to a lesser extent, in direction Y 1 so as to keep the fabric taut. The hinged arm 14 is connected to the load bar by a first hinge 15 . The hinged arm comprises other hinges, in particular a second hinge 16 connecting it to the fixed structure 17 of the installation, which comprises the motorized winding tube. Load bar, fabric and jointed arms constitute the mobile structure.
The installation 10 also comprises a sensor device 20 mounted on the load bar 13 . The sensor device 20 could be located anywhere such that the wind (represented by a solid arrow WND) acting on the fabric 11 causes the mobile structure, and in particular the location where the sensor device is situated, to move about. The sensor device 20 transmits a safety signal to a control unit 19 . This control unit generates the commands which control the motorized tube. The control unit comprises a radiofrequency receiver with an antenna, and optionally some sort of weather sensor.
FIG. 2 details the components comprised in the sensor device 20 . In the preferred embodiment, the sensor device comprises a base 22 mounted on the mobile structure, and a removable part 23 forming a cover and comprising the electronic components of the sensor device.
The cover 23 comprises clips 24 for quick attachment of the cover 23 to the base 22 in recesses 25 . The base is mounted rigidly on the load bar 13 by mounting means 26 represented by circles. These may simply be fastening screws. The base also includes a primary element 27 for detecting the closure of the housing, for example a magnet, a reflective patch or a pin designed to operate a switch. The base and the cover form the housing of the sensor device.
The sensor device 20 also comprises an electronic circuit 30 . The components are mounted on a printed circuit 31 fixed to the cover 23 by means of fixing pins 28 . These components comprise a secondary element 32 for detecting the closure of the housing, such as a reed switch controlled by a magnet, an optocoupler or a single switch. The secondary element acts in conjunction with the primary element, as shown by a curved dashed line, to deliver an electrical state representing the state of closure of the housing.
Also mounted on the printed circuit is a vibration sensor means 33 , e.g. an accelerometer or a ball and contact inertial sensor, or any device for detecting movement.
A logical processing unit 34 , such as a microcontroller, a radio transmitter 35 and its antenna, and a battery 36 are also inserted into the printed circuit 31 of the sensor device.
The connections between these components are detailed in FIG. 3 .
The logic processing unit includes among other things software means for controlling the operation of the sensor device during its setting by the setting method to which the invention relates, one way of carrying this out being described in detail later. In particular, these software means comprise computer programs.
The logic processing unit 34 is powered by the battery 36 , as is the vibration sensor means 33 if a controlled switch 37 is closed. The signals produced by the vibration sensor means 33 are transmitted to a first input ACC of the logic processing unit. The output of the secondary housing-closing element 32 is connected to a second input CLS of the logic processing unit. This input is in the low logic state while the housing is closed. In this case, the signals produced by the vibration sensor means are processed, and, if they exceed one or more predetermined threshold(s), a control signal is then transmitted from a first output SGNL of the logic processing unit to an input RFI of the radio transmitter 34 , of which an output RFO supplies a radiofrequency antenna, which then transmits a safety signal “wind”.
Alternatively, the first and second elements detect not the opening of the housing but its mounting at a predetermined location of the mobile structure. For example, a magnet acts as the primary element and is located at a point of the mobile structure, while a reed sensor acts as the secondary element. The primary element may also be a simple U-shaped ferromagnetic part mounted on a mobile structure, while the magnet and the reed sensor are positioned inside the housing. When the housing is placed near the ferromagnetic part, the latter channels the magnetic flux of the magnet and returns it to the reed sensor.
To allow interchangeability of housings in the event that a defective element needs replacing, all primary elements are able to interact with all secondary elements where the elements are of the same type.
If the logic input CLS changes to the high state, the logic processing unit ignores the signal produced by the vibration sensor means. In the embodiment shown in FIG. 3 , a controlled opening switch 37 is controlled by an inhibiting output INH of the logic processing unit 34 , the effect of which is to stop the supply to the vibration sensor means 33 , and therefore stop any signal produced by the latter. Alternatively, the logic processing unit 34 may simply stop analyzing the signals present at its input ACC, or temporarily block the sending of a signal transmission command to the radio transmitter 35 , or temporarily interrupt the power to the radio transmitter 35 by a means similar to the control switch 37 , or by using the same control switch 37 to cut off the power to the vibration sensor means and to the radio transmitter.
Once the sensor device has been configured, its operation is such that, when movements or vibrations exceed a predetermined safety threshold, the sensor device transmits a safety signal that triggers a safety movement of the screen, for example winding it up in the case of an awning supported by arms.
One way of carrying out the setting method according to the invention is described in detail below with reference to FIG. 4 .
In the first step E 11 , the sensor device is put in an setting mode. This can be done in various ways. For example, if the sensor device has wireless signal receiving means, a signal to enter the setting mode can be sent to it from a remote control with which it is paired. Alternatively, the sensor device may have a special switch for putting it in the setting mode when activated. Also, if the sensor device is of the type described above, it is possible that it can be triggered to enter the setting mode by a sequence of actions of removing and/or opening and fitting and/or closing the housing of the sensor device in compliance with a specified time sequence. For example, opening the housing and then closing it again less than 10 seconds after opening it may put the sensor device into setting mode as detailed below.
In the second step E 12 , the installer shakes the screen with the sensor device mounted on it. The movement and/or vibrations introduced by the installer by applying forces to the screen will be those which are decisive in defining a safety threshold above which the sensor device will transmit a signal, once completely configured. By construction, an awning is capable of withstanding quite violent gusts of wind, but the user perceives the shaking of the structure as alarming. It is therefore desirable for the installer to give the awning a shaking movement corresponding to what the user would regard as alarming, rather than what the awning could actually cope with.
In the third step E 13 , which takes place simultaneously with step E 12 , the signal produced by the vibration sensor means is recorded. This recording step has a predetermined duration T 1 of for example between 30 seconds and 3 minutes. This duration is counted from the instant the unit enters setting mode. The data defining the signal are stored in a memory MEM of the logic processing unit 34 . These data may for example be values sampled from the signal produced by the vibration sensor means.
At the end of step E 13 , in the fourth step E 14 , one or more safety threshold values are calculated from the above recording, using algorithms or empirical rules. For this purpose the logic processing unit 34 contains a calculating program stored in memory MEM enabling it to process the values previously stored in its memory.
For example, a safety threshold may be determined from the highest measured value, or from the mean of the ten highest values. Alternatively, a first safety threshold may be determined for a high oscillation frequency (or for a pulsed mode) and a second threshold may be determined for a low oscillation frequency.
These determinations of values can be done automatically as described in the above three paragraphs by an automatic sequencing of the steps.
Alternatively, step E 13 may be stopped by an action of the installer, such as pressing a button on a remote control (e.g. pressing the stop button causing the actuator to stop when it is operating).
Lastly, steps E 13 and E 14 can be combined into a single step in which a value determined by the signal produced by the vibration sensor is continually updated. For example, this can be done by a peak detector which keeps the maximum value of the signal in memory. The most recent value obtained at the end of the step is for example the safety threshold value.
In the fifth step E 15 , the safety threshold value or values are recorded in the memory MEM.
In the sixth step E 16 , at the end of the preceding step, the sensor device automatically switches to the operating mode, termed the monitoring mode. The sensor device is now operational.
In an optional seventh step (not shown) the sensor device may tell the installer that one or more safety thresholds have been recorded and that the sensor device is operational.
FIG. 5 details an embodiment of the first step E 11 of the setting method, allowing the device to enter the setting mode.
In the first substep E 21 of the step of putting the device in the setting mode, the installer opens the housing or removes it, after first opening the awning at least partially. This is detected by the detection means.
In the second substep E 22 , the wind safety signal is inhibited. This is to ensure that the awning does not retract automatically in response to the movements applied to the housing by the user.
In the third substep E 23 , a second time period T 2 of short duration, for example between 2 and 10 seconds, is triggered.
In the fourth substep E 24 , the device tests to see whether the removal and/or opening of the housing (detected in the first substep E 21 ) is maintained during the duration of the second time period. If it is not, and the housing has been closed again or put back in position during the duration of the second time period, then the setting mode is activated and the first step E 11 is completed.
An installer who wishes to adjust the sensitivity thresholds of the sensor-transmitter must therefore carry out a very simple operation: remove the sensor-transmitter housing from its support, and put it back in place after a few seconds, alternatively open and then re-close the housing. This operation is performed while the awning is at least partly extended.
If this embodiment is used, permission to transmit the wind safety signal is re-established at the end of the sixth step E 16 .
The entry into the setting step may be confirmed to the user by a sensory signal: for example, an audible beep emitted by the sensor-transmitter, or preferably by the control unit 19 after the latter has received a radio message from the sensor-transmitter informing it that the setting step has begun.
The method according to the invention is applicable to screens other than awnings. It is particularly applicable to a roller awning or to a door. | A method for setting a safety threshold that triggers the sending, by an acceleration or movement sensor device ( 20 ), of a safety signal that causes a safety movement of a motorized screen ( 11 ) used as a closure or as a sunshade or for privacy, said method comprising the following steps:
manual shaking of the screen, recording of a signal produced by a sensor means ( 33 ) during the manual shaking step, and determination of the safety threshold from this recording. | 4 |
BACKGROUND
[0001] 1. Field of Invention
[0002] This invention relates to ozone production for domestic and industrial applications, and more particularly, to an improved ozone generator and system.
[0003] 2. Background of the Invention
[0004] Ozone gas (O 3 ) is a powerful oxidizing agent that has an oxidation potential about 1.5 times greater than that of chlorine. Ozone is used for various oxidation processes, water and air treatment and as a reactant in many chemical syntheses. Ozone is an unstable gas, which may be produced by exposing oxygen to an electric field derived from a high voltage alternating current. Ozone generators create an electric field by corona discharge between opposing electrodes with intervening dielectric. Corona discharge involves passing air between positively and negatively charged electrodes separated by a dielectric material and a discharge gap. In the process, the air in the highly-charged electric field between the electrodes becomes ionized and conductive such that oxygen in the air is converted to ozone.
[0005] Conventional ozone generators require substantial amounts of energy in order to produce a sufficient volume of ozone for commercially feasible use. For example, a conventional corona discharge ozone generator may require 100 kilowatt-hours of energy to produce 18 pounds of ozone in a 24-hour period. As a result, the cost of producing ozone can be a significant factor in considering the use of ozone as an oxidizing agent for any given process.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to an ozone generator including a pair of electrodes separated by a dielectric and at least one passage defining a corona discharge zone. The present invention is directed to an ozone generator used to generate ozone by flowing air, or other suitable gas including oxygen, through a corona discharge zone between a pair of charged elements or electrodes. In one embodiment of the invention, pressurized flowing air, or other suitable gas including oxygen, passes along a plurality of passages positioned between the one of the pair of charged elements or electrodes and the dielectric. The plurality of passages may be defined by a plurality of grooves formed on a surface of the dielectric element and a contacting surface of an electrode. In the alternative, the plurality of grooves may be formed in a surface of the electrode and the plurality of passages may be defined by the plurality of grooves formed on a surface of the electrode and a contacting surface of the dielectric element. In one embodiment of the invention, the grooves, and therefore the passages, are convoluted in the sense that the length of each passage is greater than the length of the dielectric material. As a result, a gas flowing along the plurality of passages must travel a distance greater than the length of the dielectric element in order to pass through the corona discharge zone. This configuration provides for an extended period of exposure of the gas to the electric field and may result in increased yields in the production of ozone, and the production of ozone exhibiting improved stability and oxidation rate.
[0007] In a preferred embodiment of the invention, inner and outer concentric tubular electrodes are held in spaced apart relationship by a concentric tubular dielectric. A corona discharge zone is defined between an inner surface of the outer tubular electrode and the outer surface of the concentric tubular dielectric by a plurality of passages formed on the outer surface of the concentric tubular dielectric.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a schematic representative view of an ozone generating system;
[0009] [0009]FIG. 2 is a representative perspective view of an ozone generator;
[0010] [0010]FIG. 3 is a representative side cutaway view of an ozone generator;
[0011] [0011]FIG. 4 is a representative partial cut-away side detail view of an ozone generator;
[0012] [0012]FIG. 5 representative partial cut-away side detail view of an ozone generator;
[0013] [0013]FIG. 6 is a representative cross-sectional view of an ozone generator taken substantially along lines 6 - 6 in FIG. 3;
[0014] [0014]FIG. 7A is representative side view of a dielectric element for an ozone generator;
[0015] [0015]FIG. 7B is representative side view of a dielectric element for an ozone generator; and
[0016] [0016]FIG. 8 is a representative perspective view of an alternate embodiment of an ozone generator according to the present invention.
DETAILED DESCRIPTION
[0017] [0017]FIG. 1 is a representative perspective view of ozone generating system 10 including housing 11 which provides a protective enclosure for ozone generators 100 A, 100 B and 100 C, each electrically coupled to transformer 20 which is electrically coupled to power supply 25 . Ozone generating system 10 also includes controller 40 for controlling various functions and operations of ozone generating system 10 . Ozone generating system 10 includes compressor 30 which is pneumatically connected to each of the ozone generators 100 A, 100 B and 100 C for providing a flow of air through each of the ozone generators 100 A, 100 B and 100 C. Compressor 30 is pneumatically connected to outlet 154 in such a manner that air is drawn through each of the ozone generators 100 A, 100 B and 100 C under a vacuum. Compressor 30 is an oiless compressor and has a preferred rated output in the range of 20-80 psi, and preferably an output substantially equal to 75 psi. Inlet 153 includes check valve 50 which permits pneumatic communication with each of the ozone generators 100 A, 100 B and 100 C in an inflow direction only. Outlet 154 is pneumatically connected to outlet compressor inlet 52 . Compressor outlet 53 may be fluidly connected to a fluid stream flow F contained within pipe 55 for direct treatment of the fluid with ozone. Alternatively, compressor outlet 53 may be fluidly connected to a vessel for storage or treatment, not shown. Control valve 54 prohibits a fluid flow from pipe 55 upstream to compressor 30 . Alternatively, an inline check valve may be used to prevent backflow to compressor 30 .
[0018] [0018]FIGS. 2 and 3 show ozone generator 100 electrically coupled to transformer 20 . Ozone generator 100 includes first terminal 112 conductively connected to first electrode 110 and second terminal 122 conductively connected to second electrode 120 . Inlet 153 pneumatically communicates through wall 121 of second electrode 120 with inlet plenum 138 , shown in FIG. 3, and outlet 154 pneumatically communicates through wall 121 with outlet plenum 139 , shown in FIG. 3. End caps 125 A and 125 B provide protection against impact and are configured to provide a pneumatic seal as shown in FIG. 3.
[0019] Referring to FIG. 3, ozone generator 100 is shown including first electrode 110 and second electrode 120 held in spaced apart relationship by dielectric element 130 . Dielectric element 130 is configured as shown to include a plurality of grooves 133 , which together with the fit between an outer surface of dielectric element 130 and an inner surface of second electrode 120 , form a plurality of passages 132 which collectively form corona discharge zone 135 . The fit between second electrode 120 and dielectric element 130 is preferably such that each of the resulting plurality of passages 132 are substantially pneumatically isolated from adjoining passages. This configuration results in a structure including a plurality of passages 132 through which a gas can flow between first electrode 110 and second electrode 120 without migrating laterally between passages.
[0020] In the embodiment of ozone generator 100 shown in FIG. 3, inner electrode 110 , dielectric element 130 , and second electrode 120 are all at least generally cylindrical in shape. First electrode 110 is shown formed as a solid cylindrical billet, although other configurations including tubular configurations are possible. First electrode 110 fits coaxially within dielectric element 130 , and second electrode 120 fits coaxially around dielectric element 130 . Preferably, the fit between first electrode 110 and dielectric element 130 is a clearance fit in the range of 0.005 inches to 0.010 inches and more preferably substantially equal to 0.007 inches. First electrode 110 In other embodiments, other shapes are possible for first electrode 110 , dielectric element 130 , and second electrode 120 without departing from the basic function of the ozone generator 100 . For example, these elements can all have at least generally rectangular cross-sections, ovoid cross-sections, or other configurations that produce ozone in substantially the same way as ozone generator 100 .
[0021] In one embodiment of the invention, dielectric element 130 comprises a dielectric material having a minimum dielectric loss of 450 amps per million. In another embodiment of the invention, dielectric element 130 comprises a dielectric material having a dielectric loss in the range of 450-1000 amps per million.
[0022] In one embodiment of the invention, dielectric element 130 comprises a dielectric material having a minimum dielectric strength of 375 V/mil. In another embodiment of the invention, dielectric element 130 comprises a dielectric material having a dielectric strength in the range of 375-1000 V/mil. In another embodiment of the invention, dielectric element 130 comprises a dielectric material having a dielectric strength substantially equal to 450 V/mil. Dielectric strength is defined as the maximum voltage a material can withstand without conducting electricity through the thickness of the material expressed in volts per mil thickness of material. In addition, dielectric element 130 preferably comprises a dielectric material having a maximum operating temperature equal to or greater than 275° F. In addition, dielectric element 130 preferably comprises a dielectric material having a specific gravity equal to or greater than 1.20 g/cm 3 .
[0023] In one embodiment of the invention, dielectric element 130 comprises a material identified as Polysulfone manufactured by Saint Gobain Performance Plastics. Preferably, a cylindrical tubular segment formed of Polysulfone material is machined to form dielectric element 130 . Following machining, dielectric element 130 is heat treated by soaking at a temperature in the range of 300-400 degrees Fahrenheit, and more preferably at a temperature substantially equal to 392 degrees Fahrenheit, for a period of one hour.
[0024] In other embodiments of the invention, dielectric element 130 comprises a material selected from a group of materials including polysulfone such as Udel®, a polyyetherimide such as Ultem®, a Polyethersulfone/Polyarylsulfone such as Radel® and a Polyetherether Ketone, PEEK. Another suitable material that can be used for dielectric element 130 is a dielectric ceramic material.
[0025] In one embodiment, first electrode 110 may be formed of a material having a different electrical conductivity than second electrode 120 . In another embodiment of the invention, first electrode 110 may be formed of a material having a relatively lower conductivity than second electrode 120 . For example, first electrode 110 may comprise an aluminum alloy and second electrode 120 may comprise a stainless steel alloy having a relatively lower conductivity than the aluminum alloy. In one embodiment, first electrode 110 is comprised of an aluminum alloy billet. In other embodiments, first electrode 110 is configured as a tubular segment and includes a wall thickness of 0.50 inch. Other materials having other wall thicknesses can be used for first electrode 110 . Second electrode 120 may have a wall thickness substantially equal to 0.25 inch where second electrode 120 is comprised of a stainless steel alloy. In other embodiments, other materials having other wall thicknesses can be used for second electrode 120 .
[0026] As shown in FIG. 3, ozone generator 100 is electrically connected to transformer 20 which applies a high voltage current between first electrode 110 and second electrode 120 . In one embodiment, transformer 20 is a conventional step-up transformer of 120 volts AC at 890 volt-amps primary, and 15,000 volts AC at 60 milliamps secondary. In other embodiments, other transformers may be used. Transformer 20 has a primary positive lead 21 , primary negative lead 22 , secondary negative lead 23 , and secondary positive lead 24 . Primary positive lead 21 and primary negative lead 22 are conductively connected to power supply 25 . Secondary negative lead 23 is connected to first electrode 110 at first terminal 112 , and secondary positive lead 24 is connected to second electrode 120 at second terminal 122 .
[0027] [0027]FIGS. 4 and 5 are representational cutaway details showing first electrode 110 , second electrode 120 and dielectric element 130 . Dielectric element 130 includes a plurality of grooves 133 which, together with the fit between an outer surface of dielectric element 130 and an inner surface of second electrode 120 , form a plurality of passages 132 which collectively form corona discharge zone 135 .
[0028] Referring to FIG. 4, outlet 154 pneumatically communicates with outlet plenum 139 through wall 121 of second electrode 120 for expelling a flow of gas including ozone. FIG. 4 also shows to advantage secondary negative lead 23 conductively connected to first terminal 112 which is conductively connected to first electrode 110 .
[0029] As seen in FIG. 5, inlet 153 pneumatically communicates with inlet plenum 138 through wall 121 of second electrode 120 . Inlet plenum 138 is fluidly connected to outlet plenum 139 and a flow of gas, such as air, passes along plurality of passages 132 from inlet plenum 138 to the outlet plenum 139 , as seen in FIG. 3. Gas passing through plurality of passages 132 is exposed to an electrical field in corona discharge zone 135 . FIG. 5 also shows to advantage secondary positive lead 24 conductively connected to second terminal 122 which is conductively connected to second electrode 120 .
[0030] Inlet plenum 138 , outlet plenum 139 and corona discharge zone 135 are pneumatically isolated between dielectric element 130 and second electrode 120 as follows. As shown in FIG. 4, o-ring 141 is disposed in groove 142 and provides a substantially air-tight seal between dielectric element 130 and end cap 125 A. As shown in FIG. 5, o-ring 143 is disposed in groove 144 and provides a substantially air-tight seal between the dielectric element 130 and end cap 125 B.
[0031] [0031]FIG. 6 is a cross-sectional view of dielectric element 130 taken substantially along lines 6 - 6 in FIG. 3 in accordance with a preferred embodiment of the invention. Dielectric element 130 has an inner surface radius 131 , an outer surface radius 134 , and a resulting nominal wall thickness 136 .
[0032] [0032]FIG. 7A is a side elevation of dielectric element 130 in accordance with a preferred embodiment of the invention. The plurality of grooves 133 are formed on an outer surface of dielectric element 130 and are uniformly spaced apart from each other, extending along spiral paths around dielectric element 130 . The plurality of grooves 133 extend from inlet plenum 138 at one end and outlet plenum 139 at the other end. The spiral paths of the plurality of grooves 133 increases the time period that the gas resides between first electrode 110 and second electrode 120 compared to a plurality of straight passages which lie parallel to a longitudinal axis of the dielectric element. In other embodiments, the plurality of grooves 133 can be non-uniformly spaced apart from each other and/or extend along other paths from inlet plenum 138 to the outlet plenum 139 .
[0033] [0033]FIG. 7B is a side elevation view of a dielectric element 230 in accordance with an alternate embodiment of the invention. In this embodiment, the dielectric element 230 has a plurality of serpentine grooves 233 that are uniformly spaced apart from one another and extend from the inlet plenum 238 to the outlet plenum 239 . Channel paths extending along spiral or serpentine paths over the outer surface of the dielectric element are but two examples of circuitous paths that could be used to achieve an extended exposure period.
[0034] As best seen in FIG. 1, ozone can be generated using the ozone generator 100 by flowing a gas comprising oxygen at a selected pressure from the inlet 153 through the plurality of passages 132 toward the outlet 154 , while selected electric potentials are maintained on first electrode 110 and second electrode 120 . In one embodiment, ozone is generated by introducing air through inlet 153 into inlet plenum 138 . In other embodiments, ozone can be generated by using air and other gases comprising oxygen at other pressures. Once the air enters the inlet plenum 138 , it travels through plurality of passages 132 collectively forming corona discharge zone 135 between the charged inner and second electrodes 110 and 120 .
[0035] In one embodiment of the invention, second electrode 120 comprises a 0.50 inch thick aluminum alloy, first electrode 110 comprises a 0.25 inch thick stainless steel alloy and dielectric element 130 includes a tubular dielectric material formed of polysulfone. Referring to FIG. 6, the polysulfone dielectric element 130 includes an inner surface radius 131 of 1.75 inches, an outer surface radius 134 of 2.25 inches and a nominal wall thickness 136 substantially equal to 0.50 inch. In other embodiments, the nominal wall thickness 136 can be different than 0.50 inch. The plurality of grooves 133 may each include a generally U-shaped cross-section defined by adjacent upright wall segments 146 and adjoining root wall segment 147 . In one embodiment of the invention, root wall segment 137 includes a root wall thickness 137 in the range of 0.030-0.080 inch, and preferably substantially equal to 0.063 inch. In one embodiment of the invention, the thickness of each upright wall segment 146 is approximately 0.030-0.080 inch, and preferably substantially equal to the thickness of the root wall segment 137 , or in this instance 0.063 inch. The thickness of the root wall segment 137 and upright wall segments 146 can be more or less than 0.063 inch based upon the strength of the electric field, the type of dielectric material, and other factors. The negative electric potential may be in the range of approximately −5,000 to −20,000 volts and the positive electrical potential is approximately 5,000 to 20,000 volts. More preferably, the negative electric potential is approximately −15,000 volts and the positive electric potential is approximately 15,000 volts. In other embodiments, the electric potentials applied to the first and second electrodes 110 and 120 can be more or less than these potentials. As the air flows through the plurality of passages 132 in corona discharge zone 135 , at least some of the oxygen in the air is converted to ozone by the time that the flow reaches outlet 154 .
[0036] [0036]FIG. 8 is a partial cutaway isometric view of a planar ozone generator 400 in accordance with an alternate embodiment of the invention. Ozone generator 400 has a generally planar first electrode 410 , a generally planar second electrode 420 , and a generally planar dielectric element 430 sandwiched between the first and second electrodes 410 and 420 , respectively. A plurality of grooves 433 are formed in the dielectric element 430 and span between an inlet plenum 438 and an outlet plenum 439 . Inlet 461 is attached to second electrode 420 and fluidly communicates with inlet plenum 438 . Similarly, outlet 462 is attached to second electrode 420 and fluidly communicates with outlet plenum 439 . Inlet plenum 438 fluidly communicates with outlet plenum 439 via the plurality of passages 432 . Air, or other gas including oxygen, is introduced through inlet 461 into inlet plenum 438 . Rectangular seal 442 is positioned in groove 434 in dielectric element 430 creating a substantially air-tight seal between the dielectric element 430 and second electrode 420 that surrounds the plurality of grooves 433 , inlet plenum 438 and outlet plenum 439 .
[0037] First terminal 412 is conductively connected to first electrode 410 and second terminal 422 is conductively connected to second electrode 420 . Ozone generator 400 may be electrically connected to transformer 20 which applies a high voltage current between first electrode 410 and second electrode 420 . Secondary negative lead 23 is connected to the second terminal 122 , and secondary positive lead 24 is connected to first terminal 412 .
[0038] Ozone can be generated with the ozone generator 400 in a manner substantially similar to the method employed with ozone generator 100 . Air or another gas with oxygen is introduced at a selected pressure through inlet 461 into inlet plenum 438 passing along the plurality of passages 432 toward the outlet plenum 439 . The gas passes through corona discharge zone 435 defined between first electrode 410 and second electrode 420 and more particularly between inlet plenum 438 and outlet plenum 439 and the plurality of grooves 433 formed on the upper surface of dielectric element 430 , and more particularly in a plurality of passages 432 formed as a result of the fit between the plurality of grooves 433 formed on the upper surface of dielectric element 430 and the lower or inner contacting surface of second electrode 420 . Generated ozone is expelled from outlet 462 to a storage or distribution device, (not shown).
[0039] Like the generally cylindrical ozone generator 100 shown in FIGS. 1 through 6, the generally planar ozone generator 400 may be capable of producing ozone more efficiently than conventional corona discharge ozone generators. In addition, because the basic elements of the planar ozone generator 400 are generally planar in shape, they may be easier to manufacture than the functionally similar, but cylindrically configured, elements of the ozone generator 100 . The planar ozone generator 400 may also be easier to assemble than the cylindrical ozone generator 100 , which requires assembly of coaxially disposed cylindrical elements.
[0040] From the foregoing, it will be appreciated by those of skill in the art that even though specific embodiments of the invention have been described herein for purposes of illustration, various modifications can be made without departing from the spirit or scope of the present invention. In general, the terms in the claims should not be construed to limit the invention to the specific embodiments disclosed in the foregoing description, but should be construed to include all ozone generating systems and ozone generators that operate in accordance with the claims. | An ozone generator including a pair of electrodes separated by a dielectric element including a plurality of passages defining a corona discharge zone. In one embodiment of the invention, the passages may be convoluted in the sense that the lengths of the passages defining the corona discharge zone are greater than the length of the first and second electrodes and the dielectric element. This configuration provides for an extended period of exposure of the gas to the electric field and may result in production of ozone exhibiting improved stability and oxidation rate. In one embodiment, inner and outer concentric electrodes are held in spaced apart relationship by a concentric tubular dielectric. A corona discharge zone is defined between an inner surface of the outer tubular electrode and the outer surface of the concentric tubular dielectric by a plurality of passages formed on the outer surface of the concentric tubular dielectric. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a output buffer circuit, and more specifically to a output buffer circuit used in an interface for transferring a high speed signal between LSIs.
2. Description of Related Art
With a recent advancement of a multi-function and a low power consumption of systems, an interface between LSIs (large scaled integrated circuits) are required to be a high speed and a small amplitude. In order to realize a high speed interface, it is necessary to make the amplitude of an output waveform small. However, since the amplitude is determined by a ground potential or a power supply potential as a reference, an internal operation threshold becomes different from an output signal threshold, with the result that a time ratio between a high level period and a low level period of the output signal waveform cannot be maintained at 1:1 (50%), and becomes apt to greatly vary. In addition, since many functions are incorporated in one LSI, the number of pins of a LSI package becomes large, and therefore, a noise becomes a problem at a testing time because a plurality of buffers operate concurrently. In order to avoid this problem, a noise suppressing circuit is inserted, but this circuit becomes a cause attributable to change of the duty ratio of the output signal waveform.
The change of the duty ratio is a factor lowering the data transfer speed. Therefore, in order to realize a high speed interface so as to elevate performance of the system, it is necessary to maintain the duty ratio of the output signal waveform of an output buffer around 50%
Referring to FIG. 5, there is shown, as an example of a first prior art output buffer circuit, a circuit of a buffer circuit of a HSTL (high speed transceiver logic) interface standardized by E1A/JEDEC, which is recently used as one of interfaces for transferring a high speed signal between semiconductor integrated circuits. This first prior art output buffer circuit includes an inverter 1 responding to an input signal H01 to generate an inverted signal "a", an inverter 9 responding to an input signal TEST to generate an inverted signal "d", an inverter 2 responding to the signal "a" to generate an inverted signal "b", an inverter 3 responding to the signal "b" to generate an inverted signal P11, a transfer gate 4 formed of a P-channel transistor having a gate receiving the input signal TEST and an N-channel transistor having a gate receiving the inverted signal "d" for controlling passage/block of the signal P11 in accordance with the level of the signal TEST so as to output a signal P12, and a P-channel transistor MP5 having a drain receiving the signal P12, and a gate receiving the signal "d" and a source connected to a 2.5 V power supply voltage.
The first prior art output buffer circuit further includes an inverter 6 receiving the signal "a" to generate an inverted signal "d", an inverter 7 responding to the signal "c" to generate an inverted signal P13, a transfer gate 8 formed of a P-channel transistor having a gate receiving the input signal TEST and an N-channel transistor having a gate receiving the inverted signal "d" for controlling passage/block of the signal P13 in accordance with the level of the signal TEST so as to output a signal P14, and an N-channel transistor MN5 having a drain receiving the signal P14, and a gate receiving the signal TEST and a source connected to ground. Furthermore, the first prior art output buffer circuit includes a P-channel transistor MP10 having a gate receiving the signal P12, a source connected to a 1.5 V power supply voltage, and a drain for outputting an output signal N01, an N-channel transistor MN10 having a gate receiving the signal P14, a source connected to the ground and a drain connected to the drain of the P-channel transistor MP10, a P-channel transistor MP11 having a gate receiving the signal P11, a source connected to the 1.5 V power supply voltage, and a drain connected to the drain of the P-channel transistor MP10, and an N-channel transistor MN11 having a gate receiving the signal P13, a source connected to the ground and a drain connected to the drain of the P-channel transistor MP10. The inverters 1 to 3, 6, 7 and 9 are driven with the 2.5 V power supply voltage.
In addition, the transistors MP10 and MN10 constitute an inverter 10, and the transistors MP11 and MN11 constitute an inverter 11.
Now, an operation of the first prior art output buffer circuit will be described with reference to FIG. 5. First, when the input signal TEST is at a low level, the transfer gates 4 and 8 are on, and the transistors MP5 and MN5 are off. Therefore, the input signal H01 is supplied to the inverter 10 formed of the transistors MP10 and MN10, an to the inverter 11 formed of the transistors MP11 and MN11, so that these inverters 10 and 11 output the output signal N01 in accordance with the input signal H01.
On the other hand, when the input signal TEST is at a high level, the transfer gates 4 and 8 are off, and the transistors MP5 and MN5 are on, so that the transistors MP10 and MN10 of the inverter 10 are rendered off. Accordingly, the output signal N01 in accordance with the input signal H01 is outputted by only the inverter 11, namely, only the transistors MP11 and MN11. Therefore, the driving power is lowered, so that a switching noise is suppressed.
Next, an operation waveform of the first prior art output buffer circuit will be described in detail with reference to FIGS. 6A and 6B, which are timing charts showing various operation waveforms of the first prior art output buffer circuit.
When the input signal H01 is brought to the high level, after the signal P11 inputted to the gate of the transistor MP11 is brought to the low level, the signal P12 inputted to the gate of the transistor MP10 is brought to the low level. Simultaneously, after the signal P13 inputted to the gate of the transistor MN11 is brought to the low level, the signal P14 inputted to the gate of the transistor MN10 is brought to the low level. This is because the potential of the signal P11 is transferred through the transfer gate 4 as the signal P12 and the potential of the signal P13 is transferred through the transfer gate 8 as the signal P14.
In the HSTL interface, a terminating method of a transmission path is divided into four classes (class 1 to class 4). Referring to FIG. 7 which is a block diagram for illustrating the construction of the HSTL class-2 interface, this HSTL class-2 interface includes an output buffer 101 driven with a 1.5 V power supply voltage to output an output signal N01 in accordance with an input signal H01, a resistor 102 of a resistance of 50Ω having one end connected to a 0.75 V power supply voltage and the other end connected to the output of the output buffer 101, a transmission path 104 having an impedance of 50Ω and one end connected to the output of the output buffer 101, another resistor 103 of a resistance of 50Ω having one end connected to a 0.75 V power supply voltage and the other end connected to the output of the transmission path 104, and a differential amplifier 105 having a non-inverted input connected to the output of the transmission path 104, an inverted input connected to a reference signal Vref of 0.75 V. Here, the output buffer 101 is constituted of the first prior art output buffer circuit mentioned above or a second prior art output buffer circuit which will be described hereinafter.
Referring to FIG. 8, which is a timing chart illustrating input and output signal waveforms in the HSTL class-2 interface using the first prior art output buffer circuit as the output buffer 101, since the output of the output buffer 101 is connected to the resistors 102 and 103 clamped to 0.75 V, the output signal N01 of the output buffer 101 can obtain the amplitude of 0 V to 1.5 V.
Referring to FIG. 9, there is shown a circuit diagram of the second prior art output buffer circuit used in the HSTL interface. In FIG. 9, elements similar to those shown in FIG. 5 are given the same Reference Numerals and Signs, and explanation will be omitted. This second prior art output buffer circuit includes, in addition to the inverters 1, 2, 3, 6, 7, 9, 10 and 11 in common to the first prior art output buffer circuit, a two-input NOR gate 12 receiving the input signal TEST and the output signal "a" of the inverter 1 for outputting a NOR output signal "f", an inverter 13 responding to the signal "f" to output an inverted signal "g" to the gate of the transistor MP11 of the inverter 11, a two-input NAND gate 14 receiving the output signal "d" of the inverter 9 and the signal "a" for outputting a NAND output signal "h", and an inverter 15 responding to the signal "h" to output an inverted signal "i" to the gate of the transistor MN11 of the inverter 11. In addition, the output signal P11 of the inverter 3 is supplied directly to the gate of the transistor MP10 of the inverter 10, and the output signal P14 of the inverter 7 is applied directly to the gate of the transistor MN10 of the inverter 10. The inverters 1 to 3, 6, 7, 9, 13 and 15, the NOR gate 12 and the NAND gate 14 are driven with the 2.5 V power supply voltage.
Now, an operation of the second prior art output buffer circuit will be described with reference to FIG. 9. First, when the input signal TEST is at the low level, the NOR gate 12 responds to the low level of this signal TEST received at its one input, to output the inverted signal "f" of the inverted signal "a" of the input signal H01 received at its other input. On the other hand, the NAND gate 14 responds to the high level of the signal TEST received at its one input, to output the inverted signal "h" of the input signal H01 received at its other input. Accordingly, the inverters 10 and 11 output the output signal N01 corresponding to the input signal H01.
When the input signal TEST is at the high level, the NOR gate 12 outputs the signal "f" of the low level in response to the high level of the signal TEST, and the NAND gate 14 outputs the signal "h" of the high level in response to the low level of the inverted signal "d" of the signal TEST. Accordingly, the transistors MP11 and MN11 of the inverter 11 are rendered off, so that the output signal N01 corresponding to the input signal H01 is outputted by only the inverter 10. Thus, the driving power is lowered, so that the switching noise is suppressed.
Referring to FIG. 10, there is shown a circuit diagram of a third prior art output buffer circuit, which is a buffer circuit of a SSTL (stub series terminated logic) interface standardized by E1A/JEDEC, and which is recently used as one of interfaces for transferring a high speed signal between semiconductor integrated circuits, similarly to the first and second prior art output buffer circuits. In FIG. 10, elements similar to those shown in FIG. 5 are given the same Reference Numerals and Signs, and explanation will be omitted.
This third prior art output buffer circuit includes, in addition to the inverters 1, 3, 7, 9, 10 and 11, the transfer gates 4 and 8, and the transistors MP5 and MN5 in common to the first prior art output buffer circuit, level shift circuits 22 and 26 receiving the output signal "a" of the inverter 1 for outputting predetermined level-shifted signals "j" and "k" to the inverters 3 and 7, respectively.
The inverter 1 is driven with the 2.5 V power supply voltage, and the other inverters 3, 7, 9, 10 and 11, the transfer gates 4 and 8, and the transistors MP5 and MN5 are driven with a 3.3 V power supply voltage.
Now, an operation of the third prior art output buffer circuit will be described with reference to FIG. 10. First, when the input signal TEST is at the low level, the transfer gates 4 and 8 are rendered on and the transistors MP5 and MN5 are rendered off, similarly to the first prior art output buffer circuit. Accordingly, the input signal H01 is supplied to the inverter 10 formed of the transistors MP10 and MN10 and the inverter 11 formed of the transistors MP11 and MN11, so that these inverters 10 and 11 output the output signal N01 in accordance with the input signal H01.
On the other hand, when the input signal TEST is at a high level, the transfer gates 4 and 8 are off, and the transistors MP5 and MN5 are on, so that the transistors MP10 and MN10 of the inverter 10 are rendered off. Accordingly, the output signal N01 in accordance with the input signal H01 is outputted by only the inverter 11, namely, only the transistors MP11 and MN11. Therefore, the driving power is lowered, so that a switching noise is suppressed.
This third prior art output buffer circuit is so configured to have an internal macro power supply voltage of 2.5 V, which is lower than 3.3 V of the output voltage, in order to reduce the power consumption of the LSI. Because of this, the output buffer requires the level shifting circuits 22 and 26 in order to elevate from 2.5 V to 3.3 V.
Referring to FIG. 11, which is a circuit diagram showing the construction of the level shift circuit 22, this level shift circuit 22 includes a P-channel transistor MP21 having a gate receiving the input signal "a", a source connected to the 2.5 V power supply voltage and a drain for outputting a signal P01, an N-channel transistor MN21 having a gate receiving the input signal "a", a source connected to ground and a drain connected to the drain of the transistor MP21, an N-channel transistor MN22 having a gate connected to the drain of the transistor MP21, a source connected to the ground and a drain for outputting a signal P02, a P-channel transistor MP22 having a gate receiving the output signal "j", a source connected to the 3.3 V power supply voltage and a drain connected to the drain of the transistor MN22, a P-channel transistor MP23 having a gate connected to the drain of the transistor MP22, a source connected to the 3.3 V power supply voltage and a drain for outputting the output signal "j", and an N-channel transistor MN23 having a gate receiving the input signal "a", a source connected to the ground and a drain connected to the drain of the transistor MP23.
Now, an operation of the level shift circuit 22 will be described with reference to FIG. 11 and FIG. 12 which illustrates operating waveforms of various points. When the input signal "a" is brought to a high level (2.5 V), the transistor MN23 is turned on. At this time, the transistor MP23 of the last stage is also turned on, but since the size of the transistor MN23 is larger than that of the transistor MP23, a path-through current flows through the transistors MP23 and MN23, so that the output signal "J" becomes lower than a threshold of a next stage block, namely, becomes a low level. Thereafter, when the signal P02 reaches the high level of 3.3 V, the path-through current stops.
Then, when the input signal "a" is brought to the low level, the signal P01 is brought to the high level (2.5 V), and the transistor MN22 is turned on so that the signal P02 is brought to the low level, and therefore, the transistor MP23 is turned on. At this time, since the transistor MN23 has been turned off, the output signal "j" becomes the high level (3.3 V). Accordingly, a time TpdLH from the moment the input signal "a" is brought to the low level to the moment the output signal "j" is brought to the high level is longer than a time TpdHL from the moment the input signal "a" is brought to the high level to the moment the output signal "j" is brought to the low level. Namely, a delay time is long.
In accordance with the method for terminating the transmission path, the SSTL interface is divided into two classes (class 1 and class 2). Referring to FIG. 13, which a block diagram for illustrating the construction of the SSTL class-2 interface, this SSTL class-2 interface includes an output buffer 201 driven with a 3.3 V power supply voltage to output an output signal N01 in accordance with an input signal H01, a resistor 202 of a resistance of 50Ω having one end connected to the output of the output buffer 201, a transmission path 204 having an impedance of 50Ω and one end connected to the other end of the resistor 202, another resistor 203 of a resistance of 25Ω having one end connected to a 1.5 V power supply voltage and the other end connected to the output of the transmission path 204, and a differential amplifier 205 having a non-inverted input connected to the output of the transmission path 204, an inverted input connected to a reference signal Vref of 1.5 V. Here, the output buffer 201 is constituted of the third prior art output buffer circuit mentioned above.
Even in this case, similarly to the first prior art output buffer circuit, the output signal N01 of the output buffer 201 can obtain the amplitude of 0 V to 3.3 V because of the resistor 202 connected to the output N01 of the output buffer 201 and the resistor 203 connected to the resistor 202 and clamped to 1.5 V.
A first problem of the first, second and third prior art output buffer circuits as mentioned above is that in the output signal of the first, second and third prior art output buffer circuits which are high speed buffers, since the duty ratio (the ratio between the high level period and the low level period) changes from 50% (called a "duty distortion" hereinafter), if the operating frequency is elevated, the level change occurs in the level having a shorter period so that a waveform distortion occurs, and in an extreme cases the output waveform disappears. Thus, the speed-up cannot be realized.
The reason for this is as follows: In the high speed buffer of the HSTL interface such as the first and second prior art output buffer circuits, the power supply voltage of the final stage inverter is 1.5 V, but in for example a 0.25 μm process, the power supply voltage of a pre-buffer is 2.5 V which is higher than 1.5 V. Therefore, at the rising time of the output signal of the buffer, the threshold of the final stage inverter is lower than the output signal waveform of the pre-buffer, and therefore, a long time is required until the output signal level of the pre-buffer becomes lower than the threshold of the final stage inverter. Namely, the delay time of the buffer becomes large. On the other hand, at a falling time of the output signal of the buffer, the output signal level of the pre-buffer immediately becomes higher than the threshold of the final stage inverter, and therefore, the delay time is small. Thus, the duty ratio of the output signal waveform becomes out of 50%.
Therefore, in order to effectively equalize the delay time in the rising and the delay time in the falling of the buffer output signal, it may be considered to adjust the size ratio between the P-channel transistor and the N-channel transistor in the output stage of the pre-buffer so as to minimize the duty distortion. However, since the difference between the pre-buffer output signal level and the threshold of the final stage inverter is as large as about 0.5 V, it is not possible to completely prevent the duty distortion of the output signal waveform.
In addition, in the high speed buffer as in HSTL, since the high level and the low level of the input and the output are prescribed in a DC standard, it is impossible to adjust the duty ratio by adjusting the size ratio between the P-channel transistor and the N-channel transistor in the output stage of the output buffer, since this results in change of the DC level. Accordingly, the duty distortion cannot be prevented by this adjustment of the size ratio.
Furthermore, in the buffer such as the first prior art output buffer circuit having the driving power control circuit for reducing the switching noise at the testing time, since the transfer gate is inserted between the pre-buffer and the final stage inverter, the output signal waveform of the pre-buffer is blunted by the on-resistance of the transfer gate so that the duty ratio changes. Therefore, if the size of the transfer gate is enlarged to reduce the on-resistance of the transfer gate, the diffused capacitance becomes large, with the result that the signal waveform of the pre-buffer is further blunted.
In the high speed buffer of the SSTL interface such as the third prior art output buffer circuit, the power supply voltage of the final stage inverter is 3.3 V, but in for example a 0.25 μm process, the power supply voltage of the pre-buffer is 2.5 V which is lower than 3.3 V. Therefore, the level shift circuit for elevating from 2.5 V to 3.3 V. However, since the signal transfer path is different between the high level outputting time and the low level outputting time as mentioned above, the delay time is greatly different. In addition, since the high level and the low level of the input and the output in the SSTL buffer are prescribed in the DC standard similarly to the HSTL, the duty distortion cannot be improved by adjusting the size ratio between the P-channel transistor and the N-channel transistor in the final state inverter.
In the first, second and third prior art output buffer circuits as mentioned above, because the internal operation threshold is different from the threshold of the output signal, because there is inserted the circuit for reducing the noise in the concurrent operation of a plurality of buffers at the testing time in an LSI package having a number of pins, the duty ratio of the output signal waveform (the ratio between the high level period and the low level period) changes from 50% (called a "duty distortion" hereinafter). Therefore, if the operating frequency is elevated, the level change occurs in the level having a shorter period so that a waveform distortion occurs, and in an extreme case, the output waveform disappears. Thus, the speed-up cannot be realized.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an output buffer circuit which has overcome the above mentioned defect of the conventional ones and capable of maintaining the duty ratio of the output signal at an ideal 50%.
The above and other objects of the present invention are achieved in accordance with the present invention by an output buffer circuit including a first inverter formed of a first transistor of a first conductivity type and a second transistor of a second conductivity type, a second inverter formed of a third transistor of the first conductivity type and a fourth transistor of the second conductivity type, and a switch circuit for controlling respective gates of the first transistor and the second transistor in accordance with a test control signal, so as to change a driving power, respective outputs of the first and second inverters being connected in common to output an output signal having a predetermined signal level in accordance with an input signal, a duty ratio adjusting circuit being provided to control the respective gates of the first and second transistors to substantially equalize a first delay time until the output signal changes from a first level to a second level in response to transition of the input signal and a second delay time until the output signal changes from the second level to the first level in response to transition of the input signal, thereby to maintain substantially at 50% the duty ratio which is a ratio between the sustaining time of the first level and the sustaining time of the second level in a waveform of the output signal.
The above and other objects, features and advantages of the present invention will be apparent from the following description of preferred embodiments of the invention with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of a first embodiment of the output buffer circuit in accordance with the present invention;
FIGS. 2A and 2B are timing charts illustrating an operation of the first embodiment of the output buffer circuit in accordance with the present invention;
FIG. 3 is a timing chart illustrating input and output signal waveforms in the HSTL class-2 interface using the first embodiment of the output buffer circuit in accordance with the present invention;
FIG. 4 is a circuit diagram of a second embodiment of the output buffer circuit in accordance with the present invention;
FIG. 5 is a circuit diagram of the first prior art output buffer circuit;
FIGS. 6A and 6B are timing charts illustrating an operation of the first prior art output buffer circuit;
FIG. 7 is a block diagram for illustrating the construction of the HSTL class-2 interface;
FIG. 8 is a timing chart illustrating input and output signal waveforms in the HSTL class-2 interface using the first prior art output buffer circuit;
FIG. 9 is a circuit diagram of the second prior art output buffer circuit;
FIG. 10 is a circuit diagram of the third prior art output buffer circuit;
FIG. 11 is a circuit diagram showing the construction of the level shift circuit;
FIG. 12 is a timing chart illustrating operating waveforms of various points; and
FIG. 13 which a block diagram for illustrating the construction of the SSTL class-2 interface.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown a circuit diagram of a first embodiment of the output buffer circuit in accordance with the present invention. In FIG. 1, elements similar to those shown in FIG. 5 are given the same Reference Numerals and Signs, and explanation will be omitted. This embodiment of the output buffer circuit includes, in addition to the inverters 1, 2, 3, 6, 7, 9, 10 and 11, the transfer gates 4 and 8, and the transistor MP5 in common to the first prior art output buffer circuit, a duty ratio adjusting circuit 18 for controlling the gates of the transistors MP10 and MN10 of the inverter 10 so as to quicken the rising time thereby to approach the duty ratio of the output signal to 50%
This duty ratio adjusting circuit 18 includes a two-input NOR circuit 81 receiving the input signal TEST (test control signal) and the output signal "a" of the inverter 1 to generate a NOR output signal P1, an N-channel transistor MN81 having a gate receiving the signal P1, a drain connected to the gate of the transistor MP10 of the inverter 10 and a source connected to ground, a two-input NAND gate 82 receiving the output signal "d" of the inverter 9 and the signal "a" to generate a NAND output signal P2, and an N-channel transistor MN82 having a gate receiving the signal P2, a drain connected to the gate of the transistor MN10 of the inverter 10 and a source connected to ground.
Now, an operation of the shown embodiment will be described with reference to FIG. 1. First, when the input signal TEST is at a low level, the signal "d" is at a high level, so that the transfer gates 4 and 8 are on, and the transistors MP5 is turned off. In this condition, if the input signal H01 is brought to the high level, the inverted signal "a" is brought to the low level, and the output signal P1 of the NOR gate 81 in the duty ratio adjusting circuit 18 is brought to the high level. In response to this high level of the signal P1, the transistor MN81 is turned on, so that the drain potential of the transistor MN81, namely, the gate potential of the transistor MP10 of the inverter 10 lowers, with the result that the transistor MP10 is turned on. Furthermore, in response to the low level of the signal "a", the output signal P2 of the NAND gate 82 is brought to the high level. In response to the high level of the signal P2, the transistor MN82 is turned on, so that the drain potential of the transistor MN82, namely, the gate potential of the transistor MN10 of the inverter 10 lowers, with the result that the transistor MN10 is turned off.
Here, since it is so designed that the size of the transistors MP10 and MN10 of the inverter 10 is larger than the size of the transistors MP11 and MN11 of the inverter 11, the buffer output signal N01 becomes the high level, regardless of the operating condition of the inverter 11. In addition, after some delay, the output signal P11 of the inverter 3 is brought to the low level, so that the transistor MP11 of the inverter 11 is turned on, and simultaneously, the output signal P13 of the inverter 7 is brought to the low level, so that the transistor MN11 of the inverter 11 is turned off. Thus, the output signal N01 becomes the high level.
When the input signal H01 is brought to the low level, the output signal P1 of the NOR gate 81 in the duty ratio adjusting circuit 18 is brought to the low level, contrary to the above mentioned situation. In response to this low level of the signal P1, the transistor MN81 is turned off, so that the gate potential of the transistor MP10 of the inverter 10 elevates, with the result that the transistor MP10 is turned off. Furthermore, the output signal P2 of the NAND gate 82 is brought to the low level. In response to the low level of the signal P2, the transistor MN82 is turned off, so that the gate potential of the transistor MN10 of the inverter 10 elevates, with the result that the transistor MN10 is turned on. In addition, after some delay, the output signal P11 of the inverter 3 is brought to the high level, so that the transistor MP11 of the inverter 11 is turned off, and simultaneously, the output signal P13 of the inverter 7 is brought to the high level, so that the transistor MN11 of the inverter 11 is turned on. Thus, the output signal N01 becomes the low level.
On the other hand, when the input signal TEST is at a high level, the transfer gates 4 and 8 are off, and the transistors MP5 and the transistor MN82 of the duty ratio adjusting circuit 18 are turned on, so that the transistors MP10 and MN10 of the inverter 10 are rendered off. Accordingly, the output signal N01 in accordance with the input signal H01 is outputted by only the inverter 11, namely, only the transistors MP11 and MN11. Therefore, the driving power is lowered, so that a switching noise is suppressed.
Next, an operation of the duty ratio adjusting circuit 18 will be described with reference to FIG. 1. In a recent highly integrated LSI, the microfabrication of the circuit has been advanced to realize a high integration density, so that macro-circuits which constitute internal logic circuits are formed with a very small size. With this inclination, the size of the final stage inverter of the output buffer circuit is on the order of 350 times the size of the macro-circuits of general logic circuits driving the output buffer circuit. For example, in the case of the 0.25 μm rule, the size of the macro-circuits of general logic circuits is 3.32 μm, and the final stage inverter of the HSTL class-2 in this embodiment is 1190 μm. Therefore, in the case of designing the high speed buffer circuit, the pre-buffer for driving the final stage inverter is required to be constituted of a plurality of inverters connected in a cascaded manner, with the size of the cascaded inverters being gradually enlarged towards the final stage inverter. In this embodiment, the inverters 1, 2, 3 and the inverters 6 and 6 constitute the pre-buffers, respectively.
The duty ratio adjusting circuit 18 is so featured that, when the output signal N01 of the output buffer circuit rises up, the transistors MN81 and MN82 is turned on by the output signal "a" of the inverter 1 of the first stage of the pre-buffer, so as to forcibly pull down the gate potential of the transistors MP10 and MN10 of the final stage inverter 10.
For pulling down the gate potential of the transistors MP10 and MN10, the first prior art output buffer circuit uses the inverters 3 and 7, and the second prior art output buffer circuit uses the inverters 13 and 15. However, the shown embodiment uses the N-channel transistors MN81 and MN82 for pulling down the gate potential of the transistors MP10 and MN10. Since it is not necessary to directly drive the P-channel transistor MP10 having a large gate size, of the final stage inverter 10, the driving load can be reduced. Thus, the size of the transistors which constitute each of the NOR gate 81 and the NAND gate 82, can be made small, and therefore, the rising speed of the output signal N01 of the output buffer circuit can be elevated.
Now, an operation waveform of the duty ratio adjusting circuit 18 will be described in detail with reference to FIGS. 2A and 2B, which are timing charts showing operation waveforms at various points of the duty ratio adjusting circuit 18.
When the output signal N01 of the output buffer circuit rises up, the output signal P1 of the NOR gate 81 is brought to the high level to forcibly turn on the transistor MN81 so as to bring the gate voltage P12 of the transistor MP10 of the inverter 10. Thus, the signal P12 is caused to change earlier than the signal P11 supplied to the gate of the transistor MP11 of the inverter 1. Simultaneously, the output signal P2 of the NAND gate 82 is brought to the high level to turn on the transistor MN82 so as to forcibly bring the gate voltage P14 of the transistor MN10. Therefore, the signal P14 is caused to change to the low level earlier than the signal P13 supplied to the gate of the transistor MN11 of the inverter 11.
Referring to FIG. 3 which is a timing chart illustrating input and output signal waveforms when the output buffer circuit of this embodiment is used as the output buffer 101 of the HSTL class-2 interface shown in FIG. 7, the time TpdHH from the moment the input signal H01 is brought to the high level to the moment the output signal N01 actually becomes the high level is improved to 761 ps by action of the duty ratio adjusting circuit 18, while it was 1189 ps and 909 ps in the first and second prior art output buffer circuits, respectively. On the other hand, the time TpdLL from the moment the input signal H01 is brought to the low level to the moment the output signal N01 actually becomes the low level is elongated to 699 ps to some degree, while it was 679 ps and 641 ps in the first and second prior art output buffer circuits, respectively.
As a result, when the output signal frequency is 267 Mhz, the duty ratio of the output signal waveform was 36.3% and 42.8% in the first and second prior art output buffer circuits, respectively, but is 48.3% in this embodiment. In other words, this embodiment greatly improves the duty ratio of the output signal waveform to a value near to 50%.
Referring to FIG. 4, there is shown a circuit diagram of a second embodiment of the output buffer circuit in accordance with the present invention. In FIG. 4, elements similar to those shown in FIG. 1 are given the same Reference Numerals and Signs, and explanation will be omitted.
In order to apply the output buffer circuit to the SSTL interface, the second embodiment is different from the first embodiment in that the inverters 2 and 3 are replaced with level shift circuits 22 and 23 for elevating the signal level to 3.3 V, respectively, in that there are added a level shift circuit 27 for elevating the signal level of the test signal TEST to output a level-shifted signal "1" and an inverter 28 for inverting the signal "1" to generate an inverted signal "m", and in that the inverter 1 is driven with the 2.5 V power supply voltage and the other inverters 3, 7 and 28, the transfer gates 4 and 8 and the transistor MP5 are driven with the 3.3 V power supply voltage.
Now, describing an operation of the second embodiment with reference to FIG. 4, the operation is the same as that of the first embodiment, excepting the level shift operation for elevating the input signal H01 of 2.5 V to the output signal N01 of 3.3 V. Accordingly, the operation of the duty ratio adjusting circuit is the same as that in the first embodiment.
As mentioned above, since the output buffer circuit of the present invention can shorten the delay time in the rising of the output signal by means of the duty ratio adjusting circuit, it is possible to maintain the duty ratio at a value near to an ideal 50%, and therefore, to speed up the signal transfer rate between LSIs.
As mentioned above, the output buffer circuit of the present invention includes the duty ratio adjusting circuit for controlling the respective gates of the first and second transistors to substantially equalize a first delay time until the output signal changes from a first level to a second level in response to transition of the input signal and a second delay time until the output signal changes from the second level to the first level in response to transition of the input signal. Since the duty ratio adjusting circuit responds to the output signal of the first stage inverter in the pre-buffer circuit composed of a plurality of cascaded inverters and directly controls the gates of the respective transistors in the final stage inverter, the delay time in the rising of the output signal can be shortened so as to maintain the duty ratio at a value near to the ideal 50%. Therefore, the signal transfer rate between LSIs can be elevated.
The invention has thus been shown and described with reference to the specific embodiments. However, it should be noted that the present invention is in no way limited to the details of the illustrated structures but changes and modifications may be made within the scope of the appended claims. | An output buffer circuit for transferring a high speed signal between large scale integrated circuits includes a first inverter with first and second transistors of opposite conductivity type, a second inverter with third and fourth transistors of opposite conductivity type, and a switch circuit for controlling the gates of the first and second transistors in accordance with a test control signal so as to change a dividing power. The respective outputs of the first and second inverters are connected in common to an output signal having a predetermined signal level related to an input signal. The circuit includes a duty ratio adjusting circuit which controls the respective gates of the first and second transistors to substantially equalize the first delay time until the output signal changes from a first level to a second level in response to a transition of the input signal, and a second delay time until the output signal changes from the second level to the first level in response to a transition of the input signal. The output buffer circuit maintains the duty ratio at about 50%. | 7 |
FIELD
The present embodiments relate to apparatus that can be used during drilling operations. The apparatus can be used for the purposes of clamping and holding drilling tubulars to allow assembly to a specified torque or disassembly of the drilling tubulars.
BACKGROUND
During drilling operations, threaded lengths of drilling tubulars, such as drill pipe and casing, need to be assembled together or disassembled. For example, with drill pipe, the threaded joints between adjacent lengths of drill pipe must be tightened to a specified torque (made up) and then later unscrewed from one another (broken out) during the drilling process.
Though prior art makeup/breakout wrenches have worked efficiently in several applications, a need exists for an apparatus capable of clamping, holding and exerting high level torques on varying diameters of drilling tubulars, without allowing the tubulars to move or slip while clamped and held by the apparatus. More specific, the apparatus must be capable of holding and maintaining a certain orientation of the drilling tubular with respect to the grips of the apparatus to enable the drilling tubulars to be assembled with a required high level torque and to be disassembled safely.
In the use of existing wrenches, the problem of slippage between the tubular and the makeup/breakout wrenches has existed and is particularly acute in connection with small diameter drilling tubulars, where extremely high levels of friction between the jaws of the makeup/breakout wrenches and the drilling tubulars may be required.
The present embodiments meet these needs.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description will be better understood in conjunction with the accompanying drawings as follows:
FIG. 1 depicts a side, perspective view of an embodiment of an apparatus for clamping a drilling tubular against rotation.
FIG. 2 depicts the opposite side, perspective view of the embodiment depicted in FIG. 1 .
The present embodiments are detailed below with reference to the listed Figures.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Before explaining the present embodiments in detail, it is to be understood that the embodiments are not limited to the particular embodiments and that it can be practiced or carried out in various ways.
The present embodiments relate to an improved clamp that can be used during drilling operations. The present embodiments have inserts for clamping and holding drilling tubulars, such as drill pipe. The embodied clamp utilizes a double-push link to ensure that the arms holding the grips move in a plane perpendicular to the drilling tubular. The embodied clamps are particularly useful in connection with makeup and breakout wrenches used with drilling rigs for drilling bore holes in earth formations.
The present embodiments are devices that provide strong clamping assemblies without the use of a slot. The present embodiments can clamp the tubulars with out the need of inserts, chokes, or spacers. The embodiments are more reliable because of the lack of movement of the frame.
The embodied clamping devices are adapted to accommodate a range of diameters of drilling tubulars. For example, the clamping device can accommodate drilling tubulars ranging from about 2 inches in diameter to about 14 inches in diameter.
The embodied clamping apparatus includes two or more grips. If two grips are used, the grips are located on opposite sides of the drilling tubular. Each grip is located in a grip block.
Each grip includes a receiving recess with one or more inserts. Each insert includes a plurality of teeth to clamp the drilling tubular and to provide high levels of friction. The teeth can be orientated in a variety of orientations. For example, the teeth can be orientated in a first orientation adapted for clockwise rotation of the drilling tubular, a second orientation adapted for counter-clockwise rotation of the drilling tubular, a third orientation parallel to the drilling tubular, a fourth orientation perpendicular to the drilling tubular, or in an asymmetrical orientation.
The insert can be fixed in the grip or can be rotatably positioned within the recess. The teeth on the face of the insert can extend beyond the face of the grip to contact and frictionally engage the tubular. If the inserts are rotatably positioned within the recess, means are provided for positioning the insert in the recess such that the insert is free to rotate within the recess through a selected range to allow the toothed surface to orient into contact with the tubular, yet the insert is impeded from rotating beyond the selected range.
Each grip block is a housing that includes two or more connectors that attach the grip block to an arm. The connectors in the grip block allow the user to position the grip and inserts so that the grip and inserts are perpendicular to the drilling tubular. The grip block can include a linkage in order to allow the grip and the inserts to be a set distance from the arm.
The embodied clamping devices include a driving means attached to the arms. The driving means is used to move the grip blocks towards and away form the drilling tubulars. An example of a driving means is a dual hydraulic cylinder. Other examples of driving means can include a makeup and breakout wrench.
The embodied clamping devices include a double-push link connected to the two arms that each connect to the grip blocks. The double-push link ensures that the grips move in a plane perpendicular to the drilling tubular. By ensuring the grip blocks move in a plane perpendicular to the drilling tubular, the embodied clamping device provides the benefit of allowing the grips to be readily configured to exert maximum frictional forces against the different diameters of tubulars, regardless whether the clamp is being used to rotate the tubular in a clockwise or alternatively a counter-clockwise direction. Further, by moving in the same plane, the embodied clamps can orient itself as necessary to conform to the surface of the various diameters of tubulars in order to maximize the contact area between the teeth of the insert and the clamped tubular.
An embodiment of the double-push link includes a brace that connects to the two arms. The brace includes a hole in the midpoint. A disc with a center hole is aligned to the hole in the brace. A pivot cylinder is disposed through the midpoint hole in the brace and the center hole of the disc. The pivot cylinder allows the disc to rotate. For each arm, a link is connected to the disc and to the arm.
The embodied clamping devices can include a frame to house and support the grip blocks, the arms, the driving means, and the double-push link. The embodied clamping devices can include a protective plate to cover the grip blocks, the arms, the driving means, and the double-push link.
The embodied clamps can be useful in connection with makeup/breakout devices. Such devices are used to tighten and loosen threaded connections between adjacent lengths of tubulars, such as drill pipe. The embodied clamp and design of moving the clamps in one plane perpendicular to the tubular provide an excellent frictional engagement between the clamp and the clamped tubular in order to provide the high torque needed to break threaded connections between adjacent drilling tubulars in some applications.
With reference to the figures, FIG. 1 depicts a side, perspective view of an embodiment of an apparatus for clamping a drilling tubular against rotation. FIG. 2 depicts the opposite side, perspective view of the embodiment depicted in FIG. 1 .
FIG. 1 depicts an embodiment with a first grip ( 5 ) and a second grip ( 10 ) located opposite of one another. The first and second grips ( 5 and 10 ) have a recess that allows the first and second grips ( 5 and 10 ) to fit around a drilling tubular.
FIG. 1 depicts the second grip ( 10 ) in the second grip block ( 20 ). The first grip block ( 15 ), is depicted in FIG. 2 , but shown in FIG. 1 as cutaway. The grip can be connected to the grip block in various manners. FIG. 1 and FIG. 2 depict the embodiment wherein the grip is fastened to the grip block using bolts. Examples of other fasteners include screws, pin connections, or welding.
The grip blocks can be connected directly to the arm as shown in FIG. 1 , wherein the second grip block ( 20 ) is connected to the second arm ( 30 ). The grip block can be connected to the arm in various manners. Examples of other fasteners include screws, pin connections, or welding. As shown in FIG. 1 and FIG. 2 , the grip blocks ( 15 and 20 ) can each be located in a respective guide ( 17 and 22 ). The guides ( 17 and 22 ) aid in ensuring that the grip blocks ( 15 and 20 ) move in the same plane perpendicular to the drilling tubular.
Alternatively, an arm extension or linkage ( 27 ) can be used. FIG. 1 depicts the embodiment wherein the linkage ( 27 ) is used with the first arm ( 25 ). The linkage ( 27 ) can be used in order to allow the grip ( 5 ) and the inserts to be a set distance from the arm. The linkage ( 27 ) can be used to ensure that the grip and the grip block remain in a plane perpendicular to the drilling tubular. As shown in FIG. 1 , the linkage ( 27 ) can have two connections which are rotatable.
The grips ( 5 and 10 ) can have one or more inserts to grip the drilling tubular. FIG. 1 and FIG. 2 depict the embodiment, wherein each grip ( 5 and 10 ) includes four inserts ( 12 a , 12 b , 12 c , and 12 d ). Each insert can have a plurality of teeth in various orientations to aid in gripping the drilling tubular. The figures depict the embodiment, wherein the teeth are in an orientation perpendicular to the drilling tubular.
Continuing with FIG. 1 and FIG. 2 , the grip blocks ( 15 and 20 ) are each connected to an arm ( 25 and 30 ). The arms ( 25 and 30 ) are connected to a driving means ( 35 ). The driving means ( 35 ) depicted in the figures is a dual hydraulic cylinder. The driving means ( 35 ) applies force to the arms ( 25 and 30 ) in order to force the grip blocks ( 15 and 20 ) and grips ( 5 and 10 ) to engage and disengage the drilling tubular. The driving means ( 35 ) can be connected to the arms ( 25 and 30 ) in various manners. FIG. 1 and FIG. 2 depict the embodiment wherein the driving means ( 35 ) is fastened to the arms ( 25 and 30 ) using pin connections. Examples of other fasteners include screws or welding.
A double-push link ( 40 ) is used to ensure that the grip blocks ( 15 and 20 ) and grips ( 5 and 10 ) move in the same plane perpendicular to the drilling tubulars. As depicted in FIG. 1 , the double-push link ( 40 ) includes a main brace ( 42 ). The main brace ( 42 ) is connected to the first and second arms ( 25 and 30 ). The main brace ( 42 ) includes a hole near the midpoint. As depicted in FIG. 1 , the double-push link ( 40 ) includes a disc ( 44 ). The disc ( 44 ) includes a hole in the center. A pivot cylinder ( 46 ) is disposed in the midpoint hole in the main brace ( 42 ) and the center hole in the disc ( 44 ). The pivot cylinder ( 46 ) allows the disc to rotate. A first linking arm ( 48 a ) is connected to the first arm ( 25 ) and the disc ( 44 ). A second linking arm ( 48 b ) is connected to the second arm ( 30 ) and the disc ( 44 ).
As depicted in FIG. 2 , the apparatus for clamping a drilling tubular can include a face plate ( 50 ) to protect the apparatus during use.
While these embodiments have been described with emphasis on the preferred embodiments, it should be understood that within the scope of the appended claims, the embodiments might be practiced other than as specifically described herein. | An apparatus that can be used during drilling operations for the purposes of clamping and holding drilling tubulars is disclosed. The embodiments relate to machinery that clamp and hold drilling tubulars to allow assembly to a specified torque or disassembly of the tubulars. The apparatus comprises a first grip with teeth inserts housed in a gripping block that opposes a second grip with teeth inserts housed in a second gripping block. The first and second grips are spaced and adapted to accommodate a range of diameters of drilling tubulars. Further, the gripping blocks are held by opposing arms connected to a driving means to create a tightening or loosening movement of the grips and maintain a certain orientation with regard to the tubulars. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The instant application claims the benefit of U.S. Provisional Serial App. No. 60/747,340, which is incorporated by reference herein in its entirety. The instant application further claims the benefit of U.S. patent application Ser. No. 10/965,813, which, in turn, claims the benefit of U.S. Provisional Serial App. No. 60/583,358, both of which are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The present invention relates to fibers and more particularly to methods for making cellulose nanofibers.
BACKGROUND
[0003] Various naturally occurring polymers are of particular interest due to their abundant availability and biodegradability. Cellulose, for example, is one of the most abundant naturally occurring polymers on earth, and finds use in countless applications. Yet, cellulose has proven difficult to transform into fibers because of its relatively high degree of intermolecular and intermolecular hydrogen bonding, which renders it substantially insoluble in common solvents. The effective manufacture of cellulose fibers, therefore, is an area of interest.
SUMMARY OF INVENTION
[0004] The present invention relates to improved fibers comprising organic polymers and methods for making the same.
[0005] In one aspect, a process for making organic fibers comprises electrospinning a dispersion comprising an organic polymer. In one embodiment, the process comprises providing a starting material comprising an organic polymer, dissolving the starting material in a polar solvent to create a dispersion, electrospinning the dispersion by providing an electric charge on droplets of the dispersion to produce a charged jet of polymer and provide a plurality of electrically induced bending instabilities and/or whipping motions, collecting a plurality of the charged jets as fibers and submerging the plurality of fibers into a coagulation bath as they are collected. In another embodiment, the process comprises providing a starting material comprising cellulose, dissolving the starting material in a polar solvent unreactive with cellulose to create a dispersion, electrospinning the dispersion by providing an electric charge on droplets of the dispersion to produce a charged jet of polymer and provide a plurality of electrically induced bending instabilities and/or whipping motions, collecting a plurality of substantially amorphous non-derivatized cellulose nanofibers on a rotating collector and submerging the rotating collector comprising the plurality of substantially amorphous non-derivatized fibers into a coagulation bath on a periodic basis. The collector may, for example, be submerged in regular time intervals between about 1 and about 3.
[0006] The above-identified processes may incorporate various additional features and steps. The solvent used in the dissolving step may, for example, be sufficiently volatile to substantially dissolve during the electrospinning step and can comprise lithium chloride and N, N-dimethylacetamide. The electrospinning step may be carried out in an electric field between about 1.0 kV/cm to about 4.0 kV/cm at a flow rate between about 0.03 ml/min. and about 0.05 ml/min. Further, co-axial electrospinning may be employed. After the collecting step, the recovered fibers may be exposed to at least one of water and alcohol for removing residual solvent without dissolving the fibers or heating at temperatures between about 70° C. and 110° C. Typically, the collected fibers exhibit substantially uniform diameters. The fibers may comprise substantially uniform diameters and a degree of crystallinity between about 1% and about 40%. The fibers may also comprise a substantially amorphous form of cellulose exhibiting an X-ray diffraction pattern comprising at least two 2θ values selected from about 7.0 degrees and about 17.8 degrees. The coagulation bath may comprise at least one of water and alcohol for removing residual solvent without dissolving the fibers.
[0007] In another aspect, an apparatus for making fibers comprises a chamber, pump, syringe, voltage supplier and syringe. In one embodiment, the apparatus comprises a chamber for receiving a dispersion, a pump upstream of the chamber for dispensing the dispersion, a syringe for receiving the dispersion from the pump and comprising an opening for providing droplets of the dispersion, a voltage supplier in electrical communication with the syringe and a collector. The voltage supplier provides an electric charge in the droplets emanating from the opening to produce a plurality of charged jets and provide a plurality of electrically induced bending instabilities and/or whipping motions. The collector receives and collects the charged jets as non-woven fibers and automatically moves between a first position and a second position, wherein at least a portion of the collected fibers are submerged in a coagulation bath in the first position and spaced apart from the coagulation bath in the second position. The collector may be a rotating collector.
[0008] The apparatus may further comprise a heating chamber constructed of an electrically and thermally insulating material, shielded from the voltage supplier. Additionally or alternatively, a heating gun for heating the collector may be employed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Certain embodiments of the present invention are illustrated by the accompanying figures. It should be understood that the figures are not necessarily to scale and that details not necessary for an understanding of the invention or that render other details difficult to perceive may be omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.
[0010] FIG. 1A is a scanning electron microscope (“SEM”) image of cellulose nanofibers made in accordance with one embodiment of the present invention;
[0011] FIG. 1B is an SEM image of FIG. 1A ;
[0012] FIG. 2B is an SEM image of nanofibers on filter media for dust collection made in accordance with a second embodiment of the present invention;
[0013] FIG. 2A is an SEM image of FIG. 2A ;
[0014] FIG. 3A is a perspective view of one embodiment of an electrospinning apparatus used to prepare the nanofibers of the present invention;
[0015] FIG. 3B is a perspective view of an alternate embodiment of the electrospinning apparatus of FIG. 3A ;
[0016] FIG. 4 is a graph illustrating the volatility of DMAc, with mass measurements plotted as a function of time; and
[0017] FIG. 5 is an X-ray diffraction pattern for the cellulose starting material, and cellulose nanofibers made in accordance with the present invention before and after coagulation.
DETAILED DESCRIPTION
[0018] The nanofibers of the present invention may be made from organic polymeric starting materials. These organic polymeric starting materials are typically mixed with a solvent comprising a relatively high volatility (i.e., the readiness with which a material vaporizes), and then subjected to an electrospinning process. Ideally, the solvent is sufficiently volatile to substantially dissolve during the electrospinning process.
[0019] Nanofibers made in accordance with the present invention comprise an organic polymer, and typically exhibit fiber diameters between about 50.0 nm and 1.0 micron, more particularly between about 100.0 nm and 300.0 nm and still more particularly between about 100.0 nm and 200.0 mm. The nanofibers may be relatively amorphous, comprising a degree of crystallinity less than about 60% and more particularly between about 1.0% and 50.0% and still more particularly between about 1.0% and 40.0%. The degree of crystallinity is determined through X-ray diffraction patterns and may be modified by adjustments to the electrospinning process, including spinning distance, flow rate and spinning temperature. The specific surface area of the nanofibers may be between about 1.0 m 2 /g and 50.0 m 2 /g and more particularly between about 5.0 m 2 /g and 10.0 m 2 /g, as measured by the BET surface area testing methodology. The degree of polymerization of the nanofibers may be between about 50 and about 2000 and more particularly about 200 to about 1150.
[0020] When the nanofibers are randomly dispersed, with at least some of the nanofibers in physical contact with one another, a nanofiber mat is formed. The nanofiber mat can comprise a plurality of pores or interstices between individual fibers. The pores typically comprise diameters between about 0.5 microns and 3.0 microns.
[0021] The nanofibers may be composed of various materials, such as cellulose-based polymers. In one embodiment the nanofibers comprise non-derivatized substantially amorphous cellulose, which comprises the repeat unit:
[0000]
[0000] in random orientations and positions. SEM images of a plurality of cellulose nanofibers made in accordance with certain embodiments of the present invention are shown at FIGS. 1A-2B .
[0022] The nanofibers and nanofiber mat of the present invention may be made through a step-wise process. Typically, a starting material is pre-treated and subjected to electrospinning, with heating and an optional coagulation step.
[0023] Various starting materials may be employed, including without limitation, organic polymers such as cellulose. The starting materials are often substantially insoluble in common solvents like water. The molecular weight of the starting material may be between about 10,000 and 325,000 g/mol and more particularly between about 30,000 and 200,000 g/mol. The degree of polymerization of the starting material may be between about 50 and about 2,000 and more particularly about 200 to about 1,150. Suitable examples of cellulose starting materials include cotton linter paper, cotton batting, recycled cellulose and purified bast fibers.
[0024] The starting material is typically ground into fine particles and soaked in water to break or weaken hydrogen bonding. The starting material may be ground to particle sizes between about 5.0 mesh and 50.0 mesh and more particularly between about 15.0 mesh and 25.0 mesh. The finely divided starting material is placed in water and soaked at room temperature for a period of between about 6.0 hours to about 15.0 hours and more particularly between about 8.0 hours and 12.0 hours. The water may be high performance liquid chromatography water available from Mallinckrodt of Phillipsburg, NI. The starting material is thereafter dried under vacuum at between about 55° C. and about 65° C.
[0025] After the starting material is dried, it may be dissolved in a solvent, comprising a relatively high volatility. Preferably, the solvent does not chemically react with the starting material and is sufficiently volatile to substantially dissolve during the electrospinning process. The term “solvent” as used herein means any compound or substance or mixture of liquid compounds or substances used to dissolve part or all of the starting material.
[0026] The solvent may, for example, be a polar solvent used to help weaken or break hydrogen bonding within the organic starting material. The loosening or breakage of hydrogen bonds enhances the solubility of the starting material within the solvent. Polar solvents are beneficial during the electrospinning step because of their relatively high conductivities. In addition, depending on the selection of the solvent, dissolution may proceed without side reactions, leading to a non-derivatized end product. In one embodiment, the solvent comprises DMAc, to which lithium chloride may be added. This solution has been shown to dissolve cellulose from different sources over a large range of concentrations without side reactions. The presence of lithium chloride bridges electrostatic interactions between cellulose and DMAc. In other embodiments, solutions of NMMO/H 2 0 may be employed. Dissolution typically proceeds for about 2.0 hours under constant stirring, with mild heating between about 50° C. to about 60° C. The final concentration of starting material in the solution may be between about 1.0% by weight to about 10% by weight and more particularly between about 3.0% by weight to about 6% by weight. The final solution may exhibit a zero shear viscosity between about 2,500 Pa*s and 3,500 Pa*s. After dissolution of the starting material in the solvent, the dispersion is subjected to electrospinning.
[0027] Electrospinning is a fiber formation process that relies on electrical, rather than mechanical forces to form thin fibers (sub-micron fibers for example). With electrospinning, an electric field is used to draw a solution from the tip of a capillary to a grounded collector. The electric field causes a pendant droplet of the solution at the capillary tip to deform into a conical shape. When the electrical force at the surface of the tip overcomes the surface tension of the solution, a charged jet is ejected and undergoes a series of electrically induced bending instabilities, whereby repulsion of adjacent charged segments generates vigorous whipping motions, which elongate the charged segments into fibers for passage onto a collector. The solvent begins to evaporate after jet formation, causing the deposit of thin fibers on the collector. To the extent residual solvent remains, the collected fibers may be heated to about 150° C. for removal thereof.
[0028] Referring now to FIGS. 3A and 3B , two embodiments of an electrospinning apparatus 100 for use with the present invention are illustrated. Apparatus 100 comprises syringe 102 , tip 104 , high voltage supplier 106 positioned at or near tip 104 , micropump 108 , positioner 109 , heating unit 110 , rotating collector 112 , coagulant bath 114 and motor 116 for driving rotation of collector.
[0029] As shown in FIGS. 3A and 3B , syringe 102 is positioned horizontally on micropump 108 and typically comprises an inner diameter between about 0.10 millimeters to about 0.60 millimeters. The diameter of collected nanofibers may be decreased by decreasing the inner diameter of syringe 102 . Micropump 108 may be a PHD 2000 Infusion syringe pump, available from Harvard Apparatus, Inc. of Holliston, Mass. Positioner 109 may be used to control the height of micropump 108 .
[0030] Voltage supplier 106 may be set between about 1 OkV to about 30 kV and more particularly between about 15 kV and about 25 kV. Voltage supplier 106 provides an electric field between about 1.0 kV/cm to about 4.0 kV/cm.
[0031] Collector 112 may be mesh or a plate and constructed of a conductive material, such as aluminum, stainless steel or a surface oxidized silicon. Collector 112 may also comprise a flat sheet of non-woven cellulose, mixed with about 10% to about 20% polyester fibers.
[0032] Collector 112 is grounded to create an electric field difference between tip 104 and collector 112 , allowing material to move from the high electric field at tip 104 , to grounded collector 112 . The distance between tip 104 and collector 112 may be between about 5.0 cm and 15.0 cm and more particularly between about 7.0 cm and 12.0 cm. A stepper motor 116 may be connected to collector 112 to provide continuous rotation into coagulant bath 114 at predetermined intervals. The intervals may be between about 1.0 to about 10.0 revolutions per minute and more particularly between about 3.0 to about 5.0 revolutions per minute.
[0033] Once apparatus 100 is assembled, a solution comprising the starting material and solvent is placed into syringe 102 , and pumped therethrough at a relatively constant flow rate of about 0.03 milliliters per minute to about 0.05 milliliters per minute. As pumping continues, a charged jet is ejected and elongates as it moves towards collector 112 . A plurality of randomly oriented substantially dry non-woven fibers are collected on collector 112 . The collected fibers typically exhibit uniform diameters (i.e., substantially all the collected fibers exhibit the same or similar fiber diameters)
[0034] In an alternate embodiment, co-axial electrospinning may be employed. Co-axial electrospinning employs a dual syringe which comprises an internal tube positioned within an external tube. Under this construction, an internal jet within an external jet is ejected from the syringe; the internal jet may comprise organic substances, such as mineral oil, while the external jet comprises the aforementioned solution. When mineral oil is used, hollow nanofibers or nanotubes emerge. The term nanofiber, as used herein, is intended to cover nanotubes.
[0035] The presence of residual solvent in the collected nanofibers can lead to unwanted clumps or film-like structures on nanofiber surfaces. There are various ways to decrease residual solvent.
[0036] To enhance evaporation of solvent during processing, a heating step may be employed. The heating step causes vaporization of the relatively volatile solvent, while leaving the starting material substantially intact. As shown in FIG. 4 , for example, DMAc evaporates rapidly at temperatures beyond 50° C.
[0037] Heating may be carried out through heating unit 110 or electric heating guns. Heating unit 110 , the features of which are described in co-pending co-owned U.S. patent application Ser. No. 10/965,813, heats the solution as it travels through syringe. Heating unit 110 , typically comprises an electrically and thermally insulating material and may be shielded from high voltage supplier 106 to prevent induced voltage in the heating source. A Faraday cage or screen, comprising an enclosure made of metal mesh, may serve as the shield. Heating unit 110 is typically used for cellulose mixed with solutions of NMMO/water at temperatures ranging between about 70.0° C. and about 110.0° C. for about one hour. Alternatively or additionally, collector 112 may be heated to between about 90.0° C. and about 120.0° C. and more particularly between about 100.0° C. to about 110.0° C. Commercially available electric heating guns may be utilized for this purpose. Such electric heating guns are often used in connection with cellulose solutions comprising DMAc and LiCl. By applying heat to collector 112 rather than the system as a whole, the viscoelastic properties of the solution up to formation of jet are conserved. Heating in this manner also does not significantly degrade the starting material because of the relatively rapid evaporation of the more volatile solvent at elevated temperatures.
[0038] Coagulation bath 114 may also be used to remove solvent from the electrospun fibers. In the DMAc/LiCl system, the presence of hygroscopic salt causes localized moisture absorption, which leads to the formation of water droplets on the intersection of the collected fibers and unwanted fiber swelling. Coagulation bath 114 helps removes residual LiCl by dissolving it. X-ray diffraction patterns, shown at FIG. 5 , confirms the removal of salt from the collected fibers, as the characteristic peak of salt, at 2θ=30.09, is only observed in the untreated fibers and essentially disappears after coagulation. With the NMMO/water system, residual NMMO is exchanged with the contents of coagulation bath 114 .
[0039] Coagulation bath 114 may comprise any substance or solution that removes residual solvent but does not dissolve the starting material within the collected fibers. Suitable examples include analytical grade water or alcohol. Exposure to coagulation bath may occur about 1.0 to 3.0 seconds after the substantially dry fibers have been electrospun onto collector 112 . This 1.0 to 3.0 second interval is automatically maintained by controlling the rotation speed of rotating collector to between about 1.0 to about 10.0 revolutions per minute and more particularly to between about 3.0 to about 5.0 revolutions per minute. Collected fibers may be exposed to coagulation bath 114 for about 30.0 to 40.0 minutes.
[0040] It bears noting that in the case of cellulose based fibers, collector 112 may comprise cellulose filter media. Under these circumstances, the surrounding cellulose filter media is adapted to distribute moisture absorption uniformly throughout the electrospun fibers, thereby preventing formation of large droplets of water that lead to swelling of the fibers.
[0041] Practice of the above-described methods yields nanofiber mats comprising a plurality of nanofibers typically constructed of a non-derivatized organic polymer. The term non-derivatized, as used herein, means that although residual solvent may be physically entrapped within the matrix, the atoms or elements of the starting material have not been substituted or replaced with the atoms or elements of another material. For example, a non-derivatized cellulose nanofiber comprises the structure of the repeat unit for cellulose shown above, without substitution or replacement of atoms.
[0042] The present invention may be used in a variety of different ways, including, without limitation, in sensing and filtering applications. For instance, nanofibers made in accordance with the present invention may be used for filtration of sub-micron dust particles. The collection efficiency of the nanofibers is relatively high, with collection of about 30% to about 50% of dust passed through a filter comprising the nanofibers of the present invention is typical. The nanofibers are also useful in medical applications. The nanofibers may be used as a hemostatic wound dress, to mimic the formation of fibrin to aid in blood clotting at wound surfaces. In addition, the nanofibers may be used as a barrier after surgery. Since the nanofibers with small fiber dimension can comprise amorphous cellulose, they typically degrade faster than conventional, thick cellulose membranes. With fibers of the present invention, the degradation process within the body occurs in about three to five days. Additionally, the need to dispose of conventional crystalline cellulose in landfills and the like is substantially decreased.
[0043] While certain embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims. | An apparatus for making electrspun fibers comprises a collector that may be submerged in a coagulation bath. The collector may be automatically movable between a first position and a second position, wherein at least a portion of the collected fibers are submerged in a coagulation bath in the first position and spaced apart from the coagulation bath in the second position. The collector may be a rotating collector. A process for making electrospun fibers comprises electrospinning a dispersion and collecting a plurality of electrospun fibers, followed by submerging the collected fibers in a coagulation bath. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to and incorporates by reference the entire contents of European Patent Application No. 11 005 765.0 filed on Jul. 14, 2011.
BACKGROUND OF THE INVENTION
The present invention relates to a thermoelectric device, in particular an all-organic thermoelectric device, and to an array of such thermoelectric devices. Furthermore, the present invention relates to a method of manufacturing a thermoelectric device, in particular an all-organic thermoelectric device. Moreover, the present invention relates to uses of the thermoelectric device and/or the array in accordance with the present invention.
State of the art thermoelectric devices, i.e. thermogenerators and Peltier elements, are made of inorganic semiconductors, mostly based on bismuth and tellurium. While these materials have large advantages as superior efficiency or high output voltages, they also show several disadvantages. They are expensive, belong to the group of heavy metals, with all the environmental problems associated therewith, are rigid and brittle, and are therefore somewhat difficult to process and to manipulate. Moreover, metal pads are needed in order to contact the inorganic semiconductors from the outside in thermogenerators and Peltier elements made thereof. Accordingly, it was an object of the present invention to provide for a thermoelectric device that avoids the problems associated with the prior art devices. More particularly, it was an object of the present invention to provide for a thermoelectric device that is easy to manufacture and that allows the adaptation of simple manufacturing processes. It was furthermore an object of the present invention to provide for a thermoelectric device that avoids the use of heavy metals.
BRIEF SUMMARY OF THE INVENTION
All these objects are solved by a thermoelectric device, comprising:
a first substrate and a second substrate,
and a plurality of pairs of semiconducting members sandwiched between said first and second substrate,
each pair of semiconducting members consisting of an electron conducting member and of a hole conducting member, wherein said electron conducting member and said hole conducting member are made of an organic n-type semiconducting material and an organic p-type semiconducting material, respectively, wherein, in each pair, said electron conducting member and said hole conducting member contact each other,
wherein on said first substrate, a first subset of said plurality of pairs of semiconducting members are arranged in a first pattern such that said pairs are spaced apart from each other by a first set of gaps between said pairs on said first substrate, and
wherein on said second substrate, a second subset of said plurality of pairs of semiconducting members are arranged in a second pattern such that said pairs are spaced apart from each other by a second set of gaps between said pairs on said second substrate,
wherein said first pattern and said second pattern are complementary to each other, such that, when said first and second substrates are arranged opposite each other with said first and second subsets facing each other, electrical contacts between neighboring pairs of said first subset are established by pairs of said second subset, and electrical contacts between neighboring pairs of said second subset are established by pairs of said first subset.
In one embodiment, said first subset of said plurality of pairs fills said second set of gaps, and said second subset of said plurality of pairs fills said first set of gaps, and wherein said first subset of said plurality of pairs physically contacts said second subset of said plurality of pairs, and wherein each physical contact is established by electron conducting members of said first subset physically contacting electron conducting members of said second subset only and by hole conducting members of said first subset physically conducting hole conducting members of said second subset only.
In one embodiment, electrical contacts between neighboring pairs of said first subset and electrical contacts between neighboring pairs of said second subset are established without metal contacts or metal electrodes.
In one embodiment, said organic n-type semiconducting material and said organic p-type semiconducting material are organic polymers.
In one embodiment, said organic n-type semiconducting material is independently, at each occurrence in each pair, selected from organic polymers doped with electron donors, and charge transfer complexes.
In one embodiment, said organic p-type semiconducting material is independently, at each occurrence in each pair, selected from organic polymers doped with electron acceptors.
In one embodiment, the first and second substrates are made of a material independently at each occurrence selected from insulating materials, such as glass, plastics, paper.
In one embodiment, the first and second substrates are not rigid, but flexible and can, as such, preferably, be rolled, such that they are amenable to roll-to-roll-manufacturing processes.
In one embodiment, the thermoelectric device according to the present invention has at least two points for making electrical contacts to a power supply or for connecting the thermoelectric device to another electrical or thermoelectric device.
The objects of the present invention are also solved by an array of thermoelectric devices as defined above, wherein a plurality of thermoelectric devices according to any of the foregoing claims are electrically connected in series with each other and are arranged such that their respective first substrates all face in one direction, and their respective second substrates all face in the opposite direction.
In one embodiment, the array according to the present invention is located in a housing.
The objects of the present invention are also solved by a method of manufacturing a device according to the present invention, said method comprising the steps:
providing a first and a second substrate, applying a first subset of a plurality of pairs of semiconducting members onto said first substrate in a first pattern such that said pairs in said first subset are spaced apart from each other by a first set of gaps between said pairs on said first substrate, and applying a second subset of said plurality of pairs of semiconducting members onto said second substrate in a second pattern such that said pairs in said second subset are spaced apart from each other by a second set of gaps between said pairs on said second substrate, wherein said first pattern and said second pattern are complementary to each other, such that when said first and second substrates are arranged opposite each other with said first and second subsets facing each other, electrical contacts between neighboring pairs of said first subset are established by pairs of said second subset, and electrical contacts between neighboring pairs of said second subset are established by pairs of said first subset, assembling and bonding the first and second substrates together, with said first and second subsets of said plurality of pairs of semiconducting members facing each other.
“Bonding” substrates together may be achieved by any means suitable and known to a person skilled in the art, e.g. by gluing the substrates together, pressing the substrates together at an elevated temperature, or joining them together by other means such as clamp(s) etc.
In one embodiment, said pairs of semiconducting members, said electron conducting members, said hole conducting members, said first subset, said second subset, said first set of gaps and said second set of gaps, said first substrate and said second substrate are as defined above.
In one embodiment, the applying steps occur by printing or vapor depositing.
The objects of the present invention are also solved by the use of a device according to the present invention or of an array according to the present invention for generating a voltage or a heat gradient, wherein preferably, the device or array is incorporated in an electronic device, in a medical device, such as a sensor or a band aid, in clothing, in wall paper, in a laboratory device, such as a thermocycler. For example, it may be used to generate a voltage for a sensor or for a medical device, e.g. a band-aid.
The present inventors have found that it is possible to produce an all-organic thermoelectric device, wherein the semiconducting components are made from all-organic components. The term “all-organic”, as used herein, is meant to refer to compounds which are carbon-based. In one embodiment, the term “all-organic” refers to the exclusive use of carbon-based polymers.
The term “contact” may refer to an interaction, whereby an electrical contact or a physical contact is established. An “electrical contact”, as used herein, is a contact that allows the flow of electrons between the two entities electrically contacting each other. A “physical contact”, as used herein, is meant to refer to a scenario wherein the two entities actually touch each other. The unspecified term “contact” may mean any type of contact, for example an electrical contact or a physical contact.
The inventors have devised a method by which pairs of semiconducting members are applied to the surface of a substrate, wherein each such pair consists of an electron conducting member and of a hole conducting member. The two members contact each other, wherein, preferably, such contact is physical, in the sense that they actually touch each other. Applying such pairs on one substrate in a first defined pattern, with gaps in between the pairs, and by applying a complementary pattern of pairs on a second substrate, it is possible to provide for a layer of pairs of semiconducting members sandwiched between the first and the second substrate, wherein the two subsets of pairs of semiconducting members engage with each other and form an array of n-type semiconducting components and p-type semiconducting components, which array can be used to function as a heat pump, upon application of a voltage thereto.
Metal bridges are avoided in this setup, because the electrical contacts are established via the complementary pairs of semiconducting members on opposite substrates. Likewise, inorganic semiconductors, such as bismuth and tellurium, are also avoided. Since the semiconducting members are made of organic materials, in particular organic polymers, they can be applied by a variety of application processes, in particular printing and vapor depositing. This makes the present invention particularly amenable to large area (>1 m 2 ) applications as well as applications on flexible substrates, which are not rigid, but which can be rolled up and are amenable to roll-to-roll-manufacturing processes. The present invention envisages also an array of such thermoelectric devices within a Peltier element, wherein the thermoelectric devices are connected in series with each other. Such Peltier elements may have additional features, such as a heat sink etc.
The present invention also relates to a method of manufacturing, wherein the pairs of semiconducting members are applied to two different substrates in complementary patterns, such that these two patterns on the opposite substrates may engage with each other and may thus establish electrical contact or contactability. In preferred embodiments, the respective application steps occur by printing methods or vapor deposition methods, such as thermal evaporation. The devices and arrays in accordance with the present invention can be scaled up to very large sizes (i.e. >1 m 2 ), they can be made using flexible substrates, and they can be used in a wide range of applications, for example in medical applications, such as for the generation of electrical energy generated by body heat to power medical sensors or in heating/cooling band aids, for lifestyle products, for example in actively heating/cooling clothing, for building infrastructures, for example generating electrical energy for sensors based on air conditioning systems or heating/cooling wall papers, or in electric devices, where already now those typically thermoelectric devices, such as Peltier elements are used.
The present invention has the advantage that the thermogenerators in accordance with the invention are simple and easy to produce. The expected costs are low, because of cheap materials and amenable production steps being used. Toxic or harmful materials, such as heavy metals, can be avoided altogether. The process can be scaled up, and flexible substrates can be used, thereby widening the possible applications enormously.
BRIEF DESCRIPTION OF THE DRAWINGS
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
In the following, reference is made to the figures, wherein
FIG. 1 shows an example of the application of an electron conductor and hole conductor on a substrate, using an inject printer and applying pairs of semiconducting members spaced apart.
FIG. 2 shows the two complementary patterns applied on two substrates which are to be combined.
FIG. 3 shows a cross-section of the two substrates of FIG. 2 before they are assembled together showing that the respective patterns bridge the respective gaps in the respective other pattern.
FIG. 4 shows the two substrates brought together with the two patterns combined.
FIG. 5 shows a cross-section of FIG. 4 and the effect that may be achieved thereby when an electrical voltage is applied.
FIG. 6 shows the P-type and N-type semiconducting materials that are used in the prototype.
FIG. 7 shows the prototype produced by the present inventors.
DETAILED DESCRIPTION OF THE INVENTION
Moreover, reference is made to the following examples, which are given to illustrate, not to limit the present invention.
EXAMPLES
Example 1
An embodiment of the process is depicted in FIGS. 1 to 5 . Two substrates need to be coated with hole and electron conducting organic material (for example using a solution-based ink-jet printer as depicted in FIG. 1 , but any other printing technique or thermal evaporation can be used as well). The two substrates need to have a complementary design, for example the ones depicted in FIG. 2 . FIG. 3 illustrates how the two complementary top and bottom substrates are brought together to build a single device. The same is illustrated in FIG. 4 for the design of FIG. 2 after the two halfs have been brought together (top view). The two electron and hole conducting regions on the bottom substrate that protrude out beyond the top substrate are used as contacts to either collect the generated electrical voltage (thermogenerator) or to apply the external voltage (Peltier element). FIG. 5 shows the final usage of the device. It either acts as a thermogenerator, i.e. it produces electrical energy out of an external heat gradient, or it can be used as a Peltier element, i.e. it converts applied electric energy into a heat gradient, so the device can be used for heating or cooling purposes. As can bee seen the whole process is a simple two step process, consisting of just printing the organic material and assembling the two halfs (top and bottom) together. This is far superior to any state of the art process of producing a thermogenerator or a Peltier element. In addition the process can easily be scaled up to huge dimensions, only limited by the printable substrate size. (For example when using a roll to roll printing process with combined assembling of the two halfs into one device.)
Example 2
In a prototype-production, a thermogenerator was printed using a nano-plotter and a commercial accessory, “Delo-Dot”, which is a microdispensing valve (www.venso.se/pdf/delo/delodot.pdf) for printing highly viscous liquids. The exemplary P-type semiconducting material and N-type semiconducting material are shown in FIG. 6 . The dimensions to be used for the prototype thermogenerator were as follows:
Dimensions:
Squares: 3×3 mm (16×16 dots, 0.2 mm grid) Rectangles: 5×3 mm (26×16 dots, 0.2 mm grid) Gap: 1 mm
Settings of the Delo-Dot:
100V 40 μs 100 Hz 0.5 bar 1 droplet per point
Substrate: HP LaserJet transparency foil (roughly 5×5 cm)
Substrate cleaning: 15 min in UVO-cleaner
Pressed the two substrates together on a hotplate at 120° C. for 15 min using pressure of approximately 800N/m 2
The resultant thermogenerator that was thus produced can be seen in FIG. 7 .
Example 3
In the following some suitable materials are shown that can be used as organic semiconducting materials of the n-type and p-type. Typically, for these materials organic polymers can be used, which may or may not be doped using electron donors, e.g. phosphorus, to give n-type conduction, or using electron acceptors, e.g. boron, to give p-type conduction.
Suitable polymers include for example poly(3-hexylthiophene) (P3HT), polyaniline, poly(phenylene vinylene)-disperse red 1 (PPV-DR1), polysiloxane carbazole (PSX-Cz), polypyrrole, poly(o-anthranilic acid) (PARA), poly(aniline-co-o-anthranilic acid) (PANI-PARA) and poly(3,4-ethylenedioxythiophene) (PEDOT). The structural formulas of some the above mentioned polymers are shown below:
Mixtures of polymers (e.g. PEDOT:PSS or PEDOT:Tos) or copolymers can also be used.
In order to induce charges into the polymer these materials can be doped, using for example electron donors (e.g phosphorous→n-type conduction) or electron acceptors (e.g. boron→p-type conduction). Most polymers are oxidized by air and therefore show p-type conduction in their undoped state.
Likewise, charge transfer complexes may be used.
Charge Transfer Complexes:
Generally and as used herein, these materials referred to as charge-transfer complexes are electron-donor-electron-acceptor complexes that are characterized by at least one electronic transition to an excited state in which there is a partial transfer of an electronic charge from the donor to the acceptor moiety.
Donor and acceptor molecules in the charge transfer complex are so defined that the highest occupied molecule orbital (HOMO) of the donor and the lowest unoccupied molecule orbital (LUMO) of the acceptor are close enough to each other such that upon application of an electric field an electron of the HOMO of the donor can transfer to the LUMO of the acceptor and vice versa depending on the electric field direction.
Donor molecules are molecules that donate electrons during the formation of the charge transfer complex.
Donor molecules can include one or more of the following donor groups without being restricted thereto: O − , S − , NR 2 , NAr 2 , NRH, NH 2 , NHCOR, OR, OH, OCOR, SR, SH, Br, I, Cl, F, R, Ar. They can be single molecules, oligomers or polymers.
Acceptor molecules are molecules that accept electrons during the formation of a charge transfer complex.
Acceptor molecules can contain one or more of the following acceptor groups without being restricted thereto: NO 2 , CN, COOH, COOR, CONH 2 , CONHR, CONR 2 , CHO, COR, SO 2 R, SO 2 OR, NO, Ar. They can be single molecules, oligomers or polymers.
Acceptor molecules are found also among the fullerene derivatives, semiconductor nanodots and electron poor transition metal complexes.
The material can comprise an acceptor molecule of the group comprising C60 fullerene, C61 fullerene, CdSe, and platinum octaethyl porphine.
Alternatively, the material undergoing a charge transfer can be a material having conjugated main-chain as well as side-chain liquid crystalline polymers which can be aligned in mono-domain or multi-domain structures.
The material can have the following formula without being restricted thereto:
wherein R4 and R5 are independently at each occurrence selected from the group comprising:
R1 and R2 being independently selected from the group comprising straight chain C 1-20 alkyl, branched C 1-20 alkyl, aryl, substituted aryl, alkylaryl, substituted alkylaryl, alkoxyaryl, substituted alkoxyaryl, aryloxyaryl, substituted aryloxyaryl, dialkylaminoaryl, substituted dialkylaminoaryl, diarylaminoaryl and substituted diarylaminoaryl,
R3 being selected from the group comprising straight chain C 1-20 alkyl, branched C 1-20 alkyl, aryl, substituted aryl, alkylaryl and substituted alkylaryl, and wherein R6 and R7 are independently at each occurrence selected from the group comprising straight chain C 1-20 alkyl, branched chain C 1-20 alkyl, aryl, substituted aryl, alkylaryl, substituted alkylaryl, —(CH 2 ) q —(O—CH 2 —CH 2 ) r —O—CH 3 ,
q being selected from the range 1<=q<=10, r being selected from the range 0<=r<=20, and wherein L and M are independently at each occurrence selected from the group comprising thiophene, substituted thiophene, phenyl, substituted phenyl, phenanthrene, substituted phenanthrene, anthracene, substituted anthracene, any aromatic monomer that can be synthesized as a dibromo-substituted monomer, benzothiadiazole, substituted benzothiadiazole, perylene and substituted perylene, and wherein m+n+o<=10, each of m, n, o being independently selected from the range 1-1,000, and wherein p is selected from the range 0-15, and wherein s is selected from the range 0-15, with the proviso that, if R4 is H, R5 is not H, and if R5 is H, R4 is not H.
Alternatively, the material can have the following formula without being restricted thereto:
wherein L independently at each occurrence is selected from the group consisting of thiophene, substituted thiophene, phenyl, substituted phenyl, phenanthrene, substituted phenanthrene, anthracene, substituted anthracene, any aromatic monomer that can be synthesized as a dibromo-substituted monomer, benzothiadiazole, substituted benzothiadiazole, perylene and substituted perylene, and wherein R 6 and R 7 are independently at each occurrence selected from the group consisting of straight chain C 1-20 , branched chain C 1-20 alkyl, aryl, substituted aryl alkylaryl, —(CH 2 ) q —(O—CH 2 — CH 2 ) r —O—CH 3 , q being selected from the range 1-10, r being selected from the range 0-20 and wherein R4 and R5 are independently at each occurrence selected from the group comprising:
According to another alternative the material can have one of the following formulas without being restricted thereto:
Alternatively, the material can be an endcapped polyfluorene of the formula without being restricted thereto:
The combination of donor and acceptor regulates the charge conduction properties. N-type conduction can be established using charge transfer complexes. (e.g. 6,6-Phenyl-C61 butyric acid) or tetrathiafulvalene:tetracyanoquinodimethane (TTF:TCNQ) as examples).
The features of the present invention disclosed in the specification, the claims and/or in the accompanying drawings may, both separately and in any combination thereof, be material for realizing the invention in various forms thereof. | The present invention relates to a thermoelectric device, in particular an all-organic thermoelectric device, and to an array of such thermoelectric devices. Furthermore, the present invention relates to a method of manufacturing a thermoelectric device, in particular an all-organic thermoelectric device. Moreover, the present invention relates to uses of the thermoelectric device and/or the array in accordance with the present invention. | 7 |
FIELD OF THE INVENTION AND RELATED ART STATEMENT
The present invention relates to a method of incinerating wastes from environmental facilities and products and an apparatus therefor, and more particularly to a method for low-pollution (limited dioxin production) incineration of domestic refuses, industrial wastes, sewage, human wastes, sludges from paper industry, and other wastes such as organic compounds containing chlorine compounds and also to an apparatus therefor.
Detection of highly toxic dioxins in the flue gas, ash residue, flyash, etc. from municipal refuse incinerators is causing a growing concern these days. Investigations on the methods of analysis, the mechanism of evolution, and techniques for control of the dioxins are under way in industrial-academic circles throughout the world. Reports have been made on high-temperature combustion, retention time, etc. aimed at complete incineration. However, the data presented on the subjects are rather meager, and a breakthrough is being sought in vain.
OBJECTS AND SUMMARY OF THE INVENTION
In view of the state of art described above, the present invention has for its object to provide a low-pollution incineration method and apparatus capable of controlling the production of highly toxic dioxins upon incineration of various wastes including organic wastes that contain chlorine compounds.
The invention realizes the object by providing:
(1) A method of incinerating wastes while controlling the production of dioxins, characterized in that water vapor or water is sprayed in the main combustion zone of an incinerator; and
(2) An apparatus for incinerating wastes having a line for supplying main combustion air, either alone or together with a line for supplying recycled combustion gas, to an incinerator from below the hearth thereof, characterized in that a line for supplying water vapor or water is provided in communication with said line or lines.
The invention has now been arrived at after extensive experimental studies on ways for controlling the secondary production of dioxins and decomposing any such products in consideration of the fact that they are aromatic chlorine compounds. The invention thus provides a method and an apparatus for incineration adopting a system for supplying water vapor or water to the main combustion zone of the incinerator using primary combustion air as the entraining medium.
With regard to the mechanism of formation of dioxins, reports have been made that they easily form during the thermal decomposition process of organic substances and that there are many competing reactions for their production. However, much remain to be clarified and diverse investigations have just got under way at various research institutes and laboratories.
The present inventors were interested in the fact that dioxins are aromatic (cyclic hydrocarbon) chlorine compounds and conceived of either thermally decomposing (i.e., opening) their benzene rings or preventing the formation of the rings. As a consequence, injection of water vapor or water to the main combustion zone has now been adopted. In this way decomposition of dioxins and control of dioxin production can be accomplished concurrently by thermal decomposition and combustion reactions. Thus, low-pollution incineration can be realized.
This mechanism of decomposition and control of dioxins is presumably represented by an overall reaction formula:
C.sub.m H.sub.n +mH.sub.2 O→mCO+(n/2+m)H.sub.2
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the first embodiment of the present invention as applied to a fluidized-bed incinerator;
FIG. 2 is a schematic view of the second embodiment of the invention as applied to a stoker-fired incinerator;
FIG. 3 is a schematic view of the third embodiment of the invention as applied to a fluidized-bed incinerator;
FIG. 4 is a schematic view of the fourth embodiment of the invention as applied to a rotary kiln;
FIG. 5 is a vertical sectional view of the fifth embodiment of the invention as applied to a fluidized-bed incinerator;
FIG. 6 is a cross sectional view of the fifth embodiment;
FIG. 7 is a sectional view of a water spray nozzle for use in the present invention;
FIG. 8 is a flow chart of a testing equipment used to confirm the effects of the invention; and
FIG. 9 is a graph showing the relation between the water vapor injection rate and the dioxins concentration.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
As the first embodiment, the present invention as applied to a fluidized-bed incinerator for municipal wastes including organic wastes that contain chlorine compounds will now be described with reference to FIG. 1. In FIG. 1, the numeral 1 designates a waste feeder, 2 a fluidized-bed incinerator, 3 a fluidizing-air fan, 4 a flue gas-circulating blower, 5 a secondary-air fan, 6 an ash cooler, 7 an ash hopper, 8 a heat recoverer, 9 a flue gas fan, 10 a flue gas-treating unit, 11 a stack, and 12 a wind box assembly.
The flue gas-circulating blower 4 and secondary-air fan 5 are driven when necessary.
Water vapor or water is supplied at the points shown in FIG. 1. The construction is such that it can be injected into either (A) a fluidizing-air line or (B) a flue gas-circulating line.
Wastes to be incinerated are fed via the feeder 1 to the fluidized-bed incinerator 2. Fluidizing air (primary air) is ordinary atmospheric air supplied by the fluidizing-air fan 3. Depending on the type of wastes being handled, treated flue gas is supplied as a part of primary air by the flue gas-circulating blower 4 to the wind box assembly 12 to adjust the percentage of excess air and the fluidized state in the fluidized-bed zone. In that case multistage combustion is carried out, effecting controlled combustion (low air excess percentage combustion) in the fluidized-bed zone and combustion in the freeboard with secondary air supplied by the secondary-air fan 5.
The ash residue and other noncombustible matter that collect at the bottom of the furnace are cooled by the ash cooler 6, separated from fluidized sand, and stored in the ash hopper 7. The gas, on the other hand, is conducted through the heat recoverer 8, flue gas fan 9, and flue gas-treating unit 10, and then released from the stack 11 to the atmosphere.
In experiments with the apparatus described above, water vapor or water was sprayed over the fluidizing air to capture dioxins that are produced by the incineration of wastes containing chlorine compounds. It was confirmed that up to 99.1% of the dioxin contents was thus removed.
The amount of water, or water vapor as water, added was, in terms of the molar weight to the carbon amount in the combustibles, 0.88 (H 2 O/C molar ratio). The combustion temperatures were as given in Table 1. The properties of the treated gas, also shown in the table, reflected favorable low-pollution incineration.
TABLE 1______________________________________ Experiment With water added in accordance Without water with the additionItem invention as usual______________________________________Furnace outlet 1.68 1.62air ratio*Amount of water added 0.88 0(H.sub.2 O.sup.mol /C.sup.mol)Temperature inside 672° C. 898° C.the fluidized bedFreeboard temperature 930˜1000° C. 950˜990° C.Retention time at ab. 2 sec. ab. 2 sec.or above 850° C.Furnace outlet gascompositionO.sub.2 8.49% 8.02%CO.sub.2 12.37% 12.8%CO 45 ppm 25 ppmNO.sub.x 69 ppm 72 ppmDioxins 60 ng/Nm.sup.3 6500 ng/Nm.sup.3______________________________________ *Furnace outlet air ratio = quantity of actually supplied air/theoretical combustion air quantity
In FIG. 2 is shown the second embodiment of the invention as applied to a stoker-fired incinerator.
In the figure, 21 is a feed hopper for introducing waste to be incinerated, 22 is a feeding chute, 23, 24, 25 are a plurality of stoker units arranged stepwise, 26 is a draft line for forcing primary air into the individual stoker units, and 27 is an ash conveyor installed beneath the stoker units.
A spray nozzle 28 is provided in the upper part of the combustion chamber above the stoker and is supplied with water or water vapor by a supply line 29. A line 29a branches off from the line 29 into communication with the draft line 26.
Waste to be incinerated is introduced through the feed hopper 21 and feeding chute 22 into the furnace, burned by the stoker units 23, 24, 25, and discharged in the form of ash. Here water or water vapor as an agent to be injected is forced into the primary air draft line 26 or into the main combustion zone 31 above the stoker.
FIG. 3 illustrates the third embodiment of the present invention as applied to a fluidized-bed incinerator.
As shown, 35 is the main body of the incinerator, 36 a fluidized bed, 37 wind boxes, 38 a freeboard, 39 an inlet for feeding waste to be incinerated, 40 a conduit for introducing water or water vapor, and 42 an inlet pipe for supplying fluidizing air to the lower part of the fluidized bed 36.
The waste to be incinerated, fed through the inlet 39 into the incinerator body 35, is gasified by thermal decomposition in the fluidized bed 36. The resulting gas flows upward through the main combustion zone 43, secondary combustion zone 44, and tertiary combustion zone 45. Secondary air is supplied to the main and secondary combustion zones 43, 44, and tertiary air is supplied between the second and tertiary combustion zones 44, 45.
When water or water vapor is used, it is introduced into the main combustion zone 43 where apparently benzenes and phenols as precursors of dioxins are being produced.
FIG. 4 shows the fourth embodiment of the invention as applied to a rotary kiln.
In the figure, 50 is a rotary kiln, 51 a waste feeder, 52 a gas recombustion chamber, and 53 an after-burning stoker provided in the lower part of the recombustion chamber 52. In the recombustion chamber 52, combustion gas from a main combustion zone 54 is discharged by way of a secondary combustion zone 55. Numeral 56 indicates a line through which secondary air is supplied. Spray nozzles 57, 58 for introducing water or water vapor are mounted in end walls of the rotary kiln 50 and recombustion chamber 52, respectively.
Waste to be incinerated is fed by the feeder 51 to the rotary kiln 50. Inside the kiln 50, the waste is thermally decomposed into a gaseous form by the radiant heat from the recombustion chamber 52 at a high temperature, and then is secondarily burned in that chamber. Water or water vapor as an injection agent is either forced by the nozzle 57 directly into the decomposing-gasifying zone of the rotary kiln 50 where the precursors of dioxins are easily formed or introduced by the nozzle 58 into the main combustion zone 54.
FIGS. 5 and 6 show the fifth embodiment of the invention as applied to a fluidized-bed incinerator, intended to clarify a typical arrangement of water spray nozzles.
Referring to the figures, 62 is the main body of the fluidized-bed furnace, 63 a fluidized bed, 64 wind boxes, 65 a freeboard, 66 a waste hopper, 67 an ash residue outlet, 68 a plurality of water spray nozzles mounted in the surrounding wall of the fluidized-bed incinerator body 62, and 69 a plurality of secondary air nozzles likewise mounted in the surrounding wall. The water spray-nozzles 68 and secondary air nozzles 69 are located with inclination at predetermined angles to the axial center of the incinerator (in a pattern represented by alternate long-and-short-dashes lines in FIG. 6) so as to produce a swirl flow in the furnace and achieve an enhanced gas-water mixing and stirring effects.
FIG. 7 illustrates the construction of an embodiment of the water or water vapor spray nozzle for use in the present invention. This spray nozzle is of a type which can maintain water supply to the spray tip at the front end constant by keeping a constant water supply pressure and adjusting the return water pressure (water quantity), and hence can maintain the size of sprayed water droplets constant regardless of the flow rate. In the figure, 68 is the main body of the spray nozzle, 70 a protective sleeve, 71 an inlet pipe for introducing spray water, 72 a return pipe, and 73 a refractory wall of the furnace body. The quantity of spray issuing from the nozzle is increased or decreased by adjusting the opening of a flow regulating valve (not shown) installed downstream of the return pipe 72. In the practice of the invention water or water vapor is constantly injected at a controlled rate.
FIG. 8 is a flow chart of a testing equipment used to confirm the advantageous effects of the present invention. First, waste to be burned is fed to a cylindrical fluidized-bed incinerator 81 via a metering hopper 82 and a feeder 83. The combustion gas leaving the top of the furnace is cooled as it passes through two indirect air-cooled gas coolers 85, 86 in tandem. After dust removal by a bag filter 87, the cleaned gas is discharged by an induced draft fan 89 to the atmosphere via a stack 90.
Meanwhile, water vapor is used as an injection agent and is injected at a predetermined rate into primary air which is boosted in pressure by a forced draft fan 91 and heated to a given temperature by an air heater 92. For the purposes of the experiments the amounts of dioxins produced were measured at the inlet of the bag filter 87. The symbol 81a indicates a (propane) gas burner and G, a gas sampling point.
With the testing equipment described above, experiments were made on ordinary combustion without the injection of water vapor and on combustion at varied rates of water vapor injection. Resulting concentrations of dioxins (PCDDs +PCDFs) are graphically represented in FIG. 9. As for the combustion conditions used, the fluidized-bed temperature was 700° C. and the O 2 concentration in the combustion gas was 7%.
The water vapor injection rate was varied over the range of 0.1 to 0.46 kg H 2 O/kg waste (H 2 O/C molar ratio =0.2 to 0.88). The graph shows that the presence of only a small amount of water vapor reduced the overall dioxin concentration sharply, to less than one-twentieth of the concentration when no such vapor was injected. The largest injection reduced the concentration to nearly one-hundredth, indicating the amazing effect of the invention.
For the injection of water or water vapor in conformity with the invention it is only necessary to keep the injecting point at a temperature of 700° C. or upwards, decide an injection rate according to the desired dioxin reduction ratio, and inject the water or water vapor constantly at a controlled rate corresponding to the rate of incineration.
As described above, the present invention renders it possible to control or reduce markedly the secondary production of dioxins during the incineration of wastes containing chlorine compounds that is causing a global concern today. The invention thus realizes low-pollution incineration and its contribution to the protection of earth environments is unmeasurably great. | A method of incinerating wastes while controlling the production of dioxins wherein water vapor or water is sprayed in the main combustion zone of an incinerator. An apparatus for practicing the method of waste incineration, including a line for supplying main combustion air, either alone or together with a line for supplying recycled combustion gas, to the incinerator from below its hearth, is provided with a line for supplying water vapor or water in communication with the line or lines. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 12/562,608, filed on Sep. 18, 2009, which claims the benefit of U.S. Provisional Application No. 61/098,185 filed Sep. 18, 2008, the entire contents of application Ser. No. 12/562,608 and Application No. 61/098,185 are specifically incorporated herein by reference without disclaimer.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] This invention relates to disease identification and management and more particularly relates to an apparatus system and method for presenting a natural history and natural progression of disease.
Description of the Related Art
[0003] Most typical health treatment plans are reactive rather than proactive. For example, a physician typically only treats patients for symptoms or diseases that have presented. Even when there are known relationships between diseases or symptoms, these diseases and symptoms are often left untreated until they present in a patient.
[0004] Some resources available to physicians present treatment plans or protocols for physicians treating patients with certain diseases. Although such treatment plans are often helpful, they typically do not present a clear picture of the disease from start to finish, and they often fail to provide the physician with assistance in determining the patient's current status within a typical progression of the disease.
[0005] It is important for a treating physician to have a clear understanding, not only of the disease progression and possible treatments, but also of the patient's status within the progression, so that the proper treatments and tests are administered at appropriate times. Additionally, it is useful for the patient to have a clear understanding of the disease progression, and their current status, so that they can plan for future expenses, complications, and treatments.
[0006] Similarly, health insurance companies may wish to identify a patient's status within their disease progression, so that they are more able to assist their customers by suggesting preventative treatments or procedures, allocate expenses, and the like.
[0007] In a further embodiment, it may be useful for healthcare researchers to identify a patient's status within a disease progression, along with typical decision points and historical outcomes, so that better treatment plans, protocols, medications, and procedures may be developed.
[0008] Additionally, physicians may be able to use such treatment plans and protocols to take a proactive, rather than reactive, approach to healthcare and disease management.
[0009] The referenced shortcomings are not intended to be exhaustive, but rather are among many that tend to impair the effectiveness of previously known techniques disease management; however, those mentioned here are sufficient to demonstrate that the methodologies appearing in the art have not been satisfactory and that a significant need exists for the techniques described and claimed in this disclosure.
SUMMARY OF THE INVENTION
[0010] From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method for presentation of a natural history and the progression pathway of a disease.
[0011] An apparatus for presentation of a natural history and the progression pathway of a disease is presented. In one embodiment, the apparatus includes an input/output adapter configured to receive information to generate a health profile for an individual. The apparatus may also include a processor configured to retrieve a disease progression map comprising one or more disease progression states from a data storage device, and determine a disease progression state associated with the individual in response to the health profile. In a further embodiment, the apparatus may include a display adapter coupled to the state determination module, the display module configured to display a graphical representation of the disease progression state with reference to the disease progression map.
[0012] A computer program product comprising a computer readable medium having computer usable program code comprising computer operable software modules is also presented. In one embodiment, the modules may include a profile module, a disease progression module, a state determination module, and a display module. The profile module may generate a health profile for an individual. In one embodiment, the disease progression module may retrieve a disease progression map comprising one or more disease progression states from a data storage device. The state determination module may determine a disease progression state associated with the individual in response to the health profile. Additionally, the display module may display a graphical representation of the disease progression state with reference to the disease progression map.
[0013] In a further embodiment, the profile module may include an automatic profile generator configured to automatically generate the health profile for the individual from data previously stored in association with the individual. In a further embodiment, the profile module may include an interactive profile generator configured to generate the health profile in response to data entered by a user regarding the individual through an interactive display.
[0014] In one embodiment, the state determination module may include a question predictor module configured to predict one or more questions that the individual may have regarding their health state in response to the determination of the disease progression state associated with the individual. The state determination module may also include a cost analysis module configured to analyze costs associated with one or more disease progression scenarios based on the disease progression state associated with the individual. In a further embodiment, the state determination module may include a treatment protocol generator configured to determine an optimized treatment protocol for the individual in response to the disease progression state associated with the individual. Additionally, the state determination module may include a co-morbidity analyzer configured to identify a potential co-morbidity with an increased probability of presentation as a result of the disease progression state associated with the individual.
[0015] In one embodiment, the display module may include a chart presenter configured to display one or more graphical charts representing information generated by the state determination module.
[0016] A system is also presented for presentation of a natural history and the progression pathway of a disease. In one embodiment, the system may include a data storage device configured to store one or more disease progression maps, the disease progression maps comprising one or more disease progression states. The system may also include a server. In one embodiment, the server may include a profile module configured to generate a health profile for an individual, a disease progression module configured to retrieve a disease progression map comprising one or more disease progression states from the data storage device, a state determination module configured to determine a disease progression state associated with the individual in response to the health profile, and a display module configured to display a graphical representation of the disease progression state with reference to the disease progression map.
[0017] A method is also presented for presentation of a natural history and the progression pathway of a disease. The method in the disclosed embodiments substantially includes the steps necessary to carry out the functions presented above with respect to the operation of the described apparatus and system. In one embodiment, the method includes generating a health profile for an individual, retrieving a disease progression map comprising one or more disease progression states from a data storage device, determining a disease progression state associated with the individual in response to the health profile, and displaying a graphical representation of the disease progression state with reference to the disease progression map.
[0018] The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically.
[0019] The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise.
[0020] The term “substantially” and its variations are defined as being largely but not necessarily wholly what is specified as understood by one of ordinary skill in the art, and in one non-limiting embodiment “substantially” refers to ranges within 10 %, preferably within 5 %, more preferably within 1 %, and most preferably within 0 . 5 % of what is specified.
[0021] The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes” or “contains” one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed.
[0022] Other features and associated advantages will become apparent with reference to the following detailed description of specific embodiments in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.
[0024] FIG. 1 is a schematic block diagram illustrating one embodiment of a system for presenting a natural history and progression pathway of a disease;
[0025] FIG. 2 is a schematic block diagram illustrating one embodiment of a database system for storing data used in presenting a natural history and progression pathway of a disease;
[0026] FIG. 3 is a schematic block diagram illustrating one embodiment of a computer system that may be used in accordance with certain embodiments of the system for presenting a natural history and progression pathway of a disease;
[0027] FIG. 4 is a schematic logical diagram illustrating the various layers of operation in a system for presenting a natural history and progression pathway of a disease;
[0028] FIG. 5 is a schematic block diagram illustrating another embodiment of a system for presenting a natural history of a disease;
[0029] FIG. 6 is a schematic block diagram illustrating one embodiment of an apparatus for presenting a natural history and progression pathway of a disease;
[0030] FIG. 7 is a schematic block diagram illustrating a further embodiment of an apparatus for presenting a natural history and progression pathway of a disease;
[0031] FIG. 8 is a schematic flow chart diagram illustrating one embodiment of a method for presenting a natural history and progression pathway of a disease in accordance with the present invention;
[0032] FIG. 9 is a schematic flow chart diagram illustrating a further embodiment of a method for presenting a natural history and progression pathway of a disease in accordance with the present invention;
[0033] FIG. 10 is a screen-shot diagram illustrating one embodiment of a user interface display;
[0034] FIG. 11 is a screen-shot diagram illustrating another embodiment of a user interface display;
[0035] FIG. 12 is a graphical representation of a health profile associated with an individual;
[0036] FIG. 13 is a graphical representation of one embodiment of a disease progression map for presenting a natural history and progression pathway of a disease;
[0037] FIG. 14 is a screen-shot diagram illustrating one embodiment of a graphical chart for presenting information associated with the natural history and progression pathway of a disease;
[0038] FIG. 15 is a screen-shot diagram illustrating another embodiment of a graphical chart for presenting information associated with the natural history and progression pathway of a disease;
[0039] FIG. 16 is a screen-shot diagram illustrating another embodiment of a graphical chart for presenting information associated with the natural history and progression pathway of a disease; and
[0040] FIG. 17 is a graphical representation of a natural history of disease enhanced progression pathway of a disease.
DETAILED DESCRIPTION
[0041] The invention and the various features and advantageous details are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known starting materials, processing techniques, components, and equipment are omitted so as not to unnecessarily obscure the invention in detail. It should be understood, however, that the detailed description and the specific examples, while indicating embodiments of the invention, are given by way of illustration only and not by way of limitation. Various substitutions, modifications, additions, and/or rearrangements within the spirit and/or scope of the underlying inventive concept will become apparent to those skilled in the art from this disclosure.
[0042] Many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.
[0043] Modules may also be implemented in software for execution by various types of processors. An identified module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module.
[0044] Indeed, a module of executable code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices.
[0045] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
[0046] Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
[0047] FIG. 1 illustrates one embodiment of a system 100 for presenting a natural history of a disease. The system 100 may include a server 102 a data storage device 104 , a network 108 , and a user interface device 110 . In a further embodiment, the system 100 may include a storage controller 106 or storage server configured to manage data communications between the data storage device 104 and the server 102 or other components in communication with the network 108 . In an alternative embodiment, the storage controller 106 may be coupled to the network 108 . In a general embodiment, the system 100 may facilitate identification of patterns in a progression of a disease. Specifically, the system 100 may obtain user inputs, retrieve stored information related to the individual, search for and identify a physician or service provider that is a best match for the individual, identify historical “twins” or individuals with similar histories, identify cohorts, determine the individuals attitudes toward certain services or programs, determine possible answers to questions that the user may be considering, determine health trajectories or likely progressions of the individual's disease, determine life expectancy, determine cost information , and the like.
[0048] In one embodiment, the user interface device 110 is referred to broadly and is intended to encompass a suitable processor-based device such as a desktop computer, a laptop computer, a Personal Digital Assistant (PDA), a mobile communication device or organizer device having access to the network 108 . In a further embodiment, the user interface device 110 may access the Internet to access a web application or web service hosted by the server 102 and provide a user interface for enabling the service consumer (user) to enter personal information. For example, the user may enter identifying credentials or login information, disease symptoms, questions, search terms, or the like.
[0049] The network 108 may facilitate communications of data between the server 102 and the user interface device 110 . The network 108 may include any type of communications network including, but not limited to a direct PC to PC connection, a local area network (LAN), a wide area network (WAN), a modem to modem connection, the Internet, a combination of the above, or any other communications network now known or later developed within the networking arts which permits two or more computers to communicate, one with another.
[0050] In one embodiment, the server 102 is configured to generate a health profile for an individual, retrieve a disease progression map comprising one or more disease progression states from a data storage device, determine a disease progression state associated with the individual in response to the health profile, and display a graphical representation of the disease progression state with reference to the disease progression map. Additionally, the server may access data stored in the data storage device 104 via a Storage Area Network (SAN) connection, a LAN, a data bus, or the like.
[0051] The data storage device 104 may include a hard disk, including hard disks arranged in an Redundant Array of Independent Disks (RAID) array, a tape storage drive comprising a plurality of magnetic tape data storage devices, an optical storage device, or the like. In one embodiment, the data storage device 104 may store health related data, such as insurance claims data, consumer data, or the like. The data may be arranged in a database and accessible through Structured Query Language (SQL) queries, or other data base query languages or operations.
[0052] FIG. 2 illustrates one embodiment of a data management system 200 configured to store and manage data for generating a natural history of a disease. In one embodiment, the system 200 may include a server 102 . The server 102 may be coupled to a data-bus 202 . In one embodiment, the system 200 may also include a first data storage device 204 , a second data storage device 206 and/or a third data storage device 208 . In further embodiments, the system 200 may include additional data storage devices (not shown). In such an embodiment, each data storage device 204 - 208 may host a separate database of customer information. The customer information in each database may be keyed to a common field or identifier, such as an individual's name, social security number, customer number, or the like. Alternatively, the storage devices 204 - 208 may be arranged in a RAID configuration for storing redundant copies of the database or databases.
[0053] In one embodiment, the server 102 may submit a query to each of the data storage devices 204 - 206 to collect a consolidated set of data elements associated with an individual or group of individuals. The server 102 may store the consolidated data set in a consolidated data storage device 210 . In such an embodiment, the server 102 may refer back to the consolidated data storage device 210 to obtain a set of data elements associated with a specified individual. Alternatively, the server 102 may query each of the data storage devices 204 - 208 independently or in a distributed query to obtain the set of data elements associated with a specified individual. In another alternative embodiment, multiple databases may be stored on a single consolidated data storage device 210 .
[0054] In various embodiments, the server 102 may communicate with the data storage devices 204 - 210 over the data-bus 202 . The data-bus may comprise a SAN, a LAN, or the like. The communication infrastructure may include Ethernet, Fibre-Chanel Arbitrated Loop (FC-AL), Small Computer System Interface (SCSI), and/or other similar data communication schemes associated with data communication. For example, there server 102 may communicate indirectly with the data storage devices 204 - 210 ; the server first communicating with a storage server or storage controller 106 .
[0055] In one example of the system 200 , the first data storage device 204 may store data associated with insurance claims made by one or more individuals. The insurance claims data may include data associated with medical services, procedures, and prescriptions utilized by the individual. In one particular embodiment, the first data storage device 202 included insurance claims data for over 56 million customers of a health insurance company. The database included claims data spanning over 14 years. Of those 56 million members, 26 million had a five year history or more. In one embodiment, individuals suffering from a common illness may be aggregated to identify many, if not all, of the possible decisions points and their resulting outcomes related to the progression of the disease.
[0056] In one embodiment, the second data storage device 206 may store summary data associated with the individual. The summary data may include one or more diagnoses of conditions from which the individual suffers and/or actuarial data associated with an estimated cost in medical services that the individual is likely to incur. The third data storage device 208 may store customer service and program service usage data associated with the individual. For example, the third data storage device 208 may include data associated with the individual's interaction or transactions on a website, calls to a customer service line, or utilization of a preventative medicine health program. A fourth data storage device (not shown) may store marketing data. For example, the marketing data may include information relating to the individual's income, race or ethnicity, credit ratings, etc. In one embodiment, the marketing database may include marketing information available from a commercial direct marketing data provider.
[0057] The server 102 may host a software application configured for generating a natural history of a disease. The software application may further include modules or functions for interfacing with the data storage devices 204 - 210 , interfacing a network 108 , interfacing with a user, and the like. In a further embodiment, the server 102 may host an engine, application plug-in, or application programming interface (API). In another embodiment, the server 102 may host a web service or web accessible software application.
[0058] FIG. 3 illustrates a computer system 300 adapted according to certain embodiments of the server 102 and user interface device 110 . The central processing unit (CPU) 302 is coupled to the system bus 304 . The CPU 302 may be a general purpose CPU or microprocessor. The present embodiments are not restricted by the architecture of the CPU 302 as long as the CPU 302 supports the modules and operations as described herein. The CPU 302 may execute the various logical instructions according to the present embodiments. For example, the CPU 302 may execute machine-level instructions according to the exemplary operations described below with reference to FIG. 8 .
[0059] The computer system 300 also may include Random Access Memory (RAM) 308 , which may be SRAM, DRAM, SDRAM, or the like. The computer system 300 may utilize RAM 308 to store the various data structures used by a software application configured to present a natural history of a disease. The computer system 300 may also include Read Only Memory (ROM) 306 which may be PROM, EPROM, EEPROM, or the like. The ROM may store configuration information for booting the computer system 300 . The RAM 308 and the ROM 306 hold user and system 100 data.
[0060] The computer system 300 may also include an input/output (I/O) adapter 310 , a communications adapter 314 , a user interface adapter 316 , and a display adapter 322 . The I/O adapter 310 and/or user the interface adapter 316 may, in certain embodiments, enable a user to interact with the computer system 300 in order to input information for authenticating a user, identifying an individual, or receiving health profile information. In a further embodiment, the display adapter 322 may display a graphical user interface associated with a software or web-based application for presenting a natural history of a disease.
[0061] The I/O adapter 310 may connect to one or more storage devices 312 , such as one or more of a hard drive, a Compact Disk (CD) drive, a floppy disk drive, a tape drive, to the computer system 300 . The communications adapter 314 may be adapted to couple the computer system 300 to the network 106 , which may be one or more of a LAN and/or WAN, and/or the Internet. The user interface adapter 316 couples user input devices, such as a keyboard 320 and a pointing device 318 , to the computer system 300 . The display adapter 322 may be driven by the CPU 302 to control the display on the display device 324 .
[0062] The present embodiments are not limited to the architecture of system 300 . Rather the computer system 300 is provided as an example of one type of computing device that may be adapted to perform the functions of server 102 and user interface device 110 . For example, any suitable processor-based device may be utilized including without limitation, including personal data assistants (PDAs), computer game consoles, and multi-processor servers. Moreover, the present embodiments may be implemented on application specific integrated circuits (ASIC) or very large scale integrated (VLSI) circuits. In fact, persons of ordinary skill in the art may utilize any number of suitable structures capable of executing logical operations according to the described embodiments.
[0063] FIG. 4 illustrates one embodiment of a network-based system 400 for presenting a natural history or progression of a disease. In one embodiment, the network-based system 400 includes a server 102 . Additionally, the network-based system 400 may include a user interface device 110 . In still a further embodiment, the network-based system 400 may include one or more network-based client applications 402 configured to be operated over a network 108 including an intranet, the Internet, or the like. In still another embodiment, the network-based system 400 may include one or more data storage devices 104 .
[0064] The network-based system 400 may include components or devices configured to operate in various network layers. For example, the server 102 may include modules configured to work within an application layer 404 , a presentation layer 406 , a data access layer 408 and a metadata layer 410 . In a further embodiment, the server 102 may access one or more data sets 422 - 422 that comprises a data layer or data tier 412 . For example, a first data set 422 , a second data set 420 and a third data set 422 may comprise data tier 412 that is stored on one or more data storage devices 204208 .
[0065] One or more web applications 412 may operate in the application layer 404 . For example, a user may interact with the web application 412 though one or more I/O interfaces 318 , 320 configured to interface with the web application 412 through an I/O adapter 310 that operates on the application layer. In one particular embodiment, a web application 412 may be provided for presenting a natural progression of a disease that includes software modules configured to perform the steps of generate a health profile for an individual, retrieve a disease progression map comprising one or more disease progression states from a data storage device, determine a disease progression state associated with the individual in response to the health profile, and display a graphical representation of the disease progression state with reference to the disease progression map.
[0066] In a further embodiment, the server 102 may include components, devices, hardware modules, or software modules configured to operate in the presentation layer 406 to support one or more web services 414 . For example, a web application 412 may access a web service 414 to perform one or more web-based functions for the web application 412 . In one embodiment, a web application 412 may operate on a first server 102 and access one or more web services 414 hosted on a second server (not shown) during operation.
[0067] For example, a web application 412 for presenting charts, graphs, treatment plans, or other information may access a first web service 414 for locating a twin associated with an individual and a second web service 414 for locating a cohort associated with the individual. The web services 414 may receive an identifier associated with the individual as an input and return an identifier associated with the twin or the cohort as an output. Alternatively, the web service 414 may return data associated with the twin or cohort for analysis. One of ordinary skill in the art will recognize various web-based architectures employing web services 414 for modular operation of a web application 412 .
[0068] In one embodiment, a web application 412 or a web service 414 may access one or more of the data sets 418 - 422 through the data access layer 408 . In certain embodiments, the data access layer 408 may be divided into one or more independent data access layers 416 for accessing individual data sets 418 - 422 in the data tier 412 . These individual data access layers 416 may be referred to as data sockets or adapters. The data access layers 416 may utilize metadata from the metadata layer 410 to provide the web application 412 or the web service 414 with specific access to the data set 412 .
[0069] For example, the data access layer 416 may include operations for performing a query of the data sets 418 - 422 to retrieve specific information for the web application 412 or the web service 414 . In a more specific example, the data access layer 416 may include a query for identifying claim information associated with an individual, a twin associated with the individual, or a cohort associated with the individual.
[0070] FIG. 5 illustrates a further embodiment of a system 500 for presenting a natural history of a disease. In one embodiment, the system 500 may include a service provider site 502 and a client site 504 . The service provider site 502 and the client site 504 may be separated by a geographic separation 506 .
[0071] In one embodiment, the system 500 may include one or more servers 102 configured to host a software application 412 for presenting a natural history of a disease, or one or more web services 414 for performing certain functions associated with presenting a natural history of a disease. The system may further comprise a user interface server 508 configured to host an application or web page configured to allow a user to interact with the web application 412 or web services 414 for presenting a natural history of disease. In such an embodiment, a service provider may provide hardware 102 and services 414 or applications 412 for use by a client without directly interacting with the client's customers.
[0072] FIG. 6 illustrates one embodiment of an apparatus 600 for presenting a natural history of a disease. In one embodiment, the apparatus 600 is a server 102 configured to load and operate software modules 602 - 608 configured for presenting a natural history of a disease. Alternatively, the apparatus 600 may include hardware modules 602 - 608 configured with analogue or digital logic, firmware executing FPGAs, or the like configured to generate a health profile for an individual, retrieve a disease progression map comprising one or more disease progression states from a data storage device, determine a disease progression state associated with the individual in response to the health profile, and display a graphical representation of the disease progression state with reference to the disease progression map. In such embodiments, the apparatus 600 may include a profile module 602 , a disease progression module 604 a state determination module 606 , and a display module 608 .
[0073] In one embodiment, the profile module 602 is configured to generate a health profile for an individual. In a further embodiment, an input/output adapter 310 may receive information to generate a health profile for an individual. In a further embodiment, the input output adapter 310 may include a communications adapter 314 configured to receive input from a network 108 . For example, the profile module 602 may generate the health profile based on insurance claims data, previously stored profile data, socioeconomic data, or the like. Alternatively, the profile module 602 may collect the health profile information from the user through an interactive display. The information used to generate the profile may include history of enrollment in a healthcare plan, demographic data, insurance claims data, lab data, pharmacy data including compliance level, race/ethnicity data, psychographic data, disability, absenteeism, workers compensation data, health risk assessment data, genetic tags, and the like. Further embodiments of the profile module 602 are described below with relation to FIG. 7 .
[0074] In a certain embodiment, the server 102 may include a CPU 302 configured to retrieve a disease progression map comprising one or more disease progression states from a data storage device, and to determine a disease progression state associated with the individual in response to the health profile. In a particular embodiment, the CPU 302 may be configured to execute computer executable instructions configured in software modules. The software modules may be configured to cause the CPU 302 to retrieve a disease progression map comprising one or more disease progression states from a data storage device, and to determine a disease progression state associated with the individual in response to the health profile. For example, these software modules may include a disease progression module 604 and a state determination module 606 .
[0075] In one embodiment, the disease progression module 604 is configured to retrieve a disease progression map comprising one or more disease progression states from a data storage device. For example, the user profile module 602 may receive some indication or identification of a disease with which the individual has been diagnosed. The disease progression module 604 may then retrieve disease progression data from a data storage device 104 . In one embodiment, the disease progression data may include a disease progression map or graph. Alternatively, the disease progression module 604 may generate the disease progression map in response to the disease progression data retrieved from the data storage device 104 . The disease progression data may include a chart, a table, a data listing, a database report, a graph, a timeline, or the like. In one particular embodiment, the disease progression map may include a decision or event tree style graph. The disease progression map is described in greater detail below with reference to FIG. 13 .
[0076] In one embodiment, the state determination module 606 is configured to determine a disease progression state associated with the individual in response to the health profile. For example, as described in FIG. 13 , a disease progression map may include one or more disease progression states. The state determination module 606 may then use the health profile information to determine a disease progression state within the disease progression map that most closely matches the individuals current health status. For example, the state determination module 606 may match certain diagnosis codes, medication prescriptions, symptoms, or the like to identify a predetermined disease progression state that is approximately a match for the individual's current state.
[0077] In one embodiment, the display module 608 is configured to display a graphical representation of the disease progression state with reference to the disease progression map. For example, the display module 608 may present a flag or indicator on the disease progression state that approximately matches the current status of the individual. In a particular embodiment, a display adapter 322 may be configured to receive information from the display module 608 and display a graphical representation of the disease progression state with reference to the disease progression map. In particular, the display adapter 322 may display the graphical representation on a computer monitor 324 .
[0078] FIG. 7 illustrates a further embodiment of an apparatus 600 for presenting a natural history of a disease. The apparatus 600 may include a server 102 as described in FIG. 6 .
[0079] In a further embodiment, the profile module 602 may include an automatic profile generator 702 and/or an interactive profile generator 704 . In one embodiment, the profile module 602 may request a user identification credential, such as a login name and password. If the individual can be authenticated a secure connection may be established. The automatic profile generator 702 may then automatically generate the health profile for the individual from data previously stored in association with the individual. For example, the automatic profile generator 702 may query datasets 418 - 422 stored on various data storage devices 204 - 210 to collect user profile information including health insurance claims data, socio-economic data, gender/race data, health insurance plan enrollment histories, and the like.
[0080] Alternatively, if the user does not provide a valid credential, or there is no information stored in the data storage devices 204 - 210 that can be associated with the individual, then the interactive profile generator 704 may generate the health profile in response to data entered by a user regarding the individual through an interactive display. For example, the interactive profile generator 704 may generate a user-interactive web page, form, field, or set of questions used to elicit information required to build the health profile for the individual. For example, an interactive form may include questions regarding symptoms, diagnoses, medications, age, gender, race/ethnicity, and the like.
[0081] In a further embodiment, the disease progression module 604 may include a disease progression map builder 716 . The disease progression map builder 716 may be configured to generate the predetermined disease progression maps. In one embodiment, the disease progression data and/or disease progression map may be generated through a data-mining process. For example, a database comprising insurance claim information history of enrollment in a healthcare plan, demographic data, insurance claims data, lab data, pharmacy data, race/ethnicity data, psychographic data, disability, absenteeism, workers compensation data, and the like may be stored for a large number of customers of a health insurance company or the like. In a particular embodiment, such a database may include historical data spanning ten or more years for several million customers. In such an embodiment, the breadth and depth of the database may provide detailed information regarding a large number of diseases and their associated stages, treatments, and outcomes.
[0082] For example, a disease progression map may be generated for adult-onset, type II diabetes. In such an embodiment, disease progression map builder 716 or a separate device or process may query one or more datasets 418 - 422 containing insurance claims data, lab data, pharmacy data, and other data associated with up to several million individuals. The query may include terms for identifying individuals who have a health administration code (e.g., an ICD9™ code) associated with a diagnosis for diabetes. The disease progression map builder 716 may then search for information in the other data sets 418 - 422 to identify additional information for the individuals who have been diagnosed with diabetes.
[0083] In such an embodiment, the disease progression map builder 716 establishes a scaling parameter for the disease progression map. For example, the scaling parameter may be time increments, disease progression stages, disease progression states, or the like. In this example, the scaling parameter may be time. In such an embodiment, the disease progression map builder 716 may then align the disease progression information according to a date of diagnosis, and normalizing the data so that the various disease progression states may be aligned or analyzed in according to a normalized time frame.
[0084] For example, a first individual may have been diagnosed with diabetes in February, 2005 and a second individual may have been diagnosed with diabetes in November, 2005 . In such an embodiment, the date of diagnosis for both the first individual and the second individual may be aligned and normalized (e.g., to 2005 ) so that the dates of various subsequent codes or disease progression states match, or are aligned to a normalized time frame. In such an embodiment, the various decisions, lab tests, treatments, procedures, prescriptions, and the like may be positioned on a single map to show the various states and resulting
[0085] The disease progression map builder 716 may then determine an association of the various disease progression states, and the resulting bifurcations and end results of various decisions made at the various disease progression states may then be determined. This information may be compiled and aggregated for the identified individuals, and a consolidated disease progression map or presentation of the natural history of the disease may be established from or before the time of diagnosis up through various times of cures or death. In a further embodiment, pre-disease information may be analyzed to determine certain precursors or events that may have lead to the disease. Such an embodiment, may allow a health care professional to determine how he/she may have intervened to prevent the disease. A further embodiment of a disease progression map is described below with reference to FIG. 13 .
[0086] Disease progression data and/or disease progression maps may be stored in the data storage device 104 . This same process may be iteratively performed for a set of diagnosis codes to generate a set of predetermined diseases progression maps. In an alternative embodiment, these various steps, or a subset of these steps, may be performed on demand, although this process may be more time consuming to an end user than generating and storing the disease progression maps in advance.
[0087] In a further embodiment, the state determination module 606 may include a question prediction module 406 configured to predict one or more questions that the individual may have regarding their health state in response to the determination of the disease progression state associated with the individual. For example, the question prediction module 706 may use information associated with the individual's disease progression state, including the various paths that may result from that disease progression state to determine likely issues, symptoms, decisions, or the like that the individual may be facing. For example, a person who has just been diagnosed with diabetes may be wondering how to find a specialist in diabetes, a person with advanced diabetes may be wondering what his/or her life expectancy may be, or the like. The question prediction module 706 may be able to artificially identify common questions based on the individual's disease progression state, and then present helpful information that may resolve such questions.
[0088] In one embodiment, the state determination module 606 may also include a cost analysis module 708 configured to analyze costs associated with one or more disease progression scenarios based on the disease progression state associated with the individual. For example, the cost analysis module 708 may determine one or more disease progression paths that may result from the disease progression state at which the individual is positioned. The cost analysis module 708 may then retrieve cost information from historical insurance claim data, price lists, or other sources to determine the cost associated with each of the disease progression paths. In one embodiment, the cost analysis module 708 may compare costs of two separate disease progression paths, or two options at a disease progression state.
[0089] In one embodiment, the state determination module 606 may also include a treatment protocol generator 710 configured to determine an optimized treatment protocol for the individual in response to the disease progression state associated with the individual. For example, the treatment protocol generator 710 may compare one or more actions or treatment decisions and move through several possible disease progression paths to determine which path or decision yields an optimum result. In this example, the treatment protocol generator may move through the disease progression states as though the disease progression map were a decision tree optimization graph. The treatment protocol generator 710 may evaluate each path to an end result at each disease progression state until the optimum result is obtained. In such an example, the optimum result may include a total cure of the disease. Alternatively, the optimum result may include a most cost efficient management of a disease, or the like.
[0090] In one embodiment, the state determination module 606 may also include a co-morbidity analyzer 712 configured to identify a potential co-morbidity with an increased probability of presentation as a result of the disease progression state associated with the individual. For example, the co-morbidity analyzer 712 may identify a cause of death from insurance claim data, government records, or the like associated with the individuals identified in the disease progression data. Alternatively, the co-morbid conditions may be identified in advance and stored with the disease progression data. In such an embodiment, the co-morbidity analyzer 712 may generate a list of co-morbid conditions that one suffering from a specified disease may encounter. For example, the co-morbidity analyzer 712 may determine that individuals suffering from diabetes may also have an increased likelihood of suffering from kidney failure.
[0091] In a further embodiment, the display module 608 may include a chart presenter 714 configured to display one or more graphical charts representing information generated by the state determination module. For example, the chart presenter may retrieve disease progression data from the data storage device 104 including life expectancy data, cost data, or the like and generate graphs for displaying the disease progression data to a user. Alternatively, the chart generator 714 may receive data from the question prediction module 706 , the cost analysis module 708 , the treatment protocol generator 710 , or the co-morbidity analyzer 712 and generate the graphs based on that data. The graphs may be generated according to one or more predetermined graph templates or formats.
[0092] The schematic flow chart diagrams that follow are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.
[0093] FIG. 8 illustrates one embodiment of a method 800 for presenting a natural history of a disease. In one embodiment, the method 800 starts when the profile module 602 generates 802 a health profile for an individual. The disease progression module 604 may then retrieve 804 a disease progression map comprising one or more disease progression states from a data storage device 104 . In a further embodiment, the state determination module 606 may determine 806 a disease progression state associated with the individual in response to the health profile generated 802 by the profile module 602 . The method 800 may end when the display module 608 displays 808 a graphical representation of the disease progression state with reference to the disease progression map.
[0094] FIG. 9 illustrates a further embodiment of a method 900 for presenting a natural history of a disease. In one embodiment, the method 900 starts when the profile module 602 presents 902 a user interface page. The profile module 602 may then determine 904 whether the individual is an authorized member of the service or of a health care plan. If the user is an authorized member, then the automatic profile generator 702 may automatically generate 906 a health profile from data previously stored in association with the individual (e.g., claims data, gender, age, etc.). If the user is not an authorized member, the interactive profile generator 704 may generate 908 the health profile in response to data entered by the user through an interactive display.
[0095] In a further embodiment, the disease progression module 910 may then retrieve 910 a disease progression map comprising one or more disease progression states from a data storage device 104 . The question prediction module 706 may then predict 912 one or more questions that the individual may have regarding his/her health state. In a further embodiment, the cost analysis module 708 may analyze 914 costs associated with one or more disease progression scenarios based on the disease progression state at which the individual is located. In still a further embodiment, the treatment protocol generator 710 may determine 916 an optimized treatment protocol for the individual in response to the disease progression state at which the individual is located. Finally, the co-morbidity module 712 may identify 918 a potential co-morbidity condition that has an increased probability of presentation as a result of the disease progression state.
[0096] In one embodiment, the method 900 may end when the chart presenter 714 displays 918 a graphical chart representing information generated by the various modules 706 - 712 of the state determination module 606 .
[0097] FIGS. 10 and 11 illustrate embodiments of user interactive web pages or forms that may be generated by the profile module 602 for interacting with a user. For example, FIG. 10 illustrates one embodiment of an interactive profile collection form 1000 that may receive health profile information related to an individual. For example, the user may enter a disease, a diagnosis code, a symptom, or the like. The user may then click “it's about me” or “it's about a friend.” If the user enters “it's about me” the user may be prompted for authentication information such as a login name and password. If the user clicks “it's about a friend” or “I′m not a member” the interactive profile generator 704 may present one or more interactive forms or web pages for collecting health profile information.
[0098] FIG. 11 illustrates a display results page 1100 that may be generated by the display module 608 . In the depicted example, the results page may include a section that prompts for information or displays answers regarding questions that have been predicted by the question prediction module 706 . Additionally, the results pate 1100 may include links to graphs, links to the disease progression map, links to cost information and cost estimation tools, and physician information related to physicians that specialized in the identified disease.
[0099] FIG. 12 illustrates one embodiment of a health profile 1200 associated with an individual. The health profile 1200 may include a listing of various insurance codes and other information that is arranged in graphical or tabular format according to a time from diagnosis. Alternative scaling may be employed, and one of ordinary skill in the art will recognize alternative profile organization schemes.
[0100] FIG. 13 illustrates one embodiment of a presentation 1300 of a natural history of disease. In one embodiment, the presentation 1300 may include a disease progression map 1302 divided into a plurality of segments 1304 . The presentation 1300 disease progression map 1302 may include a graphical representation of the disease progression that may include one or more bifurcated decision points or events 1308 and one or more disease progression states 1306 . In a specific embodiment, the state determination module 606 may use the health profile information 1200 to determine which disease progression state 1306 the individual has reached and present a flag or indicator at that disease progression state 1306 . For example, the flag or indicator in the depicted embodiment is an arrow and text that states “you are here.”
[0101] FIGS. 14-16 illustrate various embodiments of graphs or charts that may be generated and displayed by the chart presenter 714 . For example, the chart presenter 714 may present an age of death comparison chart 1400 that illustrates the average age of date in the presence of the diagnosis and a comparison chart that illustrates an average age of death for the general population. FIG. 15 illustrates a survivability graph 1500 that illustrates a number of individuals that survive one year or two years from the date of diagnosis. FIG. 16 illustrates a demographic chart configured to illustrate demographics related to the onset of the disease, including average age of onset and percent of male/female onset.
[0102] FIG. 17 is a graphical representation of a natural history of disease enhanced progression pathway 1700 of a disease. In one embodiment, a typical progression pathway of a disease includes certain pre-onset conditions 1702 , onset 1704 of the disease, and one or more outcomes 1706 . However, as described in FIG. 17 , the typical progression pathway of a disease may be enhanced or modified in response to the natural history of disease system 100 , apparatus 600 , and methods 800 , 900 of the present embodiments.
[0103] For example, the present embodiments may analyze the various pre-onset 1702 conditions, such as obesity, insomnia, abnormal glucose tolerance, and the like which make up the individuals health profile. The server 102 may then retrieve 804 a disease progression map comprising one or more disease progression states 1306 from a data storage device 104 . The server 102 may then determine a disease progression state 1306 associated with the individual. Then, the server 102 may generate a lifestyle health management plan and present options for avoiding onset 1704 of the disease at the NHD-enhanced decision point 1708 . If, at the NHD-enhanced decision point 1708 , the individual chooses to implement the suggested lifestyle health management plan, an alternative outcome 1710 may result.
[0104] All of the methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the apparatus 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 methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. In addition, modifications may be made to the disclosed apparatus and components may be eliminated or substituted for the components described herein where 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. | A relationship management device and method providing a user interface containing treatment protocol for an individual comprising: (a) a user interface electrically connected with a data storage device; (b) a server electrically connected with the user interface and the data storage device; and (c) a treatment processor electrically connected with the server, wherein the treatment processor is configured to generate an optimized treatment protocol for the individual. | 6 |
This application is a continuation of application Ser. No. 08/306,539, filed Sep. 15, 1994, now U.S. Pat. No. 5,656,732, which was a continuation of Ser. No. 08/120,311, filed Sep. 13, 1993, now abandoned, which was a continuation of Ser. No. 07/447,810, filed Dec. 8, 1989, now abandoned, which was:
a continuation-in-part of Ser. No. 07/348,784, filed May 8, 1989, now abandoned, which was a continuation-in-part of Ser. No. 07/293,906, filed Jan. 5, 1989, now U.S. Pat. No. 5,219,725, which was a continuation-in-part of Ser. No. 07/279,989, filed Dec. 5, 1988, now abandoned; and
a continuation-in-part of Ser. No. 07/446,008, filed Dec. 5, 1989, now U.S. Pat. No. 5,117,014.
BACKGROUND OF THE INVENTION
This invention relates to purification of polypeptides from feline T-cell lymphotropic lentivirus (FIV).
FIV is a retrovirus originally isolated from cats which exhibit an AIDS-like syndrome. Pederson et al., 235 Science 790, 1987. The virus belongs to the same group as the human immunodeficiency virus (HIV), the causative agent of human AIDS. Pederson et al., describe detection of antibody to FIV by an immunofluorescent assay, and by Western blots, using virus purified by centrifugation on sucrose gradients in Tris base, pH 7.4, containing 0.1M NaCl and 1 mM EDTA. A few protein bands were detected and, although antigenic comparison was not made, the positions of these bands were tentatively said to correspond to the major core protein, p24 the gag precursor protein, p55, and the endonuclease protein, p32, of HIV.
Pederson et al., U.S. Patent Application Filed Aug. 26, 1987 entitled “Feline T-Lymphotropic Lentivirus” (which is not admitted to be prior art to the present application) describes the results presented by Pederson et al., supra, and states that Western blotting of FIV infected cell lysates yielded major protein bands at approximately 22-26 kD, usually about 24 kD; 50-60 kD, usually about 55 kD; and 28-36 kD, usually about 32 kD.
SUMMARY OF THE INVENTION
In a first aspect, the invention features a purified polypeptide having an epitope of an antigenic polypeptide of FIV. The polypeptide may be glycosylated or unglycosylated. By antigenic polypeptide is meant a polypeptide which is able to raise (with the aid of an adjuvant if necessary) an antibody response in cats. The polypeptide may be a polypeptide fragment of at least 5 amino acids, or a polypeptide naturally occurring in FIV particles. The fragment may be obtained from a naturally-occurring polypeptide, for example, by enzymatic digestion of a naturally occurring polypeptide, or may be produced by isolation or synthesis of a gene encoding a desired polypeptide and expression of that polypeptide within a desired expression system, for example, a bacterial, yeast, or mammalian expression system.
By epitope is meant a single antigenic site of an antigenic polypeptide. Such an epitope is recognized specifically by a monoclonal antibody to an antigenic polypeptide of FIV.
By purified is meant that the polypeptide is separated from other cell components with which it naturally occurs, for example, FIV polypeptides. Preferably, the polypeptide is sufficiently pure to permit its use to prepare a monoclonal antibody to the polypeptide, and even more preferably, pure enough to allow the amino acid sequence of the polypeptide to be determined by standard procedure. Generally, the purified polypeptide is biologically active in that it is suitable for preparation of a monoclonal antibody, or is suitable for detection of naturally-occurring antibodies within the serum of a cat.
In preferred embodiments, the purified polypeptide has at least 75% amino acid homology to a polypeptide fragment of at least 20 amino acids obtained from an FIV gag or env polypeptide, most preferably the purified polypeptide includes an amino acid sequence having at least 75% homology to a whole of a gag or env polypeptide, even more preferably, the purified polypeptide is an entire gag or env amino acid sequence. Examples of gag and env polypeptides include p10, p15, p26, gp40, gp100, and gp130.
In a second aspect, the invention features a method for detecting an antibody to FIV within a sample, including the steps of providing a purified polypeptide as described above, and contacting that polypeptide under conditions suitable to allow an antibody/polypeptide complex to form between antibodies within the sample and the purified polypeptide, and detecting the formation of such complexes. The presence of antibody/polypeptide complexes is indicative of antibody to FIV present within the sample.
In a third aspect, the invention features a purified nucleic acid including a 50 nucleotide sequence having at least 90% homology with a 50 nucleotide sequence naturally occurring in an FIV particle. By purified is meant that the nucleic acid is substantially separated away from all of the components with which it naturally occurs, e.g., polypeptides and other nucleic acids. Preferably, the nucleic acid is completely separated from such components, and is a pure solution of nucleic acid, or is held within a cell in which it does not naturally occur, e.g, a bacterial cell, another viral particle or a non-feline eucaryotic cell. By 90% homology is meant that the nucleotide sequence is identical at at least 45 of the 50 nucleotides.
In preferred embodiments, the nucleic acid encodes a polypeptide including an epitope of an antigenic polypeptide of FIV, e.g., an epitope of a gag or env polypeptide of FIV. Most preferably the nucleic acid is carried in an expression vector and can be expressed in a bacterial, fungal or other eucaryotic cell, e.g., a mammalian cell.
In a related aspect the invention features purified polypeptide including ten or more contiguous amino acids taken from the sequence (using standard letters to represent amino acids) V-Q-S-R-G-S-G-P-V-C-F-N-C-K-K-P-G-H-L-A-R-Q-S-H or P-I-Q-T-V-N-G-V-P-Q-Y-V-A-L-D-P-K-M-V-S or S-V-Q-S-R-G-Q-G-P-V-A-F-N.
Applicants have provided polypeptides suitable for specific detection of FIV antibodies and thus have allowed accurate detection of infection with FIV. Applicants have also provided polypeptides useful for production of vaccines to prevent disease caused by FIV in cats.
Other features and advantages of the invention will be apparent from the following description of the preferred embodiment thereof, and from the claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The drawings will first briefly be described.
Drawings
FIG. 1 is a photograph of the major viral associated proteins of FIV identified by polyacrylamide gel electrophoresis (PAGE) and stained with Commassie Blue R250 (lane A); molecular weight standards are shown in lane B;
FIG. 2 is a photograph of a Western immunoblot analysis of antibodies to FIV found in serum from cats identified as positive by an ELISA assay for FIV antibodies;
FIG. 3 is a graphical representation of elution of FIV polypeptides during HPLC purification;
FIG. 4 is a photograph of an SDS-polyacrylamide gel after electrophoresis and staining with silver, showing purity of various FIV polypeptides; and
Antigenic FIV Polypeptides
FIV polypeptide antigens useful in this invention are generally described above. Polypeptides useful in this invention may be purified from virus isolated as described below and fragments of the purified polypeptides isolated by enzymatic treatment or other standard procedures. Further, the polypeptides may be synthesized by standard in vitro expression systems in which DNA encoding for the FIV polypeptide is cloned and expressed in a bacterial, yeast, or mammalian cell expression system. Such DNA may be isolated and expressed as described below. The polypeptides may also be synthesized by standard chemical methods, for example, the polypeptide segments of various FIV polypeptides given below can be synthesized. In the following example FIV polypeptides were obtained directly from FIV-infected cells and took the form of polypeptides naturally occurring in an FIV virus particle. This example is not limiting to the present invention, and those skilled in the art will recognize the many alternative methods for obtaining polypeptides of this invention. The polypeptides are referred to according to molecular weight, thus a polypeptide of 30 kD is termed p30, and a glycoprotein of this weight is termed gp30.
Master seed virus producing cultures were obtained in the form of a continuous feline cell line infected with FIV isolate #2427 (CRFK-FIV or Petaluma strain) from Dr. Neils Pederson (University of California, Davis, Calif.). The parent cell line is Crandell feline kidney cell persistently infected with FIV. The cell line was deposited with the American Type Culture Collection on Jul. 13, 1988 and assigned the number CRL9761. Applicants and their assignees acknowledge their responsibility to replace this culture should it die before the end of the term of a patent issued hereon, 5 years after the last request for a culture, or 30 years, whichever is the longer, and its responsibility to notify the depository of the issuance of such a patent, at which time the deposit will be made irrevocably available to the public. Until that time the deposit will be made available to the Commissioner of Patents under the terms of 37 C.F.R. §1-14 and 35 U.S.C. §112.
Other virus cultures can be obtained as described by both Pederson et al. references, supra, or by Harbour et al., 122 The Veterinary Record 84, 1988. Seed stocks of virus producing cell cultures were obtained by freeze-downs of FIV-infected master seed cell cultures following at least 19 post infection passages in culture. Additional seed stocks of virus producing cultures were obtained by either infection of the continuous feline cell culture with FIV master seed virus or by single cell microwell cloning of high level FIV producers from the original FIV infected master seed cell culture. For propogation, master seed virus infected feline cell cultures were inoculated into tissue cell culture flasks. Following growth to a confluent monolayer of cells, tissue culture fluid was harvested at intervals of 2-5 days.
Working seed virus was produced by propogation by the master seed cell line permanently infected with FIV. An inoculum was added to tissue culture flasks, in Dulbecco's Modified Eagles medium containing 2 mM L-glutamine and 4.5 g per liter/glucose (DME) containing 100 units per ml. penicillin and streptomycin and 2 mM glutamine. An inoculum was added to tissue culture flasks, incubated, and the spent tissue culture fluid harvested when the cells were grown to confluence. The cells were released from the culture vessel with trypsin/EDTA and diluted between 1:5 and 1:25 (typically 1:8) in medium. Typically the flasks were incubated at 36°-38° C. for a maximum of 7 days (between 3 and 7 days) before fluid and cell harvest. The harvested fluid, including cell material, was centrifuged in a high speed centrifuge (Sorval RC-5B or Beckman J2-21) leading to separation of supernatant and cell pellet material. The cell pellet was discarded, and the supernatant culture fluid used to prepare working virus. The clarified supernatant was made 0.5 M in NaCl and 4%-10% (usually 7%) in polyethylene glycol (PEG 8000, Sigma). Following overnight incubation at 2° C.-7° C., virus was pelleted (at 13,000×g for 30 min.) and resuspended in buffer (10 mM Tris, pH 7.6 300 mM NaCl, 1 mM EDTA, at 2° C.-7° C.). After overnight incubation the virus was centrifuged at 13,000×g for 15 min., the pellet discarded and the supernatant centrifuged on a 50%/80% discontinuous glycerol step gradient in 10 mM Tris 300 mM NaCl, 1 mM EDTA at pH 7.6. Centrifugation was at 100,000×g for 3 hrs. at 4° C. and the FIV viral band at the 50%-80% interface collected. The band was suspended in 10 mM Tris, 0.3 M NaCl and 1 mM EDTA and diluted 1:3 in the buffer and repelleted at 100,000×g for 1 hr. The resulting pellet was purified virus and was resuspended in the above buffer and stored at −70° C. The resulting virus was substantially free from FIV host cell proteins and was composed of at least 5% p26 (the major nucleocapsid protein, as measured by densitometric scans of Commassie Blue 250 stained SDS/PAGE as total protein).
Such purified virus may be obtained by other techniques, however, applicants have found that high molecular weight contaminants present in virus preparations may be eliminated by use of the high salt (i.e., greater than physiological range salt concentration) used in the gradient centrifugation procedure.
Referring to FIG. 1, polypeptides associated with purified FIV were analyzed by SDS/PAGE and compared with polypeptides isolated in an identical manner from the spent culture medium of uninfected cells. Analysis of the Commassie Blue stained gels revealed three major polypeptides with molecular weights of about 10, 15, and 26 kD, named p10, p15 and p26, respectively.
When an ELISA test was performed using disrupted FIV to identify cats possessing polyclonal antibody to FIV polypeptides, and Western blot analysis then performed on feline sera determined to be positive by ELISA, each of the cats had antibodies which reacted with one or more polypeptides of molecular weight p10, 15, 26, 40 and 65 kD under the conditions used.
Referring to FIG. 2, a standard Western immuno blot was performed as described by Towbin et al., 76 Proc. Natl. Acad. Sci USA 4350, 1979. Briefly, FIV was disrupted with SDS and proteins transferred to a sheet of nitrocellulose. The nitrocellulose sheet was blocked with 30% calf serum, 1% bovine serum albumin (BSA), and 0.05% Tween 20 in Dulbecco's phosphate buffer saline. The sheets were cut into 0.5 cm strips and incubated with a 1:100 dilution of serum sample in blocking buffer for 2 hrs. for 20-22° C. Strips were repeatedly washed with washing buffer (0.05% Tween 20 in Dulbecco's phosphate buffer saline) and then incubated with a second antibody (specific for feline heavy and light chain Ig) horseradish peroxidase conjugate (obtained from Kirkguard and Perry Laboratories Inc. Gaithersburg, Md.). After 1 hr. incubation, the strips were repeatedly washed with washing buffer and incubated with the precipitating substrate 4-chloronaphthol for 10 min. The strips were partially dried and the results interpreted immediately. The serum in each of the lanes A-G was obtained from various cats infected with FIV. Predominant cross-reactivity is detected with p26 and p15 and to a lesser extent with p10. Other proteins of 32, 40, 47 and 65 kD molecular weight are also detected.
Certain viral polypeptides, such as the gag (e.g., p26) antigenic polypeptides, are abundant in purified viral preparations, others such as the viral envelope polypeptides (e.g., gp130) tend to be lost during viral purification, and electrotransfer less efficiently for Western blot analysis than the gag antigens. Therefore, in order to more readily detect the viral envelope (env) and the gag precurser polypeptides, FIV cell extracts were labeled with 35 S-methionine and cysteine and examined by immunoprecipitation (RIPA). Confluent cultures of cells infected with FIV were incubated for 30 min. in methionine and cysteine-free Dulbecco's modified Eagle's medium. The cell cultures were then incubated for 4 hrs. in 8 ml of the same medium containing 100 microCuries per ml of 35 S-methionine and 35 S-cysteine (specific activity 1200 Curies per mM, New England Nuclear Corporation, Boston, Mass.). The radioactive tissue culture fluids were removed and the cells lysed with 5 ml of 10 mM sodium phosphate buffer pH 7.5 containing 100 mM NaCl, 1% Triton X 100, 0.5% sodium deoxycholate, 0.1% SDS, 0.1 mM phenylmethylsulfonylfluoride, and 100 Kallikren inactivator units of aprotenin per ml. (Sigma Chemical Co., St. Louis, Mo.). Before use, the cell lysates were clarified by centrifugation 100,000×g for 30 min. and the pellet discarded. Aliquots of the labelled cell lysates (0.1 ml) and 5 μl of serum being tested were mixed in a microcentrifuge tube and incubated for 1 hr. at 37° C. and then overnight at 4° C. The next day, 0.2 ml of a 5% suspension of protein A Sepharose CL-4B beads (Pharmacia, Piscataway, N.J.) in 10 mM of phosphate buffer, pH 7.5 containing 100 mM NaCl, 1% Triton X-100 and 0.1% SDS was added to each tube and mixed for 30 min. at 4° C. The antibody/antigen complexes bound to the protein A Sepharose beads were collected by centrifugation (2 min. at 20,000×g) and washed 3 times in lysing buffer. The final pellet was resuspended in 25 μl SDS/PAGE loading buffer and heated and 100° C. for 3 minutes. The Sepharose beads were removed by centrifugation and the supernatant applied to a PAGE. Gels were processed for fluorography using enlightening™ (New England Nuclear Corporation, Boston, Mass.) and exposed at −70° to Kodak XR-5 film. Sera from experimentally infected cats recognize polypeptides of 15, 22, 36, 40, 47, 110 and 130 kD. Although there were some quantitative and qualititative differences all cats appear to mount a response to p22, gp40, gp47 and gp130.
In order to determine which of the polypeptides identified by RIPA-PAGE analysis were related to the major internal structural protein, p26, RIPA-PAGE analysis was carried out using monoclonal antibodies which reacted with p26 as determined by Western blotting. This monoclonal immunoprecipited proteins p47, p36, p22 and p15. High molecular weight polypeptides (130 kD) of FIV which were not detected by the p26 specific monoclonal antibody, were identified by RIPA-PAGE. A protein of molecular weight 100 kD was also detectable utilizing serum antibodies obtained from some infected cats.
In another example, antigenic glycopeptides of FIV can be obtained as follows. Actively growing CRFK FTLV infected cells were scraped from roller bottles, gently washed with phosphate-buffered saline (PBS), and pelleted. The cell pellet was gently resuspended in 10 mM sodium phosphate, pH 7.2, at a ratio of 1 ml buffer to 0.1 ml of cell pellet. This suspension was incubated on ice or refrigerated for 5-10 min., vigorously vortex mixed for 30 seconds, and four volumes of PBS with 1 mM PMSF added. The mixture was then vigorously homogenized for 90-120 seconds with a Brinkmann Homogenizer PT10/35 with a PTA 20 generator.
The resulting homogenate was clarified for 20 minutes at 5,000×g. The supernatant fraction was discarded and the cell membrane pellet resuspended in PBS+0.2% Triton X-100 at a ratio of 2.5 ml buffer to 0.1 ml original cell pellet. The mixture was then vigorously homogenized for 90-120 seconds with a Brinkmann Homogenizer PT 10/35 with a PTA 20 generator. The resulting homogenate was clarified at 100,000×g for 1 hr, the supernatant decanted off and batch bound overnight at 20-23° C. on Pharmacia Lentil Lectin Sepharose 4B at a ratio of 6 ml of resin to 5 ml of original cell pellet.
The Lentil Lectin Suspension was poured through a column, the resin collected, and washed with 15 column volumes of PBS+0.2% Triton X-100. The glycoproteins were then eluted from the resin by subjecting the resin to 5-10 column volumes of PBS+0.2% Triton X-100+200 mM methyl α-D mannopyranoside, collecting fractions of 1 column volume/tube.
The isolation of glycoproteins was verified by 9% SDS-PAGE electrophorisis, and checked using 35 S-radiolabeled cell preparations in conjunction with RIPA data.
Further purification of viral glycoprotein from host cell glycoprotein includes use of HPLC, or of a polyclonal or monoclonal antibody for affinity chromotography.
EXAMPLE 1
gag Polypeptide Purification
Isolated virus (250-500 microliters) was combined with two volumes of 6M guanidine hydrochloride, pH 3 (adjusted with 20% trifluoro acidic acid in water). The mixture was vortexed and incubated at 37° C.-40° C. in a water bath for 20-25 minutes. The incubated solution was filtered through a pre-wetted (100 microliters of 6M guanidine hydrochloride, pH 3) 0.45 micron gel aquadisk filter (No. 4184) and the filter rinsed with 100 microliters of 6M guanidine hydrochloride pH 3. The filtered sample was loaded onto an HPLC column for purification.
The HPLC system consisted of a Beckman HPLC having three 110 V pumps, a 421 controller, a 166 variable wavelength detector, a 427 integrator, a 210A injector with dynamic mixer, and a 1000 microliter sample. The column was a Waters radial compression cartridge held in an RCM-100 column holder with a modified inlet connector (Waters MicroBond-A-Pak Fenile 10 MU 8 mm×10 cm cartridge No. 85722 with a guard pak resolve CN cartridge, No. 85826). The system was set such that two levers were compressed and the pressure was in the mid-yellow zone.
Purification was by a multi-step gradient from aqueous 0.1% trifluoroacetic acid (v/v solvent A) to aceto nitrol containing 0.1% trifluoroacetic acid (v/v, solvent B).
Fractions were collected and condensed by a Savant Speed Vac to remove all solvents to a final volume ranging from 50-100 microliters. The condensed fractions where neutralized by addition of 200-300 microliters of 50 mM or 100 mM sodium phosphate buffer, pH 7.2. The buffered fraction pHs were then checked with pH paper and, if the pH was still below 6, 1N NaOH added until the pH was brought within the range of 6.5-7.5. The neutralized fractions were frozen at −20° C. until use.
Referring to FIG. 3, the printout from an HPLC column described above is shown. The flow rate was at 1 ml per minute starting with 100% of solvent A. After 15 min. the solvent was changed to contain 26% solvent B, 10 min. later to 31% solvent B, 12 min. later to 37.5% solvent B, 5 min. later to 40% solvent B, 6 min. later to 43% solvent B, 8 min. later to 45% solvent B, 15 min. later to 60% solvent, and 20 min. later to 100% solvent B. Peaks corresponding to p10, p15, and p26 are indicated in FIG. 3 . Fractions containing these peaks were collected.
Referring to FIG. 4, fractions corresponding to p10, p15 and p26 were run in an SDS-polyacrylamide gel containing 15% bis-acrylamide at 70 V. The gel was stained with silver using a Biorad Silver Staining Kit 161-0443. The isolated fractions corresponding to p15, p10, and p26 were essentially homogeneous solutions of the FIV polypeptides.
The isolated FIV polypeptides were analyzed by standard technique for their amino acid sequence, yielding the following results (? indicates uncertainty in the actual amino acid, or no knowledge at all).
p26
Number 1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20
Amino Acid P-I-Q-T-V-N-G-V-P-Q-Y-V-A-L-D-P-K-M-V-S
p10
Number 1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-
Amino Acid V-Q-S-R-G-S-G-P-V-C-F-N-C-K-K-P-G-H-L-
Number 20-21-22-23-24
Amino
Acid A-R-Q-S-H
P15
Number 0-1-2-3-4-5-6-7-8-9-10-11-12-13
Amino
Acid S-V-Q-S-R-G-Q-G-P-V-A-F-N-?
In order to determine if the purified polypeptide is useful in this invention, that is, whether the polypeptide is antigenic, any standard procedure can be used. For example an ELISA test can be performed using a polyclonal antibody from cat serum to determine whether the polypeptide is cross-reactive. Alternatively, the polypeptide can be injected with or without an adjuvant, into an animal, e.g., a mouse, to determine if it causes antibodies to be raised to it. These polypeptides are useful for production of vaccines to prevent FIV-caused disease symptoms and FIV infection in cats. These vaccines are produced by standard procedure. Preferably the gag or env polypeptides are provided in a standard inoculation medium and injected intravenously, intrarterially or otherwise into a cat at a level of 1-100 μg/kg animal at intervals of 3-4 weeks until immunity to FIV is produced.
FIV Monoclonal Antibodies
Antibodies to FIV polypeptides are useful aids for identification of a purified polypeptide (as described above), and for purifying polypeptides. They are also useful to determine the antigenicity of any polypeptide. An example of preparation of useful antibodies follows. These antibodies are monoclonal antibodies which allow specific detection and purification of either individual or a small number of FIV polypeptides.
Balb/CJ (Jackson Labs) mice were immunized with an initial injection of 50 micrograms of FIV virus (prepared as described above) per mouse mixed 1:1 with Difco Bacto adjuvant complete. After two weeks a booster injection of 100 micrograms of FIV virus was injected into each mouse intravenously without adjuvant. Three days after the booster injection a fusion was performed with mouse myeloma cell lines FO or p3X63-Ag8.653. Mid log phase myeloma lines were harvested on the day of fusion and checked for viability. The cells were spun at 300×g for 8 min., separated from the growth medium, and resuspended in serum free DME.
For fusion, an FIV-inoculated mouse was killed by cervical dislocation and the spleen aseptically removed. The spleen was washed three times in serum free DME and placed in a sterile Petri dish containing 20 mls of complete medium (DME containing 20% bovine fetal serum, 100 units per ml. of penicillin and streptomycin, and 1 mM sodium pyruvate). To release cells, the spleen was perfused with a 23 gauge needle.
Cells were placed in a 50 ml conical centrifuge tube and pelleted at 300×g for 8 min. The pellet resuspended in 5 ml of 0.17M ammonium chloride and placed on ice for 8 min. 5 ml of bovine fetal serum (20%) was added and the cells pelleted again at 300×g for 8 min. After resuspension in 10 ml DME the cells were counted and the spleen and myeloma cells mixed in a ratio of 3:1. The cell mixture was pelleted at 200×g for 10 minutes, the supernatant decanted, and the pellet allowed to stand for 5 min. Over a period of 1 min., 1 ml of 50% PEG (PEG 1500 mixed 1:1 with Hepes pH 8.1) at 37° C. was added. After 1 min. incubation at 37° C., 1 ml of DME was added over a period of another 1 min. and then a second 1 ml of serum free medium added over a period of 1 min. Finally, 10 mls of DME was added over a period of 2 min., the cells pelleted at 200×g for 8 min., and the pellet resuspended in complete medium containing 0.016 mM thymidine, 0.1 mM hypoxanthine, 0.5 micromolar aminopterin, and 10% hybridoma cloning factor (1×HAT). The cells were plated into 96-well plates.
After 3, 5 and 7 days half of the medium in the fusion plates were removed and replaced with fresh 1×HAT. After 11 days the hybridoma cell supernatant was screened by an ELISA test. In this test, 96 well plates were coated with FIV virus by standard technique. One hundred microliters of supernatant from each well was added to a corresponding well on a screening plate and incubated for 1 hr. at 20-22° C. After incubation, each well was washed three times with distilled water and 100 microliters of a horseradish peroxidide conjugate of goat anti-mouse IgG (H+L), A, M (1:1500 dilution) was added to each well and incubated for 1 hr. at 20-22° C. After three washes with distilled water, the substrate OPD/hydrogen peroxide was added and incubation continued for five to fifteen minutes. One hundred microliters of a stop solution (1 M hydrochloric acid) was then added and the absorbance at 490 nm read. Cultures which had an optical density reading greater than the control wells were removed to 2 cm 2 culture dishes, with the addition of normal mouse spleen cells in 1×HT medium. After a further three days all of the 2 cm 2 cultures were rescreened for antibody and those testing positive again were cloned by limiting dilution. The cells in each 2 cm 2 culture were counted and cell concentration adjusted to 1×10 5 cells per ml. The cells were diluted in complete medium and normal mouse spleen cells at concentrations of hybridoma cells of 5, 10 and 50 cells per ml added. The cells were plated into 96-well plates for each dilution. After 10 days the cloning plates were screened for growth. About 37% of all wells showed growth. The growth-positive wells were screened for antibody and those testing positive expanded to 2 cm 2 cultures and provided with normal mouse spleen cells. The cloning procedure was repeated 2 times until a stable antibody-producing hybridoma was obtained. At this point the cell culture was expanded from 2 to 9 to 75 to 150 cm 2 culture vessels, at which point ascite production could be commenced.
For ascites production, pristane primed IRCF1 female mice were used. 0.5 ml of pristane was injected intraperitoneally (IP) to each mouse, and the mouse allowed to rest for 10-60 days. At this time 4.5×10 6 cells were injected IP into each mouse and ascites formed in 7-14 days. Ascites fluid was harvested with a pasteur pipette through a hole in the peritoneum.
Antibodies to glycoproteins can also be isolated and detected. In particular, antibodies to two glycoproteins of molecular weight 40 kD (gp40) and 130 kD (gp130) which are detected using PAGE and RIPA respectively.
Monoclonals useful in this invention for purification and identification of specific polypeptides of FIV include those which are specific for FIV and form a sufficiently strong interaction with an FIV epitope, and an FIV antigen, to be useful in an immunoassay, for example, an ELISA, to detect an FIV antigen. In order to determine which of the above monoclonal antibodies are useful in this invention one main test was used. This entailed determination of whether the monoclonal antibody can bind FIV antigen and be detected with a conjugate of polyclonal antibody to FIV (an ELISA test, described above).
Another test is to perform a Western blot to determine whether the monoclonal antibody has good reactivity with one or more FIV antigens. Generally, those monoclonals which show poor reactivity, that is, produce faint bands on the Western blot, are not suitable in this invention. Yet another test involves radioimmunoprecipitation assay (RIPA) where FIV virus labeled with 35 S-methionine is reacted with a monoclonal antibody to form within immunoprecipitate, and the immunoprecipitate run in a SDS-PAGE and autoradiographed to detect the labelled proteins. This analysis determines which of the monoclonal antibodies is able to detect precursor FIV antigenic polypeptides and not just mature polypeptides.
Antibody Detection
The above antigenic polypeptides can be used to detect naturally occurring antibodies produced by cats. Such detection can be any standard immunoassay procedure, for example, by an ELISA test, as described above. One example of such a test follows. This example is not limiting to the present invention and those skilled in the art will recognize that any of many other standard procedures can be used.
EXAMPLE 2
Antibody assay
Materials required to perform this assay include 96 well flat bottom microtiter strips coated with a solution containing the appropriate test antigen (e.g., p26, p15, or p10). The test wells were coated with 100 μl of a solution containing 0.15 micrograms antigen in 0.25 molar sodium citrate, pH 7.5. The wells were covered with parafilm, incubated overnight at 4° C., and tapped until dry. The antigen was then overcoated by adding 200 μl 1% BSA in 0.25 molar sodium citrate, incubating at room temperature (20-25° C.) for 1 hour, and tapping the wells dry. 200 microliters of 7.5% sucrose in 0.25 molar sodium citrate was then added to each well and incubated at room temperature for 30 minutes. The resulting strips were used immediately, or dried under vacuum for 6 hours at room temperature for later use.
Assays were performed by adding 100 μl of feline serum sample (positive control, negative control, or test sera) diluted 1 to 100 in Dulbecco's PBS containing 0.1% Bovine serum albumin, 30% calf serum, and 0.05% Tween-20 (Sigma Chemical, St. Louis, Mo.) to a well, incubating at room temperature for 30 minutes, and tapping the well dry. The wells were washed immediately two times with Dulbecco's PBS containing 0.05% Tween-20, tapping the wells dry after the second wash.
100 μl of a solution containing antibodies to feline immunoglobulin was then added. These antibodies were conjugated to an indicator enzyme (e.g., alkaline phosphatase) and then dissolved in a solution of 50% fetal calf serum, 0.05% Tween-20 in 0.05M Tris-HCl, pH 7.6. The wells were incubated at room temperature for 30 minutes, tapped dry, and then washed two times with Dulbecco's PBS containing 0.05% Tween-20.
A solution containing 0.1% 3,3′,5,5′Tetramethylbenzidene in 40% Glycerol and 60% methanol was mixed with an equal volume of a solution containing 22.82 grams dibasic potassium phosphate, 19.2 grams citric acid and 1.34 milliliters 30% hydrogen peroxide solution per liter. One hundred microliters of this solution was added to each well, and then incubated at room temperature for 15 minutes. At the end of the incubation period, 100 μl of 0.25% hydrofluoric acid was added to each well. The optical density at 650 nanometer of the solution in each well was then determined with a microtiter plate reader. An immune response to p10, p15 and p26 was detectable either following experimental infection of a cat with FIV, or in feline sera possessing antibodies to FIV.
FIV Nucleic Acid
FIV nucleic acid is useful for production of large amounts of FIV polypeptides, or fragments thereof, and also for detection of homologous nucleic acid in vivo, using standard techniques. There follows an example of cloning of FIV viral DNA. The specific FIV strain chosen is not meant to be limiting in this invention and those skilled in the art will recognize that equivalent nucleic acid may be isolated by use of the cloned sequences which are provided as specific deposits, or by techniques similar to those described in this example.
A Crandal feline kidney cell line productively infected with FIV strain 2428 (Pentaluma isolate) was used as a source of unintegrated viral DNA. The unintegrated viral DNA was prepared by Hirt extraction and CsCl-ethidium bromide centrifugation to resolve linear and supercoiled viral DNA. (Hirt, 26 J Mol. Biol. 365, 1967; Canaani et al., 282 Nature 378, 1979).
The supercoiled viral DNA was used to construct libraries which contain overlapping viral DNA sequences. The procedures used to construct these libraries were similar to those described by Maniatis et al., Molecular Cloning, A Laboratory Manual, Cold Spring Harbor Lab, Cold Spring Harbor, N.Y.) and Glover, DNA Cloning, Vol. 1, A Practical Approach, IRL Press, Washington, D.C.) and are familiar to those of ordinary skill in the art.
Two viral DNA libraries were generated by cleavage of supercoiled viral DNA by one of two restriction endonucleases. Partial cleavage by the restriction endonuclease RsaI, which recognizes the DNA sequence 5′GTAC3′, or cleavage by the restriction endonuclease HaeIII, which recognizes the DNA sequence 5′GGCC3′, of the supercoiled viral DNA generates two sets of blunt-ended DNA molecules whose sequences overlap. The blunt-ended DNA molecules were then treated with EcoRI methylase, according to the manufacturer's directions, to modify the 3′ adenine residue of the EcoRI recognition sequence 5′-GAATCC-3′. Methylation at this site inhibits the cleavage of treated DNA by the restriction endonuclease EcoRI. The methylated DNA molecules were then ligated to linker DNA molecules which contained a cleavage site for the restriction endonuclease EcoRI. The linker containing DNA molecules were then treated with the restriction endonuclease EcoRI to generate molecules whose termini were compatible with the EcoRI cloning site in the recombinant DNA phage vector λ ZAP™ (Stratagene, La Jolla, Calif.). Linker fragments resulting from this cleavage were separated from the large DNA molecules by size separation on a quickspin column (Boehringer, Mannheim, Indianapolis, Ind.). The DNA molecules were then ligated into the EcoRI cleaved λ ZAP vector using T4 DNA ligase (New England Biolabs, Beverly, Mass.). Ligated DNA molecules were then packaged into phage using Gigapack gold (Stratagene, La Jolla, Calif.). Viable phage from the packaging reaction were then amplified by infecting BB4 cells (Stratagene) and harvesting plate lysates of those infected cells in order to obtain a stock of recombinant λZAP clones.
Because the insert DNA of the recombinant λZAP clones contain host cellular DNA as well as FIV proviral DNA sequences, it was necessary to screen each library with an FIV DNA probe that contains a readily detectable label. Such a probe was made from RNA isolated from FIV. A radioactive complementary DNA was synthesized from total viral RNA essentially as described by Maniatis et al. 1982, supra except that selection of poly A-containing RNA was not performed, and methymercuric hydroxide was omitted from the protocol.
The bacteriophage libraries were plated at a density of 10,000 bacteriophage per 150 mm dish. They were then screened by hybridization of the radioactively labeled probe to phage DNA which was immobilized on nitrocellulose filters (Maniatis, et al., 1982 supra). Each hybridizing bacteriophage plaque was then picked, replated, and hybridized as described, until a single well was isolated which contained a λZAP recombinant clone. XL-1-Blue cells (Stratagene) were then infected with recombinant λZAP phage, and plasmids containing the insert DNA were obtained following superinfection with R408 helper phage according to the manufacturer's directions (Stratagene, La Jolla, Calif.). This procedure also provides both recombinant plasmids (which can be isolated from the cell) and single stranded phage stock which can be isolated from the medium for DNA sequence analysis.
The above recombinant plasmids were analyzed for inserts by preparing plasmid DNAs from overnight culture of bacteria replicating these plasmids as follows. One and one half ml. of an overnight culture was placed in a microcentrifuge tube and spun for four minutes at 4000×g. The supernatant was removed and the tube respun for four minutes at 4000×g. The supernatant was removed and the tube respun for a few seconds, and residual liquid removed carefully with a pasteur pipet. The bacterial pellet was then thoroughtly resuspended in 200 microliters of a solution contaiing 8% sucrose, 50 mm EDTA, 5% Triton X-100 and 50 MM Tris/HCl, pH 8.05. 20 microliters of a lysozome solution at a concentration of 10 milligrams lysozyme per milliliter in 10 millimolar Tris/HCl, pH 8 and one millimolar EDTA was then added, mixed, and the mixture was incubated at 4° C. for 15 minutes. The solution containing bacteria was then placed in a boiling water bath for 90 seconds. The mixture was chilled on ice, and spun in a microfuge in the cold for 10 minutes at 11,000×g. The pellet was carefully removed with a glass pipet. Ice cold isopropanol (200 microliters) was then added, the solution thoroughly mixed, and incubated at −20° C. for 5 minutes. The chilled solution was centrifuged at −20° C. at 11,000×g for 10 minutes to pellet the plasmid DNA. The supernatant was carefully removed and the pelleted DNA briefly air dried. The DNA pellet was then dissolved in 100 microliters of sterile double distilled water. Plasmid DNAs thus isolated were anlayzed for inserts by restriction enconuclease cleavage and electrophoresis in 0.8% agarose gels (Maniatis et al., 1982 supra).
Standard dideoxy sequence analysis was performed on the recombinant DNA containing clones. Single stranded phage were isolated from the media used to propagate cells containing the bluescript plasmid using the method generally described in the M13 dideoxy sequencing manual published by Bethesda Research Laboratories (Gaithersburg, Md.). A number of clones were sequenced and analyzed by this method. These amino acid sequences show homology with the amino acid sequence of the envelope gene of equine infectious anemia virus, a lentivirus, immunologically closely related to FIV.
Nucleic acid probes derived from the 2BY DNA sequence hybridize to DNA isolated from FIV infected but not uninfected cells. These probes can be used to isolate other FIV genes from other strains and can be expressed by standard procedures to provide the purified polypeptides described above.
Deposit
Strains 10CX, 2B4 and R5X have been deposited with the ATCC 12301 Parklawn Drive, Rockville, Md. 20852 and assigned numbers 67937, 67938, and 67939, respectively.
Applicants' and their assignees acknowledge their responsibility to replace these cultures should they die before the end of the term of a patent issued hereon, 5 years after the last request for a culture, or 30 years, whichever is the longer, and its responsibility to notify the depository of the issuance of such a patent, at which time the deposits will be made irrevocably available to the public. Until that time the deposits will be made available to the Commissioner of Patents under the terms of 37 CFR Section 1-14 and 35 USC Section 112.
Other embodiments are within the following claims. | An isolated envelope polypeptide of Feline Immunodeficiency Virus (FIV) that reacts specifically with a gp-130 envelope specific monoclonal antibody. Immunoassays using such isolated polypeptides are also disclosed. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part application of Ser. No. 10/935,944 filed Sep. 8, 2004, now U.S. Pat. No. 7,178,547 issued Feb. 20, 2007, which claims priority of provisional application No. 60/501,297, filed Sep. 8, 2003, the disclosures of which are each hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to inflation valves for compressed gas cylinders used for inflating inflatable articles such as life rafts. More particularly, this invention relates to inflation valves that utilize the pressure of the gas in the gas cylinder to assist in the opening of the valve to a fully-open position by pulling on an inflation handle.
2. Description of the Background Art
Presently, there exists many types of inflation valves designed to be used in conjunction with compressed gas cylinders or the like. In their simplest forms, inflation valves may comprise a knob or handle which is turned to open a flow passageway allowing the compressed gas within the cylinder to inflate the inflatable article. However, even more prevalent are inflation valves for sealed gas cartridges that are operable by means of a jerk handle and lanyard cord that allow the inflatable article to be quickly inflated by a simple jerking of the handle which forces a pierce pin to fracture the frangible seal of the gas cartridge allowing the compressed gas therein to flow to and inflate the inflatable article.
Due to the large force necessary to fracture the frangible seal of a conventional gas cylinder, more contemporary designs of inflation valves employ a powerful spring which is held in its cocked position by means of a sear. Upon jerking of the jerk handle by the user, the sear is released allowing the powerful spring to very forcibly force the pierce pin through the frangible seal of the gas cartridge.
To eliminate the need for inflators having powerful firing springs held in cocked positions, still more contemporary inflation valves utilize the internal pressure of the gas cylinder to assist in driving the pierce pin fully through an internal frangible seal. A representative inflation system with such a pneumatic assist feature, is disclosed in my U.S. Pat. No. 6,089,403, the disclosure of which is hereby incorporated by reference herein. However, there presently exists a need for pneumatically assisted inflators that are configured in such a manner that virtually all of the components thereof may be manufactured from a high-strength, injectable plastic thereby obviating the need for extensive machining of metal parts and the attendant manufacturing and assembly costs thereof.
Therefore, it is an object of this invention to provide an improvement which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the inflation art.
Another object of this invention is to provide an inflator with pneumatic assist that is configured in such a manner that its component parts may be manufactured from an injectable high-strength plastic material.
Another object of this invention is to provide an inflator with pneumatic assist having an inflator body removable from a valve body such that the valve body may be mounted on the gas cylinder and the gas cylinder filled with compressed gas and then at some later point in time, the inflator body installed thereon.
Another object of this invention is to provide a pneumatically assisted inflator having an inline configuration such that the O-ring seal of the pneumatic piston does not wipe across the exhaust port as taught by my prior patent, U.S. Pat. No. 6,089,403.
The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
For the purpose of summarizing this invention, this invention comprises a pneumatically assisted inflator for gas cylinders. The inflator of the invention uniquely comprises an inline configuration such that gas contained within the gas cylinder flows axially through the inflator to be exhausted therefrom and inflate the inflatable article. The inline configuration of the inflator of this invention reduces the stress otherwise imparted to the component parts thereof, and thereby allows most of the component parts to be manufactured from an injection molded high-strength plastic or the like.
Moreover, the inline configuration of the present invention eliminates the need for the O-ring seal of the inflator piston to wipe across the exhaust opening possibly bursting the O-ring through the exhaust opening. Further, possible damage to the O-ring by the edge of the exhaust hole as it is explosively wiped thereacross is eliminated.
The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of the inflator of the invention;
FIG. 2 is a side elevational view of the inflator of the invention;
FIG. 3 is another perspective view of the inflator of the invention showing several of the components thereof in shaded phantom;
FIG. 4 is a longitudinal cross-sectional view of the inflator of the invention with its inflator position in its “at ready” position;
FIG. 5 is a perspective view of the inflator piston;
FIG. 6 is a longitudinal cross-sectional view of the inflator of the invention with the inflator piston in its pin-hole piercing position;
FIG. 7 is a longitudinal cross-sectional view of the inflator of the invention with the inflator piston in its fully fired position with its pierce pin fully fracturing its internal frangible seal; and
FIG. 8 is a longitudinal cross-sectional view of the inlet valve.
Similar reference characters refer to similar parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2 , the inflator 10 of the invention comprises a valve portion 12 to which is threadably coupled an inflator portion 14 . As will become evident hereinafter, the valve portion 12 may be threadably coupled to the threaded neck of a gas cylinder 13 (shown in phantom) to then be filled via inlet 15 without necessarily requiring the installation of the inflator portion 14 . Then, after the gas cylinder 13 has been filled with the appropriate gas, the inflator portion 14 may be installed by simple threaded engagement with the valve portion 12 .
The inflator portion 14 comprises a rotatable inflator collar 16 having a side opening 18 through which is threaded a lanyard cord 20 of a conventional jerk-to-inflate handle 22 . The end of the lanyard cord 20 is connected to a rotatable cam 16 C positioned inside the collar 16 . The underside of the rotatable cam 16 C including a cam surface 16 S.
As shown in FIGS. 3 and 4 , the inflator portion 14 further comprises an inflator piston 24 having hollow pierce pin 32 with a pointed tip 30 , which are as an assembly reciprocatably mounted within a piston cylinder 26 in alignment with the internal frangible seal 28 of the valve portion 12 . The inflator piston 24 is in operative engagement with the cam surface 16 S to move inwardly as the cam 16 C is rotated.
In operation, upon pulling of the jerk handle 22 , cord 20 causes the rotatable cam 16 C inside the collar 16 to rotate. Upon rotation of the cam 16 C, inflator piston 24 is forced downwardly until the very tip 30 of the hollow pierce pin 32 coupled to the inflator piston 24 makes a small pin-hole in the frangible seal 28 of the valve body 12 (see also FIG. 6 ). Upon making the pin hole opening in the frangible seal 28 , the high-pressure gas contained within the gas cylinder 13 flows therefrom through the inflator piston 24 to pressurize the top portion of the piston cylinder 26 above the inflator piston 24 , whereupon the inflator piston 24 is then forced by the high-pressure gas further downwardly to fully drive the pierce pin 32 through and hence fully open the frangible seal 28 (see FIG. 7 ).
Upon fully piercing the frangible seal 28 , a full flow of escaping gas from the gas cylinder flows through the pierce pin 32 and exits therefrom via side openings 32 S to then flow through center bore 34 B of the connector boss 34 to which an inflation tube may be threadably coupled.
Referring to FIG. 5 in conjunction with FIGS. 4 , 6 and 7 , the inflation piston 24 comprises two upstanding arms 24 A with bearing surfaces 24 S which cam against the cam surface 16 S of the collar 16 as it is rotated upon pulling of the lanyard handle 22 . Correspondingly, the piston cylinder 26 comprises two ports 26 P configured and dimensioned to slidably receive the upstanding arms 24 A and allow reciprocal movement thereof. The inflation piston 24 further includes a depending neck 24 DN that is configured and dimensioned to slidably engage into a reduced-diameter portion 26 N of the piston cylinder 26 . Finally, the inflation piston 24 further includes an upstanding neck 24 UN that is configured and dimensioned to slidably engage into the longitudinal bore 34 B formed in the connection boss 34 .
Both of the upstanding arms 24 A may be provided with O-ring slots and O-rings 240 A to prevent leakage of gas through the ports 26 P into the collar 16 . Likewise, inflation piston 24 may be provided with an O-ring slot and O-ring 240 C for sealing against the lumen of the piston cylinder 26 . The depending neck 24 DN of the piston 24 may be provided with an O-ring slot and O-ring 240 P to seal the depending neck 24 DN within the reduced diameter portion 26 N of the cylinder 26 . The upstanding neck 24 UN of the inflator piston 24 is sealed against the lumen of the longitudinal bore 34 B by means of an annular wiper seal 38 . Finally, as shown, the frangible seal 28 is sealed within the valve portion 12 by means of a corresponding O-ring slot and O-ring 280 .
The operation of the inflator 10 of the invention is best seen upon comparison of FIGS. 4 , 6 and 7 wherein FIG. 4 depicts the inflator piston 24 at its “cocked” position; FIG. 6 illustrates the inflator piston 24 moved slightly downwardly to make a pin hole in the frangible seal 28 ; and FIG. 7 illustrates the inflator piston 24 forced fully downwardly to fully fracture the frangible seal 28 allowing full flow of pressurized gas therethrough.
More particularly, in its “cocked” position as shown in FIG. 4 , the inflator piston 24 is positioned within the piston cylinder 26 and sealed with the lumen thereof by means of the O-ring 240 C. In this position, the bearing surfaces of two upstanding arms 24 A bear against the cam surface 16 S of the collar 16 and are sealed within the respective ports 26 P by means of the O-ring 240 A. The upstanding neck portion 24 UN is positioned fully upward within the longitudinal bore 34 B and is sealed therewith by means of the annular wiper seal 38 . The depending neck 24 DN is inserted within the reduced diameter portion 26 N and sealed therewith by means of the O-ring 280 P.
Referring now to FIG. 6 , upon pulling of the jerk handle 22 to “fire” the inflator 10 , the rotatable collar 16 C is caused to rotate whereupon its cam surface 16 S cams against the bearing surfaces 24 S of the upstanding arms 24 A forcing them downwardly toward the interior of the inflation valve 10 . The degree of taper of the cam surface 16 S relative to the dimensions of the inflator piston 24 and the frangible seal 28 are such that upon full rotation of the rotatable cam 16 C, the tip 30 of the pierce pin 32 makes a small pin hole in the frangible seal 28 . The pin hole thus formed allows high pressure gas from the gas cylinder 13 to flow through the longitudinal bore 12 B from the pierced frangible seal 28 through the pierce pin 32 and exiting the side openings 32 S. Since the longitudinal bore 32 B is sealed by means of the wiper seal 38 , the gas pressurizes the uppermost portion 26 U of the cylinder 26 .
As shown in FIG. 7 , as the uppermost portion 26 U of the cylinder 26 is pressurized, the inflation piston 24 is forcibly urged further inwardly to a position in which the pierce pin 32 completely fractures the frangible seal 28 of the inflator 10 . Once the frangible seal 28 is fully pierced and hence fully open, a full flow of compressed gas from the cylinder 13 is allowed to flow through the pierce pin 32 to exit therefrom via openings 32 S into the upper portion of cylinder 26 . Moreover, since the wiper seal 38 has now moved fully out of the longitudinal bore 34 B, the escaping gas flows from the upper portion 26 U of the cylinder 26 into the longitudinal bore 34 B to inflate the article to be inflated that is fluidly connected to the connector boss 34 . It is noted that in this fully opened position, gas is precluded from escaping from the ports 26 P by O-rings 240 .
Returning now to FIG. 4 , it should be appreciated that the valve portion 12 may be threadably coupled to the threaded neck of the gas cylinder 13 without necessarily requiring the installation of the inflator portion 14 . Specifically, once the valve portion 12 is threadably coupled to the threaded neck of the gas cylinder 13 , the gas cylinder 13 may be filled via inlet 15 and fill port 15 P connected in fluid communication with the longitudinal bore 12 B of the inflator portion 12 . Since the longitudinal bore 12 B is sealed by means of the frangible seal 28 of the inflator portion 12 , the fill air is forced into the gas cylinder 17 and is not allowed to escape therefrom. Once filled, the fill inlet 16 may be closed by means of a valve (not shown), which may comprise a check valve allowing filling but not discharging of air from the gas cylinder 13 . The inflator portion 14 of the inflator 10 of the invention may then be threadably connected to the valve portion 12 by means of thread 12 T. Conversely, removal of the inflator portion 14 from the valve portion 12 may be allowed for periodic inspection during maintenance.
Referring to FIG. 8 , a preferred embodiment of the inlet valve 15 comprises a generally circular cylindrical body 52 with external threads 52 T. The exposed proximal end 54 of the inlet valve 15 comprises a hex configuration for grasping by a suitable wrench. The internal distal portion end 56 of the inlet valve comprises a shank portion 58 and a reduced-diameter portion 60 . The shank portion 58 includes an O-ring groove 58 G for receiving an O-ring 580 . The reduced-diameter portion 60 likewise includes an O-ring groove 60 G for receiving an O-ring 600 .
The proximal end 54 of the inlet valve 15 includes a threaded central bore 62 for receiving a fill hose or the like. A central reduced-diameter bore 64 extends from the bottom of the central bore 62 to be in fluid communication with a transverse hole 66 formed through the shank portion 58 of the inlet valve 15 forward of its O-ring groove 58 G.
As best seen in FIGS. 3 and 4 , an inlet hole 68 is formed in the wall of the valve portion 12 . The inlet hole 68 includes a proximal threaded portion 68 T for threadably receiving the external threads 52 T of the generally circular cylindrical body 52 . The distal end 70 of the inlet hole 68 includes a generally circular cylindrical portion 72 and a generally frustro-conical portion 74 that extends into the port 15 P of the longitudinal bore 12 B.
The generally circular cylindrical portion 72 is dimensioned to sealingly receive the shank portion 58 by virtue of its O-ring 580 . The generally frustro-conical portion 74 is shaped to allow the O-ring 600 of the reduced-diameter portion 60 to seal against it when the inlet valve 15 is fully threaded into the inlet hole 68 and to allow venting of pressurized gas from the longitudinal bore 12 B when the inlet valve 15 is slightly threaded outwardly to crack the seal between the O-ring 600 and the frustro-conical portion 74 whereupon the pressurized gas is allowed to vent via transverse hole 66 through central bore 62 .
After sufficient bleeding of the pressurized gas to reduce its pressure, further outward threading of the inlet valve 15 to a point where the O-ring 600 moves into the generally circular cylindrical portion 72 allows full fluid flow through transverse hole 66 through central bore 62 for subsequent filling via inlet valve 15 .
The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.
Now that the invention has been described, | A pneumatically assisted inflator for gas cylinders comprises an inline configuration such that gas contained within the gas cylinder flows axially through the inflator to be exhausted therefrom and inflate an inflatable article. The inline configuration of the inflator reduces the stress otherwise imparted to the component parts thereof and thereby allows most of the component parts to be manufactured from an injection molded high-strength plastic or the like. The inflator comprises an inflator piston positioned within a piston cylinder that moves against a rotatable cam surface, such as a rotatable collar connected to a pull lanyard, to force a pierce pin to make at least a small pin hole in a frangible seal and allow high pressure gas from the gas cylinder to flow into the piston cylinder, whereupon the high pressure gas in the piston cylinder further moves the inflator piston to more fully force the pierce pin into the frangible seal to fully open the frangible seal. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a method for the simultaneous production of acid and base of high purity through the electrodialytic splitting of a corresponding salt in aqueous solution using an electrodialysis cell. The invention also relates to an electrodialysis cell for carrying out the method.
[0003] In a number of chemical process steps, salt solutions accumulate and, as such, are not directly used further or cannot or should not be introduced into a drainage canal as waste either. Furthermore, salt solutions with high concentrations are obtained in leaching processes of salt deposits or in the leaching of salts which are already conveyed as well as pure prepared salts. In many cases, it is in the interest of chemical engineering and economy to produce from such salt solutions more highly refined valuable substances in the form of acids and bases corresponding to the ions of the respective salt. Electrolytic or electrodialytic methods are frequently used for that purpose. The known electrodialytic methods used for that purpose operate with a three-chamber system (see report of Fraunhofergesellschaft: Institut fur Grenzflächen- und Bioverfahrenstechnik [Fraunhofer Association: Institute for Interface and Bio-Material Processing], April 1999, “Elektrodialyse mit bipolaren Membranen” [Electrodialysis with Bipolar Membranes]).
[0004] In that respect, the salt solution which is to be prepared electrodialytically is conducted through a middle chamber of an electrodialysis cell being formed of three chambers. The cations travel from that cell, under the influence of the electrical field, through a cationic exchanger membrane into an adjacent chamber which contains the cathode, and form the base there with cathodically developed OH − -ions. Accordingly, the anions travel through an anionic exchanger membrane into the adjacent anode chamber on the other side and form the corresponding acid with the H + -ions developed anodically there. However, the production methods of acids and bases from salt solutions, which operate according to that method, have disadvantages. One disadvantage resides in the fact that unwanted reactions with anions take place at the anode, which lead to the contamination of the acid being formed. In that way, for example, hydrohalic acids, formed in the anode chamber with free halogens which are produced at the anode by the discharging of halide ions, are contaminated and their service value is therefore reduced. Moreover, the anode can be corrosively attacked or the ion exchanger membranes can be damaged by the halogen being released. Another disadvantage resides in the fact that the anodically formed acids are frequently not sufficiently concentrated and are therefore of little value in terms of chemical engineering and commerce.
[0005] In U.S. Pat. No. 4,212,712 a method is described for the electrodialytic production of a more highly concentrated sodium hydroxide solution from sodium chloride solutions in a three-chamber cell. However, with that method, hydrochloric acid is not directly electrodialytically formed, but instead, chlorine is separated anodically. The intermediate chamber lying between the anode chamber and the cathode chamber is separated from both adjacent chambers by cationic exchanger membranes which, in addition to being permeable to the Na + -ions, are permeable to water to differing degrees. The permeability to water is less towards the cathode region than the anode region into the intermediate chamber. Through the use of that configuration it is possible to generate a comparatively concentrated sodium hydroxide solution in the cell. In the authoritative literature it is also mentioned that it would be possible to use, in place of one intermediate chamber, two or more such intermediate chambers which are equipped in the direction of the cathode chamber with cationic exchanger membranes, that are permeable to water to an increasingly poorer extent. In that way, the sodium hydroxide solution in the cathode chamber is concentrated even more. However, in practice such a solution is not used because of the associated difficulties in achieving a satisfactory efficiency of flow.
SUMMARY OF THE INVENTION
[0006] It is accordingly an object of the invention to provide a method and an electrodialysis cell for the simultaneous production of acid and base through the electrodialytic splitting of a corresponding salt in an aqueous solution using an electrodialysis cell, which overcome the hereinaforementioned disadvantages of the heretofore-known methods and devices of this general type and with which unwanted anode effects can be avoided and acids and alkalis can be produced with comparatively high concentrations and high purity. In particular, it is an object of the method according to the invention to produce, from sodium chloride solutions, hydrochloric acid of high purity and in concentrations which were heretofore not accessible with electrodialytic measures on an industrial scale.
[0007] With the foregoing and other objects in view there is provided, in accordance with the invention, a method for the simultaneous production of acid and base of high purity by the electrodialytic splitting of a corresponding salt in aqueous solution with an electrodialysis cell, which comprises providing a cathode chamber having a cathode, an inlet opening and at least one outlet opening for fluids. A salt chamber is separated from the cathode chamber by a cationic exchanger membrane. The salt chamber has an inlet opening and an outlet opening for conducting a salt solution. An acid is formed in an acid chamber separated from the salt chamber by an anionic exchanger membrane. The acid chamber does not contain an anode. An anode chamber is separated from the acid chamber by a cationic exchanger membrane through which protons required for forming the acid pass from the anode chamber into the acid chamber. The anode chamber has an inlet opening and an outlet opening for a liquid proton carrier flowing through the anode chamber. The anode chamber has a hydrogen-consuming anode for converting hydrogen into protons to an extent required for forming the acid. An electrical voltage is applied between the anode and the cathode for maintaining an electrodialytic process. Cations of a salt travel under the effect of the electrical field, from the salt chamber, through the cationic exchanger membrane into the cathode chamber and form a base there with OH − -ions produced by catholytic splitting of water into hydrogen and OH − -ions. Simultaneously, anions of the salt travel from the salt chamber, under the effect of the electrical field, through the anionic exchanger membrane into the acid chamber and form the acid there with protons formed analytically from hydrogen at the hydrogen-consuming anode.
[0008] With the objects of the invention in view, there is also provided an electrodialysis cell for the simultaneous production of acid and base of high purity from a corresponding salt by electrodialysis, comprising a cathode chamber having a cathode, an inlet opening and at least one outlet opening for fluids. A salt chamber is separated from the cathode chamber by a cationic exchanger membrane. The salt chamber has an inlet opening and an outlet opening for conducting a salt solution. An acid chamber in which an acid is formed is separated from the salt chamber by an anionic exchanger membrane and does not contain an anode. An anode chamber is separated from the acid chamber by a cationic exchanger membrane through which protons required for forming the acid pass from the anode chamber into the acid chamber. The anode chamber has an inlet opening and an outlet opening for a liquid proton carrier flowing through the anode chamber and a hydrogen-consuming anode for converting hydrogen into protons to an extent required for forming the acid. A device applies an electrical voltage between the anode and the cathode for maintaining an electrodialytic process. The device simultaneously causes cations of a salt to travel under the effect of the electrical field, from the salt chamber, through the cationic exchanger membrane into the cathode chamber and form a base there with OH − -ions produced by catholytic splitting of water into hydrogen and OH − ions, and causes anions of the salt to travel from the salt chamber, under the effect of the electrical field, through the anionic exchanger membrane into the acid chamber and form the acid there with protons formed from hydrogen at the hydrogen-consuming anode.
[0009] The chamber in which the acid is formed is separated from the anode region by a cationic exchanger membrane due to the introduction of a fourth chamber into the known three-chamber cell. This avoids a situation where component parts which are located in the chamber in which the acid is formed and which could enter into electrochemical reactions at the anode arrive at the anode and are converted there to form disturbing impurities which remain in the acid. An example of such an impurity is elemental, dissolved chlorine which can be formed by the discharging of chloride ions at the anode. Very generally, with the suggested configuration very pure acids can be produced because only the substances which can pass through the cationic exchanger membrane out of the anode chamber and which can pass through the anionic exchanger membrane out of the middle, salt-carrying chamber can arrive by way of the membranes, acting in an ion-selective manner, in the region in which the acid is formed. Moreover, as tests have shown, the service life of the anode is increased several times with the new configuration.
[0010] It is also surprisingly possible for the first time, with the method and device according to the invention, to use an electrodialytic device to produce hydrochloric acid on an industrial scale, having a concentration which amounts to over 10% by weight HCl in the acid. Efforts by the inventors to obtain pure hydrochloric acid with concentrations over 10% by weight HCl with conventional three-chamber systems had failed. With the new cell structure it is now possible to produce hydrochloric acid with concentrations to over 20% by weight HCl in the hydrochloric acid and at the same time sodium hydroxide solution with concentrations over 30% by weight NaOH in the alkali. The method can also be carried out with two or more electrodialysis cells connected in parallel. The method operates particularly effectively if two or more electrodialysis cells are connected in series.
[0011] In order to carry out the method, the solution of a salt, for example the aqueous solution of NaCl, NaBr, KCl, KBr, KNO 3 , NaNO 3 or an acetate which is preferably somewhat acidified, is conducted into the chamber of the electrodialysis cell which is limited on one side by a cationic exchanger membrane and on the other side by an anionic exchanger membrane. The chamber which contains the cathode and in which the base or alkali is formed, is connected to the cationic exchanger membrane. The chamber in which the acid is formed is connected to the anionic exchanger membrane. However, this chamber does not contain any anode. The anode is located in a further, fourth chamber which is connected to the chamber in which the acid is formed. Both latter chambers are separated by a cationic exchanger membrane. When the salt solution passes through the chamber into which it has been introduced, cations of the salt dissolved in it constantly pass through the cationic exchanger membrane into the cathode chamber of the cell. The cathode can be formed of any material which is resistant to alkalis and which is suitable for the reaction:
2 H 2 O+2 e − . . . H 2 + 2 OH − .
[0012] Such electrodes are commercially obtainable and are formed, for example, of nickel or of titanium and are activated with precious metal oxides from the group Pt, Pd, Rh, Ru, Ir, Re, Au or with titanium oxides. Advantageously, the cathodes which are used have as low an overvoltage as possible for the aforementioned reaction for the formation of hydrogen. A commercially available nickel cathode activated without the addition of foreign elements or foreign oxides has proven to be particularly advantageous. A diluted aqueous solution of the base is in the cathode chamber. A portion of the water of the solution is split at the cathode into hydroxyl ions and hydrogen to the extent that cations enter into the cathode chamber. The cations form the base together with the hydroxyl ions. The diluted solution is concentrated by this process. The alkali is continuously drawn off from the cathode chamber. The hydrogen which is likewise produced is taken and is supplied from the cathode chamber by a pipeline to the anode, which is constructed as a hydrogen-consuming anode, for conversion into positively charged hydrogen ions, that are referred to below as protons. Negative charges in the form of anions of the salt pass through the anionic exchanger membrane into the chamber in which the acid is formed, to the extent that positive charges in the form of cations pass into the cathode chamber. A diluted proton acid flows through the chamber in which the acid is formed. This proton acid is characterized by the anion which is also the anion of the salt that is to be electrodialytically split. The protons which are required for forming the acid enter from the anode chamber through the cationic exchanger membrane into the chamber in which the acid is formed, to the extent that anions enter into this chamber. The diluted acid which is initially present in the chamber is concentrated by this acid formation process. To the extent that protons travel into the chamber in which the acid is produced, the corresponding number of protons is formed from hydrogen at the hydrogen-consuming anode.
[0013] Any purchasable anode which is suitable for generating protons from water could be used as the anode. However, depolarized hydrogen-consuming electrodes are used, with the aid of which protons can be generated from gaseous hydrogen. A lower cell voltage can be used with the use of this anode type, because only the standard hydrogen potential of 0 volt is required for the conversion of hydrogen into protons. However, with water-decomposing anodes the higher potential of +1.21 V is required for the reaction 2 H 2 O - - 4 H + +O 2 . Suitable gas diffusion anodes can be purchased (for example from the firm E-TEK, Inc., Natick, Mass.). A diluted proton acid which can be dissociated well, preferably an acid from the group sulfuric acid, perchloric acid, phosphoric acid, is disposed in the anode chamber as a transport medium for the protons. This acid is not consumed. Nevertheless, it is advantageous to circulate it by pumping. Membranes made from a polymer or copolymer, which is doped with an anionic ligand, for example of the sulphonic acid group, and which has been produced from monomers from the group tetrafluoroethylene, hexafluoropropylene, monochlorotrifluoroethylene, vinylidene fluoride and α,β,β-trifluorostyrene, are preferably used as the cationic exchanger membranes. Such membranes are commercially obtainable under the trademark NAFION (owned by Du Pont). The use of NAFION 117 for the cationic exchanger membrane between the anode chamber and the chamber in which the acid is formed, and of NAFION 324 for the cationic exchanger membrane which separates the salt-carrying chamber from the cathode chamber, has proven advantageous for the present invention. However, the invention is not restricted to the use of the named types of cationic exchanger membranes. Other types of cationic exchanger membranes, for example NAFION 115, Fumatec FKF, FKC, FKL and FKE or Tokuyama Alkali CMS, CIMS, CM-2 or Asahi Class SELEMION CAV, CSV can also be used. Commercially available membranes are likewise used as anionic exchanger membranes between the salt-carrying chamber and the chamber in which the acid is formed. The membrane ACM of Tokoyama Alkali has proven advantageous. However, other membranes such as, for example, the membranes AHA, AMH and ACS of Tokoyama Alkali, or the qualities FAB and FAA of the firm Fumatec or the membranes PCAPC Acid 35 and PC Acid 35 PEEK of the firm PCA GmbH or the membrane AAV of Asahi Class SELEMION or the membrane ARA of Morgan, can also be used. The cell voltage when carrying out the method also depends on the cell construction, in addition to the standard potentials and overvoltage effects to be observed. It lies in the range of 1.5 to 6 V. It is advantageous to set the process temperature to 40° C. or more, preferably to 80° C. It is, of course, also possible to produce, according to the method of the invention, acids and alkalis from salts such as, for example, Na 2 SO 4 , NaHSO 4 , or phosphates, which have already been electrodialyzed according to the known three-chamber method.
[0014] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0015] Although the invention is illustrated and described herein as embodied in a method and a device for the simultaneous production of acid and base of high purity, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0016] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a diagrammatic, sectional view of an electrodialysis cell according to the invention;
[0018] [0018]FIG. 2 is a schematic and block diagram of a circuit for carrying out a method according to the invention; and
[0019] [0019]FIG. 3 is a schematic and block diagram of a circuit which illustrates coupling of the method according to the invention with a concentration method for the production of hydrochloric acid.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Operation of an electrodialysis cell shown in FIG. 1 and performance of a method illustrated in FIGS. 2 and 3 will be described by way of example with reference to obtaining hydrochloric acid and sodium hydroxide solution from sodium chloride. However, the invention is not restricted thereto.
[0021] Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen an electrodialysis cell 1 which has four chambers, namely a cathode chamber 2 ; a chamber 3 , referred to below as a “salt chamber”, through which sodium chloride solution flows; a chamber 4 , referred to below as an “acid chamber”, in which hydrochloric acid is formed; and an anode chamber 5 . The cathode chamber 2 has a cathode 6 with a contact bar 7 for supplying electric current. The cathode 6 is formed of nickel and has an activated nickel surface. The contact bar 7 is likewise formed of nickel. In the cathode chamber 2 , on one hand water is electrolytically split to form hydroxyl ions and hydrogen, and on the other hand sodium hydroxide solution is formed from the hydroxyl ions and sodium ions. The liquid which is to be electrolyzed enters into the cathode chamber 2 by way of an inlet opening 8 . This liquid can be water. However, a diluted alkali, in this case sodium hydroxide solution, is preferably used. The sodium hydroxide solution which is formed, or the sodium hydroxide solution that is concentrated by way of the sodium hydroxide solution formation process, leaves the cathode chamber 2 through an outlet opening 9 together with the formed hydrogen. Cations, that is to say sodium ions in the present example, pass from the salt chamber 3 through a cationic exchanger membrane 11 into the cathode chamber 2 . A solution of the salt which is to be electrodialytically split flows through the salt chamber 3 . In the present case this is a concentrated solution of sodium chloride. The NaCl solution passes through an inlet opening 12 into the salt chamber 3 and leaves this chamber 3 , after depletion of Na + -ions and Cl − -ions has taken place, through an outlet opening 13 . Chloride ions pass from the salt chamber 3 through an anionic exchanger membrane 14 into the acid chamber 4 , to the extent that cations travel through the cationic exchanger membrane 11 into the cathode chamber 2 , forming hydrochloric acid with protons within the acid chamber 4 . Water, or preferably a diluted hydrochloric acid, is introduced into the acid chamber 4 through an inlet opening 15 . The hydrochloric acid is then concentrated by the hydrochloric acid formation process and leaves the chamber 4 through an outlet opening 16 . Protons for the process of forming hydrochloric acid come from the anode chamber 5 in which they are formed. They pass from the anode chamber 5 through a cationic exchanger membrane 17 into the hydrochloric acid chamber 4 . A diluted proton acid, in the present case sulfuric acid or perchloric acid, flows through the anode chamber 5 . The acid passes through an inlet opening 18 into the anode chamber 5 and leaves it through an outlet opening 19 . In practice, this acid is not consumed. It serves only as a transport device for the protons which are produced from hydrogen at a hydrogen-consuming anode 20 . For this purpose, gaseous hydrogen is supplied to the hydrogen-consuming anode by a supply line 23 leading into a distributing region 24 which is formed of a thin, chambered fiber network. A conversion into simply positive hydrogen ions then takes place in the anode with the removal of electrons. The hydrogen-consuming anode 20 is depolarized and is bounded by a cationic exchanger membrane 21 on its side which faces the chamber 5 . Current removal is symbolized herein by a bar 22 . The depolarized hydrogen-consuming anode 20 is commercially obtainable. Walls 25 of the chambers 2 , 3 , 4 , 5 of the electrodialysis cell 1 are formed of a material which is resistant to the media located in them. Synthetic materials such as, for example, polyvinyl chloride, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene or other perfluorinated or partially fluorinated synthetic materials which can also be reinforced by inlaid fibers or fiber composites or even metal parts, preferably steel parts, lined with one of the named synthetic materials, and rubber-lined steel, are preferably used for this purpose. In the present case, the walls 25 of the cell 1 were formed of polypropylene which was joined together in the form of non-illustrated blocks and plates that were worked so as to fit, and held together by likewise non-illustrated tension rods. Elements 7 and 22 provide a device for applying an electrical voltage between the anode 20 and the cathode 6 for maintaining the electrodialytic process.
[0022] A flow chart which illustrates the method in FIG. 2 shows two electrodialysis cells 1 , 1 ′ connected in series. The structure of both cells 1 , 1 ′ corresponds to the cell described with reference to FIG. 1. A connection of two or more electrodialysis cells in series is advantageously used with the method according to the invention because the concentration effect in only one electrodialysis cell is comparatively small. In addition, the concentration effect is maximized both with the acid formation and with the base formation by connecting the cells in series. Of course, it is also possible to use only one electrodialysis cell. In this case, however, it is advantageous to conduct the acid or the alkali or both, where necessary, through the cell with the continuous method until the desired concentration in the receiver is achieved.
[0023] In the present case, initially a pump 27 is used to pump a diluted sodium hydroxide solution out of an intermediate and buffer container 26 , through a pipeline 28 and the inlet opening 8 , into the cathode chamber 2 of the electrodialysis cell 1 . The alkali is concentrated in this chamber 2 to a certain degree by the catholytic formation of OH − -ions and by Na + -ions diffusing in from the salt chamber 3 , that is to say by way of the new formation of alkali. Hydrogen is produced at the cathode 6 in parallel therewith. The hydrogen travels together with the sodium hydroxide solution through the outlet opening 9 and a pipeline 29 and arrives in a separating container 10 . The hydrogen is conveyed from the container 10 through a pipeline 29 ′ into a supply and buffer container 30 for hydrogen. Alkali from the separating container 10 , which is only partially concentrated, arrives at a three-way valve 34 , and from there a larger partial flow flows through a pipeline 31 and an inlet opening 8 ′ into a cathode chamber 2 ′ of the electrodialysis cell 1 ′. The alkali is concentrated further in this cathode chamber 2 ′ by the process described above and is then conveyed through an outlet opening 9 ′ and a pipeline 32 into a separating container 10 ′. The alkali is conveyed from there through a pipeline 32 ′ into a collecting and storage container 33 for the alkali, the concentrating of which is complete. Hydrogen developed in this cathode chamber 2 ′ arrives together with sodium hydroxide solution in the separating container 10 ′ and travels from there, through a pipeline 37 , to the supply and buffer container 30 for hydrogen. Another smaller partial flow of the alkali which is partially concentrated in the first cathode chamber 2 is drawn off at the three-way valve 34 and is returned through a pipeline 35 into the intermediate and buffer container 26 . There, water is added to the returned alkali through a pipeline 36 in the same quantity as the volume of alkali which has flowed out of the second cathode chamber 2 ′ and the concentration of which is complete. In this way, the process for forming sodium hydroxide solution and for concentrating this alkali, taking place in the cathode chambers 2 , 2 ′, remains in equilibrium in chemical engineering terms.
[0024] Sodium ions which are required for forming the sodium hydroxide solution come from a sodium chloride solution which is pumped by a pump 39 out of an intermediate and buffer vessel 38 , through pipelines 40 , 40 ′ and through inlet openings 12 , 12 ′, into salt chambers 3 , 3 ′. It is advantageous to ensure that a salt solution of the same, highest possible concentration as is located in the first chamber 3 advantageously also flows through the downstream chamber 3 ′. Therefore, the flow of the salt solution after the pump 39 is divided through the use of a three-way valve 67 into two equal flows. One of the flows is conducted by the pipeline 40 into the salt chamber 3 and the other by the pipeline 40 ′ into the salt chamber 3 ′ of the downstream cell 1 ′. In both chambers 3 , 3 ′ a depletion of the salt solution takes place by the electrodialytic separation of the salt. The salt is separated into Na + -ions on one hand, which travel through the cationic exchanger membranes 11 , 11 ′ into the cathode regions 2 , 2 ′, and Cl − -ions on the other hand, which migrate through the anionic exchanger membranes 14 , 14 ′ into the acid chambers 4 , 4 ′ of the two series-connected electrodialysis cells 1 , 1 ′. The partially deionized solutions leave the salt chambers 3 , 3 ′ through outlet openings 13 , 13 ′ and are returned by pipelines 41 , 41 ′, 41 ″ into the intermediate and buffer vessel 38 . There they flow over a salt bed and are concentrated again. The salt solution is then conducted anew in the circulation through the salt chambers 3 , 3 ′. Should it be necessary, although it has not been shown, the salt solution can also be conducted successively through both chambers 3 , 3 ′ and then back into the container 38 .
[0025] In order to generate the hydrochloric acid, a pump 43 pumps a diluted hydrochloric acid out of an intermediate and buffer container 42 , through a pipeline 44 and the inlet opening 15 , into the acid chamber 4 of the electrodialysis cell 1 . Hydrochloric acid is formed anew in this chamber 4 from the chloride ions which have passed through the anionic exchanger membrane 14 from the salt chamber 3 and from the protons which have migrated and traveled in through the cationic exchanger membrane 17 from of the anode chamber 5 . The diluted hydrochloric acid is thus concentrated to a certain degree. The acid, which is only partially concentrated, leaves the acid chamber 4 through the outlet opening 16 . A larger partial flow thereof arrives by way of a three-way valve 45 , a pipeline 46 and the inlet opening 15 ′ in an acid chamber 4 ′ of the electrodialysis cell 1 ′. In this acid chamber 4 ′, the acid is concentrated further by the process described above and is then conveyed through an outlet opening 16 ′ and a pipeline 47 into a collecting and storage container 48 for the hydrochloric acid, the concentration of which is complete. Another smaller partial flow of the partially concentrated acid is drawn off at the three-way valve 45 and is returned through a pipeline 49 into the intermediate and buffer container 42 . There, as much water as a water balance of the cell requires is added to the returned hydrochloric acid through a pipeline 50 . In this way, the process for forming hydrochloric acid and for concentrating this acid, which takes place in the acid chambers 4 , 4 ′, remains in equilibrium in chemical engineering terms.
[0026] According to another advantageous embodiment, in addition to the water which must be replaced, diluted hydrochloric acid, that originates as return acid from a further known concentration process subsequent to the method according to the invention, is supplied by way of the pipeline 50 . The coupling of the method with this process will be discussed in more detail below. The concentrated acid collected in the collecting and storage container 48 can either continue to be used directly, or preferably, it can be concentrated to form concentrated acid according to one of the known methods. The protons which are required for forming the hydrochloric acid in the acid chambers 4 , 4 ′ are formed from hydrogen in anode chambers 5 , 5 ′ at respective hydrogen-consuming anodes 20 , 20 ′. The hydrogen required for this purpose is supplied from the hydrogen tank 30 to the hydrogen-consuming anodes 20 , 20 ′ through a pump 56 , pipelines 55 , 55 ′, 55 ″, a three-way valve 57 and supply lines 23 , 23 ′. Diluted sulfuric acid, which is located in containers 51 and 51 ′, is used in anode chambers 5 , 5 ′ as a transport device or carrier for the protons. The diluted sulfuric acid is pumped from these containers by pumps 52 and 52 ′ and travels through pipelines 53 and 53 ′ and inlet openings 18 and 18 ′ to the anode chambers 5 and 5 ′. It returns into the containers 51 and 51 ′ through outlet openings 19 , 19 ′ and pipelines 54 and 54 ′. Instead of the two acid circulations shown in this figure, with the two containers 51 and 51 ′, one circulation can also be used, in which the chambers 5 and 5 ′ are loaded from only one non-illustrated container and in which the acid flows back into the one container after flowing through the chambers 5 , 5 ′. The protons respectively formed at the hydrogen-consuming anodes 20 and 20 ′ replace the protons which have changed over from the sulfuric acid by the cationic exchanger membranes 17 and 17 ′ leading into the acid chambers 4 , 4 ′. This takes place simultaneously to the extent that hydroxyl ions have been formed at cathodes 6 and 6 ′.
[0027] The further concentration of the hydrochloric acid which is obtained by the electrodialysis process, to form concentrated hydrochloric acid, takes place in a particularly advantageous manner by coupling the method according to the invention with a known method. A schematic diagram illustrating the method can be seen in FIG. 3. The electrodialytic concentration of the hydrochloric acid is carried out at temperatures of over 40° C., preferably in the region of 80° C. The 80° C. hot acid exiting from the electrodialysis cell 1 in FIGS. 2 and 3 or the 80° C. hot acid collected in the container 48 in FIG. 2, having a concentration which must lie above an azeotropic concentration, is expanded through the use of a pressure-maintaining device or throttle 59 into a container or vessel 60 in which a partial vacuum prevails in comparison with a pipeline upstream of the pressure-maintaining device 59 . This partial vacuum is set through the use of a pump 62 and a pressure control device 61 , 61 ′. A heating device 58 which is used to heat the hydrochloric acid originating from the electrodialysis cell 1 , should it not have a sufficiently high temperature, is advantageously located upstream of the pressure-maintaining device 59 . In running operation, however, the method operates largely autothermally. The portion of the liquid evaporated upon the expansion of the hydrochloric acid into the container or vessel 60 contains more hydrogen chloride than the hydrochloric acid supplied for evaporation. Accordingly, after condensing of acid vapor in a cooler 63 , a concentrated hydrochloric acid of at least 30% by weight HCl in the acid is obtained and collected in container 64 . The portion of the liquid which has not evaporated, that collects in the expansion vessel or container 60 , is formed of diluted hydrochloric acid. It is again supplied to the electrodialysis cell 1 through the use of a pump 66 for renewed concentration. Water can be supplied to the diluted acid by a three-way valve 65 , if the supply of water, which always takes place in parallel with the passage of the ions through the membranes 14 and 17 in FIG. 1, is not sufficient in order to compensate for a liquid loss produced by the removal of the concentrated hydrochloric acid by the container 64 .
[0028] The method will be explained further in the following text with reference to examples:
EXAMPLE 1
[0029] An electrodialysis cell which was used for a test described below had the following structure:
[0030] cationic exchanger membrane between cathode chamber and salt chamber: Nafion 324, active membrane surface 0.35 m 2 ;
[0031] anionic exchanger membrane between salt chamber and hydrochloric acid chamber: ACM of Tokuyama Alkali, active membrane surface 0.35 m 2 ;
[0032] cationic exchanger membrane between hydrochloric acid chamber and anode chamber: Nafion 117, active membrane surface 0.35 m 2 ; cathode: expanded nickel metal, activated;
[0033] hydrogen-consuming anode: gas diffusion anode, manufacturer De Nora;
[0034] only one electrodialysis cell was used, through the chamber of which the following liquid flows were conducted:
[0035] cathode chamber: NaOH, 160 l/hour;
[0036] salt chamber: NaCl-solution, 160 l/hour, concentration at inlet: 20% by weight NaCl in the solution;
[0037] acid chamber: HCl, 160 l/hour;
[0038] anode chamber: sulfuric acid, 160 l/hour, concentration: 15% by weight H 2 SO 4 in the acid.
[0039] The electrolytes had a temperature of 53° C., the electrical voltage between anode and cathode amounted to 3.5 V, the cell current was fixed at 700 A and the specific current load amounted to 2 kA/m 2 .
[0040] The test was begun both in the cathode chamber and in the hydrochloric acid chamber with deionized water. The maximum hydrochloric acid concentration achieved at the output of the hydrochloric acid chamber amounted to 23.5% by weight and the concentration of sodium hydroxide solution at the output of the cathode chamber amounted to 33% by weight. The maximum acid concentration is determined by the quantity of the water which passes together with the protons through the cationic exchanger membrane into the hydrochloric acid circulation. Membranes with less permeability for water could make the production of more highly concentrated acids possible in keeping with the method according to the invention.
EXAMPLE 2
[0041] This example shows how hydrochloric acid, which has been concentrated in an electrodialysis cell according to exemplary embodiment 1, can be processed to form concentrated hydrochloric acid through the use of an expansion/condensation method, as has been described with regard to FIG. 3. An 80° C. hot hydrochloric acid with a concentration of 23.5% by weight was drawn off from the electrodialysis cell, the data of which is indicated in Example 1. The hydrochloric acid was drawn off at a quantity of 150 l/hour, heated to 84° C. in an electrical heating device and then expanded by way of a throttle into a tank in which a pressure of 0.2 bar absolute prevailed. In this procedure a portion of the hydrochloric acid evaporated. This hydrochloric acid vapor was drawn off from the tank and condensed in a cooler. The hydrochloric acid obtained in this way had a concentration of 30% by weight HCl in relation to the acid and 3.14 kg of such an acid were obtained per hour. The portion of the hydrochloric acid which did not evaporate and which remained in liquid form in the tank had a concentration of 23.4% by weight HCl. It was returned into the electrodialysis cell at a temperature of 70 to 72° C. Upstream of the electrodialysis cell, 2.2 kg of water per hour were added to this depleted hydrochloric acid as a replacement for the removed quantity of concentrated hydrochloric acid. In the cell, the acid was heated again by the electrolytic process and concentrated. As can be seen, the method operates largely autothermally.
[0042] Tests show that, with the method according to the invention, through the use of the electrodialysis cell in accordance with the invention, on an industrial scale, hydrochloric acid can be generated with a concentration of over 20% by weight and sodium hydroxide solution with a concentration of over 30% by weight. Furthermore, it is seen that by coupling the inventive method with a known method, through utilization of heating of the electrodialytically generated hydrochloric acid according to the method, concentrated hydrochloric acid can also be produced in a simple and effective manner.
[0043] The method according to the invention can also be transferred to other salt/acid/alkali systems.
[0044] The advantages of the invention are:
[0045] pure acids and pure alkalis are produced from the corresponding salts;
[0046] the discharging of anions of the acid-base pair at the anode is avoided. There is therefore, for example, the possibility of producing completely halogen-free hydrohalic acids, specifically chlorine-free hydrochloric acid; and
[0047] for the first time, hydrochloric acid with concentrations of over 10% by weight HCl, can be produced on an industrial scale using an electrodialytic device. | An electrodialytic method and device for the simultaneous production of acids and bases of high purity and higher concentration operates by splitting corresponding salts in aqueous solution using an electrolysis cell. The electrolysis cell includes a cathode chamber in which an alkali is formed, a salt chamber for supplying a salt to be split, an acid chamber in which the acid is formed, and an anode chamber through which a mineral acid flows as a proton carrier. The anode is a hydrogen-consuming electrode. The method and device are preferably used in the production of hydrochloric acid and sodium hydroxide solution. | 1 |
RELATED APPLICATION
[0001] This application is a divisional of U.S. application Ser. No. 11/678,251, filed Feb. 23, 2007, which will issue as U.S. Pat. No. 8,127,783, which is a divisional of U.S. application Ser. No. 10/758,968, filed Jan. 16, 2004, which claims the benefit of U.S. Provisional Application No. 60/440,928, filed Jan. 17, 2003. The contents of U.S. application Ser. No. 10/758,968 and U.S. Provisional Application No. 60/440,928 are incorporated here by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to process fluid control assemblies, and more particularly to shut-off valves for process fluid control assemblies.
BACKGROUND
[0003] Almost every process step during semiconductor wafer processing that adds, alters or removes material on silicon wafers utilizes one or more process fluids. These process fluids range from inert fluids, such as helium, to toxic and corrosive fluids, such as chlorine. Consequently, semiconductor wafer processing requires sophisticated fluid delivery systems that can delivery a variety of process fluids in precise amounts to a wafer processing chamber.
[0004] In a typical processing assembly, the process fluids are contained in individual pressurized cylinders that are under the control of a facility system external to the processing equipment. The fluids are then supplied to the equipment through tubing, and a fluid panel controls the flow of fluid from the point of connection to that tubing to the process chamber. The fluid panel is commonly divided into individual process fluid control assemblies, each of which is a complete assembly of components (such as valves, filters, fluid purifiers, pressure regulators, and transducers) for one fluid stream.
[0005] FIG. 1 shows a process fluid control assembly 101 configuration in a typical prior art fluid panel. The configuration shown is of the type commonly used for toxic fluids, such as chlorine. The process fluid control assembly comprises a manual diaphragm valve 103 that serves as a safety device by allowing the flow of fluid through the assembly to be manually turned off for maintenance and service. Fluid pressure is controlled by a pressure regulator 105 and a pressure transducer 107 . A filter 109 is provided to remove impurities from the fluid stream. First 111 and second 113 pneumatic valves operate to allow the flow of fluid to be remotely turned on and off by sending an electronic signal to both pneumatic valves and to the mass flow controller (MFC) 115 , the latter of which provides precision control of fluid flow through the process fluid control assembly. Third 117 and fourth 119 pneumatic valves are provided so that the mass flow controller can be purged for maintenance. (The third and fourth pneumatic valves are typically not present in process fluid control assemblies of this type which are designed for use with inert fluids.) A communication port 121 is provided on the mass flow controller to allow it to be accessed and controlled remotely.
[0006] While the process fluid control assembly configuration of FIG. 1 allows the fluid panel to provide good control over fluid delivery to the wafer processing chamber, the number of components in this configuration causes the fluid panel to be exceedingly bulky and complex. This is especially so for wafer processing chambers that require several different process fluids.
[0007] There is thus a need in the art for process fluid control assembly and fluid panel configurations that are more compact and/or have fewer components, without sacrificing functionality, ease of serviceability and modularity of the configuration. These and other needs are met by the devices and methodologies disclosed herein.
SUMMARY
[0008] In one aspect, a device is provided which comprises an actuator and a handle. The actuator is adapted to move the device, in response to a pneumatic signal, from a first state (which may be a closed state) into a second state (which may be an open state), and the handle is adapted to move the device from the second state into the first state regardless of whether a pneumatic signal is present. The device may be, for example, a fluid control assembly equipped with a valve, wherein the valve is closed in the first state and is open in the second state, or it may be a pneumatically driven latch, wherein the latch is closed in the first state and is open in the second state. The handle is typically manually driven, as by rotating it about an axis, and the actuator is typically pneumatically driven. The device may comprise a diaphragm and a valve seat, and the actuator may be adapted to move the device, in response to a pneumatic signal, from a first state in which the diaphragm is pressed against the valve seat, to a second state in which the diaphragm is not pressed against the valve seat. The device may further comprise a valve chamber having a fluid inlet and a fluid outlet, wherein the diaphragm and the valve seat form a seal between the fluid inlet and the fluid outlet. In such embodiments, the fluid inlet and the fluid outlet will typically be in open communication with each other when the device is in the second state.
[0009] In another aspect, a combination manual/pneumatic valve for a process fluid control assembly is provided. The valve comprises (a) a housing, (b) a valve chamber disposed in the housing which has a fluid inlet and a fluid outlet and which may also contain a diaphragm and a valve seat, (c) a pneumatically driven actuator which is adapted to move the valve, in response to a pneumatic signal, from a first state in which the flow of fluid between the fluid inlet and the fluid outlet is stopped, into a second state in which flow of fluid between the fluid inlet and the fluid outlet is permitted; and (d) a handle adapted to move the valve from the second state into the first state, regardless of whether a pneumatic signal is present at the actuator. When the valve is in the first state, the diaphragm and the valve seat typically form a seal between the fluid inlet and the fluid outlet; conversely, when the valve is in the second state, the fluid inlet and the fluid outlet are typically in open communication with each other. The valve may further comprise an expansion chamber having a piston therein which is adapted to move the diaphragm from a position in which it is pressed against the valve seat to a different position in response to a signal, as, for example, by advancing along a longitudinal axis in a first direction, and the expansion chamber may be equipped with an inlet adapted to introduce pressurized air into the expansion chamber, and an outlet adapted to exhaust the expansion chamber. The valve may also comprise a spring adapted to maintain a compressive force on the diaphragm.
[0010] The handle of the valve may be equipped with a threaded cylinder that rotatingly engages a complementarily threaded aperture in the housing, thereby moving the valve into the first state. The handle of the valve may have a shaft that is equipped with a passageway defined by first and second apertures that are in open communication with each other, and wherein the first aperture is in open communication with the expansion chamber. The second aperture may be adjustable, by rotation of the handle, from a first position in which it is in open communication with the inlet, to a second position in which it is in open communication with the outlet. The valve seat may be an o-ring and may be disposed about the fluid inlet such that the actuator compresses the diaphragm against the o-ring when the valve is in the first state.
[0011] In some configurations, the valve is adapted such that a spring holds the diaphragm against the valve seat when the valve is in the first state and the pneumatic chamber and piston counteract the spring to allow the diaphragm to move so that the valve can enter the second state. The disconnection of the pneumatic chamber from the inlet and the connection of the pneumatic chamber to the outlet (accomplished by the single act of rotating the handle), places the valve in a closed position and disables the pneumatic control. Such a configuration may also include a mechanical linkage such that the rotation of the handle causes axial force to be applied to the diaphragm, holding it against the seat with a force in addition to that provided by the spring.
[0012] In still another aspect, a process fluid control assembly is provided herein which comprises first and second pneumatic valves, a mass flow controller, and a combination manual/pneumatic valve, wherein the first pneumatic valve is upstream from the mass flow controller, wherein the second pneumatic valve is downstream from the mass flow controller, and wherein the combination valve is upstream from the first pneumatic valve.
[0013] In yet another aspect, a fluid panel is provided herein which comprises a substrate, and a plurality of process fluid control assemblies disposed on said substrate. Each of the plurality of process fluid control assemblies comprises first and second pneumatic valves, a mass flow controller, and a combination manual/pneumatic valve. The first pneumatic valve is upstream from the mass flow controller, the second pneumatic valve is downstream from the mass flow controller, and the combination valve is upstream from said first pneumatic valve.
[0014] These and other aspects are described in greater detail below.
DESCRIPTION OF DRAWINGS
[0015] FIG. 1 is a schematic illustration of a prior art process fluid control assembly.
[0016] FIG. 2 is a schematic illustration of a combination valve/manual handle (shown in a manually enabled, pneumatically closed position) in accordance with the teachings herein.
[0017] FIG. 3 is a schematic illustration of a combination valve/manual handle (shown in a manually enabled, pneumatically open position) in accordance with the teachings herein.
[0018] FIG. 4 is a schematic illustration of a combination valve/manual handle (shown in a manually disabled valve with a pneumatic signal to open the valve being provided, but with the valve closed) in accordance with the teachings herein.
[0019] FIG. 5 is a schematic illustration of a stem/handle interface in accordance with the teachings herein.
[0020] FIG. 6 is an illustration of the functionalities combined into a mass flow controller made in accordance with the teachings herein.
[0021] FIG. 7 is a functional illustration showing the fluid path of a conventional thermal-based mass flow controller.
[0022] FIG. 8 is a schematic illustration of the fluid path of a mass flow controller made in accordance with the teachings herein.
[0023] FIG. 9 is a graph illustrating crosstalk in a conventional fluid panel.
[0024] FIG. 10 is a graph illustrating the elimination of crosstalk through the use of a mass flow controller made in accordance with the teachings herein.
[0025] FIG. 11 is a schematic illustration of a process fluid control assembly configuration made in accordance with the teachings herein.
[0026] FIG. 12 is an illustration of a fluid pallet made in accordance with the teachings herein.
[0027] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0028] As used herein, the term “fluid” is meant to include both liquids and gases. It has now been found that the length of process fluid control assemblies, and hence the size of fluid panels, can be reduced by combining the functionalities of a manual valve and a pneumatic valve (such as the first pneumatic valve 111 of FIG. 1 ) into a single valve. The resulting combination manual/pneumatic valve reduces the length of the process fluid control assembly and the size of the fluid panel without adversely affecting the serviceability of the fluid panel or process fluid control assembly and the modularity thereof It has also been found that further reductions in the length of the process fluid control assembly and the size of the fluid panel can be obtained, again without adversely affecting the serviceability of the fluid panel or process fluid control assembly and the modularity thereof, by combining the functionalities of the pressure regulator, pressure transducer, and filter of a conventional process fluid control assembly such as that shown in FIG. 1 into the mass flow controller. These and other aspects and features of the systems and devices disclosed herein are discussed in greater detail below.
[0029] FIGS. 2 -4 illustrate one embodiment of a combination manual/pneumatic valve 11 made in accordance with the teachings herein. The combination valve has a housing 13 which is typically cylindrical and which contains a centrally disposed expansion chamber 15 and a centrally disposed valve chamber 17 . The expansion chamber and the valve chamber are typically coaxially aligned. The valve chamber has a process fluid inlet 19 and a process fluid outlet 21 defined therein, and is fitted with a diaphragm 23 and a valve seat 25 that cooperate to control the flow of fluid into and out of the valve chamber. Thus, when the diaphragm is spaced apart from the valve seat, the process fluid inlet and process fluid outlet are in open communication, and fluid is permitted to flow into and out of the valve chamber. However, when the diaphragm is compressed against the valve seat (that is, when the valve is if the “off” position), the process fluid inlet and process fluid outlet are isolated from each other, and the flow of fluid through the valve chamber is terminated. Typically, the valve seat will comprise an elastomeric material that has sufficient compliance to achieve a tight seal when a sufficient compressive force is applied to it, yet has sufficient resiliency to return to its original shape when the compressive force is removed. The valve seat will most typically comprise a fluoroelastomer which may be coated with a perfluoropolymer, given the chemical resistance of the latter to commonly used process fluids such as chlorine.
[0030] The expansion chamber 15 of the valve is typically cylindrical and has a coaxially aligned and longitudinally extending shaft 27 disposed therein. The shaft is connected on one end via a mandrel 28 to an actuator 29 which makes contact with the diaphragm 23 , and terminates on the other end in a handle 31 . The shaft is fitted with a spring-loaded piston 33 which is maintained under a minimum compressive force by means of a spring 35 .
[0031] The handle is fitted with a threaded male cylinder 37 that rotationally engages a complementary threaded female receptacle 39 . The handle is typically designed to be operated with an ergonomically reasonable amount of force. Consequently, as the handle is rotated in the (typically clockwise) disabling direction, the shaft 27 is advanced along the longitudinal axis such that the actuator compresses the diaphragm 23 against the valve seat 25 , thereby cutting off the flow of fluid between the process fluid inlet 19 and the process fluid outlet 21 and manually placing the valve in the disabled position. Conversely, when the handle is rotated in the (typically counterclockwise) enabling direction, the shaft is withdrawn along the longitudinal axis, and the valve is returned to a pneumatically controlled state. In this state, and in the absence of a pneumatic signal, the spring 35 continues to force the piston 33 , the shaft 27 coupled directly thereto, and the actuator 29 against the diaphragm 23 , thereby maintaining the valve in a closed position. Hence, the handle provides a mechanism whereby pneumatic control of the valve can be overridden solely for the purposes of disabling the valve (that is, to stop the flow of fluid). By contrast, the flow of fluid through the valve is enabled only when the handle is in a manually enabled position and a pneumatic opening signal is present. This aspect of the combination manual/pneumatic valve is significant from a safety aspect, since it does not allow manipulation of the valve to override the safety interlock circuits that function by disabling the pneumatic signal.
[0032] The housing 13 is also equipped with an air inlet 41 and an air exhaust 43 which can be alternatively brought into open communication with a central passageway 45 disposed in the shaft 27 by rotation of the handle 31 . The central passageway is in open communication with the portion of the expansion chamber disposed below the piston. When the handle 31 is in a manually enabled position as shown in FIG. 2 —that is, when the central passageway is in open communication with the air inlet, and when there is no air signal (i.e., air pressure sufficient to displace the piston against the spring is not applied) at the air inlet—the compressive force exerted by the spring 35 against the piston 33 causes the actuator to press against the diaphragm, hence maintaining the valve in a closed position.
[0033] When the handle 31 is in a manually enabled position as shown in FIG. 3 —that is, when the central passageway is in open communication with the air inlet 41 , and an air signal is present (i.e., sufficient air pressure is applied at the air inlet)—pneumatic pressure is applied to the spring loaded piston 33 , by way of the central passageway 45 . So long as the force exerted by this pneumatic pressure is greater than the expansive force exerted by the spring 35 , the spring will be compressed, the piston will be driven into abutment with a stop surface 47 on the shaft, and the actuator 29 will be withdrawn along its longitudinal axis. This, in turn, allows the diaphragm 23 to expand and bring the fluid inlet 19 and outlet 21 into open communication with each other, thereby permitting a flow of fluid through the valve chamber.
[0034] In valves of the type depicted, the diaphragm is typically driven upward by at least two forces. The first is that the pressure of the fluid in the inlet 19 or outlet 21 imposes an upward force on the diaphragm. The second is that the diaphragm's resting shape is usually concave downwards, so that it flexes unless it is being forced down against the valve seat 25 . With respect to this latter feature, it is to be noted that, in some embodiments, the actuator 29 is not connected to the piston 33 by a means that allows the piston 33 to pull the actuator 29 . In these embodiments, the upward motion of the piston 33 may simply allow the actuator 29 to be moved upward by the flexion of the diaphragm.
[0035] As shown in FIG. 4 , when the handle 31 is in a manually disabled position—that is, when the handle is manually rotated such that the central passageway 45 is in open communication with the air exhaust 43 —the pressure in the expansion chamber is at ambient pressure even if a pneumatic signal is present at air inlet 41 . Moreover, the advancement of the shaft 27 along the longitudinal axis as the handle 31 is rotated into a disabled position drives the actuator 29 against the diaphragm 23 . Consequently, the valve is disabled by the longitudinal displacement of the shaft that precludes the piston being moved away from the diaphragm by the pneumatic signal.
[0036] The combination manual/pneumatic valve 11 may be lockable in the disabled position using a padlock, a cable, or other available locking devices (not shown). Hence, the valve may function as a Lock Out Tag Out (LOTO) device. Moreover, to ensure safety in case of failure in the fluid control components upstream of the manual valve, the valve may also be designed to withstand an inlet pressure of at least 3000 PSIA in the disabled position without allowing fluids to pass through the valve for 72 hours (irreversible damage to the valve is reasonable in this unlikely scenario).
[0037] It will be appreciated from the above description that the valve can be disabled manually or closed pneumatically, though manual disablement is independent of the pneumatic input state. Hence, the valve can be opened pneumatically to allow the flow of fluid, only if it is manually in the enabled position, and the valve can also be disabled manually to stop the flow of fluid, even if a pneumatic signal to open is present. This feature of the valve is highly advantageous from both an emergency shut-off and maintenance aspect.
[0038] FIG. 5 illustrates the shaft/handle interface 61 of the combination valve disclosed herein. This interface would typically be disposed inside the threaded male cylinder 37 in the combination manual/pneumatic valve depicted in FIGS. 2-4 . The interface may be machined onto, or soldered onto, one end of the shaft 27 in the valve of FIGS. 2-4 . The handle has a hollow cylindrical underbody which is adapted to mate with a complimentary shaped male member (shaft/handle interface FIG. 5 ) that protrudes from the shaft 27 of the valve of FIGS. 2-4 . The interface is also provided with an aperture 65 which is adapted to receive an Allen screw or other fastening device for securing a handle to the interface.
[0039] The shaft/handle interface 61 of FIG. 5 is advantageous in that it can be provided on each component of the fluid panel that requires a handle, thus allowing the fluid panel to be readily standardized so that the same handle can be used to operate each component of the panel. This also allows each component fitted with the interface to be easily retrofitted and standardized as a LOTO device. The dimensions of the features on the shaft/handle interface 61 of FIG. 5 can vary.
[0040] The combination manual/pneumatic valve described above in reference to FIGS. 2-4 has several important safety advantages over many existing valves. One of these safety advantages relates to the use of the combination valve to provide Lockout/Tagout (AKA, LOTO, Hazardous Energy Isolation (HEI)). For example, reduction in fluid panel size could be obtained by placing a conventional lockable, manually-operated valve in the pneumatic control line to the valves, and this would permit the disabling of pneumatic control in a manner that would arguably meet the regulatory requirements for Lockout/Tagout devices. However, this approach is flawed in that the energy isolation could be subverted by connecting (deliberately or accidentally) another source of actuating pressure to the process fluid valve. For example, an accidental connection could be the result of an attempt to connect a control line to a different valve, or from the connection of the manually operated valve to a process chemical valve other than the one the person intended to isolate.
[0041] In addition, overriding the pneumatic control signal of a normally disabled valve leaves the valve in a state in which it relies on the spring force being greater than the force applied to the underside of the diaphragm by the fluid to keep the valve disabled. Valves can be made in accordance with the teachings herein that eliminate these flaws by disconnecting the pneumatic control within the valve assembly (preventing cross connection of control lines) and by providing a rigid mechanical linkage that applies closing force to the diaphragm (reducing the dependence on spring pressure to overcome the opening force applied by the gas). Notably, the opening force applied by a fluid of a given pressure at the valve outlet is approximately an order of magnitude greater than the opening force applied by a fluid of the same pressure on the fluid inlet. Consequently, the valves which rely on a spring to maintain closure are subject, when disabled, to reverse flow at much lower pressure than that at which they are subject to forward flow.
[0042] Another safety advantage is that the combination of the manual override and pneumatic actuation into a single valve renders moot the competition for first (closest to the point of connection to the fluid supply) position between pneumatic and manual valves. The manual valves, as described previously, are used to isolate the downstream fluid panel elements and the process chamber from the fluid supply. The safety advantage of placing the manual valve first is that it is then positioned to isolate all of the other elements of the fluid panel from the supply. This minimizes the chance of accidental release (either from component failure or human error) by minimizing the number of components that are still connected to the supply.
[0043] The pneumatic valves serve a different safety function. They may be used as the actuating elements of several interlock circuits that, in response to various conditions, disconnect the fluid supply from the elements of the fluid panel downstream of them and from the process chamber. Among the sensors in such interlock circuits are fluid detectors. If the detectors sense a leak and remove the actuating signal from a valve, control of the flow through the leak depends on whether the leak is upstream or downstream of the valve which is no longer being actuated. Therefore, it is advantageous in many applications to have the pneumatic valve that is the actuating element for such interlocks as far upstream in the assembly as possible. Consequently, the manual and pneumatic valves “compete” for the first position. As noted above, the combination valve described herein renders this matter moot, as the same valve is subject to control by both means.
[0044] The combination manual/pneumatic valve described above and illustrated in FIGS. 2-4 enables significant reductions in process fluid control assembly length and fluid panel size by combining the functionalities of a pneumatic valve and manual shut-off valve into a single component. However, it has also been found that even further reductions in the length of the process fluid control assembly and in the size of the fluid panel can be obtained, without adversely affecting the serviceability of the fluid panel or process fluid control assembly and the modularity thereof, through modifications to the MFC. The resulting MFC is referred to herein as a “Pressure Insensitive MFC” (PIMFC). As seen in FIG. 6 , the PIMFC 71 combines into a single unit the functionalities of a pressure regulator 73 , pressure transducer 75 , filter 77 , and MFC 79 as those elements are found in a conventional process fluid control assembly such as that shown in FIG. 1 . The PIMFC is described in greater detail below.
[0045] FIG. 7 is a functional illustration of a conventional thermal-based MFC 81 . The MFC consists primarily of a control valve 83 and a thermal flow sensor 85 . The use of an MFC of this type necessitates the use of a pressure regulator to eliminate “crosstalk”, that is, pressure perturbations in the supply line supplying fluid to a first process fluid control assembly that can occur when a second process fluid control assembly operating from the same fluid source is brought online. Crosstalk commonly occurs when the second process fluid control assembly is supplying the fluid at a significantly higher pressure than the first fluid control assembly. Such pressure perturbations cause the MFC controlling the first process fluid control assembly to temporarily register an indicated fluid flow rate that is substantially different (typically much lower) than the actual flow rate.
[0046] The effect of crosstalk in a process fluid control assembly controlled by a conventional MFC (and without the aid of a regulator) is shown in the graph of FIG. 9 . This graph was generated on a test station using a stimulus MFC to create a pressure perturbation of about 3 psi (20.7 MPa). The curve denoted “XDOR6” indicates pressure in the fluid line as a function of time as measured by a pressure transducer. The curve denoted “indicated flow” is the fluid flow through the process fluid control assembly as indicated by the MFC, while the curve denoted “ROR” is the Rate of Rise flow, a standard measurement of the actual fluid flow in the fluid control assembly.
[0047] After the initial perturbation of about 3 psi (20.7 MPa), the pressure perturbation relaxed to a pressure difference of about 2 psi (13.8 MPa). However, during the initial perturbation, the difference in indicated and actual fluid flow at the MFC was about 3 sccm. This demonstrates the tendency of the MFC, in the absence of a pressure regulator, to overcompensate for the initial pressure drop in the fluid supply at the process fluid control assembly inlet by ramping up the actual flow rate. The use of pressure regulators is thus necessitated with conventional MFCs of this type. The pressure regulator functions by controlling crosstalk by dampening out the pressure perturbations giving rise to crosstalk. This, in turn, allows the indicated flow rate to more closely track the actual flow rate.
[0048] FIG. 8 is a functional illustration of a PIMFC 91 made in accordance with the teachings herein. The specific details of the components of the PIMFC may vary significantly from one product to another, and have been omitted for purposes of clarity. However, these components are individually well understood in the art, and hence one skilled in the art will appreciate various specific implementations from the functional presentation of these components here.
[0049] As with the conventional MFC illustrated in FIG. 7 , the PIMFC also contains a control valve 93 and a thermal flow sensor 95 . However, the PIMFC additionally contains a pressure sensor 97 and a filter 99 . The pressure sensor is upstream of the flow sensor and can be tied into the control loop operating the control valve. Consequently, the PIMFC can rapidly compensate for any changes in the inlet pressure through suitable manipulation of the valve. Since the PIMFC is thus adapted to deal with pressure perturbations in the fluid control assembly, the need for a separate regulator is eliminated. Moreover, since the filter 99 in a conventional process fluid control assembly exists primarily to filter out from the fluid stream debris created by the pressure regulator before the fluid stream enters the MFC, the need for a stand-alone filter is also eliminated. Consequently, the filter may be simplified and incorporated directly into the PIMFC 91 to protect the sensors and actuators from particulate accumulation generated elsewhere upstream. Also, since the PIMFC already contains a pressure sensor, there is no need for an external pressure transducer, and the display functionalities associated with the pressure transducer may be incorporated directly into the PIMFC (that is, the PIMFC may be provided with a display to indicate the pressure already being measured by the pressure sensor).
[0050] FIG. 10 illustrates the effectiveness of the PIMFC disclosed herein in eliminating crosstalk in a process fluid control assembly without the use of an external pressure regulator. As with the conventional MFC that was the subject of the graph in FIG. 8 , the PIMFC was subjected to an initial pressure perturbation of about 3 psi (20.7 MPa), after which the pressure perturbation relaxed to a pressure difference of about 2 psi (13.8 MPa). However, unlike the conventional MFC, the PIMFC closely tracked the actual fluid flow rate through the process fluid control assembly during the entire perturbation. This demonstrates that the PIMFC, unlike a conventional MFC, will not overcompensate for pressure perturbations, and hence does not require the use of a separate pressure regulator.
[0051] FIG. 11 illustrates a process fluid control assembly 131 made in accordance with the teachings herein which is suitable for use with toxic fluids and which incorporates the combination manual/pneumatic valve and PIMFC described above. The process fluid control assembly comprises a combination manual/pneumatic valve 133 of the type illustrated in FIGS. 2-4 , first 135 and second 137 pneumatic valves, and a PIMFC 139 . The first 135 and second 137 pneumatic valves allow the flow of fluid to be remotely turned on and off by sending an electronically controlled pneumatic signal (pressurized air) to both pneumatic valves. A communications port 141 is provided on the mass flow controller to allow it to be accessed and controlled remotely. This communications port, which may be adapted to accept wires, optical cables, and other such communications means, may be situated on various surfaces of the mass flow controller and may have various configurations.
[0052] In contrast to the conventional process fluid control assembly of FIG. 1 , which requires a pressure regulator 105 , pressure transducer 107 , and filter 109 , in the process fluid control assembly 131 of FIG. 11 , the pressure regulator has been eliminated and the functionalities of the remaining elements have been combined into the PIMFC 139 as described above. Consequently, pneumatic valve 113 of FIG. 1 is no longer required, since the aforementioned elements can be isolated for purging or maintenance in the process fluid control assembly of FIG. 11 via the first 135 and second 137 pneumatic valves. Furthermore, pneumatic valve 111 of FIG. 1 has been combined into the manual/pneumatic valve 133 in the process fluid control assembly of FIG. 11 , also as described above. Therefore, the process fluid control assembly of FIG. 11 is sufficiently more compact than the conventional process fluid control assembly of FIG. 1 . This compact design also simplifies pallet design for the fluid panel and reduces the cost thereof Moreover, because the process fluid control assembly of FIG. 11 has fewer components than conventional process fluid control assemblies such as that shown in FIG. 1 , Mean Time Before Failure (MTBF) is higher for the entire system, and thus maintenance costs are reduced.
[0053] The process fluid control assembly 131 of FIG. 11 is adapted for use with toxic fluids such as chlorine. However, one skilled in the art will appreciate that the principles herein may also be extended to process fluid control assemblies adapted for use with inert fluids. This may be accomplished, for example, by modifying the process fluid control assembly of FIG. 11 through the elimination of pneumatic valves 135 and 137 .
[0054] FIG. 12 depicts one non-limiting example of a fluid panel 151 which incorporates a series of process fluid control assemblies 153 of the type depicted in FIG. 11 . In a typical configuration, some of the process fluid control assemblies (typically the first six, going from left to right) control toxic, corrosive or flammable fluids, and the remainder of the process fluid control assemblies control the flow of inert fluids. These two types of process fluid control assemblies are referred to herein as toxic process fluid control assemblies and inert process fluid control assemblies, respectively.
[0055] Each of the process fluid control assemblies is supported on a common pallet 155 and comprises a combination manual/pneumatic valve 157 (of the type illustrated in FIGS. 2-4 ), first 159 and second 161 pneumatic valves, and a PIMFC 163 equipped with a communication port 165 . The fluid panel further includes a main manifold 167 where various process fluids under the control of individual process fluid control assemblies can be mixed to form a fluid stream. The fluid stream exits the main manifold via the main manifold outlet 171 , from which it can be directed to a process chamber (not shown) or other end use device.
[0056] The main manifold is provided with a fluid inlet 173 and a fluid outlet 175 that allow it to be flushed with an inert fluid such as N 2 for maintenance purposes or to clear it of residual toxic fluids. The fluid flow through fluid inlet 173 and fluid outlet 175 may be controlled by purge valve 177 , in addition to one or more of the other valves on the main manifold. A fluid line 179 is provided through which the main manifold 167 and a purge manifold 160 , the latter of which is disposed under the set of first pneumatic valves 159 , can be brought into open communication, thus allowing the PIMFCs 163 to be isolated for maintenance or other purposes.
[0057] The main manifold 167 is provided with a first, second and third pair of valves that respectively consist of first 181 , second 185 and third 189 inlet valves and first 183 , second 187 and third 191 outlet valves. The first 183 and second 187 outlet valves are pneumatically coupled, with the first outlet valve operating to control the flow of inert fluids from the inert process fluid control assemblies into the main manifold, and the second outlet valve operating to control the flow of toxic fluids from the toxic process fluid control assemblies into the main manifold. Thus, for example, the first six process fluid control assemblies (from left to right) may be under control of the second outlet valve 187 , and the next six process fluid control assemblies may be under control of the first 183 outlet valve. Hence, when the first 183 and second 187 outlet valves are both enabled, the fluid streams from any enabled inert process fluid control assemblies will mix with the fluid streams from any enabled toxic process fluid control assemblies inside of the main manifold 167 and the resulting mixed fluid stream will exit the main manifold through the main manifold outlet 171 .
[0058] The fluid panel 151 is further provided with pass-through valves 181 and 185 . These pass-through valves, which are kept enabled during normal operation of the fluid panel, cooperate with the first 183 and second 187 outlet valves, respectively, to regulate the flow of fluid through the pump/purge manifold 186 and to allow for bidirectional pumping and purging of the fluid panel.
[0059] The third outlet valve 191 on the fluid panel regulates the flow of fluid through inlet 173 for purging and maintenance of the fluid panel. Similarly, the third inlet valve 189 regulates the flow of fluid into the pump/purge manifold 186 for purging and maintenance purposes. Thus, for example, if the third inlet valve 189 is disabled and the third outlet valve 191 is enabled, then fluid can be made to flow through fluid line 179 and subsequently through the purge manifold 160 under the set of first pneumatic valves 159 so that toxic fluids can be purged from the toxic process fluid control assemblies.
[0060] The principles disclosed herein have been described primarily with reference to combination manual/pneumatic valves and to the use of such valves in process fluid control assemblies. However, it will be appreciated that the manual/pneumatic actuators described herein have a number of applications that extend beyond process fluid control assemblies. For example, such actuators could be employed in various latching systems, such as those used in industrial and high security settings. In such applications, the manual/pneumatic actuators would maintain the latch in a closed position (and therefore maintain a door, hatch or other device under control of the latch in a closed position) unless a pneumatic signal is present. Moreover, even if a pneumatic signal is present, the manual/pneumatic actuator would allow for manual override of the pneumatic signal for safety, security, or maintenance purposes.
[0061] More generally, the principles disclosed herein may be applied to devices in which an energy input is provided to cause the movement of one or more movable components of the device. Such devices may be modified in accordance with the teachings herein to effect, as the result of a single manipulation of a manual control, the disconnection of the energy input and the engagement of a mechanical means of keeping the movable component (or components) from moving. Specific, non-limiting examples of such modified devices include valves in which the energy input is a control signal that allows a hazardous material to flow, and latches in which the energy input is a control signal which allows access to a hazardous area. The modified device could also be a manual valve that controls actuation air to a pneumatically powered device (e.g., a gate valve), and that includes a mechanism that, in the disabled state, engages a mechanical lock on the pneumatically powered device, precluding movement of one or more pneumatically driven components of the device.
[0062] It will also be appreciated that, while the principles disclosed herein have been frequently illustrated in reference to pneumatically actuated devices, these principles are also applicable to devices having various other energy inputs and actuating signals. Such energy inputs include, but are not limited to, electrical and fluid (e.g., hydraulic) signals.
[0063] A combination manual/pneumatic actuator has been described herein. A combination manual/pneumatic valve has also been described herein that utilizes such an actuator and that combines the functionalities of a manual valve and a pneumatic valve into a single valve. This combination valve allows for reductions in the length of process fluid control assemblies and of fluid panels incorporating these process fluid control assemblies, without any loss in functionality, ease of serviceability and modularity. Fluid panel configurations that make advantageous use of the shortened process fluid control assemblies have also been provided.
[0064] All the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps or any method or process so disclosed, may be combined in any combination, except combinations where at least some of the features and/or steps are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same equivalent or similar purpose, unless expressly stated otherwise. Thus unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. Moreover, although a specific embodiment is specifically illustrated and described herein, it will be appreciated that modifications and variations of the invention are covered by the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention. | A method of preventing a mass flow controller from participating in crosstalk in an array of mass flow controllers is described. The method includes sensing and providing a signal indicative of a fluid pressure inside of a mass flow controller with a pressure sensor contained within the mass flow controller, determining a response of a control valve to a rapid pressure perturbation at the inlet of the mass flow controller using the signal indicative of the fluid pressure to avoid overcompensation for the rapid pressure perturbation, and adjusting a control valve contained within the mass flow controller downstream of the pressure sensor, based on the determined response, so that the mass flow controller avoids overcompensating for the rapid pressure perturbation. The pressure sensor is positioned such that the pressure sensor is sensitive to rapid pressure perturbations at the inlet of the mass flow controller. | 5 |
This is a continuation of application U.S. Ser. No. 09/513,275 filed Feb. 24, 2000 now U.S. Pat. No. 6,235,681 which is a division of U.S. Ser. No. 09/209,061 filed Dec. 10, 1998 now U.S. Pat. No. 6,238,684, incorporated herein by reference.
BACKGROUND OF THE INVENTION
Many herbicides require the addition of an adjuvant to the spray mixture to provide wetting and spreading on foliar surfaces. Often that adjuvant is a surfactant, which can perform a variety of functions, such as increasing spray droplet retention on difficult to wet leaf surfaces, or to provide penetration of the herbicide into the plant cuticle. These adjuvants are provided either as a tankside additive or used as a component in herbicide formulations.
Gaskin, et al., ( Pestic. Sci. 1993, 38; 185-192) demonstrated that some trisiloxane ethoxylates (TSE), such as Silwet L-77® surfactant (available from OSi Specialties, Inc. of Greenwich, Conn.), can antagonize cuticular penetration of a herbicide into grasses, when compared to the herbicide alone. The term antagonism is used to indicate that the treatment of herbicide plus adjuvant is less effective than the comparative herbicide treatment.
Gaskin, et al., ( Pest. Sci. 1993, 38, 192-200) showed that this antagonism can be mitigated if the number of ethylene oxide (EO) units contained in the TSE is increased to 17 or more; however, superspreading of the TSE is reduced dramatically once the degree of ethoxylation exceeds about 12 EO, and TSE's containing the higher EO adducts show spreading properties similar to conventional nonsilicone surfactants.
Sandbrink, et al., ( Pest. Sci. 1993, 38, 272-273) published that a TSE antagonized glyphosate performance relative to glyphosate alone in the control of Panicum maximum Jacq. Snow, et. al., Langmuir, 1993, 9, 424-30, discusses the physical properties and synthesis of novel cationic siloxane surfactants. These siloxanes are based on the reaction of a chloropropyl modified trisiloxane with an alkanolamine, such as N-methylethanolamine, which was further reacted with a halide to make a quaternary surfactant.
Petroff, et al., (EP 92116658) describes the use of cationic, quaternary trisiloxanes to enhance the efficacy of glyphosate on velvetleaf, a broadleaf weed. Henning, et al., (DE4318537) describes cationic siloxanyl modified polyhydroxy hydrocarbon or carbohydrate for use with plant protection agents. These compounds are derived from a saccharide containing 1 to 10 pentose and/or hexose units, modified with a quaternary ammonium group, and a siloxane moiety.
Reid. et al., (U.S. Pat. No. 3,389,160) describes amino modified siloxane alkoxylates where the amino functionality appears as the terminal group on the alkyleneoxide moiety, opposite the siloxane group.
Policello in PCT WO 97/32475 discloses amino modified siloxanes wherein the amine is bound by an ether bond to the siloxane backbone wherein the amine may be terminal or pendant to the backbone.
SUMMARY OF THE INVENTION
The present invention teaches the composition of terminally modified, amino, polyether, siloxanes, known henceforth as amino siloxane alkokylates, and their use as adjuvants. The amino siloxane alkoxylates of the present invention enhance the efficacy of agrichemicals on plants as compared to conventional TSE's alone. Optionally, the amino siloxane alkoxylates of this invention may be blended with conventional trisiloxane alkoxylates. Blends of these unique amino siloxanes with more traditional trisiloxane alkoxylates (TSA) provide superspreading properties, on difficult to wet surfaces, that are equal to, or greater than what is contributed by the individual components.
DETAILED DESCRIPTION OF THE INVENTION
These compositions are especially useful in overcoming the antagonistic effects on pesticide efficacy associated with superspreading, TSAs. Mixtures of the compositions of the present invention with TSAs provide enhanced spreading properties relative to the individual components alone. In addition, these products provide a low aqueous surface tension (≦25 mN/m at 0.1 wt %), which is desirable for enhanced spreading of pesticide solutions.
COMPOSITION
The amino siloxane alkoxylates of the present invention have the average general formula: ZMe 2 SiO[(Me) 2 SiO] x SiMe 2 Q, wherein x=0 to 2, preferably 1. Q=C a H 2a O(C 2 H 4 O) b (C 3 H 6 O) c R, a=2 to 4, preferably 3, b=1 to 12, preferably 3 to 8, c=0 to 5, providing that when c is >0, (b+c)=2 to 12, preferable =4 and 8, R is hydrogen, acetyl or a hydrocarbon radical between 1 and 4 carbon atoms, Z is BN[DO(C d H 2d O) e R] 2-z V z , each d is 2 to 4, preferably 2 to 3, each e is 0 to 15, preferably 0 to 8, z=0 to 2, preferably 2, each V is a univalent group, D is an alkylene divalent bridging group on which there may be hydroxyl substituents, and B is a divalent bridging group.
V groups preferably are alkyl (which may be branched, linear or cyclic) of less than 8 carbons, which may or may not contain hydroxyl functionalities. Another preferred V is an alkyl amine functionality, the nitrogen of which may be further substituted (e.g. with an alkyl) or be further alkoxylated. Exemplary V are ethyl, 2-hydroxyethyl, 3-hydroxypropyl, methyl, and 2-aminoethyl.
B groups may be of the formula D(O) y (C d H 2d O) j D wherein D and d are as above, j=0 to 8, preferably 0 to 2, and y=0 or 1. Preferably D has 2 to 6 carbon atoms, B may also preferably be a divalent alkylene group of C 2 -C 4 .
When Q or B is a mixture of oxyalkylenes, it may be blocked or random. One skilled in the art will understand the advantages in the position of the oxyethylene relative to the oxypropylene, when the alkyleneoxide croup is blocked.
The Z groups may include protonated amines, i.e, where there is a hydrogen ion attached to the nitrogen in the Z group, which can occur to the amino siloxane alkoxylates under acidic conditions. Also contemplated herein are quaternary versions of Z, i.e., where there is a third R 3 group on the nitrogen in Z, but said quaternary compounds are not preferred for use in the present invention.
Preferred Z structures are wherein R is hydrogen or methyl, D is a divalent organic group of 2 to 4 carbons, B is a divalent organic group of 2 to 4 carbons, in which at least one carbon radical contains a hydroxyl group, and V is 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, propyl, ethyl or methyl. Preferred amino siloxane alkoxylates are trisiloxanes.
In addition the compositions of the present invention optionally may include nonionic siloxane alkoxylates of the general formula:
R 4 Me 2 SiO[MeSi(G)O] g SiMe 2 R 4
wherein g=0 to 2, preferably 1, G=C 2 H 2a O(C 2 H 4 O) t (C 3 H 6 O) w R, a and R are as above, t=3 to 12, preferably 4 to 8, w=0 to 8, providing that when w is >0, (t+w) is preferably between 5 and 12. R 4 is G, or an alkyl of one to four carbons. The preferred nonionic siloxane alkoxylates are trisiloxane alkoxylates, where g=1, d=3, t=4 to 8, w=0, R 4 is Me, R is H or Me.
The compositions of the present invention also optionally include ingredients for use herein are pesticides, especially acid functionalized ones, i.e., compounds that contain at least one carboxylic, sulfonic or phosphonic acid group or their salt or ester. The term pesticide means any compound used to destroy pests, e.g., rodenticides, fungicides, and herbicides. Illustrative examples of pesticides which can be employed include, but are not limited to, growth regulators, photosynthesis inhibitors, pigment inhibitors, mitotic disrupters, lipid biosynthesis inhibitors, cell wall inhibitors, and cell membrane disrupters. The amount of pesticide employed in compositions of the invention varies with the type of pesticide employed. More specific examples of pesticide compounds that can be used with the compositions of the invention are: phenoxy acetic acids, phenoxy propionic acids, phenoxy butyric acids, benzoic acids, triazines and s-triazines, substituted ureas, uracils, bentazon, desmedipham, methazole, phenmedipham, pyridate, amitrole, clomazone, fluridone, norflurazone, dinitroanilines, isopropalin, oryzalin, pendimethalin, prodiamine, trifluralin, glyphosate, sulfonylureas, imidazolinones, clethodim, diclofop-methyl, fenoxaprop-ethyl, fluazifop-p-butyl, haloxyfop-methyl, quizalofop, sethoxydim, dichlobenil, isoxaben, and bipyridylium compounds.
MANUFACTURE
The amino siloxane alkoxylates of the present invention may be made by the hydrosilation of a terminal hydridosiloxane with allyl glycidal ether, and allyl started polyalkyleneoxide. This is followed by ring opening of the epoxide moiety with a primary or secondary amine. The components described are available commercially and may be made as known in the art. Alternatively, the hydrosilation may take place with an allyl amine and an allyl started polyalkyleneoxide. Hydrosilation reaction conditions may be found in Marcienic, ed., 122-23 and 558-568 (1995), which is incorporated herein.
The amine intermediate (e.g., allyl amine) may be prepared by reaction of an unsaturated halide (e.g., allyl bromide) and an amine. The allyl amine also may be prepared by reaction of an allyl glycidyl ether (or similar unsaturated epoxide) with an amine (which result in an ether bond in the bridging group B). An alternative method uses aziridine, which is not preferred for toxicity reasons, are disclosed in PCT US97/04128, which is incorporated herein by reference.
The hydrosilation products may be blends of the product of the present invention with amine terminated siloxanes and polyether terminated siloxanes. If desired, one may separate these, e.g., by distillation; however, these blends may be used without such purification.
The nonionic siloxane and the pesticides are available commercially and their manufacture is known in the art.
USE
The amino siloxane alkoxylates primarily are intended for use in the agricultural field as adjuvants for pesticide containing aqueous formulations. The composition of the present invention is useful as a tank side additive, or as a component in a herbicide formulation. In addition the compositions of the present invention are useful as adjuvants for other pesticides, such as, fungicides, insecticides, plant growth regulators, acaracides and the like.
The siloxanes are added directly to a spray tank along with an acid functional pesticide, or as part of a pesticide formulation. When used as a tankside additive, the amino siloxane alkoxylates are present at weight concentrations between 0.01% and 5.0%, preferably between 0.025% and 0.5%. Likewise, when the aminosiloxane alkoxylates are used in a pesticide formulation (In-can), they are present at weight concentrations that will deliver between 0.01% and 5.0% to the final use dilution, preferably between 0.025% and 0.5%, of the final use dilution.
It is noted that most dilutions will be made with water, but in the case of crop oil concentrates, oils will be the diluents.
When the compositions of the present invention are used in conjunction with a nonionic siloxane alkoxylate, the weight ratio of the nonionic siloxane alkoxylate to the amino siloxane alkoxylates is between 5:95 and 95:5, preferably between 5:95 and 40:60. The blend may be accomplished by physically mixing the two components together as a formulation, or by adding them separately to a spray mixture at point of use.
The amino siloxane alkoxylates also may be used generally as surface active agents in aqueous formulation where there is an acid functionalized component. The amino siloxane alkoxylates of the present invention also may be used generally as surface active agents, including, but not limited to, surfactants, wetting agents and softeners for textiles, as flowing and leveling agents in coatings, in hair care products, skin care and creams for personal care applications and as anti-static agents, detergents and softeners for laundry products. Other uses will be obvious to those of skill in the art.
Optionally, the amino siloxane alkoxylates may be blended with other nonionic, cationic or anionic co-surfactants, especially those with hydrophobes of C 5 -C 10 (short chain alkoxylates) and GEMINI surfactants (see WO 97/23281).
EXAMPLES
The following examples are presented to further illustrate and explain the present invention and should not be taken as limiting in any regard. Unless otherwise indicated, all parts and percentages are by weight, and are based on the weight at the particular stage of the processing being described.
Example 1
a. Epoxy Siloxane Alkoxylates Intermediate:
25.0 g (0.1199 moles) of 1,1,3,3,5,5-hexamethyltrisiloxane (>97% by GC) was added to a 250 mL, 4 neck round bottom flask, equipped with a mechanical agitator, a Claisen adapter containing a reflux condenser and a thermometer (with Therm-o-Watch), a nitrogen bypass, and a 100 mL addition funnel containing 13.7 g (0.1199 moles) of allyl glycidal ether (AGE). The 1,1,3,3,5,5-hexamethyltrisiloxane was heated to 65° C. and catalyzed with 0.02 g of platinum catalyst. The AGE then was added dropwise to the reaction mixture which exothermic to a maximum of 72° C. The temperature was maintained by the addition rate of the AGE, and supplemented as needed by a heating mantle. After all of the AGE was added, the temperature was adjusted to 80° C. At this point 10 g (0.0442 moles) of allylpolyethyleneoxide (Allyl=18.2 wt %, Moles EO=4) was added to the flask, along with an additional 0.03 g of platinum catalyst. The reaction exothermed to 82.9° C. within 5 minutes. At this point the temperature was adjusted to 90° C. and the remaining 25.24 g (0.1117 moles) of allylpolyethyleneoxide was added dropwise from the addition funnel to the flask contents. The temperature was maintained between 98° C. and 101° C. by the addition rate of the allylpolyethyleneoxide, and supplemented, as needed, by a heating mantle. Once all of the allylpolyethyleneoxide was added, the temperature was adjusted to 95° C. and stirred for 1 hour. The reaction mixture showed no traces of SiH when introduced to a fermentation tube containing KOH/water/ethanol solution. The product was cooled to 60° C. and treated with 4 g NaHCO 3 , and stirred for 1 hour. The mixture was filtered through a fine filter pad and stripped on a Rotovap for 1.5 hours at 70° C. and 1.0 mm Hg to afford a clear amber liquid with an epoxy content of 6.0 wt % (92.4% of theory based on initial charge).
b. Amino Siloxane Alkoxylate
The epoxy siloxane intermediate (55.0 g; 0.0825 moles), along with 11.28 g (0.1073 moles) of diethanolamine (corresponding to an 30% molar excess), and 28.4 g of 2-propanol (solvent), were added to a 250 mL, 4 neck round bottom flask, equipped with a mechanical agitator, a Claisen adapter containing a reflux condenser and a thermometer (with Therm-O-Watch), and a nitrogen bypass. The mixture was heated to 80° C., and catalyzed with 0.1 g titanium(IV) butoxide. The reaction time was approximately 6 hours, at which point the temperature was adjusted to 50° C., and 0.5 g water was added to deactivate the catalyst. Mixing time was approximately 1 hour. The product was then filtered through a fine filter pad and stripped on a Rotovap for 1.5 hours at 70° C. and 1.0 mm Hg to afford a clear amber liquid with a Brookfield viscosity of 257 cps at 21° C. (spindle SG-2, 60 rpm).
The structure for the amino siloxane alkoxylate was confirmed by 29 Si and 13 C NMR. The amino siloxane alkoxylate used here as an example, is shown as ASA-1, in Table 1. Other compositions of amino siloxane alkoxylates shown below were prepared according to this procedure.
Example 2
a. Composition Examples of Invention
Table 1 describe the amino siloxane alkoxylates used herein as illustrative examples of the compositions of the present invention.
TABLE 1
Description of Amino Siloxane Alkoxylates
10
Reference
X
Q Group
Z Group
ASA-1
1
C 3 H 6 O(C 2 H 4 O) 4 H
C 3 H 6 OCH 2 CH(OH)CH 2 NV 2
ASA-2
1
C 3 H 6 O(C 2 H 4 O) 5 H
C 3 H 6 OCH 2 CH(OH)CH 2 NV 2
ASA-3
1
C 3 H 6 O(C 2 H 4 O) 5 (C 3 H 6 O) 2.5 H
C 3 H 6 OCH 2 CH(OH)CH 2 NV 2
ASA-4
0
C 3 H 6 O(C 2 H 4 O) 4 H
C 3 H 6 OCH 2 CH(OH)CH 2 NV 2
V = —C 2 H 4 OH
b. Comparative Silicone Based Surfactants:
Table 2 provides structural information on two comparative trisiloxane alkoxylates that are commercially used as wetting agents for agrichemicals. These materials were prepared by standard hydrosilation of an allyl terminated polyether with an Si—H intermediate, such as heptamethyltrisiloxane. The SiH intermediates were prepared by acid equilibration as is known in the art.
TABLE 2
Description of Conventional Trisiloxane Alkoxylates
Me 3 SiO[MeSi(G)O] 1 SiMe 3
Reference
G Group
Sil-A
C 3 H 6 O(C 2 H 4 O) 8 CH 3
Sil-B
C 3 H 6 O(C 2 H 4 O) 8 H
c. Comparative Nonsilicone Surfactants:
Table 3 provides descriptions of typical, comparative, nonsilicone surfactants, used as agricultural wetting agents.
TABLE 3
Description of Comparative Conventional Nonsilicone Surfactants
Reference
Moles EO
Remarks
OPE
10
Octylphenol ethoxylate (Triton X-100)
(Union Carbide Corp., Danbury, CT)
TAE
15
Tallow amine ethoxylate (Ethomeen T/25)
(Akzo Nobel Chemicals Inc.: Chicago, IL)
Example 3
Surface Tension
This example compares commonly used surfactants with the amino siloxane alkoxylate (ASA) compositions of the present invention for their ability to provide a reduction of the aqueous surface tension to values ≦25 mN/m, which is necessary for enhanced spreading of pesticide solutions (Table 4). The aqueous surface tension was determined by the Wilhelmy plate method, using a sand blasted platinum blade as the sensor. Surfactant solutions (0.1 wt %) were prepared in 0.005 M sodium chloride solution either alone or as mixtures. The mixtures of the ASA component and SIL-B were prepared by blending 0.1 wt % solutions of the individual surfactants at a ratio of 80/20 (ASA/SIL-B). Therefore, Blend-1=ASA-1/SIL-B, Blend 2=ASA-2/SIL-B, Blend-3=ASA-3/SIL-B, and Blend-4=ASA-4/SIL-B (all at a ratio of 80/20).
TABLE 4
Comparison of Surface Tension Properties
Composition of
Surface (a)
Surfactant
Invention
Tension
ASA-1
Yes
23
ASA-2
Yes
24
ASA-3
Yes
23
ASA-4
Yes
25
Blend-1
Yes
21
Blend-2
Yes
20
Blend-3
Yes
21
Blend-4
Yes
20
Sil-A
No
21
Sil-B
No
21
OPE
No
29
TAE
No
41
None (b)
N/A
72
a. Surface tension in mN/m at 25° C.
b. Surface tension of water from CRC Handbook of Chemistry and Physics; 63 Edition, 1982-1983.
Example 4
In addition the compositions of the present invention provide enhanced spreading when combined with nonionic trisiloxane ethoxylates, meaning that the combination of the two components gives a greater degree of spreading then either of the components alone, at concentrations equivalent to that contained in the mixture (Table 5).
Spreading was determined by applying a 10 μL droplet of surfactant solution to a polyester film (3M, IR 1140 transparency film) and measuring the spread diameter after 30 seconds. The solution was applied with an automatic pipette to provide droplets of reproducible volume. Deionized water that was further purified with a Millipore filtration system was used to prepare the surfactant solutions.
To demonstrate the enhanced spreading observed with blends of the ASA components of this present invention and traditional nonionic trisiloxane ethoxylates, 0.1 wt % solutions of each component were prepared in distilled water. The solutions were blended in various ratios of the AMA component to SIL-B (See Table 5) to achieve the desired blend composition. For example, a blend consisting of 9.0 g ASA-1 (0.1 wt %) was combined with 1.0 g SIL-B (0.1 wt %) to afford a mixture that contained 0.09 wt % ASA-1, plus 0.01 wt % SIL-B (a 90/10 blend ratio). Likewise the comparative is SIL-B alone at concentrations equivalent to what is contained in the corresponding blend. For example, the comparative blend with SIL-B for the 90/10 ratio, combines 9.0 g distilled water with 1.0 g SIL-B. This yields 0.01 wt % SIL-B, which is equivalent to the amount contained in the 90/10 blend.
TABLE 5
Spreading Properties of Amino Siloxane Alkoxylate/SIL-B Blends
(0.1 wt % Blend)
Com-
parative
Blend Ratio
ASA-1 +
ASA-2 +
ASA-3 +
ASA-4 +
None +
ASA/SIL-B
SIL-B
SIL-B
SIL-B
SIL-B
SIL-B*
100/0
11
9
8
nd
NA
90/10
13
11
10
10
8
80/20
25
14
14
16
17
70/30
36
23
27
26
17
60/40
30
33
30
32
28
50/50
45
41
30
36
34
40/60
44
44
44
nd
36
0/100
NA
NA
NA
NA
51
*None + SIL-B indicates that water was substituted for the ASA component to provide spreading contributed by SIL-B.
Example 5
Nonionic trisiloxane alkoxylates have been shown to antagonize the uptake of glyphosate into grasses, giving a lower degree of uptake (Gaskin. et al., Pestic. Sci. 1993, 38, 185-192), or a lower degree of control then achieved with glyphosate treatments alone. The compositions of the present invention provide enhanced glyphosate activity on grasses relative to trisiloxane ethoxylates or glyphosate alone.
The effect of adjuvant on glyphosate isopropylamine salt (Gly-IPA) efficacy was determined using a barnyardgrass assay. Barnyardgrass ( Echinochloa crus - galli ) was grown in the lab under fluorescent growth lights, and trimmed 11 days after planting, from 9 cm to 4 cm. When the plants reached to 8-9 cm in height (3 days after trimming) they were treated with spray solutions containing either glyphosate alone, or with glyphosate (Gly-IPA at 1.0%, 0.5% and 0.25%), plus a surfactant at 0.1 wt %, using a spray volume of 96 l/ha. Efficacy was determined by visual observation of plant regrowth 2 weeks after treatment, using a rating system were 0 indicates no weed control, and 100% indicates complete control.
Table 6 provides the compositions for the various spray mixtures used to treat barnyardgrass in this example.
TABLE 6
Surfactant Composition for Spray Treatments
Wt %
Treatment
AMA-1
SIL-B
Treatment-1
0.1
0
Treatment-2
0.08
0.02
Treatment-3
0.07
0.03
Treatment-4
0.06
0.04
Treatment-5
0.05
0.05
Treatment-A
0
0
Treatment-B
0
0.1
Table 7 demonstrates that the compositions of the present invention (Treatments 1-5) provide an overall significant enhancement to glyphosate response relative to glyphosate alone (Treatment-A), or to the comparative trisiloxane ethoxylate SIL-B (Treatment-B).
TABLE 7
The Effect of Adjuvant on Glyphosate Efficacy on Barnyardgrass
14 Days After Treatment
Percent Barnyardgrass Control
Glyphosate Rate
Treatment
1.0%
0.5%
0.25%
Mean
Treatment-1
77.5 a
42.5 b
36.3 a
52.1 a
Treatment-2
38.8 b
75.0 a
36.3 a
50.0 a
Treatment-3
80.0 a
42.5 b
23.3 a
48.6 a
Treatment-4
73.3 a
42.5 b
7.5 b
41.1 a
Treatment-5
36.3 a
33.3 c
5.3 b
24.9 b
Treatment-A
8.7 c
28.0 c
1.0 b
12.3 c
Treatment-B
8.8 c
5.0 d
3.0 b
5.6 c
Data with different letters indicate a statistically different result. Data with common letters are not statistically different according to Tukey test (p=0.05).
Example 6
Barnyardgrass (BYG) was treated with glyphosate-isopropylamine salt (0.25%, 0.5% and 1.0%) using 0.1 wt % ASA-1, alone or as mixtures with SIL-B. The applications were made using a spray volume of 103 l/ha. Simulated rainfall (0.25 in.) was applied 2 h after treatment to remove any glyphosate that was not absorbed by the BYG. This was done to determine how effective the treatments were at making glyphosate rainfast (resistant to wash-off), which is associated with the rapid uptake of chemical into the plants. Efficacy was determined by visual observation of plant regrowth 2 weeks after treatment, using a rating system were 0 indicates no weed control, and 100% indicates complete control.
Table 8 indicates that the ASA-1 and its blends with SIL-B are more effective at enhancing glyphosate efficacy on BYG than SIL-B. As anticipated, SIL-B demonstrated the classical antagonism of glyphosate efficacy on grass species, when used with glyphosate rates below 1 wt %. However, even the treatment at 1 wt % glyphosate plus SIL-B, the enhancement in efficacy was not statistically different form glyphosate alone.
TABLE 8
Effect of Adjuvant on Glyphosate-IPA Efficacy on Barnyardgrass
(2 Wks after treatment)
% Glyphosate
% ASA-1
1.0
0.5
0.25
100
99.5 a
87.5 a
68.75 a
80
83.25 b
76.75 a
31.25 bc
70
92.25 b
60.0 a
32.5 bc
60
92.0 b
77.5 a
17.5 c
50
92.5 ab
81.0 a
51.25 ab
0
57.5 c
7.5 b
8.75 c
(100% SIL-β)
27.5 c
16.25 b
15.3 c
No Surfactant
Note:
Mean followed by same letter, within the same column, is not significantly different by Tukey test (p = 0.05). | The present invention teaches the composition of terminally modified, amino, polyether, siloxanes, known hereforth as amino siloxane alkokylates, and their use as adjuvants. The amino siloxane alkoxylates of the present invention enhance the efficacy of agrichemicals on plants as compared to conventional TSE's alone. The amino siloxane alkoxylates have at one end, an amine functionality and at the other end, a polyalkyleneoxide functionality. | 2 |
[0001] The present claims priority to U.S. Provisional Application No. 62/076,839 filed on Nov. 7, 2014, the entire contents of which are specifically incorporated herein by reference without disclaimer.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to transgenic fish, particularly blue transgenic fish.
[0004] 2. Description of Related Art
[0005] Transgenic technology involves the transfer of a foreign gene into a host organism enabling the host to acquire a new and inheritable trait. Transgenic technology has many potential applications. For example, it can be used to introduce a transgene into a fish in order to create new varieties of fish. There are many ways of introducing a foreign gene into fish, including: microinjection (e.g., Zhu et al., 1985; Du et al., 1992), electroporation (Powers et al., 1992), sperm-mediated gene transfer (Khoo et al., 1992; Sin et al., 1993), gene bombardment or gene gun (Zelenin et al., 1991), liposome-mediated gene transfer (Szelei et al., 1994), and the direct injection of DNA into muscle tissue (Xu et al., 1999). The first transgenic fish report was published by Zhu et al., (1985) using a chimeric gene construct consisting of a mouse metallothionein gene promoter and a human growth hormone gene. Most of the early transgenic fish studies have concentrated on growth hormone gene transfer with an aim of generating fast growing fish. While a majority of early attempts used heterologous growth hormone genes and promoters and failed to produce these fish (e.g. Chourrout et al., 1986; Penman et al., 1990; Brem et al., 1988; Gross et al., 1992), enhanced growth of transgenic fish has been demonstrated in several fish species including Atlantic salmon, several species of Pacific salmons, and loach (e.g. Du et al., 1992; Delvin et al., 1994, 1995; Tsai et al., 1995).
[0006] The black skirt tetra ( Gymnocorymbus ternetzi ) has been commercially cultured in the United States at least as early as 1950 (Innes, 1950). However, for the ornamental fish industry the dark striped pigmentation of the adult black skirt tetra does not aid in the efficient display of the various colors. The albino black skirt tetra, or “white tetra” is a variant that arose during domestication and shows decreased pigmentation. The availability of such fish having modified pigmentation for transgenesis with fluorescent proteins would result in better products for the ornamental fish industry due to better visualization of the various colors.
[0007] Many fluorescent proteins are known in the art and have been used to investigate various cellular processes, including fluorescent proteins exhibiting various green, red, pink, yellow, orange, blue, or purple colors. Although transgenic experiments involving fluorescent proteins have provided new markers and reporters for transgenesis, progress in the field of developing and producing ornamental fish that express such proteins has been limited.
SUMMARY OF THE INVENTION
[0008] In certain embodiments, the present invention concerns making transgenic fluorescent fish and providing such fish to the ornamental fish industry.
[0009] In some embodiments, transgenic fish or methods of making transgenic fish are provided. In certain aspects, the transgenic fish are fertile, transgenic, fluorescent fish. In a particular embodiment, the fish for use with the disclosed constructs and methods is the white tetra. Tetra skin color is determined by pigment cells in their skin, which contain pigment granules called melanosomes (black or brown color), xanthosomes (yellow color), erythrosomes (orange or red color), or iridosomes (iridescent colors, including white color). The number, size, and density of the pigment granules per pigment cell influence the color of the fish skin. White tetra have diminished number, size, and density of melanosomes and hence have lighter skin when compared to the wild type black skirt tetra.
[0010] In certain specific embodiments there are provided transgenic tetra or progeny thereof comprising specific transgenic integration events, referred to herein as transformation events. These fish are of particular interest because, for example, they embody an aesthetically pleasing blue color. Transgenic fish comprising these specific transgenic events may be homozygous or heterozygous (including, for example, hemizygous) for the transformation event. Homozygous fish bred with fish lacking a transformation event will in nearly all cases produce 100% heterozygous offspring. Eggs, sperm, and embryos comprising these specific transgenic events are also included as part of the invention.
[0011] In one such embodiment regarding a specific transgenic integration event, a blue transgenic tetra or progeny thereof is provided comprising chromosomally integrated transgenes, wherein the tetra comprises the “Blue tetra 1 transformation event,” sperm comprising the Blue tetra 1 transformation event having been deposited as ECACC accession no. 14103001. The chromosomally integrated transgenes may be present on one integrated expression cassette or two or more integrated expression cassettes. In certain aspects, such a transgenic tetra is a fertile, transgenic tetra. In more specific aspects, such a tetra is a transgenic White tetra. Such a transgenic tetra may be homozygous or heterozygous (including, for example, hemizygous) for the transgenes or integrated expression cassette(s).
[0012] Also disclosed are methods of providing a transgenic tetra comprising the Blue tetra 1 transformation event to the ornamental fish market. In some embodiments, the method comprises obtaining a transgenic tetra or progeny thereof comprising chromosomally integrated transgenes, wherein the tetra comprises the “Blue tetra 1 transformation event,” sperm comprising the Blue tetra 1 transformation event having been deposited as ECACC accession no. 14103001, and distributing the fish to the ornamental fish market. Such fish may be distributed by a grower to a commercial distributor, or such fish may be distributed by a grower or a commercial distributor to a retailer such as, for example, a multi-product retailer having an ornamental fish department.
[0013] In some aspects, methods of producing a transgenic tetra are provided comprising: (a) obtaining a tetra that exhibits fluorescence and comprises one or more chromosomally integrated transgenes or expression cassettes, wherein the tetra comprises the “Blue tetra 1 transformation event,” sperm comprising the Blue tetra 1 transformation event having been deposited as ECACC accession no. 14103001; and (b) breeding the obtained tetra with a second tetra to provide a transgenic tetra comprising the Blue tetra 1 transformation event. The second tetra may be a transgenic or non-transgenic tetra.
[0014] In further embodiments, also provided are methods of producing a transgenic organism, the method comprising using sperm comprising the Blue tetra 1 transformation, such sperm having been deposited as ECACC accession no. 14103001, to produce transgenic offspring. Such offspring may be, for example, a tetra, a species of the Gymnocorymbus genus, a fish species or genus related to tetra, or another fish species or genus. In some aspects, the fish may be produced using in vitro fertilization techniques known in the art or described herein.
[0015] As used in this specification, “a” or “an” may mean one or more. As used herein in the claim(s), when used in conjunction with the word “comprising,” the words “a” or “an” may mean one or more than one.
[0016] The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.” As used herein “another” may mean at least a second or more.
[0017] Throughout this application, the term “about” is used to indicate that a value includes the inherent variation of error for the device, the method being employed to determine the value, or the variation that exists among the study subjects.
[0018] Any embodiment of any of the present methods, kits, and compositions may consist of or consist essentially of—rather than comprise/include/contain/have—the described features and/or steps. Thus, in any of the claims, the term “consisting of” or “consisting essentially of” may be substituted for any of the open-ended linking verbs recited above, in order to change the scope of a given claim from what it would otherwise be using the open-ended linking verb.
[0019] Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the 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.
DETAILED DESCRIPTION OF THE INVENTION
Transgenic Fish
[0020] In some aspects, the invention regards transgenic fish. Methods of making transgenic fish are described in, for example, U.S. Pat. Nos. 7,135,613; 7,700,825; 7,834,239, each of which is incorporated by reference in its entirety.
[0021] It is preferred that fish belonging to species and varieties of fish of commercial value, particularly commercial value within the ornamental fish industry, be used. Such fish include but are not limited to catfish, zebrafish and other danios, medaka, carp, tilapia, goldfish, tetras, barbs, sharks (family Cyprinidae), angelfish, loach, koi, glassfish, catfish, discus, eel, tetra, goby, gourami, guppy, Xiphophorus, hatchet fish, Molly fish, or pangasius. A particular fish for use in the context of the invention is a tetra, Gymnocorymbus ternetzi . Tetra are increasingly popular ornamental animals and would be of added commercial value in various colors. Tetra embryos are easily accessible and nearly transparent. A fish that is of particular use with the disclosed constructs and methods is the White Tetra. Tetra skin color is determined by pigment cells in the skin, which contain pigment granules called melanosomes. The number, size, and density of the melanosomes per pigment cell influence the color of the fish skin. White Tetra have diminished number, size, and density of melanosomes and hence have lighter skin when compared to the wild type tetra.
[0000] Fertilization from Frozen Sperm
[0022] Fish sperm freezing methods are well-known in the art; see, e.g., Walker and Streisinger (1983) and Draper and Moens (2007), both of which are incorporated herein by reference in their entireties. To obtain the transgenic fish disclosed herein, frozen tetra sperm may be used to fertilize eggs.
[0023] Briefly, one or two breeding pairs of tetra should be placed in a shoebox with an artificial spawning mat. The water level in the shoebox should be ˜2-3 inches and kept at 75-85° F. Low salinity (conductivity 100-200 uS/cm) and slight acidity (˜pH 6.9) promote spawning. The fish may be exposed to a natural or artificial light cycle; the photoperiod starts at 8 am and ends at 10 pm. The following morning, remove and discard the eggs. Tetra may be anesthetized by immersion in tricaine solution at 16 mg/100 mL water. After gill movement has slowed, remove one female, rinse it in water, and gently blot the belly damp-dry with a paper towel. The eggs should not be exposed to water as this will prevent fertilization. Gently squeeze out the eggs onto a slightly concave surface by applying light pressure to the sides of the abdomen with a thumb and index finger and sliding the fingers to the genital pore. Ready to spawn females will release the eggs extremely easily, and care should be taken not to squeeze the eggs out while blotting the fish. Good eggs are yellowish and translucent; eggs that have remained in the female too long appear white and opaque. The females will release the eggs only for an hour or so. Eggs from several females may be pooled; the eggs can be kept unfertilized for several minutes. The sperm is thawed at 33° C. in a water bath for 18-20 seconds. 70 μl room temperature Hanks solution is added to the vial and mixed. The sperm is then immediately added to the eggs and gently mixed. The sperm and eggs are activated by adding 750 μl of fish water and mixing. The mixture is incubated for 5 minutes at room temperature. The dish is then filled with fish water and incubated at 28° C. After 2-3 hours, fertile embryos are transferred to small dishes where they are further cultured.
[0024] Parichy and Johnson, 2001, which is incorporated by reference in its entirety, provides additional examples regarding in vitro fertilization.
[0025] The invention further encompasses progeny of a transgenic fish containing the Blue tetra 1 transformation event, as well as such transgenic fish derived from a transgenic fish egg, sperm cell, embryo, or other cell containing a genomically integrated transgenic construct. “Progeny,” as the term is used herein, can result from breeding two transgenic fish of the invention, or from breeding a first transgenic fish of the invention to a second fish that is not a transgenic fish of the invention. In the latter case, the second fish can, for example, be a wild-type fish, a specialized strain of fish, a mutant fish, or another transgenic fish. The hybrid progeny of these matings have the benefits of the transgene for fluorescence combined with the benefits derived from these other lineages.
[0026] The simplest way to identify fish containing the Blue tetra 1 transformation event is by visual inspection, as the fish in question would be blue colored and immediately distinguishable from non-transgenic fish.
EXAMPLES
[0027] Certain embodiments of the invention are further described with reference to the following examples. These examples are intended to be merely illustrative of the invention and are not intended to limit or restrict the scope of the present invention in any way and should not be construed as providing conditions, parameters, reagents, or starting materials that must be utilized exclusively in order to practice the art of the present invention.
Example 1
Blue Transgenic Tetra
[0028] Transgenic fish exhibiting a blue color are provided. The specific transgenic events embodied in these fish are designated the “Blue tetra 1 transformation event”. Sperm from these fish may be used to fertilize tetra eggs and thereby breed transgenic tetra that comprise these specific transgenic integration events. Sperm from this line was deposited at the European Collection of Cell Cultures (ECACC), Public Health England, CRYOSTORES, Bld. 17, Porton Down, Salisbury, SP4 OJG, United Kingdom, under the provisions of the Budapest Treaty as “Blue tetra 1” (the deposit was designated as accession no. 14103001).
[0029] The fluorescent transgenic fish have use as ornamental fish in the market. Stably expressing transgenic lines can be developed by breeding a transgenic individual with a wild-type fish, mutant fish, or another transgenic fish. The desired transgenic fish can be distinguished from non-transgenic fish by observing the fish in white light, sunlight, ultraviolet light, blue light, or any other useful lighting condition that allows visualization of the blue color of the transgenic fish.
[0030] The fluorescent transgenic fish should also be valuable in the market for scientific research tools because they can be used for embryonic studies such as tracing cell lineage and cell migration. Additionally, these fish can be used to mark cells in genetic mosaic experiments and in fish cancer models.
[0031] All of the compositions and/or 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 both chemically and 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.
REFERENCES
[0032] The following references, to the extent that they provide exemplary procedural or other details supplementary to those set forth herein, are specifically incorporated herein by reference.
U.S. Pat. No. 7,135,613 U.S. Pat. No. 7,700,825 U.S. Pat. No. 7,834,239
[0036] Brem et al., Aquaculture, 68:209-219, 1988.
Chourrout et al., Aquaculture, 51:143-150, 1986. Delvin et al., Nature, 371:209-210, 1994. Draper and Moens, In: The Zebrafish Book, 5 th Ed.; Eugene, University of Oregon Press, 2007. Du et al., Bio/Technology, 10:176-181, 1992. Innes, W. T., Exotic Aquarium Fishes : A work of general reference, Innes Publishing Company, Philadelphia, 1950. Gross et al., Aquaculature, 103:253-273, 1992. Khoo et al., Aquaculture, 107:1-19, 1992. Lamason et al., Science, 310(5755):1782-1786, 2005. Penman et al., Aquaculture, 85:35-50, 1990. Powers et al., Mol. Marine Biol. Biotechnol., 1:301-308, 1992. Sin et al., Aquaculture, 117:57-69, 1993. Szelei et al., Transgenic Res., 3:116-119, 1994. Tsai et al., Can. J. Fish Aquat. Sci., 52:776-787, 1995. Walker and Streisinger, Genetics 103: 125-136, 1983. Xu et al., DNA Cell Biol., 18, 85-95, 1999. Zelenin et al., FEBS Lett., 287(1-2):118-120, 1991. Zhu et al., Z. Angew. Ichthyol., 1:31-34, 1985. | The present invention relates to transgenic blue ornamental fish, as well as methods of making such fish by in vitro fertilization techniques. Also disclosed are methods of establishing a population of such transgenic fish and methods of providing them to the ornamental fish industry for the purpose of marketing. | 0 |
CROSS REFERENCE TO OTHER APPLICATION
This is a Continuation-in-Part Application of application Ser. No. 198,830, filed Oct. 20, 1980 now abandoned.
BACKGROUND OF INVENTION
It is known in the construction industry, particularly the building of dwelling houses and other buildings, to erect a rain gutter at roof edges. Such gutters usually have associated downpipes. By these means, water coming off the roof may be intercepted, collected, and diverted into desired locations. This avoids splashing, "trenching", flooding, and other undesired effects. A persistent problem with such gutters is that they collect leaves, sticks, roof granules, pine needles, and other debris as well. This causes the gutters and/or down-pipes to become blocked. As a result, water backs up, causing it to flood over the gutter edges and sometimes down the side of the building, and permitting freezing in the gutter to occur. It may also or alternatively cause the gutter to accumulate pools of water which do not drain off rapidly or readily, and cause weeping and/or rusting of joint areas and sometimes freeze into ice in cold weather. Additionally, gutters may become broken by snow and/or ice sliding off the associated roof.
In an attempt to overcome the necessity for manually clearing the gutters and/or down pipes periodically, usually by ascending a ladder, various proposals have been made. They range from applying screens to cover the gutter openings, to deflector means. The general experience has been that the installation of screens basically does little more than relocate the problem of debris blocking from the gutter to the screen, necessitating periodic manual removal anyway. From time to time, it has been proposed to use "deflector" type devices, by which it was contended it would be possible to redirect the flow of rainwater coming off of the top surface of a roof into a gutter, free of debris which will, in the meantime have been ejected off of the roof onto the ground. Some of such deflector type devices include a lower arcuate surface by which, theoretically, water coming down the roof will, by the effect of surface tension, be forced to follow around the arcuate surface. By this means, it was postulated that the water may be deposited in the gutter which is positioned inside and below the arcuate surface, while debris carried by the water is jettisoned off, more or less tangentially to the curved surface, and falls to the ground. In this connection, reference is made to the following U.S. Pat. Nos.: Van Horn 546,042; Nye 603,611; Cassen 836,012; Cassens 891,405; Yates 1,101,047, Goetz 2,672,832, Bartholomew 2,669,950; Heier 2,873,700; Natthews et al 2,935,954; Foster 3,388,555; Homa 3,507,396; and Zukauskas 3,950,951.
A remarkable thing about devices such as the foregoing is that although the basic theory has been available for some time, as far as is now known, it has never actually been adopted or used in what might reasonably be described as a commercial embodiment. In part, this may be because there is little to impell builder-contractors to incur whatever extra cost or expense involved in making such installation initially. Once a conventional system has been installed, to "retrofit" an existing installation involves troublesome, time-consuming, costly, basic and/or aesthetically undesirable structural alterations to the existing gutter installation and, in many cases, to the building with which it is associated. It also appears that a reason why the concept has not found significant or widespread use is because, as disclosed to date, it didn't work with a sufficient degree of reliability or effectiveness to make it practically feasible. That is, practicing the extant disclosures as taught, it has been found that surface tension of the water often is not sufficient to contain the water through an arcuate travel path against counter-forces typically encountered from factors such as a large volume of water, steep slopes, "rivuletting", etc. Whatever the particular reasons, the impressive fact is the lack of their adoption and use to date, in spite of the obvious advantages which might occur if they could be used, in light of the costs and difficulty of obtaining maintenance labor, particularly in recent times.
Accordingly, it is an object of the present invention to provide means for accomodating roof-water while segregating debris therefrom.
Another object of this invention is to provide such means in a form which is substantially maintenance free.
Still another object of this invention is to provide means for accomplishing some or all of the foregoing objectives in a form which is structurally simple and easy to install.
Yet another object of this invention is to provide means for accomplishing some or all of the foregoing objectives which is adapted for retrofitting existing installations.
SUMMARY OF INVENTION
Desired objectives may be achieved through practice of the present invention, embodiments of which include a rain gutter debris deflector for disassociating rain water from debris and depositing the rain water in an associated rain gutter while ejecting debris so that it does not pass into the rain gutter, characterized by having an upper sloped portion, a lower arcuate deflector portion for re-directing water through operation of surface tension, and means for controlling the normal flow of water through the arcuate portion so that centripetal forces thereon substantially throughout will not exceed the surface tension of the water.
DESCRIPTION OF DRAWINGS
This invention may be understood from the descriptions herein set forth and from the accompanying drawings in which:
FIG. 1 illustrates a prior art device,
FIG. 2 illustrates another prior art device,
FIG. 3 is a cross-sectional view of an embodiment of the present invention,
FIG. 4 is a plan view of the embodiment of this invention illustrated in FIG. 3,
FIG. 5a through 5d illustrate various geometric patterns of embodiments of this invention,
FIG. 6 is a side elevation view of a rain deflector device,
FIG. 7 is a side elevation view of another embodiment of this invention,
FIG. 8 illustrates an embodiment of this invention, and
FIG. 9 illustrates details of an embodiment of this invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to FIG. 1, there is depicted a prior art device 10, for use in connection with a known per se rain gutter 12, which has an outer edge lip 14. Normally, such rain gutters are positioned higher up on the fascia 17 of the building 19 than as shown in FIG. 1, so that the plane of the shingles 15 is intercepted by the lip 14 of the gutter 12, so that rain coming off the roof shingles 15 will be caught by the gutter 12.
It will be obvious from FIG. 1 that installation of the water deflection device 10 has made it necessary to lower the gutter 12. Even with a new installation, this presents some difficulties because the positioning of the gutter 12 and the device 10 must be carefully regulated with respect to the amount of overhang and angle of the roof 15. In a "retrofit", or installation of a water deflector 10 to an existing installation, the problem is even more difficult, because it involves the added problem of having to move and relocate installed gutters and downspouts. According to the prior art, a water deflection device 10 may be installed contiguous with the edge of the roof. It includes a flat main portion 16 and a curved or arcuate portion 18 between the main portion 16 and the lower edge 20. The device 10 is so positioned that the lower edge 20 is between the front edge 14 and the rear wall of the gutter 12, and the curved portion is of sufficiently large radius as to extend beyond the trough 11 portion of the gutter 12, and to cause water 22 traversing the device 10 to be caused, by surface tension, to follow around the curved portion 18 and leave the device 10 at the lower edge 20. While this is going on, leaves and other debris 24 being impelled along by the water 22, if not being subject to the same surface tension forces will tend to generate sufficient centripetal force to fly free of the water and jettison free of the device 10 without ending up in the gutter 12. FIG. 2 illustrates a result which occurs when the prior art teachings, without more, are followed. As illustrated, substantial quantities of water 22, as well as unwanted debris, may break loose from the deflecting forces induced by the arcuate surface 18, causing water 22 to spill free of the gutter 12 without being caught by it. Without intending to be bound by any theory, it is believed that this occurs when the kinetic forces acting on the water are sufficient to overcome the surface tension, as a result of which the surface tension is inadequate to deflect the water into a reversing path and into the gutter 12. Such kinetic forces may so become excessive through any or a combination of a number of causes. Included among them are a steep slope of the roof 15 and or the main section 16 by which gravity induced forces become excessive, a high volume of water by which the total force becomes excessive; and "rivuletting" by which the thickness of the sheet of water traversing the device is not uniform but, instead, accumulates into more or less discrete streams with dry voids inbetween, so that excessive volumes of water are localized intermittantly across the face of the device 10 with consequent excessive forces in the rivulet areas sufficient to cause the water stream to break away at one or more places. One way, it was thought, that this adverse result might be remedied, is by increasing the radius of the arcuate portion. However, this induces other difficulties. For example, lowering the gutter to accomodate the consequent lowering of the bottom edge of the deflector is time consuming, difficult, expensive, and disruptive of the aesthetics of the building. These factors, in which the lack of acceptance and use of such devices may lie, are avoided through practice of the present invention.
FIGS. 3 and 8 illustrate embodiments of the present invention. Each includes a main body 16, a curved portion 18, and a lower edge 20, and is positioned with respect to an associated gutter 12 so that its arcuate section 18 is outside the trough 11 and the lower edge 20 is between the front and back walls of the gutter 12. Unlike prior art devices, however, these embodiments of this invention include ridges 30, arrayed substantially parallel to the axis of the arcuate portion 18. Three ribs are shown. Although it is within the contemplation of this invention that any number of such ribs may be used, it has been found that a single such rib is of minimal effectiveness for the purposes herein described, that two work well, and that excellent results are obtained with three or more. Generally speaking, it may be postulated that the number of ribs should be increased correspondingly to increases in the maximum quantity of water it is desired to accomodate, particularly where, through the operation of such material as an oil film, the surface wetting characteristics are more or less inhibited. It will be clear that such ribs may easily be incorporated into the sheet metal, plastic or other material from which the device 10 is made by initial casting, rolling, including them as an added part of the cross-section, or other known per se means, and that usually the ribs will have the added feature of strengthening the device against deflection in the longitudinal direction. As will be apparent from FIGS. 3, 8 and 9, the effect of the ribs 30 is to form longitudinal weirs and ponds 33 down the length of the device. As a result, water traversing the device has its velocity interrupted as it collides with the upper surfaces of the ribs and is distributed more or less uniformly across the face of the device. This effect is further enhanced when a second rib is added, and more so with a third. Past a certain number, further enhancement may occur in decreasing amount but not significantly so. In practice, it has been found advantageous to have the plane of the top surface of the deflector intersected by the upstream surface of the uppermost ridge at least (and preferably the other ribs as well) at a pronounced angle, rather than a gentle slope. This causes water moving across the deflector to be confronted by a relatively abrupt barrier at each such intersection, rather than a ramp over which the moving water will shoot, instead of cascading substantially evenly after having first collided with the rib and become more or less co-mingled with the pool of water formed above the ridge. This is emphasized in FIG. 9 where the intersection angle ρ is shown to be steep; i.e. in the range of 55°-85°. Obviously, the intersection angle may be made greater for ribs of semi-circular cross-section by raising the center, or shallower by lowering it. Further, other cross-sectional shapes may be utilized to exploit the phenomenon more effectively. For example, sectors of ellipses can be made to combine lower crowns of the ribs with steeper top and bottom intersections than circular cross-sections, while tear drop shapes can produce regulated crown heights with abrupt "up-stream" intersections while having tapered or shallow sloped "down-stream" intersections. It should also be clear that the upper surfaces of the ribs need not necessarily be arcuate in cross-section. For example, ribs which are merely linear, are quadrilateral, or are "saw-tooth" in cross-section will also function effectively.
As this implies, the height of the crown, or top-most point on the rib with respect to the plane of the upper deflector surface, can also have an affect on achieving the desired "pooling" and cascading attenuation, rather than overshooting with consequent rivuletting and disruption of the desired surface tension phenomenon. These parameters may be individually or collectively manipulated by those skilled in the cognizant arts in light of the particular roof slope-angle, deflector angle, anticipated water flow volume and other determinative factors.
The effectiveness of such ribs may also be enhanced by having the lowest (i.e., most "down-stream") of them in close proximity to the top of the curved portion, since this gives the water less opportunity to accelerate beyond desired limits after passing over the lowest rib. It has been found advantageous in certain installations for this spacing to be about 11/2 inches. The effect of such velocity attenuations and lateral re-distributions is to reduce the kinetic forces which tend to cause water traversing the device to break free in the course of traversing the arcuate portion 18 of the device, thereby permitting the surface tension forces to dominate the behavior of the water and to cause the water to follow the device around and into the gutter 12; all as shown in FIGS. 3 and 4. They also tend to break up "rivuletting". Note particularly that with the present invention, a smaller radius arcuate section 18 and/or positioning the deflector so that its upper flat surface is at a shallower angle than that of the roof surface, as hereinafter described, can obviate the necessity of relocating the gutter lower on the fascia board, particularly in "retrofit" installations.
Optionally, raised crowns 31 may be formed on the top surface of the main body 16, more or less throughout, or in isolated areas to hold leaves and debris up away from the principal water paths. This has the effect of keeping the water paths unblocked and of making leaves particularly easier to remove because they are less likely to stick down than on a flat surface. Such crowns may be of any suitable geometric shape in plan view, such as squares, circles, ellipses, trapezoids, and the like. Such crowns, which also facilitate removal of debris by the wind by keeping the debris raised above the deflector, may also or alternatively be positioned between the ribs hereinbefore described.
The embodiments illustrated in FIGS. 3, 4 and 8 are shown as having a plurality of continuous ribs 30. Although this is a desired configuration, as shown in FIG. 5, other configurations, such as the continuous and intermittent patterns shown in 5a, 5b, 5c, and 5d, may also be effectively used. Further, although linear ribbings are shown, they may be in other forms, such as broader bands, depressions, or other geometric configurations which will produce the desired barrier and/or redistribution effects. Note particularly that as shown in FIG. 5d, it is also within the contemplation of this invention that a multiplicity of staggered arcuate ribs might also be used. In this connection, the reference herein to the "long dimension" of such an arcuate rib means the general orientation indicated by a fictitious line joining its ends a-a 1 .
FIG. 6 illustrates the previously referred to "rivuletting" phenomenon. Here, because of uneven distribution of the water and/or incapacity for ready and uniform "wetting" of the surface of the device, the water 22 tends to concentrate in some areas 25, while being less concentrated, thinner, or even totally lacking in other areas 23. As a result, the concentrations of mass in the increased volume areas 25, reacting to the pull of gravity, may set up kinetic forces in the areas of concentration in excess of the surface tension forces, causing water not to follow the contour of the arcuate portion 18 of the device but rather to spill over the outside of the front wall of the gutter 12.
As shown in FIG. 7, this "rivuletting" effect may be controlled within tolerable limits or even eliminated by improving the "sheeting" of the water or otherwise rendering it so that it is substantially of uniform thickness across the face of the device. This is analagous to the lateral redistribution effect of the ribs 30 shown in FIGS. 3, 4, and 5, but may be produced by other means. One such means is in the choice of finish applied to the exposed upper surface of the device. For example, acrylic-latex paints generally are very wettable, while surfaces painted with certain polyester based paints are not. The latter, tending to exhibit a much greater tendency to "rivuletting" of the type shown in FIG. 6 than the former, therefore exhibit a greater tendency to "spillover" with devices of the type herein discussed than do the former. The more unified "sheeting" of the water 22 attainable through utilization of "wettable" surfaces is illustrated in FIG. 7 where a sheet of water 22 is shown to have traversed the main portion 16 and to have followed the arcuate contour 18 into the gutter 12. Such surface treatment may be used alone or in combination with the aforementioned ribs and/or other flow interruption devices.
As shown in FIG. 8, devices made in accordance with this invention may be affixed to the eave of a building in appropriate relationship to an associated rain gutter according to known per se means. The upper end of the main portion may be slid under a course of shingles or affixed thereto, or even merely placed in contact with the upper surface thereof as shown in FIG. 3, since, even if there is water leakage between its lower surface and the upper surface of the shingles, debris is not thereby admitted to the gutter and the roof continues to pass water to the gutter merely in the fashion that it was originally intended to do. An additional advantage of such devices is that they also facilitate avoiding the accumulation of ice and or snow at the roof edge both because they present a relatively smooth, adhesionless surface to such materials, and because they cover the gutters themselves which otherwise present "pockets" in which such ice or snow may deposit. It should be noted in particular that devices made in accordance with this invention will function effectively whether the underside of the upper region is substantially flush throughout with the upper surface of the associated roof as shown in FIG. 3, or whether there is an angular displacement therebetween as shown in FIG. 8. Furthermore, in practice, it has been found that it doesn't matter significantly even if the upper edge of devices made in accordance with this invention are not overlayed by a course of shingles since, in any event, the upper edge region will be more or less tight to the upper surface of the roof anyway, and any leakage of water at that point will filter out the significant portion of debris and the water so leaking will merely be handled by the lower edge of the roof and into the associated gutter, functioning entirely in the manner for which they were intended and constructed. In fact, advantages may be realized by positioning the deflector device at a more shallow angle (i.e., more nearly horizontal) than that of the plane of the roof as shown in FIG. 8 since, as will be apparent from the foregoing explanations, this will have the effect, beneficial in terms of operability of the arcuate portion as a debris-water segregator, of reducing the gravity-induced kinetic energy of water coming off the roof and of being aesthetically more pleasing. FIG. 8 also illustrates that it is not necessary to relocate the gutter 12 downward from the location in which traditionally it is placed; i.e., high up on the facia board 17 with its back wall under the overhang of the roof shingles. With the deflector at a shallower angle "β" than the angle "α" of the slope of the roof (with respect to horizontal), the curved portion 18 of the deflector may be of comparatively large radius, thus enhancing the effectiveness of the surface tension phenomenon. By this means, not only is considerable bother and expense avoided in retro-fitting an existing installation, but the final result in a new or retro-fit installation looks better and does not derogate materially from the appearance of the structure as a whole.
It should be noted that the embodiment shown in FIG. 3, where the uppermost edge of the top section of the deflector is not positioned under a course of shingles, may also be oriented at an angle shallower than that of the roof, by raising its curved portion and causing the entire structure to raise upward as it pivots along its upper edge. It has been found advantageous to adapt the upper edge region of deflectors embodying this invention for substantially continuous contact with the upper surface of the roof. This may be done by a variety of means, such as inserting the upper edge region as shown at "c" in FIG. 8, or simply having the upper edge rest on the roof as shown in FIG. 3 with the upper edge region of the deflector having some downward bias to hold it in contact with the roof, or with a strip of tape bridging the top edge region and the top of the roof, or with nails, adhesives, asphalt "spots" or other known per se means. Thus, the top region might be made to end with its top edge abutting the lower edge of a course of shingles, (shown as position "b" in FIG. 8), or with it ending (as shown at position "a" in FIG. 8) partway along the top surface of a shingle so as to afford a flat surface contiguous with the top of the roof, or with its top edge in "line" contact with the top of the roof.
As previously noted, substantial continuity is sufficient, since some water leakage under the deflector is usually of no significant moment to the utilization of such embodiments of this invention. If it is desired, however, as where the debris to be excluded from the gutter includes materials which are smaller than the gap between the deflector and the roof, the interface may be substantially totally sealed off. To enhance such continuity, particularly with the use of adhesives, it may be desirable to introduce an angulation to bring the top region into planar abuttment with the top surface of the roof while the mid-region of the deflector is at a comparatively shallower angle, all as shown in FIG. 8, but this is not critical to operability of this invention.
FIG. 8 also illustrates a support hanger 35 which is particularly adapted for such shallower angle deflectors when used with metal gutters of current design. The hanger may be made from any suitable material, such as metal or plastic, and may be fastened to the deflector by any of a number of known per se fastening means such as sheet metal screws, clips, rivets, welds or brazes, bolts and nuts, adhesives, or the like. As shown, it does not extend all the way along the underside of the top portion of the deflector to the roof, but it may do so and thus provide some added support. The outermost end 37 of the support 35 is formed in a "V" shape at the end of a horizontal span. Thus, the "V" shape may be inserted inside the closure forming the lip 14 of the gutter while the support is attached to the deflector and the deflector is oriented more or less vertical. The support-deflector combination may then be swung pivotally downward to position atop the roof. This hanger provides a structurally simple, effective, and inexpensive support means which is also adapted for facilitating maintenance.
Example
An embodiment of the present invention utilizing a deflector of design substantially like the deflectors shown in FIGS. 3 and 8 was installed at an angle of about 11° on a residence in Raleigh, N.C., the roof of which is at about 221/2°. The deflector was made from 0.019" aluminum with a painted finish. The length of the curve through the curved portion was about 21/2" and the length of the rest from the curved portion to the topmost edge was about 91/2". The radius of the curved portion was about 3/4". It had, each 0.15" high and 0.175" wide at the base, of arcuate cross section. The ridges were spaced about 11/2 apart, with the bottom-most ridge about 13/8" back from the top of the curved section. The device was found to work well, delivering virtually all of the water and virtually none of the debris crossing it to the associated gutter throughout the rainy seasons, sometimes during rainstorms which were considered heavy for the region.
Variants of the present invention may include modifications to accomodate the particular roof slope, edge contours and configurations, and/or building materials which characterize any specific structure. Additionally, local or regional climatic conditions may also be accomodated. For example, the National Weather Service publishes various data showing the maximum amounts of rainfall which occur for a range of time intervals (e.g., 5 minutes, 15 minutes, 60 minutes, etc.) over several spans of time (e.g., 2 years, 100 years, etc.). Data such as these may be utilized in varying the exact design configuration of a given deflector, for example, as to the number, nature, configurations, and/or dimensions and comparative proportions of the various elements, the radius and cross-sectional configuration of the curved portion, the surface textures and/or wetability, the angular disposition of the various elements with respect to each other and to the roof, etc., all as will be apparent to those ordinarily skilled in the cognizant arts in view of the present invention. Additionally, a wide variety of materials may be utilized to produce devices according to the present invention. Galvanized steel, aluminum, and other metals, as well as various plastics may also be used to particular advantage since they are easily formed according to technology which is known per se into complex and intricate shapes and configurations, are durable and weather resistant with minimum maintenance requirements, and may be made inherently to have desired surface characteristics such as improved wettability. All of the foregoing are within the skills, competence and knowledge of the person with ordinary skills in the cognizant arts.
Accordingly, it is to be understood that the embodiments of this invention herein described are by way of illustration and not of limitation, and that a wide variety of embodiments may be made without departing from the spirit or scope of this invention. | Embodiments useful as means for inhibiting the accumulation of leaves and other debris in household rain gutters. Embodiments include structures which comprise a deflector having a sloped portion, the top edge region of which is adapted for juxtapositioning to the roof shingles, and the bottom edge region of which is arcuate through a large radius cross-section. In such embodiments, the farthest outward extension is outside the outermost edge of the associated rain gutter and the lower edge is positioned between the edges of the rain gutter. Embodiments include means for attenuating the force of water and reducing the localized concentrating of water flowing thereover, such as longitudinal ridges and/or means for improving the surface wettability. Through practice of this device, kinetic gravity-induced forces on up to normal volumes of water flowing down the sloped portion may be kept, through the arcuate portion, below the forces acting counter-directionally thereto due to surface tension of the water normally to prevent substantially centripetal ejection of water as its direction of travel is changed to deposit it in the gutter while ejecting water carried debris carried outside the gutter. | 4 |
RELATED APPLICATION DATA
This application is a Continuation of U.S. Application No. 11/683,269 filed Mar. 7, 2007, now U.S. Pat. No. 7,521,938, which is a Continuation of U.S. application No. 11/534,864 filed Sep. 25, 2006 now abandoned, which is a Continuation of U.S. application No. 10/975,441 filed Oct. 29, 2004 now abandoned, which is a Continuation of U.S. application No. 10/289,286 filed Nov. 7, 2002, now U.S. Pat. No. 6,842,012, which claims the benefit of and priority under 35 U.S.C. §119(e) to U.S. patent application Ser. No. 60/344,927, filed Nov. 7, 2001, entitled “A Method for the Determination of the System Parameters of an Echo Measurement System,” each of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to time-domain reflectometry. In particular, this invention relates to systems and methods for calibrating a time-domain reflectometer to precisely determine the reflectometer's response when connected to an electrical network.
2. Description of Related Art
Time-domain reflectometry (TDR) systems use electrical measurements to estimate the physical structure and electrical nature of a conducting medium, which will be referred to herein as the Device Under Test (DUT). An example of a DUT is a twisted pair subscriber line, which comprises one or more interconnected electrical transmission lines generally having unknown terminations. Features of the DUT that can be estimated include the length of the line, the existence of bridged taps, the bridged tap locations, the bridged tap lengths, changes in gauge, terminations, and the like. Exemplary DUTs, such as subscriber lines, are constructed of twisted pairs, which distort the amplitude and phase of electrical waveforms that propagate through the line. Since, the amplitude of the waveforms decrease exponentially with travel distance, the waveforms received from long subscriber lines are extremely weak and require a precise TDR system to capture minute variations that contain information about the characteristics of the subscriber line.
SUMMARY OF THE INVENTION
Identifying, measurizing and characterizing the condition of a transmission line is a key element of any Digital Subscriber Line (DSL) deployment. In cases where the transceiver connection is not performing as expected, for example, the data rate is low, there are many bit errors, a data link is not possible, or the like, it is important to be able to identify characteristics about the loop including the length of the loop, and the existence, location and length of any bridged taps without having to send a technician to a remote modem site to run diagnostic tests. In these cases a TDR system can be used to measure and characterize the transmission line in order to determine the problem with the connection. It is particularly desirable to implement the TDR system in the DSL transceiver that is already connected to the transmission line. This allows the DSL service provider to determine transmission faults without physically disconnecting the telephone line from the DSL transceiver, thus effectively converting the DSL. transceiver into a TDR system.
The TDR system discussed herein includes a three-port network, which will be referred to herein as the “front-end.” The TDR front-end is used to transmit signals and receive the corresponding reflected signals to obtain info-nation about the characteristics of the DUT. As discussed above, one exemplary implementation of such a three-port device is the front-end of a DSL. transceiver.
A TDR front-end comprises numerous components. An artifact of these components is that information-bearing TDR signals are distorted as they pass through these components. With a perfect model of the response of the front-end, a TDR system can usually compensate for the artifacts introduced by the front-end components. In reality, however, the electrical characteristics of each component vary from design-to-design, board-to-board, slowly over time, and based on temperature. This is especially an issue when the TDR system is implemented in a DSL transceiver utilizing the DSL transceiver front-end. Since the DSL transceiver must also operate as a regular information transmission device, the transceiver is designed using different design criteria than a dedicated TDR system. For example, DSL transceivers are consumer devices that are produced in large volume at low cost and therefore the components used may not be as high a quality as dedicated TDR systems. The result is imperfect knowledge about the true response of the front-end, errors in the model of the front-end and degraded TDR performance.
For at least this reason, it is important to precisely characterize the response of the TDR front-end. In particular, a front-end calibration method is required to determine the exact characteristics of the TDR system thereby removing the uncertainty of the electrical characteristics of the components in the TDR front-end. Since the TDR system is a three port system the calibration method determines the three independent parameters that completely specify any three port system. In the calibration process, the TDR system is connected to at least three predetermined DUTs and the TDR front-end is used to transmit signals and receive the corresponding reflected signals with each DUT connected. Next, the TDR system is calibrated by determining the three independent parameters of the three port TDR system using the transmitted and received waveforms along with the predetermined DUT characteristics.
As an example, the TDR system can be implemented in a DSL transceiver and the DUT that needs to be characterized can be the transmission line that is causing problems in the DSL connection, e.g., bit errors. In this case, it is necessary to first calibrate the DSL transceiver front-end to characterize the electrical characteristics of all its components. Therefore, the DSL transceiver is connected to three known impedances and the DSL transceiver front-end is used to transmit signals and receive the corresponding reflected signals with each impedance connected. Next, the front-end is calibrated by determining the three independent parameters of the DSL front-end using the transmitted and received waveforms along with the known impedance values. Then, for example, as discussed in co-pending application Ser. No. 09/755,173, entitled “Systems and Methods for Establishing a Diagnostic Transmission Mode and Communicating Over the Same,” filed Jan. 8, 2001 and incorporated herein by reference in its entirety, one or more of the calibration information, characterization of the transmission line, or any other relevant information can be transmitted to a location, such as a central office modem.
Accordingly, the systems and methods of this invention at least provide and disclose a model of the TDR front-end and a method for determining the parameters of the model using experimental measurements.
Aspects of the invention also relate to a generalized model of the TDR front-end.
Aspects of the invention further relate to modeling the behavior of a composite system where an arbitrary DUT is connected to port three of the TDR system.
Aspects of the invention also relate to calibrating the TDR front-end model.
Furthermore, aspects of the invention further relate to determining the TDR front-end model parameters.
These and other features and advantages of this invention are described in, or apparent from, the following detailed description of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The embodiments of the invention will be described in detail, with reference to the following figures, wherein:
FIG. 1 is a functional block diagram illustrating an exemplary generalized model of a three port TDR front-end according to this invention;
FIG. 2 is a functional block diagram illustrating an exemplary three-port TDR front-end model according to this invention;
FIG. 3 illustrates a first exemplary method of characterizing a DUT according to this invention;
FIG. 4 illustrates a second exemplary method of characterizing a DUT according to this invention;
FIG. 5 illustrates a third exemplary method of characterizing a DUT according to this invention;
FIG. 6 is a flowchart illustrating an exemplary method of calibrating the TDR front-end model according to this invention; and
FIGS. 7-10 illustrate exemplary experimental results comparing the measured and predicted values.
DETAILED DESCRIPTION OF THE INVENTION
The exemplary embodiments of this invention will be described in relation to the application of a model to describe the TDR front-end and a method for determining the parameters of the model. However, it should be appreciated, that in general, the systems and methods of this invention will work equally well for modeling any type of three port TDR system.
The exemplary systems and methods of this invention will also be described in relation to a TDR system that can be used in conjunction with a DUT such as a twisted-pair transmission line. However, to avoid unnecessarily obscuring the present invention, the following description omits well-known structures and devices that may be shown in block diagram form or otherwise summarized.
For the purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the present invention. It should be appreciated however, that the present invention may be practiced in a variety of ways beyond these specific details. For example, the systems and methods of this invention can generally be applied to any type of transmission line.
Furthermore, while the exemplary embodiments illustrated herein show the various components of the TDR system collocated, it is to be appreciated that the various components of this system can be located at distant portions of a distributed network, such as a telecommunications network and/or the Internet, or within a dedicated TDR system. Thus, it should be appreciated that the components of the TDR system can be combined into one or more devices, such as a DSL transceiver, or collocated on a particular node of a distributed network, such as a telecommunications network. As will be appreciated from the following description, and for reasons of computational efficiency, the components of the TDR system can be arranged at any location within a distributed network without affecting the operation of the system. For example, the various components can be located in a CO modem, CPE modem, or some combination thereof.
Furthermore, it should be appreciated that the various links connecting the elements can be wired or wireless links, or any combination thereof or any other know or later developed element(s) that is capable of supplying and/or communicating data to and from the connected elements. Additionally, the term module as used herein can refer to any known or later developed hardware, software, or combination of hardware and software that is capable of performing the functionality associated with that element.
FIG. 1 illustrates an exemplary generalized model of the TDR front-end. The TDR front-end can be modeled as a linear, time-invariant three-port electrical network. Specifically, as illustrated in FIG. 1 , the TDR system 10 comprises a transmitter 100 , a receiver 110 , which may also include any necessary measurement components for measuring the received waveform as well processors and/or memory (not shown), a front-end 120 , a device under test (DUT) 130 , a first port 140 , a second port 150 , a third port 160 , a first voltage (v 1 ) 170 corresponding to the voltage across the first port 140 , a second voltage (v 2 ) 180 corresponding to a voltage across the second port, a third voltage (v 3 ) 190 corresponding to a voltage across the third port, a first current (i 1 ) 200 , a second current (i 2 ) 210 and a third current (i 3 ) 220 . In general, signals are transmitted from the transmitter 100 , such as a digital-to-analog converter or other waveform generator, at port 1 , reflections received by the receiver 110 , such as an analog-to-digital converter or other measurement device, on port 2 , with port 3 being connected to the DUT 130 , such as a subscriber line or other one-port electrical network The TDR system 10 is also connected via link 5 to a transfer function module 20 , a storage device 30 and a parameter and matrix determination module 50 .
This three-port model of the front-end captures any linear, time-invariant implementation that may be present within the front-end, including, but not limited to, transmit path filtering inside port 1 , receive path filtering inside port 2 , hybrid circuitry connecting the ports, output filtering inside port 3 , echo cancellers, or the like. Exemplary TDR front-ends that are characterized by the three-port model of the front-end include a wired or wireless modem, a DSL modem, an ADSL modem, a multicarrier transceiver, a VDSL modem, an SHDSL modem, and the like.
FIG. 2 illustrates an exemplary configuration within the three-port TDR front-end model 120 . For this exemplary implementation, the front-end model 120 comprises a transmit path filter 230 , a receive path filter 240 , an analog hybrid circuit 250 and an output filter 260 .
However, regardless of the specific implementation inside the front-end model, any linear time-invariant three-port network can be described by the matrix equation u=Yw, where
Y = ( y 11 y 12 y 13 y 21 y 22 y 23 y 31 y 32 y 33 )
is an admittance matrix describing the relationships between currents and voltages of each port, and
u = ( i 1 i 2 i 3 ) and w = ( v 1 v 2 v 3 )
are vectors containing the currents and voltages, respectively, at each port. Further details regarding the vector relationship can be found in Microwave Engineering , Second Edition, by D. M. Pozar, Wiley, New York, 1998, which is incorporated hereby by reference in its entirety, and in particular pp. 191-193.
In general, each of the quantities y ij are a complex function of frequency. Explicit notation of frequency dependence has been omitted for clarity. Therefore, it should be assumed that all parameters are complex functions of frequency unless noted otherwise.
The DUT typically comprises one or more interconnected electrical transmission lines with unknown terminations. More generally, the DUT may be any linear, time-invariant, one-port electrical network. An exemplary DUT is a subscriber line.
There are several exemplary ways to completely characterize the DUT including, for example:
1) As a complex, frequency-dependent input impedance Z, as shown in FIG. 3 . The input impedance includes all aspects of the DUT 130 and is not just limited to the characteristic impedance of the first section. 2) As a voltage impulse response v ir (t), also denoted h(t), when connected to a voltage source with source impedance Z source as shown in FIG. 4 , where δ(t) is an impulse voltage waveform. 3) As a complex, frequency-dependent one-port scattering parameter S 11 with respect to reference impedance Z ref as shown in FIG. 5 , where v + is the forward-traveling voltage wave, v − is the backward-traveling voltage wave and
S
11
=
v
-
v
+
.
However, it is to be appreciated that while only three exemplary methods of characterizing a DUT are enumerated, there are an infinite number of ways to completely characterize a DUT. Each representation provides the same amount of information about the DUT such that each characterization is fundamentally equivalent. Therefore, changing the representation of the DUT does not change the behavior of the DUT, the representation merely changes the description of how the DUT behaves.
Each of the various representations can be mapped to one another using transformations. For example, if the DUT is described by its voltage impulse response h(t), then it is related to input impedance Z of the DUT in accordance with:
h
(
t
)
=
Z
Z
source
+
Z
.
Similarly if the DUT is described by its complex, frequency-dependent one-port scattering parameter S 11 , then it is related to the input impedance Z of the DUT in accordance with:
S
11
=
Z
-
Z
ref
Z
+
Z
ref
.
For ease of understanding, the remaining disclosure will use the complex, frequency-dependent input impedance Z to describe the DUT. However, it should be appreciated, that any other equivalent representation can be substituted without changing the underlying behavior of the model.
Specifically, the system attempts to model the behavior of the composite system when an arbitrary DUT is connected to port 3 of the TDR system 10 . The behavior of the system is described by the response at the receiver port 2 150 to a stimulus at transmitter port 1 140 . Either voltage or current can be applied at port 2 140 , and either voltage or current can be measured at port 2 150 . Therefore, there are at least four possible ways to obtain the system transfer function. However, it should be appreciated, that the system transfer function is but one or many equivalent ways to completely characterize the system. Any of these four methods provides the same information about the system, the choice of using one method over another depends, for example, on which one is more efficient to implement.
As an example, voltages can be used at port 1 and port 2 so the voltage transfer function for the system is
H = v 2 v 1 ,
which is a complex function of frequency. It should be appreciated however, that the models for each of the other three possible implementations are equivalent, so the analysis presented below applies equally to each.
It can be assumed that the voltage is measured at port 3 160 using a device with infinite impedance, which yields i 2 =0. If the voltage measurement device at port 3 160 were not to have an infinite input impedance, then its finite input impedance could be absorbed into the three-port network. Therefore, there is no loss in generality by assuming that i 2 =0.
The voltage transfer function of the TDR system is given by
H = a Z + b c Z + 1 ( 1 )
where a, b and c are complex functions of frequency. Relating a, b, and c to y ij ,
a = y 23 y 31 - y 21 y 33 y 22 , b = - y 21 y 22 , c = y 22 y 33 - y 23 y 32 y 22 .
Therefore, the three-port TDR front-end can be completely characterized by three independent parameters. Like the DUT, these three TDR front-end parameters can be represented in many different ways. For example, a, b, and c can be mapped to an alternative set of parameters as follows:
a ~ = a Z ref - b c Z ref + 1 , b ~ = a Z ref + b c Z ref + 1 , c ~ = c Z ref - 1 c Z ref + 1 .
This allows H to be expressed as a function of S 11 for the DUT as follows:
H = a ~ S 11 + b ~ c ~ S 11 + 1 .
Again, there are an infinite number of ways to completely characterize the three TDR front-end parameters. Each representation provides the same amount of information about the TDR front-end, so they are fundamentally equivalent.
However, it should be noted that the system could be completely characterized by more than three parameters. Nevertheless, any representation that uses more than three parameters can be reduced to three independent parameters by the appropriate mapping. For example,
H = a ′ Z + b ′ c ′ Z + d ′
can be reduced to the three independent parameters of Eq. 1 using:
a
=
a
′
d
′
,
b
=
b
′
d
′
,
and
c
=
c
′
d
′
.
Another example is:
H = a ^ Z + b ^ c ^ Z + 1 + d ^
which can be reduced to three independent parameters using
a=â+ĉ{circumflex over (d)},b={circumflex over (b)}+{circumflex over (d)} , and c=ĉ.
The transfer function H has been formulated in terms of a three-port electrical network and the DUT 130 . Although the three-port representation is commonly used to characterize the loading effects of analog circuitry, the transfer function H may generally include the effects of digital signal processing. For example, digital filters and digital echo cancellers could be absorbed into the a, b, and c parameters. In this case, the transmitted signal v 1 is digital in nature and does not necessarily exist as a physical voltage, but eventually is converted to a voltage through a digital-to-analog converter (DAC). Similarly, the received digital signal corresponds to v 2 , which at some point was converted from a physical voltage to a digital signal using, for example, an analog-to-digital converter (ADC).
As noted above, the models of the TDR front-end can be based on as few as three complex, frequency-dependent parameters. As discussed hereinafter, a technique for determining the value of these parameters based on actual measurements is illustrated. This technique will be referred to as “calibration.”
The response of the front-end model must match the response of the actual front-end precisely enough to capture minute details of the waveforms that propagate through the actual front-end. Calibration is necessary since the electrical characteristics of the real front-end components can vary from design-to-design, and from board-to-board. Sometimes, component characteristics will vary slowly over time, which necessitates that the system be calibrated within a certain time period, for example during an initialization, before TDR measurements are performed on the DUT.
As an example, the system could be calibrated by measuring each component individually, and incorporating the actual values into a complex system model that takes into account the relationships between each component. In reality, however, this approach would be time-consuming and impractical because systems typically contain hundreds of components with complex relationships. The front-end of a typical DSL modem exemplifies a system with numerous components.
Using a model of the TDR front-end, such as the three-parameter model disclosed above, greatly simplifies the calibration process. The model allows a precise response of a front-end to be captured by taking far fewer measurements and combining them in a much simpler fashion.
Since the model of H contains three independent parameters that describe the TDR front-end, not including the parameter that characterizes the DUT, then at least three different measurements with different known DUTs are required to solve for each of the independent parameters.
If N measurements have been taken with N different DUTs, each with known impedance, then the TDR system transfer function can be determined for each of these N configurations. It is possible to determine values for a, b, and c that best fit Eq. 1 for the collection of all N configurations. The notion of “best fit” depends on the criterion chosen to quantify how well the measured values fit the data, such as minimizing some measure of error. One common criterion for establishing best fit is to minimize error in the least-squares sense. It should be noted however, that other optimization criteria are possible. If another optimization criterion is used, the underlying concept remains the same.
The following example demonstrates optimization of a, b, and c in the least-squares sense. Assume that N measurements have been taken. Let Z n and H n denote the DUT impedance and TDR system transfer function, respectively, obtained for measurement n. Rearranging Eq. 1, aZ n +b−cZ n H n =H n for each n. This system of equations can be re-written in matrix form as Av=h where
v = ( a b c )
contains the parameters to be determined and
A
=
(
Z
1
1
-
Z
1
H
1
Z
2
1
-
Z
2
H
2
⋮
⋮
⋮
Z
N
1
-
Z
N
H
N
)
and
h
=
(
H
1
H
2
⋮
H
N
)
.
(
2
)
If N=3, the values of a, b and c can sometimes be obtained by solving v=A −1 h. In practice, however, measurement errors sometimes cause this system of equations to be inconsistent. If N>3, the system of equations is over-specified and is usually inconsistent.
Therefore, a solution for v can be found that minimizes some measure of the error. To minimize the error in the least-square sense, the optimal v, and thus the optimal a, b and c, can be found by satisfying the normal equations A *T Av opt A *T h where *T denotes transposition followed by complex conjugation. See G. Strange, Linear Algebra and Its Application, 3 rd Ed., Harcourt Brace, San Diego, 1986, incorporated herein by reference in its entirety, and in particular pp. 154-156. It should be noted however, that other en-or minimization criterion are possible. If another error minimization is used, the underlying concept remains the same. This results in the following optimal value:
v opt =[A *T A] −1 A *T h, (3)
Because a, b, and c are frequency-dependent, this equation must be solved separately for each frequency of interest.
An exemplary technique for calibration according to this invention is accomplished with the aid of the transfer function module 20 , the storage device 30 and the matrix and parameter determination module 40 .
In particular, a DUT 130 of known impedance Z n is connected to port 3 160 . The value of Z n should be known precisely and should be preferably chosen to maintain the front-end 120 within operational limits. A waveform v 1 is then generated and transmitted from the waveform generator 100 at port 1 . The transmitted waveform is received as the returned waveform v 2 at port 2 150 and consequently at the receiver 110 .
The transfer function module 20 determines the transfer function of the TDR system for the current DUT, i.e., DUT n , in accordance with
H n = v 2 v 1
and stores the corresponding value pairs of Z n and H n in the storage device 30 . This process is repeated for each n with the corresponding value pairs of Z n and H n being stored in the storage device 30 .
Having the pairs of Z n and H n , the matrix and parameter determination module 40 determines matrix A and vector h based on Eq. 2, as well as the parameters a, b, and c based on Eq. 3. The TDR system response H for any arbitrary DUT characterized by Z, can then be predicted by the transfer function module 20 based on the optimal parameters a, b, and c identified in Eq. 1.
FIG. 6 illustrates an exemplary technique for calibration according to this invention. In particular, control begins in step S 100 and continues to step S 110 . In step S 110 , a DUT of a known impedance is connected to port 3 . The value of Z n should be known precisely. Ideally, Z n can be any value, but practical considerations dictate that care be taken to ensure that the front-end remains within its proper operating region. For example, port 3 should not be short-circuited if the short circuit would cause the front-end to exhibit non-linear behavior. The value of Z n can be complex and frequency-dependent, but usually a constant, real resistance is adequate.
Next, in step S 120 , a waveform v 1 is transmitted at port 1 . Then, in step S 130 , the transmitted waveform is received as the returned waveform v 2 at port 2 . The transmitted waveform v 1 should be chosen such that it adequately illuminates all frequencies for which the transfer function of the TDR system is to be determined, and it should also adhere to the sampling rate and dynamic range limitations of the front-end. Otherwise, any arbitrary v 1 can be used.
Furthermore, averaging can be performed to reduce uncorrelated background noise that might be present during each transmission. Control then continues to step S 140 .
In step S 140 , the transfer function of the TDR system is determined for the current DUT in accordance with
H n = v 2 v 1 .
Only v 1 and v 2 are used in this calculation. Z 1 , a, b, and c are not used.
Next, in step S 150 , the values of Z n and H n are recorded. Then, in accordance with step S 160 , for each n, steps S 110 -S 150 are repeated. It should be ensured that Z n covers at least three distinct values. It is desirable to have a range of Z n that approximates many possible DUTs. When this step is complete, N pairs of measurements for Z n and H n will have been recorded, where N is the number of complex impedances used, and N≧3. Experiments have shown that results are improved by using more than three measurements, sometimes as many as ten (S 170 ). Control then continues to step S 180 .
In step S 180 , the parameters a, b, and c are determined to best fit Eq. 1 for the collection of all N values of Z n and all N values of H n . One exemplary method for determining a, b, and c, is to minimize error in the least-squares sense using Eq. 2 and Eq. 3. Then, in step S 190 , the TDR system response H for any arbitrary DUT characterized by Z, is predicted using the optimal parameters a, b, and c used in Eq. 1. Control then continues to step S 200 where the control sequence ends.
An experimental example of implementing the above calibration method was performed using a TDR system implemented on a DSL, transceiver. In particular, three measurements on a particular DSL, transceiver front-end were performed by connecting 10Ω, 51Ω, and 100Ω resistors to the DSL line interface port, i.e., port 3 . V L (f) was obtained by sampling the analog voltage waveform at a rate of 2204 k samples per second, since this corresponds to the standard DSL transceiver sampling rate. The final measurement of the response of the DSL, front-end was obtained by dividing V L (f) into the input voltage waveform V s (f). The DSL front-end parameters a, b, and c were then determined in accordance with the above-described method. FIG. 7 shows the DSL front-end parameters obtained by solving Eq. 2. To test how well the given formulation can predict the actual echo responses, the measured and predicted echo responses were plotted in FIGS. 8-10 . The predicted echo responses were obtained by plugging in the determined DSL front-end parameters a, b, and c into Eq. 1 for Z=10Ω, 51Ω, and 100Ω. As observed, the exemplary measured and predicted echo responses very closely approximate each other confirming the model for the DSL, front-end and validating that the approach of calibrating the transceiver by determining the parameters a, b, and c via experimental measurements is accurate.
The above-described TDR modeling system can be implemented on a telecommunications device, such a modem, a DSL modem, an SHDSL modem, an ADSL modem, a multicarrier transceiver, a VDSL modem, or the like, or on a separate programmed general purpose computer having a communications device. Additionally, the systems and methods of this invention can be implemented on a special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit element(s), an ASIC or other integrated circuit, a digital signal processor, a hard-wired electronic or logic circuit such as discrete element circuit, a programmable logic device such as PLD, PLA, FPGA, PAL, modem, transmitter/receiver, or the like. In general, any device capable of implementing a state machine that is in turn capable of implementing the flowchart illustrated herein can be used to implement the various TDR modeling methods according to this invention.
Furthermore, the disclosed methods may be readily implemented in software using object or object-oriented software development environments that provide portable source code that can be used on a variety of computer or workstation platforms. Alternatively, the disclosed TDR modeling system may be implemented partially or fully in hardware using standard logic circuits or VLSI design. Whether software or hardware is used to implement the systems in accordance with this invention is dependent on the speed and/or efficiency requirements of the system, the particular function, and the particular software or hardware systems or microprocessor or microcomputer systems being utilized. The TDR modeling systems and methods illustrated herein however can be readily implemented in hardware and/or software using any known or later developed systems or structures, devices and/or software by those of ordinary skill in the applicable art from the functional description provided herein and with a general basic knowledge of the computer and telecommunications arts.
Moreover, the disclosed methods may be readily implemented in software executed on programmed general purpose computer, a special purpose computer, a microprocessor, or the like. In these instances, the systems and methods of this invention can be implemented as program embedded on personal computer such as JAVA® or CGI script, as a resource residing on a server or graphics workstation, as a routine embedded in a dedicated TDR modeling system, or the like. The TDR modeling system can also be implemented by physically incorporating the system and method into a software and/or hardware system, such as the hardware and software systems of a communications transceiver.
It is, therefore, apparent that there has been provided, in accordance with the present invention, systems and methods for TDR modeling. While this invention has been described in conjunction with a number of embodiments, it is evident that many alternatives, modifications and variations would be or are apparent to those of ordinary skill in the applicable arts. Accordingly, it is intended to embrace all such alternatives, modifications, equivalents and variations that are within the spirit and scope of this invention. | A three-port TDR front end comprises numerous components. An exemplary three-port TDR front end is a DSL modem. Information-bearing TDR signals are distorted as they pass through these components. With a perfect model of the response of its front-end, a TDR system usually can compensate for the effects of its front-end. In reality, however, the electrical characteristics of each component vary from design-to-design, board-to-board, and slowly over time The result is imperfect knowledge about the true response of the front-end, errors in the model of the front-end, and degraded TDR performance. At least for this reason it is important to precisely calibrate the response of the TDR front-end through the use of a TDR modeling system. | 6 |
RELATED APPLICATION
[0001] The present application claims 35 USC 119(e) priority from U.S. Provisional application Ser. No. 61/748,953 filed Jan. 4, 2013.
[0002] Portions of this disclosure are included in U.S. Provisional Application No. 61/581,505 filed Dec. 29, 2011, which is now U.S. patent application Ser. No. 13/685,801 filed on Nov. 27, 2012.
BACKGROUND OF THE INVENTION
[0003] In processes involving printing on sheets of material such as paper, or processing folding carton blanks, it is typically desirable that in the case of a rectangular sheet or blank that the side edges of the sheet or blank are parallel to the conveying direction and/or the leading edge is perpendicular to the conveying direction. This allows operations such as printing to be properly oriented with respect to the sheet or blank. In carton folding/gluing operations, flat carton blanks are folded along score lines and glued along a seam or at a corner or corners to provide a carton ready for subsequent uses such as erecting or filling. Carton folder/gluers typically include a feeder which dispenses a flat, die-cut carton blank from the bottom of a stack of blanks. These feeders often do not dispense a carton blank with the desired orientation alignment because of many factors, e.g., asymmetry of carton shape and uneven weight distribution in the feeder, varying feeder belt friction coefficients, differences in feed gate settings and other factors. Immediately after leaving the feeder, cartons are gripped by carrier belts. To create a desired spacing between each carton blank on the carrier belts, the carrier belts run faster than the feeder belts. This creates a brief ‘tug of war’ while the carton is released by the slower moving feeder belts and engaged by the faster moving carrier belts. The feeder and carrier belt positioning is often asymmetric with respect to the carton and this ‘tug of war’ can cause a carton blank to twist out of the desired orientation.
[0004] Folder/gluer operators strive to make cartons feed “square” or “aligned”, i.e., in the desired orientation with the conveying direction on carrier belts. This requires a high degree of operator skill based on years of experience.
[0005] To reduce the level of operator skill required to some extent and to better assure proper orientation regardless of machine parameters that often vary during operation, carton folders/gluers often include a carton aligner or aligning section. In prior art aligning processes, the sheets or carton blanks have been conveyed by carrier belts with overlying balls or rollers that lightly grip the sheet or blank and laterally urge the sheet or blank against a mechanical guide comprised of an adjustable steel plate with a smooth, flat surface. This section of the machinery is known as an aligning section. The loose contact between belts and rollers allows the sheet to shift so that it can become aligned with respect to the guide which typically sets one side edge of a blank parallel with subsequent lower carrier belts and upper gripping belts or rollers. This is intended to desirably align the sheet or blank for subsequent operations.
[0006] There are some drawbacks to the prior art method of aligning:
Set up of the aligning section involves adjusting numerous components and variables and requires an experienced operator. The sheet or blank is not firmly gripped or controlled during the aligning process. Thus the speed and position of the blank in the aligning section is not well defined, repeatable, or predictable. There are some subsequent processes such as applying adhesive with systems provided by Nordson of Westlake, Ohio or applying window film patches with windowing systems such as provided by Tamarack Products of Wauconda, Ill. that require the speed and position of the blank to be known so that subsequent speed and position can be accurately predicted. For example, the Tamarack® Vista® windowing machine uses a scanner approximately two feet ahead of the Vista windower to sense carton position. Carton speed is indirectly sensed by an encoder that measures the speed of a lower carrier belt. During aligning, substantial slippage occurs between the blank and the carrier belts in the aligning section, the carton speed will not be sensed properly, the blank's subsequent position will not be predicted accurately, with the result that the window application position will not be accurate. For these applications, the carton blank must be sensed later in the process, after aligning. This means the scanning of the blank must occur later in the folder/gluer and this can result in an undesirable or impractical location for the Vista windower.
SUMMARY OF THE PRIOR ART
[0009] The machines in the web pages listed below use a typical alignment guide bar and angled rollers or belts to urge a carton blank against the guide bar.
[0010] Various means are used to drive the blank, while at the same time allow the blank to shift to bring one edge of the blank into compliance with the guide bar.
[0000] http://www.aim-inc.net/new_machines/elite.cfm
http://www.robertspolypro.com/products/folder-fluer/
[0011] U.S. Pat. No. 6,162,157 to Morisod shows an alignment device that, while using a traditional guide bar 100 , also uses air flow to lightly contact and urge blanks of “low specific gravity”, partly folded blanks and other delicate blanks against an angled belt which otherwise traditionally urges the blank against the guide bar.
[0012] The aforementioned Provisional Application No. 61/581,505 to Machamer uses two scanners to sense the lead edge of the blank. The signals from the scanner are fed to a processor which evaluates the timing difference (or the difference in master encoder or virtual master pulses) between each scanner's signal. Two sets of grippers engage each sheet or blank towards its side edges. The grippers are capable of operating at different speeds via a differential drive or electronically controlled servo drives. Differing speeds are commanded at each gripper in order to steer or rotate the blank relative to subsequent carrier belts.
OBJECTS AND SUMMARY OF THE INVENTION
[0013] In my previous application (Provisional Application No. 61/581,505), a novel aligner using servo-driven gripper wheels to steer and align the carton blanks works well in practice. However, the servo drive used in at least one embodiment is relatively expensive.
[0014] An effective aligner, that also provides a firm grip and control of the blanks during alignment, has been developed using simpler, less costly components. Further, the improved aligner system can be largely adjusted by the manufacturer and requires no programming or entry of parameters by an operator and little subsequent mechanical adjustment on the part of an operator. This substantially lowers the skill level required of an operator, as well as improving the productivity of the operator and the equipment.
[0015] Carton blanks or sheets are conveyed on vacuum belt cartridges as is known. The blanks are generally held in contact with belts via vacuum supplied through or between belts, however, the contact with the belts is light enough to allow the cartons to shift or twist on the belts when an aligning force is applied.
[0016] The blanks carried on the vacuum belt may be undesirably skewed or angled relative to the vacuum belts. The blanks may also be laterally out of position for subsequent operations such as longitudinal folding. Or, the blanks may have a combination of skew and lateral displacement. Both skew and lateral displacement are considered errors in position that will later cause errors in the process, such as incorrectly positioned longitudinal folds, window films, or glue lines.
[0017] In one embodiment of the improved apparatus, a series of upper and lower castered or bias-angled rollers or wheels are positioned adjacent the vacuum belts. The carton blanks are gripped firmly by the upper and lower wheels. The initial angle of the wheels causes a sidewards force that urges the blank against a side guide. The side guide may be a stationary straight edge as is known, or a moving belt. The moving belt may be driven with pulleys having rotational axes either horizontal or vertical, i.e., to engage the edge or the flat side of the belt, respectively, and provides both an alignment side guide and a driving surface. The moving belt advantageously minimizes friction acting against the blank, compared to a typical stationary side guide.
[0018] The upper and lower wheels are mounted on pivots. The pivots are positioned ahead, or upstream, of the wheels so that each wheel can swivel to align with the direction of motion of the blanks in a manner similar to a caster wheel on a shopping cart. However, at least some of the upper and lower wheels are biased or angled toward the side guide by a spring acting on each wheel assembly.
[0019] As each blank is gripped by an upper and lower wheel, the blank is generally moving parallel to the vacuum belt(s). The upper wheel attempts to swing on its pivot and align itself with the direction of motion of the carton, however, that aligning tendency is resisted by the spring. The resulting lateral force pulls both the upper and lower wheels and in turn pulls the blanks towards the side guide. Once the blank is rotated and/or laterally displaced against the side guide, the blank can no longer be further displaced and it continues along the vacuum belts in alignment with the side guide. At this time, the upper and lower wheels caster, or align, themselves parallel to the side guide. At the end of the aligner section, the blank enters typical upper and lower carriers in state of the art folder/gluers and then leaves the upper and lower wheels (and also the side guide) and tends to remain in the desired orientation and position defined by the side guide. This allows subsequent operations such as folding, windowing, and gluing to be performed in the desired locations and positions on the blanks.
[0020] The instant invention provides a number of advantages over prior art methods and apparatuses.
[0021] The castered wheel assemblies of the instant invention are relatively inexpensive compared to the servo-driven system of the earlier Provisional Application No. 61/581,505. The instant invention requires no servo programming or operator interface such as a touch screen.
[0022] The castered wheel apparatus requires little operator set up or intervention, a major benefit for the operator and productivity.
[0023] The castered wheel assemblies and side guide allow a firm grip of the blanks during the aligning process so the longitudinal speed of the blanks remains nearly constant. The firm grip of the wheels on the blank provide a substantial transverse force against the side guide belt. In embodiments where the guide belt is driven at the intended conveying speed, this provides a positive driving force on the carton blank. This positive drive means that the blank's speed is matched to the conveying speed and allows the blank's longitudinal position to be sensed during alignment, and its speed will closely match the guide belt speed so that the carton blank's subsequent speed and position may be accurately predicted; an important benefit that assures accuracy for subsequent timed operations such as gluing and windowing. The freedom to sense the position of the blanks during (instead of after) alignment allows a wider choice of installation position for windowing equipment such as a Tamarack Vista window applicator and may also eliminate the need to lengthen the folder/gluer to provide enough length to perform the position sensing ahead of the window film equipment—typically about two feet upstream of window application. So, the new invention has a clear advantage over prior art alignment mechanisms which require a relatively light contact with the blank so the blank can slip during the aligning process—in contrast, the new invention provides a firm grip on the carton blank during the aligning process and so that the blank's speed and position can be accurately established during aligning, instead of after aligning. While this advantage of allowing the sensing of carton position at an earlier point in the folder gluer machine is similar to the servo-driven system of Provisional Application No. 61/581,505, this new invention achieves it with a significantly simpler, lower cost, and easier to use apparatus.
[0024] The side aligning force can be easily limited by selecting ‘light’ springs, i.e., springs having a relatively small spring constant, or by adjustably loaded springs. This allows the instant invention to be readily used with sheets of paper which have a relatively low stiffness relative to bending. In other words, the instant invention can be adjusted so that relatively lightweight sheets or carton blanks can be aligned without buckling the sheets as they contact the side guide. The possibility of sheet buckling may also be reduced by placing the castered wheel assemblies in close proximity to the side guide.
[0025] The driven belt side guide reduces or eliminates any drag on the carton blank during the alignment process, as does to a slightly lesser extent a non-driven but idled belt or roller side guide. This reduction in drag or friction is not to be underappreciated—the fixed side guide plate of a prior art aligner can become far too hot to touch due to friction between the blanks and the fixed side guide. This reduction of friction further minimizes carton blank slippage in the longitudinal direction and again allows for more reliable position sensing. The reduced drag also reduces any tendency to buckle a corner or edge of a relatively delicate carton blank or sheet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The appended claims set forth those novel features which characterize the invention. However, the invention itself, as well as further objects and advantages thereof, will best be understood by reference to the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawings, where like reference characters identify like elements throughout the various figures, in which:
[0027] FIGS. 1 a , 1 b , 1 c represent a progression of schematic top views of the prior art apparatus and method for aligning folding cartons.
[0028] FIG. 2 illustrates a schematic partial side view of the prior art apparatus.
[0029] FIG. 3 is a schematic top view of the inventive apparatus for aligning sheets and folding cartons that illustrates the carton blank in four sequential positions.
[0030] FIG. 4 a is a schematic top view of an alternative embodiment of the inventive apparatus.
[0031] FIG. 4 b is a schematic side view of the embodiment of FIG. 4 a.
[0032] FIG. 5 is a schematic top view of a modification of the embodiment of FIGS. 4 a and 4 b.
[0033] FIG. 6 is a schematic top view of an alternative embodiment of the inventive apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Prior Art
[0034] FIGS. 1 a and 1 b show a top view schematic of a prior art carton aligner used with prior art carton folder/gluers such as those provided by American International Machinery of Oak Creek, Wis., Bobst of Lausanne, Switzerland and Heidelberger Druckmaschinen AG of Heidelberg, Germany. Carton blank 11 , shown here in a skewed orientation relative to its intended conveying direction D and is carried on driven carrier belt 12 . Carrier belt 12 is typically driven by drive pulleys on a drive shaft via a motor drive system (not shown). In FIG. 1 a , side edge 11 a of blank is about to contact alignment bar 13 . Guide bar 13 is supported by side frame 16 a , by conventional means, not shown. Blank 11 is driven towards aligning surface 13 a of bar 13 by a series of rollers 17 that are held on an adjustable frame 18 via pivot 14 and adjuster 15 . The frame 18 is supported by side frame 16 a . The rollers 17 are shown in an angled orientation relative to side frames 16 a , 16 b and guide bar 13 such that the rollers develop a side force that urges blank 11 towards alignment bar 13 so that carton edge 11 a is crowded or pushed into contact with alignment edge 13 a . Unlike carrier belt 12 , rollers 17 are not directly driven. Rather, rollers 17 rotate by virtue of frictional contact with the carton blank 11 and if the blank is absent, by contact with carrier belt 12 .
[0035] FIG. 1 b shows a subsequent moment in time in relation to FIG. 1 a . Carton blank 11 has moved to the left, or downstream, and has rotated clockwise as a result of contact with guide bar 13 and the side force caused by the skewed rollers 17 .
[0036] FIG. 1 c illustrates a still later moment in time. Carton blank 11 has rotated and come into contact with aligning edge 13 a so that carton 11 is now traveling parallel to aligning edge 13 a , which is typically also parallel with side frames 16 a and 16 b . Edge 13 a defines the desired carton 11 conveying direction D. Edge 13 a also defines the lateral position of carton edge 11 a relative to side frames 16 a , 16 b so that subsequent operations such as folding at various scores, window application, labeling, die cutting, and other operations known in the art (but not shown here) can be performed at the desired lateral locations on carton blank 11 .
[0037] FIG. 2 is a side view schematic of the prior art apparatus of FIGS. 1 a - c . Carrier belt 12 is supported by rollers 19 . Rollers 17 are spring loaded to grip the carton blank 11 between rollers 17 and carrier belt 12 . The grip of the rollers 17 and belt 12 on the carton blank 11 is adjustable so that the blank is driven forward (to the left relative to FIGS. 1 a - c and FIG. 2 ) in the folder gluer reliably and also driven against the alignment bar 13 , but not so tightly that the carton blank is deformed against the alignment bar 13 by excessive side forces. Also the carton blank must be lightly enough gripped to allow the carton blank 11 to rotate (relative to the plane illustrated in FIGS. 1 a - c ) into the desired orientation with alignment edge 13 a . The requirements for positively driving the blank forward while allowing it to slip so it can be aligned are at cross-purposes and require skilled operator adjustment for a particular job. For more reliable performance, the alignment bar 13 and frame 18 with angled rollers 17 are quite long and an aligning module to support the aligning components typically adds about 3-4 ft to the length of an already long and sizable carton folder/gluer. While the carton blank is in the alignment section, the twisting and slippage of the carton blank means that its speed and position are not accurately defined or predictable. This can interfere with operations like in-line window affixing such as provided by the Vista window applicator of Tamarack Products Inc of Wauconda, Ill. whose operation is disclosed in U.S. Pat. Nos. 6,772,663 and 7,901,533, the disclosures of which are incorporated herein.
Inventive Method and Apparatus:
[0038] FIG. 3 is a schematic top view of the inventive apparatus for aligning sheets and folding carton blanks. Carton blank 11 is shown in four sequential positions, Pos. 1, 2, 3, 4. Carton blank 11 has a side or lateral edge 11 e . It is desirable that edge 11 e be oriented parallel to an intended blank direction D. It is also desirable that edge 11 e be positioned in a known and repeatable lateral position so that subsequent operations such as longitudinal folding or windowing may be accurately positioned. In Position 1 the carton blank is laterally out of position but no skew is shown for the purpose of simplification. The inventive aligner can correct both lateral position error and/or skewing error. Carton blank 11 is conveyed on vacuum belts 32 a and 32 b . Vacuum belts are known in the art of conveying sheets and carton blanks. Openings in the belts such as 32 h are provided to allow vacuum, e.g., air at a pressure below normal atmospheric pressure, to communicate from a source (not shown) below the belt, through the belt, and with the atmosphere if the holes 32 h are not covered with a carton blank. When a carton blank 11 covers vacuum holes, the difference in pressure causes the blank 11 to be forced onto the belts so the carton blank 11 may be conveyed by belts 32 a , 32 b in an intended direction D. In other embodiments, the belts 32 a , 32 b do not need holes such as 32 h . Instead each belt 32 a may be replaced by a plurality of belts running parallel but with a gap of, e.g., ⅛″ between their inner edges so that the vacuum source may communicate with the atmosphere via the gap between the belts. This is also known in the art of conveying sheets and carton blanks. In another embodiment, belts 32 a , 32 b need not utilize vacuum at all, rather, belts 32 a , 32 b may be lower carrier belts and at least one upper carrier belt may be located in an opposing manner above one or more lower carrier belts so that blank 11 is gripped therebetween as is typical in the art.
[0039] A series of gripper wheel assemblies such as 35 A- 35 F are provided to grip carton blank 11 as it moves along the aligner apparatus. Each wheel 35 w is supported by a pivoting frame 35 f which can pivot on pivot pin 35 p . The supporting framework for the gripper wheel assemblies is not shown, but the framework is typically connected to the guide 36 . Supporting framework is understood in the art and deleting it in the following schematic figures allows the method of operation to be more easily shown. Each wheel assembly 35 is held at an angle relative to intended blank direction D by a biasing spring 35 s . Not shown in this view are opposing wheel assemblies below each wheel assembly 35 . This provides a pair of upper and lower wheels such that each blank 11 is gripped therebetween. When blank 11 is gripped by a wheel assembly 35 , the wheel assembly will try to swing in alignment with the direction of travel of blank 11 much like the caster wheel of a shopping cart swings with the direction of travel of the cart.
[0040] A side guide 36 is provided to provide a lateral edge guide for the blank 11 and defines a target line TL with which blank lateral edge 11 e is to be parallel and coincident with. It is known in the art to provide an adjustable but stationary side guide, however, use of a moving belt as an edge guide is novel in the folding carton alignment art. In one embodiment of the current invention, a moving belt 36 b is provided and the belt is supported on pulleys 36 p . Pulleys 36 p may be unpowered, a.k.a. idling, or pulleys 36 d may be driven so that the belt 36 b surface speed is essentially the same as blank 11 speed in intended direction D. Driving the belt 36 b to run at essentially the same speed as the carton blanks reduces friction relative to the blank 11 which may be beneficial in avoiding damaging, e.g. wrinkling or buckling a corner of blank 11 that first contacts belt 36 b if carton 11 is skewed. Reducing friction relative to carton blank 11 also reduces or eliminates the tendency of blank 11 to undesirably twist or skew as a result of contact with a stationary guide 36 . In another embodiment, unpowered pulleys may be suitable in the case where blank 11 is relatively thick and stiff so that the driving forces required to move the belt 36 b are small compared to the forces which might buckle a corner or edge 11 e of blank 11 when it contacts the belt 36 b.
[0041] In general, it is desirable that wheel assemblies 35 are in relatively close proximity to guide 36 thus increasing the effective stiffness of blank 11 to avoid bending or buckling of the blank 11 between wheels 35 and guide 36 .
[0042] It is also desirable that the wheel assemblies 35 and guide 36 be adjustable in terms of their proximity to conveying belt 32 b to allow for blanks of various shapes and sizes.
[0043] In position 1, blank 11 is conveyed by belts 32 a , 32 b and has not yet entered any gripper wheel assemblies 35 .
[0044] In position 2, blank 11 has just been gripped by one of the gripper assemblies, 35 F.
[0045] In position 3, two of the gripper assemblies, 35 E and 35 F are in contact with blank 11 . The angle of the wheel relative to intended direction D causes a side force F1 at 35 F and F2 at 35 E. The wheel assemblies 35 E and 35 F try to swing into alignment with intended direction D on pivot 35 p , however spring 35 s provides a resisting force. This results in a lateral force on blank 11 . The lateral force becomes sufficient to overcome the frictional force provided by vacuum belts 32 a , 32 b on blank 11 , so that blank 11 begins to move laterally towards the side guide 36 . Spring 35 s begins to extend as the wheel assemblies 35 E and 35 F begin to pivot away from the side guide 36 as a result of the lateral force exerted by wheel assemblies 35 E and 35 F.
[0046] In Position 4, the blank 11 has moved laterally into contact with guide belt 36 b and is now “aligned”, that is, aligned in the desired orientation and with its lateral edge 11 e traveling on the intended line TL, i.e., along the line defined by the guide 36 . A guide stop 36 s serves as a stop or back up bar to belt 36 b so that the belt is not deflected undesirably by the side force acting against belt 36 b caused by biased wheels 35 C and 35 D acting through blank 11 . Guide stop 36 s could be a row of wheels to reduce friction and power consumption. As a consequence of blank edge 11 e contacting the guide belt 36 b wheel assembly 35 D has swung so that it is approximately parallel with the intended direction of blank 11 motion. The corresponding spring 35 s has extended further than the spring 35 s for wheel assemblies 35 E and 35 F in Pos. 3, generating force F3. The spring constant is chosen so that the blank 11 is laterally shifted with respect to its original position, Pos. 1, on the belts 32 a and 32 b , yet is not buckled by side force F3. Wheel assembly 35 c has recently engaged blank 11 in Pos. 4 and it has not yet swung parallel to TL, but it will swing parallel so long as blank 11 remains against guide 36 .
[0047] A very similar aligning action will occur if the blank is skewed, i.e., rotated clockwise or counterclockwise with respect to the plane defined by belts 32 a and 32 b or blank 11 . As will a similar aligning action occur if the blank 11 is skewed and laterally displaced away from guide 36 .
[0048] Generally, an operator will set up a carton feeder (not shown, but known in the art) so that blank edge 11 e is intentionally offset somewhat away from target line TL. However the inventive aligner will also tolerate to some extent a blank edge 11 e that is already interfering with target line TL, as will further be disclosed in FIG. 6 .
[0049] FIG. 4 a illustrates another embodiment of the invention in which the belt assemblies 32 a and 32 b and wheel assemblies 35 are similar to the embodiment of FIG. 3 , but the guide 46 is repositioned essentially 90 degrees from that of guide 36 in FIG. 3 . That is, pulleys 46 p rotate about horizontal axes instead of vertical axes. This may be advantageous when it is desired to drive at least one of the pulleys 46 p because the drive axle is parallel to other axles in the carton folder/gluer and can thus be readily driven with belt drive, for example, whereas the vertical axes of pulleys 36 p of FIG. 3 may, in that case, need to be driven through a generally more costly right angle gearbox. A stop bar 46 s is provided to support belt 46 b against lateral forces so that the guiding edge of belt 46 b is coincident with target line TL. The edge of the belt 46 b is generally thicker than a carton blank 11 (not shown in FIG. 4A ) and so provides adequate guiding of blank edge 11 e.
[0050] FIG. 4 b is a side view of the embodiment of FIG. 4 a which further shows the upper and lower wheel assemblies, 35 upper and 35 lower. Wheels 35 upper and 35 lower are initially biased as seen in FIG. 4 a , however, the bias is not clearly visible in the side view of FIG. 4 b . The upper wheels may be arranged to swing independently of the lower wheels, or may be linked so that each upper and lower wheel pair swings together.
[0051] In another embodiment, the wheels could be preset at a fixed, i.e., non-swinging, bias or angle. In this embodiment the tires would need to slip laterally in order to prevent buckling the blank 11 due to excessive side force. Such tires could provide a slip angle by means of a pneumatic or otherwise flexible, elastic sidewall construction.
[0052] Performance of the aligning apparatus may be adjusted by the machine designer or, where appropriate, the operator. Such adjustments may include:
The amount of gripping force between the upper and lower wheels, 35 upper and 35 lower. The gripping force may be adjusted by the amount of opposing preload which may be provided by additional springs, not shown, but known in the art of paper handling and carton folding machines, or similarly, elastomeric or pneumatic tires for wheels 35 upper and lower. Changing the initial bias angle of the wheels 35 . Changing the spring constant and/or preload of springs 35 s.
[0056] FIG. 5 illustrates a modification of the embodiment of FIG. 4A where wheels or rollers 56 w support the guide belt 46 b instead of stop bar 46 s . This reduces friction in the mechanism thereby reducing power requirements. Similarly the reduced friction could allow guide belt 46 b to be ‘freewheeling’ or idling and thereby driven by contact with edge 11 e of blanks 11 (not shown in FIG. 5 ) to more easily drive the guide belt 46 b . This has potential to reduce the apparatus cost provided it can process blanks 11 of a useful thickness without buckling the blank. In a further modification, the belt 36 b could be replaced by an array or series of wheels or rollers (not shown).
[0057] FIG. 6 illustrates a further embodiment of FIG. 3 in which conveying belts 32 a and 32 b may be eliminated because blanks 11 are driven though the aligner by way of driven guide assembly 36 in which belt 36 b is driven via pulleys 36 p and blank 11 is forced against belt 36 b by wheel assemblies 35 . In this embodiment, blanks must be inserted into the aligner by a known feeder and the feeder is adjusted to intentionally feed blanks 11 with an offset IO as in Position 1 to assure blank 11 is introduced into the aligning apparatus in firm contact with guide belt 36 b.
[0058] In Position 2, the blank may become somewhat undesirably skewed as a result of the initial offset IO. Wheel assembly 35 f is shown near its initial bias as it has just engaged blank 11 in Pos. 2. The skewed orientation of Pos. 2 however is quickly corrected by the aligning apparatus as seen in Position 3 where blank 11 is adjusted into the desired orientation and position with edge 11 e coincident and parallel to target line TL, and wheel assemblies 35 D and 35 E have accordingly swung into a parallel orientation to the Pos. 3 blank 11 and intended direction D.
[0059] Guide bar 62 is a simple metal bar that supports blank 11 from below as is known in the art of carton folder gluers. Guide bar 62 supports blank 11 so it does not droop and so blank 11 remains in an approximately horizontal plane for subsequent transfer to other operations and equipment in, e.g., a carton folder gluer.
[0060] While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the relevant arts that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications that fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.
[0061] This invention contemplates a method wherein a sheet-like blank having a lateral edge is conveyed in a general direction and including the steps of;
[0062] gripping the blank by at least one pair of wheels, said wheels being mounted at an angle or bias to said general direction;
[0063] providing a side force by deflecting the said biased wheels;
[0064] shifting the blank against a guide so that the lateral edge is adjusted into a predetermined desired orientation and parallel and coincident with a predetermined target line.
[0065] The guide is provided by a moving belt having a face surface and an edge surface and said belt is supported on at least two pulleys.
[0066] The moving belt face surface provides an opposing surface for said lateral edge of blank.
[0067] The moving belt edge surface provides an opposing surface for said lateral edge of blank.
[0068] The belt is driven by at least one pulley.
[0069] The guide is provided by a plurality of rollers.
[0070] The biased wheels pivot about a caster axis
[0071] The biased wheels are mounted at a fixed amount of bias.
[0072] A method biased wheels may pivot to provide a variable bias and equipped with a spring to provide a varying side force. | An improved apparatus and method for properly orienting and aligning flat sheets or strip material, such as in the form of folding carton blanks, on a conveying system such as used in carton folders/gluers is disclosed. A moving sheet is engaged on at least one surface by plural non-driven movable casters oriented at an angle relative to the sheet's intended direction of travel, or target direction. The casters apply a lateral force to the sheet so that a linear lateral edge of the sheet is brought into contact with an adjacent guide member aligned with the target direction, with the sheet assuming a predetermined orientation relative to the target direction. Each caster is resiliently biased such as by a spring at a predetermined angle relative to the target direction. With the sheet's lateral edge in intimate contact with the guide member, the moving sheet is in the aforementioned predetermined orientation relative to, and is displaced in, the target direction. | 1 |
CROSS REFERENCE TO RELATED APPLICATION(S)
This United States application stems from PCT International Application No. PCT/DE88/00275 filed May 6, 1988.
BACKGROUN OF THE INVENTION
The invention relates to a device for acting upon and float-conveying webs of material, more particularly paper webs.
In known devices in which air is blown against a moving web in order to dry it, "nozzle chambers" are present and air is discharged therefrom towards the web, normally through slot-shaped nozzles (e.g., see German Patent Reference No. DE-PS 31 30 450). The nozzle chambers are spaced apart in the direction of travel of the web, the intermediate spaces serving as air outlets. The process of conveying webs of material through such devices is beset with numerous problems. More particularly the web must be held in transit so as to avoid contact with the nozzle chambers or other parts of the device, since otherwise the web may be damaged or its surface may be adversely affected.
BRIEF SUMMARY OF THE INVENTION
An object of the invention is to take account of the existing difficulties and construct a device of the initially-mentioned kind which guide s the web in transit with particularly good efficiency and also obtains the other desired effects, i.e. dries the web or the surface thereof, in advantageous manner. The invention also aims at an advantageous construction of the device in particular. Other associated problems addressed by the invention will be clear from the following explanation Of the disclosed solution.
According to the invention, a guide element extending as far as the nozzle chambers is disposed between each pair thereof on at least part of the web path, and has a closed central area and orifices at the side thereof and opening into the air outlets; lateral areas are provided on the nozzle boxes and project beyond the adjacent parts of the guide elements in the direction towards a longitudinal plane through the web path, and the angle between the outsides of the lateral areas and the longitudinal plane is not less than 90°.
In an aforementioned device, the moving web is guided with particular efficiency and is protected from damage, and also advantageous effects are obtained. More particularly the web can be guided in corrugated manner, which is very advantageous in many cases.
The lateral areas on the nozzle chambers, which project beyond the guide elements in the direction of the plane in which the web moves, can be at an angle of up to 90° to the aforementioned plane. In a very advantageous embodiment the lateral areas are constructed so that they extend backwards like an undercut. The lateral areas are advantageously substantially planar, but a curved embodiment is not excluded.
Advantageously a well-defined edge is formed at the transition between the lateral areas of the nozzle chamber and the end face thereof. This is particularly advantageous as regards flow conditions.
The guide elements between the nozzle chambers can have various forms. Advantageously the closed central area of each guide element is made planar.
The guide element can have inclined parts, more particularly in a transition region between the central part and edge regions. Advantageously at least some of the orifices are formed in the inclined parts.
In a device of the previously-explained kind, the nozzle chambers themselves can be constructed in various ways. Particularly advantageously, individual air outlets, each opposite a respective guide surface for the air flow, are provided in the nozzle region of each nozzle chamber in the wall parts adjacent the air duct on both sides of a transverse plane in the longitudinal direction of the air duct and perpendicular to the plane in which the web moves.
The outlets can be mouthpieces, individual nozzles or the like. In a very advantageous embodiment the air outlets are holes in the wall parts of the air duct.
The nozzle chambers, including the guide elements between them, can be efficiently manufactured and operate satisfactorily even under varying conditions. Even if wall parts are slightly displaced under unfavourable conditions, the amount of air remains constant, and the flow cOnditions are also fully maintained in the desired manner.
A particularly advantageous embodiment is characterized in that two wall parts formed with outlets are disposed directly adjacent one another and each wall part at least partly constitutes a guide surface for the air flows leaving the outlets in the other wall part. This construction can give very advantageous conditions in numerous cases. More particularly it can be used to produce air flows in accordance with the "coanda" effect.
BRIEF DESCRIPTION OF THE DRAWINGS
With regard to further disclosure of the detailed features and advantages of the invention, express reference is made to the following explanation with reference to the accompanying drawings and wherein.
FIG. 1, is a schematic perspective view of a unit equipped with devices according to the invention for treating a moving web of material;
FIG. 2 is an enlarged schematic cross-sectional view of a part of FIG. 1 showing an embodiment of the device;
FIG. 3 is a top plan view of part of the device in FIG. 2, seen from the longitudinal plane of the web path;
FIGS. 4 and 5 are enlarged schematic detail views show details on a larger scale;
FIG. 6 is a view similar to FIG. 2 showing another embodiment of the device in
FIG. 7 is a view similar to FIG. 3 of part of the device in FIG. 6;
FIG. 8 is a greatly enlarged perspective view of part of FIG. 1
FIG. 9 is a top diagram of a nozzle region;
FIG. 10 is a plan view of part of a nozzle region;
FIG. 11 is a cross-sectional view of another embodiment of a nozzle region taken through a nozzle chamber; and
FIG. 12 another embodiment of a nozzle region.
DETAILED DESCRIPTION
FIG. 1 shows a plant used e.g. for drying a paper web B which moves in a straight line in the direction of arrow P and is guided between a top unit l and a bottom unit 2. The de vices for driving the web are not shown and can be constructed in known manner. Air supply ducts in the form of "nozzle chambers" 9 are spaced apart in the longitudinal direction of the web in the bottom part of unit 1 and in the top part of unit 2, leaving spaces 3 serving as air outlets between the nozzle chambers 9 and connected to the interior of unit 1, the rest of which is enclosed by walls 4. The same applies to the nozzle chambers 9 in the bottom unit 2.
In this embodiment, the nozzle chambers 9 in the top unit 1 are offset by half a spacing from the nozzle chambers 9 in the bottom unit 2, so that a nozzle region 0 in a top nozzle chamber 9 is opposite a space between two bottom nozzle chambers 9, and vice versa. However, the structure can vary according to requirements and individual circumstances.
A guide element 16 extending up to the nozzle chambers 9 is provided between each pair thereof and is formed with orifices 17 opening into the air outlet 3. Various embodiments of such guide elements will be described in detail hereinafter.
Air at the desired temperature and pressure travels through an inlet 5 in the direction of arrow F1 into a distribution casing 6 in unit 1 and thence to a branch casing 7, connected to each nozzle chamber 9 by orifices (not shown). Corresponding remarks apply to the bottom unit 2. The air flowing from nozzle regions D travels over web 8 and through the orifice s in guide elements 16 into the air outlets 3 and thence into the aforementioned interior of unit 1, which it leaves through an outlet B. Corresponding devices for supplying and discharging to and from unit 1 can be constructed in known manner. Arrow F2 denotes the outflowing air. The bottom unit 2 is provided with means for air guidance corresponding to unit 1. Alternatively the aforementioned features can be provided on one side only.
FIGS. 2 and 3 show an embodiment of the device on a larger scale. Guide elements 16 are provided between each top and bottom nozzle chamber 9 and have substantially the same length as nozzle chambers 9 and, like them, extend transversely to the direction in which the web moves. Their edges abut the side walls 9a of nozzle chambers 9 and are connected thereto in suitable manner, depending on the material used. Advantageously the guide elements 16 and the nozzle chambers 9 are made of sheet-metal. The joints or places of transition are denoted by 18.
Each guide element 16 has a closed central region 16a. At the side of the central region, orifices 17 open into the air outlets 3. The orifices are advantageously disposed in mutually offset rows. Advantageously the central closed region 16a of guide element 16 is planar, but it can also be slightly curved if required.
On each side the central region 16a is adjacent bent parts 16c which in this embodiment are also formed with the orifices 17. The bent parts merge into edge regions 16c which can extend parallel to the central region 16a and as far as the connections 18 to the side walls 9a of nozzle chambers 9.
The side walls of chambers 9 have lateral areas 19 which project beyond the guide elements 16 or beyond the connection to the edge parts 16c of guide elements 16 and in the direction of a longitudinal plane E through the web path. This is shown particularly clearly in FIG. 4. In this embodiment, the angle β between the longitudinal plane E and the outer side of the laterally projecting areas 19 is about 90°.
It may be particularly advantageous with regard to flow conditions if there is a well-defined edge 20 at the transition between the lateral areas 19 and an end face 13 of nozzle chamber 9.
The nozzle regions 0 on nozzle chambers 9 can be constructed in various ways. The advantageous embodiment shown in FIGS. 2 and 6 will be described in detail hereinafter.
The air from the nozzle regions flows as shown by arrows in FIG. 2. The air flows follow parts of the end surfaces of nozzle chambers 9 in accordance with the coanda effect and travel as illustrated by arrows along guide elements 16 until the air is discharged through orifices 17 into regions 3. In the process, web B is advantageously guided without interruption and is caused to corrugate, as shown in FIG. 2.
FIGS. 5 to 7 show another very advantageous embodiment. Similar or corresponding parts are given the same reference numbers as in FIGS. 2 to 4. In this embodiment the front side areas 29 of nozzle chambers 9 each extend backwards like an undercut. The angle β between an aforementioned area 20 and the longitudinal plane E is greater than 90°, i.e. obtuse. The guide elements 16 can be connected to the side walls 9a of nozzle chambers 9 at places 18. Alternately, as shown in FIG. 6 they can be continued by bent areas 28 which are at the same angle as areas 29 and can be adjacent thereto or permanently connected thereto in suitable manner. In that case the outer sides of areas 28 are equivalent to the outer sides of areas 19. As before, reference 20 denotes a well-defined edge.
FIGS. 8 to 10 show an advantageous embodiment of the nozzle region D, with some modifications.
A wall 10 forming part of the boundary of an air supply duct 9 is shaped so that wall regions at an acute angle to one another merge into a respective curved part 12 adjacent plane parts 13. Parts 12 and 13 can be described as a guide surface L for an air flow.
Wall regions 10 have air outlets in the form of punched holes 14, the outlets on one side being offset relative to the outlets on the other side in the longitudinal direction of nozzle region D, i.e. transverse to the direction of the web, as shown more particularly in FIG. 10. The facing regions of walls 10 constitute baffle surfaces 11. Air flowing from holes 14 on one side strike the baffle surface 11 opposite, and vice versa. Subsequently the air flows along the curved region 12 and the adjacent region 13. In FIG. 8 this is diagrammatically indicated by line S on one side.
In the embodiment shown, the baffle surfaces 11 are each inclined at the same angle a relative to a transverse plane V perpendicular to the longitudinal plane E through the direction of travel of web B, as shown in FIG. 9. Alternatively the two baffle surfaces can be given different inclinations, depending on requirements. FIG. 9 illustrates this by means of a chain-dotted baffle surface 11', which is inclined at an angle b greater than that of the other baffle surface 11.
Advantageously the inclination is in the range from about 10° to 40°. Angles of about 15° are particularly advantageous.
In the embodiment shown in FIG. 8, all parts are im the form of a continuous wall 10, which is suitably bent in the bottom apical region. Alternatively, as shown by chain-dotted lines, the baffle surfaces 11 can be separate wall parts 1O', which come together at the ends and are joined in sealing-tight manner by spot welding or another suitable method.
Advantageously a nozzle region of the aforementioned kind is disposed approximately at the center of a nozzle chamber 9 as shown in FIG. 1. In other embodiments, two such nozzle regions are spaced apart on each nozzle chamber 9.
Another possibility is to provide only one baffle surface 11 in the nozzle region, and suitable outlets will then be disposed opposite it. For example, the wall part 10 constituting the baffle surface 11 to the right in FIG. 8 can be without outlets 14, which are provided only in the wall part 10 to the left in FIG. 8. In that case no guide surface L need be provided on this side, but wall part 10 can e.g. have a bent continuation 15 constituting a normal boundary of a supply duct, as shown by chain-dotted lines in FIG. 8.
Irrespective of the details of the embodiment, the diameter d of the outlets is advantageously about 3 to 7 mm. The distances e between the outlets (FIG. 10) may more particularly be in the range from about 10 to 30 mm.
Optionally also according to the invention, more than one row of outlets 14 can be provided and/or the outlets 14 can also be vertically staggered.
The height of each wall part constituting a baffle surface 11 (FIG. 9) is advantageously in the range from H=15 mm to H=30 mm, although this should not be regarded as limiting.
The radius R of the bent part 12 adJacent each baffle surface 11 is advantageously in the range from about 5 to 25 mm. Other values, however, are possible depending on circumstances.
FIG. 11 shows an embodiment in which a closure member 21 is disposed at the base of the nozzle region D. Member 21 extends over the entire width of air duct 9 and, on its side facing the plane in which web B moves, has guide surfaces 22 which in this embodiment are roof-shaped. Air outlets in the form of bores 14 are formed in curved wall parts 23 in the immediate neighborhood of guide surfaces 22, which bound the closure member 21. The air flowing from bores 14 travels along the associated guide surface 22 and then strikes the curved wall area 23, where the coanda effect is operative as in the embodiment in FIG. 8, so that the air flows along this wall area and along the adjacent planar wall area 13 and in the process acts upon and float-conveys the web B.
Advantageously the closure member 21 is an exchangeable unit ready for fitting. More particularly it can e.g. be a drawn sectional metal part.
A closure member of the aforementioned or similar kind can simply be inserted between two wall parts 24 of air duct 9, the wall parts bearing tightly against the closure member. The closure member can be secured e.g by screws 26, indicated by central lines only in FIG. 11, and extending through boles in flange parts 25 of air duct 9 and in flange parts 27 of closure member 21.
FIG. 12 shows a closure member 31 which, like the closure member 21 in the embodiment in FIG. 11, is disposed at the base of the nozzle region D and has guide surfaces 32 on facing sides of a part 33 projecting in the transverse plane V in the direction of the plane E in which the web moves.
As before, air outlets 14 are provided in the immediate neighborhood of the beginning of the guide surfaces 32 in wall parts 23. Air flowing out of orifices 14 is guided by surfaces 32, so that the jet is deflected substantially perpendicular to the plane of motion E.
As an alternative to the embodiment in FIG. 12, the projecting part 33 of closure member 31 can lie outside the transverse plane V, more particularly at an angle thereto. Also, the two guide surfaces 32 can have different positions or inclinations relative to one another. The same applies to the guide surfaces 22 in the embodiment in FIG. 11.
Some important features of the invention will be discussed in general hereinafter, together with some special features.
The air outlets 17 in the nozzle regions or the associated wall parts can also be nozzles instead of holes. Preferably, nozzle outlets of the aforementioned kind are produced from the wall material by pressing or stamping, so as to obtain an air jet in the desired direction.
In principle, the air outlets 17 may advantageously be disposed in wall parts 10 or 23 so that the air flowing therefrom travels round the facing bent surface of nozzle chamber 9 and, if no web is present, then travels towards the orifices 17 in the guide elements 16.
More particularly, an embodiment of the aforementioned kind is present also in those end regions of the nozzle chambers D which normally lie outside the area occupied by the web. This has an advantageous lateral closure effect and also advantageously influences the stability of web motion
In the embodiments in FIGS. 2, 3, and 6, 7 the orifices 17 opening into the air outlets 3 are formed in inclined parts 16b of guide elements 16. In another very advantageous embodiment the orifices 17 are in the edge parts 16c, i.e. near nozzle chambers 9. In that case the guide elements 16 have a closed central region 16a. The transition to the edge parts can either be an inclined surface or alternatively the cross-section at this place can be approximately arcuate or circular. As a final alternative, the guide elements 16 can be completely plane.
The closed central region 16a is essential, since pressure builds up here, so that the web is efficiently held and guided at this place also In the advantageous embodiment shown e.g. in FIG. 2 or FIG. 6, a nozzle region D of a nozzle chamber 9 is opposite the central region 16a of each guide element 16. At this place, therefore, there is a region at a lower pressure than the region on the other side of the web. In principle, the web is guided with great stability by the alternating reduced-pressure and pressure zones in the longitudinal direction of the web. The same applies in the transverse direction of the web, so that the web is efficiently kept in position during travel and cannot move sideways.
According to the invention also, the construction of the nozzle regions can vary within a plant or treatment section, e.g. the nozzles can be as in FIG. 11 in one part of the treatment section and as in FIG. 12 in another part thereof.
All the features mentioned in the preceding description or shown in the drawing should be regarded, either alone or in combinations, as coming under the invention as far as permitted by the known prior art. | A device for acting upon and float-conveying webs of material, more particularly paper, using air or another fluid medium, inter alia, for drying the web, including a number of spaced-apart air ducts (9) on at least one side of the path of the web (B) and in the form of "nozzle chambers", each chamber having at least one nozzle region extending over the width of the web path, air outlets (D) between the nozzle chambers (9), a guide element (16) extending as far as the nozzle chambers (9) disposed between each pair of nozzle chambers on at least a part of the web path, and a joint or connection (18) between the guide element and the nozzle chamber (9) set back (19) relative to the side of the nozzle chamber facing the web path (E), the guide element having a closed central region (16a) and outlet orifices (17) at the sides thereof and opening into an air outlet (3). | 3 |
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for driving a solid state camera, especially a method for driving a solid state camera having high sensitivity.
A solid state camera using a single-chip solid state image sensor has many advantages over a conventional tube type camera, such as small scale, light weight, low power consumption, no sticking, no image lag, long life and stability. On the other hand, the solid state camera has some inherent problems, such as vertical smear, fixed pattern noise (hereinafter FPN) and blooming. Especially, the vertical smear is a serious problem, which is not generated in the conventional tube type camera.
There are three types of the solid state camera in the market, that is, the Metal Oxide Semiconductor type, the Charge Priming Device type and the Charge Coupled Device type (hereinafter MOS type, CPD type and CCD type, respectively). The CPD type solid state camera is able to sweep out vertical smear charges from vertical signal lines to the outside prior to reading out signal charges from photodiodes to the vertical signal lines, so that it can easily suppress the vertical smear.
Hereinafter, examples of this CPD type solid state camera are explained using the FIGS. 1, 2 and 3. FIG. 1 shows an example of the CPD type solid state camera having a circuit for sweeping out the vertical smear charges. The numerals 1, 2 and 3 denote a photodiode, a MOS transistor used as a vertical switch, and a vertical signal line, respectively. The numeral 9 designates a charge transfer device (hereinafter CTD, for example, a buried channel type CCD), which can transfer the signal charges of the photodiodes belonging to two adjacent horizontal rows during a horizonal scanning period. A combination part constructed by MOS transistors 4 to 8 combines the vertical signal line 3 and the CTD 9. The MOS transistor 5 is preferably a depletion type used as a capacitance. The numeral 10 denotes a vertical scanning circuit, each output of which is connected to each vertical gate line 11.
In the first increment of the horizontal blanking period, excess charges, which are generated by vertical smear, blooming, etc. are swept out from the vertical signal lines 3 through the transistors 4, 5, 6 and 7 to a blooming sweep out drain (hereinafter BD). After that, the signal charges of the photodiodes 1 belonging to the designated horizontal line are read into the vertical signal lines 3 and are transferred to the CTD 9 through the transistors 4, 5, 6 and 8. Usually, this execution is repeated twice so that the signal charges of two adjacent horizontal lines are transferred to the CTD9. During the following horizontal period, the CTD9 is scanned to supply the signal charges to an output terminal. The method of simultaneously reading out the video signal of the two adjacent horizontal lines is not directly related to this invention, but it is effective to get a single-chip solid state color camera having high picture quality.
FIGS. 2A and 2B show an equivalent circuit and driving pulses of the CPD type solid state camera shown in FIG. 1, respectively. The equivalent circuit shown in FIG. 2A is related to a signal charge transferring path from one of the photodiodes 1 to the CTD9. Cpd, Cv and C4 indicate capacitances of the photodiode 1, the vertical signal line 3 and the gate of the transistor 5, respectively. T1, T2, T3 and T4 indicate driving pulses for the gates of the MOS transistors 8, 6, 4 and 5, respectively. H1 indicates one of clock pulses for driving the CTD9. Referring to FIG. 2B, time periods t1-t9 construct one horizontal blanking period. During the time period t1, inner bias charges are poured into the capacitance Cv from the capacitance C4, and the excess charges accumulated in the capacitance Cv are efficiently transferred to the capacitance C4 together with the inner bias charges. During the time period t2, outer bias charges are injected into the capacitance C4 from the BD in the form of the constant voltage. Concurrently with the injection, the excess charges are swept out from the capacitance C4 to the BD. After that, the outer bias charges are swept out to the BD. As the transistor 4 is in the OFF state during the time period t2 (see the driving pulse T3 shown in FIG. 2B), the signal charges in the capacitance Cpd can be read out to the capacitance Cv by making the pulse VG corresponding to the designated horizontal line into the ON state. During the time period t3, the inner bias charges are poured again from the capacitance C4 into the capacitance Cv, and the signal charges in the capacitance Cv are efficiently transferred to the capacitance C4 together with the inner bias charges. During the time period t4, other outer bias charges (hereinafter CTD bias charges) are injected from the CTD 9 to the capacitance C4, and the signal charges are efficiently read out from the capacitance C4 into the CTD 9 together with the CTD bias charges. During the time period t5, all the signal charges in the CTD 9 are shifted by one stage. During the time periods t6-t9, the same process as mentioned above is executed except that the adjacent horizontal line is designated. For example, if the pulse VG depicted as a continuous line corresponds to the pulse VGn+2 shown in FIG. 1, the pulse VG drawn by a dotted line corresponds to the pulse VGn+1 shown in FIG. 1.
The reason for using the bias charges in the process of transferring charges from the capacitance Cv to the capacitance C4, and from the capacitance C4 to CTD 9 is to improve a transfer efficiency. Generally, in a case where small signal charges are transferred from a capacitance C through a MOS transistor in a saturated region having a channel conductance β with bias charges B during a transfer period τ, a transfer inefficiency ε is shown by the following formula: ##EQU1## Accordingly, using the bias charges is a usual practice in order to improve the transfer efficiency.
Now, the formula (1) shows that the transfer efficiency is sensitive to the capacitance C. The capacitance Cv is several pF and extremely larger than other capacitances (Cpd≈0.05 pF, C4≈0.1 pF). Therefore, in order to efficiently transfer the charges from the capacitance Cv, it is necessary to enlarge the bias charges B because it is difficult, as a practical matter, to enlarge the transfer period τ and the channel conductance β. So, the conventional method using the inner bias charges is very useful. In this method, to enlarge the bias charges B infinitely does not result in reduction of the dynamic range, because the inner bias charges come and go only between the capacitance Cv and the capacitance C4. Further, if the driving pulses T2, T3 and T4 balance between the sweep out period and the read out period, the FPN does not generate in the charge transferring process from the capacitance Cv to the capacitance C4.
Next, the suppression effect of the vertical smear will be explained. There are two types of the vertical smear, which are not swept out and are read out. One type of the vertical smear is due to bad transfer efficiency in the sweep out period. Another type of the vertical smear is generated by the mixture of the charges in the vertical signal line 3 during the period from the end of sweeping out the excess charges from the capacitance Cv to the end of reading out the signal charges from the capacitance Cv. If the radio of the period (t2+t3+t7+t8), which corresponds to a non-sweep out period, to the horizontal period (about 64 μS) is α, and the transfer inefficiency ε from the capacitance Cv to the capacitance C4 is εv, a reducing rate R of the vertical smear by means of the sweep out is shown as the following formula:
R=εv(1-α)+α (2)
It is apparent from the formula (2) that the vertical smear can be endlessly suppressed by raising up the transfer efficiency and shortening the transfer period τ. However, as the formula (1) shows, raising up the transfer efficiency conflicts with shortening the transfer period τ. So, in the CPD type solid state camera shown in FIG. 1, a desirable reducing rate R of about 0.1 (-20 dB) is not feasible.
FIG. 3 shows another example of the CPD type solid state camera which is improved at this point. The difference between the example shown in FIG. 3 and the one shown in FIG. 1 is that the former circuit has an inverter 22 constructed by an enhancement type MOS transistor 20 and a depletion type MOS transistor 21, an input of which is connected to the vertical signal line 3 and an output of which is connected to the gate of the MOS transistor 4. The timing of the driving pulses is the same as the one shown in FIG. 2B except that the driving pulse T3 is supplied to a terminal VD, and a terminal VS is connected to the ground. The effect of adding the inverter 22 having a gain (-G) is to equivalently make the capacitance of the vertical signal line 3 Cv/(1+G). Apparently from the formula (1), the inverter 22 immensely contributes to the improvement of the transfer efficiency so that the reducing rate R shown in the formula (2) can readily be made lower than 0.1 (-20 dB).
Now, as mentioned above, the CPD type solid state camera can be expected to be superior in picture quality and sensitivity to the MOS type solid state camera. On the other hand, the CCD type solid state camera has some problems, i.e., image lag, vertical smear and a roughness of a color filter arrangement in the vertical direction so that it is inferior in picture quality to the CPD type and the MOS type. However, it is superior in sensitivity when compared to the other types. In the CCD type, the factor of reducing sensitivity is random noise generated in a horizonal transferring CCD, which corresponds to the CTD9 shown in FIGS. 1 and 3. On the other hand, in the CPD type, there are other factors of suppressing sensitivity, i.e., random noise, FPN and shading generated in the combination part (i.e., the transistors 4 to 8 which combine the vertical signal line 3 to the CTD9). However, in the CPD type, an aperture ratio of the photodiode is about two times as large as one of the CCD type so that the CPD type is superior in all aspects to the CCD type, if total noise of the CPD type is reduced lower than half of one of the CCD type.
So, hereinafter, the random noise, the FPN and the shading generated in the combination part will be explained. The random noise is mainly generated in the charge transfer process from the capacitance Cv to the capacitance C4. FIG. 4 illustrates randon charge fluctuations q1,q2,--on the capacitance Cv in the same time scale as one shown in FIG. 2B. When the transistor 4 is in the OFF state, that is, the time periods t2, t4, t5, t7 and t9, the charges on the capacitance Cv do not vary. Further, if the transfer efficiency from the capacitance Cv to the capacitance C4 is sufficiently high, the charge fluctuations q1, q2--have no correlation, mutually. The main cause of the charge fluctuations q1,q2,--of the camera shown in FIG. 3 differs from one of the camera shown in FIG. 1. In the latter, they come from thermal noise generated in the channel of the MOS transistor 4, and in the former, they are caused by random noise generated in the inverter 22 and the variation of the gate voltage of the MOS transistor 4 with random noise. In both of them, the charge fluctuations can be illustrated by FIG. 4. During the time period t3, noise charges (q3-q2) are read out and during the time period t8, noise charges (q5-q4) are read out. Assuming that a root means square value (hereinafter rms value) of the charge fluctuations q1,q2--is qn, the rms value of random noise charges per one picture element becomes √2 qn. The random noise generated in the charge transfer process from the capacitance C4 to the CTD9 or the BD can be neglected, because the capacitance C4 is extremely smaller than the capacitance Cv.
On the contrary, the FPN is generated in the charge transfer process from the capacitance C4 to the CTD 9 or the BD. There are two kinds of the FPN in the charge transfer process from the capacitance C4, one of which comes from a dispersion ΔB of the bias charges. The CTD bias charges, which are injected into the CTD 9, for example, by the potential balance method, do not have the dispersion theoretically, but in fact have the dispersion caused by the dispersion in shapes of the transfer gates of the CTD 9. If all the CTD bias charges can be injected into the combination part, the injection dispersion does not occur. However, the charges do not flow easily in the direction to the combination part. So, as all the CTD bias charges can not be injected to the combination part, the injection dispersion ΔB exist. As a result, the FPN comes from a leftover part of the injection dispersion ΔB. With the same manner described above, the injection dispersion of the outer bias charges generates the FPN.
Another kind of the FPN is caused by a structure of the gate of the MOS transistor 6. FIG. 5 illustrates a plane figure of the gates of the MOS transistors 5 to 8. Apparently from FIG. 5, the gate of MOS transistor 6 has a narrow part, which can control a current flow by itself. However, there is a difference of the current flows between the side of the CTD 9 and the side of the BD, so that effective threshold voltages are different. The difference ΔVt of the threshold voltages disperses in response to the dispersion of the parameters of the MOS transistor 6. If this dispersion is ΔΔVt and the dispersion of the capacitance C4 is ΔC4, the charges (ΔC4.ΔVt+C4.ΔΔVt) of the FPN generate per one picture element.
The shading comes from a long time constant of the vertical gate line 11. As the vertical gate line 11 is made of poli-silicon, it has the time constant, approximately equal to 1 us. Therefore, even if the pulse VG has an ideal wave form shown in FIG. 2B at the left end of the vertical gate line 11, the pulse VG becomes to have a dull wave form at the right end thereof. So, the response does not completely cease at the next read out period t3. The vertical gate line 11 crosses over the vertical signal line 3 and there is a large capacitive coupling so that the shading in the horizontal direction generates.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a method for driving a CPD type solid state camera in order to obtain high sensitivity and an apparatus thereof.
It is another object of the present invention to provide a method for removing some factors which reduce sensitivity of a CPD type solid state camera having means for sweeping out undesired excess charges from vertical signal lines and apparatus thereof.
Briefly, to attain the above mentioned objects, according to the present invention, in the CPD type solid state camera having means for sweeping out undesired excess charges from vertical signal lines, the sweep out is controlled in response to a scene illumination or the quantity of the vertical smear charges. Namely, the sweep out of undesired excess charges is not executed when the condition exists that the scene illumination is lower than a predetermined level. Further, the sweep out of the excess charges is not executed when the condition exists that the scene illumination and the quantity of the vertical smear charges are lower than predetermined levels, respectively. According to applicants' experiments, stopping the sweep out of the undesired excess changes in this manner causes a large suppression of the factors which reduce the sensitivity.
Random noise can be reduced more than 3 dB, and, if the frequency characteristic of eyes is taken into consideration, it can be reduced even further. This will be explained by using FIG. 4. When the MOS transistor 7 is always in an OFF state and the charges are not swept out, the random noise charges read out into the CTD 9 during the time period t4 become (q3-q1), and ones during the time period t9 are (q5-q1). Here, it is important that both of them have a negative correlation because two picture elements, from which signal charges are read out during the time periods t4 and t9, are located in the same horizontal position, and a final luminance signal is produced by adding the signal charges thereof. Accordingly, the random noise charges become (q5-q1), the rms value thereof becomes √2 qn, and the rms value per one picture element becomes qn. As a result, the random noise is reduced by 3 dB in comparison with the case of executing the sweep out. Further, if the sweep out is not executed, the random noise changes have another negative correlation in the vertical direction. If the random noise charges within the luminance signal read out after one horizontal scanning period is (q5'-q1'), an equality q5= q1' comes into existence. In this case, spectra of the random noise in the vertical direction come to have triangular forms so that the random noise becomes less conspicuous.
For representing the aformentioned matter by a formula, it is assumed that a power spectral density S of the random noise within the luminance signal in the case of executing the sweep out equals to 1. So, a power spectral density S' thereof in the case of stopping the sweep out is shown as the following formula:
S'=sin.sup.2 πf/fh (3)
Here, fh equals to 1/H≃15 kHz. FIG. 6 shows the power spectral densities S and S'. Referring to FIG. 6, N indicates integral numbers. A difference between the density S and the density S' is 3 dB in power, that is, 3 dB in a measured value. However, apparently from FIG. 6, the peaks of the density S' are located in the frequencies (N+1/2)fh which correspond to 250 TV lines in the vertical direction. On the other hand, the bottoms of the density S' are located in the frequencies Nfh which correspond to 0 TV lines in the vertical lines. So, the difference between the density S and the density S' becomes more than 3 dB by using a low pass type correction. That is, by using a comb filter, the difference thereof becomes clear. If the comb filter having a feedback ratio k (=0.5) is inserted, the difference becomes just 6 dB. The comb filter will be explained later. FIG. 6 shows the characteristics in the case using the comb filter having a feedback ratio k (=0.5).
The above-mentioned explanation is based on the fact that the picture elements, that is, the photodiodes are arranged in a square disposition, but in the case where the picture elements are shifted a half picture element pitch on every horizontal line, almost the same effect will be obtained.
The FPN and the shading does not quite occur in the case of stopping the sweep out. The FPN, due to the structure of the gate of the MOS transistor 6 becomes zero, because the charges pass only through the gate of the MOS transistor 8. The FPN due to the injection dispersion ΔB of the bias charges does not occur, because the leftover part thereof can. not go everywhere and comes back to the CTD 9. Further, concerning the shading, charges other than the random noise charges on a vertical signal line just after the time period t3, in which period the first read-out from the capacitance Cv is executed, have the same quantity as ones just after the time period t8, in which period the second read-out from the capacitance Cv is executed, so that the shading does not occur in the combination part.
Sumarizing the above mentioned explanation, it is possible to eliminate the FPN and the shading and to suppress the random noise more than 3 dB by stopping the sweep out. However, to always stop the sweep out causes the problem of the vertical smear and results in poor picture quality again. So, according to this invention, the sweep out is automatically or manually stopped on condition that improving the sensitivity has priority to suppressing the vertical smear. In the case of an ordinary video camera, there are two situations where improving the sensitivity thereof has priority. That is, (1) where the average light level of a scene is dark, and (2) where a contrast ratio of the scene is small so that the S/N ratio of the vertical smear is high. Therefore, it is considered that the sweep out is stopped in the case (1) or in the case (1) and (2). Generally, from a point of view of improving the sensitivity, it is better to stop the sweep out in the case where the average light level of a scene becomes dark, that is, the scene illumination goes down. However, in some cases when the scene is generally dark but receives light from a candle or a fluorescent lamp, the vertical smear becomes extreme and as a result the picture quality becomes poor. In order to cope with this problem, it becomes necessary, too, to consider the quantity of the vertical smear in addition to the scene illumination.
FIG. 7 shows general curves of the signal gain of a standard video camera. The abscissa represents the scene illumination, which is usually detected from an average signal, that is, a mean value of the luminance signal, in a central part of a screen. If the scene illumination is higher than a standard scene illumination a, for example, when the S/N of the luminance signal is higher than 46 dB, an output signal level is made constant by stopping down an iris. On the other hand, when the scene illumination is lower than the standard scene illumination a, to prevent the output signal level from becoming considerably reduced, the iris is fully open and an AGC is worked from the standard scene illumination a to a lowest scene illumination b, for example, in which the S/N of the luminance signal becomes 35 dB. In the case that the scene illumination is lower than the lowest scene illumination b, the AGC is made into the maximum gain so that the noise does not increase. The aforementioned method of this invention for improving the sensitivity is applied to the video camera having the curve of the signal gain as shown in FIG. 7. First, scene illuminations C and C' are determined on the following condition, that is, a≧C'>C≧b. Then, if the scene illumination is lower than C, the sweep out is stopped. Next, when the scene illumination is more than C', the sweep out is executed. If there is no hysteresis on the control for executing and stopping the sweep out, the motion near by an exchanging point becomes unstable. Further, it is apparent that the gain of the AGC can be raised until a lowest scene illumination b' in the case of stopping the sweep out as shown with a dotted line in FIG. 7.
FIG. 8 illustrates a TV monitor having a screen 180 which can be coupled to the video camera of the present invention to illustrate the scene illumination. On this screen 180 a part 181 in which the scene illumination is detected is shown with oblique lines. As shown in FIG. 8, pictures in the upper and lower parts are usually ignored. Specially, there are many cases in which the sky exists in the upper part of the screen and the sky is usually brighter than other objects. So, if the scene illumination is detected by containing the signal of the sky in order to control the iris and the AGC, pictures of the objects become darker. Accordingly, it is better to widely ignore the upper part of the screen. Further, in the method for detecting the scene illumination, there are more cases in which not only the mean value of the luminance signal in the central part is used, but also the peak value thereof is detected together with the former. They will be explained in more detail later.
Now, as mentioned above, there are some cases where it is necessary to suppress the vertical smear, even if the scene is dark. In particular, as shown in FIG. 8, the iris and the AGC are ordinarily controlled by only the video signals in the central part. So, if there is a fluorescent lamp in the upper part of the screen, the vertical smear becomes remarkable. Therefore, it becomes necessary to execute the sweep out in the dark scene by detecting the quantity of the vertical smear directly or indirectly. It is possible to detect the quantity of the vertical smear directly by using the output signal from the sensor 52 during the vertical blanking period. The output signal during the vertical blanking period is equivalent to the vertical smear charges, so that it is possible to obtain information concerning the vertical smear by passing the output signal through an appropriate low pass filter and peak-detecting it. If a more accurate value of the vertical smear charges is needed, it is better to shut off the MOS transistor 8 during several horizontal periods, to accumulate the information concerning to the vertical smear on the vertical signal line 3 or the combination part during those periods and to read out the accumulated signals. Further, there are some methods to detect the quantity of the vertical smear indirectly. One is to detect a contrast ratio of the whole screen. Another is to detect a white area having a higher level than an appropriate level. In the cases of controlling the sweep out by using the vertical smear, needless to say, hysteresis on the control is necessary, too.
Last, an arrangement of color filters on the photodiode array suitable for this invention will be explained. In the above explanation, the random noise for the luminance signal is considered. But, it is necessary to take random noise for a color signal into consideration, too.
Generally, sensitivity for blue is not good in the solid state image sensor, so that it is necessary to pay attention to noise of the blue signal. The arrangement of the complementary color filters has four color elements, that is, white (W), yellow (Ye), cyanic (Cy) and green (G). The luminance signal Y and a blue signal B are obtained by the following formulas, respectively:
Y=W+Ye+Cy+G
B=W-Ye+Cy-G
On the other hand, the reduction of the random noise within the luminance signal in the case of stopping the sweep out is due to the addition of the random noises having the negative correlation. Therefore, in general, color signals do not have this effect. However, in the arrangements of the color filters shown in FIGS. 9A and 9B, charges under the filters W and Cy, and charges under the filters G and Ye are read out through the same vertical signal lines, respectively, so that noises within the signal charges W and Cy, and G and Ye have negative correlations. Therefore, the blue signal B can have the effect of reducing the random noise by stopping the sweep out like the luminance signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of a prior art CPD type solid state image sensor,
FIG. 2A represents, an equivalent circuit diagram of the circuit shown in FIG. 1, FIG. 2B illustrates waveforms of driving pulses for the circuit shown in FIG. 1,
FIG. 3 is a circuit diagram of another prior art CPD type solid state image sensor,
FIG. 4 illustrates a timing chart for showing random noises on a capacitance Cv of a vertical signal line,
FIG. 5 illustrates a plane structure of gates of the MOS transistors 5,6,7 and 8 shown in FIGS. 1 and 3,
FIG. 6 represents a characteristic of a power spectral density of the random noises,
FIG. 7 represents a characteristic of a signal gain of a CPD type solid state camera in response to a scene illumination,
FIG. 8 illustrates a screen of a TV monitor,
FIGS. 9A and 9B illustrate arrangements of complementary color filters, respectively.
FIG. 10 is a block diagram representation of a CPD type solid state camera according to an embodiment of this invention,
FIG. 11 is a block diagram of the detector 72 for a scene illumination level shown in FIG. 10,
FIG. 12 is a circuit diagram of the control circuit 75 of BG pulses shown in FIG. 10,
FIG. 13 represents a characteristic of an AGC voltage and a gate voltage of the MOS transistor 93 for explaining a hysteresis control,
FIG. 14 is a block diagram representation of a CPD type solid state camera according to another embodiment of this invention,
FIG. 15 represents a block diagram of an embodiment of the signal level detector 76 shown in FIG. 14,
FIG. 16 is a block diagram representation of a CPD type solid state camera according to the third embodiment of this invention,
FIG. 17 is a block diagram of a CPD type solid state camera according to the fourth embodiment of this invention,
FIG. 18 represents a block diagram of an embodiment of the detector 100 shown in FIG. 17,
FIG. 19 represents a circuit diagram of an embodiment of the BG pulse controller 175 shown in FIG. 17,
FIG. 20 represents a circuit diagram for varying a set up of a block level according to an embodiment of this invention,
FIG. 21 represents a circuit diagram for a comb filter used by this invention, and
FIG. 22 represents a circuit diagram for another comb filter used by this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, some embodiments of the present invention will be explained by using FIGS. 10 to 22. Referring to FIG. 10, the numeral 52 denotes a CPD type solid state image sensor shown in FIGS. 1 or 3, which is generally formed on one chip. The numerals 70 and 71 designate an output terminal of the CTD 9 and an input terminal of the BG pulses, respectively. An arrangement of color filters on the image sensor 52 such as that shown in FIG. 9A is provided. The numerals 51, 53 and 54 denote a barrel having a lens and an iris, an AGC amplifier and a sampling circuit, respectively. The sampling circuit 54 separates the signal charges W, Ye, Cy and G. The numeral 55 denotes a delay circuit for adjusting phases of the signal charges W, Ye, Cy and G based on the arrangement of the color filters. A matrix circuit 56 produces a luminance signal Y, a red signal R and a blue signal B by calculating the signal charges W, Y, Cy and G. If the arrangement of the color filters shown in FIG. 9B is used, the luminance signal Y can be directly obtained from the output of the AGC amp. 53, so that the delay circuit 55 is not necessary. The numerals 57, 58, 59, 60, 61, 62 and 63 denote an amplifier, a clamp circuit, a γ correction circuit, a blanking circuit, a delay circuit, and a white clip circuit, respectively. The numerals 64 and 66 designate a color signal processor and a synchronous signal generator, respectively. The color signal processor 64 will be explained in FIG. 16 in more detail. A NTSC video signal is produced by adders 65 and 67, amplified by an output amplifier 68 and supplied to an output terminal 69. All of the elements 53 to 68 are commercially available units and/or can be designed according to well-known principles for the purposes discussed. A detector 72 for detecting a scene illumination produces control signals for an iris controller 73 and a BG pulse controller 75. The numeral 74 indicates a BG pulse generator.
In this embodiment, the iris control and the BG pulse control are of a forward type (i.e., a type of AGC wherein the AGC is generally executed by controlling a bias current of a transistor). This type controller is easy to understand in correspondence to the curves shown in FIG. 7. An embodiment of the detector 72 is shown in FIG. 11. The numeral 79 denotes a photoelectric converter, for example, a photodiode, a photoconductor or other equivalent device, which is attached the camera outside the barrel 51, or inside the barrel 51 and outside the iris. The numerals 80 and 86 designate an amplifier and voltage converter, respectively. The voltage converter 86 supplies appropriate voltages dependent to the curves shown in FIG. 7 to a voltage terminal 87 for the iris controller 73 and a voltage terminal 88 for the BG pulse controller 75.
An embodiment of the BG pulse controller 75 is shown in FIG. 12. The numeral 90 denotes a BG pulse output terminal of the BG pulse generator 74, which is connected to the BG pulse input terminal 71 of the sensor 52 through a n-channel MOS transistor 93. A terminal 71 is connected to a ground through a resistor 94. When a low level voltage is supplied to a gate of the MOS transistor 93 and the MOS transistor 93 takes the OFF state, the BG pulse input terminal 71 is connected to the ground. As the value of resistor 94 is set sufficiently larger than an on-impedance of the transistor 93 and an output impedance of the BG pulse generator 74, the output of the BG pulse generator 74 is supplied to the BG pulse input terminal 71 of the sensor 52 in the ON state of the transistor 93. The AGC voltage from an input terminal 88 is supplied to the gate of the transistor 93 through a Schmitt trigger amplifier 92, which is set in order to give hysteresis on the sweep out mentioned above. FIG. 13 shows an example of the hysteresis control for the sweep out. As the hysteresis control is apparent from FIG. 13, a detailed explanation is omitted. Anyway, in this embodiment, when the scene illumination becomes lower than a constant value C (e.g., 20 to 30 lux), the sweep out is stopped in order to reduce the noise, and as the scene illumination becomes higher than a constant value C', the sweep out is executed in order to reduce the vertical smear.
FIG. 14 represents another embodiment of the present invention. In comparison with the embodiment shown in FIG. 11, it has a difference that the iris control and the BG pulse control are feedback type. Namely, the iris and the AGC are controlled in order to make an average level of the output of the clamp circuit 59, the γ correction circuit 60, or the blanking circuit into a fixed value. The numeral 76 denotes a signal level detector, in which a luminance signal level (for example, the S/N level of the luminance signal) of the central part 181 shown with the oblique lines in FIG. 8 is detected. In general, the signal level is a value between an average value and a peak value. If the signal level does not reach a predetermined level, output signals of the detector 76 are varied to make the iris more open, and in a case where the iris is fully open, to increase the gain of the AGC amplifier 53. If the signal level is higher than the predetermined level, the output signals thereof are varied to decrease the gain of the AGC amplifier 53, and in a case where the gain is the lowest, to close the iris more. An embodiment of the signal level detector 76 is shown in FIG. 15. In FIG. 15, the numerals 78, 81, 82, 83, 84 and 85 denote an input terminal, a gate, a low pass filter (hereinafter LPF), a peak detector, a hold circuit and a control voltage generator, respectively. The gate 81 passes only the signal of the central part 181 shown in FIG. 8. By selecting a pass band of the LPF 82, it is possible to make the signal level near the average value, or near the peak value. Namely, a wide pass band of the LPF 82 makes the signal level near the average value and by making the pass band narrow the signal level becomes near the peak value. It is possible to attach the function of the gate 81 to the hold circuit 84. The control voltage generator 85 compares the output with the fixed value, and varies the iris control voltage and the AGC voltage in response to the result of the comparison by using the same method as that mentioned above. In this embodiment, the control of the sweep out is the same as the embodiment shown in FIG. 10.
FIG. 16 shows another embodiment of this invention, in which an AGC amplifier is inserted in the latter part of the circuit. In this case, it is necessary to control a color difference signal by the AGC, so that the color signal processor is shown in detail. The numerals 151 and 152 denote an amplifier having a constant gain and a low pass filter (hereinafter, LPF), respectively. Usually the LPF 152 has different characteristic to the luminance signal from one to the color signals R and B. The numeral 153 designates a delay circuit to compensate for this. However, this delay circuit is not necessary if the characteristic of the LPF 152 to the luminance signal is the same for both the color signals R and B. The numerals 154, 155, 156, 157, 158, 159, 160, 161 and 162 denote an amplifier, a clamp circuit, a white balance amplifier, a γ correction circuit, a blanking circuit, a color difference matrix circuit and an AGC amplifier, respectively. The clamp circuit is not necessary in the case that a direct current is held from the clamp circuit 155 to the clamp circuit 162. The color modulator 163 frequency-modulates a color sub-carrier by the color difference signal. The numerals 164 and 165 denote a band pass filter (hereinafter BPF) and a blanking circuit, respectively. In this embodiment, the system for controlling the sweep out, for example, the signal level detector 76 is the same as one shown in FIG. 14.
FIG. 17 represents the fourth embodiment of this invention, which contains a control circuit for allowing control based on the level of the vertical smear. Referring to FIG. 17, the numeral 100 denotes a detector for the vertical smear, which is shown in detail in FIG. 18. The numerals 101, 102, 103, 104 and 105 designate an input terminal, a low pass filter (LPF), a peak detector, a sample hold circuit and an output terminal of a vertical smear level, respectively. A BG pulse controller 175 controls the sweep out by using the AGC voltage and the vertical mear level. FIG. 19 shows an embodiment of the BG pulse controller 175. The numerals 105, 107 and 108 denote a vertical smear level terminal, a Schmitt trigger amplifier and an OR circuit, respectively. As is apparent from FIG. 19, the sweep out is stopped on condition that the gain of the AGC is larger than the fixed value, that is, the scene illumination is lower than another fixed value, and the vertical smear level is lower than an appropriate level.
FIG. 20 shows a circuit diagram of an embodiment for varying a set up of a black level in response to the control of the sweep out. This embodiment is applied to the circuit shown in FIG. 17 and is coupled to receive the output of the gate 108 of the PG pulse generator of FIG. 19, as shown. Referring to FIG. 20, an emitter follower amplifier is inserted between the output terminal 70 of the sensor 52 and an input terminal 201 (which is coupled to the input of AGC amplifier 53 in FIG. 17), so that the set up of the black level is varied. In practice, it has been found that there is a small difference in the black level between the case of executing the sweep out and the case of stopping the sweep out. Therefore, the arrangement of FIG. 20 permits correcting this. The numeral 202 denotes a bipolar transistor and the numeral 203 denotes a n-channel MOS transistor. The numerals 204, 205 and 206 denote resistances. The numerals 207 and 208 designate a pulse generator and a power line, respectively. The pulse generator 207 generates a pulse corresponding to a picture element of an optical black. By using this pulse, the optical black level in the case of executing the sweep out is varied. As a result, the set up of the black level will be the same regardless of whethersweep out occurs or not.
Next, an embodiment of a comb filter will be explained. FIG. 21 shows a general comb filter having a gain 1 which can be inserted between the color signal processor 64 and the adder 65 shown in FIG. 10. The numerals 300, 301, 302, 303, 304 and 305 designate an input terminal, an output terminal, an amplifier having a gain (1-k), an amplifier having a gain k, an adder, and a 1H delay circuit. k is a feedback ratio and 0≦k<1. This comb filter has a characteristic A(f) of frequency vs. amplitude as shown in the following formula. ##EQU2## As mentioned before, it is possible to reduce the random noise by using the comb filter. If the noise is a flat noise, the power thereof becomes (1-k)/(1+k) multiple and the noise goes down 4.8 dB at k=0.5. Concerning to the random noise represented by the formula (3), the power thereof becomes (1-k) 2 /(1+k) multiple and the random noise goes down 7.8 dB at k=0.5. It is apparent that the method of suppressing the random noise by using the comb filter is more effective. Therefore, using the comb filter shown in FIG. 21 in co-operation with stopping the sweep out improves the sensitivity remarkably. Further, it is possible to improve the effect of raising up the sensitivity without the sweep up by increasing the feedback ratio k of the comb filter in response to increase of the gain of the AGC amplifier.
FIG. 22 shows an embodiment of increasing the feedback ratio k together with the gain of the AGC amplifier. The numeral 306 denotes an AGC amplifier, in which it is possible to vary the gain. In consideration of a signal pass band, it is desirable that the AGC amplifier having a comb filter characteristic is applied to an AGC amplifier which is set in the latter part as shown in FIG. 16. Specifically, three circuits corresponding to FIG. 22 can be used to replace the AGC amplifier 160 of FIG. 16. In this case, all of the terminals 88 of the three circuits will be coupled to the output terminal of the signal level detector 76. The respective input terminals 300 of the three circuits will be arranged so that one is coupled to the output terminal of the blanking circuit 158 and the other two are coupled to respective outputs of the color difference matrix circuit 159. The output terminals 301 of the three circuits are respectively coupled to the input terminal of the signal level detector 76 and the input terminals of the low pass filter 161.
As mentioned above, the CPD type solid state camera of the present invention can have the effect of suppressing the vertical smear by executing the sweep out on condition that the vertical smear is remarkable, and can suppress the random noise generated in the combination part more than 3 dB, eliminate completely the FPN and the shading generated in the combination part and obtain the effect of raising up the sensitivity extremely by stopping the sweep out on condition that the scene illumination becomes dark. | A method and apparatus for increasing the sensitivity of a charge priming type solid state camera having means for sweeping out undesired excess charges generated by a vertical smear from vertical signal lines. When the scene illumination is higher than an appropriate value, the sweep out of the undesired excess charges is executed within each horizontal blanking period in order to reduce the vertical smear. When the scene illumination becomes lower than the appropriate value, the sweep out thereof is stopped in order to increase the sensitivity. Alternatively, when the scene illumination is lower than the appropriate value but the quantity of the vertical smear is larger than a fixed value, the sweep out thereof is executed within each horizontal blanking period in order to suppress vertical smear which is at an unacceptably high level even though the illumination level is relatively low. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to mufflers. More particularly the present invention relates to an improved discharge gas muffler for refrigerant compressors.
In the case of refrigerant compressors used for air conditioning and heat pump applications, sound has become an increasingly important criteria for judging acceptability. Accordingly, there is a demand for improved refrigerant compressors which are quieter than those presently available, but sacrificing none of the advantages of existing compressors.
It is therefore a primary objective of the present invention to provide a refrigerant compressor muffler which operates on the principle of a closed chamber resonator. The present invention provides an improved discharge gas muffler which is relatively simple in construction and does not result in a significant loss of efficiency.
From the subsequent detailed description, appended claims and drawings, other objects and advantages of the present invention will become apparent to those skilled in the art.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view of a multi-cylinder hermetic refrigerant compressor incorporating a discharge gas muffler embodying the principles of the present invention.
FIG. 2 is an enlarged vertical sectional view of the discharge gas muffler of the present invention.
FIG. 3 is a partial sectional view taken in the direction of arrow 3--3 in FIG. 2.
FIG. 4 shows a plot of the amount of attenuation versus the frequency.
FIG. 5 shows a plot of input pressure reflection coefficient versus frequency.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is illustrated for exemplary purposes embodied in a two cylinder reciprocating compressor. The major components of the compressor include a hermetic shell 10, a suction gas inlet fitting 12, a discharge fitting 14, and a motor-compressor unit 16 disposed therein. The motor-compressor unit is spring supported in the usual manner (not shown) and positioned at the upper end by means of a spring 18 located on a sheet metal projection 20. The motor-compressor unit 16 generally comprises a compressor body 22 defining a plurality of pumping cylinders 24 (two parallel radially disposed cylinders in this case). A reciprocating pumping member is disposed in each of these cylinders in the form of a piston 26 connected in the usual manner by connecting rod 28 to a crankshaft 30. The crankshaft 30 is rotationally journalled in a bearing 32 disposed in body 22. The upper end of crankshaft 30 is affixed to a motor rotor 34 rotatively disposed within a motor stator 36. The upper end of the motor stator is provided with a motor cover 38 which has a recess 40 receiving spring 18 and an inlet opening 42. The inlet opening 42 is positioned to receive suction gas entering through fitting 12 for purposes of motor cooling prior to induction into the compressor. Each cylinder 24 in body 22 is opened to an outer planar surface 44 on body 22 to which is bolted the usual valve plate assembly 46 and cylinder head 48, all in the usual manner. Cylinder head 48 defines interconnected discharge gas chambers 50 and 52 which receive the discharge gas pumped by the compressor through discharge valve assemblies 51 and 53, respectively. Up to this point the compressor as described is known in the art and the essential details thereof are disclosed in the U.S. Pat. No. 4,412,791, the disclosure of which is hereby incorporated herein by reference.
Referring now to FIGS. 2 and 3, the discharge muffler 60 comprises a generally J-shaped discharge tube 62, an outer shell 64 and a fitting 66.
The outer shell 64 comprises an upper portion 70 and a lower portion 72. The upper and lower portions 70, 72 are telescoped and sealingly brazed together at 74 to define an elongated chamber 76 which is of generally circular cross section for stiffness and has a generally circular opening 73 and 75 at each end. The diameters of the circular openings 73 and 75 are not equal and both are smaller than the diameter of the elongated chamber 76.
The fitting 66 has an annular body 80 which defines a cylindrical opening 82 extending through the fitting 66. The inside diameter of the cylindrical opening 82 is substantially the same as the inside diameter of opening 73 and is equal to or slightly less than the outside diameter of the J-shaped tube 62 as will be discussed later herein. The outside surface of the fitting 66 comprises a threaded section 84 and a generally circular section 86. The threaded section 84 is designed to be threadably affixed to head 48 of the motor-compressor unit 16. The generally circular section 86 has a diameter which is equal to or slightly larger than the diameter of opening 75 and is sealingly brazed to one end of the outer shell 66 as shown in FIG. 2.
One side 90 of the J-shaped tube 62 extends through opening 73 of the outer shell, through the elongate chamber 76 and into the cylindrical opening 82 of the fitting 66. The fitting 66 and the outer shell 64 are sealing brazed to J-shaped tube 62 at positions 92 and 94 respectively. The other end 96 of the J-shaped tube 62 extends downwardly under the compressor to the inlet end of a secondary muffler (not shown). The outlet of the secondary muffler is connected via tubing 98 to discharge fitting 14.
The side 90 of the J-shaped tube 62 which is located within elongated chamber 76 has a plurality of arrangements 100 of apertures. Each arrangement 100 includes a plurality of circular holes 102. The size of each hole 102 is determined by a relationship of the size of the hole to the size of the J-shaped tube 62. The total cross sectional area of each arrangement of circular holes 102 is less than 20% of the cross sectional area of the J-shaped tube 62, and each arrangement 100 preferably comprises a pair of equally sized holes 102. The space between adjacent holes is approximately equal to the diameter of the holes. This gives a center line to center line distance between adjacent holes equal to approximately two times the diameter of the hole. While the present invention is being described using circular holes, it is understood that any shape of hole is acceptable as long as the relationships of the cross sectional areas and the spacing are maintained.
Each arrangement of apertures is placed in line axially with the other arrangements of apertures and separated from an adjacent arrangement of apertures by a center to center distance which is equal to approximately one-eighth of the wavelength of the primary frequency to be attenuated. The holes are located axially in line to make it easier to fabricate the tube. Chamber 76 is as large as possible, as dictated by cost and space factors, and has a length which results in an arrangement 100 being located closely adjacent each end of chamber 76. This positioning improves the acoustics of the system as well as providing an oil drain for the elongated chamber when the muffler is positioned vertically.
In designing the muffler, it is first necessary to determine the fundamental harmonic frequency to be attenuated. The frequency components requiring attenuation are determined by actual measurement of the machine in question. First, a plot of discharge pressure versus time is made using a pressure transducer located several feet from an unmuffled compressor in the discharge line with an anechoic termination. This data is then subjected to a conventional Fourier analysis to provide a plot of magnitude of the pressure pulsations versus frequency. This plot will visually reveal the frequencies which are the noisiest and hence require attenuation.
One example of the present invention was developed to attenuate a primary frequency of approximately 600 to 800 hertz, and particularly approximately 630 hertz. This frequency was found to excite both the motor-compressor unit and the condenser unit. The discharge muffler of the present invention is directed towards attenuation of this primary frequency. The secondary muffler positioned downstream of this primary muffler is designed to attenuating other less significant frequencies.
The above referenced example uses a J-shaped tube 62 which is approximately 0.500 inches in diameter (0.196 square inches). Each arrangement of holes 102 comprises two holes. Each hole has a diameter of approximately 0.116 inches (0.011 square inches). Each hole is spaced at a centerline to centerline distance of approximately 0.24 inches. The plurality of arrangements of apertures 100 comprises three sets of the two holes spaced approximately 1.36 inches apart.
This muffler was found to significantly improve the attenuation in the desired frequency range as well as significantly reducing the undesirable build up of back pressure in the discharge chambers 50 and 52 at and over twice the primary frequency. This is demonstrated by the graphs shown in FIGS. 4 and 5. The graph in FIG. 4 shows a plot of the amount of attenuation versus the frequency. The curve marked "Expansion Chamber" represents the attenuation of a typical expansion chamber design of the muffler. The curve marked "Muffler" represents a plot of a muffler in accordance with the present invention. The graph shows that the attenuation in the targeted range of 600-800 hertz or more particularly approximately 630 hertz is significantly improved. The attenuation for frequencies above the primary frequency are accommodated for by the secondary muffler positioned downstream of the primary muffler.
FIG. 5 shows a similar plot of input pressure reflection coefficient versus frequency. Again, the curve marked "Expansion Chamber" design is a plot for a typical expansion chamber design or muffler and the curve marked "Muffler" is a plot for a muffler in accordance with the present invention. The graph shows a significant decrease in the input pressure reflection at and over twice the primary frequency of approximately 630 hertz. This reduction of back pressure has been found to significantly improve the performance of the refrigerant compressor.
While it will be apparent that the preferred embodiment of the invention disclosed are well calculated to provide the advantages above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims. | A refrigerant compressor discharge muffler which operates on the principle of a closed chamber resonator is disclosed. The muffler includes a generally J-shaped tube and an outer shell adapted to be threadably affixed to the head of a motor-compressor unit. The J-shaped tube is partially disposed within the outer shell and has a plurality of arrangements of apertures extending through the wall of the tube interconnecting the internal passage of the tube with a chamber defined by the outer shell. The spacing and size of the apertures are determined by a relationship to a frequency desiring to be attenuated. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to a technique for creating a delivery plan in a logistics system, and more particularly to a technique for creating a delivery plan in which a plurality of delivery vehicles start from a distribution center, deliver one or more packages to one or more destinations (delivery destinations) and return to the distribution center.
BACKGROUND OF THE INVENTION
[0002] One of the most important current issues in enterprise management is reducing logistics costs; that is, the cost of distributing products. A large enterprise delivers a large number of packages to various parts of the whole country by using hundreds or thousands of trucks per day. The logistics cost is enormous, and the creation of an efficient delivery plan leading to the reduction of the logistics cost is very important for an enterprise or a transportation company which contracts for delivery.
[0003] In the past, delivery plans were created manually by experienced, skilled people. However, it was never easy to find enough people with the necessary skills and the effort to find, train and retain such people was a significant contributor to logistics costs. It is becoming common to automatically create delivery plans using a computer program. Such programs are in great demand.
[0004] In general, in a case where a delivery plan is to be created using a computer, certain constraints (for instance, a load limit for each delivery vehicle, a limit to the number of the delivery vehicles, a limit to the total operating time of the delivery vehicles, etc.) exist as conditions. A delivery instance (the positions of delivery destinations, the items and weights of loads to-be-delivered, etc.) is included under the conditions. Also included as a condition is a need to deliver packages in such a way that the delivery vehicles start from a distribution center (the base of the delivery vehicles) and return thereto after making a round of the plurality of destinations (delivery destinations). Optimization is executed by the computer and with an objective function concerning the constraints, the necessary number of the delivery vehicles, the total operating time of the delivery vehicles, etc., whereby the delivery plan satisfying the given conditions is automatically generated.
[0005] A program product, which creates a delivery plan satisfying the conditions, through such optimization, is “Vehicle Routing Planner for Windows (R) (hereinbelow, abbreviated to “VRP”)” which is offered by International Business Machines Corporation.
[0006] The VRP executes optimization by creating the tentative delivery plan (initial or tentative solution) with a given delivery instance and then executing a local search for the tentative delivery plan, thereby to create the final delivery plan which satisfies conditions. Here, in the “local search”, predefined processing called a “local operation”, by which the topology of the tentative delivery plan is altered, is executed for the tentative delivery plan so as to obtain a new delivery plan (new solution). The new delivery plan resulting from the execution of the local operation is evaluated so as to determine if it has been improved on the tentative delivery plan preceding the local operation. If the new delivery plan has improved on the tentative delivery plan, the local operation is adopted, and the processing is iterated, thereby to obtain a better solution.
[0007] According to the local search method, constraints such as the necessary number of delivery vehicles, the total operating time of the delivery vehicles, etc. are dynamically considered, and an optimized delivery plan is obtained. However, unforeseen situations such as the absence of a customer at a delivery destination occur on some occasions. In a case where such an unforeseen situation has occurred in a delivery plan in which destinations extend over a geographically wide range, a longer time can be eventually expended on the actual delivery though the constraints, the necessary number of the delivery vehicles, the total operating time of the delivery vehicles, etc. are optimized on the original delivery plan.
[0008] More specifically, in a case where a package cannot be delivered due to the absence of a customer at a certain delivery destination, a delivery vehicle needs to return to the delivery destination and deliver the package after it has delivered packages to other delivery destinations. When the delivery destinations extend over a geographically wide range, a time period required for returning to the delivery destination where the customer was absent becomes long. It is accordingly desired to form a delivery plan so that delivery destinations may lie within a narrow geographical distribution range.
[0009] An “area division method” for solving this problem is disclosed in Japanese Patent Laid-Open No. 311702/1997. The area division method divides a delivery area into blocks on the basis of the data of past delivery instances and allocates a plurality of vehicles to each divisional block. Regarding a given delivery instance, the vehicles are tentatively allocated by forming delivery plans for the respective blocks. Thereafter, adjustments are made among the blocks so as to finally determine an optimal delivery plan.
[0010] With the area division method, however, the blocks are originally the predetermined fixed ones, and delivery destinations cannot be dynamically grouped. Even if the adjustments are made among the blocks after the tentative allocation of the vehicles, this method is sometimes unsatisfactory from the viewpoint of creating a flexible delivery plan.
[0011] As a result, the application of the area division method sometimes creates an inefficient, inflexible and non-versatile plan. By way of instance, a situation where the delivery vehicles are allocated to a block having low delivery requirements, depending upon the contents of the delivery instance and how to divide the area into the blocks. Moreover, a situation can occur where two successive destinations are quite far apart even though in the same block, and where the delivery of a package by the delivery vehicle allocated to an adjacent block would clearly more efficient than using a delivery vehicle within the block containing the destinations.
SUMMARY OF THE INVENTION
[0012] The present invention is a method, a system and a computer program for narrowing the geographical distribution range of delivery destinations assigned to respective delivery vehicles through an improvement in the local search method.
[0013] The present invention, implemented in a computer system including a processor and memory means, includes the steps of: (1) generating a tentative delivery plan from given data of delivery instance stored in the memory means; (2) calculating an evaluation value for the tentative delivery plan; (3) executing an operation altering the topology of the tentative delivery plan to generate a new delivery plan; (4) calculating an evaluation value of the new delivery plan; (5) comparing the evaluation value of the tentative delivery plan and that of the new delivery plan; (6) replacing the tentative delivery plan with the new delivery plan where the evaluation value of the new delivery plan is better than that of the tentative delivery plan; and (7) outputting the selected delivery plan.
[0014] In the above method, a total operating time of the delivery vehicle is one of the factors of the evaluation value; and each of the steps (2) and (4) of calculating the evaluation values includes the steps of: determining a travel time from the distribution center to the first destination for each of the delivery routes included in the delivery plan; multiplying the travel time from the distribution center to the first destination by a first coefficient k 1 (0<k 1 <1) to calculate a first value, for each of the delivery routes included in the delivery plan; determining a travel time from the last destination to the distribution center for each of the delivery routes included in the delivery plan; multiplying the travel time from the last destination to the distribution center by a second coefficient k 2 (0<k 2 <1) to calculate a second value, for each of the delivery routes included in the delivery plan; and calculating the total operating time of the plurality of delivery vehicles as one of the factors of the evaluation value by using the first and second values.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 shows a hardware architecture for one embodiment of a delivery plan creation system according to the present invention.
[0016] [0016]FIG. 2 is a functional block diagram of an instance of the embodiment of the delivery plan creation system according to the present invention.
[0017] [0017]FIG. 3 is a flow chart showing an instance of the flow of processing in the embodiment of the present invention.
[0018] [0018]FIG. 4 is a flow chart showing the contents of the processing of the calculation of the evaluation value of a delivery plan in the processing flow in the embodiment of the present invention.
[0019] [0019]FIG. 5 shows a delivery plan created by applying a prior-art local search method to a certain delivery plan.
[0020] [0020]FIG. 6 shows a delivery plan created by applying the present invention to the same delivery instance as in FIG. 5
[0021] [0021]FIG. 7 shows an instance (“2-Opt local operation”) of a local operation in the embodiment of the present invention.
[0022] [0022]FIG. 8 shows an instance (“ladder local operation”) of the local operation in the embodiment of the present invention.
[0023] [0023]FIG. 9 shows an instance (“path shifting local operation”) of the local operation in the embodiment of the present invention.
[0024] [0024]FIG. 10 shows an instance (“path exchanging local operation”) of the local operation in the embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENT
[0025] An embodiment of the present invention will be described in detail with reference to the drawings. The present invention, however, can be performed in a large number of different aspects and shall not be construed as being restricted to the stated contents of the embodiment. The same reference numerals are assigned to the same constituents throughout the embodiment.
[0026] In this embodiment, a method or a system will be mainly described, but as obvious to those skilled in the art, the present invention can be performed as a program usable in a computer. Accordingly, the present invention can be embodied as hardware, software, or a combination of software and hardware. The program can be recorded in any desired computer-readable medium such as a hard disk, CD-ROM, optical storage device or magnetic storage device.
[0027] Shown in FIG. 1 is an embodiment of the typical hardware architecture of a computer system in which the present invention is performed. The computer system 100 includes a central processing unit (CPU) 1 which is a so-called “processor”, and a main memory 4 which serves as memory means. The CPU 1 and the main memory 4 are connected through a bus 2 to a hard disk drive 13 serving as an auxiliary storage device. Also, removable storage systems (external storage systems capable of exchanging recording media), such as a flexible disk drive 20 , an magnetic disk drive 28 and CD-ROM drives 26 , 29 , are connected to the bus 2 through a flexible disk controller 19 , an IDE controller 25 and a SCSI controller 27 associated therewith. The storage media such as a flexible disk, an MO and CD-ROMs are respectively inserted into the removable storages such as the flexible disk drive 20 , the MO drive 28 and the CD-ROM drives 26 , 29 . The codes of a computer program for giving instructions to the CPU etc. in cooperation with an operating system so as to perform the present invention can be recorded in the flexible disk etc., the hard disk drive 13 and a ROM 14 . The computer program is loaded into the main memory 4 to be executed. This computer program can also be recorded in the plurality of media in a state where it is compressed or where it is divided into a plurality of parts.
[0028] The computer system 100 can further include a mouse or the like pointing device 7 , a keyboard 6 , and a display 12 for presenting visual data to a user, as user interface hardware elements. Besides, the computer system 100 can be connected to a printer (not shown) through a parallel port 16 or to a modem (not shown) through a serial port 15 . This computer system 100 can communicate with another computer or the like when connected to a network through the serial port 15 as well as the modem, or through a communicating adapter 18 (Ethernet (R) card or token ring card) or the like. A loudspeaker 23 receives through an amplifier 22 an audio signal subjected to D/A conversion (digital-to-analog conversion) by an audio controller 21 , and outputs the received signal as voice. Besides, the audio controller 21 subjects audio information received from a microphone 24 , to A/D conversion (analog-to-digital conversion), whereby the audio information outside the system is permitted to be accepted into the system.
[0029] It will be understood from the above description that the computer system 100 of the present invention can be embodied by any information processing apparatus, such as ordinary personal computer (PC), workstation, laptop PC, notebook PC, palmtop PC or network computer, or the combination of such information processing apparatus. A number of the elements are described as examples of a typical system. Not all of them are necessary to the present invention. In particular, the removable storage systems, the printer, the modem and the audio elements can be omitted from the hardware architecture described here without affecting an implementation of the invention.
[0030] [0030]FIG. 2 is a functional block diagram of an instance of the embodiment of a delivery plan creation system according to the present invention. Various elements shown in the functional block diagram are embodied by the cooperation of hardware and software on the computer system shown in FIG. 1 by way of instance. Referring to FIG. 2, the system 200 of this embodiment includes a delivery plan optimizer 2100 , which includes an initial delivery plan generator 2110 . The optimizer 2100 further includes a local search unit 2200 . The local search unit 2200 includes a local operation generator 2210 , a local operation application unit 2220 and a delivery plan evaluation unit 2230 .
[0031] Also referring to FIG. 2, it is understood that delivery destination information 2310 , distribution center information 2320 , delivery vehicle information 2330 , delivery item information 2340 and pickup/delivery information 2350 are contained as input data 2300 in the system 200 of this embodiment. Further, the system 200 of this embodiment has a table for the times/distances between distribution centers and delivery destinations 2360 which have been generated from the delivery destination information 2310 , the distribution center information 2320 , and electronic road map data 2510 contained in map data 2500 , by the use of a unit for computing distances between the distribution centers and the delivery destinations, 2400 .
[0032] The delivery destination information 2310 contains the information of the latitudes/longitudes, names and addresses of the delivery destinations. The distribution center information 2320 contains the information of the latitudes/longitudes, appellations, addresses and deliverable time zones of the distribution centers which are the start points and end points of deliveries by delivery vehicles. The delivery vehicle information 2330 can contain information on the delivery vehicles, specifically, the information on maximum vehicle loads, and the costs and deliverable items of the individual vehicles. The delivery item information 2340 can contain information on the carrying loads (weights and sizes) of delivery items to be delivered. The pickup/delivery information 2350 contains information for managing pickups/deliveries, specifically, delivery items to be picked up/delivered and the quantities of the respective items are defined. The electronic road map data 2510 should appropriately contain the geographical information of roads and the mean speed information of the respective roads. Stored in a table format in the time/distance table 2360 are the travel times between the places and between the distribution centers as have been calculated from the latitudes/longitudes of the places contained in the place information 2310 , the latitudes/longitudes of the distribution centers contained in the distribution center information 2320 , the geographical information of the roads and the mean speed information of the respective roads contained in the electronic road map data 2510 , and so forth.
[0033] The initial delivery plan generator 2110 generates a tentative delivery plan (initial solution) on the basis of the input data 2300 . The local search unit 2200 generates, from the tentative delivery plan, a local operation for altering the topology (the sequence in which the individual delivery vehicles are to visit the destinations) of the tentative delivery plan, and evaluates the local operation and the delivery plan (as described in detail later), to execute optimization and to output a final delivery plan satisfying constraint conditions.
[0034] The local search unit 2200 includes the local operation generator 2210 , the local operation application unit 2220 and the delivery plan evaluation unit 2230 . The local operation generator 2210 generates the local operation applied to the tentative delivery plan. The local operation application unit 2220 executes the local operation for the tentative delivery plan. The delivery plan evaluation unit 2230 evaluates delivery plans by the use of an objective function such as the total operating time of the delivery vehicles, etc.
[0035] [0035]FIG. 3 is a flow chart showing an instance of the flow of processing in the embodiment of the present invention.
[0036] In the embodiment of the present invention, the processing is started from a step 3000 , and input data which contain the information of a delivery instance, such as delivery destination information, distribution center information and delivery vehicle information, are loaded into a main memory at a step 3010 , and the processing proceeds to a step 3020 . At the step 3020 , the initial delivery plan generator 2110 generates an initial delivery plan to which a local operation is to be applied, on the basis of the input data derived from the main memory and using a CPU, and it stores the initial delivery plan in the main memory. The initial delivery plan can be created, for instance, by generating a suitable number of routes in which delivery vehicles start from the distribution center, visit proper delivery destinations clockwise and lastly return to the distribution center.
[0037] Subsequently, the processing proceeds to a step 3030 , at which the local operation to be executed for the tentative delivery plan is generated by the local operation generator 2210 . The local operation may be generated by defining sets each of which consists of a destination, and other destinations belonging to a range for the local operation of the particular destination (for instance, a circle having a predetermined radius about the particular destination may be set as the range), and then selecting the local operation which is to be executed for the set.
[0038] Considered as such local operations are a “2-Opt local operation” which eliminates the twisted state of the route of the delivery vehicle (FIG. 7), a “ladder local operation” in which the certain destination, et seq. of a certain route are exchanged for the certain destination, et seq. of another route (FIG. 8), a “path shifting local operation” in which a destination (or a plurality of successive destinations) on a certain route is assigned onto another route (FIG. 9), and a “path exchanging local operation” in which a destination (or a plurality of successive destinations) on a certain route is exchanged for a destination (or a plurality of successive destinations) on another route (FIG. 10). In FIGS. 7 through 10, an arrow indicates the route between the distribution center and the destination or between the destinations, a single circle represents the destination, and a double circle represents the distribution center.
[0039] Although the four types of local operations have been briefly introduced above, they shall not be described in more detail for the reasons that the contents of the local operations are not essential to the present invention in themselves, and that those skilled in the art can properly design and realize different variations.
[0040] At a step 3040 , the local operation is executed using the CPU, whereby the new delivery plan is generated and is stored in the main memory. Subsequently, at a step 3050 , the evaluation value of the new delivery plan, which is derived from the main memory, is calculated using the CPU. By the way, in the first loop, the evaluation value of the initial delivery plan may well be calculated on this occasion. The calculation of the evaluation value of the delivery plan at the step 3050 will be detailed later.
[0041] Subsequently, at a step 3060 , it is determined whether the evaluation value obtained at the step 3050 has been improved as compared with the evaluation of the delivery plan previous to the local operation. Subject to the determination of the step 3060 that the evaluation value has not been improved, the local operation is restored at a step 3070 , and the processing proceeds to a step 3080 . Subject to the determination of the step 3060 that the evaluation value has been improved, the processing immediately proceeds to the step 3080 .
[0042] Regarding the determination on the improvement at the step 3060 , consider a case where the variables of an objective function are the violations of constraints (such as the load limits of delivery vehicles), the number of the necessary delivery vehicles, and the total operating time of the delivery vehicles. In such a case, a delivery plan which affords a smaller number in the constraint violations may be decided to be better. When the numbers of the constraint violations are equal, a delivery plan which affords a smaller number in the necessary delivery vehicles may be determined better. When the numbers of the constraint violations and the numbers of the necessary delivery vehicles are equal, a delivery plan which provides the lowest total operating time of the delivery vehicles may be decided better.
[0043] At a step 3080 , it is determined if a new local operation to be executed for the tentative delivery plan exists. In a case where the new local exists and where the local operation can be generated anew, the processing returns to the step 3030 , at which the new local operation is generated, whereupon the processing steps 3040 through 3080 stated above are executed.
[0044] This loop is iterated until the determination of the step 3080 that a new local operation does not exist. As optimization proceeds, the improvement is determined (that is, the tentative delivery plan is substituted) at the step 3060 less frequently, and hence, the new generation of the local operation becomes less frequent.
[0045] Subject to the determination of the step 3080 that the new local operation to be executed for the tentative delivery plan does not exist, the processing proceeds to a step 3090 , at which the tentative delivery plan is retrieved from the main memory and outputted. Processing ends at a step 3100 .
[0046] For better understanding of the present invention, the details of the calculation of the evaluation value of the delivery plan at the step 3050 will be described in conjunction with the flow chart of FIG. 4.
[0047] The calculation of the evaluation value begins at step 4000 . At a step 4010 , a travel time from the distribution center to the first destination (first delivery destination) is acquired for each delivery vehicle. The times/distances between the distribution centers and the first destinations of the respective routes which are held in the table 2360 prepared beforehand and stored in the main memory.
[0048] Subsequently, the processing proceeds to a step 4020 , at which the travel time from the distribution center to the first destination acquired at the step 4010 is multiplied by a coefficient k 1 (0<k 1 <1) using the CPU, and the resulting time is added to the total operating time of the delivery vehicle of each route, whereupon the processing proceeds to a step 4030 . Herein, a stop time for the first destination (the time the delivery vehicle is expected to remain at the first destination) may be added to the total operating time.
[0049] At the steps 4030 through 4050 , the travel time between the successive destinations on each route is added to the total operating time of the delivery vehicle. More specifically, the travel time from the first destination to the second destination is acquired at the step 4030 , and is added to the total operating time at the step 4040 . Herein, a stop time at the second destination may be added to the total operating time. As at the step 4010 , the travel time between the destinations may be acquired by reference to table 2360 . At the subsequent step 4050 , if another destination exists, the processing returns to the step 4030 . These processing steps are iterated until the addition of a travel time from the penultimate destination to the last destination and a stop time in the penultimate destination. The processing then proceeds to a step 4060 .
[0050] At the step 4060 , the travel time between the last destination of each route and the distribution center is acquired. As at the step 4010 , the travel time may be acquired by reference to the table 2360 .
[0051] Subsequently, the processing proceeds to a step 4070 , at which the travel time between the last destination of each route and the distribution center is multiplied by a coefficient k 2 (0<k 2 <1) and the resulting time is added to the total operating time of the delivery vehicle of each route. The value of the coefficient k 2 may or may not be the same as the value of the adjustment coefficient k 1 used at the step 4020 .
[0052] After the execution of the processing step 4070 , the processing proceeds to a step 4080 , at which another objective function of constraints, the number of the necessary delivery vehicles or the like, is computed using the CPU. Thereafter, the processing proceeds to a step 4090 , at which the evaluation of the delivery plan is ended.
[0053] It is understood from the above description that the objective function concerning the total operating time in this embodiment is given as follows:
T = ∑ t = 1 N T t T t = k 1 d 01 + ∑ i = 1 n - 1 d i + j + 1 + k 2 d nn + 1 + ∑ i = 1 n s i
[0054] where
[0055] T: Total operating time of Delivery vehicles
[0056] The number of the delivery vehicles is assumed to be N.
[0057] T t : Operating time of the t-th delivery vehicle
[0058] k 1 , k 2 : coefficients
[0059] d ij : Travel time between i-th and j-th destinations
[0060] The number of the places included in a route is assumed to be n.
[0061] The O-th and (n+1)th places are indicated to be a distribution center.
[0062] S i : Stop time in the i-th place.
[0063] It is understood that the coefficients k1, k2 reduce the weight of the travel time between the distribution center and the first and the last stops on the route as compared with the travel time between successive destinations within the route.
[0064] In a case where the total operating times of the delivery vehicle without any weighting by coefficients are equal before and after the local operation, the delivery plan in which the travel times of the delivery vehicle between the in-route destinations is shorter and the actual travel times between the distribution center and the first and last stops is considered to be the better of the two plans.
[0065] Incidentally, for the purpose of permitting a user to designate how the geographical distribution of destinations is laid out, the user should have the ability to modify coefficients k 1 and k 2 .
[0066] Incidentally, the total operating time of the delivery vehicle used as the evaluation value in this embodiment is modified by applying the coefficients to the travel time from the distribution center to the first destination and to the travel time from the last destination back to the distribution center. It is therefore to be noted that the total operating time used is not the “actual” total operating time, but instead an evaluation value.
[0067] A delivery plan created for a certain delivery instance by the prior-art local search method (in the state where k1=k2=1) is shown in FIG. 5. A delivery plan created for the identical delivery instance by the local search method in accordance with the present invention is shown in FIG. 6. In creating the delivery plan shown in FIG. 6, the coefficients were k1=k2=0.13. Dots expressive of the destinations are indicated in shapes which are different for the respective delivery vehicles. The destinations assigned to each of the delivery vehicles are surrounded with an ellipse. As seen from FIGS. 5 and 6, the shape of each ellipse (that is, the geographical range of the destinations for which each delivery vehicle) is smaller in the case of FIG. 6 than in the case of FIG. 5. It is accordingly understood that the geographical range of the destinations for each delivery vehicle can be narrowed by applying the present invention.
[0068] The above embodiment of the present invention is intended for the purpose of illustration only. While the described emobidment deals with the creation of delivery plans, those skilled in the art will recognize that the present invention is applicable to many other fields, for instance, the routing of buses, the delivery of mail or newspaper, the collection of garbage, and the delivery of fuel. | Where a plurality of delivery vehicles must start at a product distribution center, deliver products to one or more destinations on a route and then return the distribution center, a delivery plan is used to minimize operating costs. Possible delivery plans, having a plurality of delivery routes, are established. Plan evaluation values are established by accumulating the travel times for each route in the plan. The travel time for each route is the sum of the actual inter-destination travel times and weighted travel times for the initial (distribution center to first destination) and final (last destination to distribution center) segments of the route. The weighting reduces the effect of the initial and final segments relative to the effect of the inter-destination travel times. The evaluation values are compared in a series of iterations until it is determined that no further improvement can be obtained in evaluation value. | 6 |
PRIORITY CLAIM
This patent application claims priority to U.S. Provisional Patent Application No. 61/366,921, entitled “Flexible Hollow Sleeve Frame Support Structure with Integral Fabric Hub Intersections,” filed Jul. 22, 2010, which is incorporated herein in its entirety.
FIELD OF INVENTION
The present invention generally relates to tent constructions, and more specifically, to an improved tent assembly that can easily be erected by a user, where the improved tent assembly uses a web truss for providing an internal frame structure, where the web truss is a flexible hollow sleeve frame support structure with integral fabric hub intersections.
BACKGROUND OF THE INVENTION
Tents of conventional construction are typically time-consuming to erect. For example, tents with conventional internal frames require substantial effort by more than one person to place all the poles in position and then build a tent body around the pole structures. Some prior art tent assemblies allow for tent bodies to have provisions for pole structures to enable ease of construction. However, even in such tent assemblies, it is difficult to enable the tent body to form a certain structure without provisioning additional poles within the tent assembly. Moreover, given the number of poles that need to be erected to provide frame support on each side of the tent assembly, users have to hassle with dealing with a large number of poles during the assembly of the tent. Also, when erecting prior art tent assemblies, a fly sheet and/or tent body has to be added to the tent assembly to provide adequate structural integrity to the tent assembly. Attaching fly sheets or tent bodies is particularly challenging in high wind conditions. Several other such disadvantages exist in prior art necessitating a need for an improved tent assembly. Overall, the examples herein of some prior or related systems and their associated limitations are intended to be illustrative and not exclusive. Other limitations of existing or prior systems will become apparent to those of skill in the art upon reading the following Detailed Description.
SUMMARY OF THE DESCRIPTION
In at least one embodiment, the techniques described herein relates to a structure and method of assembling and positioning compression members using a singular or plurality of flexible hollow sleeve structures with integral fabric hub intersections that are held in tension in combination with compression members that can be used for a variety of applications. The present invention makes assembling structures significantly easier than known prior art since the intersecting flexible hollow sleeve structures can be made continuous. This allows users to erect the structure without the need for additional help. In addition, the improved tent assembly discussed herein is significantly stronger when deployed with compression members because the hollow sleeve structures, with integral fabric hub intersections, can be tensioned, thus significantly increasing the strength of the overall structure.
In embodiments, a further advantage of the improved tent assembly includes ease of assembly in, for example, high wind conditions. The web truss of the disclosed tent assembly may be set up merely with the tent poles without a need for a flysheet and/or a tent body. The pole sleeves of the web truss may be tensioned merely using provisions of the web truss it self, at which time the tent assembly is at full strength even before the flysheet and/or tent body is added. In embodiments, the tent assembly achieves complete structural integrity when the web truss is fitted with the poles. In prior art, since poles are added to the tent body or flysheet one at a time, high wind conditions often damage (e.g., snap) the poles and damage the tents, especially because complete structural integrity of the tent is not attained until the tent is fully erected with all tent poles in position.
In at least these respects, the improved tent assembly discussed here substantially departs from the conventional concepts and designs of the prior art. Other advantages and features will become apparent from the following description and claims. It should be understood that the description and specific examples are intended for purposes of illustration only and not intended to limit the scope of the present disclosure.
BRIEF DESCRIPTION OF DRAWINGS
These and other objects, features and characteristics of the present invention will become more apparent to those skilled in the art from a study of the following detailed description in conjunction with the appended claims and drawings, all of which form a part of this specification. In the drawings:
FIGS. 1 to 6 illustrate examples of pitching an improved test assembly;
FIG. 7 illustrates one exemplary embodiment where the pole sleeves may be tightened for providing additional tension;
FIG. 8 depicts an embodiment of the improved tent assembly that specifically illustrates an example of a flexible hollow pole sleeve structure with 12 integral fabric hub intersections;
FIG. 9 illustrates one exemplary embodiment of a pole intersection point;
FIG. 10 illustrates an example of how a tent pole is automatically guided in the correct pole sleeve section inside the integral fabric hub intersections because of the curved shape of the integral fabric hub intersections;
FIG. 11 illustrates an embodiment of a fully assembled flexible hollow pole sleeve structure with integral flexible material hub intersections, flysheet and tent poles;
FIG. 12 further depicts an embodiment of a fully assembled flexible hollow pole sleeve structure with integral fabric hub intersections, flysheet, and tent poles with the flysheet door open;
FIG. 13 illustrates the rear of the flysheet on an exemplary embodiment of a tent assembly;
FIG. 14 illustrates a tent body affixed to the flexible hollow pole sleeve structure with clips;
FIG. 15 illustrates a scenario where a plastic clip with a stainless steel gate is used for secure attachment to an o-ring;
FIG. 16 illustrates an embodiment of the tent assembly with a different method of attaching the tent body;
FIG. 17 shows an end view of an exemplary embodiment of a flexible hollow pole sleeve structure with an inner tent body;
FIG. 18 shows the vestibule area inside the flysheet and in front of the tent door;
FIG. 19 illustrates a single wall tent with a waterproof coated fabric in combination with a flexible hollow pole sleeve structure;
FIG. 20 illustrates flexible an exemplary embodiment of a hollow pole sleeve frame structure with integral fabric hub intersections that form of a sphere; and
FIG. 21 illustrates an embodiment of an improved tent assembly where a display banner is attached from the interior of the flexible hollow pole sleeve frame structure.
DETAILED DESCRIPTION OF THE INVENTION
Various examples of the invention will now be described. The following description provides specific details for a thorough understanding and enabling description of these examples. One skilled in the relevant art will understand, however, that the invention may be practiced without many of these details. Likewise, one skilled in the relevant art will also understand that the invention can include many other obvious features not described in detail herein. Additionally, some well-known structures or functions may not be shown or described in detail below, so as to avoid unnecessarily obscuring the relevant description.
The terminology used below is to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific examples of the invention. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section.
FIGS. 1 to 6 illustrate examples of pitching an improved test assembly. FIG. 1 depicts an exemplary embodiment of a flexible hollow pole sleeve structure 100 . The overall web of sleeve structures may sometimes be referred to herein as a web truss. Such a web truss provides the basic framework allowing a user to build a tent assembly frame, as will be explained in detail herein.
FIG. 2 illustrates examples of tent poles (or simply, “poles”) 105 used in conjunction with the improved tent assembly. In embodiments, the tent poles 105 are segmented and are held together with special elastic cord such as a shock cord. FIG. 3 illustrates an exemplary procedure for sliding in or directing poles within the web truss. As illustrated in FIG. 3 , a first tent pole 105 is inserted into the opening of one of the flexible hollow pole sleeve structures 100 . It is noted that while some of these exemplary figures show equal length tent poles fully inserted in the flexible hollow pole sleeve structure 100 , it is envisioned that non-equal poles may also be used as required in a particular application.
FIG. 5 illustrates an embodiment of an improved tent assembly where a water resistant or waterproof flysheet 130 is placed over the flexible hollow pole sleeve structure 100 to form a weatherproof enclosure. It is noted that the improved tent assembly can be configured to form a frame with either a flysheet or a tent body (that is internal to the frame formed by the web truss) as will be discussed further below. It is important to note that the frame, enabled by the insertion of the tent poles within the sleeve structures of the web truss, is independent of and does not require either for fly sheet or the tent body for completion of formation of a structurally complete structure for use as a tent. In contrast, all known prior art tent assemblies utilize either a fly sheet or a tent body as an essential component of formation of the eventual frame structure of a tent assembly.
FIG. 6 illustrates an embodiment of the improved tent assembly where a flysheet is partially draped over the flexible hollow pole sleeve structure 100 . A zipper 140 entrance on the flysheet allows for user ingress and egress. FIGS. 1 through 6 discussed an exemplary embodiment of an improved tent assembly where multiple poles were used in conjunction with multiple pole sleeves of a web truss in order to create a frame structure that formed the improved tent assembly. While the exemplary figures illustrate the use of as many as 6-12 web hubs (or fabric hubs) that provide housing for pole intersections, it is understood that a frame may be formed using a web truss that has even a single fabric hub. In such an embodiment, two poles may be used to intersect within the fabric hub and still be able to provide support to form a structurally sound frame. In the disclosed embodiments, as can be evidenced from the supporting figures, the improved tent assembly allows for continuous feeding and insertion of tent poles from just one end or base of the web truss. The tent pole extends all the way out to the other end. Issues are normally encountered when two tent poles need to cross over or intersect each other. In such scenarios, the web hubs of the disclosed improved tent assembly has separate angled housing that, as discussed herein, allows the two intersecting tent poles to slide through without allowing the two to collide with each other. This enables a user to simply feed in the poles from just one end of the web truss, while the pole sleeves and the web hubs cause the tent poles to be slid through in a direction and structure so as to form the entire frame of the improved tent assembly.
FIG. 7 illustrates one exemplary embodiment where the pole sleeves (and hence the corresponding web hubs coupled with the pole sleeves) may be tightened for providing additional tension (and hence additional strength) to the overall frame. In the illustrated embodiment, the web truss includes tent body grommet tab 125 , grommets 120 , webbing 170 loop, perimeter fabric skirt 150 , tension wings 155 , tensioning system 160 for the flexible hollow pole sleeve structure 100 , pole sleeve opening 175 , pole sleeve reinforcements 155 and o-ring 180 . In the disclosed exemplary embodiment, the tensioning system 160 for the flexible hollow pole sleeve structure 100 comprises of a buckle 165 which is attached to or near the pole sleeve opening 175 and a webbing 170 strap that is affixed at one end to the o-ring 180 , with the opposite end of the webbing 170 threaded through the tensioning buckle 165 . In the illustrated embodiment, the tension of the flexible hollow pole sleeve structure 100 can be adjusted by pulling 190 on the webbing 170 strap as shown in FIG. 7 . The amount of tension applied to the flexible hollow pole sleeve structure 100 may be adjusted based on the need for additional strength for extreme environmental conditions such as high wind or heavy snow loads. It is understood that the above description is merely one example of how the tensioning system may be applied to the web truss in order to enable control of tension applied to adjust and control the tension (and corresponding strength) of the frame of the improved tent assembly. For example, the arrangement of the o-ring, the webbing, the tensioning buckle, etc. may be altered with respect to the web truss and the sleeve structures as may be suited for a particular design or an application of the tent assembly. Other arrangements or provisions for providing a tensioning mechanism, as may be understood by people of ordinary skill in the art may also be used to substitute the illustrated tensioning mechanism.
FIG. 8 depicts an embodiment of the improved tent assembly that specifically illustrates an example of a flexible hollow pole sleeve structure 100 with 12 integral fabric hub intersections 195 . The flexible hollow pole sleeve structure 100 has an inner 270 flexible material layer and an outer 275 layer of flexible material. When joined, the inner and outer layers of material form the flexible hollow pole sleeve structure 100 with integral fabric hub intersections 195 . The tent poles are fed into the flexible hollow pole sleeve structure 100 at any pole sleeve opening 175 . The tent poles are located in-between the inner 270 flexible material layer and an outer 275 flexible material layer which form the flexible hollow pole sleeve structure 100 .
FIG. 9 illustrates one exemplary embodiment of a pole intersection point 200 . The integral fabric hubs 195 help guide the tent poles 105 in the correct direction without snagging or hanging up on another tent pole 105 or fabric. FIG. 10 illustrates an example of how a tent pole 105 is automatically guided in the correct pole sleeve section 205 inside the integral fabric hub intersections 195 because of the curved shape 265 of the integral fabric hub intersections 195 . In the illustrated embodiment, the integral fabric hubs 195 can be cut on the straight of grain and eliminates bias stretch which helps increase the strength of the structure by holding the poles 105 more securely in place. FIG. 10 shows the outer 275 and inner 270 integral fabric hub intersections 195 .
FIG. 11 illustrates an embodiment of a fully assembled flexible hollow pole sleeve structure 100 with integral flexible material hub intersections 195 , flysheet 130 and tent poles 105 . In the illustrated embodiment, a perimeter skirt 150 is shown with a modified tension wing 155 . The tension wings 155 have been connected to create a perimeter sidewall 210 . The perimeter sidewall 210 helps keep wind blown snow, spindrift, rain, etc. from entering the tent assembly. FIG. 12 further depicts an embodiment of a fully assembled flexible hollow pole sleeve structure 100 with integral fabric hub intersections 195 , flysheet 130 and tent poles with the flysheet door 215 open.
FIG. 13 illustrates the rear of the flysheet 130 on an exemplary embodiment of a tent assembly. This embodiment further illustrates a perimeter sidewall 210 . FIG. 14 illustrates a tent body 220 affixed to the flexible hollow pole sleeve structure 100 with clips 225 . FIG. 15 illustrates a scenario where a plastic clip 225 with a stainless steel gate 230 is used for secure attachment to an o-ring 180 . In embodiments, this protects the clips 225 from disengaging from the o-rings 180 when encountering, for example, high buffeting winds. In embodiments, the tent body 220 may be affixed to the flexible hollow pole sleeve structure 100 via clips, webbing, grosgrain, o-rings, quick links, carabineers, hooks or other temporary or permanent means as may be understood by a person of ordinary skill in the art.
FIG. 16 illustrates an embodiment of the tent assembly with a different method of attaching the tent body 220 to the o-rings 180 located on the flexible hollow pole sleeve structure 100 . In embodiments, multiple webbing 170 straps are attached to a plurality of o-rings 180 that are attached to the webbing or a flexible material, which are turn is attached the flexible hollow pole sleeve structure 100 . The clip 225 on the tent body 220 may then be attached to a single o-ring 280 on the flexible hollow pole sleeve structure 100 .
FIG. 17 shows an end view of an exemplary embodiment of a flexible hollow pole sleeve structure 100 with an inner tent body 220 . In embodiments, the tent body 220 is shaped in such a manner as to create several vestibule areas 235 when the flysheet is engaged. FIG. 18 shows the vestibule area 235 inside the flysheet 130 and in front of the tent door 240 . FIG. 19 illustrates a single wall tent 285 with a waterproof coated fabric in combination with a flexible hollow pole sleeve structure 100 . This configuration is an example of a preferred structure for mountaineers. FIG. 20 illustrates flexible an exemplary embodiment of a hollow pole sleeve frame structure 100 with integral fabric hub intersections 195 that form of a sphere. In embodiments, the poles are connected at the terminal ends to form a continuous loop inside flexible hollow pole sleeve frame structure 100 to create the sphere structure. Here, in embodiments, the tent poles are inserted or removed via an opening 255 in a pole sleeve segment 250 . The flexible hollow pole sleeve frame structure 100 can be tensioned as per the pole sleeve tensioning system illustrated in FIG. 7 .
FIG. 21 illustrates an embodiment of an improved tent assembly where a display banner 260 is attached from the interior of the flexible hollow pole sleeve frame structure 100 with integral fabric hub intersections 195 . The display material may be held in place by o-rings 180 or webbing 170 loops located on the inner 270 layer of the flexible hollow pole sleeve frame structure 100 .
Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense (i.e., to say, in the sense of “including, but not limited to”), as opposed to an exclusive or exhaustive sense. As used herein, the terms “connected,” “coupled,” or any variant thereof means any connection or coupling, either direct or indirect, between two or more elements. Such a coupling or connection between the elements can be physical, logical, or a combination thereof. Additionally, the words “herein,” “above” “below,” and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word “or,” in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.
The above Detailed Description of examples of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above. While specific examples for the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. While processes or blocks are presented in a given order in this application, alternative implementations may perform routines having steps performed in a different order, or employ systems having blocks in a different order. Some processes or blocks may be deleted, moved, added, subdivided, combined, and/or modified to provide alternative or sub-combinations. Also, while processes or blocks are at times shown as being performed in series, these processes or blocks may instead be performed or implemented in parallel, or may be performed at different times. Further any specific numbers noted herein are only examples. It is understood that alternative implementations may employ differing values or ranges.
The various illustrations and teachings provided herein can also be applied to systems other than the system described above. The elements and acts of the various examples described above can be combined to provide further implementations of the invention.
Any patents and applications and other references noted above, including any that may be listed in accompanying filing papers, are incorporated herein by reference. Aspects of the invention can be modified, if necessary, to employ the systems, functions, and concepts included in such references to provide further implementations of the invention.
These and other changes can be made to the invention in light of the above Detailed Description. While the above description describes certain examples of the invention, and describes the best mode contemplated, no matter how detailed the above appears in text, the invention can be practiced in many ways. Details of the system may vary considerably in its specific implementation, while still being encompassed by the invention disclosed herein. As noted above, particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the invention to the specific examples disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the invention encompasses not only the disclosed examples, but also all equivalent ways of practicing or implementing the invention under the claims. | Disclosed are structures and methods of assembling and positioning an improved tent assembly where members of the assembly use flexible hollow sleeve structures with integral fabric hub intersections that are held in tension in combination with compression members that can be used for a variety of applications. Disclosed techniques make assembling tent assemblies significantly easier than known prior art since the intersecting flexible hollow sleeve structures can be made continuous. In addition, the improved tent assembly is significantly stronger when deployed with compression members because the hollow sleeve structures, with integral fabric hub intersections, can be tensioned, thus significantly increasing the strength of the overall structure. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of co-pending U.S. patent application Ser. No. 10/395,031, filed Mar. 21, 2003, now U.S. Pat. No. ______, which is a continuation of International Application PCT/NL01/00697, filed Sep. 21, 2001, designating the United States, published in English Mar. 28, 2002, as WO 02/024906 A1 and subsequently published with corrections Jan. 23, 2003, as WO 02/024906 C2, the contents of the entirety of each of which are hereby incorporated herein by this reference.
TECHNICAL FIELD
[0002] The invention relates to the fields of biotechnology and gene therapy.
BACKGROUND
[0003] Given the rapid advances of human genome research, professionals and the public expect that the near future will bring us, in addition to understanding of disease mechanisms and refined and reliable diagnostics, therapies for many devastating genetic diseases.
[0004] While it is hoped that for some (e.g., metabolic) diseases, the improved insights will bring easily administrable small-molecule therapies, it is likely that in most cases one or another form of gene therapy will ultimately be required, i.e., the correction, addition or replacement of the defective gene product.
[0005] In the past few years, research and development in this field have highlighted several technical difficulties which need to be overcome, e.g., related to the large size of many genes involved in genetic disease (limiting the choice of suitable systems to administer the therapeutic gene), the accessibility of the tissue in which the therapeutic gene should function (requiring the design of specific targeting techniques, either physically, by restricted injection, or biologically, by developing systems with tissue-specific affinities) and the safety to the patient of the administration system. These problems are to some extent interrelated, and it can be generally concluded that the smaller the therapeutic agent is, the easier it will become to develop efficient, targetable and safe administration systems.
BRIEF SUMMARY OF THE INVENTION
[0006] This problem is addressed by inducing so-called “exon-skipping” in cells. Exon-skipping results in mature mRNA that does not contain the skipped exon and thus, when the exon codes for amino acids, can lead to the expression of an altered product. Technology for exon-skipping is currently directed toward the use of so-called “Anti-sense Oligonucleotides” (AONs).
[0007] Much of this work is done in the mdx mouse model for Duchenne muscular dystrophy (DMD). The mdx mouse, which carries a nonsense mutation in exon 23 of the dystrophin gene, has been used as an animal model of Duchenne muscular dystrophy. Despite the mdx mutation, which should preclude the synthesis of a functional dystrophin protein, rare, naturally occurring dystrophin-positive fibers have been observed in mdx muscle tissue. These dystrophin-positive fibers are thought to have arisen from an apparently naturally occurring exon-skipping mechanism, either due to somatic mutations or through alternative splicing.
[0008] AONs directed to, respectively, the 3′ and 5′ splice sites of introns 22 and 23 in dystrophin pre-mRNA have been shown to interfere with factors normally involved in removal of intron 23 so that exon 23 was also removed from the mRNA (Wilton, 1999). In a similar study, Dunckley et al. (1998) showed that exon skipping using AONs directed to 3′ and 5′ splice sites can have unexpected results. They observed skipping of not only exon 23 but also of exons 24-29, thus resulting in an mRNA containing an exon 22-exon 30 junction.
[0009] The underlying mechanism for the appearance of the unexpected 22-30 splicing variant is not known. It could be due to the fact that splice sites contain consensus sequences leading to promiscuous hybridization of the oligos used to direct the exon skipping. Hybridization of the oligos to other splice sites than the sites of the exon to be skipped of course could easily interfere with the accuracy of the splicing process. On the other hand, the accuracy could be lacking due to the fact that two oligos (for the 5′ and the 3′ splice site) need to be used. Pre-mRNA containing one but not the other oligo could be prone to unexpected splicing variants.
[0010] To overcome these and other problems, provided is a method for directing splicing of a pre-mRNA in a system capable of performing a splicing operation comprising contacting the pre-mRNA in the system with an agent capable of specifically inhibiting an exon inclusion signal of at least one exon in the pre-mRNA, the method further comprising allowing splicing of the pre-mRNA. Interfering with an exon inclusion signal (EIS) has the advantage that such elements are located within the exon. By providing an antisense oligo for the interior of the exon to be skipped, it is possible to interfere with the exon inclusion signal, thereby effectively masking the exon from the splicing apparatus. The failure of the splicing apparatus to recognize the exon to be skipped thus leads to exclusion of the exon from the final mRNA.
[0011] The processes and compounds disclosed herein do not interfere directly with the enzymatic process of the splicing machinery (the joining of the exons). It is thought that this allows the method to be more robust and reliable. It is thought that an EIS is a particular structure of an exon that allows splice acceptor and donor to assume a particular spatial conformation. In this concept, it is the particular spatial conformation that enables the splicing machinery to recognize the exon. However, the invention is certainly not limited to this model.
[0012] It has been found that agents capable of binding to an exon can inhibit an EIS. Agents may specifically contact the exon at any point and still be able to specifically inhibit the EIS. The mRNA may be useful in itself. For instance, production of an undesired protein can be at least in part reduced by inhibiting inclusion of a required exon into the mRNA. In certain embodiments, the method further comprises allowing translation of mRNA produced from splicing of the pre-mRNA. In certain embodiments, the mRNA encodes a functional protein. In various embodiments, the protein comprises two or more domains, wherein at least one of the domains is encoded by the mRNA as a result of skipping of at least part of an exon in the pre-mRNA.
[0013] Exon skipping will typically, though not necessarily, be of relevance for proteins in the wild-type configuration, having at least two functional domains that each performs a function, wherein the domains are generated from distinct parts of the primary amino acid sequence. Examples are, for instance, transcription factors. Typically, these factors comprise a DNA binding domain and a domain that interacts with other proteins in the cell. Skipping of an exon that encodes a part of the primary amino acid sequence that lies between these two domains can lead to a shorter protein that comprises the same function, at least in part. Thus, detrimental mutations in this intermediary region (for instance, frame-shift or stop mutations) can be at least in part repaired by inducing exon skipping to allow synthesis of the shorter (partly) functional protein.
[0014] Using a method described herein, it is also possible to induce partial skipping of the exon. In this embodiment, the contacting results in activation of a cryptic splice site in a contacted exon. This embodiment broadens the potential for manipulation of the pre-mRNA leading to a functional protein. In certain embodiments, the system comprises a cell. In certain embodiments, the cell is cultured in vitro or in the organism in vivo. Typically, though not necessarily, the organism comprises a human or a mouse.
[0015] In certain embodiments, provided is a method for at least in part decreasing the production of an aberrant protein in a cell, the cell comprising pre-mRNA comprising exons coding for the protein, the method comprising providing the cell with an agent capable of specifically inhibiting an exon inclusion signal of at least one of the exons, the method further comprising allowing translation of mRNA produced from splicing of the pre-mRNA.
[0016] Any agent capable of specifically inhibiting an exon exclusion signal can be used for the invention. In certain embodiments, the agent comprises a nucleic acid or a functional equivalent thereof. In certain embodiments, but not necessarily, the nucleic acid is in single-stranded form. Peptide nucleic acid and other molecules comprising the same nucleic acid binding characteristics in kind, but not necessarily in amount, are suitable equivalents. Nucleic acid or an equivalent may comprise modifications to provide additional functionality. For instance, 2′-O-methyl oligoribonucleotides can be used. These ribonucleotides are more resistant to RNAse action than conventional oligonucleotides.
[0017] In various embodiments, the exon inclusion signal is interfered with by an antisense nucleic acid directed to an exon recognition sequence (ERS). These sequences are relatively purine-rich and can be distinguished by scrutinizing the sequence information of the exon to be skipped (Tanaka et al., 1994 , Mol. Cell. Biol. 14, p. 1347-1354). Exon recognition sequences are thought to aid inclusion into mRNA of so-called weak exons (Achsel et al., 1996 , J. Biochem. 120, p. 53-60). These weak exons comprise, for instance, 5′ and or 3′ splice sites that are less efficiently recognized by the splicing machinery. In the invention, it has been found that exon skipping can also be induced in so-called strong exons, i.e., exons which are normally efficiently recognized by the splicing machinery of the cell. From any given sequence, it is (almost) always possible to predict whether the sequence comprises putative exons and to determine whether these exons are strong or weak. Several algorithms for determining the strength of an exon exist. A useful algorithm can be found on the NetGene2 splice site prediction server (Brunak, et al., 1991 , J. Mol. Biol. 220, p. 49-65). Exon skipping by a means of the invention can be induced in (almost) every exon, independent of whether the exon is a weak exon or a strong exon and also independent of whether the exon comprises an ERS. In certain embodiments, an exon that is targeted for skipping is a strong exon. In another preferred embodiment, an exon targeted for skipping does not comprise an ERS.
[0018] Methods of the invention can be used in many ways. In one embodiment, a method described herein is used to at least in part decrease the production of an aberrant protein. Such proteins can, for instance, be oncoproteins or viral proteins. In many tumors, not only the presence of an oncoprotein but also its relative level of expression has been associated with the phenotype of the tumor cell. Similarly, not only the presence of viral proteins but also the amount of viral protein in a cell determines the virulence of a particular virus. Moreover, for efficient multiplication and spread of a virus, the timing of expression in the life cycle and the balance in the amount of certain viral proteins in a cell determines whether viruses are efficiently or inefficiently produced. Using a method described herein, it is possible to lower the amount of aberrant protein in a cell such that, for instance, a tumor cell becomes less tumorigenic (metastatic) and/or a virus-infected cell produces less virus.
[0019] In certain embodiments, a method described herein is used to modify the aberrant protein into a functional protein. In one embodiment, the functional protein is capable of performing a function of a protein normally present in a cell but absent in the cells to be treated. Very often, even partial restoration of function results in significantly improved performance of the cell thus treated. Due to the better performance, such cells can also have a selective advantage over unmodified cells, thus aiding the efficacy of the treatment.
[0020] This aspect is particularly suited for the restoration of expression of defective genes. This is achieved by causing the specific skipping of targeted exons, thus bypassing or correcting deleterious mutations (typically stop-mutations or frame-shifting point mutations, single- or multi-exon deletions or insertions leading to translation termination).
[0021] Compared to gene-introduction strategies, this novel form of splice-modulation gene therapy requires the administration of much smaller therapeutic reagents, typically, but not limited to, 14-40 nucleotides. In certain embodiments, molecules of 14-25 nucleotides are used since these molecules are easier to produce and enter the cell more effectively. The methods of the invention allow much more flexibility in the subsequent design of effective and safe administration systems. An important additional advantage of this aspect is that it restores (at least some of) the activity of the endogenous gene, which still possesses most or all of its gene-regulatory circuitry, thus ensuring proper expression levels and the synthesis of tissue-specific isoforms.
[0022] This aspect can, in principle, be applied to any genetic disease or genetic predisposition to disease in which targeted skipping of specific exons would restore the translational reading frame when this has been disrupted by the original mutation, provided that translation of an internally slightly shorter protein is still fully or partly functional. Preferred embodiments for which this application can be of therapeutic value are: predisposition to second hit mutations in tumor suppressor genes, e.g., those involved in breast cancer, colon cancer, tuberous sclerosis, neurofibromatosis etc., where (partial) restoration of activity would preclude the manifestation of nullosomy by second hit mutations and thus would protect against tumorigenesis. Another preferred embodiment involves the (partial) restoration of defective gene products which have a direct disease causing effect, e.g., hemophilia A (clotting factor VIII deficiency), some forms of congenital hypothyroidism (due to thyroglobulin synthesis deficiency) and Duchenne muscular dystrophy (DMD), in which frame-shifting deletions, duplications and stop mutations in the X-linked dystrophin gene cause severe, progressive muscle degradation. DMD is typically lethal in late adolescence or early adulthood, while non-frame-shifting deletions or duplications in the same gene cause the much milder Becker muscular dystrophy (BMD), compatible with a life expectancy between 35-40 years to normal. In the embodiment as applied to DMD, the invention enables exon skipping to extend an existing deletion (or alter the mRNA product of an existing duplication) by as many adjacent exons as required to restore the reading frame and generate an internally slightly shortened, but still functional, protein. Based on the much milder clinical symptoms of BMD patients with the equivalent of this induced deletion, the disease in the DMD patients would have a much milder course after AON-therapy.
[0023] Many different mutations in the dystrophin gene can lead to a dysfunctional protein. (For a comprehensive inventory see WorldWideWeb.dmd.nl, the internationally accepted database for DMD and related disorders.) The precise exon to be skipped to generate a functional dystrophin protein varies from mutation to mutation. Table 1 comprises a non-limiting list of exons that can be skipped and lists for the mentioned exons some of the more frequently occurring dystrophin gene mutations that have been observed in humans and that can be treated with a method described herein. Skipping of the mentioned exon leads to a mutant dystrophin protein comprising at least the functionality of a Becker mutant. Thus, in one embodiment, provided is a method described herein wherein the exon inclusion signal is present in exon numbers 2, 8, 19, 29, 43, 44, 45, 46, 50, 51, 52 or 53 of the human dystrophin gene. The occurrence of certain deletion/insertion variations is more frequent than others. In the invention, it was found that by inducing skipping of exon 46 with a means or a method described herein, approximately 7% of DMD-deletion containing patients can be treated, resulting in the patients to comprise dystrophin-positive muscle fibers. By inducing skipping of exon 51, approximately 15% of DMD-deletion containing patients can be treated with a means or method described herein. Such treatment will result in the patient having at least some dystrophin-positive fibers. Thus, with either skipping of exon 46 or 51 using a method described herein, approximately 22% of the patients containing a deletion in the dystrophin gene can be treated. Thus, In various embodiments, the exon exclusion signal is present in exon 46 or exon 51. In a particularly preferred embodiment, the agent comprises a nucleic acid sequence according to hAON#4, hAON#6, hAON#8, hAON#9, hAON#11 and/or one or more of hAON#21-30 or a functional part, derivative and/or analogue of the hAON. A functional part, derivative and/or analogue of the hAON comprises the same exon skipping activity in kind, but not necessarily in amount, in a method described herein.
[0000]
TABLE 1
Therapeutic for
DMD-deletions
Frequency in
Exon to be skipped
(exons)
WorldWideWeb.dmd.nl (%)
2
3-7
2
8
3-7
4
4-7
5-7
6-7
43
44
5
44-47
44
35-43
8
45
45-54
45
18-44
13
46-47
44
46-48
46-49
46-51
46-53
46
45
7
50
51
5
51-55
51
50
15
45-50
48-50
49-50
52
52-63
52
51
3
53
53-55
53
45-52
9
48-52
49-52
50-52
52
[0024] It can be advantageous to induce exon skipping of more than one exon in the pre-mRNA. For instance, considering the wide variety of mutations and the fixed nature of exon lengths and amino acid sequence flanking such mutations, the situation can occur that for restoration of function more than one exon needs to be skipped. A preferred but non-limiting example of such a case in the DMD deletion database is a 46-50 deletion. Patients comprising a 46-50 deletion do not produce functional dystrophin. However, an at least partially functional dystrophin can be generated by inducing skipping of both exon 45 and exon 51. Another preferred but non-limiting example is patients comprising a duplication of exon 2. By providing one agent capable of inhibiting an EIS of exon 2, it is possible to partly skip either one or both exons 2, thereby regenerating the wild-type protein next to the truncated or double exon 2 skipped protein. Another preferred but non-limiting example is the skipping of exons 45 through 50. This generates an in-frame Becker-like variant. This Becker-like variant can be generated to cure any mutation localized in exons 45, 46, 47, 48, 49, and/or 50 or combinations thereof. In one aspect, the invention therefore provides a method described herein further comprising providing the cell with another agent capable of inhibiting an exon inclusion signal in another exon of the pre-mRNA. Of course, it is completely within the scope of the invention to use two or more agents for the induction of exon skipping in pre-mRNA of two or more different genes.
[0025] In another aspect, provided is a method for selecting the suitable agents for splice-therapy and their validation as specific exon-skipping agents in pilot experiments. A method is provided for determining whether an agent is capable of specifically inhibiting an exon inclusion signal of an exon, comprising providing a cell having a pre-mRNA containing the exon with the agent, culturing the cell to allow the formation of an mRNA from the pre-mRNA and determining whether the exon is absent the mRNA. In certain embodiments, the agent comprises a nucleic acid or a functional equivalent thereof, the nucleic acid comprising complementarity to a part of the exon. Agents capable of inducing specific exon skipping can be identified with a method described herein. It is possible to include a prescreen for agents by first identifying whether the agent is capable of binding with a relatively high affinity to an exon containing nucleic acid, preferably RNA. To this end, a method for determining whether an agent is capable of specifically inhibiting an exon inclusion signal of an exon is provided, further comprising first determining in vitro the relative binding affinity of the nucleic acid or functional equivalent thereof to an RNA molecule comprising the exon.
[0026] In yet another aspect, an agent is provided that is obtainable by a method described herein. In certain embodiments, the agent comprises a nucleic acid or a functional equivalent thereof. Preferably the agent, when used to induce exon skipping in a cell, is capable of at least in part reducing the amount of aberrant protein in the cell. More preferably, the exon skipping results in an mRNA encoding a protein that is capable of performing a function in the cell. In a particularly preferred embodiment, the pre-mRNA is derived from a dystrophin gene. In certain embodiments, the functional protein comprises a mutant or normal dystrophin protein. In certain embodiments, the mutant dystrophin protein comprises at least the functionality of a dystrophin protein in a Becker patient. In a particularly preferred embodiment, the agent comprises the nucleic acid sequence of hAON#4, hAON#6, hAON#8, hAON#9, hAON#11 and/or one or more of hAON#21-30 or a functional part, derivative and/or analogue of the hAON. A functional part, derivative and/or analogue of the hAON comprises the same exon skipping activity in kind, but not necessarily in amount, in a method described herein.
[0027] The art describes many ways to deliver agents to cells. Particularly, nucleic acid delivery methods have been widely developed. The artisan is well capable of determining whether a method of delivery is suitable for performing the invention. In a non-limiting example, the method includes the packaging of an agent of the invention into liposomes, the liposomes being provided to cells comprising a target pre-mRNA. Liposomes are particularly suited for delivery of nucleic acid to cells. Antisense molecules capable of inducing exon skipping can be produced in a cell upon delivery of nucleic acid containing a transcription unit to produce antisense RNA. Non-limiting examples of suitable transcription units are small nuclear RNA (SNRP) or tRNA transcription units. The invention, therefore, further provides a nucleic acid delivery vehicle comprising a nucleic acid or functional equivalent thereof of the invention capable of inhibiting an exon inclusion signal. In one embodiment, the delivery vehicle is capable of expressing the nucleic acid of the invention. Of course, in case, for instance, single-stranded viruses are used as a vehicle, it is entirely within the scope of the invention when such a virus comprises only the antisense sequence of an agent of the invention. In another embodiment of single strand viruses, AONs of the invention are encoded by small nuclear RNA or tRNA transcription units on viral nucleic encapsulated by the virus as vehicle. A preferred single-stranded virus is adeno-associated virus.
[0028] In yet another embodiment, provided is the use of a nucleic acid or a nucleic acid delivery vehicle of the invention for the preparation of a medicament. In certain embodiments, the medicament is used for the treatment of an inherited disease. More preferably, the medicament is used for the treatment of Duchenne Muscular Dystrophy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 . Deletion of exon 45 is one of the most frequent DMD-mutations. Due to this deletion, exon 44 is spliced to exon 46, the translational reading frame is interrupted, and a stop codon is created in exon 46 leading to a dystrophin deficiency. Our aim is to artificially induce the skipping of an additional exon, exon 46, in order to reestablish the reading frame and restore the synthesis of a slightly shorter, but largely functional, dystrophin protein as found in the much milder affected Becker muscular dystrophy patients affected by a deletion of both exons 45 and 46.
[0030] FIG. 2 . Exon 46 contains a purine-rich region that is hypothesized to have a potential role in the regulation of its splicing in the pre-mRNA. A series of overlapping 2′O-methyl phosphorothioate antisense oligoribonucleotides (AONs) was designed directed at this purine-rich region in mouse dystrophin exon 46. The AONs differ both in length and sequence. The chemical modifications render the AONs resistant to endonucleases and RNaseH inside the muscle cells. To determine the transfection efficiency in our in vitro studies, the AONs contained a 5′ fluorescein group which allowed identification of AON-positive cells.
[0031] FIG. 3 . To determine the binding affinity of the different AONs to the target exon 46 RNA, we performed gel mobility shift assays. In this figure, the five mAONs (mAON#4, 6, 8, 9, and 11) with highest affinity for the target RNA are shown. Upon binding of the AONs to the RNA, a complex is formed that exhibits a retarded gel mobility as can be determined by the band shift. The binding of the AONs to the target was sequence-specific. A random mAON, i.e. not specific for exon 46, did not generate a band shift.
[0032] FIGS. 4A and 4B . The mouse- and human-specific AONs which showed the highest binding affinity in the gel mobility shift assays were transfected into mouse and human myotube cultures.
[0033] FIG. 4A . RT-PCR analysis showed a truncated product, of which the size corresponded to exon 45 directly spliced to exon 47, in the mouse cell cultures upon transfection with the different mAONs#4, 6, 9, and 11. No exon 46 skipping was detected following transfection with a random AON.
[0034] FIG. 4B . RT-PCR analysis in the human muscle cell cultures derived from one unaffected individual (C) and two unrelated DMD patients (P 1 and P 2 ) revealed truncated products upon transfection with hAON#4 and hAON#8. In the control, this product corresponded to exon 45 spliced to exon 47, while in the patients, the fragment size corresponded to exon 44 spliced to exon 47. No exon 46 skipping was detected in the non-transfected cell cultures or following transfection with a random HAON. Highest exon 46 skipping efficiencies were obtained with hAON#8.
[0035] FIG. 5 . Sequence data from the RT-PCR products obtained from patient DL279.1 (corresponding to P 1 in FIG. 4 ), which confirmed the deletion of exon 45 in this patient (upper panel), and the additional skipping of exon 46 following transfection with hAON#8 (lower panel). The skipping of exon 46 was specific, and exon 44 was exactly spliced to exon 47, which reestablishes the translational reading frame.
[0036] FIG. 6 . Immunohistochemical analysis of the muscle cell culture from patient DL279.1 upon transfection with hAON#8. Cells were subject to two different dystrophin antibodies raised against different regions of the protein, located proximally (ManDys-1, ex. 31-32) and distally (Dys-2, ex. 77-79) from the targeted exon 46. The lower panel shows the absence of a dystrophin protein in the myotubes, whereas the hAON#8-induced skipping of exon 46 clearly restored the synthesis of a dystrophin protein as detected by both antibodies (upper panel).
[0037] FIG. 7A . RT-PCR analysis of RNA isolated from human control muscle cell cultures treated with hAON#23, #24, #27, #28, or #29. An additional aberrant splicing product was obtained in cells treated with hAON#28 and #29. Sequence analysis revealed the utilization of an in-frame cryptic splice site within exon 51 that is used at a low frequency upon AON treatment. The product generated included a partial exon 51, which also had a restored reading frame, thereby confirming further the therapeutic value.
[0038] FIG. 7B . A truncated product, with a size corresponding to exon 50 spliced to exon 52, was detected in cells treated with hAON#23 and #28. Sequence analysis of these products confirmed the precise skipping of exon 51.
[0039] FIG. 8A . Gel mobility shift assays were performed to determine the binding affinity of the different h29AON#'s for the exon 29 target RNA. When compared to non-hybridized RNA (none), h29AON#1, #2, #4, #6, #9, #10, and #11 generated complexes with lower gel mobilities, indicating their binding to the RNA. A random AON derived from dystrophin exon 19 did not generate a complex.
[0040] FIG. 8B . RT-PCR analysis of RNA isolated from human control muscle cell cultures treated with h29AON#1, #2, #4, #6, #9, #10, or #11 revealed a truncated product of which the size corresponded to exon 28 spliced to exon 30. These results indicate that exon 29 can specifically be skipped using AONs directed to sequences either within (h29AON#1, #2, #4, or #6) or outside (h29AON#9, #10, or #11) the hypothesized ERS in exon 29. An additional aberrant splicing product was observed that resulted from skipping of both exon 28 and exon 29 (confirmed by sequence data not shown). Although this product was also present in non-treated cells, suggesting that this alternative skipping event may occur naturally, it was enhanced by the AON-treatment. AON 19, derived from dystrophin exon 19, did not induce exon 29 skipping.
[0041] FIG. 8C . The specific skipping of exon 29 was confirmed by sequence data from the truncated RT-PCR fragments. Shown here is the sequence obtained from the exon 29 skipping product in cells treated with h29AON#1.
[0042] FIG. 9A . RT-PCR analysis of RNA isolated from mouse gastrocnemius muscles two days post-injection of 5, 10, or 20 μg of either mAON#4, #6, or #11. Truncated products, with a size corresponding to exon 45 spliced to exon 47, were detected in all treated muscles. The samples -RT, -RNA, AD-1, and AD-2 were analyzed as negative controls for the RT-PCR reactions.
[0043] FIG. 9B . Sequence analysis of the truncated products generated by mAON#4 and #6 (and #11, not shown) confirmed the precise skipping of exon 46.
DETAILED DESCRIPTION OF THE INVENTION
Examples
Example 1
[0044] Since exon 45 is one of the most frequently deleted exons in DMD, we initially aimed at inducing the specific skipping of exon 46 ( FIG. 1 ). This would produce the shorter, largely functional dystrophin found in BMD patients carrying a deletion of exons 45 and 46. The system was initially set up for modulation of dystrophin pre-mRNA splicing of the mouse dystrophin gene. We later aimed for the human dystrophin gene with the intention to restore the translational reading frame and dystrophin synthesis in muscle cells from DMD patients affected by a deletion of exon 45.
[0000] Design of mAONs and hAONs
[0045] A series of mouse- and human-specific AONs (mAONs and hAONs) was designed, directed at an internal part of exon 46 that contains a stretch of purine-rich sequences and is hypothesized to have a putative regulatory role in the splicing process of exon 46 ( FIG. 2 ). For the initial screening of the AONs in the gel mobility shift assays (see below), we used non-modified DNA-oligonucleotides (synthesized by EuroGentec, Belgium). For the actual transfection experiments in muscle cells, we used 2′-O-methyl-phosphorothioate oligoribonucleotides (also synthesized by EuroGentec, Belgium). These modified RNA oligonucleotides are known to be resistant to endonucleases and RNaseH, and to bind to RNA with high affinity. The sequences of those AONs that were eventually effective and applied in muscle cells in vitro are shown below. The corresponding mouse and human-specific AONs are highly homologous but not completely identical.
[0046] The listing below refers to the deoxy-form used for testing, in the finally used 2-O-methyl ribonucleotides all T's should be read as U's.
[0000]
mAON#2:
5′ GCAATGTTATCTGCTT
(SEQ ID NO:1)
mAON#3:
5′ GTTATCTGCTTCTTCC
(SEQ ID NO:2)
mAON#4:
5′ CTGCTTCTTCCAGCC
(SEQ ID NO:3)
mAON#5:
5′ TCTGCTTCTTCCAGC
(SEQ ID NO:4)
mAON#6:
5′ GTTATCTGCTTCTTCCAGCC
(SEQ ID NO:5)
mAON#7:
5′ CTTTTAGCTGCTGCTC
(SEQ ID NO:6)
mAON#8:
5′ GTTGTTCTTTTAGCTGCTGC
(SEQ ID NO:7)
mAON#9:
5′ TTAGCTGCTGCTCAT
(SEQ ID NO:8)
mAON#10:
5′ TTTAGCTGCTGCTCATCTCC
(SEQ ID NO:9)
mAON#11:
5′ CTGCTGCTCATCTCC
(SEQ ID NO:10)
hAON#4:
5′ CTGCTTCCTCCAACC
(SEQ ID NO:11)
hAON#6:
5′ GTTATCTGCTTCCTCCAACC
(SEQ ID NO:12)
hAON#8:
5′ GCTTTTCTTTTAGTTGCTGC
(SEQ ID NO:13)
hAON#9:
5′ TTAGTTGCTGCTCTT
(SEQ ID NO:14)
hAON#11:
5′ TTGCTGCTCTTTTCC
(SEQ ID NO:15)
Gel Mobility Shift Assays
[0047] The efficacy of the AONs is determined by their binding affinity for the target sequence. Notwithstanding recent improvements in computer simulation programs for the prediction of RNA-folding, it is difficult to speculate which of the designed AONs would be capable of binding the target sequence with a relatively high affinity. Therefore, we performed gel mobility shift assays (according to protocols described by Bruice et al., 1997). The exon 46 target RNA fragment was generated by in vitro T7-transcription from a PCR fragment (amplified from either murine or human muscle mRNA using a sense primer that contains the T7 promoter sequence) in the presence of 32P-CTP. The binding affinity of the individual AONs (0.5 μmol) for the target transcript fragments was determined by hybridization at 37° C. for 30 minutes and subsequent polyacrylamide (8%) gel electrophoresis. We performed these assays for the screening of both the mouse and human-specific AONs ( FIG. 3 ). At least 5 different mouse-specific AONs (mAON#4, 6, 8, 9 and 11) and four corresponding human-specific AONs (hAON#4, 6, 8, and 9) generated a mobility shift, demonstrating their binding affinity for the target RNA.
[0000] Transfection into Muscle Cell Cultures
[0048] The exon 46-specific AONs which showed the highest target binding affinity in gel mobility shift assays were selected for analysis of their efficacy in inducing the skipping in muscle cells in vitro. In all transfection experiments, we included a non-specific AON as a negative control for the specific skipping of exon 46. As mentioned, the system was first set up in mouse muscle cells. We used both proliferating myoblasts and post-mitotic myotube cultures (expressing higher levels of dystrophin) derived from the mouse muscle cell line C2C12. For the subsequent experiments in human-derived muscle cell cultures, we used primary muscle cell cultures isolated from muscle biopsies from one unaffected individual and two unrelated DMD patients carrying a deletion of exon 45. These heterogeneous cultures contained approximately 20-40% myogenic cells. The different AONs (at a concentration of 1 μM) were transfected into the cells using the cationic polymer PEI (MBI Fermentas) at a ratio-equivalent of 3. The AONs transfected in these experiments contained a 5′ fluorescein group which allowed us to determine the transfection efficiencies by counting the number of fluorescent nuclei. Typically, more than 60% of cells showed specific nuclear uptake of the AONs. To facilitate RT-PCR analysis, RNA was isolated 24 hours post-transfection using RNAzol B (CamPro Scientific, The Netherlands).
RT-PCR and Sequence Analysis
[0049] RNA was reverse transcribed using C. therm. polymerase (Roche) and an exon 48-specific reverse primer. To facilitate the detection of skipping of dystrophin exon 46, the cDNA was amplified by two rounds of PCR, including a nested amplification using primers in exons 44 and 47 (for the human system), or exons 45 and 47 (for the mouse system). In the mouse myoblast and myotube cell cultures, we detected a truncated product of which the size corresponded to exon 45 directly spliced to exon 47 ( FIG. 4 ). Subsequent sequence analysis confirmed the specific skipping of exon 46 from these mouse dystrophin transcripts. The efficiency of exon skipping was different for the individual AONs, with mAON#4 and #11 showing the highest efficiencies. Following these promising results, we focused on inducing a similar modulation of dystrophin splicing in the human-derived muscle cell cultures. Accordingly, we detected a truncated product in the control muscle cells, corresponding to exon 45 spliced to exon 47. Interestingly, in the patient-derived muscle cells, a shorter fragment was detected, which consisted of exon 44 spliced to exon 47. The specific skipping of exon 46 from the human dystrophin transcripts was confirmed by sequence data. This splicing modulation of both the mouse and human dystrophin transcript was neither observed in non-transfected cell cultures nor in cultures transfected with a non-specific AON.
Immunohistochemical Analysis
[0050] We intended to induce the skipping of exon 46 in muscle cells from patients carrying an exon 45 deletion in order to restore the translation and synthesis of a dystrophin protein. To detect a dystrophin product upon transfection with hAON#8, the two patient-derived muscle cell cultures were subject to immunocytochemistry using two different dystrophin monoclonal antibodies (Mandys-1 and Dys-2) raised against domains of the dystrophin protein located proximal and distal of the targeted region respectively. Fluorescent analysis revealed restoration of dystrophin synthesis in both patient-derived cell cultures ( FIG. 5 ). Approximately at least 80% of the fibers stained positive for dystrophin in the treated samples.
[0051] Our results show, for the first time, the restoration of dystrophin synthesis from the endogenous DMD gene in muscle cells from DMD patients. This is a proof of principle of the feasibility of targeted modulation of dystrophin pre-mRNA splicing for therapeutic purposes.
Targeted Skipping of Exon 51
Simultaneous Skipping of Dystrophin Exons
[0052] The targeted skipping of exon 51. We demonstrated the feasibility of AON-mediated modulation of dystrophin exon 46 splicing, in mouse and human muscle cells in vitro. These findings warranted further studies to evaluate AONs as therapeutic agents for DMD. Since most DMD-causing deletions are clustered in two mutation hot spots, the targeted skipping of one particular exon can restore the reading frame in series of patients with different mutations (see Table 1). Exon 51 is an interesting target exon. The skipping of this exon is therapeutically applicable in patients carrying deletions spanning exon 50, exons 45-50, exons 48-50, exons 49-50, exon 52, and exons 52-63, which includes a total of 15% of patients from our Leiden database.
[0053] We designed a series of ten human-specific AONs (hAON#21-30, see below) directed at different purine-rich regions within dystrophin exon 51. These purine-rich stretches suggested the presence of a putative exon splicing regulatory element that we aimed to block in order to induce the elimination of that exon during the splicing process. All experiments were performed according to protocols as described for the skipping of exon 46 (see above). Gel mobility shift assays were performed to identify those hAONs with high binding affinity for the target RNA. We selected the five hAONs that showed the highest affinity. These hAONs were transfected into human control muscle cell cultures in order to test the feasibility of skipping exon 51 in vitro. RNA was isolated 24 hours post-transfection, and cDNA was generated using an exon 53- or 65-specific reverse primer. PCR-amplification of the targeted region was performed using different primer combinations flanking exon 51. The RT-PCR and sequence analysis revealed that we were able to induce the specific skipping of exon 51 from the human dystrophin transcript. We subsequently transfected two hAONs (#23 and #29) shown to be capable of inducing skipping of the exon into six different muscle cell cultures derived from DMD-patients carrying one of the mutations mentioned above. The skipping of exon 51 in these cultures was confirmed by RT-PCR and sequence analysis ( FIG. 7 ). More importantly, immunohistochemical analysis, using multiple antibodies raised against different parts of the dystrophin protein, showed in all cases that, due to the skipping of exon 51, the synthesis of a dystrophin protein was restored.
[0054] Exon 51-specific hAONs:
[0000]
hAON#21:
5′ CCACAGGTTGTGTCACCAG
(SEQ ID NO:16)
hAON#22:
5′ TTTCCTTAGTAACCACAGGTT
(SEQ ID NO:17)
hAON#23:
5′ TGGCATTTCTAGTTTGG
(SEQ ID NO:18)
hAON#24:
5′ CCAGAGCAGGTACCTCCAACATC
(SEQ ID NO:19)
hAON#25:
5′ GGTAAGTTCTGTCCAAGCCC
(SEQ ID NO:20)
hAON#26:
5′ TCACCCTCTGTGATTTTAT
(SEQ ID NO:21)
hAON#27:
5′ CCCTCTGTGATTTT
(SEQ ID NO:22)
hAON#28:
5′ TCACCCACCATCACCCT
(SEQ ID NO:23)
hAON#29:
5′ TGATATCCTCAAGGTCACCC
(SEQ ID NO:24)
hAON#30:
5′ CTGCTTGATGATCATCTCGTT
(SEQ ID NO:25)
Simultaneous Skipping of Multiple Dystrophin Exons
[0055] The skipping of one additional exon, such as exon 46 or exon 51, restores the reading frame for a considerable number of different DMD mutations. The range of mutations for which this strategy is applicable can be enlarged by the simultaneous skipping of more than one exon. For instance, in DMD patients with a deletion of exon 46 to exon 50, only the skipping of both the deletion-flanking exons 45 and 51 enables the reestablishment of the translational reading frame.
ERS-Independent Exon Skipping
[0056] A mutation in exon 29 leads to the skipping of this exon in two Becker muscular dystrophy patients (Ginjaar at al., 2000, EJHG, vol. 8, p. 793-796). We studied the feasibility of directing the skipping of exon 29 through targeting the site of mutation by AONs. The mutation is located in a purine-rich stretch that could be associated with ERS activity. We designed a series of AONs (see below) directed to sequences both within (h29AON#1 to h29AON#6) and outside (h29AON#7 to h29AON#11) the hypothesized ERS. Gel mobility shift assays were performed (as described) to identify those AONs with highest affinity for the target RNA ( FIG. 8 ). Subsequently, h29AON#1, #2, #4, #6, #9, #10, and #11 were transfected into human control myotube cultures using the PEI transfection reagent. RNA was isolated 24 hrs post-transfection, and cDNA was generated using an exon 31-specific reverse primer. PCR-amplification of the targeted region was performed using different primer combinations flanking exon 29. This RT-PCR and subsequent sequence analysis ( FIGS. 8B and 8C ) revealed that we were able to induce the skipping of exon 29 from the human dystrophin transcript. However, the AONs that facilitated this skipping were directed to sequences both within and outside the hypothesized ERS (h29AON#1, #2, #4, #6, #9, and #11). These results suggest that skipping of exon 29 occurs independent of whether or not exon 29 contains an ERS and that, therefore, the binding of the AONs to exon 29 more likely inactivated an exon inclusion signal rather than an ERS. This proof of ERS-independent exon skipping may extend the overall applicability of this therapy to exons without ERS's.
[0000]
h29AON#1:
5′ TATCCTCTGAATGTCGCATC
(SEQ ID NO:26)
h29AON#2:
5′ GGTTATCCTCTGAATGTCGC
(SEQ ID NO:27)
h29AON#3:
5′ TCTGTTAGGGTCTGTGCC
(SEQ ID NO:28)
h29AON#4:
5′ CCATCTGTTAGGGTCTGTG
(SEQ ID NO:29)
h29AON#5:
5′ GTCTGTGCCAATATGCG
(SEQ ID NO:30)
h29AON#6:
5′ TCTGTGCCAATATGCGAATC
(SEQ ID NO:31)
h29AON#7:
5′ TGTCTCAAGTTCCTC
(SEQ ID NO:32)
h29AON#8:
5′ GAATTAAATGTCTCAAGTTC
(SEQ ID NO:33)
h29AON#9:
5′ TTAAATGTCTCAAGTTCC
(SEQ ID NO:34)
h29AON#10:
5′ GTAGTTCCCTCCAACG
(SEQ ID NO:35)
h29AON#11:
5′ CATGTAGTTCCCTCC
(SEQ ID NO:36)
AON-Induced Exon 46 Skipping In Vivo in Murine Muscle Tissue.
[0057] Following the promising results in cultured muscle cells, we tested the different mouse dystrophin exon 46-specific AONs in vivo by injecting them, linked to polyethylenimine (PEI), into the gastrocnemius muscles of control mice. With mAON#4, #6, and #11, previously shown to be effective in mouse muscle cells in vitro, we were able to induce the skipping of exon 46 in muscle tissue in vivo as determined by both RT-PCR and sequence analysis ( FIG. 9 ). The in vivo exon 46 skipping was dose-dependent with highest efficiencies (up to 10%) following injection of 20 μg per muscle per day for two subsequent days.
REFERENCES
[0000]
Achsel et al., 1996 , J. Biochem. 120, pp. 53-60.
Bruice T. W. and W. F. Lima, 1997 , Biochemistry 36(16): pp. 5004-5019.
Brunak at al., 1991 , J. Mol. Biol. 220, pp. 49-65.
Dunckley M. G. et al., 1998 , Human molecular genetics 7, pp. 1083-1090.
Ginjaar et al., 2000 , EJHG, vol. 8, pp. 793-796.
Mann et al., 2001 , PNAS vol. 98, pp. 42-47.
Tanaka et al., 1994 , Mol. Cell. Biol. 14, pp. 1347-1354.
Wilton S. D., et al., 1999 , Neuromuscular disorders 9, pp. 330-338.
Details and background on Duchenne Muscular Dystrophy and related diseases can be found on website WorldWideWeb.dmd.nl | Described is a method for at least in part decreasing the production of an aberrant protein in a cell, the cell comprising pre-mRNA comprising exons coding for the protein, by inducing so-called exon skipping in the cell. Exon-skipping results in mature mRNA that does not contain the skipped exon, which leads to an altered product of the exon codes for amino acids. Exon skipping is performed by providing a cell with an agent capable of specifically inhibiting an exon inclusion signal, for instance, an exon recognition sequence, of the exon. The exon inclusion signal can be interfered with by a nucleic acid comprising complementarity to a part of the exon. The nucleic acid, which is also herewith provided, can be used for the preparation of a medicament, for instance, for the treatment of an inherited disease. | 2 |
REFERENCE TO RELATED APPLICATIONS
This application claims one or more inventions which were disclosed in Provisional Application No. 61/102,088, filed 2 Oct. 2008, entitled “APPARATUS AND METHOD FOR REDUCING TORQUE IN A COMPOUND BALANCE”. The benefit under 35 USC §119(e) of the United States provisional application is hereby claimed, and the aforementioned application is hereby incorporated herein by reference.
FIELD OF THE INVENTION
The invention pertains to the field of compound window balances. More particularly, the invention pertains to a device and method for connecting the extension spring of a compound balance to the torsion spring/spiral rod sub-assembly.
BACKGROUND OF THE INVENTION
Vertically sliding window assemblies are also known as hung windows and may consist of either a single sash or two sashes, respectively referred to as single hung or double hung windows. A hung window assembly generally includes a window frame, at least one sash, a pair of opposing window jambs, each jamb having a channel for allowing the vertical travel of each sash, and at least one window balance to assist with the raising and lowering of the sash to which it is attached by providing a force to counterbalance the weight of the sash.
Springs are utilized to provide the counterbalancing force and are especially useful for operating very heavy sashes. Compound balances are preferred for facilitating the operation of these very heavy sashes. In compound balances, a torsion spring provides a lifting force over the full travel of the sash through the jamb channel. The torsion spring force is converted into a lifting force by extending an elongated spiral rod. The torsion spring and elongated spiral rod are surrounded by an extension spring. Alternative designs have the sub-assembly encapsulated within a containment tube. It is desirable to have the combined axial forces of the torsion spring of the sub-assembly and extension spring provide substantially constant lifting force over the full vertical travel of the compound balance. The compound balance has an open end, from which the free end of the spiral rod extends, and a closed end, which is securely fastened to the wall of the jamb channel of the window frame.
The open end of the compound balance sub-assembly is often capped by a rotatable coupling having a central opening through which the elongated spiral rod extends. When the free end of the spiral rod is attached to a window sash, depending on the direction of vertical movement required to open the window, the spiral rod is either substantially fully extended or substantially fully retracted into the balance. In a double hung window design, the upper sash moves in a downward direction to open that portion of the window while the lower sash moves upwardly to open that respective portion of the window.
In tilting window sashes, the free end of the spiral rod connects to a shoe or carrier which traverses up and down the jamb channel of the window assembly with the sash. The window sash and window balance are linked together via a shoe or carrier.
Alternatively, the free end of the spiral rod may attach directly to the sash itself. In this case, a clip is securely attached to the end of the spiral rod. The conventional means of attaching the clip to the spiral rod includes the use of a rivet or an interference fit clip.
Especially with respect to windows having large, very heavy sashes, it is highly desirable to design a balance that provides the most lifting assistance. If the torsion spring exhibits too much torsional force, then the window operator must overcome the surplus frictional force caused by the torsional forces upon the carrier moving through the jamb channel. It is very desirable therefore to eliminate or substantially limit the amount of torque transferred from the compound balance to the connecting hardware. A reduction in the transfer of this torque lowers the lifting force required and therefore facilitates the raising and/or lowering of the sash.
SUMMARY OF THE INVENTION
An apparatus and method substantially canceling out the torsional force exerted on the spiral rod by the torsion spring so that the force on the spiral rod of a compound balance is substantially in a state of equilibrium and exhibits either no or very limited torque which would otherwise result in added frictional forces that increases the amount of energy needed to raise and lower the sash.
In embodiments of the present invention, an extension spring, co-axial with and surrounding the spiral rod sub-assembly is wound a number of turns to create a torque that opposes the torque imposed on the spiral rod by the torsion spring. The extension spring is preferably attached to the spiral rod either by an assembly connector attached to the end of the extension spring or a multi-angled series of bends in proximity to the end of the extension spring which provides for its attachment to the spiral rod by a pin or small rod. With the extension spring secured to the spiral rod, the extension spring is prohibited from unwinding when torque from the torsion spring of the spiral rod sub-assembly is applied. The attachment means functions to maintain the torsional force provided by the extension spring. This cancels out the torsional force of the torsion spring acting on the spiral rod with the opposing torsional force of the extension spring.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows two cross-sectional views of a conventional compound balance inner sub-assembly, each view 90 degrees opposed from the other.
FIG. 1B shows two cross-sectional views of the compound balance of the present disclosure where the extension spring encapsulates the inner sub-assembly.
FIG. 2A shows an isometric view of an assembly connector in an embodiment of the present disclosure.
FIG. 2B shows a side plan view of the assembly connector of FIG. 2A .
FIG. 2C shows an isometric view of the assembly connector of FIG. 2A having internally configured ramp elements for interaction with locking elements on the spiral rod.
FIG. 2D shows a cross-sectional view of the assembly connector of FIG. 2A showing approximately one half of the segments of the internally configured ramp elements.
FIG. 3 shows an isometric view of an assembly connector having externally configured ramp elements.
FIG. 4A shows an assembly connector, the spiral rod, and the extension spring secured to the assembly connector.
FIG. 4B shows a cross-section of the assembly connector of FIG. 4A with elements of the spiral rod engaging the internally configured ramp elements of the assembly connector.
FIG. 5 shows an isometric view of an assembly connector with a lock.
FIG. 6 shows an isometric view of the assembly connector of FIG. 5 separated from a progressively tapered internal sleeve located within the assembly connector.
FIG. 7 shows an isometric view of an assembly connector in which a slot rather than a round hole provides the opening through which the end of the spiral rod extends.
FIG. 8 shows a plan view of an assembly connector in which the end of the extension spring is configured to interact with a pin or small rod to connect the extension spring to the spiral rod.
FIG. 9 shows a plan view of the assembly connector of FIG. 8 as viewed along line A-A of FIG. 8 .
FIG. 10 shows an isometric view of the assembly connector of FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1A , the inner sub-assembly of a conventional compound window (or sash) balance is shown in 90° opposed views. The combination of the spiral rod 10 and the torsion spring 14 are conventionally referred to as the “inner” sub-assembly 1 . It includes at least a spiral rod 10 having a first end 12 that extends from a first end 20 of the inner sub-assembly 1 . The spiral rod 10 is secured to a spiral shaped torsion spring 14 within the inner sub-assembly 1 . The torsion spring 14 may be either encapsulated by an optional containment tube 16 or it may remain non-encapsulated. FIG. 1A shows the sub-assembly encapsulated by a containment tube 16 . Nonetheless, whether a containment tube 16 is present or not, an extension spring 18 encapsulates either the containment tube 16 , if present, or the torsion spring 14 (see FIG. 1B ) to form a compound balance 2 . In the present invention, the direction of the turns applied to the torsion spring 14 and the extension spring 18 are preferably opposite each other in order to provide the balance manufacturer with the ability to cancel out opposing torsional forces acting on the spiral rod 10 . The more these opposing forces are canceled out, the less friction exists within the window system and the more lifting assistance is provided to help the operator move the sash (not shown) either up or down. In conventional compound balances, there are no (counter torque) turns applied to the extension spring 18 to create an opposite torsional force that substantially cancels out the opposing torsional force of the torsion spring acting on the spiral rod 10 .
The first end 12 of the inner sub-assembly 1 extends out of the first end 20 of the compound balance 2 . The second end 22 of the inner sub-assembly 1 is non-permanently secured to an internal anchoring means 23 , as shown in FIGS. 1A and 1B . The second end 22 of the compound balance 2 is firmly secured to a wall of the jamb channel (not shown) by means of a screw, rivet or locking pin inserted through hole 27 . As the first end 12 of the inner sub-assembly 1 is extended, the torsional force of the torsion spring 14 is transferred to the spiral rod 10 . Although the torsional force is intended to provide a progressively increasing axial force along the axis of the balance and the jamb channel of the window frame to retract the spiral rod 10 into the inner sub-assembly, thereby assisting the operator with the vertical movement of the sash, this torsional force also creates substantial friction, especially at the interface between the carrier to which the spiral rod is attached and the jamb channel of the window frame. This is counterproductive with respect to the goal of achieving easy movement of the sash.
In some embodiments of the present disclosure, an assembly connector 100 , as shown in several variations in FIG. 2A through FIG. 7 , transfers the torsional force of the extension spring to the spiral rod. The assembly connector substantially alleviates the undesired transfer of the torsionally induced friction from the torsion spring of the inner sub-assembly 1 to other components of the window assembly.
These counterproductive torsionally induced frictional forces are substantially eliminated by use of the assembly connector 100 ( FIG. 2A-FIG . 7 ). FIG. 2A shows an isometric view of the assembly connector 100 . It includes an extension spring attachment portion 102 , a bore 104 through which the first end 12 of the spiral rod 10 extends, a hole 101 through which a spiral rod pin 24 (see FIGS. 1A and 1B ) may be inserted, and an adjustment portion 106 . In FIGS. 2A , 5 , 6 and 7 , the adjustment portion 106 is shown as being hexagonally shaped. However, any suitable geometric configuration may be used so long as it achieves the desired objective which is to provide a means to rotate or hold the assembly connector 100 while the extension spring 18 is being rotated. The unattached or first end 108 of the extension spring 18 is spun onto the threads of the extension spring attachment portion 102 , which can be designed to accommodate either a right or left hand turned extension spring.
In a method of assembling the first embodiment of the present invention, the spiral rod 10 is rotated, which creates a torsional force maintained by the torsion spring 14 . Then, the spiral rod 10 is allowed to retract into the inner sub-assembly 1 to be seated within the internal anchoring means 23 ( FIGS. 1A and 1B ) to prevent further rotation until the spiral rod 10 is extended during use. Next, a counter torque is applied to the extension spring 18 by turning it in a direction opposite from the direction of the turns applied to the spiral rod of the inner sub-assembly 1 . In one variation, the assembly connector 100 is attached to the extension spring 18 and the turns are then applied to the assembly connector 100 . In another variation, the turns on the extension spring 18 may be applied prior to engagement with the assembly connector 100 . The preferred means of attachment is by first securing the extension spring 18 onto the extension spring attachment portion 102 of the assembly connector 100 . This is preferably performed by turning or “screwing” the first end 108 of the extension spring 18 onto threads formed on the exterior of the extension spring attachment portion 102 (see FIG. 4A ).
Another method of assembling the compound balance of the invention involves rotating the extension spring attachment portion 102 of the assembly connector 100 axially in a direction that is opposite from the pretension rotations applied to torsion spring 14 . The spiral rod pin 24 ( FIGS. 4B , 5 and 6 ) is then inserted through hole 101 in the assembly connector 100 to maintain the torque applied to the extension spring 18 . FIGS. 2A and 2B show two locations for hole 101 . However, these images are provided to show alternate locations for this hole. Only one hole 101 is necessary to receive spiral rod pin 24 .
As noted earlier, a compound balance of the invention can be assembled with a non-pretensioned inner sub-assembly. In this case, the extension spring is turned to contain more torque than would be needed under normal operating conditions so that when the connector 100 is secured to the rod 10 by insertion of spiral rod pin 24 and the rod is disengaged from the pretension anchor 23 , the spiral rod 10 rotates, thereby winding the torsion spring 14 in an opposite direction from the turns applied to the extension spring 18 to a point where the torsional forces between the torsion spring 14 and the extension spring 18 substantially cancel out each other. In this manner, the excess torque of the extension spring 18 is transferred to the inner subassembly 1 , winding the torsion spring 14 until the opposing torsional forces of the extension spring and the torsion spring substantially cancel out the undesired torsional force acting on the spiral rod 10 .
Another method of assembling the compound balance involves rotating the extension spring attachment portion 102 of the assembly connector 100 axially in a direction that is opposite from the pretension rotations already applied to the spiral rod 10 . The assembly connector 100 is seated against the pin retaining portion 26 (see FIGS. 2C and 2D ) via spiral rod pin 24 . The pin retaining portion 26 , best shown in FIGS. 2C and 2D , includes two diametrically opposed hemi-spherically shaped ramps 28 that guide the spiral rod pin 24 to a seat portion 30 . Once the spiral rod pin 24 of the spiral rod 10 is secured within seat portion 30 , the torque applied to the extension spring 18 is maintained. If assembled properly, the pretension torque applied to the torsion spring 14 (by turning the spiral rod 10 ) is cancelled out by the torsional forces applied to the extension spring 18 . If further adjustment is necessary, due to the ease of moving the spiral rod pin along ramps 28 , the assembly connector 100 may be further turned until the opposing torsional forces between the torsion spring 14 of the inner sub-assembly 1 and that of the extension spring 18 are substantially cancelled out.
A first variation of the assembly connector 100 is shown in FIG. 3 . The primary difference between the embodiment shown in FIGS. 2A-2D and that shown in FIG. 3 is that the variation of FIG. 3 shows the ramped pin retaining portion 26 ′ being located external to the main body of the assembly connector 100 . The spiral rod pin 24 is retained against seat portion 32 . Otherwise, the external ramped pin retaining portion 26 ′ embodiment of FIG. 3 operates essentially the same as does the internal pin retaining portion 26 of the embodiment shown in FIGS. 2C and 2D .
A second variation of the assembly connector 100 is shown in FIGS. 5 and 6 . In this variation, a sleeve 34 is non-permanently interference fitted between the spiral rod 10 and the assembly connector 100 . Referring specifically to FIG. 6 , the outer diameter of the sleeve 34 is tapered so that the outer diameter gradually decreases as it approaches the end 12 of the spiral rod 10 . The distal end (opposite the adjustment portion 106 ) of the assembly connector 100 contains at least one “paired” diametrically opposed “U” shaped notches 26 ″. The preferred number of “U” shaped notches is two, which, of course would engage only one spiral rod pin 24 . The increasing outer diameter of the sleeve 34 provides for a progressively increasing interference fit between the sleeve 34 and the inner diameter of the assembly connector 100 . The assembly connector 100 of this variation permits the non-permanent engagement between “U” shaped notches 26 ″ and the spiral rod pin 24 to maintain substantial equilibrium between the respective torsional forces of the torsion spring 14 and the extension spring 18 .
A slight modification of the assembly connector 100 of FIGS. 2A-2D is shown in FIG. 7 . Referring back to FIG. 5 , this embodiment of the assembly connector 100 exhibits a circular hole that allows for the easy passage therethrough of a spiral rod 10 containing rod pins 40 . These rod pins 40 are used for engagement with a hook or similar device for attachment to an edge of the window sash. FIG. 7 shows a bore slot 38 designed to accommodate the size of the spiral rod 10 only. During assembly, the counter torque is first applied to the extension spring 18 and then the bore slot 38 of the assembly connector 100 is aligned with the spiral rod 10 . The assembly connector 100 is then allowed to slip over the spiral rod 10 . Of course, rod pins 40 must be installed onto the spiral rod 10 after the assembly connector 100 is installed onto the compound balance 2 because they will not fit through the bore slot 38 . Once all elements of the compound balance 2 are returned to their resting states, the torsional forces between the torsion spring 14 and the extension spring 18 substantially cancel out each other.
A second embodiment of the attachment means of the invention is shown in FIGS. 8 , 9 and 10 . It includes configuring the final windings 119 , which are located at the first end 108 of extension spring 18 , so as to create two “U” shaped seats, a first seat 126 and a second seat 126 ′ ( FIG. 10 ). These two seats are designed to retain a pin 124 that is secured to spiral rod 10 . When the torsional forces between the torsion spring (not shown in these Figures) and the extension spring 18 substantially cancel out each other, the pin 124 is inserted through a hole 128 in proximity to the first end 12 of the spiral rod 10 and the pin is then urged into the “U” shaped seats 126 and 126 ′. The pin 124 maintains continuity between the torsional forces of the torsion spring (via the spiral rod 10 ) and the torsional forces of the extension spring 18 . Now that the torsional forces of the torsion spring and the extension spring have substantially canceled out each other, the compound balance 2 may be installed into the jamb channel of a window frame.
Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention. | A method and apparatus for reducing the torque of a compound balance in order to substantially cancel out the torsional force of the torsion spring acting on the spiral rod by creating an equal and opposing torsional force on the extension spring. The apparatus is an assembly connector that is non-permanently engaged with the extension spring, with the spiral rod being tensioned by the torsional force of the torsion spring. Alternatively, the extension spring may be turned in a direction to apply more torque than is required for operation of the compound balance. It is then engaged with a non pre-tensioned spiral rod sub-assembly to transfer the excess torque to the torsion spring of the spiral rod sub-assembly. In this manner, the opposing torsional forces of the torsion spring and the extension spring acting on the spiral rod substantially cancel out each other. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an object detecting system in an automatic focusing camera having a macro-photographing function.
2. Description of Related Art
There is known an automatic focusing camera in which a zoom photographing optical system is automatically moved to a focus point in accordance with distance data which are detected by an object distance measuring device based on a triangulation measuring principle. The zoom photographing optical system is also moved, at least partially, by a predetermined amount in the macro-photographing mode (i.e., for photographing objects at a close distance).
For instance, FIG. 7 schematically shows a simple optical arrangement of a known two-group zoom lens which forms the zoom photographing optical system. In the arrangement shown in FIG. 7, the object distance U between the focal point F of the entire two-group zoom lens and an object to be photographed is given by the following equation:
U=f.sub.1 (2+X/f.sub.1 +f.sub.1 /X)+HH+Δ (1)
wherein
X: feed displacement of the zoom photographing lens
f 1 : focal length of the first lens group 1
HH: principal point distance of the first lens group 1
Δ: distance between the focal point F 1 of the first lens group 1 and the focal point F
From the equation (1), the displacement can be expressed as: ##EQU1##
Note that in FIG. 7, the second lens group is designated 2, and H and H' designate principal points of the first lens group 1.
FIG. 8 shows a conventional object distance measuring optical system based on the triangulation measuring principle, in which 3 designates a light source, 4 a position detecting element, such as a PSD (photo sensitive detector), 5 a light projecting lens, and 6 a light receiving lens. In this measuring optical system, the light emitted from the light source 3 is reflected by the object, so that the reflected light, which is the distance measuring light, is received by the position detecting element 4 to detect the object distance. The relationship between the distance U of the object from a film plane 7 and a deviation t of the light on the position detecting element 4 is given by the following equation:
t=L·f/(U-f-d) (3)
wherein
L: base length between the light emitting lens 5 and the light receiving lens 6
f: focal length of the light receiving lens 6
d: distance between the film plane 7 and the focal plane of the light receiving lens 6
Note that a reference position in which the deviation t is zero (t=0) is a point on the position detecting element on which an image of the light source is focused at an infinite object distance (∞).
The deviation t can be detected by a value of the electrical current to which the amount of light received by the position detecting element 4 is converted, as is well known. The zoom photographing optical system is moved to the focal point in accordance with the value of the electrical current, on the basis of the above-mentioned equations (2) and (3) to effect automatic focusing. A drive mechanism for such a zoom photographing optical system in an automatic focusing camera is well known.
In the automatic focusing camera, it is necessary to shift the range of measurement of the object distance toward a close object distance side to enable the macrophotographing function.
In the close photographing function, at least a part of the zoom photographing optical system is moved further toward the object from an extreme focal length in the normal photographing mode, so that the focusing operation can be effected, as is well known. In the zoom photographing optical system shown in FIG. 7, the first lens group 1 of the photographing lens system is moved by a constant displacement independently of the displacement which is caused by the automatic focusing device.
FIG. 9 shows a known optical arrangement in which the distance range which can be measured by the distance measuring device is shifted toward the close distance side. As shown in FIG. 9, a prism 8 having an apex angle of θ and a mask (not shown) are retractably located in front of the light receiving lens 6, so that the measurable distance range can be shifted toward the close distance side.
Supposing that the refractive index of the prism 8 is n, the deviation t 1 of the image of the light source on the position detecting element 2 in connection with the object distance U 1 can be obtained by the following steps.
The mask mentioned above is provided on the front face of the prism 8 and has an aperture center coaxial to the optical axis l 1 .
First, the incident angle α of the light P 1 upon the surface S 1 of the prism 8 adjacent to the object is determined by the following equation:
α=tan.sup.-1 {L/(U.sub.1 -f-d)}θ (4)
The refraction angle β of the light P 1 incident upon the prism 8 having an apex angle θ at an incident angle αis given by the following equation.
β=α-θ+sin.sup.-1 [n·sin {θ-sin.sup.-1 (sin α/n)}] (5)
For γ=α-θ-β, the deviation t 1 on the position detecting element 4 with the apex angle θ satisfies the following equation:
t.sub.1 =f·tanγ (6)
Accordingly, the deviation t 1 of the image of the light source on the position detecting element 4 can be obtained by the equations (5) and (6).
If the object distance at which the light meeting with the optical axis l 1 of the light receiving lens 6 intersects the optical axis l 2 of the light emitting lens 5 is Umf 1 , and if the thickness of the prism 8 is neglected, the following equation is obtained:
Umf.sub.1 =L/tan {sin.sup.-1 (n·sinθ)-θ}+f+d (7)
For a photographing optical system composed of a two-group zoom lens, Table 1 shows the calculation results in which the focal length f 1 of the first lens group 1 is f 1 =24.68 mm, the principal point distance HH=7.02 mm, the distance Δ between the focal point F 1 of the first lens group and the focal point F of the two-group zoom lens is Δ=30.04 mm, the distance d between the film plane 7 and the focal plane of the light receiving lens 6 is d=6.292 mm, the shift displacement of the first lens group 1 at the close photographing mode is 0.5502 mm, the base length L of the distance measuring device is L=30 mm, the focal length f of the light receiving lens 6 is f=20 mm, the apex angle θ of the prism 8 is θ=2.826°, the refractive index n of the prism is n=1.483 (wavelength=880 nm), the measurable distance range is 0.973 m˜∞, the number of steps of forward feeding movement is 18 among which the range of 0.973 m˜6 m is divided into 17 steps. The calculation is directed to the shift of the range of 0.973 m˜6 m to the range of 0.580 m˜1.020 m.
In the table, 17-18 designates the transfer point between the 17th step and the 18th step and 0-1 a transfer point between zero and the 1st step. In Table 1, the deviation t was obtained from the equation (3) and the deviation t 1 was obtained from the equations (4), (5), and (6).
TABLE 1______________________________________COMPARISON OF POSITIONS OF IMAGE OFLIGHT SOURCE ON POSITION DETECTING ELEMENTAT DIFFERENT DISTANCES IN NORMALPHOTOGRAPHING MODE AND CLOSE PHOTOGRAPHINGMODE WITH PRIOR ART APPARATUS DIFF. INSTEP STEPNO. U(m) U.sub.1 (m) t(mm) t.sub.1 (mm) t.sub.1 -t(mm) (STEP)______________________________________17-18 6.000 1.020 0.1004 0.1274 0.0270 +0.81817 5.154 0.996 0.1170 0.1423 0.0253 +0.76716 4.027 0.951 0.1500 0.1719 0.0219 +0.67015 3.310 0.911 0.1827 0.2013 0.0186 +0.57114 2.814 0.875 0.2153 0.2305 0.0153 +0.47413 2.450 0.841 0.2476 0.2595 0.0120 +0.37412 2.172 0.810 0.2797 0.2884 0.0087 +0.27411 1.952 0.782 0.3115 0.3170 0.0055 +0.17410 1.775 0.756 0.3432 0.3455 0.0023 +0.0739 1.628 0.732 0.3747 0.3738 -0.0009 -0.0298 1.504 0.709 0.4059 0.4018 -0.0041 -0.1327 1.399 0.688 0.4369 0.4298 -0.0072 -0.2336 1.309 0.668 0.4678 0.4575 -0.0103 -0.3375 1.230 0.650 0.4984 0.4850 -0.0134 -0.4414 1.161 0.633 0.5288 0.5124 -0.0165 -0.5453 1.100 0.616 0.5591 0.5396 -0.0195 -0.6502 1.045 0.601 0.5891 0.5666 -0.0225 =0.7551 0.996 0.587 0.6189 0.5934 -0.0255 -0.8560-1 0.973 0.580 0.6338 0.6068 -0.0270 -0.906______________________________________ Umf.sub.1 = 1.283 m
From the results shown in Table 1, it can be understood that the adjustment by the prism 8 using the measuring light Which passes through the aperture of the mask coaxial to the optical axis l 1 causes a deviation of 0.027 mm on the position detecting element 4 at the extremities of the measurable distance range in the close photographing mode. This deviation corresponds to about 1 step in terms of the number of feeding steps of movement. Therefore, if the feeding movement of the photographing optical system is controlled directly in accordance with the output of the position detecting element 4, it is impossible to move the photographing lens to a correct focal point, resulting in it being out of focus. For example, in the macro-photographing mode at U 1 =0.996 m, if the deviation t 1 is 0.1170 mm, the zoom photographing lens can be moved to a correct focal point. However, since the actual deviation t 1 is 0.1423 mm, the zoom photographing lens cannot be moved beyond the 16th step, so that the zoom photographing lens cannot be exactly focused. This is because that, in a measuring optical system using a measuring light which passes through the aperture center of the mask coaxial to the optical axis l 1 , it is impossible to largely change the variation of the deviation t 1 of the image of the light source on the position detecting element 4 relative to the object distance U 1 .
To solve the problem mentioned above, the assignee of the present application has proposed a focus adjusting device for increasing the precision of the adjustment of the focus at the macro-photographing mode, in PCT Patent Application No. PCT/JP87/00293. In this prior application, a prism which has two total reflection surfaces and a mask are provided to substantially increase the measuring base length L in order to adjust the focus, so that the difference in deviation of the image of the light source on the position detecting element 4 between the normal photographing mode and the macro-photographing mode can be limited to approximately 0.0001 mm.
In the aforementioned application, it was found that complete compensation for the difference in deviation between the normal photographing mode and the macro-photographing mode can be achieved if the rate of deviation t 1 is adjusted by multiplying this rate by 1.1130 (calculated by dividing 0.5334 by 0.4794), which equals the change in t from step 0-1 to step 17-18 divided by the change in t 1 between step 0-1 and step 17-18, since decreases in the deviations t and t 1 between steps 17-18 and 0-1 are 0.5334 mm and 0.4794 mm, respectively. The prism arrangement used in the application provides that compensation.
However, in the prior application, since a prism having two total reflection surfaces is used, there are drawbacks as follows.
First, a strict tolerance for the angular dimension of the prism is necessitated.
Second, in order to ensure a large quantity of light, it is necessary to use a large prism or to use a plurality of prisms, resulting in a large optical system difficult to operate.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a simple apparatus for adjusting a focus in the macro-photographing mode in an automatic focusing camera which can increase the precision of the adjustment in comparison with the conventional focus adjusting apparatus in which the measuring light is coaxial with the optical axis of the light receiving lens.
According to the present invention, there is provided an apparatus for adjusting the focus in the macro-photographing mode of an automatic focusing camera having a triangulation measuring principle type of object distance measuring optical system. This system includes a light emitter which emits measuring light and a light receiver which receives the measuring light reflected by an object to be photographed to output distance data, and a zoom photographing optical system which is moved to the focal point thereof in accordance with the distance data and which is, in the macro-photographing mode, at least partially moved by a predetermined displacement beyond an extreme focal point in the normal photographing mode. The apparatus further includes a mask which has an aperture, the center of which is offset from the optical axis of the object distance measuring optical system, and a mechanism for deflecting the measuring light which passes through the aperture of the mask toward the light receiver. The mask and the deflecting mechanism are retractably located in front of the light receiver in the macro-photographing mode.
It is a further object of the present invention to provide an object distance measuring optical system positioned along an optical axis; a measuring light emitting source for directing measuring light toward an object; a device for receiving the measuring light reflected by the object; a mask adapted to be located between the object and the measuring light emitting source with an aperture located in the mask adapted to permit the measuring light to pass therethrough, with the aperture having a center which is offset from the optical axis; and a device for deflecting the measuring light which passes through the aperture. The device for receiving the measuring light includes a light receiving lens positioned along the optical axis.
In another aspect of the present invention, the measuring light receiving device further includes a light position detecting element positioned to detect light received from the light receiving lens.
In another aspect of the present invention, the measuring light receiving device further includes a prism having a single light receiving surface.
It is a further object of the present invention to provide a focus adjusting apparatus for a camera which incorporates the object distance measuring optical system mentioned above wherein the light position detecting element is adapted to generate an output signal for moving at least a portion of a photographic optical system of the camera.
In another object of the present invention, the focus adjusting apparatus is intended for a camera which further includes a zoom photographing optical system which includes at least two lens groups, wherein the output signal from the light position detecting element is adapted to move at least one of the lens groups.
In a still further object of the present invention, the focus adjusting apparatus is intended for a camera wherein the zoom photographing optical system further includes means to enable focusing in a macro-photographing mode.
In a still further object of the present invention, the mask and the measuring lighty deflecting device are retractable from a position adjacent the light receiving lens, which position they are occupy during the macro-photographing mode.
In a still further object of the present invention, the mask and the measuring light deflecting device are integral.
In a still further object of the present invention, the mask and the measuring light deflecting device are connected by an adhesive.
In a still further object of the present invention, the measuring light deflecting device is a prism having a surface through which the measuring light is received, and wherein the mask is located on the prism light receiving surface.
In a still further object of the present invention, the measuring light deflecting device is a prism having a surface through which the measuring light is emitted, and wherein the mask is located on the prism light emitting surface.
It is also an object of the present invention to provide an object distance measuring optical system which includes a measuring light emitter for emitting measuring light toward an object, the distance from which is to be measured, and a measuring light receiving lens positioned along the optical axis of the optical system, and which is adapted to receive only reflected measuring light from the object in which the reflected measuring light is not coaxial with the optical axis as the measuring light is received by the measuring light receiving lens.
It is a further object of the present invention to further provide a mask having an aperture therethrough, wherein the mask is adapted to be positioned adjacent the measuring light receiving lens so that the aperture is offset from the optical axis.
It is a further object of the present invention to further provide a measuring light deflecting device adapted to be positioned adjacent the measuring light receiving lens and the mask and between the measuring light receiving lens and the object.
It is a still further object of the invention to provide a focus adjusting apparatus for a camera, wherein the apparatus incorporates the object distance measuring optical system set forth above, wherein the mask and the measuring light deflecting device are retractable from the position adjacent the measuring light receiving lens, wherein the mask blocks measuring light from being received by the measuring light receiving lens along the optical axis, to a position wherein the mask blocks substantially no measuring light from being received by th measuring light receiving lens.
It is a still further object of the present invention to further provide at least one photographic lens for the focus adjusting apparatus, and wherein the measuring light receiving device further includes a light position detecting element which is adapted to generate a signal for moving the at least one photographic lens to thereby focus the photographing optical system.
It is a still further object of the present invention to provide an automatic focus adjusting apparatus for a camera which includes a zoom photographing optical system adapted for operation in a normal photographing mode and a close photographing mode, wherein at least a portion of the zoom photographing optical system is moved a predetermined amount for operation in the close photographing mode, wherein the apparatus includes a light source for emitting measuring light toward an object to be photographed; a measuring light receiving lens positioned along an optical axis adapted to receive measuring light reflected from the object to be photographed; a light position detection element adapted to receive measuring light from the measuring light receiving lens and to detect thereupon a deviation of the measuring light depending upon the distance between the object and a predetermined point on the camera; a mask adapted to be moved to a position adjacent the measuring light receiving lens when the camera is set for operation in the close photographing mode and adapted to be retracted from the position when the camera is set for operation in the normal photographing mode, the mask including at least one aperture offset from the optical axis; and a measuring light deflecting device adapted to be located adjacent the mask and the measuring light receiving lens; whereby the apparatus further includes a predetermined number of feed movement measurement steps for focusing the camera in both the normal photographing mode and the close photographing mode between predetermined ranges of object distances, respectively, and wherein the deviation detected by the light position detection element at each of the steps when the camera is set at the normal photographing mode is substantially the same as the deviation detected by the light position detection element at each of the steps when the camera is set at the close photographing mode.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be described below with reference to the accompanying drawing, in which:
FIG. 1 is a schematic view illustrating the optical path of an apparatus for adjusting the focus in the macro-photographing mode of an automatic focusing camera according to the present invention;
FIG. 2 is an enlarged schematic view of a mask and a prism shown in FIG. 1;
FIG. 3 is a schematic view illustrating particular details of the apparatus shown in FIG. 1;
FIGS. 4A and 4B are front elevation views of different apertures formed in the mask shown in FIG. 1;
FIG. 5 is a schematic view illustrating the optical principle of the focus adjusting apparatus according to the present invention;
FIG. 6 is an, enlarged view of FIG. 5; and
FIGS. 7, 8 and 9 are schematic views of a known focus adjusting apparatus in an automatic focusing camera illustrating different optical systems.
DETAILED DESCRIPTION
FIGS. 5 and 6 illustrate the principle of the present invention. With regard to the light which is transmitted through the light receiving lens 6 of the distance measuring optical system and which is incident upon the light receiving surface 4S of the position detecting element 4, when the object is located at the infinite distance, the light rays P 2 which are transmitted through the center of the light receiving lens 6 on the optical axis l 1 , and which are incident upon the position detecting element 4, and the light rays P 3 which are transmitted through the portion of the light receiving lens 6 other than the optical axis (center point of the lens 6), and which are incident upon the position detecting element 4, are both accurately imaged on a point Q 1 of the light receiving surface 4S on the optical axis l 1 . However, when the object is at a closer distance, the light rays P 2 passing through the center of the lens 6 (on the optical axis l 1 ) and the light rays P 3 off from the center of the lens 6 are imaged on different points Q 2 , Q 3 , and Q 4 which are deviated from the optical axis l 1 and which are not included in the light receiving surface 4S. The deviation becomes large as the object distance becomes small.
As can be seen from FIG. 6, the intersecting points 0 1 of the light rays P 2 with the light receiving surface 4S are different from the intersecting points 0 2 of the light rays P 3 with the light receiving surface 4S. The light rays P 3 are always located farther from the optical axis l 1 than the light rays P 2 which pass through the center of the lens 6. The deviation (separation) of the light from the optical axis increases as the object comes closer, as mentioned above.
The PSD which is usually used as the position detecting element 4 can detect the position, so long as the light receiving surface 4S receives a quantity of light above a predetermined lower limit. Namely, even if the light rays which are transmitted through the light receiving lens 6 are not correctly imaged on points of the light receiving surface 4S, the object distance can be detected at the incident points.
According to the present invention, the light which is transmitted through the center of the light receiving lens 6 on the optical axis l 1 and which is incident upon the position detecting element 4 is not used to detect the object distance, and only the light which does not pass through the center of the lens 6 is used as a measuring light to effectively utilize the position detecting element 4 so as to exactly detect the object distance. This will be explained in more detail with reference to FIG. 6.
In FIG. 6, as the object moves from the infinite object distance (the longest distance at the macro-photographing mode) to a closer distance, the points upon which the light P 2 and the light P 3 are imaged are moved from Q 1 to Q 4 . If the distance is measured by using the light P 2 , the deviation of the incident point 0 1 of the light upon the receiving surface 4S of the position detecting element 4 is B 1 . On the other hand, if the light P 3 is used to detect the object distance, the deviation of the incident point 0 2 of the light upon the receiving surface 4S of the position detecting element 4 is B 2 which is clearly larger than B 1 (B 2 >B 1 ). Namely, the variation of the light P 3 incident upon the position detecting element 4 with respect to the variation of the object distance is larger than that of the light P 2 , thus resulting in an increase of the measuring efficiency and accordingly an accurate measurement. The present invention is based on the aforementioned optical principle.
In FIGS. 1 to 4 which show an embodiment of the present invention, the elements corresponding to those in FIGS. 8 and 9 are designated with the same reference numerals.
One of the significant features of the present invention resides in the provision of the prism 8 and the mask 9 which are brought in front of the light receiving lens 6 of the distance measuring optical system in the macro-photographing mode. The mask 9 has an aperture (opening) 10 which has a center axis 0 3 which is offset from the optical axis of the light receiving lens 6 in the macro-photographing mode.
The distance d ec between the center axis 0 3 of the aperture 10 and the optical axis l 1 of the light receiving lens 6 is preferably as large as possible, as mentioned above. However, in practice, the distance d ec is properly determined, taking the size and the optical efficiency of the prism 8 into consideration. The aperture 10 can be a slit 10A (FIG. 4A) or a pin-hole 10B (FIG. 4B). The slit lOA extends in a direction perpendicular to the base length of the position detecting element 4. The size of the slit 10A or pin-hole 10B is such that the quantity of light which passes therethrough to be incident upon the position detecting element 4 is large enough to output the distance signal.
Preferably, the prism 8 and the mask 9 are located on the opposite side of the optical axis l 1 to the light emitting lens 5 so as to effectively utilize the length (especially, the upper half) of the position detecting element 4, when the prism and the mask are inserted in front of the light receiving lens 6 at the macro-photographing mode.
Preferably, the mask 9 and the prism 8 are integrally interconnected by means of, for example, an adhesive 40 (FIG. 2) therebetween. No adhesive 40 is located at a portion corresponding to the aperture 10 of the mask 9.
It is also possible to hold the mask and the prism together by means of a holding tool or any other equivalent means (not shown).
The mask 9 is located on the side of the prism that is located far from the light receiving lens 6. Alternatively, it is also possible to put the mask 9 on the side of the prism 8 that is located close to the light receiving lens 6, as shown by an imaginary line 9' in FIG. 2.
Preferably, the mask 9 and the prism 8 can move between a retracted position as shown in phantom lines in FIG. 1, in which they are not in use, and an inserted position in which the center axis 0 3 of the aperture 10 is located at a distance d ec from the optical axis l 1 of the light receiving lens 6.
Supposing that the apex angle of the prism 8 is θ 1 , the refractive index is n, the deviation (distance) between the center axis 0 3 of the aperture 10 of the mask 9 and the optical axis l 1 of the light receiving lens 6 is d ec , the deviation t 2 of the image of the light on the position detecting element 4 with respect to the object distance U 2 can be determined by the following steps, with reference to FIGS. 1 and 2.
In FIGS. 1 and 2, the optical path R 1 shown by a solid line designates the measuring light which is reflected by a furthest object (light source image). The path R 1 reaches the position detecting element 4 at a point on the optical axis l 1 of the light receiving lens 6. The path R 1 is parallel with the optical axis l 1 between the prism 8 and the light receiving lens 6. The optical path R 2 shown in phantom lines designates the light which is reflected by a closer object. The thinner solid lines in FIG. 2 show extensions of the optical paths R 1 and R 2 .
The incident angle l 1 of the light R 2 upon the surface S of the prism 8 adjacent to the object side is obtained by the following equation.
α=tan.sup.-1 {(L+d.sub.ec)/(U.sub.2 -f-d)} (8)
This equation indicates that the base length of the triangulation distance increasing device is extended from L to L+d ec .
The refraction angle β 1 of the light which is incident upon the prism 8 having an apex angle θ 1 at an incident angle α 1 is given by the following equation.
β.sub.1 =α.sub.1 -θ.sub.1 +sin.sub.-1 [n·sin {θ.sub.1 -sin.sup.-1 (sin α.sub.1 /n)}]
Accordingly, an angle θ 2 (θ 2 =α 1 -β 1 ) between the light R 2 emitted from the prism 8 and the center axis l 1 of the light receiving lens 6 is given by the following equation.
θ.sub.2 =θ.sub.1 -sin.sup.-1 [n·sin {θ.sub.1 -sin .sup.-1 (sin α.sub.1 /n)}]
On the other hand, γ 1 =tan -1 (d ec /f), γ 2 =γ 1 -θ 2 f'=d ec /tan γ 2 , δ=f'-f.
Accordingly, the deviation t 2 (=δ×tan γ 2 ) of the image of the light source on the position detecting element 4 can be obtained by the aforementioned equations.
Umf 2 is an object distance at which the light R 1 emitted from the prism 8 is parallel with the optical axis l 1 of the light emitting lens 6, namely, when the image of the light source on the position detecting element 4 is located at the center of the light receiving lens 6, and is given by the following equation, when the thickness of the prism 8 and the distance between the prism 8 and the light receiving lens 6 are neglected:
Umf.sub.2 =[(L+d.sub.ec)/tan [sin.sup.-1 {n·sin(θ.sub.1 -sin.sup.-1 (sinθ.sub.1 /n))}]]+f+d
Table 2 shows, by way of an example, the calculation results in which the focal length f 1 of the first lens group is f 1 =24.68 mm, the principal point distance HH=7.02 mm, the distance Δ between the focal point F 1 of the first lens group and the focal point F of the entire two-group zoom lens is Δ=30.04 mm, the distance d between the film plane 7 and the focal plane of the light receiving lens is d=6.292 mm, the shift displacement of the first lens group at the close photographing mode is 0.5502 mm, the base length L of the distance measuring device is L=30 mm, the focal length f of the light receiving lens is f=20 mm, the apex angle of the prism 8 is θ 1 =3.361°, the refractive index n of the prism 8 is n=1.483, the deviation dec of the aperture center of the mask 9 from the optical axis l 1 of the light receiving lens 6 is d ec =3 mm, the measurable distance range is 0.973 m˜∞, the number of steps of movement is 18 among which the range of 0.973 m ˜6 m is divided into 17 steps. The calculation is directed to the shift of the range of 0.973 m˜6 m to the range of 0.580 m˜1.020 m. The numerical conditions are same as those of Table 1 mentioned above.
TABLE 2______________________________________COMPARISON OF POSITIONS OF IMAGE OFLIGHT SOURCE ON POSITION DETECTING ELEMENTAT DIFFERENT DISTANCES IN NORMALPHOTOGRAPHING MODE AND CLOSE PHOTOGRAPHINGMODE WITH PRESENT INVENTION DIFF. INSTEP STEPNO. U(m) U.sub.2 (m) t(mm) t.sub.2 (mm) t.sub.2 -t(mm) (STEP)______________________________________17-18 6.000 1.020 0.1004 0.1005 0.0001 -0.04517 5.154 0.996 0.1170 0.1171 0.0001 -0.04216 4.027 0.951 0.1500 0.1500 0 -0.01815 3.310 0.911 0.1827 0.1827 0 -0.01214 2.814 0.875 0.2153 0.2152 -0.0001 -0.02513 2.450 0.841 0.2476 0.2475 -0.0001 012 2.172 0.810 0.2797 0.2796 -0.0001 +0.01611 1.952 0.782 0.3115 0.3115 0 +0.01310 1.775 0.756 0.3432 0.3432 0 +0.0109 1.628 0.732 0.3747 0.3746 -0.0001 +08 1.504 0.709 0.4059 0.4059 0 +0.0267 1.399 0.688 0.4369 0.4369 0 +0.0306 1.309 0.668 0.4678 0.4677 -0.0001 +0.0495 1.230 0.650 0.4984 0.4984 0 +0.0304 1.161 0.633 0.5288 0.5288 0 +0.0173 1.100 0.616 0.5591 0.5591 0 +0.0672 1.045 0.601 0.5891 0.5891 0 +0.0501 0.996 0.587 0.6189 0.6190 0.0001 +0.0230-1 0.973 0.580 0.6338 0.6338 0 +0.027______________________________________ Umf.sub.2 = 1.190 m
It can be seen from Table 2 that according to the resent invention the measurement difference between the normal photographing mode and the close photographing mode is restricted to less than ±0.1 step, and that the deviation of the images on the position detecting element at different steps between the normal photographing mode and the macro-photographing mode will be within ±0.0001 mm. Thus, in the present invention, the accuracy of measurement at the macro-photographing mode can be increased in comparison with the prior art in which the aperture center 0 3 meets with the optical axis l 1 of the light receiving lens 6, so that the light passing through the aperture 10 of the mask 9 is used to detect the object distance. Furthermore, according to the present invention, since only the mask 9 (together with the prism 8, if integral therewith) is moved so that the aperture center 0 3 thereof is deviated from the optical axis l 1 , the apparatus of the present invention can be easily manufactured and operated. As can be seen from FIG. 3, upon assembling and adjusting the apparatus of the invention, when at least one of the prism 8 and the mask 9 is moved toward the base length (in the direction shown by an arrow H), the focus point M is displaced in the optical axis direction, so that the image of the light source on the position detecting element 4 is displaced accordingly so as to easily adjust the focus.
Also, according to the present invention, since the prism 8 does not have two total reflection surfaces, unlike the prior art, no strict angular tolerance of the prism is necessitated, resulting in an easy adjustment thereof. Preferably, the prism 8 and the mask 9 are integral with each other after they are adjusted in position.
As can be understood from the above discussion, according to the focus adjusting apparatus of the present invention, since the light which is incident upon a portion of the light receiving lens different from the optical axis thereof and which is emitted from a portion of the light receiving lens different from the optical axis thereof is used as the measuring light so as to adjust the focus at the macro-photographing mode, the object distance can be easily and accurately measured by the focus adjusting apparatus of the present invention with a small and simple prism.
Although the invention has been described with reference to particular means and embodiments, it is to be understood the invention is not limited to the particulars disclosed and extends to all equivalents within the scope of the claims. | An apparatus for adjusting the focus in the macro-photographing mode of an automatic focusing camera. The apparatus includes an object distance measuring optical system further including a light emitting lens of a measuring light reflected by an object, a zoom photographing optical system which is moved to the focal point thereof in accordance with the distance data of the light receiving lens and which is, in the macro-photographing mode, at least partially moved by a predetermined amount beyond an extreme focal length in the normal photographing mode, a mask which has an aperture having a center which is offset from the optical axis of the object distance measuring optical system and a prism for deflecting the measuring light which passes through the aperture of the mask toward the light receiver. The mask and the deflecting means are retractably located in front of the light receiver in the macro-photographing mode. | 6 |
FIELD OF THE INVENTION
The invention relates to methods and apparatus for mounting a roller shaft in the frame of a roller conveyor in order to reduce motion of the shaft and the sound which is produced thereby.
BACKGROUND OF THE INVENTION
A conveyor roller is mounted on a shaft which traditionally is hexagonal in cross-section. The simplest method of mounting a roller shaft to a conveyor frame is to form a mounting aperture such as a slot or a hexagonal hole in the frame which will receive the shaft. It is also traditional to position the hex shaft in the mounting aperture with the points of the shaft facing up and down, although it is known that in some constructions the points of the shaft face side-to-side.
The shaft is generally loose in the mounting aperture and vibration of the roller causes the shaft to bounce, causing noise and wear on both the shaft and the aperture. Over time, the wear from shaft vibration results in enlargement of the mounting aperture, creating an even looser fit between the shaft and the frame and generating even more noise. Eventually, the shaft vibration causes the frame to cut through the roller shaft, resulting in the roller dropping out of the frame.
It would accordingly be desirable to modify the mounting of a roller shaft in a conveyor frame to minimize the vibration of the shaft in the frame and thereby lessen the noise which is produced and the wear which occurs on both the shaft and the frame.
SUMMARY AND OBJECTS OF THE INVENTION
According to the invention, the mounting of a roller shaft in a conveyor frame is modified to tighten the fit between the shaft and the frame. This is accomplished by either modifying the roller shaft or using an additional member which has the effect of restricting the relative motion between the shaft and the frame. In one embodiment, the portion of the shaft which mounts in the frame is tapered or a tapered cap is fitted onto the end of the shaft, so that in the final mounting position, the shaft fits tightly in the frame thus greatly reducing relative motion between the shaft and the frame. In other embodiments, an insert or washer is used to control the motion of the shaft in the frame and thus reduce any relative motion therebetween. In all of the embodiments, the reduced motion reduces the generation of noise and the amount of wear on both the roller shaft and the frame.
It is accordingly an object of the invention to provide an improved mounting for a roller shaft in the frame of a conveyor.
It is another object of the invention to provide a mounting for a roller shaft in a conveyor frame which reduces the vibration of the shaft during conveyor operation.
It is another object of the invention to provide a mounting for a roller shaft in a conveyor frame which reduces the vibration of the shaft in the frame and thus lessens the noise which is produced during conveyor operation.
It is still another object of the invention to provide a modified roller shaft which will fit tightly into the shaft mounting hole to reduce the vibration and noise which is produced during conveyor operation.
It is yet a further object of the invention to provide an insert which restricts the motion of a roller shaft in a conveyor frame to lessen the sound which is produced and the wear which occurs during conveyor operation.
These and other objects of the invention will become apparent from the following detailed description in which reference numerals used throughout the description correspond to numerals found on the drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a prior art conveyor roller mounted in a conveyor frame.
FIG. 2 shows a first embodiment of the invention in which one end of the roller shaft is tapered.
FIG. 3 shows a tapered shaft end mounted in a six sided hole.
FIG. 4 shows a tapered shaft end mounted in a round hole.
FIG. 5 shows a second embodiment of the invention utilizing a roller shaft having a tapered end.
FIG. 6 shows another embodiment of the invention in which a plastic cone is placed on the end of the roller shaft.
FIG. 7 shows another embodiment of the invention in which a plastic bushing is used to mount the roller shaft in the conveyor frame.
FIGS. 8 and 9 are end and top views respectively of the bushing of FIG. 7.
FIG. 10 shows a further embodiment of the invention in which a resilient washer is used between one end of the conveyor roller and the conveyor frame.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a conveyor roller mounted in a conveyor frame according to the prior art is generally designated by the reference numeral 10. The conveyor roller comprises an outer cylindrical shell 12 which is mounted on a hexagonal roller shaft 14 by means of bearings 16. The bearings 16 are press-fit into the ends of the roller shell 12 but are slip fit onto the hexagonal roller shaft 14. One end of the roller includes a compression spring 17 which is mounted between one of the bearings 16 and an interference nick 18 formed on the roller shaft. A second interference nick 19 on the other end of the roller shaft acts as a stop for the second bearing 16 and prevents the shaft from being removed from the roller. The shaft 14 is mounted in hex hole apertures 22 which are formed in the conveyor side frame members 21. The side frame members 21 are held in a spaced relationship by a spreader bar 24. In order to mount the roller shaft between the two frame members 21, the end 26 of the shaft 14 having the compression spring 17 is first placed into one of the apertures 22. The second end 27 of the shaft is then pressed against the bias of the spring 17 until the second end clears the inside edge 23 of the frame 21. The second end 27 is aligned with the left aperture 22 and then released whereby the bias of the spring 17 causes the second end 27 to extend through the second aperture 22. Those skilled in the art will recognize that once the roller is fully inserted in the frame members 21, the spring is no longer under compression and therefore exerts no force. If removal of the roller shaft from the conveyor frame is later required for repair or inspection purposes, the opposite procedure is used to first remove the second end 27 of the roller shaft from the frame member 21 by pushing the second end 27 against the bias of the spring 17. After the second end clears the inside edge 23 of the frame member, the first end 26 of the shaft may be removed from the other aperture 22 by displacing the conveyor roller toward the second end 27.
Turning now to FIG. 2, a first embodiment of the invention is shown in which the end of the roller shaft 14 which is opposite the biasing spring is formed with a taper 30. No portion of the taper 30 has a radial cross-sectional dimension which is greater than the radial cross-sectional dimension of the shaft 14. The mounting hole 32 in the frame which receives the taper 30 is smaller than the cross section of the non-tapered portion of the shaft 14 so that the taper 30 will fit tightly in the hole 32. The end 26 of the shaft which is adjacent the biasing spring 17 is not tapered and mounts into a standard size hex hole 22.
The conveyor roller of FIG. 2 is mounted in the conveyor frame in the same manner as the prior art roller of FIG. 1. The end 26 of the roller shaft adjacent the spring 17 is placed in the mounting hole 22 in one side frame member 21 and the tapered end 30 is then pressed against the bias of the spring 17 until the end 30 clears the inside edge 23 of the other frame member 21. The tapered end 30 of the shaft is then aligned with the mounting hole 32 on the conveyor frame 21 and released to allow the spring 17 to force the taper into the mounting hole 32. The spring 17 remains under compression and presses the tapered end 30 snugly into the hole 32 when the roller is in its final position between the side members 21. This snug fit greatly reduces vibration and motion of the shaft 14 in both holes 22 and 32. Using this embodiment, the vibration energy is reduced by a factor of 1000, and results in the generation of less noise and less wear.
It should be noted that both the tapered end of the shaft 14 and the mounting hole which receives it may have any number of shapes. FIG. 3 shows a hexagonal tapered end 30 in a hexagonal hole 32. FIG. 4 shows a hexagonal tapered end 30 in a round hole 33. Those skilled in the art will recognize that other complimentary or interfering shape patterns may be used for the tapered shaft end and mounting hole.
FIG. 5 shows another embodiment of the invention in which an enlarged tapered end 34 is formed on the shaft 14 by a cold forming operation. The enlarged tapered end 34 is preferably hexagonal in cross section and has a portion with a radial cross-sectional dimension which is greater than the radial cross-sectional dimension of the shaft 14. Using this method, the aperture 22 which is formed in the conveyor side member 21 may be standard size but still snugly engaged by the tapered end 34 of the shaft since the shaft end is enlarged from its normal size. As in the previous embodiment, the mounting hole 22 and the enlarged tapered end 34 may be complimentary shapes such as hexagonal or interfering shape combinations.
FIG. 6 shows a variation of the embodiment of FIG. 3 in which a plastic cone 35 is fit onto the end of the roller shaft 14. The plastic cone may be hexagonal in cross section to mate with a standard hex hole 22. The plastic cone 35 which has a portion with a radial cross-sectional dimension which is greater than the radial cross-sectional dimension of the roller shaft 14 allows a standard size roller shaft to be used with a standard size hex hole 22 while obtaining a tight fit between the tapered surface of the cone and the sides of the hole. The outer surface of the cone 35 and the mounting hole 22 may be the same shape, such as hexagonal, or may have any number of interfering shape combinations, such as hexagonal and round, or other combination as desired.
Turning now to FIGS. 7-9, another embodiment of the invention is shown in which a plastic bushing 36 is used to mount a roller shaft in a conveyor frame. The bushing 36 comprises a body 37 with two latching legs 38 and two tapered legs 40 which are attached thereto. The body 37 and the inner surface of the legs 38 and 40 form a six-sided bore 42 which will receive a hexagonal roller shaft. The latching lees 38 are formed with a latch 39 which engages the side of the frame member 21 to prevent withdrawal of the bushing once it has been pressed into a mounting hole 22. The tapered legs 40 are formed with a taper 41 on the outer surface thereof which causes the tapered lees 40 to squeeze together and reduce the size of the bore 42 as the bushing is pressed into the mounting hole. As shown in FIG. 8, each tapered leg 40 is "V" shaped to engage two sides of the mounting hole 22.
In order to use the bushing, a roller shaft 14 is first mounted between two frame members 21 in the conventional way. The bushing is then slipped over the end of the shaft 14 which extends through the frame member and pressed into the hex hole 22. The tapered outer surface 41 of the tapered legs 40 cause them to squeeze together and grip the roller shaft as the bushing is pressed to its final position. Once the latches 39 on the latching legs 38 are pressed through the hole, the latches 39 catch on the inner side 43 of the frame member to hold the bushing in place.
The gripping action of the tapered legs 40 on the roller shaft greatly reduces vibration of the shaft and any noise which may be produced thereby. It has been seen that this embodiment reduces vibration energy by a factor of 100. The bushing 36 itself eliminates the metal on metal contact between the shaft 14 and the mounting hole 22. The bushing 36 may be formed of conductive nylon or other material which exhibits the required wear characteristics and allows the static charge which builds up on the rollers to be bled off to ground. In the preferred embodiment, two bushings 36, one on each end of the roller shaft, are used to mount each roller to the frame members.
FIG. 10 shows another embodiment of the invention in which a bias is created between the roller bearings 16 and the frame members 21 by putting a compliant washer 45 on one end 46 of the roller shaft 14. The compliant washer 45, which may be urethane or other suitable material, is compressed as the roller is mounted between the frame members 21. Once the roller has been mounted, the opposite end 47 of the roller is pressed against the frame by the washer 45. The bias caused by the compliant washer 45 reduces vibration of the roller shaft 14 in the hex holes 22. It has been seen that this embodiment reduces vibration energy by a factor of 100. The bearings are dimensioned so that only the inner race 48 of each bearing presses against the compliant washer 45, or the opposite side frame member 21, as the case may be. As a result, the compliant washer does not restrict the rotation of the roller shell 12 which is supported on the outer race 49 of each bearing. This embodiment works equally well whether the side members 21 are provided with hex holes 22 or slots 50, as shown, to receive the roller shaft 14.
Having thus described the invention, various alterations and modifications will occur to those skilled in the art, which alterations and modifications are intended to be within the scope of the invention as defined by the appended claims. | The mounting for a roller shaft in the frame of a conveyor is designed to reduce the vibration of the shaft and the sound produced during conveyor operation. In several embodiments, the end of the shaft is provided with a taper, and a spring which is internal to the roller is used to bias the taper into the mounting hole. The resulting tight fit of the taper in the hole greatly reduces the vibration energy of the shaft. In another embodiment, a bushing separates the shaft and the hole and is designed to grip the shaft as it is pressed into place in the hole. | 1 |
CROSS-REFERENCES TO CO-PENDING APPLICATIONS
Co-pending application Ser. No. 735,452, filed on May 17, 1985, entitled "Adjustable Hydraulic Shock Absorber", which corresponds to Federal Republic of Germany Application No. P 34 18 262.4, filed May 17, 1984; co-pending application Ser. No. 778,606 filed on Sept. 20, 1985, entitled "Hydraulic Adjustable Shock Absorber", which corresponds to Federal Republic of Germany Application No. P 34 34 877.8, filed Sept. 22, 1984, for which U.S. application the issue fee was paid for on Nov. 3, 1986; co-pending application Ser. No. 772,316 filed on Sept. 4, 1985, entitled "Hydraulic Vibration Damper Having Adjustable Damping Valve", which corresponds to Federal Republic of Germany Application No. P 34 32 465.8, filed Sept. 4, 1984; co-pending application Ser. No. 864,451 filed on May 16, 1986, entitled "Adjustable Hydraulic Vibration Damper", which corresponds to Federal Republic of Germany Application No. P 35 18 327.6, filed May 22, 1985; and co-pending application Ser. No. 915,265, filed on Oct. 3, 1986, entitled "A Vibration Damper for Motor Vehicles Having an Arrangement for Varying Damping Thereof", which corresponds to Federal Republic of Germany Application No. P 35 35 287.6, filed Oct. 3, 1985, all of which are assigned to at least one of the same assignees as the instant application, are incorporated herein by reference as if the texts thereof were fully set forth herein.
Additionally, issued U.S. Pat. Nos. 4,635,765, issued Jan. 13, 1987, entitled "Adjustable Hydraulic Damper Apparatus" and 4,577,840, issued Mar. 25, 1986, entitled "Self-pumping Hydropneumatic Spring Leg or Strut With Internal Level Control For Motor Vehicles", both relate to similar subject matter as the instant application, are assigned in common with the instant application and are incorporated herein by reference as if the texts thereof were fully set forth herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an adjustable shock absorber, particularly for use with motor vehicles, which includes a cylinder containing damping fluid, a piston rod which projects into the cylinder in a sealed manner and moves axially, and a piston attached to the piston rod and dividing the cylinder into two working chambers, the shock absorber being provided with at least one passage producing a damping force, the effective cross section of which can be adjusted by a throttle valve.
2. Description of the Prior Art
German Laid Open Patent Application DE-OS No. 21 19 531 relates to a hydraulic adjustable shock absorber well known in the prior art in which there is a first damping element, plus a line equipped with a control valve. There is also a control valve and a damping element in a closed circuit, always separately located. The control valve is set manually or by the action of one of the vehicle mechanisms. One disadvantage of devices of this type is that they are difficult to manufacture from a production engineering point of view, due to the line and due to the components being arranged in series. Additionally, the mechanical activation produces a certain damping force, such that reliable variability in the different damping characteristics cannot be achieved.
German Patent Publication Published for Opposition Purposes DE-AS No. 12 42 945 relates to another hydraulic shock absorber well known in the prior art, the damping characteristics of which can be adjusted by changing the flow of the hydraulic damping medium electromagnetically by means of a damping valve. In this device, there are two bypass connections, the first of which is generally used to regulate the damping force in the decompression stage, as opposed to the compression stage. A disadvantage of this configuration is that there is no provision for regulating the compression stage, and such a regulation is not possible in this design.
German Laid Open Patent Application DE-OS No. 33 34 704 relates to known prior art shock absorbers having a control apparatus to regulate the damping valves in the damping piston. By means of an electromagnetic drive, a return force is produced on the throttle valve. Additionally, there is a supporting hydraulic compensation apparatus reinforcing this return force. A disadvantage of this configuration is that the force produced by the fluid pressure is not applied directly to the throttle element, but via a supporting body, necessitating a seal, which produces friction and which, therefore, interferes with the opening and closing action of the valve, or else produces a significant oil leakage flow.
All of the aforementioned patents are incorporated by reference as if the entire contents thereof were fully set forth herein.
OBJECTS OF THE INVENTION
A principal object of the present invention is the provision, in an adjustable hydraulic shock absorber, of a simple control apparatus which can be used to control the damping force, and which exhibits an opening and closing action free of friction and, therefore, free of hysteresis and oil leakage losses, and which consumes a reduced amount of control energy.
A further object of the invention is the provision of an adjustable shock absorber having a high switching speed and which does not exhibit the effects of hysteresis.
A still further object of the invention is the provision of an adjustable shock absorber having a continuous and reproducible control characteristic and provided with a valve which exhibits precisely defined opening characteristics.
An even further object of the invention is the provision of such an adjustable shock absorber having a control system contained within the damping piston.
SUMMARY OF THE INVENTION
This object is achieved through the provision of a bypass, which includes an actuator mechanism controlling a passage in which a flexible membrane is housed in a chamber, such that, on one side of the membrane, at least one inflow hole and at least one discharge hole of the passage can be closed off from one another by the membrane and a control edge (or valve seat) interacting with the membrane, and that on the opposite side of the membrane, a control chamber is formed which is sealed off from the passage and which forms a portion of a control bypass.
One advantage of this configuration is that a pilot valve is used to control and regulate the damping medium, which valve has a self-supplied pilot stage. The pressure difference which produces the damping force is thereby used in the chambers for the adjustment of the damping force.
The membrane of the valve, as a result of its prestress and spring constant, and as a result of the surface and pressure ratios on the two sides of the membrane, assumes precisely defined opening distances with respect to the control edge (or valve seat). Another advantage is that, due to the low weight of the membrane, high switching speeds can be achieved, and the elimination of seal friction and a hysteresis-free opening and closing action becomes possible, along with a simultaneous elimination of oil leakage losses. Moreover, the presence of the membrane not only makes possible the open and closed positions, but also, a continuous and reproducible control characteristic.
These advantages are achieved by the membrane which is placed in the chamber so that on one side of the membrane, at least one inflow hole and at least one discharge hole of the passage can be closed off from one another by means of the membrane and a control edge (or valve seat) interacting with the membrane, and that on the other side of the membrane, a control chamber is formed which carries the control bypass flow and is sealed off from the passage.
A pressure within the limits determined by the pressures in the working chambers can be set in this control chamber by controlling the quantity of damping medium flowing in and/or out. Consequently, a force which determines the opening characteristic of the valve is exerted on the valve membrane over the pressurized surface of the valve. The difference pressure acting on the membrane is produced because an annular surface on the one side of the membrane is pressurized by the pressure from the inflow holes, and starting at the control chamber, the control bypass pressurizes the entire membrane on the opposite side. Depending on the position of the actuator mechanism, a relatively high pressure then builds up in the control chamber, so that when the membrane separates from the control edge, there is a connection between the inflow holes and the discharge holes.
According to another feature of the invention, the passage is a bypass connecting the working chambers, or the passage is formed by equipping each of the holes of the piston in the decompression and/or compression stage with a throttle valve. An advantage here is that the system can be used in the damping piston itself or, with the assistance of a bypass and the corresponding control bypass, as a connection of the two working chambers in a one-tube shock absorber or of one working chamber and the equalization chamber in a two-tube shock absorber.
A particularly favorable embodiment provides that at least a portion of the control bypass exhibits a cross section which is smaller than the cross section of all the inflow holes of the passage. An advantage of this embodiment is that the reduced cross section of the control bypass admits only the quantity of fluid necessary to increase the control pressure in the chamber, and the remaining volume of the damping medium must all flow via the passage.
To vary the pressure in the control chamber, an adjustable valve is provided as an actuator mechanism. Well known pressure regulators of the prior art, such as proportional valves or several miniaturized 2/2-way valves or timed and pulse-width-modulated 2/2-way valves, can be used.
Preferably, the membrane is at least one metal disc, which is clamped in the middle. The membrane can also be advantageously supported in the central portion on the side opposite the control chamber. In one embodiment, the metal disc is prestressed. The membrane thereby seals the chambers off from one another, and as a result of the contact with the control edge (or valve seat), different annular surfaces pressurized by different pressures are formed. In addition, the axial prestress of the metal disc itself is used to set the variable opening action.
Advantageously, it is possible to determine the force-velocity characteristic of the shock absorber by means of the throttle cross section, i.e., the axial distance which the membrane separates from the control edge (or valve seat).
In addition to the diameter ratios of the control edge and outside diameter of the membrane, which are determined by the design, the precise adjustment capabilities of the pressure ratio between the pressure in the inflow hole and the pressure in the control chamber can also be varied accordingly, along with the spring constant of the elastic membrane appropriate to the characteristic of the damping force adjustment required.
The ratio of the control pressure in the control chamber to the damping pressure can be determined by varying the surface ratio of the inflow cross section to the discharge cross section of the actuator mechanism to a value between 1 and 0. It is practically inconsequential for the control action of the valve whether the adjustment of the discharge cross section is made by an analogous adjustment or, at a correspondingly higher activation frequency, by a temporal adjustment, e.g., opening and closing periods of different lengths.
In one embodiment, a perfect seal on the outside edge of the metal disc, as well as a corresponding adjustment of the prestress, is achieved by axially prestressing the outer periphery of the metal disc. In such case, bilateral pressurization of the metal disc causes it to separate from the control edge (or valve seat) by a defined axial distance. The opening cross section and the opening point of the metal disc are thereby determined to achieve the connection of the inflow and discharge hole.
In another embodiment of the invention, two membranes border a common control chamber. Here, for example, the system can be installed in the piston, so that the passages of the decompression and compression stages can be controlled simultaneously.
In yet another embodiment, the bypass, the control bypass and the actuator mechanism are integrated in a separate component disposed adjacent to the working chambers.
Still yet another embodiment of the invention resides broadly in an adjustable shock absorber which comprises: a sealed cylinder containing a damping fluid; a piston rod sealingly projecting into the cylinder and axially displaceable with respect thereto: a piston attached to the piston rod and disposed within the cylinder to thereby sealingly divide the cylinder into first and second chambers; a flexible membrane having first and second sides; a valve seat disposed adjacent the first side of the flexible membrane; a principal bypass hydraulically interconnecting the first and second chambers and passing between the first side of the flexible membrane and the valve seat; and a control bypass hydraulically interconnecting the first and second chambers with the second side of the flexible membrane.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a two-tube shock absorber with a control system located in a separate component.
FIG. 2 is a cross-sectional view of the control system of FIG. 1.
FIG. 3 is a cross-sectional view of a one-tube shock absorber with two control systems which are controlled by a common actuator mechanism.
FIG. 4 is a cross-sectional view of an embodiment wherein a control system is located in the damping piston of a two-tube shock absorber and wherein two control systems share a common control chamber.
FIG. 5 is a cross-sectional view of another embodiment wherein a control system is located in the damping piston of a one-tube shock absorber and wherein two control systems share a common control chamber.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, an adjustable two-tube shock absorber generally includes a cylinder 1, which sealingly contains a hydraulic fluid, a piston rod 2, which sealingly projects into cylinder 1 and is axially displaceable with respect thereto, and a damping piston 3, sealingly disposed within cylinder 1 and connected to piston rod 2. Piston rod 2 is attached to a structure portion, e.g., of a vehicle, which is not shown. Piston 3 divides cylinder 1 into upper and lower working chambers 4 and 5, respectively, and is provided with axially throughgoing passages and associated throttle valves 8 of conventional design and well known in the art, which provide a substantially constant and non-variable resistance to the axial displacement of piston 3 and piston rod 2.
Two additional cylinders of progressively greater diameter 22 and 35 are disposed coaxially with and so as to surround cylinder 1, thereby providing two additional annular chambers, a bypass chamber 9 and an equalization chamber 21. Bypass chamber 9 interconnects with the working chambers via orifices 23, and a valve 20, located at the bottom of cylinder 1, provides a means by which the damping medium contained therein can reach equalization chamber 21.
A damping force control unit 24, which acts hydraulically in parallel with throttle valves 8 to modify the substantially constant damping force which throttle valves 8 provide, is mounted as a separate component attached to the shock absorber and is in fluid communication with bypass 9 and equalization chamber 21.
Referring now to FIG. 2, control unit 24 generally includes a bypass chamber 12 divided by a flexible membrane 13 into a control chamber 17 and a controlled chamber 25, a valve seat (or control edge) 16 disposed adjacent a first side of membrane 13, a fluid flow control valve (or fluid flow control means) 10 and associated passages as follows:
A principal fluid flow bypass is generally defined by a first passageway 14 leading from bypasschamber 9 to the first (or lower) side of membrane 13, thence between membrane 13 and valve seat 16, and into a passageway 15 which connects with equalization chamber 21. Additionally, a control fluid flow bypass generally includes a control bypass passageway 11 interconnecting bypass chamber 9 with control chamber 17 located on the upper (or second) side of membrane 13, thence through fluid flow control valve 10 and interconnecting passageway 26, and there merging with passageway 15 which, as noted above, is connected to equalization chamber 21.
In operation, control unit 24 functions as follows:
Upon administration of a sudden shock, a principal damping fluid flow is conducted through passageway 14 to controlled chamber 25. At the same time, a control damping fluid flow is conducted through passageway 11 to control chamber 17. With appropriate construction of membrane 13 and detailing of the various passageways, as explained in more detail below, membrane 13 remains in contact with valve seat 16, and thus, the principal damping fluid flow is blocked from proceeding beyond controlled chamber 25.
However, control damping fluid may still flow from control chamber 17 through fluid control valve 10 and passageways 26 and 15 to equalization chamber 21. If sufficient fluid passes through valve 10, disproportionate pressure forces acting on membrane 13 will cause membrane 13 to move away from valve seat 16, thus allowing a principal fluid flow from chamber 25, between membrane 13 and valve seat 16, through passageway 15, and thence into equalization chamber 21.
It will be appreciated that the point at which membrane 13 may be caused to move away from valve seat 16 under the action of unbalanced forces may be influenced by a number of factors. As shown in FIG. 2, the surface area on the lower (or first) side of membrane 13 exposed to the principal damping fluid flow by chamber 25 may be significantly less than the surface area of the upper (or second) side of membrane 13 exposed to the control fluid flow. Additionally, the fluid pressure in control chamber 17, tending to maintain membrane 13 and valve 16 in a closed position, may be significantly relieved via control valve 10. Moreover, passageway 11 may be provided with a portion of reduced cross section 18 which serves to ensure that only the quantity of damping fluid necessary to control membrane 13 reaches control chamber 17. Even further, control membrane 13 may be prestressed in an axial direction, as, for example, through the use of a central clamping mechanism, as shown in FIG. 2, or through the use of a circumferential clamping collar 27, also shown in FIG. 2.
Whereas the present invention contemplates that fluid control valve 10 may consist of merely an appropriate dimensioning of the control fluid passageways, control valve 10 is preferably at least an on-off fluid flow control mechanism. Even more preferably, fluid valve 10 is a selectively variable fluid flow control mechanism, as for example, a type of flow regulator well known in the prior art, such as a proportional valve or at least one miniaturized two/two-way valve or at least one timed and/or pulse-width-modulated two/two-way valve.
Preferably, in the present embodiment, membrane 13 is a prestressed metal disc, firmly clamped in its central region 19 and having an axial prestress applied thereto via collar 27.
Referring now to FIG. 3, showing a one tube shock absorber provided with a bypass control unit according to the invention, a cylinder 1 is divided by means of a separating piston 28 from an equalization chamber 21 which is filled with a compressible gas. Another cylinder of larger diameter 22 is disposed coaxially with cylinder 1 so as to form a bypass chamber 9, which includes two bypass passages 9a and 9b which communicate with each other through bypass control unit 24, bypass passages 9a and 9b communicating with the upper and lower working chambers 4 and 5 through orifices 29b and 30, respectively.
Control unit 24 includes two separate flexible membranes, 13a and 13b, which are controlled through a common fluid flow control valve 10. In this particular embodiment of the invention, one of membranes 13a and 13b controls the flow of damping fluid during a compression stroke of the shock absorber, while the other membrane controls the flow of damping fluid during a decompression stroke.
During a compression stroke, damping fluid passes via orifice 30 into bypass passage 9a and thence through passage 14a into annular controlled chamber 25a, there exerting a pressure on the lower or first side of membrane 13a. A check valve 31a is at this point closed. Damping fluid also flows from passageway 9a through control passage 11a into control chamber 17a, to thereby exert a pressure on the upper or second side of membrane 13a tending to urge it towards and in contact with valve seat 16a. Dependent upon the state of control valve 10, damping fluid may flow through control valve 10, control passage 11b and bypass passageway 9b, into upper working chamber 4.
If the pressure in control chamber 17a drops sufficiently, membrane 13a will separate from valve seat 16a, thus permitting a principal flow of damping fluid past valve seat 16a, through discharge passage 15a and passageway 9b and, ultimately, into upper working chamber 4.
In contrast, during a decompression stroke, damping fluid flows from upper working chamber 4 through bypass passageway 9b and passageway 14b to controlled chamber 25b to there pressurize the lower or first side of membrane 13b. Additionally, damping fluid flows through control passage 11b and into control chamber 17b to pressurize membrane 13b on its upper or second side. A check valve 31b is, at this point, closed.
Dependent upon the state of control valve 10, damping fluid may then flow through valve 10, passageway 11a and bypass passageway 9a into lower working chamber 5. If the fluid pressure in control chamber 17b drops sufficiently, membrane 13b will separate from valve seat 16b, thus allowing a primary flow of damping fluid to move over valve seat 16b, through discharge passage 15b, check valve 31b and bypass 9a, and into lower working chamber 5. The connection between check valve 31b and bypass 9a may be, as shown, via an annular passageway provided in the base of control unit 24, or may be via alternate routes well known in the art.
Thus, it will be seen that during both the compression and decompression strokes, there may be a modification of the substantially constant damping resistance provided by throttle valves 8 provided in piston 3.
In FIG. 4, there is shown a two-tube shock absorber, having a variable damping mechanism mounted within te working piston, and wherein a pair of bottom valves 20 provide a hydraulic connection between a lower working chamber 5 and an equalization chamber 21.
A piston 3 divides cylinder 1 into an upper working chamber 4 and a lower working chamber 5 and is attached to a piston rod 2 which projects outside cylinder 1 and is attached to a structural portion, e.g., of a vehicle. Piston 3 is provided with passages 6 and 7 which are provided with associated check valves 31b and 31a, respectively. In the embodiment of FIG. 4, the throttling of the damping fluid between the working chambers is effected only by membranes 13a and 13b and their associated valve seats 16a and 16b.
During a compression stroke, damping fluid flows via passage 14a into controlled chamber 25a to pressurize a first side of membrane 13a and at the same time, via control passage 11a into control chamber 17 to pressurize a second side of membrane 13a. If fluid control valve 10 is closed and if the constricted prethrottle regions 18 are identical in control passages 11a and 11b, the resulting pressure in control chamber 17 is one-half the pressure in controlled chamber 25a. By appropriate proportioning of the diameters of valve seat 16 and collar 27, membrane 13a will be in contact with valve seats 16a, independently of the pressure in controlled chamber 25a. Thus, the primary flow of damping fluid will be closed off from discharge passageway 15a.
If fluid control valve 10 is more or less in an open position, control damping fluid can flow out partly through control passage 11b and hole 33 into upper working chamber 4, and partly via passages 32 and 34 and fluid control valve 10 into equalization chamber 21. With a sufficient pressure drop in control chamber 17, membrane 13a separates from valve seat 16a, such that aprincipal flow of damping fluid may pass through passage 15a and passage 7 and, thence, through check valve 31a and into upper working chamber 4.
During a decompression stroke, damping fluid flows through inflow passage 14b to enter controlled chamber 25b and there pressurize a first side of membrane 13b. Damping fluid also enters hole 33 and travels via bypass passage 11b to control chamber 17 to thereby pressurize the second side of membrane 13b. From control chamber 17, control damping fluid again travels through passages 32 and 34, through fluid control valve 10 and into equalization chamber 21, as well as, through bypass passage 11a and into lower working chamber 5.
In the embodiment of FIG. 4, control passages 11a and 11b are again preferably provided with a constricted portion 18 of reduced cross sectional area, the diameter of the control passages 11a and 11b being smaller than that of the inflow passages 14. Constricted portions 18 permit passage of only that fraction of the damping fluid necessary to control membranes 13a and 13b. The remainder of the damping fluid must (i.e., the principal fluid flow), therefore, pass through the throttle point between the membranes 13a and 13b and the respective valve seats 16a and 16b.
In FIG. 5, there is shown an embodiment wherein an equalization chamber 21 is formed adjacent cylinder 1 by means of a separating piston 28. The principal of operation of the damping piston 3 in FIG. 5 is the same as that of FIG. 4, set forth above. For operation of the FIG. 5 embodiment, all that is additionally necessary is the provision of a check valve 31a for the compression stroke and a check valve 31b for the decompression stroke, insuring that fluid control valve 10 cannot be pressurized in a reverse direction. Otherwise, the operation of membranes 13a and 13b in FIG. 5 is identical to that described above, with respect to the embodiment of FIG. 4.
The invention as described hereinabove in the context of the preferred embodiments is not to be taken as limited to all of the provided details thereof, since modifications and variations thereof may be made without departing from the spirit and scope of the invention. | Adjustable shock absorber, particularly for motor vehicles, which includes a cylinder containing damping fluid, an axially-movable piston rod which projects in a sealed manner into the cylinder, and a piston fastened to the rod and dividing the cylinder chamber into two working chambers interconnected by at least one passage which produces a damping force, the effective cross section of which can be adjusted by means of a throttle valve. The bypass includes a flexible membrane enclosed in a chamber such that on the one side of the membrane, there is at least one inflow passageway and at least one outflow passageway of the passage which can be sealed off from one another by the membrane, a control edge (or valve seat) which interacts with the membrane, and on the other side of the membrane, a control chamber carrying a control bypass flow and sealed off from the passage. | 5 |
RIGHT OF THE GOVERNMENT
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
BACKGROUND OF THE INVENTION
This invention relates to a method for the coating of continuous tows.
Composite materials are widely known and widely used. By combining a polymer with another material, such as glass, carbon, another polymer, or the like, is it possible to obtain unique combinations or levels of properties. Similarly, by combining a metal or glass with selected fibers, it is possible to obtain unique combinations or levels of properties. Advanced composites have evolved as a class of structural materials as a result of the development of high-modulus, high-strength, low-density reinforcing fibers.
The presence of a carbon interlayer along the fiber-matrix interface has been shown to be responsible for the high toughness and strain to failure of Nicalon® (SiC fiber)/lithium aluminosilicate glass composites and Nicalon®/Ba-Si-Al oxynitride glass composites. However, these composites are not viable for high temperature oxidizing environments. Such environments require oxidation resistant fibers, matrices and interlayers. One approach to fabricating a fiber-matrix interface is to introduce an interlayer as a fiber coating before the composite is densified. After densification, the interlayer chosen should cause crack deflection and fiber pullout similar to carbon interlayers, or should provide oxidation resistance for other interlayers.
Several types or combinations of interlayers are considered to be feasible, including microporous interlayers, reactive interlayers which lose volume, and interlayers with ductile particles. However, application of a coating, particularly a uniform coating, to continuous fibers and fiber tows can be difficult. Measurement of coating thickness can also be difficult.
Several techniques are known for applying coatings to continuous fibers. Fiber coating may be accomplished by passing the fibers through a container filled with a coating liquid, which container has one or more rollers or wheels to keep the fiber immersed in the liquid while coating. One disadvantage of this process is that the fibers must be bent around the roller(s) or wheel(s) and may sustain damage from bending or abrasion. Another disadvantage is that the fibers may be contaminated from contact with the wheel or roller.
Coatings may also be applied by spraying. The primary disadvantage of this coating method is that spraying is a line of sight process, so coating thickness is dependent upon the angle at which the spray jet contacts the fiber. Other disadvantages are that spray jets tend to clog easily, the characteristics of the jet may change with time, making control of the process difficult, viscous coating solutions are difficult to apply as a spray, and low viscosity solutions tend to run off the fiber before they are cured.
Fibers may be coated by passing same through a container having a gasket which seals around the moving fiber and prevents coating liquid from flowing out. The disadvantages of this method are that the fiber surface may be contaminated or abraded by contact with the gasket, and fibers having irregular cross-sections or multifilament fibers or tows tend to get caught along irregularities or at broken fibers in gaskets tight enough to prevent leakage of the liquid.
The coating of multifilament tow or cloth is particularly vexing. Most methods used to apply liquid-based coatings to monofilaments do not uniformly coat individual filaments of a fiber tow or cloth because the coating cements the filaments together, or forms thin bridges between filaments. There are, however, methods which may be used to coat each filament individually.
If the coating liquid is a acidic sol, it may be applied in dilute concentration, then gelled on the individual filaments by passage through ammonia. The use of an ammonia atmosphere together with dilute acidic sols is a disadvantage.
The tow may be sprayed with a coating liquid. As mentioned previously, spraying is a line of sight process, so coating thickness depends on the angle of contact of the spray jet relative to each filament in the tow. Thus, some filaments may be completely shadowed by other filaments and receive no coating.
The individual filaments in a tow may be uniformly coated by chemical vapor deposition (CVD). Although this technique works well for many different types of tow and coatings, it carries with it several disadvantages, including slow coating rates, equipment expense, precursor expense and its unsuitability for applying complex oxide coatings.
It is an object of the present invention to provide a method for coating continuous tow.
Other objects, aspects and advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of the invention.
DESCRIPTION OF THE DRAWINGS
In the drawings,
FIG. 1 illustrates the coating apparatus of this invention;
FIG. 2 illustrates an overall coating process; and
FIGS. 3, 4, 5, 6, 7 and 8 illustrate a bundle of tow fibers at each stage of the coating process.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a method for coating continuous tow which comprises the steps of: (a) transporting a tow through a coating composition to provide a coated tow having a layer of uncured coating thereon, (b) transporting the coated tow through a liquid which is immiscible with the coating composition and (c) curing the coating on the tow to provide a coated tow having a layer of cured coating on the individual filaments thereof, wherein the tow has contact only with the coating composition and the immiscible liquid between the uncoated state of the tow prior to coating step (a) and the cured, coated state of the tow subsequent to curing step (c).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a coating apparatus for use in this invention, designated generally by the numeral 10, comprises a coating composition container 20 having a nozzle 30 in the bottom portion thereof through which a continuous fiber 40 can be drawn. Inlet 50 is provided in container 20 for replenishing the coating composition.
Nozzle 30 has an throat passage or orifice 60 having an inner dimension sufficiently large that fiber 40 has no contact therwith, even with vertical misalignment of fiber 40. Nozzle 30 has an exit portion 70 which flares downwardly and outwardly. Because passage 60 has a dimension greater than that of the fiber 40, the coating composition continuously flows through passage 60. Catch vessel 80 is positioned below nozzle 30 to catch excess coating composition flowing therethrough. The coating composition in vessel 80 is continuously removed through outlet 90 and recycled by way of various conduits 100 and pump 110 to inlet 50 of container 20. Catch vessel 80 is shown as having an upwardly extending funnel-shaped standpipe 140 through which fiber 40 can pass.
The nozzle 30 is preferably fabricated from a material which is wetted by the coating composition. When such a material is employed, the excess coating composition, after leaving passage 60, will follow the exit wall 70 and discharge into the catch vessel 80. Container 20 may optionally be provided with a deflector spout 120 and a gas jet 130 positioned so as to propel excess coating composition away from fiber 40 and into catch vessel 80.
In the embodiment shown, container 20 contains a liquid coating composition, designated 150, and a liquid 160 which is immiscible with the coating composition.
The tows employed according to the invention are high strength tows comprising a plurality of fibers such as, for example, carbon or graphite, silica, silicon carbide, silicon nitride, silicon carbide-coated boron, boron carbide-coated boron, silicon-coated silicon carbide, alumina, mullite, yttrium-aluminum oxides, beryllium-titanium composites, boron-aluminosilicate, and the like.
The coating composition may be a clay slip or slurry, a solution of a metal salt or a polymer solution or a sol. A polymer solution is an inorganic oxide network containing glass- or ceramic-forming elements such as Si, Al, Ti, Zr and the like and, optionally, modifying elements such as Mg, B and the like. The oxide network is formed by controlled hydrolysis of an organo-metallic compound such as a metal alkoxide. The net reaction to form an anhydrous oxide is generally represented by:
M(OR).sub.n +xH.sub.2 O-→M(OH).sub.x (OR).sub.n-x +xROH(1)
M(OH).sub.x (OR).sub.n-x -→MO.sub.n/2 +x/2H.sub.2 O+(n-x)ROH(2)
The hydrolysis reaction (1) may be catalyzed by the addition of acid or base. Depending on pH and water content, the hydrolysis of, for example, tetraethylorthosilicate (TEOS) can result in the formation of polymeric species ranging from polysiloxane chains to colloidal particles of essentially pure silicon dioxide. Conditions employed in the preparation of monolithic glasses or ceramics normally consist of the hydrolyzation of the alkoxide precursors with a small to large excess of water (in equation 1, above, x greater than n/2) at low to intermediate pH (about 1 to 9). These conditions can result in structures that are intermediate between linear chains and colloidal particles. The oxide network can be dried, then thermally converted to glass or ceramic. Multicomponent glasses/ceramic may be similarly prepared.
For use in the present invention, a solution is prepared containing at least about 1 weight percent, preferably at least about 4 weight percent equivalent oxide. The metal alkoxides may be prepared using techniques known in the art. For example, silicon tetrakis isopropoxide may be prepared by reacting silicon tetrachloride with isopropyl alcohol. As another example, aluminum trisisopropoxide may be prepared by the reaction of aluminum metal foil with excess isopropyl alcohol using mercuric chloride as a catalyst.
The metal alkoxide may be diluted with a C1 to C4 alcohol, e.g., methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, t-butanol or sec-butanol, preferably with the alcohol corresponding to the alkoxide group, to a concentration sufficiently low to avoid gellation when later hydrolyzed, yet sufficiently high to provide the desired concentration of equivalent oxide.
The ceramic materials include silicates, aluminates, yttriates, titanates, zirconates, and the like, as well as combinations therof, such as the aluminosilicates, yttrium-aluminum garnet and yttrium-aluminum monoclinic. These materials may, optionally, be modified with one or more of boron, alkali metals, alkaline earth metals, lead and the like.
In general, the immiscible liquid can be any liquid which is not miscible with the coating composition. Since the coating composition is, in general, a largely aqueous solution, the immiscible liquid can be any water-immiscible hydrocarbon. The immiscible liquid should satisfy the relation:
γ.sub.IF >γ.sub.IC +γ.sub.CF (3)
where γ represents the interfacial energy or tension, and the subscripts I, C and F refer to immiscible liquid, coating composition and filament, respectively. It is also advantageous if the immiscible liquid wets the coating composition/air interface, as expressed by the relation:
γ.sub.AC >γ.sub.IC +γ.sub.AI (4)
where the subscripts C and I are as above and the subscript A refers to air. Good results have been obtained using hexane as the immiscible liquid. Other liquids which may be employed include heptane, perfluorohexane, dichlorohexane, 1-octanol, isoamyl alcohol and the like.
FIG. 2 illustrates the overall process of this invention wherein uncoated continuous tow 40 is provided from a source, not shown, to lower alignment and tensioning means 200 which aligns the fiber for a pass through the coating apparatus. Tow 40 is passed through a first furnace 210, through the coating apparatus 10, through drying means 220, through a second furnace 230 to an upper alignment and tensioning means 240, thence to takeup means, not shown. The first furnace 210 is operated at a temperature sufficient to clean and/or burn off sizing from the tow to be coated, i.e., about 500° C. to 1000° C.; this step may be omitted if the tow is known to have a clean surface. The drying means 220 is operated at a temperature sufficient to drive off a majority of the immiscible liquid, i.e., about 100° C. to 250° C. The second furnace 230 is preferably operated at a temperature sufficient to calcine the coating applied, i.e., about 750° C. to 1500° C.
FIG. 3 represents a tow having a plurality of fibers 300. With reference to FIG. 1, as the tow is transported through the coating composition 150 in container 20, the composition penetrates between individual fibers 300, wets them and displaces air between them, as shown in FIG. 4. If the thus-coated tow were now calcined, the result would be as shown in FIG. 5, with bridges of cured coating 310 between fibers 300.
Referring again to FIG. 1, the coated tow is transported through the immiscible liquid layer 160, wherein a major portion of the coating composition is displaced by the immiscible liquid, as illustrated by FIG. 6. As the tow is transported out of the immiscible liquid 160, a major portion of the liquid flows away from the tow, leaving a two-layered coating of coating composition 150 and immiscible liquid 160 on fibers 300, as shown in FIG. 7. is the tow is transported through the drying means 220 and furnace 230, the immiscible liquid is evaporated from the surface and the coating composition is converted to the desired coating 320, as shown in FIG. 8.
Although the method of this invention has been illustrated and described with the tow being transported through the apparatus in the upward direction, it is within the scope of the invention to coat tow by transporting same in the downward direction, through proper choice of coating composition and immiscible liquid.
Various modifications may be made to the invention as described without departing from the spirit of the invention or the scope of the appended claims. | A method for coating continuous tow which comprises the steps of: (a) transporting a tow through a coating composition to provide a coated tow having a layer of uncured coating thereon, (b) transporting the coated tow through a liquid which is immiscible with the coating composition and (c) curing the coating on the tow to provide a coated tow having a layer of cured coating on the individual filaments thereof, wherein the tow has contact only with the coating composition and the immiscible liquid between the uncoated state of the tow prior to coating step (a) and the cured, coated state of the tow subsequent to curing step (c). | 3 |
[0001] The present invention concerns a method according to the preamble of claim 1 and a device according to the preamble of claim 7 .
THE PRIOR ART
[0002] In association with either one of the bleaching and the delignification of cellulose pulp in bleaching lines, the pulp passes between different treatment steps in which the pulp is subjected to bleaching or the delignifying effect of various treatment chemicals. The treatment typically alternates between alkaline and acidic treatment steps in which typical sequences may be of ECF type (elemental chlorine-free, Cl, in which chlorine dioxide may be used) such as O-D-E-D-E-D, O-D-PO or sequences of TCF-type (totally chlorine-free) such as O-Z-E-P. Other bleaching steps, such as Pa steps and H steps may be used.
[0003] The treatment steps may take place either at medium consistency (8-16%) or at high consistency (.gtoreq.20-30%), but it is vitally important to wash out after each treatment step degradation products and lignin precipitated during the treatment step and to reduce to a minimum the remaining fraction of fluid, since the latter will otherwise lead to an increased requirement for pH-adjusting chemicals for the subsequent treatment steps and transfer of precipitated lignin and other degradation products, which subsequent step generally takes place at a completely different pH.
[0004] Simple vacuum filters with dewatering drums that are partially (typically 20%-40% of the drum) immersed in the pulp suspension that is to be dewatered were used in certain older types of washing step after a bleaching step or a delignification step. In these vacuum filters, a bed of pulp forms spontaneously against the outer surface of the drum under the influence of a negative pressure in the interior of the drum, and the pulp bed is drawn up from the pulp suspension by the rotation of the drum and is scraped off with a scraper on the side of the drum that is moving downwards. A consistency higher than 8-14% is generally never achieved for the pulp bed that has been dewatered, due to the limited degree of dewatering that is achieved, and the dewatered pulp that is scraped of can be readily formed to a slurry with a low consistency again in a subsequent collecting trough. The technique used here is a lower degree of dewatering followed by slurry formation with a cleaner filtrate, and this takes place in a series of vacuum filters in order to achieve the required washing effect. For this reason, it is attempted to achieve as high a degree of dewatering as possible before the dewatered pulp is again formed to a slurry with cleaner filtrate before the subsequent treatment stage.
[0005] A dominating washing machine on the market for bleaching lines is the conventional dewatering press, or thickening press, in which pulp is applied to at least one outer surface of the dewatering drum and subsequently passes a nip between the drums and acquires a consistency of 20-30% or greater after the nip. A practical upper limit lies at 35-40%, where a higher degree of dryness cannot be achieved without affecting the strength properties of the fibres negatively. A representative washing press of this type is disclosed in the U.S. Pat. No. 6,521,094.
[0006] The dewatered mat of cellulose pulp that is fed out from the washing machine's nip must first be shredded due to the high degree of dewatering, which shredding takes place in a shredder screw.
[0007] The purpose of the shredder screw has been exclusively to break up the mat of dewatered cellulose pulp and feed it onwards to equipment in which the cellulose pulp is rediluted to a consistency that makes it possible to pump it onwards to the next treatment step.
[0008] The redilution thus preferably takes place in association with adjustment of the pH, which after an alkaline wash normally involves the addition of powerful acidifiers, or the addition of acidic return water/filtrate from subsequent process steps, before the subsequent acidic treatment step. These acidic conditions have involved the dilution in general being held well separated from the previous alkaline wash as well as the associated shredder screw, since the alkaline wash can be built from simpler material than that which is normally required for washing machines that resist acidic conditions. Acidic conditions require material that can resist acids, and this is significantly more expensive that other material.
[0009] The pulp on exit from the shredder screw has a very high level of dryness, a consistency of 20-30% or greater, and this means that redilution has been carried out in all installed plants in at least one separate dilution screw arranged after the shredder screw, where the dilution fluid is added during intensive agitation from the dilution screw in order to achieve a suitable homogenous consistency that makes pumping onwards to the next treatment stage possible. The diluted pulp that is achieved after the dilution screw is fed to a stand pipe in the bottom of which a pump is arranged.
[0010] A second alternative for washing is the use of a dewatering screw, in which the cellulose pulp is first diluted and subsequently dewatered in a dewatering screw (of the Thune type or Sudor press type) to a level of dryness that considerably exceeds 20-30%. In this way, what is known as “wash-by-dilution” is achieved. A compacted and well-consolidated dewatered pulp is obtained at the exit from the dewatering screw also in this case. A redilution has been used also in this case after the dewatering screw, with the addition of dilution fluid during intensive agitation from a dilution screw.
[0011] The very high consistency of the pulp after the dewatering press or the dewatering screw has given rise to the belief that dilution to a homogenous medium consistency cannot be achieved unless dilution occurs under the influence of intensive agitation from the dilution screw. A consistency of the pulp of 20-30% or greater is experienced as dry and compacted. It can be mentioned for the sake of comparison that medium-consistency pulp is so compact that it is just about possible to walk on this pulp, when it is at the upper part of the consistency range.
[0012] The use of a dilution screw at this position, however, increases the requirement for energy, it increases investment costs, it raises the requirement for maintenance and it involves a further mechanical treatment of the pulp which has a negative influence on the strength properties of the pulp.
AIM AND PURPOSE OF THE INVENTION
[0013] The present invention is intended to remove the above-mentioned disadvantages and is based on the surprising insight that even if the pulp has been dewatered to give a very high consistency, 20-30% or more, no mechanical agitation at all is required during the dilution provided that the pulp bed has been shredded to give small granules of a suitable size, and provided that the dilution fluid is added evenly over a flow of the freely falling granulated pulp.
[0014] It has surprisingly turned out to be the case that the granulated pulp demonstrates the properties of a sponge, despite its high consistency, and that, provided the dilution fluid is added evenly to a flow of non-tightly packed granulated pulp in freefall, a primary homogenised dilution of the pulp takes place that is fully adequate such that it can subsequently be pumped or led onwards to the following bleaching stage or treatment stage.
[0015] It is sufficient in laboratory experiments with small quantities of well-granulated pulp with a consistency around 30-35% to pour the required amount of fluid to obtain the required consistency into a container with granulated and non-compressed pulp, and the complete mixture has been homogenised to an even consistency after the addition of the fluid totally without mechanical agitation. Observation of the granulated pulp has shown that there lie cavities between the granules, and the fluid rapidly penetrates between the granules through the complete volume of the granules, after which the granules absorb the fluid as sponges.
[0016] This primarily homogenised pulp is fully adequate to be pumped with a subsequent pump, in which a secondary or complementary homogenisation takes place, and these together ensure that the same degree of homogenisation of the pulp can be achieved for the subsequent treatment stage completely without mechanical agitation from a dilution screw. The principal aim of the invention is thus to redilute pulp from a high consistency of 20-30% or higher without the use of a dilution screw and without intensive mechanical agitation, which reduces losses in the strength of the pulp.
[0017] A second aim is to reduce operating costs and maintenance costs for the process equipment in the redilution, since no operation of dilution screw is necessary.
[0018] A further aim is to reduce the investment cost of the process equipment. A reduction of both operating costs and investment costs in the process equipment entails a reduction in the cost of manufacturing bleached pulp to an equivalent degree, and this saving is multiplied by the number of washing machines that are used in the bleaching line. No less than six washing machines are included in an O-D-E-D-E-D sequence, and thus the reduction in costs can be significant.
[0019] Approximately 50 kW is required solely for the operation of one dilution screw, and the investment cost is approximately SEK 500,000 (depending to a certain extent on requirements on materials, i.e. whether it needs to be acid-resistant or not).
[0020] The operating costs per year in an O-D-E-D-E-D bleaching line will be: 6*50 kW*SEK 0.20 (the price for an operator in Sweden)*24 hours*350 days (the number of operating days per year, excluding stoppages)=SEK 500,000 SEK per year;
[0021] and the investment cost will be: 6*SEK 500,000=SEK 3,000,000.
[0022] This investment cost at an interest rate of 5% corresponds to an annual expense of SEK 150,000.
[0023] In summary, implementation of the invention involves a total annual saving that approaches SEK 650,000-1,000,000 SEK including maintenance costs and building space (frameworks, etc.) in a bleaching line with a capacity of 1,000 tonnes per day.
[0024] Furthermore, availability of the mill increases since six machines can be removed, each of which has an MTBF (mean time between failure).
[0025] A further aim is to remove a treatment step between the washing machine and the subsequent pumping, which makes possible a more compact mill and opportunities to place the washing machines at a lower height over the ground in the mill. The washing machines are normally placed at a great height over the ground, and the pulp falls downwards after being washed in the washing machine while it passes through various conditioning steps. If one of these conditioning steps (such as the dilution screw) becomes unnecessary, the building height can be reduced, which In turn gives a saving.
[0026] With these aims, the invention is characterised by the characteristics of claim 1 with respect to the method according to the invention, and by the characteristics of claim 7 with respect to the device according to the invention.
DESCRIPTION OF DRAWINGS
[0027] FIG. 1 shows a typical treatment step for the pulp in a reactor with a subsequent washing press according to the prior art;
[0028] FIG. 2 shows part of the system in FIG. 1 (prior art);
[0029] FIG. 3 shows a dilution system according to the invention;
[0030] FIG. 4 shows a detail of FIG. 3 ; and
[0031] FIG. 5 shows a view seen from underneath in FIG. 4 , seen at the level of the section A-A.
[0032] FIG. 6 shows an alternative dilution system according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] FIG. 1 shows a conventional treatment step for cellulose pulp, hereafter denoted “pulp”. The pulp is fed by the pump 1 to a mixer 2 in which necessary treatment chemicals are added. These treatment chemicals can be, for example, oxygen gas, ozone, chlorine dioxide, chlorine, peroxide, pure acid or a suitable alkali for an extraction step, or a mixture of these, and possibly other chemical or additives such as a chelating agent. The pulp is transported after the addition of the necessary chemicals by the mixer 2 to a reactor system 3 , here shown in the form of a single-vessel tower 3 of upwards flow. The reactor system can, however, be constituted by simple pipes or by one or several reactors in series, and possibly with the batchwise addition of chemicals between the towers in those cases In which the bleaching processes are compatible and do not require washing between the towers.
[0034] The treated pulp is fed after treatment in the reactor system 3 to a pulp chute/stand pipe 4 , which establishes the buffer volume and static pressure required, to a pump 5 arranged at the bottom of the pulp chute. The pulp is fed from the pump 5 to a washing machine 7 , shown here in the form of a washing press with two drums 7 a , 7 b . The pulp is applied to the drums, here at the 12 o'clock position, and is led by convergent pulp collectors during the addition of washing fluid (not shown in the drawing) to a final dewatering nip between the drums, from where a mat of dewatered pulp is fed upwards to a shredder screw 8 .
[0035] The drums in FIG. 1 rotate in opposite directions and the pulp mat is dewatered through the outer surface of the drum while the pulp is lead approximately 270.degree. around the circumference of the drum to the nip. The washing press may be preferably equivalent to that revealed by the U.S. Pat. No. 6,521,094. Any other type of dewatering press or washing press, however, having a drum or drums, may be used, in which a consistency of 20-30% or higher is achieved, for example a washing press with a single dewatering drum and an opposing roller, or other types of washing press with two dewatering drums.
[0036] The pulp is fed upwards from the nip in the form of a dewatered and compressed mat 20 of cellulose pulp that has been consolidated into large pieces to a shredder screw 8 , the shredding axis of which is arranged to be essentially parallel to the axes of rotation of the drums. A small oblique mounting of a maximum of 5-10.degree. may, for example, be present if a conical shredder screw is used, where the mat is fed to an inlet slit in the outer casing of a conical shredder screw, where the inlet slit lies parallel with the axes of the drums. The fragmented pulp is led after this shredder screw 8 out from an outlet in the casing of the shredder screw in the flow 21 to a dilution screw 30 that is driven by a motor 31 . The dilution screw exposes the pulp to continuous tumbling during the addition of dilution fluid Liq2, and the pulp is subsequently fed to a stand pipe 40 at its finally conditioned consistency. The pulp can subsequently be pumped from the stand pipe 40 to the next treatment step of similar type in the bleaching line.
[0037] FIG. 2 shows another view of a part of the same process in which the shredder screw 8 is oriented in the same direction as the dilution screw 30 . It can be seen more clearly here how the dewatered and compressed mat 20 of pulp that has been consolidated into large pieces is fed into the shredder screw 8 . The shredder screw contains a threaded screw 8 a that is driven by a motor 8 c , and that may also be equipped with a number of beaters 8 b at its outlet, which beaters further whip and break up the shredded pulp. The purpose of the shredder screw is primarily to break into smaller pieces the dewatered and compressed mat 20 of pulp that has been consolidated into large pieces, and it may sometimes be sufficient with one such shredder screw. The beaters 8 b may be arranged on the same shaft as the shredder screw and they provide an extra fragmentation effect, but they are primarily used to hold the outlet from the shredder screw free from the formation of blockages.
[0038] The fragmented flow 21 of pulp particles is fed thereafter to fall under its own weight to the subsequent dilution screw 30 .
[0039] FIG. 3 shows the dilution system according to the invention in a treatment step that is otherwise equivalent to that shown in FIG. 1 . The dewatered web of pulp, which has a consistency of 20-30% or greater, is fed in this case in to the shredder screw 8 in the same way as shown in FIGS. 1 and 2 . However, dilution occurs in the outlet from the shredder screw according to the invention in a significantly simplified manner. It is important that the web or mat 20 of pulp, which maintains a consistency of 20-30% or higher, is first fragmented by the shredder screw such that the mat 20 is granulated to a particle size that is normally distributed around a mean size that lies in the interval 5-40 mm. This is taken to denote that the fragmented pulp has a particle size that is normally distributed around a maximum size that is less than 40 mm, preferably less than 30 mm, and even more preferably less than 20 mm. It is appropriate that the normal distribution is distributed such that 90-95% of the fragmented pulp lies within .+−.5 mm of the maximum size, 40-30 or 20 mm, of the fragmented pulp.
[0040] The granulated pulp is then fed out from the outlet of the shredder screw in free fall into a stand pipe 22 connected to the outer casing of the shredder screw at its outlet. The dilution fluid LiqDIL is subsequently added under pressure into the stand pipe through a number of fluid jets preferably arranged around the periphery of the stand pipe and above a level LiqLEV of diluted cellulose pulp established in the stand pipe. Alternatively, some or all of the fluid jets may originate from a central pipe that is located in the flow of the fragmented pieces of pulp that are standing in free fall, and where the fluid jets are directed essentially radially outwards. A certain oblique adjustment may be established, but it is preferable that the jets are directed towards the freely falling flow with an angle of attack of 90.degree., or within the interval 90.degree.+−.60.degree. (=30.degree.−155.degree.), such that a certain minimum angle of attack is established. There may be so many fluid jets that an essentially continuous “fluid curtain” is established, or the dilution fluid may be injected into the flow of freely falling fragmented pulp through one or several slits. The important fact is that the dilution fluid is added to the flow at several points and at points at which the granulate is falling freely before it reaches the underlying surface of pulp that has been diluted to its final degree.
[0041] In the embodiment shown in FIG. 3 , the upper connection 22 of the stand pipe to the outer casing of the shredder screw has a smaller diameter than the lower part 40 ′ that lies below. The principle is that the pulp falls under the influence of gravity down through the parts 22 , 40 ′ of the stand pipe, and its lower part 40 ′ is given a larger diameter in order to be able to establish a suitable buffer volume before the pumping with the pump 41 ′ at a given level of pulp LiqLEV in the stand pipe 22 , 40 ′.
[0042] The amount of dilution fluid LiqDIL added establishes a consistency of the cellulose pulp within the range of medium consistency 8-16%, which is a consistency that allows the pulp to be sent onwards using an MC pump. The amount of dilution fluid that is required in order to establish the consistency at which the pulp is subsequently pumped is constituted to more than 75-90% of the fluid that is added at the said nozzles arranged above the level/surface that has been established in the stand pipe. A certain amount of chemicals such as acidifiers/alkali or chelating agents may be added at the bottom of the stand pipe 22 / 40 ′, but the principal dilution takes place with the dilution fluid above the pulp level established in the stand pipe.
[0043] The cellulose pulp at this medium consistency is fed by the pump 41 onwards from the lower end of the stand pipe to subsequent treatment steps for the cellulose pulp.
[0044] The dilution of the pulp from high consistency of 20-30% or greater at the upper part of the stand pipe to a medium consistency of 8-16% before the pumping from the lower part of the stand pipe takes place in this manner exclusively under the influence of the hydrodynamic effect from the addition of the dilution fluid through the said nozzles.
[0045] FIG. 3 and FIG. 4 show an embodiment of the manner in which addition of the dilution fluid can be realised. The dilution fluid is added by a pump to a distribution chamber 60 that is arranged concentrically around the stand pipe 22 . The pump pressurises the fluid to a suitable level, an excess pressure of approximately 0.1-0.8 bar. Alternatively, high-pressure nozzles can be used, which finely distribute the dilution fluid in the form of fanned plumes of fluid, oriented at a suitable angle relative to the vertical, a suitable angle being 30-90.degree.
[0046] A number of nozzles 62 are arranged at the bottom of the distribution chamber oriented obliquely downwards, in the direction of flow of the granulate, and inwards towards the centre of the flow. The amount of obliqueness in the mounting is appropriately 45.+−.15.degree. relative to the vertical. The oblique orientation downwards is favourable for achieving an ejecting influence on the granulate flow, and for avoiding the risk that the dilution fluid splashes upwards in the stand pipe.
[0047] A number of nozzles, at least four, are arranged around the stand pipe 22 / 40 ′, preferably with equal distances between them. With a stand pipe 22 having a diameter of 800-1,500 mm, it is appropriate that 10-40 nozzles are arranged around the periphery of the stand pipe. It is appropriate that the distance between adjacent nozzles be less than 50-300 mm. If high-pressure nozzles with fanned plumes of fluid are used, the nozzles may be arranged with a greater distance between neighbouring nozzles. It is important that the dilution fluid is added evenly around the complete circumference of the flow of granulate and at a sufficiently high pressure in order to penetrate to the centre of the granulate flow. The pressure setting is an engineering adaptation that is based on the nozzles being used, the diameter of the pipe and the rate of flow of fragmented pulp.
[0048] FIG. 6 shows an alternative embodiment of the invention. The difference between the embodiment shown in FIG. 3 and this embodiment is that the dewatering arrangement in this case is a deewatering screw (of Thune type or Sudor type) in which a conical screw 80 a compresses an incoming flow 20 of pulp during dewatering against a surrounding space through a screwed surrounding perforated housing, and in which filtrate 80 b is led away from this space. The driving force for the screw is normally located at its inlet, but the motor 8 c is here shown connected to the outlet of the screw.
[0049] The dewatered and compressed pulp that has been consolidated into large pieces is also in this case fed from the outlet of the screw to a simpler fragmentation arrangement in the form of a number of beaters 8 b that may be located on the same shaft as the conical screw while being located at its outlet. These beaters 8 b whip and break up the pulp that is fed out from the dewatering screw in the form of dewatered and compressed pulp that has been consolidated into large pieces. It Is preferable that these beaters have their own source of power, and that they are driven at a rate of revolution that considerably exceeds the rate of revolution of the screw.
[0050] The fragmented flow 21 of pulp particles is subsequently fed by falling under its own weight to the fall 40 , in the same manner as that shown in FIG. 3 . Furthermore, a second dewatering screw 90 is arranged to receive the diluted pulp suspension at the bottom of the fall 40 . The dewatering screw 90 may be another transport arrangement or another distribution arrangement, such as, for example, a distribution screw in the inlet arrangement to a dewatering press.
[0051] The dilution otherwise functions in the same manner as in the embodiment shown in FIG. 3 , and those parts that are the same have the same reference numerals.
[0052] The invention can be modified in a number of ways within the scope of the claims. The nozzle 62 for the addition of dilution fluid may, for example, be constituted by a simple drilled hole in a thick corrugated sheet, with a minimum thickness of 8-10 mm. However, specially adapted nozzles are preferred, which preferably generate a fan-shaped plume of fluid, in order to ensure optimal penetration of the granulate flow and an even distribution over the complete circumference of the flow. Addition of dilution fluid can also take place at a sufficiently high pressure that the dilution fluid more forms a very finely divided mist in the region that the granulated pulp passes.
[0053] Addition of dilution fluid takes place in the preferred embodiment in association with an increase in the area of the stand pipe 22 to a lower part 40 ′ of the stand pipe having a larger diameter, but it is not necessary that the addition takes place in association with an increase in area. A small amount may also be added at the outlet end of the shredder screw, with the addition flow directed down towards the stand pipe. But the dilution is to take place principally through the hydrodynamic mixing effect from the addition of the dilution fluid into the flow of granulate. | The method and a device is for the dilution of dewatered cellulose pulp that maintains a consistency of 20-30% or greater. By shredding of the pulp to a finely divided dry-granulate, dilution to a homogeneous consistency in the medium consistency range can take place exclusively through hydrodynamic effects from the addition of dilution fluid. The dilution fluid is added to granulate at a position at which granulate is in free fall in a standpipe and above a level Liq.sub.LEV of diluted pulp in the standpipe. A number of nozzles are arranged around the periphery of the stand pipe, directed in towards the centre of the stand pipe, obliquely downwards in the direction of fall of the granulate. It is possible through this simplified procedure to avoid completely the conventional dilution screws, and this reduces the investment costs and operating costs, while at the same time unnecessary mechanical influence of the pulp fibres can be avoided. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2011 012 282.6, filed Feb. 24, 2011; the prior application is herewith incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a method for controlling inking in a printing press with compensation of an ink requirement in an inking unit and/or compensation of a dampening solution requirement in a dampening unit of the printing press, in the event of a change in printing speed.
[0003] A satisfactory print quality is set in offset printing presses only when ink metering and dampening solution metering are adapted to the printing subject and are set correctly during the continuous printing phase. As soon as the continuous printing speed of the printing press is changed, the ink metering and dampening solution metering have to be adapted. Misprinted sheets or waste paper is produced in that transition phase, with the result that it is an aim, in the development of inking control systems in offset printing presses, to keep the transition phase as short as possible in the event of speed changes. One approach is so-called speed compensation which is known from German Published Patent Application DE 197 01 219 A1. In the method disclosed therein for controlling the inking, it is provided that the metering of the fluid which is to be applied to a printing material is changed as a function of the printing speed. In addition, in the event of a change in the printing speed, the fluid is transferred simultaneously with the printing speed change in a temporarily overdriven manner. The so-called speed compensation takes place by way of such overdriving, with the result that the time for carrying out speed changes in the transition phase of a printing press is reduced, as a result of which the print quality is improved during and after the performance of speed changes and the proportion of misprinted sheets or waste paper is reduced. In that speed compensation, substantially the continuous printing speed before the speed change and the continuous printing speed after the speed change are taken into consideration. However, it has been proven in practice that there are also further influencing variables which have an effect on the ink and dampening solution metering in the event of a change in the printing speed.
SUMMARY OF THE INVENTION
[0004] It is accordingly an object of the invention to provide a method for controlling inking in a printing press with machine-dependent compensation in inking and dampening units, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known methods of this general type, which follows an integrated approach in the event of changes in the printing speed and, as far as possible, takes all factors which have an influence on inking into consideration in the event of a printing speed change.
[0005] With the foregoing and other objects in view there is provided, in accordance with the invention, a method for controlling inking in a printing press. The method comprises compensating an ink requirement in an inking unit and/or a dampening solution requirement in a dampening unit of the printing press upon a change in printing speed, and taking a printing speed profile or course or a machine state prevailing before an instant of change in the printing speed into consideration in a compensation of metering of ink and/or dampening solution.
[0006] The method according to the invention presupposes the use of a control computer for controlling the ink and/or dampening solution metering in a printing press. In this case, the control computer detects the printing speed profile and/or the machine state of the running or stationary printing press and, as a function of the detected printing speed profile or detected machine state, decides which compensation is carried out in the metering of ink or dampening solution in the event of printing speed changes, in order to keep misprinted sheets or waste paper as low as possible during the printing speed change. The machine state is to be considered, in particular, as the stopping of the printing press and the restarting without washing of a rubber blanket in the printing unit of the printing press, stopping of the printing press and restarting with preceding washing of the rubber blanket in the printing unit of the printing press, start-up of the printing press after an ink input, and start-up after a print job change. The printing speed profile is to be considered as all changes in the printing speed before the instant of the current change in the printing speed. This detection and evaluation of the machine states and printing speed profiles before the instant of the change in the printing speed make optimum speed compensation possible with regard to the metering of ink or dampening solution and thus reduce the production of misprinted sheets or waste paper to a minimum in the event of a change in the printing speed. The present invention can be used in all offset printing presses, in particular sheet-fed printing presses, web-fed rotary printing presses as well as offset printing presses with anilox inking units.
[0007] In accordance with another mode of the invention, a different speed compensation during the ink metering or dampening solution metering is carried out as a function of the machine state or the speed profile before the instant of the speed change. According to the present invention, the speed compensation for metering dampening solution and ink does not necessarily take place at the same time and in parallel as in the prior art, but rather the speed compensation of ink and dampening solution can be configured differently, depending on which machine state or speed profile was present before the instant of the speed change. The number of machine states and the speed profile thus result in numerous possible combinations for the different actuation of ink metering and dampening solution metering during the speed compensation. In this way, a different speed compensation during the ink metering and dampening solution metering is carried out depending on the machine state and speed change and the preceding speed profile.
[0008] In accordance with a further mode of the invention, if there is too much ink in the inking unit, the speed compensation of the ink metering is carried out in a delayed manner in the event of an increase in the printing speed, but the compensation of the dampening solution metering is carried out immediately. In this way, the excess of ink is first of all reduced, before more ink passes into the inking unit again as a result of the speed compensation of the ink metering during the speed change. However, the dampening solution metering is carried out immediately, independently of the former.
[0009] In accordance with an added mode of the invention, if there is too little ink in the inking unit, the speed compensation of the ink metering is carried out immediately in the event of an increase in the printing speed, but the speed compensation of the dampening solution metering is carried out in a delayed manner in contrast. In this case, first of all the lack of ink in the inking unit is rectified by the immediate speed compensation of the ink metering, and the dampening solution metering is likewise only raised later. This avoids having too much dampening solution applied to the printing plate in comparison with the ink as a result of an immediate speed compensation of the dampening solution metering.
[0010] In accordance with an additional mode of the invention, the delay takes place proportionally to the speed difference. This means that the greater the speed change, the later the occurrence of the speed compensation of that component which is carried out in a delayed manner in the respective method step.
[0011] In accordance with yet another mode of the invention, if the machine speed during the ink input is greater than the continuous printing speed or the printing press is started up after washing of the rubber blanket on the blanket cylinder, the speed compensation of the ink metering and the speed compensation of the dampening solution metering are carried out immediately. In the machine states ink input and washing of the rubber blanket, the machine is situated in an unstable state with an empty inking unit, with the result that both ink and dampening solution can be metered immediately in an increased manner through the control of the speed compensation, in order to thus minimize the time of the production of misprinted sheets or waste paper.
[0012] In accordance with yet a further mode of the invention, if the machine speed during the ink input is lower than the continuous printing speed or a change is made during the print job change to an identical or higher continuous printing speed than in the preceding print job, the speed compensation of the ink metering is carried out immediately and the speed compensation of the dampening solution metering is carried out in a delayed manner. In this refinement of the invention, the initially also continuous printing speed of the preceding print job is evaluated and, in the case of an identical or higher continuous printing speed in comparison with the preceding print job, an immediate speed compensation during the ink metering is carried out with delayed speed compensation during the dampening solution metering.
[0013] In accordance with a concomitant mode of the invention, during start-up of the printing press without washing of the rubber blanket on the blanket cylinder or in the case of the print job change at a lower continuous printing speed than in the case of the preceding print job, the speed compensation of the ink metering is carried out in a delayed manner and the speed compensation of the dampening solution metering is carried out immediately. If the continuous printing speed during the following print job is lower than during the preceding print job, first of all a certain dissipation of ink is to take place in the inking unit, before the speed compensation of the ink metering is carried out. This is not the case for the dampening solution metering, with the result that the dampening solution metering is carried out immediately.
[0014] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0015] Although the invention is illustrated and described herein as embodied in a method for controlling inking in a printing press with machine-dependent compensation in inking and dampening units, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0016] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0017] FIG. 1 is a diagrammatic, longitudinal-sectional view of a sheet-fed offset printing press having a control computer which is programmed according to the invention;
[0018] FIG. 2 is a flow chart showing an overview of decision criteria of the control computer during selection of a suitable speed compensation of ink and dampening solution;
[0019] FIG. 3 is a flow chart showing a speed compensation during a change in the printing speed in a stable continuous printing phase;
[0020] FIG. 4 is a flow chart showing a speed compensation during ink input as a function of a continuous printing speed of a current print job in comparison with a speed during ink input;
[0021] FIG. 5 is a flow chart showing a speed compensation during start-up of the printing press after washing of a rubber blanket;
[0022] FIG. 6 is a flow chart showing a speed compensation during start-up of the printing press without washing of the rubber blanket;
[0023] FIG. 7 is a flow chart showing a speed compensation during a print job change as a function of the continuous printing speed of the current print job in comparison with that of a preceding print job; and
[0024] FIG. 8 is a diagram showing a relationship of printing speed compensation for overdriving inking after washing of the rubber blanket to printing speed difference.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a printing press 1 which has two printing units 3 , 4 , each having a respective inking unit 16 , 17 and dampening unit 18 , 19 . The inking units 16 , 17 serve for ink metering and have electric actuating motors which are connected to a control computer 5 of the printing press 1 . The ink which is metered in the inking units 16 , 17 can be dampened by way of the dampening units 18 , 19 . The dampening solution metering in the dampening units 18 , 19 can also be controlled by the control computer 5 . The metered and dampened ink is first of all transferred onto plate cylinders 11 , 12 carrying printing plates in the printing units 3 , 4 , and from there onto blanket cylinders 13 , 26 . From there, a printing image is then transferred in a press nip between the blanket cylinders 13 , 26 and impression cylinders 10 , 28 onto printing sheets 9 which are situated in the printing press 1 . The printing materials or sheets 9 are transferred between the two printing units 3 , 4 through the use of a transport cylinder 14 . Required new printing sheets 9 are raised up from a feed stack 8 in a feeder 2 through the use of a suction apparatus and are fed to the first printing unit 3 over a suction belt table. Following the second printing unit 4 , the finished printing materials 9 are transferred to gripper chains in a delivery 6 and are deposited on a delivery stack 7 .
[0026] The control computer 5 of the printing press 1 is connected over communications links 22 to all of the electric adjusting motors of the printing press 1 , in order to be able to perform the desired adjusting operations. In particular, the control computer 5 can adjust individual inking zones in the inking units 16 , 17 in order to meter the ink. Moreover, a display screen 15 is connected to the control computer 5 . The operating state of the printing press 1 is shown on the display screen 15 and inputs of the operating staff are possible through the display screen 15 . Furthermore, an external color measuring instrument 20 is connected to the control computer 5 through a communications link 22 . The color of finished printed sheets 9 which are deposited in the delivery stack 7 can be measured by way of the external color measuring instrument 20 . To this end, the printed sheets 9 have to be removed from the delivery stack 7 by the operating staff and have to be placed under the color measuring instrument 20 . Furthermore, the printing press 1 has an inline color measuring device 21 at the outlet or exit of the second printing unit 4 , which can likewise measure the color of the printed sheets 9 . The produced printed sheets 9 can have their color measured continuously by way of the inline color measuring device 21 , with the result that color measured values can be transmitted continuously to the control computer 5 by the inline color measuring instrument 21 . In the control computer 5 , the color measured values which are detected in this way are compared with a setpoint coloring S which is predefined by the operating staff and is dependent on the respective print job and the associated printing original. The setpoint coloring S serves as a target value for a corresponding ink presetting characteristic curve in the inking units 16 , 17 of the printing press 1 .
[0027] FIG. 2 depicts decision criteria for the control computer 5 which detects the machine state and the change in the printing speed. First of all, the control computer 5 determines whether or not a change in the printing speed is carried out. If this is not the case, nothing is changed about the ink and dampening solution metering. If, however, the control computer 5 has determined a change in the printing speed, the machine state is retrieved. By way of example, but not exclusively, five machine states which the control computer 5 retrieves through sensors or a running printing program of the printing press 1 are shown in FIG. 2 . If a change in the printing speed takes place in a stable continuous printing phase, a speed compensation 1 is performed. If the printing press 1 is currently situated in an ink input phase, a printing speed compensation 2 is performed. During start-up of the printing press 1 , after washing the rubber blanket (RB) on the blanket cylinder 13 , 26 , a speed compensation 3 takes place. If the printing press 1 is started up without washing of the rubber blanket on the blanket cylinder 13 , 26 , a speed compensation 4 takes place. If there is a print job change, a speed compensation 5 is performed. These five speed compensations are shown in the following FIGS. 3 to 7 .
[0028] FIG. 3 depicts the speed compensation 1 which is performed during a change in the printing speed in the stable continuous printing phase. In the stable continuous printing phase, the printing unit 3 , 4 is situated in a stationary stable state. If, however, the printing speed is increased, more ink and dampening solution have to be supplied. Since, however, the increase in the dampening solution metering is discernible much more rapidly than the increase in the ink metering, the dampening solution metering is initiated subsequently in a delayed manner, in order to prevent a reduction in the ink density on the printing material 9 . In the case of a reduction in the printing speed, however, a distinction has to be made as to whether a new stable state is aimed for or the printing press 1 is stopped. If the printing press 1 is to be stopped, the compensations of ink and dampening solution take place immediately. Otherwise, the procedure is as in the case of an increase in the printing speed.
[0029] In FIG. 4 , a speed compensation takes place during the ink input. In this machine state, the printing unit 3 , 4 is not situated as a rule in a stationary stable state. The ink input usually takes place at a different speed than at a continuous printing speed. The speeds of the ink input and continuous printing therefore have to be taken into consideration in this case. If the ink input speed S II is lower than the continuous printing speed S Continuous Printing, the ink has to be compensated immediately and dampening solution metering has to be compensated in a delayed manner, in order to achieve equalization as rapidly as possible. If, however, the ink input speed S II is greater than the continuous printing speed S Continuous Printing, this leads to an excessive supply of ink, and ink and dampening solution are compensated immediately.
[0030] A further machine state illustrated in FIG. 5 is the start-up of the printing press 1 after washing of the rubber blanket on the blanket cylinder 13 , 26 . In this case, that ink quantity which corresponds to the continuous printing state is situated in the printing unit 3 , 4 . Since, however, the resistance of the printing unit 3 , 4 as a rule rises at higher printing speeds, the ink quantity is too great for the starting speed. However, the corresponding ink quantities are missing at the start on the rubber blankets of the blanket cylinders 13 , 26 . The first printed sheets 9 are therefore usually underinked, for which reason ink and dampening solution are compensated immediately, in order to avoid such underinking.
[0031] FIG. 6 illustrates speed compensation during start-up of the printing press 1 without washing of the rubber blanket on the blanket cylinder 13 , 26 . That ink quantity which corresponds to the continuous printing state is also situated in the printing unit 3 , 4 in this case. Since, however, the rubber blanket is not washed, ink is still situated correspondingly on the rubber blanket. Since the resistance of the printing unit 3 , 4 as a rule rises at higher speeds, the ink quantity is too great for the starting speed. In this case, this leads to clear overinking of the first sheets 9 . In order to avoid such overinking, the dampening solution is compensated immediately and the ink metering is initiated subsequently in a delayed manner.
[0032] FIG. 7 shows the speed compensation after the print job change. In this case, the state is similar to after an ink input. The printing unit 3 , 4 is not situated as a rule in a stationary stable state. The most important influencing parameter in this case is the printing speed of the preceding print job S PR. If this printing speed S PR is greater than that of the following job S Continuous Printing, the ink quantity in the inking unit is too great; if it is lower, the ink quantity is too small. In the first case, the ink is therefore compensated in a delayed manner and the dampening solution is compensated immediately, in order to dissipate the excessive ink quantity. In the second case, the ink is compensated immediately and the dampening solution metering is compensated in a delayed manner, in order to obtain correspondingly more ink in the inking unit 16 , 17 .
[0033] FIG. 8 shows the start-up behavior of the printing press 1 during restarting of the printing press after washing of the rubber blanket. In this case, the printing speed difference (ds), that is to say the speed difference between the starting sheet and the continuous printing speed S Continuous Printing, is plotted on the x axis, and the difference in the ink density which results from the overinking during restarting after washing of the rubber blanket, is plotted on the y axis. The greater the printing speed difference, the greater the difference in the ink density. | A method for controlling the inking in a printing press includes compensation of an ink requirement in an inking unit and/or compensation of a dampening solution requirement in a dampening unit of the printing press in the event of a change in the printing speed. The printing speed profile or machine state prevailing before the instant of the change in the printing speed is taken into consideration in the compensation of the metering of ink or dampening solution. | 1 |
BACKGROUND OF THE INVENTION
The invention relates to a method for producing a rail substructure for railroad tracks, for which a rail bed is concreted and dowels are used to anchor the rails positively in the concrete.
For conventional railroad tracks, the substructure generally consists of a bed of road metal and railroad ties of wood or concrete, to which fastening claws are attached with bolts, so that the rails can be fastened adjustably. If the railroad ties are fabricated parts made from concrete, the dowels, into which the bolts are screwed later on, are cast in the finished concrete parts already during the manufacture of the railroad ties. The dowels can thus be anchored reliably in the concrete.
Rail substructures are also already known, for which a rail bed of concrete is provided instead of a bed of road metal. In the case of a known method for producing such a rail substructure, a rail bed is concreted with a flat surface in a first concreting step. When the concrete has set, the pre-fabricated railroad ties are placed upon it. These railroad ties are then concreted in a second step in a further layer of concrete. However, this method is time-consuming and costly.
SUMMARY OF THE INVENTION
It is an object of the invention to indicate a method of the type named above, which makes it possible to produce rail substructure more easily, more quickly and less expensively.
Pursuant to the invention, this objective is accomplished owing to the fact that, when concreting the rail bed, the dowels are inserted in the concrete, while the latter is still deformable.
This method has the advantage that pre-fabricated railroad ties are no longer required and that the rail substructure can be produced rationally in a single concreting step.
In the simplest case, the positive anchoring of the dowels in the concrete can be achieved owing to the fact that the dowels, which are provided with outwardly protruding projections, are simply pressed from above into the soft concrete. Since the concrete is still somewhat flowable, it flows around all the projections, so that the desired positive connection is brought about. In order to increase the reliability of this method, it is possible, after the dowels have been inserted, to consolidate the concrete with the help of a shaker or the like, the dowels being held in position during the shaking preferably with the help of an inserted mandrel. Moreover, it is possible to carry out the consolidation process so that, at the same time, railroad tie-like elevations are formed in the surface of the track bed at the same time, either in the form of continuous railroad ties for both rails or in the form of two isolated islands, on which in each case a single rail is to be fastened. At the same time, this method has the advantage that, during the consolidation process, there is flow of material in the still deformable concrete in the direction of the islands and, with that, in the direction of the dowels, so that the flow of concrete around the dowels is supported.
Another possibility for ensuring a reliable positive connection between the dowels and the concrete consists therein that the dowels are formed as straddling dowels, which initially are pressed into the concrete in the unexpanded state and expanded only then, so that they are set positively into the surrounding concrete. Since the expansion of the dowels at the same time leads to a consolidation of the surrounding concrete, reliable anchoring of the dowels can be achieved.
Pursuant to a further variation of the method, which is regarded as particularly preferred at the present time, the dowels are provided with thread-like projections on their peripheral surface and, as they are lowered into the concrete, are caused to rotate, so that they are screwed into the concrete. In this way, it can be achieved that the spaces between the projections are filled with concrete from the very start and, with that, a reliable indenting of the dowels in the concrete is achieved.
A dowel for implementing this variation of the method is also an object of the invention.
Preferably, an internal thread, into which later on the bolt for fastening the rail foot claw can be screwed, is prepared in the dowel. So that this thread (machine thread) does not become contaminated prematurely with concrete, the dowel preferably has a closing mechanism for temporarily closing the upper opening of the dowel. This closing mechanism can be formed by an inserted or slipped-on cap, a slider, by soft lips or by closing elements with break-off sites, which are gated to the dowel.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, examples of the invention are explained in greater detail by means of the drawing, in which
FIG. 1 shows a diagrammatic sketch to explain the method,
FIGS. 2 and 3 show a side view of and an axial section of a dowel for a first embodiment of the method and
FIGS. 4 and 5 show axial sections of a straddling dowel for a second embodiment of the method in different stages during the insertion of the dowel in the concrete.
DETAILED DESCRIPTION
For the method shown in FIG. 1, temporary rails 10 for a concreting carriage 12 are put down first. With the help of the concreting carriage 12 traveling on the rails 10 , a flat track bed 14 is concreted in the space between the two rails 10 .
The concreting carriage 12 is followed by a dowel-setting machine 16 , which also runs on the rails 10 . Alternatively, the dowel-setting machine may also be integrated in the concreting carriage 12 . With the help of the dowel-setting machine 16 , the plastic dowels 18 are pressed at regular intervals, corresponding to the distances between the railroad ties of a conventional rail substructure, into the still deformable concrete. By the curing of the concrete, the dowels are anchored firmly in the concrete. In each dowel-setting step, a total of four dowels is set, two for each of the rails of the track. However, only one of these four dowels can be seen in FIG. 1 .
In the example shown, the dowel-setting machine is combined with a shaker 20 , which, with the help of a molding plate 22 , deforms the surface of the track bed 14 , so that railroad tie elevations 24 are formed, which in each case surround two dowels 18 , which are assigned to the same rail. During shaking, material flows from the spaces between the elevations 24 into the region of the elevations, that is, in the direction of the dowels 18 , and the concrete material is consolidated in the immediate vicinity of the dowels, so that a firm anchorage of the dowels in the concrete is achieved.
In a modified embodiment of the method, however, the formation of the elevations 24 can be omitted. The dowels are then simply inserted into the flat track bed 14 and, correspondingly, the rails are also laid on the flat track bed. In a further variation of the method, it is possible, with the help of the concreting machine 12 , to produce a track bed, which has two parallel, continuously “extruded” elevations, on which the two rails are then mounted. Accordingly, greater clearance of the rail-bound vehicles is achieved in the region between the rails.
Two examples of the dowels 18 , with which positive anchorage of the dowels in the track bed 14 can be ensured with high reliability, are described below.
FIGS. 2 and 3 show a plastic dowel 18 , which, on its outer peripheral surface, has an arrangement of projections 26 , which form a continuous screw thread 28 with a constant slope. The projections 26 have a trapezoidal cross section and their height increases steadily from the upper to the lower end of the dowel. As a result, the spaces 30 between the individual threads become smaller from the bottom to the top.
With the help of the dowel setting machine 16 , the dowel 18 is lowered at a constant rate from above into the track bed 14 and, at the same time, rotates about its vertical axis at a suitably adapted rate, so that the dowel is screwed into the soft concrete composition, without displacing the concrete material from the interstices 30 . In contrast to this, the composition, displaced from the core region of the dowel, leads to a consolidation of the concrete and moreover, especially in the upper region of the dowel there is further consolidation of the material present there due to the decrease in the space between the threads. In this way, an entirely reliable anchorage of the dowel in the concrete is achieved.
As shown in FIG. 3, the hollow dowel 18 is reinforced in the upper region on the inside by helical reinforcing ribs 32 . The tip of the dowel is reinforced by an injected insert 34 . Between the upper region, reinforced by the reinforcing ribs 32 , and the insert 34 , a tapped bush 36 is injected and firmly interlocked with the surrounding plastic. A bolt, which is not shown and is used for fastening to the rail foot claw, can be screwed later on into the internal thread of this tapped bush 36 .
While the dowel 18 is lowered into the track bed 14 with the help of the dowel-setting machine, it is held on a mandrel of the dowel-setting machine, which extends through the tapped bush 36 into the tip of the dowel and, accordingly, fixes the dowel stably in its position. In this way, a precisely vertical alignment and a positionally correct setting of the dowel is made possible. Subsequently, the mandrel can be pulled freely upward from the dowel. Optionally, this takes place together with the lifting of the mold plate 22 , which is shown in FIG. 1 .
As further examples, FIGS. 4 and 5 show a dowel 18 ′, which is constructed as a straddling dowel. In the state, shown in FIG. 4, this dowel 18 ′ has a smooth, outer peripheral surface. The mantle wall of the dowel is, however, interrupted on a portion of its length by vertical slots 38 . Between these slots and distributed over the periphery, the mantle wall forms inwardly protruding projections 40 , which are sloped at the upper and lower ends and, in the center of the dowel, leave a channel for the already mentioned mandrel 42 of the setting machine. This mandrel extends through the tapped bush 36 up to the tip of the dowel.
With the help of the mandrel 42 , the dowel 18 ′, to begin with, is pressed into the fresh track bed 14 in the state shown in FIG. 4, the concrete material in the vicinity of the dowel being consolidated. Subsequently, the mandrel 42 of the dowel-setting machine moves back upward and, within the dowel-setting machine, an expansion sleeve 44 (FIG. 5) is moved into a position, in which it is centered on the axis of the dowel 18 ′. With the help of a tubular stamp, which surrounds the mandrel 42 , the expansion sleeve 44 is then pressed downward into the dowel 18 ′, as shown in FIG. 5 . At the same time, the projections 40 are pressed outward, so that they are pressed outwards into the concrete and bring about a positive anchoring of the dowel in the concrete. The expansion sleeve 44 remains in the dowel. Its internal diameter is large enough so that the bolt can be screwed into the tapped bush 36 later on.
In the example shown, the expansion sleeve 44 is closed by a gated sealing plate 46 , which is weakened by break-off sites 48 . The concrete mortar is prevented from penetrating into the dowel and contaminating the internal thread of the tapped bush 36 by this sealing plate 46 . Later on, when the bolt is to be screwed, the sealing plate 46 can simply be ruptured with the end of the bolt. The material of the sealing plate then remains in the space between the bolt and the expansion sleeve 44 .
A sealing device, corresponding to the sealing plate 46 , can also be provided in the case of the dowel 18 of FIGS. 2 and 3. In this case, however, the sealing device must be constructed so that, when the mandrel 42 is introduced, it yields and then, later on, it can assume, optionally automatically, its closed position once again. This can be achieved, for example, owing to the fact that the sealing plate is formed by soft lips or by elastic, circular tongues, which open and close in the manner of a heart valve. | A method for producing a rail substructure for railroad tracks, for which a rail bed is concreted and dowels are anchored positively in the concrete in order to fasten the rails, such that the dowels are inserted into the still deformable concrete during the concreting of the track bed. | 4 |
RELATED APPLICATIONS
This application is a division of application Ser. No. 640,945, filed Dec. 5, 1975, and entitled INLAY WHEEL AND METHOD (now U.S. Pat. No. 4,043,152 issued Aug. 23, 1977.
BACKGROUND OF THE INVENTION
The majority of double knit machines in existence today are fine gauge machines and more particularly 18 gauge machines. These machines were used to knit the majority of the double knit fabrics used in making slacks and trousers for ladies and gentlemen. But today many of these 18 gauge machines stand idle because of decreased demand for the fabric customarily produced on these machine.
Recently, there has appeared an apparatus utilizing a wheel for inlaying a yarn into fabric being knit on a double knit machine. See British Pat. No. 1,382,286 published Jan. 29, 1975. The inlay wheel in said British Patent comprises a shaft with a drive gear fixed to one end and a plurality of vanes fixed to the other end, each of which successively registers with the space between two adjacent needles in either the dial or cylinder bed, as desired. The drive gear has teeth which mesh with the stems or needles as the needle bed rotates in a conventional manner during knitting. Engagement of successive needle stems with the drive gear on the inlay wheel causes the inlay wheel to rotate on its shaft in the same direction as its associated needle bed and present successive vanes to the needle bed which register with the spaces between successive pairs of adjacent needles. The inlay yarn is trained circumferentially around successive vanes on one side of the inlay wheel and the vanes lay the inlay yarn on selected needles advanced to the tuck position and beneath other needles retained in welt position. The rotation of the inlay wheel delivers the inlay yarn to the needle bed and it is the correspondence in spacing of the gear teeth and the stems of the needles that causes the inlay wheel to rotate and deliver the inlay yarn to selected needles preparatory to being laid in the fabric.
Difficulty has been experienced in the use of the needle stems to rotate the inlay wheel because the critical correlation of spacing between the vanes and the spacing between needles in the needle bed is not reliably maintained; that is the rotation of the vanes on the inlay wheel is not reliably synchronized with the rotation of the dial. Consequently, the vanes sometimes hit the needles instead of meshing with the space between adjacent needles, causing a smash-up.
According to the invention, selected needles are removed (preferably alternate needles to half gauge the machine) to accommodate the inlay of coarse yarn, and the removed needles are replaced with drive elements which provide improved means to rotate the vanes of the inlay wheel in reliably precise synchronization with the rotation of the needle bed. The drive elements are of sturdier stock than the delicate needle stems used in the prior art to impart rotation to the drive gear and the drive elements are provided with butts so as to be under control of the needle cams but the drive elements do not have hooks or latches and play no part in knitting. The drive elements directly contact the vanes to impart rotational movement thereto as the needle bed rotates so that the separate gear of the prior art is eliminated.
The use of the inlay wheel in combination with the novel drive elements enables the production of a novel two gauge ground or body yarn and the surface side is apparently formed of a heavy or coarse gauge yarn; although in reality the heavy yarn is laid in spaced courses and tightly locked in place by stitches of the ground yarn.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a serviceable and decorative multi-gauge fabric or novel construction on a conventional fine gauge double knit machine.
It is another object of the invention to provide a novel method and apparatus for producing said fabric on said machine.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view, partially in elevation, of fragments of the dial and needle cylinder of a double knit machine and an associated inlay wheel,
FIG. 2 is a view similar to FIG. 1 but looking at the right side of FIG. 1 and showing the novel drive elements which replace alternate dial needles after the dial has been half-gauged;
FIG. 3 is an enlarged view of the inlay wheel in use and illustrating its relevant spacing to the knitting needles and drive elements;
FIG. 4 is an elevation of a drive element of this invention removed from the machine;
FIG. 4A is an elevation of a prior art knitting needle removed from the machine;
FIG. 5 is a view similar to FIG. 1 but in elevation;
FIG. 6 is a diagram of a first inlay construction;
FIG. 7 is the stitch construction according to the diagram of FIG. 6; and
FIGS. 8 and 9 are diagrams of alternate inlay constructions within the scope of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring more specifically to the drawings, the numeral 10 broadly designates the dial of a double knit machine having a plurality of radially extending grooves or tricks 11 within each of which conventionally radially reciprocable dial knitting needles 12. The machine also conventionally includes a needle cylinder 13 having vertically reciprocable needles 25 whose configuration is the same as the dial needles 12. In the illustrated embodiment, an inlay wheel 15 is associated with the dial 10. The usual form of camming arrangement is provided for operating the dial and cylinder needles, and the usual feed stations are circumferentially spaced around the machine from each of which fabric 14 extends.
It will be understood that the inlay wheel 15 may be associated with the cylinder of the machine and whereas in the construction shown in the drawings the dial and cylinder rotate, these parts may be fixed and the cylinder cam box and the dial cap rotated.
The attachment 15 includes a frame B which is adapted to be secured to the dial cap (not shown). The frame mounts a spindle 17 on which is mounted the inlay wheel 15 having on its periphery, circumferentially spaced and radially extending vanes or blades 20. The circumferential spacing of the blades 20 is approximately the width of two adjacent grooves 11. Thus, as most clearly seen in FIG. 2, adjacent blades 20 straddle adjacent grooves 11. Each blade is provided at its outer end with a V-shaped recess 21 to receive inlay yarn Y.
The frame mounts a yarn guide 16 for the inlay yarn Y and tensioning means (not shown) may be provided on the frame so that the tension of the inlay yarn may be adjusted. The guide 16 feeds the inlay yarn to V-shaped recesses 21 as best seen in FIGS. 1 and 5. The attachment is mounted intermediate a pair of thread feeds of the machine at a position which would normally be occupied by a thread feed so that there may be as many inlay attachments as there are thread feeds depending on the effect required in the finished fabric. In the illustrated embodiment, there is an inlay wheel attachment at every eighth feed, as is apparent from FIGS. 6-9.
According to the invention, selected needles are removed from the dial. This serves the dual purpose of providing additional space between dial knitting needles to accommodate a much coarser yarn than the body or ground yarn from which the fabric 14 is knit, and of providing space for the insertion of drive elements 30. In the illustrated embodiment alternate dial needles are removed so that the dial is half-gauged. A drive element is positioned in each of the vacant tricks or grooves 11 from which a dial needle has been removed. Each drive element 30 is dimensioned like the needle it replaces and includes butts 31 engagable with the conventional cams for actuating the elements 30 like the knitting needles during the knitting cycle. The drive elements 30 are under control of the conventional camming and are radially reciprocable within their respective grooves 11 according to a selected pattern. The drive elements differ from the knitting needles only in that the elements are slightly shorter than the needles, the elements do not have any hooks or latches and play no part in the formation of stitches, and the stem of the element is sturdier than the corresponding stem of the needle. The elements 30 function as spacers between needles and as drive members to engage the vanes 20 on the inlay wheel 15 responsive to rotation of the dial in a given direction indicated by the arrow D in FIG. 2. Engagement of vanes 20 by the driving elements 30 imparts rotation to the inlay wheel 15 in the same direction of movement as the dial 10.
Referring to FIG. 2, it will be observed that the peripheral spacing of the vanes 20 on the inlay wheel 15 coincides with the spacing between adjacent elements 30 in the dial 10, it being understood that there is a dial needle 12 between adjacent drive elements 30. Thus, in FIG. 2, it is shown that vane 20A is engaged by drive elements 30A just before vane 20B will be engaged by driving element 30B.
With a mechanical set-up as described above, the dial and cylinder needles form the fabric 14 from body or ground yarn such as 15 denier monofilament, for example. The fabric 14 may be of any desired construction such as Ponti Di Roma, Swiss Bouque, or the like. A plurality of inlay wheels 15 are positioned about the circumference of the dial 10, there being an inlay wheel at every eighth feed in the described form of invention to inlay yarn Y at every eighth course of the fabric. The inlay yarn Y is of a higher yarn such as, for example, 1500 denier and is locked to the fabric 14 formed from the 15 denier ground yarn in such a way as to appear only on the front or surface side of the fabric. In the completed fabric the higher denier inlay yarn Y substantially obscures the fine denier body yarn on the surface of the fabric and gives the appearance the entire fabric is formed of heavy denier yarn when in fact the heavy denier yarn is only laid in every eight courses or more or less as desired.
The inlay yarn Y is locked into the fabric 14 by presenting it from the inlay wheel 15 to selected needles 12t in the tuck position while passing selected needles 12w in the welt position. As most clearly seen in FIG. 3, the selected needles in the tuck position are the alternate odd numbered needles and the selected needles in the welt position are the intervening even numbered needles.
According to FIGS. 6 and 7, the inlay yarn Y is layed on the alternate odd numbered dial needles 12(1), 12(3), 12(5) in tuck position and floated across the intervening alternate even numbered dial needles 12(2), 12(4), 12(6) in welt position and also floated across the space occupied by intervening drive elements 30. Consequently, in the illustrated embodiment of FIGS. 6 and 7 the inlay yarn Y is laid in every 4th wale and floated across the three intervening wales, the alternate even numbered of every fourth wale being non-knit. The body yarn 29, according to FIGS. 6 and 7, is knit on every cylinder needle 25 in the inlay course 1 and on alternate odd numbered dial needles 12 in course 1. In course 2 of FIGS. 6 and 7 the body yarn 29 is knit on all the dial needles 12 but is not knit on any of the cylinder needles 25. It is apparent from FIG. 6 that this arrangement results in the body yarn 29 being knit all around the inlay yarn Y when it is laid on the alternate odd numbered dial needles 12, that is it is confined between body yarn knit in the same wale in adjacent courses and between the body yarns knit in adjacent wales in the same course.
In the alternate inlay construction of FIG. 8, the inlay course is also represented at 1 and the inlay yarn Y is laid on the odd numbered dial needles 12 in tuck position and floated across the intervening wales where the even numbered dial needles 12 are in welt position. As in FIG. 6, the body yarn 29 is knit on all the cylinder needles in course 1 and on the odd numbered alternate dial needles 12. In FIG. 8, however, the inlay yarn Y is locked in position by knitting the body yarn 29 on the same dial needles 12 in course 2 of FIG. 8.
The construction of FIG. 9 is similar to FIG. 8, the only difference occurring in courses 2 and 6. Courses 2 and 6 of FIG. 9 are the same as the corresponding courses in FIG. 6, where the ground yarn is not knit on the cylinder needles, but is knit on all the dial needles.
The drive elements 30 are indicated at X in the diagram of FIG. 6 and the effect of the drive elements 30 is shown by the non-knit area in every fourth wale of FIG. 7, there being three wales of knit construction between adjacent element wales.
There is thus provided a novel method of knitting on a conventional fine gauge double knit machine and the resulting fabric which includes a relatively course inlay yarn securely locked in and completely dominating the front or surface side of the fabric, to provide a highly ornamental and useful fabric. The scope of the invention is defined in the following claims. | A double knit fabric of a given gauge (usually fine gauge) is provided with an inlay of a coarser gauge yarn on a knitting machine with two needle beds. One side of the fabric is formed of only relativey fine gauge yarn and the relatively coarser inlay yarn is confined to the other or surface side of the fabric. Selected needles in one of the needle beds are replaced by drive elements. The inlay yarn is laid in by an inlay wheel driven in synchronization with the needle bed by said drive elements. | 3 |
TECHNICAL FIELD
The present invention relates to an improved method and apparatus for fabricating a sectional fishing rod suitable for casting, particularly fly casting. More particularly, the present invention relates to a method and apparatus for forming an improved ferrule structure at the butt end of the tip section of such a fishing rod.
BACKGROUND OF THE INVENTION
Fishing rods suitable for fly casting are generally so long as to require that the rod be fabricated in sections, usually a butt section and a tip section, so that it may be stored and transported conveniently. The sections are commonly joined together at a ferrule which is secured to the end of one section and telescopically receives the adjoining end of the second section. The ferrule must not only securely engage both sections; it must also provide sufficient strength to preclude permanent deformation or rupture under bending load without detracting from the tip flexibility required for efficient casting. Prior art ferrules generally require one or more separate steps during fabrication of the rod if they are to meet the stated strength and flexibility requirements.
It is an object of the present invention to provide a method and apparatus for fabricating a ferrule arrangement for a sectional fishing rod whereby the ferrule is formed along with one of the rod sections.
It is conventional to form sections of a fishing rod blank by wrapping resin-impregnated heat-curable sheets of material about a mandrel, compacting the wrapped material about the mandrel, and then curing the wrapped material with heat until the material solidifies. The compacting forces and the mandrel are then removed, leaving a tubular rod of desired configuration and properties. The mandrels used in these fabrication processes are generally tapered rods which have varying rates of taper along their lengths. Each rod section requires its own mandrel.
It is another object of the present invention to provide a mandrel for use in fabricating a fishing rod section, which mandrel permits a ferrule to be formed as an integral part of the rod section at the time the rod section is fabricated.
SUMMARY OF THE INVENTION
In accordance with the present invention, a mandrel for forming a tip section of a fishing rod has two tapered sections joined end-to-end at an annular shoulder. The smaller diameter section of the mandrel has one or more sheets of heat-curable material wrapped about it until the outside diameter of the material corresponds to the diameter of the second section of the mandrel adjacent the shoulder. In this manner, the wrapped material forms a smooth transition from the second or larger diameter section of the mandrel beyond the shoulder. Additional material can then be smoothly wrapped about the second section and the material which is wrapped about the first section. Material wrapped about the second section corresponds to the ferrule portion of the rod and, upon curing of the rod section, becomes integral with that section. The smooth transition of the wrapped material over the second section and the wrapped first section provides for a strong yet flexible ferrule section while permitting the ferrule to be fabricated inexpensively as part of the fabrication of the tip section of the rod.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and still further objects, features and advantages of this invention will become apparent upon consideration of the following detailed description of a specific embodiment thereof, especially when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a side view of an assembled fishing rod, the view being partially broken to accommodate the length of the rod;
FIG. 2 is an enlarged side elevation view of the tip and butt sections of the fishing rod of FIG. 1;
FIG. 3 is an enlarged side view showing the tip end of the butt section of the fishing rod in plan and showing the butt end of the tip section of the rod in partial cross-section;
FIG. 4 is a side view of a mandrel employed to fabricate the tip section of FIG. 3;
FIG. 5 is a side view showing a portion of the mandrel of FIG. 4 partially wrapped during fabrication of the tip section of the fishing rod;
FIG. 6 is a view of the mandrel, similar to FIG. 5, in a further stage of fabrication of the tip section of the fishing rod; and
FIGS. 7-13, inclusive, are plan views of respective sheets of wrap material which are successively wrapped about the mandrel of FIG. 4 to form the tip section of the fishing rod illustrated in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring specifically to FIG. 1 of the accompanying drawings, the fishing rod 10 includes a butt section 11 and a tip section 12. Apart from the formation of the ferrule 13 described below, these rods are essentially conventional and may be formed of fiberglass, graphite, or boron. The ferrule 13 formed as part of the present invention is most advantageously employed in a boron rod. The fabricated butt section 11 and tip section 12 are provided with conventional line guides 14, grip 15, and reel seat 16. The butt section 11 and tip section 12 are shown in FIG. 2 in greater detail with the ferrule 13 illustrated as comprising an integral part of the butt end of the tip section 12.
In forming the butt section blank 11, conventional techniques are employed whereby one or more sheets of resin-impregnated material (such as fiberglass, boron, graphite, etc.) are wrapped concentrically about a mandrel and then compacted against the mandrel by a spiral wrapping of cellophane strip material or the like. The compacted wrap material and mandrel are then heated until cured so that the material solidifies in the form of a hollow rod. The compacting cellophane and mandrel are removed leaving the rod as a separate structure. Both the tip and butt sections of the present rod are manufactured in substantially the same way, the difference residing in the inventive concept herein for forming the ferrule 13 in the manner described below.
As seen in FIG. 3, the ferrule 13 extends from the butt end of tip section 12 a comparatively short way along the length of the tip section 12. The hollow interior of ferrule 13 is tapered to conform to the outside periphery of the tip end of butt section 11 so that the butt section can be received in the ferrule in a friction fit engagement. The leading edge 17 of the butt end of tip section 11 is inserted into the ferrule when the tip and butt sections are to be joined. The interior of the ferrule 13 terminates in an annular shoulder 18 at which point the internal diameter steps down to a much smaller value before continuing its gradual taper toward the opposite end of tip section 12. When the tip and butt sections are engaged, as shown in phantom in FIG. 3, the leading edge 17 of the tip end of butt section 11 is spaced somewhat (i.e. on the order of 1/4 inch or less) from the shoulder 18 marking the end of ferrule 13.
A mandrel for forming tip section 12 integral with the ferrule 13 is illustrated in FIG. 4 and is designated by the reference numeral 20. The mandrel 20 includes two primary longitudinally aligned sections 21 and 22 which adjoin one another at an annular shoulder 23. Viewing mandrel 20 from left to right in FIG. 4, section 22, which corresponds to thef errule portion of the tip member 12, tapers gradually until reaching the step or annular shoulder 23. At shoulder 23, the diameter of the mandrel steps down suddenly and thereafter tapers until the end of section 21 is reached. The taper may be at a constant rate versus mandrel length beyond shoulder 23; alternatively, different longitudinal parts of section 21 may taper at different rates with mandrel length, such parts being demarked by dotted lines extending cross-wise to the length of the mandrel in FIG. 4. A pulling slot 24 is defined at the end of mandrel section 22 remote from shoulder 23 by removing material from the periphery of the mandrel. Pulling slot 24 is employed to grab the mandrel when removing it from the cured rod after heating.
Referring to FIG. 5 of the accompanying drawings, in forming the tip section 12 of the fishing rod, one or more sheets of heat-curable material 30 is wrapped about section 21 of the mandrel 20 from shoulder 23 to the opposite end of mandrel section 21. This material 30 is wrapped until its outside diameter corresponds to the outside diameter of mandrel section 22 at shoulder 23. In this manner, the wrapped material 30 provides a continuation of the taper in mandrel section 22 which would otherwise be interrupted by shoulder 23. After material 30 has been wrapped to the stated outside diameter, additional heat-curable material 31 is wrapped about section 22 and a portion of wrapped material 30 so as to overlap the shoulder 23. When material 31 has been wrapped to the desired thickness, a cellophane strip (not shown) is spirally wrapped about the entire length of the mandrel to compact the fibers in material 30 and 31 and hold them in the desired shape. The compacted unit is then heated so that material 30 and 31 is cured and hardened. The cellophane and the mandrel are then removed leaving the solidified tip section 12. The particular number of sheets employed to form wrap materials 30 and 31 are totally matters of choice, depending upon the nature of the material, the desired thickness of the annular tip section 12, the desired flexibility of the tip section 12 and the strength to be imparted to the ferrule 13. For example, material 30 can be a single sheet wrapped to the necessary number of thicknesses to provide an outer diameter adjacent shoulder 23 which conforms to the outer diameter of mandrel section 22. Likewise, material 31 can be a single sheet configured as necessary and wrapped to the desired thickness to provide the characteristics required of the ferrule 13. On the other hand, each of materials 30 and 31 may comprise plural sheets which are sucessively wrapped about the mandrel to provide the resultant tip section after curing. FIGS. 7-13 illustrate successive sheets of wrapping material which I have successively employed to form a tip section in accordance with the present invention.
Referring specifically to FIG. 7, a first sheet 33 of wrap material has a generally trapezoidal configuration in plan. Sheet 33 has a base 34 extending perpendicular to two sides 35 and 36. A top edge 37 tapers such that side 35 is longer than side 36. The degree or rate of taper with length changes at various points along the length of the side 37 as indicated, by way of example, by the dashed lines in FIG. 7. In applying sheet 33 to mandrel 20, base 34 is tacked to the mandrel so as to extend from shoulder 23 to the distal end of section 21. The mandrel is then rotated so that sheet 33 is wound about section 21 with side 35 of the sheet abutting shoulder 23 of the mandrel. In an actual embodiment, the material of sheet 33 is boron fibers plus a woven scrim material and impregnated with a suitable resin.
Sheet 38 illustrated in FIG. 8 is also of generally trapezoidal configuration and has a base 39, sides 40 and 41, and a tapered top side 42. Sheet 38 is wrapped about sheet 33 so that the two sheets together correspond to the material 30 illustrated in FIGS. 5 and 6. In the exemplary embodiment described, the material for sheet 38 is a scrim material impregnated with a suitable heat-curable resin.
Sheet 44, illustrated in FIG. 9, is generally rectangular in configuration with long sides 45 and 48 and short sides 46 and 47. Sheet 44 is wrapped about mandrel section 22 and a portion of the length of wrapped material 30 by tacking down one of sides 45 or 48 and then rotating the mandrel. In the exemplary embodiment described, sheet 44 includes fibers of graphite plus a woven scrim material and impregnated by a suitable heat-curable resin. Another rectangular configured sheet 49, illustrated in FIG. 10, is then wrapped over sheet 44 after which a further sheet 50, illustrated in FIG. 11, is wrapped over sheet 49 and an additional portion of the material 30. Sheet 50 has an odd-shaped plan configuration rendering it wider in the portion which overlaps the shoulder 23 than in the portion which wraps about mandrel section 22 remote from shoulder 23. Sheet 49, in the exemplary embodiment is fabricated from the same material as sheet 33 whereas sheet 50 is fabricated from the same material as sheet 44. Two additional odd-shaped sheets 51 (as illustrated in FIG. 12) and 52 (as illustrated in FIG. 13) are wrapped about the previous sheets in the vicinity of mandrel section 22 and overlapping shoulder 23 to complete the wrapping. Both sheets 51 and 52 are fabricated from the same material as sheet 38. Sheets 44, 49, 50, 51, and 52 correspond to the second wrap material 31 in FIG. 6.
The particular configuration of the various sheets and number of sheets utilized to form the ferrule described hereinabove are matters of choice which, as noted above, depend upon the various characteristics and features of the rod and ferrule section.
The resulting tip section 12, with its integrally formed ferrule 13, receives the tip end 17 of butt section 11 in a friction fit engagement when the fishing rod 10 is assembled for use. The ferrule 13, being integral with the tip section 12 and having material 31 overlapping shoulder 18, is resistant to rupture during flexure of the tip section.
It is important that shoulder 23 extend generally or substantially perpendicular to or radially from the longitudinal axis of mandrel 20 so that the material 30 can be wrapped in a position with its edge snugly abutting the shoulder. This permits the outer diameter of the wrapped material 30 to effect a smooth and continuous transition from mandrel section 22 along the mandrel length. This in turn permits material 31 to be wrapped over section 22 and material 30 without gaps between the two materials. The absence of such gaps enhances the strength of the resulting ferrule 13. It is to be understood that "generally or substantially" perpendicular as used herein, means an angle of 90°±10°.
While I have described and illustrated one specific embodiment of my invention, it will be clear that variations of the details of construction which are specifically illustated and described may be resorted to without departing from the true scope and spirit of the invention as defined in the appended claims. | A method of fabricating a tip section of a fishing rod with, an integral ferrule located at the butt end of the tip section, employs a mandrel having an annular shoulder separating two discrete mandrel sections. Heat-curable sheet material is wrapped about the first section adjacent the shoulder until the outer diameter of the wrapped material corresponds to the diameter of the second section of the mandrel. The result is a smooth transition from the second section to the wrapped material. Additional heat-curable material is then wrapped about the second section and the previously wrapped material overlapping the shoulder section. The wrapped material is compacted against the mandrel and heated until cured. Upon removal of the compacting forces of the mandrel, the cured material is in the form of a hollow rod having a ferrule for receiving another rod within the region of the second wrapped material. | 1 |
TECHNOLOGY AREA
The present invention relates to methods, systems, and media for combining conferencing signals.
BACKGROUND
Since the invention of the telephone, it has been possible for individuals to verbally communicate with each other without being physically located in the same place. More recently, voice and video conferencing systems have allowed groups of individuals to interact with each other as if they were sitting around the same table even though they may be half way around the world.
In order to enable multiple audio sources, such as multiple people speaking, to be heard at the same time, such conferencing systems frequently contain mixers to mix the audio signals. These mixers typically receive several input signals, select a subset of those signals as being active, e.g., based on amplitude, and then mix the active signals together.
Mixers are typically limited in how many input signals they can receive, however. In order to overcome this problem, prior systems have cascaded mixers so that an output of one mixer is feeding the input of another. In this way, a single input of a mixer can be used to receive multiple input signals that have already been mixed together from another mixer.
Similarly, video composers have combined video signals in an analogous fashion.
FIG. 1 is an illustration of such an arrangement of mixers. As shown, the arrangement may include three mixers 10 , 20 , and 30 . Each of these mixers may include an input section 14 , 24 , and 34 and a mixing section 15 , 25 , and 35 . One mixer, here mixer 10 , is the master mixer and the other mixers, here mixers 20 and 30 , are the slave mixers with their outputs connected to inputs of mixer 10 . As also shown in FIG. 1 , three participants 11 , 12 , and 13 are illustrated as being connected to mixer 10 , three participants 21 , 22 , and 23 are illustrated as being connected to mixer 20 , and three participants 31 , 32 , and 33 are illustrated as being connected to mixer 30 .
As shown, each of the participants 11 , 12 , 13 , 21 , 22 , 23 , 31 , 32 , and 33 receives an output signal from a mixing section of one of mixers 10 , 20 , and 30 . These output signals are a combination of the signals from the local mixer (e.g., mixer 10 for participants 11 , 12 , and 13 ) as well as remote mixers (e.g., mixers 20 and 30 for participants 11 , 12 , and 13 ).
In order to provide this combination of signals, the input sections of mixers 10 , 20 , and 30 first select a subset of their inputs for mixing. For example, the input section of mixer 10 will compare the signals from participants 11 , 12 , and 13 and the outputs of mixers 20 and 30 to identify a subset of signals to be mixed. This signals could be four signals from participants 11 and 12 and mixers 20 and 30 , as a more particular example. The mixing sections of the mixers then combine the selected signals and produce an output to be provided to the local participants and other mixers.
Because at least one output of each mixer 10 , 20 , and 30 is connected to an input of another mixer, the input from each participant can propagate to all participants through the other mixers. For example, assume participant 31 is speaking loudly enough to be selected by input section 34 of mixer 30 . The signal from that participant would be selected and mixed with some other set of signals (e.g., one or more of participants 32 and 33 and/or the output signal from mixer 10 ) and output to participants 31 , 32 , and 33 and mixer 10 . Mixer 10 would then select and mix signals from participants 11 , 12 , and 13 and mixers 20 and 30 . Again, assuming that the signal from participant 31 is suitably loud, the signal from participant 31 would then be included in the output of mixer 10 . Mixer 20 would then receive the output signal of mixer 10 , compare it to the signals from participants 21 , 22 , and 23 , select some set of these signals, mix the set of signals, and then output the mixed signal to participants 21 , 22 , and 23 and mixer 10 . Thus, the signal from participant 31 would propagate through mixer 30 to mixer 10 and then to mixer 20 , and then to participant 21 (for example).
This approach to mixing signals is problematic, however, in that it increases delay, accumulates signal quality degradation, and limits audio mixing capabilities. For example, because an input signal originating at a slave mixer needs to travel through that slave mixer and the master mixer in order to arrive at another slave mixer, there is increased delay over a configuration in which the two slave mixers were connected directly, for example. Similarly, as another example, this routing of the input signal also accumulates signal quality degradation because each mixer introduces its own signal degradation. And, because each mixer selects and produces a mixed signal that cannot be separated based upon its own inputs, audio mixing capabilities by the other mixers are limited to what signals are chosen to generate the mixed signal.
Likewise, combining of video signals in a similar fashion is also problematic.
Accordingly, improved methods, systems, and media for mixing conferencing signals are desired.
SUMMARY
Methods, systems, and media for combining conferencing signals are provided. In some embodiments, methods for mixing conferencing signals are provided, wherein the methods include: selecting first selected signals from a plurality of first input signals; combining the first selected signals to provide first combined signals; sending the first combined signals to at least one of an audio mixer and a video composer; receiving second combined signals from the at least one of an audio mixer and a video composer; separating a second input signal from the second combined signals; selecting second selected signals from the plurality of first input signals and the second input signal; combining the second selected signals to provide an output signal; and outputting the output signal.
In some embodiments, systems for combining conferencing signals are provided, wherein the systems include: a plurality of local participants that produce a plurality of first input signals; at least one of a first mixer and a first video composer that receives first combined signals and transmits second combined signals; and at least one of a second mixer and a second video composer coupled to the plurality of local participants that: receives the plurality of first input signals, selects first selected signals from the plurality of first input signals, combines the first selected signals to provide first combined signals, transmits the first combined signals to the at least one of a first mixer and a first video composer, receives the second combined signals from the at least one of a first mixer and a first video composer, separates a second input signal from the second combined signals, selects second selected signals from the plurality of first input signals and the second input signal, combines the second selected signals to provide an output signal, and outputs the output signal to the plurality of local participants.
In some embodiments, computer-readable media containing computer-executable instructions that, when executed by a computer, cause the computer to perform a method for combining conference signals, are provided, the method including: selecting first selected signals from a plurality of first input signals; selecting first selected signals from a plurality of first input signals; combining the first selected signals to provide first combined signals; sending the first combined signals to at least one of an audio mixer and a video composer; receiving second combined signals from the at least one of an audio mixer and a video composer; separating a second input signal from the second combined signals; selecting second selected signals from the plurality of first input signals and the second input signal; combining the second selected signals to provide an output signal; and outputting the output signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a prior art system for mixing conferencing signals in which the mixers are in a cascaded arrangement;
FIG. 2 is a block diagram of a system for mixing conferencing signals in accordance with certain embodiments of the present invention;
FIG. 3 is a diagram illustrating a method for mixing conferencing signals in accordance with certain embodiments of the present invention; and
FIG. 4 is a block diagram showing more detail of a mixer in accordance with certain embodiments of the present invention.
DETAILED DESCRIPTION
In accordance with certain embodiments of the present invention, methods, systems, and media for mixing conferencing signals are provided. For example, as shown in FIG. 2 , a configuration of mixers 110 , 120 , and 130 that may be used in methods, systems, and media of in accordance with certain embodiment is provided. As shown, each of mixers 110 , 120 , and 130 is coupled to corresponding ones of participants 111 , 112 , 113 , 121 , 122 , 123 , 131 , 132 , and 133 . These participants may be any suitable devices for engaging in a conference including, but limited to, video conferencing units, telephones, cellular phones, computers, and personal digital assistants. Although the outputs from the participants are shown as being coupled to the inputs to the mixers via a separate path from the path used to couple the outputs from the mixers to the inputs to the participants, the same path, or more than two paths, for each combination of mixer and participant can additionally or alternatively be used. Moreover, paths between mixers and different participants can be combined. These paths may be any suitable mechanism for coupling the participants and the mixers, including, but not limited to, dedicated connections, wired computer networks, wireless computer networks, telephone networks, the Internet, etc.
As also shown, mixers 110 , 120 , and 130 may be coupled together. For example, as illustrated each mixer may be coupled to each other mixer. The paths used to couple the mixers may be bidirectional, as shown, or may be unidirectional in various embodiments. These paths may be any suitable mechanism for coupling the mixers, including, but not limited to, dedicated connections, wired computer networks, wireless computer networks, telephone networks, the Internet, etc.
Although there are three mixers 110 , 120 , and 130 , each with three participants 111 , 112 , 113 , 121 , 122 , 123 , 131 , 132 , and 133 , and each being coupled to the other mixers, it should be apparent that any suitable numbers of mixers, with any suitable numbers of participants, coupled in any suitable manner, may be used in accordance with various embodiments. Any of the mixers and participants may be separate devices, may be combined together, or may be incorporated into other devices in accordance with various embodiments. For example, the mixers may be present in audio bridges, multi-conferencing units, etc.
Referring to FIG. 3 , a diagram of a method for mixing signals that may be used in mixers 110 , 120 , and 130 in accordance with various embodiments of the present invention is shown. Although FIG. 3 is described herein in connection with mixer 110 , it should be apparent that the method of FIG. 3 could be used with mixers 120 and/or 130 as well.
As illustrated, at 202 , the input section 114 of mixer 110 may select local inputs for further processing. These local inputs may include inputs from participants 111 , 112 , 113 , and/or any other participants coupled to mixer 110 . These inputs may be selected based upon any suitable criteria or criterion, including, but not limited to, which input is currently active, which input is most energetic, the absolute volume of the input signal, a relative volume of the input signal, a predetermined selection, a randomly made selection, etc. The number of inputs selected may be fixed or variable. For example, if volume is used as a criterion, in a fixed approach, the inputs with the four (or any other number) highest volume levels may be selected. In a variable approach, any inputs over a volume level may be selected. Thus, any suitable number of inputs may be selectable, from zero to all inputs, in accordance with various embodiments.
At 204 , input section 114 may combine the selected input signals together. The combining may produce one or more packets. The combining may occur in any suitable manner in which the input signals can be separated out after being combined, for example by using multiplexing. A header may be included within the combined output that contains a table of contents. An entry in the table of contents may refer to an input in the combined output and contain a unique identifier for the input and an indicator based on the criteria or criterion used to select the input (e.g., the input's volume level).
At 206 , the combined output may be sent from mixer 110 to mixers 120 and 130 (and/or any other mixers). The output may be sent using any suitable technique. For example, the output may be sent to specific mixers, may be broadcast to a set of mixers, may be multicast to specific mixers, etc.
At 208 , the input section 114 of the mixer may receive combined outputs from other mixers and separate-out the input signals from the combined outputs. The separating may occur in any suitable manner in which the inputs signals can be separated out from the combined signal, for example by de-multiplexing. The separating may be done for every signal in the combined output or may be done for only certain signals. For example, by inspecting the table of contents of a combined output, a mixer may determine that none, only certain, or all of the input signals need to be separated.
At 210 , the mixing section 115 of the mixer may select signals to be mixed and sent to the local participants (e.g., 111 , 112 , and/or 113 ) from the separated-out signals and local input signals. These signals may be selected based upon any suitable criteria or criterion, including, but not limited to, which signal is currently active, which signal is most energetic, the absolute volume of the signal, a relative volume of the signal, a predetermined selection, a randomly made selection, etc. The number of signals selected may be fixed or variable. For example, if volume is used as a criterion, in a fixed approach, the signals with the four (or any other number) highest volume levels may be selected. In a variable approach, any signals over a volume level may be selected. Thus, any suitable number of signals may be selectable, from zero to all signals, in accordance with various embodiments.
At 212 , the signals selected at 210 may be mixed using any suitable technique. For example, the signals may be mixed by summing the signals together and normalizing the level of the resultant mixed signal to an audible output level.
At 214 , the mixed signal from 212 may then be provided to the local participants. In order to reduce echo, each local participant's input signal (after suitable delay) may be subtracted from the mixed signal.
In some embodiments, 204 may be omitted and the inputs not combined, in which case rather than sending a combined output at 206 , the inputs may be sent individually. Whether to omit 204 may be determined on a mixer-by-mixer basis.
Turning to FIG. 4 , further details of mixer 110 in accordance with certain embodiments are illustrated. As shown, in addition to input section 114 and mixer section 115 , mixer 110 may include a decoder 116 , a DTMF detector 117 , a voice amplitude device 118 , a rate control device 119 , a rate control device 126 , an automatic gain control 127 , a DTMF injector 128 , and an encoder 129 .
Decoder 116 may be used decode compressed audio signals into linear streams. The DTMF detector 117 may be used to analyze the streams, detect DTMF signals, and perform DTMF suppression. Voice amplitude device 118 may be used to weight the streams' energies to detect voice activity and perform automatic gain control to ensure smooth audio energy levels in the input. Rate control device 119 may be used to change the sampling rate of the incoming streams, if necessary, by performing up or down sampling. Similarly, rate control device 126 may be used to change the sampling rate of output streams, if necessary, by performing up or down sampling. Automatic gain control 127 may be used to ensure smooth audio level energies in the output. DTMF injector 128 may be used to inject DTMF signals into the output. And encoder 129 may be used to encode the output linear streams into compressed audio signals.
Although FIG. 4 is shown and described as corresponding to mixer 110 , it should be apparent that FIG. 4 could equally apply to mixers 120 and 130 , or any other mixers, in accordance with various embodiments.
Methods, systems, and media in accordance with various embodiments may be applied to teleconferencing, video conferencing, Voice Over IP conferencing, Voice Plus Video Over IP conferencing, and any other variations of conferencing.
Although the present invention has been described and illustrated in the foregoing illustrative embodiments, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the details of implementation of the invention can be made without departing from the spirit and scope of the invention, which is limited only by the claims which follow. For example, although the present invention is illustrated herein as being implemented with audio mixers, the present invention may additionally or alternatively be implemented with video composers (for combining video signals) or any other suitable signal combining mechanisms. | Methods, systems, and media for combining conferencing signals are provided. In some embodiments, methods for combining conferencing signals are provided, wherein the methods include: selecting first selected signals from a plurality of first input signals; combining the first selected signals to provide first combined signals; sending the first combined signals to at least one of an audio mixer and a video composer; receiving second combined signals from the at least one of an audio mixer and a video composer; separating a second input signal from the second combined signals; selecting second selected signals from the plurality of first input signals and the second input signal; combining the second selected signals to provide an output signal; and outputting the output signal. | 7 |
BACKGROUND
[0001] Asymmetric phase transfer catalysis has been recognized as a convenient and powerful methodology in organic chemistry. This synthetic approach provides many advantages, including simple procedure, mild conditions, suitability for large scale reactions, and safety.
[0002] Various chiral phase transfer catalysts have been developed in the past thirty years, e.g., N-alkylated cinchomimium halide and N-spiro chiral ammonium salt. See O'Donnell et al., J. Am. Chem. Soc., 1989, 111, 2353; Ooi et al., J. Am. Chem. Soc., 1999, 121, 6519.
[0003] Yet, there is a need for less expensive and more efficient chiral phase transfer catalysts.
SUMMARY
[0004] This invention is based on the discovery that certain pentanidium compounds can be used as chiral phase transfer catalysts. The term “pentanidium compounds” herein refers to alkylated or arylated salts of pentanidines that contain five nitrogen atoms in conjugation.
[0005] In one aspect, this invention features pentanidium compounds of formula (I):
[0000]
[0006] In this formula, each of R 1 and R 8 , independently, is C 1 -C 10 alkyl, C 3 -C 20 cycloalkyl, C 3 -C 20 heterocycloalkyl, aryl, or heteroaryl; or R 1 and R 8 form C 1 -C 10 alkyl, C 3 -C 20 cycloalkyl, C 3 -C 20 heterocycloalkyl, aryl, or heteroaryl; each of R 2 , R 3 , R 6 , and R 7 , independently, is H, C 1 -C 10 alkyl, C 3 -C 20 cycloalkyl, C 3 -C 20 heterocycloalkyl, aryl, or heteroaryl; or R 2 and R 3 , together with the two carbon atoms to which they are attached, form C 4 -C 20 cycloalkyl, C 4 -C 20 heterocycloalkyl, aryl, or heteroaryl; or R 6 and R 7 , together with the two carbon atoms to which they are attached, form C 4 -C 20 cycloalkyl, C 4 -C 20 heterocycloalkyl, aryl, or heteroaryl; each of R 4 and R 5 , independently, is C 1 -C 10 alkyl, C 3 -C 20 cycloalkyl, C 3 -C 20 heterocycloalkyl, aryl, or heteroaryl; X − is a halide ion, a hydroxide ion, a tetrafluoroboric acid ion, a nitric acid anion, a hexaflorophosphoric acid ion, a tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, a sulfuric acid anion, a phosphoric acid anion, a citric acid anion, a methanesulfonic acid anion, a trifluoroacetic acid anion, a malic acid anion, a tartaric acid anion, a fumaric acid anion, a glutamic acid anion, a glucuronic acid anion, a lactic acid anion, a glutaric acid anion, a maleic acid anion, an acetic acid anion, or a p-toluenesulfonic acid ion; and at least one of the four carbon atoms to which R 2 , R 3 , R 6 , and R 7 are attached has an R or S configuration.
[0007] One subset of the above-described compounds are those in which R 1 is identical to R 8 , R 2 is identical to R 7 , R 3 is identical to R 6 , and R 4 is identical to R 5 . In these compounds, all the carbon atoms to which R 2 , R 3 , R 6 , and R 7 are attached have an R or S configuration (e.g., all of them having an R configuration, or all of them having a S configuration); each of R 2 , R 3 , R 6 , and R 7 , independently, is aryl or heteroaryl, or R 2 and R 3 , together with the two carbon atoms to which they are attached, form C 4 -C 20 cycloalkyl, and R 6 and R 7 , together with the two carbon atoms to which they are attached, form C 4 -C 20 cycloalkyl; and each of R 1 , R 4 , R 5 , and R 8 , independently, is C 1 -C 10 alkyl.
[0008] Another subset of the compounds described above are those in which R 1 is identical to R 8 , each of R 2 and R 7 is H, and R 4 is identical to R 5 ; all the carbon atoms to which R 3 and R 6 are attached have an R or S configuration; each of R 3 and R 6 , independently, is aryl or heteroaryl; and each of R 1 , R 4 , R 5 , and R 8 , independently, is C 1 -C 10 alkyl.
[0009] Still another subset of the compounds described above are those in which R 1 is identical to R 8 , each of R 3 and R 6 is H, and R 4 is identical to R 5 ; all the carbon atoms to which R 2 and R 7 are attached have an R or S configuration; each of R 2 and R 7 , independently, is aryl or heteroaryl; and each of R 1 , R 4 , R 5 , and R 8 , independently, is C 1 -C 10 alkyl.
[0010] The term “alkyl” refers to a saturated hydrocarbon moiety, either linear or branched. The term “cycloalkyl” refers to a saturated, cyclic hydrocarbon moiety, such as cyclohexyl. The tenn “heterocycloalkyl” refers to a saturated, cyclic moiety having at least one ring heteroatom (e.g., N, O, or S), such as 4-tetrahydropyranyl. The term “aryl” refers to a hydrocarbon moiety having one or more aromatic rings. Examples of aryl moieties include phenyl (Ph), phenylene, naphthyl, naphthylene, pyrenyl, anthryl, and phenanthryl. The term “heteroaryl” refers to a moiety having one or more aromatic rings that contain at least one heteroatom (e.g., N, O, or S). Examples of heteroaryl moieties include furyl, furylene, fluorenyl, pyrrolyl, thienyl, oxazolyl, imidazolyl, thiazolyl, pyridyl, pyrimidinyl, quinazolinyl, quinolyl, isoquinolyl and indolyl.
[0011] Alkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl mentioned herein include both substituted and unsubstituted moieties, unless specified otherwise. Possible substituents on cycloalkyl, heterocycloalkyl, aryl, and heteroaryl include, but are not limited to, C 1 -C 10 alkyl, C 2 -C 10 alkenyl, C 2 -C 10 alkynyl, C 3 -C 20 cycloalkyl, C 3 -C 20 cycloalkenyl, C 1 -C 20 heterocycloalkyl, C 1 -C 20 heterocycloalkenyl, C 1 -C 10 alkoxy, aryl, aryloxy, heteroaryl, heteroaryloxy, amino, C 1 -C 10 alkylamino, C 1 -C 20 diallcylamino, arylamino, diarylamino, C 1 -C 10 alkylsulfonamino, arylsulfonamino, C 1 -C 10 alkylimino, arylimino, C 1 -C 10 alkylsulfonimino, arylsulfonimino, hydroxyl, halo, thio, C 1 -C 10 alkylthio, arylthio, C 1 -C 10 alkylsulfonyl, arylsulfonyl, acylamino, aminoacyl, aminothioacyl, amido, amidino, guanidine, ureido, thioureido, cyano, nitro, nitroso, azido, acyl, thioacyl, acyloxy, carboxyl, and carboxylic ester. On the other hand, possible substituents on alkyl include all of the above-recited substituents except C 1 -C 10 alkyl. Cycloalkyl, heterocycloalkyl, aryl, and heteroaryl can also be fused with each other.
[0012] In another aspect, this invention features a method of preparing pentanidium compounds of formula (I) shown above.
[0013] The method includes reacting a compound of formula (II) with a compound of formula (III). The two formulae are shown below:
[0000]
[0014] In formulae (II) and (III), R 1 to R 8 , and X − are defined above. Also, at least one of the four carbon atoms to which R 2 , R 3 , R 6 , and R 7 are attached has an R or S configuration.
[0015] In still another aspect, this invention features a method of preparing a chiral compound of formula (IV):
[0000]
[0016] This method includes reacting an enone of formula (V):
[0000]
[0000] with a Schiff base of formula (VI):
[0000]
[0000] in the presence of a catalyst, which is a compound of formula (I) shown above.
[0017] In formulae (IV), (V), and (VI), R 11 is H, C 1 -C 10 alkyl, C 3 -C 20 cycloalkyl, C 3 -C 20 heterocycloalkyl, aryl, or heteroaryl; each of R 12 and R 13 , independently, is H, C 1 -C 10 alkyl, C 3 -C 20 cycloalkyl, C 3 -C 20 heterocycloalkyl, aryl, or heteroaryl; or R 12 and R 13 , together with the carbon atom to which they are attached, is C 3 -C 20 cycloalkyl, or C 3 -C 20 heterocycloalkyl; each of R 14 and R 15 , independently, is H, C 1 -C 10 alkyl, C 3 -C 20 cycloalkyl, C 3 -C 20 heterocycloalkyl, aryl, or heteroaryl; or R 14 and R 15 , together with the carbon atom to which they are attached, is C 3 -C 20 cycloalkyl, or C 3 -C 20 heterocycloalkyl; R 16 is C 1 -C 10 alkyl, C 3 -C 20 cycloalkyl, C 3 -C 20 heterocycloalkyl, aryl, or heteroaryl.
[0018] The details of one or more embodiments of the invention are set forth in the description below. Other features, objects, and advantages of the invention will be apparent from the description and also from the claims.
DETAILED DESCRIPTION
[0019] The pentanidium compounds of this invention can be prepared by methods well known in the art, e.g., Ma et al., J. Am. Chem. Soc., 2011, 133, 2828. The route shown in Scheme 1 below exemplifies synthesis of these compounds.
[0000]
[0020] Specifically, a diamine compound i can react with triphosgene in the presence of a base to form compound ii, which can be converted into compound iii through alkylation. Compound iii can be treated with oxalyl chloride under a heating condition to yield an imidazoline salt. This salt can react with ammonia to obtain imidazolidin-2-imine iv, which in turn is treated with an imidzaoline salt to form the compounds of the invention, e.g., Compound 1a-1f shown below:
[0000]
[0021] A pentanidium compound thus synthesized can be purified by any suitable method, such as column chromatography, high-pressure liquid chromatography, or recrystallization.
[0022] Other pentanidium compounds of this invention can be prepared using other suitable starting materials through the above-described synthetic routes and others known in the art. The methods set forth above may also additionally include steps to add or remove suitable protecting groups in order to ultimately allow synthesis of the pentanidium compounds. In addition, various synthetic steps may be performed in an alternate sequence or order to give the desired compounds. Synthetic chemistry transformations and protecting group methodologies (protection and deprotection) useful in synthesizing applicable pentanidium compounds are known in the art and include, for example, those described in R. Larock, Comprehensive Organic Transformations, VCH Publishers (1989); T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, 2 rd Ed., John Wiley and Sons (1991); L. Fieser and M. Fieser, Fieser and Fieser's Reagents for Organic Synthesis, John Wiley and Sons (1994); and L. Paquette, ed., Encyclopedia of Reagents for Organic Synthesis, John Wiley and Sons (1995) and subsequent editions thereof.
[0023] The pentanidium compounds described herein may contain a non-aromatic double bond and one or more asymmetric centers. Thus, they can occur as single enantiomers, individual diastereomers, diastereomeric mixtures, and cis- or trans-isomeric forms. All such isomeric forms are contemplated.
[0024] Also within the scope of this invention is a method of preparing the pentanidium compounds described above.
[0025] These pentanidium compounds can be used as chiral phase transfer catalysts in asymmetric reactions, such as asymmetric alkylation, Michael addition, aldol reaction.
[0026] The specific examples below are to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. Without further elaboration, it is believed that one skilled in the art can, based on the description herein, utilize the present invention to its fullest extent. All publications cited herein are hereby incorporated by reference in their entirety.
General Information
[0027] 1 H and 13 C NMR spectra were recorded on a Bruker ACF300 (300 MHz), Bruker DPX300 (300 MHz), 500 MHz Bruker DRX NMR spectrometer, or AMX500 (500 MHz) spectrometer. Chemical shifts were reported in parts per million (ppm). The residual solvent peak was used as an internal reference. Low resolution mass spectra were obtained on a Finnigan/MAT LCQ spectrometer in ESI mode. High resolution mass spectra were obtained on a Finnigan/MAT 95XL-T spectrometer. Enantiomeric excess values were determined by chiral HPLC analysis on Dionex Ultimate 3000 HPLC units, including a Ultimate 3000 Pump, Ultimate 3000 variable Detectors. Optical rotations were recorded on a Jasco DIP-1000 polarimeter with a sodium lamp of wavelength 589 nm and reported as follows; T °Cλ [α] (c=g/100 mL, solvent). Melting points were determined on a BÜCHI B-540 melting point apparatus. Flash chromatography separations were performed on Merck 60 (0.040-0.063 mm) mesh silica gel. Toluene was distilled from sodium/benzophenone and stored under N 2 atmosphere. MeCN was dried by Molecular Sieve. Dichloromethane was distilled from CaH 2 and stored under N 2 atmosphere. Other reagents and solvents were commercial grade and were used as supplied without further purification, unless otherwise stated. Experiments involving moisture and/or air sensitive components were performed under a positive pressure of nitrogen in oven-dried glassware equipped with a rubber septum inlet. Reactions requiring temperatures −20 ° C. were stirred in either Thermo Neslab CB-60 with Cryotrol temperature controller or Eyela PSL-1400 with digital temperature controller cryobaths. Isopropanol was used as the bath medium. All experiments were monitored by analytical thin layer chromatography (TLC). Instrumentations Proton nuclear magnetic resonance ( 1 H NMR), carbon NMR ( 13 C NMR), phosphorous NMR ( 31 P NMR), and fluorine NMR ( 19 F NMR) spectra were recorded in CDCl 3 otherwise stated. 1 H (500.1331 MHz), 13 C (125.7710 MHz) with complete proton decoupling, 31 P (121 MHz) with complete proton decoupling, and 1 H NOESY NMRs were performed on a 500 MHz Bruker DRX NMR spectrometer. 19 F NMR (282.3761 MHz) was performed on a 300 MHz Bruker ACF spectrometer. All compounds synthesized were stored in a −34° C. freezer.
EXAMPLE 1
Synthesis of Compound 1a: (S,S)-Tetraphenyl-tetramethyl-pentanidium chloride
[0028] Provided below are the scheme and detailed procedures for synthesizing intermediates (Compounds B-D) and Compound 1a from Compound A.
[0000]
Step 1. Synthesis of (S,S)-4,5-Diphenylimidazolidin-2-one (Compound B)
[0029] To a solution of Compound A, a chiral diamine (2.12 g, 10 mmol) and Et 3 N (4.1 ml, 30 mmol) in CH 2 Cl 2 (25 mL), was added triphosgene (977 mg, 3.3 mmol, dissolved in 5 mL CH 2 Cl 2 ) in a dropwise manner, keeping the temperature lower than 5° C. all the time. After allowing the temperature to rise to room temperature, an additional 4-5 hours of stirring was required to allow the reaction to complete (monitored by TLC). After diamine A was completely consumed, reaction was quenched by water (20 mL) and extracted using CH 2 Cl 2 3 times (30 mL×3). The combined organic layer was washed by brine and dried by Na 2 SO 4 . Solvent was removed under reduced pressure. Compound B was pale yellow solid, which can be used in the next step without any further purification. 1 H NMR (300 MHz, CDCl 3 ): δ 7.38-7.34 (m, 6H), 7.27-7.30 (m, 4H), 5.83 (s, 2H), 4.57 (s, 2H). 13 C NMR (126 MHz, CDCl 3 ) δ 163.1, 140.2, 128.7, 128.2, 126.4, 65.9; LRMS (ESI) m/z 239.1 (M+H + ), HRMS (ESI) m/z 239.1185 ([M+H + ]), calc. for [C 15 H 14 N 2 O+H + ]239.1179.
Step 2. Synthesis of (S,S)-1,3-Dimethyl-4,5-diphenylimidazolidin-2-one (Compound C)
[0030] To a suspension of NaH (720 mg, 30 mmol, 3.0 equiv) in THF (15 mL) was added a solution of Compound B (from step 1) in THF (20 mL). After 0.5 h, 2.3 mL of MeI (37 mmol, 3.7 equiv) was added in one portion. Upon completion of the reaction (monitored by TLC), the mixture was filtered through a short pad of Celite. Solvent was removed under reduced pressure and Compound C was obtained by flash chromatography (silica gel, hexane-ethyl acetate 3:1), as a white solid, 2.10 g (2 steps, 80% overall yield). 1 HNMR (300 MHz, CDCl 3 ): δ 7.34-7.32 (m, 6H), 7.14-7.11 (m, 4H), 4.07 (s, 2H), 2.69 (s, 6H); 13 C NMR (126 MHz, CDCl 3 ) δ 161.7, 137.9, 128.7, 128.3, 127.2, 70.2, 29.9; LRMS (ESI) m/z 267.1 (M+H + ), HRMS (ESI) m/z 267.1497 ([M+H + ]), calc. for [C 17 H 18 N 2 O +H + ]267.1492.
Step 3. Synthesis of Imidazoline Salt
[0031] A 100 mL RBF was charged with a solution of Compound C (1.60 g, 6 mmol, 1 equiv) in toluene (40 mL) with a condenser under N 2 atmosphere. (COCl) 2 (5.2 mL, 60 mmol, 10 equiv) was added via syringe in one portion. The mixture was refluxed overnight until C was completely reacted. Toluene was removed under reduced pressure and solid imidazoline salt (1.93 g) was obtained for the next step without any purification. Note that imidazoline salt is air and moisture sensitive, which should be stored under nitrogen atmosphere or vacuum.
Step 4. Synthesis of (4S,5S)-1,3-Dimethyl-4,5-diphenylimidazolidin-2-imine (Compound D)
[0032] Separate half of imidazoline salt for the step 5. The other part (960 mg) was dissolved in dry MeCN/MeOH (volume ratio 1:1, 20 mL), NH 3 was bubbled into the solution at 0° C. for 0.5 h. Then, the seal tube was sealed and placed in 60° C. oil bath. After stirring overnight to complete reaction, pressure was released and water was added (40 mL). The mixture was extracted by CH 2 Cl 2 3 times (20 mL×3). The combined organic layer was dried by Na 2 SO 4 . After removing solvent under reduced pressure, Compound D was obtained as a brown solid, 801 mg, >99% yield. 1 H NMR (300 MHz, CDCl 3 ): δ 7.17-7.14 (m, 6H), 6.99-6.97 (m, 4H), 4.48 (b, 1H), 3.87 (s, 2H), 2.52 (s, 6H); 13 C NMR (125.77 MHz, CDCl 3 ): δ 163.3, 137.9, 128.6, 128.2, 127.4, 72.1, 31.4; LRMS (ESI) m/z 266.1 (M+H + ), HRMS (ESI) m/z 266.1664 ([M+H + ]), calc. for [C 17 H 19 N 3 +H + ]266.1652.
Step 5. Synthesis of (S,S)-Tetraphenyl-tetramethyl-pentanidium chloride (Compound 1a)
[0033] To a solution of Compound D (800 mg, 3.06 mmol) and Et 3 N (0.45 mL, 3.24 mmol) in MeCN (15 mL) was added a solution of imidazoline salt (from step 4, 970 mg, 1.0 equiv) in dry MeCN (10 mL) in a dropwise manner. The reaction mixture was stirred until the reaction was completed. Reaction was quenched by water (20 mL), and extracted using CH 2 Cl 2 3 times (20 mL×3). The combined organic layer was dried by Na 2 SO 4 . Solvent was removed under reduced pressure. The brown solid obtained was re-crystallized by CH 2 Cl 2 /ethyl acetate solvent system. Compound la was isolated as a white solid, 820 mg, 48% yield. mp 276-278° C.; 1 H NMR (500 MHz, CDCl 3 ): δ 7.35-7.34 (m, 12H), 7.24-7.21 (m, 8H), 4.67 (s, 4H), 2.93 (s, 12H); 13 C NMR (126 MHz, CDCl 3 ) δ 159.5, 135.4, 129.3, 129.3, 127.6, 72.6, 32.5; LRMS (ESI) m/z 514.5 ([M−Cl − ]) + , HRMS (ESI) m/z 514.2970 ([M−Cl − ]) + , calc. for [C 34 H 36 N 5 + ]514.2965. [α] D 29 =+171.2 (c 1.18, CHCl 3 ).
Example 2
Synthesis of Compound 1b: (S,S)-Tetraphenyl-tetraethyl-pentanidium chloride
[0034] Compound 1b was prepared in a manner similar to that described in Example 1, with two additional steps described below. See Ryoda, A et al., JOC, 2008, 73, 133.
[0000]
[0035] White solid. 1 H NMR (500 MHz, CDCl 3 ) δ 7.42-7.40 (m, 12H), 7.17-7.15 (m, 8H), 4.53 (s, 4H), 4.31-4.24 (m, 4H), 3.05-3.03 (m, 4H), 1.16 (t, J=7.5, 12H); 13 C NMR (126 MHz, CDCl 3 ) δ 157.1, 136.5, 129.4, 129.4, 127.0, 69.8, 39.0, 11.3; LRMS (ESI) m/z 570.5 ([M—Cl − ]) + , HRMS (ESI) m/z 570.3586 ([M−Cl − ]) + , calc. for [C 38 H 44 N 5 + ] 570.3591.
Example 3
Synthesis of Compound 1c: (S,S)-Tetra-4-methoxy-phenyl-tetraethyl-pentanidium chloride
[0036] Compound 1c was prepared in a manner similar to that described in Example 1 except that a different starting material, i.e., (1S,2S)-1,2-bis(4-methoxyphenyl)ethane-1,2-diamine, was used.
[0037] White solid; 56% yield. 1 H NMR (300 MHz, CDCl 3 ) δ 7.19 (d, J=8.7 Hz, 8H), 6.89 (d, J=8.7 Hz, 8H), 4.60 (s, 4H), 3.79 (s, 12H), 2.90 (s, 12H); 13 C NMR (75 MHz, CDCl 3 ) δ 160.2, 159.2, 129.0, 127.3, 114.6, 72.2, 55.2, 32.3; LRMS (ESI) m/z 634.5 ([M−Cl − ]) + , HRMS (ESI) m/z 634.3403 ([M−Cl − ]) + , calc. for [C 38 H 44 N 5 O 4 + ] 634.3388.
Example 4
Synthesis of Compound 1d: (S,S)-Tetraphenyl-tetramethyl-pentanidium tetrafluoroborate
[0038] Compound 1d was synthesized by reacting Compound la (prepared in Example 1) with sodium tetrafluoroborate in the following manner:
[0000]
[0039] White solid; 98% yield. 1 H NMR (300 MHz, CDCl3) δ 7.40-7.37 (m, 12H), 7.26-7.22 (m, 8H), 4.62 (s, 4H), 2.91 (s, 12H); 13 C NMR (75 MHz, CDCl3) δ 159.5, 135.5, 129.30, 129.2, 127.6, 104.9, 72.7, 32.2; 19 F NMR (282 MHz, CDCl 3 ) δ-76.59.
Example 5
Synthesis of Compound 1e: (S,S)-Tetraphenyl-tetramethyl-pentanidium hexafluorophosphate
[0040] Compound le was synthesized by reacting Compound la (prepared in Example 1) with sodium hexafluorophosphate in the following manner:
[0000]
[0041] White solid; 99% yield. 1 H NMR (300 MHz, CDCl 3 ) δ 7.43-7.40 (m, 12H), 7.27-7.24 (m, 8H), 4.63 (s, 4H), 2.92 (s, 12H); 13 C NMR (75 MHz, CDCl 3 ) δ 159.4, 135.4, 129.4, 129.3, 127.6, 72.7, 32.2; 19 F NMR (282 MHz, CDCl 3 ) δ 3.32 (d, 710Hz). 31 P NMR (121 MHz, CDCl 3 ) δ-143.6 (tt, J 1 =709 Hz, 1418 Hz).
Example 6
Synthesis of Compound 1f: (S,S)-Dicyclohexyl-tetramethyl-pentanidium chloride
[0042] Compound 1f was prepared in a manner similar to that described in Example 1 except that a different starting material, i.e., (1S,2S)-cyclohexane-1,2-diamine, was used. Also, the compound thus-synthesized was purified by flash chromatography (silica gel, CH 2 Cl 2 /MeOH, 50:1).
[0043] Colorless oil. 1 H NMR (300 MHz, CDCl 3 ) δ 3.01-2.99 (m, 4H), 2.79 (s, 12H), 2.19-2.10 (m, 8H), 1.93 (d, J =6.2 Hz, 4H), 1.45-1.42 (m, 4H); 13 C NMR (75 MHz, CDCl 3 ) δ 162.7, 66.2, 31.4, 27.8, 23.8; LRMS (ESI) m/z 318.5 ([M−Cl − ]) + , HRMS (ESI) m/z 318.2659 ([M−Cl − ]) + , calc. for [C 18 H 32 N 5 + ] 318.2652.
Example 7
Use of Compound 1a as a Chiral Phase Transfer Catalyst in Michael Addition
7-1. Synthesis of Compounds 4a-4f
[0044] Table 1 below lists Michael addition of a Schiff Base (i.e., Compound 2) with various vinyl ketones and acrylates (i.e., Compounds 3a-3f) to yield Compounds 4a-4f in the presence of Compound la as the catalyst. Compounds 3a-3f were prepared following the procedures described in Ma et al., J. Am. Chem. Soc., 2011, 133, 2828.
[0000]
TABLE 1
Entry
3 [R]
4
Time (h)
Yield (%) b
ee (%) c
1
3a [Et]
4a
4
92
93
2
3b [Me]
4b
3
86
91
3
3c [n-Bu]
4c
1
97
93
4
3d [Ph]
4d
1
50
88
5
3e [OEt]
4e
6
71
97
6
3f [OBn]
4f
4
80
96
7 d
3f [OBn]
4f
6
77
93
8 e
3f [OBn]
4f
12
75
91
a Reactions were performed by using Compound 2 (0.06 mmol) and Compounds 3a-3f (0.12 mmol) in 0.6 ml mesitylene for indicated time.
b Yield of isolated product.
c Determined by HPLC analysis using a Chiralcel OD-H column.
d 0.1 mol % of catalyst was used.
e 0.03 mol % of catalyst was used.
Synthesis of (R)-tert-Butyl-2-((diphenylmethylene)amino)-5-oxoheptanoate (Compound 4a)
[0045] tert-Butyl glycinate benzophenone Schiff base, Compound 2 (17.7 mg, 0.06 mmol, 1.0 equiv), (S, S)-1a (0.66 mg, 0.0012 mmol, 0.02 equiv) and Cs 2 CO 3 (97 mg, 0.2 mmol, 5.0 equiv) were placed in mesitylene (0.6 mL) and stirred at −20 ° C. for 10 min, then ethyl vinyl keton 3a (12.8 μL, 0.12 mmol, 2.0 equiv) was added by syringe in one portion. The reaction mixture was stirred at −20° C. and monitored by TLC. After indicated time, upon complete consumption of 2, the reaction mixture was directly loaded onto a short silica gel column, followed by gradient elution with hexane/ethyl acetate (15/1-12/1 ratio). After removing the solvent, product 4a (20.9 mg, 92% yield) was obtained as colorless oil. 1 H NMR (300 MHz, CDCl 3 ) δ 7.67-7.58 (m, 2H), 7.47-7.27 (m, 6H), 7.16 (dd, J =6.4, 3.1 Hz, 2H), 3.95 (t, J =6.1 Hz, 1H), 2.59-2.32 (m, 4H), 2.15 (dd, J=13.6, 7.6 Hz, 2H), 1.43 (s, 9H), 1.01 (t, J=7.3 Hz, 3H); 13 C NMR (75 MHz, CDCl 3 ) δ 210.8, 170.9, 170.3, 139.4, 136.4, 130.2, 128.5, 127.9, 127.6, 81.0, 64.7, 38.4, 35.8, 27.8, 7.67; LRMS (ESI) m/z 402.1 (M+Na + ), HRMS (ESI) m/z 402.2037 ([M+Na + ]), calc. for [C 24 H 29 NO 3 +Na + ] 402.2040; [α] D 29 =+72.8 (c 1.55, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=92/8, 0.8 mL/min, 230 nm, 23° C.), 5.9 (major), 8.0 min, 93% ee.
Synthesis of (R)-tert-Butyl-2-((diphenylmethylene)amino)-5-oxohexanoate (Compound 4b)
[0046] Colorless oil; 86% yield. 1 H NMR (300 MHz, CDCl 3 ) δ 7.67-7.58 (m, 2H), 7.47-7.27 (m, 6H), 7.17-7.15 (m, 2H), 3.95 (t, J =6.1 Hz, 1H), 2.59-2.45 (m, 2H), 2.35-2.15 (m, 2H), 2.12 (s, 3H), 1.43 (s, 9H); 13 C NMR (75 MHz, CDCl 3 ) δ 208.2, 170.9, 170.4, 139.4, 136.4, 130.2, 128.7, 128.5, 128.4, 128.4, 127.9, 127.6, 81.1, 64.6, 39.7, 29.8, 28.0, 27.7; LRMS (ESI) m/z 388.1 (M+Na + ), HRMS (ESI) m/z 388.1900 ([M+Na + ]), calc. for [C 23 H 27 NO 3 +Na + ] 388.1883; [α] D 29 =+64.2 (c 1.30, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=92/8, 0.8 mL/min, 210 nm, 23° C.), 6.5 (major), 7.2 min, 91% ee.
Synthesis of (R)-tert-Butyl-2-((diphenylmethylene)amino)-5-oxononanoate (Compound 4c)
[0047] Colorless oil; 97% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 7.66-7.60 (m, 2H), 7.47-7.41 (m, 3H), 7.38-7.37 (m, 1H), 7.32 (t, J=7.5 Hz, 2H), 7.19-7.13 (m, 2H), 3.95 (t, J=12.1 Hz,1H), 2.55-2.42 (m, 2H), 2.41-2.33 (m, 2H), 2.14 (dd, J=13.8, 7.5 Hz, 2H), 1.54-1.47 (m, 2H), 1.43 (s, 9H), 1.27 (dd, J=15.0, 7.4 Hz, 2H), 0.88 (t, J=7.3 Hz, 3H); 13 C NMR (75 MHz, CDCl 3 ) δ 210.6, 171.0, 170.3, 139.4, 136.4, 130.2, 128.7, 128.5, 128.4, 127.9, 127.6, 81.0, 64.7, 42.4, 38.8, 28.0, 27.7, 25.8, 22.2, 13.8; LRMS (ESD m/z 430.1 (M+Na + ), HRMS (ESI) m/z 430.2364 ([M+Na + ]), calc. for [C 26 H 33 NO 3 +Na + ] 430.2353; [α] D 29 =+43.4 (c 1.62, CHCl 3 ); HPLC analysis: Chiralcel OD-H+Chiralcel OD-H (Hex/IPA=95/5, 0.5 mL/min, 230 nm, 23° C.), 19.4 (major), 23.6 min, 93% ee.
Synthesis of (R)-tert-Butyl-2-((diphenylmethylene)amino)-5-oxo-5-phenyl pentanoate(Compound 4d)
[0048] Colorless oil; 50% yield. 1 H NMR (300 MHz, CDCl 3 ) δ 7.95-7.93 (m, 2H), 7.65 (d, J=7.1 Hz, 2H), 7.56-7.53 (m, 1H), 7.45-7.39 (m, 6H), 7.32 (t, J=7.3 Hz, 2H), 7.15-7.13 (m, 2H), 4.08 (t, J=6.0 Hz, 1H), 3.16-3.01 (m, 2H), 2.33 (dd, J=13.3, 6.9 Hz, 2H), 1.45 (s, 9H); 13 C NMR (75 MHz, CDCl 3 ) δ 199.6, 176.1, 171.0, 170.1, 136.8, 132.9, 132.4, 130.3, 130.0, 128.8, 128.5, 128.4, 128.2, 128.1, 128.0, 127.7, 64.7, 34.7, 28.0; LRMS (ESI) m/z 450.1 (M+Na + ), HRMS (ESI) m/z 450.2056 ([M+Na + ]), calc. for [C 28 H 29 NO 3 +Na + +450.2040; [α] D 29 =19.1 (c 0.5, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=92/8, 0.8 mL/min, 254 nm, 23° C.), 6.5 (major), 8.8 min, 88% ee.
Synthesis of (R)-1-tert-Butyl-5-ethyl-2-((diphenylmethylene)amino)pentanedioate (Compound 4e)
[0049] Colorless oil; 71% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 7.67-7.6 (m, 2H), 7.47-7.41 (m, 3H), 7.40-7.35 (m, 1H), 7.35-7.29 (m, 2H), 7.20-7.14 (m, 2H), 4.05 (q, J=7.1 Hz, 2H), 3.97 (dd, J=6.9, 5.7 Hz, 1H), 2.35 (dd, J=8.6, 6.8 Hz, 2H), 2.33-2.21 (m, 2H), 1.44 (s, 9H), 1.19 (t, J=7.1 Hz, 3H); 13 C NMR (75 MHz, CDCl 3 ) δ 210.8, 170.9, 170.3, 139.4, 136.4, 130.2, 128-.5, 127.9, 127.6, 81.0, 64.7, 38.4, 35.8, 27.8, 7.67; LRMS (ESI) m/z 418.1 (M+Na + ), HRMS (ESI) m/z 418.1997 ([M+Na + ]), calc. for [C 24 H 29 NO 4 +Na + ] 418.1989; [α] D 29 =+ 75.2 (c 1.38, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=95/5, 0.5 mL/min, 254 nm, 23° C.), 9.5 (major), 11.6 min, 97% ee.
Synthesis of (R)-5-Benzyl-1-tert-butyl-2-((diphenylmethylene)amino)pentanedioate (Compound 4f)
[0050] Colorless oil; 80% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 7.67-7.63 (m, 2H), 7.44-7.39 (m, 3H), 7.39-7.36 (m, 1H), 7.36-7.27 (m, 7H), 7.18-7.13 (m, 2H), 5.04 (s, 2H), 3.98 (dd, J=7.4, 5.2 Hz, 1H), 2.43 (dd, J=11.3, 5.2 Hz, 2H), 2.31-2.20 (m, 2H), 1.44 (s, 9H). 13 C NMR (75 MHz, CDCl 3 ) δ 172.9, 170.7, 139.4, 136.4, 135.9, 130.2, 128.7, 128.5, 128.4, 128.3, 128.1, 127.9, 127.6, 81.1, 66.1, 64.8, 30.7, 28.5, 28.0; LRMS (ESI) m/z 480.1 (M +Na + ), HRMS (ESI) m/z 480.2165 ([M +Na + ]), calc. for [C 29 H 31 NO 4 +Na + ] 480.2145; [α] D 29 =+57.5 (c 1.72, CHCl 3 ); HPLC analysis: Chiralpak AD-H+Chiralcel OD-H (Hex/IPA=92/8, 0.8 mL/min, 210 nm, 23° C.), 12.9 (major), 13.8 min, 96% ee.
7-2. Synthesis of Compounds 6a-6p
[0051] Table 2 below lists Michael addition of a Schiff Base (i.e., Compound 2) with various chalcones (i.e., Compounds 5a-5p) to yield Compounds 6a-6p in the presence of Compound la as the catalyst. Compounds 5a-5p were prepared following the procedures described in Ma et al., J. Am. Chem. Soc., 2011, 133, 2828.
[0000]
TABLE 2
entry
R 1 ,R 2
Product
Time (h)
Yield (%) b
ee (%) c
1
Ph, Ph
6a
12
98
92
2
Ph, 1-naphthyl
6b
12
91
92
3
Ph, 2-naphthyl
6c
24
93
90
4
Ph, 4-PhC 6 H 4
6d
21
88
91
5
Ph, 4-FC 6 H 4
6e
18
89
90
6
Ph, 4-ClC 6 H 4
6f
15
98
92
7
Ph, 4-BrC 6 H 4
6g
15
96
92
8
Ph, 4-NO 2 C 6 H 4
6h
10
91
94
9
Ph, 2-ClC 6 H 4
6i
12
93
94
10
Ph, 4-MeOC 6 H 4
6j
36
89
85
11
4-ClC 6 H 4 , Ph
6k
12
90
92
12
4-NO 2 C 6 H 4 , Ph
6l
12
91
91
13
4-MeOC 6 H 4 , Ph
6m
18
83
87
14
2-naphthyl, Ph
6n
11
80
91
15
2-fural, Ph
6o
12
95
90
16
2-thiophenyl, Ph
6p
12
92
90
17 d
Ph, 4-ClC 6 H 4
6f
24
89
92
a Reactions were performed by using Compound 2 (0.06 mmol) and Compounds 5a-5p (0.072 mmol) in 0.6 ml mesitylene for indicated time.
b Yield of isolated product.
c Determined by HPLC analysis using Chiralcel OD-H column. Only one diastereomer was observed, absolute configuration was verified by single crystal X-ray diffraction of 7.
d 2 (0.1 mmol), 5f (0.12 mmol) and 2.5 equiv Cs 2 CO 3 was used with catalyst loading of 0.05 mol %.
Synthesis of (2R, 3S)-tert-Butyl2-((diphenylmethylene)amino)-5-oxo-3,5-diphenylpentanoate (Compound 6a)
[0052] tert-Butyl glycinate benzophenone Schiff base 2 (17.7 mg, 0.06 mmol, 1.0 equiv), (S, S)-1a (0.66 mg, 0.0012 mmol, 0.02 equiv) and Cs 2 CO 3 (97 mg, 0.2 mmol, 5.0 equiv) were placed in mesitylene (0.6 mL) and stirred at −20° C. for 10 min, followed by chalcone 5a (15.0 mg, 0.072 mmol, 1.2 equiv). The reaction mixture was stirred at −20° C. and monitored by TLC. After indicated time, upon complete consumption of 2, the reaction mixture was directly loaded onto a short silica gel column, followed by gradient elution with hexane/ethyl acetate (15/1-12/1 ratio). After removing the solvent, product 6a (29.6 mg, 98% yield) was obtained as colorless oil. 1 H NMR (300 MHz, CDCl 3 ) δ 8.00-7.96 (m, 2H), 7.74-7.64 (m, 2H), 7.58-7.27 (m, 9H), 7.22-7.08 (m, 5H), 6.73 (d, J=6.4 Hz, 2H), 4.27-4.16 (m, 2H), 3.83-3.70 (m, 1H), 3.69-3.57 (m, 1H), 1.33 (s, 9H); 13 C NMR (75 MHz, CDCl 3 ) δ 198.6, 171.0, 170.0, 141.3, 139.3, 137.2, 136.2, 132.7, 130.3, 128.8, 128.5, 128.4, 128.3, 128.1, 128.0, 127.9, 127.5, 126.5, 81.2, 70.9, 44.8, 40.0, 27.8; LRMS (ESI) m/z 526.1 (M+Na + ), HRMS (ESI) m/z 526.2373 ([M+Na + ]), calc. for [C 34 H 33 NO 3 +Na + ] 526.2353; [α] D 29 =+58.8 (c 2.48, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=95/5, 0.5 mL/min, 230 nm, 23° C.), 10.9 (major), 21.5 min, 92% ee.
(2R,3S)-tert-Butyl-2-((cliphenylmethylene)amino)-3-(naphthalen-1-yl)-5-oxo-5-phenylpentanoate (Compound 6b)
[0053] Colorless oil; 91% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 8.10 (d, J=8.2 Hz, 1H), 8.05-7.98 (m, 2H), 7.80 (d, J=7.6 Hz, 1H), 7.70-7.60 (m, 3H), 7.56-7.52 (m, 1H), 7.48-7.36 (m, 5H), 7.33 (t, J=7.4 Hz, 2H), 7.30-7.23 (m, 2H), 7.11 (t, J=7.4 Hz, 1H), 6.96 (t, J=7.4 Hz, 2H), 6.27 (s, 2H), 5.20-5.10 (m, 1H), 4.30 (d, J=3.7 Hz, 1H), 4.11 (dd, J=17.3, 9.8 Hz, 1H), 3.81 (dd, J=17.3, 4.2 Hz, 1H), 1.35 (s, 9H); 13 C NMR (75 MHz, CDCl 3 ) δ 198.5, 171.1, 170.3, 139.3, 137.2, 135.8, 133.9, 132.7, 131.7, 130.2, 128.7, 128.5, 128.4, 128.1, 127.9, 127.7, 127.1, 126.9, 125.9, 125.2, 124.8, 123.0, 81.3, 69.2, 39.2, 27.8; LRMS (ESI) m/z 576.1 (M+Na + ), HRMS (ESI) m/z 576.2494 ([M+Na + ]), calc. for [C 38 H 35 NO 3 +Na + ] 576.2509; [α] D 29 =+87.8 (c2.79, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=95/5, 0.5 mL/min, 254 nm, 23° C.), 12.1 (major), 14.0 min, 92% ee.
(2R,3S)-tert-Butyl-2-((diphenylmethylene)amino)-3-(naphthalen-2-yl)-5-oxo-5-phenylpentanoate (Compound 6c)
[0054] Colorless oil; 93% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 7.98 (dd, J=5.1, 3.3 Hz, 2H), 7.74-7.54 (m, 5H), 7.60 (s, 1H), 7.55-7.52 (m, 1H), 7.45-7.30 (m, 9H), 7.22-7.19 (m, 2H), 6.64 (d, J=7.0 Hz, 2H), 4.40-4.37 (m, 1H), 4.29 (d, J=5.0 Hz, 1H), 3.89 (dd, J=17.0, 10.2 Hz, 1H), 3.72 (dd, J =17.0, 3.8 Hz, 1H), 1.31 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) δ 198.7, 171.2, 170.0, 141.1, 140.6, 139.4, 137.2, 136.3, 132.8, 130.4, 129.0, 128.9, 128.7, 128.5, 128.4, 128.2, 128.2, 128.1, 127.5, 127.0, 127.0, 126.8, 81.4, 70.9, 44.5, 39.9, 27.9; LRMS (ESI) m/z 576.1 (M+Na + ), HRMS (ESI) m/z 576.2496 ([M+Na + ]), calc. for [C 38 H 35 NO 3 +Na + ] 576.2509; [α] D 29 =+44.8 (c 2.74, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=95/5, 0.5 mL/min, 210 nm, 23° C.), 12.4 (major), 22.7 min, 90% ee.
(2R,3S)-tert-Butyl-3-([1,1′-biphenyl]-4-yl)-2-((diphenylmethylene)amino)-5-oxo-5-phenylpentanoate (Compound 6d)
[0055] Colorless oil; 88% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 8.04 -7.94 (m, 2H), 7.72-7.65 (m, 2H), 7.56-7.51 (m, 3H), 7.48-7.34 (m, 10H), 7.30 (t, J=7.4 Hz, 3H), 7.21 (d, J=8.2 Hz, 2H), 6.73 (d, J=7.1 Hz, 2H), 4.26-4.20 (m, 2H), 3.81 (dd, J=17.0, 10.0 Hz, 1H), 3.66 (dd, J=17.0, 3.6 Hz, 1H), 1.34 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) δ 198.7, 171.2, 170.0, 141.1, 140.6, 139.4, 137.2, 136.3, 132.8, 130.4, 129.0, 128.9, 128.7, 128.5, 128.4, 128.2, 128.1, 127.5, 127.0, 127.0, 126.8, 81.4, 70.9, 44.5, 39.9, 27.9; LRMS (ESI) m/z 602.1 (M+Na + ), HRMS (ESI) m/z 602.2664 ([M +Na + ]), calc. for [C 40 H 37 NO 3 +Na + ] 602.2677; [α] D 29 =+41.0 (c 0.98, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=92/8, 0.8 mL/min, 254 nm, 23° C.), 9.4 (major), 13.1 min, 91% ee.
(2R,3S)-tert-Butyl-2-((diphenylmethylene)amino)-3-(4-fluorophenyl)-5-oxo-5-phenylpentanoate (Compound 6e)
[0056] Colorless oil; 89% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 7.95 (d, J=7.3 Hz, 2H), 7.70-7.66 (m, 2H), 7.54 (t, J=7.4 Hz, 1H), 7.46-7.32 (m, 8H), 7.11 (dd, J=8.6, 5.5 Hz, 2H), 6.86 (t, J=8.7 Hz, 2H), 6.77 (d, J=6.9 Hz, 2H),.4.22-4.09 (m, 2H), 3.69 (dd, J=16.9, 10.0 Hz, 1H), 3.60 (dd, J=16.9, 3.7 Hz, 1H), 1.33 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) δ 198.6, 171.3, 169.9, 162.6, 160.6, 139.3, 137.1, 136.2, 132.9, 130.5, 130.1, 130.0, 128.8, 128.5, 128.5, 128.3, 128.2, 128.1, 127.5, 115.0, 114.8, 81.4, 70.9, 44.1, 40.2, 27.9; LRMS (ESI) m/z 544.1 (M+Na + ), HRMS (ESI) m/z 544.2258 ([M +Na + ]), calc. for [C 34 H 32 FNO 3 +Na + ] 544.2258; [α] D 29 =+ 54.5 (c 1.26, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=95/5, 0.5 mL/min, 254 nm, 23° C.), 10.2 (major), 19.9 min, 90% ee.
(2R,3S)-tert-Butyl-3-(4-chlorophenyl)-2-((diphenylmethylene)amino)-5-oxo-5-phenylpentanoate (Compound 61)
[0057] Colorless oil; 98% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 7.99-7.93 (m, 2H), 7.69-7.66 (m, 2H), 7.59-7.51 (m, 1H), 7.46-7.40 (m, 3H), 7.39-7.31 (m, 5H), 7.16-7.12 (m, 2H), 7.11-7.06 (m, 2H), 6.76 (d, J=6.9 Hz, 2H), 4.18-4.14 (m, 2H), 3.73 (dd, J=17.1, 9.7 Hz, 1H), 3.61 (dd, J=17.1, 3.4 Hz, 1H), 1.34 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) δ 198.4, 171.4, 169.8, 140.1, 139.3, 137.1, 136.2, 133.0, 132.3, 130.5, 129.9, 128.8, 128.5, 128.5, 128.3, 128.2, 128.2, 128.1, 127.5, 81.5, 70.7, 44.1, 39.9, 27.9; LRMS (ESI) m/z 560.0 (M+Na + ), HRMS (ESI) m/z 560.1966 ([M +Na + ]), calc. for [C 34 H 32 ClNO 3 +Na + ] 560.1963; HPLC analysis: [α] D 29 =+40.9 (c 2.88, CHCl 3 ); Chiralcel OD-H (Hex/IPA=95/5, 0.5 mL/min, 230 nm, 23° C.), 10.1 (major), 16.9 min, 92% ee.
(2R, 3S)-tert-Butyl-3-(4-bromophenyl)-2-((diphenylmethylene)amino)-5-oxo-5-phenylpentanoate (Compound 6g)
[0058] Colorless oil; 96% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 7.99-7.93 (m, 2H), 7.68-7.66 (m, 2H), 7.57-7.53 (m, 1H), 7.47-7.40 (m, 3H), 7.40-7.31 (m, 5H), 7.31-7.27 (m, 2H), 7.06-7.01 (m, 2H), 6.75 (d, J=6.9 Hz, 2H), 4.19-4.10 (m, 2H), 3.79-3.69 (m, 1H), 3.65-3.56 (m, 1H), 1.34 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) δ 198.4, 171.4, 169. 8, 140.6, 139.2, 137.1, 136.2, 133.0, 131.2, 130.5, 130.3, 128.8, 128.5, 128.4, 128.3, 128.2, 128.1, 127.5, 120.4, 81.6, 70.6, 44.2, 39.7, 27.9; LRMS (ESI) m/z 604.0 (M +Na + ), HRMS (ESI) m/z 604.1262 ([M +Na + ]), calc. for [C 34 H 32 BrNO 3 +Na + ] 604.1458; [α] D 29 =+36.7 (c 2.73, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=95/5, 0.5 mL/min, 230 nm, 23° C.), 10.2 (major), 16.7 min, 92% ee.
(2R, 3S)-tert-Butyl-2-((diphenylmethylene)amino)-3-(4-nitrophenyl)-5-oxo-5-phenylpentanoate (Compound 6h)
[0059] Colorless oil; 91% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 8.05 (m, 2H), 7.97-7.95 (m, 2H), 7.68-7.66 (m, 2H), 7.58-7.55 (m, 1H), 7.48-7.31 (m, 10H), 6.75 (d, J =7.1 Hz, 2H), 4.31-4.27 (m, 1H), 4.20 (d, J=4.8 Hz, 1H), 3.87 (dd, J=17.6, 10.5 Hz, 1H), 3.69 (dd, J=17.6, 3.6 Hz, 1H), 1.36 (s, 9H); 13 C NMR (75 MHz, CDCl 3 ) δ 197.9, 171.9, 169.4, 149.6, 146.6, 138.9, 136.7, 135.9, 133.2, 130.7, 129.4, 128.8, 128.6, 128.4, 128.2, 128.1, 127.3, 123.3, 81.9, 69.9, 44.4, 39.5, 27.9; LRMS (ESI) m/z 571.1 (M +Na + ), HRMS (ESI) m/z 571.2187 ([M+Na + ]), calc. for [C 34 H 32 N 2 O 5 +Na + ] 571.2203; [α] D 29 =+26.1 (c 3.00, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=92/8, 0.8 mL/min, 230 nm, 23° C.), 8.9 (major), 13.9 min, 94% ee.
(2R,3S)-tert-Butyl-3-(2-chlorophenyl)-2-((diphenylmethylene)amino)-5-oxo-5-phenylpentanoate (Compound 6i)
[0060] Colorless oil; 93% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 8.05-7.98 (m, 2H), 7.69-7.61 (m, 2H), 7.55 (t, J=7.4 Hz, 1H), 7.50-7.42 (m, 2H), 7.42-7.37 (m, 1H), 7.34 (q, J=7.1 Hz, 3H), 7.29-7.23 (m, 3H), 7.18 (dd, J=7.3, 2.0 Hz, 1H), 7.09-7.03 (m, 2H), 6.57 (d, J=6.7 Hz, 2H), 4.73 (dt, J=10.4, 4.0 Hz, 1H), 4.31 (d, J=4.2 Hz, 1H), 3.99 (dd, J=17.3, 10.5 Hz, 1H), 3.70 (dd, J=17.3, 3.9 Hz, 1H), 1.39 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) δ 198.4, 171.6, 170.0, 139.3, 138.6, 137.1, 136.2, 134.5, 132.9, 130.3, 129.6, 129.2, 128.8, 128.5, 128.4, 128.2, 128.2, 128.0, 127.6, 127.3, 126.3, 81.4, 67.9, 40.7, 38.7, 27.9; LRMS (ESI) m/z 560.1 (M+Na + ), HRMS (ESD m/z 560.1962 ([M+Na + ]), calc. for [C 34 H 32 ClNO 3 +Na + ] 560.1963; [α] D 29 =+72.4 (c 2.55, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=95/5, 0.5 mL/min, 230 nm, 23° C.), 11.0 (major), 13.7 min, 94% ee.
(2R,3S)-tert-Butyl-2-((diphenylmethylene)amino)-3-(4-methoxyphenyl)-5-oxo-5-phenylpentanoate (Compound 6 j )
[0061] Colorless oil; 89% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 7.97-7.95 (m, 2H), 7.70-7.68 (m, 2H), 7.54-7.51 (m, 1H), 7.45-7.31(m, 8H), 7.07-7.05 (m, 2H), 6.78 (d, J=6.9 Hz, 2H), 6.72-6.70 (m, 2H), 4.16-4.14 (m, 2H), 3.72 (s, 3H), 3.67-3.63 (m, 1H), 3.60-3.56 (m, 1H), 1.32 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) δ 198.9, 171.1, 170.1, 158.3, 139.43, 137.3, 136.4, 133.4, 132.8, 130.3, 129.5, 128.9, 128.5, 128.4, 128.2, 128.2, 128.0, 127.6, 113.5, 81.2, 71.1, 55.2, 44.2, 40.4, 27.9; LRMS (ESD m/z 556.1 (M+Na + ), HRMS (ESD m/z 556.2444 ([M+Na + ]), calc. for [C 35 H 35 NO 4 +Na + ] 556.2458; [α] D 29 =+52.7 (c 2.34, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=90/10, 1.0 mL/min, 254 nm, 23° C.), 5.4 (major), 9.2 min, 85% ee.
(2R,3S)-tert-Butyl-5-(4-chlorophenyl)-2-((diphenylmethylene)amino)-5-oxo-3-phenylpentanoate (Compound 6k)
[0062] Colorless oil; 90% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 7.92-7.90 (m, 2H), 7.68-7.65 (m, 2H), 7.42-7.40 (m, 3H), 7.37-7.29 (m, 5H), 7.18-7.12 (m, 5H), 6.70 (d, J=7.0 Hz, 2H), 4.19-4.15 (m, 2H), 3.71-3.65 (m, 1H), 3.61 (dd, J=16.6, 3.6 Hz, 1H), 1.32 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) δ 197.6, 171.3, 167.0, 141.3, 139.4, 139.2, 136.3, 135.5, 130.4, 129.7, 128.8, 128.8, 128.5, 128.4, 128.2, 128.2, 128.1, 127.5, 126.7, 81.4, 70.8, 44.9, 40.1, 27.9; LRMS (ESI) m/z 560.1 (M +Na + ), HRMS (ESI) m/z 560.1951 ([M+Na + ]), calc. for [C 34 H 32 ClNO 3 +Na + ] 560.1963; [α] D 29 =+44.2 (c 2.12, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=95/5, 0.5 mL/min, 254 nm, 23° C.), 11.6 (major), 18.1 min, 92% ee.
(2R,3S)-tert-Butyl-2-((diphenylmethylene)amino)-5-(4-nitrophenyl)-5-oxo-3-phenylpentanoate (Compound 61)
[0063] Colorless oil: 91% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 8.28-8.27 (m, 2H), 8.10-8.08 (m, 2H), 7.66-7.65 (m 2H), 7.42-7.41 (m, 1H), 7.37-7.34 (m, 3H), 7.30 (t, J=7.5 Hz, 2H), 7.18-7.11 (m, 5H), 6.68 (d, J=7.1 Hz, 2H), 4.18-4.14 (m, 2H), 3.78-3.68 (m, 2H), 1.32 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) δ 197.5, 171.5, 169.9, 150.2, 141.7, 141.0, 139.3, 136.2, 130.5, 129.2, 128.8, 128.5, 128.4, 128.3, 128.2, 128.1, 127.4, 126.8, 123.7, 81.5, 70.6, 44.8, 40.7, 27.9; LRMS (ESI) m/z 571.1 (M+Na + ), HRMS (ESI) m/z 571.2188 ([M+Na + ]), calc. for [C 34 H 32 N 2 O 5 +Na + ] 571.2203; [α] D 29 =+36.5 (c 2.70, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=92/8, 0.8 mL/min, 210 nm, 23° C.), 12.9 (major), 15.1 min, 91% ee.
(2R, 3S)-tert-Butyl-2-((diphenylmethylene)amino)-5-(4-methoxyphenyl)-5-oxo-3-phenylpentanoate (Compound 6m)
[0064] Colorless oil; 83% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 7.96 (d, J=8.8 Hz, 2H), 7.69-7.67 (m, 2H), 7.41-7.30 (m, 6H), 7.15-7.11 (m, 5H), 6.92 (t, J=5.8 Hz, 2H), 6.72 (d, J=6.8 Hz, 2H), 4.21-4.17 (m, 2H), 3.86 (s, 3H), 3.72-3.66 (m, 1H), 3.56-3.52 (m, 1H), 1.32 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) δ 197.2, 171.1, 170.1, 163.3, 141.4, 139.4, 136.3, 130.5, 130.4, 130.3, 128.9, 128.6, 128.4, 128.2, 128.1, 128.0, 127.5, 126.5, 113.6, 81.3, 71.0, 55.4, 45.0, 39.7, 27.9; LRMS (ESI) m/z 556.1 (M+Na + ), HRMS (ESI) m/z 556.2446 ([M+Na + ]), calc. for [C 35 H 35 NO 4 +Na + ] 556.2458; [α] D 29 =+18.0 (c 2.73, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=90/10, 1.0 mL/min, 254 nm, 23° C.), 6.4 (major), 11.8 min, 87% ee.
(2R,3S)-tert-Butyl-2-((diphenylmethylene)amino)-5-(naphthalen-2-yl)-5-oxo-3-phenylpentanoate (Compound 6n)
[0065] Colorless oil; 80% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 8.55 (s, 1H), 8.01-7.98 (m, 2H), 7.86 (d, J=8.4 Hz, 2H), 7.71-7.70 (m, 2H), 7.60-7.54 (m, 2H), 7.42-7.30 (m, 6H), 7.19-7.13 (m, 5H), 6.73 (d, J=6.8 Hz, 2H), 4.29-4.24 (m, 1H), 4.22 (d, J=5.1 Hz, 1H), 3.89 (dd, J=16.7, 10.0 Hz, 1H), 3.76 (dd, J=16.7, 3.9 Hz, 1H), 1.33 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) 8 198.7, 171.3, 170.1, 141.4, 139.5, 136.4, 135.5, 134.6, 132.6, 130.3, 129.8, 129.6, 128.9, 128.6, 128.4, 128.3, 128.2, 128.2, 128.1, 127.7, 127.5, 126.6, 126.6, 124.1, 81.3, 71.0, 45.0, 40.1, 27.9; LRMS (ESI) m/z 576.1 (M +Na + ), HRMS (ESI) m/z 576.2485 ([M +Na + ]), calc. for [C 38 H 35 NO 3 +Na + ] 576.2509; [α] D 29 =+8.0 (c 2.00, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=90/10, 1.0 mL/min, 210 nm, 23° C.), 5.6 (major), 7.2 min, 91% ee.
(2R,3S)-tert-Butyl-2-((diphenylmethylene)amino)-5-(furan-2-yl)-5-oxo-3-phenyl pentanoate (Compound 6o)
[0066] Colorless oil; 95% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 7.68-7.66 (m, 2H), 7.53-7.53 (m, 1H), 7.42-7.29 (m, 6H), 7.17-7.10 (m, 6H), 6.74 (d, J=6.9 Hz, 2H), 6.47 (dd, J=3.5, 1.6 Hz, 1H), 4.21-4.15 (m, 1H), 4.16 (d, J=5.4 Hz, 1H), 3.57 (dd, J=16.3, 9.8 Hz, 1H), 3.42 (dd, J=16.3, 4.2 Hz, 1H), 1.31 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) δ 187.8, 171.1, 169.9, 153.0, 146.0, 141.1, 139.4, 136.3, 130.3, 128.9, 128.6, 128.4, 128.2, 128.1, 128.0, 127.6, 126.6, 116.9, 112.1, 81.3, 70.9, 44.7, 40.1, 36.6, 27.8, 24.7; LRMS (ESI) m/z 516.1 (M+Na + ), HRMS (ESI) m/z 516.2135 ([M+Na + ]), calc. for [C 32 H 31 NO 4 +Na + ] 516.2145; [α] D 29 =+52.1 (c 2.13, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=90/10, 1.0 mL/min, 254 nm, 23° C.), 6.1 (major), 10.7 min, 90% ee.
(2R,3S)-tert-Butyl-2-((diphenylmethylene)amino)-5-oxo-3-phenyl-5-(thiophen-2-yl)pentanoate (Compound 6p)
[0067] Colorless oil; 92% yield. 1 H NMR (500 MHz, CDCl 3 ) δ 7.82 (dd, J=3.8, 1.0 Hz, 1H), 7.69-7.66 (m, 2H), 7.57 (dd, J=4.9, 1.0 Hz, 1H), 7.26-7.42 (m, 6H), 7.18-7.10 (m, 6H), 6.72 (d, J=7.0 Hz, 2H), 4.21-4.16 (m, 2H), 3.66 (dd, J=16.3, 9.6 Hz, 1H), 3.53 (dd, J=16.3, 3.7 Hz, 1H), 1.32 (s, 9H); 13 C NMR (126 MHz, CDCl 3 ) δ 191.5, 171.2, 170.0, 144.7, 141.1, 139.4, 136.3, 133.3, 131.9, 130.3, 128.9, 128.6, 128.4, 128.2, 128.2, 128.0, 128.0, 127.5, 126.6, 81.4, 70.9, 45.1, 40.8, 27.9; LRMS (ESI) m/z 532.1 (M+Na + ), HRMS (ESI) m/z 532.1902 ([M+Na + ]), calc. for [C 32 H 31 NO 3 S+Na] 532.1917; [α] D 29 =+67.7 (c 2.36, CHCl 3 ); HPLC analysis: Chiralcel OD-H (Hex/IPA=95/5, 0.5 mL/min, 230 nm, 23° C.), 13.3 (major), 35.5 min, 90% ee.
Other Embodiments
[0068] All of the features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.
[0069] From the above description, one skilled in the art can easily ascertain the essential characteristics of the present invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Thus, other embodiments are also within the scope of the following claims. | Compounds of formula (I): wherein R 1 to R 8 , and X − are defined herein. Also disclosed are methods of making and using these compounds. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to capacitance type displacement measuring instruments, and more particularly to improvements in a capacitance type displacement measuring instrument wherein a charge in electric capacitance between electrodes due to a relative displacement between two members movable relative to each other results in a change in phase of a detection signal, and the relative displacement between the two members is determined from the change in phase.
2. Description of the Prior Art
Measuring instruments for measuring a length or the like of an article, wherein the movement of articles movable relative to each other, such as the movement of a measuring element to a main body or movement of a slider to a column is measured, are known. For example, capacitance type displacement measuring instruments, in which a frame member holding a main scale is held in one hand and a detector including an index scale is held in the other hand, and a relative displacement value is read by an electrostatic method have been used.
Of these capacitance type displacement measuring instruments (in which a change is electric capacitance between the electrodes due to a relative displacement between two members movable relative to each other is detected on the basis of the change in phase of a detection signal and the relative displacement between two members is determind from the change in phase), there has been proposed one similar to the present invention, in which there are used two sine wave pattern electrodes having the forward end portions formed into complementary sine wave patterns, as disclosed in U.S. Pat. No. 3,068,457 for example. However, according to this U.S. Pat. No. 3,068,457, it is necessary that at least two sets of sine wave pattern electrodes be provided on two members movable relative to each other in the widthwise directions thereof. Thus, four sets of sine wave pattern electrodes must be provided in the embodiment thereof. This has been unsuitable for use in a compact sized displacement measuring instrument.
Furthermore, in Japanese Patent Laid-Open No. 94354/79 (corresponding to U.S. Pat. No. 4,420,754), there has been proposed one in which only one set of plates may be provided on two members movable relative to each other in the widthwise direction thereof. However, in this case, a polysphase oscillator of three phases or more is required, and further, when the digital process is conducted, the circuit arrangement becomes disadvantageously complicated.
SUMMARY OF THE INVENTION
The present invention has been developed to obviate the above-described disadvantages of the prior art and has as its object the provision of a capacitance type displacement measuring instrument wherein only one set of sine wave pattern electrodes is used, no polyphase oscillator is required, and the digital processing can be conducted by a simple circuitry arrangement, so that the measuring instrument can easily be rendered compact in size.
To this end, the present invention contemplates that, in a capacitance type displacement measuring instrument, wherein a change in electric capacitance between the electrodes due to a change in displacement between two members movable relative to each other is detected on the basis of a change in phase of a detection signal and a displacement between the two members is determined from the change in phase, the measuring instrument comprises:
square-wave generating means for generating square wave signals;
two transmitting electrodes provided on a first one of the members movable relative to each other in the moving direction thereof, to which the square wave signals from the squarewave generating means are applied in inverted phase;
two sets of wave pattern electrodes provided on the other (second) of the members movable relative to each other in the moving direction thereof, the base portions of which are opposed to the aforesaid two transmitting electrodes, respectively, and the forward end portions of which are formed into complementary continuous wave patterns;
receiving electrodes provided in plural number on the aforesaid first movable member in the moving direction thereof, and opposed to the forward end portions of the aforesaid two sets of wave pattern electrodes;
a multiplexer for successively taking in outputs from the receiving electrodes;
demodulating means for processing the amplitude-modulated square wave signals outputted from the multiplexer to thereby obtain demodulated signals corresponding to the amplitude modulation; and
phase detecting means for detecting a change in phase of the demodulated signal outputted from the demodulating means.
According to the present invention, only one set of wave pattern electrodes need be provided; moreover, no polyphase oscillator is required, and the signal processing can be conducted by a simple circuitry arrangement, so that the measuring instrument can be rendered compact in size.
A specific form of the present invention is of such an arrangement that the frequency of the square wave signal generated by the square wave generating means is a high-frequency wave of 1-50 MHz, whereby the capacitive reactance is minimized.
Another specific form of the present invention is of such an arrangement that the wave pattern electrodes are separated and insulated from one another, whereby the measuring instrument is not easily subjected to the influence of external noises.
A further specific form of the present invention is of such an arrangement that the forward end portions of the wave patten electrodes are formed into complementary sine wave patterns, so that the amplitude-modulated signals can easily be demodulated.
A still further specific form of the present invention is of such an arrangement that the receiving electrodes include active receiving electrodes connected to the multiplexer and inactive receiving electrodes provided at opposite end portions in the moving direction thereof and not connect to the multiplexer, so that the boundary conditions at the end portions of the active electrodes are well controlled.
A still further specific form of the present invention is of such an arrangement that a plurality of sets of the active receiving electrodes are provided, so that the capacitance can be increased and the measuring accuracy can be improved.
A still further specific form of the present invention is of such an arrangement that one set of the acitve receiving electrodes includes 2-100 electrodes.
A still further specific form of the present invention is of such an arrangement that the length of a set of the active receiving electrodes is made to be equal to a pitch of the wave pattern or an integral multiple of it so that the best performance can be obtained.
A still further specific form of the present invention is of such an arrangement that a switching frequency of the multiplexer is made to be 10-100 KH Z , so that a satisfactory response can be obtained even when the speed of relative displacement is high.
A still further specific form of the present invention is of such an arrangement that a change-over frequency signal of the multiplexer is formed by frequency-dividing the square wave signals generated by the square-wave generating means, so that the device can be further simplified.
A still further specific form of the present invention is of such an arrangement that the demodulating means includes a peak detector for detecting the amplitude-modulated square wave signals outputted from the multiplexer, and a high-pass filter for removing the direct current (DC) offset, so that demodulated signals can be obtained by a relatively simple electronic circuit.
A still further specific form of the present invention is of such an arrangement that the demodulating means includes a synchronous demodulator for extracting the amplitude-modulation component from the amplitude-modulated square wave signals outputted from the multiplexer, so that it can be easily fabricated in integrated circuit form.
A still further specific form of the present invention is of such an arrangement that the phase detecting means detects a phase difference between the demodulated signals outputted from the demodulating means and scan control signals of the multiplexer, so that a change in phase can be easily detected.
A still further specific form of the present invention is of such an arrangement that the phase detecting means can detect a change in phase through more than 360 degrees, so that a change in phase of one cycle or more can be accurately measured.
BRIEF DESCRIPTION OF THE DRAWINGS
The exact nature of this invention, as well as other objects and advantages thereof, will be readily apparent from consideration of the following specification relating to the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof and wherein:
FIG. 1 is a plan view showing the arrangement of the electrodes on the scale in a first embodiment of the capacitance type linear displacement measuring instrument, to which the present invention is applied;
FIGS. 1A and 1B are plan views showing alternative embodiments of the capacitance type linear displacement measuring instrument;
FIG. 2 is a plan view showing the arrangement of the electrodes on the slider in the first embodiment;
FIG. 3 is a block diagram showing the arrangement of the electronic circuitry in the first embodiment;
FIG. 4 is a chart showing examples of the waveforms of the signals in the respective portions of the electric circuitry in the first embodiment; and
FIG. 5 is a plan view showing the essential portions of the arrangement of the electrodes on the slider in a second embodiment of the capacitance type linear displacement measuring instrument, to which the present invention is applied.
DETAILED DESCRIPTION OF THE INVENTION
Detailed description will hereunder be given of the capacitance type linear displacement measuring instrument, to which the present invention is applied, with reference to the drawings.
FIG. 1 shows a configuration of the electrodes on a scale or a stator in the first embodiment of the present invention, and FIG. 2 shows a configuration of the electrodes on the slider, which are movable relative to the scale in the longitudinal direction of the scale with the slider electrodes being spaced a predetermined distance from the scale. The electrodes partly shown in FIG. 1 have two rows of sine wave pattern electrodes 1-7 and 8-14, which are disposed in the moving direction of the slider, formed at the forward end portions thereof into complementary sine wave patterns of a pitch P, and separated and insulated from one another in the moving direction of the slider by an insulating portion 17. In FIG. 1, the upper row consits of the sine wave electrodes 1-7 and lower row consists of the sine wave electrodes 8-14. FIG. 1 shows only a short section of the stator, and the sine wave electrodes 1-7 and 8-14 are repeatedly provided over the total length of the stator.
As shown in FIG. 2, on the slider, there are provided two relatively large transmitting electrodes 20 and 21 opposed to the base portions of the two rows of sine wave electrodes 1-7 and 8-14, respectively, and relatively small receiving electrodes 22-53 provided in plural number (32 in number in this embodiment) in the moving direction of the slider and opposed to the forward end portions of the aforesaid two rows of the sine wave electrodes 1-7 and 8-14. When the slider is disposed on the scale as in the normal manner in the measuring operation, the electrodes of the slider are opposed to and spaced a very small distance, e.g., about 0.1 mm apart from the electrodes of the scale. To show the relationship between the electrodes of the slider and the electrodes of the scale, the position of the insulating portion 17 is indicated by broken lines in FIG. 2. During the measuring operation, the slider is movable relative to the scale in a direction indicated by an arrow A.
As shown in FIG. 2, the receiving electrodes 22-53 include active receiving electrodes 30-45 in the central portion, connected to an electronic circuitry used for determining the position of the slider relative to the scale; and inactive receiving electrodes 22-29 and 46-53 provided at opposite end portions of the receiving electrodes in the moving direction of the slider, not connected to the external circuit, but being useful in controlling the boundary conditions. These inactive receiving electrodes 22-29 and 46-53 may be dispensed with, in which case, however, the measuring accuracy may be lowered slightly.
In this embodiment, sixteen (16) electrodes 30-45 are used as the active receiving electrodes. However, the number N of these active receiving electrodes need not be limited as long as N is at least two. However, in practice, the upper limit of the number N 3 is about 100. In FIG. 2, it should be noted that the length of the scale covered by the active receiving electrodes 30-45 is equal to the pitch P of the sine wave electrodes (refer to FIG. 1). The length need not necessarily be equal to the pitch P, however, when the length of the active receiving electrodes is equal to the pitch P or an integral multiple of P, the measuring instrument can display the best performance.
FIG. 3 shows electronic circuitry for determining the position of the slider and the connection between the slider to the electrodes. The transmitting electrodes 20 and 21 are connected to two output terminals of a square wave generator 60. For the sake of simplification, the transmitting electrode 20 is assumed to be ground of the circuit. In order to avoid an overly-complicated drawing, FIG. 3 represent a simplification of the actual circuitry in two ways. More specifically, as for the active receiving electrodes 30-45, only the first eight active receiving electrodes 30-37 are clearly shown in FIG. 3. Similarly to the first eight ones, the other eight active receiving electrodes 38-45 are connected through eight signal lines 63, respectively, as shown in FIG. 3. Furthermore, instead of showing the respective sine wave electrodes on the scale, in FIG. 3 all of the sine wave electrodes 1-7 in the upper row are treated as a single electrode indicated by reference numeral 64. Similarly, the sine wave electrodes 8-14 in the lower row on the scale are treated as a single electrode indicated by reference numeral 65. As is apparent from the analysis of the circuitry, all the scale electrodes in each row, which are beneath the slider, have potentials substantially equal to one another. Therefore, showing the electrodes of each row connected together as has been done in FIG. 3 is electrically equivalent to the actual measuring instrument which has the various electrodes of each row insulated from each other.
In consideration of the above-described simplification, as shown in FIG. 3, sixteen (16) active receiving electrodes 30-45 are connected to input terminals of a multiplexer 68 having sixteen (16) input channels. The action of the multiplexer 66 is indicated schematically by broken lines in FIG. 3. An address input of the multiplexer 66 consisting of signal lines 67 is connected to the count register of a 4-bit binary counter 68.
Consideration of the relative electrode areas shown in FIG. 2 will reveal that the capacitor formed by the transmitting electrode 21 and the upper row of the sine wave pattern electrodes 1-7 has a relatively large capacitance compared to the capacitance between any single receiving electrode and either row of scale electrodes. This capacitor formed by the transmitting electrode 21 and the upper row of the sine wave pattern electrodes 1-7 is indicated by reference numeral 69 in FIG. 3. Similarly, the capacitor formed by the transmitting electrode 20 and the lower row of the sine wave pattern electrodes 8-14 is denoted by reference numeral 70 in FIG. 3. This capacitor also has a relatively large capacitance. The capacitors formed by the active receiving electrodes and the scale electrodes are shown as variable capacitors in FIG. 3. In fact, the capacitance of each of these capacitors will vary as the slider is moved relative to the scale.
Bearing in mind that the capacitance of capacitors 69 and 70 is relatively large, one can see from the circuit of FIG. 3 that each active receiving electrode is the output electrode of a capacitive voltage divider, and the voltage on each of these electrodes will be a certain fraction of the voltage generated by the square-wave generator 60. When the slider is positioned as shown in FIG. 2, this fraction is rather small for electrodes 36, 37 and 38, and is rather large (i.e., nearly equal to 1.0) for electrodes 30, 31, 44 and 45. For electodes 33 and 41, the fraction would be about 0.5.
The frequancy of the square-wave generator 60 is preferably rather high (e.g., 1-50 MHz) in order to minimize capacitive reactance. Referring to FIG. 3, a frequency divider 71 is used for generating a clock frequency suitable for the counter 68. This clock frequency determines the number of cycles of generator 60 per measuring operation, and, to conduct the measuring opertion with high accuracy, a rather low clock frequency is desirable. However, in order for th circuitry to accurately respond to the maximum expected slider velocity, the clock frequency must be sufficiently high. In consequence, a suitable clock frequency would probably be between 10-100 KHz. Therefore, a value of frequency dividing ratio C in the frequency divider 71, capable of providing a required clock frequency to the counter 68 should be selected.
Referring still to FIG. 3, the output of the multiplexer 66 on a signal line 72 is an amplitude-modulated square wave signal. The carrier frequency of this amplitudemodulated signal will be equal to the frequency of the squarewave generator 60. Furhtermore, the frequence of modulation will be equal to the counter clock frequency (on signal line 73) divided by 16. Referring to FIG. 2 in addition ot FIG. 3 will reveal that the phase of the modulation, relative to the phase of the most significant bit (MSB) output of the counter 68 will depend on the position of the slider relative to the scale. The circuit of FIG. 3 is designed to measure this phase difference φ and thereby measure the position of the slider relative to the scale.
An amplitude-modulated signal on the signal line 72 is amplified by an amplifier 74, and a resulting output signal from the amplifier 74 is detected by a peak detector composed of a diode 75, resistor 76, and a capacitor 77. The detected modulation signal is found on the signal line 78, but this signal has a DC offset. A high-pass filter composed of a capacitor 79 and a resistor 80 removes the DC offset leaving a zero-centered modulation signal on the signal line 81. Numerous circuits for demodulation are known and could be used. For example, instead of the diode 75, resistors 76 and 80, and capacitors 77 and 79, which are used in FIG. 3, a synchronous demodulator might be used. One advantage of a synchronous demodulator is that it can be easily fabricated in integrated circuit form using the minimum number of large capacitors. The capacitors 77 and 79 used in FIG. 3 must have relatively large capacitance and would therefore be difficult to fabricate in integrated circuit form.
Referring again to FIG. 3, the demodulated signal on the signal line 81 is fed to one input terminal (IN 1) of a phase detector 82. An input signal to the other input terminal (IN 2) of the phase detector 82 is the MSB output from the counter 68. Thus, the output of the phase detector 82 on signal line 83 has a voltage proportional to the phase φ of the demodulated signal relative to the MSB signal of the counter 68 and therefore represents the position of the slider relative to the scale.
Instead of the phase detector 82 with analogue output as shown in FIG. 3, a phase detector with digital output could be used. It is necessary that the phase detector 82 be capable of phase measurement over a range of several times 360 degrees. This feature permits the measuring instrument to make accurate and unambiguous measurement of distance equal to several times the pitch P of the sine wave pattern. Phase detectors capable of measuring greater than 360 degrees typically have provision for being reset. In FIG. 3, the reset input to the phase detector 82 is shown as the signal line 84.
FIG. 4 shows examples of the wave forms of the signals in the respective portions of the first embodiment.
It is desirable to make the capacitance between the active receiving electrodes 30-45 and the scale electrodes as large as practically possible in order to maximize the signal-to-noise (S/N) ratio of the received signal. It is also desirable to minimze the pitch P of the sine wave pattern electrodes until photolithography limitations are reached in order to obtain high resolving power. Unfortunately, descreasing the pitch P will also decrease the active electrode capacitances, which would desirably be maximized. This dilemma can be avoided by using the scheme of the second embodiment shown in FIG. 5.
An improved arrangement for the receiving electrodes is shown in FIG. 5. Each active receiving electrode is connected to a number (three in this second embodiment) of similar receiving electrodes, each located a distance P from each other. For example, the additional electrodes connected to the active receiving electrode 30 are denoted by 30', 30" and 30'" in FIG. 5. Additional electrodes connected to the active receiving electrode 31 are denoted by 31', 31" and 31'" in FIG. 5, and so on. In order to avoid a cluttered drawing, three dots (. . .) are used in FIG. 5 to denote the continuation of a repetitive pattern of the active receiving electrodes or of conductors.
It should be apparent that the technique of FIG. 5 could be extended to any number of active receiving electrodes in each set. For example, six active receiving electrodes per set would result in the active receiving electrode 30 being connected to the active receiving electrodes 30', 30", 30'", 30"", and 30'"".
Another advantage of this second embodiment is that the capacitance of several cycles is added together, whereby certain errors in dimensions of the active receiving electrodes and the like are absorbed, so that measuring accuracy can be improved.
A further advantage of this second embodiment concerns the inactive receiving electrodes 22-29 and 46-53 (refer to FIG. 2). Note that in FIG. 2, these inactive electrodes take up a relatively large fraction (about 25%) of the total surface area of all the slider electrodes. On the other hand, the FIG. 5 arrangement can reduce this fraction to a negligible value (about 8% in FIG. 5). Reducing the area of the inactive electrodes is desirable so that the total size of the slider assembly can be minimized. Minimizing the slider area is especially important if this measuring instrument is to be used as a hand-held caliper.
Due to the scale of the FIG. 5 drawing, it was not possible to show the inactive electrodes 47-53 in FIG. 5.
In the embodiment described above with reference to FIGS. 1 and 2, the scale or stator is provided with an upper row of sine wave pattern electrodes 1-7 and a lower row of sine wave pattern electrodes 8-14. However, it is noted that one row of sine wave pattern electrodes can be eliminated, as illustrated in FIG. 1A. Further, it is noted that a single ground-plane electrode 100 can be substituted for one row of a plurality of sine wave patten electrodes, as illustrated in FIG. 1B.
In all the embodiments described above, the wave patten of the scale electrodes has been a sine wave. However, the wave form of the wave pattern need not necessarily be limited to the sine wave pattern, and other wave forms such as triangular or trapezoidal waveforms may be used.
In all the embodiments described above, the present invention has been applied to the linear displacement measuring instrument. However, the scope of application of the present invention need not necessarily be limited to this, and it is clear that the present invention is applicable to a rotary displacement measuring instrument such as a rotary encoder. | In a capacitance type displacement measuring instrument, wherein a change in electric capacitance between electrodes due to a relative displacement between two members movable relative to each other is detected on the basis of a change in phase of a detection signal, and a relative displacement between the two members is measured from the change in phase, square waveform signals are applied in inversed phase to two transmitting electrodes provided on one of the members and signals induced on two wave pattern electrodes provided on the other of the members are received by receiving electrodes provided on the first of the members. Outputs from the receiving electrodes are successively taken in by a multiplexer, and then the amplitude-modulated square wave signals, outputted from the multiplexer, are demodulated. A phase detector measures the phase of the demodulated waveform, thereby measuring the relative displacement on the basis of change in phase. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to the production, on the paper machine, of paper which is patterned in contrasting colours without the use of printing techniques. Papers of this general kind are commercially available from Arjo Wiggins Limited under the trademark COUNTRYSIDE and are typically used when it is desired to impart distinctive aesthetic appeal to products such as brochures, folders, menus, invitations, and stationery. Although the paper is patterned during its production on the paper machine, it can be overprinted if desired to give additional decorative effects.
The pattern is introduced into the paper by the incorporation in the papermaking furnish of inclusions which contrast in appearance with the papermaking fibres which make up the bulk of the finished paper. The contrast in appearance arises as a result of the papermaking fibres being of a contrasting colour, shade or hue from that of the inclusions. For example, the papermaking fibres can be coloured and the inclusions white or vice versa. Alternatively both the papermaking fibres and the inclusions can be coloured, provided that the contrast between their colours is adequate.
Suitable inclusions are long contrasting-colour fibres of the kind known in the paper industry as "Silurian fibres", which impart a mineral or rock-like appearance to the paper; planchettes of contrasting appearance to the paper itself; or dark coloured particulate or fibrous material, which imparts a dark-speckled effect.
Just as dark-coloured inclusions give a dark-speckled effect, a white- or colour-speckled effect can be achieved by the addition to the papermaking furnish of small pieces of partially wet-disintegrated white or coloured paper (or, in principle, other material). The wet-disintegration can be carried out in a hydropulper or other apparatus of the kind used to disintegrate pulp bales at the start of the papermaking process (the starting paper must be a wet-strengthened or water-resistant coated paper, or else it will disintegrate to such an extent that it will not produce suitable speckles). Whilst a speckled paper produced in this way is fairly distinctive, the speckles lack sharpness, and hence the aesthetic appeal is not as great as desirable.
It is an object of the present invention to provide a method of making patterned paper with a white- or colour-speckled effect in which the speckles are of generally random size and shape and are sharp and well-defined, and which consequently has an attractive appearance.
SUMMARY OF THE INVENTION
We have now found that the key to achievement of this objective lies in the manner in which the speckle-forming material is produced. Specifically, we have found that suitable speckle-forming material can be formed by pre-agglomerating a mixture of papermaking fibre, particulate pigment and a binder, or by dry comminution of cellulose fibre aggregates. These starting aggregates can be in the form of paper, or of clumps of entangled fibres such as are obtained on breaking up bales of papermaking or other fibre pulp, and need not consist entirely of cellulose fibre. Dry comminution as just referred to is to be contrasted with wet disintegration as described above.
Accordingly, the present invention provides a process for the production of speckle- or similarly-patterned paper, said process comprising the steps of:
(1) preparing speckle-forming material by either
(A) agglomerating a mixture of papermaking fibre, particulate pigment and, preferably, a latex or other binder, by the addition to the mixture of one or more flocculants, coagulants or other agglomerating agents ("Process Variant A"); or
(B) dry comminution of cellulose fibre aggregates ("Process Variant B")
(2) introducing the resulting speckle-forming material into a papermaking furnish of which the fibres are of a contrasting colour to that of the speckle-forming material and on which dye, if present, has been fully fixed; and
(3) draining the speckle-containing furnish to produce a patterned paper web.
The invention also extends to the patterned paper so produced and to the production of speckle-forming material for use in the process.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The term "paper" in this specification includes heavyweight papers of the kind often referred to as "boards".
Of the two process variants set out above, we have so far found Process Variant A to be preferred.
The speckles in the final paper product are of varying dimensions, being of generally random size and shape (in contrast to conventional planchettes). They are generally elongate or fibrous in appearance (particularly when produced by Process Variant A), and appear sharp and well-defined, the whole giving an attractive decorative effect.
The speckle-forming material can be white or coloured. If the latter, the colour can be the result of the use of coloured starting materials. Alternatively, the speckle-forming material can be dyed during or after its production. When dye is used, it should desirably be fully-fixed before the speckle-forming material is mixed with the papermaking furnish.
The presence of fibres in the speckles is thought to assist in anchoring the speckles in the paper, since the speckle fibres can bond chemically and mechanically with the other fibres in the normal way.
The speckle-forming material is introduced to the furnish at a point close to the headbox of the papermaking machine, in order that the agglomerated or comminuted material is not re-dispersed or otherwise adversely affected by conditions of heavy shear and is not removed from the furnish altogether (as might happen, for example, if the agglomerated or comminuted material were introduced prior to a stock cleaning operation). It is important that any dye present should be fully fixed before addition of the speckle-forming material, as otherwise the speckle-forming material might itself become dyed to a colour similar to that of the background paper.
In Process Variant A, the agglomerating agent is typically a material of the kind used in the paper industry for increasing retention of fibre fines and/or fillers on the papermaking wire, i.e. a so-called retention aid, or a flocculant of the kind used to promote sedimentation in waste water treatment in the paper or other industries. The agglomerating agent can be termed either a flocculant or a coagulant (usage of these expressions in the paper industry tends to be imprecise).
Preferably, a combination of oppositely-charged agglomerating agents is used to generate an enhanced agglomerating action and thereby agglomerate said mixture.
In a preferred embodiment of Process Variant A, the fibre and pigment to be agglomerated are mixed in aqueous suspension, together with a suitable latex, for example a styrene-acrylic or styrene-butadiene latex, and an anionic flocculant is added (typically this has a relatively high molecular weight and a relatively low charge density). A cationic flocculant (typically having a relatively high molecular weight and a relatively low charge density) or a cationic coagulant (typically having a relatively low molecular weight and relatively high charge density) is then added to enhance the stability of the initial agglomerate. This enhancement probably results from reaction or interaction between the cationic flocculant or coagulant on the one hand and the anionic flocculant and the latex (also anionic) on the other. However, we do not wish to be bound by any particular theory as to the processes involved. The papermaking fibre content of the aqueous suspension prior to the anionic flocculant addition is typically from 1.5% to 3% by weight.
Although the mixing sequence and order of addition just described is currently considered to be preferred, it will be appreciated that the key point is the formation of adequately stable fibre/pigment agglomerates, and that the precise sequence of mixing and addition of raw materials which achieves this is secondary. However, we have found that although satisfactory agglomerates can be formed when cationic flocculant or coagulant is added prior to addition of anionic flocculant, the agglomerate formation is more difficult to control and is not always achieved satisfactorily. This sequence of addition is therefore not preferred. We have also found that addition of pigment after the agglomerating agent(s) have been added tends to lead to formation of pigment lumps, which is undesirable.
Although the use of a latex or alternative binder is currently considered highly desirable, papermaking fibre and pigment can be flocculated in the absence of latex or other binder, and suitably stable agglomerates obtained in this way can be used in the present process. Our experience is that the aesthetic effect obtained in the final product is less attractive when no latex or other binder is present. When latex is used, the amount is typically about 20%, based on the weight of dry latex to weight of dry fibre in the speckle-forming mixture.
The types of fibre used for producing speckle-forming material by the Process Variant A route can vary quite widely, but a significant proportion of relatively long softwood fibres is desirable in order to enhance the cohesion or tangled character of the fibre/pigment agglomerate formed. We have found that a 50/50 blend of hardwood and softwood fibres gives good results, but this precise ratio is not critical, although when agglomerates were made with a 70/30 hardwood/softwood blend, they were less satisfactory than those obtained with higher proportions of softwood fibres.
The pigment used, in the case of white speckles formed by the Process Variant A route, is preferably titanium dioxide, since this imparts a high degree of both opacity and whiteness. However, other white pigments can be used, for example barium sulphate in the form of blanc fixe or baryta; calcium sulphate in the form of gypsum or anhydrite; kaolin; or, if neutral- or alkaline-sizing is used in the papermaking operation, chalk or precipitated calcium carbonate. The amount of pigment present in the speckle-forming stock can vary widely, depending on the aesthetic effect desired. We have successfully used titanium dioxide in amounts of from below 25% to approaching 150% (specifically from 24% to 143%) based on the total dry weight of fibre in the speckle-forming mixture.
The amount of agglomerating agent(s) to be used can also vary quite widely, for example from about 0.2% to about 1.0% by weight, based on the dry weight of fibres in the speckle-forming mixture (these figures apply to each agglomerating agent when both cationic and anionic agents are used). These agents are used in solution and the concentration of this solution affects the agglomerating action. We have so far found concentrations of the order of 0.5 to 0.75% by weight to be most satisfactory. Concentrations of 1% were less satisfactory as large clumps of fibre and pigment were mainly formed, with few smaller agglomerates--this was found to detract from the aesthetic effect achieved. The solutions of agglomerating agent should be used soon after being made up, say within about 1 hour, as otherwise their agglomerating action may deteriorate. Addition of the agglomerating agent solutions should be carried out quickly, preferably within a period of well below two minutes and ideally over a period of less than about 30 seconds, as otherwise the agglomerating action is less effective (although this may depend on the particular chemical being used).
The mixture of fibre, pigment and latex, when present, is normally kept stirring during at least part of the agglomeration stage of the process. The intensity and duration of this stirring influences the size and shape of the agglomerates obtained and hence affords a degree of control over the appearance of the final paper product.
In the case of Process Variant B, dry comminution can be achieved using conventional granulators, disintegrators or disc grinders, such as are available from a variety of machinery makers, or by employing refiners as used in the paper industry for stock preparation, but in a "dry" mode, as opposed to the normal aqueous suspension mode. In general, granulators and disintegrators were found to give speckles with sharper edges than disc grinders or dry refining. Sharper edges generally give rise to a more attractive aesthetic effect.
It will be appreciated that the term "dry comminution" as used in this specification does necessarily not mean bone dry, but merely dry in the sense of not being in aqueous suspension or saturated with water.
The duration of the dry comminution treatment, the type of comminution equipment used, and the nature of the starting paper or other fibre aggregate all influence the size of the speckle-forming material obtained. More precise size control, if needed, can be achieved through the use of mesh screens, for example 1, 2, 3 or 4 mm mesh screens.
Paper is the preferred starting material for dry comminution into speckle-forming material. It can be white or coloured, depending on the decorative effect desired in the final product, for example white on a coloured background, or coloured on a white or contrasting colour background. Suitable papers for comminution include blade-coated art paper, white opaque board, white high wet strength paper, and coloured card, for example red card as commonly used in Christmas cards.
When clumps of fibre are used as the starting material for dry comminution, the fibres are preferably of a strong nature, for example abaca fibres, (also known as Manila hemp), or other hemp fibres. Disc grinding of abaca fibre clumps broken from a pulp bale produced speckle-forming material of an elongated shape which proved particularly attractive in the finished paper.
The amount of speckle-forming material to be added to the papermaking furnish is determined both by the aesthetic effect desired and the process variant used to produce the speckle-forming material. In the case of Process Variant A, the speckle-forming material is added typically at a level of about 10 to 20% of the final paper (based on dry weight of speckles to dry weight of the fibre and filler in the main furnish). The proportion of visible speckles in the final paper is less than this, as not all the fibres in the fibre/pigment mixture become incorporated in agglomerates. Hence they become effectively invisible constituents of the final paper product.
In the case of Process Variant B, the speckle-forming material is conveniently added in the form of an aqueous suspension of about 1.5 to 3% concentration by weight. The addition level is chosen such as to give a speckle content in the final paper of about 5 to 15% (based on dry weight of speckles to dry weight of the fibre and filler in the main furnish).
Regardless of the Process Variant used to produce the speckle-forming material, the papermaking furnish to which the speckle-forming material is added is generally conventional in nature, and typically comprises a blend of hardwood and softwood pulps. It may include a major proportion of recycled fibre.
In a typical production operation, given by way of example only, a 70% hardwood/30% softwood fibre stock is prepared in conventional manner in a pulper at about 5 to 6% consistency and subjected to conventional refining. Dye fixing agent is added, followed later by dyes and internal sizing agent (e.g. alkyl ketene dimer). The stock is then pumped to a header tank. A chalk loading can be added between the header tank and fan pump, prior to conventional stock cleaning. The speckle stock is then added to the furnish at a point just prior to the headbox, typically at additional levels already referred to. The resulting speckle stock/furnish mixture is then projected on to the papermaking wire from the headbox slice and paper is produced in the normal way to give a product having sharply defined speckles of varying dimensions against a continuous contrasting background.
The invention will now be illustrated by the following Examples, in which all parts and percentages are by weight unless otherwise stated:
EXAMPLE 1
This illustrates the manufacture of approximately one tonne of patterned paper using Process Variant A.
a) Preparation of Speckle Stock
A pulper of capacity c. 14200 liters was approximately three-quarter filled with water. 86 Kg of c.10% moisture content eucalyptus pulp, 86 Kg of c.10% moisture content softwood kraft pulp and 75 Kg titanium dioxide were added with normal mixing agitation. The fibre consistency was then adjusted to about 1.5% by the addition of further water. The resulting aqueous dispersion was then pumped to a larger chest, and 29 Kg of 50% solids content styrene-acrylic latex ("ACRONAL S360D"* supplied by BASF, and stated by the suppliers to be a copolymer based on n-butyl acrylate, acrylonitrile and styrene) were added with normal agitation. 120 liters of a 0.75% solution of high molecular weight anionic flocculant ("NALCO A626"* supplied by Nalco Chemical Company were added batchwise from a bucket over a target period about 30 seconds. After around 5 to 10 minutes, 120 liters of 0.75% solution of high molecular weight cationic polyelectrolyte flocculant ("NALCO 4634-SC"* also supplied by Nalco Chemical Company) were added in the same manner. Agglomerated clumps of latex-bound fibre and filler were seen to begin forming immediately.
b) Preparation of Main Furnish
A 70% hardwood/30% softwood fibre stock was prepared in conventional manner in a pulper at about 5 to 6% consistency and subjected to conventional refining. Dye fixing agent was added, followed later by dyes and internal sizing agent (alkyl ketene dimer). The dyes chosen were such as to produce a grey shade in the final paper. The stock was then pumped to a header tank. A chalk loading was added between the header tank and fan pump, prior to conventional stock cleaning.
c) Preparation of Patterned Paper
The speckle stock from (a) above was added to the furnish from (b) above at a point just prior to the headbox at an addition level of about 10 to 20% (based on dry weight of fibre and pigment in the speckles to dry weight of the remaining fibre and filler in the furnish). The resulting speckle stock/furnish mixture was then projected on to the papermaking wire from the headbox slice and paper was produced in the normal way. It had sharply defined white speckles of generally fibrous appearance but varying dimensions against a continuous grey background.
EXAMPLE 2
This illustrates, on a laboratory scale, a process similar to that of Example 1 but in which the fibre consistency in the speckle-forming operation is 3%.
35 ml of 3% hardwood pulp suspension and 35 ml of 3% softwood pulp suspension were first mixed (total dry fibre weight of 2.1 g). 0.8 ml of 50% solids content styrene-acrylic latex ("ACRONAL S360D") and 1 g of titanium dioxide were added and the mixture was stirred for 5 minutes. 12 ml of 0.1% anionic flocculant ("NALCO A626") were added over a period of about 20 to 30 seconds, and the mixture was stirred for a further 5 minutes. 12 ml of 0.1% cationic flocculant ("NALCO 4634-SC") were then added over a period of 20 to 30 seconds. Clumps of entangled fibre and pigment were seen to start forming immediately. The resulting mixture was then added to 450 ml of 1.5% consistency 50/50 hardwood/softwood fibre blend which had been previously dyed grey and fixed. Approximately 100 gm -2 handsheets were produced using a British Standard Sheet Making machine. The resulting sheet had a random pattern of white speckles on a grey background.
EXAMPLE 3
This illustrates the production of white-speckled grey papers using Process Variant A and a variety of relative proportions and types of raw materials in the speckle-forming process.
50 ml of 3% hardwood fibre stock and 20 ml of 3% softwood fibre stock were mixed and 1.5 g titanium dioxide pigment were added with stirring, followed by 50 ml water. 0.4 g of styrene-acrylic latex ("ACRONAL S360D") were added, followed by 2 ml of 0.1% solution of anionic flocculant ("NALCO A626"). After stirring for 5 minutes, 2 ml of 0.1% cationic flocculant ("NALCO 4634-SC") were added, resulting in formation of entangled fibre/pigment agglomerates.
These agglomerates were filtered off and then re-dispersed in water to give a total volume of dispersion of 200 ml. 20 to 40 ml additions of the resulting speckle-forming stock were added to 100 ml portions of previously dyed and fixed grey 1.5% papermaking stock and made into handsheets, generally as described in Example 2. The handsheets exhibited white speckles against a grey background.
In variants of the above procedure, the following changes were made, either separately or in combination:
a) amount of titanium dioxide (1 g and 0.5 g additions instead of 1.5 g)
b) amount of speckle-forming stock added (50 ml instead of 20 to 40 ml)
c) amount of flocculants added (two or three times as much of each, and/or 1.5 times as much anionic flocculant used as cationic, or vice versa, instead of the same amounts)
d) titanium dioxide was added after instead of before the flocculants
e) styrene-butadiene latex ("DL950" supplied by Dow Chemical) used instead of styrene-acrylic latex
f) mixing times varied
g) latex amount varied (0.2 ml instead of 0.4 ml)
h) blanc fixe or kaolin used instead of titanium dioxide
i) latex omitted altogether
j) flocculant concentration increased (1%, 0.75% and 0.5% instead of 0.1%)
k) speckle-stock fibre dispersion consistency reduced (1.5% instead of 3%).
Speckled paper was obtained in all cases, but the size and appearance of the speckles in the paper varied considerably.
EXAMPLE 4
This further illustrates the production of speckle-patterned paper on a full-size papermachine using Process Variant A.
344 Kg of c. 10% moisture content softwood kraft pulp were added to c. 10,600 liters of fresh water in a pulper and the mixture was stirred until the pulp had fully disintegrated. 60 Kg of styrene-acrylic latex ("ACRONAL S360D") were then added, whilst maintaining stirring. This represented c. 9.7% latex on a dry basis, based on dry fibre content. 125 Kg titanium dioxide were than added, still with stirring, and the mixture was pumped to a mixing chest, where agitation was continued. 404 liters of a 0.5% solution of anionic flocculant ("NALCO A626") were pumped in, after which agitation was continued for a further 10 to 15 minutes before being stopped (or, in a repeat run, slowed down). 404 liters of a 0.75% solution of cationic flocculant ("NALCO 4634-SC") were then added by means of a bucket (or, in a repeat run, pumped in). Full agitation was then resumed, and was continued for 10 to 15 minutes. 200 liters of a 25% aqueous talc dispersion were then added to counteract any tendency for polymeric deposits to form on the paper machine at a later stage. The mixture was then pumped to a header tank by means of a relatively low shear pump. The subsequent procedure was then generally as described in Example 1, except that the main furnish was blue rather than grey. The final paper was thus blue with white speckles.
In a further repeat run, 225 Kg of titanium dioxide were used, in order to achieve speckles of a different appearance.
EXAMPLE 5
This illustrates the use of different anionic and cationic flocculants from those used in previous Examples.
0.8 ml of 50% solids content styrene-acrylic lated ("ACRONAL S360D") was added to 140 ml of 3% softwood pulp suspension, and the mixture was stirred rapidly (1300 rpm). 1.34 g of titanium dioxide were added and stirring was continued at the same speed for a further 5 minutes. 5.5 ml of 0.5% high molecular weight medium anionic acrylamide copolymer flocculant ("POLYPLUS 430" supplied by Betz Limited of Winsford, Cheshire, Great Britain) were then added, and stirring was continued at 1300 rpm for a further 5 minutes. 5.5 ml of 0.75% moderate molecular weight high cationic charge density polyacrylamide flocculant emulsion ("POLYMER 1268L", also supplied by Betz Limited) were then added, and the mixture was stirred less rapidly (200 rpm) for 1 minute. 2.3 g of 30% aqueous talc suspension were then added and stirring was continued for one minute. Fibre/pigment agglomerates were seen to have formed, and these were incorporated into handsheets, generally as described in Example 2. The resulting sheet had a random pattern of elongate white speckles on a coloured background.
EXAMPLE 6
This illustrates the production of speckle-pattern paper on a laboratory scale, using Process Variant B.
Dye fixing agent was added to 400 ml of a 1.5% consistency hardwood stock and the mixture was stirred for 10 minutes. A blend of dyes such as to produce a grey shade was then added and the mixture was stirred for a further 10 minutes. 0.3 g of paper speckles produced by dry comminution of A4 size blade-coated art paper sheets in a Blackfriars Granulator (product of Blackfriars Limited, Market Harborough, Leicestershire, England) were then added, giving a furnish comprising c. 95% hardwood and 5% speckles, and c. 100 gm -2 handsheets were then produced using a British Standard Sheet Making machine. The resulting sheet had a random pattern of white speckles on a grey background.
The procedure was then repeated using a variety of different coloured paper furnishes and speckles derived by dry comminution of a variety of types of paper and of clumps of abaca fibres. A disc grinder was used for making certain of the speckles, instead of a granulator. The resulting papers had a random speckle pattern on a contrasting colour background. | Speckle-patterned paper is produced on the paper machine without the use of printing techniques by first preparing speckle-forming material and then introducing this into a contrasting color papermaking furnish. Paper is then made from the speckle-containing furnish in the normal way. The speckle-forming material is produced either by agglomerating a mixture of papermaking fiber, particulate pigment and, preferably, a latex or other binder or by dry comminution of cellulose fiber aggregates in the form of paper or entangled fiber clumps. | 8 |
The application is a divisional patent application of and claims priority to U.S. application Ser. No. 10/050,513 filed Jan. 16, 2002, now abnd.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the field of photonics and in particular to tapered dielectric slab waveguides for input and output coupling of light into photonic crystal devices.
2. Description of the Prior Art
Photonic crystals are very advantageous for use in small optical devices. Recently, it has become possible to microfabricate high reflectivity mirrors by creating two- and three-dimensional periodic structures. These periodic “photonic crystals” can be designed to open up frequency bands within which the propagation of electromagnetic waves is forbidden irrespective of the propagation direction in space and to define photonic bandgaps. When combined with high index contrast slabs in which light can be efficiently guided, microfabricated two-dimensional photonic bandgap mirrors provide the geometries needed to confine light into extremely small volumes.
For example, two dimensional Fabry-Perot resonators with microfabricated mirrors are formed when defects are introduced into the photonic bandgap structure. It is then possible to tune these cavities lithographically by changing the precise geometry of the microstructures surrounding the defects. By using the same microfabrication techniques, it is also possible to guide, bend, filter and sort light in two dimensional photonic crystals. For example, by introducing line defects, photonic crystal waveguides can be constructed, and light can be guided around sharp corners without the normally associated bend losses.
Although photonic crystal devices show promise for future optical devices, the coupling of light into and out of the optical devices made from photonic crystals has been inefficient. This is due to the very small size of these devices (typically 0.2 μm) compared to the size of the input beam (for example, from an optical fiber) and the size of the output device (for example, also an optical fiber). While the typical thickness of a photonic crystal waveguide is about 0.2 μm, the smallest size of the light beam normally coupled into such a photonic crystal waveguides is around 1.0 μm. This results in a large insertion loss.
What is needed is some means whereby such insertion losses can be avoided or minimized.
BRIEF SUMMARY OF THE INVENTION
One of the key limitations of planar waveguides formed from high refractive index material is the poor mode-matching between such waveguides and optical fibers. This leads to large insertion losses when light is to be coupled onto and off the chip, even when the fiber pigtails are perfectly aligned. Single mode fiber cores are typically 6 microns in diameter, whereas the typical dimensions of silicon waveguides are about 0.3 microns. Even if focusing optics is employed, the diffraction limited spot size is still substantially larger than the cross section of a single mode high index waveguide.
One approach to reducing the mode-matching difficulties may again be borrowed from the microwave technologies, and lies in the form of an adiabatic taper. Such a taper, when constructed, may provide a funnel for light to be coupled into the high index material, and must be three dimensional in nature. Of course, this provides a fabrication challenge, since while it is easy in most planar processing protocols to define a lateral taper through lithography, the change in height of the waveguide is a much more difficult task. Fortunately, it is possible by shadow deposition or sputtering to form such tapers from polysilicon, which can be used to match the refractive index of the waveguiding material. When designed with the correct shape and adequate smoothness, such tapers form efficient waveguide couplers. Once the light has been coupled through the adiabatic coupler into an index guide on a wafer or chip, proper design of the transition between the index guide and photonic crystal is necessary to ensure low loss coupling with a minimum of diffraction and back reflection.
The invention is thus defined as a method for fabricating a tapered optical coupling into a slab waveguide comprising the steps of providing a sputtering source; providing at least one mask between the source and the mask; and disposing a tapered layer of material onto a substrate, which includes a waveguiding layer by means of shadow deposition defined by the sputtering source and the at least one mask. The tapered layer extends in a first two dimensional plane and is optically coupled to the waveguiding layer. A second taper is photolithographically defined in the tapered layer. The second taper extends in a second two dimensional plane and intersects the first two dimensional plane.
The step of photolithographically defining a second taper in the tapered layer defines the second two dimensional plane so as to perpendicularly intersect the first two dimensional plane.
The method further comprises photolithographically defining a slab waveguide in the waveguiding layer simultaneously with photolithographically defining a second taper in the tapered layer.
The method further comprises coupling the slab waveguide to a photonic crystal. Coupling the slab waveguide to the photonic crystal comprises forming the slab waveguide integrally with the photonic crystal.
The step of disposing the tapered layer of material onto the substrate comprises disposing the tapered layer by means of shadow deposition defined by the sputtering source and the at least two masks.
The step of disposing the tapered layer of material onto the substrate comprises disposing polycrystalline silicon.
The step of disposing the tapered layer of material onto the substrate comprises disposing a material with an approximately matching refractive index to the waveguiding layer.
The method further comprises repeating the method on an opposing side of the substrate to form another tapered optical coupling on the opposing side aligned with the tapered optical coupling.
The method further comprises first forming a tapered substrate by means of shadow deposition and then forming the tapered optical coupling on the tapered substrate to obtain a fully flared, funnel-shaped, optical coupling.
The invention is also a tapered optical coupling comprising a substrate; a slab waveguide on or in the substrate, and a funnel-shaped termination on or in the substrate and optically coupled to the slab waveguide.
The apparatus further comprises a photonic crystal. The photonic crystal is optically coupled to the slab waveguide. The slab waveguide is integral with the photonic crystal.
The apparatus further comprises an optic fiber and the funnel-shaped termination is optically coupled to the optic fiber. The funnel-shaped termination is formed by shadow deposition.
The funnel-shaped termination is composed of material having an index of refraction approximately matching the slab waveguide. In one embodiment the funnel-shaped termination is composed of polycrystalline silicon and the slab waveguide is composed of GaAs.
The funnel-shaped termination is a half-funnel shape or a full-funnel shape. The funnel-shaped termination comprises a surface for optical coupling inclined with respect to the substrate.
While the apparatus and method has or will be described for the sake of grammatical fluidity with functional explanations, it is to be expressly understood that the claims, unless expressly formulated under 35 USC 112, are not to be construed as necessarily limited in any way by the construction of “means” or “steps” limitations, but are to be accorded the full scope of the meaning and equivalents of the definition provided by the claims under the judicial doctrine of equivalents, and in the case where the claims are expressly formulated under 35 USC 112 are to be accorded full statutory equivalents under 35 USC 112. The invention can be better visualized by turning now to the following drawings wherein like elements are referenced by like numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic top plan view of the coupling of a dielectric slab waveguide to a photonic crystal waveguide.
FIG. 2 is a graph of the power transmission coefficient as a function of frequency for the coupling of FIG. 1 .
FIG. 3 is a perspective view of a linearly tapered dielectric waveguide in which the direction of the wave propagation is defined as the z-axis and in which there is tapering in both the x-z and y-z planes.
FIG. 4 a is a diagrammatic plan view of the tapering of the waveguide of FIG. 3 in the x-z plane.
FIG. 4 b is a diagrammatic plan view of the tapering of the waveguide of FIG. 3 in the y-z plane.
FIGS. 5 a and 5 b are diagrammatic perspective views of the method of microfabricating a tapered waveguide coupling as shown in FIGS. 3 , 4 a and 4 b.
FIG. 6 is a diagrammatic side view of an embodiment where two shadow masks are employed in order to provide an inclined face to the end of the tapered waveguide.
The invention and its various embodiments can now be better understood by turning to the following detailed description of the preferred embodiments which are presented as illustrated examples of the invention defined in the claims. It is expressly understood that the invention as defined by the claims may be broader than the illustrated embodiments described below.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is an apparatus whereby the insertion loss from a source of light, such as an optic fiber, into a photonic crystal is reduced by use of a tapered dielectric slab waveguides at both input and output ports of a photonic device. Dielectric slab waveguides 10 can be efficiently coupled to photonic crystal waveguides 12 . FIG. 1 is a diagrammatic top plan view, which illustrates one way in which this coupling is performed, and FIG. 2 is a graph of the power transmission spectrum (ratio of the transmitted to the incident power at different frequencies) for a coupling of the design of FIG. 1 .
Slab waveguide 10 is a parallelepiped of conventional photonic material defining a longitudinal axis 18 and having an homogenous or heterogeneous structure which integrally extends into or out of the body of photonic crystal 12 . In the illustrated embodiment shown in FIG. 1 slab waveguide 10 effectively extends into photonic crystal 12 bisecting the periodic hole pattern, generally denoted by reference numeral 14 . The longitudinal axis of slab waveguide 10 is parallel with the direction of the rows of holes 16 in pattern 14 . The longitudinal axis of holes 16 are perpendicular to the longitudinal axis 18 of slab waveguide 10 . The optical properties of slab waveguide 10 and crystal 12 are chosen according to well understood principles to optimize the matching therebetween and hence the launch of the optical wave in slab waveguide 10 efficiently into the waveguide structure of photonic crystal 12 . Many different types of geometries and topologies of slab waveguide 10 and crystal 12 can be employed, which are equivalent in their coupling efficiencies to the illustrated embodiment and hence are to be understood as being within the scope of the teachings of the invention.
FIG. 2 shows the dependence of the power transmission coefficient as a function of normalized frequency. As FIG. 2 shows, it is possible to obtain efficient coupling from a slab waveguide 10 into a photonic crystal waveguide 12 (and vice versa) over a relatively wide frequency range. A major advantage of using dielectric slab waveguides 12 are their simplicity and the fact that these waveguides have been used for a long time in integrated optics. Therefore, the technology needed for the optimization of their properties is widely available and well worked out.
By using the dielectric slab waveguides for input and output coupling of the photonic crystal devices, what is needed then is some means to improve the insertion loss into and out of a dielectric slab waveguide. While the slab-to-photonic waveguide coupling can be high, slab waveguide 10 is similar in size to the photonic crystal 12 itself, so that insertion of light efficiently into slab waveguide 10 from a macroscopic source, such as a fiber optic, remains to be solved. The light must be coupled from the dielectric slab waveguide 10 to the photonic crystal waveguide 12 that is in turn coupled to other photonic crystal devices.
To reduce the insertion loss into the dielectric slab waveguide 10 , we use a slowly tapered waveguide 14 at both the input and output of a slab waveguide 10 as shown in FIGS. 3 , 4 a and 4 b . The idea of slowly tapering the guiding structure to increase the mode size, while keeping the single-mode propagation in the slab waveguide 10 has been used in frequency regimes different than the optical frequencies. For example, horn antennas in the microwave regime are provided by slowly tapering a rectangular metallic waveguide. Due to the scaling property of the Maxwell's equations, similar ideas function similarly in the optical regime. Therefore, the efficiency of the coupling of a large beam to a dielectric slab waveguide 10 is improved by slowly tapering the waveguide 10 in the propagation direction 20 or the longitudinal axis of waveguide 10 as shown in FIG. 3 . As FIG. 3 shows, the tapering is performed both in the x-z and in the y-z planes, with z being the direction of propagation, just as in a microwave horn antenna or coupling.
The challenge, however, is how to make such a tapered waveguide 14 in both x-z and y-z planes in microphotonic materials and scales. We can certainly taper the waveguide 14 in one plane (for example x-z plane in FIG. 3 ) by conventional planar lithography. However, we cannot taper the waveguide 14 in the other plane (y-z plane in FIG. 3 ) by conventional planar lithography. FIG. 4 a shows the plan view of tapered waveguide 14 of FIG. 3 in the x-z plane and FIG. 4 b shows the plan view of tapered waveguide 14 of FIG. 3 in the y-z plane.
This tapering is performed according to the invention by the use a Si sputtering source and an appropriately designed shadow mask or masks 22 as described in greater detail below in connection with FIGS. 5 a – 5 c . Although a sputtering source is described in the illustrated embodiment, any other source of material which is capable of projecting a shadow from the sharp edge of a mask may be equivalently substituted. Therefore, for simplicity, a “sputtering source” shall be defined in this specification and claim to include not only true sputtering sources, but all sources capable of casting a shadow of disposed material. Due to the presence of the shadow mask 22 , the Si that is sputtered onto the waveguide layer has a different thickness at different locations. The tapering, i.e., the variation of the waveguide thickness (in y-z plane in FIG. 3 ), can be controlled by changing the shape and the placement of the shadow mask. Conventional ray tracing of the mask and source geometry can be used to accurately predict the shape of the sputtered shadow layer formed. Therefore, we can taper the waveguide in the vertical plane (y-z in FIG. 3 ) using this technique. Then, we can taper the waveguide in the horizontal plane (x-z plane in FIG. 3 ) by conventional planar lithography so that the tapering in the two planes have similar properties. Using this idea, we the insertion loss is considerably improved.
Reference to FIGS. 5 a and 5 b will make the methodology of the invention clearer. A dielectric waveguide layer 26 is formed in a conventional manner on substrate 24 . Thereafter, mask 22 is positioned appropriately between the sputtering source, which is diagrammatically depicted by arrows 30 , and layer 26 . Mask 22 creates a sputtering shadow layer 28 beyond its edge 32 onto layer 26 , which thickens as the distance of edge 32 increases. Additional planar layers could be formed on shadow layer 28 if desired, for example a cladding or passivating layer if desired. Conventional planar lithography is then used as shown in FIG. 5 b to define tapered waveguide 14 and slab waveguide 10 on substrate 24 . Shadow sputtering defines the degree of tapering in the x-z plane in FIGS. 5 a and 5 b , while conventional planar lithography defines the same or a different degree of tapering in the y-z plane.
For example, if we want to couple a Gaussian beam of light with beam waist of ω o =1 μm into a dielectric slab waveguide 10 with the slab cross section of 0.2 μm by 0.2 μm. We can improve the insertion loss (at one side) by at least 3 dB, if we use a tapered slab waveguide 14 as explained above.
Note that this idea can also be applied to the structures made from other materials than Si (for example, GaAs). We can taper the waveguide in the vertical plane by Si sputtering, and the taper in the horizontal plane by lithography as explained before. The index of refraction of Si is close enough to that of GaAs to result into an acceptable loss due to index mismatch.
Many alterations and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the invention. For example, substrate 24 is shown in FIGS. 5 a and 5 b as a planar slab. It is also possible that substrate 24 may itself be tapered. By the same shadow deposition the material of substrate 24 may be provided with a reversely oriented taper so that when the Si is sputtered in FIG. 5 a , it is laid down on a substrate surface, which falls away from a plane parallel to the plane of mask 22 instead of onto a parallel planar opposing surface. In this way it is possible to create a taper both into and out of the plane of substrate 24 to provide a full or symmetric funnel shape to the coupling as shown in FIG. 3 rather than the half-funnel shape shown in FIGS. 5 a and 5 b.
Alternatively, a half-funnel can be formed on one side of substrate 24 and then an aligned and corresponding half-funnel defined on the opposing side of substrate 24 to provide a full funnel-shaped coupling with substrate 24 sandwiched in between and including a preformed slab waveguide therein aligned with the two half-funnels, one on each side of the preformed waveguide.
The illustrated embodiment has shown mask 22 as planar, but it must be understood that mask 22 may be a surface of arbitrary curvature, which is dictated by the shape of the shadow desired, which in turn may have an arbitrary curvature. Thus, complex and arbitrarily shaped tapers are possible with the methodology of the invention.
Still further multiple masks 22 a and 22 b may be used in combination to create compound tapered shapes. In FIG. 6 for example the coupling of FIG. 5 b is created using mask 22 b while at the same time mask 22 a is used to create a reverse taper 34 to the terminal end of tapered waveguide 14 . Such a reverse taper 34 can be advantageously used to couple an angled optic fiber to waveguide 14 if access in the plane of substrate 24 is for any reason difficult or undesirable.
Therefore, it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the invention as defined by the following claims. For example, notwithstanding the fact that the elements of a claim are set forth below in a certain combination, it must be expressly understood that the invention includes other combinations of fewer, more or different elements, which are disclosed in above even when not initially claimed in such combinations.
The words used in this specification to describe the invention and its various embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification structure, material or acts beyond the scope of the commonly defined meanings. Thus if an element can be understood in the context of this specification as including more than one meaning, then its use in a claim must be understood as being generic to all possible meanings supported by the specification and by the word itself.
The definitions of the words or elements of the following claims are, therefore, defined in this specification to include not only the combination of elements which are literally set forth, but all equivalent structure, material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements in the claims below or that a single element may be substituted for two or more elements in a claim. Although elements may be described above as acting in certain combinations and even initially claimed as such, it is to be expressly understood that one or more elements from a claimed combination can in some cases be excised from the combination and that the claimed combination may be directed to a subcombination or variation of a subcombination.
Insubstantial changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalently within the scope of the claims. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements.
The claims are thus to be understood to include what is specifically illustrated and described above, what is conceptionally equivalent, what can be obviously substituted and also what essentially incorporates the essential idea of the invention. | A three dimensional adiabatic taper provides a funnel for light to be coupled into high index material. The taper is formed by shadow deposition or sputtering from polysilicon, which can be used to match the refractive index of waveguiding material to which the taper is optically coupled. When designed with the correct shape and adequate smoothness, such tapers form efficient waveguide couplers. Once the light has been coupled through the adiabatic coupler into an index guide on a wafer or chip, an integral design of the transition between the index guide and photonic crystal ensures low loss coupling with a minimum of diffraction and back reflection. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to the field of baby bottles. More particularly, the invention relates to a baby bottle having sterilized features.
BACKGROUND OF THE INVENTION
[0002] A baby bottle includes a vessel commonly made of polycarbonate, a teat commonly made of liquid silicone rubber or natural rubber, and a coupling which couples the vessel to the teat in a leak-proof manner.
[0003] Prior art baby bottles can be sterilized by boiling in hot water. However, these bottles are difficult to sterilize in boiling water due to their tendency to float.
[0004] Thus, practically, baby bottles are not sterilized but rather are only cleaned with hot soapy water.
[0005] The mouth of the bottles is narrower than of the vessels themselves, thus, washing too is difficult and usually insufficiently performed.
[0006] Disposable bottles were introduced. However, the structure of these bottles makes them relatively expensive since the sealing requires sealing elements of both the vessel and the teat.
[0007] For example, U.S. Pat. No. 3,777,753 discloses a teat for feeding bottles for babies. The teat has a nipple portion for being fitted upon a bottle neck so as to grip around the latter. The bottle is gripped between a sealing lip and a cylindrical wall of the teat.
[0008] However, this gripping assumes that the bottle includes a thread or an oblique sealing lip. Thus, this bottle is not suited for being disposable.
[0009] All the methods described above have not yet provided satisfactory solutions neither to the problem of washing and sterilizing baby bottles, nor to manufacturing of inexpensive disposable baby bottles.
[0010] It is an object of the present invention to provide a method and apparatus for providing sterilized baby bottles.
[0011] It is an object of the present invention to provide a solution to the above-mentioned and other problems of the prior art.
[0012] Other objects and advantages of the invention will become apparent as the description proceeds.
SUMMARY OF THE INVENTION
[0013] In one aspect, the present invention is directed to a baby bottle ( 10 ) comprising:
a vessel ( 12 ) ending with a wall ( 20 ) at the top thereof, a teat ( 50 ) comprising two arms ( 26 A, 26 B) splitting at the bottom thereof, the arms ( 26 A, 26 A) disposed parallel to the wall ( 20 ) elastically embracing the wall ( 20 ) in a sealed manner, thereby the sealing is substantively based on sealing elements of the teat ( 50 ) only, thereby the vessel ( 12 ) may constitute a common element.
[0018] Each of the arms ( 26 A, 26 B) may comprise a protrusion ( 18 ) bending towards the wall ( 20 ) of the cup ( 12 ), thereby enhancing the elastic embracing.
[0019] The protrusion ( 18 ) of at least one of the arms ( 26 B) may comprise bending towards a folded edge ( 52 ) of the wall ( 20 ), thereby the protrusion ( 18 ) prevents sliding of the vessel ( 12 ) out of the teat ( 50 ).
[0020] The vessel ( 12 ) may be formed as a cone, allowing packing a plurality of vessels of the same form in a compact manner,
[0000] thereby allowing packing a plurality of baby bottles ( 10 ) in a compact, disposable and sterile form.
[0021] The vessel ( 12 ) may be foldable, for allowing packing a plurality of vessels of the same form in a compact manner, thereby allowing packing a plurality of baby bottles ( 10 ) in a compact, disposable and sterile form.
[0022] The foldability of the vessel ( 12 ) may comprise a member selected from a group including: a bellows form diminishing the height, foldability diminishing the width.
[0023] The vessel ( 12 ) may comprise transparent zones ( 14 ) for viewing the contents level.
[0024] The reference numbers have been used to point out elements in the embodiments described and illustrated herein, in order to facilitate the understanding of the invention. They are meant to be merely illustrative, and not limiting. Also, the foregoing embodiments of the invention have been described and illustrated in conjunction with systems and methods thereof, which are meant to be merely illustrative, and not limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Embodiments and features of the present invention are described herein in conjunction with the following drawings:
[0026] FIG. 1 depicts a baby bottle according to one embodiment of the present invention.
[0027] FIG. 2 depicts the baby bottle of FIG. 1 as marketed.
[0028] FIG. 3 is a sectional side view of the baby bottle of FIG. 1 .
[0029] FIG. 4 depicts a baby bottle according to another embodiment of the present invention.
[0030] FIG. 5 is a sectional side view of the baby bottle of FIG. 4 .
[0031] FIG. 6 is a sectional side view of the baby bottle of FIG. 4 according to another embodiment.
[0032] FIG. 7 depicts the bellows form of the vessel of FIG. 4 .
[0033] FIG. 8 depicts a bellows form according to another embodiment of the present invention.
[0034] FIG. 9 depicts a baby bottle according to another embodiment of the present invention.
[0035] FIG. 10 is a sectional side view of the baby bottle of FIG.
[0036] FIG. 11 is a sectional side view of the baby bottle of FIG. 7 or other bottles, indicating additional features.
[0037] FIG. 12 depicts the baby bottle having the transparent zones of FIG. 11 .
[0038] FIG. 13 is a sectional side view of the baby bottle of FIG. 1 according to another embodiment.
[0039] FIG. 14 is a sectional side view of the baby bottle of FIG. 1 according to another embodiment.
[0040] It should be understood that the drawings are not necessarily drawn to scale.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0041] The present invention will be understood from the following detailed description of preferred embodiments, which are meant to be descriptive and not limiting. For the sake of brevity, some well-known features, methods, systems, procedures, components, circuits, and so on, are not described in detail.
[0042] The solution disclosed by the present invention to the above-mentioned problems is attaching a non-disposable teat to a disposable vessel.
[0043] FIG. 1 depicts a baby bottle according to one embodiment of the present invention.
[0044] Baby bottle 10 of the present invention includes a disposable vessel 12 for being substituted, and a non-disposable teat 50 for drinking the formula therethrough.
[0045] The formula is poured into disposable vessel 12 through mouth 56 thereof, and teat 50 then covers vessel 12 in a sealed manner, for drinking through a hole 64 of teat 50 .
[0046] Unlike the prior art vessel of the baby bottle that is made of polycarbonate, disposable vessel 12 is preferably made of paper or a disposable plastic. Non-disposable teat 50 may also be made of liquid silicone rubber or natural rubber like the prior art teats.
[0047] FIG. 2 depicts the baby bottle of FIG. 1 as marketed.
[0048] Disposable vessels 12 may be designed to be compactly packaged together. A large amount of disposable vessels 12 may thus be compactly packaged together for marketing thereof, or with one non-disposable teat 50 , or a small number of teats.
[0049] According to one embodiment, the compact design may feature a widening shape from bottom to top, as depicted in FIG. 2 , like common disposable vessels, for inserting one vessel inside the other.
[0050] Thus, unlike the prior art baby bottles which require cleaning and sterilizing the vessels, disposable vessels 12 may be marketed clean and sterilized for a single use of each.
[0051] This embodiment is disadvantaged of requiring a non-standard teat.
[0052] FIG. 3 is a sectional side view of the baby bottle of FIG. 1 .
[0053] Baby bottle 10 is leak-proof due to contact between surrounding complementary edge 52 of vessel 12 and edge 54 of teat 50 .
[0054] FIG. 4 depicts a baby bottle according to another embodiment of the present invention.
[0055] According to this embodiment, disposable vessel 12 includes a top 48 having a narrow mouth 56 , which may fit the size of a standard teat. This thus allows using a standard teat 50 .
[0056] According to one embodiment, top 48 is inherent within disposable vessel 12 .
[0057] The embodiment of FIG. 4 provides packaging of many vessels 12 together by providing vessel 12 a bellows form.
[0058] FIG. 5 is a sectional side view of the baby bottle of FIG. 4 .
[0059] Baby bottle 10 is leak-proof due to contact between surrounding edges 60 and 62 of top 48 and of teat 50 respectively, which is based on the springy feature of teat 50 .
[0060] FIG. 6 is a sectional side view of the baby bottle of FIG. 4 , according to another embodiment.
[0061] Since mouth 56 of disposable vessel 12 , made of paper or plastic, is not firm, a firm mouth 28 may be attached to mouth 56 of vessel 12 in a sealed manner, for avoiding bending mouth 56 of vessel 12 . Firm mouth 28 is thus sealed to teat 50 . Firm mouth 28 is disposable, together with vessel 12 .
[0062] FIG. 7 depicts the bellows form of the vessel of FIG. 4 .
[0063] According to another embodiment, the compact design may feature foldability provided by a bellows form.
[0064] In order to allow packaging many vessels 12 together, each vessel 12 is foldable, diminishing the height thereof.
[0065] FIG. 8 depicts a bellows form, according to another embodiment of the present invention.
[0066] According to another embodiment, each vessel 12 is foldable, diminishing the width thereof.
[0067] The embodiments of FIGS. 4 to 8 are disadvantaged of a small mouth 56 , thus, pouring the formula may not be convenient.
[0068] FIG. 9 depicts a baby bottle according to another embodiment of the present invention.
[0069] Unlike the embodiment wherein top 48 is inherent within disposable vessel 12 , according to the embodiment of FIG. 9 , top 48 is a coupling, which is separate from vessel 12 , for being coupled to vessel 12 and to teat 50 . According to this embodiment, mouth 56 may also be sized to fit a standard teat of a baby bottle. Coupling 48 thus functions as a coupling for coupling non-disposable teat 50 to disposable vessel 12 .
[0070] This embodiment allows using a standard teat 50 . Also, this embodiment provides the packaging feature depicted in FIG. 2 . Further, pouring the formula may be performed through the mouth of vessel 12 , which is sufficiently large.
[0071] FIG. 10 is a sectional side view of the baby bottle of FIG. 9 .
[0072] Baby bottle 10 is leak-proof due to contact between surrounding complementary edges 52 and 58 of vessel 12 and of coupling 48 , respectively.
[0073] FIG. 11 is a sectional side view of the baby bottle of FIG. 7 or other bottles indicating additional features.
[0074] Vessel 12 may be designed for fitting several standards of teats 50 . For example, each of depressions 22 and 24 of disposable vessel 12 may fit a different size of a teat.
[0075] Vessel 12 may include notches and transparent zones 14 for viewing and measuring the water level.
[0076] FIG. 12 depicts the baby bottle having the transparent zones 14 of FIG. 11 .
[0077] FIG. 13 is a sectional side view of the baby bottle of FIG. 1 according to another embodiment.
[0078] According to this embodiment baby bottle 10 is leak-proof due to contact between surrounding wall of vessel 12 and arms 26 A and 26 B splitting from teat 50 .
[0079] Since the sealing is based on sealing elements 26 A and 26 B of teat 50 only, baby bottle 10 may include a disposable vessel 12 for being substituted, and a non-disposable teat 50 .
[0080] Arms 26 A and 26 B are disposed parallel to the wall 20 of vessel 12 , forming a fork 16 embracing wall 20 inside and outside it.
[0081] The sealing is not based on edge 52 of vessel 12 , but only on wall 20 of vessel 12 , which is commonly formed smooth and thus suits the sealing of the present embodiment.
[0082] Preferably, not the surface of arms 54 seal, but rather protrusions 18 of each arm 54 which are bent towards wall 20 make the sealing. Thus the springy feature of the material of teat 50 presses protrusions 18 onto wall 20 , enhancing the sealing between arms 54 and wall 20 .
[0083] According to a preferred embodiment vessel 12 may be a standard inexpensive (e.g. 10 cents) disposable cup, preferably a paper cup (coffee cup) withstanding heat. Edge 52 at the top of a standard paper cup includes a fold or a roll of the paper.
[0084] This folded edge 52 of vessel 12 is inserted within fork 16 of teat 50 sealing the connection.
[0085] FIG. 14 is a sectional side view of the baby bottle of FIG. 1 according to another embodiment.
[0086] According to this embodiment fork 16 provides also a mechanical barrier from vessel 12 sliding out. Arm 26 B is bent not only to press wall 20 but also towards folded edge 52 of vessel 12 .
[0087] Edge 52 at the top of the standard paper cup which includes the fold is trapped by the bent edge 54 B upon inserting edge 52 of vessel 12 therein.
[0088] In the figures and/or description herein, the following reference numerals have been mentioned:
numeral 10 denotes a baby bottle according to one embodiment of the present invention; numeral 12 denotes a disposable vessel; numeral 14 denotes a transparent zone; numeral 16 denotes a fork formed at the edge of a teat; numeral 18 denotes protrusions numeral 20 denotes a wall of the vessel; numerals 22 and 24 denote depressions within the disposable vessel, each for fitting a different size of teat; numerals 26 A and 26 B denote arms of the teat; numeral 28 denotes a firm mouth, attached to the inherent mouth of the vessel; numeral 48 denotes a top of the vessel having a narrow mouth; top 48 may be an inherent or a separate coupling; numeral 50 denotes a teat; numeral 52 denotes an edge of the vessel; numeral 54 denotes an edge of the teat; numeral 56 denotes the mouth of the vessel, or the top thereof, numeral 58 denotes the edge of the coupling; numeral 60 denotes the edge of the top; numeral 62 denotes the edge of the teat; and numeral 64 denotes a hole of the teat.
[0106] The foregoing description and illustrations of the embodiments of the invention has been presented for the purposes of illustration. It is not intended to be exhaustive or to limit the invention to the above description in any form.
[0107] Any term that has been defined above and used in the claims, should to be interpreted according to this definition.
[0108] The reference numbers in the claims are not a part of the claims, but rather used for facilitating the reading thereof. These reference numbers should not be interpreted as limiting the claims in any form. | A baby bottle ( 10 ) comprising: a vessel ( 12 ) ending with a substantially smooth wall ( 20 ) at the top thereof; and a teat ( 50 ) comprising two circumferential arms ( 26 A, 26 B) splitting at the bottom thereof, the arms ( 26 A, 26 A) disposed parallel to the wall ( 20 ) elastically embracing the wall ( 20 ) in a sealed manner, wherein each of the arms ( 26 A, 26 B) comprises a circumferential protrusion ( 18 ) bending towards the wall ( 20 ) of the cup ( 12 ), for enhancing the elastic embracing, and slowing amortization of the teat ( 50 ), and wherein the vessel ( 12 ) is formed as a cone, allowing packing a plurality of vessels of the same form in a compact manner, thereby allowing packing a plurality of vessels ( 12 ) in a compact, disposable and sterile form for use with the teat ( 50 ). | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] The JarCar Ladder is a fire/emergency escape apparatus designed specifically to provide an emergency exit to enable individuals to safely evacuate a building from any level above ground level in the event of a fire or other emergency.
BRIEF SUMMARY OF THE INVENTION
[0005] The JarCar Ladder is an invaluable fire/emergency escape apparatus because it allows the exiting of the tallest buildings in guaranteed safety. The twin towers disaster is probably the best example of how helpful this invention would have been in saving lives. When the buildings were hit, people in upper floors were basically confmed to the stairwell to exit the building, a near hopeless journey.
[0006] The JarCar Ladder is a portable apparatus (capable of being made larger and non-portable) and would be set up inside or outside a building structure adjacent to any window above ground level which can be used as an exit. The major component parts of the JarCar Ladder are [ 1 ] the window mounting bar, [ 2 ] the window brace, [ 3 ] the rope guide, [ 4 ] pre-drilled holes, [ 5 ] steel wire cables, [ 6 ] safety seat with back rest, [ 7 ] sturdy rope with quick release hooks on each end, [ 8 ] the base pipe, [ 9 ] steel wire cable hooks, [ 10 ] the rope ring located under the safety seat, [ 11 a] seat hook lock, [ 11 b] eye hook, [ 12 ] the concrete base, and [ 13 ] U-hooks.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0007] FIG. 1 depicts the JarCar Ladder set up for use from the window of a multi-story building.
[0008] FIG. 2 depicts the JarCar Ladder displayed laying down with all its component parts.
[0009] FIG. 3 depicts the separated component parts of the JarCar Ladder, numbered to correspond to the assembled JarCar Ladder shown in FIGS. 1 and 2 .
[0010] FIG. 4 depicts the last two separated component parts of the JarCar Ladder, numbered to correspond to the assembled JarCar Ladder shown in FIGS. 1 and 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0011] The JarCar Ladder is a fire/emergency escape apparatus designed specifically to provide an emergency exit to enable individuals to safely evacuate a building from any level above ground level in the event of a fire or other emergency.
[0012] The JarCar Ladder is a portable apparatus (capable of being made larger and non-portable) and would be set up inside or outside a building structure adjacent to any window above ground level which can be used as an exit. The major component parts of the JarCar Ladder are [ 1 ] the window mounting bar, [ 2 ] the window brace, [ 3 ] the rope guide, [ 4 ] pre-drilled holes, [ 5 ] steel wire cables, [ 6 ] safety seat with back rest, [ 7 ] sturdy rope with quick release hooks on each end, [ 8 ] the base pipe, [ 9 ] steel wire cable hooks, [ 10 ] the rope ring located under the safety seat, [ 11 a] seat hook lock, [ 11 b] eye hook, [ 12 ] the concrete base, and [ 13 ] U-hooks.
[0013] The window mounting bar, or pipe, would be inserted on the inside of an open window and used to anchor the upper part of the JarCar Ladder to the house. A brace is attached to each end of the window mounting bar which would be abutted against the wall. The mounting bar has a circular opening on the left and right side for the routing of the two, 30 foot lengths (or more) of wire cable. The wire cables go though pre-drilled holes on the left and right side of the seat base, functioning as a guide for ascending and descending. The lower ends of the wire cables travel through pre-drilled holes on a second steel bar which then terminates with two metal hooks. The hooks can be secured to [1] a concrete base or [2] any heavy, sturdy, solid object which is extremely difficult to move, such as a truck or car; also, the steel bar next to the hooks can be held by any strong person(s) weighing three times the weight of the escaping individual(s). The safety seat with backrest is pulled downward or upward by the sturdy rope. The upper end and bottom end of the rope is attached to an eye-ring under the safety seat. The rope is then routed through guides on the upper and bottom steel pipes.
[0014] The JarCar Ladder could be easily and quickly set up and could be an invaluable piece of equipment for any multi-story building or structure in the event of a fire or other emergency.
[0015] Generally, the JacCar Ladder would be assembled as follows: the braces ( 2 ) and the rope guide ( 3 ) would be placed on the window mounting bar ( 1 ). The steel wire cables ( 5 ) would be routed through the pre-drilled holes ( 4 ) on both sides of the window mounting bar ( 1 ). Then, they would be routed through the safety seat ( 6 ). The steel wire cables ( 5 ) would be routed through the pre-drilled holes ( 4 ) on both sides of the base pipe ( 8 ). The rope guide ( 3 ) would be placed on the base pipe ( 8 ). The steel wire cable hooks ( 9 ) are attached to the end of the steel wire cables ( 5 ) near the base pipe ( 8 ). U-Hooks ( 13 ) are attached to the steel wire cables ( 5 ) near the window mounting bar ( 1 ). The sturdy rope with quick release hooks on each end ( 7 ) is routed through the rope guide ( 3 ) on the window mounting bar ( 1 ). Then, one of the quick release hooks on the sturdy rope ( 7 ) is attached to the rope ring ( 10 ) under the safety seat ( 6 ). The other end of the sturdy rope with quick release hooks ( 7 ) is routed through the rope guide ( 3 ) on the base pipe ( 8 ). Then, the quick release hook on the sturdy rope ( 7 ) is attached to the rope ring ( 10 ) under the safety seat ( 6 ). The concrete base ( 12 ) is separate but part of The JarCar Ladder for purposes of connecting the steel wire cable hooks ( 9 ) to the eye hooks ( 11 b ) on the concrete base.
DRAWINGS
[0016] The drawing in FIG. 1 shows the JarCar Ladder connected to the window of a multi-story building with the window mounting bar (# 1 of FIG. 3 ). The bottom of the JarCar Ladder is connected to the concrete base on the ground (# 12 of FIG. 4 ). The safety seat (# 6 of FIG. 3 ) is located at the top of the JarCar Ladder. The rope (# 7 of FIG. 3 ) extends from the top to the bottom of the JarCar Ladder. It travels around both the window mounting bar (# 1 of FIG. 3 ) and the base pipe (# 8 of FIG. 3 ) by the rope guides (# 3 of FIG. 3 ). One end of the rope has a quick release hook (# 7 of FIG. 3 ) and the other end has a quick release hook (# 7 of FIG. 3 ). The quick release hooks attach to the rope ring (# 10 of FIG. 3 ) under the seat. On the front of the seat (# 6 of FIG. 3 ) is the seat hook lock (# 11 a of FIG. 3 ), which is to be connected to the eye hook (# 11 b of FIG. 3 ) of the window mounting bar, preventing the seat from moving when mounting. Traveling up and down the JarCar Ladder on the right and left are the steel cables (# 5 of FIG. 3 ), which pass through pre-drilled holes on the window mounting bar (# 4 of # 1 of FIG. 3 ), the safety seat (# 4 of # 6 of FIG. 3 ), and the base pipe (# 4 of # 8 of FIG. 3 ), with the hooks at the bottom of each cable (# 9 of FIG. 3 ) connected to the concrete base (# 12 of FIG. 4 ) and the U-locks at the top of each cable (# 13 of FIG. 4 ) connected to the window mounting bar (# 1 of FIG. 3 ).
[0017] The drawing in FIG. 2 is the JarCar Ladder laying down with its component parts displayed and numbered to correspond to FIG. 3 and FIG. 4 .
[0018] The drawing in FIG. 3 shows the component parts of the JarCar Ladder, namely, [ 1 ] the window mounting bar, [ 2 ] the window brace, [ 3 ] the rope guide, [ 4 ] pre-drilled holes, [ 5 ] steel wire cables, [ 6 ] safety seat with back rest, [ 7 ] sturdy rope with quick release hooks on each end, [ 8 ] the base pipe, [ 9 ] steel wire cable hooks, [ 10 ] the rope ring located under the safety seat, [ 11 a] seat hook lock, and [ 11 b] eye hook.
[0019] The drawing in FIG. 4 shows the two remaining component parts of the JarCar Ladder, namely, [ 12 ] the concrete base, and [ 13 ] U-hooks. | The JarCar Ladder presents an effective, safe, sure, way for people to escape buildings of all heights in emergencies by using commonplace materials (concrete, steel bar, wire cables, hooks, rope, wooden seat, etc.) in a unique life-saving manner, requiring no great intellect to use or employ. The newness of the invention is in its revelation of how minor things can work together as a complete unit for major accomplishments under the most dire circumstances when time is “of the essence.” | 4 |
BACKGROUND OF THE INVENTION
In the literature until today there are described in the literature two processes according to which 3-mercapto-propanediol-1,2, also called monothioglycerine, can be produced by the addition of hydrogen sulfide to glycidol.
According to L. Smith and B. Sjoberg (Ber. deutsch. chem. Ges. Vol. 69, pages 678-680, (1936)) and Sjoberg (Ber. deutsch. chem. Ges. Vol. 75, pages 13-29, (1942)) 1/3 mole of glycidol is dropped into a solution of 1/3 mole barium hydrogen sulfide saturated with hydrogen sulfide with running introduction of hydrogen sulfide. In the highest case the yield according to this process is 61% of theory, whereby it is stated that in increasing the charge beyond 1/3 mole the yield drops off. Besides there are formed higher molecular weight condensation products of glycidol. By distillation monothioglycerine can be separated from water and the byproducts. Because of the difficulties in enlarging the charge this method of production does not represent an industrially usable process for making monothioglycerine.
In German Pat. No. 910296 there is described a continuous process for the production of monothioglycerine whereby there should be produced yields of about 80-95%. Hereby there is employed a recycling apparatus which is charged with aqueous alcohol, e.g. isopropanol, and catalytic amounts, e.g. 0.3% of alkali or alkaline earth hydrogen sulfide, such as calcium hydrogen sulfide. Gaseous hydrogen sulfide is introduced into the apparatus in such manner that continuously hydrogen sulfide is present in the form of finely divided gas bubbles in the entire apparatus or solution and its concentration is greatest at the place of introduction of the glycidol. The temperature of the reaction mixture is held between 20° and 35° C. The reaction mixture is continuously drawn off from the recirculating apparatus.
By introduction of carbon dioxide the catalyst is precipitated as carbonate, the solution subsequently filtered and the alcohol employed recovered by distillation.
The water is removed in a next distillation step and the residue finally subjected to fractionation in vacuum whereby then monothioglycerine is obtained. In all of the examples the catalyst is removed before the distillation of the product from the crude product in order that the distillation of the product should proceed without difficulties.
In the first place the known process is tied to a special apparatus since there must be continuously present sufficient hydrogen sulfide to catch the hydroxide formed from the hydrogen sulfide. Otherwise, condensation reactions occur between glycidol and the monothioglycerine formed.
Besides the catalyst employed after the end of the reaction must be converted into a carbonate by introduction of carbon dioxide. The carbonate cannot be inserted again as such.
Furthermore, the distillation of the crude product can not be carried out in the presence the catalyst carbonate.
Therefore, the object of the invention is the development of a process which is industrially simple to carry out which likewise leads to high yields.
SUMMARY OF THE INVENTION
It has now been found that monothioglycerine can be produced in high yields in an industrially simple manner if liquid hydrogen sulfide is allowed to react with glycidol in the presence of a catalyst in heterogeneous or homogeneous phase.
As solid catalysts which do not dissolve in the reaction medium there are particularly well suited weakly basic catalysts such as aluminum oxide, preferably activated alumina containing 0.02 to 5 weight % alkali, sodium aluminum silicates such as zeolites and hydroxysodalite. These solid catalysts are distinguished by a high time on stream. They are preferably employed as solid bed catalysts. A very suitable zeolite is e.g., montmorillonite. As catalysts for working in homogeneous phase there are suited alkali and alkaline earth metal hydroxides which are soluble in the reaction medium of glycidol and liquid hydrogen sulfide, e.g. sodium hydroxide potassium hydroxide, calcium hydroxide, and barium hydroxide. Sodium hydroxide and potassium hydroxide are preferred.
The process is carried out under pressures of 15 to 200 bar.
The temperature in the heterogeneous phase at the solid bed is between 30° and 150° C., in the homogeneous phase generally at the upper mentioned temperature limit or somewhat higher. Generally temperatures of 30° to 180° C. are employed.
The molar ratio of liquid hydrogen sulfide to glycidol is between 3:1 to 10:1, preferably 4:1 to 6:1, independent of whether operating in heterogeneous or homogeneous phase.
The process can be carried out either continuously or discontinuously (batchwise).
For example, a continuous carrying out of the process with solid bed catalyst will be explained in more detail.
Liquid hydrogen sulfide and glycidol were dosed into a solid bed reactor filled with catalyst via two pumps.
The pressure which is necessary in order to keep hydrogen sulfide in the liquid phase is controlled through a pressure release valve at the outlet of the solid bed reactor.
The desired temperature in the solid bed reactor was maintained by withdrawal of heat of reaction via the outer jacket.
The reaction mixture was relieved to atmospheric pressure via the pressure release valve. Hereby the excess hydrogen sulfide escaped nearly quantitatively. After condensation it can be returned again to the reaction system.
The reaction product remaining behind which is free of catalyst and only contains still about 0.25 weight % of hydrogen sulfide is subsequently purified by distillation under a vacuum.
It has been found that a molar ratio of "hydrogen sulfide:glycidol" below 3:1 the yield of monothioglycerine is greatly reduced and in the same measure the formation of the bis adduct of glycidol to hydrogen sulfide (bis-(2,3-dihydroxy-propyl)sulfide increases. The molar ratio "hydrogen sulfide:glycidol" in itself does not set an upper limit. However, it does show that from a molar ratio of 6:1 a substantial increase in yield no longer occurs but probably a reduction of the space-time yield.
The temperature range at which the reaction is carried out should be chosen below 150° C. when working in the heterogeneous phase since over this temperature in heterogeneous phase appreciable self condensation of glycidol leads to increasingly larger losses of yield. The reaction temperature, however, should not be chosen below 30° C. in order that the addition proceeds with economically meaningful speed. Between 30° and 150° C. there could not be established any temperature influence on the yield of monothioglycerine in heterogeneous phase.
In homogeneous phase it is also possible to exceed 150° C. and still obtain a yield of about 81% of theory, see Example 10.
As stated in carrying out the reaction there is no need to be limited to the above-described continuous method of working. The addition likewise permits carrying out the process in autoclaves or other pressure reactors discontinuously.
With homogeneous catalysis likewise yields of up to 95% of theory can be obtained, see Example 8. At a temperature above 150° C., however, the yield obtained is reduced but as already stated, still a value of around 81%.
With homogeneous catalysis there is obtained a crude product which contains the catalyst in dissolved form. Surprisingly the presence of the catalyst in the crude product does not create a problem in the distillative working up and therefore does not lead to loss in yield. The use of the homogeneous catalysis is especially suited for disontinuous operation in autoclaves or stirred containers.
Finally it is also possible to carry out the reaction between liquid hydrogen sulfide and glycidol in the presence of small amounts of solvents such as water or lower aliphatic alcohols, e.g. alkanols such as methanol, ethanol, propanol-1 and propanol-2. Glycidol and solvent are used in the weight ratio 1:0.5 to 1:5.
Monothioglycerine is an industrially interesting synthesis building block and can be employed:
in hair cosmetics, see U.S. Pat. No. 3,415,606;
in depilatory agents, see German OS 2253117;
as protective agent against UV and X-rays, see Protoplasma Vol. 45, page 293;
for the stabilization of medicinal preparations, see U.S. Pat. No. 3,026,248;
in photographic developer solutions, see French Pat. No. 1410426;
as color stabilizer in polymers, see Webb U.S. Pat. No. 2,560,053;
as enzyme activator in enzyme containing wshing agents, see German OS 1953816.
Unless other indicated, all parts and percentages are by weight.
The process can comprise, consist essentially of, or consist of the steps set forth with the stated materials.
The invention will be explained in more detail in connection with the following examples:
DETAILED DESCRIPTION
Example 1
A 2 liter stainless steel autoclave was charged with 10 grams of aluminum oxide (spherical, diameter 2-4 mm, BET surface area=300 m 2 /g, Na 2 O=0.08 weight %). 1020 Grams of liquid hydrogen sulfide (30 moles) and 444 grams of glycidol (6 moles) were charged. The mixture was heated with stirring for 4 hours at 70° C.
Subsequently the autoclave was relieved and the liquid content subjected to a vacuum distillation. At 89° C. and 0.9 mbar there were obtained 614.5 grams of 3-mercapto-propanediol-1,2-corresponding to 94.8% of theory, boiling point=95° C. (1 Torr), purity≧99.5 weight % (iodometric titration).
Example 2
A 2 liter stainless steel autoclave was charged with 50 grams of zeolite (montmorillonite), 1020 grams of liquid hydrogen sulfide (30 moles) and 444 grams of glycidol (6 moles). The mixture was heated with stirring for 4 hours at 30° C.
Subsequently the autoclave was relieved of pressure and the liquid contents subjected to a vacuum distillation. There were obtained 591 grams of 3-mercapto-propanediol-1,2, corresponding to 91.2% of theory. The boiling point and purity were the same as in Example 1.
Example 3
A 2 liter stainless steel autoclave was charged with 50 grams of hydroxysodalite, 1020 grams of liquid hydrogen sulfide (30 moles) and 444 grams of glycidol (6 moles). The mixture was treated with stirring for 4 hours at 70° C. After working up by distillation there were obtained 587 grams of 3-mercapto-propanediol-1,2, corresponding to 90.6% of theory. The boiling point and purity were the same as in Example 1.
Example 4
A 2 liter stainless steel autoclave was charged with 5 grams of aluminum oxide (spherical, diameter 4-6 mm, BET surface area 250 m 2 /g, Na 2 O=3 weight %), 1020 grams of liquid hydrogen sulfide and 444 grams of glycidol (6 moles). The mixture was heated with stirring for 4 hours at 70° C. After working up the crude product by distillation there were obtained 616 grams of 3-mercapto-propanediol-1,2, corresponding to 95.1% of theory.
Example 5
The experiment mentioned in Example 4 was repeated 10 times under exactly the same conditions but the same catalyst without replacement or regeneration, thus in the used condition, was always employed again. The following results were produced:
______________________________________Experiment Yield [g] Yield [% of theory]______________________________________Repetition 1 615 94.9Repetition 2 618 95.3Repetition 3 616 95.0Repetition 4 605 93.3Repetition 5 617 95.2Repetition 6 612 94.5Repetition 7 614 94.7Repetition 8 608 93.8Repetition 9 614 94.7Repetition 10 613 94.6______________________________________
After eleven uses the catalyst, namely aluminum oxide according to Example 1, thus showed no loss in its activity.
Example 6
A 2 liter stainless steel autoclave was charged with 5 grams of aluminum oxide, corresponding to Example 1, 510 grams of liquid hydrogen sulfide (15 moles) and 444 grams of glycidol (6 moles). The mixture was heated with stirring for 4 hours at 70° C. After working up by distillation there were obtained 338 grams of 3-mercapto-propanediol-1,2, corresponding to 52.2% of theory.
Example 7
A 2 liter stainless steel autoclave was charged with 5 grams of aluminum oxide, according to Example 1, 1020 grams of liquid hydrogen sulfide (30 moles) and 222 grams of glycidol (3 moles). The mixture was heated with stirring for 4 hours at 30° C. After working up by distillation there were obtained 309 grams of 3-mercaptopropanediol-1,2, corresponding to 95.3% of theory.
Example 8
A 2 liter stainless steel autoclave was charged with 1 gram of potassium hydroxide, 1020 grams of liquid hydrogen sulfide (30 moles) and 444 grams of glycidol (6 moles). The mixture was heated with stirring for 4 hours at 70° C. After working up by distillation there were obtained 612 grams of 3-mercapto-propanediol-1,2, corresponding to 94.5% of theory.
Example 9
A 2 liter stainless steel autoclave was charged with 1 gram of sodium hydroxide, 1020 grams of liquid hydrogen sulfide (30 moles) and 444 grams of glycidol (6 moles). The mixture was heated for 30 minutes at 145° C. After working up by distillation there were obtained 605 grams of 3-mercapto-propanediol-1,2, corresponding to 93.3% of theory.
Example 10
A 2 liter stainless steel autoclave was charged with 1 gram of potassium hydroxide, 1020 grams of liquid hydrogen sulfide (30 moles) and 444 grams of glycidol (6 moles). The mixture was heated for 30 minutes at 170° C. After working up by distillation there were obtained 521 grams of 3-mercaptopropanediol-1,2, corresponding to 80.5% of theory.
Example 11
There were dosed into a water jacketed container having an internal volume of 4.2 liters and filled with aluminum oxide, according to Example 1, via two pumps per hour, 444 grams of glycidol (6 moles) and 1020 grams liquid hydrogen sulfide (30 moles). The temperature inside the reactor, with the help of warm water, which was pumped through the outer jacket, was held at 50° C. The necessary pressure (35 mbar) to maintain the reaction mixture as liquid, was maintained through a pressure release regulatory valve by which the reaction mixture was relieved of pressure after passing through the reactor. The crude product obtained after running the apparatus for ten hours after working up by distillation gave 6.17 kg of monothioglycerine, corresponding to a yield of 95.2% of theory.
The reactor volume thus was so chosen that the component in deficiency, namely glycidol reacted to 100%.
In examples 4-11 also the boiling point and the purity of the product corresponded to that in Example 1. | The production of 3-mercapto-propanediol-1,2 is attained with good yields and in an industrially simple manner by reacting liquid hydrogen sulfide with glycidol under pressure, namely either in the presence of aluminum oxide or a sodium aluminum silicate, i.e., in heterogeneous phase or in the presence of an alkali or alkaline earth hydroxide dissolving in reaction medium, i.e. in homogeneous phase. | 2 |
FIELD OF THE INVENTION
This invention relates to the field of infrared imaging of films and plates for use in graphic arts.
BACKGROUND OF THE INVENTION
The use of infrared laser beams in imaging processes has a long history. Braudy, in U.S. Pat. No. 3,745,586, describes a laser transfer process whereby ink coated on the back of a thin film element is selectively transferred to an adjacent material by use of laser energy. Roberts, in U.S. Pat. No. 3,787,210 describes laser blow off using a laser beam for image recording on film. Kasai et al, in Patent No. U.S. Pat. No. 4,214,249 set out the problems of laser beam recording utilizing thermal melting deformation and/or evaporation removal using a laminate of non-metal and metal layers. Oransky et al, in U.S. Pat. No. 4,245,003 describe a laser imageable film with a dried coating of graphite with resin.
Recording films have wide application in the Graphics Arts Industry. They are in use as intermediates in the preparation of various types of printing plates. For instance, they are used as ultra violet (UV) and visible light masks to image pre-sensitized offset printing plates as well as flexographic plates, gravure cylinders and printing screens. They are also used for preparing proofs for inspection before printing. In general, films are in themselves multi-purpose, in that the same material may be imaged with data in a suitable form for a particular type of printing plate and may then be used as a mask so that the plate may be selectively exposed either to UV or visible light, as part of the process of creating the printing master suitable for the particular printing process.
In the field of recording films and their applications in printing, films may now be imaged using digital information. Although silver films predominate in this market, it would be an advantage to have films that do not use conventional silver chemistry, which is a non-renewable resource and which is used with environmentally problematic processing materials. It would also be advantageous if the material could be used in daylight, without taking any special precautions. It is preferable to have the recording material imaged in such a way that no processing is necessary, but if processing must be carried out, it should be simple and fast and if a liquid is required, it should be an environmentally innocuous liquid such as water.
The use of relatively cheap laser diodes in imaging has generated potential solutions to satisfy these demands. Imaging by ablating parts of the masking layer provides the basis for a process that meets the demands of providing almost processless or processless materials and simplifies the mask preparation to a minimum number of steps. To provide adequate performance, the film must have a high D max (the optical transmission density of the black areas of the film) and a low D min (the optical transmission density in the transparent areas of the film). Such values must relate to the actinic radiation involved when the film is used as a photomask to expose a printing plate.
Although ablation recording films may be produced and have many advantages over conventional films, they have had little impact on the market despite these advantages. One reason for this is that silver-based films are relatively inexpensive. They are made in such large quantities, and as such give economy of scale. Large volumes mean that raw materials can be purchased at minimum prices and long production runs mean relatively low wastage and high productivity. While there may be a significant range of grades of these conventional films, they use common ingredients and this fact contributes to the economy of scale. Thermally ablatable films do not have advantages of economy of scale because of market limitations.
A similar situation exists with infrared ablatable waterless and conventional wet printing plates of various types that are produced for imaging. The same advantages as for thermally ablatable film may be applied to the use of ablatable printing plates, namely, daylight stability, no processing other than harmless solutions etc. The relatively low quantities manufactured compared to non-digital, conventional presensitized plates gives the latter a cost advantage due to economy of scale.
An example of a waterless thermally ablatable plate is that sold by Presstek under the name of Presstek Pearl plate. U.S. Pat. No. 5,339,737 to Lewis et al describes infrared ablatable offset plates—both for waterless printing and for wet conventional offset printing. At present, the Presstek Pearl plate is as much as four times the cost of the cheapest presensitized offset plate and suffers from the same problems of economy of scale described above.
A further example of the contrast between price of conventional printing members and ablatable members is concerned with flexo printing, where patents such as U.S. Pat. No. 5,262,275 to Fan describe flexo plates imaged by infrared laser ablation. Such plates are far more expensive than conventional flexo plates.
One working in the Graphics Arts Industry and using films and plates has to stock a wide range of products such as films and printing plates. Stocking such a range is costly.
Thus, it would be desirable to provide a graphic arts tool that would provide a solution to economy of scale for infrared ablatable graphic arts products.
SUMMARY OF THE INVENTION
Accordingly, it is a broad object of the present invention to overcome the problems of the prior art and provide solutions to economy of scale for infrared ablatable Graphics Arts products by a novel modular approach of using common ingredients and by combining functions to produce multipurpose materials with synergistic advantages over the component products from which they have been derived. This is done by combining the properties of a photomask film with those of a printing plate, so that the same material can be used as a film or a plate or can function as both to produce a plate with proofing functions.
In accordance with a preferred embodiment of the present invention there is provided a dual function printing member usable both as a printing plate and a recording film, comprising:
a transparent substrate; and
a coating on a top side of said substrate, said coating comprising at least one layer, wherein said coating has a measured optical density of at least 3.0 both in visible and UV light and wherein the uppermost surface of said at least one layer of said coating is scratch-resistant.
In addition, there is provided a method of producing a dual function printing member for use as both a printing plate and a recording film, comprising:
providing a transparent base layer;
applying a coating on top of said base layer, said coating comprising at least one layer, wherein said coating has a measured optical density of at least 3.0 both in visible and UV light and wherein the uppermost of said at least one layer of said coating is scratch-resistant; and
imaging said coated base layer.
Furthermore, there is provided a graphic tool constructed from selected members of a group of modular components said group comprising:
substrates from the group of: polyester and aluminum; and
ablatable coatings from the group of: carbon black, UV absorbing dye, amino resin, nitrocellulose resin and cross-linking catalysts,
wherein each tool functions as at least one of a film and a plate;
and each of said tools comprises:
a substrate; and
at least one ablatable coating.
Other features and advantages of the invention will become apparent from the following drawings and the description.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention with regard to the embodiments thereof, reference is made to the accompanying drawings, in which like numerals designate corresponding elements or sections throughout and in which:
FIG. 1 is a cross-sectional representation of a member of a first embodiment of the present invention comprising coatings and substrate;
FIG. 2 shows the absorption spectrum of Primulin, by way of example; and
FIG. 3 is a cross-sectional representation of a member of a second embodiment of the present invention comprising coatings and substrate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In a first embodiment of the invention, there is provided a printing member with combined functions of a printing plate and a recording film.
Referring now to FIG. 1, there is shown a cross-sectional representation of a member of a first embodiment of the present invention, comprising substrate film 20 that is substantially transparent to ultra violet and visible light. Film 20 is coated with polymeric layer 21 , preferably based on an amino resin or a nitrocellulose resin, or a combination of the two. The thickness of this layer is less than 3 microns. Polymeric layer 21 contains carbon black, an ultra-violet absorbing dye and optionally an infrared absorbing dye.
Amino resins are generally polycondensation products of carbonyl compounds with NH— functional compounds, an example of which is
Examples of useful compounds in this group are partially methylated melamine formaldehyde resins with a high content of methylol groups. An example of such a resin is Cymel 385 (Dyno-Cytec, Botleweg 175, 3197 Rotterdam, The Netherlands), which is a proprietary material, described as having a medium degree of alkylation and a high imino functionality. The material is a complex mixture, containing different degrees of hydroxymethylation, alkylation and condensation attached around the melamine structure, as shown below:
Cymel 385 is water-soluble and can undergo condensation reactions to form a strong hard film by acid catalysis—for instance using paratoluene sulfonic acid. A similar useful amino resin is sold under the name of Cymel 373 (Dyno-Cytec, Botleweg 175, 3197 Rotterdam, The Netherlands), but has a low imino content giving greater flexibility but lower curing speed.
Cymel 1170 (Dyno-Cytec, Botleweg 175, 3197 Rotterdam, The Netherlands) is a butylated glycoluril-formaldehyde amino resin used in this invention in solvent-based systems to cross-link with hydroxyl groups of nitrocellulose resin.
Examples of carbon blacks are Cab-O-Jet 200 and 300. These are specially treated carbon black pigments, sold as aqueous dispersions and are used in this invention in the water-based coatings. Mogul L (Cabot Corporation, Billerca, Mass., USA) and Regal 400R (Cabot Corporation, Billerca, Mass., USA) are examples of carbon blacks, which may be used in the invention both in the water-based coatings and the solvent based coatings. If used, they need to be dispersed in the system by, for instance, high-speed cavitation stirring, triple roller milling or by ball milling.
The ultra-violet absorbing dye is usually a yellow one with an absorption peak between 320 and 400 nm—what is known as the UVA region. This region of the UV is commonly used in the processes of photopolymer plate making. Examples of water-soluble dyes suitable for this application are 4 phenylazo aniline hydrochloride, Primulin (Direct Yellow 59) and Thioflavin (Direct Yellow 7). Examples of suitable solvent soluble dyes are 4-phenyl azoaniline (solvent yellow 1) and phenyl azophenol (solvent yellow 7). FIG. 2 shows the absorption spectrum of Primulin by way of example.
Uppermost layer 22 is a protective surface comprised of a polysiloxane layer, which may contain a UV absorbing dye. The member is imaged by digital writing with an infrared source that ablates layers 21 and 22 , to leave a clean transparent substrate. Thus, layer 21 is the infrared absorbent layer and layer 22 is the non-infrared absorbent, ablatable layer. Layer 22 , on its own, would not be ablated using the level of energy used in the implementation of this invention. It is only ablated by transference of energy from layer 21 . If necessary, the surface is wiped clean with a dry or damp rag to remove any remnants of ablated material that remains on the surface after imaging.
The member must have the following combination of properties:
The base must be transparent;
The combined coatings must give a measured optical density of not less than 3.0 both in the visible and UV (all measurements were made with a Macbeth TD 904 Densitometer);
The uppermost layer must protect the material from scratching, solvent and water attack and other handling damage;
The fully ablated areas of the plate must have an optical transmission density of less than 0.2;
The imaged member must function as a waterless offset printing plate and produce at least 10,000 good printing impressions.
With the above stated combination of properties, the Graphics Arts customer can purchase and stock such a product for multiple uses. It can be used as a recording film mask to image any conventional presensitized offset lithographic printing plates. It is particularly suitable for use with both liquid and solid flexographic members as a contact mask. Solid flexographic members have, in general, a slightly sticky surface and contact films are recommended to be matte. The member of this embodiment is shiny, permitting better film-to-plate contact, but at the same time, the silicone surface provides a release layer that prevents any sticking between the flexo surface and the recording film. Also, the film can be used with a liquid flexo plate, without the need for an intermediate protective film. Before use, the imaged film is treated with an oil or grease, which remains on the imaged areas and provides them with release properties. The resulting method improves the imaging quality by removing the intervening protective layer, which is generally used to protect the film from the liquid polymer.
The member can also be used as a computer-to-plate waterless plate. After imaging of such a plate, the plate can be used in proofing processes, which generally use film masks such as those known commercially as Chromalin (Du Pont) and Matchprint (Kodak). Thus, the proofing is made using the exact image to be printed, avoiding all risks of errors. This is a unique application engendered by the combination of film and plate functions. Such plate and film material may be imaged on computer-to-plate setters such as Trendsetters and Lotems manufactured and sold by CreoScitex. It can also be imaged in on-press offset lithographic printing machines such as the Heidelberg Quickmaster DI, wherein it would be supplied as a roll of master material.
As intimated above, the film properties have significant advantages over conventional film. The film is handleable in daylight. In the unablated areas of the coating, it has a built-in D max , which does not vary with processing. It does not fog. It has no underexposure memory. It is close to being processless. It does not use environmentally problematic solutions, which have disposal problems as well as stability problems.
A second embodiment is depicted in FIG. 3 . Substrate 20 is coated with carbon-loaded layer 23 , bonded with an amino resin combined with a cross-linked hydrophilic system, preferably with a UV absorbing dye and optionally with an infrared absorbing dye. Layer 23 has a thickness between 0.5 and 3 microns. The member must have the following combination of properties:
The base must be transparent;
The coating must give a measured optical density of not less than 3.0 both in the visible and UV, as measured with a Macbeth Densitometer;
The uppermost layer must not be susceptible to scratching or other handling damage;
The fully ablated areas of the plate must have an optical transmission density of less than 0.2;
The imaged member must function as a conventional wet offset printing plate and produce at least 10,000 good printing impressions.
With the above stated combination of properties, the Graphics Arts customer can purchase and stock such a product for multiple uses. It can be used as a recording film mask to image any conventional presensitized offset lithographic printing plates. It is particularly suitable for use with solid flexographic members as a contact mask. Solid flexographic members have in general a slightly sticky surface and contact films are recommended to be matte. The member of this invention is matte and therefore suitable for use as a film with solid flexographic members.
The member can also be used as a computer-to-plate conventional wet offset plate. After imaging of such a plate, the plate can be used in proofing processes where a photomask is used, such as those known commercially as Chromalin (Du Pont) and Matchprint (Kodak). Thus, the proofing is made using the exact image to be printed, avoiding all risks of errors. This is a unique application engendered by the combination of film and plate functions. The plate and film material may be imaged on computer-to-plate setters such as Trendsetter and Lotem machines manufactured by CreoScitex. It can also be imaged in on-press systems where a conventional wet plate system is preferred over a waterless system. In its use as a plate, the ablation process of such a one-coat system as described herein removes most, if not all the ablated material by vacuum evacuation, which is usually part of the imaging system. The plate may be offered for printing without any treatment whatsoever, as any small amount of detritus is carried away on the roll-up copies that are wasted at the beginning of any printing run.
As mentioned in the previous embodiment, the film properties have significant advantages over conventional film. The film is able to be handled in daylight. The unablated areas provide a built-in D max , which does not vary with processing. It does not fog. It has no underexposure memory. It is close to being processless. It does not use environmentally problematic solutions, which have disposal problems as well as stability problems.
Because of the multiplicity of functions of the above two embodiments, the same materials can be sold to a wider market and can have the opportunity of reduced costs due to economy of scale.
The third embodiment involves the production of a combination of films and plates which are all ablatable and have a commonality of ingredients that reduces the costs of raw materials purchase and of production, but not necessarily with multi-functionality as described in previous embodiments. The three types of members are, by way of example, polyester recording film, wet offset and dry offset plates. The common ingredients are for instance a polyester substrate, carbon black, UV absorbing dye, amino resin and cross-linking catalyst. It is preferable that the substrate and ingredients used in all of the members are identical for optimum cost benefit, but if they are of the same generic type and are from the same supplier this still provides sufficient advantage.
In addition to the above combinations coated on polyester, it is also possible to include coatings on aluminum and the coating formulation mixture itself for plateless application, as described in the U.S. Pat. Nos. 5,713,287 and 5,996,499 to Gelbart.
EXAMPLES
Example 1
Example 1 describes the first embodiment as shown in FIG. 1, where the material produced can perform the dual function of a waterless offset printing plate and a recording film that is used as a photomask.
The following mixture was made up (all quantities quoted as parts by weight):
First Coat
1.98% Thioflavin solution in water
22.1
Cymel 385
8.73
Cab-O-Jet 200 (Cabot Corporation, Billerca, Massachusetts,
43.73
USA)
Bayerscript solution (Bayer, Phila., PA USA)
21.85
Tegowet KL245 (Tego Chemie Service, Hopewell VA 23860)
1.23
Cycat 4040 (Dyno-Cytec, Botleweg 175, 3197 Rotterdam, The
2.36
Netherlands)
The mixture was well stirred before coating with a wire wound rod onto clear 100 micron polyester and drying and curing at 140° C. for 4 minutes to give a dry film of 1.8 microns thick. Although this coating had been deposited from water solution, it was water insoluble after curing. The following second coat was mixed and then applied (all quantities quoted as parts by weight):
Second Coat
Alcosil part A
10
parts
Alcosil part B
5
parts
Alcosil gum
5
parts
(Alcosil products from Allcock and Sons, Ltd., Manchester, England)
The mixture was coated on top of the above coating and dried and cured at 140° C. for 4 minutes to give a dry film of 1.9 microns.
The resulting film was shiny and not easily damaged by handling. It had a D max of 4.5 in the visible region and 4.0 in the UV region, as measured with a Macbeth T0904 Densitometer. The blank was imaged on a Lotem Flexo at 100 lines per millimeter at 600 mJ/cm 2 . The image was wiped with a damp cloth and then gave a D min of 0.08 in the visible region and 0.1 in the UV. The resulting film was then capable of acting as a mask to image printing plates, or of being used as a printing plate, by printing on a water-cooled offset litho machine using waterless printing ink.
Example 2
Example 2 describes the second embodiment as depicted in FIG. 3, where the imaged member can be used as a recording film photomask and as a conventional wet offset lithographic printing plate.
The following mixture was made up (all quantities quoted as parts by weight):
24% water solution of 99% hydrolysed polyvinyl alcohol
12.92
Kaolin
1.12
Cab-O-Jet 200
26.18
Cymel 385
1.12
Ethanol
2.2
Aerosol OT (BDH Laboratory Supplies, Poole, Dorset, England)
0.04
1.98% Thioflavin solution in water
6.46
The mixture was ball milled overnight and then 0.22 parts of Cycat 4040 and 1.29 parts of Titanium bis (ammoniumlactohydroxide) were added and mixed in.
The mixture was coated to a dry thickness of 1.8 microns. The resulting film was matte and not easily damaged by handling. It had a D max of 4.5 in both the visible region and the UV region. The blank was imaged on a Lotem Flexo at 100 lines per millimeter at 600 mJ/cm 2 . The image was wiped with a damp cloth and then gave a D min of 0.05 in the visible region and 0.1 in the UV. The resulting film was then capable of acting as a mask to image printing plates. It was suitable as a mask for solid flexographic plates. The imaged blank could also be mounted directly on an offset lithographic printing machine without cleaning in any way and was then printed using standard fount and printing ink.
Example 3
The following example demonstrates the third embodiment where there is commonality between all component members.
Member 1—Recording Film Phototool.
First Coat Formulation and substrate—as in Example 1
Second Coat Formulation (all quantities quoted as parts by weight):
Cymel 385
21.1
Water
78.01
Cycat 4040
0.89
This solution was bar coated onto the first coat and was dried and cured at 140° C. for 4 minutes to a dry thickness of 0.7 microns. The resulting product was an infrared ablatable recording film of sensitivity of 600 mJ/cm 2 , with a glossy surface that was extremely resistant to any surface scratching, delamination or general damage. It had a D min of 0.08 in the visible region and 0.1 in the UV. It had a D max of 4.5 in the visible region and 4.0 in the UV region, as measured with a Macbeth TO904.
Member 2—Wet Offset Plate
First Coat Formulation and substrate as in Example 1.
Second Coat Formulation (all quantities quoted as parts by weight):
24% water solution of 99% hydrolysed polyvinyl alcohol
6.46
Kaolin
1.12
Cymel 385
1.12
Ethanol
2.2
Aerosol OT
0.04
1.98% Thioflavin solution in water
6.46
This formulation was bar coated and dried and cured to a thickness of 0.7 microns. The product was an infrared ablatable conventional wet offset lithographic printing plate of sensitivity 600 mJ/cm 2 .
Member 3—Waterless Offset Plate
First Coat Formulation and substrate as in Example 1
Second Coat Formulation (all quantities quoted as parts by weight):
Dehesive 410E (Wacker Chemie GmbH, Munich
68
Germany)
Water
25
Cymel 373
11
Cycat 4045
2.9
V72 (Wacker Chemie GmbH, Munich
13
Germany)
Superwetting agent (Dow Corp. Midland MI,
3
USA)
This was coated onto the first coat and cured to a dry coating thickness of 2.5 microns. The resulting member was a processless infrared ablatable wet conventional offset printing plate.
The above three members constitute a group of products with a commonality of ingredients. They have the same substrate, the same first coat and all contain amine resin systems in the top coat.
Taking the first three members together they all have;
identical polyester substrates
identical first coat formulations
two out of three have the same amine resin and catalyst. The third has an amine and catalyst from a common manufacturing source.
Further Members
The two plate material formulations can also be coated onto an aluminum or anodized aluminum substrate to give more robust plates. The mixture used in Example 2 can be sprayed onto a thermally insulative surface of plate cylinder of an offset lithographic printing press, dried and cured and then imaged by ablation. The surface will then constitute a printing plate surface and can be used in conventional wet offset printing to produce multiple impressions. At the end of the run, the surface is washed with a material such as ethyl lactate which removes the entire layer and the material is then re-coated onto the drum for use in the next printing job. This is in accordance with the Gelbart U.S. Pat. No. 5,713,287.
Example 4
Member 1—Recording Film
The following mixture was made up (all quantities quoted as parts by weight):
Methyl ethyl ketone
76.99
4 Phenylazoaniline
0.69
cellulose nitrate
4.66
Molgul L carbon black.
15.64
Cymel 1170
1.79
This mixture was ball milled over a period of 24 hours and then 0.24 parts of Cycat 4040 added. It was then coated onto 100 micron polyester and dried and cured at 140° C. for 4 minutes to a dry thickness of 2.5 microns. This coating was easily scratched. The following mixture was made up (all quantities quoted as parts by weight):
Water
67.96
Cymel 385
28.58
Tegowet 245
0.88
Syloid 7000 (W. R. Grace and Co., Cambridge, England)
1.33
This mixture was ball milled overnight and 1.25 parts of Cycat 4040 added. The mixture was gap coated to a dry thickness of 1.5 microns and dried and cured at 140° C. for 4 minutes.
The resulting film had a matte finish, had a D max of 3.8 and after imaging had a D min of 0.18 in the visible and D max of 4.1 and D min of 0.16 in the UV. It was scratch resistant and fit to use as a photomask for preparing, by way of example, any dry flexographic printing plates.
Member 2—Waterless Plate
The above-mentioned first coat of this example was coated onto 170 micron polyester and cured and dried as above. It was then coated with the second coat of Example 3, Member 3, to give a waterless printing plate of similar performance.
Member 3—Conventional Wet Plate
The above mentioned first coat of this example was coated onto 170 micron polyester and cured and dried as above. It was then coated with the second coat of Example 3, Member 2, to give a conventional wet offset printing plate of similar performance.
Having described the invention with regard to certain specific embodiments thereof, it is to be understood that the description is not meant as a limitation, since further modifications may now suggest themselves to those skilled in the art, and it is intended to cover such modifications as fall within the scope of the appended claims. | The multi-purpose modular infra-red ablatable graphic arts tool provided comprises solutions to economy of scale for infrared ablatable Graphics Arts products by a novel modular approach of using common ingredients and by combining functions to produce multipurpose materials with synergistic advantages over the component products from which they have been derived. This is done by combining the properties of a photomask film with those of a printing plate, so that the same material can be used as a film or a plate or can function as both to produce a plate with proofing functions. | 1 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to document authentication. The use of electronic documents is gaining popularity and a variety of different formats of electronic documents exist that can be processed by different computer software applications. One example of a common, platform-independent type of electronic document is a PDF (Portable Document Format) document, which has been developed by Adobe Systems Incorporated, San Jose, Calif. PDF documents can be read by PDF readers, such as Adobe® Acrobat® and Adobe® Acrobat® Reader®, or other types of software applications.
[0002] While electronic documents are convenient from many points of view, they also present new problems that do not have to be addressed for regular paper documents. One example of such a problem is that an electronic document can be modified in different ways than a conventional printed paper document. Malicious users may, for example, manipulate an electronic document such that the document no longer reflects what the author originally wrote.
SUMMARY OF THE INVENTION
[0003] In general, in one aspect, this invention provides methods and apparatus, including computer program products, implementing and using techniques for document authentication. An electronic document is presented to a user. The electronic document has data representing a signed state and a current state. An unauthorized difference between the signed state and the current state is detected, based on one or more rules that are associated with the electronic document. A digital signature associated with the electronic document is invalidated in response to the detecting.
[0004] Advantageous implementations can include one or more of the following features. The signed state of the electronic document can be presented to the user. The electronic document can include an object hash representing the signed state of the electronic document. The object hash can be generated subject to the rules that are associated with the electronic document. The object hash can be based on content items of the electronic document that are invariant to a set of one or more operations authorized by the rules associated with the electronic document. The set of one or more operations can be authorized by an author providing the signed state of the electronic document. Detecting a difference can include generating an object hash of the current state according to a set of rules associated with the signed state of the electronic document and comparing the generated object hash with the object hash in the electronic document.
[0005] The electronic document can include a byte range hash. Detecting a difference can include generating a byte range hash according to a saved version of the electronic document and comparing the generated byte range hash with the byte range hash in the electronic document. The difference between the signed state and the current state can relate to one or more of the following operations performed on data in the electronic document: digitally signing the electronic document, entering data into predefined fields of the electronic document, and annotating the electronic document. An input defining a second signed state can be received and a difference between the second signed state and the current state can be detected.
[0006] A digital signature relating to the second signed state can be invalidated if the detected difference between the current state and the second signed state represents a difference that is not permitted by the rules associated with the electronic document. A digital signature associated with the electronic document can be validated prior to detecting a difference. Invalidating the digital signature can include invalidating the digital signature if the detected difference between current state and the signed state represents a difference that is not permitted by an author providing the digital signature.
[0007] The invention can be implemented to realize one or more of the following advantages. An author or content provider can ensure that individual users can only make changes to an electronic document that are allowed by the author of the electronic document. The allowed changes can be governed by rules that the author defines for the object, and/or rules that are defined for a recipient of the document. Together these two types of rules define permissions authorizing the recipient to perform operations on the document. Generating a digitally signed digest of objects invariant to authorized changes provides a mechanism for detecting unauthorized changes to the document. This enables workflows in which the author of an electronic document can control to what extent a particular electronic document can be changed. One example of such a workflow might feature a government agency, such as the Internal Revenue Service (IRS), that would like to distribute forms (such as tax forms) electronically to a large number of recipients. At the same time, the agency has the ability to limit the ways in which users can make changes in the document—for example, by limiting what fields can be changed and what type of changes can be made to those fields. If a user with malicious intent manages to make unauthorized changes to an electronic document, for example, by using a different software application than the application in which the electronic document is normally used, the unauthorized changes will be discovered when the document is opened again in the application. A user may also view (or “roll back” to) a signed state of the electronic document, since the electronic document includes both the signed state and the current state both are part of the same electronic document. This functionality can also make it possible to display the differences between the signed state and the current state, and remove any unauthorized changes from the current state of the electronic document. The author may also completely prevent any recipients of the electronic document from making changes. For example, a company may put out a press release in an electronic document and add a rule preventing any changes from being made to the press release. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will become apparent from the description, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a flowchart illustrating a method for generating an electronic document including a set of document rules.
[0009] [0009]FIG. 2 is a flowchart illustrating a method for detecting unauthorized modifications to an electronic document.
[0010] [0010]FIG. 3 is a flowchart illustrating a method for preventing unauthorized modifications to an electronic document.
[0011] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0012] The document modification and prevention techniques that will be described below enable controlled interaction between two major categories of people or entities: document authors and document users. Related techniques have been described in the following three copending patent applications, which are also incorporated by reference in their entireties: U.S. Ser. No. 10/080,923, filed on Feb. 21, 2002; U.S. Ser. No. 10/306,635, filed on Nov. 27, 2002; and U.S. Ser. No. 10/306,779, also filed on Nov. 27, 2002. A document author is someone who for a particular electronic document defines a set of rules that specify what parts of an electronic document are allowed to change as a result of user interaction with the document. A user is generally a person or an entity for which the electronic document is intended. The user is only allowed to make modifications to the electronic document that do not violate the rules that the author has defined for the electronic document. If the user tries to make changes that are not allowed by the author, the electronic document will be classified as invalid, for example, by invalidating a signature that the author has added to the document. An electronic document, as used herein, refers to a collection of information that can be read or otherwise processed as a single unit in a computer or some type of electronic document reader. A document can contain plain or formatted text, graphics, sound, other multimedia data, scripts, executable code; or hyperlinks to other documents. An electronic document does not necessarily correspond to a file. A document may be stored in a portion of a file that holds other documents, in a single file dedicated to the document in question, or in multiple coordinated files.
[0013] As can be seen in FIG. 1, a method 100 for generating an electronic document begins by receiving an electronic document (step 105 ). In the present example, the received electronic document is prepared in an authoring software application, such as a PDF authoring application. The electronic document can be authored by an author, that is, the same person who determines what rules should apply to the content of the electronic document, or it can be obtained from a different source. It should be noted that although the invention is explained by way of example, with reference to PDF documents, the techniques described apply to other types of electronic documents or data types in which rules relating to the content of the document can be included.
[0014] A set of rules is then received (step 110 ). The set of rules defines the extent to which changes are authorized to the contents of the electronic document when a user views the electronic document in an electronic document reader. Typically, the set of rules is provided by the author and reflects the author's intent for the document. Alternatively, some or all of the rules can be selected automatically for the document—for example, depending on the document's content and format. Examples of changes that can be allowed by the rules include digitally signing the electronic document (for example, in a predefined signature field), entering data into predefined fields of the electronic document (such as fill-in form fields or importing form data) and annotating the electronic document (such as adding, deleting, editing, or importing comments or annotations). The rules can be received as part of the electronic document, or separately from the electronic document. It should be noted that rules can apply both globally (i.e., to the entire electronic document) or locally (i.e., to an individual content item of the electronic document or to a group of content items in the electronic document). As will be seen below, the rules are specified permanently when the author signs the electronic document. Thus, the rules are made part of what is covered by the author's signature and cannot be modified by any recipients of the document.
[0015] Next, an object digest (also referred to as selective digest) is generated (step 115 ). A digest is generally a piece of data of specific length, calculated from a file or message, in such a way that there is a high probability that any change to the original file or message will result in a change to the digest. The digest typically embodies a one-way mapping function in that is relatively easy to generate the digest from the file or message, but extremely hard to generate the message from the digest. An object digest, as defined in this application, is a digest that is based on selected content items of an electronic document. In particular, in one implementation, the object digest is based on the content items of the electronic document that are not allowed to change based on the rules that the author of the electronic document has assigned—that is, content items that are invariant to authorized changes to the document. For instance, if the rules do not allow alterations of page content, addition or deletion of pages, addition or deletion of form fields, any changes to these types of content items will result in an electronic document having a different object digest. On the other hand, the rules may allow form fill in, addition or deletion of comments, and so on, and such changes will not cause the object digest to change.
[0016] To generate the object digest, the rules are first read to determine filter criteria to be used when selecting which objects will be considered in the generation of the object digest. For each content item in the electronic document, it is then determined whether the rules allow the content item to change. If the content item is not allowed to change, then the content item is included in the generation of the object digest. If the content item is allowed to change, then the content item is ignored and not used in creating the object digest. The object digest is generated from content items that reside in the memory of the computer or electronic document reader on which the electronic document is processed, that is, the absolute latest version of the electronic document, which typically corresponds to what is displayed on a computer screen. In one implementation, the object digest is represented as a hash, which acts as a fingerprint of the electronic document and the associated rules, and thus uniquely identifies the electronic document. In another implementation, the object digest acts as a fingerprint of only one or more parts of the electronic document and the rules associated with these parts, and thus uniquely identifies only those specific parts of the electronic document.
[0017] A specific implementation of calculating an object digest will be described below with reference to a PDF document. PDF is a file format that is used to represent a document in a format that is independent of the computer software application, hardware, and operating system used to create it. A PDF file contains a PDF document and other supporting data. A PDF document can contain one or more pages. Each page in the document can contain any combination of text, graphics, and images in a device-independent and resolution-independent format. This combination is also referred to as the page description. A PDF document can also contain information possible only in an electronic representation, such as executable code, hypertext links, and so on. In addition to a document, a PDF file contains the version of the PDF specification used in the file and information about the location of different important structures in the file.
[0018] A PDF document can conceptually be thought of as having four parts. The first part is a set of basic object types used by PDF to represent content items. Examples of such data types include booleans, numbers, strings, names, arrays, dictionaries, and streams. The second part is the PDF file structure. The file structure determines how the content items are stored in a PDF file, how they are accessed, and how they are updated. The file structure is independent of the semantics of the content items. The third part is the PDF document structure. The document structure specifies how the basic object types are used to represent various parts of a PDF document, such as pages, annotations, hypertext links, fonts, and so on. The fourth and final part is the PDF page description. The PDF page description is a part of the PDF page object, but only has limited interaction with other parts of the PDF document. A further explanation of PDF files and documents can be found in “Portable Document Format Reference Manual” by Tom Bienz and Richard Cohn, Adobe Systems Incorporated, Addison-Wesley Publishing Company, 1993.
[0019] In an implementation in which the electronic document is a PDF document, the content items that are evaluated for inclusion/non-inclusion in the object digest can, for example, include: MediaBox regions, CropBox regions, resource dictionaries, and the entire page content stream. In this implementation, the object digest is represented as a hash based on the content items of the document that are invariant to user changes. The hash has a bottom layer, an intermediate layer and a top layer. The bottom layer of the hash is a recursive algorithm and contains the functionality for digesting a basic PDF content item. Simple content items, such as booleans, integers, numbers, strings, and names form the basis of recursion in the bottom layer algorithm. Compound content items, such as dictionaries, arrays, and so on, are digested by recursively digesting the content items making up the compound content items. Special consideration may be necessary for some types of content items, such as PDF language streams (which are combinations of a dictionary and a stream), but ultimately all content items are mapped to a sequence of bytes, which is digested by a byte hashing algorithm. For each content item, an object type identifier and the length of the data being digested is included in the digest along with the digest of the particular content item instance. For example, if the digesting algorithm encounters an integer of value 42 , a type identifier corresponding to the integer type will be included in the digest, along with the byte length of the integer when represented as data, along with a four byte value signifying the value 42 . This makes it possible to distinguish the integer representation 42 from an identical 4 byte string, and so on.
[0020] The hashing algorithm can be a conventional hashing algorithm, such as a SHA-1 algorithm, which is a version of the Secure Hash Algorithm (SHA) and described in the ANSI X9.30 (part 2) standard. SHA-1 produces a 160-bit (20 byte) digest. Similarly, an MD5 hash algorithm, which has a 128 bit (16 byte) digest and often is a faster implementation than the SHA-1 algorithm, can be used. The hashing algorithm must be capable of providing a condensed and unique representation of the invariant document content, so that the result can be used to determine whether unauthorized changes have been made to the document.
[0021] The intermediate layer of the object hash contains the functionality for digesting semi-complex content items, such as annotations and form fields. The intermediate layer calls the bottom layer whenever necessary. For every field annotation in the PDF document, the content items can include: an annotation region, a text label for the annotation's pop-up window, a field type, a content stream of the page on which the field annotation resides, a normal appearance stream, a default field value, and if form rights are turned off, an actual field value. PDF form field content items have associated annotation content items. The form field content items are therefore digested by including selected elements from the annotation as well as the field dictionary.
[0022] The top layer of the object hash contains the functionality for digesting complex content items, such as pages or an entire PDF document. A PDF page is digested by digesting selected elements from the associated page dictionary. A page template is digested by including a content stream of the page template, and optionally annotations on the page template. An entire PDF document is digested by digesting all the pages, all the form fields, and all page templates, if available.
[0023] A few further considerations arise when the hash forming the object digest of a PDF document is generated, as will now be described. First, in order to avoid infinite recursions, the method for creating the object digest keeps track of all indirect content items visited during a recursive descent into each content item. No recursion is performed on an indirect content item that has already been visited once. If an already visited content item is encountered, the object hash generating method merely adds the object type and a fixed integer into the object digest to indicate that the content item was encountered again.
[0024] Second, if form fill-in is allowed by the rules set by the author, the content of a value field in a field dictionary of the PDF document is never included in the object digest, since this value could be modified during form fill-in. However, if form fill-in is not allowed, or if some form fields are present before the digest is present and the author wishes to lock these form fields, the content of the value field in the field dictionary of the PDF document is included in the object digest, so that the form fields cannot be changed. In one implementation, it is also possible to select which form fields to include in the object digest, such that some form fields can be changed while others must remain unchanged. The same is true for the content stream of the widget annotation corresponding to a field.
[0025] Returning now to FIG. 1, after the object digest has been generated, a byte range digest is generated (step 120 ). The byte range digest can be described as a “snapshot” of the bytes representing the electronic document as saved on disk. Like the object digest, the byte range digest can be stored as a hash, although this hash is simpler to compute than the object hash, since only a range of bytes are hashed and not any complex objects, which is the case with the object hash. The byte range hash makes it possible for a user to see the version of the document that was signed, since the hash will change between different versions as new bytes are added due to modifications of the document. The byte range hash alone cannot be used to detect or prevent any changes beyond the signed version of the document. For example, the document may contain JavaScripts that execute when the document is viewed. As a result, the document displayed to the user may have a different appearance than the signed version of the document, upon which the byte range hash is based. The combination of the byte range hash and the object hash, however, allows a user to view the version of a document that was actually signed, and provides for control by the author over what changes can be made to the document subsequent to the author's signing of the document. This is possible since the object hash is regenerated every time a user attempts to validate the document. Several types of advanced workflows can be enabled through this mechanism.
[0026] Finally, the author adds the object digest, and the byte range digest to the electronic document and signs this aggregate (step 130 ), which completes the electronic document generating method and results in an electronic document that is ready to be provided to one or more users. The digital signature is a unique sequence of bytes that identifies the author. The form of the digital signature of the electronic document can vary and can be generated from, for example, a document digest that has been encrypted with a public/private key, a biometric signature (such as a fingerprint or a retinal scan), and so on. Signing the electronic document, the MDP settings, and the attestations simply means appending the unique sequence of bytes to the document in such a way that the recipient can read and identify it as a signature document.
[0027] [0027]FIG. 2 shows a method 200 for detecting modifications made to an electronic document when the electronic document is opened on a computer or other type of electronic document reader. First, an electronic document signed by an author (and optionally one or more intermediate users) is received along with a set of rules, an object digest, and a byte range digest (step 205 ). The electronic document can be received by any type of conventional means, such as through a network as e-mail or be downloaded to a user's computer. Alternatively, the electronic document can be stored on some type of carrier for digital data, such as a floppy disk or a CD that is sent or given to a user.
[0028] When the document has been received, the electronic document reader verifies the author's (and optionally any intermediate user's) identity (step 210 ). The verification can, for example, be performed using a public key that matches a private key with which the author signed the electronic document.
[0029] The electronic document reader then generates a new object digest and a new byte range digest of the electronic document (step 215 ). The generation is performed in the same manner as described above with reference to FIG. 1, with the set of rules included in the document as a content filtering guide for the generation of the object digest.
[0030] The new object and byte range digests are compared with the signed object and byte range digests that are stored in the electronic document (step 220 ). The new object digest and byte range digest are identical to the stored object digest and byte range digest, respectively, only if the invariant content items in the electronic document matches the electronic document that the author signed. If the new object digest and the stored object digest are identical (the “Yes” branch of step 225 ), the author's signature is considered to be valid and the electronic document reader opens the electronic document (step 235 ) in the electronic document reader and the operations that are allowed by the rules can be performed on the electronic document by a user. The opened document that is displayed to the user can be referred to as the current state of the document, as opposed to the signed state, which represents the original document that the author signed. As long as no changes have been made to the document, the current and signed states are identical.
[0031] On the other hand, if it is found in step 225 that the new object digest and the stored object digest are not identical (the “No” branch of step 225 ), an error message is displayed (step 230 )—for example, a warning that an unauthorized change has been detected, and/or a warning that the author's (and/or one or more intermediate user's) digital signature is invalid, and the user is prevented from making any modifications to the document.
[0032] [0032]FIG. 3 shows a method 300 for preventing a user from making modifications to a document that are not allowed by the rules established by the author of the document. The method starts with the display in an electronic document reader of the current state of an electronic document (step 305 ), as described above with reference to FIG. 2. A user input is then received, with the purpose of altering the current state of the electronic document to generate a new current state of the electronic document (step 310 ). The user input is then checked against the rules established by the author to determine whether the changes proposed by the user are allowed or not (step 315 ). For example, if the user input describes a modification to an annotation, the user input is checked against any rules relating to annotations of the document to determine whether the modification can take place. If the user input represents an allowed change (i.e. the “Yes” branch of step 315 ), then the method accepts the change, displays the modified document, and waits for a new user input. However, if the user input does not represent an allowed change (i.e. the “No” branch of step 315 ), then the prevention method invalidates the author signature (step 320 ). Consequently, a user cannot make unauthorized changes to the document, since the document in any subsequent workflow steps will have an invalid signature that indicates that the content of the document is not approved by the author and cannot be trusted. Optionally, the method can also reject any unauthorized changes and the display can revert to a previous state (such as the signed state) of the electronic document. Note that some viewing applications may not honor the rules and may therefore permit any changes without restriction, but any unauthorized changes will be detected using the detection method discussed above with reference to FIG. 2.
[0033] As was described above, in one implementation, in addition to the rules that have been defined for the document, there may also be a different set of rules that are associated with the user for whom the document is intended. For example, the document may be encrypted in addition to having the rules described above, so that only a particular group of users can access the content of the document. Alternatively, the document may contain additional information about enabling or disabling features of the user's electronic document reader. Together with the rules for the document, these user-specific rules, form a set of user permissions that define which operations a user can perform on the electronic document. The permissions thus constitute the logical “AND” group of the rules defined for the document and the rules defined for the recipient. In the simplest case, there are no user-specific limitations, and the permissions are governed exclusively by the rules of the document.
[0034] In another implementation of the invention, it is possible for the author to define operations that are associated with user signatures of the electronic document. The principles of this implementation are easiest described by way of example. Assume that a government agency, such as the Internal Revenue Service (IRS), is the author of an electronic document, for example, a tax form. The tax form contains three signature fields where users may digitally sign the document. For the sake of this example, it can be assumed that the users are a husband, his wife, and their accountant. The author, that is, the IRS, can add rules to the document that define what will happen when each individual user signs the electronic document. For example, there can be a rule for the husband saying “When the husband signs the document, all the fields that relate to his personal income will be locked”, a rule for the wife saying “When the wife signs the document, all the fields that relate to her personal income will be locked,” and a rule relating to the accountant saying “when the accountant signs this tax form, no more changes can be made.” As soon as one of these three people signs the document, all of their fields will be locked according to the rules established by the original author. If an unauthorized change is made to, for example, a field in which the husband's income is listed, the husband's signature will become invalid, while the wife's signature still remains valid. If the accountant had signed the form at the time the unauthorized change was made, the accountant's signature would also become invalid, since the rule for the accountant stated that no field could be changed. This mechanism is possible through the computation of one object digest each that includes the locked fields for the husband, wife, and accountant, respectively, at the time of signing. These individual object digests can then be recomputed and verified, as described above, to make sure that none of the locked fields that were used in computing each respective digest has changed. Many similar scenarios can be constructed in which parts of documents are signed by different users and only a particular part becomes invalid in the event of unauthorized changes being made to the electronic document.
[0035] The invention can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. The invention can be implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, e.g., in a machine-readable storage device or in a propagated signal, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. A computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.
[0036] Method steps of the invention can be performed by one or more programmable processors executing a computer program to perform functions of the invention by operating on input data and generating output. Method steps can also be performed by, and apparatus of the invention can be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).
[0037] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in special purpose logic circuitry.
[0038] To provide for interaction with a user, the invention can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input.
[0039] The invention has been described in terms of particular embodiments. Other embodiments are within the scope of the following claims. For example, the steps of the invention can be performed in a different order and still achieve desirable results. The processes above have been described for situations with only one author, but in some situations there may also be an original author and one or more subsequent authors in a workflow who may change the rules associated with the entire document, or parts of the document. The methods discussed above also allow these additional authors to supply their signatures as author signatures in addition to the original author, and a chain of signatures can be created in which permissions on each level may vary. | Methods and apparatus, including computer program products, implementing and using techniques for document authentication. An electronic document is presented to a user. The electronic document has data representing a signed state and a current state. A disallowed difference between the signed state and the current state is detected, based on one or more rules that are associated with the electronic document. A digital signature associated with the electronic document is invalidated in response to the detecting. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a device for detecting and measuring variations in the height of a free level of a liquid and more particularly a liquid contained in a field pressurized enclosure, e.g. the vessel of a pressurized water nuclear reactor.
At present there are various methods which make it possible to measure the height of the free level of a liquid contained in a pressurized enclosure. A first method uses a level indicator in the form of a differential manometer, whose connecting tubes are horizontal and positioned at different heights. The main disadvantage of this device is that the upper connecting tube is continuously filled with a mixture of the liquid and its vapour, due to the partial boiling in the connecting tube, even when the level in the enclosure drops, which leads to measuring errors. A second method consists of positioning in the vicinity of the wall of the enclosure and outside the latter, a certain number of radioactive sources located at different heights and a certain number of detectors, which are generally diametrically opposite to the said sources. The comparison of the readings given by the different detectors makes it possible to determine the height of the free surface of the liquid. The latter solution requires complex equipment and therefore significantly increases the cost of such installations.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a device, which obviates the aforementioned disadvantages, whilst being simple to instal and having maximum operational reliability.
According to the main feature of the device according to the invention the liquid is contained in a pressurized field enclosure. The device comprises:
a first vertically positioned tube or "short tube", whose lower end issues into the enclosure in the vicinity of its upper wall and whose upper end issues to the exterior of the enclosure into a first container or "condensation pot";
a second tube or "long tube" having a lower end issuing into the enclosure at a level below that of the short tube and which is provided with a hydraulic seal in order that the long tube remains constandtly filled with liquid when the level thereof in the enclosure drops below the lower end of the long tube, and having an upper end issuing into a second container or condensation pot, the long tube and the second condensation pot consequently being constantly filled with liquid;
and a differential manometer making it possible to measure the pressure difference between the first and second condensation pots.
According to a first variant of this device, the long and short tubes are remote from one another, the two condensation pots having similar dimensions and are located substantially in the same horizontal plane.
According to another variant, the long tube is positioned within the short tube and the first condensation pot, the second condensation pot being positioned abover the latter.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail hereinafter relative to non-limitative embodiments and the attached drawings, wherein show:
FIG. 1 a diagrammatic view showing a first variant of the device in which the short and long tubes are remote from one another.
FIG. 2 a diagrammatic view of a second variant in which the long tube is positioned within the short tube and is concentric thereto.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an enclosure 1 partly filled with a liquid 2 and whose upper part is sealed by an upper wall or cover 4. A first tube or "short tube" 6 having a large diameter is positioned vertically above enclosure 1 and the lower end 8 of tube 6 issues into the upper part of the vessel in the vicinity of cover 4. The upper end 10 of short tube 6 issues into a first enclosure or "condensation pot" 11, at a height 1 above the bottom thereof. A second tube or "long tube" 12, which is vertical in the present embodiment, passes into vessel 1 and its lower end 14 issues into the latter at a level well below that at which end 8 of short tube 6 enters said vessel. The lower end 14 of tube 12 is provided with a hydraulic or liquid seal 15 which, in the present embodiment is constituted by a bucket. This device enables tube 12 and second container 18 to remain constantly filled with a liquid, even if the free level thereof in vessel 1 drops below bucket 15. The pressure of the gas in enclosure 1 bears on the free surface of the liquid contained in the bucket and therefore prevents the emptying of tube 12. The upper end 16 of tube 12 issues into a second container, or condensation pot 18, which is of essentially the same size as the first condensation pot 11 and is located in the same horizontal plane as the latter. A differential manometer 20 indicates at all times the difference between pressure P B in the first condensation pot 11 and pressure P A in the second condensation pot 18. Two pipes 21, 22, provided with isolating valves 23, 24 connect manometer 20 to condensation pots 11, 18 respectively. There are also two valves 26, 27 for draining and cleaning pipes 21, 22, as well as a valve 30 for bypassing manometer 20. Pipes 21, 22 issue into the bottom of containers 11 and 18, where the pressurization points are located. It is of interest in this variant that the bottoms of the condensation pots are in the same horizontal plane because, when vessel 1 and short tube 6 are filled with liquid, we obtain: P B -P A =0.
The device operates in the following way. On taking as the reference plane, the horizontal plane corresponding to the lower end 14 of the long tube 12 and on designating by x the height of the free level of the liquid 2 above said reference plane, the pressure difference P B -P A is given by the following formula:
P.sub.B -P.sub.A =-ρgx+ρg(L+l)
with ρ=density of liquid, g=acceleration of gravity, L=height of long tube between its lower part 14 and the bottom of the second condensation pot 18, l=difference in level between the upper part of the short tube 6 and the bottom of the first condensation pot 11.
Thus, when the level of the free surface of the liquid 2 is between the reference plane and the upper part of the vessel or within the short tube 6, the pressure difference P B -P A varies in a linear manner as an inverse function of the height x of the liquid. When the free surface of the liquid in tube 6 reaches the upper end 10 thereof, the pressure difference P B -P A is cancelled out because x=L+l and the points where these pressures are taken are located in the same horizontal plane within the same liquid mass.
When the free surface of liquid 2 drops below the lower end 14 of long tube 12 and no matter what the height of the liquid, the pressure difference P B -P A is constant and not zero, because the hydraulic seal 15 prevents long tube 12 and the second condensation pot 18 from being emptied.
Initially when vessel 1 and tube 6 are entirely filled with liquid up to a level equal to or above that of the upper end 10 of tube 6, the pressure difference P B -P A is zero. In the case of an accidental leak in vessel 1, a free level appears in the upper part thereof and tube 6 immediately empties. The fact that it is vertical facilitates the downward movement of the liquid and prevents it from being blocked by a possible condensation of the vapour of liquid 2. The manometer then detects a sudden increase in the differential pressure P B -P A and can, if necessary, initiate a standby supply 17 by means of a servocontrol system. Conversely, during the filling of the vessel, the manometer can act to stop the supply as soon as the difference P B -P A is cancelled out again. The hydraulic seal 15 in the lower end 14 of the long tube 12 keeps the latter constantly filled with liquid, when the level thereof in the enclosure drops below the reference plane. As a result there is a constant differential pressure reading (difference P B -P A not being zero) whilst the free level of the liquid in the enclosure in below the lower end of the long tube. If the latter were emptied, there would be a zero pressure difference and it would not be possible to tell whether the container was full or partly empty.
FIG. 2 illustrates a variant in which the short and long tubes are no longer separate as in FIG. 1 and are instead arranged concentrically with respect to one another. In FIG. 2 it is possible to see short tube 32, whose diameter is larger than that of tube 6 of FIG. 1 positioned in the upper part of vessel 1. Short tube 32 issues into a first condensation pot 34. It is also possible to see long tube 36, which issues into the vessel at a level below that of tube 32, but which is positioned within and concentric to the latter. Long tube 36 consequently traverses tube 32, as well as the first condensation pot 34 and its upper end issues into a second condensation pot 38 positioned above the first.
The operating principle of this second variant is the same as that of the variant described with reference to FIG. 1. However, it is pointed out that when the vessel and tube 32 are filled with liquid, the pressure difference P B -P A is constant, but is not zero because the pressurizing points are not located in the same horizontal plane of the same liquid mass. However, it is still possible to set off an alarm by setting the manometer to the critical differential pressure value corresponding to the filling of tube 32. In this variant, when the level of the free surface of the liquid 2 in vessel 1 drops below the reference plane, the difference P B -P A is still constant, but differs from the differential pressure corresponding to the filling of tube 32. Thus, it is still possible to control the supply to the vessel by taking into account the two critical differential pressure values.
It is clear that the device according to the invention has a number of particularly important advantages. Firstly it has a simple and inexpensive construction and the fact that the short tube 6 is vertical prevents measuring errors due to the possible clogging thereof by condensed steam. In addition, the fact that the long tube is provided with a hydraulic seal enabling it to stay constantly filled with liquid ensures that the pressure difference P B -P A is constant and not zero when the liquid level in vessel 2 drops below the reference plane. Therefore it is particularly easy to know whether the vessel is full or whether it is partly emptied. Thus, it is possible to start up or stop an external supply or trigger off an alarm as a result of the manometer reading.
Moreover, the arrangement of a condensation pot vertically with respect to the long tube makes it possible to recondense the steam which forms there during the accidental depressirization of the enclosure, thus preventing density variations in the tube, which could interfere with the pressure measurement.
The invention is obviously not limited to the variants described hereinbefore and numerous further variants can be conceived without passing beyond the scope of the invention. Thus, the fact that short tube 6 is always vertical does not mean that the long tube need also be vertical although, as has been stated hereinbefore, it is the simplest and most advantageous solution. Furthermore the hydraulic seal enabling the latter to be constantly filled with liquid is in the form of a bucket in the two embodiments described, but numerous variants can be considered, e.g. giving it a curved shape at the lower end of the long tube. | The present invention relates to a device making it possible to detect variations in the height of the free level of a liquid in an enclosure.
The device comprises a vertical short tube issuing into the upper part of the vessel and whose upper end issues into a first condensation pot, a long tube whose long end issues into the vessel at a level below that at the end of the short tube, the end of the long tube being provided with a hydraulic seal, while the upper end of the long tube issues into a second condensation pot, a differential manometer indicating any pressure differences between the two condensation pots.
Application to the measurement of the level of the water contained in the vessel of a pressurized water nuclear reactor. | 6 |
The present application is related to copending application Ser. No. (97-0828), entitled "Adaptive Noise Reduction Filter with Continuously Variable Sliding Bandwidth".
BACKGROUND OF THE INVENTION
The present invention relates in general to dynamic noise reduction of an audio signal, and more specifically to an adaptive audio filter having a continuously variable sliding bandwidth to control the energy leaving the audio filter as a fixed percentage of the energy entering the audio filter, wherein the adaptation is disabled under low modulation conditions.
Audio systems, such as radio receivers, have used dynamic noise reduction in an attempt to control background noise when low level audio signals are present or when a radio receiver receives a weak RF signal. In some systems, high frequency content of the demodulated signal is compared with a fixed threshold to detect noise, and a lowpass filter is engaged when high frequency content is above the threshold. Such systems are not effective on all types of broadcast signals and often result in audible "breathing" effects due to the switching in and out of the lowpass filter.
U.S. Pat. No. 3,889,108 issued to Cantrell discloses an adaptive lowpass filter for reducing noise in an audio signal. However, in controlling the adaptive filter, Cantrell divides an expected noise power by an RMS error. Thus, the predetermined known or estimated noise power of the noise signal that will be received is required. In practice, this value may not be subject to accurate estimation. Furthermore, the requirement to perform a division is cumbersome and expensive to implement in digital signal processing (DSP) hardware, as opposed to implementations using only multiply functions. Furthermore, Cantrell compares the difference of instantaneous signals, and thereby inadvertently includes phase difference information in the comparison which is not relevant for determining a desired bandwidth of the filter. The phase difference results in larger error signals which reduces the filter bandwidth farther than desired.
SUMMARY OF THE INVENTION
The present invention has the advantage that an adaptive noise reduction filter is obtained using efficient, simple DSP hardware while obtaining accurate filter tracking to the energy of the audio signal. Furthermore, the present invention avoids having the filter adapt to variations in noise content of a signal by disabling adaptation when low audio signal levels are detected.
In one aspect, the invention provides a method for dynamic noise reduction of an audio signal in an audio reproduction system. The audio signal is lowpass filtered in an adaptive lowpass filter having a plurality of filter coefficients to control an upper cutoff frequency of the lowpass filter. An input audio signal at an input to the adaptive lowpass filer is time averaged to obtain an input average. An output audio signal at an output of the adaptive lowpass filter is time averaged to obtain an output average. One of the averages is multiplied by a percentage constant. A difference is formed between the multiplied average and the other one of the averages to obtain an error. The filter coefficients are adapted to cancel the error. The input average is compared with a low modulation threshold, and at least a portion of the adapting step is inhibited if the input average is below the low modulation threshold.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing the adaptive noise reduction filter of the present invention.
FIG. 2 is a waveform plot showing the relationship between the filter bandwidth and the input signal total energy.
FIG. 3 is a waveform diagram showing the adapted filter bandwidth for a reduced energy and reduced bandwidth input signal.
FIG. 4 is a block diagram showing the adaptive noise reduction filter in greater detail.
FIG. 5 is a block diagram showing additional features to provide a high frequency cut function under poor received signal conditions.
FIG. 6 is a block diagram showing an improvement for handling signals received at a low modulation level.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1, a lowpass filter (LPF) 10 may preferably be comprised of an infinite impulse response (IIR) filter implemented in DSP. LPF 10 includes a plurality of filter coefficients which are adjustable in order to produce a continuously variable sliding upper cutoff frequency. The bandwidth of LPF 10 is controlled to provide an amount of filtering which results in the filter output providing a fixed percentage of the input signal energy. Thus, an audio signal (e.g., resulting from the demodulation of a radio broadcast signal or reproduction from prerecorded media and then digitized) is coupled to the input of LPF 10 and to the input of an input averager 11. Likewise, the output of LPF 10 is connected to the input of an output averager 12 which has its output connected to a subtracting input on a summer 13. The output of input averager 11 is coupled through a multiplier 14 to an adding input of summer 13. A fixed percentage constant k is applied to a second input of multiplier 14 so that summer 13 produces a signal indicating the difference between the average output of LPF 10 and a fixed percentage of the average input to LPF 10. The output of summer 13 thus provides an error signal for correcting the bandwidth of LPF 10.
The rate of adaptation to the existing error is controlled according to either a decay time or an attack time provided through a multiplexer 15 to a multiplier 16. A comparator 17 compares the error signal from summer 13 with zero (i.e. comparator 17 determines the positive or negative sign of the error). The output of comparator 17 controls multiplexer 16 to select the attack time when the error is negative (i.e., when filter bandwidth should be decreased) and selects the decay time when the error is positive (and the filter bandwidth needs to increase). The decay time constant is larger than the attack time constant so that the adaptation rate is fast when increasing the bandwidth and slow when decreasing the bandwidth to prevent audible breathing and loss of high frequency information on sudden transients (e.g., in a radio receiver). The error multiplied by either the decay time or the attack time constant provides an adaptation delta which is provided to an LMS adaptation block 18 for generating adaptive filter coefficients for LPF 10.
Percentage constant k preferably falls in the range of between about 90 and 100%, and most preferably equals about 98%. It has been found that a beneficial signal-to-noise ratio results under most conditions with the adaptive noise reduction filter removing about 2% of the total energy in the audio signal. Alternatively, rather than multiplying the input average, the output average could be multiplied by a constant between 100% and about 110%.
FIG. 2 shows a frequency spectrum 20 of an audio signal being transmitted through a transmission channel including the audio system, and channel noise 21 which is also present in the transmission channel of the audio system and/or the RF broadcast channel and which adds to the audio signal. The adaptive filter of the present invention automatically configures itself with a filter passband which passes nearly all the original audio signal content while blocking extraneous noise which is separable from the audio signal. Thus, a passband characteristic 22 is automatically achieved having an upper cutoff frequency 23 which dynamically reduces more noise than original signal. Thus, when the audio signal spectrum changes to one having lower frequency content (and less overall energy) as shown at 24 in FIG. 3, the passband of the adaptive lowpass filter reduces to a new upper cutoff frequency at 25. Consequently, the audio signal is passed through the filter with maximum reduction of noise.
The adaptive filter and its operation will be described in greater detail with reference to FIG. 4. The input averager is comprised of an absolute value block 30 providing a rectified audio signal to a lowpass filter 31. Similarly, the output audio signal is provided through an absolute value block 32 to a lowpass filter 33. Lowpass filters 31 and 33 are preferably comprised of butterworth IIR filters having an upper cutoff frequency of about 100 Hz. The difference between the average audio output from LPF 33 and the ratioed input average from multiplier 14 is derived in summer 13. A threshold circuit 34 is a preferred digital implementation of comparator 17 in FIG. 1. Threshold block 34 receives a constant C 2 which is preferably equal to zero so that threshold block 34 identifies the positive or negative sign of the difference from summer 13. If the difference is negative (i.e., the output signal average is greater than intended), then threshold block 34 controls multiplexer 15 to switch to an attack time constant c 2 . Otherwise, multiplexer 15 is switched to decay time constant c 3 . The product of the error and the attack or delay time constant produces an adaptation delta for adapting the filter.
The adaptive filter of the present invention preferably takes the form of an infinite impulse response (IIR) filter. A second order filter is preferred having the form of
y.sub.n =b.sub.0 (x.sub.n +x.sub.n-1)+a.sub.1 (y.sub.n-1)
where y is the filter output, x is the filter input and b 0 and a 1 are the adaptive filter coefficients. In order to ensure that the filter coefficients track one another to provide unity gain in the filter, a relationship between the filter coefficient preferably exists as follows:
a.sub.1 =(0.5 -b.sub.0)×2.
As shown in FIG. 4, filter coefficient b 0 is obtained at the output of a multiplexer 35. Coefficient b 0 is delayed through a z -1 unit delay block 36 and then applied to one input of a summer 37. A second input of summer 37 receives the adaptation delta from multiplier 16 so that coefficient b 0 can be updated according to the adaptive value of delta. The output of summer 37 is coupled to the input of a threshold block 38 and to one input of multiplexer 35. Threshold block 38 compares the output of summer 37 (i.e., the updated value of coefficient b 0 ) to a constant c 5 representing the minimum frequency to which the upper cutoff frequency of the filter should be lowered. In other words, c 5 represents a lower adaptation limit value for coefficient b 0 . Constant c 5 is also coupled to the remaining input of multiplexer 35. The output of threshold block 38 controls multiplexer 35 to select the updated value of coefficient b 0 from summer 37 unless the b 0 would fall below constant c 5 , in which case multiplexer 35 is switched to select the minimum value c 5 .
In order to obtain coefficient a 1 , the current value of b 0 is coupled to a subtracting input of a summer 40. An adding input of summer 40 receives a constant c 6 which is preferably equal to 0.5. The output of summer 40 is doubled in an doubling block 41 to provide coefficient a 1 at its output.
Adaptive filter 10 includes a multiplier 45 for multiplying coefficient b 0 and the current value of the audio input signal x n . The output of multiplier 45 is connected to a summing input of summer 46 and to a second input of summer 46 through a unit delay block 47. The output of summer 46 is connected to a summing input of summer 48. Filter coefficient a 1 is provided to one input of a multiplier 49. The output of summer 48 is applied to a second input of multiplier 49 through a unit delay block 50. Thus, filter 10 implements the second order IIR filter equation specified above. In the embodiment shown, the input to the output averager (i.e., to absolute value block 32) is shown as being derived from the output of delay block 50 (i.e., the filter output delayed by one sample). Deriving a signal for absolute value block 32 at this point may be more convenient for a particular DSP implementation; however, the signal could equally well be derived from the input to delay block 50 (i.e., the current sample).
FIG. 5 shows a further improvement of the present invention for providing an upper adaptation limit for the filter coefficients so that the upper cutoff frequency of the filter is not adapted above a high cut frequency determined according to other detected properties of the audio signal. In particular, this improvement relates to use of the invention in a radio receiver with a radio tuner receiving a broadcast signal having a received quality which may be degraded from time to time. Thus, if multipath noise or other distortion is present in the received broadcast signal, this can be determined by monitoring signal quality at the intermediate frequency (IF) stage of the radio tuner and a high cut frequency can be established for eliminating or reducing noise in the audio output. Thus, a maximum coefficient calculator 51 receives a radio tuner signal-strength signal and a noise level detector signal from the radio tuner (not shown). The high cut frequency is determined in a conventional manner and then converted to a maximum coefficient value which is coupled to one input of a multiplexer 52 and to one input of a threshold block 53. Multiplexer 52 has a second input receiving the output from multiplexer 35 and provides at its output the value of coefficient b 0 . Threshold block 53 receives the updated coefficient value from summer 37 which is compared to the upper adaptation limit and controls multiplexer 52 accordingly. Thus, if an certain upper adaptation limit is established due to the presence of noise or a loss of signal strength, then the updated coefficient value will be compared to the upper adaptation limit and if the updated coefficient value would raise the upper cutoff frequency of the filter to above the high cut frequency, then multiplexer 52 is switched to select the upper adaptation limit for the value of coefficient b 0 .
Particularly when the audio signal is derived from a radio tuner, filter adaptation may become unable to follow the actual broadcast signal content and may begin adapting to the noise signal under low signal modulation conditions. To avoid that situation, FIG. 6 shows an improved adaptation scheme for detecting the presence of low input modulation and halting at least a portion of the adaptation. Thus, the average input signal value from lowpass filter 31 is compared to a low modulation threshold constant c 7 in a threshold block 55. Constant c 7 is preferably set to a level of about 1% modulation (i.e., 1% of the maximum signal level). If modulation is greater than this threshold, then threshold block 55 controls a multiplexer 56 to provide normal attack time constant c 2 to the input of multiplexer 15. If modulation is below this threshold, then multiplexer 56 is switched to provide a value of zero as the attack time constant to the input of multiplexer 15. As a result, reductions in the upper cutoff frequency are disabled during low modulation so that the bandwidth remains wide enough to pass whatever input signal may be present. | An infinite impulse response (IIR) lowpass filter is placed in the audio path of an audio system wherein the upper cutoff frequency of the filter is adaptively controlled based on a comparison between the average audio signal entering the filter and the average audio signal leaving the filter. An adaptive LMS process is used to control the filter bandwidth so that the average output signal reaches a predefined percentage of the average input signal. An adaptation rate is selected depending on whether the filter bandwidth needs to increase or decrease. Adaptation is fastest for increasing bandwidth and slowest for decreasing filter bandwidth to prevent audible breathing and loss of high frequency information on sudden signal transients. Adaptation is disabled (at least to the extent that decreasing of the filter bandwidth is disabled) whenever low signal modulation is detected. | 7 |
This is a divisional, of application Ser. No. 08/028,359filed Mar. 9,1993.
Field of the Invention
The invention relates to methods of bonding bodies of Refractory Hard Material (RHM) or other refractory composites to the cathodes of cells for the production of aluminium by electrcolysis of alumina dissolved in a cryolite-based molten electrolyte, which cathodes are made of carbonaceous or other electrically conductive refractory materials. The invention also relates to such cells having bodies of RHM or refractory composites bonded to their cathodes, as well as the use of these cells for the production of a aluminium.
BACKGROUND OF THE INVENTION
Aluminium is produced conventionally by the Hall-Heoult process, process, by the electrolysis of alumina dissolved in cryolite-based molten electrolytes at temperatures up to around 950° C. A Half-Heroult reduction cell typically has a steel shell provided with an insulating lining of refractory material, which in turn has a lining of carbon which contacts the molten constituents. Conductor bars connected to the negative pole of a direct current source are embedded in the carbon cathode substrate forming the cell bottom floor. The cathode substrate is usually an anthracite based carbon lining made of prebaked cathode blocks, joined with a ramming mixture of anthracite, coke, and coal tar.
In Hall-Heroult cells, a molten aluminium pool acts as the cathode. The carbon lining or cathode material has a useful life of three to eight years, or even less under adverse conditions. The deterioration of the cathode bottom is due to erosion and penetration of electrolyte and liquid aluminium as well as intercalation of sodium, which causes swelling and deformation of the cathode carbon blocks and ramming mix. In addition, the penetration of sodium species and other ingredients of cryolite or air leads to the formation of toxic compounds including cyanides.
Difficulties in operation also arise from the accumulation of undissolved alumina sludge on the surface of the carbon cathode beneath the aluminium pool which forms insulating regions on the cell bottom. Penetration of cryolite and aluminium through the carbon body and the deformation of the cathode carbon blocks also cause displacement of such cathode blocks. Due to displacement of the cathode blocks, aluminium reaches the steel cathode conductor bars causing corrosion thereof leading to deterioration of the electrical contact, non uniformity in current distribution and an excessive iron content in the aluminium metal produced.
A major drawback of carbon as cathode material is that it is not wetted by aluminium. This necessitates maintaining a deep pool of aluminium (at least 100-250 mm thick) in order to ensure a certain protection of the carbon blocks and an effective contact over the cathode surface. But electromagnetic forces create waves in the molten aluminium and, to avoid short-circuiting with the anode, the anode-to-cathode distance (ACD) must be kept at a safe minimum value, usually 40 to 60 mm. For conventional cells, there is a minimum ACD below which the current efficiency drops drastically, due to short-circuiting between the aluminium pool and the anode. The electrical resistance of the electrolyte in the inter-electrode gap causes a voltage drop from 1.8 to 2.7 volts, which represents from 40 to 60 percent of the total voltage drop, and is the largest single component of the voltage drop in a given cell.
To reduce the ACD and associated voltage drop, extensive research has been carried out with Refractory Hard Metals or Refractory Hard Materials (RHM) such as TiB 2 as cathode materials. TiB 2 and other RHM's are practically insoluble in aluminium, have a low electrical resistance, and are wetted by aluminium. This should allow aluminium to be electrolytically deposited directly on an RHM cathode surface, and should avoid the necessity for a deep aluminium pool. Because titanium diboride and similar Refractory Hard Metals are wettable by aluminium, resistant to the corrosive environment of an aluminium production cell, and are good electrical conductors, numerous cell designs utilizing Refractory Hard Metal have been proposed, which would present many advantages, notably including the saying of energy by reducing the ACD.
The use of titanium diboride and other RHM current-conducting elements in electrolytic aluminium production cells is described in U.S. Pat. Nos. 2,915,442, 3,028,324, 3,215,615, 3,314,876, 3,330,756, 3,156,639, 3,274,093 and 3,400,061. Despite extensive efforts and the potential advantages of having surfaces of titanium diboride at the cell cathode bottom, such propositions have not been commercially adopted by the aluminium industry.
The non-acceptance of tiles and other methods of applying layers of TiB 2 and other RHM materials on the surface of aluminium production cells is due to their lack of stability in the operating conditions, in addition to their cost. The failure of these materials is associated with penetration of the electrolyte when not perfectly wetted by aluminium, and attack by aluminium because of impurities in the RHM structure. In RHM pieces such as tiles, oxygen impurities tend to segregate along grain boundaries leading to rapid attack by aluminium metal and/or by cryolite. To combat disintegration, it has been proposed to use highly pure TiB 2 powder to make materials containing less than 50 ppm oxygen. Such fabrication further increases the cost of the already-expensive materials. No cell utilizing TiB 2 tiles as cathode is known to have operated for long periods without loss of adhesion of the tiles, or their disintegration. Other reasons for failure of RHM tiles have been the lack of mechanical strength and resistance to thermal shock.
Various types of TiB 2 or RHM layers applied no carbon substrates have failed due to poor adherence and to differences in thermal expansion coefficients between the titanium diboride material and the carbon cathode block.
U.S. Pat. No. 4,093,524 discloses bonding tiles of titanium diboride and other Refractory Hard Metals to a conductive substrate such as graphite. But large differences in thermal expansion coefficients between the RHM tiles and the substrate cause problems.
EP-A 0 164 830 discloses bonding of solid carbide, boride, nitride, silicide and sulfide bodies by laminating a reactant mixture of precursors of the materials of the bodies, then heating to initiate an exothermic reaction producing a layer that bonds the bodies together. However, such methods have not been successfully applied in bonding plates or tiles of TiB 2 or like materials to a carbonaceous or other conductive refractory substrates.
SUMMARY OF THE INVENTION
The invention provides a method of bonding bodies of Refractory Hard Material (RHM) or other refractory composites to cathodes or other components of cells of different configurations for the production of aluminium by electrolysis of a molten electrolyte, which cathodes or components are made up of carbonaceous or other electrically conductive refractory materials, usually carbonaceous material. According to the invention, the method comprises placing the RHM or refractory composite bodies onto a cell cathode or other component, with a colloidal slurry comprising particulate preformed RHM in a colloidal-carrier selected from colloidal alumina, colloidal yttria and colloidal ceria in between the bodies and the cathode or other component. The slurry is then dried to bond the bodies to the cathode or other component, the dried slurry acting as a conductive thermally-matched glue which provides excellent bonding of the bodies to the cathode or other component.
Based on adherence tests, it is predicted that such bonded aluminium-wettable cathode bodies should provide a service life of from 5 to 20 years, depending on the cell operating conditions. This is far longer than with any prior method of bonding the bodies to the cathode.
Application of the bodies by means of this non-reactive colloidal slurry is very simple. The formation of an adherent interlayer comprising the pre-formed TiB 2 or other refractory composite in the dried colloid ensures an adequate bonding while allowing for thermal expansion when the cell is brought to operating temperature. The excellent adherence is believed to be due to the fact that the bodies of RHM or other refractory composites and the relatively "thick" layers of the dried slurry (usually from about 200 to about 1500 micrometer) have very similar thermal expansion coefficients.
It should be noted that the use of non-reactive colloidal slurries has very suprisingly been found to outperform reactive mixtures which had previously been tried for the same purpose. The reason for this is not known.
The colloidal slurry usually comprises preformed particulate TiB 2 in colloidal alumina, and the RHM bodies are made of or comprise TiB 2 , for instance TiB 2 --Al 2 O 3 composites, in particular the reaction products of a mixture of particulate titanium dioxide, boron oxide and aluminium in the molar proportion 3TiO 2 +3B 2 O 3 +10Al mixed with an amount of preformed particulate TiB 2 .
The colloidal slurry preferably comprises 5-100 g of TiB 2 per 10 ml of colloid. The colloidal slurry may further comprise particulate carbon which serves to provide an excellent conductive bond, particularly with carbonaceous cell bottoms.
In one method of application, the colloidal slurry is applied to the surface of the cathode and to the faces of the bodies to be bonded, and the slurry-coated faces of the bodies to be bonded are applied on the slurry-coated face for the cathode.
Alternatively, the colloidal slurry is conveniently applied to the top surface of a cathode formed by a cell bottom, and the faces of the bodies to be bonded are applied on the slurry-coated top surface of the cell cathode bottom, without having to apply a separate layer of the slurry onto the surfaces of the bodies.
The bodies may be tiles, plates, slabs or bricks of the RHM or other refractory composite material, and the slurry may also be applied between adjacent edges of the tiles, plates, slabs or bricks to bond them together.
The bodies to be bonded may be coated on all faces with the slurry so that a layer of the dried slurry is deposited also onto the outer active face of the bodies. Thus, at least one face of the bodies which is not to be bonded to the cathode may be coated with said slurry and/or with a reactive slurry comprising precursors of an RHM or other refractory composite. When a reactive slurry is applied to such faces of the body, these faces will be coated with an RHM-containing coating formed by reaction.
The cell cathode bottom possibly has recesses for receiving parts of the bodies which are bonded in said recesses by the applied slurry.
After application of the slurry and placing of the tiles, plates, slabs or bricks of the RHM or other refractory composite material, the slurry can simply be allowed to dry in the ambient air, possibly assisted by blow heating.
The method is particularly advantageous for carbonaceous cell bottoms which serve as a conductive cell cathode.
The cell cathode bottom may however be coated with a coating containing RHM or other refractory composites onto which the tiles, plates, slabs or bricks of the RHM or RHM composite are placed and bonded by means of the colloidal slurry. This is particularly applicable where a conductive refractory composite material is used as the cell bottom.
Prior to bonding, the RHM or other refractory composite bodies are advantageously aluminized on the face not to be bonded, for instance by placing them in contact with molten aluminium preferably in the presence of a fluxing agent such as a cryolite-alumina flux.
The invention also concerns a cell for the production of aluminium by electrolysis of a cryolite-based molten electrolyte, comprising a cell bottom cathode made of carbonaceous or .other electrically conductive refractory material to which are bonded bodies of RHM or other refractory composites. The cell according to the invention is characterized in that the bodies are bonded to the cell bottom cathode by a dried slurry comprising particulate preformed RHM in a colloidal carrier selected from colloidal alumina, colloidal yttria and colloidal ceria. This cell incorporates the various features set out above in discussing its method of production. The invention applies to Hall-Heroult cells of classic design and other aluminium production cells of different configurations including those with deep pool and drained cathode configurations. Thus, bonded bodies of aluminium-wettable refractory materials may be arranged in a drained cell configuration, where molten product aluminium is drained permanently from the bodies. Alternatively, bonded bodies of refractory material are arranged on a cell bottom cathode in a deep or shallow pool of molten aluminium.
The invention applies to the bonding of tiles, plates, slabs or bricks to cell bottoms and also to cathodes placed in other configurations, as well as to the side walls and to other components of the cell such as weirs or baffles associated with the cathodic cell bottom.
The invention concerns mainly bodies of TiB 2 or other aluminium-wettable refractory materials which in use will be in contact with the molten product aluminium and/or with the cryolite-based electrolyte. But the invention also contemplates bonding the bodies to carbon pieces, with aluminium between such bodies and a current conductor bar, this aluminium serving to electrically connect the bodies to the conductor bar.
A further aspect of the invention is the use of said cell for the production of aluminium by the electrolysis of alumina dissolved in molten cryolite, where the product aluminium is in contact with said bodies bonded on the cell bottom cathode.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic cross-section through part of a cell bottom cathode of an aluminium production cell to which a layer of tiles has been bonded in accordance with the invention; and
FIG. 2 is a schematic cross-section through part of another cell bottom cathode of an aluminium production cell having slabs bonded in recesses in the cell bottom.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows part of a carbon cell bottom 1 of a cell for the production of aluminium by electrolysis of a molten electrolyte. Current is supplied to the cathodic cell bottom 1 by means of one or more transverse current collector bars 2 made of steel or a suitable alloy. On the top of the cell bottom 1 are bonded tiles 3 of Refractory Hard Material (RHM) composite material, usually a TiB 2 --Al2O 3 composite material, made by the method detailed below. The tiles 3 are bonded to the cell bottom 1 by a dried slurry 4 comprising particulate performed RHM in finely divided alumina obtained by applying to the upper surface of the cell bottom 1 and/or to the undersides of tiles 3, a non-reactive colloidal slurry comprising particulate preformed TiB 2 in colloidal alumina and allowing the slurry to dry, as explained in greater detail below.
The adjacent edges of the tiles 3 are spaced apart by gaps 5 sufficient to accommodate for thermal expansion of the tiles when the cell is brought to the operating temperature which may be about 950° C. The aforesaid slurry is also applied in these gaps 5, so as to bond together the edges of the tiles 3 while allowing for thermal expansion.
Usually, the layer of the dried slurry 4 is about 200 to about 1500 micrometer thick. The tiles 3 can have any convenient dimensions, usually several millimeters or tens of millimeters thick.
Once the tiles 3 have been bonded onto the cell bottom 1, which involves simple drying at ambient temperature, possibly assisted by blowing hot air using an air gun, the cell can be filled with aluminium and a cryolite-alumina electrolyte and raised to operating temperature by the usual methods.
The bonding of the tiles 3 by the method of the invention resists the thermal stresses during start up. The RHM materials in the tiles 3 ensure excellent wetting of the cell bottom by molten aluminum, which protects the carbon of cell bottom 1 against attack by electrolyte components. Because the tiles 3 remain firmly bonded to the cell bottom 1 for extended periods, despite the aggressive environment, the life of carbon cell bottoms can be extended from the usual 2-3 years to 5-20 years.
FIG. 2 illustrates another possible cell bottom configuration in which a carbon cell bottom 1 has recesses in the form of rectangular grooves 8 receiving therein rectangular slabs 6 of RHM composite material, usually the TiB 2 --Al2O 3 composite material made by the method detailed below, which protrude from the cell bottom 1.
Inside the grooves 8 the bottom parts of the slabs 6 are bonded firmly by a dried slurry 4 comprising particulate preformed RHM in finely divided alumina. As before, this dried slurry is obtained by applying to the insides of grooves 8 and/or to the underneath parts of slabs 6, a non-reactive colloidal slurry comprising particulate preformed TiB 2 in colloidal alumina and allowing the slurry to dry.
The flat upper surface of the carbon cell bottom 1 and the protruding upper part of the slabs 6 are coated with a layer 7 containing RHM obtained from a colloidal slurry of reactants, as explained above. Alternatively, it is possible to utilize protruding slabs or other shapes of carbonaceous material having the flat upper surface, or any surface in contact with the cryolite electrolyte, covered with RHM tiles.
When this cell is in operation, the protruding parts of slabs 6 act as drained cathodes from which the product aluminium flows down onto the aluminium-wettable layer 7 on the cell bottom. Of course, FIG. 2 merely schematically shows one type of drained cathode configuration. Many other cell designs and configurations can use the described non-reactive slurry bonding technique.
The invention will be further described in the following laboratory-scale examples.
Plates (and other shapes) of TiB 2 composite materials were prepared by mixing together particulate reactants in the molar ratio 3TiO 2 +3B 2 O 3 +10Al together with a selected amount of particulate preformed TiB 2 . The TiO 2 was 99% pure (metals basis; Johnson Matthey, Catalog Number 11396) with a particle size of 1.5 to 2.0 micrometer. The B 2 O 3 was obtained from Messrs Fischer, Catalog Number A76-3. The aluminium was -100 mesh or -325 mesh 99.5% pure, from Johnson Matthey. The TiB 2 was from Johnson Matthey, Catalog Number 11364.
The powders were mixed and blended for 15 to 30 minutes. Preferably the reaction powders and TiB 2 are mixed In a weight ratio of about 50:50, but this ratio can range from 90:10 to 30:70, usually in the range 40:60 to 60:40. The mixed powders are then vibration poured into a die, without segregation during pouring.
The die is pressed at 35 Ksi (=5.43 K/cm 2 ) for 5 minutes. For large plates, a load release and repressing operation may be used, or the load application may be gently increased over three minutes. Optimal pressing conditions can be determined for each shape and size being manufactured. After ejection from the die, the pressed plate or other shape should not have any cracks.
The plates are then combusted, for example with a torch in a CO 2 atmosphere, or in a furnace under controlled atmosphere. Prior to firing, very light refractory bricks are placed below and above the plates in order to minimize distorsion during firing.
After firing, the surface is examined for color and for any melting of the refractory. Any skin formed by melting should be removed by machining.
Next, the plates are aluminized, on their face which is to be in contact with molten aluminium and which is not to be bonded, by contact of this face with molten aluminium in the presence of a cryolite-alumina flux, as follows. Aluminium chunks are loaded into a crucible and placed in a furnace at 1000° C. until the aluminium has melted. The crucible is removed from the furnace and the plate inserted into the molten aluminium. Pre-mixed powders of cryolite and alumina 90/10% by weight are then spread on top of the melt.
The crucible is placed back in the furnace at 1000° C. for 3 to 24 hours, as long as is necessary to aluminize the plate surface to the required degree. Longer times are preferable; shorter times will provide a less complete aluminization than for longer times. The required amount of aluminization will depend on whether the plate is to be used as cathode in configurations where it is exposed to cryolite, where fuller aluminization is desirable.
The plate is then removed from the melt. Examination of the surface shows that the surface contains aluminium and has slightly increased in thickness. The aluminized surfaces are shiny and well wettable by molten aluminium.
The plates were then bonded by their nonaluminized face to a carbon block forming the cathode of a laboratory aluminium production cell as follows.
A slurry was prepared from a dispersion of 10 g TiB 2 , 99.5% pure, -325 mesh (<42 micrometer), in 25 ml of colloidal alumina containing about 20 weight % of solid alumina. Coatings with a thickness of 150±50 to 500±50 micrometer were applied to the faces of the plates and of the carbon blocks to be applied together. Just after the slurry was applied, and while still tacky, the slurry-coated faces of the plates were applied on the slurry-coated blocks and allowed to dry for about 30 minutes.
The above procedure was repeated varying the amount of TiB 2 in the slurry from 5 to 15 g and varying the amount of colloidal alumina from 10 ml to 40 ml. Coatings were applied as before. Drying took 10 to 60 minutes depending on the dilution of the slurry and the thickness of the coatings.
In a further series of tests, a sub-layer of the slurries was applied to each surface and dried or partly dried before applying the next coating. The two parts were applied together while the last coating was still tacky.
In all cases, after drying the plates adhered strongly to the carbon blocks. The thermal cycle resistance of the bonded plates/blocks was tested by placing them in a furnace at 900° C. for several minutes, then removing them, allowing them to cool in air, and reinserting them in the furnace. This operation was repeated five times. All of the tiles remained adherent to the blocks after this thermal cycling treatment.
Several of the blocks were tested as cathodes in a laboratory aluminium production cell with the bonded plates in a drained-cathode configuration. The cells operated at low cell voltage and the plates remained adherent after long periods of electrolysis without showing any sign of delamination.
In a variation of the invention, the same bonding technique can be used to bond together pieces of carbonaceous materials. | Bodies (3) such as tiles, plates, slabs or bricks of Refractory Hard Material (RHM) or other refractory composites are bonded to the cathodes or to other components, in particular to a carbon cell bottom (1), of a cell for the production of aluminium by electrolysis of a cryolite-based molten electrolyte, made of carbonaceous or other electrically conductive refractory material, by a non-reactive colloidal slurry (4) comprising particulate preformed RHM in a colloidal carrier selected from colloidal alumina, colloidal yttria and colloidal ceria. The slurry usually comprises preformed particulate TiB 2 in colloidal alumina. The bodies (3) are usually TiB 2 --Al 2 O 3 composites. The bonding is achieved simply by applying the slurry and allowing it to dry. | 2 |
FIELD OF THE INVENTION
The invention relates generally to construction vehicles such as backhoes. More particularly, it relates to construction vehicles having auxiliary control valves for controlling the flow of hydraulic fluid to implements attached to the vehicle. Even more particularly, it relates to such vehicles with dual hand controls for controlling the auxiliary valve.
BACKGROUND OF THE INVENTION
Construction and agricultural vehicles such as backhoes, front loaders, dozers and the like are provided with implements that are physically attached to the vehicles and are used in conjunction with other moveable elements of the vehicle.
For example, front loaders may equipped with post-hole diggers mounted on the front of the vehicle in place of the bucket that is normally used.
These implements are commonly dynamic, and include hydraulic motors that are powered by a hydraulic pump on the vehicle itself. Thus, the hydraulic pump can move the various jointed arms and levers of the vehicle using hydraulic power, and can also power the attachable implements using the same power source.
A further advantage to these assemblies is that the vehicle manufacturers typically put a valve control and switch or other manually operable member in the cab to control the flow of hydraulic fluid to the implement. This is understandably necessary, since not every implement requires the same amount of hydraulic fluid flow or pressure to operate.
Typical two-handled construction vehicles, such as those described above were modified to include a pressure regulator valve configured to regulate the flow of hydraulic fluid to the implement and a switch connected to an on-off valve to turn the flow either on or off to the implement.
For many implements, this was satisfactory. The operator could adjust the fluid flow rate by turning the flow control valve's knob, then flip the on-off switch to start the implement moving. For those implements that needed a constant fluid flow rate, this was sufficient.
Unfortunately, other implements needed a variable flow rate as they were moved. In order to move the implements, it was necessary to hold and manipulate the two handles of the vehicle. The movement of the handles forward and backward causes the entire vehicle to go forward or backward. By pressing buttons on the handles, the various linkages in the vehicle's boom or front loader linkage were caused to raise, lower, swing left, swing right, extend and retract.
It was impossible to vary the flow rate to the implement as the vehicle and its boom and loader linkages moved. In order to vary the flow rate, either by turning the auxiliary valve switch on and off, or by rotating the pressure regulator valve required the operator to remove his hands from the handles. Unfortunately, when he removed his hands from the handles, he could no longer either move the vehicle or the boom and loader linkages coupled to it.
More recently, a spring-loaded thumbwheel was provided on one of the hand controls to permit the aux flow rate to be changed without the operator's hands being removed. Unfortunately, this required the operator to constantly maintain thumb pressure on the wheel to keep the desired flow rate. If for any reason the wheel was accidentally released, it would spring back to an “off” position. This arrangement was awkward, at best.
What is needed therefore, is an apparatus for controlling an attachable implement of a construction vehicle while permitting the operator to simultaneously move the vehicle, its boom or its loader. It is an object of this invention to provide such an apparatus.
SUMMARY OF THE INVENTION
In accordance with a first embodiment of the invention a work vehicle is described that is configured to be coupled to an implement operated by a flow of hydraulic fluid. the vehicle includes a chassis, an engine coupled to the chassis, a hydraulic pump rotationally coupled to the engine to generate a flow of pressurized hydraulic fluid, an auxiliary proportional control valve fluidly coupled to the pump to receive regulate and transmit the flow of pressurized hydraulic fluid and configured to be fluidly coupled to the implement and responsive to a valve-opening signal, an implement support arm pivotally coupled to the chassis and configured to be moved in at least two directions, a first hand control manipulable to move the arm in a first direction, the hand control including a first operator actuable switch, a second hand control configured to move the arm in a second direction different from the first direction, the second hand control including a second operator actuable control having a plurality of positions, and a digital controller coupled to both the first operator actuable switch and the second operator actuable control, wherein the controller is configured in a first mode of operation to generate the valve opening signal indicative of the position of the second operator-actuable control when the second control is in each of said plurality of positions, and further wherein the controller is configured in a second mode of operation to record a digital value indicative of the valve opening signal when the second operator actuable control is in each of the plurality of positions and when the operator actuates the first switch.
The first hand control may be disposed to be operated by one hand of the operator and the second hand control may be disposed to be operated by another hand of the operator. The first and second hand controls may be disposed to permit simultaneous operation by the operator. The support arm may be a backhoe assembly including a boom, a dipper and a bucket linkage. A first of the two directions may be the boom's rotation about the pivotal axis.
In accordance with a second embodiment of the invention, a method of setting and retrieving a predetermined auxiliary hydraulic fluid flow rate for an implement actuated by a variable flow of hydraulic fluid that is attached to a hydraulically moveable arm extending from a work vehicle having an operator's station and at least two hand controls, wherein one hand control is configured to drive a first actuator to move the member in a first direction and the second hand control is configured to drive a second actuator to move the member in a second direction different than the first direction, wherein the first hand control includes a first finger control configured to generate a signal when actuated by a finger, and the second hand control includes a second finger control that generates a varying signal based upon the degree of deflection of the second finger control is disclosed, the method including manipulating the first hand control to position the member in a first position, manipulating the second hand control to position the member in a second position different from the first position, engaging the first finger control, engaging the second finger control to generate a signal indicative of a desired auxiliary hydraulic fluid flow rate, substantially simultaneously with the first finger control, and automatically recording a digital value indicative of the desired auxiliary fluid flow rate based upon the simultaneous engagement of the first and second finger controls and a degree of deflection of the second finger control.
The method may include the steps of, releasing the first and second finger controls, re-engaging the first finger control after the step of releasing, and automatically generating the desired auxiliary hydraulic fluid flow rate in response to the step of re-engaging. The method may also include the steps of releasing the first and second finger controls, re-engaging the first finger control, re-engaging the second finger control to generate a second signal indicative of a second desired auxiliary hydraulic fluid flow rate, substantially simultaneously with the first finger control, and automatically recording a second value indicative of the second desired auxiliary fluid flow rate based upon the simultaneous engagement of the first and second finger controls. The method may also include the steps of turning the work vehicle off, turning the work vehicle on, and going to a predetermined auxiliary flow rate different from the desired auxiliary fluid flow rate.
In accordance with a third embodiment of the invention, a method of setting a predetermined auxiliary hydraulic fluid flow rate for an auxiliary hydraulic valve of a backhoe/excavator having two hand controls, and a seat, wherein one hand control is disposed to be grasped and operated by a left hand of the operator, and another hand control is disposed to be grasped and operated by a right hand of the operator, and further wherein the two hand controls are configured to perform the functions of swinging the backhoe boom, raising and lowering the backhoe boom, raising and lowering the dipper, and opening and closing a bucket linkage, and further wherein one of the hand controls has a momentary contact button, and another of the hand controls has a proportional input device disposed for use by the operator's finger is disclosed, the method including the steps of engaging the button, engaging the proportional input device to generate a signal indicative of a desired auxiliary hydraulic fluid flow rate, substantially simultaneously with the button, automatically recording a value indicative of the desired auxiliary fluid flow rate based upon the simultaneous engagement of the button and proportional input device and a degree of deflection of the proportional input device, releasing the button and the proportional input device, re-engaging the button after the step of releasing, and automatically generating the desired auxiliary hydraulic flow rate after the step of re-engaging the button.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a construction vehicle, a backhoe, having an implement, a rotary well digger, attached to the end of its boom, as well as the digital controller that controls the operation of the boom and the implement attached to the boom;
FIG. 2 is a schematic representation of the controller, with its associated operator controls, hydraulic cylinders for controlling boom position, and auxiliary control valve for regulating the flow of hydraulic fluid to the implement.
FIG. 3 is a plan view of the left hand lever or joystick showing what functions are performed when the lever is tilted front-to-back and side-to-side;
FIG. 4 is a rear elevation view of the left-hand lever;
FIG. 5 is a plan view of the right hand lever or joystick showing what functions are performed when the lever is tilted front-to-back and side-to-side;
FIG. 6 is a rear elevation view of the right hand lever;
FIG. 7 is a flow chart of a polling routine executed by the digital controller that enables the controller to respond to the operator's manipulation of the thumbwheel and the auxiliary switch.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, a construction vehicle, here shown as backhoe 10 , has a jointed arm 12 with an implement 14 coupled to its free end. The implement, shown here as a posthole digger, includes a rotating hydraulic motor 16 that is coupled to and drives a digger bit 18 . The posthole digger is extended away from the vehicle until it is located over the proper location for a posthole. The drive of the digger is engaged, and the rotating bit is brought into contact with the ground. As the digger rotates, a downward force is applied as it digs into the ground, and a posthole is created.
Inside the cab of vehicle 10 are two operator levers 20 , 22 , which are disposed on each side of the operator's seat (not shown) where one can be grasped by the right and the other can be grasped by the left hand of the operator. Levers 20 , 22 each have several operator controls disposed at their upper ends that are coupled to digital controller 24 . Digital controller 24 , in turn is coupled to and controls the opening and closing of proportional control valve 26 . Valve 26 , in turn, is fluidly coupled between hydraulic pump 30 and implement 14 to control the flow of fluid to the implement. Engine 28 drives pump 30 .
Referring now to FIG. 2, controller 24 includes a microprocessor 32 , RAM 34 and ROM 36 coupled together over bus 38 . ROM 36 stores a program that is executed by microprocessor 32 when microprocessor 32 is energized.
The controls shown in left-hand control group 40 are located on the upper end of the left-hand lever 20 (FIGS. 3, 4 ) that is located in cab of vehicle 10 . The controls shown in right-hand control group 42 are located on the upper end of right-hand lever 22 that is located in the cab of vehicle 10 . When the operator grasps the upper ends of the two levers 20 , 22 , he is able to manipulate any and all of these controls with the fingers of his left and right hands, respectively, without removing his hands from the levers.
The controls in the left-hand control group 40 include buttons 44 and 46 , and thumbwheel 48 . The controls in the right-hand control group 42 include buttons 50 , 52 , 54 , 56 ; and thumbwheel 58 . These controls and their orientation on the end of the lever handgrips 60 , and 62 (the left and right hand grips, respectively), can be seen in FIGS. 4 and 6. The two thumbwheels, 48 , 58 are spring-loaded such that they can be rolled toward or away from the operator. If they are oriented in a vertical position in the hand controls this would correspond to down or up with respect to the operator. When they are released, they return to a neutral and central position. The switches on each handgrip are spring loaded momentary-contact switches, and return to an un-depressed position when they are released.
The base of each lever 20 , 22 where it is coupled to the inside of the cab has two potentiometers that are arranged to sense the tilting of the levers about their bases in two orthogonal directions. One potentiometer on each lever senses the lateral tilt of the lever, i.e. side-to-side tilt, from the operator's perspective, and one potentiometer on each lever senses fore-and-aft tilt, i.e. away from and towards the operator, respectively. In this manner, the operator, by moving the joystick in the direction shown in FIGS. 3 and 5, can move the arm and the implement in a variety of directions without removing his hands from either the left or right hand controls. The potentiometer responsive to forward and backward motions of the left joystick (i.e., away from and toward the operator's body) is potentiometer 64 . The potentiometer that is responsive to side-to-side motion of the left hand lever is potentiometer 66 . The potentiometer that is responsive to fore and aft motion of right lever is potentiometer 68 and the potentiometer that is responsible for side-to-side motion of the right lever is potentiometer 70 .
Each of these four potentiometers is configured to generate a signal indicative of the degree of deflection of its associated lever. When the levers are released, they are spring-loaded to return to a neutral position, in which the levers are neither tilted forward or aft, or side-to-side. Thus, when the levers are in their neutral position, they can be moved fore or aft and leftward or rightward, depending upon the operator's inclination. The levers are disposed on either side of the operator as the operator faces directly backwards toward boom 12 in the seat position shown in FIG. 1, away from the front of the vehicle. In this position, the levers are disposed on either side of the operator within easy grasp of his left and right hands.
Referring back to FIG. 1, the posthole digger implement is located on the end of several jointed arms that permit the operator to move the digger from place to place. The joint arm includes a boom 78 that is coupled to the base of the backhoe vehicle 10 . There are two boom swing cylinders 72 coupled to the base of the boom to pivot it side to side about a substantially vertical axis located at the rear of the backhoe. The arrangement of these cylinders, and the manner in which they are coupled to the boom are well known in the art. In addition to boom swing cylinders 72 , is a boom lifting cylinder 74 . This cylinder is located along the lower end of the boom. In a typical arrangement, when this cylinder is retracted, the boom is lifted upward at its outer end, pivoting about a substantially horizontal axis 76 disposed at the rear of the backhoe.
Another arm 80 , called a “dipper”, is pivotally coupled to the free end of the boom—the end located away from the backhoe. The dipper pivots up and down with respect to the end of the boom about a substantially horizontal axis 82 located at the free end of the boom. A dipper cylinder 84 , typically extending along the length of the boom is coupled to the boom and the dipper such that (in a typical arrangement) the dipper is lifted upwards at its free end when the dipper cylinder retracts, and is lowered at its free end when the dipper cylinder extends.
The end of the dipper has a bucket (or implement) linkage 98 to which a digging bucket (or implement) is normally attached. In the present embodiment, a hydraulically driven implement 14 —the post hole digger—is attached to bucket linkage 98 in place of the bucket itself.
A bucket cylinder 86 is coupled to bucket linkage 98 and to dipper 80 such that when bucket cylinder 86 extends, the bucket linkage curls up inward toward the dipper. In other words, the bucket (or implement) rotates counter-clockwise with respect to the end of the dipper to which it is coupled. When the bucket cylinder is retracted, the bucket linkage uncurls. In other words, it rotates clockwise with respect to the end of the dipper to which it is coupled.
By combining the operation of all five cylinders—the bucket cylinder 86 , the dipper cylinder 84 , the boom cylinder 74 and the two boom swing cylinders 72 —the implement can contact the ground at virtually any location within the fully extended operating range of the backhoe.
The operator positions, the post hole digger for example, by manipulating the two levers and the various controls that are mounted on the handgrips of levers 20 , 22 shown in FIGS. 3-6. As shown in FIGS. 3 and 4, when the left hand lever is pivoted away from the operator, the dipper moves outward by retracting the dipper cylinder. When the lever pivots inward, the dipper is retracted, by extending the dipper cylinder. The microprocessor monitors potentiometer 64 , shown in FIG. 2, senses when the dipper potentiometer 64 is pivoted away from its neutral, central position, and energizes the dipper cylinder proportional control valve 88 proportionate to the degree of deflection of the lever. Valve 88 , in turn controls the flow of pressurized hydraulic fluid to and from the dipper cylinder, causing it to extend and retract according to the left-hand lever position. When the left-hand lever is released, it returns to a neutral position, and the dipper and dipper cylinder stop extending or retracting.
In a similar fashion, when the left-hand lever is moved laterally from its central position to the left, the microprocessor monitors the corresponding leftward deflection of the boom swing potentiometer 66 and energizes the boom swing cylinder valve 90 an amount proportionate to the degree of leftward deflection. The valve is energized and directs flow to the boom swing cylinders 72 such that the boom swings to the left at a rate proportionate to the degree of leftward deflection of the left-hand lever.
When the left-hand lever is moved laterally from its central position to the right, the microprocessor monitors the corresponding rightward deflection of boom swing potentiometer 66 and energizes the boom swing cylinder valve 90 an amount proportionate to the degree of rightward deflection. The valve is energized and directs flow to the boom swing cylinders 72 such that the boom swings to the right at a rate proportionate to the degree of rightward deflection of the left-hand lever.
When the right-hand lever is pivoted away from the operator, the boom pivots downward (outward) by extending boom cylinder 74 . When the lever is pivoted inward, the boom pivots upward (inward), by retracting boom cylinder 74 .
The microprocessor monitors potentiometer 68 , shown in FIG. 6, and senses when that potentiometer is pivoted away from its neutral, central position, and energizes the boom cylinder proportional control valve 92 proportionate to the degree of deflection of the lever. Valve 92 , in turn, controls the flow of pressurized hydraulic fluid to and from boom cylinder 74 , causing it to extend and retract according to the right-hand lever position. When the right-hand lever is released, it returns to a neutral position, and the boom and boom cylinder stop extending or retracting.
In a similar fashion, when the right-hand lever is moved laterally from its central position to the left, the microprocessor monitors the corresponding deflection of the bucket potentiometer 70 and energizes bucket cylinder control valve 94 an amount proportionate to the degree of leftward deflection. The bucket cylinder valve is energized such that the bucket linkage 98 curls inward (counterclockwise in FIG. 1) at a rate proportionate to the degree of leftward deflection of the right-hand lever.
When the right-hand lever is moved laterally from its central position to the right, the microprocessor monitors the corresponding deflection of bucket potentiometer 70 and energizes the bucket cylinder valve 94 an amount proportionate to the degree of rightward deflection. The bucket cylinder valve is energized such that the bucket linkage uncurls (clockwise in FIG. 1) at a rate proportionate to the degree of rightward deflection of the right-hand lever.
Auxiliary Valve Control
The section above described how the operator can move the boom, dipper and bucket linkage by manipulating the two levers 20 , 22 . At the same time that the operator is manipulating the boom, dipper and bucket linkage, he can also dynamically control the operation of the implement attached to the end of the bucket linkage in the following manner.
Thumbwheel 48 is located on the left-hand handgrip and controls the flow rate to the auxiliary proportional control valve 96 . This valve controls the flow of hydraulic fluid to drive motor 16 of implement 14 .
The program stored in ROM 36 controls the operation of controller 24 in response to the operator actuating auxiliary valve button 52 and auxiliary valve thumbwheel 48 . This operation is shown in the flowchart of FIG. 7 .
The process shown in FIG. 7 is a portion of the polling loop performed by controller 24 at frequent intervals during the operation of the vehicle 10 . In this polling loop, which typically occurs every 10 milliseconds or so, the microprocessor checks the position of all the switches and thumbwheel potentiometers located on the hand grips, and the positions of the potentiometers that are coupled to the base of the levers. Thus, although the flowchart says “START” and “STOP”, it should be understood that this process is repeated again and again, many times each second.
Auxiliary button 52 and auxiliary thumbwheel 48 function overall as follows. Whenever the thumbwheel is deflected and the auxiliary button is not depressed, controller 24 commands auxiliary valve 96 to open proportional to the degree of deflection of the thumbwheel. Whenever the auxiliary button is depressed and the thumbwheel is not deflected, the controller commands auxiliary valve 96 to open to a predetermined position. This position may be a position that corresponds to the full flow rate of the auxiliary valve, or it may correspond to some different flow rate that has been dynamically saved by the operator. The operator can select and save such a flow rate by substantially simultaneously manipulating the auxiliary button and the thumbwheel together as described below.
To set a particular flow rate, the operator simultaneously presses the auxiliary button 52 and deflects the auxiliary thumbwheel 48 . If both are manipulated simultaneously, controller 24 records a flow rate equivalent to the flow rate commanded by the auxiliary thumbwheel. Once the auxiliary button is released, this flow rate is preserved in the memory, either RAM or ROM, as desired, of controller 24 . It is preferably preserved in RAM, and is therefore deleted when vehicle 10 is turned off.
Once a particular flow rate has been preserved in memory by releasing the auxiliary button, as described above, each time the operator presses the auxiliary button (while not deflecting the auxiliary thumbwheel), the auxiliary valve 96 opens to the previously saved flow rate.
A computer program that will provide this capability is illustrated in FIG. 7 . In block 502 of the flow chart of FIG. 7, microprocessor 32 polls auxiliary thumbwheel 48 on the handgrip of lever 20 —the left lever—to determine if it has been deflected away from its neutral position. If it has been deflected away from its neutral position, the voltage arriving at controller 24 from the central tap of the thumbwheel potentiometer 48 A will be different, either greater or lesser, than the voltage generated at the central tap when the thumbwheel is in its neutral position. If the voltage is greater, it indicates that the thumbwheel has been deflected in one direction. If the voltage is lesser it indicates that the thumbwheel has been deflected in the opposite direction. In either case, a voltage different from the neutral position voltage on one of the potentiometer lines indicates that the thumbwheel has been deflected.
As we described above, controller 24 will take different actions based upon whether the thumbwheel has been actuated by itself or substantially concurrently with an actuation of the auxiliary button 52 . In block 502 controller 24 checks to see if the thumbwheel has been moved away from neutral. If so, controller 24 proceeds to block 506 and sets the auxiliary valve flow rate substantially proportional to the degree of deflection of the thumbwheel. Controller 24 then checks to see if the auxiliary button has been pressed in block 508 . If so, the processor memorizes the current flow rate—the flow rate indicated by the thumbwheel position. In block 510 , this value is saved in RAM or ROM for future use.
If the auxiliary button is not pressed in block 508 , processor 32 leaves this portion of the polling loop without taking further action without shutting off the auxiliary valve.
Since this loop is executed quite frequently, whenever the operator changes the position of the thumbwheel, the signal sent to the auxiliary valve will change responsively and at substantially the same time. This will preferably occur with no discernable time lag between changing the thumbwheel position and changing the flow rate.
On the other hand, if the thumbwheel is not deflected by the operator block 502 , controller 24 branches to block 504 . In block 504 , controller 24 checks to see whether the auxiliary button is pressed. If it is pressed, controller 24 checks to see if there is a previously saved auxiliary valve flow rate in block 512 . If there is a previously saved flow rate, controller 24 determines the appropriate signal to be applied to the auxiliary valve to supply that flow rate and applies that signal to auxiliary valve 96 in block 514 and exits this portion of the polling loop.
On the other hand, if there is no previously saved flow rate, controller 24 applies a signal to the auxiliary valve calculated to cause the maximum valve flow rate block 516 and exits this portion of the polling loop.
The operator can record a flow rate, return to a previously saved flow rate, and vary the flow rate proportional to a variable input device (the auxiliary thumbwheel) without removing his hands from either lever. Thus, the system enables the operator to move the jointed arm while simultaneously varying and recording the flow rate to an implement attached thereto. | A method of automatically setting an auxiliary hydraulic valve's flow rate and returning to that flow rate automatically is disclosed. The work vehicle such as a backhoe has two hand controls, one of which has a button, and the other has a thumb wheel. To set the hydraulic flow rate, one both presses the button one hand control and moves the thumb wheel on the other hand control until the proper flow rate is reached. At this point, both button and thumb wheel are released. This causes the flow rate to be saved in RAM or ROM memory. The flow rate can be varied at any time by rolling the thumb wheel up or down. One can return to the previously save flow rate by pressing the button. Both controls are preferably spring loaded. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field:
[0002] The present invention relates to electronic circuits, and in particular, to power consumption in electronic circuits.
[0003] 2. Description of Related Art:
[0004] As engineers seek ever increasing speeds in VLSI chips, complex problems continue to rise to the forefront. Power consumption in digital logic is dominated by clocks used to control and synchronize circuit operations across a logic domain or an electronic chip. The digital logic consists of circuit elements such as NAND and NOR logic gates and latches being used as clocked gates. VLSI technology continues to advance by increasing the number of circuit elements on VLSI chips and increasing the frequency at which these circuit elements are driven.
[0005] The frequency is increased further by reducing the number of logic gates between latches. These methods result in an increased amount of overall power consumption by these circuit elements and an even higher portion taken up by clocked gates. However, only a fraction of these clocked gates are, in any large design, on cycle time limiting paths.
[0006] Some prior art power consumption reduction mechanisms have primarily focused on logic reduction and logic gate sizing. However, selective reduction of clock power by substitution of clock gates addresses the main source of power consumption in state-of-the-art digital circuits.
[0007] Therefore, it would be advantageous to provide an active circuit that can reduce power consumption, such as is produced by high power consumption clocked gates, and it would be particularly advantageous to provide an active circuit to reduce power consumption by replacing those high power consumption clocked gates with lower power consumption clocked gates without affecting the target cycle time of the circuit.
SUMMARY OF THE INVENTION
[0008] The present invention provides a method and apparatus for reducing the power consumption of a clocked circuit containing a plurality of latches. A first latch, within the plurality of latches, is located which has more than a predetermined slack. The possibility of substituting an available second latch (requiring less power to operate) is then determined, subject to the constraint that the slack after substitution should still be positive, although it may be less than the predetermined number mentioned above. Where such a possibility is determined to exist, the first latch is then replaced with the available second latch.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0010] [0010]FIG. 1 is a schematic diagram of a clock distribution system in accordance with a preferred embodiment of the present invention;
[0011] [0011]FIG. 2 is a circuit diagram of a latch circuit in accordance with a preferred embodiment of the present invention;
[0012] [0012]FIG. 3 is an exemplary illustration of the timing constraint for data input into a latch in a clocked circuit in accordance with a preferred embodiment of the present invention;
[0013] [0013]FIG. 4 is an exemplary illustration of a process of power reduction in a clocked circuit by replacing high power latches with low power latches and a high power local clock buffer with a low power local clock buffer in accordance with a preferred embodiment of the present invention; and
[0014] [0014]FIG. 5 is an exemplary flowchart illustrating the process of power reduction in a clocked circuit by replacing high power latches with low power latches and a high power local clock buffer with a low power local clock buffer in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] The present invention provides a method and apparatus for power reduction in clocked circuits. The criticality of any clocked gate is identified to a target cycle time objective. A clocked gate with positive slack is replaced with a lower power consumption version of the clocked gate. Latches may have to meet a set slack threshold. Input slack, may be, for example, greater than 100 ps (picoseconds) and output slack, may be, for example, greater than 300 ps. If a latch does have sufficient slack time according to a predetermined slack threshold, this latch may be replaced by a low-power version of the latch. The mechanism of replacing low power latches in and out of a netlist may enable fine tuning of a clocked circuit design after technology mapping and during a timing correction process occurring after the initial physical design.
[0016] The clocked gate with the lower power consumption does not adversely affect the target cycle time. The ability to apply this replacement technique of a higher power consuming clocked gate with a lower power consuming clocked gate late in a design process of an electronic circuit maximizes the benefit of reduced power consumption without constraining the design process in the early stages. To minimize impact on a given electronic circuit design, an electrical equivalent and physically compatible replacement clocked gate is provided.
[0017] Referring now to FIG. 1, a schematic diagram of a clock distribution system in accordance with a preferred embodiment of the present invention. A clock source 105 is input into chip 110 from an oscillator source such as a saw-tooth wave generator or a phase-locked loop type clock source by way of wiring 115 on the chip. This oscillator signal is input into two receiver circuits 120 . Receiver circuits 120 each drive two central clock buffers 125 . Each clock buffer 125 in turn drives an H-tree that terminates with 16 sector buffers 130 used to re-power the clock signal. Each sector buffer 130 then drives a secondary H-tree (not shown) which terminates onto a single clock mesh (not shown), also called a clock grid, covering the entire chip area. The clock mesh is a series of vertical and horizontal low resistive wires that short together the outputs of all the clock buffers of the secondary H-tree, thus minimizing clock skew across the chip.
[0018] The clock mesh serves as the clock reference point (mclk) for the chip. The mclk signal is a “free-running” clock signal in that the clock never stops unless there is a problem with the clock source or distribution system. Devices such as latches, dynamic logic, and RAMs tap onto the mesh through local clock buffer circuits which are attached to the mesh. Some devices also connect directly to the mesh without being gated by a local clock buffer. One skilled in the art will recognize that other methods of distributing the clock may be implemented without departing from the scope and spirit of the invention.
[0019] [0019]FIG. 2 is a circuit diagram of a latch circuit in accordance with a preferred embodiment of the present invention. Latch circuit 210 includes inverters 211 - 213 and transistors 214 - 219 . Latch circuit 210 also includes clock signal 201 , data input 202 , and output 203 . The clock load represented by the latches is dependent on the size of the clock gates inside the latch. The data delay through the latch is directly dependent upon the clock gates inside the latch.
[0020] [0020]FIG. 3 is an exemplary illustration of the timing constraint for data input into a latch in a clocked circuit in accordance with a preferred embodiment of the present invention. In this example, data 302 is input into latch 304 . When clock signal 310 transitions from low to high, as illustrated by clock signal waveform 309 at point 332 , data 302 is sent to logic device 306 . Data 302 may remain in logic device 306 for maximum logic delay 316 until 340 before sent to latch 308 . As represented by timing diagram the time between points 334 and 340 is the maximum logic delay 316 . Therefore, for proper transmission of data 302 , data 302 must be transferred between latch 304 and latch 308 within maximum logic delay 316 , illustrated by points 334 and 340 . Data 302 must be launched from latch 304 by point 334 and be received by latch 308 by point 340 .
[0021] However, actual logic delay through logic 306 may be smaller than maximum logic delay 316 such that the characteristic of each latch may be altered, for example, latch 304 and 308 . Latch 304 may include latch 304 low power with increased launch time represented by the distance between points 334 and 336 . Latch 308 may include latch 308 low power with increased setup time represented by the distance between points 338 and 340 . Therefore, for proper transmission of date between latch 304 , logic device 306 and latch 308 , these low power logic delays may be taken into account.
[0022] [0022]FIG. 4 is an exemplary illustration of a process of power reduction in a clocked circuit by replacing high power latches with low power latches and high power local clock buffer with low power local clock buffer in accordance with a preferred embodiment of the present invention. In this example, high power latches 402 - 412 may be replaced by low power latches 420 - 430 . When clock input 418 is input into a clocked circuit, replacement of a high clock power local clock buffer 414 by a low power local clock buffer 432 may complement the process of replacing one or more high power latches 402 - 412 with one or more low power latches 420 - 430 . As described above in FIG. 1, mesh clock 416 serves as the clock reference point. Devices such as latches 402 - 412 tap onto the mesh through local clock buffer circuits, such as high clock power local clock buffer 414 which may be attached to the mesh. Based on the availability of a low power latch, one or more of high power latches may be replaced.
[0023] A timing procedure is run to test the clocked circuit. A determination is then made as to whether or not any of the latches within the plurality of latches in the clocked circuit has a slack greater than a slack threshold. If there is a latch within the plurality of latches with a slack greater than a slack threshold, then a determination is made as to whether or not this latch can be replaced by an equivalent latch with a slack still greater than zero. Furthermore, a determination is made as to whether or not any of the local clock buffers within the plurality of local clock buffers has upon latch replacement a lowered loading on the clock net example 418 to allow replacement by a low power local clock buffer.
[0024] [0024]FIG. 5 is an exemplary flowchart illustrating the process of power reduction in a clocked circuit by replacing high power latches with low power latches and a high power local clock buffer with a low power local clock buffer in accordance with a preferred embodiment of the present invention. In this example, the operation begins by designing a clocked circuit (step 502 ). Then the clocked circuit is built per the design (step 504 ). The circuit may consist of a plurality logic gates and a plurality of latches. Then a timing procedure is run to test the clocked circuit (step 506 ). A determination is then made as to whether or not any of the latches within the plurality of latches in the clocked circuit have a slack greater than a threshold slack (step 508 ). If there is not a latch within the plurality of latches with a slack greater than a threshold slack (step 508 :NO), a determination is then made as to whether or not local clock buffers with a reduced load is located (step 510 ). If local clock buffers with a reduced load is not located (step 510 :NO), the operation terminates. If local clock buffers with a reduced load are located (step 510 :YES), then the existing local clock buffers are replaced with local clock buffers with a lower power (step 512 ), and thereafter the operation terminates.
[0025] Returning to step 508 , if there is a latch within the plurality of latches with a slack greater than a threshold slack (step 508 :YES), then the latch with slack greater than the threshold slack is replaced with a latch with a slack greater than zero (step 514 ). Then the modified circuit design is retimed (step 516 ). Then a determination is made as to whether or not the slack is less than zero for the modified circuit design (step 518 ). If the slack is not less than zero for the modified circuit design (step 518 :NO), the operation returns to step 510 in which a determination is made as to whether or not there is a latch with a slack greater than the threshold slack. If the slack is less than zero for the modified circuit design (step 518 :YES), then replacement of the latch is reversed (step 520 ) and then the operation returns to step 510 in which a determination is made as to whether or not there is another latch with a slack greater than the threshold slack.
[0026] Therefore, the present invention provides a mechanism by which power consumption of an active circuit can be reduced, such as produced by high power consumption clocked gates, and to provide an active circuit to reduce power consumption by replacing those high power consumption clocked gates with lower power consumption clocked gates without affecting the target cycle time of the circuit. If such a replacement is made, the modified circuit is then tested to determine whether the slack of such clocked circuit is still greater than zero. If such condition in the clocked circuit is found, the replacement latch remains in the circuit. However, if the characteristics of the clocked circuit results in slack less than zero, then the replacement latch is taken out of the modified circuit and the original latch reinserted. Upon completion of latch replacement, the load characteristic of all latches driven by a given local clock buffer is evaluated and a lower power level is inserted based on the actual load reduction on, for example, clock net 418 in FIG. 4.
[0027] The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | A method and apparatus for reducing power consumption of a clocked circuit containing a plurality of latches is provided. A first latch, within the plurality of latches, is located which has more than a predetermined slack. The possibility of substituting an available second latch (requiring less power to operate) is then determined, subject to the constraint that the slack after substitution should still be positive, although it may be less than the predetermined number mentioned above. Where such a possibility is determined to exist, the first latch is then replaced with the available second latch. | 6 |
CROSS-REFERENCE TO COPENDING APPLICATION
This application is a Continuation-in-Part of U.S. patent application Ser. No. 134,665 filed Mar. 27, 1980, now U.S. Pat. No. 4,296,188, the disclosure of which is hereby incorporated by reference thereto.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a novel process for the production of a semiconductor or a semiconductor-containing layer which may be used in semiconductor-containing devices such as solar cells and particularly photoelectrochemical cells.
2. Description of Prior Art
U.S. Pat. No. 4,064,326 discloses a photoelectrochemical cell (PEC) device for directly converting radiant energy into electrical energy. FIG. 1 schematically illustrates a PEC having a photoelectrode 11, counterelectrode 13 and electrolyte 15, all contained within container 17. A load 19 is connected across the photoelectrode and counterelectrode. We have developed significant improvements of several components of such devices, e.g., the counterelectrode (see U.S. Patent Application Ser. No. 118,761, now abandoned), as well as improving cell construction and cell interconnections.
The photoelectrode is the key element of the phtoelectrochemical cell and is usually the most expensive part of the cell as it must often be monocrystalline. U.S. Pat. No. 4,064,326 discloses techniques for inexpensively preparing the photoelectrode, such as by electroplating, spraying, or sublimation.
Although such methods are satisfactory for certain semiconductor materials, other semiconductors do not lend themselves well to such methods of preparation and more expensive methods, such as sputtering or vacuum evaporation, may therefore become necessary.
Methods whereby a semiconductor paste is applied to a substrate and sintered, typified on the large scale by silk-screen printing, are well known for printing passive circuit components, in particular, the use of Cd(S,Se) and their mixtures as photoresistors. In 1967, Sihvonen et al. used printed CdS,Se for producing field effect transistors (PET's) and claimed that this was the first use of such a method for preparing other than passive components (J.Electrochem. Soc. 114, 96 (1967)).
Of greater interest is the use of silk-screened CdS for the preparation of solid state CdS-Cu 2 S photovoltaic cells, described by Vojdani et al, (Electron Lett., 9, 128 (1973)). The results obtained were poor, due mainly to a high series resistance of the cells.
Until this time, no generally applicable, versatile method for the preparation of thin film photoelectrodes, which is both cheap and simple, has been described.
SUMMARY OF THE INVENTION
It is, therefore, an object of the invention to provide a generally applicable technique for the production of semiconductors and semiconductor layers, which semiconductors find particular use in solid state and in particular in PEC solar cells.
It is a further object of the invention to provide a process particularly suitable for the production of PEC electrodes.
The invention provides a general, versatile, inexpensive and simple technique for preparing thin film electrodes, and is particularly suited for forming photoelectrodes used in photoelectrochemical cells. However, the applicability of the inventive technique is not limited to PEC's, and is applicable to a much broader variety of semiconductors and fluxing agents than has been previously described for similar methods.
The invention is particularly suited to the production of photoelectrodes since in a PEC, the photoactive semiconducting layer is required to perform quite differently from the semiconductor used in a solid-state junction solar cell. For example, the degree of crystallinity of the semiconducting layer is less critical in a PEC than in a solid state junction device, and increased polycrystallinity may even exert a beneficial effect on PEC stability.
According to a preferred embodiment of the invention, a photoelectrode of a given composition is prepared from at least one semiconductor starting material. The starting material may be either single or multiple-phase. When referring to "single phase" starting materials, solid solutions and the like are intended while "multi-phase" starting materials may be in the form of non-homogeneous particles. In order to prepare a thin film photoelectrode from such a semiconductor, the semiconductor is mixed with a suitable flux and the resulting mixture is dispersed in a suitable liquid phase to form a slurry. While the semiconductor starting material and flux may be added to the liquid vehicle after first having been mixed themselves, the order of mixing is not critical. The resulting slurry is then applied to a suitably treated electrically conducting substrate and annealed under suitable conditions of temperature and atmosphere. The resulting photoelectrode may be used, as is, or be further treated to improve its performance when the electrode is subsequently inserted within a cell such as a PEC or a solid state cell.
As used herein the term "annealed" is not used in the conventional metallurgical sense, but, instead, is intended to connote the treatment of the applied layer under conditions of temperature and pressure resulting in at least the partial dissolution of at least one semiconductor material in the flux material prior to removal of the flux so as to result in a structurally integral stable layer. Generally, this means heating the layer to at least near the melting point of the flux so as to allow for at least partial dissolution. Quite obviously, higher temperatures above the melting point may be used.
Semiconductor materials may be used to "tailor" the photoactive spectral region of the photoelectrode; a feature of great value for producing mixtures of chalcogenide (O, S, Se, Te) semiconductors.
As used throughout the specification, the term "semiconductor" is meant to include semiconductor components which comprise a semiconductor layer mounted on a conductive substrate.
According to another aspect of the invention, a process is provided wherein a semiconductor is formed by preparing a slurry of at least one semiconductor starting material, a flux and a liquid vehicle. A layer of the slurry is applied to an electrically conductive substrate and the layer is than annealed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of a photoelectrochemical cell (without storage means);
FIG. 2 is a plot of photocurrent density vs. photovoltage of a 0.22 cm 2 CdSe 0 .65 Te 0 .35 photoelectrode in a solution of 1 M each KOH, Na 2 S.9H 2 O and S under illumination equivalent to 0.85×AM1; and
FIG. 3 is a plot of the photocurrent of a CdSe 0 .65 Te 0 .35 photoelectrode in a solution 1 M each in KOH, Na 2 S.9H 2 O and S, under illumination of ˜2.5×AM1 and under short circuit conditions, as a function of time of illumination.
DESCRIPTION OF PREFERRED EMBODIMENTS
According to a basic embodiment of the instant invention, photoelectrodes may be prepared using commercially available semiconductors of the desired composition. Table I shows some non-restrictive examples of such semiconductors, and some of the possible electrolytes in which they may be used.
TABLE I______________________________________Semiconductor Electrolyte______________________________________CdSe S.sub.x.sup.2-CdTe Te.sub.x.sup.2-, S.sub.x.sup.2-GaAs Se.sub.x.sup.2-, I.sub.x.sup.-MoSe.sub.2 I.sub.x.sup.-CuInS.sub.2 S.sub.x.sup.2-ZnSe S.sub.x.sup.2-GaP Se.sub.x.sup.2-WSe.sub.2 Fe.sup.2+/3+______________________________________
The semiconductor material(s) used to form the slurry is (are) preferably in the powdered state prior to admixture with the flux and liquid vehicle. As noted previously, it is one advantage of the invention that use of a wide variety of fluxes is possible, thus not limiting the invention to CdS, CdSe, and mixtures and alloys thereof. Such fluxes may include indium halides, aluminium halides, gallium halides or mixtures thereof.
Photoelectrodes of most compositions, such as binary, ternary, quaternary or higher multi-element compounds, solid solutions or physical mixtures, may be prepared using powders which comprise the parent or constituent semiconductor materials in the correct proportions and compositions.
Physical mixtures of the powders can be prepared by simple mixing of different single or multi-component semiconductor starting materials.
Solid solutions or semiconductor materials may be formed by hot pressing, or heating (annealing) the starting materials with a suitable flux; the pressed or sintered products being then reduced to a powder. The flux used in the course of the heating of the starting materials prior to grinding may be the same or different from the flux added to the slurry prior to application of the layer. The ground powders thus formed are then formed into a slurry together with the flux, applied and then annealed. The flux used to form the ground powder once again serves to effect at least partial dissolution of the starting materials in the flux as they are heated. The flux once again may vaporize away during heating. Table II shows some non-restrictive examples of such mixtures, and the method of their preparation.
TABLE II______________________________________Parent materials Final mixture Method of preparation______________________________________CdSe, CdTe CdSe.sub.0.55 Te.sub.0.45 Flux, SinteringCdS, CdSe CdS.sub.0.9 Se.sub.0.1 Flux, SinteringCdS, CdTe, ZnSe (Cd.sub.1-x Zn.sub.x) (S,Se,Te) Hot pressingAlAs, GaAs GaAlAs Flux, sinteringCu.sub.2 S, In.sub.2 S.sub.3 CuInS.sub.2 Hot pressingCr, CdSe Cr + CdSe* Simple mixing______________________________________ *Isolated Cr metal particles in CdSe matrix.
Beginning with a final mixture of the semiconductor materials used to form the device, the semiconductor material is first reduced to a powder, if not already in powdered form, of a suitable particle size. Fine powders, of about 2-30 micron size, are preferred since they can be more easily slurried in a suitable liquid vehicle, although other sizes may be used.
The process for the production of semiconductor and/or semiconductor-containing layers, and particularly for the production of photoelectrodes is basically as follows:
The powder is mixed intimately with a suitable flux material. The requirements of such a flux are that it melts during annealing when heated with the semiconductor powder to a temperature at least near its melting point, and that it effects at least partial dissolution of the powder semiconductor in the flux. The flux itself may be in powdered form and should preferably volatize during the annealing step, although any remaining flux may also be subsequently dissolved away from the semiconductor. Such fluxes, which are suitable for many different semiconductors, include Cd and Zn halides, i.e., fluorides, bromides, chlorides and iodides. Other fluxes such as mercury halides may likewise be used. Fluxes may be used singly or in combination. Additionally, according to one embodiment of the invention, the flux may also serve to dope the semiconductor, such as when In, Ga or Al halides, are incorporated in the flux. As an example, an InCl 3 containing flux can be used for the preparation of n-type CdTe layers. While fluxes consisting of only dopant materials may be used, such are not preferred since the resulting semiconductor may be too highly doped.
The addition of small quantities of less-readily volatilizable materials can also advantageously be used, e.g. the addition of CdSO 4 or ZnSO 4 to the semiconductor and flux.
A liquid vehicle is added to the semiconductor powder to form a slurry. The liquid may be water or an organic solvent which results in a mixture having a suitable viscosity so as to result in a smooth slurry of the powder and flux, suitable for application to the photoelectrode substrate by rolling, brushing (painting) and the like. If water is used for dispersing the powder it may be advantageous to add a suitable surface active agent so as to ensure homogeneous wetting and a slurry having good dispersion. The boiling point of the liquid vehicle should be low, so as to ensure its total evaporation during the annealing process, but not so low that the slurry dries up during its application to the substrate. Furthermore, the liquid should boil homogeneously so that no trace of it is left in the annealed mass.
The slurry is then applied as a thin layer to a suitable electrically conductive substrate. The substrate must preferrably be chemically inert, and relatively electrochemically inert to the solution in which the photoelectrode will be used. The electrode substrate must be conductive and can be prepared from most metals or alloys by covering the metal or alloy with a thin layer of an appropriate corrosion resistant or inert metal or alloy prior to application of the slurry. Quite obviously, in non-corrosive systems a coating is unnecessary. For example, Cr-plated steel substrates are very suitable for use in polysulfide solutions. Quite obviously, if the semiconductor layer will not be used in an electrolyte containing PEC but in a solid state device, the above restrictions relative to the electrolyte do not apply.
Prior to applying the slurry to a metal substrate, the substrate is heated in an O 2 -containing atmosphere to form a thin oxide layer, typically on the order of about 0.1-0.3 microns thereby giving a characteristic yellowish or purple coloration to the metal.
A variety of electrically conducting materials is available for use as substrates for the semiconductive layer, and the final choice will be a function of cost, chemical and electrochemical inertness, adhesion of the layer to the substrate, and the like, as well as the intended use of the layer.
The applied semiconductor layer is then annealed in an inert atmosphere by heating the layer to at least near the melting point of the flux, so as to effect at least partial dissolution in the flux. It is possible also, and at times even preferred to add an oxidizing or reducing component to the annealing atmosphere so as to control the electrical properties (electrical conductivity and type) of the semiconductor. Annealing temperatures between 600° and 700° C. degrees are commonly used, and annealing times of 5 to 20 minutes will be sufficient for most materials. For each slurry specific optimal conditions in this range can be determined.
After cooling the annealed electrode is ready for use. However, in many cases at least one specific additional treatment may be beneficial for photovoltaic performance. Such treatments include not only normal etchings (e.g. acid etch), well known in the semiconductor field, but also specific ion "etchings". Such "etching" can be effected advantageously by dipping the electrode in a solution containing the "etchant". For example, solutions of Zn +2 , Cr +6 and Ce +4 ions, their complex ions, or a combination of any of these metal ions and/or their complex ions, are suitable for etching certain Cd and Zn chalcogenides. The ion etchings may be performed with or without a previous acid etch.
FIGS. 2 and 3 illustrate the characteristics of a 0.22 cm 2 CdSe 0 .65 Te 0 .35 photoelectrode when used in a PEC such as shown in FIG. 1 with a 1 M each KOH, Na 2 S.9H 2 O and S electrolyte solution under illumination equivalent to 0.85×AM1.
Table III illustrates some non-restrictive examples of the preparation process of semiconductive layers by the inventive technique. The ion etchings may be performed with or without a previous acid etch.
TABLE III__________________________________________________________________________ PER- FORM- Flux (for Specific Electrolyte Light ANCE mixed Flux ion KOH/Na.sub.2 S/S intensity mV Ω/mV mACompound powders) (for paint) Post-treatment "etch" (M).sup.2 × AMI (OCV) max-power (SCC)__________________________________________________________________________CdS (BDH -- CdCl.sub.2 -- ZnCl.sub.2 1/1/0.1 1 500 230/370 2.5reagent grade)ZnSe -- ZnBr.sub.2 /CdSO.sub.4 -- ZnCl.sub.2 1/2/0.1 U.V. 650 -- 2.0CdS.sub.0.9 Se.sub.0.1 CdCl.sub.2 CdCl.sub.2 -- ZnCl.sub.2 1/2/0.1 U.V. 850 30/555 32.5CdTe.sub.0.6 S.sub.0.4 CdCl.sub.2 CdCl.sub.2 /CdSO.sub.4 -- None 1/1/1 0.90 502 100/386 5.8CdSe.sub.0.65 Te.sub.0.25 CdCl.sub.2 CdCl.sub.2 -- None 1/1/1 0.82 585 60/409 10.2S.sub.0.1CdSe.sub.0.74 Te.sub.0.26 CdCl.sub.2 CdCl.sub.2 /CdSO.sub.4 -- None 1/1/1 0.84 645 60/454 11.0CdSe.sub.0.65 Te.sub.0.35 CdCl.sub.2 CdCl.sub.2 /CdSO.sub.4 -- None 1/1/1 0.82 610 55/446 12.0CdSe.sub.0.55 Te.sub.0.45 CdI.sub.2 CdCl.sub.2 /CdSO.sub.4 -- None 1/1/1 0.80 520 40/340 14.0 (+1mM Se)CdTe.sub.0.75 Se.sub.0.25 CdCl.sub.2 CdCl.sub.2 /CdSO.sub.4 H.sub.2 /250° C./5 min None 1/1/1 0.82 407 -- 15.0CdTe -- CdCl.sub.2 H.sub.2 /290° C./5 min None 1/1/1 0.83 570 -- 10.2CdTe CdCl.sub.2 InCl.sub.3 /CdCl.sub.2 -- None 1/1/1 0.83 441 50/259 7.0(0.3% In.sub.2 S.sub.3)CdTe -- CdCl.sub.2 1 min 300° in air None (3/0.1/0.1) ˜0.90 30 (p-type) 0.7 OH.sup.- /Te.sup.2- /TeZnTe -- ZnCl.sub.2 -- None (3/0.1/0.1) ˜0.90 35 (p-type) 0.6 OH.sup.- /Te.sup.2- /TeCuInS.sub.2 * -- InCl.sub.3 5 min H.sub.2 @ 240° C. 1/2/1 0.83 100 mV -- 1.1(Cd annealed)GaAs -- CdI.sub.2 Heat at 450° C. -- 2M KI 0.82 130 (n-type) 0.2 for 10 min in air 0.1M I (no previous anneal)MoS.sub.2 -- CdI.sub.2 as for GaAs None as for GaAs 0.93 75 (n-type) 0.05CdSe.sub.0.5 Te.sub.0.5 CdCl.sub.2 CdCl.sub.2 -- K.sub.2 CrO.sub.4 1/1/1 0.79 642 50/429 12.4 (0.93__________________________________________________________________________ cm.sup.2) All electrodes of area 1 cm.sup.2 except last example (0.93 cm.sup.2) on Ti/TiO.sub.2 substrate annealed for 8-12 mins. at 625-650° C. (except GaAs and MoS.sub.2). *=Annealed in an atmosphere of Cd vapor.
Table IV gives some non-restrictive examples of substrates on which the slurry may be applied and the layers applied together with the results achieved.
TABLE IV______________________________________ Output parameters (1 cm.sup.2 electrode under AMI conditions) Short circuit Open circuit Semiconducting current voltageSubstrate layer (mA) (mV)______________________________________Ti CdSe.sub.0.5 Te.sub.0.5 16.9 642Cr-plated CdSe.sub.0.65 Te.sub.0.35 10.2 570steelGraphite CdSe.sub.0.65 Te.sub.0.35 8.1 480conducting CdSe 3.1 430glass (annealed at 500° C. for 12 min.).______________________________________
EXAMPLES
Example 1
CdSe powder of 99.999% purity (3 micron average particle size) is mixed with ZnCl 2 powder (flux) of reagent grade in a weight ratio of 25:2. This mixture is ground together with a mixture of 5% nonionic detergent in water (v/v) to give a smooth paint. For each 50 mg. of powder (0.05 ml of the detergent containing water is used. This paint is applied to a piece of titanium metal, 0.6 mm thick, 3.5 cm 2 area, using a fine paint brush. Only the amount of paint needed to coat this area once is used. The titanium metal is preheated at 650 degrees C. for 40 seconds in an atmosphere of inert gas (argon), containing 20 ppm of O 2 , which has been previously passed over a water-soaked glass wool plug prior to entering the heating zone. The heated treated Ti exhibits a yellow to purple coloration. The coated substrate is dried at room temperature and is then heated under the same conditions of temperature and atmosphere as used for the Ti substrate, for a period of 12 minutes. The coated substrate is cooled slowly (during 5 minutes) to room temperature, in the same atomosphere. The annealed, coated substrate is then used as a photoelectrode in a PEC, further comprising a sulfided brass gauze counterelectrode (see U.S. Patent Application Ser. No. 118,761) and an aqueous solution 1 M in each of KOH, Na 2 S.9H 2 O and S. This PEC gives, under simulated AM1 conditions a short circuit current of 26.2 mA, an open circuit voltage of 530 mV and a photopotential of 388 mV over an optimal load of 24 ohms, thus yielding a maximal power ourput of 6.3 mW (1.8% radiant energy conversion efficiency). The CdSe photoelectrode is etched for 5 seconds in 3% HNO 3 in conc. HCl (v/v). After this treatment the same PEC containing the etched photoelectrode yields, a short circuit current of 36.5 mA, an open circuit voltage of 605 mV, and a photopotential of 424 mV over an optimal load of 17 ohms. This corresponds to an optimal power output of 10.6 mW (3% conversion efficiency). The photoelectrode is dipped for 3 seconds in a 1 M aqueous ZnCl 2 solution and subsequently rinsed with 0.06 ml H 2 O and blotted dry. This photoelectrode in the same PEC now yields a short circuit current of 36.8 mA, an open circuit voltage of 660 mV and a photopotential of 463 mV over an optimal load of 18 ohms. This corresponds to an optimal power output of 11.9 mW (3.4% conversion efficiency).
Example 2
A 1 cm 2 electrode is prepared as in Example 1, using reagent grade CdS and CdCl 2 .2.5H 2 O as starting materials which form the starting powder in a weight ratio of 50:3. This electrode, after etching in 50:50 HCl:H 2 O (v/v) for 5 seconds and a ZnCl 2 treatment as in Example 1, when used in a PEC as in Example 1, but with 0.1 M S instead of 1 M, gives a short circuit current of 2.5 mA, an open circuit voltage of 500 mV and a photopotential of 370 mV over an optimal load of 230 ohms, yielding an optimal power of 0.6 mW (0.6% conversion efficiency) under simulated AM1 conditions.
Example 3 A powder of nominal composition CdSe 0 .50 Te 0 .50 is prepared as follows: 99.999% CdSe (3 micron) and 99.99% CdTe (˜10 micron) are mixed in 1:1 molar ratio with 25% (by weight) CdCl 2 .2.5H 2 O. This mixture is ground with 2 drops of ethanol per 100 mg mixture. The mixture is allowed to dry at room temperature and the dry powder is fired at 660 degrees C. for 40 minutes in an atmosphere containing 10 ppm of oxygen in argon, and cooled subsequently in the same atmosphere. This material is used as the starting powder (after light grinding) to prepare a 0.93 cm 2 photoelectrode as in Example 2. When incorporated in a PEC as in Example 1, under 0.79 AM1 illumination and etched as in Example 1, the PEC gives a 12.6 mA short circuit current, 582 mV open circuit voltage, and a 400 mV photopotential over an optimal load of 50 ohms yielding 3.2 mW (4.35% conversion efficiency). After treating this electrode with 2 M aqueous K2CrO 4 solution, by dipping for 3 seconds and patting the electrode dry, the PEC gives a 12.4 mA short circuit current, 642 mV open circuit voltage and 429 mV photopotential at 50 ohms (5% conversion efficiency).
Example 4
An electrode is prepared as in Example 3, but on a different substrate and by using a 65:35 molar ratio mixture of CdSe and CdTe on Cr-plated steel. This substrate is pretreated by plating mechanically cleaned steel in a solution of 3 M CrO 3 and 0.026 M H 2 SO 4 in H 2 O, using a Pt anode and a current density of 200 mA/cm 2 for 10 minutes, at room temperature. This gives a somewhat roughened surface. This substrate is heated under the same conditions as used for Ti in Example 1, but for 3 minutes. The 1 cm 2 electrode, when used in a PEC as in Example 1, gives an 8.5 mA short circuit current, a 570 mV open circuit voltage and a 385 mV photopotential over an optimal load of 70 ohms, yielding 2.1 mW under 0.82 AM1 simulated conditions (˜2.6% conversion efficiency).
Example 5
CuInS 2 is prepared from elemental Cu, In and S by heating stoichiometric quantities in an evacuated silica tube at 1150 degrees C. for 24 hours. The product is ground and the resultant powder is used to prepare a 1 cm 2 electrode as in Example 1, but wherein InCl 3 replaces the ZnCl 2 . The annealed electrode is treated for 5 minutes in an atmosphere of 1:2 H 2 :Ar at 240 degrees C. This electrode is etched in 3% HNO 3 in HCl for 5 seconds and rinsed. This electrode is used in a PEC as in Example 1, containing 2 M Na 2 S.9H 2 O instead of 1 M. The PEC gives a 1.1 mA short circuit current, a 100 mV open circuit voltage at 0.83 AM1 simulated sunlight.
Example 6
An electrode is prepared as in Example 1. The paint slurry is formed in this case by mixing 1 drop of ethylcellulose in toluene (saturated solution) and 5 drops of ethylene glycol monobutylether with 90 mg CdSe, and 5 mg CdCl 2 .2.5H 2 O. The 1 cm 2 electrode when used in a PEC as in Example 1, using an electrolyte solution 2 M in KOH, Na 2 S.9H 2 O and S, and after etching in HCl/HNO 3 and dipping in ZnCl 2 solution as in Example 1, yields 8 mA short circuit current, a 675 mV open circuit voltage and a 530 mV photopotential over an optimal load of 100 ohms, yielding a power output of 2.8 mW (2.9% conversion efficiency) under simulated 0.95 AM1 conditions.
Example 7
Cd 0 .95 Zn 0 .05 Se powder is prepared by precipitation from a solution of CdSO 4 and ZnSO 4 in a 95:5 molar ratio by H 2 Se. 50 mg of the dride powder is mixed with 5 mg CdCl 2 .2.5H 2 O and 1 mg CdSO 4 , and a paint is prepared from water and detergent as in Example 1. This paint is used to make an electrode as in Example 1, and the 1 cm 2 electrode gives, after etching and treatment with ZnCl 2 as in Example 1, a 7.4 mA short circuit current, a 650 mV open circuit voltage and a 480 mV photopotential over an optimal load of 100 ohms.
Although the invention has been described with reference to particular methods of preparing the starting powders, particular electrodes, and particular electrolytes, it is to be understood that the invention is not limited to the particulars disclosed but extends to all equivalents falling within the scope of the claims. | Process for forming a semiconductor finding use in solid state and PEC cells as a photoelectrode, comprising preparing a slurry of at least one semiconductor starting material used to form the semiconductor, a flux and a liquid vehicle; applying a layer of the slurry to an electrically conductive substrate; and annealing the layer. The semiconductor produced by the process and a photoelectrochemical cell including the semiconductor. | 8 |
CROSS-REFERENCE TO RELATED U.S. APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC
[0004] Not applicable.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] cycleThe present invention relates generally to a fitness cycle, and more particularly to an innovative cycle with electric driving and resistance functions, allowing for multi-speed adjustment, cycle
[0007] 2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
[0008] cycleA conventional fitness cycle can be referred to as a track stepper, which allows a user to set a damping value for a damping device, this value being adjustable when necessary. The user will sense the resistance as if stepping on a trampoline, having to drive the stepper with greater force to achieve the desired fitness purpose. So, a fitness cycle is an piece of active fitness equipment for healthy users.
[0009] For physically disabled users, a self-driven fitness cycle is also developed for driving force against resistance. When the user steps on the equipment, a switch button is pressed to activate the trampoline-like stepping movement, thereby achieving the purpose of fitness or rehabilitation. So, this fitness cycle is a piece of passive fitness equipment for physically disabled users.
[0010] However, the aforementioned structures are unavailable with a dual motion mode that can be switched between active and passive motions. Thus, there is still a room for improvement in this industry.
[0011] Moreover, the seating unit of existing fitness cycles is generally equipped with an adjustment mechanism. However, such adjustment mechanisms have a single position or height configuration that does not allow the user to adjust in dual directions. So, the motion angle cannot be adapted efficiently to meet customized ergonomic demands.
[0012] Thus, to overcome the aforementioned problems of the prior art, it would be an advancement in the art to provide an improved structure that can significantly improve efficacy.
[0013] Therefore, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products.
BRIEF SUMMARY OF THE INVENTION
[0014] cycleWith the configuration of a control circuit, the fitness cycle, users drive along with a DC motor to generate a multi-speed steering effect, when intended for passive movement. Conversely, if the users need resistance, the control circuit allows for free switching into the resistance training with foot movements on a trampling unit, so as to generate resistance by the same DC motor through current control, The resistance value is adjusted to generate a multi-speed resistance movement effect.
[0015] Thus, the present invention is suitable for physically healthy users or disabled users, who can physically exercise through manual or automatic switching between a fitness purpose or recovery purpose.
[0016] With the configuration of the seating unit, users flexibly adjust the guide device and slide device via the chair seat in a manual or automatic adjustment mode. An optimum ergonomic movement gesture is adapted for each user. For example, the included angle between two legs and feet can be set at 45° when the feet step on the footplate.
[0017] Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0018] cycle FIG. 1 depicts a perspective view of the present invention.
[0019] FIG. 2 depicts a side elevation view of the present invention.
[0020] FIG. 3 depicts a schematic view of an illustration of the flow control of the present invention.
[0021] FIG. 4 depicts another schematic view of an illustration to the flow control view of the present invention.
[0022] FIG. 5 depicts a schematic view of the circuit of the present invention.
[0023] FIG. 6 depicts a side elevation view of the chair adjustment of the present invention.
[0024] FIG. 7 depicts a side elevation view of the usual chair adjustment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] cycleThe features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of a preferred embodiment of the present invention with reference to the accompanying drawings.
[0026] FIGS. 1-7 depict preferred embodiments of the fitness cycle of the present invention. The embodiments are provided for only explanatory purposes with respect to the patent claims.
[0027] The fitness cycle A comprises a carriage 1 , a trampling unit 2 on the carriage 1 , a control device 3 as an operating display panel, and a seating unit 4 .
[0028] The trampling unit 2 is composed of DC motor 20 , trampling set 21 and secondary drive unit 22 . The secondary drive unit 22 is composed of a big pulley, fly wheels 23 , 24 and drive belt 25 . The DC motor 20 is driven by a power supply and also connected with the control device 3 . The control device 3 comprises a circuit control unit 30 and an output module 31 connected to the circuit control unit 30 . A signal control and switching unit 32 connects with output module 31 . A vector compensation module 33 connects with the signal control and switching unit 32 . A resistance control loop 34 and a steering control loop 35 connect with the signal control and switching unit 32 . A brake module 36 connects to resistance control loop 34 .
[0029] When the control device 3 inputs a signal to the circuit control unit 30 enabling the power supply to feed an output power to DC motor 20 for generating a rated voltage, the signal is transmitted via the output module 31 to the signal control and switching unit 32 . Next, the signal is read and computed along with vector compensation module 33 , and then output to the steering control loop 35 , enabling DC motor 20 to drive the trampling set 21 so as to form an electric steering system. Conversely, if the trampling set 21 is applied to drive DC motor 20 when the input voltage of trampling set 21 is greater than the rated voltage of DC motor 20 , the signal will be detected by circuit control unit 30 and fed back reversely to output module 31 , then being transmitted to signal control and switching unit 32 for reading and computation. Finally, output to the resistance control loop 34 and the damping value is output by the brake module 36 , so as to shape a motion resistance system.
[0030] Said seating unit 4 is equipped with a mobile unit 40 , a lifting unit 41 and a chair seat 42 . The mobile unit 40 is composed of a slide device 43 and a mobile motor 44 . The mobile motor 44 is adapted onto the front end of the carriage 1 , and also provided with a shifting axle 45 mated with the slide device 43 . The lifting unit 41 is coupled with the mobile unit 40 , and also provided with a support frame 46 , a guide device 47 and a lifting motor 48 . The support frame 46 is fastened onto the slide device 43 , and the guide device 47 is mounted onto the support frame 46 . The lifting motor 48 is mounted onto the slide device 43 , and also provided with a lifting shaft 49 . The chair seat 42 is coupled with the lifting unit 41 . The back of the chair seat 42 is coupled with the guide device 47 of lifting unit 41 , and the bottom of the chair seat 42 coupled with the lifting shaft 49 of lifting motor 48 .
[0031] DC motor 20 is a brush motor or brushless motor.
[0032] The circuit control unit 30 is operated through the control device 3 to change the revolution number of DC motor 21 , allowing for multi-speed variation.
[0033] The signal control and switching unit 32 is an OP AMP (operation amplifier).
[0034] The circuit control unit 30 is equipped with an A/D converter to detect the change of rated voltage.
[0035] The control device 3 is available with a manual mode or a manual/auto switching mode. The control device is provided with a startup key, a manual switching key, an auto switching key, a mode switch key and a stop key, all of which are connected with the circuit control unit 30 .
[0036] Based upon above-specified structures, the present invention is operated as follows:
[0037] FIGS. 3 and 4 depict flow control views of the present invention, which are read in conjunction with the schematic view of the circuit of FIG. 5 . Since DC motor 20 is used as a drive motor, the drive power of the DC motor is power supply E, and the operation amplifier (OP AMP) Q 2 is applied to control the feedback circuit. According to the relational expression of Vref 2 =Vo×R 4 /(R 4 +R 3 ), rated voltage will be generated at both ends of DC motor 20 , the positive and negative electrodes.
[0038] Generally, the output of operation amplifier (OP AMP) is switched through Pulse Width Modulation circuit (PWM), and Tr 1 (FET or IGBT) switched via drive unit. Then, the rated voltage Vo will be generated. Referring to FIG. 4 , although the input of operation amplifier (−) is switched through a circuit at both ends of the DC motor, the input is performed through a low-pass filter in an actual circuit. Additionally, given the fact that the rated voltage Vo of Tr 1 is higher than the potential of grounding end (GND), the basic potential of operation amplifier (OP AMP) Q 2 is the potential of grounding end (GND), and the drive level of Tr 1 must be switched. A High Side Driver and optical coupler shall be required. Subsequently, Vref 2 is controlled by a microcomputer (MPU). Due to a proportional relationship between revolution number of controlled motor and the rated voltage Vo, there is also a proportional relationship between revolution number and Vref 2 , and the revolution number of DC motor 20 can be set randomly via microcomputer (MPU). In such a case, since the growing load of DC motor 20 leads to increase of current, the motor current must be controlled, thus forming a rated current circuit controlled by operation amplifier (OP AMP) Q 3 . The upper limit of motor current could be determined as the voltage of Vref 3 ×(R 2 /R 1 ) generated at both ends of Re 2 is measured from the current. When the fitness cycle A is used as a DC motor 20 , the revolution number obtained from Vref 2 and maximum torque could be determined, and the torque load for the feet is also set for the safety of the elderly users and physically disabled users.
[0039] If the user steps on the footplate more energetically, namely, making the rotational speed faster than the revolution number decided by Vref 2 , the generating voltage of DC motor 20 will be bigger than the aforementioned rated voltage Vo. The feedback circuit controlled by operation amplifier (OP AMP) Q 2 will be switched off, while the output voltage of operation amplifier (OP AMP) Q 2 will be smaller than the feedback circuit. The voltage change is detected by an A/D converter of microcomputer (MPU). The output voltage of operation amplifier (OP AMP) Q 2 will make Tr 1 in an OFF state.
[0040] The aforementioned describes the principle of generating electricity by stepping on the footplate, whereby electricity is generated by DC motor 20 , and whereby voltage is generated from the positive and negative electrodes as shown in FIG. 5 . In the feedback circuit of operation amplifier (OP AMP) Q 1 , the electric energy generates via Tr 2 a rated current Io from the positive electrode of the DC motor to Re 1 , and finally back to the negative electrode of DC motor. The current of power supply (E) does not flow to the DC motor when Tr 1 is in OFF state. The rated current Io is determined by Vref 1 controlled by microcomputer (MPU). The load of fitness cycle A is caused from trampling set 21 since there is a proportional relationship between rated current value Io and torque of DC motor. This torque will increase the footplate torque for the gear ratio of the big pulley and fly wheel 23 , 24 .
[0041] It is thus learnt that, this circuit can be applied to the fitness cycle. Since the DC motor can be switched smoothly from a drive motor to a generator, it is possible to increase Vref 1 from 0V, and also to convert the current in reverse, thereby achieving an active/passive switching mode to meet customer demands.
[0042] FIGS. 6 and 7 depict the application view of seating unit 4 of the present invention, which controls the mobile unit 40 and lifting unit 41 of seating unit 4 through chair seat controller 50 , so that the chair seat 42 moves forward/backward and lifts up/down in the carriage 1 along with the slide device 43 and guide device 47 , allowing flexible adjustment according to the stature of users and achieving a most comfortable and appropriate motion angle.
[0043] Additionally, said chair seat controller 50 could be arranged at a preset location of the chair seat 42 by manual adjustment or onto the control device 4 by electrical adjustment.
[0044] With the use of the electric steering/resistance switching system, a bigger resistance ratio may be set when a healthy user starts to step on the footplate. After the foot muscles gradually adapt, the resistance ratio may be reduced by an automatic electric switching system, and the stepping motion of user is driven by a DC motor for a better movement effect. As for female users, the muscle of legs could also be trimmed.
[0045] When a physically disabled user starts the fitness movement, the DC motor is used to drive the movement along with the trampling set. When the legs gradually recover, a resistance ratio may be set through the control device 4 , enabling the user to step continuously via the user's own force for better recovery efficacy. | The fitness cycle of the present invention is equipped with a DC motor along with a control circuit, enabling the users to drive the trampling set via the DC motor. Multiple speeds can be adjusted via a control device to generate a steering effect. Conversely, if the users need an increased movement resistance load, the fitness cycle allows for free switching to generate resistance by the same DC motor through current control. The resistance value to generate a multi-speed resistance movement effect is adjustable. With the configuration of the seating unit, the users flexibly adjust and adapt themselves to an optimum ergonomic posture. | 0 |
[0001] The invention relates to a device for dosing and aerosolization of aerosolizable material, in particular powdery medical substances such as, e.g., pharmaceutical preparations for inhalation. The device is particularly suited for the aerosolization of powdery lung surfactant preparations.
BACKGROUND OF THE INVENTION
[0002] Devices for aerosolization (“dry nebulization”) of aerosolizable (“nebulizable”) dry material are known to the skilled person. For example, for the aerosolization of powdery pharmaceutical preparations, so-called dry powder inhalers (DPIs) have been described. In these devices, an aerosolizable material, for example a powdery medical substance, is acted upon by a compressed gas or carrier gas in a specially provided chamber and, within this chamber, is converted to a state which is referred to as aerosol or dry mist. The particles of the material are in this case present in a preferably uniform and finely dispersed form across the entire volume of compressed gas or carrier gas and are then discharged from the chamber in this state via suitable devices.
[0003] Such devices can be used for administration of medical substances to spontaneously breathing or ventilated patients. For use in spontaneously breathing patients, the devices are generally connected to a suitable mouthpiece or a breathing mask. In invasive use, i.e. on ventilated patients, these devices feed the aerosolized medical substance into a ventilator system which then delivers the aerosolized material to the patient's lung.
[0004] In the devices known hitherto for aerosolization of powdery material, however, the problem generally found was that large amounts of medical substances could be delivered to the patient only, if at all, with considerable outlay in terms of equipment, for example using extensive mechanical dosing devices. Generally, the known devices were suitable for the aerosolization of pharmaceutical quantities in the range from approximately 1 μg up to approximately 20 mg. However, certain medical substances such as, e.g., lung surfactant preparations, require administration of large amounts, for example more than 100 mg or even in the gram range which, when using conventional DPIs, requires very long inhalation times. A second problem of devices known from the art can be the reproducibility of the amount of aerosolized material delivered to the patient. This is particularly the case when during storage or even during action of the inhaler the particles of the aerosolizable material agglomerate to larger particles with a different aerodynamic behaviour. Large particles will have a much smaller chance to reach their target, the deeper lung, since they tend to be deposited in the upper airways or throat or even somewhere in the inhaling apparatus.
[0005] The problem of administering large amounts of aerosolizable material such as lung surfactant preparations in precise doses concerns all sections of the apparatus used for inhalation: the air supply and its controller, the aerosolizing unit itself, the piping and valve system (including, where appropriate, the inner surfaces of a ventilator system), and the respiratory endpieces (mask, tube), in other words all sections in which an uncontrolled loss by unwanted deposition of aerosolized particles and thus reduction of the dose delivered to the patient and obstruction may occur.
[0006] In conventional aerosolizing units, one problem generally found was that the aerosolizable material, which is present as a loose charge in a storage container, for example a commercially available pharmaceutical vial, tends to agglomerate, by reason of its surface quality and/or its moisture content, which can result in blockage of a comparatively narrow aperture cross section of the vial. Such agglomeration may also occur in lung surfactant preparations. Such blockages can normally be obviated only by suitable mechanical means, in order to ensure a continuous dosing of the aerosolizable material over quite a long period of time. In addition, as already pointed out above, agglomerated particles of aerosolizable material, for example lung surfactant preparations, are not generally able to access the lungs with the same efficiency and following the same local distribution/deposition pattern as smaller, non-agglomerated particles.
[0007] In the prior art aerosolizing unit of GB 24 848 A, a reservoir of aerosolizable material is connected via a narrow passage to a chamber into which supply air is pressed by means of a syringe. Deagglomeration of the aerosolized particles takes place as the supplied air is further forced into the reservoir and performs a whirling action therein; where after the dispersed aerosolizable material is expelled through the chamber and out of a nozzle towards the patient. In FR 2 598 918 A the aerosolizable material is, in contrast, conveyed by an Archimedean screw into a jet of compressed air where dispersion takes place.
[0008] In many instances it is necessary to ensure rapid and high-dose administration of aerosolizable material, in a form accessible to the alveoli, into the lungs with a constant dosage, in rapid sequence and over a period of several minutes. Both above-mentioned systems cannot, however, provide administration of high doses of aerosolizable material and are, due to their geometry and dispersion mechanism, still prone to agglomeration, e.g. in the chamber or in the hopper provided with the screw, so that accurate dosing remains an issue. In fact, such administration was possible, if at all, only with considerable outlay in terms of equipment.
[0009] WO 2006/108558 A1 discloses a device for dosing and powder aerosolization in which deagglomeration of the aerosolizable material, such as a powdery lung surfactant preparation, is achieved by means of pressure compensation between the pressure pulses sent into the aerosolization channel of the device. The shear force necessary for deagglomeration is created by taking advantage of the high pressure during the pulses. While this system delivers superior results over the known prior art systems in terms of concentration of aerosolized material delivered, issues of concern remain regarding residues of aerosolizable material adhering to the inner surfaces of the system such as the reservoir walls or the bottom of the aerosolization channel.
[0010] A further issue concerns the output characteristics of a dosing device such as the one disclosed in WO 2006/108558 A1. As the dosing device uses pressure pulses to deagglomerate, the question arises about the effect these may have on the patient. The pressure pulses are of substantial magnitude and, thus, the dosing device cannot be connected directly to the patient's breathing front ends such as masks in the case of spontaneously breathing patients. For ventilated patients, the output of the dosing device must be connected to the ventilator in order to allow for both adequate and precise dosage, and for the necessary oxygen supply. In the case of infants, moreover, the volume and dosage of the supplied aerosol as well as the partial pressure of oxygen as well as the airway pressure are even more critical than in adults and need special consideration. Since for infants the conventional approach of supplying airborne drugs via pressure respirators and tubes is extremely stressful, specialized equipment and rooms are required.
SUMMARY OF THE INVENTION
[0011] It is therefore an object of the present invention to provide a device for dosing and aerosolization of aerosolizable dry material which overcomes the above problems of residues of aerosolizable material and allows essentially all the aerosolizable material present in the device to be aerosolized and delivered to the patient, thereby allowing for a yet unachieved dosing accuracy also in the case in which large volumes of dry powder need to be administered.
[0012] Since the utility of the device according to the invention is not limited to the dosing and aerosolization of substances used in a medical context, such as substances used for diagnostics and/or for treatment, it is a further object of the invention to provide a device for dosing and aerosolization of aerosolizable dry material which overcomes the above problems of residues of aerosolizable material and allows essentially all the aerosolizable material present in the device to be aerosolized.
[0013] It is also an object of the invention to provide a system for dosing and aerosolization of aerosolizable dry material which allows treatment of spontaneously breathing as well as ventilated patients and can be used both with adults and infants.
[0014] These objects are achieved by means of a device for dosing and aerosolization of aerosolizable dry material according to claim 1 . Further optional and preferred embodiments are defined in the respective dependent claims.
[0015] In a first aspect of the invention, the novel device for dosing and aerosolization of aerosolizable dry material comprises a body with an aerosolization channel having a distal attachment portion connectable to a source of pulsed carrier gas which provides pressure pulses of the gas to the aerosolization channel and a proximal attachment portion for outputting aerosolized material (the “aerosol”) towards a patient, and a reservoir for receiving aerosolized material (“proximal” and “distal” as seen from the patient). It is further preferred that the device has an attachment portion connectable to a source of non-pulsed carrier gas serving to transport the generated aerosol from the aerosolization channel or from the reservoir towards the patient. The reservoir comprises walls and is connected in a gas-tight manner to the body and is in flow connection with the aerosolization channel. At least parts of the walls are membranes that can be put into oscillation. While the latter could be realized by any sort of actuator, it is preferred that the membranes are self-exciting membranes that can be put into oscillation by the pressure pulses.
[0016] Preferably, the novel device comprises means for transferring oscillation energy between different areas of the membranes. Advantageously said means can recircle oscillation energy induced by the pressure pulses. It is preferred to transfer the oscillation energy from stronger oscillating areas of the membranes to weaker oscillating areas. This serves to compensate for pressure differences between the membranes. Thus activating weaker oscillating areas. Such a transfer can be assured for example by a tubing connecting the proximal attachment portion and/or the aerosolization channel and the distal reservoir of the device.
[0017] The term “membrane” as used herein refers to any sheet-like structure that is impermeable to gas, liquid and the aerosolizable material, and that forms at least part of the containment for the aerosolizable material in the reservoir. “Self-exciting” as used herein refers to the property of the membrane to elastically deform and oscillate in response to pressure pulses of the carrier gas supplied to the device. As such it is to be understood that, as a function of the membrane's material, the membrane needs to be thin and flexible enough in order to be deformed by the pressure pulses. Examples of membrane materials are elastic polymers such as silicone, but other materials will be apparent to the skilled person.
[0018] By being provided with membrane walls, the inventive device is capable of utilising essentially the complete amount of aerosolizable dry material stored in the reservoir and transform it into an aerosol because the oscillation of the membrane walls of the reservoir loosens up aerosolizable material, so it can fall into the dosing chamber beneath the reservoir. The process of aerosolization is, for example, described in WO 2006/108558.
[0019] According to the invention it is thus possible to have a uniformly loose charge of aerosolizable dry material available in the device for dosing and aerosolization after each pressure pulse, as a result of which a gradually increasing compaction of the material is avoided and a uniform dosing is guaranteed over a considerable time period. The device according to the invention thus easily allows aerosolizable material to be dosed in large amounts in a highly reproducible manner and preferably without moving parts. In addition, during the pressure compensation between aerosolization channel and reservoir, a loosening of the charge of the aerosolizable material is achieved. It is thus possiblethat the mixture of compressed carrier gas and material predominantly contains deagglomerated particles, preferably exclusively or almost exclusively particles having the size of the primary, non-agglomerated particles of the aerosolizable material. If the aerosolizable material is in the form of a powdery medical substance such as, e.g., powdery lung surfactant, it is possible that the primary particles of the medical substance located in the reservoir are present in the mixture of compressed gas and material. To this extent, the device according to the invention permits, preferably completely free of mechanical moving parts, optimal aerosolization of the aerosolizable dry material even down to the size of the primary particles.
[0020] In the preferred case that the device is used for dosing and aerosolization of substances for therapeutic and/or diagnostic purposes, the size of the primary particles of the aerosolizable material preferably corresponds to a mass median aerodynamic diameter (MMAD) which is such that the particles are able to access the lungs, i.e. the site of action in the airways or the alveoli of the lungs. The MMAD of particles that can access the lungs is in the range of 1 to 5 μm. The desired MMAD range, according to the invention, of the particles in the mixture of compressed gas and material is consequently 1 to 5 μm.
[0021] Preferably, a funnel portion tapered towards the aerosolization channel is provided in the body between the reservoir and the channel, and the walls of the funnel portion are self-exciting membranes. The funnel portion is where the aerosolizable material falls to and accumulates from the reservoir before entering the aerosolization channel. The differential pressure pulses generated as a result of the pressure pulses utilizing the Venturi principle create a pressure gradient which serves to suck the aerosolizable material into the aerosolization channel and entrains it into the carrier gas stream, by this generating a highly concentrated aerosol. As the walls of the funnel portion are self-exciting membranes, no material accumulated in the funnel portion will be left adhering to its walls and substantially all of it can be entrained in the carrier gas.
[0022] The reservoir may preferably be provided with a lid that comprises a membrane towards the reservoir. While the cover as such allows the reservoir to be (re)filled, the membrane on the cover will also oscillate and support a complete deagglomeration and detachment of aerosolizable material from the inner surfaces of the reservoir. If desired, between membrane and lid a gas- and/or humidity absorber can be inserted.
[0023] Additionally, a self-exciting membrane may be provided as part of the bottom of the aerosolization channel beneath the connection thereof with the reservoir. When aerosolizable material falls into the aerosolization channel, not all of it is always immediately entrained in the carrier gas stream, and some material may deposit and accumulate beneath the mentioned connection. By providing this area with a self-exciting membrane, the pressure pulses sent through the aerosolization channel excite this membrane to oscillate so that the material is reentrained in the carrier gas. This configuration can be termed a “passively controlled” membrane. It is also conceivable to dispose an actuator connected to the membrane so as to drive the membrane to oscillate. This is called “actively controlled”.
[0024] Finally, it is preferred that the reservoir and the body are integrally formed. This has the advantage that a disposable device can be provided in which the total dose of aerosolizable material is carefully controlled by the manufacturer and contamination and wrong dosage due to filling inaccuracies can be prevented.
[0025] In a second aspect of the invention, a system for dosing and aerosolizaticn of aerosolizable dry material comprises the above-described device for dosing and aerosolization of aerosolizable dry material. In addition, a first hollow spacer is connected to the proximal attachment portion of the device and comprises a distal portion having inner walls tapered towards the proximal attachment portion, and a proximal portion having inner walls tapered towards the patient, with preferably a central cylindrical portion there between.
[0026] The term “spacer” as used herein refers to an additional piece of pathway for respiratory or carrier gas/aerosol to traverse, which introduces expansion space for the pulsed gas stream. The geometry of the first hollow spacer allows to dampen the pressure pulse of the gas carrying the aerosol to the patient and to reduce at the same time the associated noise, much in the same way as a silencer. Thus, both for spontaneously breathing and for ventilated patients, the aerosol arrives more uniformly and without unacceptable pressure spikes.
[0027] According to a preferred embodiment, the inner walls of the distal portion, the central portion and/or the proximal portion of the first hollow spacer comprise self-exciting membranes. When a differential pressure pulse arrives in the system, the membranes oscillate due to their elasticity so that this construction avoids that particles from the aerosol adhere to and stay on the walls of the spacer.
[0028] It is also preferred that an annular gap is provided between the distal and the central portions of the first hollow spacer, which is connectable to an auxiliary air supply. This annular gap can be supplied with auxiliary air that rinses the inside of the spacer and makes sure no residue of aerosolizable material stays adhered to the wall. It is most preferred that the geometry of the annular gap allows formation of a sheath flow of auxiliary air along the walls of the cylindrical part of the spacer, thus ensheathing the aerosol stream entering the spacer and efficiently helping to avoid the aerosolized particles to deposit on the spacer's walls.
[0029] In a preferred embodiment, the system according to the second aspect of the invention further comprises a second hollow spacer connected to the proximal portion of the first hollow spacer and distally to a patient connector, the second hollow spacer having an ambient air inlet with a non-return valve provided at the distal end and an exhaled gas outlet provided at the proximal end of the second hollow spacer. The second hollow spacer preferably has a larger cross-section and volume than the preceding first hollow spacer, and may preferably be cylindrical, although the invention does not provide any limitation on shape.
[0030] This arrangement is particularly advantageous for administration of aerosolized material to spontaneously breathing patients. Like the first hollow spacer, the second hollow spacer serves to attenuate the differential pressure pulses coming from the supply of compressed air through the dosage and aerosolization device and to reduce the associated noise. But it also has the function of providing an intermediate storage for the aerosol, that is the aerosolized material entrained in the carrier gas. From this intermediate storage, which is connected to the patient's mouth piece, a spontaneously breathing patient can inhale the predetermined dose of aerosolized material. Due to the expanded cross-section and larger volume of the second hollow spacer with respect to the first hollow spacer, the negative respiratory pressure necessary to draw and inhale the aerosolized material from the second hollow spacer does not become excessive as would be the case if the dosage and aerosolization device and first hollow spacer were directly connected to the patient. Moreover, inhalation of aerosolized material from the first or second spacer is further facilitated by the provision of auxiliary air as described above.
[0031] In an alternative preferred embodiment, the aerosolization device is connected to a ventilator system operated as CPAP System (continuous positive airway pressure) delivering ventilatory support to a patient. In such a setup, the aerosol is introduced into a ventilator or CPAP system via a T-connector to a patient side respiratory front end. This system provides numerous advantages to patients on mechanical ventilation or on ventilatory support, in particular in case of infants and neonates. In acute situations, these little patients may need carefully controlled administration of aerosolized medical substances. By connecting the ventilator or CPAP system and the dosing and aerosolization device via a T-connector that is connecting the device in parallel to the respirator, it is possible to control both how much air or oxygen is provided from the ventilator (by controlling the air and/or oxygen pressure) and, separately, how much aerosolized material is provided to the patient. Furthermore, in contrast to delivery of the aerosol into the inspiration branch of the respirator, this configuration allows for higher aerosol concentrations in the gas delivered to the patient since dilution is minimized.
[0032] As mentioned above means can be provided to transfer oscillation energy from one area of the membranes to another.
[0033] Preferably, a compensation tubing is provided between the interior of the first hollow spacer and the interior of the funnel portion. This tubing serves to compensate for pressure differences between spacer and reservoir and at the same time to activate the funnel membrane.
[0034] The above-described systems may be integrated in standard ventilator systems for routine administration/addition of aerosolizable material, such as lung surfactant, to the respiratory gas.
[0035] It is obvious to the person skilled in the art that the aerosolization device as described hereinabove can be used in a variety of technical fields. Actually the device according to the invention will be applicable whenever efficient and uniform aerosolization of powders is desired. While preferred uses of the device according to the invention are in the field of therapy and administration of inhalable drugs, pharmaceutical preparations and other medical substances, in particular lung surfactant, the device will be useful for the aerosolization of any sort of aerosolizable substances in the range of less than 100 mg up to several grams of substance. It is even conceivable that an adequately sized version of the device allows aerosolization of even higher amounts of substances up to technical scales. The particle size or particle size distribution of the material to be aerosolized will depend on the particular application. For example, as is known from the art, particles to be administered to the lung by inhalation ideally will have a size in the range of 1-5 μm MMAD. Of course, the device according to the invention is not limited to aerosolization of particles in this size range. Rather, smaller as well as larger particles would lend themselves for aerosolization by use of this device. To give an example, powder coating of workpieces which has gained considerable importance in recent years would be a possible application where relatively large quantities of particles having a very small size (e.g., <1 μm) have to be aerosolized.
[0036] Accordingly, the present invention relates to a device for dosing and aerosolization of aerosolizable material comprising a body with an aerosolization channel having a distal attachment portion connectable to a source of carrier gas which provides pressure pulses of the gas to the aerosolization channel and a proximal attachment portion for outputting aerosolized material towards a patient, a reservoir for receiving aerosolizable material, the reservoir comprising walls and being connected in a gas-tight manner to the body and in fluid connection with the aerosolization channel, characterized in that at least part of the walls are self-exciting membranes that can be put into oscillation by the pressure pulses.
[0037] The present invention also relates to the above device, wherein a funnel portion tapered towards the aerosolization channel is provided in the body between the reservoir and the channel, and wherein walls of the funnel portion are self-exciting membranes.
[0038] The present invention also relates to any of the above devices, wherein the reservoir is provided with a top cover and the top cover comprises a self-exciting membrane towards the reservoir.
[0039] The present invention also relates to any of the above devices, wherein a self-exciting membrane is provided in a wall of the aerosolization channel beneath the connection thereof with the reservoir.
[0040] The present invention also relates to any of the above devices, wherein the reservoir and the body are integrally formed.
[0041] The present invention also relates to any of the above devices, wherein the reservoir is connected with the aerosolization channel via a valve. In one embodiment, the valve is a rotary valve.
[0042] In summary the present invention uses the energy of a pressure pulse generated for example by expansion of compressed gas to excite elastic elements. As mentioned before, these elements can be membranes, especially self-exciting membranes. By exciting the membranes energy is taken up from the original pressure pulse, thus weakening this pressure pulse. As a result the aerosolizable material is aerosolized in a more continous, constant and homogeneous form compared to a rapid output initiated by an unweakened pressure pulse. By such an attenuation of the pressure pulse the aerosole produced is comfortable breathable by a patient.
[0043] Additionally an agglomeration of the aerosolizable material, especially in the reservoir, is prevented.
BRIEF DESCRIPTION OF DRAWINGS
[0044] FIG. 1 is a longitudinal sectional view of an embodiment of a system for dosing and aerosolization according to the invention;
[0045] FIG. 2 is schematic view of an embodiment of a system for dosing and aerosolization for use with spontaneously breathing adult patients;
[0046] FIG. 3 is schematic view of an embodiment of a system for dosing and aerosolization for use with ventilated infants; and
[0047] FIG. 4 is schematic view of an embodiment of a system for dosing and aerosolization for use with ventilated adults.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0048] In FIG. 1 , a longitudinal sectional view of a first embodiment of the system for dosing and aerosolization is shown. The system 100 comprises a device 1 for dosing and aerosolization, in which an aerosolization channel 3 is arranged inside a body 2 . At its distal end (on the right in FIG. 1 ), the body 2 comprises a capillary seat 4 into which a capillary tube holder 14 supporting a capillary tube 13 is fitted. This capillary tube holder 14 can in turn be connected via connecting lines and a valve (both not shown) to a supply of pulsed compressed carrier gas. At its proximal end (on the left in FIG. 1 ), the aerosolization channel 3 opens into a dispersing nozzle 5 whose cross section increases continuously in a direction extending away from the capillary tube 13 .
[0049] Above the aerosolization channel 3 , the device 1 comprises a reservoir 9 for the powdery material to be aerosolized. The reservoir 9 comprises an outer wall 10 and an inner portion having a cylindrical wall 11 and conically tapering wall 12 . The walls 11 and 12 are self-exciting membranes made of, e.g., medical grade silicone having a wall thickness of about 0.5 mm. Between the outer wall 10 and the cylindrical and conical walls 11 and 12 , spaces 6 and 7 are respectively formed. At the bottom, the reservoir 9 forms an aperture 19 located above the aerosolization channel 3 that is partially integral part of the dosing chamber 8 . Located above this aperture 19 will be a charge of the powder to be aerosolized (not shown) which may be clumped together to such an extent that almost no grain of aerosolizable material enters the aerosolization channel 3 . The whole assembly consisting of parts 5 , 3 , 15 , 8 , 13 , and 4 may be turned by 90 degrees around the apparatus' longitudinal axis to prevent powder from falling into the chamber 8 , thus closing the reservoir. Accordingly, said assembly together with the body 2 forms a rotary valve which allows to interrupt supply of the powder stored in the reservoir 9 to the dosing chamber 8 and aerosolization channel 3 .
[0050] On top of the reservoir 9 , a lid 16 is provided that tightly closes the reservoir. At the bottom side of the lid, towards the interior of the reservoir, a self-exciting membrane 17 is provided that seals the top opening of the reservoir 9 . Above the membrane, a humidity (or generally gas) absorber 18 is included in the cover that eliminates residual humidity or other trace gases in the reservoir which otherwise could have adverse effects. Furtheron, a space is formed between the membrane 17 and the humidity absorber 18 (not shown).
[0051] In the present embodiment, the reservoir 9 and the body 2 with the aerosolization channel 3 are integrally formed, whereby complete gas-tightness and sterility is guaranteed. However, it is to be understood that they may also be separate elements that are fitted together in an gas-tight manner.
[0052] The dispersing nozzle 5 opens into a proximal attachment piece 2 a which is an integral component part of the body 2 . Onto the attachment piece 2 a , a hollow spacer 20 is fitted in a gas-tight manner. The spacer 20 comprises a cylindrical outer wall 21 , a distal portion with conical inner walls 22 tapered distally, a proximal portion with conical inner walls 24 tapered proximally, and a central portion having cylindrical walls 23 arranged there between. As with the reservoir, also the walls 22 , 23 , 24 of the spacer 20 are self-exciting membranes made of, e.g., silicone. Between the outer wall 21 and walls 22 , 23 , 24 corresponding spaces 25 , 26 , 27 are provided. An annular gap is formed between the distal and central portions of the spacer 20 and is connected to an auxiliary gas supply (not shown).
[0053] In operation, pressure pulses of carrier gas enter the aerosolization channel 3 of device 1 through the capillary 13 and, due to the pressure difference created between the gas exiting from capillary 13 and the reservoir 9 by Venturi's principle, aerosolizable material is sucked from the reservoir 9 into the aerosolization channel 3 , dispersed and entrained in the carrier gas. At the same time, this differential pressure pulse also acts on the membrane walls 11 , 12 of the reservoir 9 and the membrane walls 22 , 23 , 24 of the spacer 20 , causing them to bulge and oscillate according to the frequency of the pressure pulses. Thus, aerosolizable material adhering to the walls is reentrained into the bulk material and free to enter the carrier gas stream.
[0054] It is to be understood that in alternative embodiments only some of the inner walls of the device are carried out as self-exciting membranes. For example, in an alternative embodiment only the tapered wall 12 is a self-exciting membrane. Obviously, each inner wall of the device which is not carried out as self-exciting membrane does not require a hollow space between this inner and the corresponding outer wall. For example, when only the tapered wall 12 is carried out as self-exciting membrane, spaces 6 and 25 - 27 are dispensable.
[0055] The amount of aerosolizable material that can be administered with the devices and systems of the present invention exceeds 50 mg and is coupled with a high precision of dosage. On one hand, the precision allows the use of drugs having a very narrow “therapeutic window” and on the other hand the large volumes make the system suitable for use with substances that need to be administered in large quantities. For example, aerosolizable medical substances other than lung surfactant which can be administered by use of the device according to the invention include antibiotics, nucleic acids, retard formulas, peptides/proteins, vaccines, antibodies, insulin, osmotically active substances like mannitol, hydroxyethyl starch, sodium chloride, sodium bicarbonate and other salts, enzymes (e.g., DNAse), N-acetyl cystein, etc.
[0056] Turning now to FIG. 2 , an embodiment of a system for dosing and aerosolization 200 is shown, which is employed for large volume dry powder inhalation of spontaneously breathing patients. The system 200 comprises the device 1 for dosing and aerosolization and the first spacer 20 of the first embodiment, wherein additionally a compensation tubing 29 connects the spaces 6 , 7 of the reservoir with spaces 25 , 26 , 27 of the spacer 20 . On the upstream side, the system 200 comprises a controller 50 that is connected via a compressed air line 51 to a compressed air supply 52 (e.g., the compressed air supply of a hospital) providing the compressed air through a main connecting line 41 to the dosing and aerosolization device 1 . The main connecting line 41 is connected to the capillary holder 14 (distal attachment portion) of the device 1 . The flow of the compressed air to the device is regulated by a fast-switching solenoid valve 40 which is caused to open and close by a current pulse 43 sent from the controller so as to achieve a determined number, duration and frequency of air pressure pulses. In use, the flow of compressed air may be triggered automatically by the controller, but may also be triggered by the breathing of the patient so as to adapt the timing of aerosolization and the volume of aerosolized material provided in the second spacer to the patient's breathing characteristics.
[0057] An auxiliary connecting line 42 supplies un-pulsed air to the annular gap 28 of the spacer 20 (the connection is not shown) to thereby flush the spacer of residues of aerosolizable material. Both connecting lines 41 and 42 comprise filters F to block contamination by undesired particles.
[0058] On the downstream side, a second spacer 30 is connected to the first spacer 20 . At the same time, an ambient air inlet 31 provided with a no-return valve 32 is provided at the distal end of the second spacer 30 . At the proximal end of the second spacer 30 , a straight connector 34 with a mouth piece 35 is positioned, while an exhaled gas outlet 36 (optionally with a filter F) branches perpendicularly off the straight connector 34 .
[0059] FIG. 3 shows an embodiment of the system for dosing and aerosolization that is particularly suited for acute respiratory therapy of very young children such as infants and neonates. Several components which are the same or are equivalent to those described with respect to FIGS. 1 and 2 bear the same reference numerals and will not be discussed again. The system 300 comprises the device 1 for dosing and aerosolization and the spacer 20 , and a controller 50 which is connected to it in the same way as in the embodiment of FIG. 2 . Connected to the output of spacer 20 is a ventilator tubing 60 that in turn connects to the first port of a T-piece 61 . Further, in this embodiment a ventilator in CPAP mode 70 is provided that supplies respiratory gas via respiratory gas line 64 to a manifold 65 while keeping the ventilator pressure at a constant level. From the manifold 65 , a common ventilating line 62 connects to the second port of the T-piece 61 . The third port is connected to a nasopharyngeal tube 66 that is introduced through the infant's nose so that its tip is positioned just above the glottis.
[0060] Further, a flow rate sensor 67 is disposed at the manifold to measure the gas flow rate V 3 of the gas in common line 62 . The measurement signals are fed back to the ventilator 70 , which directly controls the pressure in line 64 and in line 63 by controlling the respective flow rates, and therefore indirectly controls V 3 . By means of this pressure control additional flow from the disperser dosing unit causes V 3 to be down regulated so that the pressure and hence total flow to the infant (V 5 ) is kept constant.
[0061] In addition, an oxygen sensor 69 is provided at the third port of the T-connector 61 , monitoring oxygen content of the respiratory gas mixture actually administered to the lungs of the infant. The respective measurement signals are fed back to the ventilator 70 , where together with the flow rate information a comprehensive picture of the properties of the supplied respiratory gas mixture is obtained. These properties are then in turn controlled by the ventilator 70 . In summary, by connecting the device 1 in parallel with the respiratory system, it becomes possible both to provide oxygen-rich respiratory gas and the correct dose of aerosolized material, such as lung surfactant.
[0062] Finally, turning to FIG. 4 , another embodiment of a system for dosage and aerosolization is shown. The system 400 is used with ventilated adult patients and comprises the device 1 for dosing and aerosolization, the controller 50 , a ventilator 71 and a hollow spacer 80 . The controller is connected in the above-described manner to a hospital air supply 52 and via a main connecting line 41 with valve 40 to the device 1 , just as described in the foregoing embodiments. However, in this embodiment, the spacer 80 is much larger than spacer 20 , both in diameter and in volume, in order to accommodate the needs of an adult ventilated patient. The spacer 80 is connected at its distal end to the proximal attachment piece 2 a of the device 1 and has at its proximal end a straight connector 84 leading to a breathing mask 85 . A respiratory gas inlet 81 with a non-return valve 82 is disposed laterally on the distal end of the spacer 80 and is connected in the usual manner via a filter and respiratory gas line 64 to the ventilator 71 . Similarly, at the proximal side an exhaled gas outlet 86 is connected via a non-return valve 82 and exhaled gas return line 63 to the ventilator.
[0063] The amount of aerosolizable material that can be administered with the devices and systems of the present invention exceeds 50 mg and is coupled with a high precision of dosage. On the one hand, the precision allows the use of drugs having a particularly narrow “therapeutic window” and on the other hand the large volumes make the system suitable for use with substances that need to be administered in large quantities. For example, aerosolizable medical substances other than lung surfactant which can be administered by use of the device according to the invention include contrast agents, antibiotics, nucleic acids, retard formulas, peptides/proteins, vaccines, antibodies, insulin, osmotically active substances like mannitol, hydroxyethyl starch, sodium chloride, sodium bicarbonate and other salts, enzymes (e.g. DNAse), N-acetyl cystein, etc. | The claimed subject matter relates to a device for dosing and aerosolization of aerosolizable material. The device comprises: a body with an aerosolization channel with a distal attachment portion connectable to a source of carrier gas which provides pressure pulses to the aerosolization channel; a proximal attachment portion for outputting aerosolized material and a reservoir for receiving aerosolizable material. The reservoir comprises walls and is connected in a gas-tight manner to the body and in fluid connection with the aerosolization channel. At least part of the walls of the device are self-exciting membranes that can be put into oscillation by the pressure pulses. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
Dry Wall Outlet Box Locator and Cutter Assembly.
2. Description of the Prior Art
In modern construction practice the electrical outlet boxes and associated conduit is installed in permanent positions in the framing of a building which may be either studs or joists. After such installation sheets of dry wall are permanently secured to the studs or joints. A troublesome problem and one that requires time consuming measurements that may be subject to error is to locate openings in the dry wall sheets that will be transversely aligned with the interiors of the outlet boxes when the dry wall sheets are permanently secured to the framing. Occassionally errors will be made in locating such openings, and the dry wall sheets will either have to be discarded or the positions of the outlet boxes changed to coincide with the erroneously located opening. In either event a substantial amount of time is wasted in correcting the situation and with a substantial expense to the builder or contractor.
A major object of the present invention is to provide an assembly that eliminates the above-mentioned problem by removably inserting a device in the framing supported outlet box that will register the center thereof on a sheet of dry wall when the later is temporarily positioned in the position it will permanently occupy relative to the outlet box, and the center registered on the dry wall sheet serving to align a cutting tool which may be used manually to cut an opening in the dry wall sheet that will be transversely aligned with the interior of the outlet box when the drywall sheet is permanently secured to the framing.
SUMMARY OF THE INVENTION
An assembly comprising a locator that is removably installed in the forward interior portion of a framing supported electrical outlet box that includes a transversely movable centered member that normally occupies a first retracted position. When a sheet of wall board is temporarily disposed to occupy the position it will permanently occupy when nailed or otherwise secured to the framing the transversely movable member is actuated to move outwardly to a second position where it registers the center of the outlet box on the inner surface of the wall board sheet. A bladed cutter forms a second part of the assembly. After the center of the outlet box interior has been registered on the wall board sheet, the sheet is laid on a flat surface. The cutter includes three projecting prongs. The center prong is disposed over the registered center on the wall board, and the cutter is struck a sharp blow to drive the three prongs completely through the wall board and the cutters partially passing through the wall board to outline the opening therein that will be transversely aligned with the outlet box when the wall board is permanently secured to the framing. The sheet of wall board is now turned over with the three prongs inserted in the three openings. The cutter is now struck a second sharp blow for the cutters to pass through the uncut portion of the wall board to merge with the cuts previously made. The core or plug of wall board within the confines of the cuts made by the cutter may now be pushed or knocked out of the sheet of wall board. The sheet of wall board is now nailed or otherwise secured to the framing, with the opening in the wall board sheet being transversely aligned with the interior of the electrical outlet box. By forming outlet box openings in sheets of wall board as above described, the possibility of an opening in the wall board being misaligned with the interior of an electrical outlet box is eliminated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a framing supported electrical outlet box with a first form of locator removably supported in the forward interior portion thereof;
FIG. 2 is a transverse cross-sectional view of the locator taken on the line 2--2 of FIG. 1;
FIG. 3 is a second transverse cross-sectional view of the locator taken on the line 3--3 of FIG. 2;
FIG. 4 is a longitudinal cross sectional view of the locator mounted in the outlet box and taken on the line 4--4 of FIG. 3;
FIG. 5 is the same view of the locator shown in FIG. 4 but in a fully expanded longitudinal position;
FIG. 6 is a side elevational view of the locator being actuated to register the center of an outlet box on a sheet of wall board that is temporarily disposed to occupy the position it will permanently occupy on stud or joist framing;
FIG. 7 is a perspective view of the cutter used in forming an opening in a sheet of wall board;
FIG. 8 is a side elevational view of the cutter after the latter has been struck to drive the three prongs thereof through the wall board sheet and the blades to at least partially penetrate the wall board to define the opening that will be formed therein;
FIG. 9 is a front elevational view of the locator removably mounted in a double electrical outlet box;
FIG. 10 is a perspective view of a second form of locator particularly adapted for use with ceiling supported outlet boxes;
FIG. 11 is a transverse cross-sectional view of the second form of locator;
FIG. 12 is a cross-sectional view of the second form of locator taken on the line 12--12 of FIG. 11;
FIG. 13 is a transverse cross-sectional view of a third form of locator; and
FIG. 14 is a fragmentary end elevational view of the third form of locator taken on the line 14--14 of FIG. 13.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first form of the invention A-1 as shown in FIGS. 1 to 6 is used in conjunction with a cutter B illustrated in FIGS. 7 and 8 as an assembly to locate and form an opening C in a sheet of wall board D in alignment with an electrical outlet box E secured to the framing F of a building (not shown), which framing may include either studs or joists. In using the invention A-1 the wall board sheet D is temporarily disposed adjacent the framing F in the position it will permanently occupy when subsequently secured to the framing, with the invention A-1 then being used to register the center of the interior of the outlet box E on the rearward surface of wall board sheet D. The wall board sheet D is then removed from this position and the cutter B then used to form the opening C in the wall board sheet using the registration as a guide.
The registration effected on the rearward surface of the wall board sheet will normally be an indentation although a mark on the wall board sheet would also serve as a guide to dispose the cutter B in a position to initially sever a part of the wall board sheet D to define opening C. The forming of the opening C is completed by reversing the position of the wall board sheet D and using the cutter B on the reversed side to complete the forming of opening C. After the abovedescribed operation, the wall board sheet D may be disposed in the position it will occupy permanently on the framing F when secured thereto, with the assurance that the opening C will be transversely aligned with the interior of the outlet box E.
The electrical outlet box E is of a design currently in use and is of generally rectangular shape. Outlet box E as may be seen in FIG. 1 includes a back 10, a pair of side walls 12, an upper end wall 14, and lower end wall 16. The end walls 14 and 16 have apertured tabs 14a and 16a extending towards one another from the forward edges of the end walls as may be seen in FIG. 3, which tabs are used as supports to secure an electric switch (not shown) in a permanent position within the interior 18 of the outlet box E.
The first form of the invention A-1 as best seen in FIGS. 2 to 5 inclusive includes a rigid, non-magnetic connector block G. Connector block G as shown in FIG. 2 includes a rearwardly disposed plate 20 that has a pair of laterally spaced projections 22 extending forwardly therefrom, with pairs of first and second elongate parallel openings 22a and 22b extending downwardly through the projections as best seen in FIG. 3. A center space 26 is provided between the pair of projections 22 as may best be seen in FIG. 2.
First and second grippers 28 and 40 are operatively associated with the connector block G as may be seen in FIGS. 3, 4 and 5. The first gripper 28 includes a first generally rectangular body 30 that has a flat upper end surface 30a. A pair of laterally spaced, parallel, first legs 32 extend downwardly from body 30 and are slidably disposed in the first pair of openings 22a as shown in FIG. 2. Plate 20 has an elongate transverse stop 24 extending forwardly from substantially the center thereof. The first pair of legs 32 have lips 34 on the lower ends thereof that contact the stop 24 when the legs move upwardly to their maximum upper position as shown in FIG. 5. A transverse rib 38 extends upwardly from the forward edge of first body 30 as shown in FIG. 4.
The second gripper 40 is identical to the first gripper 28. Second gripper 40 includes a second body 42 that has a pair of laterally spaced parallel legs 44 projecting therefrom that are slidably mounted in the second pair of openings 24a. The second pair of legs 44 has a second pair of lips 46 exending outwardly from the upper ends thereof that contact stop 24 when the second pair of legs are in their downwardmost position as shown in FIG. 5. A transverse rib 50 projects outwardly from the end surface 42a of second body 42 as best seen in FIG. 5. The first and second bodies 28 and 42 have openings 36 and 48 therein of greater size than the tabs 14a and 16a as may be seen in FIG. 3.
A non-metallic wall 52 spans the space 26 as may be seen in FIG. 2, which wall has a transverse opening 54 therein in which a prong 56 is slidably mounted. The prong 56 has a forward pointed end 56a. A body 58 of soft iron or other magnetically attractable material is mounted on prong 56 adjacent the pointed end 56a as may be seen in FIG. 2.
First and second compressed helical springs 64 and 66 are provided that extend away from one another as shown in FIG. 3, which springs abut against the first and second bodies 30 and 42 and at all times tend to move them in opposite directions to the positions shown in FIG. 5. The first and second springs 64 and 66 are secured to upper and lower end portions of wall 52 by conventional means (not shown).
When the first and second grippers 28 and 40 are manually moved inwardly to a minimum distance from one another the first form of the invention A-1 may be inserted into the interior of outlet box E, and the first and second springs 64 and 66 allowed to expand to force the first and second grippers into pressure frictional contact with the interior surfaces of the outlet box end walls 14 and 16 to removably hold the first form of invention A-1 in the outlet box. The sheet of wall board D is now temporarily disposed adjacent the framing F in the position it will occupy permanently when secured to the framing. A powerful permanent or electro magnet H as shown in FIG. 6 is now moved over the exterior surface of the wall board sheet D adjacent the outlet box E. Magnet H due to attracting the body 58 results in the prong 56 being drawn forwardly with the end 56a registering an identation or mark 68 on the rearward surface of wall board sheet D, which mark will indicate on the wall board sheet the center of the interior of the outlet box E. The wall board sheet D is now removed, and the first form A-1 of the invention removed from the outlet box E for future use.
The cutter B is in the form of a rectangular box open on one side, and is of substantially the same or slightly less than the transverse area of the interior of outlet box E. Cutter B includes a rectangular back wall 70 that has a heavy rigid metallic strap 72 secured to the exterior surface thereof. A pair of side walls 74 and pair of end walls 76 project outwardly from back 70 in a direction away from strap 72, with the side walls and end walls 74 and 76 on the free edges thereof being ground to define spaced knife edges 74a and 76a as may be seen in FIG. 7.
A centered prong 78 extends forwardly from back 70. A pair of prongs 80 are situated on opposite sides of prong 78 and also extend forwardly from the back 70, to which the prongs 78 and 80 are secured by conventional means.
The wall board sheet D is now abutted against a supporting structure (not shown) and the prong 78 aligned with the registry indentation 68. The strap 72 is now struck a sharp blow with a hammer (not shown) that causes the prongs 78 and 80 to pass completely through the wall board sheet D as shown in FIG. 8 and the knife edge 74a and 76a to partially sever the same. The cutter B is now withdrawn from the wall board sheet D and the same operation performed on the opposite side thereof, with the prongs 78 and 80 being inserted in the transverse openings 82 previously made in the wall board. The transverse openings 82 serve as guides for the second operation. After the first and second operations have been completed the portion D' of the wall board with the cut portions as shown in FIG. 8 may be knocked out to provide the opening C. The wall board sheet D may now be permanently secured to the framing F with the assurance that the opening C will be transversely aligned with the interior of the outlet box E.
The first form A-1 of the invention may be used with a double electrical outlet box E-1, for such boxes concurrently in use include laterally spaced tabs 82 between which the invention A-1 may be disposed. The first form A-1 of the invention produces a registered identation 68 that is the center of the double outlet box E-1.
A third form A-3 of the invention is illustrated in FIGS. 13 and 14 that is similar to first form A-1. Elements common to the first form A-1 of the invention in third form A-3 are identified by the numerals and letters previously used but with primes added thereto. In the third form A-3 of the invention it will be seen that the iron body 58 and magnet H have been eliminated. The prong 56' in the third form A-3 of the invention extends rearwardly through a transverse opening 124 in plate 20' to terminate in a handle. The forward portion of prong 56' extends through a transverse opening 128 in a trigger 130 that is pivotally supported by conventional means from one of the projections 22, and is at all times urged to the angular position shown in FIG. 13. The trigger 130 has a forwardly disposed extension 132 that projects beyond the forward face of block G. The trigger 130 when in the angular position shown in FIG. 14 frictionally binds on the prong 56', and prevents the compressed helical spring 62' moving the prong forwardly. When the third form of the invention A-3 is mounted in an outlet box E, and a sheet of wall board D moved adjacent framing F, the trigger 130 is pivoted inwardly allowing the prong 56' to be driven forwardly to register an indentation 68 on the wall board sheet D to indicate the center of electrical outlet box E. The sheet of wall board E is now moved from the framing F, and the cutter B is employed to form opening C using the identation 68 as a guide in the same manner as previously described in connection with the first form A-1 of the invention.
The use and operation of the inventions have been described previously in detail and need not be repeated. | An assembly for determining the center of a stud or joint supported electrical outlet box on a sheet of dry wall prior to the latter being permanently secured to the studs or joints, and for forming an opening in the dry wall as a result of the determination that will be transversely aligned with the interior of the outlet box when the sheet of drywall is permanently secured to the framing supporting the outlet box. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 62/050,704, “Dynamic Bleeder Current Control For LED Dimmer,” filed Sep. 15, 2014, which is incorporated herein by reference in its entirety.
BACKGROUND
1. Technical Field
The present disclosure relates to driving LED (Light-Emitting Diode) lamps and, more specifically, to adaptively dimming the LED lamps.
2. Description of the Related Arts
A wide variety of electronics applications now use LED lamps. These applications include architectural lighting, automotive head and tail lights, backlights for liquid crystal display devices, flashlights, and electronic signs. LED lamps have significant advantages compared to conventional lighting sources, such as incandescent lamps and fluorescent lamps. These advantages include high efficiency, good directionality, color stability, high reliability, long life time, small size, and environmental safety. Accordingly, LED lamps have replaced conventional lighting sources in many applications. For example, LED lamps are often used in applications where the brightness of the light source is adjusted, such as in a dimmable lighting system.
Dimmable lighting systems often use phase cut dimmer switches that employ a triac device to regulate the power delivered to a lamp by conducting during a certain period of an AC voltage supplied to the triac. To maintain the triac in the conducting state, a minimum holding current needs to be supplied to the triac. However, because LED lamp loads vary widely, triac devices may be unable to operate reliably. Furthermore, the minimum holding current varies widely among triac devices, which may further complicate the design of LED-based dimmable lighting systems. When the current through the triac device is less than a minimum holding current threshold, the triac device resets and pre-maturely turns off. As a result, LED lamps may prematurely turn off when they should be on, which may result in a perceivable light flicker or complete failure in the LED lamp.
SUMMARY
LED lamp systems as described herein include a dimmer switch and a bleeder circuit. The bleeder circuit provides a bleeder current to prevent the dimmer switch from turning off prematurely. Triac dimmers usually require about 100-200 mA to be turned on during a triggering operating mode. When triggered, triac dimmers enter into a triac conducting operating mode, where a triac dimmer continues to conduct until the current through the triac dimmer drops below a threshold current level (e.g., 5-20 mA). During the conducting operating mode, a triac dimmer may turn off when the current through the triac dimmer drops below the threshold current level, resulting in a perceivable flicker in the LED lamp. The bleeder circuit may monitor the AC input voltage outputted by the dimmer switch. When the AC input voltage is less than a first threshold, the bleeder circuit provides a bleeder current. When the AC input voltage is greater than a second threshold, the bleeder circuit adjusts the bleeder current to less than a predetermined level.
The features and advantages described in the specification are not all inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings and specification. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
The teachings of the present disclosure can be readily understood by considering the following detailed description in conjunction with the accompanying drawings.
FIG. 1 is a circuit diagram illustrating an LED lamp system, according to one embodiment.
FIG. 2 is a circuit diagram illustrating an LED lamp system, according to one embodiment.
FIG. 3A illustrates example voltage waveforms of the LED lamp system of FIG. 2 , according to one embodiment.
FIG. 3B illustrates an example control signal waveform of the LED lamp system of FIG. 2 , according to one embodiment.
FIG. 3C illustrates an example bleeder circuit control signal waveform of the LED lamp system of FIG. 2 , according to one embodiment.
FIG. 4A illustrates example voltage waveforms of the LED lamp system of FIG. 2 , according to another embodiment.
FIG. 4B illustrates an example control signal waveform of the LED lamp system of FIG. 2 , according to another embodiment.
FIG. 4C illustrates example bleeder current waveforms of the LED lamp system of FIG. 2 , according to another embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
The Figures (FIG.) and the following description relate to embodiments of the present disclosure by way of illustration only. It should be noted that from the following discussion, alternative embodiments of the structures and methods disclosed herein will be readily recognized as viable alternatives that may be employed without departing from the principles of the present disclosure.
Reference will now be made in detail to several embodiments of the present disclosure, examples of which are illustrated in the accompanying figures. It is noted that wherever practicable similar or like reference numbers may be used in the figures and may indicate similar or like functionality. The figures depict embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the embodiments of the disclosure described herein.
FIG. 1 is a circuit diagram illustrating an LED lamp system 100 comprising an alternating current (AC) mains 114 , a dimmer switch 104 , and an LED lamp circuit 102 . The AC mains 114 provides an AC voltage 122 to the LED lamp circuit 102 . The dimmer switch 104 is coupled in series with the AC mains 114 and the LED lamp circuit 102 including an LED string 112 . The LED string 112 includes one or more LEDs. The dimmer switch 104 controls the amount (i.e., intensity) of light output by the LED string 112 by phase modulating the AC mains 114 to provide a regulated AC input voltage to the LED lamp circuit 102 . In one embodiment, the dimmer switch 104 is a phase cut dimmer including a triac device (not shown). A triac device included in the dimmer switch 104 is a bidirectional device that can conduct current in either direction when it is turned on (or triggered). One example of a dimmer switch that includes a triac device is described in U.S. Pat. No. 7,936,132. When the dimmer switch 104 including a triac device is turned on, the dimmer switch 104 continues to conduct until the current through the dimmer switch 104 and the LED string 112 drops below a holding current threshold.
The dimmer switch 104 determines the amount of adjustment applied to AC voltage 122 provided by the AC mains 114 based on the value of a dimming input signal 116 applied to the dimmer switch 104 . That is, the AC input voltage outputted by the dimmer switch is generated based on the value of the dimming input signal 116 . In some implementations, the dimming input signal 116 is an analog signal produced by a knob, slider switch, or other suitable electrical or mechanical device capable of providing an adjustment signal with a variable range of adjustment settings. In other implementations, the dimming input signal 116 is a digital signal. The dimmer switch 104 outputs an AC input voltage 118 to the LED lamp circuit 102 . The LED lamp circuit 102 adjusts the light output intensity of the LED string 112 substantially proportionally to the received AC input voltage 118 , exhibiting behavior similar to incandescent lamps. The LED lamp circuit 102 controls the current through the LED string 112 in a regulated manner that provides a smooth transition in light intensity level output of the LED lamp circuit 102 responsive to the dimming input signal 116 without perceivable flicker.
The LED lamp circuit 102 comprises a rectifier circuit 106 , a bleeder circuit 108 , a driver circuit 110 , and the LED string 112 . The rectifier circuit 106 receives the AC input voltage 118 and outputs a rectified voltage 120 corresponding to the AC input voltage 118 . The dimming level of the LED string 112 may be adjusted such that the current through the LED string 112 is below the holding current threshold of the triac device of the dimmer switch 104 . In such case, the bleeder circuit 108 ensures the triac device of the dimmer switch 104 to remain conducting while the LED string 112 can be adjusted within a dimming setting. The bleeder circuit 108 turns on to provide a bleeder current when the AC input voltage 118 is below a first threshold voltage. As such, the bleeder circuit 108 provides a current path across the output of the rectifier circuit 106 . The bleeder current provided by the bleeder circuit 108 discharges an input capacitor and provides a low impedance current path to ensure the triac device of the dimmer switch 104 to function properly. The internal timer of the triac device of the dimmer switch 104 can reset properly and charge up at the same time, which prevents dimmer phase jitter from cycle to cycle. In some embodiments, the bleeder circuit 108 provides bleeder current at different levels to reduce thermal loss and to increase the over-all system efficiency. When the AC input voltage 118 exceeds a second threshold voltage, the bleeder circuit 108 reduces the bleeder current. The second threshold voltage is greater than the first threshold voltage. Details of the bleeder circuit 108 will be further described with reference to FIG. 2 . The driver circuit 110 provides a driving current to the LED string 112 . The driver circuit 110 switches on and off thereby to regulate the driving current through the LED string 112 according to a duty cycle determined based on the rectified voltage 120 .
FIG. 2 is a circuit diagram illustrating an LED lamp system 100 including a dimmer switch 104 used in conjunction with an LED lamp circuit 102 . The LED lamp circuit 102 controls dimming of the LED string 112 to achieve the desired dimming based on the dimming input signal 116 . The LED lamp circuit 102 adaptively controls dimming in a manner that reduces or eliminates perceivable flickering of the LED string 112 throughout the dimming range, and causes the LED string 112 brightness to respond quickly and smoothly when the dimmer switch 104 is adjusted. In the illustrated example, the rectifier circuit 106 comprises a diode bridge 202 and a capacitor 204 . The rectifier circuit 106 provides a rectified voltage 120 , which is an unregulated direct current (DC) voltage to the bleeder circuit 108 . The capacitor 204 is coupled in parallel to the output of the diode bridge 202 . The diode bridge 202 generates a rectified voltage 120 based on the AC input voltage 118 outputted by the dimmer switch 104 based on the dimming input signal 116 . The rectified voltage 120 is provided to the capacitor 204 .
The bleeder circuit 108 comprises a bleeder circuit controller 206 , a bleeder current switch 208 , and a resistor 210 . The bleeder circuit controller 206 regulates the bleeder current switch 208 to provide a bleeder current path across the output of the rectifier circuit 106 when the AC input voltage 118 outputted by the dimmer switch 104 is below a first threshold voltage. The bleeder circuit controller 206 monitors the AC input voltage 118 , detects characteristics of the AC input voltage 118 , and determines when the AC input voltage 118 reaches the first threshold voltage indicating that the AC input voltage 118 is at or near 0 volts (i.e., a zero crossing voltage). The bleeder circuit controller 206 may use one or a combination of digital or analog circuit techniques. In one implementation, the bleeder circuit controller 206 includes a digital sampling circuit (not shown) and a comparator (not shown). The digital sampling circuit samples the AC input voltage 118 at a specified interval or over a specified period of time. The samples are provided to the comparator that compares the value of a specified number of samples to detect whether the AC input voltage 118 is at or near the zero crossing voltage.
When the bleeder circuit controller 206 determines that the AC input voltage 118 is at or near the zero crossing voltage, i.e., below the first threshold voltage, the bleeder circuit controller 206 generates a control signal 242 to enable the bleeder circuit 108 by turning on the bleeder current switch 208 thereby to provide a path for the bleeder current through the resistor 210 across the output of the rectifier circuit 106 . The bleeder current switch 208 may be a semiconductor power switch such as a metal oxide field effect transistor (MOSFET) as illustrated, a bipolar junction transistor (BJT), and the alike. As illustrated, the source of the bleeder current switch 208 may be coupled to a terminal of the output of the rectifier circuit 106 , a drain may be coupled to the other terminal of the output of the rectifier circuit 106 via the resistor 210 , and a gate is coupled to the output of the bleeder circuit controller 206 . By determining when the AC input voltage 118 zero crossing occurs, the bleeder circuit controller 206 avoids enabling the bleeder circuit 108 during high dissipative periods and enables the bleeder circuit 108 when the triac of the dimmer switch 104 is in the OFF state. That is, when the AC mains 114 is disconnected from the dimmer switch 104 .
The bleeder circuit 108 provides a current path across the output of the rectifier 106 during specified time periods to provide a low impedance current path to ensure the triac device of the dimmer switch 104 operates properly, such as stabilizing the dimmer phase. For example, the bleeder circuit 108 detects when the rectified voltage 120 outputted by the rectifier circuit 106 is at or below a first threshold value during each half cycle of the AC input voltage 118 , at which point it enables the bleeder circuit 108 to provide a bleeder current having a value sufficient to discharge the capacitor 210 . The bleeder circuit 108 may provide a bleeder current at different levels to ensure the triac device of the dimmer switch 104 operates properly and to reduce the thermal loss. For example, a bleeder circuit 108 may provide a high bleeder current at around 250 mA to 300 mA and a low bleeder current at around a half or a quarter of the high current level. While the dimmer switch 104 operates in the conducting state, the bleeder circuit 108 may regulate the amount of the bleeder current supplied to the dimmer switch 104 to ensure the dimmer switch remains in the conducting state. Such a regulation scheme avoids enabling the bleeder circuit 108 when the amount of energy stored in the capacitor 204 in the rectifier circuit 106 is at the maximum during each half cycle of the AC input voltage 118 . This increases the overall system efficiency while ensuring the proper operation of the dimmer switch 104 because the bleeder circuit 108 is disabled during high dissipative operating periods, such as when the power stage is operating in output regulation mode.
The bleeder circuit 108 accurately detects the correct timing of the AC input voltage 118 to determine the bleeder current control and avoids enabling the bleeder circuit 108 when the amount of energy stored in the bulk capacitor 204 is at the maximum during each half cycle of the AC input voltage 118 . This increases the overall efficiency of the LED lamp system 100 while ensuring the proper operation of the dimmer switch 104 .
The bleeder circuit controller 206 reduces the bleeder current when the AC input voltage 118 is above a second threshold value during each half cycle of the AC input voltage 118 . In one implementation, the bleeder circuit controller 206 disables the bleeder circuit 108 when the AC input voltage 118 is above a second threshold value. That is, when the driver circuit 110 operates, the bleeder circuit 108 is disabled and the bleeder current is reduced to zero. The bleeder circuit controller 206 may receive from the power stage controller 216 , a signal 240 indicating whether the switching cycles of the driver circuit 110 have been enabled. The bleeder circuit controller 206 disables the bleeder circuit 108 by switching off the bleeder current switch 208 when the driver circuit 110 has been enabled.
In one embodiment, the bleeder circuit 108 provides different levels of bleeder current. For example, during periods when the driver circuit 110 is disabled, the bleeder circuit 108 may provide different levels of bleeder current to properly manage voltage and to reduce thermal loss. As another example, during periods when the driver circuit 110 is enabled, the current through the LED string 112 may still be below the holding current of the dimmer switch 104 . The bleeder circuit 108 may provide a bleeder current to ensure the dimmer switch 104 remains conducting while the driver circuit 110 is enabled. In one implementation, the power stage controller 216 determines whether the regulation threshold is met by determining whether the energy being delivered to the output stage 214 is sufficient to maintain the proper output regulation of the LED string 112 . The power stage controller 216 may measure the current loading of the dimmer switch 104 and compare the measured current to the holding current threshold or a range of threshold values. The regulation threshold value may be specified or dynamically adjusted based on the loading characteristics of the dimmer switch 104 and the LED string 112 . When the bleeder circuit 108 determines that the driver circuit 110 is not operating, and based on an indication to maintain the output regulation, for example, provided by the power stage controller 216 , the bleeder circuit 108 returns to the operating mode as previously described. The power stage controller 216 may generate the indication to maintain the output regulation in response to determining the regulation threshold is not met.
The driver circuit 110 provides a driving current to the LED string 112 . The driver circuit 110 comprises a power stage 212 and an output stage 214 . The power stage 212 regulates the amount of energy provided to the output stage 214 , and the output stage 214 supplies the driving current to the LED string 112 . The power stage 212 includes a power stage controller 216 , a power stage switch 218 , and an inductor 220 . The power stage controller 216 may detect the AC input voltage 118 outputted by the dimmer switch 104 and output a control signal 242 to activate or deactivate the power stage switch 218 . For example, in one implementation, the power stage controller 216 may comprise an input coupled to the output of the dimmer switch 104 and measure the AC input voltage 118 outputted by the dimmer switch 104 . When the measured AC input voltage 118 meets a specified threshold voltage level or range, the triac included in the dimmer switch 104 transitions into a conducting state during each half cycle of the AC input voltage 118 . The power stage controller 216 regulates the driving current provided to the LED string 112 by controlling the duty cycle of the power stage switch 218 . The power stage controller 216 generates a control signal 242 in a first state (e.g., ON) to activate the power stage switch 218 based on a determination that the measured AC input meets or exceeds the specified threshold value or range. When the AC input voltage 118 is at the threshold value during each half cycle of the AC voltage 122 of the AC mains 114 , the power stage controller 216 generates a control signal 242 that transitions from the first state (e.g., ON) to a second state (e.g., OFF) to maintain output regulation. On the other hand, when the power stage controller 216 determines that the measured AC input voltage 118 is greater than a threshold indicating that the amount of energy being delivered to the output stage 214 is sufficient to maintain proper output regulation, the power stage controller 216 generates a control signal 242 in the second state (e.g., OFF) to deactivate the power stage switch 218 . The power stage switch 218 may be a semiconductor power switch such as a MOSFET as illustrated, a BJT, and the alike.
The output stage 214 comprises a rectifier diode 222 and an output capacitor 224 . The anode of the rectifier diode 222 is coupled to the drain of the power stage switch 218 and the cathode of the rectifier diode 222 is coupled to the positive terminal of the output capacitor 224 . The rectifier diode 222 ensures the current through the LED string 112 flows from the anode of the LED string 112 to the cathode of the LED string 112 . The capacitor 224 is connected in parallel with the LED string 112 , where the anode of the LED string 112 is connected to the positive terminal of the output capacitor 224 and the cathode of the LED string 112 is connected to the negative terminal of the output capacitor 224 . The capacitor 224 maintains the voltage across the LED string 112 is substantially constant. The rectifier diode 222 and the capacitor 224 together ensure reliable operation of the LED string 112 .
FIGS. 3A through 3C illustrate example waveforms of the LED lamp system 100 of FIG. 2 . FIG. 3A shows voltage waveforms of the LED lamp system 100 of FIG. 2 . Waveform 302 is the AC input voltage 118 outputted by the dimmer switch 104 and waveform 304 is the AC voltage 122 supplied by the AC mains 114 . Waveform 304 (dotted line) is superimposed on the waveform 302 . As illustrated, the AC input voltage 118 includes a first portion 302 a where the AC input voltage 118 is zero and a second portion 302 b where the AC input voltage 118 is non-zero. The first portion and the second portion alternate. FIG. 3B illustrates an example waveform representing a control signal 242 generated by the power stage controller 216 of the LED lamp system 100 of FIG. 2 . As shown in FIG. 3B , the power stage controller 216 generates a control signal 242 when the AC input voltage 118 meets or exceeds the specified threshold value V TH1 or range at time t 1 . The control signal 242 cycles between ON and OFF states to switch on and off the power stage switch 218 . The power stage controller 216 continues to generate a control signal 242 that cycles between ON and OFF states until a regulation threshold (i.e., whether the energy being delivered to the output stage 214 is sufficient to maintain the proper output regulation of the LED string 112 ) is met as previously described with respect to FIG. 2 .
FIG. 3C illustrates an example waveform representing a control signal 242 generated by the bleeder circuit controller 206 of the LED lamp system 100 of FIG. 2 . As shown in FIG. 3C , the bleeder circuit controller 206 monitors the waveform 302 of the AC input voltage 118 and enables the bleeder circuit 108 when the AC input voltage 118 is less than the threshold value V TH1 . As illustrated, during the period (t 0 -t 1 ) corresponding to the first portion 302 a of the AC input voltage 118 , the voltage level of the AC input voltage 118 is less than the first threshold value V TH1 and the bleeder circuit 108 is enabled to provide a bleeder current. The bleeder circuit controller 206 disables the bleeder circuit 108 , at time t 1 , when the voltage level of the AC input voltage 118 is greater than the threshold value V TH2 . As illustrated, during the period (t 1 -t 3 ) corresponding to the second portion 302 b of the AC input voltage 118 when the voltage level of the AC input voltage 118 is non-zero, the bleeder circuit 108 is disabled. The bleeder circuit 108 is not enabled during high dissipative periods. As illustrated, the bleeder circuit 108 is disabled even during the period (t 2 -t 3 ) when the switching of the power stage switch 218 is disabled, and enabled at or near the zero crossing voltage of the AC input voltage 118 when the dimmer switch 104 is turned off and the AC mains 114 is disconnected from the rectifier circuit 106 .
FIGS. 4A-4C illustrate example waveforms of the LED lamp system 100 of FIG. 2 according to another embodiment. FIGS. 4A and 4B are equivalent to FIGS. 3A and 3B , respectively. As illustrated, the AC input voltage 118 includes a first portion 402 a where the AC input voltage 118 is zero and a second portion 402 b where the AC input voltage 118 is non-zero. The first portion and the second portion alternate. FIG. 4C illustrates an example bleeder current waveform provided by the bleeder circuit 108 of the LED lamp system 100 of FIG. 2 . As shown in FIG. 4C , the bleeder circuit generates a bleeder current having different output levels. During the period (t 0 -t 1 ) corresponding to the first portion 402 a of the AC input voltage 118 , the voltage level of the AC input voltage 118 is less than the first threshold value V TH1 and the bleeder circuit is enabled to provide a bleeder current to discharge the capacitor included in the rectifier circuit. The driver circuit 110 is enabled, at time t 1 , when the voltage level of the AC input voltage 118 is greater than the threshold value V TH2 . During the period (t 1 -t 3 ) corresponding to the second portion 402 b of the AC input voltage 118 when the voltage level of the AC input voltage 118 is non-zero, the bleeder current is reduced. For example, as illustrated, during the time period (t 1 -t 2 ), the bleeder current circuit 110 generates a bleeder current at a low level to ensure the triac included in the dimmer switch 104 remains in the conducting state while the power stage 212 switching cycles are enabled. The low level of the bleeder current is set based on the holding current threshold of the dimmer switch 104 and the driving current through the LED string 112 . During the time period (t 2 -t 3 ), the bleeder current is reduced to approximately 0 A and the driver circuit 110 disables the switching cycles.
Upon reading this disclosure, those of skill in the art will appreciate still additional alternative designs for controlling dimming of an LED lamp using an adaptive bleeder current control. Thus, while particular embodiments and applications of the present disclosure have been illustrated and described, it is to be understood that the disclosure is not limited to the precise construction and components disclosed herein and that various modifications, changes and variations which will be apparent to those skilled in the art may be made in the arrangement, operation and details of the method and apparatus of the present disclosure disclosed herein without departing from the spirit and scope of the disclosure. | LED lamp systems as described herein include a dimmer switch and a bleeder circuit. The bleeder circuit provides a bleeder current to management voltage and to prevent the dimmer switch from turning off prematurely. The bleeder circuit may monitor the AC input voltage outputted by the dimmer switch. When the AC input voltage is less than a first threshold, the bleeder circuit provides a bleeder current. When the AC input voltage is greater than a second threshold, the bleeder circuit adjusts the bleeder current to less than a predetermined level. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to lost wax casting of thin walled hollow objects, especially metal golf club heads, more particularly to the molding process for creating the wax pattern of the club head to be cast, and even more particularly to a core for; a wax mold that can be readily stripped from the mold without first removing the wax pattern therefrom.
Many golf clubs, in particular the metal woods, have hollow metal heads with precisely formed thin walls to provide advantages in striking a golf ball. Typically such heads are made by lost wax casting. Precision is required in the casting process in order to ensure that precise dimensions are maintained so that the final product incorporates the advantages which may be achieved from the thin walled head. Such thin walls have created difficulties in the casting process due, at least in part, to the need to provide a core to create the hollow wax pattern, which core must be stripped from the wax pattern before use. The typical prior art process required a skilled operator to open the wax pattern mold and remove the core from the wax pattern by hand. Such hand stripping of the core often causes deformation or other damage to the wax pattern, which jeopardizes the precision of the casting.
A wax pattern molding process using a stripable core which attempts to address some of these difficulties with the prior art is described in U.S. Pat. Nos. 5,204,046, 5,417,559 and 5,547,630. In these patents, a molding process is described in which a core made of multiple pieces, held together by T-shaped sliding interconnections, is wedged within a double door mold. One door of the mold creates at least part-of the mold cavity and the second door has a wedge which forces the core in place within the cavity. While addressing certain difficulties with stripping of the mold, this solution is not ideal. In particular, the wedging action which holds the core in place does not necessarily guarantee the precise positioning of the core due to inconsistencies as a result of force application being dependent on the degree of mold closure in such a wedging arrangement. Also the double door configuration adds complication to the mold. There thus remains a need in the art for an easily stripable mold which locates the core with precision.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a wax pattern mold with a stripable core that permits greater control over dimensional integrity of the walls of hollow thin walled objects to be molded.
This and other objects are achieved according to the present invention by a mold which comprises a mold body and a mold core. The mold body is made up of at least two mating parts together defining a cavity configured and dimensioned to define the outside of the hollow object to be molded, preferably the wax pattern of a metal wood golf club head. The mold parts also define a channel for delivering molten wax to the cavity and an opening configured and dimensioned to receive the mold core therethrough and extending into the cavity. The mold parts are separable to remove the molded object. In a preferred embodiment, the mold body parts are two halves hinged together for opening and closing.
The mold core has an upper portion configured and dimensioned to define the inside of the hollow object to be molded and a stem portion configured and dimensioned to be received in the mold body opening and mate with the mold body parts. The core is made up of a plurality of interfitted parts configured and dimensioned to be sequentially removable through the mold body opening without opening the mold halves. Also part of the invention are means for registering the position of the mold core in the mold cavity, and means for locking the core parts together.
According to one embodiment of the invention, the registering means comprises at least one registration member extending out from the core stem and at one least recess defined in the mold body around the mold body opening to receive the registration member in close fitting, positive engagement. In various alternative embodiments the registration member is a ridge formed at least partly around the core stem, at least one pin extending out from the core stem or a key extending out from the core stem wherein the recess receiving the registration member is a keyway.
In another alternative embodiment the registering means comprises at least one registration member extending out from the mold body around the mold body opening and at least one recess defined in the core stem to once again receive the registration member in close fitting, positive engagement. The same alternatives are again possible, in opposite relationship.
According to a further aspect of the invention, locking means comprises an extendable locking finger mounted on one core part and a slot for receiving the finger defined in a mating core part. In an alternative embodiment, locking means may comprise a locking member and at least one slot for receiving the locking member, wherein the slot is formed in one of the mold parts and the locking member bears against the core to lock the core in position when received in the slot. According to this alternative, the locking member may comprise an extendable locking finger disposed on an outer surface of the core, the finger being extendable from the core to be received in the slot, or a locking gate, slidably received over the core in two opposed slots defining in the mold parts. In further alternative embodiments, the locking means may comprise dowels inserted through close-fitting holes in the core stem portion to lock the parts together, either through the mold body or outside the mold body, or a locking gate carried in grooves in the mold body that bears against the mold stem portion.
The core according to the invention also may comprise a base plate with one of the plurality of core parts fixed thereto and a plurality of upstanding pins also fixed to the base plate. In this embodiment the other core parts have holes defined in them to receive the pins such that the parts may be removably assembled over the pins.
A further aspect of the invention is a method for forming a wax pattern of a hollow, thin walled object, such a golf club head, including the following steps: providing a wax pattern mold made up of at least two parts together defining a cavity configured and dimensioned to form the outside of the wax pattern, placing in the mold cavity a core configured and dimensioned form the hollow inside of the wax pattern wherein said core is comprised of multiple core parts, said placing including registering the core with the mold cavity to ensure dimensional integrity of the thin walls of the object, closing the mold parts together, locking the multiple core parts together in a step separate from said placing step, flowing molten wax into the mold cavity, permitting the wax to harden to form the thin walled wax pattern, removing the core while maintaining mold parts closed, opening the mold parts, and removing the wax pattern.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will be more readily apparent from the following detailed description illustrated in the drawing figures, wherein:
FIG. 1 is a perspective view of a closed wax pattern mold according to the present invention with the core in place;
FIG. 2 is an enlarged side view of one embodiment of stripable core according to the present invention;
FIG. 3 is a top side view of the core of FIG. 2;
FIG. 4 is a plan view of an open mold according to an embodiment of the invention, with the core in place;
FIG. 5 is a partial perspective view of a portion of an open mold and core according to an alternative embodiment of the invention;
FIG. 6 is an exploded view of one embodiment of a core according to the present invention;
FIGS. 7-12 are partial perspective views, sequentially illustrating stripping of the core according to an embodiment of the present invention;
FIG. 13 is a side view of an alternative core according to the present invention;
FIG. 14 is a plan view of a core having an alternative locking means shown in hidden lines;
FIG. 15 is a perspective view of an alternative mold according to a further embodiment of the present invention;
FIG. 16 is a perspective view of the mold shown in FIG. 13 with the locking gate removed;
FIG. 17 is an exploded perspective of an alternative core and locking means according to the invention;
FIG. 18 is a partial perspective view of a closed mold using the core and locking means shown in FIG. 17; and
FIG. 19 is a partial perspective view of a closed mold according to another alternative embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, wax pattern mold 10 for forming the wax pattern of a metal wood is shown with core 20 in place. The mold is preferably made of two mold halves 12 , 14 (although any number of mold parts may be used), held together at one side by hinge 16 . Shown outside the mold is hosel pin 18 , which forms the core for the hosel portion of the wax pattern club head. Note that throughout the description and FIGS. numbers are repeated where they refer to similar parts.
Enlarged views of the core are shown in FIGS. 2 and 3. In this embodiment core 20 includes a plurality of core pieces 20 A-F, mounted on base plate 22 . In this case, six core pieces are shown by way of example, but any number may be used. Upper core portion 24 is shaped to match the hollow interior of the club head and, in combination with the mold cavity, provide the precise wall thickness for the thin club head walls. Core stem portion 26 is smaller in diameter, to match the opening in the sole of the club head (the opening through which the core is stripped) and is held between mold halves 12 , 14 to ensure precise positioning of the core. It is not required that the opening be through the sole. Alternatively, the opening may be provided through the face or the crown of the club head. The opening also may be provided in the heel of the club, but that may require that the core be made up of a higher number of pieces due to the heel having a smaller area than other club surfaces. Registration channel 28 extends at least partially around core stem portion 26 . Channel 28 cooperates with registration ring 46 (FIG. 4) to precisely locate the core with respect to the mold cavity, as explained in greater detail below. Rotatable handle 30 controls the internal locking finger 56 (see FIG.6) which holds the core together while in the mold.
Core 20 is shown in place in open mold 10 in FIG. 4 . As is generally known in the art, mold halves 12 and 14 provide wax flow channel 32 , cavity halves 34 , 36 for the club head and cavity halves 38 , 40 for the sole plate. Preferably the cavity halves may be lined with epoxy. At the bottom of each mold half is a recess that defines the mold core opening 44 (best seen, for example, in FIG. 11 ). Mold core opening 44 has registration ring 46 disposed therearound to mate with registration channel 28 in core stem portion 26 . Ring 46 does not extend across flat 48 in order to permit first core piece 20 A to be removed as described below. Ring 46 may be machined directly out of the metal mold halves or it may be a separate part (such as epoxy) inserted into a corresponding groove in the mold halves.
The interfitting of registration channel 28 and registration ring 46 provides a precise and positive location for core 20 within the mold cavity. In this manner the location cannot be accidentally varied and is not dependent upon a degree of wedging or other force applied between mating parts. Alternatives to the ring and channel may be used. For example, discontinuous ring segments or individual, short pins may be used. FIG. 5 illustrates the use of pin 43 received in hole 45 in core 20 to replace the registration ring and channel. A similar pin and hole on the opposite mold half and side of core 20 are not visible in the figure. Pins also may be employed in pairs. Various key and keyway constructions would also be suitable for positively guaranteeing proper registration as between the mold cavity and core. Whatever registration means is used in combination with the core pieces, it should permit a first piece to be removed when the core is stripped. For example, as shown in FIG. 14, a center core piece may be alternatively provided as the first piece to be removed.
Referring to FIG. 6, assembly and placement of the core will be described. Base plate 22 has a number of upstanding pins 52 which closely mate with holes 54 B-F in the bottom of core pieces 20 B-F. The fit between the pins and holes should be close enough so that the core pieces do not wobble when placed thereon, but also loose enough to allow easy placement and removal of the core pieces. Core piece 20 A is fixed to base plate 22 by screws or other suitable means. Handle 30 extends into core piece 20 A and cooperates with locking finger 56 . Locking finger 56 is disposed in slot 58 on the interior surface of core piece 20 A and rotates in and out when handle 30 is rotated in the corresponding in or out direction. A suitable geared, cammed, pin and slot or other mechanism may be provided for this purpose by a person skilled in the art. The interior surface of core piece 20 B, which mates with core piece 20 A, is provided with locking slot 60 to receive locking finger 56 . Other than slots 58 and 60 , the interior mating surfaces of the core pieces are preferably, but not necessarily, square and free of slots, grooves or ridges in order to provide a close and relatively seam free fit. To assemble core 20 , each core piece 20 B-F is placed over its corresponding pins 52 on base 22 with its interior surfaces mating with adjacent core pieces. Handle 30 is turned to cause locking finger 56 to engage locking slot 60 . The core thus assembled appears as shown, for example, in FIG. 2 . The assembled core 20 is then placed in the open mold as shown in FIG. 4 . Once placed in mold 10 , registration ring 46 engages registration channel 28 to ensure the proper location of the core within the mold cavity. The mold is then closed and the cavities are filled with wax via channel 32 as is known in the art.
Once the wax pattern has cooled to the desired degree, the core may be stripped, without opening the mold. In this manner, the dimensional integrity of the wax pattern is ensured. Handle 30 is rotated to move locking finger 56 into core piece 20 A and disengage it from core piece 20 B. Once this is done, core piece 20 A, including base plate 22 and handle 30 , may be removed from the mold, without opening the mold as shown in FIG. 7 . This can be accomplished because flat 48 (which provides a break in registration ring 46 ) mates against the outside of core piece 20 A, permitting its sliding removal once the locking finger is disengaged. Removal of core piece 20 A with base plate 22 also causes pins 52 to be removed from the other core pieces. With the pins removed, the other core pieces may be sequentially, laterally moved into the void left by core piece 20 A and then withdrawn through the opening in the sole plate of the club head as shown in FIGS. 8-12.
An alternative embodiment of the invention is shown in FIG. 13 . In this embodiment, core 20 ′ is provided with locking finger 56 on the outside of core piece 20 A′; which extends outward in the locking position, rather than locking internally as in the previous embodiment. Thus, locking slot 60 instead is provided in flat 48 on mold half 14 to receive the locking finger. This alternative is otherwise as described above in connection the embodiment of FIGS. 1-12.
Another alternative embodiment is illustrated in FIG. 14 . In this embodiment, core 20 ″ is provided with a double finger mechanism 56 A, 56 B. An additional, outer core piece 20 G is provided so that first core piece 20 A″ is a center piece. Finger 56 A extends from center core piece 20 A″ into slot 60 A in outer core piece 20 B″. Similarly, finger 56 B extends from center core piece 20 A″ outward, into slot 60 B in outer core piece 20 G. The double finger arrangement provides more secure holding and greater stability for the core. Also, because first core piece 20 A″ is a center piece, the registration channel and ring (or other registration means) may engage every outer core piece to provide further stability for the core and still permit the first core piece to be removed without opening the mold.
In a further alternative embodiment shown in FIGS. 15 and 16, mold 110 employs locking gate 164 instead of a locking finger and slot. Core 120 is assembled as explained above except for the lack of locking finger and slot. Registration ring 46 and channel 28 may be used to ensure proper registration of the core within the mold. However, in order lock the core pieces in the mold during the molding process, locking gate 164 is slid into locking grooves 166 on both mold halves 112 , 114 . Locking gate 164 abuts against base plate 22 of core 120 to prevent its movement. As shown in FIG. 16, recess 168 may be provided to receive base plate 22 and the extending part of core stem portion 26 . Once the wax pattern has suitably hardened, the locking gate is removed and the core may be stripped from the mold as described above.
An additional alternative embodiment is shown in FIGS. 17 and 18. In this embodiment the locking means comprises a double dowel arrangement rather than the lever arrangement previously described. Here, double dowel member 270 has two dowels 272 extending parallel from handle 274 . Alternatively, a single dowel may be used in the same manner. First core piece 220 A has two half-channels 276 which align mating half-channels 278 on core pieces 220 E and 220 F, respectively, when the core is assembled. The half channels may be lined with bushings 277 , such as brass or bronze if desired. Thus, when the core is assembled, holes are formed by the mated half-channels to receive dowels 272 and lock together the core pieces. As shown in FIG. 17, it is preferred that the half-channels are also formed in mating relationship in core pieces 220 D, 220 B and 220 C so that dowels 272 may directly lock all core pieces. Pins 52 (not shown) are used as previously described to hold together the core pieces in a lateral direction. The pins may be mounted in base plate 22 or passed through appropriately sized holes in the base plate. Also as shown in FIG. 17, the registration means comprises channel 28 . Alternative registration means such as keys, pins, etc. previously described, may be used.
FIG. 18 shows the assembled mold 10 using alternative core 220 . Core 220 , when employing channel 28 , may be used with mold halves 12 and 14 , previously described. In an alternative preferred embodiment core 220 is provided with hole 45 , as shown in FIG. 5, so that pin 43 may be used as registration means. Once again, a person of ordinary skill in the art will appreciate that the core pieces must be configured in cooperation with the registration means to permit removal of the first piece without opening the mold. For example, a first center piece as in FIG. 14 may be preferable with the pin arrangement shown in FIG. 5 .
FIG. 19 illustrates yet another alternative embodiment. In this embodiment, upper half 312 of mold 310 is provided with dished area 380 to permit double dowel member 270 as previously described to be passed through lined holes 376 and into core 320 . By passing dowels 272 through upper mold half 312 , greater security of the core parts may be achieved. Core 320 is otherwise formed in a similar configuration to core 220 , previously described. With core 320 only a single registration pin 43 and hole 45 is required between the core and lower mold half 314 .
As will be apparent to persons of ordinary skill in the art, various modifications and adaptions of the structure and method above described will be possible without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims. For example, a person of skill in the art may elect to provide a suitable taper to selected interfitting parts such as various pins or dowels to facilitate sliding fits and compensate for machining tolerances without departing from the scope of the invention. | A wax pattern mold and molding process are disclosed for forming a wax pattern of a hollow, thin walled object, in particular, a golf club head. A mold is provided in at least two halves defining a mold cavity. A core made up of a plurality of interfitted parts is placed in the mold to precisely define the thin walls. The core and mold are provided with a registration channel such that the core is properly registered in the cavity to ensure dimensional integrity of the thin walls. Pins, holes, slots, and fingers are provided to lock the core parts together while the wax pattern is formed and to permit the core parts to be disassembled through an opening in the mold without separating the mold halves. | 8 |
FIELD OF THE INVENTION
The present invention relates generally to the field of automotive seats and more particularly to a seat release mechanism having an anti-rattle torsion spring and cross bar.
BACKGROUND OF THE INVENTION
Seat release mechanisms for reclining the back portion of an automotive seat assembly, or for rotating or removing the automobile seat structure from the automobile floor pan are well known. An activator such as a lever or knob is located on the outside portion of the seat and is operatively connected to a release mechanism on both sides of the seat. The two release mechanisms are attached by a cable mechanism or a cross member that translates the movement of the activator from one side of the seat to the other. As a result of design clearances between the cross bar and associated components attaching the cross bar to the first and second release mechanisms there is a certain amount of play or clearance in the system. While, the clearance allows for ease of assembly, the clearance in the system also may permit the cross bar to vibrate or rattle in response to movement of the automobile. Accordingly, it would be desirable for a release mechanism to permit ease of manufacture and assembly while also eliminating any vibration or rattle in the system.
SUMMARY OF THE INVENTION
One embodiment relates to an apparatus for adjusting an automotive seat assembly. A first release is located on a first side of the seat assembly, and a second release is located on a second side of the seat assembly. A cross member operatively connects the first release and the second release. A spring applies a rotational force to the cross member about a longitudinal axis of the cross member in a first direction. The spring further applies a linear force along the longitudinal axis of the cross member and biases the cross member toward the second release.
Another embodiment relates to a method for connecting a pair of release mechanisms for a seat assembly. A first release is provided on a first side of the seat assembly and a second release is provided on a second side of the seat assembly. The first and second releases are coupled with a cross member. A spring is coupled to the cross member and provides a rotational force to the cross member about a longitudinal axis of the cross member and provides a linear force to the cross member. The cross member is biased by the spring away from the first release toward the second release.
In a further embodiment, an anti-rattle mechanism for an automotive seat release includes a cross member connecting a first and second release. A torsion spring is operatively coupled to the cross member and applies a rotational force to the cross member in a first direction, and applies a linear force to the cross member in a direction parallel to a longitudinal axis of the cross member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of the release mechanism.
FIG. 2 is a partial cross sectional view of the release mechanism taken generally along lines 2 — 2 of FIG. 1 .
FIG. 3 is a partial cross sectional view of the release mechanism taken generally along lines 3 — 3 of FIG. 2 .
FIG. 4 is a cross sectional view of the release mechanism taken generally along lines 4 — 4 of FIG. 1 .
FIG. 5 is a cross sectional view of the release mechanism in the activated position, taken generally along lines 4 — 4 of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, release mechanism 10 includes a first and second base plate or support 12 , 14 secured to a respective side of a seat (not shown). A first release or activator 16 and a second release or activator 18 are releasably secured to a respective latch member 20 , 22 attached to the car floor panel 24 . The first and second releases 16 , 18 are pivotally attached to the first and second base plates 12 , 14 by a cross member 11 having a respective first and second stud, or plug or connector 26 , 28 . The first release 16 is operatively connected to the second release 18 by a cross tube 30 . A torsion spring 32 includes a first end 34 operatively connected to the first base plate 12 , and a second end 36 operatively connected to the first stud 26 . As will be described below, torsion spring 32 imparts both a torsional force to the first stud and compressive force against the cross tube 30 .
Referring to FIG. 2, first stud 26 extends through an opening in the first base plate 12 . The opening provides a bearing surface upon which first stud 26 may rotate. First stud 26 includes a first free end 38 extending outward of the first base plate 12 , and a second end 40 having a beveled portion 42 that is located within a first end 44 of cross tube 30 . Second end 40 of first stud 26 includes a slot 46 for receiving the second end 36 of the spring 30 .
As shown in FIGS. 1, 4 and 5 first release 16 includes a lever handle 48 extending in a frontward direction away from the first base plate 12 in a plane parallel to the plane of the first base plate 12 . Release 16 further includes an aperture 50 through which first stud 26 extends. The aperture 50 is “D” shaped to receive the “D” shaped first stud 26 . An exterior surface 52 of bearing journal 50 is in contact with a portion of spring 32 . Release 16 , 18 also includes a hook portion 62 , 64 releasably engaging latch 20 , 22 respectively. First release 16 is positively located with respect to first stud 26 .
Referring to FIG. 2, second stud 28 includes a first end 54 extending through an aperture in the second base plate 14 and a second end 56 located within a second end 58 of cross tube 30 . Second stud 28 may be formed as a unitary part of part of the cross tube 30 or may be a separate component that is either press fit within the opening of the cross tube 30 or may be further fit within the cross tube 30 with a clearance fit. Second release 18 includes a bearing 60 having a “D” shaped opening through which the “D” shaped second stud 28 extends. Second release 18 includes a hook portion 64 releasably engaging the latch 22 . Second release 18 is positively located with respect to second stud 28 .
The assembly of the release mechanism 10 will now be described. To aid in the description of the assembly, the release mechanism will be described as a drivers seat mechanism, such that the first base plate 12 will be referred to as the left or drivers side of the release mechanism and the second base plate 14 will be referred to as the right or passenger side of the release mechanism. Of course the release mechanism may be used on a passenger seat such that the lever 48 is located on the right or passenger side for convenience. The front direction will be defined by the direction that the lever 48 points in FIG. 1 .
The first and second base plates 12 , 14 are secured to the seat frame or are integral with the seat frame. Torsion spring 32 is placed over first stud 26 with the first leg or end 36 located within slot 46 of the first stud. The first end 38 of first stud 26 is passed through the D shaped opening in release 16 , and through the opening in plate 12 . The first end 44 of cross tube 30 is then slid on to the beveled portion 42 of first stud 26 . The cross tube 30 is pressed toward plate 12 thereby compressing torsion spring 32 , until there is sufficient clearance to insert second stud 28 through release 18 and plate 14 . After the second stud 28 has been positioned, the cross tube 30 is permitted to receive the beveled portion 57 of second stud 28 . The torsion spring 32 will then exert a force against end 44 of cross tube 30 until second end 58 of cross tube 30 is flush against the base portion of the stud 28 . Alternatively, the second end 58 of cross tube 30 may be pressed against another member such as release 18 . Finally, second end or leg 34 of torsion spring 32 is attached to an opening in plate 12 .
The operation of the release mechanism will now be described. FIGS. 1-4 illustrate the release mechanism in the engaged position with hook portions 62 , 64 engaged with latches 20 , 22 .
Rotation of release 16 is caused by an upward movement of handle 48 as illustrated in FIG. 5 . Since aperture 50 of release 16 is “D” shaped, the first stud 16 which is also “D” shaped is also rotated about its axis. Rotation of the first stud 16 will be translated to rotation of cross tube 30 which in turn will rotate release 18 . The rotation of releases 16 , 18 disengages hook portions 62 , 64 from latches 20 , 22 .
Rotation of release 16 will cause torsion spring 32 to tighten about first stud 26 , such that upon release of handle 48 by a user, the release 16 , cross tube 30 and second release 18 will be biased back to the engaged position. During both the engaged position in which both release 16 and 18 are engaged with latches 20 , 22 respectively, and the non-engaged position illustrated in FIG. 5, the torsion spring 32 exerts a rotational force to first plug 26 and a translational force along the cross car axis extending from left to right biasing cross tube 30 toward second plate 24 . In this manner rattle and noise is substantially eliminated by the compressive nature of the torsion spring 32 .
The compressive element of the spring should provide a force greater than the frictional force created by the coils as the torsion spring is wound about the stud. In this manner the friction opposing linear movement of the spring in the cross car direction will not prevent the spring from biasing the cross tube against the second release mechanism.
While the detailed drawings, specific examples and particular formulations given describe exemplary embodiments, they serve the purpose of illustration only. The systems shown and described are not limited to the precise details and conditions disclosed. For example, the system described is applied to a latch release mechanism to release the seat from a latch on the floor of the vehicle, however the release mechanism may also be employed in a seat reclining mechanism or any other dual release mechanism in which rotational movement is translated from a first and second release mechanism in which a translational force is also required. In the preferred embodiment the translational force is in the axial direction of the cross member. Additionally, the torsion spring may have additional configurations that provide both a rotational and linear force to the cross bar. The spring may also be attached to the cross bar in various ways such as internally within the cross bar. Furthermore, other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the exemplary embodiments without departing from the scope of the invention as expressed in the appended claims. | An apparatus for reducing rattle in an automotive seat release mechanism includes a torsion spring applying both a rotational force and a linear force to a cross member operatively connecting a first release and a second release. The spring force biases the cross member toward the second release linearly, and biases the cross member in a first rotational direction to reduce rattle between the cross member and components connecting the cross member to the first and second releases. | 1 |
FIELD OF THE INVENTION
This invention relates to electron beam lithography apparatus used for the manufacture of semiconductor integrated circuits.
BACKGROUND OF THE INVENTION
Electron beam exposure tools have been used for lithography in semiconductor processing for more than two decades. The first e-beam exposure tools were based on the flying spot concept of a highly focused beam, raster scanned over the object plane. The electron beam is modulated as it scans so that the beam itself generates the lithographic pattern. These tools have been widely used for high precision tasks, such as lithographic mask making, but the raster scan mode is found to be too slow to enable the high throughput required in semiconductor wafer processing. The electron source in this equipment is similar to that used in electron microscopes, i.e. a high brightness source focused to a small spot beam.
More recently, a new electron beam exposure tool was developed based on the SCALPEL (SCattering with Angular Limitation Projection Electron-beam Lithography) technique. In this tool, a wide area electron beam is projected through a lithographic mask onto the object plane. Since relatively large areas of a semiconductor wafer (e.g. 1 mm 2 ) can be exposed at a time, throughput is acceptable. The high resolution of this tool makes it attractive for ultra fine line lithography, i.e sub-micron.
The requirements for the electron beam source in SCALPEL exposure tools differ significantly from those of a conventional focused beam exposure tool, or a conventional TEM or SEM. While high resolution imaging is still a primary goal, this must be achieved at relatively high (10-100 μA) gun currents in order to realize economic wafer throughput. The axial brightness required is relatively low, e.g. 10 2 to 10 4 Acm −2 sr −1 , as compared with a value of 10 6 to 10 9 Acm −2 sr −1 for a typical focused beam source. However, the beam flux over the larger area must be highly uniform to obtain the required lithographic dose latitude and CD control.
A formidable hurdle in the development of SCALPEL tools was the development of an electron source that provides uniform electron flux over a relatively large area, has relatively low brightness, and has an electron emitter with a sufficient lifetime to avoid excessive downtime. Lanthanum hexaboride (LaB 6 ) emitters in a modified Wehnelt electron gun arrangement were found to be promising for this application, and the first SCALPEL tools were built with these electron sources. Efforts to improve the uniformity of the electron emission profile over the surface of the LaB 6 have continued, but with limited success. Replacement of the LaB 6 emitter with a simple tantalum disk was found to improve the surface emission uniformity and stability. While SCALPEL systems are regarded as highly successful fine line lithographic exposure tools, efforts continue toward improving the efficiency and uniformity of the electron beam source.
STATEMENT OF THE INVENTION
We have developed a new electron beam source for SCALPEL systems which uses an electron beam shaping element to smooth the electron beam profile of the primary emitting surface over the wide emission area. The beam shaping element is a mesh grid that is installed over the opening in the Wehnelt gun. The mesh grid is an equipotential screen with each aperture in the screen acting as a separate Wehnelt emitter with its own funnel-shaped electrical field. The result is a highly uniform wide area electron beam that is ideally suited for SCALPEL tools.
The optical analog of the proposed gridded Wehnelt is a fly's eye lens, or scatter plates or diffusers, which transform non-uniform light beams into uniform beams in optical illumination systems.
The invention will be described more specifically in the following detailed description which, taken with the drawing, will provide a greater understanding of the features that distinguish this invention from conventional electron beam sources.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1 is a schematic diagram of a conventional Wehnelt electron gun with a tantalum disk emitter;
FIG. 2 is a schematic diagram of a Wehnelt electron gun modified in accordance with the invention;
FIG. 3 is a schematic representation of the electron emission profile from the mesh grid of a conventional Wehnelt electron gun;
FIG. 4 is a schematic representation of the electron emission profile from the mesh grid of the modified Wehnelt electron gun of the invention;
FIG. 5 is a schematic diagram of a mesh grid of the invention showing the relevant dimensions; and
FIG. 6 is a schematic diagram illustrating the principles of the SCALPEL exposure system.
DETAILED DESCRIPTION
Referring to FIG. 1, a conventional Wehnelt electron gun assembly is shown with base 11 , cathode support arms 12 , cathode filament 13 , Wehnelt electrode comprised of Wehnelt support arms 15 and conventional Wehnelt aperture 16 . The base 11 may be ceramic, the support members 12 may be tantalum, steel, or molybdenum. The filament 13 may be tungsten wire, the material forming the Wehnelt aperture may be steel or tantalum, and the electron emitter 14 is, e.g., a tantalum disk. The effective area of the electron emitter is typically in the range of 0.5-3 mm 2 . The electron emitter is preferably a disk with a diameter in the range 0.5-2.0 mm. The anode is shown schematically at 17 , and the electron beam at 18 . For simplicity the beam control apparatus, which is conventional and well known in the art, is not shown. It will be appreciated by those skilled in the art that the dimensions in the figures are not necessarily to scale.
An important feature of the electron source for SCALPEL exposure tools is relatively low electron beam brightness, as mentioned earlier. For most effective exposures, it is preferred that beam brightness be limited to a value less than 10 4 Acm −2 sr −1 . This is in contrast with conventional scanning electron beam exposure tools which are typically optimized for maximum brightness. See e.g. U.S. Pat. No. 4,588,928 issued May 13, 1986 to Liu et al.
The improved electron gun according to the invention is shown in FIG. 2 . The opening for the Wehnelt is provided with mesh grid 23 , disposed in the path of the electron emission 25 . The mesh grid 23 is at a potential equal to the Wehnelt electrode and functions as a secondary emitter with multiple sources.
The electron emission pattern from a standard round bore Wehnelt gun, i.e. the gun of FIG. 1, is shown in FIG. 3 . The relatively non-uniform, bell curve shaped output from the Wehnelt is evident. The electron emission pattern from the mesh grid equipped Wehnelt gun of the invention, i.e. the gun of FIG. 2, is shown in FIG. 4 . The multiple emission patterns can be seen, which serve to spatially distribute the electron flux across a wide aperture and ensure a flat averaged electrical field over the cathode surface. At the object plane, the individual electron beams overlap and the integrated electron flux is highly uniform.
The screen element that forms the mesh grid can have a variety of configurations. The simplest is a conventional woven screen with square apertures. However, the screen may have triangular shaped apertures, hexagonal close packed apertures, or even circular apertures. It can be woven or non-woven. Techniques for forming suitable screens from a continuous layer may occur to those skilled in the art. For example, multiple openings in a continuous metal sheet or foil can be produced by techniques such as laser drilling. Fine meshes can also be formed by electroforming techniques. The mesh grid should be electrically conducting but the material of the mesh is otherwise is relatively inconsequential. Tantalum, tungsten, molybdenum, titanium, or even steel are suitable materials. These metals may be overcoated with, e.g., gold or hafnium to decrease parasitic emission from the mesh grid. The mesh grid preferably has a transparency in the range 40-90%, with transparency defined as the two dimensional void space divided by the overall mesh grid area. The spacing between the electron emitter surface and the mesh grid is typically in the range 0.1 to 1.0 mm.
With reference to FIG. 5, the mesh grid has bars “b” of approximately 50 μm, and square cells with “C” approximately 200 μm. This mesh grid has a transparency of approximately 65%. Mesh grid structures that were found suitable are represented by the examples in the following table.
TABLE I
Cell dimension “C”, μm
Bar width “b”, μm
Grid #100
200
50
Grid #200
88
37
Grid #300
54
31
The cell dimension “C” is the width of the opening in a mesh with a square opening. For a rectangular mesh grid the dimension “C” is approximately the square root of the area of the opening. It is preferred that the openings be approximately symmetrical, i.e. square or round.
The thickness t of the mesh grid is relatively immaterial except that the aspect ratio of the openings, C/t, is preferably greater than 1. Desirable relationships between the mesh grid parameters is given by:
D:b>= 4 ; C:t >=1.5
where D is the cathode-to-grid distance.
As indicated above the electron gun of the invention is most advantageously utilized as the electron source in a SCALPEL electron beam lithography machine. Fabrication of semiconductor devices on semiconductor wafers in current industry practice contemplates the exposure of polymer resist materials with fine line patterns of actinic radiation, in this case, electron beam radiation. This is achieved in conventional practice by directing the actinic radiation through a lithographic mask and onto a resist coated substrate. The mask may be positioned close to the substrate for proximity printing or may be placed away from the substrate and the image of the mask projected onto the substrate for projection printing.
SCALPEL lithography tools are characterized by high contrast image patterns at very small linewidths, i.e 0.1 μm or less. They produce high resolution images with wide process latitude, coupled with the high throughput of optical projection systems. The high throughput is made possible by using a flood beam of electrons to expose a relatively large area of the wafer. Electron beam optics, comprising standard magnetic field beam steering and focusing, are used to image the flood beam onto the lithographic mask, and thereafter, onto the substrate, i.e. the resist coated wafer. The lithographic mask is composed of regions of high electron scattering and regions of low electron scattering, which regions define the features desired in the mask pattern. Details of suitable mask structures can be found in U.S. Pat. No. 5,079,112 issued Jan. 7, 1992, and U.S. Pat. No. 5,258,246 issued Nov. 2, 1993, both to Berger et al.
An important feature of the SCALPEL tool is the back focal plane filter that is placed between the lithographic mask and the substrate. The back focal plane filter functions by blocking the highly scattered electrons while passing the weakly scattered electrons, thus forming the image pattern on the substrate. The blocking filter thus absorbs the unwanted radiation in the image. This is in contrast to conventional lithography tools in which the unwanted radiation in the image is absorbed by the mask itself, contributing to heating and distortion of the mask, and to reduced mask lifetime.
The principles on which SCALPEL lithography systems operate are illustrated by FIG. 6 . Lithographic mask 52 is illuminated with a uniform flood beam 51 of 100 keV electrons produced by the electron gun of FIG. 2 . The membrane mask 52 comprises regions 53 of high scattering material and regions 54 of low scattering material. The weakly scattered portions of the beam, i.e. rays 51 a , are focused by magnetic lens 55 through the aperture 57 of the back focal plane blocking filter 56 . The back focal plane filter 56 may be a silicon wafer or other material suitable for blocking electrons. The highly scattered portions of the electron beam, represented here by rays 51 b and 51 c , are blocked by the back focal plane filter 56 . The electron beam image that passes the back focal plane blocking filter 56 is focused onto a resist coated substrate located at the optical plane represented by 59 . Regions 60 replicate the features 54 of the lithographic mask 52 , i.e. the regions to be exposed, and regions 61 replicate the features 53 of the lithographic mask, i.e. the regions that are not to be exposed. These regions are interchangeable, as is well known in the art, to produce either negative or positive resist patterns.
The vitalizing feature of the SCALPEL tool is the positioning of a blocking filter at or near the back focal plane of the electron beam image. Further details of SCALPEL systems can be found in U.S. Pat. No. 5,079,112 issued Jan. 7, 1992, and U.S. Pat. No. 5,258,246 issued Nov. 2, 1993, both to Berger et al. These patents are incorporated herein by reference for such details that may be found useful for the practice of the invention.
It should be understood that the figures included with this description are schematic and not necessarily to scale. Device configurations, etc., are not intended to convey any limitation on the device structures described here.
For the purpose of definition here, and in the appended claims, the term Wehnelt emitter is intended to define a solid metal body with an approximately flat emitting surface, said flat emitting surface being symmetrical, i.e. having the shape of a circle or regular polygon. Also for the purpose of definition, the term substrate is used herein to define the object plane of the electron beam exposure system whether or not there is a semiconductor workpiece present on the substrate. The term electron optics plane may be used to describe an x-y plane in space in the electron beam exposure system between the electron emitting surface of the electron gun and the surface onto which the electron beam image is focused, i.e. the object plane where the semiconductor wafer is situated.
Whereas the electron beam optics required for implementing the invention are well known and not described here in detail, the grid bias required for far field beam shaping and for regulating exposure dose in the modified Wehnelt gun of the invention is not. The cut-off bias in conventional Wehnelt guns is typically 400 V or more. Because of the presence of the mesh grid in the modified Wehnelt gun of the invention, cut-off for the grid bias is less than 100 V, and in most structures, e.g. the embodiment described above, less than 50 V. This voltage can be applied directly to the Wehnelt electrode and can be switched or modulated using semiconductor drive circuits, which sharply reduces the cost of the apparatus and the response time of the beam control system.
Because of the relatively low cut-off voltage for the electron gun design of the invention, it is convenient and relatively simple to further enhance beam uniformity by introducing a deliberate beam wobble in the electron beam source. The wobble can be produced by a low frequency, i.e. 1-10 kHz, beam drive signal that is superimposed on the Wehnelt grid bias. This wobble changes the beam pattern at the frequency of the wobble so that any peaks or hot spots in the electron beam front are moved periodically and the integrated flux over time is more spatially equalized.
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 method and apparatus for electron beam lithography wherein a Wehnelt electron gun is modified to improve the uniformity of the electron beam. A mesh grid is applied to the Wehnelt aperture and the mesh grid functions as a multiple secondary emitter to produce a uniform beam flux over a wide area. The grid voltage of the modified gun is substantially lower than in a conventional Wehnelt gun, i.e. less than 100 volts, which can be switched conveniently and economically using semiconductor drive circuits. | 8 |
SUMMARY OF THE INVENTION
The present invention is a unity gain amplifier based on CMOS technology designed to drive a large capacitive load such as a piezoelectric speaker with a 5V power supply. The invention utilizes a rail-to-rail voltage range (i.e., ground to power supply voltage) at its input as well as at its output and is capable of entering into a power down mode. In this manner, it is possible to produce as a single application specific integrated circuit (ASIC), a circuit for converting a digital signal to an analog signal and amplifying the analog signal so as to be capable of driving a large capacitive load. A power down circuit is employed in order to reduce power consumption by allowing a user to input a signal which turns the amplifier off.
In the prior art, external discrete bipolar Operational Amplifiers (OpAmps) are used to perform the same function. However, OpAmps require a higher device count resulting in a higher cost and increased board space as compared to the present invention. The invention reduces manufacturing costs so that the discrete OpAmps can be replaced with this design. Furthermore, this invention provides a rail-to-rail dynamic range and operates at low noise.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block overview diagram of an ASIC implementing the invention coupled to a microprocessor and speaker.
FIG. 2 is a block diagram of unity gain amplifiers 11 and 13.
FIG. 3 is a circuit diagram of transconductance amplifiers 17a and 17b.
FIG. 4 is a circuit diagram of the biasing element, current mirror voltage divider 21.
FIG. 5 is a circuit diagram of power down circuit 15.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the invention utilizes two unity-gain, rail-to-rail, input/output amplifiers 11 and 13 forming a fully differential amplifier, also known as a bridge amplifier. In this manner, the dynamic range obtained is twice that of a single OpAmp because both positive and negative input voltages are utilized. The invented design provides additional advantages such as good rejection of common-mode signals, the elimination of system clock feedthrough noise from a digital environment and reduction of offset voltage (i.e., differences between input voltage and output voltage). Microprocessor 22 produces digital data which is input to digital to analog converter 23 which produces a differential analog signal input to amplifiers 11 and 13. Amplifiers 11 and 13 amplify the differential analog signal to drive piezoelectric speaker 27 or other device with a high capacitive load. Microprocessor 22 also generates a power down signal PWRDN which is input to bias circuit 21 which operates to disable amplifiers 11 and 13 and disable power down bias circuit 15. Bias circuit 15 outputs signals to bias NMOS and PMOS transistors used by amplifiers 11 and 13.
In order to achieve a rail-to-rail dynamic range output, as shown in FIG. 2, each single unity-gain amplifier 11 and 13 is configured as two very-wide-common-mode-range differential amplifiers (VCDA) 14a/14b and 16a/16b driving a corresponding operational transconductance amplifier (OTA) 17a/17b and biased by a compensated, current mirror voltage divider 21. The amplifier formed by unity gain amplifiers 11 and 13 is capable of driving a large capacitive load up to 200 nanofarads with a 5 volt power supply.
The signals shown in FIG. 2 have the following descriptions:
______________________________________Signal Type Description______________________________________AVINP Input Internal analog voltage input (Positive) from digital to analog converter 23AVINN Input Internal analog voltage input (Negative) from digital to analog converter 23PWRDN Input Internal power down control signal from microcomputer 22AVOUTP Output External analog voltage output (Positive) to speaker 27AVOUTN Output External analog voltage output (Negative) to speaker 27______________________________________
OTAs 17a and 17b are push-pull class AB operational transconductance amplifiers, each of which provides a large output current for quick slewing and an adequate phase margin for good stability while driving a large capacitive load. OTAs 17a and 17b utilize the VCDA outputs OUTA and OUTB to provide additional gain. The input PWRDNB to OTA 17a and OTA 17b disables P transistor 37a as shown in FIG. 3. The input PWRDOWN to VCDAs 16a and 16b disables appropriate N transistors of the VCDAs. The bias signals BIASP and BIASN input to OTAs 17a and 17b from bias circuit 21 bias transistors 39a and 39b (see FIG. 3). Power down circuit 15 inputs the signals PWRDNB and PWRDOWN to enable transistors 81 and 87 (see FIG. 5).
FIG. 3 illustrates circuit details for OTA 17a and 17b. Also, each amplifier is compensated using two Miller capacitors 43a and 43b along with their corresponding zero nulling MOS resistors 41a and 41b. This compensation guarantees enough gain margin for wide range capacitive loads up to 200nF.
FIG. 3 is a circuit diagram of OTAs 17a or 17b, both components being identical, and having the signals OUTA, OUTB, PWRDNB, BIASP and BIASN as inputs and the signal AVOUTP (for OTA 17a) or AVOUTN (for OTA 17b) as outputs. The signal OUTA is input to N channel enhancement mode transistor 35a. The signal PWRDNB is input to P channel enhancement mode transistor 37a. The signal BIASP is input to transistor 39a and the signal BIASN is input to Transistor 39b. The drain of transistor 45a protects transistor 47a so that ESD (Electro-Static Discharge) does not punch through its input gate. The output signal AVOUTP/AVOUTN is fed-back from a depletion MOS capacitor 43a cascading with a MOS null resistor 41a to stabilize the entire amplifier system. Again, the drain of transistor 51a is to protect the MOS depletion capacitor 43a from ESD punch through. The network of transistors 35a, 37a, 39a, 41a, 43a and 45a provides sufficient gain to drive the output P transistor 47a for charging up a very large capacitor, e.g., greater than 0.4 μF.
In a similar manner, the signal OUTB is coupled to the P channel enhancement mode transistor 35b with transistors 39b, 41b, 43b, 45b and 47b operating in a corresponding manner as transistors 35a, 39a, 41a, 43a, 45a and 47a excepting that the network of transistors operating on the signal OUTB is for, driving the output N MOS transistor 47b with a sufficient discharging current.
The device sizes of the transistors in the circuit of FIG. 3 are important and are determined by the load. For example, for a load having an impedance of 300 nanofarads at 8KHz, the devices have values shown in Table I.
TABLE I______________________________________ Transistor TransistorTransistor Width Length______________________________________35a 50 837a 8 839a 200 1541a 10 9043a 200 20047a 4500 5.535b 500 839b 200 1541b 10 9043b 200 20045b 24 547b 1800 5.551a 24 551b 24 5______________________________________
There are two different VCDAs 14a/14b and 16a/16b for each OTA providing voltage shifting for driving the OTAs so that low power supply voltage and process variations will not affect the proper operation of the output stage. Each VCDA utilizes self-biasing to extend the dynamic input range thus achieving a rail-to-rail input capability. This self-biasing created by a negative feedback loop greatly reduces the sensitivity of bias voltage to variations in processing and supply voltage. Therefore, the input stage designed with two VCDAs can tolerate a 3.3 volt minimum, which of course is a basic requirement in digital and analog mixed-mode design. Details for suitable VCDAs 15a/15b and 16a/16b may be found in U.S. Pat. No. 4,958,133 issued Sep. 18, 1990.
Referring next to FIG. 4, an implementation of current mirror voltage divider 21 is shown which provides bias voltages to OTAs 17a and 17b. The bias voltages minimize variations in the output of OTAs 17a and 17b due to power supply variations and process variations which may occur during fabrication. A power down signal PWRDN is generated by microprocessor 22 to save power consumption when the amplifier system is not used during the idle mode. The PWRDN signal is coupled to two inverter buffers 51a/51b and 53a/53b to isolate any digital noise propagating through the bias circuit. The inverter 55a/55b generates an inverse power down signal PWRDNB to turn off the output P transistor 47a. Furthermore, the PWRDNB and PWRDOWN signals shut off the DC path current in the bias network by enabling the N transistor 61 and disabling the transistor 63.
The voltage divider is formed when the power down signal is not enabled. P MOS transistor 73 provides a threshold voltage for OTA transistor 39a. Thus, transistor 39a mirrors the drain current of the transistor 73 based on their ratio. In a similar manner, N MOS transistor 65 provides a mirror current for OTA transistor 39b. The transistors 71, 67 and the resistor 69 are used to control the bias current as required. In this design, the bias is adjusted for an AB class amplifier which can reduce the cross-talk noise. In case of a power drop, the transistor 77 is turned on to sustain a DC current to replace the function of the transistors 71, 67 and the resistor 69.
Referring to FIG. 5, which shows the details of power down circuit 15, the power down signals PWRDNB and PWRDOWN also control two MOS resistors 81 and 87 to eliminate clicking noise when the amplifier is disabled by PWRDN. The transistors 83 and 85 are ESD protection transistors which provide protection to transistors 81 and 87. | A unity gain amplifier based on CMOS technology designed to drive a large capacitive load such as a piezoelectric speaker with a 5V power supply. The invention utilizes a rail-to-rail voltage range (i.e., ground to power supply voltage) at its input as well as at its output and is capable of entering into a power down mode, In this manner, it is possible to produce as a single application specific integrated circuit (ASIC), a circuit for converting a digital signal to an analog signal and amplifying the analog signal so as to be capable of driving a large capacitive load with a rail-to-rail dynamic range and which operates at low noise. | 7 |
FIELD OF THE INVENTION
[0001] The invention pertains to multi-function (including openable and closeable) surge reduction tools for use in down-hole environments.
BACKGROUND OF THE INVENTION
[0002] Casing is used in oil and gas well construction. In certain applications a string of casing may be deployed using a work string, for example, drill pipe, so that the casing string does not extend all of the way back to the drilling rig. These scenarios can include a liner and a sub-sea casing longstring.
[0003] A longstring is a string of casing whose upper end extends up to the wellhead. So a longstring used on a sub-sea well is one that does not extend up to the drilling rig once installed but whose top resides in the sub-sea wellhead which sits on the sea floor. A liner is a string of casing whose top end resides within the length of a previously installed casing string. The top end of a liner does not reside at surface or within a wellhead.
[0004] Both of these scenarios utilize drill pipe in order to deploy the casing string. It is known in the industry that the deployment a casing string may exert excessive pressure on an open formation. The excessive pressure may overcome the strength of the formation and thus cause the formation to break down and cause a cement job. Surge reduction tools exists that when used in conjunction with auto-fill float equipment allow the fluid that is being displaced from the well bore to move up the inside of the casing and deployment string, thus reducing the surge pressure. Specifically, the surge reduction tools divert fluid flow from the inside of the deployment string to the annular space above the casing string. Once it is determined that casing string must be washed down and or cemented then surge tool is closed so that the fluid flow is no longer diverted to the annular space above the casing. Reliable closing of the flow diversion is critical for ensuring successful cementing operations.
[0005] With the onset of dual gradient drilling methods a need exists which will require that a surge reduction tool begin in the closed position until it is deployed below the sea floor, then be allowed to open to allow fluid diversion from the inside to the annulus, and then be closed again to allow wash down or cementing operations.
[0006] It is possible that other applications may exist for this type of tool. It is also possible that applications exist requiring a tool to be opened and closed multiple times.
[0007] The present invention incorporates multiple shifting sleeves controlled by pressure enabled by sealing balls or plugging devices that land on seats and which shift the tool into an open or closed position. The seats then allow the ball or plugging device to be released through the tool. Proper sizing of the seats for balls or other plugging devices allows selective opening and closing of the tool, as well as allowing for a multi-stage tool that may be opened and closed repeatedly.
[0008] Additionally, the invention may incorporate a test sub that allows the work string to be pressure tested after the tool is closed, providing a positive indication to the surface that successful closure and sealing has occurred, and that further operations may proceed.
SUMMARY OF THE INVENTION
[0009] The invention provides a multiple-sleeve tool, in which each sleeve is provided with a respective landing device, or seat, for a plugging tool. (Plugging tools, such as darts or balls, are typically dropped from the surface and either fall or are pumped downhole.) As the tool is run downhole, it is in a closed position, preventing fluid communication between its exterior and its interior.
[0010] When the tool is in the desired position, it is opened by sending a first plugging device downhole to engage a landing seat. Because the tool provides multiple landing seats, the plugging device will be sized to pass through any up hole landing seats it may encounter until it reaches the desired one. Once the plugging device is sealingly engaged with the desired landing seat, pressure is used to release the sleeve associated with that landing seat, such as by shearable pins, screws, or rings, or other such pressure-releasable devices, thus shifting the sleeve downward.
[0011] In a preferred embodiment, the first such shifting action shifts a first sleeve into position so that holes in the sleeve body align with holes in the tool body, opening fluid communication between the exterior and interior of the tool.
[0012] In a similar manner, when it is desirable to again close and seal the tool, a second plugging device engages a second seat associated with a second sleeve. Upon increasing the work string fluid pressure, a second set of holding devices, such as shear screws, releases and allows the second sleeve to shift downward, closing off and sealing the fluid communication that was created by the shift of the first sleeve.
[0013] As those of skill in the art will recognize, multiple stages, each providing two such sleeves, can be “stacked” along a work string, either together or with desired separations between them, so that fluid diverter operations may be repeatedly opened and closed without the need to withdraw the work string from the wellbore.
[0014] Additionally, the invention provides for an optional test device comprising a yieldable seat, which yieldable seat can be sized to capture one or more of the plugging devices after they are released from the second sleeve seat(s). This test device allows the work string to be pressurized after the closing operation is completed, to test and insure that the closure occurred properly and that the device is sealed. After such testing, additional pressure may be used to release the plugging device and resume normal operations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1A is a sectional view of one embodiment of a tool of the present invention in the run-in position.
[0016] FIG. 1B is a sectional view of one embodiment of a tool of the present invention in the open position.
[0017] FIG. 1C is a sectional view of one embodiment of a tool of the present invention in the closed position.
[0018] FIG. 2A is a sectional view of an alternative embodiment of a tool of the present invention in the run-in position.
[0019] FIG. 2B is a sectional view of an alternative embodiment of a tool of the present invention in the open position.
[0020] FIG. 2C is a sectional view of an alternative embodiment of a tool of the present invention in the closed position.
[0021] FIG. 3 is a perspective view showing the locking dogs of FIG. 2 in greater detail.
[0022] FIG. 4 is a sectional view of a test device mountable below a multi-function diverter tool of the present invention.
DETAILED DESCRIPTION
[0023] Referring to FIG. 1A , one embodiment of a tool of the present invention is shown in the run-in position. Multi-function diverter tool 10 comprises body 12 , upper sub 14 , lower sub 20 , ports 66 , and internal assemblies as described below. Upper sub 14 comprises upper threaded attachment 16 for connection to a work string, and upper body seal 18 . Lower sub 20 comprises lower threaded attachment 22 for connection to a work string, and lower body seal 24 .
[0024] Internal assemblies include upper slider assembly 26 and lower slider assembly 44 . Upper slider assembly 26 comprises upper guide 28 connected to upper ball seat 30 , and also connected to upper slider 32 by upper slider connector 34 . Lower slider assembly 44 comprises lower guide 46 connected to lower ball seat 48 , and also connected to lower slider 50 by lower slider connector 52 . In a preferred embodiment, upper ball seat 30 is a larger diameter seat than lower ball seat 48 .
[0025] In one embodiment of the invention, disassembly sleeve 62 is positioned above lower sub 20 and a sealing relationship with tool body 12 is provided by disassembly sleeve seals 64 . Alternatively, disassembly sleeve 62 may be omitted and tool body 12 may be formed to provide the same shape as if disassembly sleeve 62 were in place. However, the addition of disassembly sleeve 62 provides greater ease in disassembly after recovery of the mult-function diverter tool 10 , because it allows the internal portions of the tool 10 to slide out the bottom after removal of lower sub 20 .
[0026] As seen in FIG. 1A , in the run-in position ports 66 are sealed away from the inner bore 84 by the sealing relationship provided by first upper slider seals 80 , first lower slider seals 68 , second lower slider seals 70 , and disassembly sleeve seals 64 . Once the tool 10 is in the desired position downhole, it may be opened to allow diversion of fluid from the inner bore 84 to the exterior of the tool 10 .
[0027] To open the tool 10 into the position shown in FIG. 1B a first ball (not shown) is dropped from the surface, and falls or is pumped downhole. The first ball is preferably of insufficient diameter to engage the upper ball seat 30 , but of sufficient diameter to engage lower ball seat 48 . Those of skill in the art will recognize that the first ball may engage upper ball seat 30 if it can be pumped through upper ball seat 30 at a pressure insufficient to shear upper shear screws 36 .
[0028] Once the first ball is engaged on lower ball seat 48 , pressure in the inner bore 84 is increased until lower shear screws 54 shear. Lower slider assembly 44 will then shift downward until lower slider 50 lands on landing 61 . Lower latch ring 56 rides in lower latch ring groove 58 in lower slider 50 . As lower slider 50 lands on landing 61 , lower latch ring 56 reaches lower latch 60 and expands outward, thus engaging both lower latch ring groove 58 and lower latch 60 . This action locks lower slider 50 relative to disassembly sleeve 62 (or tool body 12 ), and prevents upward motion of lower slider assembly 44 .
[0029] In the open position, ports 66 are aligned with lower slider windows 74 . Once the first ball is pumped clear, the exterior of tool 10 is in fluid communication with inner bore 84 , and the sides of the fluid pathway so provided are sealed by first upper slider seals 80 , second lower slider seals 70 , third lower slider seals 72 , and disassembly sleeve seals 64 .
[0030] To close the tool 10 , for example to allow wash down and cementing operations, a second ball (not shown) is dropped from the surface, and falls or is pumped downhole. The second ball is of sufficient diameter to engage upper ball seat 30 . Once the second ball is in position on upper ball seat 30 , fluid pressure is increased to shear upper shear screws 36 , allowing the upper slider assembly to shift downward until it reaches the position shown in FIG. 1C . Upper latch ring 38 rides in upper latch ring groove 40 until it reaches upper latch 42 . At this point, upper latch ring 38 expands outward so that it engages both upper latch ring groove 40 and upper latch 42 , preventing any upward shifting of upper slider assembly 26 .
[0031] As upper slider assembly 26 shifts downward, any fluid trapped in outer annulus 78 is vented to the inner bore 84 via vents 76 , preventing hydraulic locking of the tool.
[0032] In the closed position, ports 66 are isolated from the inner bore 84 by the sealing relationship between first upper slider seals 80 , second upper slider seals 82 , and tool body 12 .
[0033] As those of skill in the art will recognize, it is possible to stack multiple stages of this invention by sizing upper and lower ball seats in each stage so that the ball seat diameter progressively increases going up the work string. In this way, the opening and closing operations can be repeated, stage by stage, as many times as desired or as space in the affected section of the wellbore allows.
[0034] Referring to FIG. 2 , an alternative embodiment of the present invention is shown. Upper slider 32 is radially penetrated by one or more locking dogs 86 . Locking dogs 86 engages groove 88 in locking sleeve 90 . In the run-in position ( FIG. 2A ), locking dogs 86 are prevented from inward movement because their inner surfaces engage lower slider 50 . (A more detailed view of one embodiment of the locking dogs 86 is seen in FIG. 3 , in which locking dogs 86 are shown extended through the body of upper slider 32 .)
[0035] The presence of locking dogs 86 serves to lock upper slider 32 in position, preventing any loading of upper shear screws 36 until lower slider 50 has been shifted into the open position. ( FIG. 2B ). With lower slider 50 in the open position, locking dogs 86 are free to move inward, disengaging from locking sleeve 90 and allowing loading of upper shear screws 36 . Upper shear screws 36 may then be sheared to move upper slider 32 and place the tool into the closed position. ( FIG. 2C ).
[0036] Referring to FIG. 4 , in an additional embodiment of the invention, test sub 92 may be installed in the work string somewhere below a multi-function diverter tool 10 of the present invention. Yieldable ball seat 94 is sized to catch a ball (not shown) released from upper ball seat 30 , which was used to shift the multi-function diverter tool 10 into the closed position. With the ball so caught, the work string may be pressure-tested to ensure that the multi-function diverter tool 10 has properly closed and is sealed. As those of skill in the art will recognize, when multiple multi-function diverter tools 10 are present in the work string, one or more test subs 92 may be used, depending on the sizing of the yieldable ball seat 94 and the operational requirements for the work string.
[0037] Those of skill in the art will recognize that the above descriptions are by way of example only, and do not serve to limit the scope of the invention as claimed below. | A multi-function diverter tool is disclosed that allows positive-indication opening and closing of the tool in a downhole environment. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
This invention is a continuation in-part of application Ser. No. 945,643 having a filing date of Dec. 23, 1986 for DRYING FRAME, now abandoned.
BACKGROUND OF THE INVENTION
This invention is related to a collapsible drying rack having particular utility for supporting garments that must be laid flat and aired during the drying process. Such racks are normally stacked so that several layers of material may be dried. Similar racks are commonly employed for a variety of articles such as pies, fruit, glue, shellac and the like.
A drying rack, generally of the type to which this invention pertains, is illustrated in U.S. Pat. No. 1,587,573 which issued to C. H. Young on June 8, 1926. Although such racks in the past have been useful for industrial processes, they are inconvenient for use in the home or for a traveler, who wants to dry a freshly cleaned garment but has limited drying facilities.
Other knock-down racks are to be found in U.S. Pat. No. 4,630,550 which issued Dec. 23, 1986 to Harry L. Weitzman; and U.S. Pat. No. 2,654,487 which issued to R. K. Degener on Oct. 6, 1953. These racks are formed of a steel material and usually used for industrial applications. Their weight is such that they cannot be easily used by travelers who need a lightweight, easily assembled, relatively compact unit.
Other drying racks specifically designed for drying garments are disclosed in U. S. Pat. No. 3,358,388 which issued to E. Weiss, et al, on Dec. 19, 1967; and U.S. Pat. No. 2,521,100 which issued to E. S. Sublette on Sept. 5, 1950. These devices support the garment between two mesh surfaces for drying.
SUMMARY OF THE INVENTION
The broad purpose of the present invention is to provide a collapsible drying rack that can be easily carried in its collapsed condition in a bag, and then readily assembled to support a mesh material on which garments may lay during the drying process.
The preferred embodiment of the invention includes a lightweight plastic corner member having short hollow arms extending in mutually perpendicular directions. Each arm has a square cross-section and a pair of longitudinal ridges which terminate a short distance from the end of the arm.
The corner members are telescopically connected to tubular, extruded plastic frame members to form a frame or rack. The ridges engage the frame member and compensate for the substantial manufacturing tolerances of plastic extrusions that do not exist with tubular steel members, such as is illustrated in the Degener and Weitzman patents.
The ridges provide little frictional resistance when the arm is being assembled or disassembled. The major frictional engagement is between the two, non-ridged sides of each arm that are in surface-to-surface contact with the frame member. The ease of assembly differs from steel racks which are normally assembled in a semi-permanent installation.
For example, in the Degener patent, the flat ridges frictionally engage with the tubes that are received in the ridged member. This is satisfactory for a relatively stiff material such as steel that is inherently stiff because of its load-bearing requirements. However, a thin walled plastic tube is not as stiff as a corresponding steel tube. The ridges of the preferred embodiment of the present invention increase the stiffness of the walls carrying the ridges because they increase the overall thickness of the wall in the ridge location.
The garment being dried is supported on a mesh sheet that is clipped to a pair of spaced parallel frame members. The garment is sandwiched flat between two mesh sheets as the garment is being air dried outdoors to keep the garment from being blown off the horizontal surface by gusts of wind.
The preferred embodiment of the invention includes a group of components that can be assembled to form a stacked configuration or an elongated horizontal configuration.
Another advantage of the invention is that the plastic material permits the consumer to readily cut the frame members to convenient lengths. The cut, exposed surfaces are not susceptible to rust or corrosion as in the case of coated metals.
The various components are extremely versatile because they can be assembled in a variety of configurations. The corner members can be employed either in a corner or in the center of the rack. The tubing can come in various lengths and assembled in a variety of configurations.
The mesh sheet has a sleeve in its midsection so that it can be combined with the tubing in at least three different configurations. Where a single surface is desired, the sleeve is mounted on one horizontal support and the free edge clipped to another horizontal support. In a side-by-side configuration, the sleeve is mounted on a horizontal support forming the frame midsection, and the opposite edges of the mesh sheet are clipped to the opposite ends of the frame. In a third configuration, the frames are stacked one above the other. One end of the mesh sheet is clipped to one end of the lower frame and the opposite end of the sheet connected to the upper frame.
Still further objects and advantages of the invention will become readily apparent to those skilled in the art to which the invention pertains upon reference to the following detailed description.
DESCRIPTION OF THE DRAWINGS
The description refers to the accompanying drawings in which like reference characters refer to like parts throughout the several views, and in which:
FIG. 1 is a perspective view of a collapsible drying rack illustrating the preferred embodiment of my invention formed in a pair of side-by-side frames;
FIG. 2 is a partially exploded view of my rack showing a pair of frames stacked one above the other;
FIG. 3 is a view illustrating the manner in which a mesh sheet is clipped around a frame member;
FIG. 4 is a sectional view illustrating the manner in which the frame member is telescopically engaged with a corner arm;
FIG. 5 is a cross-sectional view illustrating the manner in which the ridges engage the inside of a frame member; and
FIG. 6 is a view illustrating a garment sandwiched on a single frame;
FIG. 7 is a view illustrating the mesh sheet supported in a side-by-side frame configuration; and
FIG. 8 is a view illustrating the mesh sheet supported in a stacked configuration.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a preferred collapsible drying rack 10. Rack 10 includes six identically shaped, plastic, corner members 12, 14, 16, 18, 20 and 22 supported on six square, plastic, hollow tubular legs 24, 26, 28, 30, 32 and 34 respectively.
The corner members also support seven extruded plastic hollow tubular frame members 36, 38, 40, 42, 44, 46 and 48 to form an elongated, rectangular drying frame. A flexible, mesh drying sheet 50 is mounted on the drying frame.
Seven clips 52 connect one end of the mesh sheet to frame member 36. Seven clips 54 connect the opposite end of the flexible sheet to frame member 42. The sheet has a stitched sleeve 56 wrapped around frame member 48.
FIG. 2 shows a partially disassembled version of the preferred embodiment in which the legs, frame members and corner members cooperate to form a double stacked arrangement 110 using elements having the same configuration as is illustrated in FIG. 1.
FIG. 4 illustrates a typical corner member 14. Corner member 14 has a central, cube-shaped body 56, and four hollow, square arms 58, 60, 62, and 64. Each arm is identical in length.
A wall 74 is mounted adjacent the extreme end of arm 58.
Each arm has a wall-to-wall outside diameter somewhat less than that of the internal diameter of the frame members. Each arm has a pair of longitudinal ridges 76 and 78 along two adjacent sidewalls. The extreme end of each ridge is spaced about 1/4 from the extreme outer end of the arm on which it is mounted. Further, the extreme end of each ridge is rounded to ease the receipt of an arm in a frame member.
The manner in which each arm receives a frame member is best illustrated in FIGS. 4 and 5. The inner diameter "A" of frame member 38, perpendicular to each sidewall, is slightly greater than the outer diameter "B" of the arm. However, the height of ridges 76 and 78 is such that the diameter of the arm, including the ridge, is slightly greater than the inner diameter of the frame member. Further, each ridge is parallel to the longitudinal axis of the arm on which it is mounted. Each ridge is formed on the midsection of the arm wall on which it is mounted to increase the overall thickness of the wall at such location. Thus the wall has a stiffened midsection.
As frame member 38 is being slipped over arm 64, the two ridges engage the inside surface of the frame member with a minimal frictional resistence to the assembly motion. The frame member is received on the arm until the frame member end abuts body 56. The ridges accommodate dimensional variations in the manufacturing of both the frame members and the arms. The ridges also permit the frame members and the arms to be quickly assembled and disassembled.
Referring to FIG. 3, a typical clip 80 is shown being snapped over the mesh sheet which is partially wrapped around square frame member 42. The clip is a four-sided member having a short side 82 and a short side 84 connected to sides 86 and 88 so as to define an opening 90 for receiving the support. The user, mounts the clip on the opposed sides of the frame member. He then applies a pressure with his thumb 92 on the clip until it snaps around the four sides of the frame member.
The clip can be easily released by pulling on one of the short sides to separate it from the frame member.
The rack illustrated in FIG. 1 has side-by-side frames, but a single rack can be used by not assembling frame members 40 and 44.
Referring to FIG. 6, a garment, such as a sweater 94, is mounted on the lower portion 96 of the mesh sheet and the upper portion 98 of the mesh sheet is lowered from position "C" on the garment to sandwich it in a drying position.
The free edge of the mesh sheet is then wrapped around support 48, and clip means 80 snapped around the edges of the mesh sheet.
FIGS. 7 and 8 illustrate other configurations for using the mesh sheet. In FIG. 7, sleeve 56 is mounted on intermediate frame member 100, one end of the sheet is wrapped around frame member 102 and its opposite end wrapped around frame member 104. The three frame members are parallel to one another. Clip means 106 and 108 connect the ends of the sheet to the end frame members.
FIG. 8 illustrates another arrangement in which one end of the sheet is wrapped around frame member 110, and sleeve wrapped around frame member 112 and then the opposite end of the sheet looped around frame member 114. The frame members are all parallel to one another. Clip means 116 connect one end of the sheet to frame member 118 and clip means 120 connect the opposite end to frame member 110. The sleeve is somewhat off-center on the sheet as illustrated in FIG. 8, so that one end of the sheet is longer than the others. Further, it is to be noted that because all the frame members are parallel, one to the other, the sleeve functions to square-up the mesh sheet on the frames as well as providing an initial attachment.
The clips complete the assembly of the sheet to the frame to create a surface.
Thus, it is to be understood that I have described an improved knock-down drying rack that can be assembled into different configurations, allowing several sweaters or other hand washable garments to be flat dried in a minimal amount of space. It can be assembled into racks that can be snapped together for side-by-side drying, or stacked two, three or four high to fit a standard size bathtub to save space. The flat surface prevents woven materials from stretching out-of-shape and forming creases. The entire assembly can be knocked down and stored in a 10" by 32" canvas bag (not shown) when not in use. Preferably the frame components are each formed of a high-impact styrene plastic. They can be made of other suitable plastics, such as polyvinyl chloride. | A collapsible drying rack includes a series of horizontal tubular plastic frame elements connected together by corner elements. Each corner element has four hollow tubular arms that telescopically receive the frame members. A pair of integral, longitudinal ridges on each arm engage the inside of the tubular frame members to form an easily releasable connection compensating for variations in manufacturing tolerances of the plastic members. A mesh sheet mounted on the frame, supports a garment such as a sweater, in a sandwiched position for drying. | 3 |
BACKGROUND OF THE INVENTION
[0001] The present application is a continuation-in-part of co-pending U.S. patent application Ser. No. 09/956,474 filed Sep. 19, 2001, which is a continuation of U.S. patent application Ser. No. 09/384,165, filed Aug. 27, 1999 and now issued as U.S. Pat. No. 6,356,192, which claims priority to U.S. provisional patent application serial No. 60/135,862, filed May 25, 1999 and to U.S. provisional patent application serial No. 60/105,493 filed Oct. 23, 1998. The present application is also a continuation-in-part of a co-pending U.S. patent application filed Mar. 28, 2002, entitled “Method and System for Wireless Tracking”, which claims priority to a provisional patent application serial No. 60/279,401, filed Mar. 28, 2001.
[0002] The present invention relates generally to bi-directional personal and health-wellness provider communication system and in particular to a personal communication system suitable for use with children, vulnerable adults (such as those in assisted living situations), and more specifically, medically distressed persons and those in whom an personal medical device has been deployed, for medical testing, and for other life enhancements.
[0003] There are several trends which taken together are causing a change in the way medical services are delivered. Among other things, these include longer lifespan, medical technology improvements, automation of diagnostic processes, specialization of caregivers, the rapid pace of technology that causes a shortening of the amortization of development and investment costs, increasing expense of medical care centers, and the shortage of health care workers.
[0004] The results of these trends are manifold. They include moving more of the delivery of services out of a medical center and away from the direct supervision of highly trained medical personnel. They include providing personal medical devices to allow long-term patients to resume a more mobile lifestyle. They include allowing patients to be treated from home for issues of cost and comfort. They include reducing the level of training associated with caregivers so that in some cases, even a casual passerby is able to provide meaningful assistance with devices once associated only with properly trained medical personnel, for example using Portable Automated Defibrillators. However, the remoteness of patients from professional caregivers increases the need for communications systems to monitor the patient, deliver care, and communicate.
[0005] What is needed in the art is an improved detection system that is friendly to a mobile user, that is easy to adapt to existing devices, that is easy to install, that is inexpensive, and that provides substantial interoperability between wireless technologies, communication network providers, and other widely used medical and public systems.
SUMMARY OF THE INVENTION
[0006] One skilled in the art will readily recognize that the embodiments described solve all of these problems and many more not mentioned expressly herein.
[0007] Personal Medical Devices (PMD) take many forms. PMDs may be surgically implanted, strapped externally to the body, carried in a pocket, transported in a carrying case, or installed as a home appliance. They may be used only for rare emergencies, on an occasional basis, on a regular schedule, or in a continuous or nearly continuous fashion. PMDs may monitor individual or combinations of body functions such as heart function, respiration, body chemistry, brain function, or muscular/skeleton actions. PMDs may provide body functions such as mechanical hearts, kidney dialysis, digestive or respiratory activities. PMDs may be used to deliver drugs, heart defibrillation, or other treatment. PMDs may be used to enhance wellness, test drug therapies, monitor patient health, deliver long-term care, or treat acute conditions.
[0008] We describe a device and method to couple with PMDs to provide wireless communication and locating functions. The purpose for communications include but are not limited to the following: to provide health care professionals with access to information for remote diagnostic capabilities; to provide notification of acute conditions possibly requiring immediate assistance, transportation to a medical center, or remote treatment action; to provide a location information of mobile persons for caregivers; to notify responsible parties of the occurrence of a medical condition; and to provide remote intervention assistance by caregivers through verbal or visual interaction.
[0009] In one embodiment, in order to provide mobility for users of PMDs in a public environment, we employ standard network communication systems to deliver a comprehensive medical communications service. In one embodiment, the communications network links together the PMD, casual caregivers, a medical center, an emergency dispatch center, medical databases, and related responsible parties. This group of associated parties is able to combine resources to improve the survivability during an acute medical event.
[0010] In one embodiment, the medical communications system delivers an end-to-end comprehensive solution to provide care to a remote or mobile user of a PMD.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a block diagram showing the overall structure of the system of the present invention.
[0012] [0012]FIG. 2 is a block diagram showing the internal structure of a portable device.
[0013] [0013]FIG. 3 is a block diagram showing the structure of a user interface module.
[0014] FIGS. 4 A- 4 F are block diagrams showing various configurations of the system of the present invention.
[0015] [0015]FIG. 5 is a network diagram showing communications through the system of the present invention.
[0016] [0016]FIG. 6 is a chart showing the uses of various data by a dispatcher or medical caregiver.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] This detailed description provides a number of different embodiments of the present system. The embodiments provided herein are not intended in an exclusive or limited sense, and variations may exist in organization, dimension, hardware, software, mechanical design and configuration without departing from the claimed invention, the scope of which is provided by the attached claims and equivalents thereof.
[0018] The present system provides many benefits, including but not limited to, low cost, easy installation, limited power requirements and wireless operation and signal transmission. Many other benefits will be appreciated by those skilled in the art upon reading and understanding the present description.
[0019] U.S. Provisional Patent Application No. 60/098,392, filed Aug. 29, 1998; U.S. Provisional Patent Application No. 60/098,270 filed Aug. 28, 1998; U.S. Provisional Patent Application No. 60/105,493 filed Oct. 23, 1998; and U.S. Provisional Patent Application No. 60/135,862 filed May, 25, 1999, are all hereby incorporated by reference in their entirety.
[0020] Personal Medical Device
[0021] [0021]FIG. 1 is a block diagram showing the interoperability of a personal medical device (PMD) 100 with a medical device interface (MDI) 200 and a network 400 . As can be seen, the PMD 100 may interact directly with the network 400 or through the mediation of the MDI 200 . Alternatively, the PMD may interact with a personal wireless device 500 which in turn interacts with the network.
[0022] [0022]FIG. 2 is a block diagram depicting the components of one embodiment of a PMD 100 . In one embodiment, the PMD includes a power module 110 . The power module 110 may be a battery or a line connection. If a battery, it may be rechargeable. In one embodiment the PMD includes a memory 120 . In one embodiment the PMD includes a processor 130 . The processor 130 executes instructions from its programming and also may participate in data transfer between other components of the PMD 100 .
[0023] Optionally, PMD 100 has connections to related external or embedded devices. In one embodiment, PMD 100 includes connections to detectors 140 . Detectors 140 may be any sensor of bodily or physiological parameters such as, but not limited to: temperature, motion, respiration, blood oxygen content, electrocardiogram (ECG), electroencephalogram (EEG), and other measurements.
[0024] Optionally, PMD 100 has connections to outputs 150 . The outputs may be signaled by changes in voltages, impedance, current, magnetic field, electromagnetic energy such as radio frequency signals, infrared signals or optical signals, and audible or other forms of mechanical energy. The outputs may be direct changes of state, analog, or digital in form. Several embodiments are possible, and the examples given herein are not intended in a limiting or restrictive sense. The outputs may be activated and controlled by the medical device interface 200 or the processor 130 , or by the actuation of the detector 140 or a combination of these. The outputs 150 may be used, for example, to actuate solenoids, operate motors, or apply electrical current to the heart.
[0025] Optionally, PMD 100 has connections to data input/output ports 160 . Data I/O ports 160 may include, but are not limited to: serial, parallel, USB, etc.
[0026] Optionally, PMD 100 includes a User Interface Module (UIM) 200 . The UIM 200 may allow users to view or enter data, conduct voice communications, use a camera to transmit images, or view a screen for graphical images.
[0027] Optionally, PMD 100 includes a wireless communications module 300 . In one embodiment the wireless communications module includes systems and standards for Local Area Wireless 330 . In one embodiment the wireless communications are designed to be Network Based Communications (NBC) 360 .
[0028] User Interface
[0029] [0029]FIG. 3 depicts User Interface Module (UIM) 200 . In one embodiment of UIM 200 , display 220 is included. Display 220 may be any standard device for displaying information, such as a CRT, plasma display, LED, LCD, etc. or equivalent.
[0030] Preferably the UIM 200 includes data input means 240 . Data input means may be any standard means for inputting information, such as a keypad, touch screen, bar code scanner, telephone keypad, buttons, switches, etc., or equivalent.
[0031] In one embodiment of UIM 200 , a speaker/microphone module 260 is included. Speaker/microphone module may be any device for producing sound, such as a speaker or microphone or the equivalent.
[0032] In one embodiment of UIM 200 , a camera 280 is included. Camera 280 may be a still camera, video camera, etc.
[0033] Communications
[0034] FIGS. 4 A- 4 E depict various possible wireless communication paths that may be used by the PMD 100 to connect to the long-range bi-directional network 400 .
[0035] [0035]FIG. 4A depicts one embodiment of the present system. PMD 100 communicates to Personal Wireless Device (PWD) 500 with local area wireless (LAW) 330 . PWD 500 includes a LAW 330 compatible with LAW 330 in PMD 100 . In one embodiment, PWD 500 includes a UIM 200 . PWD 500 includes network based communications (NBC) 360 . NBC 360 communicates information received from LAW 330 to long-range bi-directional network 400 .
[0036] [0036]FIG. 4B depicts another embodiment of the present system. PMD 100 communicates to the network 400 through NBC 360 . LAW 330 is not employed.
[0037] [0037]FIG. 4C depicts another embodiment of the present system. PMD 100 communicates through data port 160 to Medical Device Interface (MDI) 600 . In one embodiment, MDI 600 includes a UIM 200 . In this embodiment, MDI 600 includes a LAW 330 and communicates to PWD 500 through LAW 330 . PWD 500 includes a LAW 330 compatible with MDI 600 . Preferably, PWD 500 includes UIM 200 . Preferably, PWD 500 includes NBC 360 and communicates to long-range bi-directional 400 through NBC 360 .
[0038] [0038]FIG. 4D depicts another embodiment of the present system. PMD 100 communicates through data port 160 to MDI 600 . MDI 600 may include UIM 200 . Preferably, MDI 600 includes NBC 360 and communicates to long-range bi-directional network 400 through NBC 360 .
[0039] [0039]FIG. 4E depicts another embodiment of the present system. PMD 100 communicates through LAW 330 to another PMD 100 , which in turn communicates through data port 160 to a third PMD 100 .
[0040] [0040]FIG. 4F shows that a single medical device interface 600 can communicate simultaneously with multiple PMDs 100 .
[0041] About Local Area Wireless Communications
[0042] LAW 330 may include, but is not limited to, infrared or radio frequency (RF). Any suitable RF system that conforms to FCC requirements and power requirements may be used. Preferably, the BLUETOOTH standard is used. BLUETOOTH is a 2.4 GHz wireless technology employed to transport data between cellular phones, notebook PCs, and other handheld or portable electronic gear at speeds of up to 1 megabit per second. The BLUETOOTH standard was developed by the Bluetooth Special Interest Group (“BSIG”), a consortioum formed by Ericsson, IBM, Intel, Nokia, and Toshiba. The BLUETOOTH standard is designed to be broadband compatible and capable of simultaneously supporting multiple information sets and architecture, transmitting data at relatively high speeds, and providing data, sound, and video services on demand. Of course, other suitable wireless communication standards and methods now existing or developed in the future are contemplated in the present invention. In addition, embodiments are contemplated that operate in conjunction with a BLUETOOTH or BLUETOOTH-like wireless communication standard, protocol, or system where a frequency other than 2.4 GHz is employed, or where infrared, optical, or other communication means are employed in conjunction with BLUETOOTH or BLUETOOTH-like wireless RF communication techniques.
[0043] In one embodiment, the present system includes a transceiver in compliance with BLUETOOTH® technical specification version 1.0, herein incorporated by reference. In one embodiment, the present system includes a transceiver in compliance with standards established, or anticipated to be established, by the Bluetooth Special Interest Group.
[0044] In one embodiment, the present system includes a transceiver in compliance with standards established, or anticipated to be established, by the Institute of Electrical and Electronics Engineers, Inc., (IEEE). The IEEE 802.15 WPAN standard is anticipated to include the technology developed by the BLUETOOTH® Special Interest Group. WPAN refers to Wireless Personal Area Networks. The IEEE 802.15 WPAN standard is expected to define a standard for wireless communications within a personal operating space (POS) which encircles a person. In one embodiment, the transceiver is a wireless, bi-directional, transceiver suitable for short-range, omni-directional communication that allows ad hoc networking of multiple transceivers for purposes of extending the effective range of communication. Ad hoc networking refers to the ability of one transceiver to automatically detect and establish a digital communication link with another transceiver. The resulting network, known as a piconet, enables each transceiver to exchange digital data with the other transceiver. According to one embodiment, BLUETOOTH® involves a wireless transceiver transmitting a digital signal and periodically monitoring a radio frequency for an incoming digital message encoded in a network protocol. The transceiver communicates digital data in the network protocol upon receiving an incoming digital message.
[0045] According to one definition, and subject to the vagaries of radio design and environmental factors, short-range may refer to systems designed primarily for use in and around a premises and thus, the range generally is below a mile. Short-range communications may also be construed as point-to-point communications, examples of which include those compatible with protocols such as BLUETOOTH®, HomeRFTM, and the IEEE 802.11 WAN standard (described subsequently). Long-range, thus, may be construed as networked communications with a range in excess of short-range communications. Examples of long-range communication may include, Aeris MicroBurst cellular communication system, and various networked pager, cellular telephone or, in some cases, radio frequency communication systems.
[0046] In the event that transceiver includes a transceiver compatible with BLUETOOTH® protocol, for example, then the personal device may have sufficient range to conduct bidirectional communications over relatively short-range distances, such as approximately 10 to 1,000 meters or more. In some applications, this distance allows communications throughout a premise.
[0047] LAW 330 may include a separate, integrated or software based short-range bi-directional wireless module. The short-range network may be based upon HomeRF, 802.11, Bluetooth or other conventional or unconventional protocols. However, these are short-range networks and the meaning imposed herein is to include premises and facility based wireless networks and not to describe long-range networks such as cellular telephone networks used to communicate over long-distances. Such a system may include programmable or automatically selecting electronics to decide whether to conduct communications between the network module and an optional base station using the short-range module or the network module. In one embodiment the system may employ different portions of the network to provide short-range or long-range network connections, depending on the distance between the devices and the base stations. In one such embodiment, the network automatically adjusts for different required transmission distances.
[0048] In one embodiment, the transceiver is compatible with both a long-range communication protocol and a short-range communication protocol. For example, a person located a long distance away, such as several miles, may communicate with the transceiver using a cellular telephone compatible with the long-range protocol of transceiver.
[0049] Other short-range communication protocols are also contemplated and the foregoing examples are not to be construed as limitations but merely as examples.
[0050] About Long-Range Bi-directional Network Based Communications
[0051] Long-range network based communications 360 refers to a type of communications system that has a greater range than LAW 330 , primarily because more power is available and/or because of an FCC license.
[0052] NBC 360 may include a long-range wireless communications network 362 , such as a cellular network, satellite network, paging network, narrowband PCS, narrowband trunk radio, or other wireless communication network. Combinations of such networks and other embodiments may be substituted without departing from the present system.
[0053] In one embodiment, the long-range wireless network 362 is a cellular communications network. In another embodiment, the long-range wireless network is a paging network. In another embodiment the long-range wireless network is a satellite network. In another embodiment the long-range wireless network is a wideband or narrowband PCS network. In another embodiment the long-range wireless network is a wideband or narrowband trunk radio module. Other networks are possible without departing from the present system. In one embodiment, the NBC 360 supports multiple network systems, such as a cellular module and a two-way paging module, for example. In such embodiments, the system may prefer one form of network communications over another and may switch depending on a variety of factors such as available service, signal strength, or types of communications being supported. For example, the cellular network may be used as a default and the paging network may take over once cellular service is either weak or otherwise unavailable. Other permutations are possible without departing from the present system.
[0054] The long-range wireless network 362 employed may be any consumer or proprietary network designed to serve users in range of the detection system, including, but not limited to, a cellular network such as analog or digital cellular systems employing such protocols and designs as CDPD, CDMA, GSM, PDC, PHS, TDMA, FLEX™, ReFLEX™, iDEN™, TETRA™, DECT, DataTAC™, and Mobitex™, RAMNET™ or Ardis™ or other protocols such as trunk radio, Microburst™, Cellemetry™, satellite, or other analogue or digital wireless networks or the control channels or portions of various networks. The networks may be proprietary or public, special purpose or broadly capable. However, these are long-range networks and the meaning imposed herein is not to describe a premises or facility based type of wireless network.
[0055] The long-range wireless network 362 may employ various messaging protocols. In one embodiment Wireless Application Protocol (WAP) is employed as a messaging protocol over the network. WAP is a protocol created by an international body representing numerous wireless and computing industry companies. WAP is designed to work with most wireless networks such as CDPD, CDMA, GSM, PDC, PHS, TDMA, FLEX, ReFLEX, iDEN, TETRA, DECT, DataTAC, and Mobitex and also to work with some Internet protocols such as HTTP and IP. Other messaging protocols such as iMode™, WML, SMS and other conventional and unconventional protocols may be employed without departing from the design of the present embodiment.
[0056] As an example, these long-range communication protocols described above may include, but are not limited to, cellular telephone protocols, one-way or two-way pager protocols, and PCS protocols. Typically, PCS systems operate in the 1900 MHZ frequency range. One example, known as Code-Division Multiple Access (CDMA, Qualcomm Inc., one variant is IS-95) uses spread spectrum techniques. CDMA uses the full available spectrum and individual messages are encoded with a pseudo-random digital sequence. Another example, Global Systems for Mobile communications (GSM), is one of the leading digital cellular systems and allows eight simultaneous calls on the same radio frequency. Another example, Time Division Multiple Access (TDMA, one variant known as IS-136) uses time-division multiplexing (TDM) in which a radio frequency is time divided and slots are allocated to multiple calls. TDMA is used by the GSM digital cellular system. Another example, 3G, promulgated by the ITU (International Telecommunication Union, Geneva, Switzerland) represents a third generation of mobile communications technology with analog and digital PCS representing first and second generations. 3G is operative over wireless air interfaces such as GSM, TDMA, and CDMA. The EDGE (Enhanced Data rates for Global Evolution) air interface has been developed to meet the bandwidth needs of 3G. Another example, Aloha, enables satellite and terrestrial radio transmissions. Another example, Short Message Service (SMS), allows communications of short messages with a cellular telephone, fax machine and an IP address. Messages are limited to a length of 160 alpha-numeric characters. Another example, General Packet Radio Service (GPRS) is another standard used for wireless communications and operates at transmission speeds far greater than GSM. GPRS can be used for communicating either small bursts of data, such as e-mail and Web browsing, or large volumes of data.
[0057] In one embodiment, a long-range communication protocol is based on two way pager technology. Examples of two way pager protocols include ReFLEX™ (Motorola) format, InFLEXion© (Motorola) format, NexNet© (Nexus Telecommunications Ltd. of Israel) format and others.
[0058] Other long-range communication protocols are also contemplated and the foregoing examples are not to be construed as limitations but merely as examples.
[0059] About the Personal Wireless Device and Medical Device Interface
[0060] A medical device interface 600 is similar to a personal wireless device 500 except that network based communications 360 is optional with a medical device interface 600 .
[0061] The personal wireless device 500 or medical device interface 600 may be of several different designs. For example, in one embodiment it may be a “response messaging” capable two-way pager. This is service where a two-way pager receives a message and optional multiple-choice responses. The user can select the appropriate responses. Such a design may be adapted to provide basic control options related to the system.
[0062] In another embodiment, the personal wireless device 500 or medical device interface 600 may be a programmable two-way paging device such as the Motorola PageWriter™ 2000. This is a class of device that acts as both a two-way pager and a handheld computer also known as a PDA (Personal Digital Assistant).
[0063] In another embodiment, the personal wireless device 500 or medical device interface 600 may be a cellular telephone. The cell phone may be analog or digital in any of the various technologies employed by the cell phone industry such as PCS, or CDMA, or TDMA, or others. The cell phone may have programmable capability such as is found in a Nokia™ 9000 series of devices.
[0064] In embodiments where the user employs standard or adapted paging or cell phones as their personal wireless device 500 or medical device interface 600 , security passwords may be entered by using numeric or other keys on a phone. In another embodiment, the security password may be entered by speaking words. In this embodiment, the system may use word recognition, voice recognition or a combination of these technologies. In the embodiment of a pager, a distinct order of pressing certain keys could provide the equivalent of a security code. For example, 3 short and 1 long on a certain key; or once on key ‘a’, once on key ‘b’, and once more on key ‘a’.
[0065] In another embodiment, the personal wireless device 500 or medical device interface 600 is a handheld computer. Many personal digital assistants (PDAs) offer programmable capability and connectivity to various types of long-range wireless networks. An example of this type of device is the PalmPilot™ or Palm series of devices manufactured by Palm, Inc. In these embodiments where a programmable personal wireless device 500 or medical device interface 600 is used such as a PalmPilot, PageWriter or programmable cell phone, the programmable nature of the devices facilitates the implementation of industry-standard designs and would allow for the development of a program written for the devices.
[0066] In another embodiment, a special manufactured device may be manufactured to serve the needs of the system user.
[0067] In another embodiment, the personal medical device 100 is directly connected to a personal wireless device 500 that is manufactured as an integrated unit.
[0068] About the Central Communications Base Station
[0069] In one embodiment, the personal medical device 100 communicates with a device referred to herein as central communication base station 700 . Central communication base station 700 may include a first transceiver compatible with BLUETOOTH® or other short-range wireless network as described herein. Base station may provide a repeater service to receive a message using BLUETOOTH® and to retransmit the message using a different communication protocol or also using BLUETOOTH® communication protocol.
[0070] Base station 700 may also include a second transceiver or a wired interface having access to another communication network 750 . The second transceiver or wired interface may retransmit the signal received from the personal device 100 or received from some other device. In this way, central communication base station 700 may serve to extend the communication range of the personal device. For example, a message between the personal device and an emergency-dispatch center may be coupled to communication with the base station 700 connected network 750 and a short-range wireless network. Communications between the personal device 100 and a device coupled to communicate with the base station 700 connected network 750 may be considered long-range communications.
[0071] Base station may 700 also communicate bi-directionally within the premise with one or more additional compatible devices. These may be a second personal device 100 or any other device.
[0072] The base station connected network 750 may be a public switched telephone network (PSTN), a pager communication network, a cellular communication network, a radio communication network, the Internet, or some other communication network. It will be further appreciated that with a suitable repeater, gateway, switch, router, bridge or network interface, the effective range of communication of a short-range transceiver may be extended to any distance. For example, base station 700 may receive transmissions on a BLUETOOTH® communication protocol and provide an interface to connect with the base station connected network 750 , such as the public switched telephone network (PSTN) using the base station link. In this case, a wired telephone at a remote location can be used to communicate with the personal device 100 . As another example, the range may be extended by coupling a BLUETOOTH® transceiver with a cellular telephone network, a narrow band personal communication systems (“PCS”) network, a CELLEMETRY® network, a narrow band trunk radio network or other type of wired or wireless communication network.
[0073] Examples of devices compatible with such long-range protocols include, but are not limited to, a telephone coupled to the public switched telephone network (PSTN), a cellular telephone, a pager (either one way or two way), a personal communication device (such as a personal digital assistant, PDA), a computer, or other wired or wireless communication device.
[0074] In one embodiment, the long distance network 750 may include a telephone network, which may include an intranet or the Internet. Coupling to such a network may be accomplished, for example, using a variety of connections, including a leased line connection, such as a T-1, an ISDN, a DSL line, or other high-speed broadband connection, or it may entail a dial-up connection using a modem. In one embodiment, the long distance network 750 may include a radio frequency or satellite communication network. In addition, one or more of the aforementioned networks may be combined to achieve desired results.
[0075] Short-range communication protocols, compatible with the base station may include, but are not limited to, wireless protocols such as HomeRFTM, BLUETOOTH®, wireless LAN (WLAN), or other personal wireless networking technology. HomeRFTM, currently defined by specification 2.1, provides support for broadband wireless digital communications at a frequency of approximately 2.45 GHz.
[0076] Other long-range and short-range communication protocols are also contemplated and the foregoing examples are not to be construed as limitations but merely as examples.
[0077] The base station 700 may be compatible with more than one communication protocol. For example, the base station may be compatible with three protocols, such as a cellular telephone communication protocol, a two-way pager communication protocol, and BLUETOOTH® protocol. In such a case, a particular personal device 100 may be operable using a cellular telephone, a two-way pager, or a device compatible with BLUETOOTH®.
[0078] In one embodiment, the personal device 100 can communicate with a remote device using more than one communication protocols. For example, the personal device may include programming to determine which protocol to use for communicating.
[0079] The determination of which communication protocol to use to communicate with a remote device may be based on power requirements of each transceiver, based on the range to the remote device, based on a schedule, based on the most recent communication from the remote device, or based on any other measurable parameter. In one embodiment, the personal device 100 communicates simultaneously using multiple protocols.
[0080] In one embodiment, there are various types of networks connected to the base station 700 . These may be telephone networks, modem connections, frame relay systems, spread-spectrum, DSL, cable modems, dedicated line or other similar wire based communication and data networks. In addition, these may be long-range, bi-directional, wireless networks as describe above.
[0081] In one embodiment, there is a connection to the Internet using various Internet protocols such as TCP/IP/HTTP/HTCP and others.
[0082] Other Connections from the Personal Medical Device
[0083] In one embodiment, signals generated by the medical device are received by a central monitoring station 800 . The central monitoring station 800 may include operators that provide emergency dispatch services. An operator at the central monitoring station 800 may also attempt to verify the authenticity of a received alarm signal. In one embodiment, the alarm signal generated by the personal device 100 is first transmitted to a user, using either a short-range or long-range communication protocol, who then may forward the alarm signal to a monitoring station if authentic or cancel the alarm signal if the alarm is not valid.
[0084] In one embodiment, the personal device 100 may communicate with a building control or security system 900 by communicating using its transceiver. For example, the personal device may operate as an auxiliary input to a building control or security system. In which case, if the personal device 100 detects a security event, by way of a sensor coupled to the personal device, then an alarm signal is transmitted from the personal device, via its transceiver, to the building security system. The building security system, if monitored by a central monitoring station, then forwards the alarm signal to the monitoring station. In one embodiment, the personal device 100 can receive a transmission from a separate building control or security system. If the building security system detects an alarm condition, then the security system can, for example, instruct the personal device to repeatedly toggle power to load a flashing light visible from the exterior of the building that may aid emergency personnel in locating an emergency site. Alternatively, the personal device can establish communications with a predetermined remote device or a central monitoring service.
[0085] Routing Paths from the Personal Medical Device
[0086] The present invention includes, but is not limited to, the following routing paths from the personal device 100 :
[0087] 1) short-range wireless to long-range wireless in a pre-designed system. That is, both the personal device 100 and the device with which it communicates have been set up in communication in advance. For example, the personal device 100 is connected to a short-range wireless module that communicates to a cell phone or other wireless network device carried by the user.
[0088] 2) short-range wireless to long-range wireless “ad hoc”: the personal device sets up a short-range “ad hoc” network to any available long-range network connection.
[0089] 3) short-range wireless to any network connection. For example, the personal device 100 is connected to a short-range wireless module that communicates to a telephone or Internet base station in a person's home.
[0090] 4) long-range wireless directly. For example, the personal device 100 is directly connected to a long-range wireless network module.
[0091] Transmission to the Personal Medical Device
[0092] In addition, feedback may be transmitted to a remote device based on the operation of the personal device. For example, if a user issues a command to the personal device using a cellular telephone, then the display of the phone will indicate the changes arising from the command. In one embodiment, the cellular telephone, the base station, emergency monitoring center, or other device displays real time information from the personal device 100 .
[0093] Various methods may be used to communicate with, or send a message or instruction to, the personal device 100 from a remote location. For example, using a cellular telephone, a user may speak a particular phrase, word or phoneme that is recognized by the cellular telephone which then generates and transmits a coded message to the personal device 100 . As another example, the user may manipulate a keypad on the telephone to encode and transmit a message to the personal device.
[0094] Data Types Communicated to and from the Personal Medical Device
[0095] Table I below shows the types of data that may be communicated to and/or from the personal device 100 , and the direction of data flow.
TABLE I Data Type Direction of transmission diagnosis (suggested by PMD/MDI or from bi-directional medical center manual request from PMD identification (e.g., bluetooth serial from PMD number, PMD ID, account number) use alert (e.g., opening a container, etc.) from PMD activation (shock, release medication, brain bi-directional stimulation) body reading (electrical, chemical, analog, from PMD digital, mechanical, temperature, etc.) two-way voice (to responding agency, bi-directional bystander, or patient) digital instructions bi-directional standard I/O ports bi-directional camera: visual, video exhange bi-directional authorizations and authentications bi-directional Security codes, data confirmations, bi-directional acknowledgements transceiver activation to PMD encryption bi-directional interaction with related PMDs bi-directional verification (alarms, emergencies) bi-directional
[0096] Data Flow Examples
[0097] One possible example of data flow to and from the personal device 100 is shown in FIG. 5.
[0098] The personal device 100 may be implanted in the victim V, or carried on the person of the victim V. For example the personal device 100 may be a pacemaker that is imbedded in the chest cavity of the victim V and connected by leads to the victim's heart, as is well known in the art.
[0099] In this example, the victim V undergoes some sort of cardiac problem, such as tachycardia, that causes the personal device 100 to attempt to establish communication with a caregiver. While this is going on, a bystander B attempts to give aid to the victim V. The bystander B is carrying on his person a medical device interface 500 or a personal wireless device 600 . When the personal device 100 attempts to establish communication, it sets up communication with the personal wireless device 600 by local area wireless 330 . For example, if the personal device 100 and personal wireless device 600 both use BLUETOOTH for local area wireless communications, the personal device 100 and personal wireless device 600 will follow the communications protocols of the BLUETOOTH standard and establish communications.
[0100] Next, the personal device 100 may request the personal wireless device 600 to establish a connection to the dispatcher or medical caregiver D, using network based communications 360 . For example, the personal wireless device 600 may be a cell phone or PDA. Using network based communications 360 , the personal wireless device establishes a connection to the computer of the dispatcher or medical caregiver D.
[0101] Alternatively, the personal wireless device 600 may establish a connection to an automatic processor P, which has database DB that contains information on the victim's medications, medical history, pre-existing conditions, possible diagnoses, personal records, personal device information, treatment strategies, response plans, identities or responsing agencies, and other data.
[0102] Either the dispatcher D or the processor P may then send an inquiry through the personal wireless device 600 to the personal device 100 , instructing the personal device 100 to send various data, for example, electrocardiogram data. Using this transmitted data, the dispatcher or processor may then make a diagnosis and identify a treatment strategy.
[0103] The dispatcher D may then alert responding personnel R, such as a paramedic unit, to travel to the victim V. In the event that the victim's personal device 100 has location identification capability (discussed below), the dispatcher D will be able to give the exact location of the victim to the responding personnel R. The dispatcher D may also alert responsible parties RP such as the victim's parents of the location.
[0104] Until the responding personnel R reach the scene, the dispatcher D may establish voice communications with the bystander B through the bystander B's personal wireless device 600 . The dispatcher may ask the bystander B to use the camera 280 of the personal wireless device to transmit an image of the victim V. The dispatcher D may give the bystander B instructions on how to render first aid to the victim V until the responding personnel R arrive.
[0105] When the responding personnel R reach the victim, they may establish communications through local area wireless 330 from their medical device interface 500 to the victim's personal device 100 , request data from the personal device 100 , and request the personal device 100 to take some action, such as dispensing medication to the victim V. Their medical device interface 500 may also establish communication with the dispatcher D or medical caregiver using network based communications 360 .
[0106] The above is just one example of possible data flow to and from the personal device 100 . Many other scenarios are possible.
[0107] [0107]FIG. 6 summarizes data flow from the point of view of a remote caregiver, showing that comprehensive data creates the best options for the remote caregiver.
[0108] Location Management
[0109] Optionally, the personal device 100 includes the ability to detect its own location and to communicate this location to authorized requesters. The location-determining function may be device-based, network-based, or a combination of device-based and network-based, as described in co-pending U.S. Patent Application entitled “Method and System for Wireless Tracking”, filed Mar. 28, 2002, herein incorporated by reference, in the Detailed Description, and in FIGS. 4A, 4B and 4 C therein.
[0110] As discussed in the referenced patent application (FIG. 4A), the personal device 100B may include a GPS receiver positioned internal to device 100b. FIG. 4B of the referenced patent illustrates a communication network 200A having integral LDS 165A. Location information, in one embodiment, is based on a geographical location of first device 100C and is determined based on timing information for wireless signals between network 200A and device 100C. Second device 300 is also connected to communication network 200A. In one embodiment, a server coupled to network 200A includes programming to determine location information and selected clients accessing the server are able to receive the location information. Selected clients are those authorized to receive the location information. FIG. 4C of the referenced patent application illustrates LDS 145B and LDS 165B within first device 100D and network 200B, respectively. In such an embodiment, the combination of information generated by LDS 145B and LDS 165B provides the location information.
[0111] As described in the referenced patent application, the device 100 may include an electronic circuit or an electronic circuit and programming to determine location. In one embodiment, LDS 145 uses a terrestrial location system. There are several varieties of terrestrial solutions, including time differential, signal strength, angle of arrival and varieties of triangulation. In one described embodiment, LDS 145 uses a combination of terrestrial and satellite navigation systems.
[0112] Security
[0113] The system and method of the present invention may also include various types of security arrangements.
[0114] It will be appreciated that the ability of various entities spread around a network to receive and/or transmit to and control the personal device 100 requires some measure of security. Only authorized agents should be allowed access to the device 100 . For example, in the example shown in FIG. 5, only responding personnel RP (such as trained paramedics) who are on the scene of the event may be allowed to send a command to the personal device 100 causing the personal device 100 to dispense medication to the victim. Certainly, the bystander B should not be allowed this level of access, even though the bystander B's personal wireless device 600 may be acting as an intermediary in communication from the personal device 100 to the dispatcher D.
[0115] The following are possible embodiments of security and not meant to be exclusive.
[0116] First, data transmitted to and from the personal device 100 may be encrypted by standard encryption algorithms, making it essentially impossible for the unsophisticated interceptor to interpret the data.
[0117] Second, voice and visual channels of transmission may be controlled for activation by the personal device 100 or by an authorized entity, but may not necessarily be encrypted.
[0118] Third, security keys may be held by a central agency and provided to the responding personnel RP.
[0119] Fourth, the user of the personal device 100 may have a security key that he can enter to release information or access to authorized parties.
[0120] A number of strategies may be employed for authorization and authentication. For example, biometrics may be used. Biometrics refers to the measurement of some bodily parameter (such as fingerprint, retinal scan, etc.) that is unique to the individual.
[0121] Second, a public/private key system can be used in which access to both keys is required for decoding an encrypted message. Each party that wishes to participate in secure communications must create a key set for encrypting and decrypting messages. One key is private and the other is public. The public key is for exchanging with other parties with whom you who wish to participate in secure communication sessions. Each individual owner must keep the private portion of the key secure. The private key also has a secret pass phrase, in the event that it is ever ‘misappropriated’. Public key/private key technology allows the sender to sign a message with their private key. When the recipient receives the message, they can validate the authenticity of the signature because they have the sender's public key.
[0122] Third, a user needing access to the device 100 may make a request for such access to a responsible third party.
[0123] Fourth, the personal device 100 may have pre-authorized authority for certain users.
[0124] A number of authorization strategies are discussed in co-pending U.S. Patent Application, entitled “Method and System for Wireless Tracking”, filed Mar. 28, 2002, herein incorporated by reference, in the Detailed Description.
[0125] About Power Management
[0126] In a number of scenarios, the power consumed by the personal device 100 is critical. For example, it the personal device 100 is implanted in a human being, long battery life is essential.
[0127] Although some communications systems, such as BLUETOOTH, have low power consumption states, nevertheless power is being consumed. Further, in an environment such as BLUETOOTH, a BLUETOOTH transceiver that is powered on may constantly be wakened from the low power states whenever a transmission is received from another BLUETOOTH transceiver.
[0128] It is therefore an important aspect of the present invention to provide a completely powered-off state for the bi-directional communications module, and for a means of signaling the bi-directional communications module to transition from the powered-off state to the powered-on state. The transceiver must consume no power in the powered-off state.
[0129] A number of mechanisms for doing this signaling are possible. First, a mechanical signal, such as throwing a switch or applying pressure to a pad, may be used. Second, a magnetic signal may be used, as in passing a magnet in the vicinity of the communications module. Third, sound or ultra-sound may be used. Fourth, infrared may be used provided there is a direct line of sight to the communications module. Sixth, radio frequency may be used, which has the advantage of not requiring line of sight to the communications module.
[0130] Radio frequency is already being used for applications such as automated meter reading and electronic article surveillance. Such applications included un-powered RF receivers such as RFID tags.
[0131] [0131]FIG. 7 shows a general block diagram of this power management function. The personal device 100 is modified to include an un-powered RF receiver 710 that is tuned to a particular frequency. Power-up device 800 has an RF transmitter tuned to the same frequency. When a signal is sent to the RF receiver 710 , the receiver 710 gathers the RF energy and activates logic 720 . Any code transmitted on the frequency is passed to the logic 720 , which decodes it and compares it to a proper wake-up code. If a proper wake-up code is received, logic 720 signals the processor 130 to power-on the communications module 300 . The wake-up code is optional, in that the receiver 710 may just signal the processor 130 directly without decode. | A personal and/or institutional health and wellness communications system, which may be used for a variety of emergency and non-emergency situations using two-way communication devices and a bi-directional communication network. In one application two-way pagers are adapted for use in the system. In one application cellular devices are adapted for use in the system. In one application an assisted living response center is established using various embodiments of the present personal and/or institutional communications system. The system provides multiple levels of prioritization, authentication of person (task, step, process or order), and confirmation via interrogation of person, device, or related monitor. One embodiment provides a method for receiving, evaluating and responding to calls received from a subscriber, patient, related party, or health care provider or health care system. | 7 |
BACKGROUND OF THE INVENTION
The present invention generally relates to circuit board apparatus and, more particularly, to an improved circuit board assembly having a mechanism to generate induced air flow for heat dissipation.
In order to enable desktop and other computers to rapidly process graphics and game technology, add-on units generally referred to as “graphics cards” or “VGA” cards” are often installed in computer devices. Such cards include a separate processor, called a GPU, one or more memory chips, and other required circuitry, all mounted to a circuit board including an edge connector that is adapted to plug into an available slot in the associated computer device.
Such cards often have extremely large computing power and, as a consequence, generate substantial heat that if not dissipated will adversely affect operation of the graphics card. Heretofore, various approaches have been tried to dissipate or otherwise remove heat from the thermal energy generating components and normally include some type of fan for blowing air across the heat generating components, and perhaps some type of thermal mass capable of sinking the heat generated. The thermal energy generated by the GPU and memory chips for more sophisticated graphics and games, such as 3-D graphics, may approach the maximum capacity of the existing heat dissipation mechanisms. Thus, there is a need for an improved heat extraction or dissipation mechanism, which can be added to a standard graphics card to efficiently remove thermal energy generated thereby.
SUMMARY OF THE INVENTION
In one aspect of the present invention, an apparatus with improved heat dissipation includes a circuit board having at least one heat generating component affixed thereto. The apparatus also includes a fan and carrier therefor including a heat sink plate having a portion thermally coupled to the heat generating component. The heat sink plate includes a means for forming at least one slot proximate the portion. The fan is adapted to direct airflow cross the portion. The thermal energy generated by the heat generating component is transferred to the fan carrier and ultimately removed from the fan carrier by the airflow. The airflow inducts a secondary airflow drawn through the slot during operation thereby to enhance transfer of the thermal energy from the heat generating component.
In another aspect of the present invention, an assembly includes a printed circuit board with at least one heat generating component affixed thereto, and a heat dissipating mechanism also affixed to the printed circuit board for removing thermal energy from the heat generating component. An improved heat dissipating mechanism includes a fan and carrier therefor including a heat sink plate having a portion thermally coupled to the heat generating component. The heat sink plate includes a means for forming at least one slot proximate the portion. The fan is adapted to direct airflow cross the portion. The thermal energy generated by said heat generating component is transferred to the fan carrier and ultimately removed from the fan carrier by the airflow. The airflow inducts a secondary airflow drawn through the slot during operation thereby to enhance transfer of the thermal energy from the heat generating component.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a presently preferred embodiment of a graphics card assembly including a heat dissipating subassembly in accordance with the present invention;
FIG. 2 is an exploded perspective view showing the several components of the assembly illustrated in FIG. 1 ;
FIG. 3 is a partial cut away perspective view of a fan carrier of FIG. 2 , showing the thermal block included therein;
FIG. 4 is a top perspective view of the thermal block of FIG. 3 ;
FIG. 5 is a broken bottom perspective view showing the lower plate of FIG. 2 and the thermal block affixed thereto;
FIG. 6 is a schematic cross sectional view of the assembly of FIG. 1 , taken along the direction 6 - 6 in FIG. 4 ;
FIG. 7 is a schematic cross sectional view of another embodiment of a graphics card assembly, taken along the direction 7 - 7 of FIG. 4 in accordance with the present invention;
FIG. 8 is a schematic cross sectional view of yet another embodiment of a graphics card assembly, taken along the direction 7 - 7 in accordance with the present invention; and
FIG. 9 is a schematic cross sectional view of still another embodiment of a graphics card assembly, taken along the direction 7 - 7 in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The following detailed description is of currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
Referring to FIG. 1 of the drawing, a graphics card assembly in accordance with the present invention is illustrated at 10 and includes a printed circuit board 12 having an edge connector 14 . For the purpose of illustration, the printed circuit board 12 is described as a graphics card in the present application. However, it should be apparent to those of ordinary skill that the printed circuit board 12 can be other types of circuit board, such as motherboard, having one or more heat generating components, such as CPU and chipset. Various cabling connectors 16 , 18 , and 20 are secured to the printed circuit board 12 and used to communicate electrical signals into and out of the assembly. Affixed to the printed circuit board 12 is a fan carrier 40 secured to a top cover 22 by means of screws or other suitable fasteners 51 a. The near right side portion of the top cover 22 , as depicted, can be formed by bending a portion of the top cover 22 that is preferably formed of, but not limited to, metal, along the substantially entire length of the assembly 10 . The top cover 22 includes a circular aperture 23 and slots 26 , 28 through which airflow can pass. Positioned within the aperture 23 and affixed to and carried by the carrier 40 is a fan unit 24 . Note that the upper surface of the top cover 22 is substantially flat and ideally suited for decorative graphics, manufactures or marketers trademarks, etc.
In use, the graphics card assembly 10 is oriented so as to have the near right side of the assembly, as depicted, facing a slot on a computer motherboard and mounted thereto by slipping the edge connector 14 into the slot so that the assembly communicates with devices on the motherboard via the edge connector 14 . As describe in more detail below, heat generated by the electronic components of the assembly is transferred to the fan carrier 40 that is cooled by the airflow created by the fan unit 24 , as will also be further elucidated below.
In FIG. 2 , the top cover 22 , fan unit 24 , and fan carrier 40 are shown exploded away from the printed circuit board 12 . The board 12 includes various types of electronic components 32 . Active heat generating components (or, shortly active component) will be positioned at 30 and can generate heat energy during operation. The active heat generating components, such as memory, are not shown in FIG. 2 for brevity. As will be further explained below, the lower plate 41 of the fan carrier 40 may have protrusions that intimately engage the top surfaces of the active components and transfer heat energy therefrom.
The foremost side of the top cover 22 , as depicted in FIG. 2 , overlaps the front side of the fan carrier 40 along the length of the fan carrier 40 . The fan carrier 40 includes threaded openings 50 for receiving the screws or other suitable fasteners 51 a that secure the top cover 22 to the fan carrier 40 . The top cover 22 also includes a tap 25 with a hole or opening through which the screw 51 b for mounting the top cover 22 to the fan carrier 40 pass. The top cover 22 further includes one or more holes or openings (not shown in FIG. 2 ) formed on the rearmost right side, as depicted in FIG. 2 , through which one or more the screws 51 c for mounting the top cover 22 to the fan carrier 40 pass. The screws 51 a , 51 b , and 51 c engage threaded openings formed in the fan carrier 40 .
As depicted, a GPU PCB 34 is mounted on the board 12 by means of Ball Grid Array (BGA) solder bumps 38 , and a GPU 36 is mounted on the GPU PCB 34 . The GPU 36 may generate substantial amount of heat energy during operation, which will be transferred to and dissipated by the fan carrier 40 . As will be further explained below, the fan carrier 40 includes a thermal block positioned above and being in physical contact with the GPU 36 to transfer heat energy therefrom. As discussed above, the assembly 10 can be used to remove thermal energy from other types of heat generating components, such as CPU and chipset, affixed to a motherboard (not shown in FIG. 2 ).
The fan carrier 40 includes heat conducting components: a lower plate (or, equivalently a heat sink plate) 41 , an upper plate 44 , and elongated vanes 42 disposed between the lower and upper plates. The heat conducting components may be formed of aluminum, copper, steel, or other suitable material capable of serving as heat sink. The fan unit 24 will be installed inside a space 46 in the fan carrier 40 . In FIG. 2 , for the purpose of illustration, a portion of the upper plate 44 is broken away, revealing the vanes 42 and the lower plate 41 thereunder. The fan carrier 40 with fan unit 24 installed thereto is aligned with the aperture or opening 23 so that the fan unit 24 can draw cooling air therethrough during operation. The air drawn in by the fan unit 24 passes through the air passageways defined by the upper plate 44 , lower plate 41 and vanes 42 , extracting thermal energy from the fan carrier before it is discharged through the slots 26 and the openings in the rearmost left side of the top cover 22 , as depicted in FIG. 2 . The fan carrier 40 further includes radiator fins 48 standing up from the lower plate 41 and configured to radiate heat energy to the surrounding air. The top cover 22 includes slots 28 and 54 for ventilating the radiator fins 48 .
The lower plate 41 of the fan carrier 40 is secured to the printed circuit board 12 by multiple screws or other suitable fasteners 52 , providing a firm contact between the top surface of the GPU 36 and the lower plate 41 , more specifically, the thermal block (now shown in FIG. 2 ) affixed to the lower plate 41 .
It is noted that two or more of the components of the fan carrier 40 may be formed as an integral body. For instance, the radiator fins 48 and the lower plate 41 may be formed as an integral body by means of molding. It is also noted that the top flat portion of the top cover 22 may be spaced apart from the upper plate 44 or in direct contact with the upper plate 44 so that a portion of the heat energy contained in the upper plate 44 can be transferred to the top cover 22 and dissipated by the top cover 22 .
FIG. 3 is a partial cut away perspective view of the fan carrier 40 revealing the upper surface of the thermal block 60 included therein as well as the flow direction vanes 42 which cross thereover, the vanes 42 being broken away and shown in phantom dashed lines for clarity. FIG. 4 is a perspective view showing the top surface of the thermal block 60 removed from an opening 63 in the plate 41 (depicted in FIG. 3 ) together with some of the vanes 42 (shown in phantom dashed lines for clarity). As depicted, the thermal block 60 has a generally rectangular shape with tabs 70 formed at the four corners thereof. Each tab 70 has a hole 73 through which a fastener 72 for securing the thermal block 60 to the lower plate 41 passes. As a variation, the tabs 70 may be soldered or brazed to the lower plate 41 . The thermal block 60 is installed in the rectangular opening 63 formed in the lower plate 41 and includes recessed portions 64 formed on two opposite side edges thereof. The thermal block 60 also includes two elongated recessed portions 62 formed in the opposite ends thereof. When installed in the opening 63 , the recessed portions 62 , 64 form slots through which airflow can pass. Hereinafter, the terms recessed portion and slot are used interchangeably. The size, shape and number of recessed portions 62 , 64 may be varied without deviating from the spirit and scope of the present invention. The thermal block 60 may be formed of aluminum, steel, copper, or other suitable material capable of serving as a heat sink.
As will be further explained below in conjunction with FIG. 6 , the thermal block 60 is flush-mounted relative to the upper surface of lower plate 41 so that the top surface of the thermal block 60 and the top surface of the lower plate 41 are on the same plane. In FIG. 3 , only three vanes are shown to extend across the thermal block 60 . However, it should be apparent to those of ordinary skill that the lateral intervals between vanes 42 can be varied so as to change the number of vanes crossing the thermal block 60 .
As the cooling air drawn in by the fan unit 24 through the aperture 23 ( FIG. 2 ) is caused to pass through the air passageways 65 formed by the vanes 42 , the air extracts heat energy from the fan carrier 40 . Due to the airflow across the passageways 65 , the pressure in the passageways 65 is lower than the ambient atmospheric pressure, generating a pressure difference between the top and bottom surfaces of the lower plate 41 . This pressure difference in turn induces secondary air flow 67 through the slots 62 and 64 , i.e., the pressure difference inducts additional airflow for cooling the thermal block 60 into the air passageways 65 . An experiment performed by the present inventor shows that the secondary flow 67 reduces the temperature of the thermal block 60 by at least one degree Celsius.
FIG. 5 is a broken perspective view showing the bottom surfaces of thermal block 60 and a portion of the lower plate 41 . FIG. 6 is a schematic cross sectional view of a portion of the assembly 10 , taken along the line 6 - 6 in FIG. 4 . As depicted, the thermal block 60 is aligned with the GPU 36 in the horizontal direction so that the bottom surface of the thermal block 60 physically engages the top surface of the GPU 36 . Alternatively, the thermal block 60 may be secured to the GPU 36 by applying heat conducting adhesive therebetween. As discussed above, the secondary air flow 67 passes through the slots 62 , 64 , further cooling the thermal block 60 during operation.
Formed on the bottom surface of the lower plate 41 are multiple rectangular pads or protrusions 33 intended to physically engage the top surfaces of active components to be positioned at 30 (shown in FIG. 2 ) and to transfer thermal energy therefrom to plate 41 . The lower plate 41 may also include spacing legs or risers 35 ( FIG. 5 ) having threaded holes that receive the fasteners 52 (shown in FIG. 2 ) for securing the lower plate 41 to the printed circuit board 12 . The thermal energy generated by the CPU 36 and active components will be respectively transferred to the thermal block 60 and the protrusions 33 , and thence to the lower plate 41 .
In an alternative embodiment, one or more flow directing fences 68 (shown in dashed lines in FIGS. 5 and 6 ) may be disposed beneath the bottom surface of the lower plate 41 . The fences 68 may have a substantially bar shape and extend in a direction substantially parallel to the elongated slots 62 , defining opposite sides of a space that surrounds the bottom surface of the thermal block 60 (and the GPU 36 ). The fences 68 impede airflow thereacross so that most of the air flowing in the secondary flow 67 into and through the openings 62 and 64 comes from the space surrounding block 60 to thereby enhance the flow motion around and beneath the perimeter of the thermal block 60 . As a variation, the fences 68 and the lower plate 41 may be formed as an integral body.
FIG. 7 is a schematic cross sectional view of another embodiment of a graphics card assembly 100 , taken along a line similar to the direction 7 - 7 shown in the embodiment of FIG. 4 . As depicted, a plurality of vanes 104 may be affixed to the top surfaces of the lower plate 102 and the thermal block 112 by means of soldering, brazing, or heat conduction adhesive to form flow passageways 106 directed normal to the plane of the drawing. Each vane 104 has a generally c-shaped cross section, i.e., each vane is formed by an elongated c-shaped channel member having upper and lower flanges. The flanges of each vane member contact an adjacent vane member to form an air passageway 106 . For those vane members passing directly over openings 108 in the perimeter of the thermal block 112 , a corresponding opening 107 is formed in the lower flange thereof so as not to block the openings 108 . As in the previously described embodiment, a secondary flow induced by the pressure difference between the top and bottom surfaces of the lower plate 102 passes through the slots 108 and openings 107 . In this embodiment, the top flanges of the vanes 104 collectively form a substantially flat plate having segmented sections, where the plate is substantially equivalent to and thereby replaces the upper plate 44 in the embodiment of FIG. 3 . It is noted that the assembly 100 may have flow directing fences (not shown in FIG. 7 ) beneath the lower plate 102 as an option.
FIG. 8 is a schematic cross sectional view of yet another embodiment of a graphics card assembly 120 , taken along the direction 6 - 6 in accordance with the present invention. As depicted, the components of the assembly 120 are similar to those of the assembly 10 , with the principal difference being that the upper plate 122 includes a varying surface curvature relative to the lower plate 126 . More specifically, the upper plate 122 has a portion A that is convex relative to the lower plate 126 , and the slots 124 are located within the portion A. The pressure in an air duct or passageway decreases as the cross sectional area of the passageway decreases. Thus, in air passageways defined by the upper plate 122 , lower plate 126 , and vanes 128 , the air pressure within the portion A will be lower than that outside the portion A. Given that the static pressure at the bottom surface of the lower plate 126 is the same as the pressure at the bottom surface of the lower plate 41 in FIG. 3 , the pressure difference between the top and bottom surfaces of the lower plate 126 will be larger than that between the top and bottom surfaces of the lower plate 41 . As the flow rate of secondary flow 130 increases as the pressure difference increases, the configuration of the upper plate 122 will enhance the secondary flow rate and thereby enhance the efficiency in cooling the thermal block 132 during operation. As a variation, flow directing fences 134 may be disposed beneath the lower plate 126 .
It is noted that the fan 24 could be reversed to draw cooling air from the slots 26 and opening sides of the top cover 22 and exhausted out through the opening 23 in the top cover 22 . Flow in this direction would likewise induct the secondary flow through the slots 62 , 64 , enhancing the efficiency in cooling the thermal block during operation.
In FIGS. 3 and 4 , the thermal block 60 and the lower plate 41 are shown as two components secured to each other. However, it should be apparent to those of ordinary skill that they can be molded as an integral body with the slots 62 and 64 formed therein. FIG. 9 is a schematic cross sectional view of yet another embodiment of a graphics card assembly 140 , taken along the direction 6 - 6 in accordance with the present invention. In this embodiment, the thermal block and lower plate form an integral body 142 . As a variation, flow directing fences 144 may be disposed beneath the plate 142 .
As discussed above, the exemplary embodiments of the assembly in FIGS. 1-9 are described as means for removing thermal energy from GPUs and active electronic components, such as memories. However, it should be apparent to those of ordinary skill that the assembly can be used to remove heat energy from other types of heat generating components, such as CPUs and chipsets. For instance, the thermal bock may be in contact with a CPU and/or a chipset affixed to a motherboard and transfer thermal energy from the CPU and/or a chipset. As a variation, the protrusion 33 can be arranged to physically engage the top surfaces of CPUs and/or chipsets and transfer thermal energy therefrom.
Notwithstanding that the present invention has been described above in terms of several alternative embodiments, it is anticipated that still other alterations and modifications will become apparent to those of ordinary skilled in the art after having read this disclosure. It is therefore intended that such disclosure be considered illustrative and not limiting, and that the appended claims be interpreted to include all such alterations, modifications and embodiments as fall within the true spirit and scope of the invention. | A cooling mechanism to dissipate thermal energy generated by the heat generating components of a graphics card assembly. An apparatus includes a circuit board having at least one heat generating component affixed thereto. The apparatus also includes a fan and carrier therefor including a heat sink plate having a portion thermally coupled to the heat generating component. The heat sink plate includes a means for forming at least one slot proximate the portion. The fan is adapted to direct airflow cross the portion. The thermal energy generated by the heat generating component is transferred to the fan carrier and ultimately removed from the fan carrier by the airflow. The airflow inducts a secondary airflow drawn through the slot during operation thereby to enhance transfer of the thermal energy from the heat generating component. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional patent application 61/442,374 filed Feb. 14, 2011 and hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to a method of straightening a foundational wall and in particular for use in the repair and reinforcement of basement walls comprised of blocks or other materials.
BACKGROUND OF THE INVENTION
Below ground walls, such as those which provide for the walls of the basement, must be able to support the weight of a structure resting thereon and to resist lateral forces associated with the surrounding soil and hydrostatic pressure from water in the soil.
Particularly when a basement wall is constructed of masonry block, lateral pressure may cause the wall to deflect inwardly and cracks to appear on the inner surface of the wall as mortar joints yield to a tensile force component. If such deflection continues unabated, the entire wall may buckle and collapse with damage to the supporting structure.
A number of methods of straightening walls experiencing initial stages of deflection employ applying a counterbalancing force on the inner surface of the basement wall by means of cables or a threaded rod passing from a plate on the inner surface of the basement wall through the wall and anchored at a position outside the wall, for example, in a trench. Tightening the cable or threaded rod may then pull the wall back into alignment. A system of this type is taught by U.S. Pat. No. 4,189,891.
In a different approach, U.S. Pat. No. 4,353,194 teaches applying force by means of an ellis jack braced between the floor of the basement and the wall suffering from deflection.
SUMMARY OF THE INVENTION
The present invention provides an improved method of straightening walls that coordinates multiple jacks simultaneously with monitoring of the wall alignment during the jacking operation. In this way, a faster and more uniform straightening process may be obtained, the latter minimizing wall damage. Further, the wall may be straightened substantially immediately, and not over a lengthy period of time as required of other more gradual processes.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a hydraulic jack mounted on a fixture for attachment to a concrete slab basement floor in one embodiment of the invention;
FIG. 2 is a side elevational view of the hydraulic jack of claim 1 positioned with a bracing system against a foundational wall shown in cross-section;
FIG. 3 is a top plan view of multiple braces of FIG. 2 , each with a hydraulic jack;
FIG. 4 is a fragmentary elevational view showing the interconnection of an electronic level-sensor to a control valve of the hydraulic cylinder of FIG. 1 ;
FIG. 5 is a figure similar to that of FIG. 4 showing an alternative mechanical implementation of the present invention;
FIG. 6 is a plot of data that may be sensed by the level-sensor of FIG. 4 to control hydraulic fluid gated to the cylinders to minimize wall damage;
FIG. 7 is a perspective view of a foot bracket used to prevent push-out of the basement wall near the floor.
Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 , a hydraulic cylinder 10 of the type known in the art may receive hydraulic fluid through electronically controllable valve 12 from hydraulic hose 14 . As is understood in the art, hydraulic cylinders provide for an enclosed chamber that may be pressurized with a hydraulic fluid to apply force to a shaft communicating with the enclosed chamber through a piston or the like.
The hydraulic cylinder 10 may provide for a piston driven shaft 15 having a portion extending from an end of the hydraulic cylinder 10 along an axis 16 tipped at approximately 45 degrees with respect to a plane of the floor 20 on which the hydraulic cylinder 10 rests. The end of the shaft 15 may connect with one end of a diagonal brace 22 also extending along the axis 16 .
A base of a hydraulic cylinder 10 may be attached to and supported by a bracket 24 orienting the shaft 15 along axis 16 , for example, the bracket 24 being fabricated of welded steel plate having a base plate 26 that may rest against the floor 20 with holes receiving anchor screws 28 or the like therethrough to anchor the bracket 24 to the floor 20 . The bracket 24 further provides an angled steel plate against which the base of the hydraulic cylinder 10 may rest so that the piston driven shaft 15 extends along the axis 16 . In an alternative embodiment, (not shown) the bracket 24 may provide a hinge plate allowing flexible adjustment of the angle of the base of the hydraulic cylinder 10 as required.
Referring now to FIG. 2 , the diagonal brace 22 may extend toward a basement wall 30 and be aligned to abut at a hinge 23 an upright brace 32 between the ends of the upright brace 32 . The upright brace 32 may fit against an inner surface of the wall 30 extending approximately vertically by about four feet so that pressure can be directed to a specific spot on the wall 30 . The position of the upright brace 32 is moved up or down the wall 30 depending on where the deflection is. For example, if the wall 30 is bowed at the center then that is where the center of the upright brace is located, if the wall 30 is tipped but essentially flat, then the upright brace is put as high as possible. In the case of severely bowed walls, this fitting against the inner surface may only contact portions of the inner surface. The lower end of the upright brace 32 will generally be above the floor 20 . The diagonal brace 22 and the upright brace 32 may be, for example, rectangular steel pipes or other steel shape including angles, tubes, or I-beams . . . .
Referring now to FIG. 7 , the foot bracket 39 may provide for an L-shaped bracket having a first face that may be attached to the floor 20 with anchor bolts and a second face extending vertically therefrom adjacent to the wall 30 to be anchored thereto. The foot bracket 39 prevents the base of the wall 30 from separating from the floor 20 and moving outward as the wall 30 is straightened. A similar top bracket may be used when it is desired to prevent movement of the top of the wall 30 with respect to the house joists.
Soil 34 outside of the wall 30 may be excavated to provide for a trench 36 on the outside of the wall 30 allowing the wall 30 to be pushed outward into alignment. This trenching operation may be used to replace a drain 33 placed at the bottom of the trench 36 .
A tilt sensor 37 may be attached to the top of the upright brace 32 (or other convenient location) to provide an indication of whether the brace 32 is level and/or to detect movement or acceleration of the top of the upright brace 32 . Typically before the straightening process, the brace 32 will not be vertical but will lean toward the cylinder 10 caused by inward deflection of the wall 30 .
Referring now to FIG. 3 , multiple brace systems comprised each of a cylinder 10 , a diagonal brace 22 , and an upright brace 32 (here shown as cylinders 10 a - d , diagonal braces 22 a - d , and upright braces 32 a - d ) may be simultaneously applied against the wall 30 with the cylinders 10 a - d connected to a common hydraulic pressure source 40 , for example an electric pump.
Referring now to FIG. 4 , in a first embodiment, an electronic control system 42 , for example a microcontroller or programmable logic controller, may receive a signal from tilt sensor 37 , for example a mercury switch, a pendulum and angle sensor (for example a potentiometer) combination, or a solid-state accelerometer, providing an indication of the vertical orientation of the upright brace 32 . In the case of the accelerometer, an angular deviation of a gravitational vector from the axis of the upright brace 32 may be determined as well as acceleration of the top of the upright brace 32 . It will further be appreciated that the indication of vertical orientation of the upright brace may be detected by measuring displacement of the shaft 15 (using a displacement sensor) and trigonometric formulae, for example using known positioning of the bracket 24 with respect to a base of the wall and the height of the hinge 23 .
The electronic control system 42 also provides electrical signals controlling valves 12 , one for each cylinder 10 a - d . Generally, during operation, the electronic control system 42 may, in a first embodiment, allow all valves 12 to be open and the cylinders 10 a - d to extend their shafts 15 outward to press upward on the brace 22 straightening the wall until a signal from the tilt sensor 37 of any upright brace 32 indicates that the upright brace 32 is vertical at which time the electronic control system 42 may shut the valve 12 associated with that upright brace 32 only. In this way each of the brace systems of FIG. 3 may operate simultaneously to bring the wall back into alignment.
Referring now to FIG. 6 , the ability to monitor the orientation of the braces 32 permits more sophisticated control strategies where a most out of alignment section of the wall 30 , indicated by signal 50 a from a tilt sensor 37 , is moved first during time terminating at t 1 and the other sections of the walls indicated by signals 50 b - c from corresponding tilt sensors 37 are moved only after time t 1 is passed. Upon completion of time t 1 , the other sections of the wall may be moved, for example the upright brace 32 associated with signal 50 b being moved after time t 1 , and the upright brace 32 associated with signal 50 c being moved after time t 2 is complete, and the upright brace 32 associated with signal 50 d being moved after time t 3 is complete. Using this technique, the amount of distortion of the wall 30 during this alignment may be significantly reduced thereby reducing additional damage from the alignment process.
Another possible control strategy moves the upright braces 32 at substantially constant angular rates that are different in proportion to the misalignment of the wall associated with that upward brace so that all upward braces move to reach alignment with vertical at substantially the same time.
It will be appreciated that even more sophisticated control algorithms may be developed that look at acceleration to control the valves 12 to reduce or warn of sudden acceleration, or that detect overcenter travel where the wall moves beyond vertical to provide warnings of this situation, or that monitor pressure differentials using pressure gauges (not shown) on each hydraulic hose 14 .
Referring now to FIG. 5 , the present invention contemplates that the sensing of the orientation of the upright braces 32 may be performed mechanically, for example, by attaching a pivot point 60 to the upper end of the upright brace 32 communicating via tie arm 62 to a lever-operated valve 12 ′ with a turnbuckle or other length adjusting mechanism used to cause movement of the upright brace 32 to shut off the valve 12 when the upright brace 32 is in the vertical position. In this case, the tie arm 62 provides a tilt sensor based on a known geometry of the system.
It will also be appreciated that the hydraulic cylinders may be replaced with, for example, electric screw jacks or the like. Further, it will be understood that the present invention is applicable to a wide variety of different types of walls beyond the block walls depicted but also including poured walls.
Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “left”, “right”, “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence, or order unless clearly indicated by the context.
References to an electronic control system can be understood to include one or more processors that can communicate in a stand-alone and/or a distributed environment(s), and can thus be configured to communicate via wired or wireless communications with other processors, where such one or more processor can be configured to operate on one or more processor-controlled devices that can be similar or different devices.
When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
Various features of the invention are set forth in the following claims. It should be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth herein. The invention is capable of other embodiments and of being practiced or carried out in various ways. Variations and modifications of the foregoing are within the scope of the present invention. It also being understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. | A wall straightening apparatus provides multiple independently controllable jacking members pressing outward on diagonal braces to push those braces against the wall to move the wall into a vertical alignment. Feedback control of the jacking members provides coordinated straightening of large wall sections with lessened cracking and distortion. | 4 |
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