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FIELD OF THE INVENTION
The present invention provides a means to integrate planar coils on silicon, while providing a high inductance. This high inductance is achieved through a special back- and front sided shielding of a material.
BACKGROUND OF THE INVENTION
In many applications, high-value inductors are a necessity. In particular, this holds for applications in power management. In these applications, the inductors are at least of the order of 1 pH, and must have an equivalent series resistance of less than 0.1Ω. For this reason, those inductors are always bulky components, of a typical size of 2×2×1 mm 3 , which make a fully integrated solution impossible.
On the other hand, integrated inductors, which can monolithically be integrated, do exist. However, these inductors suffer either from low inductance values, or very high DC resistance values.
US2006157798 discloses a way to mount both an RF circuit including an inductor formed therein and a digital circuit on a single chip. MOSFETs are formed on a semiconductor substrate in regions isolated by an element isolation film. A plurality of low-permittivity insulator rods including a low-permittivity insulator embedded therein and penetrating a first interlevel dielectric film to reach the internal of the silicon substrate is disposed in the RF circuit area. An inductor is formed on the interlevel dielectric film in the RF circuit area by using multi-layered interconnects. A high-permeability isolation region in which a composite material including a mixture of high-permeability material and a low-permittivity material is formed in the region of the core of the inductor and periphery thereof.
JP08017656 discloses a magnetic shielding method and magnetic shielding film forming method of a semiconductor device. The purpose is to minimize the external magnetic effect from inductor conductors formed on a semiconductor substrate. Two inductor conductors are formed on the adjacent positions on the surface of a semiconductor substrate. The inductor conductors are respectively covered with magnetic bodies. In such a constitution, the magnetic fluxes generated by respective inductor conductors are distributed using the magnetic bodies respectively covering said conductors as the magnetic paths so that the magnetic fluxes of the magnetic bodies will be hardly dissipated externally thereby enabling the magnetic effect of respective inductor conductors on any external elements as well as the magnetic coupling with mutual inductor conductors to be avoided.
US2006080531 discloses an implementation of a technology, described herein, for facilitating the protection of computer-executable instructions, such as software. At least one implementation, described herein, may generate integrity signatures of one or more program modules which are sets of computer-executable instructions-based upon a trace of activity during execution of such modules and/or near-replicas of such modules. With at least one implementation, described herein, the execution context of an execution instance of a program module is considered when generating the integrity signatures. With at least one implementation, described herein, a determination may be made about whether a module is unaltered by comparing integrity signatures. This abstract itself is not intended to limit the scope of this patent.
US2003034867 discloses a coil and coil system which is provided for integration in a microelecronic circuit. The coil is placed inside an oxide layer of a chip, and the oxide layer is placed on the surface of a substrate. The coil comprises one or more windings, whereby the winding(s) is/are formed by at least segments of two conductor tracks, which are each provided in spatially separated metallization levels, and by via-contacts which connect these conductor track(s) and/or conductor track segments. In order to be able to produce high-quality coils, a coil is produced with the largest possible coil cross-section, whereby a standard metalization, especially a standard metalization using copper, can, however, be used for producing the oil. To this end, the via contacts are formed from a stack of two ore more via elements arranged one above the other. Parts of the metallization levels can be located between the via elements.
US2003184426 discloses an inductor element having a high quality factor, wherein the inductor element includes an inductor helically formed on a semiconductor substrate and a magnetic material film on a surface of the inductor for inducing magnetic flux generated by the inductor. The magnetic material film preferably includes a first magnetic material film disposed on a lower surface of the inductor, between the substrate and the inductor, and a second magnetic material film disposed on an upper surface of the inductor. The magnetic material film may be patterned according to a direction along which the magnetic flux flows, for example, radial. Since the magnetic material film induces the magnetic flux proceeding toward the upper part and lower part of the inductor, the effect of the magnetic flux generated in the inductor on external circuits may be reduced and the efficiency of the inductor may be enhanced.
Thus there is a need for improved planar coils, not suffering from one or more of the above mentioned disadvantages and drawbacks.
The present invention seeks to provide such an improved coil, not suffering from the one or more drawbacks and disadvantages, which coil further has a high inductance.
SUMMARY OF THE INVENTION
The present invention relates to a planar, monolithically integrated coil, wherein the coil is magnetically confined.
DETAILED DESCRIPTION OF THE INVENTION
In a first aspect the invention relates to a planar, monolithically integrated coil, wherein the coil is magnetically confined.
In a preferred embodiment the present invention relates to a coil according to the invention further provided with a substrate, and back and front sided shielding, wherein the back and front side are magnetically coupled by substantially through substrate hole vias, which holes are preferably, in a 2-D projection in the plane of the coil, and inside and outside the coil.
Typically, a coil is made up of materials, which can be fashioned into a spiral or helical shape. An electromagnetic coil (or simply a “coil”) is formed when a conductor (usually a solid copper wire) is wound around a core or form to create an inductor or electromagnet. One loop of wire is usually referred to as a turn, and a coil consists of one or more turns. For use in an electronic circuit, electrical connection terminals called taps are often connected to a coil. Coils are often coated with varnish and/or wrapped with insulating tape to provide additional insulation and secure them in place. A completed coil assembly with taps, etc. is often called a winding. A transformer is an electromagnetic device that has a primary winding and a secondary winding that transfers energy from one electrical circuit to another by magnetic coupling without moving parts.
In a semiconductor device a coil is typically provided with a substrate, such as silicon, or silicon oxide on silicon, etc. The coil typically has a spiral shape, but in principle the invention is also applicable to helical shapes. The spiral coil and substrate of the present invention are typically in parallel two-dimensional planes. The shielding of the present invention is also typical in parallel 2-D planes, also typically being parallel to the substrate. On the other hand the holes, connecting the shielding, are typically perpendicular to the above-mentioned 2-D planes, as can e.g. be visualized in FIG. 1 .
Electromagnetic shielding is the process of limiting the flow of electromagnetic fields between two locations, by separating them with a barrier made of conductive material. Typically it is applied to enclosures, separating electrical devices from the ‘outside world’, and to cables, separating wires from the environment the cable runs through.
In the present invention the substrate comprises one or more holes substantially through the substrate, which holes are also referred to as vias. In typical semiconductor manufacturing processes vias are filled with an electrically conducting material, such as a metal, such as aluminum, copper, tungsten, titanium, or doped silicon, or combinations thereof. Contrary to the prior art the present invention in a preferred embodiment relates to a coil, wherein the through wafer holes are filled with high-ohmic material, such as larger than 100 mΩ.cm. Preferably the material also has a high initial permeability at 10 MHz, such as |μ r |>500, preferably |μ r |>1000, more preferably |μ r |>2000, and still has a high initial permeability at 100 MHz, such as |μ r |>300, preferably |μ r |22 500, more preferably |μ r |>1000.
Thus, the present invention seeks to overcome the above-mentioned problems by providing a construction method for an inductor, where confining the inductor coils by materials with a high magnetic permeability at high frequencies and with high resistivity can increase the inductance. Thus, in a preferred embodiment the present invention relates to a coil according to the invention, wherein the back and front sided shielding and or the vias comprise a material with a high magnetic permeability at high frequencies and with high resistivity. Preferably said material is formed from a so-called soft-magnetic alloy material. Soft magnetic material includes e.g. a wide variety of nickel-iron and nickel-cobalt soft magnetic alloys and nanocrystalline iron for high performance components requiring high initial and maximum permeability coupled with ease of fabrication.
Throughout the description and claims the terms “through via”, “through wafer via”, “thru via”, “via hole” and similar expressions relate to holes or vias through the substrate, e.g. a silicon wafer. A via hole is a non-filled via.
A soft-magnetic alloy materials class referred to as nano-crystalline iron and described in J, Huijbregtse, F. Roozeboom, J. Sietsma, J. Donkers, T. Kuiper and E. van de Riet, J. Appl. Phys. Phys., 83 (1998) 1569, is preferred for cladding. In particular the Fe x -TM y -O z materials wherein TM represents one or more transition metals elements chosen from the Group IVa or Va elements, e.g. Ti, Zr, Hf, V, Nb, Ta, such as Fe—Hf—O, combine a high initial magnetic permeability at high frequencies with a high resistivity. A preferred material is e.g. Fe 55 Hf 17 O 28 that has a |μr|>1000 at 10 MHz and still a |μr|˜500 at 100 MHz, with further a high electrical resistivity (typically 1 mΩ·cm and up).
In a further preferred embodiment the present coil comprises a back and/or front sided shielding that are/is patterned. As such eddy currents are further reduced.
In a further preferred embodiment the present coil has a pattern and further comprises a substantially ring shaped shield, preferably a rectangular shaped shield. Theoretically such a coil and shielding is somewhat worse than a shield without a ring shaped shield. However, from a manufacturing process point of view this embodiment is easier to make with existing technology. When using electrochemical deposition, in a conducting bath, the ring shaped shield may be used to attach a contact to. Thus in principle only one contact is needed, whereas in the version without the ring various contacts are needed in a bath.
In a further preferred embodiment the present coil has via holes that are not completely through, thereby forming so-called magnetic air-gaps, which gaps are present at the back and/or front side of the coil. The shields may, while in use, be saturated. The present air-gaps reduced the risk of such saturation, and thus ensure a superior performance in use.
In a further preferred embodiment the present coil has a density of via holes that is larger in the center of the coil than outside the coil. The effect thereof is similar to that of air-gaps.
In a further preferred embodiment the present coil has a thin non-conducting and non-magnetic high permeable layer between substrate and coil on the one hand and shielding on the other hand, wherein the shielding is on the same side of the substrate as the coil. Such a layer may be formed of a material chosen from e.g. a lacquer, resist, dielectric, and combinations thereof, such as silicon oxide, and silicon nitride.
In a second aspect the present invention relates to an application wherein high-value, low resistance inductors are needed, such as a DC:DC converter, an AM reception antenna, tuned HF or IF-stages up to 100 MHz, such as in an FM radio or TV reception, comprising a coil according to the invention.
The present invention is further elucidated by the following Figures and examples, which are not intended to limit the scope of the invention. The person skilled in the art will understand that various embodiments may be combined.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a top and side view of a planar monolithical coil.
FIG. 2 shows a top view of a planar monolithical coil.
FIG. 3 shows a top view of a planar monolithical coil.
FIG. 4 shows a side view of a planar monolithical coil.
FIG. 5 shows a side view of a planar monolithical coil.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a top and side view of a planar monolithical coil. Therein a coil ( 120 ), typically formed of a conductor, such as copper or aluminum, vias ( 100 ) and shield ( 110 ), made from a soft-magnetic metal alloy, and a substrate ( 130 ), typically silicon, are shown.
Basically, the inductor can be described as comprising the following elements:
1. A metal, preferably copper, inductor pattern (the turns of the coil) on a Si substrate;
2. Through-wafer via holes (typically made by RIE-etching with 10-50 μm, such as 30 μm, in diameter with depths ranging from 100 to 200 μm, depending on the wafer thickness) around the coil, and inside the coil; the vias are filled with a soft-magnetic material such as a permalloy (Ni 0.8 Fe 0.2 ); alternatively, Fe—Hf—O and other high-permeability/high resistivity materials are also possible. Preferably the growth is carried out electrochemically, yet some other deposition techniques are possible as well (e.g. CVD or PVD, which have the advantage of laminating the magnetic layers;
3. Back and front side covering with a soft-magnetic material, with high permeability at high frequencies, such as ferrite or, even more preferred nanocrystalline iron alloys, such as Fe—Hf—O;
4. The soft-magnetic via filling material such as permalloy can be deposited by electrochemical plating after depostion of a conductive plating base of the same material.
The material with high magnetic permeability creates a flux path, due to which the effective inductance of the coil is much higher than without such material. As it is advantageous to fill the vias with a conductive material (to allow electrochemical growth of the material in the vias) the through vias should be preferably as small as possible in diameter (but still of a size to make manufacturability easy), to avoid eddy-currents, which would increase the AC-losses of the inductor. To allow control of electrochemical growth rate the total exposed area (open via holes) should be not too small. This can be sustained by a multiple arrays of via holes with a dense pitch of the order of their diameter. 5 Note that FIG. 2 contains only two single arrays.
FIG. 2 shows a top view of a planar monolithical coil. Therein a coil ( 220 ), and vias ( 200 ) and shield ( 210 ), are shown. Here, the Fe—Hf—O or ferrite is replaced by a patterned permalloy. Obviously, care should be taken that the patterning of the permalloy is such as to minimize eddy current losses in the permalloy material. The typical dimension of the patterning should be of the order of the skin depth of the material. For most NiFe alloys, this gives a typical dimension of about 5 mm at about 25 MHz. The patterning shown is an example, more complex patternings could be envisaged as well. To optimally contribute to increasing the effective permeability, the stripes must form a closed magnetic path through the permalloy-filled vias (such a closed path would exist of a single stripe on the front side, a via to a single stripe on the back, and a connection to the first via again through a second via).
FIG. 3 shows a top view of a planar monolithical coil. Therein a coil ( 320 ), and vias ( 300 ) and shield ( 310 ), are shown. Electrodeposition of the patterned layer may be difficult if no low-ohmic contacts exist. This could be solved by adding a second ring of permalloy close to the outer ring of vias, as illustrated in FIG. 3 .
Because the ring does no longer enclose any magnetic flux, no eddy currents will be generated in the material.
FIG. 4 shows a side view of a planar monolithical coil. Therein a coil ( 420 ), and vias ( 400 ) and shield ( 410 ), as well as a substrate ( 430 ), and air gaps ( 450 ) are shown. A further realization can be made exploiting the fact that the vias filled with soft magnetic material need not be completely thru-hole; when they are not completely thru-hole, a magnetic ‘air-gap’ is created. This is schematically depicted in FIG. 4 . The vias as drawn in FIG. 4 a create an air-gap at the top-side; obviously, it is equally well possible to create a gap at the bottom side ( FIG. 4 b ), as well as a combination of both.
FIG. 5 shows a side view of a planar monolithical coil. Therein a coil ( 520 ), and vias ( 500 ) and shield ( 510 ), as well as a substrate ( 530 ), and an extra layer ( 540 ) are shown. Further, it is possible the create vias that fully penetrate the silicon substrate, and are subsequently covered by a protective layer (or a photo resistive lacquer such as SU8) which may be necessary to create the copper tracks. This is illustrated in the FIG. 5 . In this picture, a realization is shown where it is also illustrated that it can be advantageous to have a relatively large density of magnetic vias in the centre of the inductor.
As an example, the following set of parameters can be used:
f=30 MHz
10 μm permalloy layer thickness
200 μm Si substrate
Mμ=1000+1000 j— which is a pessimistic estimate where the permalloy is rather lossy
This results in the following characteristics of the inductor:
Saturation current ˜100 mA
An AC resistance roughly half of the DC resistance Rdc˜0.5 Rac A DC resistance over inductance ratio R/L˜5 mΩ/nH, which is about a factor of 10 better than an air coil inductor without the magnetically active material.
The inductor is made using standard copper electroplating on silicon, and subsequent patterning as to create a planar coil (which can be square as in FIG. 1 , or any other planar geometry). The thickness of the copper layer is not specific, but for low DC resistance, thick copper (several μm's) is preferable. Then, a highly permeable material, such as is deposited by electrochemical deposition. Alternatively, RF sputter deposition can be used from, e.g. an Fe 83 Hf 17 target in reactive atmosphere (Ar+O 2 ), etc. as described in the above mentioned article.
Embodiment 1
Basically, the present inductor can be manufactured by:
1. RIE or wet etching of a pattern of through-wafer via holes in a silicon substrate, plus subsequent (electrochemical) filling by permalloy (NiFe) electrodeposition; subsequent cap layer deposition over through holes.
2. Electrodeposition and subsequent patterning of a (˜5-8 μm thick) Cu-coil pattern (the turns of the coil) on the Si substrate; can be done in pre-deposited and patterned SU-8 (or equivalent resist) or as a blanket layer that is patterned after the deposition
3. Electro deposition of a NiZn permalloy, and subsequent patterning to reduce eddy currents, or
4. Alternatively to step 3, back and front side RF sputter deposition of a soft-magnetic material, with high permeability at high frequencies, such as ferrite or, even more preferred nanocrystalline iron alloys, such as Fe—Hf—O For example: a nanocrystalline Fe 55 Hf 17 O 28 layer of up to 10 μm thickness can be sputter deposited from an Fe 83 Hf 17 target in reactive atmosphere (Ar+O 2 ), etc. as described in the above mentioned article.
Here only the major process steps have been described. Additional steps in between may be necessary to implement in order to screen off critical substrate areas in a previous flowchart step.
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The present invention provides a means to integrate planar coils on silicon, while providing a high inductance. This high inductance is achieved through a special back- and front sided shielding of a material. In many applications, high-value inductors are a necessity. In particular, this holds for applications in power management. In these applications, the inductors are at least 5 of the order of 1 μH, and must have an equivalent series resistance of less than 0.1Ω. For this reason, those inductors are always bulky components, of a typical size of 2×2×1 mm 3, which make a fully integrated solution impossible. On the other hand, integrated inductors, which can monolithically be integrated, do exist. However, these inductors suffer either from low inductance values, or 10 very-high DC resistance values.
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[0001] This application claims the benefit of U.S. Provisional Patent Application, Serial No. 60/072,560 filed Jan. 21, 1998.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to a method for assessing the risk of developing prostate cancer in an individual. Increased risk for prostate cancer is correlated with high insulin-like growth factor status (IGF status). Specifically, the method involves measurement of IGF-I and/or insulin-like growth factor binding protein-3 (IGFBP-3) in a specimen. High levels of IGF and/or low levels of IGFBP correlate with increased risk of developing prostate cancer.
[0004] In an alternative embodiment, the method involves determining the IGF/PSA status of an individual wherein the determination of IGF status is combined with a measurement of prostate specific antigen (PSA) levels. The IGF/PSA status provides an improved method of assessing the prognosis of existing prostate cancer.
[0005] Furthermore, novel treatment modalities are suggested by the discovery of the link between IGF-axis component levels and prostate cancer that involve modulating IGF-axis component levels.
[0006] 2. Description of the Prior Art
[0007] Prostate adenocarcinoma accounts for the majority of malignancies in males over the age of 65. Yearly screening for prostate cancer is recommended after the age of 45. There has been considerable effort toward identifying suitable prostate cancer markers to assist in predicting, diagnosing and monitoring this disease.
[0008] Prostate specific antigen (PSA) is recognized as the most sensitive marker of prostatic adenocarcinoma (M. K. Brawer Cancer 71(suppl):899-905 (1993); J. E. Oesterling J. Urol. 145:907-23 (1991)). PSA is also recognized as a proven screening vehicle (P. H. Gann, et al. J. Amer. Med. Assoc. 273:289-94 (1995); W. J. Catalona, et al. J. Urol. 151:1283-90 (1994)). It has been the most sensitive front line test for identifying prostate gland-contained, and hence presumably curable, cancer. PSA has also been useful in detecting clinically significant tumors, as opposed to latent, indolent micro-carcinomas. Screening for PSA is even superior to the common office practice of digital rectal examination (DRE). For example, Labrie et al. ( Clin. Invest. Med. 16:425-39 (1993)) showed that 97% of cancers detected at annual follow-up by DRE plus PSA testing were PSA-positive. Thus, only a minimal benefit accrues from including DRE in the medical evaluation.
[0009] Investigators have searched for other markers or indicators of prostate cancer, but to date PSA has been the most useful marker. No one has heretofor studied the association of IGF-axis components with prostate cancer.
[0010] Insulin-like growth factors (IGF-I and IGF-II) belong to family of peptides that mediate a broad spectrum of growth hormone-dependent as well as independent mitogenic and metabolic actions. Unlike most peptide hormones, IGFs in circulation and other physiological fluids are associated with a group of high affinity binding proteins (IGFBPs) that specifically bind and modulate their bioactivity at the cellular level. Under normal conditions about 95-98% or the IGF-I in human plasma is bound to IGFBPs. Six structurally homologous IGFBPs with distinct molecular size, hormonal control, and tissue expression and functions, have been identified (J. I. Jones, et al. Endocrinol. Reviews 16:3-34, (1995)). Most serum IGF-I circulates in a relatively stable ternary complex consisting of IGFBP-3 and a unique leucine-rich, acid-labile subunit (ALS). Less than one percent of IGF-I is estimated to exist in a “free” or unbound form.
[0011] The rate of cell proliferation is positively correlated with risk of transformation of certain epithelial cell types (1, 2). IGFs have mitogenic and anti-apoptotic influences on normal and transformed prostate epithelial cells (3-8). Most circulating IGF-I originates in the liver, but IGF bioactivity in tissues is related not only to levels of circulating IGFs and IGFBPs, but also to local production of IGFs, IGFBPs, and IGFBP proteases (9). Person-to-person variabilaity in levels of circulating IGF-I and IGFBP-3 (the major circulating IGFBP (9)) is considerable (10, 11), and heterogeneity in serum IGF-I level appears to reflect heterogeneity in tissue IGF bioactivity (12). No one has heretofore shown that markers relating to IGF-axis components can also be used as a risk marker for prostate cancer.
SUMMARY OF THE INVENTION
[0012] Abbreviations and Definitions
[0013] AAG—3-alpha-androstanediol glucuronide.
[0014] ALS—Acid Labile Subunit. A protein found in the 150 KDa ternary complex wherein most of the circulating IGF is found. ALS is sensitive to inactivation by acid.
[0015] Binary complex—A two part complex of IGFBP and ALS or IGFBP and IGF.
[0016] Body fluid—Any biological fluid, including but not limited to the following: serum, plasma, lymph fluid, synovial fluid, fofficular fluid, seminal fluid, amniotic fluid, milk, mammary fluid, whole blood, urine, spinal fluid, saliva, sputum, tears, perspiration, mucus tissue culture medium, tissue extracts and cellular extracts. Preferably, the body fluid is blood, plasma, serum or seminal fluid.
[0017] DHT—Dihydrotestosterone.
[0018] GH—Growth hormone.
[0019] GHBP—GH binding protein.
[0020] IGF—Insulin-like Growth Factor.
[0021] IGF-axis components—Those components that modulate the IGF/GH cascades including GH, GHBP, GH receptor, IGF, IGF receptor, IGF proteases, IGFBP 1 through 6 and other IGFBPs, ALS, IGF proteases, IGF and GH receptor antagonists, and the like.
[0022] IGF-axis component modulating agent—also: IGF status modulating agents. Includes any agent whose intended effect is to influence the GH or IGF cascades. Agents include GH, GHBP, IGF, IGFBP, ALS, IGFBP complex, GH receptors, IGF receptors, antibodies or modulators of any of the preceding, receptor antagonists for GH or IGF, or any drug that acts to modulate the IGF status of an individual including somatostatin, somatostatin analogues, GH antagonists, IGF antagonist, IGFBP stimulator, and the like.
[0023] IGFBP—Any IGF binding protein, including IGFBP-1 to 6 and the heretofore unsequenced IGFBPs. Preferably, the IGFBP is IGFBP-3 in the context of the assay described herein.
[0024] IGFBP-3—The major circulating IGF binding protein.
[0025] IGFBP complex—This term is defined herein to include either the binary complex of IGFBP and ALS or IGF or the ternary complex of IGFBP and ALS and IGF.
[0026] IGF status—The IGF status of an individual is reflected in the levels of IGF-axis components. For example a high IGF status is reflected by high levels of IGF and stimulators of IGF activity and low levels of inhibitors of IGF activity such as IGFBP. The IGF status of an individual is now known to vary either up or down-in in certain conditions involving the prostate, including but not limited to, prostate adenocarincoma or benign prostatic hyperplasia.
[0027] IGF/PSA status—A combination of IGF status and PSA levels. Individuals with high IGF/PSA status are at risk for developing severe prostate cancer. A high IGF/PSA status is reflected by high IGF and PSA levels and low IGFBP levels.
[0028] RR—Relative risk.
[0029] Risk index—A value indicating the risk of a patient for developing prostate disease or poor prognosis for patients with prostate disease. The risk index can be generated from data concerning the IGF-axis component levels in a patient, including IGF or IGFBP levels and/or the PSA levels of a patient.
[0030] SHBG—Sex hormone binding globulin.
[0031] T—Testosterone.
[0032] Ternary complex—The 150 KDa complex composed of IGF, IGFBP and ALS.
[0033] Treatment designed to influence IGF status—Includes any medical treatment whose intended effect is to influence the GH or IGF cascades. Treatments may include treatments with such agents as GH, GHBP, IGF, IGFBP, ALS, IGFBP complex, GH receptors, IGF receptors, antibodies or inhibitors of any of the preceding, receptor antagonists for GH or IGF, or any drug that acts to modulate the IGF-axis status of an individual. Individuals include both human and animals, such as pigs, cattle, sheep, goats, horses, poultry, cats, dogs, fish, etc.
[0034] The present invention relates to assays for measuring IGF-I levels and their use for predicting, diagnosing and monitoring prostate cancer. A strong consistent positive association between IGF-I and prostate cancer risk has been observed, especially with adjustment for IGFBP-3. High levels of IGF-I are predictive of increased risk for prostate cancers, whereas IGFBP has a protective effect. Additionally, the IGF or IGF/IGFBP assay can be combined with a test for PSA for improved ability to predict patient prognosis and monitor treatment. Further, these findings suggest hat it is possible to treat prostate cancers with agents that modulate the IGF-axis components.
[0035] In its broadest embodiment, a method of predicting increased risk of prostate cancer in an individual is provided. The method involves measuring the “IGF status” or concentration of IGF-axis components in a body fluid from an individual, wherein changes in the IGF status or concentration of IGF-axis components as compared to normal reference values indicates an increased risk for prostate cancer.
[0036] In one embodiment, the invention is a method of predicting increased risk of prostate cancer in an individual, comprising measuring the concentration of insulin-like growth factor (IGF-I) in a body fluid from an individual, wherein an elevated concentration of IGF-I above a reference range for IGF-I indicates an increased risk for prostate cancer.
[0037] In another embodiment, the invention is a method of predicting increased risk of prostate cancer in an individual. The method involves measuring the concentration of IGF-I and IGFBP in a specimen from an individual, wherein increased IGF-I and decreased IGFBP, as compared to a normal reference range value, indicates an increased risk for prostate cancer.
[0038] In yet another embodiment, the invention is a method of measuring the IGF/PSA status of an individual. High IGF and PSA levels and/or low IGFBP levels are indicative of individuals at risk for severe prostate cancer or who have prostate cancer with a poor prognosis.
[0039] A multivariate adjustment of the IGF-I concentration relative to the IGFBP-3 concentration provides an adjusted IGF-I level or “IGF status” which can be compared to an adjusted normal reference range value. An algorithm can be designed, by those with skill in the art of statistical analyses, which will allow the user to quickly calculate an adjusted IGF level or “IGF status” for use in making predictions or monitoring prostate disease. With additional patient data, generated similarly to the manner described herein, it will be possible to more accurately define normal reference range values for IGF stats parameters. The algorithm and normal reference values can be used to generate a device that will allow the end user to input IGF, IGFBP and quickly and easily determine the IGF stats or risk index of an individual. Similarly, it is possible to provide a device that indicates the IGF/PSA status of an individual.
[0040] Finally, the invention pertains to a method of treating prostate cancer, comprising administering an IGF-axis component modulating agent to an individual with prostate cancer.
DETAILED DESCRIPTION OF THE INVENTION
[0041] As used herein the term “prostate disease” includes diseases or disorders associated with pathologic conditions of the prostate, including, but not limited to prostate cancer or benign prostatic hyperplasia. The method of the present invention is most preferably used to determine the risk of an individual developing prostate cancer, diagnosing prostate cancer or assessing progress of the cancer. Accordingly, the method of the present invention may be useful in predicting prostate cancer, differentiating cancer from other prostatic diseases.
[0042] A suitable specimen is collected from an individual. Suitable specimens include any body fluid or tissue known to contain IGF-axis components and/or PSA. Preferably, the specimen is blood, serum, plasma or seminal fluid. The specimen may be collected by venipuncture or capillary puncture, and the specimen collected into an appropriate container for receiving the specimen. Alternatively, the specimen may be placed onto filter paper.
[0043] The IGF-axis components and/or PSA can be measured by techniques well known to those skilled in the art, including, but not limited to immunoassays such as enzyme-linked immunosorbent assay (ELISA), enzyme immunoassay (EIA), fluorescence polarization immunoassay (FPIA), fluorscence immunoassay (FIA) and radioimmunoassay (RIA). The assays described in U.S. application Ser. Nos. 08/626,641, 08/643,830, 08/763,244 and 08/829,094 are particularly suitable and are incorporated herein by reference. Further, the concentrations of the IGF-axis components and/or PSA may, for example, be measured by test kits supplied by DIAGNOSTIC SYSTEMS LABORATORIES, INC., Webster, Tex., USA.
[0044] In a preferred embodiment, total IGF-I can be measured. In some cases, it may be advantageous to measure total, bound and/or free IGF-I. For example, suitable highly specific and simple non-competitive ELISAs for reliable determination of IGF-I (M. J. Khosravi, et al. 1996 Clin. Chem. 42:1147-54), IGFBP-3 (Khosravi J, et al. 1996 Clin. Chem. S6:234) and IGFBP-1 (M. J. Khosravi, et al. 1996 Clin. Chem. S6: 171) have been described. The high affinity antibodies incorporated in these immunoassays have been selected for lack of cross-reactivity or interference by the closely related peptides or binding protein.
[0045] Additionally, IGFBPs can be used as an indicator of decreased risk for prostate cancer. Preferably, the binding protein is IGFBP-3 and total, complexed and/or free IGFBP-3 may be measured. In alternative embodiments, the other IGFBPs (such as, but not limited to IGFBP-1) may also be used to predict the risk of prostate cancer. Additionally, acid-labile subunit (ALS) may also be used to predict susceptibility to prostate cancer. The ALS may be total ALS complexed and/or free ALS. Other IGF-axis components may also influence the risk of prostate cancer.
[0046] Men in the highest quartile of circulating IGF-I have a relative risk of prostate cancer of 4.32 (95 percent confidence interval (CI) 1.76-10.6) compared to men in the lowest quartile, and there was a significant linear trend such that a 100 ng/ml increase in IGF-I level was associated with a doubling of risk (p=0.001). Furthermore, this association is evident among men with normal as well as elevated baseline prostate specific antigen (PSA) levels. These results indicate that circulating IGF-I is a predictor of prostate cancer risk, and perhaps progression, and thus have implications for risk reduction and treatment strategies.
EXAMPLE 1
[0047] This example shows that a higher serum IGF-I level is related to higher risk of developing prostate cancer. In view of the direct and indirect growth inhibitory properties of IGFBP-3 (reviewed in (53)), we also postulated that high levels of IGFBP-3 would be inversely related to risk.
[0048] We used a nested case-control study within the Physicians' Health Study (17) to examine serum IGF-I, IGF-II, and IGFBP-3 levels in relation to prostate cancer risk. At baseline, the men aged 40 to 82 provided information via mailed-in questionnaires on personal history of disease, usage of aspirin, vitamins, smoking habits, blood pressure, cholesterol levels, height, weight, and diet. 14,916 (68%) of the randomized physicians also provided blood specimens in 1982 (19). Through 1992, over 99% of surviving participants completed annual questionnaires reporting morbidity events and vital status was ascertained for 100%.
[0049] Following a report of prostate cancer in the annual questionnaires, we obtained medical records and pathology reports which were reviewed by physicians in the End Points Committee. Stage at diagnosis, tumor grade, Gleason score, type of presentation (e.g. symptoms and screening rectal examination), prostate specific antigen (PSA) level immediately before treatment, and treatment method were determined from medical record review by physician investigators ( 20).
[0050] Cases and controls were selected from among the 14,916 physicians who provided blood. As of March 1992, after 10 years of follow-up we confirmed 520 cases of prostate cancer, of whom 152 cases had adequate sample volume for IGF assays in 1997. Circulating steroid hormone levels (21), PSA (22), and CAG polymorphisms of the androgen receptor gene (23) had previously been measured in these cases from the same blood samples originally collected in 1982 (24). All assays reported in this study are from blood specimens collected, on average, seven years (min.=6 months, max.=9.5 years) prior to clinical diagnosis of prostate cancer.
[0051] We selected controls at random from those men who provided blood and who had not reported a diagnosis of prostate cancer up to the date of diagnosis of the case. We excluded those men without adequate blood sample volume and those who had total or partial prostatectomies by the time of the case diagnosis because they may not have been fully at risk for the disease when the cases were diagnosed. We matched one control to each case based on smoking status (never, past, or current smoker), duration of follow-up, and age within one year.
[0052] IGF-I, IGF-II, and IGFBP-3 were assayed using ELISAs with reagents from DIAGNOSTIC SYSTEMS LABORATORY INC. (DSL Inc., Webster, Tex.) (25-27). It has been shown that a single IGF-I measurement is representative of levels over time (28, 29).
[0053] Paired t-tests were used to compare the means of IGF-I, IGF-II, and IGFBP-3 between cases and controls. We then examined the age-standardized (using five groups, 40-50, 51-55, 56-60, 61-65, 66-80) mean values of various predictors for prostate cancer within quartiles of IGF-I among the controls. Conditional logistic regression was used to analyze the associations between IGF and prostate cancer adjusting for other possible risk factors for prostate cancer—PSA, height, weight, body mass index, CAG polymorphisms of the androgen receptor gene, and plasma androgen levels, including estrogen, testosterone (T), dihydrotestosterone (DHT), sex hormone binding globulin (SHBG), prolactin, and 3-alpha-androstanediol glucuronide (AAG) (21-23, 30-33).
[0054] Because we hypothesized that IGFBP-3 reduces the bioactivity of IGFs, we simultaneously adjusted for levels of both IGFs and IGFBP-3. We estimated relative risk (RR) from the odds ratios and computed 95 percent confidence intervals (CI) (33). In some analyses, we used unconditional logistic regression models and adjusted for age (eight five-year categories) and smoking (never, past, and current) in the models to make full use of the data without restriction to the matched pairs (34). We repeated the basic analyses examining only the high grade/stage cases, only low grade/stage cases, and only cases occurring after the first five years of follow-up, as prior studies have shown that some risk factors for prostate cancer are stronger for high grade/stage tumors (21, 23). We examined IGF-I and prostate cancer within age groups (<=60, >60 at baseline) and smoking categories (never, past, current) to consider potential interactions.
[0055] All exposures of interest and covariates, with the exceptions of age and smoking, were analyzed in quartile groups with the lowest quartile as the reference category. We tested linear trends for statistical significance by assigning the medians of each quartile as scores (36).
[0056] The mean level of IGF-I among the cases (269.4 ng/ml) was significantly higher than among controls (248.9 ng/ml) (p=0.03). Means of IGF-II and IGFBP-3 were similar among cases and controls (p=0.85 and 0.95 respectively). Table 1 presents age-standardized means of IGF-II, IGFBP-3, estradiol, T, DHT, SHBG, lycopene, weight, height, body mass index, and medians of PSA among 152 controls, within quartiles of IGF-I. PSA and estradiol had weak positive associations with IGF-I levels, while there was some suggestion that lycopene levels were lower among men in the highest quartile of IGF-I. There was no significant correlation between IGF-I and any of these factors except IGF-II (r=0.5) and IGFBP-3 (r=0.6).
TABLE 1 Age-standardized characteristics among 152 controls within quartiles of IGF-I* IGF Quartile 1 2 3 4 IGF-I (ng/ml) 99.4- 184.9- 236.96- 293.76- 184.8 236.95 293.75 499.6 n 38 38 38 38 Age, years (mean) 63.9 58.9 59.0 59.3 IGF-II, ng/ml 418 536 509 583 (mean) IGFBP-3, ng/ml 2234 2841 2829 3473 (mean) PSA + , ng/ml 2.19 2.27 2.81 2.49 (median) Lycopene, ng/ml 445 430 438 388 (mean) Estradiol, ng/ml 35.9 37.2 38.6 39.4 (mean) Testosterone, ng/ml 5.27 4.74 5.28 5.60 (mean) DHT +, , ng/ml 0.41 0.41 0.44 0.43 (mean) SHBG + , nmol/L 27.9 20.9 24.8 21.7 (mean) Weight, kg (mean) 77.1 78.6 78.7 77.4 Height, m (mean 1.77 1.76 1.77 1.76 BMI + , kg/m 2 (mean) 24.7 25.4 25.0 24.9
[0057] IGF-I was significantly associated with prostate cancer risk in a univariate analysis; men in the highest quartile had a relative risk of 2.41 (95 percent CI 1.23-4.74) as compared to men in the lowest quartile (Table 2). With further adjustment for IGFBP-3, these men had more than four times the risk of prostate cancer compared to the reference group (RR=4.32, 95 percent CI 1.76-10.6). IGF-II and IGFBP-3 were not associated with prostate cancer risk when examined individually, but IGFBP-3 was inversely associated with risk after controlling for IGF-I (RR for fourth vs. first quartile 0.41, 95 percent CI 0.17-1.03). There was a significant linear trend between IGF-I and prostate cancer risk, especially after adjusting for IGFBP-3; a 100 ng/ml increase in IGF-I corresponded to an approximate doubling of risk (RR=2.09 per 100 ng/ml increase, 95 percent CI 1.35-3.22). As anticipated, it was important to consider the combined I, effects of IGF-I and IGFBP-3 simultaneously, and these were examined together in subsequent analyses.
TABLE 2 Relative risk of prostate cancer according to quartiles of IGF-I, IGF-II, & IGFBP-3. Trend # Quartiles 1 2 3 4 p-value RR associated with IGF-I Quartiles IGF-I* 1.00 1.32 1.81 2.41 0.01 (0.62-2.80) + (0.92-3.56) (1.23-4.74) IGF-II 1.00 1.00 0.67 0.97 0.74 (0.54-1.84) (0.33-1.37) (0.48-1.95) IGFBP-3 1.00 0.92 0.69 1.07 0.96 (0.48-1.79) (0.33-1.44) (0.54-2.11) Simultaneous adjustment for IGF-I or IGFBP-3 IGF-I 1.00 1.94 2.83 4.32 0.001 (0.83-4.56) (1.27-6.28) (1.76-10.6) IGFBP-3 1.00 0.50 0.33 0.41 0.09 (0.23-1.10) (0.14-0.82) (0.17-1.03)
[0058] IGF-I remained a significant independent predictor of prostate cancer risk even after inclusion of quartiles of weight, height, body mass index, androgen receptor CAG repeats, and various circulating hormone levels (estradiol, T, DHT, SHBG, prolactin, and AAG) in the multivariate models. Adding quartiles of PSA to the model attenuated the association for IGF-I slightly, though the results remained significant (RR=3.31, 95 percent CI 1.09-10.1 for the fourth vs. first quartile, adjusting for IGFBP-3).
[0059] To investigate whether the observed associations between IGF-I and prostate cancer could be due to increased IGF-I levels among pre-clinical undiagnosed cases in 1982, we repeated the basic analyses including only those men who were diagnosed five years or more after the start of follow-up. With the remaining 125 cases and 152 controls, we observed very similar results to previous analyses based on all cases and controls, and the effect of IGF-I adjusted for PSA was also unaffected.
[0060] We compared the potential association between IGF-I and prostate cancer risk among men with high grade/stage vs. low grade/stage cancer at diagnosis and observed no significant difference (RR for the fourth vs. first quartile of IGF-I 3.40 (95 percent CI 1.14-10.1) for high grade/stage cancers and 5.46 (95 percent CI 1.93-15.5) for low grade/stage cancers), suggesting that IGF-I does not differentially influence the development of high vs. low grade/stage tumors.
[0061] When we stratified subjects by the median case baseline age of 60, the increased risk associated with IGF-I was stronger among the older men. Men over the age of 60 and in the highest quartile of IGF-I had a RR of 7.93 (95 percent CI 2.05-30.7), adjusting for IGFBP-3, compared to men of similar age in the lowest quartile, and we found no association between quartiles of IGF-I and risk among the men age 60 or less. Among both older and younger men, however, there was a significant linear relationship between RR and IGF-I level (RR=1.83 per 100 ng/ml increase in IGF-I, p=0.047 for younger men; RR=2.55 per 100 ng/ml increase in IGF-I, p=0.006 for older men). We also examined IGF-I within strata of smoking and within strata of six plasma androgens but observed no evidence of interaction.
EXAMPLE 2
[0062] As PSA acts as an IGFBP protease in prostatic issue (35), we also investigated possible interactions involving PSA. There was no significant correlation between circulating PSA and circulating IGFBP-3, consistent with the view that PSA is enzymatically inert in the circulation. We classified men by quartile of IGF-I and low (≦4 ng/ml) vs. high (>4 ng/ml) PSA level, creating eight mutually exclusive categories of IGF-I and PSA. The low-PSA/lowest quartile of IGF-I category was used as the reference group. Similar methods were used to examine potential interactions between IGF-I and plasma androgens (using the median among controls as the cutpoint for low and high androgen levels).
[0063] Data in Table 3 confirm that as expected, men with elevated baseline PSA were more likely to be subsequently diagnosed with prostate cancer than those with PSA less than 4 ng/ml. More importantly, serum IGF-I level was strongly related to risk of developing prostate cancer even among men with a baseline PSA less than 4 ng/ml (multivariate RR of clinical diagnois during follow-up increased from 1.00 to 4.57 across quartiles of IGF-I, adjusted for IGFBP-3 and age, and smoking). Furthermore, assuming that men with PSA greater than 4 ng/ml have a high likelihood of harboring occult prostate cancer (22), the data provide evidence for a substantial influence of IGF-I on the natural history of clinically occult prostate cancer (multivariate RR of clinical diagnosis during follow-up increased from 3.92 to 17.5 across quartiles of IGF-I among men with elevated baseline PSA). These results suggest men in the highest quartile of IGF-I have four and a half times greater risk of prostate cancer than men in the lowest quartile regardless of their PSA levels, and that a combined assessment of IGF-I level and PSA may better predict subsequent prostate cancer than a PSA measure alone.
TABLE 3 IGF-I and risk of prostate cancer by category or pre-diagnostic PSA level. RR* associated with IGF-I quartile PSA level 1 2 3 4 ≦4 ng/ml 1.00 + 1.66 2.07 4.57 — (0.70-3.92) (0.84-5.09) (1.79-11.6) >4 ng/ml 3.92 11 16 17.5 (1.01-15.3) (1.84-65.4) (4.08-62.6) (3.83-80.1)
[0064] Our data support the hypothesis that higher circulating IGF-I levels are associated with higher rates of malignancy in the prostate gland. Alternative explanations for the observations in this study include measurement error, bias, and chance (38). We measured circulating adult levee of IGF-I and IGFBP-3 using a single blood sample drawn, on average, seven years prior to cancer diagnosis. It is possible that another measure of IGF-I physiology (i.e. adolescent or early adulthood mean IGF-I assessed over time, tissue IGF bioactivity, or rate of cell turnover in the prostate gland) would better capture the true etiologically relevant variable. To the extent that our single measurement is a proxy for such a variable and that the measurement errors are non-systematic and proportionately equal among cases and controls, we have reduced the observable variation between our cases and controls, and our results are likely to underestimate the true association between IGF-I and prostate cancer risk (39). Measurement error in assessing prostate cancer outcome is minimal given the physician study base and the histologic confirmation of all cases, although there may be some under-ascertainment of existing cases which would also lead to an underestimation of effect.
[0065] A small case-control study (n=52 cases), in which blood samples were drawn from men already diagnosed with prostate cancer and healthy controls, showed a positive association of borderline significance between IGF-I level and prostate cancer risk (40). However, the retrospective design used in that study could not rule out an effect of the cancer, or its treatment, on IGF-I levels.
[0066] The association between circulating IGF-I level and risk of prostate cancer is stronger than that of any previously reported risk factor, including steroid hormone levels (21) or anthropomorphic variables (30, 31, 41-43). Prior reports showing a weak relationship between prostate cancer risk and height (41, 42) are of particular interest in the context of our results, as IGF-I levels have been reported to be correlated with height (10), and height may act as a weak surrogate for IGF-I. Circulating IGF-I level, in turn, may be related to risk because it represents a determinant of and/or a surrogate for prostate tissue IGF bioactivity and/or cellular proliferation rate.
[0067] In our study population, height was moderately associated with prostate cancer risk, independent of weight, age, smoking, IGF-I, and IGFBP-3 (RR=1.05 per cm increase in height, p=0.05). However, we did not observe an association between IGF or IGFBP-3 and height in this study, possibly due to small sample size or older age of the subjects. A small study (n=21 cases) that reported high birth weight to be associated with a higher incidence of prostate cancer (43) may also be consistent with our observations, as there is evidence that birth weight is positively correlated with IGF-I level (44).
[0068] Age-standardized prostate cancer incidence is increasing even allowing for changes in ascertainment (45). There are grounds for speculation that in certain human populations there is a trend towards increasing IGF-I levels. The physiological basis for the secular trend towards increased height over the past few generations (46) remains unexplained, but this may be correlated with increased IGF-I levels, particularly as severe malnutrition is less common, and malnutrition is known to reduce IGF-I level (47).
[0069] Until now, reduction of androgen action has been the principal strategy under investigation for prostate cancer prevention (48). Our data suggest that the HG/IGF-axis may also deserve attention in this context. Reduction of IGF-I levels by lifestyle modifications may not be possible, as a recent cross-sectional study found IGF-I to be positively correlated with younger age, male gender, and alcohol intake, but uncorrelated with lifestyle-related factors such as body fat, lean body mass, current smoking, physical activity, and use of common medications (29). However, pharmacological approaches to decreasing IGF-I levels deserve investigation as risk reduction strategies specifically targeted to those men who have elevated risk defined on the basis of high IGF-I level.
[0070] The data also provide a rationale for examining the use of this strategy in the treatment of early prostate cancer. Currently, IGF-I levels may be reduced by the use of somatostatin analogues (49) or growth hormone releasing hormone antagonists (50). The former are well-tolerated agents commonly used in treatment of acromegaly and are under investigation in other trials (51). In contrast, our results raise concern that administration of growth hormone or IGF-I over long periods, proposed for elderly men (52), may increase risk of prostate cancer.
[0071] The data reported here justify further epidemiological and biological investigation of IGF-I and IGFBP-3 as predictors of prostate cancer risk, as candidate intermediate endpoints for chemoprevention studies, and as targets for future prevention and therapeutic strategies.
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[0090] 19. Before randomization, the men were mailed blood kits with instructions to have their blood drawn into vacutainer tubes containing EDTA (anti-coagulant), to centrifuge them and to return the plasma in polypropylene cryopreservation vials by overnight pre-paid courier. Cold packs, provided with the kits, were used to keep specimens cool until receipt the following morning, when they were aliquotted and stored at −82 degrees C. No specimen thawed or warmed substantially during storage.
[0091] 20. The Whitmore-Jewett classification scheme was used to identify stage, and cases without pathological staging were considered indeterminate, unless there was evidence of metastases. “High grade/stage cancer” were those cases presenting as stage C or D, or stage A, B, or indeterminate with either poor histological differentiation or a Gleason score of seven or higher.
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[0095] 24. Selection bias is minimal here as it is unlikely that subjects returned blood samples or provided adequate blood volume differentially based on any relation between their IGF levels in 1982 and later development of prostate cancer. Previous study has shown that cases who did and did not provide blood samples were not appreciably different in their baseline lifestyle characteristics (22).
[0096] 25. This methodology was selected as it was shown to be more reproducible and more appropriate for large numbers of samples than an RIA technique we previously employed (13). The IGF-I values obtained by the ELISA were highly correlated (Pearson r=0.97) with values obtained by RIA following acid chromatography. All assays were carried out in a blinded fashion and quality control samples were embedded within assay runs. Average intra-assay coefficients of variation for IGF-I and IGF-II were 4.9% and 3.0%, respectively.
[0097] 26. The IGFBP-3 assay employed does not cross-react with other IGF binding proteins. Experiments with recombinant IGF-I and IGFBP-3 confirm that the assay detects IGFBP-3 whether or not it is complexed to IGF-I in the presence or absence of the acid labile subunit. The average intra-assay coefficient of variation for IGFBP-3 was 9.0%.
[0098] 27. To evaluate the effect of our blood collection methods on IGF-I levels, we compared IGF-I and IGFBP-3 levels in blood samples which were processed and serum frozen immediately after venipuncture (the usual collection and processing methods) to samples, which were stored as heparinized whole blood for 24 and 36 hours before processing (mimicking our collection conditions). The mean IGF-I and IGFBP-3 values were almost identical and the interclass correlations between results of the two collection methods were 0.98 for IGF-I and 0.96 for IGFBP-3, indicating that our collection methods did not adversely affect sample integrity.
[0099] 28. To examine how well a single measurement of IGF-I represents levels overtime, we collected two blood samples each from 16 people, eight weeks apart (time 1 and time 2). The correlation between blood levels taken at time 1 and time 2 was 0.65.
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Methods of predicting a propensity to developing prostate cancer are presented. The method consists of measuring the IGF status of individual. Individuals with high IGF status, as compared with normal reference range values, are at increased risk for developing prostate cancer. More particularly, the IGF status may be determined by measuring IGF-I levels and/or IGFBP-3 levels. High IGF and low IGFBP levels are indicative of a high IGF status. A method of determining the prognosis of existing prostate cancers or of monitoring disease progression involves determining the IGF/PSA status of an individual. Individuals with a high IGF/PSA status (both high IGF status and high PSA levels) tend to develop severe prostate cancer and have a poorer overall prognosis.
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BACKGROUND OF THE INVENTION
This invention relates generally to a means of driving hollow pipe casing with a reciprocating piston-powered ram, such as disclosed in U.S. Pat. No. 4,544,040, wherein the force of the blow of the drive weight is imparted to one end of a standard bowls, also known as an anvil, which transmits said force through the divergent face of the tapered body of the bowls to the divergent face of the tapered body of a collet, also known as a slips, which squeezes the inner face of the collet against the external face of the hollow pipe casing, thus imparting the force of the drive weight to the hollow pipe casing so as to drive it into the ground without requiring special adaptation of the casing, all so that raising the bowls from the collet releases the hollow pipe casing so that continuous sections of hollow pipe casing can be driven without removing the bi-directional pipe drilling ram from the hollow pipe casing.
It has been known that hollow pipe casing can be driven into the ground by means of a bi-directional pipe driving ram, such as disclosed in U.S. Pat. No. 3,474,870 and powered as disclosed in U.S. Pat. No. 4,544,040. These drive systems require the hollow pipe casing, being driven, to be equipped with a reinforced drive head to protect the pipe casing from damage. This drive head had to be removed from the section of pipe casing when it reached sufficient depth so that a new section of pipe casing was mated to it, then the drive head was installed on the end of the new section of pipe casing. This procedure was time consuming and costly. Likewise, systems such as disclosed in U.S. Pat. No. 3,474,870 were limited to pipe casing having a reinforced collar against which to impart the force of the ram, while rod-clamping devices, such as disclosed in U. S. Pat. No. 4,516,662, impart the drive force to localized jamming elements which would damage standard hollow pipe casing. In addition, types of bowls and collets similar to those described in this specification have been known and used in the drilling industry to lift or position pipe casing because of their ease of grabbing and releasing the pipe casing, but have never been considered or utilized in the new and novel manner as described and claimed herein.
The primary object of this invention is to provide a means of continuously driving sections of hollow pipe casing which does not require any special modification to the hollow pipe casing and can be utilized with existing bi-directional pipe driving rams available in the drilling profession. Another object of this invention is to accomplish the primary object with minimum expense and allow its adaptability to the gauges of pipe casing regularly utilized in the drilling industry. A further object of this invention is to accomplish the foregoing objectives in vertical or horizontal drilling situations without damage to the hollow pipe casing and to enable the driving force of the bi-directional pipe driving ram to be applied in either direction on the hollow pipe casing without the need to remove the bi-directional driving ram from the hollow pipe casing.
SUMMARY OF INVENTION
These objects are achieved by this invention in that it utilizes a standard bowls and collet assembly to receive the force of the ram and transfer said force to the exterior face of the pipe casing. Each gauge of pipe casing is capable of bearing a predetermined drive force against its external face without incurring damage and the ram impact force is adjusted to impart that degree of force.
The novel features of the invention will be best understood from the following description in light of the accompanying drawings. While particular embodiments of the present invention are shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim of the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevation of my invention.
FIG. 2 is an elevational view of a collet.
FIG. 3 is an elevational view of a bowls.
FIG. 4 is an elevational view of an alternative collet.
FIG. 5 is a front elevation of my invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the drawings and particularly FIGS. 1 and 5, the preferred embodiments of the Cable-Tool Casing Hammer are shown. The Cable-Tool Casing Hammer is a bi-directional pipe driving apparatus, having a cylindrical channel (19) throughout its length, to include the drive weight (25), of sufficient diameter to slidably accommodate a hollow pipe casing (1) to be driven, comprised of a bi-directional pipe driving ram (15), powered by suitable means, such as steam or water pressure, bowls (9), (22) and collets or slips (3), (23) located upon a hollow pipe casing (1) at either end of the bi-directional pipe driving ram (15).
Referring to FIGS. 2 and 3, this invention is comprised of a collet, or slips, (3) comprised of a circular piece of hardened metal material, with a cylindrical interior (34) and an opening (24) along its length of sufficient width to slidably accommodate a hollow pipe casing (1) within its internal diameter (31) when open and firmly grasping the external face (2) of the hollow pipe casing (1) when closed, being of sufficient length for engaging the exterior face (2) of a hollow pipe casing a sufficient area to transfer the force of the drive weight (25) of a bi-directional pipe driving ram (15) to the hollow pipe casing (1) without damage thereto, having an internal diameter (31) slightly larger than the external diameter of the hollow pipe casing (1) to be driven, so that the hollow pipe casing (1) may be slid easily through the collet (3) when the opening (24) along the length of the collet (3) is open, the internal face (4) of the collet (3) being parallel to the external face (2) of the hollow pipe casing (1), while the external face (5) of the collet (3) tapers from a thin edge (26), at the end closest to the drive weight (25), to a thick edge (27) at the opposite end, being of sufficient thickness to close the opening (24) along the length of the collet (3) when the internal face (8) of the bowls (9) which tappers outward is pressed over the tapered external face (5) of the collet (9), prior to the stop face (7) of the bowls (9) reaching the top of the stop face (6) of the collet (3). Thus, when the bowls (9) is pressed over the collet (3) to securely engage the external face (2) of the hollow pipe casing (1), the extension (11) of the base (13) of the frame (16) of the bi-directional pipe driving ram (15), by the force of gravity, rests upon the hip (42) of the bowls (9), so that the strike face (10) of the bowls (9) extends above the extension (11) of the base (13). As the bowls (9) is not attached to the frame (16), it is provided with a shoulder (43) which protrudes outwardly from its top end a sufficient distance to engage a retaining ring (44) fastened to the extension (11) of the base (13) by standard bolt means (12), which, when secured within the threaded channels (47) in the extension (11), is fully below the inside surface (46) of the base (13), while not protruding so far as to make contact with the bolts (12) when the frame (13) is withdrawn. To facilitate separation of the bowls (9) from the collet (3) after they have been pressed together and securely engaged the external face (2) of the hollow pipe casing (1), the stop face of the collet (6) contains threaded channels (47) through its depth, regularly spaced around it, to accommodate jack bolts (45) which, when installed, can push the stop face of the bowls (7) away from the stop face of the collet (6), thus releasing the bowls (9) from the collet (3) and the collet (3) from the external face (2) of the hollow pipe casing (1).
Referring to FIG. 3, the bowls (9) is comprised of suitable hardened metal having a cylindrical interior (29), having a minimum internal diameter (35) slightly larger than the external diameter of the hollow pipe casing (1) to be driven, with one end having a flattened upper strike face (10), which extends beyond the retaining ring (44) on the extension (11) of the base (13) of the frame (16) of the bi-directional pipe driving ram (15) throughout its circumference and the retaining ring (44) being removably secured to the extension by bolt means (12) at at least two locations.
Referring to FIG. 1, said flattened upper strike face (10) receives the impact of the strike face (14) of the drive weight (25) of the bi-directional pipe driving ram (15), which strike face (14) extends beyond the bottom end (28) of the drive weight (25) so as to prevent the drive weight (25) from touching the base (13) of the frame (16) at the extent of the drive weight's (25) travel and damaging the guide rod (17) or collars (18) at either end and on both opposite sides (33) of the drive weight (25) which maintain the alignment of the drive weight (25) along the guide rods (17), which run from the top (36) of the frame (16) to the base (13) of the frame (16) of the bi-directional pipe driving ram, on at least opposite sides of the drive weight (25). The bowls (9) is of sufficient length so that the half of it opposite to the end having the flattened upper strike face (10) is sufficient to override the entire tapered external face (5) of the collet (3), with the internal face (30) of the half of the bowls adjacent to the upper strike face (10) being parallel to the external face (2) of the hollow pipe casing and the internal half (8) opposite thereto tapering outward away from the parallel line of the external face (2) of the hollow pipe casing (1) at an identical rate to the taper of the external face (5) of the collet (3), so that the bowls (9), as it is pressed over the collet (3), reduces the internal diameter (31) of the collet (3) until it securely grips the external face (2) of the hollow pipe casing (1) allowing efficient transfer of the force from the bi-directional pipe driving ram (15) to the hollow pipe casing (1).
Referring to FIG. 1, the external face (2) of the hollow pipe casing (1) is released from the grip of the internal face (4) of the collet (3) merely by withdrawing the bowls (9) from engagement with the collet (3), with or without the aid of jack bolts (45), allowing the bi-directional pipe driving ram (15) to be easily repositioned along a length of hollow pipe casing (1) or to another section of hollow pipe casing (1) fastened to the end of the one previously engaged, without removing the bi-directional pipe driving ram (15) from its position relative to the hollow pipe casing (1) sections being drilled. Should the bi-directional pipe driving ram (15) be used to remove hollow pipe casing (1) previously driven into the ground, the direction of force being applied to the hollow pipe casing (1) can be easily reversed by installing a collet (23) and bowls (22) on the hollow pipe casing (1), reversing the order and orientation, at the opposite end of the bi-directional pipe driving ram (15) and reversing the drive direction of the drive weight (25), so that the strike face (20) of the opposite end of the drive weight impacts the strike face (21) of the bowls (9) on that end of the bi-directional pipe driving ram (15).
An alternative and preferred construction of a collet (36) is shown in FIG. 4. This preferred embodiment is comprised of a collet (36), machined so that the external face of the collet (5) is tapered to flare from the thin edge of the collet (26) to the thick edge of the collet (27) at the angle of 7.5 degrees, being split through, from the thin edge (26) to the thick edge (27), into two facing halves (37), (38), having vertical slots (39) in the tapered sides, cut from the thin edge of the external face of the collet (27) to just short of the stop face of the collet (6), said slots (39) being regularly spaced every 45 degrees around the circumference of the two facing halves of the collet (37), (38), said halves being removably attached to each other by bolt means (40) located in pre-drilled and threaded bolt holes (41) within the stop face of the collet (6). This alternative and preferred construction yields a collet (36) whose internal face parallel to the pipe casing (4) is at least 8 inches high, from the thin edge of the collet (26) to the stop face of the collet (6), and said stop face is an additional 2.5 inches in height. The bowls (9) to mate with this alternative and preferred embodiment of the collet (36) has its internal face of half of the bowls adjacent to the strike face (30) likewise tapered at a 7.5 degree angle and can be made in two facing halves and joined by bolt means in like manner to the alternative and preferred embodiment of the collet (36).
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.
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A novel improvement in a tubular ram device for bi-directional driving of pipe casing, vertically or horizontally, wherein the driving hammer imparts the force to the pipe casing through a bowls-anvil and removable collet, thus allowing driving of sections of pipe casing without removing the tubular ram device or making any physical change to the pipe casing.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to methods of manufacturing reduced-warp nitride substrates for semiconductors, and to nitride semiconductor substrates manufactured by the method.
2. Description of the Related Art
Substrates on which semiconductor devices are fabricated are round wafers, and given that the devices are fabricated on the front surface of the substrates by such methods as photolithography, doping, diffusion, and vapor deposition including chemical vapor deposition (CVD), the front surface must be flat, with minimal warp. When fabricating semiconductor devices onto silicon and onto gallium arsenide in particular as substrates, Si and GaAs wafers with minimal warp, polished to an optically smooth, mirror finish are employed.
Sapphire wafers are used as the substrates for blue light emitting diodes in which indium gallium nitride is the light-emitting layer. InGaN/GaN-based LEDs formed onto sapphire substrates have performed well and are dependable. The sufficiently moderate cost of sapphire substrates has meant that InGaN-based LEDs can be made at low-cost.
Nevertheless, there are drawbacks to sapphire. For one, with sapphire being an insulator, rather than attaching n electrodes to the bottom, a GaN layer onto the surface of which the n electrodes are attached is applied, thus requiring excess area. Another is that since sapphire does not cleave, it cannot be rent into chips along natural cleavages. And because it is GaN and InGaN that are grown onto the heterosubstrate there is misfit, which leads to heavy defects.
Under the circumstances, then, it is desirable that GaN itself be the substrate. GaN substrates have become producible by depositing a thick GaN film onto a heterosubstrate base using vapor-phase deposition and removing the base to create a GaN freestanding layer. And in terms of size, 50-mm diameter Substrates—long-awaited—have also become possible.
Vapor-phase grown GaN-crystal wafers are, however, used as-grown for epitaxial deposition substrates. In the front side of GaN substrates that have been vapor-phase deposited and nothing more roughness is considerable and warp is serious; growing GaN and InGaN onto such substrates will not necessarily lead to a lowering of defects over the situation with sapphire substrates. And LEDs created experimentally on as-grown GaN substrates certainly do not perform better than LEDs manufactured on sapphire.
Because the formation of semiconductor devices onto GaN substrates is by photolithography, flat, mirror-finish wafers with minimal warp are desired as the substrates. Polishing and etching technology is necessary to render the surface of a wafer optically smooth. Polishing and etching technologies have already been established for fully developed semiconductor substrates such as Si and GaAs. Si and GaAs crystal can be grown by gradually solidifying a melt, as in the Czochralski method or the Bridgeman method. Since long, columnar ingots with few dislocations can be produced by growing from the liquid phase, the ingots are sliced with an internal-diameter saw to produce wafers. This means that warp is minimal from the start.
With GaN on the other hand, growth, being impossible from the liquid phase, is by means of vapor-phase deposition. Furthermore, what form optimal polishing and etching methods should take is still not understood. If GaN is to be hetero-deposited onto crystal of a different kind, such as has three-fold symmetry, the growth will necessarily be c-axis oriented. The surfaces are a (0001) plane and a (000 1 ) plane. Because GaN crystal does not have reverse symmetry, the (0001) and (000 1 ) planes are not crystallographically equivalent. The (0001) face is one in which gallium atoms range in lines globally over the episurface, and the (000 1 ) face is one in which nitrogen atoms range in lines globally over the episurface.
The former can be referred to as the (0001) Ga face, or simply the Ga face; the latter, as the (000 1 ) N face, or simply the N face. Physiochemically the Ga face is extremely unyielding and rugged, and is not dissolved by chemical agents. The N face is also physiochemically robust, but is corroded by certain types of strong acids and alkalis. GaN crystal has such asymmetry.
When GaN is grown onto a base substrate, the front side and back side become either the Ga face or the N face. Depending on how the base substrate is selected, the front side can be made the Ga face or the N face. The back side then becomes the face with the opposite polarity.
For the sake of simplicity, a case in which the front side is the (0001) Ga face, and the back side is the (000 1 ) N face will be considered. The same statements can be made, and the same design features implemented in the opposite situation as well.
Since the subject of the present invention is warp, to begin with a definition of warp will be given. Warp can be expressed as radius of curvature, or curvature. These are exact expressions and can be given locally. Even in situations in which the warp is complex and the substrate has heavy roughness, exact warp can be expressed using a local curvature expression. For example, warp with a saddle point and cylindrical-lens-like warp can also be expressed.
But with uniform buckling in round wafers, warp is often represented by a simpler expression. If the roughness is uniform the wafer is measured taking the height H to the planar face from the surface of the center area in the convexity, according to which a value for the warp is given. This is intuitive, and facilitates measurement. The absolute value is determined by this warp measurement.
The sign of the warp will be given by its orientation. This definition is indicated in FIG. 1 . Warp curving outward along the front side will be termed positive (H>0); warp curving inward along the front side will be termed negative (H<0).
In situations in which long monocrystal ingots with few dislocations can be produced—such as is the case with Si and GaAs—since the ingots are sliced with an internal-diameter saw or a wire saw, warp is slight from the start. To produce GaN crystal, however, with growth from the liquid phase being impossible, vapor-phase growth is carried out. Because rendering GaN crystal is by heteroepitaxy onto a heterosubstrate that differs from GaN in thermal expansion coefficient, and then removal of the heterosubstrate, considerable warp appears in GaN crystal. This problem is due not only to the difference in thermal expansion coefficient, but also to the many dislocations that come about because the base substrate and the overlying film are different materials. The dislocations give rise to irregular stresses, which due to the volume of dislocations is why warp comes about.
As-grown, platelike, 20-50 mm diameter GaN crystal from which the base substrate has been removed has a warp of from ±40 μm to as much as ±100 μm, although the value will differ depending on the type and crystal-plane orientation of the base substrate, and on the vapor-phase deposition parameters.
With the warp in a GaN wafer substrate being that extensive, in a situation in which a photolithographic resist on the wafer is to be exposed its dimensions will be thrown out of balance. Thus the warp must be extensively reduced. Warp in Si and GaAs wafers also has to be lessened, but with GaN there is a special reason why warp has to be reduced. Since GaN is transparent, when the wafer is set on a susceptor with a built-in heater and heated, not much of radiant heat from the heater heating the GaN crystal occurs. Seeing as how thermal conduction from the susceptor is the principal heat-transmission means, the back side of the GaN crystal desirably is flat, with its entire surface in contact with the susceptor without gaps.
Instances of the above outward-curving (positive warp, H>0) mean that the wafer center portion comes apart from the susceptor. Such cases are still the better, because the thermal conduction is from the peripheral margin heading toward the center. Oppositely, in instances of the above inward-curving (negative warp, H<0), with only the center contacting susceptor the wafer ends up turning, leading to positional instability. Not only that, but source-material gases circle to the back side through the encompassing, lifted-up area, causing thin-film growth or etching to occur on the backside of the substrate also. Consequently, negative warp is even less suited to semiconductor fabrication needs than positive warp.
Because as-grown GaN crystal has a warp H of from ±40 μm to ±100 μm, the number one objective is to decrease the warp to be within a +30 μm to −20 μm range.
More advantageously, the warp should be decreased to within a +20 μm to −10 μm range.
Furthermore, if possible, bringing the warp to within +10 μm to −5 μm would even better meet fabrication needs.
There are any number of examples of devising a crystal growth method to minimize warp in the products. These may be grossly bifurcated into those that reduce warp by lateral overgrowth of the GaN to alleviate vertically oriented stress and reduce internal stress, and those that grow two layers having competing actions and eliminate warp by the balance between the actions. Every one of these is a way of attempting to reduce, via the deposition parameters, warp in crystal being grown; they are not ways of attempting to reduce warp in crystal already produced.
Japanese Unexamined Pat. App. Pub. No. H11-186178 addresses the problem of incidents of warp and cracking in GaN crystal that due to the difference in the coefficients of thermal expansion of Si and GaN occur when a GaN film is grown onto an Si substrate to create a GaN/Si composite substrate.
This reference relates that to prevent warp and cracking from occurring in GaN crystal, stripes of SiO 2 film are formed onto an Si substrate, and when GaN film is grown onto the substrate, atop the SiO 2 growth of GaN does not initially occur, thereby alleviating stress and reducing warp in the GaN/Si composite substrate. This substrate is not an independent film of GaN, but rather a composite substrate in which a thin GaN layer on the order of 10 μm is provided on an Si base, so that internal stress in the GaN layer can be reduced by having the SiO 2 intervene.
Japanese Unexamined Pat. App. Pub. No. 2002-208757 concerns manufacturing nitride semiconductor substrates of satisfactory crystallinity, by employing lateral overgrowth and, to keep warp under control, dispersing throughout the substrate overall the coalescence boundaries, where defects concentrate.
Japanese Unexamined Pat. App. Pub. No. 2002-335049 proposes a deposition method that by reducing dislocations by means of lateral overgrowth to diminish stress, also reduces warp.
Japanese Unexamined Pat. App. Pub. No. 2002-270528 proposes a deposition method in which reducing dislocations by means of lateral overgrowth to reduce stress keeps warp from occurring.
Japanese Unexamined Pat. App. Pub. No. 2002-228798 exploits Si crystal not as a semiconductor but as a mirror. The goal is to create concave or convex mirror surfaces from Si crystal. To get Si crystal to possess a desired curvature, it must be deformed. To do so, a thin film of diamond is built up on an Si substrate, and the Si substrate is deformed by the stress between the diamond thin film/Si substrate. In other words, the original planar article is forcibly buckled to lend it a concave or convex mirror surface. The reference states that Si can be buckled into a curvature of choice depending on the diamond formation parameters.
Japanese Unexamined Pat. App. Pub. No.2003-179022 addresses the problem that after forming semiconductor devices onto a large-caliber Si wafer, the wafer is back-side ground and the back side is mechanically planed to reduce the wafer to a desired thickness, but a processing distortion layer is formed, producing a warp of 800 μm, and etching away the layer takes too much time. This reference states that, given the realization that the processing distortion layer on the Si wafer back side is amorphous, warp is eliminated by exposing the Si back side for 5 seconds with light from a halogen lamp to momentarily heat the wafer to 600-700° C. and convert the processing distortion layer from an amorphous to a crystalline state. Thus this is an example not of ridding the wafer of the processing distortion layer, but eliminating warp in the wafer by qualitatively transforming the layer.
Inasmuch as nitride semiconductor is chiefly produced using vapor-phase deposition to build up a thin film onto a heterosubstrate and removing the base substrate, with dislocations due to the difference in thermal expansion coefficients and the mismatching lattice constants occurring at a high density, warp is serious. Although methodologies for diminishing warp by devising growth methods to diminish internal stress have been variously proposed, they are yet insufficient.
Even with such methodologies, manufacturing nitride semiconductor crystal of large film thickness and large diameter means the dislocations and warp will be considerable, and when the base substrate is removed the crystal often ends up cracking. Even if the crystal does not crack, the warp will be large, reaching ±40 μm to as much as ±100 μm.
BRIEF SUMMARY OF THE INVENTION
Objects of the present invention are in such crystal substrates in which warp is large to reduce the warp by means of a post-deposition process.
A first object is bringing out a processing method so that the warp figure for nitride semiconductor substrate as 2-inch wafers is brought to within a range of +30 μm to −20 μm. A second object is bringing out a processing method that brings the warp figure for GaN substrates to within +20 μm to −10 μm. A third object of the present invention is making available a processing method in which, the warp figure for nitride semiconductor substrates is reduced to within +10 μm to −5 μm by means of a post-deposition process. A fourth object of the present invention is bringing out nitride semiconductor substrates in which the warp is within +30 μm to −20 μm.
A method of manufacturing nitride semiconductor substrates according to one aspect of the present invention addresses warp in a nitride semiconductor substrate by mechanically grinding, to introduce a damaged layer into, the concave face of the buckled substrate, thereby extending the concave face, bringing it close to being planar and reducing the warp.
In accordance with a nitride substrate manufacturing method in another aspect of the invention, by mechanically grinding, to introduce a damaged layer into, the concave face of a nitride semiconductor substrate in which there is warp, the concave face is extended to deform it convexly; and by etching the convexly deformed surface to remove the damaged layer partially or entirely and bring down the convex face, the substrate is brought close to being planar, which reduces the substrate warp.
According to a manufacturing method in a further aspect of the invention, by mechanically grinding, to introduce a damaged layer into, the concave face of a nitride semiconductor substrate in which there is warp, the concave face is extended to deform it convexly; the convexly deformed surface is etched to remove the damaged layer partially or entirely and bring down the convex face; and by mechanically grinding, to introduce a damaged layer into, the surface that has turned into a concave face on the opposite side, the concave face is extended, rendering it a convex face; by etching the surface that has now been convexly deformed and bringing down that convex face, the substrate is brought close to being planar, which reduces the substrate warp.
A further aspect of the invention is a manufacturing method according to which, by mechanically grinding, to introduce a damaged layer into, the concave face of a nitride semiconductor substrate in which there is warp, the concave face is extended to deform it convexly; and by mechanically grinding, to introduce a damaged layer into, the surface that has turned into a concave face on the opposite side, the concave face is extended, rendering it a convex face; by etching the surface that has now been convexly deformed and bringing down that convex face, the substrate is brought close to being planar, which reduces the substrate warp.
From the following detailed description in conjunction with the accompanying drawings, the foregoing and other objects, features, aspects and advantages of the present invention will become readily apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is exaggerated, outline sectional views of a substrate, representing definitions of the sign given to warp, in which convex warp along the front side is positive, and convex warp along the backside is negative.
FIG. 2 is a graph plotting measurements of front-side roughness (Ra: μm) and damaged layer depth for when the front side of a 2-inch GaN wafer underwent a grinding operation with #80, #325, and #1000 diamond grit. The horizontal axis is the grit (mesh) number, the right vertical axis is the level of surface roughness Ra (μm), and the left vertical axis is damaged layer depth (μm). It is apparent from the graph that with the grit as the mediating agent, the deeper the damaged layer is, the larger the surface-roughness level becomes.
FIG. 3 is a graph plotting measured values of warp H against those of etching depth when a damaged layer on the back side (N face) of a post-back-side-ground GaN wafer was wet-etched utilizing a KOH solvent. The horizontal axis is the etching depth (μm), and the vertical axis is the wafer warp H (μm). From the graph it is evident that etching a wafer with an initial −33 μm concave warp (curving inward along the front side) proceeded to decrease the warp. When some 5 μm had been etched, the warp became a constant −10 μm or so, not decreasing to less than that.
FIG. 4 is a graph plotting measured values of warp H against those of etching depth when a damaged layer on the front side (Ga face) of a GaN wafer after having been ground utilizing a chlorine plasma was dry-etched. The horizontal axis is the front-side etching depth (μm), and the vertical axis is the wafer warp H (μm). From the graph it is evident that etching a wafer with an initial +41 μm convex warp (curving outward along the front side) proceeded to decrease the warp. When some 6 μm had been etched, the warp became a constant +10 μm or so, not decreasing to less than that.
FIG. 5 is crystal-section views for explaining fundamental techniques of the present invention for reducing warp in wafers by combining formation of a damaged layer by grinding, and reduction of the damaged layer by etching. The upright lines represent dislocations, and the speckles represent damaged layers. FIG. 5A illustrates a technique for a situation in which a post-growth substrate crystal is convexly buckled along the front side (H>0), in which grinding the back side creates a damaged layer on the back side, extending the back side and reducing the warp. FIG. 5B illustrates a technique for a situation in which a post-growth substrate crystal is concavely buckled along the front side (H<0), in which grinding the front side introduces a damaged layer on the front side, extending the front side and reducing the warp. FIG. 5C illustrates a technique for a situation in which grinding the back side has produced a damaged layer to excess, resulting in concave warp along the front side, in which the damaged layer on the back side is removed by etching, which thins down the damaged layer to reduce the warp.
DETAILED DESCRIPTION OF THE INVENTION
From stages in manufacturing a GaN substrate to grinding and etching in the present invention will be explained in more detail.
1. Growing GaN Ingots
GaN freestanding layers are created according to the method set forth in Japanese Unexamined Pat. App. Pub. Nos. 2000-12900 and 2000-22212. An epitaxial lateral overgrowth (ELO) mask is laid onto a (111) GaAs wafer, and the GaN is grown by a vapor-phase epitaxy technique such as hydride or metalorganic-chloride vapor phase epitaxy (HVPE or MO-chloride VPE).
The GaN is grown on the ELO mask to reduce stress in the crystal, and moreover is subjected to facet growth to reduce dislocations. The deposition yields GaN of 100 μm to several mm in thickness, and the GaAs substrate is removed to give an independent GaN substrate.
Techniques for removing the GaAs base substrate include dissolving with aqua regia, shaving off by polishing, and delaminating by a lift-off process. GaN films grown thin render single, freestanding GaN wafers; when thick they are cut with a wafer saw to yield a plurality of wafers.
As-grown GaN crystal after the GaAs has been removed is often convex along the back side, and the warp amplitude H is often ±40 μm to as much as ±100 μm. The roughness (R max ) along the back side can be 10 μm or more. Such serious warp occurs owing to the large difference in thermal expansion coefficient between the base substrate and the GaN, and to the massive dislocations produced by their mismatching lattices. Occurrences of such warp are inevitable despite a mask-utilizing lateral overgrowth technique as just discussed being carried out.
To have the GaN substrates be as they should for manufacturing semiconductor devices onto them, the warp must be decreased, and the front and back sides planarized (lowering the degree of surface roughness). Henceforth a discussion of the present invention will develop.
2. Evaluating Damaged Layer in Ground Substrates
The post-grinding damaged layer on the substrates was evaluated by cross-sectional observation using scanning electron microscopy (SEM) and cathode luminescence (CL).
From the observation results, it was evident that on a substrate in which the GaN crystal face was ground employing #325 diamond grit, the depth of the damaged layer was approximately 4.8 μm.
The mesh (size) of the diamond grit correlates with the surface roughness. The rougher the grit is the rougher the surface ground with the grit will be. With finer grit texture, the face ground with the grit will turn out planar. In turn, since the damaged layer arises from grinding, the damaged layer ought to bear a relationship to the roughness of the grit. This means that by way of the roughness of the grit texture, there ought to be a correlation between the thickness of the damaged layer and the surface roughness.
Given these considerations, the relation between the depth of the damaged layer and the surface roughness was investigated. The results are shown in the FIG. 2 graph. The horizontal axis is the mesh (#). The larger the number, the finer the grit is. Plotted in the graph are damaged layers on GaN crystal planed with #80, #325 and #1000 grit, versus roughness. The vertical axis on the left indicates damaged layer depth (thickness in μm), while the vertical axis on the right indicates surface roughness Ra (μm).
From the graph it will be understood that the lower the surface roughness, the thinner will be the damaged layer. The depth of the damaged layer is dependent on the grain size of the diamond grit employed. The significance of this is that the depth of the damaged layer can be controlled. Using a fine-textured grit diminishes the damaged layer and makes it smooth. By the same token, using a coarse-textured grit allows a thick damaged layer to be created deliberately.
Grinding with a grit of a suitable texture smoothes, and produces a damaged layer on, the GaN substrate face. The damaged layer acts to stretch the surface on which it is formed. If the action is excessive, the crystal will end up buckling oppositely. In order to rectify this, the damaged layer should be partially removed, and to do so etching was carried out. For the etch, both wet etching using chemical agents and dry etching using plasma were tried.
3. Study of Front-Side Wet Etching
After being processed, the surface of a GaN substrate underwent wet etching. KOH (aqueous solution, 8 N concentration) was heated to 80° C., and the GaN substrate was wet-etched by immersing it into the solution. The warp was not, however, altered. This means that a GaN crystal face on which a damaged layer has been produced by polishing is not wet-etched by KOH.
The (0001) faces of GaN have polarity. One face (the Ga face) is terminated with gallium atoms, and the other face (the N face) is terminated with nitrogen atoms. The Ga face is hard and unyielding, and is chemically stable. No chemical agent that can effectively etch a Ga face exists. Since the front side was the Ga face and the back side was the N face, when the substrate was dipped into the KOA solution the back-side N face was slightly etched but the front-side Ga face was not etched at all. Because the front side, being polished, had the damaged layer, KOH did not remove the front-side damage layer.
Wet-etching GaN with a strong alkali like heated KOH, or a strong acid such as H 3 PO 4 has been documented. But such instances have amounted only to erosion of the N face. The GaN that the present invention inventors manufacture possesses a composite front side in which the N face and the Ga face appear in alternation. Since wet-etching the GaN in an etchant such as KOH or H 3 PO 4 etches only the N face, creating pits, the front side ends up being ragged. Despite the pains taken to polish the front side, it ends up ruined, not amounting to anything. Ultimately, therefore, wet-etching of the front side (Ga face) proves to be impossible.
4. Back-Side Wet Etching
The back side (N face) of GaN substrates is ground. A damaged layer is created on the back side by polishing, and the substrates buckle convexly along the back side (warp: negative). It was discovered that when substrates having a negative warp are wet-etched with an 8 N KOH solution at 80° C. or with H 3 PO 4 phosphoric acid, with elapsed etch time the absolute value of the warp decreases. That is, the back side—being the N face—is etched by a strong alkali and a strong acid, and by the very diminishment of the diminishing damaged layer, the warp is curtailed. This means that back-side polishing and wet etching form a method that can be utilized to curtail warp.
Results of thus utilizing the method are shown in FIG. 3 . Under conditions for back-side wet etching identical to those just noted, the back side of a GaN substrate was wet-etched. The horizontal axis in the graph represents the wet-etching depth (μm), and the vertical axis, warp (μm). From the graph it is evident that wet-etching a concave GaN substrate whose front side possessed an initial −33 μm concave warp curtailed the warp. When some 5 μm had been etched, the warp went to around −10 μm; etching beyond that did not lead to diminishment of the −10 μm warp.
In addition, variation in the thickness was under several μm, which was at the non-problematic level.
Wet-etching the back side of the substrate gave the GaN crystal—whose front side, being globally mirror-finished, was transparent—a clouded appearance like frosted glass. This was because the back side had been surface-roughened. Since the warp was reduced, in situations in which it is acceptable for the back side to be glazy, the substrate can be used in that state.
There are situations, however, in which the back side being glazy would create Problems—in which the back side has to be a mirrorlike surface. In such cases, arrangements have to be made to remove the damaged layer by dry-etching the back side. When removal is by dry etching, the back side does not become frosted-glasslike.
The fact that wet-etching the Ga face is impossible, while wet-etching the N face is possible has been noted. The N face (back side) can be rid of a damaged layer by either wet etching or dry etching. For the front side, removal is only by means of dry etching.
5. Study of Front-Side Dry Etching
Inasmuch as wet etching is ineffectual, the only option for etching the front side (Ga face) is by dry etching. Provided that dry etching is feasible, by that means removing a damaged layer along the front side of a GaN substrate ought to be possible.
Performing dry etching of GaN under the following conditions makes it possible to etch the front side.
Equipment:
reactive ion etcher
Gas:
halogen gas (chlorine gas)
Chlorine flow rate:
5 sccm to 100 sccm
Pressure during etch:
0.1 Pa to 10 Pa
Plasma power:
antenna - 100 W to 500 W
bias - 5 W to 20 W
Plotted in FIG. 4 is the relationship between front-side etching depth and warp when the front side (Ga face) of a GaN substrate was dry-etched at: chlorine flow rate=10 sccm; pressure=1 Pa; antenna power 300 W; bias 10 W. The horizontal axis is the etching depth (μm); the vertical axis is the warp (μm). Although the warp was initially 40 μm, the etching carried out proceeded to curtail the warp: When the etching depth was 0.8 μm, the warp had decreased to +30 μm; at 1.3 μm etching depth the warp had decreased to +22 μm; at 2 μm etching depth, the warp had subsided to +16 μm; at 3.6 μm etching depth, the warp had subsided to +13 μm; at 5.5 μm etching depth, the warp had curtailed to +10 μm; and when the etching depth had gone to over 6 μm, the warp no longer subsided, staying at the +10 μm level.
It was realized that although with the front side being the Ga face, the front side could not be etched by wet etching techniques, with a dry etching technique—reactive ion etching (RIE)—the Ga face too could be etched. Then it was also realized that by means of the etching, positive warp (convexity in the front side) decreases. This was a crucial discovery. With the damaged layer being on the front side, the layer brought about positive warp (convexity along the front side). Since what gave rise to the positive warp was curtailed because the front side was reduced, the warp proceeded to decrease. Such is the plausible interpretation.
6. Study of Back-Side Dry Etching
Under the same conditions as with the front side, dry etching was possible on the back side (N face) of a GaN substrate. By means of dry etching using chlorine plasma, removal of a damaged layer from the back side was also possible. Removing the damaged layer from the back side altered the warp from being concave with respect to the front side to being convex with respect to the front side. (The warp changed heading from negative-ward to positive-ward.) And removing the damaged layer on the substrate back side was possible without spoiling the surface smoothness of the back side.
7. Controlling Warp
Herein it will become clear that warp can be controlled by combining grinding or a like mechanical process, and dry etching. A damaged layer forms when either the front side (Ga face) or the back side (N face) is ground. The damaged layer produces compressive force on the ground face, tending to stretch it. The front side therefore deflects convexly when a damaged layer is made on the front side. And the back side deflects convexly when a damaged layer is made on both sides. The warp rate can be modulated by the thickness d of the damaged layer, and the damaged layer can be removed by dry etching. If thus the thickness of the damaged layer is decreased, the warp will change from being convex to being concave. These are the reasons why warp can be controlled by the formation of a damaged layer.
Such instances are illustrated in FIG. 5 . The plural vertical lines drawn within the wafers represent dislocations. Further, fine stipples are drawn by the front/back side of the wafers; these are the damaged layer produced by grinding. FIG. 5A illustrates a technique for a wafer whose front side is convex (H>0), in which grinding the concave back side creates a damaged layer on the back side to curtail the warp. FIG. 5B illustrates a technique for a wafer whose front side is concave (H<0), in which grinding the concave front side forms a damaged layer on the front side to curtail the warp. FIG. 5C illustrates a technique of back-side dry-etching in which the back side of a wafer whose front side is concave (H<0) is ground to create on the back side a damaged layer, and the damaged layer on the back side is reduced and thinned down.
The warp in a GaN substrate deposited by a vapor-phase deposition onto a heterosubstrate, from which the base substrate is removed, is ±40 to as much as ±100 μm. If thus the warp is large, the error in the optical exposure pattern during device fabrication by photolithography will be too great. When contact exposing a substrate it is pressed upon, and if there is warp, the substrate can crack. Therefore, warp in the GaN substrate has to be +30 μm to −20 μm. More desirably, the warp is +20 μm to −10 μm, and optimally it is +10 μm to −5 μm.
GaN substrates are transparent. Forming thin films onto the GaN wafers by metalorganic chemical vapor deposition (MOCVD) or molecular-beam epitaxy (MBE), or vapor-depositing electrodes on the wafers means that they are placed on a susceptor with a built-in heater and heated; but because the wafers are transparent, they do not sufficiently absorb the radiant heat from the heater. Rather than the radiant heat, a wafer absorbs heat from the susceptor due to thermal conduction. Because the absorption route is by thermal conduction, it is vulnerable to how the wafer and susceptor are in contact. To make the heating uniform, the state of contact between the wafer and susceptor must be made uniform. If there is warp in the wafer, thermal conduction will be restricted to the central portion (concave warp) or to the peripheral portion (convex warp). With uniform heating being impossible on account of such warp, a strong, diametrically oriented temperature distribution is set up in the wafer. Consequently, the characteristics of the fabricated devices end up being inconsistent. In this respect GaN substrates differ vastly from Si and GaAs substrates.
Thus, as far as warp is concerned, more severe conditions are imposed on GaN substrates than on Si or GaAs substrates. Since in order to make thermal conduction uniform, globally even contact with the susceptor is sought, zero warp is ideal. The spread in which warp is tolerated is not identical above and below zero: a tolerance range in which above, where warp is convex, is up to 30 μm, and below, where warp is concave, is as far as 20 μm.
Thus the ranges of warp that can be tolerated are
Range (a): +30 μm to −20 μm;
Range (b): +20 μm to −10 μm; and
Range (c): +10 μm to −5 μm.
Equipment: reactive ion etcher Gas: halogen gas (chlorine gas) Chlorine flow rate: 5 sccm to 100 sccm Pressure during etch: 0.1 Pa to 10 Pa Plasma power: antenna - 100 W to 500 W bias - 5 W to 20 W
Advantageous Features of the Invention
If with warp being large semiconductor devices are fabricated by photolithography onto GaN crystal wafer obtained by using vapor-phase deposition to grow GaN onto a heterosubstrate and stripping off the heterosubstrate, error in the transfer pattern will be significant. And there will be instances of cracking in the wafer when it is vacuum-chucked.
Inasmuch as the present invention brings the wafer warp to within +30 μm to −20 μm, even vacuum-chucked the wafer will not crack. Wafers according to the present invention do not fracture even when masks for contact exposure are set onto the wafers. Since there is no warp, the mask pattern is accurately transferred onto the resist, and errors do not appear in the optical exposure pattern. These features improve device-fabrication yields.
Inasmuch as a damaged layer is exploited to eliminate warp, the damaged layer of the present invention remains behind to some extent. A maximum of 50 μm of the damaged layer along the back side, and a maximum of 10 μm of the layer along the front side will in some cases be present. The damaged layer along the front side is so thin as not to be a hindrance when fabricating devices. Even along the back side, since the damaged layer is 50 μm or less, disruptions, such as growth of cracks or incidents of fracturing, following from wafer-processing based operations do not arise.
What the present inventors discovered is that grinding a nitride substrate surface with grit having a coarse mesh produces a damaged layer and the damaged layer has a stretching effect on the surface, and that by means of etching to diminish the damaged layer this action that tends to stretch the surface is curtailed. Accordingly, a novel technique by the present invention is the production of a planar substrate with minimal warp by introducing a (grinding) damaged layer onto the front side/back side of a nitride substrate, and removing the layer in part.
When the warp H is taken into consideration including its sign, front-side damaged layer introduction S and back-side etching T increase the warp H, while front-side etching U and back-side damaged layer introduction W decrease the warp H. This means:
H Graduated Increase front-side damaged layer Processes - introduction S, back-side etching T; H Graduated Decrease front-side etching U, back-side process- Processes - transformed layer introduction W.
With front-side damaged layer introduction S and front-side etching U being stand-alone processes they do not necessarily have to form a pair. Likewise, with back-side etching T and back-side damaged layer introduction W being stand-alone processes they do not necessarily have to form a pair. But because the etching process has to be for removing a damaged layer, front-side damaged layer introduction S has to go ahead of front-side etching U. Likewise, back-side damaged layer introduction W has to precede back-side etching T.
Going a step further, the sign of these processes is taken to express increase/decrease in warp. Thus, S and T take positive values; U and W take negative values. Since the absolute value of the change in warp due to etching is smaller than that of change in warp due to a damaged layer, S+T is positive; U+W is negative. That is:
S>0; T>0 (1)
U<0; W<0 (2)
S+U> 0 (3)
W+T< 0 (4)
Letting the initial warp be H i and the final warp be H o , then fundamentally
H i +S+U+W+T=H o (5)
Ideally the final warp H o is 0, but there is an optimal range about 0, and it is satisfactory to have the range be
+30 μ m≧H o ≧−20 μm (6)
Given the significance of Equation (5), what this means is that increasing the warp through front-side grinding (since S is positive), decreasing the warp by front-side grinding (since U is negative), decreasing the warp by back-side grinding (since W is negative), and increasing the warp by back-side grinding (since T is positive) produces an appropriate (from −20 μm to +30 μm) final warp H o . For the sake of simplicity, the final warp H o may be conceived of as being 0. Given the parameters in Equations (1) through (4), no matter what the initial warp H i , it should be possible to bring the final warp to 0, or else to within the appropriate range (6).
Nevertheless, the fact that the final thickness of the damaged layer along the front side is 10 μm or less imposes a restriction on S+U (positive value). In turn, the fact that the thickness of the damaged layer along the back side is 50 μm or less imposes a restriction on W+T (negative value).
Because on W+T can be a negative number whose absolute value is considerably large, implementations in which the initial warp H i is positive mean for the present invention that with the degree of freedom being especially large, the invention is more easily embodied.
When the initial warp H i is positive—i.e., when there is a convexity along the front side (Ga face)—then steps S and U can be omitted, and the warp can be curtailed simply according to
( H i >0) H i +W+T=H o (7)
In other words, this means that back-side grinding W and back-side etching T alone are sufficient. Moreover, if it is the case that change in warp can be accurately controlled by back-side grinding, then the back-side etching T may be omitted. That is, such cases make it that
( H i >0) H i +W=H o (8)
This maintains that warp can be eliminated by back-side grinding W alone (Embodiment 3).
In instances in which the initial warp H i is negative—i.e., when there is a concavity along the front side (Ga face)—then since H has to be increased, S and T (S, T both positive) are required. But given this, because T necessarily entails W, what can be omitted is only front-side etching U. Then what is possible in such instances is
( H i <0) H i +S+W+T=H o (9)
This states that warp can be curtailed by means of front-side grinding S, back-side grinding W, and back-side etching T alone (Embodiment 2).
Nonetheless, in some cases in which the initial warp H i is negative, using all four steps will be advisable:
( H i <0) H i +S+U+W+T=H o (10)
This states that warp can be curtailed by means of front-side grinding S, front-side etching U, back-side grinding W, and back-side etching T alone (Embodiment 1).
Techniques (9) and (10) can be utilized even when the initial warp H i is positive. Accordingly, noting down altogether techniques possible by the present invention would be as follows.
( H i >0) H i +W=H o (8)
( H i >0) H i +W+T=H o (7)
( H i pos./neg. ) H i +S+W+T=H o (9)
( H i pos./neg. ) H i +S+U+W+T=H o (10)
EMBODIMENTS
GaN was grown by HVPE onto a GaAs base substrate as described earlier. The GaAs base substrate was removed to render freestanding, independent GaN crystals. The as-grown GaN crystal substrates thus obtained were 50.8 mm in diameter (2-inch) and 500 μm in thickness.
The substrates had a concavity along the front side (Ga face), with the absolute value of the warp being 40 μm or more (H<−40 μm). The surface roughness of the front side was R max 10 μm or more. The surface roughness and warp were measured employing a stylus surface profilometer (“Surfcom,” manufactured by Tokyo Seimitsu Co.).
The GaN crystals were affixed by means of wax to a platen made of alumina ceramic, and were then ground under the conditions tabulated below.
TABLE I
GaN crystal substrate front-/back-side grinding conditions
GaN Crystal
Outer diameter: 2-inch (50.8 mm φ);
Thickness: 500 μm
Grinding surface
(0001) plane; Ga face or else N face
Grinding device
Rotary-type grinder
Grinding parameters
Grit dia.: 200 mm φ
Grit/grain size: Diamond, #325
Working revs: 400 rpm
Feed rate: 5 μm/min.
Grinding slurry supply rate: 5 L/min.
The planarity (warp) of the GaN crystal substrate still affixed to the polishing platen immediately after grinding was ±2 μm, and the surface roughness R max was 0.5 μm. Because the polishing platen is perfectly flat, it stands to reason that warp in a substrate bound fast to the platen will be slight.
The polishing platen was heated to 100° C. to peel the GaN crystal substrate off the platen.
The GaN crystal substrate broken away from the polishing platen was ultrasonically cleansed in isopropyl alcohol. Warp in the GaN substrate in respective stages was then measured.
Grinding as just described was carried out on both the front side (Ga face) and back side (N face).
The grinding produced damaged layers. Arrangements were made to etch the substrate so as to remove the damaged layer at once following grinding. Although the N face (back side) could be wet-etched using KOH, on the Ga face (front side), inasmuch as wet etching is ineffectual, dry etching using a chlorine plasma was performed. Of course, dry etching the back side also is possible. The etching conditions were:
TABLE II
Dry etching parameters
Equipment
Reactive ion etcher
Gas
Chlorine
Chlorine flow rate
10 sccm
Pressure during etch
1 Pa
Plasma power
Antenna: 300 W; Bias: 10 W
Either the front side or the back side may be ground first. For Procedure A and Procedure B below, the respective sequences are indicated. It is not necessary to set the procedure so that an etching operation always follows on a grinding operation; both substrate sides may be ground, following which both sides may then be etched (Procedure C and Procedure D).
Inasmuch as cleaning and drying are performed following the respective stages, such as when the substrate is broken away from the polishing platen, and after etching, herein they have been omitted.
Procedure A
Front-side grinding Front-side dry etch (chlorine plasma) Back-side grinding Back-side wet etch (KOH), or dry etch (chlorine plasma)
The procedural order written out in slightly more detail would be as follows.
Grow substrate→Affix to platen→Grind front side→Break away from (lift off of) platen→Dry-etch front side→Affix to platen→Grind back side→Break away from (lift off of) platen→Wet-etch or dry-etch back side.
Procedure B
Back-side grinding Back-side wet etch (KOH), or dry etch (chlorine plasma) Front-side grinding Front-side dry etch (chlorine plasma)
The procedural order written out in slightly more detail would be as follows.
Grow substrate→Affix to platen→Grind back side→Break away from (lift off of) platen→Wet-etch or dry-etch back side→Affix to platen→Grind front side→Break away from (lift off of) platen→Dry-etch front side.
Procedure C
Front-side grinding Back-side grinding Front-side dry etch (chlorine plasma) Back-side wet etch (KOH), or dry etch (chlorine plasma)
Procedure D
Back-side grinding Front-side grinding Back-side wet etch (KOH), or dry etch (chlorine plasma) Front-side dry etch (chlorine plasma)
In Embodiment 1 set forth below, Procedure A is adopted, with the substrate warp being measured in the post-grown free state, in the post-grinding bound state as adhered to the platen, in the free state after being broken away from the platen, in the free state following front-side etching, in the bound state as adhered to the platen following back-side grinding, and in the free state following back-side.
Embodiment 1
Concave warp (H<0): Front-side grinding→Front-side DE→Back-side grinding→Back-side DE
The warp in the free state of a (2-inch φ, 500-μm thickness) GaN crystal from which the GaAs base substrate had been removed was H=−50 μm (front-side concavity). The back side was affixed to the polishing platen and the front side was ground. The grinding conditions were as described earlier. The absolute value of the post-grinding front-side warp in the GaN crystal as affixed in the bound state was no more than 1 μm. The warp in the GaN crystal in the free state as having been lifted off the platen was H=+30 μm.
This means that along the front side the crystal had gone convex. The reason for this is because a thick damaged layer had been introduced into the front side by the grinding, and the damaged layer generated stress that tended to stretch the front side. Because the presence of a damaged layer on the front side is not acceptable, the front side was given a dry etch (DE) with a chlorine plasma. Thereafter the warp proved to be H=+10 μm. Although the condition of convexity along the front side did not itself change, the amount of warp was reduced. In addition, the front side was affixed to the platen and the back side was ground. The grinding conditions were as described earlier. The post-grinding back-side warp in the GaN crystal as adhered fast to the platen was no more than 1 μm.
The warp in the GaN crystal in the free state as having been undone from the platen was −20 μm. The reason for this is because a damaged layer had been produced along the back side by the grinding, and the damaged layer acted to stretch that surface. The warp in the free state after the back side next had been dry-etched was H=−5 μm. This means that the warp had for the most part disappeared. This warp sufficiently satisfies according to the present invention the condition: +30 μm≧H≧−20 μm; it satisfies the more preferable condition: +20 μm≧H≧−10 μm; and in fact it satisfies the optimal condition: +10 μm≧H≧−5 μm.
Grinding gives rise to a damaged layer and since the layer pressingly stretches the ground surface, the warp changes to the opposite side. And the further significance is that when the damaged layer is removed by etching, the warp is curtailed in correspondence with the amount removed. In sum, what this means is that by combining grinding and etching, the warp can be reduced or eliminated.
TABLE III
Embodiment 1 change in warp immediately after crystal growth,
after front-side grinding, after lift-off, after front-side dry etch, after
back-side grinding, after lift-off, and after back-side dry etch
Stage
Warp H (μm)
Just after crystal-growth (free state)
−50
After front-side grinding (bound state)
0
After lift-off (free state)
+30
After front-side dry etch (free state)
+10
After back-side grinding (bound state)
0
After lift-off (free state)
−20
After back-side dry etch (free state)
−5
Embodiment 2
Concave Warp (H<0): Front-side Grinding→Back-side Grinding→Back-side DE
Embodiment 2 is one in which the front-side dry etch (DE) of Embodiment 1 was omitted.
The warp in the free state of a (2-inch φ, 500-μm thickness) GaN crystal from which the GaAs base substrate had been removed was H=−50 μm (front-side concavity). The back side was affixed to the polishing platen and the front side was ground. The grinding conditions were as described earlier. The absolute value of the post-grinding front-side warp in the GaN crystal as affixed in the bound state was no more than 1 μm. The warp in the GaN crystal in the free state as having been lifted off the platen was H=+30 μm.
This means that along the front side the crystal had gone convex. The reason for this is because a thick damaged layer had been introduced into the front side by the grinding, and the damaged layer generated stress that tended to stretch the front side. No dry etch was performed on the front side, but the front side was affixed to the platen and the back side was ground. The grinding conditions were as described earlier. In the back-side grinding there were instance in which local cracking occurred. The post-grinding back-side warp in the GaN crystal as adhered fast to the platen was no more than 1 μm.
The warp in the GaN crystal in the free state as having been undone from the platen was −30 μm. The reason for this is because a damaged layer had been produced along the back side by the grinding, and the damaged layer acted to stretch that surface. The back side was next dry-etched. Thereafter the warp in the free state was H=−20 μm. This warp satisfies according to the present invention the condition: +30 μm≧H≧−20 μm. This is a warp range within which photolithography is possible. Of particular significance here is that because front-side etching was not carried out, a factor that makes H positive was diminished.
TABLE IV
Embodiment 2 change in warp immediately after crystal growth, after
front-side grinding, after lift-off, after back-side
grinding, after lift-off, and after back-side dry etch
Stage
Warp H (μm)
Just after crystal-growth (free state)
−50
After front-side grinding (bound state)
0
After lift-off (free state)
+30
After front-side dry etch (free state)
—
After back-side grinding (bound state)
0
After lift-off (free state)
−30
After back-side dry etch (free state)
−20
Embodiment 3
Convex Warp (H>0): Back-side Grinding
The warp in the free state of a (2-inch φ, 500-μm thickness) GaN crystal from which the GaAs base substrate had been removed was H=+30 μm (front-side convexity). The crystal was affixed to a ceramic platen, and both sides were ground so as to lessen the damaged layer. That meant a fine-mesh grit was employed. The Ra was not more than 5 nm.
In this embodiment, warp could be eliminated without creating a front-side-ground damaged layer and without etching, which was simpler. The front side was affixed to the polishing platen and the back side was ground. The grinding conditions were as described earlier. The post-grinding back-side warp in the GaN crystal as adhered fast to the platen was no more than 1 μm. The warp in the GaN crystal in the free state as having been lifted off the platen was +10 μm. Because the warp was “+,” back-side etching was not performed. Significant in this embodiment—an instance in which the warp was convex—is that the warp could be curtailed simply by introducing a damaged layer into the back side.
TABLE V
Embodiment 3 change in warp immediately after crystal growth, after
back-side grinding, and after lift-off
Stage
Warp H (μm)
Just after crystal-growth (free state)
+30
After front-side grinding (bound state)
—
After lift-off (free state)
—
After front-side dry etch (free state)
—
After back-side grinding (bound state)
0
After lift-off (free state)
+10
After back-side dry etch (free state)
—
Herein, should the warp be negative after the back side is ground (convexity along back side), etching the back side to take away part of the damaged layer will bring the surface closer to planar (H→0).
Only selected embodiments have been chosen to illustrate the present invention. To those skilled in the art, however, it will be apparent from the foregoing disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing description of the embodiments according to the present invention is provided for illustration only, and not for limiting the invention as defined by the appended claims and their equivalents.
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In an independent GaN film manufactured by creating a GaN layer on a base heterosubstrate using vapor-phase deposition and then removing the base substrate, owing to layer-base discrepancy in thermal expansion coefficient and lattice constant, warp will be a large ±40 μm to ±100 μm. Since with that warp device fabrication by photolithography is challenging, reducing the warp to +30 μm to −20 μm is the goal. The surface deflected concavely is ground to impart to it a damaged layer that has a stretching effect, making the surface become convex. The damaged layer on the surface having become convex is removed by etching, which curtails the warp. Alternatively, the convex surface on the side opposite the surface having become convex is ground to generate a damaged layer. With the concave surface having become convex due to the damaged layer, suitably etching off the damaged layer curtails the warp.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to materials which may be utilized to form elastomers at room temperature and to the elastomers thus formed.
2. Description of the Prior Art
It is well known to use elastomers as binders for explosives, propellants and the like. Literally thousands of elastomers have been disclosed as being useful for such purposes. Despite the wide variety of elastomeric binders available, those wich have found wide spread use in propellants and the like have had one problem in common. That problem is the fact that they have only been curable at elevated temperatures. As a result of the need for elevated temperature cures, several sub-problems have developed.
One sub-problem or, in actuality, series of sub-problems stems from the fact that an oven is required if cure is to be carried out at an elevated temperature. Ovens are expensive. They require space. Elevated temperature cures require time. A propellant or the like must be handled in order to get it in the out of the oven. Finally, if an oven malfunctions, cure is not carried out properly and a batch of prepolymer is wasted.
More important than the sub-problems related to oven, are a series of sub-problems related to the fact that stresses are induced into an elastomer when it is cooled to ambient temperature after having been cured at an elevated temperature. These stresses often lead to cracking. Cracking is especially likely to occur if the elastomer is subjected to temperature cycling and such cycling is the rule rather than the exception.
Current theory in stress analysis is that once it is induced, stress is never entirely removed. Thus, if an elastomer is cooled below room temperature and subsequently raised back to room temperature those stresses that are induced by the cooling never completely disappear.
Since the stress is induced when an elastomer is cooled from cure temperature to ambient, it would be advantageous if cure could take place at ambient. This would eliminate a portion of the life history of a propellant or the like during which stress is induced.
SUMMARY OF THE INVENTION
According to this invention, the bis(2,4-pentadienyl ether) derivative of hydroxy terminated polybutadiene is prepared by reacting hydroxy terminated polybutadiene with naphthyl-potassium and 1-bromo-2,4-pentadiene in successive steps. Then, the bismaleimide of dimer diamine is added as a curing agent. Cure takes place at room temperature.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment may be understood from the following specific examples.
EXAMPLE 1
Preparation of the Bis(1,3-pentadienyl ether) of Hydroxy Terminated Polybutadiene
Degassed hydroxy terminated polybutadiene (40.5g, 0.029 equivalent) was placed in a glass reaction vessel. The system was swept with helium and the flask was flamed. Next, 175 ml of pure oxygen-free dimethoxyethane and 175 ml of purified toluene were added to dissolve the polymer (hydroxy terminated polybutadiene). A 0.37 molar solution of naphthyl-potassium in dimethoxyethane was added dropwise until the light green color of unreacted naphthyl-potassium persisted for at least 5 minutes. A total of 0.031 equivalents of naphthyl-potassium were used. The reaction time was approximately 2.5 hours.
10.0 g (0.068 equivalent) of 1-bromo-2,4-pentadiene were dissolved in 25 ml of pure oxygen-free dimethoxyethane and added to the reaction mixture and the mixture was stirred for 3 hours at room temperature and for 1 hour at 85° C. (The helium atmosphere was maintained.)
The crude bis(1,3-pentadienyl ether) of hydroxy terminated polybutadiene was precipitated from the reaction mixture by adding methanol. It was dissolved in benzene and centrifuged to remove potassium bromide. Purification was accomplished by repeated precipitation from an ethylene dichloride solution using methanol. The derivative was then dried in a vacuum at room temperature. The yield was 34.8 g (85.9%). The polymeric derivative had a molecular weight of 3800 and contained 2.5 moles of conjugated double bonds per mole of polymer.
EXAMPLE 2
Pretreatment of Dimer Diamine
100 g of dimer diamine were dissolved in heptane and washed with aqueous sodium chloride solution containing 4.0 g of sodium hydroxide. This formed an emulsion which was shaken periodically and allowed to set for 18 hours. The organic layer was then washed twice with aqueous sodium chloride and ethanol was added to break the emulsion. The resulting mixture was then dried over sodium sulfate and in a vacuum to completely remove the solvent.
EXAMPLE 3
Preparation of the Bismaleimide of Dimer Diamine and Cyclization
60.0g (0.2 equivalent) of pretreated dimer diamine were dissolved in 50 ml of 1,1,2-trichlorethane and 22.6 g (0.23 mole) of maleic anhydride were dissolved in 125 ml of 1,1,2-trichloroethane. The system was swept with nitrogen and the dimer diamine solution was added to the maleic anhydride solution dropwise, keeping the temperature below 35° C. After the addition was complete, stirring was continued, under nitrogen, for 1.0 hours. This formed the bismaleamic acid.
4.29 g (0.02 mole) of magnesium acetate tetrahydrate, 49.0 g (0.48 mole) of acetic anhydride and 42.5 g (0.42 mole) of triethylamine were added. The temperature was rapidly raised to 94° C., held for 1 hour and then cooled to room temperature. This cyclized the acid into the bismaleimide.
The solvent was removed on a rotary evaporator. The crude product was dissolved in cyclohexane and washed twice with aqueous sodium chloride. A centrifuge was used to break the emulsion. The material was washed with aqueous sodium hydroxide solution and then with water until free of base. Then it was dried over anhydrous sodium sulfate. The solvent was removed and the material was dried in a vacuum. The crude bismaleimide was purified by column chromatography over Florisil and eluting with benzene.
EXAMPLE 4
Curing the Conjugated Diene Prepolymer Using the Bismaleimide of Dimer Diamine
Enough of the cyclized bismaleimide was used to react with 88 percent of the conjugated double bonds; however, this range can be from approximately 80 percent to 100 percent.
0.3842 g of the bismaleimide of dimer diamine was added to 1.6612 g of the prepolymer, prepared according to Example 1, mixed and poured into a silicone mold. After curing for 48 hours at room temperature, the mixture had formed a clear elastomer having an elongation greater than 250 percent.
The foregoing examples are very specific. It will be apparent to those skilled in the art that other similar procedures might be used in lieu of those specified. For example, it will be apparent to skilled chemists that the cure takes place via a Diels-Alder reaction. Thus, bisdienophiles other than the bismaleimide of dimer diamine could be used as the curing agent provided they (1) were soluble in the bis(1,3-pentadienyl ether) derivative of hydroxy terminated polybutadiene and (2) would react with it at room temperature. As another example, reactants other than naphthyl-potassium might be used to replace the hydrogen atoms of the hydroxy groups of hydroxy terminated polybutadiene with potassium or a similar alkali metal in the first step of the preparation of the bis(1,3-pentadienyl ether) derivative of hydroxy terminated polybutadiene. Also, the bromo group of 1-bromo-2,4-pentadiene might be replacable with a similar group such as a chloro group in the second step involved in the preparation of the bis(1,3-pentadienyl ether) derivative. Obviously, other inert gases could be used in lieu of the helium and nitrogen in the above outlines procedures.
Because of the stability of the carbon to carbon bonds formed during cure, the elastomer prepared according to this invention is highly resistant to hydrolytic or oxidative degradation. Also, since the cure process involves the formation of carbon to carbon bonds, other components such as trace metal impurities in the formulation do not have an effect thereon.
The elastomer is suitable for use as a binder in either explosive compositions or propellant compositions.
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Hydroxy terminated polybutadiene is reacted with naphthyl-potassium and 1omo-2,4-pentadiene in successive steps to form a bis(1,3-pentadienyl ether) derivative. Then the bismaleimide of dimer diamine is added to the polybutadiene derivative whereby a room temperature cure to an elastomer is achieved.
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This application is a continuation of U.S. patent application Ser. No. 10/182,213, which is a national stage application under 35 U.S.C. 371 of PCT/GB00/04873, filed Dec. 18, 2000, and claims priority benefit of GB Patent Application 0002382.0, filed Feb. 3, 2000.
Almost all hospitals in the western world are provided with sterilizing equipment to ensure the sterility of instruments and devices which may come into contact with humans. The risks and dangers of conducting operative procedures on living creatures including animals and humans with non-sterile equipment and in non-sterile surroundings is well documented. In an environment in which patients expect to be treated successfully and in a sterile manner, the requirement for effective sterilization is an essential one, and devices have been developed to test the efficacy of sterilizers and sterilization.
Although the following description relates exclusively to the use of sterilizer test devices in hospitals, the device of the present invention has much wider application, and specifically can be used in bench top sterilizers such as might be provided in community healthcare and animal care clinics for the sterilization of utensils, dressings, medical textiles and the like.
Modern sterilizers, many of which are in the form of high pressure autoclaves, subject their contents to high temperature steam for a predetermined period of time. The three fundamental parameters of the sterilization process are accordingly time, temperature, and the presence of steam. Effective sterilization can only be achieved if there is steam contact with all parts of the load to be sterilized for the correct period of time. Air trapped and entrained within the load will prevent this necessary steam penetration. The thermodynamic irregularities of air/water vapour mixtures, and the necessarily hostile environment developed inside cabinet autoclaves makes the monitoring of sterilization process difficult, and therefore a simple visual indicator test was developed.
In the 1960s, the Bowie Dick test assessed whether the air removal stage of the sterilization process was sufficient to ensure rapid and even steam penetration to all parts of the load. The test involved placing within the sterilizer a stack of towels approximately 11 inches high and having a cross-sectional area roughly approximating to the size of an A4 sheet of paper. Within the stack at approximately half height thereof, there was placed a sheet of paper on one surface of which was applied a pattern of a chemical indicator ink which was extremely sensitive to and changed colour in the presence of high temperature steam. The test was performed by simply placing the stack towels within the sterilizer, and initiating a standard cycle of the sterilizer which would be carried out on, for example a tray of surgical instruments, hospital bed linen and the like, for a certain period of time, for example 3-4 minutes. On removal of the stack of towels, the indicator sheet was inspected for a uniform colour change of the indicator over the entire surface of the sheet, and if this was the case then the sterilizer air removal stage was considered to be functioning effectively.
It is well known that heat alone can provide effective sterilization, however the rapid inactivation of microorganisms is significantly faster in the presence of moist heat (steam). For example, effective sterilization can be achieved by subjecting material to dry heat at 160° C. for 1 hour, whereas the same level of sterilization can be achieved by introducing steam at 130° for 3 minutes.
In the Bowie Dick test, the towels were used as what is now termed a “porous load”. Such loads are deemed one of the most difficult to assess the penetration characteristics of the steam or to provide some resistance to the steam as it progresses towards the indicator sheet. The rationale behind this test is that if the steam can penetrate the porous load to adequately change the colour of the indicator sheet, then any medical device, textile or the like having a lower resistance to steam penetration will be effectively sterilized.
A current modification of the original Bowie & Dick test is the use of a disposable or reusable barrier surrounding a chemical indicator sheet. This is calibrated to perform in a similar manner to the original Bowie & Dick towel pack with a chemical indicator inserted. After the pack has been subjected to a conventional sterilization, the indicator sheet is removed and inspected for a uniform colour change over the entire surface area of the sheet, which is indicative of the effective operation of the sterilizer air removal stage.
A disadvantage with this method of testing is that the product once used must be discarded. When it is considered that millions of tests are conducted annually in hospitals and other sterile environments around the world, the cost saving to be made by a reusable device may be considerable.
One alternative currently available to the disposable test pack described above is a device which comprises a coiled narrow lumen approximately 2-3 metres in length and having a diameter of approximately 2 mm, open at one end and connected at its alternate end to a small accessible capsule into which a chemical indicator can be placed. In use, the coiled lumen is placed inside the sterilizer whereafter the sterilization procedure is initiated during which the steam gradually progresses along the interior of the lumen until reaching the capsule into which the lumen passes. The efficacy of steam penetration can be assessed based on the chemical indicator result. Thereafter, the device may be reused, using a new indicator in the capsule.
The length and narrow entrance of the lumen open end render the lumen arguably not analogous to a porous load for reasons of mass, directional sensitivity, and physical shape etc.
Hence there are a number of serious disadvantages associated with the lumen device. Firstly, the history of use of the device cannot easily be established and although the chemical indicator may be replaced before each use of the device, there is no guarantee that the device was not previously mistreated or was not fully prepared for the next use by the previous user. It is to be borne in mind that in a busy hospital, the device may simply left proximate the sterilizer for use by any of the numerous staff who have cause to use same.
Secondly, there is a risk that the openable capsule is not securely closed. This would allow the steam an easier path to the open end of the indicator tube within the capsule, and thus the device could give the false indication that the sterilizer was functioning satisfactorily.
Thirdly, steam has a propensity to condense on the external, and more importantly the internal walls of the lumen. If sufficient steam condenses of the internal wall of the lumen along the path to the capsule, there may be a plug of condensate which could prevent the steam from reaching the open ended indicator tube within the capsule.
Fourthly, the problem of condensation is also apparent when the lumen is removed after the test has been completed, and in some cases there can be a fine mist of water vapour or a fluid bubble retained within the lumen. When a subsequent test is conducted, the lumen is heated in the sterilizer and by means of conduction, this water vapour could also heat and be urged towards the chemical indicator within the capsule. The device could in this circumstance also provide false results.
Finally, it is contended by many of those in the art that the single narrow opening through which the steam passes before travelling the length of said lumen is too directionally sensitive, that is it does not provide a fair average of the steam penetration characteristics within the sterilization chamber.
Examples of directionally sensitive sterilization test devices are shown in consecutive published patent applications PCT/DE94/00687, PCT/DE94/00688, PCT/DE94/00689, all to Van Dijk Medezintechnik GmbH. All these documents disclose essentially cylindrical hollow test devices, one end of which is closed off from the atmosphere by means of a plug or stopper proximate to which a chemical indicator means is positioned in an inner chamber of the device, the alternate open end of the devices having different inserts provided therein to provide a penetrable barrier through which steam must pass to interact with the chemical indicator within the device.
In particular, PCT/DE94/00687 discloses the use of a threaded plug which is screwed into the open end of the device but which has threads of marginally lesser diameter than those provided internally of the device such that a helical channel is defined between the threads of the plug and those of the device. This device is effectively similar to the lumen device disclosed above, with the exception that a fixed helical path leads from the exterior of the device to the chemical indicator, as opposed to the spiral path along which the steam can travel within the lumen.
PCT/DE94/00688 discloses the use of an array of capillaries provided between the inner chamber of the device in which the indicator is located and the alternate open end of the device from which the steam within a sterilizer can penetrate, and PCT/DE94/00689 discloses the use of a porous material plug through which the steam can penetrate towards the indicator located in the inner chamber of the device. Neither of these latter two patent applications is specifically directed towards the use of a so-called “tortuous path” such as is provided by the helical path disclosed in PCT/DE94/00687 or the spiral path along which the steam travels in the lumen of the abovementioned current devices, whereas PCT/DE94/00687 does not consider the use of a so-called “porous load”.
Additionally, all the devices disclosed in the abovementioned patent applications are directionally sensitive in that steam can only begin to penetrate either the tortuous path or the porous load (or equivalent load) from one particular side, and furthermore only on one particular surface of the device. It is to be mentioned that the conditions within autoclave units in general are extreme and non-uniform, and it is possible that the directional sensitivity, which term is used to describe the generally linear path along which the steam or other sterilant travels before coming into contact with the indicator, of such devices can result in the device producing false results.
It is an object of the present invention to provide a sterilizer test device which at least mitigates if not eradicates the disadvantages of the prior art devices, and which is furthermore reusable and combines the advantageous qualities of the devices mentioned.
SUMMARY OF THE INVENTION
According to the present invention there is provided a sterilizer test device comprising a pair of bodies releasably and sealably connected together defining an internal primary chamber within the device to which access is gained by disconnecting said bodies, at least one of said bodies being essentially comprised of a porous element which allows penetration of steam therethrough and into said primary chamber, indicator means being provided between said bodies at some location within the primary chamber, said indicator means having a characteristic which changes while in the presence of steam and temperature after a predetermined time, characterised in that said porous element has one or more external surfaces through which steam can penetrate in a plurality of different directions.
Preferably intermediate tortuous path means is additionally provided internally of the device and sealingly divides the primary chamber into two secondary chambers, a first secondary chamber being defined between the tortuous path means and an inner surface of said at least one body through which steam having permeated said body emerges, and a second secondary chamber being defined to the alternate side of said tortuous path means from the first secondary chamber and having the indicator means disposed therein, said steam being constrained to flow into and around said tortuous path means before emerging into the second secondary chamber and thence coming into contact with the indicator means.
Preferably the said at least one body is provided with a substantially arcuate outer surface. In one embodiment, the said at least one body is preferably cylindrical.
Most preferably, the outer surface of the porous body is substantially continuous around at least one axis of the device.
It is most preferable that the two bodies connected together to form the device have a predetermined degree of porosity, and furthermore it is preferable that each of said two bodies is substantially hemispherical.
It is yet further preferable that at least one of the bodies is provided internally with a cavernous recess to increase the effective volume of the primary chamber.
It is further preferable that the porous bodies are manufactured from a sintered polypropylene material, which has the advantage that its porosity can be varied according to requirements of a particular device, and also that it can be formed in any desired shape. In an alternative embodiment, the porous bodies are manufactured from a spun bonded polymer material, but the manufacturing process for such materials is limited in that only articles having certain geometric shapes (such as a cylinder) can be produced because of the manner in which the polymeric material is spun.
It is yet further preferable that apertured diaphragm means is provided internally of the primary chamber substantially across the base of one of the said bodies thus defining a tertiary chamber with the surfaces of the cavernous recess in which steam having permeated the porous element from a plurality of different directions can collect before passing through said aperture into either the remainder of the primary chamber or the first secondary chamber.
It is also to be mentioned that such an apertured diaphragm could be used to sealingly divide either the first or second secondary chamber and thus define first and second tertiary chambers from said secondary chambers, and that two apertured diaphragms could be used to divide both the first and second secondary chambers as desired.
The division of the internal primary chamber into secondary and tertiary chambers has been shown experimentally to improve the overall performance of the sterilizer text device as a whole. Not wishing to be bound by theory, it is believed that this enhancement of performance is achieved because of the facility for steam to collect in the volume of the secondary and tertiary chambers in use which removes the effects on performance of the traditionally cyclical and intermittent operation of modern sterilizers, i.e. the alternate drawing of a vacuum and the introduction of steam into the sterilizer during use to substantially eliminate air.
In a further aspect of the invention there is provided a tortuous path means for use in a sterilizer test device of the type described above, said means comprising at least two substantially planar components having an outer surface and an inner surface separated by their thickness, said components being releasably connected together to bring their respective inner surfaces proximate one another, one or other or both of said components being provided with patterned grooved means on their inner surfaces following a labyrinthine, spiral or other tortuous path on said surface, one of said components being provided with an entry port leading from an outer surface of said component through the thickness thereof and opening at a particular location in said grooved means, characterised in that an intermediate member is sandwiched between the two components to sealingly close said grooved means and define a tortuous channel to at least one side of said intermediate member.
Preferably an exit port is also provided to allow fluid to escape from a particular location in the grooved means, or alternatively there is provided a recess in said inner surface of one of said components in which indication means as described above can be deposited.
Preferably the intermediate member is compressible to ensure sealing formation of said channel.
Preferably grooved means are provided on the inner surfaces of both components and the sandwiching of the intermediate member forms channels with each of said grooved means on either side of said member.
In a most preferred embodiment the components are hingedly connected over at a portion of their respective edges.
It is also preferable that the entry port of one component opens into the grooved means on the inner surface thereof proximate one end of said grooved means, and also that the exit port provided on the alternate component opens into the said grooved means in that component proximate one end thereof.
Most preferably, the intermediate member is secured to the hinged connection of the two components which ensures the correct positioning of said intermediate member when the said two components are releasably connected together.
It is yet further preferable that the intermediate member is provided with an aperture therein which links respective tortuous channels defined by said intermediate member on either side thereof.
In a yet further preferable embodiment, a chamber is defined internally of said tortuous path means in which steam can collect prior to being urged along said tortuous path.
It will be immediately understood by those skilled in the art that the provision of separable components having grooves brought together during the connection of the components to define respective channels with the intermediate compressible member allows for easy cleaning and airing of the grooved means. Hence, the device according to the invention can be both readily aired and cleaned while nevertheless being re-usable.
When the tortuous path means are used in connection with the sterilizer test device described above, the steam first permeates the porous bodies which substantially constitute the device and then is constrained to flow into a chamber of the device and thence through the tortuous path means before emerging therefrom into a further cavity in which is disposed the indicator means. The particular indicator means used is not important, and the device can be calibrated for use with a variety of different indicator types, such as chemical, biochemical, biological. It is also foreseen by the applicant that electronic sensing and detection apparatus may be used in place of the indicator means to provide accurate data logs on the characteristics of the atmosphere extant in the device in any of the chambers defined therein as a function of the time after the commencement of any particular sterilization sequence.
The fundamental advantages of the present invention are firstly that the use of cylindrical or hemi-spherical porous bodies to form the device allows steam to permeate into said bodies from any direction as substantially the entire surface of these bodies are porous, and secondly that the tortuous path means can be easily, simply, and quickly opened up to allow for airing and drying of the tortuous path. Thereafter both the test device and the tortuous path means can be reused. Obviously a quadrangular porous body having two or more of its external surfaces exposed to the steam to allow for penetration thereof would function in a similar manner.
BRIEF DESCRIPTION OF THE DRAWINGS
A specific embodiment of the invention is now given by way of example with reference to the accompanying Figures wherein:
FIG. 1 shows an exploded perspective view of a cylindrical test device in accordance with the invention,
FIG. 1A shows a perspective view of an apertured diaphragm which may be used in conjunction with the invention, and
FIG. 2 shows an exploded perspective view of a spherical test device in accordance with a different embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring firstly to FIG. 1 there is shown a sterilizer test device indicated generally at 2 comprising an annular base 4 which on which the device stands when within a sterilizer, a cylindrical porous body 6 having a cavernous bore 8 provided therein of a depth less than that of the body 6 and chosen as required by the particular application. Above the body 6 , a number of different components are provided to allow the device to function correctly. The first of these is an annular cap 10 having formations 12 , 14 , 16 , 18 which permit the rotating locking connection of other components above said cap.
It will be seen from the diagram that the cap 10 is provided both with a collar 20 which is chamfered around its outer surface shown at 22 and is marginally greater in diameter than the body 6 over which it is disposed. An annular inner surface 24 is provided at approximately the median of the depth of the cap, and above and around the periphery of said surface 24 there is provided an annular skirt 26 which defines a circular recess with the said surface 24 . An aperture 28 allows steam which has permeated through the porous body 6 to pass from the upper surface 30 thereof and from within the cavity 8 through the cap 10 .
The apertured diaphragm 25 may be sealingly disposed either on the inner surface of the body 6 over the cavernous bore 8 or in the aperture 28 so that a tertiary chamber is defined by said diaphragm and said cavernous bore internally of the body, as this has experimentally shown to improve the performance of the device, that is to more accurately determine if a particular sterilizer under test is efficacious.
In accordance with the invention there is provided a tortuous path device consisting of three components 32 , 34 , 36 which are hingedly connected together around their circumferences at hinge means 38 , 40 , 42 respectively. Specifically, the hinge means 38 is a protrusion, 40 is an aperture of marginally greater size than said protrusion and through which said protrusion is fed before locating in a recess 42 in the component 36 in which it is pinned by means of rod 44 .
With specific regard to said components 32 , 34 , 36 , the first and third components 32 , 36 are substantially planar and provided with spiral grooves 46 in one surface (only shown in respect of component 32 ). The second component 34 is an intermediate component ideally of a compressible material which is sandwiched between components 32 , 36 on releasably connecting same together and ideally sealingly forms spiral channels with the said grooves provided in the surfaces of the first and third components on either side thereof.
The first and third components 32 , 36 are provided with apertures (one of which is shown at 48 in the component 36 ) at their centres which form entry and exit ports to the spiral channels formed between said components. The intermediate component 34 is additionally provided with an aperture 50 which allows fluid communication between the channel formed in the component 32 on one side of component 34 and channel formed in component 36 . Thus the fluid enters the spiral channel formed in the first component through the aperture in said component 32 at its centre, and is subsequently constrained to spiral outwardly from said centre until reaching the aperture 50 (which is ideally located at the end of the spiral groove 46 ). The fluid can then move through the aperture 50 and into the second spiral channel and wherein it is constrained to spiral inwardly towards the aperture 48 from which it ultimately emerges.
The entire arrangement of the tortuous path device ( 32 , 34 , 36 ) is received in the upper recess defined in the cap 10 by the surface 24 and its peripherally surrounding skirt 26 and optionally locked therein behind suitable flanges provided on the skirt 26 . As the device 2 is assembled, the pre-assembled tortuous device ( 32 , 34 , 36 ) may be simply dropped into said recess and rotated by means of thumb indentations (not shown) provided on the upper surface of component 38 .
Once secured in place, an indicator (not shown or described in this application as being considered beyond the scope hereof) is positioned above the aperture 48 , and a lid 52 having depending skirt 54 is secured to the device by interengagement of formations (not shown) provided on the inner surface of said skirt 54 with the formations 12 , 14 , 16 , 18 provided on the cap 10 . The device is then placed in a sterilizer which is then activated, and after a conventional sterilization operation is complete the device is removed and opened for inspection of the indicator.
It is to be mentioned that the device may be inverted, the base 4 dispensed with, and the lid 52 may be suitably designed to function as a base having an inner surface in which an indicator may be disposed. In terms of the wording of the claims appended hereto, the primary chamber internally of the device is defined by the cavernous bore 8 and the inner surface of said lid 52 through the aperture 28 . This chamber is sealingly divided by the interposing of the tortuous path means ( 32 , 34 , 36 ) on either side of which are defined first (on the side of the cavernous bore 8 ) and secondary (on the side of the lid 52 inner surface) chambers. The first secondary chamber may again be divided by the interposing of the apertured diaphragm 25 as previously mentioned so that a tertiary chamber is defined within the body 6 by said cavernous bore 8 and said diaphragm.
It is also to be mentioned that the device described with reference to FIG. 1 can be used as a sterilizer test device without the tortuous path means described above. An indicator may simply be placed on the annular surface 24 or within the lid 52 to which steam can gain access after having first permeated the porous body 6 .
Additionally the configuration of the device 2 is adapted to be further modified so that the porous body can be removed leaving only the base 4 , cap 10 , tortuous path means ( 32 , 34 , 36 ) and lid 52 .
However, use of the complete device having both porous body and tortuous path means is preferred.
Referring now to FIG. 2 there is shown a modified configuration of sterilizer test device 100 . The device comprises of a tortuous path device ( 32 , 34 , 36 ) as hereinbefore described disposed internally of the device, and two hemispherical porous bodies 102 , 104 . Body 104 is provided internally with a cavity 106 in which steam may collect, and the portions of both bodies 102 proximate their diametral planes are received in the hingedly connectable skirt members 108 , 110 having hinge formations shown at 112 , 114 .
As with the embodiment shown in FIG. 1 , a suitably sized apertured diaphragm may be used to define a chamber with said cavity 106 as previously discussed.
The skirt member 108 is provided with a plurality of slots 116 , 118 through which steam emerging from the planar surface 120 of body 102 can pass. When assembled together, the configuration is such that steam permeating through the body 102 passes to the outside of the tortuous path device and towards and into the cavity 106 without coming into contact with the indicator (not shown) which is disposed between the outer surface of the component 32 and the rear surface 122 of the cap 108 . The disposition of said indicator, possibly within a recess defined in said rear surface 122 , and the clamping arrangement of the two caps on the tortuous path device ( 32 , 34 , 36 ) thereover ensures that steam cannot adversely affect the indicator such that the device would give rise to false results.
In a similar manner to the operation of the device shown in FIG. 1 , the device 100 can be easily and quickly opened and the tortuous path device released from over the indicator which can then be inspected to ensure that a sterilizer is functioning correctly. Additionally, the tortuous path device can be removed quickly, and opened for drying and cleaning.
It is to be mentioned that the various arrows provided on the diagrams are indicative of the possible flow of steam from outside the devices and the particular flow paths possible inside said device. It is most important to note that both the devices disclosed herein are both reusable and “directionless” in that steam drawn towards the devices when inside an operative sterilizer can permeate through the porous body as soon as it comes into contact therewith. This is in sharp distinction to the currently available devices which are either not re-usable or which although being of similar size and shape to the devices described herein, generally provide only a few discrete ports through which access to a porous medium is contained. Such devices are heavily directional, and therefore disadvantaged in comparison to the present invention.
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A re-usable sterilizer test device is disclosed which is comprised of at least two parts which are releasably connected together. An indicator device which changes color in the presence of steam after a certain time period is deposited within the two parts. One or both of the bodies is manufactured from a material having a predetermined degree of porosity as regards steam and is generally cylindrical or spherical so that the outer surface of said one or both bodies forms a significant and substantial portion of the external surface of the assembled device. Steam penetrates the porous body and passes into a cavity inside the body from where the steam can move internally of the device through suitable passageways and into a chamber where the indicator is located.
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CROSS-REFERENCES TO RELATED APPLICATIONS
The present application claims priority to U.S. patent application Ser. No. 13/535,892, filed on Jun. 28, 2012, which is herein incorporated by reference in its entirety for all purposes.
BACKGROUND
The present invention relates to equipment and accessories for flush and tilted roof installations of solar panels, and in particular, to devices, systems and methods of installation for fire suppression and prevention in roof mounted solar panels.
Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Building and construction codes in many countries and jurisdictions include stringent fire codes that require active and passive systems for stopping or limiting the spread of fire in buildings and other structures. Such fire codes include specific ratings for determining the capabilities of various aspects of buildings and structures for preventing, suppressing or retarding the ignition or the spread of fire. Pertinent to embodiments of the present invention, are the fire codes that are concerned with roofs and roofing systems.
To increase the safety of buildings, roof specific fire codes have been promulgated that require new and existing roofs be able to withstand certain specified tests. Such tests are designed to determine the efficacy of various roofs and roofing systems to resist or limit the spread of fire and heat in a variety of conditions. Typically, the tested rating or the determined efficacy of a particular roof or roofing system must be maintained despite the addition or augmentation of the roof or roofing system due to the installation of a secondary system.
Such secondary systems that can be installed on rooftops range from water towers and HVAC systems to photovoltaic solar panel installations. Each such secondary system can present a new set of challenges for the roof or roofing system to maintain its previously determined fire rating due to the fact that many of the secondary systems can include additional weight, penetrations, heat, debris traps and other factors and variables that were not present when the roof for roofing system was originally designed or installed. In the case of solar panels, there is increasing pressure from the roofing industry to ensure that both flush mounted and tilted roof mounted solar panel systems minimize their impact on the fire rating of roofs and roofing systems onto which they are installed.
Specifically, there is concern that the inclusion of solar panels may increase the likelihood that a fire on the roof for roofing system will spread more rapidly. Due to such concerns, various jurisdictions are responding by developing and promulgating new fire code standards specifically aimed at rooftop solar panel installations. For example, in the United States local, state, and federal government officials and agencies are cooperating with the roofing and solar panel industries and other organizations to determine changes to existing fire codes and developing new fire codes directed at rating the efficacy of rooftop solar panel installations to resist, suppress, or retard the ignition and spread of fire. Such codes include requirements for building-integrated photovoltaic (BIPV) products and rack mounted photovoltaic products for each of such products. Such codes include requirements for installation, materials, wind resistance, and fire classification. It is expected that the requirements for building integrated photovoltaic systems and rack mounted photovoltaic systems will be different.
Thus, there is a need for systems, methods, and devices for the installation of solar panels that meet the new and existing fire codes. The present invention solves these and other problems by providing retrofit and original installation devices and methods for the installation of solar panels on both flat and tilted roofs.
SUMMARY
Embodiments of the present invention improve fire resistance of roofs and roofing systems with solar panel installations. In one embodiment, a fire blocking apparatus for a solar panel mounted to an underlying mounting surface, the fire blocking apparatus includes a panel support structure sized and shaped to be mounted between a solar panel and the mounting surface thereby supporting and creating a gap between at least a portion of the solar panel and the mounting surface, where at least a portion of the panel support structure includes a heat or fire sensitive material configured to melt, deform, or warp at a predetermined temperature such that when the structure is mounted between the solar panel and the mounting surface and heated at or above the predetermined temperature, the panel support structure collapses to reduce the gap between the at least a portion of the solar panel and the mounting surface.
The panel support structure my include a heat or fire sensitive leg. In some embodiments, the panel support structure includes a support leg and a coupling joint that includes a heat or fire sensitive adhesive or fastener. The panel support structure may position the solar panel at an angle relative to the underlying mounting surface. In embodiments, the angle is defined by the solar panel and the underlying mounting surface. The angle may decrease when the panel support structure collapses. The panel support structure may include a first end and a second end opposite of the first end. The first end may be coupled to a bottom surface of the solar panel, and the second end is coupled to the underlying mounting surface.
In embodiments, a fire blocking apparatus for a solar panel mounted on brackets that separate the solar panel from an underlying mounting surface, the fire blocking apparatus includes a structure including a heat or fire sensitive material configured to melt, deform, or warp at a predetermined temperature, the structure having a length, a width and first and second edges spaced apart along opposing ends of the width; a first edge coupling joint configured to couple the structure to a solar panel in a first position that enables ventilation and cooling for the solar panel through a gap between the solar panel and the mounting surface; and where the structure is configured to collapse to block the gap between the solar panel and the mounting surface when coupled to the solar panel in the first position and heated above the predetermined temperature.
The first edge coupling joint may include a heat or fire sensitive material configured to melt, deform, or warp at a predetermined temperature. The first edge coupling joint may cause the second edge of the structure to make contact with the underlying mounting surface to close the gap when the first edge coupling joint melts, deforms, or warps at the predetermined temperature. In certain embodiments, the structure is perpendicular to the roof surface when the first edge coupling joint melts, deforms, or warps at the predetermined temperature. The structure may be made from a deformable material that melts, deforms, or warps at the predetermined temperature. In some embodiments, the structure deforms to make contact with the underlying mounting surface in more than one distinct location when the structure melts, deforms, or warps at the predetermined temperature.
In embodiments, a fire blocking system for a solar panel array mounted on brackets that separate the solar panel array from an underlying tilted mounting surface, the apparatus includes a downslope fire blocking apparatus an upslope fire blocking apparatus. The downslope fire blocking apparatus includes a first structure including a heat or fire sensitive material configured to melt, deform, or warp at a first predetermined temperature, the first structure having a first structure length, a first structure width and first structure first and second edges spaced apart along opposing ends of the first structure width; and a first structure edge coupling joint positioned at the first structure first edge and configured to couple the first structure to a downslope portion of the solar panel array in a first position that enables ventilation and cooling for the solar panel array through a first gap between the solar array panel and the mounting surface; where the first structure is configured to collapse from the first position to a second position when the first structure is heated above the first predetermined temperature, where in the second position the first structure blocks the first gap between the solar panel array and the mounting surface. The upslope fire blocking apparatus includes a second structure including a heat or fire sensitive material configured to melt, deform, or warp at a second predetermined temperature, the second structure having a second structure length, a second structure width and second structure first and second edges spaced apart along opposing ends of the width; and a second structure edge coupling joint positioned at the second structure first edge and configured to couple the second structure to an upslope portion of the solar panel array in a third position that enables ventilation and cooling for the solar panel through a second gap between the solar panel array and the mounting surface; where the second structure is configured to collapse from the third position to a fourth position when the second structure is heated above the second predetermined temperature, where in the fourth position the second structure blocks the second gap.
The first predetermined temperature may be equal to the second predetermined temperature. In some embodiments, the first structure edge coupling joint and the second structure edge coupling joint include a heat or fire sensitive material configured to melt, deform, or warp at the first and second predetermined temperatures, respectively. The first structure edge coupling joint and second structure edge coupling joint may cause the first structure second edge and second structure second edge, respectively, to make contact with the underlying mounting surface to close the first and second gaps when the first and second structure edge coupling joints melt, deform, or warp at the first and second predetermined temperatures. The first and second structures may be made from a deformable material that melts, deforms, or warps at the respective first and second predetermined temperatures. In some embodiments, the first and second structures each make contact with the underlying mounting surface in more than one distinct location when each of the structures melt, deform, or warp at the first and second predetermined temperatures, respectively.
The following detailed description and accompanying drawings provide a better understanding of the nature and advantages of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates conventional tilted and flat roof solar panel installations.
FIG. 2A illustrates a rooftop fire suppressing solar panel mounting system according to one embodiment of the present invention.
FIG. 2B illustrates a rooftop fire suppressing solar panel mounting system according to one embodiment of the present invention.
FIG. 3 illustrates a collapsing rooftop fire suppressing solar panel mounting system according to one embodiment of the present invention.
FIG. 4 illustrates another collapsing rooftop fire suppressing solar panel mounting system according to one embodiment of the present invention.
FIG. 5 illustrates a rooftop fire suppressing solar panel mounting system with integrated ballast according to one embodiment of the present invention.
FIG. 6 illustrates fire suppressing solar panel mounting brackets for use on flat roofs according to one embodiment of the present invention.
FIG. 7 illustrates a fire suppressing solar panel mounting bracket for use on flat roofs according to one embodiment of the present invention.
FIG. 8 illustrates a fire blocking solar panel mounting bracket for use on flat roofs according to one embodiment of the present invention.
FIG. 9 illustrates a fire blocking solar panel assembly with collapsible side skirts according to one embodiment of the present invention.
FIG. 10 illustrates a fire blocking solar panel fire skirt according to one embodiment of the present invention.
FIG. 11 illustrates a fire blocking solar panel building-integrated photovoltaic mounting system according to one embodiment of the present invention.
FIG. 12 illustrates a fire blocking solar panel mounting system for use on tilted roofs mounting system according to one embodiment of the present invention.
FIG. 13 illustrates a solar panel fire skirt assembly with diverting louvers according to one embodiment of the present invention.
DETAILED DESCRIPTION
Described herein are techniques for making, installing, and using solar panel mounting systems and add-on devices to prevent, suppress, a retard the spread of fire in rooftop solar panel installations. In the following description, for purposes of explanation, numerous examples and specific details are set forth in order to provide a thorough understanding of the present invention. It will be evident, however, to one skilled in the art that the present invention as defined by the claims may include some or all of the features in these examples alone or in combination with other features described below, and may further include modifications and equivalents of the features and concepts described herein.
As used herein, the term solar panel refers to any device in a planar or semi-planar form factor that captures, collects, or otherwise uses solar energy to produce electricity, heat, or other forms of energy. Typical forms of solar panels include panels of continuous or connected photovoltaic (PV) cells that convert photons to electrons, panels of tubing or ductwork through which water or air can be circulated to capture heat, and reflector cells that reflect solar energy in the form of heat to produce electricity or steam. Such solar panels can be installed on both flat and tilted roofs.
Such solar panels can be installed at the same time the roof for roofing system is installed in the building, as is typically done in new construction. In the case of photovoltaic solar panels, such integration into the building structure is often referred to as a building-integrated photovoltaic system (BIPV). Alternatively, solar panels can be installed on an existing roof for roofing system using various types of weights, ballast, racks, brackets, mounts, fasteners, and other hardware that can be incorporated into or augmented by various embodiments of the present invention. The discussion of various embodiments of the present invention herein refers to the types of solar panel installations with regard to new and existing flat and tilted roofs and roofing systems.
FIG. 1 illustrates several simplified fire code testing scenarios addressed by various embodiments of the present invention. As shown in FIG. 1 , solar panels 101 A can be mounted on a tilted roof surface 110 A using brackets 102 A. In such scenarios, the mounting brackets 102 A can include individual mounting brackets separately attached to a solar panel or mounting rails to which multiple solar panels can be attached. In either scenario, the mounting brackets 102 A and 102 B can have L-shaped or T-shaped cross-sections. Some embodiments of the mounting rails and brackets include extruded metal or composite materials.
In either the tilted roof for the flat roof installation, some fire codes are concerned with the ability of the combination of the solar panel, the mounting brackets or mounting rails, and the roofing system to resist the ignition and spread of fire underneath the solar panel when flames of a certain temperature, velocity, and duration are directed at the side of the solar panel and into the gap between the solar panel and the roof surface along directions 103 , 104 , 105 , 106 , 108 , and 109 . Various embodiments the present invention are directed towards blocking or redirecting the flames from directions 103 , 104 , 105 , 106 , 108 , and 109 to achieve the performance requirements of fire codes and to prevent the spread or ignition of fire on a roofing system.
FIG. 2A shows a solar panel mounting device 206 for flat roof installations according to an embodiment of the present invention. As shown, the mounting frame 206 can include a top mounting surface 202 and sloped side surfaces 203 , 204 , 207 , and 208 . Sloped side service 208 can include a ballast shelf 205 for accepting weights or ballast 210 . In such embodiments, the mounting frame device 206 can include a top mounting surface 202 other solid to which the solar panel 201 is attached. In other embodiments the top mounting surface 202 can include a recess or an opening to accept the solar panel 201 along the bottom, perimeter, or edge of the solar panel 201 or solar panel frame.
The sloped side surfaces 203 , 204 , 207 , and 208 can be coupled to the top mounting surface 202 by various means and at various angles. The angle at which the side surfaces 203 , 205 , 207 , and 208 are coupled to the top mounting surface 202 can be varied to minimize wind resistance and further enhance the capability of the mounting frame 206 to resist the spread of flames. In such embodiments, the sloped side surfaces 203 , 204 , 207 , and 208 can be angled relative to the surface of the roof onto which it is installed to redirect side directed flames away from the surface of the roof.
As shown in FIG. 2A , the side surfaces 203 , 204 , 207 , and 208 can be configured to fully enclose the space between solar panel 201 and the roofing surface 110 B. In other embodiments, in which installation of multiple solar panels is necessary or desirable, multiple mounting frame devices 206 can include variations that include different configurations having various combinations of the sloped side surfaces 203 , 204 , 207 , and 208 , that include all or some of the sides. More particularly, mounting frame device 206 can be configured to include only side surfaces 208 with ballast shelf surface 205 and a sloped side surface 207 opposing sloped side surface 208 disposed on the opposite side of solar panel 201 .
Alternatively, mounting frame device 206 can be configured to include sloped side surface 208 with shelf surface 205 and one of sloped side surface 204 or sloped side surface 203 . Using such configurations of mounting frame device 206 , multiple solar panels 201 can be installed on a roof surface in which the mounting frame devices 206 form a tessellated mounting structure with side surfaces encapsulating the volume underneath the multiple solar panels 201 .
While the side surfaces 203 , 204 , 207 , and 208 are shown as meeting one another at the corners of the mounting frame device 206 to provide a complete seal, various embodiments of the present invention also include arrangements of the four corners at which the side surfaces meet include a gap. Such gaps may be necessary if the mounting frame device 206 is installed on a site using pre-scored, precut, or pre-creased sheet-metal or other sheet material. Specifically, gaps at edges 210 , 211 , 212 , and 213 can also provide for ventilation of the backside of solar panels 201 during normal operation of the solar panels to increase efficiency and avoid overheating. In similar embodiments, the sheet material out of which mounting frame 206 is constructed, can include perforations or slits to provide ventilation to the solar panel 201 during normal operation of the solar panels.
In some embodiments, the ballasts 210 can be integrally formed with shelf surface 205 of mounting frame 206 . In other embodiments, shelf surface 205 can include indentations or cutouts to accept ballasts of a predetermined size. In one embodiment, shelf surface 205 includes a flat continuous surface onto which ballasts, such as individual masonry units (IMUs), bricks, cinderblocks, rocks, or other relatively dense and heavy objects that can fit under the gap between the underside of the top mounting surface 202 and the top surface of the mounting shelf 205 .
FIG. 2B includes a cross-sectional view and an isometric view of a mounting frame device 226 , according to another embodiment of the present invention. In such embodiments, the mounting frame device 226 includes vertical side surfaces 223 , 224 , 227 , and 228 that includes a shelf surface 225 disposed underneath the top surface 222 . Vertical side surfaces 223 , 224 , 227 and 228 can be configured to be approximately at right angles relative to top surface 222 and solar panel 201 . Similar to the embodiment shown in FIG. 2A , mounting frame device 226 can include gaps at edges 231 , 232 , 233 , and 234 to provide ventilation for solar panel 201 during normal operation. Just as mounting frame 206 , mounting frame 226 can include various sheet materials, such as sheet-metal or high temperature composites. Such materials of mounting frame device 226 can include notches, slots, or perforations to provide additional ventilation during normal operation of solar panel 201 . The notches, slots, or perforations in the sheet material of mounting frame 226 can be configured to allow air to flow to vent heat from the undersurface of solar panel 201 , but configured to restrict the spread of fire in the space between roofing surface 110 B and the underside of the top surface 222 and solar panel 201 .
Similar to the embodiments described above in reference to FIG. 2A , mounting frame device 226 can include variations having different combinations of vertical side surfaces and open sides. For example, mounting frame 226 can include a vertical side surface 227 and a vertical side surface 228 having a shelf surface 225 , wherein shelf surface 225 is disposed underneath the top surface 222 . Like shelf surface 205 , shelf surface 225 can be configured to accept weights or ballasts to secure the solar panel 201 and mounting frame 226 to flat roof surface 110 B. In other embodiments, vertical side surface 228 having shelf surface 225 can be coupled to the top surface 222 along with vertical side surface 223 or 224 . Such embodiments are useful for mounting solar panels 201 in rooftop installations having a plurality of solar panels. Various variations of mounting frame 226 can be used to create a composite tessellated mounting frame having vertical side surfaces surrounding the volume defined by the multiple top surfaces 222 and the rooftop surface 110 B.
The side surfaces 203 , 204 , 207 , and 208 of FIG. 2A and vertical side surfaces 223 , 224 , 227 , and 228 , can be arranged relative to other mounting frames and other structures present on the rooftop on which the installation is located to resist the spread of fire in the volume underneath the top surfaces 202 or 222 and the rooftop surface 110 B. In some embodiments, this can mean that the sloped side surfaces and the vertical side surfaces have different lengths and bottom edge profiles that are customized on-site or at the factory to accommodate various features on otherwise flat roofs or roofing systems. For example, vertical side surfaces 223 and 224 can be shorter than vertical side surfaces 227 and 228 to allow cables to be laid underneath mounting frame 226 and solar panel 201 . Similarly vertical side surfaces 223 and 224 can include notches or holes the pass through of cables from one solar panel to another and finally down to a an uplink/downlink electrical connection coupled to an inverter or other power conditioning or converting device or system.
FIG. 3 shows yet another embodiment of the present invention for mounting solar panels 201 onto a flat roof or roofing system surface 110 B. In such embodiments, solar panel 201 can be installed on the roof or roofing system surface 110 B as shown in configuration 301 A. In configuration 301 A solar panel 201 rests on the roof or roofing system surface 110 B at point 310 and is propped up by a fire or heat sensitive leg 330 such that the solar panel 201 is at an angle 320 relative to the surface 110 B. Installation configuration 301 A shows fire heat sensitive leg 330 in place supporting solar panel 201 at various points or along the line on one side of the bottom side of solar panel 201 . The configuration of the fire or heat sensitive leg 330 can vary based on the requirements for configuration of the roof or roofing system surface 110 B. For example, fire heat sensitive leg 330 can be in the form of a bar, a plank, individual shafts, rods, cones, pyramids, or any other shape suitable to stably holding solar panel 201 at angle 320 during normal operation.
Upon exposure to sufficient heat, fire, or flames, the material included in fire heat sensitive leg 330 can be configured to melt, deform, collapse, or otherwise fail such that the solar panel 201 will fall along direction 335 to be flush or approximately flush with the roof or roofing system surface 110 B as shown in collapsed configuration 301 B. The temperature at which the fire or heat sensitive leg 330 allows solar panel 201 to become flush or approximately flush with the roof or roofing system surface 110 B can be determined by the material used to construct the heat or fire sensitive leg 330 . In some embodiments, is advantageous for the material selected for the heat or fire sensitive leg 332 to remain structurally sound at normal operating temperatures typically encountered on a roof installation of solar panels.
When solar panel 210 is flush with the roof or roofing system surface 110 B, the application of fire from any angle parallel to the surface 110 B will be inhibited, thus preventing or suppressing the spread of fire between roof or roofing surf system surface 110 B and the solar panel 201 .
FIG. 4 shows another embodiment of the present invention which is a variation on the embodiment described above in reference to FIG. 3 . As shown the solar panel 201 can be installed on the roof or roofing system surface 110 B using a mounting bracket 402 at one end of the solar panel 210 that can pivot about a point 403 . Point 403 can include a hinge, a Cotter pin, a hinge pin, a screw, bolt, or any other elements capable of providing a pivot point. Once solar panel 201 is coupled to the mounting bracket 402 at the point 403 , it can be lifted to create an angle with roof or roofing system surface 110 B using a support structure or leg 406 attached to the solar panel on the other end or edge attachment point 405 and coupled to the roof or roofing system surface 110 B via a mounting bracket 407 via a pivot point 408 , as shown in configuration 400 A. Support structure 406 can be coupled to the solar panel 201 via a heat or fire sensitive coupling element 405 .
In some embodiments the heat or fire sensitive coupling element 405 can include a heat or fire sensitive adhesive or fastener that will melt, deform, collapse, or otherwise fail such that the solar panel 201 can fall to be flush or approximately flush with the roof or roofing system surface 110 B, as shown in collapsed configuration 400 B. The heat or fire sensitive coupling element 405 can include a number of materials including, but not limited to, metal alloys, composites, polymers, plastics, and ceramics. When exposed to excessive heat or fire temperatures, heat or fire sensitive coupling element 405 will release, thus allowing support structure to fall or rotate in the direction of arrow 409 B about pivot point 408 . As support structure 406 rotates along the direction of arrow 409 B about to the point 408 , solar panel 201 will move in the direction of arrow 409 A about to the point 403 until it is in the collapsed configuration 400 B. In such embodiments, solar panel 201 can include a side vane or guard to block the gap between the roof or roofing system surface 110 B and solar panel 201 due to the solar panel 201 resting on one or more mounting brackets 407 .
FIG. 5 shows another embodiment of the present invention for installation of solar panels 201 on flat or semi-flat roofs or roofing systems. As shown, configuration 500 A can include a solar panel 201 coupled to a number of standoffs 503 which are resting on or coupled to a mounting frame 502 . The mounting frame 502 can be coupled to a ballast structure 501 . The ballast structure 501 can include a number of materials of sufficient density and weight to affix the solar panel 201 to the roof or roofing system surface 110 B without the use of fasteners or penetrations into the roofing surface 110 B. In such embodiments, ballast structure 501 can include cementitious material, concrete foam, cinderblocks, or other fire resistance dense or heavy materials. In some embodiments, the height of standoffs 503 can be configured to provide sufficient ventilation under solar panel 201 during normal operation.
FIG. 5 also shows a variation of configuration 500 A in configuration 500 B that includes channel cuts or grooves 515 that can create wiring or cable conduits 550 when the configuration 500 B unit is placed in-line with another configuration 500 B unit. Such installations beneficially protect the wiring or cabling between solar panels 201 , inverters, and other electrical components of other flat roof solar panel installations shown in FIG. 5 .
FIG. 6 shows a number of structural support mounts the can be used in flats roof or roofing system installations of solar panels 201 to prevent the spread of fire underneath the solar panel 201 according to various embodiments of the present invention. Each of the variations of the structural support mounts shown in FIG. 5 include a multi-walled structure onto which a solar panel 201 can be placed. The multi-walled structure can include a number of vertical wall elements coupled to one another in various configurations. The shape and configuration of the vertical wall elements can be customized based on the ventilation or cooling requirements of a particular solar panel 201 as well as any local, state, or federal fire codes.
For example, configuration 600 a can include a solar panel 201 resting on or coupled to a structural support mounts 601 , 611 , or 621 . Structural support mounts 601 , 611 , and 621 can include a number of vertical wall sections having identical or varied curves to provide structure and stability to one another when placed on a roof roofing system surface on the bottom edges of the walls. The solar panel 201 can then rest on or be coupled to the top edges of the walls of the structural support mounts 601 , 611 , and 621 . The shape of the vertical wall sections of the structural support mounts 601 , 611 , and 621 can include hyperbolic, parabolic, circular and other curved profiles as illustrated in configurations 600 A, 600 B, and 600 C. In such exemplary embodiments, the shape and height of the vertical wall sections can be optimized for number of factors or requirements such as fire suppression, wind resistance, solar panel cooling, and other operational factors. For example, structural support mounts 601 can provide enhanced solar panel ventilation or cooling based on the amount of solar panel overhang beyond the interior of the vertical wall sections.
In related embodiments, a plurality of structural support mounts 601 , coupled to solar panels 201 can be installed next to one another in a tiled fashion such that the structural support mounts 601 , 611 or 621 coupled to a first solar panel 201 will match up with and abut the structural support elements 601 , 611 , or 621 of a second solar panel placed next to the first solar panel 201 . In such embodiments, it may be desirable to use a single type of structural support mounts a particular solar panel installation to maximize the efficiency and fire suppression characteristics, such as the inclusion of the least number of gaps between the solar panels and structural support mounts. Some shapes of structural support mounts can advantageously redirect or reversed the flow of fire or flames directed into the gap between a number of solar panels and the roof or the roofing system surface onto which they are placed using the structural support mounts.
For example, structural support mounts 601 when placed next to another support structure mount 601 will create a rounded or U-shaped block that can redirect the flow of fire that is directed underneath the solar panels away from the space underneath the solar panel and above the roof surface.
FIG. 7 shows yet another embodiment of a flat roof solar panel mount assembly according to an embodiment of the present invention that can redirect flames to help prevent or suppress the spread of fire on a roof under solar panel 201 . As shown, solar panel mount 713 can include a structure having a first, or bottom, wall and a second, or top, wall separated by some distance to create a duct or channel between the first and second walls. The channel can be curved, as shown, to have a rounded bend such that the internal channel transitions from a horizontal channel to a vertical channel along path 712 . Due to the curve in the top wall of the solar panel mount 713 , solar panel 201 can be placed or mounted at an angle, as shown. The space in between the top wall of the solar panel mount 713 can be enclosed by a wall or skirt structure 720 to prevent fire from entering the gap between the solar panel mount 713 and solar panel 201 .
In some embodiments, the solar panel mount 713 can include fire proof materials such as metal or a cementitious material comprising fire proof or retardant properties. In such embodiments, when flames are directed at the solar panel 201 and solar panel mount 713 combination along the direction 710 parallel with the roof surface 110 B, the flames can be redirected through the inner channel of the solar panel mount 713 along direction 712 up and away from the surface of the roof 110 B to help avoid the spread of fire on the roof or under solar panel 201 . When flames are directed at the solar panel 200 and solar panel mount 713 along direction 711 parallel with the roof surface 110 B, the flames are stopped from reaching the space underneath the solar panel mount 713 by the bottom wall.
When flames are directed in a direction into the page parallel to the roof surface 110 B, the flames are stopped by the wall 720 . When multiple solar panels are installed on a roof in a row, the solar panel mount 713 can be dimensioned such that it can support multiple solar panels in a line. Alternatively, each solar panel mount 713 can be dimensioned to support a single solar panel 201 and configured to abut and or a couple to a neighboring solar panel mount 713 to create a line of solar panels 201 and solar panel mounts 713 assemblies. In such embodiments, only the end solar panel 201 and solar panel mount 713 assemblies need include an end wall 720 to prevent flames or fire from entering the gap between the solar panel mount 713 and the solar panels 201 .
FIG. 8 shows yet another embodiment of the present invention that can be used to install solar panels 201 on both flat and tilted roof surfaces. As shown, solar panel 201 is installed on roof surface 110 B by mounting brackets 801 and 802 . Solar panel 201 can be positioned in a horizontal or tilted configuration by varying the lengths of the leg elements of brackets 801 and 802 . Each of mounting brackets 801 and 802 can include extruded metal rails having wall sections that extend from the bottom surface of the solar panel 201 to the roof surface 110 B to block flames are directed along the directions 820 and 821 parallel with the roof surface 110 B, thus preventing or suppressing the spread of fire in the space underneath the solar panel 201 in the surface of the roof.
In related embodiments, mounting bracket 801 can include the lip or shelf element 805 for excepting a fastener or ballast 810 . In flat roof installations, as shown, the top surface of shelf element 805 can include indentations or holes for accepting specifically designed or general purpose ballast blocks. In tilted roof solutions, the shelf element 805 can include pass-through holes for accepting fasteners, such as screws, bolts or rivets, to couple mounting bracket 801 to the roof surface 110 B. Mounting bracket 802 can include a leg element having a bottom edge that rests on the roof surface 110 B.
In related embodiments, each of mounting brackets 801 and 802 can be dimensioned to accept multiple solar panels 102 . In such embodiments, each mounting bracket 801 can include rails that except an edge of solar panels 201 in a clamp section. As shown, the clamp section can comprise a C-shaped or U-shaped region into which the edge of solar panel 201 can be seated or clipped.
FIG. 9 shows yet another embodiment of the present invention. In such embodiments, a solar panel 201 is mounted to a roof surface 110 B on mounting brackets 902 and 903 in the normal operating configuration 901 A. Fire block elements 910 and 913 can be affixed around the perimeter of solar panel 201 . While fire block elements 910 and 913 are shown coupled to solar panel 210 at joints 911 and 912 at a downward angle toward the surface 110 B, various embodiments can include coupling the fire block elements 910 and 913 in other angles, including parallel to the solar panel 901 . During normal operation the solar panel 201 installed in configuration 901 A, all of the elements remain stationary or static and the fire block elements 910 and 913 relative to the roof surface 110 B to provide ventilation and cooling for the solar panel 201 . Upon application of heat or flames in the direction of arrow 920 directed at the gap under the fire block elements 910 and solar panel 201 and above roof surface 110 B, fire block element 910 can collapse into either configuration 901 B or 901 C.
Configuration 900 1 B illustrates the embodiment in which fire block element 910 is coupled to solar panel 201 using a heat or fire sensitive joint 911 . At a certain temperature, joint 911 can be configured to collapse down to block fire, heat or flames coming from the direction 920 from entering the space underneath solar panel net 201 and above roof surface 110 B, thus preventing or suppressing the spread of fire under the solar panel 201 .
Configuration 901 C illustrates another embodiment in which fire block element 910 includes a material that will melt, deform, bend or otherwise fail to conform to the gap between the solar panel 201 and the roof surface 110 B, as shown. FIG. 10 shows a close-up of a variation of the configuration 901 C.
Solar panel 201 can be coupled to the roof surface 110 B by a mounting bracket 1001 using fasteners or ballast. In such embodiments, the fire blocking elements 1010 can be configured to deform or drop into position upon exposure to heat or flames of a certain temperature such that the portion of the fire blocking elements 1010 includes ripples or waves 1020 that have multiple points of contact 1030 with surface 110 B. In such embodiments, the fire blocking element 1010 can include a material that can provide tension between the multiple contact points 1030 and the roof surface 110 B. Such materials include, but are not limited to stainless steel, metal alloys, and composite plastics and polymers with spring characteristics. Advantages of having multiple contact points 1030 between fire blocking element 1010 and the roof surface 110 B include the ability to effectively block heat, fire or flames from reaching the underside of solar panel 201 .
FIG. 11 shows a building integrated photovoltaic installation on a slanted roof 1104 , according to various embodiments of the present invention. Such embodiments are advantageous when installed in a new construction or during the construction of a new roofing system. The roofing system shown in FIG. 11 is a shingle or composite roofing system that can include an underlying or sub roof surface 1104 . The underlying or sub roof surface 1104 can be made of a number of materials that provide support, structure and possibly another layer of water proof membrane onto which the other components of the roofing system 1100 can be affixed. As shown, the roofing system that includes the building integrated photovoltaic cells 1120 as part of the shingled or overlapping elements also includes mounting brackets 1115 that can be fastened, adhered, or otherwise affixed to the underlying or sub roof surface 1104 . The installation of such building integrated photovoltaic systems can begin with coupling an array of mounting brackets 1115 to the underlying or sub roof surface 1104 . Such an array of mounting brackets can include multiple rows disposed over the underlying or sub roof surface 1104 with separations 1130 between the rows that are then fitted with overlapping rows of framed or frameless photovoltaic cells 1115 . As in the shingle figuration shown in FIG. 11 , the overlapping elements 1115 and 1120 can include standard glass module laminate solar cells with and without frames.
Once the array of mounting brackets are disposed on the roof surface, installers can begin placing photovoltaic cells 1115 into the clamp section of the mounting brackets. In some embodiments, the clamp sections of the mounting brackets 1115 include a click-lock system that provides for the insertion of one edge of the photovoltaic cell 1120 . The interface with the click-lock system of the mounting bracket 1115 can be configured to engage the photovoltaic cell 1020 with a positive and secure physical coupling. In related embodiments, mounting bracket 1115 can also be configured to include wiring and wire contacts to electrically couple to contacts on the specialized photovoltaic cell 1120 to provide both physical coupling and electrical coupling when the photovoltaic cell 1120 is inserted into the clamp section of mounting bracket 1115 . In other embodiments, photovoltaic cells 1120 can be further secured by inserting or applying adhesive between the backside of the photovoltaic cell and a mounting located in a lower row of mounting brackets.
Has shown, the top row of mounting brackets and photovoltaic cells can be using metal flashing, or some other suitable material for flashing, 1110 . The flashing 1110 can be coupled to the underlying or sub roof surface 1104 at the top using traditional fastening methods and secured to the top row of mounting brackets using the adhesive under the portion of the flashing that overlaps the top of the top row of mounting brackets. All rows, including the bottom row, of photovoltaics can be stabilized and protected from mechanical stress by inserting spacers and/or adhesive in locations 1125 .
FIG. 12 illustrates yet another embodiment the present invention for the installation of solar panels on existing tilted shingled roofing system. As shown, solar panels 1210 can be installed on the roof system using a variety of mounting brackets. Such mounting brackets can include all of the roof type mounting brackets 1230 and middle of the roof mounting brackets 1235 . In such installations, solar panels 1210 can be installed in one-dimensional or two-dimensional array of solar panels disposed along a longitudinal direction of the roof. In such installations, can include a downslope fire blocking element 1201 similar to fire blocking elements described above. The fire blocking element 1201 can include an upper materials that can be configured to lower or deform into place such that the fire blocking element 1201 is disposed to block heat, fire, or flames from entering the gap between the solar panels 1210 and the roofing surface.
In similar embodiments, in which the solar panel installation includes only a single solar panel or a one-dimensional array of solar panels disposed in a latitudinal direction on the roof surface, fire blocking elements 1201 can be installed on the lower edge of the solar panel 1220 and fire blocking element 1202 can be disposed or affixed to the top edge of the solar panel 1220 . In such configurations, when exposed to temperatures exceeding a certain temperature, one or both of the fire blocking elements 1201 and 1202 can be repositioned or deform into position so as to prevent or suppress the spread of heat, fire, or flames from reaching the gap between solar panel 1220 in the surface of the roof.
FIG. 13 shows yet another embodiment of the present invention that can be using installation of solar panels 201 on a flat or tilted roof to prevent spread of heat, fire, or flames from entering the gap between the roof surface and the underside of the solar panel 201 . As shown, solar panel 201 can be mounted to the roof surface via mounting brackets 1301 . Side skirts 1320 , 1325 , 1330 , and 1335 can be affixed to the outer edges of the solar panel 200 . Each of the side skirts can include a number of louvers 1315 that extend downward toward the surface of the roof and outward from the center of the solar panel 201 . The length in the direction of the louvers 1315 can vary depending on the height of mounting brackets 1301 and the requirements of any applicable fire codes.
As depicted in the side view of the configuration 1300 , heat, fire, or flames can be directed along the direction of 1310 or 1320 . In such embodiments, at least some portion of heat, fire, or flames directed under the configuration 1300 including side skirts 1320 , solar panel 201 , and side skirts 1325 will be redirected toward the top surface of the fire skirts thus reducing the amount of heat, fire, or flames that reach the region between the underside of solar panel 201 and the roof surface. The portion of the heat, fire, or flames that reaches the region between the underside of solar panel 201 and the roofing surface can be determined by the dimensions of the louvers 1315 . The longer and wider the louvers 1315 are dimensioned, the lower the portion of the heat, fire, or flames directed along directions 1310 and 1320 between the underside of solar panel 201 and the roof surface. The reduction of the heat, fire or flames reaches the region between the underside of solar panel 201 and the roof surface will help prevent or suppress the spread of fire or flames under the solar panel 201 .
The above description illustrates various embodiments of the present invention along with examples of how aspects of the present invention may be implemented. The above examples and embodiments should not be deemed to be the only embodiments, and are presented to illustrate the flexibility and advantages of the present invention as defined by the following claims. Based on the above disclosure and the following claims, other arrangements, embodiments, implementations and equivalents will be evident to those skilled in the art and may be employed without departing from the spirit and scope of the invention as defined by the claims.
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Embodiments of the present invention are directed towards fire blocking apparatuses. A fire blocking apparatus for a solar panel is mounted to an underlying mounting surface. The fire blocking apparatus includes a panel support structure sized and shaped to be mounted between a solar panel and the mounting surface thereby supporting and creating a gap between at least a portion of the solar panel and the mounting surface, where at least a portion of the panel support structure comprises a heat or fire sensitive material configured to melt, deform, or warp at a predetermined temperature such that when the structure is mounted between the solar panel and the mounting surface and heated at or above the predetermined temperature, the panel support structure collapses to reduce the gap between the at least a portion of the solar panel and the mounting surface.
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FIELD OF THE INVENTION
The present invention relates to a printed circuit board flat flexible cable connector to contain and keep a flat flexible cable parallel to a printed circuit board, and more particularly an improvement relating to such a cable connector having a housing equipped with a plurality of terminals whose solder tails are staggered and arranged on the bottom of the housing.
DESCRIPTION OF PRIOR ART
A variety of cable connectors have been widely used. There have been ever increasing demands for the reduction of the size of the printed board, and for the increase of the density with which circuit elements can be applied to the printed board. As for connectors associated with such printed boards, it is necessary to increase the number of terminals in the housing of a cable connector, while at the same time to reduce the space on the printed board that the solder tails of the connector terminals occupy.
Typically, a flat, flexible cable has only one side with conductors exposed. If two cables are to be connected to a printed circuit board, normally two connectors will be necessary. For each connector, a solder tail footprint will be required. To eliminate these dual solder tail footprints, a connector has been provided which allows for the insertion of two cables with their insulated portions next to one another and their exposed portions directed outside. If this connector is designed to have this sandwiched dual cable inserted perpendicular to the printed circuit board then the solder tails may be staggered sufficiently so as to provide a small foot print. If, however, the sandwiched cable or a single cable with exposed conductors on both sides is to be inserted parallel to a printed circuit board with the prior art connectors, where all of the terminals are inserted into the housing from the same side, the foot print must be extended laterally so that the terminals do not contact one another at the bottom of the housing.
SUMMARY OF THE INVENTION
The main object of the present invention is to solve the problems of the prior art to provide a connector to maintain either a flat, flexible cable with exposed conductors on both sides of the cable or two flat, flexible cables having only one side with exposed conductors parallel to a printed circuit board while maintaining a small solder tail foot print.
In order solve the problems of the prior art, this invention is provided which is a connector to contain and keep a flat, flexible cable, having exposed conductors on both sides, horizontal to a printed circuit board. The connector housing has front, rear, top and bottom walls. A cable insertion slot is formed in the housing front wall. Terminal insertion slots are in the front and rear walls of the housings.
Lower terminals inserted in the front of the housing have a base with a length alternating between adjacent lower terminals and are held in the housing parallel to and just above the housing bottom wall. The lower terminals have a flexible contact arm extending into the cable insertion slot from a "C" shaped bend located at one end of the lower terminal base which is first inserted into the housing front. The contact points on the arms make electrical contact with the exposed conductors of the bottom portion of said flat, flexible cable. Tails extend from an "L" shaped bend at the end of the base opposite the "C" shaped bend, so that the tails can pass through the bottom housing wall perpendicular to the printed circuit board. As a result of the alternating length of the lower terminal bases, the tails alternate passing through the housing bottom wall at different distances from the housing front wall whereby the tails form two rows parallel to the housing front and alternating in a staggered relationship.
A plurality of upper terminals are inserted into the rear terminal insertion slots. The upper terminals have a base with equal lengths and are held in the housing parallel to and just below the housing top wall. Flexible contact arms extend into the cable insertion slot from a "C" shaped bend at one end of the upper terminal base which is first inserted into the housing rear. Contact points on the arms make electrical contact with the exposed conductors of the upper portion of the flat, flexible cable. Tails extend from an "L" shaped bend at the end of the base opposite the "C" shaped bend so that the tails travel down along the rear housing wall. The tails are bent a second time so that the tails travel parallel to and above the housing bottom wall and below the lower terminals. They are bent a third time forming lengths between the second and third bends alternating between adjacent terminals so that the tails are not only perpendicular to the printed circuit board but also due to the alternating length of the tail formed by the third bend, the tails alternate passing through the housing bottom wall at different distances from the housing rear wall whereby the tails form two rows parallel to the housing rear wall and alternating in a staggered relationship.
The housing also has shelves opposite the contact points partially defining the cable insertion slot to support the cable while the contact points are forced into contact with the exposed cable conductors. The housing bottom wall may also be separate from the housing and have holes passing therethrough in a pattern cooperating with the pattern made by the staggered tails of the terminals. After all of the terminals are inserted completely into the housing the separate bottom wall is placed over the tails and into engagement with the housing thereby holding the tails and the terminals in place in the housing. This connector can also be used to connect two flat cables sandwiched together with the exposed conductors facing away from each other.
Other objects and advantages of the present invention will be understood from the following description of a flat flexible cable connector used to contain and keep a flat flexible cable horizontal to a printed circuit board according to a description of the preferred embodiment of the present invention, which is shown in accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the flat flexible cable connector.
FIG. 2 is a front view of the connector.
FIG. 3 is a sectional view of the connector taken along the line 3--3 in FIG. 2.
FIG. 4 is a sectional view of the connector taken along the line 4--4 in FIG. 2.
FIG. 5 shows schematically the staggered arrangement of the solder tails of the terminals and the holes in the bottom wall of the housing all in relation to the bottom perimeter wall of the housing.
FIG. 6 is a sectional view of the connector showing the manner in which the edge of a flat flexible cable is contained and kept horizontally to the printed circuit board.
FIG. 7 is a sectional view of the connector showing the manner in which the edges of two flat, flexible cables sandwiched together are contained and kept horizontally to the printed circuit board.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to these drawings, a connector is discussed which contains and keeps a flat flexible cable horizontal to a printed circuit board. This connector comprises housing 1 and a plurality of terminals 30 and 31 fixed in housing 1. Housing 1 has a cable insertion slot 4 formed in its front 5 and extending in the front-to-rear direction A to permit insertion of a flexible cable 3 in housing 1, as seen from FIG. 6. The rear side of housing 1 which is the furthest from front 5 of housing 1 is indicated by 6. Insertion slot 4 extends lengthwise in direction B, which is perpendicular to the front-to-rear direction A, as seen from FIGS. 1 and 2.
As seen from FIGS. 3, 4 and 6, housing 1 has terminal mounting spaces or insertion slots 7 to communicate with the cable insertion slot 4, and has partition walls 10 provided at regular intervals longitudinally as indicated by B extending from the front to back direction A. These partition walls permit lateral arrangement of upper and lower terminals 30 and 31 at regular intervals and prevent direct contact between adjacent terminals. Upper and lower support shelves 8a and 8b are integrally connected to the upper front part and lower rear part of housing 1 respectively, extending horizontally in opposite directions in the spaces 7 toward the central longitudinal line of housing 1 to permit horizontal insertion of a flexible cable 3 with conductors 9 printed on its opposite major surfaces, as seen from FIG. 6. Specifically the upper major surface of the printed board 3 is put in contact with upper support shelve 8a to be guided thereby whereas the lower major surface of the cable 3 is put in contact with lower support shelve 8b to be guided thereby. An alternate embodiment shown in FIG. 7 would include two cables 3', 3' back to back with exposed conductors facing opposite one another.
Upper terminal 31 is fixed in the housing 1 so that it may be put in contact with a selected conductor 9 on the upper major surface 12 of the cable 3 when the upper terminal is inserted in the rear 6 of the housing 1 whereas lower terminal 30 is fixed so that it may be put in contact with a selected conductor 9 on the lower major surface 14 of cable 3 when the lower terminal is inserted in the front 5 of the housing 1. Specifically each upper terminal 31 consists of a base 33 with contact beam or arm 32 and solder tail 18 both integrally connected. Contact beam 32 extends from the base 33 from a C shaped bend into the cable insertion slot 4 and ends with contact point 13. Each contact point 13 is adapted to be put in contact with a selected conductor 9 on upper major surface 12 of printed board 3. Each contact point 13 is opposite a portion of the lower support shelf 8b which provides a resilient force to push the lower side of the cable so that a selected conductor in the upper major surface 14 makes contact with the selected contact point 13.
Likewise, each lower terminal 30 consists of a base 34 with a contact beam or arm 2 and solder tail 18 both integrally connected. Contact beam 2 extends from base 34 from a "C" shaped bend into the cable insertion slot 4 and again turns at contact point 15 and extends downward. Each contact point 15 is adapted to be put in contact with a selected conductor 9 on the lower major surface 14 of the printed board 3. Each contact point 15 is opposite a portion of the upper support shelve 8a which provides a resilient force to push the upper side of the cable so that a selected conductor in the cable lower major surface 14 makes contact with the selected contact point 15.
Housing 1 has a plurality of holes 17 on its floor 16, thereby permitting the solder tail 18 of each terminal 30 and 31 to pass through floor 16 of housing 1 and partly appear from the bottom of housing 1. These holes 17 are staggered and arranged on the bottom of housing 1 so as to form four parallel lines, and accordingly projecting solder tails 18 are staggered and arranged on the bottom of housing 1 in four parallel lines, as seen from FIG. 5.
Specifically referring to FIGS. 2 and 3, a pair of opposing terminals 30 and 31 which are crossed by the line 3--3 in FIG. 2 appear in complete form in FIG. 3. The solder tail 18 of the lower terminal 30 being on the first line and the solder tail 18 of upper terminal 31 being on the third line. Another pair of terminals 30, 31 which are crossed by the line 4--4 in FIG. 2 appear partly in FIG. 3. Specifically only their solder tails 18 appear. The solder tail 18 of the lower terminal 30 is on the second line and the solder tail 18 of the upper terminal 31 is on the fourth line. Here, it should be noted that all solder tails 18 project downwards from the bottom of housing 1, not extending laterally out of the area bounded by the four sides of the square housing bottom.
As may be understood from the above, upper and lower terminals 30 and 31 are fixed in the housing 1 so that the contact portions 13, 15 of the contact beams may be positioned above the bottom floor of housing within the lateral range of the farthest distance S from the first line of solder tails closest to insertion slot 4 to the fourth line of solder tails closest to the rear side of housing 1. In this particular embodiment contact portion 15 of lower terminal 30 whose solder tail 18 is in the first line is just above the second line of the staggered pattern, whereas the contact portion 13 of upper terminal counter-contact 31 whose solder tail 18 is in the third line is just between the second and third lines of the staggered pattern, as seen from FIG. 3.
Contact point 15 of lower terminal 30 whose solder tail 18 is in the second line is just above the second line of solder tails, whereas contact point 13 of upper terminal 31 whose solder tail 18 is in the fourth line is just between the second and third line of the staggered pattern, as seen from FIG. 4. Thus, all contact portions are arranged within the lateral range of farthest distance S from the first to fourth line of the staggered pattern. This arrangement requires no extension of the contact beams 2, 32 which are integrally connected both to contact ends 15 or 13 and bases 34 or 33 respectively, thus not necessitating increase of the lateral size W of housing 1. Specifically in FIG. 4, the distance L from the tip 19 of the lower terminal 30 which is closest to insertion slot 4 to the rear extension 24 of the upper terminal 31 which is closest to rear wall 6 need not be increased, and hence the lateral size W of housing 1 need not be increased, either. The staggering of the upper terminal 31 solder tails 18 is a result of the alternating length of the adjacent solder tail portions just above and parallel to the housing bottom. These solder tail portions are also below the bases 34 of the lower terminals.
Housing 1 has two split projections 21 on opposite bottom ends, thus permitting the mounting of housing 1 on a, printed board 20. As seen from FIGS. 1 and 2, each split projection 21 has a longitudinal slot 23 and an annular projection 22 to be resiliently fitted in and caught by a corresponding hole, which is made in a printed board.
In use, a flexible cable 3 is inserted in insertion slot 4. As the flexible cable 3 advances forward, lower terminal beam 2 is yieldingly bent downwards, thereby resiliently pushing itself against selected conductor 9 on the lower surface 14 of cable 3, and then upper terminal beam 32 is yieldingly bent upwards, thereby resiliently pushing itself against selected conductor 9 on the upper surface 12 of cable 3. At the same time, flexible cable 3 is supported by upper and lower support shelves 8a and 8b, thus putting cable 3 in correct vertical position in the direction indicated by C. Thus, reliable electric contacts are made between upper and lower terminals and conductors 9 on opposite major surfaces 12 and 14 of printed board 3.
Next, split projections 21 of housing 1 are pushed in the corresponding holes of a printed board 20. Each split projection 21 reduces its diameter when passing through an associated hole, and as seen from FIG. 6, it returns to its original size when annular projection 22 appears from printed board 20, allowing annular projection 22 to expand, thus being caught by the circumference of the hole in locking condition. Thus, the cable connector is fixed to printed board 20. Selected conductors on printed board 20 can be soldered to solder tails 18 of board edge connector, thereby making necessary electric connections between selected conductors of flexible printed board 3 and those of printed board 20 via the connector terminals.
It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and to restrictive, and the invention is not to be limited to the details given herein.
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Disclosed is an improved edge connector for making contact with conductor on a flat flexible cable and a printed circuit board requiring only a possible smallest mounting space. An edge connector according to the present invention has terminals inserted in both front and rear portions of the housing. All of the terminals have flexible arms opposite support shelves for contacting a conductor on a cable. The solder tails of the terminals are arranged on bottom of the housing in four lines in a staggered fashion.
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TECHNICAL FIELD OF THE INVENTION
The present invention relates to a container for storing and transporting products such as agricultural produce. In particular, the present invention relates to a paperboard container made from a single unitary blank that has the same if not greater stacking strength than current multi-piece designs, has the same outside dimensions as current designs and is able to fit within existing warehouse and storage racking systems, and is able to withstand up to three months in cold storage.
BACKGROUND ART
Containers made of corrugated paperboard are commonly used for storing and shipping agricultural produce. Typically, such containers are formed from a blank scored with score lines and cut lines and have a bottom and opposed sidewalls. As used herein, the term “sidewalls” refers to the side walls extending along opposite sides of a container and the end walls extending across opposite ends of a container. The term “side wall” or “end wall” is used when a particular wall is intended. The blanks are most often formed by automated machines in a continuous in-line process involving cutting, scoring and molding continuous sheets of paperboard. The paperboard is then folded along the score lines and cut lines to form a container. The blanks may be folded into a container by an automated machine or may be set up by hand.
Conventional containers used within many produce segments typically comprise three-piece Bliss style cartons. These container designs have to be run over two different machines at the box plants, requiring extra manpower to run the machines, and they require extra warehousing for the three pieces and extra labor for set-up at the customer's locations.
During use, containers are often stacked on top of one another for ease of shipping and for optimum use of space. For stability in stacking the containers it is common to have stacking tabs extending upward from the top edge of the container sidewalls. These stacking tabs often fit into corresponding notches cut into a superjacent container to help secure the stack. Since containers are usually stacked on top of like-sized containers, the stacking tabs that extend upwardly from a lower container are positioned directly into the sidewalls of a superjacent container. Thus, to accommodate the stacking tabs on a lower container, a complementary notch must be cut out of the bottom edge of the sidewall of a higher container. However, a notch in a sidewall is problematic in that it does not secure the stacking tab on all four sides. Thus, these sidewall notches do not fully prevent side-to-side movement, subjecting the stack to potential toppling. This is sometimes circumvented by having a multi-ply or multi-layer sidewall, wherein a stacking tab extends upwards from an inner layer of the sidewall, thereby aligning the stacking tabs with the bottom panel of an adjacent container as opposed to the sidewall. This, however, requires excess paperboard to be used to create the multi-layer sidewall, and results in related increased costs.
Further, it is easy to misalign a container during stacking such that a higher container falls into a lower container, usually on an angle, potentially damaging the contents of the lower container. To solve this, several prior art containers have been designed with inwardly inclined sidewalls, wherein the distance between the opposing top edges of the sidewalls is less than the distance between the opposing lower edges of the sidewalls. This eases stacking by severely limiting the probability of the higher container falling into a lower container, since the narrower upper portion creates a more functional ledge for the base of the higher container to rest on.
Some prior art containers have reinforcing corner posts to increase their stacking strength and to assist in preventing an upper container from falling into a lower container when they are stacked, but applicant is not aware of any prior art container that has both full depth reinforcing corner posts and inclined side walls with stacking tabs. One prior art container with inclined side walls has diagonally extending reinforcing corner panels at the upper margin of the container, but these panels do not extend the full height of the container.
Other prior art containers have full depth reinforcing corner posts to increase stacking strength, but they do not have inclined sidewalls.
Applicant is not aware of any prior art paperboard container that has inclined sidewalls, stacking tabs, and full height reinforcing corner posts, and especially such a structure wherein panels extending from opposite ends of the sidewalls are folded to form the corner posts and include sections adhered to adjacent portions of the side walls and end walls.
SUMMARY OF THE INVENTION
The invention comprises a one-piece container made from a single unitary blank of corrugated paperboard. The container has inwardly inclined side walls or end walls, double thickness stacking tabs with vertical corrugations, and full height reinforcing corner posts, wherein panels extending from opposite ends of the side walls or end walls are folded to form the corner posts and include sections adhered to adjacent portions of the side walls and end walls to hold or aid in holding the side walls and end walls in erected position. The stacking tabs extend in coplanar relationship with the associated inclined wall, and in a preferred construction tab locks are scored and cut in the bottom wall of the container for accepting and securing the stacking tabs of a subjacent container.
The one-piece container of the invention is made from a single unitary blank and is a replacement for the three-piece Bliss style carton currently used within many produce segments. The container has the same if not greater stacking strength than current multi-piece designs, has the same outside dimensions as current designs and is able to fit within existing warehouse and storage racking systems, and is able to withstand up to three months in cold storage. The inclined side walls or end walls of the container and the correspondingly inclined stacking tabs ensure that the stacking tabs fit into the tab locks in the bottom wall panel of a superjacent container and not into the side or end walls of the superjacent container. The tab locks capture the tabs on all four sides, resulting in a secure stack without requiring excess paperboard material. The combination of these features results in containers that are easy to stack and container stacks that are not prone to toppling, without using excess paperboard.
In a preferred construction the tab locks comprise a cut-out slot coupled with a flap, wherein the flap can bend upwards, thereby better accommodating an inclined stacking tab. Further, as stacking of adjacent containers is only possible if the pattern of the cut-out slots is configured in the same pattern as the stacking tabs, the locks are positioned to engage and lock the stacking tabs in a specific configuration. Therefore, the locks of the present invention can be scored and cut in any arrangement to fit on various arrangements of stacking tabs. For example, the bottom wall panel may contain four locks in a particular arrangement to accommodate four stacking tabs of a particular arrangement. Similarly, the locks may be inwardly spaced at different distances from an outer edge of the bottom wall panel to accept stacking tabs that are inclined at various angles.
The container of the invention incorporates internal corner posts and an internal minor flap that keep an upper container from nesting into a lower container. The container can be devoid of top flaps or lid panels, or it can have full or partial lid panels. In those embodiments incorporating lid panels, locking tabs on the lid panels engage and lock over the stacking tabs. The tab locks that trap the stacking tabs lock stacked containers to one another. The stacking tabs are of double thickness with vertical corrugations. The style and size of the corner posts can be adjusted for different tray packs but still allow the tray to run on current equipment.
The container can be made with or without top flaps and the corner posts can be adjusted to fit different product lines. The one-piece design allows the customer to handle less inventory as compared with current styles. The corner posts provide increased stacking strength and prevent containers from nesting into each other when they are stacked. The inclined side walls or end walls provide improved stacking and lock the containers to one another by trapping the stacking tabs in the tab locks of a superjacent container. The locking feature on the top flaps or lid panels prevents the top flaps from opening during shipping and handling. This locking feature also permits the opening and relocking of the flaps for product inspection.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing, as well as other objects and advantages of the invention, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like reference characters designate like parts throughout the several views, and wherein:
FIG. 1 is a top isometric view of a container in accordance with the invention.
FIG. 2 is a side view in elevation of two containers according to the invention stacked on top of one another and showing the inwardly inclined end walls.
FIG. 3 is a top isometric view of the container of FIG. 1 with one of the lid panels open.
FIG. 4 is a greatly enlarged fragmentary top isometric view of one corner of the container of the invention, showing the corner post pad in position to be folded over the top of the corner post in a preferred construction of the invention.
FIG. 5 is a greatly enlarged fragmentary plan view of one corner of the container, showing the corner post pad folded on top of the corner post.
FIG. 6 is a plan view of a blank for making the container of FIG. 1 .
FIG. 7 is an isometric view of the blank of FIG. 1 in a first, initial folded state.
FIG. 8 is an isometric view of the blank in a second folded state.
FIG. 9 is an isometric view of the blank in a third folded state.
FIG. 10 is an isometric view of the blank in a fourth folded state, erected and ready to accept product before the lid panels are folded into closed position.
FIG. 11 is a top plan view of the container of FIG. 10 , with the lid panels and corner post pads omitted for simplicity of illustration.
FIG. 12 is an isometric view of the container with one lid panel folded and locked in operative closed position.
FIG. 13 is an isometric view of the container fully erected with both lid panels folded and locked in operative closed position.
FIG. 14 is a top plan view of a blank for making a second embodiment of container according to the invention, wherein vent openings are provided in the lid panels.
FIG. 15 is a top isometric view of a container made from the blank of FIG. 14 , shown with the lid panels in open position.
FIG. 16 is a top isometric view of a third embodiment of container according to the invention, wherein the end walls and lid panels are devoid of vent openings, the corner posts do not include a diagonally extending panel, and the corner post pad is omitted.
FIG. 17 is an enlarged fragmentary top isometric view of one corner of the container of the invention, showing the detail of the corner post in accordance to the 3 rd embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first, preferred form of container 10 according to the invention and a blank B 1 for making it are shown in FIGS. 1-13 . The container has a bottom wall 11 , opposite side walls 12 and 13 , opposite end walls 14 and 15 , and partial lid panels 16 and 17 folded inwardly from opposite sides of the container. Stacking tabs 18 on the upper edges of the end walls are received in slots 19 in the lid panels, and locking tabs 20 on the lid panels are folded downwardly over the outside of the stacking tabs and against the upper outer edge of the respective end wall to lock the lid panels in closed position. Upwardly extending heels 21 on the locking tabs lie against the outside of the respective stacking tabs to hold the locking tabs in their downwardly folded locked position as shown in FIG. 1 . The locking tabs 20 and heels 21 are formed by shaped cuts 22 made in opposite ends of the lid panels, and the slots 19 result when the locking tabs and associated heels 21 are folded out of the plane of the respective lid panel.
As seen best in FIG. 2 , the end walls 14 and 15 are inwardly inclined, and the stacking tabs 18 on the upper edges of the end walls are coplanar with the end walls so that they are correspondingly inwardly inclined. Further, as seen best in FIG. 6 , opposite side edges of the stacking tabs are slightly undercut, defining shoulders 23 that aid in retaining the locking tabs in locked position over the stacking tabs.
Tab locks 24 of the type disclosed in applicant's U.S. Pat. No. 7,677,454 are cut and scored in the bottom wall 11 adjacent its folded connection 25 with an associated end wall, as shown in FIG. 6 , or inwardly spaced from fold line 25 a predetermined distance (not shown), depending upon the desired or necessary configuration. Each lock 24 comprises a cut-out slot 26 coupled with a bendable flap 27 , wherein the slot is designed to engage and secure a stacking tab 18 of a subjacent container. To fully engage and accept a stacking tab that enters through cut slot 26 on an angle, flap 27 has the ability to bend upwards along a back cut line 28 . Flap 27 has a length, width and thickness, wherein the thickness is equal to the thickness of the bottom wall 11 , and the length and width can vary within the scope of the invention as long as the flap sufficiently engages a stacking tab to frictionally hold it in the slot 26 . The flap is bordered by contact edge 29 , back cut line 28 , and side cut lines 30 and 31 . Contact edge 29 is the part of the flap that engages and holds secure stacking tabs 18 by rubbing against the tabs and holding them secure with a frictional force. Back cut line 28 is preferably a small cut line upon which flap 27 can pivot, and extends parallel to contact edge 29 and perpendicular to side cuts 30 and 31 . However, the back cut line does not run the full length of contact edge 29 , but is located intermediate and spaced from the side cuts 30 and 31 . In alternate embodiments (not shown), the back cut line is a perforated cut line that runs between side cuts 30 and 31 . Cut lines 30 and 31 are incisions that extend laterally from the back of flap 27 to the fold line 25 , parallel to each other and downwardly though the entire thickness of the bottom wall 11 . The cut lines enable the flap to extend upward about the back cut line without encountering undue resistance from the part of bottom wall panel 11 that borders flap 27 . Contact edge 29 extends from cut line 30 to cut line 31 parallel to fold line 25 , and engages tab 18 when it is inserted through slot 26 , holding the tab securely in place. In the embodiment shown, the contact edge extends in a slight, tongue-shaped outward arc. However, the shape of the contact edge may be altered in other embodiments.
Cut-out slot 26 extends across fold line 25 from contact edge 29 of flap 27 to an edge 32 in the adjacent end wall panel, and is further bordered by side cuts 30 and 31 . The width of the slot is great enough so that stacking tabs 18 can extend through the slot between the side cuts. However, the length between contact edge 29 and edge 32 may be less than the thickness of the stacking tabs, enabling the tabs to press against a portion of flap 27 , causing the flap to bend upwards to accommodate the tab.
Each slot 26 is aligned to accept a stacking tab on a slight taper. If the degree of taper changes, the alignment can change accordingly. For example, if end walls 14 and 15 are inclined at a greater angle than shown in FIG. 2 , the stacking tabs 18 will contact the bottom wall panel 11 of the superjacent container at some point closer to the center of bottom wall panel 11 . To account for this, the slots can be inwardly spaced from fold line 25 , thereby being aligned to accept the tabs.
Reinforcing corner posts 40 extend diagonally across each interior corner of the container. The corner posts extend the full height of the container and are formed by folded corner post panels on opposite side edges of each end wall. The construction of the corner posts is seen best with reference to FIGS. 3-11 .
Referring first to FIG. 6 , corner post panels 41 are foldably joined to each end of each end wall panel 14 , 15 . Each flap is divided by spaced apart parallel folds 42 and 43 into first, second and third rectangular panels 44 , 45 and 46 , respectively. The first panels 44 , positioned contiguous to the associated end wall 14 or 15 , are folded perpendicular to the end wall and adhered to an adjacent inner end surface of an adjacent side wall 12 or 13 . The second panels 45 are folded at an acute angle to the first panels so that they extend diagonally across an interior corner of the container, and the third panels 46 lie against and are adhered to the inner surface of the adjacent end wall. It will be noted that the blank preferably is cut so that the corrugations in the end walls, corner posts and stacking tabs extend vertically. A stacking tab 18 A is on the upper edge of panel 46 and is adapted to lie against stacking tab 18 on end wall 14 or 15 when the container is erected.
Small corner post pads 47 are foldably joined to the upper edge of the first panels 44 , and these pads are folded over the upper ends of the corner posts as seen best in FIGS. 4 and 5 .
The sequence of folding the blank B 1 to form the erected container of FIG. 1 is depicted in FIGS. 7 through 13 . Thus, as seen in FIG. 7 , the panels 44 - 46 are folded so that the first panels 44 extend perpendicular to the associated end wall panel 14 or 15 and the second panels 45 extend diagonally, with third panels 46 lying against and adhered to the associated end wall panel. The end wall panels are then folded up as shown in FIG. 8 so that they extend perpendicular to the bottom wall panel 11 , followed by folding the side wall panels 12 and 13 so that they extend perpendicular to the bottom wall panel, with the interior end surfaces of the side wall panels lying against and adhered to the first panels 44 . The container is then ready to be loaded with product and the lid panels closed and locked as described previously herein. When the lid panels are folded to their closed positions, the corner post pads 47 fold down and lie between the lid panels and upper ends of the corner posts.
A second embodiment of container 50 and blank B 2 for making the container are shown in FIGS. 14 and 15 . This form of the invention is essentially identical to the first form described, except that vent openings 51 are provided in the lid panels 16 ′, 17 ′, the bendable flaps 27 are omitted from the cut-outs 26 , and slight depressions 52 are formed in the upper edges of the end walls 14 and 15 at opposite side edges of the stacking tabs 18 .
A third embodiment of container 60 is shown in FIGS. 16 and 17 . This form of the invention differs from the previous forms primarily in that the reinforcing corner post does not extend diagonally but instead panel 45 ′ lies against the adjacent side wall, and the corner post pads 47 are omitted. However, the third panel 46 ′ extends over nearly half the width of the associated end wall. Further, there are no vent openings in the end walls 14 ′, 15 ′ or lid panels 16 ′, 17 ′.
While particular embodiments of the invention have been illustrated and described in detail herein, it should be understood that various changes and modifications may be made in the invention without departing from the spirit and intent of the invention as defined by the appended claims.
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A one-piece container formed from a single unitary blank of corrugated paperboard has a bottom wall, opposed side walls and inwardly inclined opposed end walls. Stacking tabs project upwardly from the end walls and tab locks in the bottom wall receive the stacking tabs of a subjacent container when the containers are stacked on top of one another. A reinforcing corner post extends the full height of the container in each corner. The corner posts are formed by panels extending from opposite ends of the end walls, wherein the panels include a first panel foldably joined to an end of an associated end wall and adhered to an adjacent side wall, a second panel foldably joined to the first panel and extending diagonally across the corner, and a third panel foldably joined to the second panel and adhered to an adjacent side wall.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 12/411,427 filed Mar. 26, 2009 and now issued as U.S. Pat. No. ______, which is a continuation of U.S. application Ser. No. 10/012,746, filed Dec. 7, 2001 and now issued as U.S. Pat. No. 7,561,872, which claims the benefit of U.S. Provisional Application 60/277,517 filed Mar. 19, 2001, with all applications incorporated herein by reference in their entireties.
TECHNICAL FIELD
[0002] The inventions generally relate to a user's control over telecommunications services provided by a service provider. More specifically, the inventions relate to systems and methods that allow a user to gain access to, view, and make changes or modifications to profile information related to the telecommunications services.
BACKGROUND
[0003] A wide variety of communications services are available including, for example, call waiting, call forwarding, call blocking, do not disturb services, customized messaging services, communications circles, etc. Generally, the services are implemented for a particular customer based on profile information relating to the customer's preferences. For example, a customer may have call forwarding service implemented so all calls to his or her home telephone number during business hours are forwarded to a network voice mail service. As another example, a customer may have call blocking service implemented so calls received from a specific number during evening hours are blocked.
[0004] A customer's preferences with respect to communications service may change from time to time. Referring to the examples above, the customer may decide to have calls that were previously forwarded to the network voice mail service forwarded instead to an office telephone. With respect to the call blocking service, the customer may decide to extend the call blocking service to block calls from another specific number. To accommodate the change in preferences, the customer's profile information relating to the communications service may need to be changed.
[0005] Generally, the service provider providing the service makes the change in the customer's profile information relating to the service. The service provider typically makes the change because the service provider delivers the service, and thus, controls the delivery of the service.
[0006] To make a change in a communications service, a customer notifies the service provider. The customer may notify the service provider in a number of different ways, which include calling a customer service number, or using the Internet to reach the service provider's web site and communicating the desired changes. Some service providers allow a customer to call a feature access code (FAC) and provide change instructions.
[0007] The necessity of having the customer contact the service provider and provide the change instructions significantly slows the desired change in the communications services. The additional necessity of having the service provider implement the change instructions further slows the desired change. Some customers may plan ahead or be patient so a delay of a desired change to communications services may not be important. Most customers, however, desire their changes to communications services to take effect as close to immediately as possible.
[0008] Therefore, there is a need for faster ways of implementing a customer's desired changes to his or her communications services. There is also a need for more convenient ways of implementing a customer's desired changes. In addition, there is a need for faster and more convenient ways of implementing a customer's desired changes to his or her communications services without sacrificing qualities such as accuracy and thoroughness in the implementation of the changes.
SUMMARY
[0009] The inventions generally relate to a user's control over telecommunications services provided to the user by a service provider. By these inventions, a user is allowed to gain access to, view, and make changes or modifications to profile information related to the telecommunications services provided to the user. Advantageously, the inventions allow a user to use almost any type of communications device to make changes in communications services provided to him or her. The changes may be made by the user quickly and efficiently, but qualities such as accuracy and thoroughness in the implementation of the changes are not sacrificed. Further, the changes to the communications services are implemented without involvement by the service provider in the change process.
[0010] More particularly, the inventions allow a user to access profile information related to communications services, view the profile information, and make changes or modifications to the profile information so as to add, delete, turn-on, turn-off, or otherwise modify the communications services. Any changes or modifications made by the user are effective almost immediately, and without involvement of the service provider in the change process.
[0011] The inventions include an exemplary method for direct access to change a telecommunications service in a telecommunications system. Per this method, profile information about the telecommunications service is stored on a server in a data network. A change action relating to the profile information may be received at the server. The change action may be received from a data device (such as a wireless unit) operating on the data network. The change action is implemented on the profile information to result in changed profile information being stored on the server. The changed profile information is provided from the server via the data network to the telecommunications system for use in providing the telecommunications service. In an embodiment, the changed profile information is provided to the telecommunications service in response to a request from the telecommunications system received at the server.
[0012] The inventions also include an exemplary system for directly changing the implementation of a telecommunications service without intervention by the service provider. The telecommunications service may be provided to a customer, and the customer may make changes directly by using a wireless unit. For example, the customer may use a personal digital assistant (PDA), an interactive pager (i-pager or IP), an interactive television (TV), or a wireless application protocol (WAP) phone. The wireless unit may be used to send an instruction relating to a change in the implementation of the telecommunications service to a service platform in a data network.
[0013] The service platform in the data network communicates with the telecommunications system. The service platform stores profile information relating to the implementation of the telecommunications service provided by the service provider. In an embodiment, the service platform stores the profile information as-a-whole. An embodiment also provides for the unique storage of the profile information by the service platform. In other words, in this exemplary embodiment, the telecommunications system does not store the profile information, and must request the service platform for the profile information. For example, the request may be made when the telecommunications system is providing a telecommunications service to the customer.
[0014] As noted, a customer may use a wireless unit to send an instruction to change the profile information relating to the telecommunications services to be provided to the customer. The service platform may receive the instruction from the wireless unit, change the profile information based on the instruction, and send the profile information to the telecommunications system. The profile information is received by the telecommunications system and the profile information is used to change the implementation of the telecommunications service.
[0015] In addition, the inventions include a method for use of a customer's telecommunications profile with another service so as to change the telecommunications service to the customer in light of the other service. This method stores the customer's profile relating to telecommunications services, and also stores an entry of information related to the customer with respect to the other service provided to the customer. The entry of information may be reviewed for relevance to the telecommunications services of the customer. Relevance may be established if the entry of information allows for changes in the provision of the telecommunications services to the customer. For example, the information may include a reference to a future activity of the customer. The future activity of the customer may necessitate a change in the telecommunications services provided to the user such as a change in a call forwarding number, etc. If the entry of information is relevant to the telecommunications services of the customer, then the customer's profile relating to the telecommunications services is changed to reflect the entry of information.
[0016] Further, the inventions may include a method for updating a customer's profile with respect to a telecommunications service provided to the customer by a telecommunications system. The method may store the customer's profile on a server in a data network. The server also may store an application for providing a service to the customer other than the telecommunications service. Application information may be received at the server in the data network. The application information may be used with the application in providing the service other than the telecommunications service to the customer. The server may determine the application information relates to the customer's profile with respect to the telecommunications service provided to the customer. If that determination is made, then the customer's profile may be updated with the application information. In an embodiment, the customer's profile updated with the application information may be provided from the server via the data network to the telecommunications system for use by the telecommunications system in providing the telecommunications service to the customer.
[0017] For example, the application providing the service other than the telecommunications service to the customer may be an itinerary application. The application information may include itinerary information. In this example, the customer's profile may be updated with the itinerary information. The updating of the customer's profile with the itinerary information may result in the telecommunications services being provided pursuant to the customer's profile as updated by the itinerary information.
[0018] The inventions, in addition, may include, a method to manage a user's telecommunications services in light of a calendar of the user. The profile information about the user's telecommunications services may be stored on a server in a data network. A calendar including entries of activities of the user also may be stored on the server. An entry in the calendar may be received with the entry indicating a future activity of the user. In response to receipt of the entry in the calendar of the future activity, the profile information about the user's telecommunications services may be changed to reflect or correspond to the future activity.
[0019] For example, the future activity may include an activity associated with a telephone number other than the directory number of the user. In this example, the profile information may be changed to include the telephone number associated with the activity so the telecommunications services provided during the activity to the user correspond to the telephone number associated with the activity.
[0020] To illustrate, the profile information may be changed to forward communications for the user received during the future activity to a number associated with the future activity. As an example, the profile information may be changed to block communications received during the future activity. The profile information also may be changed to include activation of a do not disturb feature during the future activity with respect to the directory number of the user. Further, the profile information may be changed to include a message to be provided to calls to the directory number of the user if the calls are received during the future activity. In an embodiment, in response to a request from the provider, the profile information (as changed to reflect the future activity) is provided to the provider of the user's telecommunications services.
[0021] The inventions also include a method for facilitating the narrowing of the number of possible locations of a person when the person is being sought. The facilitation includes storing profile information about telecommunications services provided to the person. The profile information may be stored on a server in a data network, and the profile information may include data about real-time use of a wireless communications unit by the person.
[0022] Access to the profile information may be allowed (or allowed only to an authorized searcher as included in the profile information) to determine whether the data about the real-time use of the wireless communications unit indicates the wireless communications unit is activated. If the data indicates the wireless communications unit is activated, a communication may be held with the wireless communications unit to determine the person's location.
[0023] In sum, the inventions described herein store profile information about a customer's communications services in such a manner that the customer may use almost any type of communications device to access the profile information, and to make changes or modifications as desired. Advantageously, the customer may use the most convenient communications device to him or her to effect changes in his or her communications services at almost any time and from almost any place so as to make the communications services best serve the needs of the customer as he or she determines.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 illustrates an exemplary wireless unit that may be used with the exemplary embodiments of the inventions.
[0025] FIG. 2 illustrates the exemplary wireless unit of FIG. 1 with additional details in the implementation of an exemplary embodiment.
[0026] FIG. 3 illustrates another exemplary wireless unit that may be used with the exemplary embodiments of the inventions.
[0027] FIG. 4 illustrates an exemplary computer display screen that may be used with the exemplary embodiments.
[0028] FIG. 5 illustrates an exemplary operating environment or architecture that may be used for implementing the exemplary embodiments.
[0029] FIG. 6 illustrates exemplary data that may be included in a customer profile in exemplary embodiments.
[0030] FIG. 7 illustrates an exemplary TCP/IP message set that may be used in exemplary embodiments.
DETAILED DESCRIPTION
[0031] Generally stated, the inventions described herein allow a customer to use almost any type of communications device to make changes in communications services provided to him or her. Advantageously, the customer may make the changes himself or herself, and the changes to the communications services are implemented without involvement by the service provider in the change process.
[0032] More particularly, the inventions allow a customer to access profile information related to communications services, view the profile information, and make changes or modifications to the profile information so as to add, delete, turn-on, turn-off, or otherwise modify the communications services. Any changes or modifications made by the customer are effective almost immediately.
[0033] Moreover, the customer may gain access to, view, and make changes or modifications to the profile information using almost any kind of device. Advantageously, a customer may use a wireless device such as a personal digital assistant (PDA), an interactive pager (IP), an interactive television (TV), a wireless telephone, or any other device having data transmission features that allow operation through the use of the wireless application protocol (WAP). A telephone or other device that may operate with the WAP is typically referred to as a WAP phone. The customer also may gain access to and make changes or modifications to profile information using a wireline device such as a telephone, a personal computer (PC), or any other similar device. The term “customer” is used herein to refer to a user (including a person or an entity) who may make use of the inventions.
[0034] For example, assume a customer subscribes to a call forwarding service on a business telephone number. Also assume the customer is going home to work and would like calls to the business telephone number to be forwarded to the home telephone number. Using the systems and methods of the inventions, the customer may change the “forwarded-to” number using almost any type of communications device, and the change may take effect almost immediately. Alternatively, the customer may specify the changes take effect at a later time/date.
[0035] FIG. 1 provides an example of how a customer may make the above call forwarding change through use of a PDA, such as the illustrated Palm VII Handheld from Palm, Inc., Santa Clara, Calif. Of course, the inventions described herein may be used with other PDAs including, but not limited to: the Cassiopeia EM-500 or E-125 from Casio, Dover, N.J.; the Sony Clie from Sony Corporation, Tokyo, Japan; the Da Vinci or the Vista from Royal, Bridgewater, N.J.; the ECHO or the PDA-256 Pen Based Organizer from Oregon Scientific, Tualatin, Oreg.; the Palm m100, m105, VIIx, Vx, Mc, or IIIxe from Palm, Inc., Santa Clara, Calif.; the iPAQ Pocket PC H3600 series or the H3100 series, or the Aero 1500 from Compaq Computer Corporation, Houston, Tex.; the jornada 720 or 680/690, or the hp 600, 300, or 200 series from Hewlett-Packard Company, Palo Alto, Calif.; the Visor, the Visor Deluxe, Platinum, or Prism from Handspring, Inc., Mountain View, Calif.; the Nino 500 or 200 from Philips CFT North America, Sunnyvale, Calif.; the Revo or Revo Plus from Psion Inc., Concord, Mass., the Mobile Companion MC 218 from Ericsson, Stockholm, Sweden, or any other suitable device.
[0036] Referring to FIG. 1 , the PDA 10 includes a graphic user interface (GUI) representing an applications manager. On the monitor 12 of the PDA 10 , the GUI displays icons 14 of applications, features, and services available for use with the PDA 10 . This display of icons 14 also may be referred to herein as the desktop of the PDA 10 . Particularly, the desktop of the PDA 10 includes an icon 16 for BellSouth Corporation (BellSouth), Atlanta, Ga. BellSouth is the communications service provider to this exemplary customer, and, in particular, the service provider of the call forwarding service to the customer's business telephone number. When the customer activates the icon 16 , the display on the monitor 12 changes to the BellSouth interface, as shown on PDA 18 .
[0037] The first display on the monitor 12 of the BellSouth interface allows the customer access to the Universal Call Control (UCC) system via a log-in prompt. The UCC system is an exemplary system that may be used to implement the systems and methods of the inventions described herein. The nomenclature of “Universal Call Control” for this exemplary system is particularly apt because the system allows a customer to control the services provided to the customer's telecommunications services, and allows the customer to have such control from almost any type of communications device. Another name for such an exemplary system may be “Multi-Mode Access” system because the customer may use one or more of multiple devices to readily access profile information so the customer's communications services may be changed as desired by the customer.
[0038] In logging-in to the UCC system, the customer may be required to provide information such as a password or other identifier for authentication and/or verification as an authorized user of the UCC system. After the customer logs-in and is deemed authorized and/or verified, if necessary, the display on the monitor 12 changes, as illustrated on PDA 20 , to show a list of the communications services to which the customer may gain access to profile information. By gaining access to the profile information, the customer may view the information, and may add, delete, turn-on, turn-off, change, or otherwise modify one or more services. The list of communications services may include services to which the customer subscribes or which otherwise may be available to the customer. The exemplary list of communications services displayed on PDA 20 includes a reference to call forwarding service.
[0039] FIG. 2 illustrates a PDA 30 , like PDA 20 in FIG. 1 , with the list of the communications services on display on the PDA's monitor 12 . The display on PDA 30 also includes a reference to the customer's business telephone number of “4043322180”. To access profile information related to the customer's call forwarding service on that telephone number, the customer activates or clicks-on the call forwarding reference. When the subscriber activates the call forwarding reference, additional displays are presented. With the additional displays, the subscriber may change the “forward-to” number from the business telephone number to the home telephone number (or any other telephone number desired by the customer).
[0040] For example, PDA 32 displays profile information related to the customer's call forwarding service. This profile information is obtained by the PDA 32 (as explained in greater detail below) through the Internet and/or the public switched telephone network (PSTN) from a service platform (server or other element) and associated with or including a database or other storage of customer profiles 34 .
[0041] Referring again to the display of profile information related to the customer's call forwarding service on PDA 32 , the customer may activate call forwarding service by clicking the “ON” reference. Should the customer change his or her mind, the customer may deactivate the service by clicking the “OFF” reference. On the display of PDA 32 , the call forwarding service is indicated as “ON” (rather than “OFF”), and three directory numbers are displayed as options for the “forward-to” number. In this example, these three directory numbers include: Home; Mobile; and Uni-Mailbox (Universal Mailbox). Typically, a customer supplies directory numbers in the profile information so these numbers may be displayed as part of the profile information as options for the “forward-to” number for call forwarding service.
[0042] As illustrated on PDA 32 , the Home directory number is highlighted, and such highlighting indicates the “forwarded-to” number for the customer's call forwarding service for telephone number “4043322180” is the home telephone number “7704432333”. Of course, the customer may choose to designate a number other than the home telephone number or the numbers presented as options on the display as the “forward-to” number. To do so, the customer simply inputs the telephone number and such input may result in a display of the telephone number as the “forward-to” number on the monitor 12 of the PDA 32 . Once the customer has made his or her choices with respect to call forwarding service, the customer may implement the choices by activating the “submit” reference on the display of the PDA 32 . The activation of the “submit” reference causes the PDA 32 again to communicate (as explained in greater detail below) over the Internet and/or the PSTN with service platform (or other element) including the customer profiles 34 . The communication with the service platform results in an update of the profile information related to the customer such that call forwarding service is turned-on and the home telephone number is included as the “forward-to” number.
[0043] As noted above, once the customer has made the desired change in the “forward-to” number, the change information is conveyed from the PDA through the Internet and/or PSTN to the service platform, web server, or other element hosting the profile information, and changes are made in the profile information. In some embodiments, the change information also may be forwarded to elements of the PSTN so information relating to the customer stored in the PSTN may be updated. When a call is received for the customer's business telephone number, the PSTN may use its profile information, or may take action by communicating over the Internet with the web server to obtain the profile information related to the customer. The profile information is then used in the PSTN to forward the call from the business telephone number to the customer's home telephone number as the “forward-to” number.
[0044] FIG. 3 provides preliminary examples of how a customer may use a WAP phone to turn-on a call forwarding service. The inventions described herein may be used with WAP phones or WAP devices such as the following: the Series 5mx16 MB or the Series 7 16 MB from Psion Inc., Concord, Mass.; the Mobile Phone R320 or R380 from Ericsson, Stockholm, Sweden; the Nokia Activ Office, ID, Security, or Alert from Nokia Mobile Internet Applications, Finland; the TalkAbout T2288, V.2288; or the Timeport P7389, P7389e, or P1088 from Motorola, Shaumburg, Ill.; or the S40 from Siemens, Munchen, Germany.
[0045] Referring to FIG. 3 , assume a customer desires to have calls to the WAP phone forwarded to his or her home telephone number. The WAP phone 56 includes a display of the BellSouth GUI for the UCC system in its monitor 57 . The WAP phone 58 includes another portion of the GUI for the UCC system on it monitor 57 , displaying a list of the communications services with respect to which the customer may have access to profile information so as to view, or to add, delete, turn-on, turn-off, change, or otherwise modify a service.
[0046] In this example, assume a customer subscribes to call forwarding service, but the service is inactive. As illustrated on the display of WAP phone 58 , there is a reference to call forwarding service in the list of services on the display. The call forwarding service includes a notation the call forwarding service is off (Call Fwd (off)). To turn-on the call forwarding service, the customer activates the Call Fwd reference. The customer has accomplished an initial step in turning-on the call forwarding service, but additional information relating to the “forward-to” number of the customer is required. In another display illustrated on WAP phone 60 , the customer is presented with a list of options for a “forward-to” or forwarding number including: Home; Mobile; and Unified Mailbox. Some embodiments of the UCC system may allow the customer to pre-designate one or more telephone numbers that may be included in a list of options for a “forward-to” number whenever the customer desires to turn-on call forwarding service. Alternatively, the customer may enter a number other than presented in the list of options. As PDA 60 shows, the Home option is activated so calls to the WAP phone are forwarded to the home telephone number.
[0047] FIGS. 1 , 2 , and 3 illustrate exemplary wireless devices (a PDA and a WAP phone) that may be used by a customer to access the UCC system so the customer may view, and add, delete, turn-on, turn-off, change, or otherwise modify communication services provided to the customer. In addition, the customer may access the UCC system through wireline devices such as a telephone, a computer, or any other suitable device.
[0048] FIG. 4 provides a preliminary example of how a customer may use a computer to view, and add, delete, turn-on, turn-off, change, or otherwise modify three exemplary services: call forwarding; do not disturb services; and customized messaging services. Initially, the customer accesses the appropriate web site for the UCC system. In the example, BellSouth is the service provider of the UCC system and provides a web site with an illustrated page 61 that allows a customer (whose telephone number is “770-555-1234” in this example) to access the UCC system by activating the Universal Call Control (UCC) reference 62 on the page 61 .
[0049] As a result of the activation of the UCC reference 62 , a window or other display 63 of information relating to the UCC system for telephone number “770-555-1234” is displayed. As with the PDA and WAP phone examples discussed above, the UCC display 63 on the computer displays profile information relating to the customer, and particularly, relating to the customer's call forwarding service. In addition, the UCC display 63 on the computer displays profile information related to two other services subscribed to and/or available to the customer: Do Not Disturb, and Customized Message. Advantageously, the UCC display 63 allows the customer to view, and add, delete, turn-on, turn-off, change, or otherwise modify any or all of the three services displayed to the customer. The profile information in the UCC display 63 is obtained by the computer through the Internet and/or PSTN from a web server hosting profile information, and in particular, customer profiles related to the UCC system. Typically, the protocol used by the computer in communicating with the web server is the hypertext markup language (HTML).
[0050] As noted above, a telephone is another wireline device that may be used by a customer to access, and add, delete, turn-on, turn-off, change, or otherwise modify communications services. Advantageously, the exemplary UCC system allows a customer to call the UCC system from any telephone. In response to the call, the UCC system “talks” to the customer and provides information related to the customer's communication services. For example, the UCC system may read the customer the present information contained in the profile information related to the customer's call forwarding service. The UCC system may then offer the customer options in adding, deleting, or otherwise changing or modifying the profile information. The customer may respond to the options orally by simply talking into the telephone and/or by inputting data through use of the telephone keypads and dual tone multi-frequency (DTMF) tones understood by the UCC system.
[0051] As explained below, the communication between the telephone being used by the customer and the UCC system is carried on through the Internet and/or PSTN. In particular, a VoiceXML (also referred to as VOXml) gateway may be included in the PSTN and/or the Internet to enable the communication. “VoiceXML” is an acronym for voice extensible markup language, and is a web development language based on XML (extensible markup language). The VoiceXML gateway enables access to and modification of web-based information through a normal voice interface. In addition, the VoiceXML gateway provides for automatic speech recognition and/or text-to-speech communication so there may be understandable communication between the customer on the telephone and the UCC system.
[0052] In sum, the inventions described herein store profile information about a customer's communications services in such a manner that the customer may use almost any type of communications device to access the profile information, and to make changes or modifications as desired. Advantageously, the customer may use the most convenient communications device to him or her to effect changes in his or her communications services at almost any time and from almost any place so as to make the communications services best serve the needs of the customer as he or she determines.
System Architecture
[0053] FIG. 5 illustrates an exemplary environment or architecture that may be used for implementing the inventions described herein and/or the UCC system including the inventions described herein. Assume a customer (also referred to as a user or a subscriber) is provided with communications service relating to the telephone number associated with the customer's telephone 64 . Also assume other communications services may be available to the customer for use on his or her telephone 64 . The specific information related to the provision and/or availability of communications services for the customer is referred to herein as the profile information related to that customer. Specific details regarding the contents of the profile information are provided below in the section entitled “System Set Up”. Suffice it to say here, that access to and the viewing of a customer's profile information reveals generally detailed information related to the communications services to which the customer subscribes, whether the services are ON or OFF; how, when, where, and with respect to whom the services are provided; whether the customer is available for communications, and if so, how the customer is available; and similar information such as the availability of other services to the subscriber, etc.
[0054] In other words, access to and the viewing of profile information provides the viewer with a profile about the implementation details related to most, if not all, of the communications services provided and/or available to the customer. Conveniently, the inventions described herein may store the profile information (as is described in detail below in the section entitled “System Set Up”) “as-a-whole” so that any part or all of the profile information may be readily accessed, viewed, changed, or otherwise modified. In some embodiments, storing the profile information “as-a-whole” may mean storing all or most of the customer's profile information in a centralized fashion such as in the same place or element. In other embodiments, storing the profile information “as-a-whole” may mean storing the customer's profile information in such a way that parts of the profile information are linked to or otherwise are in correspondence with the other parts of the profile information such that all or part of the customer's profile information may be obtained, viewed, changed, or modified.
[0055] Preferably, the customer's profile information when stored “as-a-whole” is not duplicated. In other words, the customer's profile information is typically not stored “as-a-whole” in an element(s) of the PSTN and “as-a-whole” in an element(s) of a globally-accessible computing network, such as the Internet. The storage of the profile information “as-a-whole” in the exemplary embodiments has advantages with respect to other systems that may not store such information “as-a-whole.” Profile information stored “as-a-whole” may be accessed readily from the storage location(s).
[0056] In contrast, some other methods and systems of call control available to service providers and/or customers may store the information about a customer's communications services in a “piecemeal” fashion—some information may be spread among one or more elements of the PSTN directly involved with providing services; some information may be located on servers in an intranet; still other information may be located in service platforms or elsewhere in elements of a data network such as the Internet, etc. Profile information stored in “piecemeal” fashion is not as readily accessed, viewed, and/or changed/modified as is profile information stored “as-a-whole.”
[0057] Often, other methods and systems of call control duplicate the customer's profile information whether on a “piecemeal” basis or completely duplicate, replicate, etc. the profile information of a customer. Such duplication, replication, etc. and piecemeal storage leads to problems related to keeping all of the information in synchronization or at least accurate and current.
[0058] For example, a customer may be provided with access to his or her profile information in such other systems, but such access may be access to only a single element that fails to include all of the profile information. To access other information, the customer may have to otherwise communicate or go through multiple steps and processes in accessing the information. Even if the customer succeeds in modifying his or her profile information as desired, such modifications may not be made in all of the elements necessary to effectively modify the communications services provided to the customer.
[0059] Advantageously, the inventions described herein allow a customer to use almost any type of communications device to access all of his or her profile information, to view the information, and to make changes or modifications as desired. In particular, the customer may access the profile information so as to make changes such as to add, delete, turn-on, turn-off, or otherwise modify services that are available and/or provided. For ease of reference, all of these actions (accessing, viewing, adding, deleting, turning-on, turning-off, changing, otherwise modifying, and like actions) are referred to herein as “change actions”.
[0060] As noted, profile information is stored in such a manner such that almost any type of convenient communications device may be used to access the profile information and make change actions. For example, a customer may use a wireless device such as a WAP phone 66 , a cell phone or mobile phone 68 , an interactive pager 70 , a PDA 72 , an interactive television (TV) 74 , or any other suitable device. In addition, the change actions may be implemented by a customer through use of a wireline device such as a telephone 64 , or a personal computer (PC) 75 . Generally, the communications services that may be affected by change actions by the customer are services provided through the Advanced Intelligent Network (AIN) of the public switched telephone network (PSTN) 76 . Alternatively, the communications services that may be affected by the change actions described herein may be provided by one or more entities and other than through the AIN or PSTN. For example, a service provider may use one or more communications servers 98 connected through the Internet 78 (or other data network such as a secure intranet 84 ) to provide all or part of the services and/or service logic associated with the UCC system and/or one or more of the communications services provided to the customer.
[0061] Advantageously, the change actions described herein may be used with a wide range of communications services given the present invention's storage of information related to the customer as profile information in an “as-a-whole” format rather than having the information distributed “piecemeal” and/or duplicated, replicated, etc. across multiple elements of the PSTN 76 , the Internet 78 , and/or other networks. As another example, the communications services against which the change actions may be implemented may include services provided from a network having a packet-based architecture or infrastructure because the elements of such networks (such as a “soft switch”) may directly access the web server 106 (or other platform) storing the profile information through the Internet 78 or other data network.
[0062] As noted, the change actions described herein may be used with a wide range of communications services including advanced services such as may be provided through the AIN/PSTN 76 . The present inventions are described herein with reference to a few of the advanced services with which the inventions may be used, to-wit: call forwarding service; do not disturb (DND) service; and customized message data service. Nonetheless, advanced services are not limited to these three services, and the advanced services also may include calendaring services, communications circle services, time of day/day of week (TOD/DOW) services, caller or number identification services, call diversion services, priority caller services, call waiting services, personal number services, remote event notification services such as CallerID Anywhere service, and the like.
[0063] Further, the services may include or relate to accessing, viewing, modifying, deleting, adding, transmitting, and otherwise modifying features and applications on communications devices. For example, a customer may use the inventions described herein to access and to view, add, delete, change, transmit, copy, or otherwise modify an application or service like a remote file management program on his or her PC, a PDA or interactive pager, and such as PowerPoint files or the like type of files or data that may be used by a customer on his or her wireline and wireless devices.
[0064] For additional details on the Advanced Intelligent Network (AIN) of the PSTN, the reader is referred to the commonly assigned patent to Weisser, Jr., U.S. Pat. No. 5,430,719, which is incorporated herein by reference.
[0065] The wireless devices that may be used by the customer to modify the advanced services typically operate in connection with a global data/information network such as the Internet 78 . To make the modifications from a wireless device operating on the Internet 78 to the advanced services provided to the customer's telephone 64 operating as part of the PSTN 76 , there is a connection between the Internet 78 and PSTN 76 that may be implemented through an intelligent network/internet protocol (IN/IP) gateway 82 and/or a secure intranet 84 .
[0066] FIG. 5 further illustrates some principal elements that may implement the connections among the wireless devices, other communication devices, the PSTN 76 , and the Internet 78 as they relate to the inventions described herein. For example, the WAP phone 66 operates using the WAP through a WAP gateway 86 using TCP/IP with the Internet 78 and the PSTN 76 . The wireless unit 68 operates in a wireless communications system, and particularly, communicates with a mobile switching center (MSC) 88 that may operate in a wireless intelligent network (IN) 90 and include an intelligent network/internet protocol (IN/IP) gateway 92 to the Internet 78 and the PSTN 76 . The PDA 72 may communicate through a service provider 90 and/or an Internet service provider (ISP) 96 to the Internet 78 and the PSTN 76 . The interactive TV 74 may communicate through the PSTN 76 or otherwise to the Internet 78 and the PSTN 76 .
[0067] In addition, some communications servers 98 such as third party service providers may be connected through a Secure Intranet 84 or otherwise to the Internet 78 and the PSTN 76 . As noted above, a third party service provider may be used to implement some or all of the UCC system for the service provider of the communications services. Alternatively, the communications server 98 may be used to implement some or all of the communications services provided to customers of the service provider providing communication service and/or the UCC system.
[0068] In addition, FIG. 5 illustrates that profile information about the customers of advanced services provided by a service provider may be stored in customer profiles 34 such as may be implemented in a database, table, log, server, service platform, or other suitable storage device. Typically, the profile information about a customer's services may be kept in a customer profile 34 . A customer profile 34 may include, but is not limited to, the following information:
a list of all communications services available and/or provided to the customer; for each service available to the customer, a list of the features of the service that may be affected by change actions by the customer; for each applicable service, an indication of whether the service is active (ON) or inactive (OFF); “presence” status such as any information related to how a subscriber can be reached such as an IP address, instant messaging address, e-mail address, pager address, other telephone numbers, passwords, identifiers, and the like; other information related to the customer such as files, scheduled events, calendars, log of activities, and/or communications, permissions for shareable information or public information, designation of private information, etc.
[0074] Generally, the customer's profile may be accessed by the service provider for the provision of the advanced services to the customer's designated telephone number(s). In addition, the customer's profile may be accessed by the customer to implement change actions. Further, as explained below in connection with Communications Circle (CC) services, some or all of the customer's profile may be accessed by persons or entities of the customer's communications circle. For the customer and for the persons or entities of the customer's communications circle, access to the customer's profile may be made through use of a wireless device such as a PDA or a WAP phone, or through a wireline device such as a telephone or a computer.
[0075] FIG. 5 illustrates the customer profiles 34 as connected through application servers 106 and a firewall 105 to a Secure Intranet 84 and to the Internet 78 , and through the Internet 78 or the Secure Intranet 84 to the PSTN 76 . The customer profiles 34 , however, may be connected in other ways so as to be accessible as necessary through the PSTN 76 and/or the Internet 78 . Further, the logic or programming necessary for implementation of the inventions described herein (such as the exemplary UCC system implementing some of the inventions) may be contained in application server(s) 106 such as may be included on a web server or service platform. As illustrated, the application servers 106 are shown as connected to customer profiles 34 , and such connection as being located on the same server or platform may be preferable for ease of execution of the methods and systems described herein. Nevertheless, the application servers 106 and the customer profiles 34 need not be located on the same element such as a server or platform, but may be located in distinct elements that are functionally connected whether they are elements of the Internet 78 , another data network, or the PSTN 76 .
[0076] An advantage of storing the customer profiles 34 on a web server in the Internet 78 is that such information then is universally accessible through myriad wireline and wireless devices. Whatever device the customer uses to access the UCC system, for example, and his or her customer profile, it is the same customer profile that is accessed no matter the device. The customer profile is automatically synchronized because it is updated as necessary by changes from the customer and/or from service management, and no further updates to other corresponding information are necessary.
[0077] Further, the storage of customer profiles 34 on a web server in the Internet 78 may allow third parties to write to the customer profiles or provide third party applications that may be used with the customer profiles 34 . For example, a third party may provide a calendar application used by a customer. The customer updates or modifies the calendar with an entry relating to an out-of-town visit. The calendar application may be configured to communicate with the UCC system, and particularly, with the customer profiles 34 so the customer's profile is updated as necessary with respect to the out-of-town visit.
[0078] Another example of a third party application that may be used with the inventions described herein is an itinerary application that may be maintained by a customer on a third party's server. The customer may make information related to his or her itinerary accessible to other people and through the UCC system or customer profiles 34 . Further, the itinerary application may be so sophisticated as to automatically update the customer's itinerary in cases such as flight delays, etc. The itinerary application then may update the customer's profile information in the UCC system. Colleagues of the customer who have access to his or her itinerary are provided with the most up-to-date version of the itinerary.
[0079] Of course, customer profiles 34 could be duplicated in another element in the Internet 78 and/or the PSTN 76 . To do so, the customer profiles 34 across the elements would have to be synchronized so as to provide uniformity of services. Such synchronization may require audits of the information across the elements, or other verification of proper synchronization.
[0080] As noted, FIG. 5 illustrates an exemplary environment or architecture that may be used in implementing the inventions described herein. For example, FIG. 5 illustrates an exemplary environment relating to the use of WAP phones and PDAs by customers in implementing change actions to services provided by a service provider and relating to the customer's communications services. Assume the wireline device 64 is the customer's telephone, which is served by an element of the public switched telephone network (PSTN) 76 and AIN referred to as a service switching point (SSP) 102 . To implement an advanced service for a customer, the customer's telephone number may be provisioned with a terminating attempt trigger (TAT) at the SSP 102 serving the customer's number. When a call is received for the customer's number, the TAT causes the SSP 102 to pause in the processing of the call and to request instructions from another PSTN element referred to as a service control point (SCP) 104 . The communications between the SSP 102 and the SCP 104 generally are made pursuant to the transactional capabilities application part (TCAP) and the Signaling System 7 (SS7) protocol.
[0081] The SCP 104 may include information relating to the processing of the call to the customer's telephone number, or the SCP 104 may obtain such information from another source. For example, information relating to the call may be present in a customer profile stored in the customer profiles 34 . As illustrated in FIG. 5 , the customer profiles 34 may be stored on a web server 106 or other platform connected to the Internet 78 . Thus, the SCP 104 may be configured to include applications (sometimes referred to as service package applications (SPAs)) to be able to communicate to initiate a request for information relating to the call from the PSTN 76 through the Internet 78 to the web server 106 and customer profiles 34 . The communication between the SCP 104 and the web server 106 may be made pursuant to the transmission control protocol/Internet protocol (TCP/IP). Once the SCP 104 obtains the information relating to the processing of the call, the SCP 104 provides instructions to the SSP 102 .
[0082] FIG. 5 also illustrates how a customer might use a telephone 64 to make changes to his or her customer profile. The customer uses the telephone 64 to make a call to a specified directory number that is routed through the PSTN 76 to the VoiceXML gateway. The number dialed by the customer typically maps to an internet protocol (IP) address for the server or database with the customer profiles 34 . A VoiceXML page is returned from the database to the gateway. The page includes text which is translated from text-to-speech by the gateway so the customer may hear the text. The customer responds to the speech, and the response is translated by the VoiceXML gateway and provided to the customer profiles 34 .
[0083] FIG. 5 also includes additional information on typical protocols used between and/or among the elements of the exemplary environment. For example, FIG. 5 illustrates that WAP phone 66 communicates using the wireless access protocol (WAP) with the WAP gateway 86 . The WAP gateway 86 communicates with the secure intranet 84 using TCP/IP. The secure intranet 84 also uses TCP/IP in communicating with the voice/web gateway 82 . Further, the secure intranet 84 communicates using TCP/IP through the security solution with the Internet 78 .
[0084] As noted above, the web server 106 hosting the customer profiles 34 may communicate using TCP/IP through the Internet 78 to the SCP 104 of the PSTN 76 . In addition, the web server 106 may communicate using wireless mark-up language (WML) through the Internet 78 with the WAP gateway 86 . Further, the web server 106 may communicate using voice extensible mark-up language (VoiceXML) through the Internet 78 to the voice/web gateway 82 .
[0085] As noted above, profile information relating to a customer is stored in a customer profile typically held on a web server or other platform so the customer profile may be accessed by a customer over the Internet using a wireless device such as a WAP phone or a PDA.
System Set Up
[0086] FIG. 6 includes bullet points of information related to an exemplary set up of a customer profile in the Universal Call Control (UCC) system. A customer profile, of course, may be set up in other ways, and may contain different information depending on the customer, the service provider, the architecture, the web server, the database, table, log, or registry holding the customer profile, the services available to the customer, the services subscribed to by the customer, and other factors.
[0087] In the exemplary set up of FIG. 6 , the customer profile is described as residing in a web server such as may be used with the Internet. The customer profile may be accessed via the Internet such as through use of a personal computer, through use of a telephone or other wireline device using the VoiceXML (or the like) protocol, or through a wireless device such as a PDA, WAP phone, interactive pager, or the like. Access to the customer profile may allow the customer to view the data in the customer profile and to implement change actions with respect to the data in the customer profile.
[0088] In the exemplary set up of FIG. 6 , all access to a customer profile requires a password authentication. For example, a customer may use his or her PDA to access the customer profile on a communications presence registry. After initial contact with the registry, the customer may be requested to provide a password, an identifier, or some other information that may be verified or authenticated so as to determine whether the customer is authorized to access the customer profile.
[0089] As noted above, the customer profile may be used by the service provider in providing the customer with communications services. As part of the set up of the UCC system for any particular customer, a termination attempt trigger (TAT) is set in the service switching point (SSP) serving the customer's telephone number in the PSTN. When a call is received for the customer's telephone number at the SSP, the TAT is noted and the SSP pauses in its processing of the call for instructions from a service control point (SCP). In some cases in the UCC system, the SCP may store or otherwise include the customer's profile so as to be able to instruct the SSP on how to further process the call. But generally, pursuant to the exemplary UCC system, the SCP must obtain the customer profile before the SCP can provide the SSP with instructions on how to further process the call. Thus, the SCP communicates through the Internet to the web server or other platform housing the communication presence registry, and obtains the customer profile from that registry. Once the customer profile is obtained, the SCP uses the data from the customer profile in instructing the SSP on further processing of the communication.
[0090] Further, FIG. 6 illustrates exemplary data that may be included in a customer profile relating to a customer who subscribes to three advanced services with respect to which the customer may make change actions. The three advanced services include: call forwarding service; do not disturb service; and customer message data service. The customer profile includes the customer's telephone number (also referred to as the subscriber's directory number). Typically, the customer's telephone number is used as the key in searching the communication presence registry for the customer profile relating to the customer.
[0091] For the call forwarding service, the customer profile may include an indication of the status of the call forwarding service, i.e., whether the service is active (ON) or inactive (OFF). If the customer decides to implement the call forwarding service, then calls dialed to the customer's number having the service are forwarded to another telephone number. These “forwarded-to” numbers also may be referred to as “Active Reach Numbers”. In this example, the customer has included his or her home telephone number, mobile number, and unified mailbox number as possible “forwarded-to” number. When the customer is implementing the call forwarding service using the UCC system, the customer may choose one of the listed numbers as the “forwarded-to” number. Alternatively, the customer may enter a telephone number to be used as the “forwarded-to” number.
[0092] For the do not disturb (DND) service, the customer profile may include an indication of the status of the service, i.e., whether the service is active (ON) or inactive (OFF). Generally, when the service is active, calls are not terminated to the customer's number. Some types of DND service allow a customer to specify one or more telephone numbers that may “by-pass” the DND service when the service is active so that calls from those specific telephone numbers may be terminated to the customer's telephone number. Generally, a caller who is allowed to by-pass the DND service is referred to as a priority caller. A priority caller's telephone number is referred to as a priority caller phone number. Thus, the customer profile for DND service may include one or more priority caller phone numbers. If a call is received for the customer's telephone number as originating from one of these priority caller phone numbers, then the call is put through to the customer rather than being blocked by the DND service.
[0093] For the customized message (CM) service, the customer profile may include an indication of the status of the CM service, i.e., whether the service is active (ON) or inactive (OFF). If the customer decides to implement the CM service, then the customer may specify that calls received from one or more specific telephone numbers are to be provided with a message.
[0094] Generally, a caller who is to be provided with a message per the CM service is referred to as a CM caller. A telephone number of a CM caller is referred to as a CM caller's telephone number. Thus, the customer profile for CM service may include one or more CM caller's telephone numbers. If a call is received for the customer's telephone number as originating from one of these CM caller's telephone numbers, then the call is provided with a message. The customer may specify a message to be provided to the CM callers. As indicated in FIG. 6 , the customer may compose his or her own message, and provide up to 100 characters of message (or some other predetermined number of characters). These characters of message are referred to as the CM Text and are included in the customer profile. In an alternative embodiment, the CM service may provide the customer with message options so the customer does not have to compose his or her own message. For example: the CM service may allow a customer to choose from one of the following standard messages: “Call me later”; “I'm unavailable”; etc.
[0095] As noted above, when a customer subscribes to the UCC system, a terminating attempt trigger (TAT) is provisioned with respect to the customer's telephone number at the service switching point (SSP) serving the telephone number. When a call is received for the customer's number, the SSP requests instructions from a service control point (SCP) in the PSTN. Generally, the SCP must obtain the customer profile so as to instruct the SSP on how to further process the communication. The SCP obtains this information through communication over the Internet with the web server or other platform housing the communication presence registry having the customer profile. The SCP communicates over the Internet with the web server/communication presence registry using one or more TCP/IP query/response exchanges or message sets.
[0096] FIG. 7 illustrates an exemplary TCP/IP message set such as may be exchanged between an SCP and a web server communicating over the Internet with regard to a customer who subscribes to three advanced services. These three services include: call forward service; do not disturb (DND) service; and customized message (CM) service. The left column of information on FIG. 7 begins with an exemplary specification of the types of information or data that may be included in a TCP/IP query relating to a customer from the SCP to the web server. Following the exemplary TCP/IP query, FIG. 7 also illustrates an exemplary specification of the types of information or data that may be included in a TCP/IP response corresponding to the TCP/IP query described above. The TCP/IP response is from the web server to the SCP
Exemplary Communications Service—Communications Circle Service
[0097] An example of a communications service is a communications circle (CC) service. An exemplary CC service allows a subscriber to specify person(s) or other entities who are to be included in the subscriber's communications circle. A log, table, or other structure may store information about each entity in the communications circle. The information may include a name, password, other identifier, a telephone number, a facsimile number, an e-mail address, a mobile phone number, etc. This information may be used to allow the subscriber to quickly contact the entities in his or her communications circle.
[0098] In addition, persons or other entities in the communications circle may be allowed access to some or all of the profile information in the UCC system relating to the subscriber. The access to some or all of the profile information about a subscriber in the UCC system may provide the person in the communications circle with real-time information about the subscriber, and thus, facilitate communications between the person in the communications circle and the subscriber. For example, a person in the communications circle may check profile information on the subscriber to determine whether the subscriber has turned on his or her mobile unit or interactive pager. If so, the person then may attempt to reach the subscriber at his or her mobile unit or interactive pager rather than first trying the subscriber's home or office telephone number. As a result, the person may save time in contacting the subscriber, and the subscriber at least may appear to be more readily available for communication with the person in the communications circle.
[0099] Advantageously, the person in the communications circle may access some or all of the profile information in the UCC system relating to the subscriber through use of a wireless device such as a PDA or WAP phone. For example, a person in the communications circle may use his or her PDA to access some of the subscriber's profile information in the UCC system and check whether the subscriber has turned on his or her mobile unit or interactive pager. In sum, the person in the communications circle may access some or all of the profile information in the UCC system relating to the subscriber to gain information about the subscriber. Generally, a person in the communications circle does not have the same privileges as the subscriber in implementing the change actions relating to communications services of the subscriber. Rather, the person in the communications circle typically has only “read-only” privileges relating to the profile information of the subscriber in the UCC system.
[0100] For additional details on CC services, the reader is referred to the commonly assigned patent application entitled “Shared Communication Presence Information”, filed in the United States Patent and Trademark Office on Nov. 10, 2000, assigned Ser. No. 09/709,038, and incorporated herein by reference.
[0101] In conclusion, the inventions described herein including the universal call control (UCC) systems and methods allow a customer to use almost any type of communications device to change or modify communications services provided to the customer. While the inventions have been particularly shown and described in conjunction with examples and exemplary embodiments thereof, it will be appreciated that variations in and modifications may be effected by persons of ordinary skill in the art without departing from the spirit or scope of the inventions. Further, it is to be understood that the principles described herein apply in a similar manner, where applicable, to all examples and exemplary embodiments.
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Users are provided control of their communications. Should a call be processed for a user, a text message may be automatically sent as a response to the call. The user may pre-compose different text messages. The user may also compose a custom text message. Regardless, the user's text message is automatically sent as a response to the call.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims benefit of U.S. Provisional Patent Application No. 61/930,401, filed Jan. 22, 2014, which is hereby incorporated by reference in its entirety.
BACKGROUND
This invention pertains to construction and more particularly to expansion of existing houses and the like.
Many houses constructed during the post-World War II housing boom are single story dwellings. While the ‘ranch style’ house was popular then, now, with the price of land at a premium and consumers desiring larger, more spacious houses, multi-story dwellings are becoming the standard. Multi-story houses benefit not only the inhabitants but owners as well. The additional stories increase the size and the value of the house commensurately.
Financially it often is impractical to buy an existing single story house, demolish it and rebuild a new multi-story dwelling; rather, it would be ideal if the existing structure could be modified to increase its size. If the land size is large enough, it would be a simple matter to just build the house out farther but, many times, the house is already at a maximum size allowed per regulated footprint and setbacks for the land on which it resides.
Therefore, the only way to keep the existing structure and increase the size of the dwelling is to add additional levels. Converting a single story structure to a two-story effectively doubles the size of the living space and markedly increases the value of the structure. Traditionally, the addition of levels to an existing structure is an expensive and time consuming process that often yields minimum returns on investment. A new system and method for adding levels to an existing structure at a minimal cost and time would be most beneficial.
Currently, the process of adding an additional level to an existing structure requires the complete removal and destruction of the roof. The roof must be removed to allow the new level to be constructed and to allow access for the reinforcement of the existing structure. Reinforcement of the existing structure must often be done since the initial construction was not done in a manner to support the non-existent additional level(s). Once reinforced, the additional level(s) could be constructed on top of the existing structure. Finally, a new roof structure can be formed to complete the remodeling process. The removal and reconstruction of the roof structure adds additional time and cost to the process of adding the new level(s).
The invention enables a method for raising a structure with a jacking system for installation of a building element, which comprises one or more of vertical jack assemblies and a system to control the rate at which the structure can be elevated by the jack assemblies independently of each other jack assembly.
An object of this invention is to reduce the time and cost associated with the addition of new level(s) to an existing structure. The invention preserves the existing roof structure, creates a new system to rapidly construct the new level on the existing structure and utilizes pre-manufactured components to further decrease the cost and improve efficiency.
SUMMARY OF THE INVENTION
The invention is a system and method capable of lifting an entire structure, the roof of a structure or some portion of a structure. The invention uses a system of frames about the periphery of the structure to which jack members are mounted. The jack members extend to raise the desired structure or portion thereof. A control system is also provided to manage the lifting process; the control system monitors the lifting process and controls the rate of the extension of the jack members.
The lifting system and method disclosed has many advantages over the previous systems and methods. The invention does not require the use of specialized lifting beams to lift the structure or parts thereof. Additionally, since the installation of the system is within the footprint of the structure, there is minimal clearance required about the structure to be lifted.
When used on a roof structure, the system and method preserves the existing roof by lifting the roof vertically to install an additional story in the structure below. The vertical lifting also minimizes the potential for damage to the roof structure during the construction process since the roof is not moved laterally which can shift or damage the roof structure. Typically when a roof is removed to install an additional level in the structure, the roof requires reinforcement before the lifting process can begin, with the invention, the roof does not require such strengthening.
BRIEF DESCRIPTION OF DRAWINGS
FIGS. 1-8 are conceptual drawings showing in perspective view the steps of enlarging a building structure such as a single-story house by raising the roof structure, adding floor structure and installing walls for a second story under the raised roof, using a jacking system according to an embodiment of the invention.
FIG. 9 is a side elevation view of the wall jacking installation as initially installed on a side of a building structure and coupled to the roof structure.
FIG. 10 is a side elevation view of the wall jacking system of FIG. 9 following an initial lift of the roof structure and placement of lateral bracing.
FIG. 11 is a side elevation view of the wall jacking system of FIG. 10 following a final lift of the roof structure, extension of the lateral bracing and installation of new second story floor framing.
FIG. 12A is a cross-sectional view through the building wall of FIG. 9 showing details of connection of the jacking system to the sill plate and the roof structure.
FIG. 12B is an enlarged view of the connection of FIG. 12A to the roof structure.
FIG. 13 is a cross-sectional view through the building wall of FIG. 10 showing details of connection of the upper portion of the jacking system and lateral bracing to the upper portion of the existing wall and to the roof structure.
FIG. 14 is a top plan view of the drive element 1400 used on the bottom rail for driving one of the wall jacks in FIGS. 9-13 .
FIG. 15 is a side elevation view of the drive element 1400 of FIG. 14 .
FIG. 16 is a cross-sectional view of the drive element 1400 of FIG. 15 .
FIGS. 17A-17C are side views of non-metallic slider blocks in the vertical lifting elements 230 .
FIGS. 18A-18D are cross sectional views of non-metallic slider blocks in the vertical lifting elements 230 of FIGS. 17A-17C .
FIG. 19A is a perspective view of the non-metallic lifting block 241 . FIG. 19B is a side elevation view of the lifting block 241 . FIG. 19C is a top plan view of the lifting block 241 .
FIG. 20A is a side view of the diagonal cross-brace outer tube and ‘lock pin block’ of FIGS. 11 and 13 .
FIG. 20B is a top view of the diagonal cross-brace outer tube and ‘lock pin block’ of FIGS. 11 and 13 .
FIGS. 21 and 22 are conceptual drawings showing in perspective view the steps of raising an entire building with a jacking system for repair or replacement of sill plates, supporting walls, and or footings, using a jacking system according to an embodiment of the invention.
FIG. 23 is an enlarged side elevation view of the drive element 1400 located between the floor joists for lifting an entire building.
FIG. 24 is a cross-sectional view of the drive element 1400 of FIG. 23 .
FIG. 25A is a side elevation view of the jacking system showing upper and bottom horizontal rails in preparation of securing diagonal bracing and lifting an entire building; FIG. 25B is a plan view of the bottom rail; and FIG. 25C is an enlarged view of FIG. 25B showing the interconnection to the vertical lifting element.
FIG. 26 is a side elevation view of the jacking system showing diagonal bracing secured to upper and bottom horizontal rails in preparation of and lifting an entire building.
FIG. 27 is a side elevation view showing placement of diagonal bracing to provide lateral stability of lifted structure while at same time providing sufficient space to excavate, prep and pour new footings and foundation walls.
FIG. 28 is a cross sectional view showing general location of threaded rod support blocks for the jacking system when raising either a roof structure or raising an entire building.
FIG. 29 is side elevation view showing general location of threaded rod support blocks for the jacking system when raising either a roof structure or a complete structure as shown in FIG. 25A .
FIGS. 30A-30D are cross sectional views of a vertical lifting jack assembly showing the threaded rod support blocks at various sections in FIG. 29 .
FIGS. 31A-31B show transverse sectional views of the tubing section in its normal location to keep the threaded rod support blocks in place.
FIGS. 32A-32B show transverse sectional views of the tubing section in its raised position to either install or replace the threaded rod support blocks.
DETAILED DESCRIPTION
FIG. 1 shows a single story structure 100 to which an additional level(s) will be added. The roof 102 sits atop the main section 104 which is supported by the foundation sill plate 106 .
FIG. 2 shows the structure of FIG. 1 with the lifting rails 200 , 210 , and 220 installed around the periphery of the structure 100 . The bottom lifting rail 200 is fastened to the sill plate 106 of the structure 100 and will serve as the base of the lifting system. The middle lifting rail 210 is attached about the upper periphery of the structure 100 and below the roof structure 102 . Middle rail 210 is attached through the sides of the house and into the vertical studs of the main section 104 . The upper lifting rail 220 is installed about the lower periphery of the roof 102 of the structure 100 . The rail 220 is attached to the sill of the roof and/or attached to the ends of the rafters of the roof 102 .
FIG. 3 shows the rails 200 , 210 and 220 installed on the structure 100 and roof 102 . The rails are interconnected by vertical lifting elements 230 . The vertical lifting elements 230 will exert an upward force on upper rail 220 that will cause the roof structure 102 to lift up and away from the structure 100 . In addition to the vertical lifting elements 230 , extendible cross-braces 240 are installed between rails 210 and 220 . The bottoms of cross-braces 240 are anchored to brackets affixed to the middle rail 210 , the extendible end of the cross-braces 240 are attached to the rail 220 by a bracket, the upper and lower connection points allowing the end of the cross-brace to rotate about the connection points in the vertical plane of the structure.
FIG. 4 illustrates the initial phase of the lifting process. The roof 102 is attached to the upper rail 220 that has been raised via the vertical lifting elements 230 to a first position an initial distance above the structure 100 . As the roof structure 102 is raised, the ends of the cross-braces 240 extend and the ends rotate about their respective pin joints thereby providing lateral stability to the roof structure that has been separated from the perimeter walls of the house. The cross-braces 240 are allowed to automatically extend as the structure 102 is raised, but are prevented from retracting by an internal retaining element. The internal retaining element is a feature that allows the cross-braces to act as compression only members that will provide lateral stability of the existing roof and wall structure during lateral loads from construction, wind or seismic loads. The cross-braces are retractable by a user actuating a release mechanism that releases the internal retaining element thus allowing the cross-braces to retract automatically or by the user.
FIG. 5 shows the installation of the additional floor 502 atop the main section 104 , which formerly supported the roof 102 . The roof 102 is still at the initial position as lifted to in FIG. 4 . This initial position is at a minimum height necessary to allow the installation of the floor 502 .
FIG. 6 illustrates the second phase of the lifting process. The roof 102 , attached to rail 220 , has been lifted higher than the final height of the new walls. Extendible cross-braces 240 have extended further to continue to provide lateral stability of the roof structure 102 and the existing walls 104 .
FIG. 7 shows the installation of the new walls 504 , framing the periphery of the new level atop floor 502 . Once the walls 504 are completed, the roof structure 102 is lowered down upon the new walls and reattached atop the new walls 504 to complete the two-story structure.
FIG. 8 shows the completed two-story structure with the lifting system and equipment removed from the building. The structure now has an additional story added to the pre-existing structure at minimal cost and time spent.
FIG. 9 is a schematic showing details of the lifting system attached to the structure 100 . The bottom lifting rail 200 is attached to the sill plate 106 . The bottom lifting rail 200 has holes 202 spaced regularly along the length of the rail 200 . Multiple bottom rail elements 200 are interconnected to encircle the perimeter of the sill plate 106 . The rail elements 200 are connected to one another using a butt joint 910 . The rails 200 have holes 202 A at each end. The butt joint 910 is inserted inside the end of a rail 200 and is locked in place by inserting retaining pins in the end holes 202 A and through the holes on the butt joint. The end holes 202 A are spaced to ensure that the spacing of the holes 202 is maintained across the interconnection at the butt joint 910 . The interlocked elements of the lower rail 200 form a rigid framework that encircles the sill plate 106 and will act as the lower structure of the lifting system.
The top lifting rail 220 is attached to the roof structure 102 . The top rail 220 is attached to the structure 102 via the ends of the roof rafters. Rail 220 encircles the roof structure 102 and will support the structure during the lifting process. The roof normally provides structural integrity to the structure 100 . It acts as a diaphragm and holds the wall together and, in turn, the walls provide the rigid base on which the roof 102 sits. If separated from the structure 100 , the roof structure 102 has a tendency to splay out and deform from the original shape, when this occurs, the roof is typically beyond salvage and must be rebuilt. Using this method and system, the rail 220 will maintain the form and size of the roof structure 102 when it is separated from the structure 100 . This will ensure that the roof 102 can be reattached to the new walls once they are installed atop the main section of the existing structure. The reuse of the existing roof structure 102 is more cost and time efficient than the previously existing method in which the majority of the structure would have to be rebuilt or time consumingly reshaped to fit.
The middle lifting rail 210 is attached around the upper periphery of the main portion 104 of the structure 100 . The middle rail 210 is attached to the studs of the house. Depending on the strength of the existing structure, the middle rail 210 can be attached to every stud or at some other regular or irregular interval. As with the bottom rail 200 , middle rail 210 is made of individual elements that are interconnected using butt joints 910 . Rails 210 also have the same hole pattern as that of rail 200 and 220 , in this manner, the rail combination has spaced set of vertically arrayed hole patterns. Similar to the top rail 220 , the middle rail 210 will maintain the dimensions of the main section 104 during the lifting process. With the roof removed, the walls are not braced for out of plane loads and would have a tendency to warp and move out of position, if not properly restrained in their position. This would necessitate a laborious process of “truing” or straightening the walls back to their original positions before the roof could be attached. The retention of the original dimensions and shape of the main section 104 during the lifting process allows the quick installation of a second story floor and additional walls atop and then the reattachment of the roof with minimal time and cost.
The vertical lifting elements 230 are attached at regular or irregular intervals around each side of the house and interconnect the rails 200 , 210 and 220 . Elements 230 are affixed to each rail using the holes 202 disposed on each rail. The system of holes on each rail allows for the quick attachment and removal of the lifting elements 230 , additionally, the vertically-aligned pattern of holes makes it easy for someone installing the lifting elements 230 to space them properly and position them vertically around the periphery.
FIG. 10 shows the roof lifted to the initial position. The extendible, diagonal cross-braces 240 have been installed. The upper ends of the diagonal cross-braces may be attached at a common root point 1002 or at separate locations on the top lifting rail 220 . The common root point 1002 may be a single bracket or separate brackets attached to the top rail 220 , the cross brace ends are attached to the bracket(s) by pin joints 1004 . The lower ends of the cross-braces 240 are affixed to the middle lifting rail 210 at points 1006 spaced equidistant from the root point 1002 . The connection points 1006 are brackets similar to or the same as bracket 1002 , and attach the lower end of the cross-brace 240 to the middle rail 210 . The lower end of the cross-brace 240 attaches to the bracket 1006 at a pin joint 1008 . The use of the pin joints allows the cross braces to rotate about the joint as the angle between the cross-brace 240 and middle rail 210 changes due to the lifting of the roof 102 . As the roof is lifted, the cross-braces 240 will automatically extend and lock in position. In this manner, they provide lateral stability to the roof structure 102 . The cross-braces 240 can utilize a ratcheting mechanism that allows them to be extended but will not allow them to be shortened until an external operation releases the ratchet mechanism and allows the extension pieces of the cross-braces to retract back into the main body tube of the cross-braces 240 . The locking extension action can also be achieved by shaped frictional rings that allow for free extension but are locked into position upon application of back pressure. There exists many ways to achieve the locking extension mechanism and are well known to those skilled in the art. Each face of the structure would have at least one set of the cross braces installed.
As can be seen in FIG. 11 , the vertical lifting elements 230 are telescoping. The main body 232 of the lifting element 230 is affixed at its top end to the middle lifting bar 210 , while the bottom end is affixed to the lower lifting bar 200 . The extension portion 234 is moveable within the main body 232 and connects to the top rail 220 and exerts the upward lifting force and motion to raise the roof structure 102 above the main structure 104 . The extension portion 234 may be a single telescoping piece that moves within the main body 232 , or may contain multiple telescoping pieces that nest within each other. Also seen in FIG. 11 are the extension elements 242 of the cross-braces 240 . These are one-way extendible, meaning the extension elements will extend from the cross-braces 240 as the roof structure 102 is raised by the lifting elements 230 , but will not automatically retract back within the cross-brace 240 unless an external manipulation is performed to release them. This provides lateral stability to the roof structure 102 and the existing walls 104 .
FIG. 12A is a detailed schematic view of the vertical lifting element 230 attached to the top, middle and bottom lifting rails 220 , 210 and 200 . The bottom lifting rail is attached to the sill plate via brackets 204 that are mounted to the sill plate 106 via mechanical fasteners. Before adding the additional level(s) to the structure, a study must be carried out to determine if the existing foundation and sill plate 106 is adequate to support the additional load. If the foundation and sill plate is found to not be adequate, it must be retrofitted or reinforced before the lifting system can be installed and used. The bracket used to mount the lower lifting rail to the sill plate can be integrated into the bracket that holds the vertical lifting element to the lower lifting bar 200 or it may be a separate piece. It is advantageous to use an integrated bracket that performs both functions as the added strength due to mounting of the bracket to the sill plate will help support the loads exerted on the vertical lifting element 230 as the roof load is elevated. The top of the lifting element main tube is attached to the middle rail 210 . The middle rail 210 is attached to the studs of the structure 100 by a bracket 214 affixed by mechanical fasteners like the foundation bracket. Like the foundation bracket 204 , the middle rail bracket 214 can be similar, attaching both the rail to the stud and the vertical lifting element to the rail. The top of the extension portion 234 of the vertical lifting element 230 is attached to the existing rafters or trusses with a bracket 222 attached to the top rail 220 and the perimeter roof structure 102 as better shown in FIG. 12B . At gable ends, the top rail 220 attaches to the end rafter or truss top chord just below the roof sheathing similar to the method that the mid rail 210 is attached to the exiting walls 104 .
FIG. 13 is a detailed schematic view of a wall cross-section showing the detail of the diagonal cross-brace element 240 . The bottom end of the element 240 is attached to the middle rail by a bracket 244 . Extending from the bracket is a reinforced strap 248 that is further screwed to a wall stud of the building to provide a more secure and unmoving mounting point for the cross-brace 240 . The upper end of the cross-brace 240 is attached to the top rail via a bracket 246 .
FIG. 14 is a top view detailing the mounting of the vertical lifting element drive motor. The drive element 1400 is attached to the lower mounting rail and lower mounting rail bracket. A transformer supplying power to the drive element can be mounted on the lower rail at a nearby position using a set of the pre-drilled holes 202 .
FIG. 15 shows a detailed side view of the drive element 1400 and bracket 107 A and FIG. 16 shows a detailed top view of the drive element 1400 showing lifting rod 1406 in cross-section. The drive element 1400 has a drive motor 1402 that is attached to the drive gear box 1404 that drives a self-locking Acme threaded lifting rod 1406 . Each vertical lifting element 230 has a drive block attached to the threaded lifting rod 1406 that elevates the extending portion 234 as the threaded lifting rod 1406 is rotated. The extending portion 234 is driven a pre-determined height and then pinned at that height via a cotter pin that slides through the main tube and extending portion. For lifting elements that have multiple extending portions, each telescoping portion is pinned through the surrounding tubes to hold them in their extended positions. The internal lifting element is driven upwards by a drive block which engages the thread of the threaded lifting rod 1406 . Once the internal drive block has reached the top of the threaded lifting rod 1406 , the extending portions of the vertical lifting elements 230 are pinned at that height and the internal drive block is lowered as the threaded lifting rod 1406 is reversed and lowers back to the bottom of the lifting element 230 . There a different and second drive block reengages the threaded lifting rod 1406 and is again driven upward, repeating the lifting process. By having equal lengths of internal lifting element(s) in each vertical lifting element 230 , ensures that all the vertical lifting elements 230 extend to an equal height with each lifting process. Thus the roof structure 102 does not get warped or broken and the weight stays evenly distributed across each of the vertical lifting elements. Each drive element 1400 is attached to a central driving control panel that ensures each drive element 1400 is driven the amount required to maintain the roof structure level and a controlled lift. There exist other lifting options available that can be used in this system, such as hydraulic pistons or jacks.
FIGS. 17A-17C is an exploded side view of non-metallic slider blocks 241 in the vertical lifting element 230 . The vertical lifting element 230 is composed of an inner element 230 A, a middle element 230 B and a main element 230 C. The non-metallic slider blocks 241 are secured in place by a projection that engages holes in the members of the telescoping vertical lifting element 230 . The engagement holes on the various elements 230 A, 230 B and 230 C are of two differing sizes to accommodate two differently sized non-metallic slider blocks 241 A and 241 B. The nonmetallic slider block 241 A has a sliding surface diameter nearly the width of a face of the inner element 230 A. The same slider block 241 A is also disposed at an end of the element 230 B that inner element 230 A extends outwards from an opposite end of the element 230 B, slider block 241 B is disposed, having a diameter nearly the width of the face of the middle element 230 B. Main element 230 C has a slider block 241 B disposed at an end. The non-metallic slider blocks align the elements 230 A, 230 B and 230 C of the lifting element 230 , which prevents the various elements from rubbing or twisting inside of each other during the lifting process. The outer shape of the non-metallic slider blocks 241 can be round, square, rectangular or a profile not here described. The shape of the projection on the non-metallic slider blocks 241 can be round, square, rectangular or a profile not here described. The non-metallic slider blocks are ideally made of a high molecular weight plastic having a low friction coefficient, but sufficient material strength to resist compression.
FIGS. 18A-18D is a cross sectional view of the non-metallic slider blocks 241 in the nested vertical lifting elements 230 . The projections on the non-metallic slider blocks 241 are shown engaging holes in the members of the vertical lifting elements 230 .
FIG. 19A is a perspective view of a circular example of the non-metallic lifting block 241 . The block has a large diameter 243 and a small diameter 245 . The flat face of the large diameter 243 is the friction face that contacts a portion of the lifting element 230 as it slides. The small diameter 245 sits in holes in the lifting elements 230 and provides restraint to hold the nonmetallic slider block 241 in place on the lifting element. FIG. 19B is a side elevation view of the non-metallic slider block 241 . FIG. 19C is a plan view of the non-metallic slider block 241 .
FIG. 20A is a side view and FIG. 20B is a top view of the diagonal cross-brace outer tube and a separate ‘lock pin block’ item 258 . The diagonal cross-braces 240 can utilize an internal ratcheting mechanism here defined as a ‘lock pin block’ item 258 . The ‘lock pin block’ item 258 engages with the corresponding indentations of the inner tube of the diagonal cross-braces 240 , as shown in section G-G. This allows the diagonal cross-braces 240 to be extended but does not allow the diagonal cross-braces 240 to be shortened until an external operation releases the ratchet mechanism or ‘lock pin block’ item 258 . The release of the ‘lock pin block’ item 258 enables the inner tubes of the cross-brace to retract back into the outer body tube of the cross-brace 240 . The spring loaded index plunger, as shown in FIG. 20A , is an example device that may be used to index and restrain an object, in this case, the removable ‘lock pin block’ 258 .
FIG. 21 shows a complete structure 100 which may be lifted for repair or replacement of sill plates, supporting walls, footings and other structural features. Additionally, the building may be lifted to add an additional level(s) to the structure. In a further embodiment, the structure may be lifted and the roof structure may be, simultaneously or separately, lifted to accomplish the desired construction tasks.
FIG. 22 shows the structure of FIG. 21 raised with the telescoping wall jacks 230 , with diagonal braces 240 , installed to avoid wracking.
FIG. 23 shows a detailed side view of the drive element 1400 and bracket 107 A. FIG. 24 shows a detailed top view of the drive element 1400 of FIG. 23 . The drive element 1400 has a drive motor 1402 that is attached to the drive gear box 1404 that drives a self-locking Acme threaded rod 1406 . Each vertical lifting element 230 has a drive block attached to the threaded rod 1406 that lowers the extending portion 234 as the threaded lifting rod 1406 is rotated. The extending portion 234 is driven a pre-determined length by an internal drive block and then pinned via a cotter pin that slides through the main tube and extending portion. For lifting elements that have multiple extending portions, each telescoping portion is pinned through the surrounding tubes to hold them in their extended positions. The internal lifting element is driven downwards by a drive block which engages with the threads of the threaded rod 1406 . Once the internal drive block has reached the end of the threaded lifting rod 1406 , the extending portions of the vertical lifting elements 230 are pinned. The internal drive block is returned to an initial position as the threaded rod 1406 is reversed. Once the drive block is returned, a different and second drive block is inserted and reengages the threaded rod 1406 . The new drive block is driven downward, repeating the lifting process. Having equal lengths of internal lifting element(s) in each vertical lifting element 230 ensures that all the vertical lifting elements 230 extend an equal length with each lifting process. In doing so, the building structure 100 does not get warped or damaged since the weight stays evenly distributed across each of the vertical lifting elements. There exist other lifting options available that can be used in this system, such as hydraulic pistons or jacks.
Each drive element 1400 is attached to a central driving control panel that ensures each drive element 1400 is driven, either independently or in unison, such that structure remains level and lift is controlled. An example control means could include monitoring of the amperage drawn by each drive element 1400 . A method of monitoring the amperage drawn by each of the drive elements 140 can be an ammeter attached to each drive element. The amperage drawn by each drive element 1400 is correlated to the amount of torque each drive element 1400 is exerting to lift the structure. Should the amount of amperage drawn by a drive element 1400 spike, it can be indicative of unequal loading which could mean that the load is now unbalanced or proceeding at unequal rates. The controller can vary the amount of power and lift rate of each of the drive elements 1400 to rebalance and relevel the structure.
Alternative control and measurement systems can be used, such as load cells on each drive element, voltage monitoring of the drive elements 1400 and/or the system as a whole or others, level and/or alignment sensors on the jacks and/or structure, or some combination thereof. An example alignment sensor system is a system of sensors that relay the relative position and/or extension length of a wall jack member in relation to the other wall jack members. Aligning the lifting of each of the wall jack members lifts the structure in a stable and balanced state as desired.
FIG. 25A is a schematic side elevation showing details of the lifting system attached to the structure 100 . The top lifting rail 220 is attached to the structure 100 at the underside of the floor joists as also previously shown in FIG. 23 . The bottom lifting rail 200 has holes 202 spaced regularly along the length of the rail 200 . Section A-A is identified to further define method of attachment of the bottom rail 200 .
FIG. 25B is a schematic top view of the lifting system and identifies that both top lifting rail 230 and bottom rail 200 are attached to the same side of the outer element 230 C of the vertical lifting elements 230 .
FIG. 25C shows cross Section A-A identifying bracket 247 has an integral locating pin 248 that engages in a hole in the outer element 230 C of the vertical lifting elements 230 . Hardware connects bracket 247 to the bottom rail 200 through holes 202 A, thereby rigidly linking the vertical lifting elements 230 together with top rail 220 . Multiple bottom rail elements 200 are interconnected to form a rigid framework that links together predetermined vertical lifting element assemblies 230 and acts as the lower structure of the lifting system. The bottom rail elements 200 are connected to one another using a butt joint 910 . The rails 200 have holes 202 A at each end. The butt joint 910 is inserted inside the end of a rail 200 and is locked in place by inserting retaining pins in the end holes 202 A and through the holes on the butt joint. The end holes 202 A are spaced to ensure that the spacing of the holes 202 is maintained across the interconnection at the butt joint 910 .
FIG. 26 shows a detailed method of applying extendible cross-braces 240 between ‘pairs’ of wall jacks 230 to provide lateral stability of lifted structure. The spacing of the wall jacks 230 and cross-braces 240 provides sufficient space to accomplish the desired construction steps. With the structure raised, workers can excavate, prep and pour new footings and foundation walls and or add an additional level(s) under the original level. The ‘lock pin block’ item 242 is shown on each extendible cross-braces 240 .
FIG. 27 shows a detailed method of applying extendible cross-braces 240 between predetermined ‘pairs’ of wall jacks 230 to provide lateral stability of lifted structure while providing access required to excavate, prep and pour new footings and foundation walls.
The vertical lifting elements 230 are attached at regular or irregular intervals around each side of the house, and other predetermined locations to interconnect the rails 200 , and 220 . Elements 230 are affixed to each rail using the holes 202 disposed on each rail. The system of holes on each rail allows for the quick attachment and removal of the lifting elements 230 . Additionally, the vertically-aligned pattern of holes makes it easy for someone installing the lifting elements 230 to space them properly and position them vertically around the periphery or other predetermined locations.
FIG. 28 shows a detailed schematic view of a wall cross-section showing the detail of the method using the tube 230 D to provide and retain replaceable threaded rod supports 249 thereby limiting deflection due to the applied vertical load when lifting either a roof structure or an entire building.
FIG. 29 shows a detailed schematic side view of a structure with Section B-B and Section D-D identified to show the detail of the method to provide and retain replaceable threaded rod supports 249 using the tube 230 D.
FIG. 30A shows a detailed cross Section C-C of outer element 230 C of lifting element 230 showing detail of the method to provide replaceable threaded rod supports 249 . Location where cross Section C-C is taken is shown in FIG. 32B . Location where cross Section C-C is taken is shown in FIG. 32B with the middle element in the raised position when lifting a roof structure, and the middle element in the lowered position when lifting an entire structure.
FIG. 30B shows a detailed cross Section B-B of outer element 230 C of lifting element 230 showing the detail of the method to provide and retain replaceable threaded rod supports 249 . Location where cross Section B-B is taken is shown in FIG. 29 .
FIG. 30C shows a detailed cross Section C 1 -C 1 of outer element 230 C and middle element 230 B of lifting element 230 showing detail of the method to provide replaceable threaded rod supports 249 . Location where cross Section C 1 -C 1 is taken is shown in FIG. 32B with the middle element in the lowered position when lifting a roof structure, and in the middle element in the raised position when lifting an entire structure.
FIG. 30D shows a detailed cross Section D-D of middle element 230 B of lifting element 230 showing detail of the method to provide replaceable threaded rod supports 249 . Location where cross Section D-D is taken is shown in FIG. 29 with the middle element 230 B in the raised position when lifting a roof structure, and the middle element 230 B in the lowered position when lifting an entire structure.
A drive block attached is to the threaded lifting rod 1406 that elevates the extending portion 234 B when raising a roof structure or pushes downward extending portion 234 B when raising an entire structure as the threaded lifting rod 1406 is rotated. The extending portion 234 B is driven a pre-determined distance and then pinned at that location via a cotter pin that slides through the main tube and extending portion. After the inner extending portion 234 B is pinned, replaceable threaded rod supports 249 are installed through holes in outer tube 230 C of lifting element assembly 230 . A length of tubing 230 D is utilized to secure and retain replaceable threaded rod supports 249 . One or more than one set of replaceable threaded rod supports 249 and section of tube 240 D may be used per lifting element assembly 230 .
FIG. 31A shows detailed cross Section E-E of lifting element assembly 230 showing the detail of the method to retain the replaceable threaded rod supports 249 with section of tubing 230 D in its normal position. Two differently sized non-metallic slider blocks 241 A and 241 B are inserted in holes in tube section 240 D, and make contact with replaceable threaded rod supports 249 , thereby serving as a ‘stop’ and limits the vertical travel of tube section 240 D. FIG. 31B is a detailed cross section of lifting element assembly 230 showing the detail of the method to retain the replaceable threaded rod supports 249 with section of tubing 230 D in its normal position. FIG. 31B identifies where Section E-E is taken.
FIG. 32A shows detailed cross Section F-F of lifting element assembly 230 with section of tubing 230 D in its raised position to install or replace replaceable threaded rod supports 249 . FIG. 32B identifies where Section F-F is taken.
The various elements of this apparatus can be made of steel or other suitable materials. These can include aluminum and other metals. Selection of materials is based on the likely loads each element would encounter during the lifting process. In this manner, certain materials can be chosen for their compressive or tensile strength and weight. Composite materials can also be used; the lightweight and high strength of these materials may be optimal, but must be weighed against the cost of manufacturing the various elements. Additionally, each element of this apparatus is reusable, making this system easy to install and remove on multiple building sites. Due to the modular nature of this system, it can be expanded to fit a building of many sizes.
Having described and illustrated the principles of the disclosed technology in a preferred embodiment thereof, it should be apparent that the disclosed technology can be modified in arrangement and detail without departing from such principles. We claim all modifications and variations coming within the spirit and scope of the following claims
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A system and method for raising a structure, or part thereof, the system comprising vertical jack members connected and disposed about a rail system attached about the periphery of the structure. The vertical jack members comprise an outer sleeve and a slidable inner portion that is driven vertically by a jack screw and drive block. Extensible diagonal cross-braces stabilize the jack members and structure being raised.
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This is a continuation of application Ser. No. 176,600, filed Aug. 8, 1980, now abandoned.
BACKGROUND OF THE INVENTION
The present invention is directed towards an improved cooling system for a gas turbine. More particularly, the present invention is directed towards an improved cooling system which employs flow-resistance devices to meter coolant into a plurality of platform and air foil coolant channels located in the buckets of the gas turbine.
The cooling system of the present invention is utilized in connection with a gas turbine of the type including a turbine disk mounted on a shaft rotatably supported in a casing and a plurality of turbine buckets extending radially outward from the disk. Each of the buckets includes a root portion mounted in the disk, a shank portion extending radially outward from the root portion to a platform portion, and an air foil extending radially outward from the platform portion. During operation, the buckets receive a driving force from hot fluids moving in a direction generally parallel to the axis of the shaft and convert this driving force to rotational motion which is transmitted to the shaft via the turbine disk. As the result of the relatively high temperatures of the hot fluid, a significant amount of heat is transferred to the turbine buckets. In order to remove this heat from the bucket structure, the prior art has developed a large variety of open-liquid cooling systems. Exemplary of such systems are U.S. Pat. No. 3,658,439, issued to Kydd; U.S. Pat. No. 3,804,551, issued to Moore; U.S. Pat. No. 4,017,210, issued to Darrow; and U.S. application Ser. No. 044,660, filed June 1, 1979, in the names of C. M. Grondahl and M. R. Germain, now U.S. Pat. No. 4,244,676. the disclosure of which is incorporated herein by reference.
Open circuit liquid cooling systems are particularly important because they make it feasible to increase the turbine inlet temperature to an operating range of from 2500° F. to at least 3500° F., thereby obtaining an increase in power output ranging from about 100%-200% and an increase in thermal efficiency ranging to as high as 50%. A primary requirement of open circuit liquid cooling systems is that the liquid coolant be evenly distributed to the several platform and air foil coolant channels formed in the bucket. Such a distribution is difficult to obtain as a result of the extremely high bucket tip speeds employed, resulting in centrifugal fields of the order of 25,000 G.
To obtain an even flow of coolant liquid throughout the several coolant channels, the prior art systems, as exemplified by U.S. Pat. Nos. 3,804,551 and 4,017,210, supra, utilize weir structures which meter the amount of coolant liquid supplied to each individual channel from pools of coolant liquid formed in the platform portion of the bucket. Particularly, these systems introduced liquid coolant into each end of a trough formed in the platform portion of the bucket such that liquid coolant flows in a direction parallel to the axis of rotation of the turbine disk from each end of the trough. The liquid coolant flows over the top of an elongated weir which performs the metering for each channel.
In order to perform satisfactorily, it is critical that the tops of these weirs be parallel to the axis of rotation of the turbine within a tolerance of several mils. If this relationship is not maintained, all of the coolant liquid will flow over the low end of the weir and, consequently, some of the coolant channels formed in the platform and air foil of the bucket will be starved for coolant.
In an effort to overcome the foregoing problem, the invention described in U.S. Pat. No. 4,244,676 utilizes V-shaped notched weirs which are less sensitive to variations in the orientation in the metering channels than the prior art weirs. While this invention represents an improvement over the prior art weir structures, all weir metering devices depend upon a uniform depth of water above the crest of each weir to ensure an equal supply of cooling water to the individual bucket cooling channels. While the V-shaped notched weirs make the accuracy of flow metering less sensitive to manufacturing tolerances and in-service distortion, it is still affected by waves on the surface of the water in the reservoir supplying the weirs. Such waves have been found to occur as a result of oscillations in the flow rate of water to the metering device and may also result from rotor vibrations.
BRIEF DESCRIPTION OF THE INVENTION
In order to overcome the foregoing drawbacks of the prior art metering structures, the present invention utilizes resistance flow devices to meter water into each bucket cooling channel. Such devices are not dependent upon a stable, uniform water surface for accurate metering. Thus, while flow through a resistance flow device is typically proportional to the square root of the pressure head (i.e., H 1/2 ), weir flow rates are at best about proportional to the pressure head and may be as sensitive as H 5/2 .
In accordance with the foregoing, the liquid coolant distribution system of the present invention includes:
a plurality of shank coolant channels located in the shank portion of a turbine bucket and extending to platform cooling channels located in the platform portion of a turbine bucket that extend into foil cooling channels located in the air foil of the turbine bucket; and
metering means for receiving coolant from a source of liquid coolant and for distributing the coolant evenly into each of the platform coolant supply channels, the metering means including a plurality of resistance flow devices.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of illustrating the invention, there are shown in the drawings several forms which are presently preferred, it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a perspective view of a first embodiment of the improved cooling system of the present invention.
FIG. 2 is a side plan view of a single turbine bucket and distribution channel formed in accordance with the present invention.
FIG. 3 is an exploded view of a distribution channel forming part of the cooling system of FIG. 1.
FIG. 4 illustrates the interrelationship between the distribution channel inner member of FIG. 3 and certain coolant channels formed in the distribution channel outer housing of FIG. 2.
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 4 illustrating a first embodiment of a flow resistance device which may be used in accordance with the principles of the present invention.
FIG. 6 is a cross-sectional view taken along line 5--5 of FIG. 4 illustrating a second flow resistance device which may be used in accordance with the principles of the present invention.
FIG. 7 is a cross-sectional view taken along line 5--5 of FIG. 4 illustrating a third flow resistance device which may be used in accordance with the principles of the present invention.
FIG. 8 is a cross-sectional view taken along line 8--8 of FIG. 7.
FIG. 9 is a cross-sectional view illustrating internal passages of the flow resistance device of FIG. 7.
FIG. 10 is a cross-sectional view taken along line 10--10 of FIG. 7.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, wherein like numerals indicate like elements, there is shown in FIG. 1 a turbine bucket constructed in accordance with the principles of the present invention and designated generally as 10. Bucket 10 includes a root portion 12, a shank portion 14, a platform portion 16 and an air foil 18. Root portion 12 is embedded in a turbine rotor disk 20 which is mounted on a shaft (not shown) rotatably supported in a casing (not shown). As will be recognized by those skilled in the art, an actual turbine will include a plurality of buckets 10 located about the entire periphery of the rotor disk 20.
As noted above, the present invention is directed towards an improved cooling system for use with gas turbines of the general type illustrated in FIG. 1. A water delivery system, such as described in copending patent application Ser. No. 842,407, filed Oct. 17, 1977 by Anderson et al, distributes the coolant to passage 94 and thereby to individual buckets 10. Passage 94 directs the coolant liquid to stand pipe 96, which is integral with distribution channel 28 located beneath the root portion 12 of bucket 10. The structure of distribution channel 28 is illustrated in FIGS. 2-10 and is described in detail below. The coolant liquid supplied by passage 94 collects in stand pipe 96 of distribution channel 28 and is thereafter metered into a plurality of shank coolant channels 78 formed in the shank 14.
As best shown in FIG. 4, a plurality of trap seals 98 are interposed in shank coolant channels 78 (preferably at the bottom thereof) to permit the passage of liquid coolant from distribution channel 28 to coolant channels 78 but prevent the passage of coolant vapor from coolant channel 78 to distribution channel 28. The structure of these coolant channels is described in detail in U.S. Pat. No. 4,244,676.
As best illustrated in FIG. 1, shank coolant channels 78 extend from distribution channel 28 to a plurality of platform coolant channels 30 (only two of which are shown) formed in platform 16 that in turn lead to foil coolant channels 32 formed in the foil 18. The foil coolant channels 32 extend in a generally radial direction throughout the outer perimeter of air foil 18 and serve to cool the foil.
As shown in FIG. 1, the distribution channel 28 has a flattened top 22 which mates with a flattened bottom 62 of the turbine bucket 10 when the bucket and distribution chanel are placed in the dovetail opening formed in rotor disk 20. Both surfaces 62, 22 are machined flat and parallel with the convolutions of the dovetail slot so that the centrifugal force applied to distribution channel 28 when the turbine is rotating ensures parallelism between these surfaces and the dovetail slots.
The detailed structure of distribution channel 28 will now be described with reference to FIGS. 2-10.
As shown in FIG. 3, distribution channel 28 comprises two parts: an outer casing 68, and a cylindrical member 48. Outer casing 68 fits under the bottom most convolution of the dovetail slot in rotor disk 20. A cylindrical bore 74 is formed in outer casing 68 and receives member 48 in interference fit therewith. A plurality of coolant channels 76 are formed in the top of casing 68 and each extends from bore 74 to flattened top 22. Coolant channels 76 are equal in number to the number of platform coolant channels 30 and are each connected to a respective platform coolant channel 30 by one of the shank coolant channels 78.
Member 48 has a hollow cylindrical central section 80, a threaded extension section 82, a coolant supply receiving section 84 and a side cover 50 which may, if desired, be formed integrally with member 48. The outer diameter of central section 80 is substantially identical to the inner diameter of bore 74 to ensure an interference fit when central section 80 is placed in bore 74. The length of central section 80 is equal to the length of bore 74 such that sections 82 and 84 extend beyond opposite ends of outer casing 68.
When distribution channel 28 has been placed in its position within the dovetail slot formed in rotor disk 20 (see FIG. 1), threaded extension section 82 extends through an opening 90 in ring 34. In the preferred embodiment, the external threads on extension section 82 engage a retaining nut 92 which serves to lock a ring 34 to rotor disk 20.
Coolant supply receiving section 84 of member 48 extends out the opposite side of casing 68. Coolant fluid enters a plenum 64 through stand pipe 96 which communicates with passage 94 formed in ring 34.
A plurality of grooves 56 are formed around the outer perimeter of central sction 80 at spaced intervals corresponding to the spacing of coolant channels 76 formed in outer casing 68 such that each groove 56 cooperates with a different shank coolant channel 78. Liquid coolant supplied to supply plenum 64 exits member 48 via individual exit openings 58 formed in each of the grooves 56. A respective flow resistance device 66 (see FIGS. 5-10) is located between supply plenum 64 and each exit opening 58 and meters the flow of liquid coolant into its respective opening 58.
The manner in which liquid coolant is supplied to coolant channels 76 by distribution channel 28 can best be understood with reference to FIG. 4. FIG. 4 depicts the right-hand portion of distribution channel 28 after it has been placed in position within the dovetail slot formed in rotor 20, beneath root portion 12 of bucket 10. As the bucket rotates about the central axis of the turbine, the coolant fluid is forced in a radial outward direction by centrifugal force. As such, the coolant flows through stand pipe 96 into the supply plenum 64 where it collects on the radially outward wall of plenum 64. The coolant distributes throughout the distribution channel 28 and builds up in height to a head 74 until it passes through the flow resistance device 66 and flows through the opening 58 and into the groove 56. The so-metered coolant flows into its associated outer casing coolant channel 76 and thereafter to a corresponding shank coolant channel 78, platform coolant channel 30 and foil coolant channel 32.
Three separate embodiments of flow resistance devices which may be utilized in connection with the present invention are illustrated in FIGS. 5-10. While these structures represent the preferred flow resistance devices, it should be recognized that a large number of different flow resistance devices can be used without departing from the spirit and scope of the present invention as long as such devices meter a liquid coolant into the individual coolant channels 76 in such a manner that the flow of coolant through such devices does not depend upon a stable, uniform water surface for accurate metering.
Referring now to FIG. 5, a first embodiment of a flow resistance device 66 is illustrated. In this embodiment, the flow resistance device 66 comprises a tortuous path 88 comprising a series of bends. In order to operate properly, it is essential that these passages be filled with liquid in order to generate the requisite losses. This is ensured when the liquid coolant flows radially inward against the "G" field, as shown. Head losses at each bend contribute to the total resistance of the passage. Passages of relatively large size are possible. For example, passages having a minimum cross-section dimension of 0.025 inches have been found to operate satisfactorily.
The relationship between flow and pressure drop as a function of the size and shape of constituent bend elements of the tortuous path may be found in the "Handbook of Hydraulic Resistance" authored by I. E. Idel'Chik. Since the particular size and shape of the tortuous path does not make up part of the present invention, a further discussion of the manner in which these parameters affect flow characteristics will not be set forth herein.
While the tortuous path 88 may be formed in any desired manner, one simple process is to form the path by laminating a plurality of wafer-like plates 70 each of which has been formed with an opening at the location corresponding to the tortuous path 88. These openings may be formed, for example, by using known photo-etching technology similar to that used in producing fluidic devices.
The operation of flow resistance device 66, as illustrated in FIG. 5, is as follows. As the buckets 10 are rotated about the axis of rotor disk 20, the artificially generated "G" field causes the liquid coolant to flow through supply plenum 64 pressing against the radially outward wall thereof. The height of the liquid coolant builds up and passes through a "last chance" strainer 72 located adjacent plenum 64. A separate strainer 72 is provided for each flow resistance device 66. The height of the liquid coolant continues to flow through the tortuous path 88 until it flows out the opening 58 into the groove 56 formed in the distribution channel 28. This liquid then flows into the coolant channel 76 and through its associated bucket coolant channel.
In operation, debris which is heavier than the liquid coolant is centrifuged away from strainer 72 to the bottom 54 of plenum 64. As a result, the openings formed in strainer 72 need only be smaller in diameter than the minimum dimension of tortuous path 88. In the preferred embodiment, strainer 72 is a metallic plate having a plurality of openings formed therein.
A second flow resistance device 66 which may be used in connection with the present invention is illustrated in FIG. 6. In this embodiment, an orifice 46 is used to create the desired head losses. While a single orifice 46 is illustrated, a plurality of orifices may be used. As in the embodiment of FIG. 6, the flow resistance device of FIG. 6 includes a strainer 72 adapted to prevent small debris from flowing into, and thereby clogging, orifice 46. Water builds up in standpipe 96 to a water head H (see FIG. 4) radially inward of exit opening 58. In comparative tests, it has been found that bucket channel flow will vary as a function of the square root of the water head H (see FIG. 4) when using an orifice such as that illustrated in FIG. 6. In comparison, the channel flow varies as a function of H 5/2 using a "V" shaped notched weir such as that described in U.S. Pat. No. 4,244,676. In the illustrated embodiment, orifice 46 is formed as a projection in a cylindrical flow path 58. Other orifices may, however, be used.
A third embodiment of a flow resistance device 66 constructed in accordance with the principles of the present invention is illustrated in FIGS. 7-10. In this embodiment, the flow resistance device takes the form of a plurality of vortex chambers 81, 83, 85 and 87. Liquid coolant located in supply plenum 64 passes through strainer 72 and flows into a first vortex chamber 81 wherein it is agitated in the known manner (see FIGS. 8, 9 and 10). The agitated coolant leaves vortex chamber 81 via a cylindrical opening 79 into a second vortex chamber 83.
As best illustrated in FIGS. 8, 9 and 10, liquid coolant in vortex chamber 83 passes into vortex chamber 85 via a linear passage 77. Liquid coolant leaves vortex chamber 85 via opening 75 and enters fourth vortex chamber 87 (see FIGS. 8, 9 and 10). Finally, the liquid coolant leaves vortex chamber 87 via passage 73 wherein it exits via opening 58 into groove 56.
Having described the structure and operation of the preferred flow resistance devices, the manner in which coolant flows from liquid coolant source through the entire bucket 10 will now be described. The buckets 10 receive a driving force from a hot fluid moving in a direction generally parallel to the axis of rotation of rotor disk 20. The driving force of the hot fluid is transmitted to the shaft about which the rotor disk 20 is mounted via the buckets 10 and rotor disk 20 causing the turbine to rotate about the axis of the shaft. The high rotational velocity of the rotor creates a substantial centrifugal force which urges the liquid coolant through the bucket in a radially outward direction. As the liquid coolant enters coolant supply passage 94, it is forced in a radially outward direction into stand pipe 96 where it is collected in distribution channel 28. When the level of coolant in supply plenum 64 overflows, it passes through the individual flow resistance devices 66 into the respective platform coolant channels 76 and thereafter into the respective shank coolant channels 78. The coolant continues to advance in a generally radial direction to platform and foil coolant channels 30 and 32 to the tip of foil 18.
In the foregoing embodiment, distribution channel 28 is located in the rim of rotor disc 20 below the bucket 10. In U.S. Pat. No. 4,244,676 the manner in which a distribution channel may be located in the platform portion 16 of bucket 10 is illustrated in FIGS. 1-4. A similar arrangement may be used in connection with the present application.
Although several preferred embodiments of this invention have been described, many variations and modifications will now be apparent to those skilled in the art, and it is therefore preferred that the instant invention be limited not by the specific disclosure herein, but only by the appending claims.
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An improved cooling system utilizes flow resistant devices distributing liquid coolant to air foil coolant channels in a bucket of a turbine. A separate flow resistance device associated with each of the air foil coolant channels resist the flow of liquid coolant into the coolant channels whereby a fluid head is developed in a standpipe upstream of the flow resistance devices. The fluid head, together with the outward radial acceleration meters the flow of fluid through each flow resistance device according to the head. In the disclosed embodiments, the flow resistant devices alternately take the form of a tortuous passage, an orifice and a plurality of vortex flow chambers.
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BACKGROUND OF THE INVENTION
[0001] Enclosed rotor propulsion system for marine craft, such as waterjets and Applicant's enclosed ventilated rotor Hydro Air Drive® (HAD) invention, are limited in the overall efficiency they can realize by the efficiency of recovery by their water inlets of the fluid available at their water inlets. As an example, waterjets can have very high efficiency rotors, stator vanes that straighten the discharge flow of the rotors, and discharge nozzles. The overall efficiency of the just mentioned three items are in the 90% area for a well designed high power level waterjet.
[0002] However, the overall efficiency of a waterjet is severely limited by its inlet's ability to recovery oncoming fluids efficiently. This is because the oncoming fluid flow is forced to turn into the duct that surrounds the waterjet's rotor. As an example, a waterjet's inlet may see efficiencies of fluid recovery of 92% over its lower half but only 54% or so over its upper half. This is because the fluid flow is separating over the upper part of the inlet duct as it is trying to turn from the inlet toward the rotor. This is so even though the waterjet operates as an enclosed pressurized system and thereby creating a suction at its inlet.
[0003] The HAD sees a slightly different situation in that it is not a pressurized system and therefore does not create much of a suction at its inlet. The advantage of the HAD is that it only operates with the lower half of its rotor submerged so its inlet fluid does not have to turn as far as does the waterjet's. However, the lack of inlet suction of the HAD does hamper the ability of its inlet to fully recovery fluid approaching its inlet.
[0004] What all of this means is that propulsors, such as waterjet and the HAD, would benefit greatly from having some sort of water inducer device at their inlets. As a side point, it is realized that having a straight-in inlet with the inlet in-line with the rotor with no turns would provide high inlet efficiencies. The obvious problem with this is twofold, to wit: 1) Excessive drag due to high frontal area and 2) Very deep draft. Therefore the approach of an inline inlet is generally impractical.
[0005] The Coanda Effect can be used for turning fluids around curved surfaces and has been known for many years. This Coanda Effect can be improved by use of a rotating cylinder or other curvilinear shape placed perpendicular to or at least partially perpendicular to the fluid flow to entice the fluid to turn in the direction of rotation of the rotating surface. The instant invention takes advantage of these known sciences and places a Coanda Effect Inducer (CEI), either rotating or not, at or near the entrance of the inlet of the propulsor. The effect of this is to greatly improve the recovery of fluids flowing past the propelled vehicle and of delivering such fluids to a fluid energizing device, such as a rotor, of the propulsor. This greatly improves the overall efficiency of the propulsor and hence the performance of the vehicle. The CEI is commonly called an inlet fluid inducer herein.
[0006] A discussion of the instant invention and the advantages it offers is presented in detail in the following sections.
OBJECTS OF THE INVENTON
[0007] A primary object of the invention is provide an improved propulsor for propelling a vehicle where said propulsor accelerates fluid to produce thrust and where said fluid is obtained through an inlet that intakes fluid from external to the vehicle and directs said fluid toward a fluid energizing device wherein said inlet includes an inlet fluid inducer and wherein said inlet fluid inducer directs said fluid toward a fluid energizing device such as a powered rotor.
[0008] A related object of the invention is that the inlet fluid inducer may rotate.
[0009] A directly related object of the invention is that the inlet fluid inducer provide a uniformity to the energy in the fluid supplied to the fluid energizing device.
[0010] A related object of the invention is that said inlet fluid inducer be oriented more perpendicular to than parallel to a plane that includes a rotational axis of the fluid energizing device.
[0011] A further object of the invention is that the inlet fluid inducer be capable of rotation in the direction of fluid flow.
[0012] Yet another object of the invention is that the inlet fluid inducer extend less than 60 percent of its maximum dimension perpendicular to fluid flow beyond an average height of a vehicle hull portion when said vehicle hull portion is viewed proximal to, forward of, and in line with the inlet fluid inducer.
[0013] A directly related refining object of the invention is that said inlet fluid inducer extend less than 40 percent of its maximum dimension perpendicular to fluid flow beyond an average height of a vehicle hull portion when said vehicle hull portion is viewed proximal to, forward of, and in line with the inlet fluid inducer.
[0014] A further directly related refining object of the invention is that said inlet fluid inducer extend less than 20 percent of its maximum dimension perpendicular to fluid flow beyond an average height of a vehicle hull portion when said vehicle hull portion is viewed proximal to, forward of, and in line with the inlet fluid inducer.
[0015] Another object of the invention is that the inlet fluid inducer be driven by a power source that also drives the fluid energizing device.
[0016] A directly related object of the invention is that a drive shaft of a fluid energizing device also drives the inlet fluid inducer.
[0017] Still another object of the invention is that the fluid energizing device may receive primarily liquid over one portion of its rotation and primarily gas over another portion of its rotation.
[0018] A related object of the invention is that a fluid directing device may be disposed at least in its majority downstream of the inlet fluid inducer.
[0019] A directly related object of the invention is that the fluid directing device has the ability to, in at least one mode of its operation, restrict gas from passing to the fluid energizing device.
[0020] Another object of the invention is that the fluid directing device be powered by an actuator.
[0021] Yet another object of the invention is that the inlet fluid inducer may include recesses in its periphery that are capable of energizing fluids when the inlet fluid inducer is rotating.
[0022] A further object of the invention is that the inlet fluid inducer may be driven with gears.
[0023] Still another object of the invention is that the fluid energizing device be a rotor.
[0024] An optional object of the invention is that the fluid discharge from the fluid energizing device may be given direction by a rudder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 shows a centerline cross-sectional profile view of a prior art waterjet propulsor.
[0026] FIG. 2 presents a cross-section, as taken through plane 2 - 2 of FIG. 1 , that shows the general values of recovery of fluids by the inlet as seen at a plane just forward of the fluid energizing rotor that can be expected in a commercial waterjet based on present day designs. Note that the overall inlet efficiency, based on 92% in the lower half and 54% in the upper half, comes to only about 73%.
[0027] FIG. 3 is the same centerline cross-sectional profile view as given in FIG. 1 but in this case a Coanda Effect Inducer (CEI), also called as an inlet fluid inducer herein, has been added as is a preferred embodiment of the instant invention. The direction of rotation of this inlet fluid inducer here aids in directing the inlet water in a uniform manner to the fluid energizing rotor.
[0028] FIG. 4 gives a cross-section, as taken through line 4 - 4 of FIG. 3 , that gives the predicted values for the recovery of fluids by the inlet with the inlet fluid inducer rotating. Note that the recovery value over fluids entering the lower portion of the fluid energizing device is 96% and over the upper portion 90%. This results in an overall inlet efficiency of 93%. The very important result is that there is about a twenty-five percent improvement in overall efficiency for a waterjet with the inlet fluid inducer compared to one without an inlet fluid inducer.
[0029] FIG. 5 illustrates a proposed version of a inlet fluid inducer, as taken through plane 5 - 5 of FIG. 3 , that shows one possible means of driving this cylindrical shaped inlet fluid inducer. In this particular case the drive means consists of a drive motor with power transmitted through a set of right angle gears.
[0030] FIG. 6 presents a cross-section, as taken through line 6 - 6 of FIG. 3 , that shows a preferred flat surface forward to the inlet fluid inducer. Note that the lower surface of the inlet fluid inducer is disposed more into the oncoming fluid than surfaces of the hull forward of the inlet fluid inducer in this example. This preferred approach insures optimum performance of the inlet fluid inducer while adding very little additional drag.
[0031] FIG. 7 presents a partial profile centerline cross-section of a HAD with an instant invention inlet fluid inducer applied. There are, ideally, fluid directing means—flaps in this illustration—applied to either side of the shaft here. In this instance, the fluid directing means are retracted to their most upward positions which allows water to flow to the entire HAD fluid energizing rotor from top to bottom. This is the preferred position of the fluid directing means for low vehicle speed operation when maximum low speed thrust is desired.
[0032] FIG. 8 is the same partial profile centerline cross-section of a HAD as presented in FIG. 7 but in this case the fluid directing means are extended downward to aid in directing fluids to only a portion of the fluid energing rotor. It is important to note also that a lowered position of the fluid directing means allows gas to pass to the upper portion of the fluid energizing rotor. As such, the rotor is operating only partially submerged which has advantages compared to standard pressurized system waterjets. These advantages are discussed later in this application.
[0033] FIG. 9 is a cross-sectional plane, as taken through 9 - 9 of FIG. 7 , that shows the fluid directing means in their retracted position. Note that in this position the fluid directing means restrict the flow of gases to the fluid energizing device which is normally a rotor with blades.
[0034] FIG. 10 is a cross-sectional plane, as taken through 10 - 10 of FIG. 8 , that illustrates how the fluid directing means are positioned during high speed vehicle operation where the fluid energizing device such as a rotor is only partially submerged.
[0035] FIG. 11 presents a cross-sectional plane, as taken through line 11 - 11 of FIG. 7 , that shows the fluid flow distributions just forward of the fluid energizing rotor when the fluid directing means are in their retracted position.
[0036] FIG. 12 is a cross-sectional plane, as taken through line 12 - 12 of FIG. 8 , that illustrates fluid flow distributions just forward of the fluid energizing rotor when the fluid directing means are in an extended high vehicle speed position. Note that there is gas above the fluid directing means and water below it in this instance. Inlet recovery efficiencies should be in the 98% area over the lower half of the fluid energizing rotor in this instance.
[0037] FIG. 13 illustrates fluid flow inlet characteristics when the inlet fluid inducer is not rotating. While this is very workable and considered part of the instant invention, performance is substantially better when the inlet fluid inducer is rotating in the direction of the water flow.
[0038] FIG. 14 shows a cross-sectional plane, as taken through line 14 - 14 of FIG. 13 , that illustrates water flow characteristics with the inlet fluid inducer not rotating. Comparing this FIG. 13 to FIG. 12 gives some idea of the expected performance improvements to having the inlet fluid inducer rotating.
[0039] FIG. 15 illustrates flow characteristics around a non-rotating cylinder disposed perpendicular to fluid flow. Note that the flow separates around the aft side of the cylinder.
[0040] FIG. 16 shows the same cylinder as that presented in FIG. 15 but with the cylinder rotating. It is apparent that the fluid does not detach as is the case of the non-rotating cylinder of FIG. 15 . This rotating cylinder makes for a much more efficient and low drag situation than the non-rotating cylinder of FIG. 15 . Both FIGS. 15 and 16 actually show characteristics of the Coanda Effect since the fluid is at least partially attached to the curvilinear surfaces and turn inward in both instances.
[0041] FIG. 17 shows the same HAD unit as shown previously; however, in this case the inlet fluid inducer is cylindrical and rotating in an opposite direction to travel and freestream fluid flow. This has merit in a case where a HAD or waterjet is not operating but the vehicle is still moving forward as would be the case of operating with their drive engine out but with other propulsors still operating. The reason this is so is that the forward direction of rotation of the inlet fluid inducer directs oncoming fluids away form the HAD's inlet thereby reducing drag forces that would occur with fluid entering a non-operating unit.
[0042] FIG. 18 presents a centerline profile cross-section plane that shows an alternate method of driving an inlet fluid inducer. In this case the inlet fluid inducer is directly driven by a main drive shaft of a propulsor. Also, this figure shows how an inlet fluid inducer could work when operating in reverse as is the inlet fluid inducer here. Running the inlet fluid inducer in reverse along with reverse operation of the rotor results in enhanced reverse thrust.
[0043] FIG. 19 presents a cross-section plane, as taken through 19 - 19 of FIG. 18 .
[0044] FIG. 20 is a cross-section plane, as taken through 20 - 20 of FIG. 18 . The inlet fluid inducer illustrated here is in the form of truncated cones either side of a gear drive track. Realize that the inlet fluid inducer can take many shapes to accommodate different hull shapes, inlet designs, and the like.
[0045] FIG. 21 is another cross-section plane, as taken through 21 - 21 of FIG. 18 , that shows an optional elliptical, as seen in this cross-section, shaped inlet fluid inducer.
[0046] FIG. 22 shows yet another version of an inlet fluid inducer that in this case is made up of two separate parts.
[0047] FIG. 23 is a partial centerline cross-section plane with a variation of an inlet fluid inducer that incorporates pumping recesses to enhance pumping or fluid accelerating abilities of the inlet fluid inducer.
[0048] FIG. 24 is a cross-section plane, as taken through 24 - 24 of FIG. 23 , that shows the preferred shape and workings of the inlet fluid inducer variation of FIG. 23 .
DETAILED DESCRIPTION
[0049] FIG. 1 shows a centerline cross-sectional profile view of a prior art waterjet propulsor 53 as it is propelling a vehicle 39 forward at high speed. Note that high speed is defined herein as being forward speeds of 15 knots or more and low speeds as speeds of less than 15 knots. Shown also are the shaft 31 , fluid energizing device which in this case is a rotor 42 , stator including flow straightening stator vanes 40 , and discharge nozzle 41 . Other items of interest include inlet housing 34 , vehicle hull 39 , waterline 45 , waterflow arrows 37 , turbulent water flow arrows 50 , and thrust arrow 51 . The power source is not shown to simplify the drawings. Note that the turbulent water flow arrows 37 indicate that the water flow is separating over the upper surface of the inlet housing 34 .
[0050] FIG. 2 presents a cross-section, as taken through plane 2 - 2 of FIG. 1 , that shows the general values of recovery of energy available at the inlet 55 in a plane just forward of the rotor 35 as can be expected in a large commercial waterjet 53 to today's technology. The overall inlet efficiency can be approximately determined from the inlet pressure islands 47 . Note that the approximate overall inlet efficiency, based on 92% in the lower half and 54% in the upper half, comes to only 73%.
[0051] FIG. 3 is the same centerline cross-sectional profile view as given in FIG. 1 but in this case a Coanda Effect Inducer (CEI), more commonly called an inlet fluid inducer herein, 30 has been added as is a preferred embodiment of the instant invention. The direction of rotation, as shown by rotation arrow 49 , of this inlet fluid inducer 30 aids in directing and adding energy to the recovered incoming fluid as it is directed to the fluid energizing device such as rotor 42 .
[0052] The dimension A given in FIG. 3 shows that the inlet fluid inducer 30 can extend below the average depth of the hull portion 39 forward of the inlet fluid inducer 30 . Having the inlet fluid inducer 30 on average lower than the hull portion 39 forward of it allows the inlet fluid inducer 30 to operate more efficiently and in cleaner water. This is done with very little addition to the drag of the inlet as will be discussed later in the descriptions of FIGS. 15 and 16 .
[0053] In FIG. 3 and subsequent figures in this application, dimension A is best defined as a percentage of the diameter of the inlet fluid inducer 30 and may extend to as much as 60 percent or more of the diameter of the inlet fluid inducer 30 and offer advantage in efficiency of recovery of fluids external to the inlet and still add little drag to the vehicle. For purposes of this application, the amount that the inlet fluid inducer 30 can extend beyond the average height of a hull portion 39 forward of the inlet fluid inducer 30 is either not specified or defined as less than 60% of inlet fluid inducer 30 diameter, less than 40% of inlet fluid inducer 30 diameter, or less than 20% of inlet fluid inducer 30 diameter. It is to be noted that the term diameter used here can actually be the maximum dimension of the inlet fluid inducer 30 that is perpendicular to fluid flow as could be the case for shapes other than cylindrical.
[0054] Each of these extensions, relative to the hull portions, have advantages and disadvantages. For example, in the case of a Surface Effect Ship (SES) such as applicant's SeaCoaster® that is supported by pressurized gas cushions with the propulsor inlets disposed at least primarily aft of the gas cushions it is best to have the inlet fluid inducer 30 extend beyond the hull portion in front of it as far as possible. This is because the gas cushions aerate the water and there may also be a layer of gas between the hull 39 and the water surface when it reaches the propulsor's water inlet. Having the inlet fluid inducer 30 extend outward beyond the hull means that its outward portions can work in relatively clean gas free liquid. Contrarily, it is desirable to have the inlet fluid inducer 30 not so far extended for a very high speed craft.
[0055] Large displacement hulls may find extension of the inlet fluid inducer 30 to work best when at low values also. This is because of the boundary layer associated with large displacement hulls and the desire to take in water to the propulsor from close to the hull where it has already been brought up to near ship speed. The advantage of the instant invention in such a displacement hull application is that the propulsor gets an added thrust advantage from taking in the ship's accelerated boundary layer rather than quiescent water in outer reaches of the boundary layer. It is further to be noted that the instant invention may be disposed so that it is actually has all or part of its inlet higher than its fluid energizing rotor as would be the case when operating on the upper or side surfaces of hydrofoil, submarine, or other submerged or partially submerged vehicle.
[0056] FIG. 4 presents a cross-section, as taken through line 4 - 4 of FIG. 3 , that gives the predicted values for the recovery of the inlet fluid with the inlet fluid inducer 30 rotating as shown. Note that the expected recovery over the lower portion of the fluid energizing rotor is 96% and over the upper portion 90%. This results in an overall inlet efficiency of 93%. The net result is about a twenty-seven percent improvement in overall waterjet efficiency for a waterjet with the inlet fluid inducer compared to one without.
[0057] FIG. 5 illustrates a proposed version of an inlet fluid inducer 30 , as taken through plane 5 - 5 of FIG. 3 , that shows one possible means of driving this cylindrical shaped inlet fluid inducer 30 . In this case the drive means consists of a drive motor 43 with power transmitted through a set of right angle gears 44 . The drive motor 43 may be driven electrically, hydraulically, or by other means.
[0058] FIG. 6 presents a cross-section, as taken through line 6 - 6 of FIG. 3 , that shows a preferred flat hull 39 surface forward to the inlet fluid inducer 30 . Note that the lower surface of the inlet fluid inducer 30 is disposed more into the freestream than surfaces forward of the inlet fluid inducer 30 as shown here. This preferred approach shown here insures optimum performance of the inlet fluid inducer 30 while adding very little additional drag. However, it is to be realized that, while the arrangement shown is preferred, that the instant invention's inlet fluid inducer 30 can actually be flush with the hull 30 surfaces or even recessed from them and such arrangements are considered within the spirit and scope of the instant invention.
[0059] FIG. 7 presents a partial profile centerline cross-section of a Hydro Air Drive (HAD) 54 with an instant invention inlet fluid inducer 30 applied. There are, ideally, fluid directing means 33 —flaps in this illustration—applied. These flaps 33 are to either side of the shaft 31 in this preferred arrangement of the instant invention. In this FIG. 7 , the fluid directing means 33 are retracted to their most upward positions with power supplied by actuators 32 which allows water to flow to the entire HAD fluid energizing rotor 35 from top to bottom. This is the preferred position of the fluid directing means 33 for low vehicle speed operation to provide maximum low speed thrust.
[0060] Another item of note in FIG. 7 is the optional use of low cost and low maintenance labyrinth seals 52 to restrict water from flowing freely around the inlet fluid inducer 30 . While the fluid inlet 55 is shown below the fluid energizing rotor 35 here it is to be realized that it can be fully or partially to the side of or even above the fluid energing rotor 35 as a particular installation may dictate. An optional rudder 36 that provides steering in forward and in reverse is also shown.
[0061] FIG. 8 is the same partial profile centerline cross-section of a HAD 54 as presented in FIG. 7 but in this case the fluid directing means 33 are extended downward to aid in directing liquid flow to only a portion of the fluid energizing rotor 35 . It is important to note also that a lowered position of the fluid directing means 33 allows gas to pass to the upper portion of the rotor 42 through gas passageways 57 as is indicated by gas flow arrows 38 . As such, the fluid energizing rotor 35 is operating only partially submerged which has advantages compared to standard pressurized system waterjets. Two of these advantages are: 1) The HAD rotor is not subject to cavitation damage since it is aerated and 2) Ingestion of aerated water by the HAD does not result in a severe performance decay it does in the case of a standard pressurized system waterjet.
[0062] FIG. 9 is a cross-sectional plane, as taken through 9 - 9 of FIG. 7 , that shows the fluid directing means 33 in their retracted position. Note that gas flow is restriced from entering the duct and from reaching the fluid energizing rotor 35 since it is blocked from doing so by the fluid directing means 33 .
[0063] FIG. 10 is a cross-sectional plane, as taken through 10 - 10 of FIG. 8 , that illustrates how the fluid directing means 33 are positioned during high speed vehicle operation where the fluid energizing rotor 35 is only partially submerged. Note the gas flow arrows 38 that show that gas is passing through in this arrangement. Waterlines 45 either side of the instant invention propulsor 54 are also shown.
[0064] FIG. 11 presents a cross-sectional plane, as taken through line 11 - 11 of FIG. 7 , that shows the fluid flow distributions, as indicated by fluid energy islands 47 , just forward of the fluid energizing rotor when the fluid directing means are in their retracted position.
[0065] FIG. 12 is a cross-sectional plane, as taken through line 12 - 12 of FIG. 8 , that illustrates fluid flow distributions, as indicated by fluid energy islands 47 , just forward of the fluid energizing rotor when the fluid directing means are in an extended high vehicle speed position. Note that there is gas above the fluid directing means and liquid below it in this instance. Inlet recovery efficiencies should be in the 98% area over the lower half of the fluid energizing rotor in this instance where the inlet fluid inducer is rotating and adding energy and direction to the incoming fluids.
[0066] FIG. 13 illustrates fluid flow inlet characteristics when the inlet fluid inducer is not rotating. While this is very workable and considered part of the instant invention, performance is substantially better when the inlet fluid inducer is rotating in the direction of the water flow. Expected inlet recoveries should be in about the 80% area in this case with the inlet fluid inducer not rotating. Note also that the waterline 45 is lower than in the case where the inlet fluid inducer is rotating as seen in FIG. 12 so the fluid energizing rotor would most likely not be receiving as much liquid as the fluid energizing rotor of FIG. 12 .
[0067] FIG. 14 shows a cross-sectional plane, as taken through line 14 - 14 of FIG. 13 , that illustrates liquid flow characteristics with the inlet fluid inducer not rotating. Note the lower waterline 45 here than in FIG. 12 . Also, the expected recovery is 80% while it is 98% in FIG. 12 where the inlet fluid inducer is rotating in the direction of fluid flow.
[0068] FIG. 15 illustrates flow characteristics around a non-rotating cylinder 48 disposed perpendicular to ideal fluid flow. Note that the flow, indicated by turbulent flow lines 50 , separates around the aft side of the cylinder 48 .
[0069] FIG. 16 shows the same cylinder 48 as that presented in FIG. 15 but with the cylinder 48 rotating in the direction of flow as is indicated by rotation arrow 49 . It is apparent that the fluid does not detach as is the case of the cylinder 48 that is not rotating of FIG. 15 . This rotating cylinder 48 makes for a much more efficient and low drag situation than the cylinder 48 that is not rotating of FIG. 15 . Both FIGS. 15 and 16 actually show characteristics of the Coanda Effect since the fluid is at least partially attached to the curvilinear surfaces on the aft side of the cylinder 48 and turn inward.
[0070] FIG. 17 shows the same HAD 54 as shown previously; however, in this case the inlet fluid inducer 30 is rotating in an opposite direction to travel and external fluid flow. This has merit in a case where a HAD or waterjet is not operating but the vehicle is still moving forward since this forward direction of rotation of the inlet fluid inducer 30 prevents water from entering the HAD's inlet 55 thereby reducing drag.
[0071] FIG. 18 presents a centerline profile cross-section plane that shows an alternate method of driving an inlet fluid inducer 30 . In this case the inlet fluid inducer 30 is directly driven by a main drive shaft 31 of the propulsor. Also, this figure shows how an inlet fluid inducer 30 could work when operating in reverse as is the inlet fluid inducer 30 here. Running the inlet fluid inducer 30 in reverse along with reverse operation of the fluid energizing rotor results 35 in enhanced reverse thrust.
[0072] FIG. 19 presents a cross-section plane, as taken through 19 - 19 of FIG. 18 . Note that the fluid flow directing means 33 are retracted here.
[0073] FIG. 20 is a cross-section plane, as taken through 20 - 20 of FIG. 18 . The inlet fluid inducer 30 illustrated here is in the form of truncated cones either side of a gear track 46 . Realize that the inlet fluid inducer 30 can take many shapes to accommodate different hull shapes, inlet designs, and the like.
[0074] FIG. 21 is another cross-section plane, as taken through 21 - 21 of FIG. 18 , that shows an optional elliptical shaped inlet fluid inducer 30 .
[0075] FIG. 22 shows yet another version of an inlet fluid inducer 30 that in this case is made up of two parts.
[0076] FIG. 23 is a partial centerline cross-section plane with a variation of an inlet fluid inducer that incorporates pumping recesses 56 to enhance pumping or fluid accelerating abilities of the inlet fluid inducer 30 . Note that other manners of shape and of possible recesses in the inlet fluid inducer 30 are considered within the spirit and scope of the instant invention.
[0077] FIG. 24 is a cross-section plane, as taken through 24 - 24 of FIG. 23 , that shows a preferred shape and workings of the inlet fluid inducer 30 variation of FIG. 23 .
[0078] While the invention has been described in connection with a preferred and several alternative embodiments, it will be understood that there is no intention to thereby limit the invention. On the contrary, there is intended to be covered all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims, which are the sole definition of the invention.
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Presented is a fluid propulsor for propelling a vehicle that incorporates a Coanda Effect Inducer (CEI), more commonly called an inlet fluid inducer in this application, in its inlet to induce fluids passing by the vehicle to turn uniformly toward a powered fluid energizing device such as a rotor of the propulsor. This concept enhances the efficiency of the rotor and the overall efficiency of the propulsor. The rotor is at least primarily enclosed in a housing and the rotor may operate either fully submerged in liquid or in a partially liquid and partially gaseous environment. Fluid flow directing devices may be incorporated to separate liquid from gas flowing to the rotor in some instances. The inlet fluid inducer may take the shape of a cylinder or any other flow directing shape and while more effective when rotating in the direction of fluid flow is also viable when not rotating.
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BACKGROUND OF THE INVENTION
In the operation of internal combustion engines the reactor chamber is subjected to substantial temperature fluctuations because of the diverse operating conditions of the engine resulting in considerable thermal distortions of the reactor chamber relative to the outer shell or to the reactor as a whole. The resulting stresses may cause damage to the reactor and adversely affect its performance as well as it service life.
From German publication DT 2,020,154, a reactor is proposed with a chamber arranged freely extensible in the housing shell. The inlet nozzle is attached to the housing of the engine and extends freely through the shell and the wall of the reactor chamber. The inlet nozzle is surrounded by a tubular nozzle attached to the wall of the reactor chamber extending freely through the shell, and sealed to the shell by a diaphragm. This construction is costly and difficult to assemble, and owing to the detachment of the inlet nozzle from the reactor chamber does not allow the latter to be heated up rapidly.
SUMMARY OF THE INVENTION
The object of the invention is to simplify the structure of the reactor, facilitate its attachment to the engine and make it possible to heat up the reactor rapidly.
This object is accomplished, according to the invention by the provisions of an inlet nozzle of the reactor protruding freely into the outlet passage of the engine, and the shell of the reactor having a portion thereof around the inlet nozzle in contact with the housing of the engine while being bolted at its periphery to the engine housing.
In the proposed arrangement, the direct and free protrusion of the inlet nozzle into the outlet passage of the engine serves to achieve rapid heating of the reactor chamber in the desirable manner, since the inlet nozzle is in direct thermally conductive connection with the reactor chamber but not with the engine housing. At the same time, the inlet nozzle is largely free to move in all planes in accordance with the thermal distortions of the reactor chamber, so that no stresses will be set up in the reactor. The attachment of the reactor to the combustion engine by the periphery of the shell results in considerably more convenient accessibility of the bolted connection and in a compact arrangement because of the proximity of the engine.
To achieve a simple and compact design the reactor may advantageously include a shell and the reactor chamber each defined by a substantially cylindrical member composed of two hemicylindrical shells, for example of metal sheet, approximately mirror images of each other. There emanates from the reactor chamber more or less perpendicular to its longitudinal axis an outlet nozzle jacketed in a matching prolongation of the shell. The inlet nozzle extends freely movable through a matching aperture in the shell, and opens into the reaction chamber more or less perpendicular to its longitudinal axis. The halves of the shell and the reactor chamber may be fabricated by simple pressing and stamping means.
The edges of the halves of the shell on the one hand and of the reactor chamber on the other hand are preferably welded together in each instance forming a peripheral flange, with the flange of the reactor chamber being joined to the edges of the half shell, preferably by welding only in the region of the outlet nozzle at a point distant from the chamber wall. The procedure of assembling the reactor entails first placing the reactor chamber welded up at its edge in the halves of the shell. Then to weld the edge of the reactor to the shell is welded only in the region of the outlet nozzle when welding up the edge of the shell. Thus free expansion of the reactor chamber is made possible.
Preferably, the flange of the reactor chamber is guided freely movable between the edges of the halves of the shell outside its area of attachment.
To achieve a vortex motion especially favorable to afterburning of the exhaust gases entering the reactor chamber, the inlet nozzle may open into the reactor chamber tangentially and extend partway into it. This too helps to heat up the wall of the reactor chamber rapidly.
The hemicylindrical half of the shell on the engine side preferably has a greater wall thickness than the other half of the shell, since this part of the reactor, directly in contact with the engine forms the supporting flange of the reactor, because of the bolted connection to the engine.
It is provided further that the inlet nozzle protruding into the outlet passage of the engine with clearance all around, shall be surrounded by a packing to provide a seal between the engine and the reactor. The seal may consist of a steel ring in direct contact with the inlet nozzle and a metal-asbestos ring arranged radially outside it. The steel ring prevents exhaust gas from leaking in between the inlet nozzle and the reactor shell; and the metal-asbestos ring is intended to seal the surface of contact of the reactor with the engine housing.
The packaging may be set in a recess of the housing around the outlet passage of the engine.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a cross-section of a reactor attached to an internal combustion engine having two outlet passages;
FIG. 2 shows a half of the reactor chamber in perspective; and
FIG. 3 shows a half of the reactor shell in perspective.
DETAILED DESCRIPTION
The reactor for internal combustion engines of this invention consists of a shell 1 and a heat-insulated reactor chamber 2 arranged freely movable therein, each in the form of a substantially cylindrical member. The shell 1 is composed of two metal sheet halves 1a and 1b approximately mirror images of each other; and, likewise, the reactor chamber 2 is composed of two metal sheet halves 2a and 2b approximately mirror images of each other. The reactor chamber 2 possesses two inlet nozzles 3 opening therein tangentially and extending freely movable through apertures 4 in shell 1. Each nozzle communicates with an outlet passage 5 of the engine 6. A tangentially departing outlet nozzle 7 is arranged more or less perpendicular to the longitudinal axis of the reactor chamber 2, and is jacketed in a matching prolongation 8 of the shell 1 and connected to the shell 1 exclusively in this region. The partings of the halves 1a and 1b and 2a and 2b preferably lie in one plane.
In the region of each outlet passage 5 a plane contact area 9 of the metal sheet half of shell 1 is in contact with the engine 6, and is bolted to the engine 6 by a peripheral flange 10 parallel to the contact area 9 by means of bolts 11 and spacers 12. Since the metal sheet half 1a forms the supporting flange of the reactor, it is thicker than the half 1b, in the interests of suitable rigidity of its contact areas 9. Each inlet nozzle 3 protruding into a turned recess 13 in the outlet passage 6 with clearance all around, is encircled by a steel ring 14 in direct contact with the inlet nozzle 3 and an asbestos-filled metal ring 15, both arranged in a recess 16 around the outlet passage 5. The steel ring 14 prevents exhaust gas penetrating the space formed between recess 13 and inlet nozzle 3 from escaping further through the aperture 4 between the shell 1 and the reactor chamber 2 while the metal-asbestos ring 15 seals the contact area 9 from the engine 6. The steel ring 14 fits closely but with lateral play in the recess 16, so that it can follow lateral movements of the inlet nozzle 3 due to thermal deformations of the reactor chamber 2.
FIG. 2 represents the metal sheet half 2a fabricated by pressing and stamping and having a peripheral edge 17, to be welded to the matching edge of the approximately mirror-image half 2b not shown, to form the complete reactor chamber 2. The outlet nozzle 7 is angled at its posterior end and emanates from the center of the reactor chamber 2. The two tangential inlet nozzles 3 viewed in longitudinal direction lie ahead of and behind the outlet nozzle 7, so that the incoming exhaust gases first execute a circling motion along the walls of the reactor chamber 2 before flowing out through the outlet nozzle 7.
In the region marked A and B, the contour of the reactor chamber 2 is superposable with the contour of the metal sheet half 1a or 1b shown in FIG. 3 of shell 1 to the inclusion of the holes 18 and 19. Owing to the indentations 20 the outlet nozzle 7 forms a free-standing neck enabling the reactor chamber 2, after being welded up with shell 1 in region A, B to be freely movable within shell 1 outside that region.
The metal sheet half 1a of shell 1 as shown in FIG. 3 is likewise fabricated by pressing and stamping and like its more or less mirror image half 1b has a peripheral edge 21 which after assembling of the reactor forms a peripheral flange 10 to be bolted to the engine by holes 18, 19 and 22. In the region of the apertures 4, the outer surface of the half shell 1a is provided with plane contact areas 9 which, however, may alternatively extend over the entire length of the half shell. The prolongation 8 angled at its lower end emanating from the center of the shell 1 jackets the outlet nozzle 7 of the reactor chamber 2.
To prevent the reactor chamber 2 freely movable within the shell 1 outside the region of its indentations 20, from assuming a change of position beyond the measure of thermal distortions, a guide is provided in the shell 1. The guide consists either of a pressed recess in the halves 1a and/or 1b more or less parallel to the edge 21, or of a fitted spacer ring 25 (in FIG. 1) placed between the edges 21. In this guide, the edge 17 of the reactor chamber 2 can move freely, the lateral distance being determined by the depth of the recess 23 or a matching thickness of the spacer ring 25. When the half shells 1a and 1b are welded up along the edge 21 the reactor chamber 2 is connected to the shell 1 at 27 (FIG. 1) in the region A and B of superimposability.
The heat-insulating space 26 between the shell 1 and reactor chamber 2 may contain either circulating air or a filling of insulating material. Thus the several aforenoted objects and advantages are most effectively attained. Although several somewhat preferred embodiments have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.
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An internal combustion engine possesses a reactor for afterburning of unburned constituents in the exhaust gas. The reactor includes a shell containing a heat-insulated, freely movable reactor chamber with at least one inlet nozzle extending freely through the shell and communicating with an outlet passage of the combustion engine. An outlet is also provided for escape of the exhaust gases from the reactor chamber.
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INDEX TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/085,464 filed Aug. 1, 2008, the disclosure of which is incorporated herein by reference in its entirety.
SUMMARY OF THE INVENTION
[0002] The present invention is a layered jewelry ring and method of fabrication whereby the ring is formed of two metal blanks that are bonded together.
[0003] The layered jewelry ring comprises
a. a first layer that encompasses a portion of the circumference on the outer surface of said ring; b. a second layer that encompasses substantially all of the circumference on the inner surface of said ring; c. a solder containing interface between said first layer and said second layer;
[0007] whereby said first and second layer are bonded together to form a single fused assembly shaped into a ring.
[0008] The first layer and second layer can be formed of the same material or can be formed of different materials. Each layer is formed of a metal, alloy, or combinations thereof.
[0009] In a preferred embodiment, the first layer is formed of gold and the second layer is formed of silver. The first layer of gold metal is about 0.05 to 0.50 cm thick and the second layer of silver metal is about 0.65 to 0.75 cm thick. The entire thickness of the ring is about 0.70 to 1.25 cm thick.
[0010] Preferably, the ring is formed such that the first layer is the primary visible layer when said ring is worn (i.e. when a ring is worn on a finger, about half of the ring surface is readily visible, the half that is on the back portion of a wearer's hand).
[0011] As used herein, the terms “gold” and “silver” refer to the metals and metal alloys commonly used in the art and are not limited to any pure composition.
[0012] In a preferred embodiment, the second layer comprises more than fifty percent the weight of said ring. In another preferred embodiment, the ring is formed of at least about 5% by weight of gold.
[0013] Also part of the present invention is a method for manufacturing a ring comprising the steps of:
(a) laminating a first plate to a desired thickness forming a first laminated plate; (b) laminating a second plate to a desired thickness forming a second laminated plate; (c) cutting a first blank from said first laminated plate; (d) cutting a second blank from said second laminated plate; (e) stamping a shelf on said second blank forming a stamped shelf; (f) soldering said first blank onto said second blank in an area defined by said stamped shelf, said soldered blanks collectively forming a soldered assembly; (g) passing said soldered assembly through an oven; (h) stamping said soldered assembly in a press and forming a bonded assembly with a fused edge; (i) cutting excess edge from said fused edge; (j) stamping a form onto said bonded assembly; (k) shaping said bonded assembly into a curved ring shape having two opposing ends; (l) cutting a joint on the ends of said curved bonded assembly; (m) soldering each of said ends one to another and forming a ring; and (n) polishing said ring.
[0028] The method may also include addition of desired designs, stone, stones, or combinations thereof.
[0029] In a preferred embodiment, the first laminated plate is preferably gold metal. This first laminated plate is cut to form a gold blank. The second laminated plate is preferably silver metal. The second laminated plate is cut to form a silver blank.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1A is a top view of a gold blank.
[0031] FIG. 1B is a top view of a silver blank.
[0032] FIG. 2A is a side view of a gold blank.
[0033] FIG. 2B is a side view of a silver blank.
[0034] FIG. 3 is a side view of a silver blank having a stamped shelf.
[0035] FIG. 4 is a side view of a joined assembly of gold blank placed on a stamped silver blank.
[0036] FIG. 5 is a top view of a joined assembly of gold blank placed on a stamped silver blank.
[0037] FIG. 6A is a top view of a trimmed gold blank placed on a stamped silver blank.
[0038] FIG. 6B is a side view of a trimmed gold blank placed on a stamped silver blank.
[0039] FIG. 7 is a side view of the assembled blanks that have been formed into a curved configuration having ends that are not yet joined.
[0040] FIG. 8 is a side view of the assembled blanks that have been formed into a curved configuration having ends that have been joined.
[0041] FIG. 9 is a perspective view of the ring.
[0042] FIG. 10 is a cross section of the ring along section lines A-A from FIG. 9
[0043] FIG. 11 is a cross section of an embodiment showing gold on about 60% of the outer circumferal surface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] Ring 10 of the present invention is formed by the permanent, bonded, and fused attachment of a gold blank 12 to a silver blank 14 . As shown in FIG. 4 , a gold blank 12 is secured to a silver blank 14 with a solder 16 . Initially, when gold blank 12 is secured to silver blank 14 and pressed together a border region is formed of excess solder 16 and some edging of the two metals 12 and 14 . This border region of excess solder 16 and edging of two metals 12 and 14 is referred to as a pretrim area 18 , as seen in FIG. 5 . Pretrim area 18 is removed, as seen in FIG. 6A , in procedures known in the art. Ring 10 is subsequently shaped in a curved configuration so that the joined gold blank 12 and silver blank 14 are formed into a substantially circular configuration. As shown in FIGS. 7 and 8 , ring 10 formed of gold blank 12 and silver blank 14 is formed into a curved configuration and opposing ends 11 and 13 are joined with a solder 20 . As shown in FIGS. 9 and 10 , ring 10 has a polished surface 22 and a stamped or laser logo region 26 on silver surface 28 . The laser logo is produced by laser engraving as is well known in the art. There are many commercially available machines available for laser etching and engraving on jewelry. Any type of machine that is suitable and known for laser etching and engraving may be used.
[0045] In laser etching, as the laser passes over the material, it is ablating the material, creating a constant depth and allowing fine detail.
[0046] In a preferred embodiment, stamped logo 26 is opposite a polished connection 24 said polished connection 24 overlays the surface of ring 10 and covers solder 20 .
[0047] The present invention is a ring 10 and a method for forming gold and silver layered rings. Ring 10 of the present invention advantageously gives the appearance of a gold ring although it is fabricated of two metal blanks that are bonded together. The outer visible portion of ring 10 is formed of a gold blank 12 and gold blank 12 constitutes less than fifty percent of the weight of ring 10 . A less expensive metal, such as silver, constitutes the majority of the weight of ring 10 and is on the inside of the finished ring 10 . The combination of gold and silver blanks 12 and 14 into ring 10 results in a final ring 10 that has the outward appearance of a gold ring when actually, ring 10 is less than fifty percent gold. In a preferred embodiment, ring 10 is a combination of a laminate (multiple sheets of metal soldered and pressured into a single piece) that is formed with gold blank 12 attached to a sterling silver base blank 14 . Gold blank 12 may be any gold composition, but is preferably 10, 14, or 18 karat as commonly known in the art.
[0048] A preferred metal for silver blank 14 is silver grain patented type “88” available from United Precious Metal Refining, Inc. (Alden, N.Y.).
[0049] Sterling Silver No. 88 is a proprietary deoxidized Sterling Silver formulation designed to eliminate fire scale, porosity and greatly improve tarnish resistance. Sterling Silver #88 sheet and wire products will be slightly softer than traditional Sterling Silver sheet and wire stock. Working characteristics of Sterling Silver #88 sheet and wire stock will be the same as traditional Sterling Silver.
[0050] Sterling Silver No. 88 alloy has low deoxidizing properties and helps eliminate undesired fire scale (a deep oxide of copper, formed below the surface of the silver, on prolonged heating) and porosity.
[0051] Although the present invention is described in terms of fabrication with gold and silver, the article of the invention and procedure for forming the article may be used with any combination of metals or metal alloys as desired.
[0052] Ring 10 of the present invention is made with a gold blank 12 formed such that, in a finished ring, gold from gold blank 12 is visibly perceived around a portion of outer surface 28 of ring 10 or with outer surface 28 being partially gold if desired.
[0053] In one embodiment, as seen in FIG. 11 , ring 10 has gold on 60% of the outer surface and there is 40% of silver on the outer surface. The entire interior surface is silver. Point “C” represents the center of a circle defined by ring 10 and points “A” and “B” each define a ray starting at point “C” and traveling away from the center of the circle such that central angle ACB is formed. Angle ACB has a measure of x degrees. In the embodiment depicted in FIG. 11 , angle ACB has a measure of 144° corresponding to 40% of the degree measure and circumference of a circle. The 40% silver portion is used for sizing the ring and is not readily visible when ring 10 is worn. Although the depicted embodiment provides one example of a percentage of gold on the outer circumferal surface, this percentage can be changed if desired.
[0054] The present invention uses a gold blank 12 with a thickness of about 0.05 to 0.50 cm and a sterling silver blank 14 with a preferred thickness of about 0.65 to 0.75 cm. Ring 10 of the present invention is formed of a majority of silver and is thus less expensive than a ring formed of solid gold or gold alloy.
[0055] Ring 10 of the present invention is formed by a procedure as follows:
[0056] Gold blank 12 and silver blank 14 are prepared from cut laminate metals. Each of the laminate metals that are cut to form gold blank 12 and silver blank 14 are cut to a desired thickness prior to said cut metals being cut into blanks. Each of gold blank 12 and silver blank 14 are cut using a stamping machine, which uses pressure to bend, shape, and cut metal as is known in the metalworking art. Silver blank 14 is subsequently stamped a second time such that a shelf bottom 15 and shelf side walls 17 is stamped thereon, as can be seen in FIGS. 3 and 4 . Shelf bottom 15 is surrounded on its perimeter by shelf side wall 17 . Shelf bottom 15 and side wall 17 define a cavity that is constructed and arranged to accommodate receipt of gold blank 12 therein, as shown in FIG. 4 . Gold blank 12 nests within cavity formed of side walls 17 and shelf bottom 15 . Gold blank 12 nests securely in silver blank 14 in the stamped cavity of silver blank 14 that is defined by shelf bottom 15 and shelf side walls 17 .
[0057] After the aforementioned stamping, gold blank 12 is attached to silver blank 14 using solder 16 . Gold blank 12 is placed on top of silver blank 14 and each of blanks 12 and 14 are bonded and secured together, as set forth below, by a combination of successive steps involving solder, heat and pressure.
[0058] In a preferred embodiment, solder 16 is a paste solder which is a mixture of microscopic solder particles and flux, a chemical cleaning agent that facilitates soldering.
[0059] Depending on the desired application, soft solders, having a melting point in the range of about 700-720° F., medium solders having a melting point in the range of about 745-775° F., or hard solders having a melting point in the range of about 750-780° F., are selected. Alternatively, gold solders can be used in the method of the present invention.
[0060] Solder 16 is placed between gold blank 12 and silver blank 14 in any manner known in the art. After the soldering, the stamped and soldered assembly 19 of gold blank 12 , silver blank 14 , and solder 16 , is passed through a solder oven (SM Engineering Inc., North Attleboro, Mass.) at 1650° F. degrees at a 12.5 oven speed setting. The oven control speed setting controls the speed of a belt that moves through the oven carrying assembly 19 . The scale ranges from 0 (stop) to 100 (fastest). The temperatures and speed settings are adjusted as needed in a manner known to those skilled in the art.
[0061] The soldered, heat-treated assembly 19 of gold blank 12 and silver blank 14 is subsequently stamped again using about 5 tons of pressure per square inch utilizing a press (not shown) as is known in the art. The stamping creates a fused bond between gold blank 12 and silver blank 14 . This subsequent stamping step typically produces an excess edge 18 as depicted in FIG. 5 . The excess edge 18 is then removed, typically by cutting the excess edge, and the result is a trimmed bonded form as shown in FIG. 6 .
[0062] The fused bonded assembly 19 of gold blank 12 and silver blank 14 is then turned into a ring shape using a ring bender or customized mechanical tooling, such as a foot press, as is known in the art. The foot press is used in the metalwork art to bend, shape, form and cut base metal during a fabrication process. The curved shape is shown generally in FIG. 7 .
[0063] Sides, or end edges 11 and 13 of assembly 19 must be cut to ensure a perfect union between the two edge portions 11 and 13 to be soldered. The cut must be precise to eliminate the possibility of porosity on the weld line, i.e. the edges that are ultimately joined by solder. Precision cutting is performed by procedures known in the art.
[0064] The junction of edges 11 and 13 is a joint that is then bench soldered using wire silver solder 20 . The solder is preferably a composition having the same or a substantially similar alloy composition as the ring and fine silver is used in the process.
[0065] The soldered ring 10 is then tumbled one hour in a magnetic tumbler to pre-polish.
[0066] After tumbling is complete, the ring 10 is buffed using a lapping disc on the edges and cotton and/or felt wheels on the inner and outer surfaces in a manner known in the art.
[0067] If desired, ring 10 is then stamped with a logo 26 .
[0068] Optionally, a design is then cut into the ring using a diamond faceting machine known in the art, to a thickness from 0.02 cm to 0.50 cm depth and taking care such that the cutting cuts less than 20% of gold mass in ring 10 .
[0069] The gold surface of ring 10 is optionally textured with a sandblasting machine or hand textured with different grades of sanding discs depending on desired design and finish of the outer surface of ring 10 .
[0070] If desired, a stone (not shown) may be set on ring 10 depending on design.
[0071] Ring 10 is then polished and electro cleaned.
[0072] Finished ring 10 may optionally have a coating applied. Coatings are applied in methods known in the art, which may employ using a combination of a coating pen application, dipping ring 10 in a rhodium solution, or combinations thereof. Typically, coatings are applied with a minimum thickness of about 0.10 microns and range up to and including about 2.00 microns for the coating thickness.
[0073] While the invention has been described in its preferred form or embodiment with some degree of particularity, it is understood that this description has been given only by way of example and that numerous changes in the details of construction, fabrication, and use, including the combination and arrangement of parts, may be made without departing from the spirit and scope of the invention.
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A ring formed of a first gold layer and second silver layer wherein the silver layer is more than fifty percent of the ring weight. The layers are bonded together with the gold layer on a portion of the outer surface to give an appearance of a ring formed entirely of gold. A method for fabricating the ring is also provided.
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BACKGROUND TO THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to temporary closure devices suitable for use in tube couplings and also to tube couplings incorporating temporary closure devices.
[0003] 2. Background Prior Art
[0004] U.S. Pat. No. 4,269,237 discloses a device for draining and collecting sump oil from a motor vehicle having a drain plug which is closed by a ball valve or rupturable membrane. Oil is drained from the sump by inserting a drain spigot into the plug body to open the valve or to rupture the membrane so that oil drains through a hose connected to the spigot into a shallow vessel which may be located beneath the vehicle.
[0005] British Patent Specification No. 2182320 discloses a keystone bung and a cask connector for beverage casks. The bung has an outer periphery constructed to seal with a given keystone and a through bore closed by a sealing diaphragm. The through bore has an internal screw thread to mate with an external thread on the cask connector so that it can be screwed into the through bore and a tapered inner end of the connector can rupture the diaphragm to open the bung.
[0006] This invention provides a temporary closure device for a throughway comprising a sleeve to fit in the throughway and a core located in the sleeve, the core having an encircling annular rupturable connection locating the core in the sleeve to prevent flow of fluids through the sleeve, the annular connection being rupturable by displacing the core axially in the sleeve to allow fluid to flow through the sleeve.
[0007] More specifically, the annular rupturable connection is formed by an annular web extending between the core and the sleeve.
[0008] Thus, in one arrangement according to the invention the web may be formed integrally with the core and has a rupturable connection with the sleeve.
[0009] For example, the annular web may be formed integrally with both the core and the sleeve, the connection between the web and the sleeve being rupturable to permit the core to move axially in the sleeve to allow flow through the sleeve.
[0010] In a further arrangement, the annular web may be bonded to the sleeve, the bond being rupturable to permit the core to move axially in the sleeve to allow flow through the sleeve.
[0011] In a still further arrangement, the throughway in the sleeve may have annular abutment means with which the web engages to locate the core in the sleeve and from which the web can be disengaged by pressing the core into the throughway to allow flow of fluid along the throughway.
[0012] In any of the above arrangement the sleeve may be an elongate sleeve having a front portion in which the core is located and a rear portion to which the core may be displaced to allow flow of fluid through the sleeve.
[0013] In the latter arrangement the rear portion of the sleeve may be formed with one or more axially extending slots in the wall of the sleeve through which fluid may flow when the core is located in the rear of the sleeve.
[0014] More specifically, a plurality of slots may be formed in the rear portion of the sleeve equispaced around the sleeve.
[0015] In the case where an elongate sleeve is provided and the core is moulded in the front portion of the sleeve, the core may have an end projecting from the front end of the sleeve with which a tube or other component can act to displace the core into the sleeve to open the passage through the sleeve. The projecting end of the core may taper from the integral annular web to the front of the core. Also, the front of the core may have an integral projecting cruciform shape to receive a tube or other component to displace the core.
[0016] In any of the above arrangements the sleeve and core may be moulded plastics components.
[0017] The invention also provides a tube coupling body having a throughway open at one end to receive a tube, a locking device in the throughway to engage and secure the tube in the throughway, a seal in the throughway beyond the locking device to engage and seal with the tube when the latter is fully inserted into the throughway and is engaged by the locking device and a closure device located in the throughway beyond the seal to be engaged by the tube as the latter is inserted into the throughway, the closure device incorporating a rupturable seal arranged to be ruptured by full insertion of the tube or pin to permit flow in the throughway.
[0018] The closure device may comprise a sleeve to be engaged in the throughway, a core located in the sleeve with a rupturable seal extending between the plug and sleeve, the plug being engaged by a tube or pin inserted into the throughway to rupture the seal with the sleeve and displace the plug along the sleeve to allow flow through the sleeve.
[0019] In the latter construction the closure device may comprise a sleeve and a core located in the sleeve, the sleeve having a front portion and a rear portion, the plug being located in and supported in the front portion of the sleeve by a thin breakable annular web formed integrally between the core and sleeve to prevent flow of fluids through the sleeve, the core being possibly displaceable into the rear portion of the sleeve and the rear portion of the sleeve having a passage or passages therein to permit flow of fluid passed the core when located in the rear portion.
[0020] More specifically, the rear portion of the sleeve may be formed with one or more axially extending slots in the wall of the sleeve through which fluid may flow when the core is located in the rear of the sleeve.
[0021] In one example according to the invention, a plurality of slots may be formed in the rear portion of the sleeve equispaced around the sleeve for fluid flow when the core is displaced into the rear portion of the sleeve.
[0022] In accordance with a further feature of the invention the core may be moulded in the front portion of the sleeve and may have an end projecting from the front end of the sleeve on which a tube or other component can act to displace the core into the sleeve to open the passage through the sleeve. Furthermore, the projecting end of the core may taper from the integral annular web to the front of the core and the front of the core may have an integral projecting cruciform shape to receive a tube or other component to displace the core.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The following is a description of some specific embodiments of the invention, reference being made to the accompanying drawings in which:
[0024] [0024]FIG. 1 is a partially cross-sectioned view of a tube coupling with an end part of a tube inserted partway into the coupling and a closure device located in the coupling in a closed condition;
[0025] [0025]FIG. 2 is a similar view to FIG. 1 with the tube end fully inserted into the coupling and the closure device in the open condition;
[0026] [0026]FIG. 3 is an enlarged view of part of the coupling, part of the end portion of the tube and the closure device shown in FIG. 1;
[0027] [0027]FIG. 4 is an elevation view of the closure device out of the tube coupling;
[0028] [0028]FIG. 5 is an perspective view of the closure device; and
[0029] [0029]FIG. 6 is a cut-away perspective view of the closing device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Referring firstly to FIG. 1 of the drawings, there is shown a tube coupling indicated generally at 10 and an end portion indicated at 11 of a tube which is inserted partway into the coupling. The tube coupling is generally of the type described and illustrated in my European Patent No. 829671 to which reference should be made for a detailed description of the coupling.
[0031] The coupling comprises a coupling body indicated generally at 12 comprising a short spigot 13 having a central throughway 14 and external annular ribbing 15 to engage and grip in a soft walled tube (not shown). The spigot of the coupling body leads into an enlarged diameter socket 16 having a bottom wall 17 with which the spigot is integrally formed. The throughway 14 in the spigot opens into an increased diameter bore 18 in the socket at an internal annular step 19 at the bottom of the socket facing outwardly of the socket. The socket has a further stepped increase in bore at 20 from which an enlarged diameter end portion extends to terminate in an open end 22 to the coupling body.
[0032] A collet indicated generally at 23 for locking a tube in the coupling body is mounted in the socket adjacent the open end thereof. The collet comprises an annular skirt 24 having a stepped outer surface formed with reduced diameter portion 25 at a step 26 which engages in the stepped bore 18 with the step 26 abutting the step 20 . The skirt 24 has a plurality of resilient arms 27 projecting towards the open end of the socket and is formed with inturned abutment teeth 28 to engage with a tube inserted into the coupling body.
[0033] A tube to engage in the coupling body is indicated at 29 . The tube has a reduced diameter end portion 30 which projects into the socket of the coupling body through the open end 22 , and has an integral encircling annular bead 31 with which the teeth 28 on the collet engage as the tube is inserted into the socket. As shown in FIG. 1, the tube is partially inserted into the socket and the bead 31 is in engagement with the outer sides of teeth 28 of the collet.
[0034] The bore 18 of the socket 16 contains, further along from the collet 24 , a first O-ring seal 32 to engage with the outer surface of the tube inserted into the socket, a spacer 33 and further O-ring seal 34 and finally a closure device indicated generally at 35 .
[0035] The detailed construction of the closure device is shown in FIGS. 3 to 6 to which reference will now be made. The closure device comprises a sleeve 37 having a stepped bore the sleeve having a forward portion 38 in which the larger diameter bore is formed containing a slightly small diameter portion bore and a rear portion 39 . The sleeve is located between the second O-ring seal 34 in the socket and shoulder 19 where the socket reduces in diameter to the spigot 13 . The front portion of sleeve 38 contains a core comprising a central cylindrical portion 40 which is smaller in diameter than the internal diameter of the sleeve 38 to leave a gap 41 between the core and forward portion of the sleeve. The core is located in the sleeve by means of an annular web 43 of triangular cross-section formed integrally with the core and tapering to a apex formed integrally with the inner surface of the sleeve. The connection between the apex of the web and the inner surface of the sleeve is rupturable to release the core from the sleeve as will be described later.
[0036] The core has a frusto-conical portion 42 extending from the web 43 outwardly of the sleeve and to terminate in a projecting cross or cruciform abutment 44 at the forward end of the core. The opposite, rearward end of the core is formed with a similar cruciform projection 45 . The core is a close fit in the rear near portion 39 of the sleeve which has a plurality of slots 46 extending into the sleeve from the rearward end to allow flow of fluid around the core.
[0037] As indicated earlier, the apex of the web 43 connecting the core 40 to the forward portion 43 of the sleeve is rupturable and the cruciform abutment 44 at the front end of the core is designed to be engaged by the leading end of tube portion 30 as the latter is inserted into the connecting body and the raised bead 31 on the tube comes into engagement with the teeth 28 of the collet. On pressing the tube further into the socket of the coupling body, the end of tube forces the core 35 rearwardly breaking the connection of the core to the sleeve and driving the core into the rear part of the sleeve where fluid flow around the core can take place via the slots 46 in the sleeve. At the same time the raised bead 31 snaps past the tube 28 which then engage on the rearward side of the bead to hold the tube in the socket shown in FIG. 2.
[0038] The sleeve and collet are conveniently moulded in one piece in plastics material with the web formed integrally with the core and also integrally with the sleeve as described earlier. A modification of that arrangement, the core and sleeve may be moulded as separately components with the web being formed integrally with the core and the core can be secured and placed in the front portion of the sleeve by adhering the apex of the web with the sleeve which again provides as rupturable connection. In a further modification, the web on the core projects into a annular slot in the sleeve which holds the web and prevents flow past the core. An excess force to the core will, however, force the core along the sleeve thus disengaging the web from the slot.
[0039] In a further modification, the closure device may comprise the core and the front portion of the sleeve, the rear portion being omitted.
[0040] The tube coupling may be supplied with a “stuffer pin” formed integrally with the core to position the core in the coupling. The “stuffer pin” can be used to press the core through the sleeve to open the coupling for flow. The stuffer pin is designed to snap off the core in tension to allow it to be removed.
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The disclosure relates to a temporary closure device for a throughway comprises a sleeve to fit in the throughway and a core located in the sleeve. The core has an annular rupturable connection locating the core in the sleeve to prevent flow of fluids through the sleeve. The annular connection is rupturable by displacing the core axially in the sleeve to allow fluid to flow through the sleeve.
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This is a continuation of application Ser. No. 07/174,247 filed 03/28/88.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to seeding machines.
2. Description of the Prior Art
A previously proposed seeding machine comprises a rotary drum partially immersed in a reservoir containing seeds. The drum has a plurality of holes in its outer circumferential surface, which holes can alternately be connected to a source of vacuum and source of pressure. As each hole passes through the mass of seeds in the reservoir, the vacuum applied draws the nearest seed to close or partially close the hole. As the drum rotates the attracted seed is lifted out of the mass of seeds and when the seed reaches a discharge position a source of pressure is applied to the particular hole to shoot the seed to a desired discharge tube or location. The disadvantage of this arrangement is that the seeds in the mass of seeds do not move readily so that when seeds are picked out of the mass at a predetermined withdrawal location, they are not readily replaced by adjacent seeds. Instead a hole is created in the mass at the withdrawal location so that no further seeds are withdrawn. A further problem which occurs because the seeds do not have sufficient mobility is that a seed attracted to a hole and carried round by the drum may well engage a seed located in front of it and push the seed along towards the discharge position.
This renders the seeding arrangement inefficient since not only is it wasteful of seeds, but when two seeds are planted at the same location, one of the resulting seedlings has to be picked out, usually manually, and this is then wasteful of manpower.
It is an object of the present invention to provide an improved seeding machine.
SUMMARY OF THE INVENTION
According to the present invention there is provided a seeding machine comprising first and second movable surfaces constrained to make contact along a common axis and thereafter separating to define a seed trough, means for displacing the surfaces away from the common axis to cause any seeds in the trough to tumble continuously, one of said surfaces defining a plurality of openings which can be coupled to a source of pressure difference to attract an individual seed to each opening and to allow the surface to carry the individual seeds to a location for discharge.
According to the present invention there is further provided a seeding machine comprising a rotary drum defining a plurality of axially extending rows of openings, a roller urged into contact with the drum to define with the drum a seed trough, means for rotating the drum and the roller in opposite senses so that the facing surfaces of the drum and roller are continuously rising out of the trough to tumble any seeds which have been deposited in the trough, and means for effecting a pressure difference across each opening to cause it to attract a seed as it passes through the trough and to carry the attracted seed to a location for discharge.
BRIEF DESCRIPTION OF THE DRAWINGS
Seeding machines embodying the present invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:
FIG. 1 is a perspective view of a first machine embodying the invention;
FIG. 2 is an end elevation of the machine of FIG. 1;
FIG. 3 is a fragmentary perspective view of a second machine embodying the invention;
FIG. 4 is a plan view of the machine of FIG. 3, to an enlarged scale.
FIG. 5 is an end elevation of a drum for the seeding machine;
FIG. 6 is a longitudinal section through a drum support assembly; and
FIG. 7 is a side elevation of the drum and roller drive assembly of the machine.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The seeding machine shown in FIGS. 1 and 2 is arranged to dispense seeds one row at a time into a seed tray 2 having rows and columns of individual pockets 4 filled with a seed compost (not shown). The seed tray 2 is arranged to be displaced through the seeding machine by a conveyor belt 6 which carries the tray 2.
The machine comprises an elongate rotary drum 8 and an elongate rotary roller 10 arranged in mating engagement with the drum 8. The drum 8 and roller 10 are mounted between two spaced side plates (not shown) by bearings (not shown) with their axes extending parallel to one another. The drum 8 is provided with a plurality of internal axially extending equi-angularly spaced air channels 12 (see FIG. 2). Each channel 12 communicates with a corresponding axially extending row of holes 14 in the circumferential surface of the drum. At one axial end, the drum 8 is in sliding contact with a support plate (not shown). An arcuate groove 16 in the support plate and coupled to a source of vacuum (not shown) is located along the locus of the adjacent axial ends of the channels 12. Thus as each channel 12 becomes aligned with the arcuate groove 16, the channel 12 is subjected to a vacuum.
Along the same locus but spaced from the arcuate groove 16 are two circular apertures 18 and 20 of different size. Each aperture is coupled to a source of pressure (not shown). As each channel 12 becomes aligned with the apertures 18 and 20, the channel is subject to a blast of air under pressure.
The drum 8 and the roller 10 define a trough 22 into which seeds can be poured. A hopper 24 is provided adjacent one end of the trough 22 to feed a constant supply of seeds to the trough 22. The hopper 24 may have an adjustable outlet to regulate the flow rate of seeds therefrom. Extending into the trough at the end adjacent the hopper 24 is a wall of bristles 26 mounted on a support 28. The wall of bristles 26 prevents any seeds from falling out of the trough 22 at that end. The opposite end of the trough 22 is open. A funnel 30 is located below the open end of the trough 22 to catch the seeds falling therefrom. The funnel 30 communicates with a conduit 32 which extends parallel to the axis of the drum 8 and roller 10 and passes under the roller 10 to rise at the other side to a position where it is directed downwardly into the hopper 24. The conduit 32 is supplied with air under pressure which drives any seeds entering the conduit 32 from the funnel 30, along the conduit to be discharged into the hopper 24.
A hollow tube 34 extending parallel with the drum 8 is located above the drum 8. The tube 34 which is connected to a source of pressure (not shown) is provided with a row of holes to direct air jets at the surface of the drum 8 to dislodge any seeds, clinging only loosely to the drum surface, back into the trough 22.
A doctor blade 36 engages the roller 10 in an upper portion of the trough 22 to dislodge any seeds clinging to the surface of the roller 10 to return them to the trough 22.
A drive assembly (not shown) drives the roller 10 and the drum 8 in opposite senses so that the surfaces of the roller 10 and drum 8 which define the opposite walls of the trough 22 are always rising upwardly out of the trough 22.
In operation when a seed tray 2 is to be planted with seeds, the seed tray 2 is indexed under the drum 8 at the same pace as the circumferential speed of the drum 8. The hopper 24 is loaded with a supply of seeds which run from the base of the hopper along the trough 22 to spill out of the end of the trough into the funnel 30. Seeds entering the funnel 30 are then returned to the hopper along the conduit 32 by an air flow. The drum 8 and the roller are rotated in opposite directions so that the rising sides of the trough 22, which are in frictional engagement with the seeds, raise the seeds to a level at which they fall again under gravity. The seeds in the trough 22 are thus kept continually in motion which helps the flow of seeds along the trough 22 and also tends to effect the separation of seeds from one another.
As the drum rotates, each row of holes enters the trough 22 in turn. As soon as a row of holes has entered the trough 22 the conduit 12 with which the row is associated, communicates with the arcuate groove 16 and the holes are subjected to a vacuum. The vacuum force draws a seed from the trough 22 to close or partially close each hole in the row. The vacuum for each row of holes is held while the row moves through the highest point of the drum until it approaches the lowest point. At this point the conduit 12 associated with the row becomes disconnected from the arcuate groove 16 and the vacuum force to the holes ceases. Some of the seeds will now drop into respective pockets 4 in the tray 2 waiting below. With continual rotation of the drum 8 the conduit 12 is brought into alignment with the small aperture 18 which then supplies low pressure air to the holes to dislodge, into the waiting pockets 4, any seeds which did not become released from the drum 8 upon discontinuance of the vacuum. As the drum 8 continues to rotate a doctor blade 40 of Tufnol or similar material scrapes any stubborn remaining seed from the drum surface. Finally when the conduit 20 aligns itself with the larger aperture 20 a much stronger blast of air is applied to the row of openings with a view to unclogging any aperture which had become inadvertently clogged.
As the row of holes rises again into the trough 22 the whole cycle is repeated.
The fluid nature of the seeds as they are tumbled in the trough assists in attracting seeds to the hole but there will inevitably arise the occasion where two or even three seeds are held against one hole by the vacuum or one seed will carry another in front of it. The provision of the tube 34 with air jets which are directed towards the holes, tends to unsettle any grouping of seeds around a single hole and to blow any seeds which become thus released from the vacuum forces, back into the trough 22.
The air jet from the tube 34 is preferably arranged at an angle of 45° to the tangent to the portion of the drum 8 lying directly below the tube 34. The tube 34 may be provided with an additional jet for each hole in the drum directed to blow any seeds away from the trough. The two jets in the tube 34 for each hole in the drum may be arranged at 90° to each other. Excess seeds removed by this jet are caught in the trough 41.
In the seeding machine shown in FIGS. 3 to 5 parts similar to those in FIGS. 1 to 2 are similarly referenced. As shown two hoppers 24 and 24A are provided one adjacent each end of the trough 22. Also the walls of bristles 26 and 26B are provided one at each of the two opposite ends of the trough 22.
Instead of a single roller engaging the drum 8, two half length rollers 10A and 10B are provided axially spaced from one another, to leave a central gap in the trough 22 through which seeds can fall. A funnel 30 located below the gap collects the fallen seeds and by means of an air assisted return conduit feeds the collected seeds back to one or both hoppers 24 and 24B.
With this arrangement the distance the seeds have to travel along the trough is halved and so a smoother and more uniform flow of seeds is ensured.
In a modification of the arrangement shown in FIGS. 3 and 4 the recirculation device is omitted and instead the rate at which seeds are fed from the two hoppers is controlled by gate valves (not shown) adjacent the lower part of the hoppers.
One embodiment of the drum is shown in more detail in FIG. 5. As shown the drum is formed from two components, an outer sleeve 50 of hard anodised aluminium with holes 52 arranged in separate axially extending rows, and an inner core 54 of cast aluminium comprising an inner cylinder 56 with twelve radially projecting equi-angularly spaced fins 58. When the drum is assembled, the inner core 54 is placed within the outer sleeve 50 so that the distal ends of the fins seal against the inner wall of the sleeve 50. This can be accomplished by adopting shrink fit procedures, using adhesives, or even welding. The fins define twelve axially extending channels. For normal seeding operations only six channels are needed and so every alternate channel is filled with an impermeable medium 60. The remaining six intervening channels communicate with respective rows of holes.
The drum is sealed at one axial end and to the other axial end is secured an annular ring 62 of plastics impregnated with graphite. O-rings 63 provide a seal between each channel in the drum and respective ones of six through holes 70 in the annular ring 62. The annular ring 62 is mounted on a stub shaft 72 extending from an end support 62. The end support 64 has an annular end face which is in sliding engagement with the annular ring 6. This annular end face is profiled to define the arcuate groove 16 and the two apertures 18 and 20 shown in FIG. 2. The end support 64 carries a coupling spigot 68 which is coupled to a source of vacuum 69 through a hose line 71, the coupling spigot 68 being in communication with the groove 16. The end support also carries another coupling spigot 70 which is coupled to a source of pressure 75 by a hose line 73; the coupling spigot 70 being in communication with the two apertures 18 and 20.
The drum 8 is driven by an electric motor (not shown). The drum 8 and the roller 10 are coupled by gears to ensure that their surface velocity is the same at the point of contact between the roller 8 and the drum 10. The roller 80 is narrow and positioned opposite an intermediate section of the roller 10 to provide pressure on the roller 10 and hence on the drum to ensure close contact between the drum and the roller. Another advantage of this arrangement is that the rollers 10 and 80 can be easily separated for cleaning or servicing purposes.
FIG. 7 also shows a modification for sweeping the drum 8 clean from unwanted seeds. A pivotally supported arm 94 carries a brush head 96 at its free end. Bristles or rubber strips extending from the brush head engage the drum. As the drum 8 rotates the bristles sweep the drum clean. A rotary cam 92 engaging the arm 94 is rotated in synchronism with the drum so that each time a row of holes in the drum passes the bristles, the arm 94 and therefore the bristles are lifted to allow the holes and the seeds which are attracted to the holes free passage. As soon as each row of holes has passed the cam 92 allows the arm 94 to drop to bring the bristles back into engagement with the drum again.
While a presently preferred embodiment of the present invention has been illustrated and described, modifications and variations thereof will be apparent to those skilled in the art given the teachings herein, and it is intended that all such modifications and variations be encompassed within the scope of the appended claims.
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A seeding machine has a drum and roller urged together to define a seed trough. Bristles close one end of the trough and a hopper adjacent that end feeds a continuous supply of seeds to the trough. The seeds flow along the length of the trough and are discharged at the opposite end of the trough which is open. A funnel collects the discharged seeds and returns them to the hopper. The drum is provided with a series of axially extending rows of holes which are coupled to a vacuum source as each row passes through the tumbling seeds in the trough. A single seed is attracted to each hole and is carried by the drum to a discharge location where the hole in question is disconnected from the vacuum source and instead connected to a source of pressure which then acts to eject the seed from the drum.
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FIELD
The present invention is directed generally to distributed contact centers and more specifically to the transfer of status information and control signals between different sites in a distributed contact center.
BACKGROUND
Contact centers are employed by many enterprises to service customer contacts. A typical contact center includes a switch and/or server to receive and route incoming packet-switched and/or circuit-switched contacts and one or more resources, such as human agents and automated resources (e.g., Interactive Voice Response (IVR) units), to service the incoming contacts. Contact centers distribute contacts, whether inbound or outbound, for servicing to any suitable resource according to predefined criteria. In many existing systems, the criteria for servicing the contact from the moment that the contact center becomes aware of the contact until the contact is connected to an agent are customer-specifiable (Le., programmable by the operator of the contact center), via a capability called vectoring. Normally, in a present-day Automatic Call Distributor (ACD) when the ACD system's controller detects that an agent has become available to handle a contact, the controller identifies all predefined contact-handling queues for the agent (usually in some order of priority) and delivers to the available agent the highest-priority oldest contact that matches the agent's highest-priority queue.
Originally, contact centers were designed as single site operations. In other words, all of the contact center resources such as servers, agents, managers, and the like were located at a single site. A single site contact center was relatively easy to manage because all of the resources were essentially in a common environment. When an agent became available, the server controlling workflow was apprised of the availability almost instantly and could monitor the contact and agent queues in real-time.
As businesses become global and contact center job outsourcing becomes a viable option to many companies, contact centers are beginning to grow into multiple site operations. The resources for a contact center may be redundantly provided at each site such that every site can operate autonomously and communication between sites is not a requirement for operation. However, providing fully redundant contact center sites can become costly when the only additional resource really required is contact center agents. For this reason, many multiple site contact centers share resources. For example, one site may have all of the resources to be a complete contact center, whereas another site only has contact center agents or other resources with specific skills. The complete contact center receives all incoming contacts and routes the contacts to the other site having only agents or specialized resources. Under this scenario, contact center agent status information has to be relayed from the remote site to the ACD at the complete contact center. In fact, it is often the case in multiple site call centers that large amounts of information about the agents, skills (services), queues, and other status information needs to be transmitted between sites. An example of such a geographically distributed call center is described in US Patent Application No. 20060067506 to Flockhart et al., the entire disclosure of which is hereby incorporated herein by reference.
Functions that are performed as part of network management and in managing contact centers specifically include controlling, planning, allocating, deploying, distributing, coordinating, and monitoring the resources of a network. Network planning, traffic routing, load balancing, resource optimization, cryptographic key and/or license distribution, configuration management, fault management, and many other functions are examples of such data. A number of methods exist to support such network management function including, but not limited to, Simple Network Management Protocol (SNMP), Command Line Interfaces (CLIs), eXtensible Mark-up Language (XML) variants, Comm on Management Information Protocol (CMIP), and others.
Specifically, in fully distributed architectures such as Services Oriented Architectures (SOAs), contact centers and other large distributed telecommunications environments, such a method of data distribution would be particularly useful. Illustratively, in contact centers, large amounts of information about agents, skills (services), and queues need to be transmitted between the distributed contact center locations. The communications link should be established to the other sites by first finding them, then by making a connection (usually through firewalls), and finally providing real-time, encrypted communications with some guarantee of minimum latency.
SUMMARY
Mechanisms have been developed to facilitate the efficient transmission of status and control information between geographically disparate call centers using codec tunneling. U.S. patent application Ser. No. 11/619,504 to Davis et al., the entire contents of which are incorporated herein by reference, describes how to utilize Session Initiation Protocol (SIP) and a Real-time Transport Protocol (RTP) to communicate data between separate communication elements. This particular patent application proposed to use the capabilities of SIP to find and connect two endpoints and establish an RTP session between the endpoints. To find additional sites, a SIP INVITE message is used to establish a new session with additional remote servers, thereby making the expansion of the system somewhat inefficient.
Embodiments of the present invention propose the use of conference call facilities to allow interested parties (e.g., distributed locations in the case of a contact center) to dial into or connect with a secure conference call and then publish and subscribe to data which is published by other participants of the conference call. Therefore, use of conference call facilities provides an efficient mechanism for expanding the number of parties that share status and control information.
In the context of a contact center, the concept of using a secure conference call for data communications amongst the distributed contact center locations provides the advantage of creating a clearing house that any distributed application can participate in when they are in an active contact center location or in the case of SOA when they are a required application.
In accordance with at least some embodiments of the present invention, a method of sharing status and/or control information is provided that generally comprises:
subscribing, at a first communication site, with a conference mechanism;
establishing, by the first communication site, a Real-time Transport Protocol (RTP) stream with the conference mechanism; and
receiving, at the first communication site, at least one of status information and control signals associated with a second communication site from the conference mechanism via the RTP stream.
Another method is provided that generally comprises:
subscribing, at a first communication site, with a conference mechanism;
establishing, by the first communication site, a Real-time Transport Protocol (RTP) stream with the conference mechanism; and
providing, by the first communication site, at least one of status information and control signals to the conference mechanism for publishing to a second communication site via a separate RTP stream.
As can be appreciated by one skilled in the art, a single communication endpoint and/or site may be adapted to publish and subscribe to published information. The conference mechanism is a mechanism that facilitates the sharing of this published information among other subscribing entities (e.g., other communication endpoints and/or sites).
An RTP packet and header structure as well as the Real-time Transport Control Protocol (RTCP) is described more fully in US Patent Application No. 20030120789 to Hepworth et al., the entire disclosure of which is hereby incorporated by reference. Although embodiments of the invention are described in connection with the use of RTP, it can be appreciated by one of skill in the art that a similar media transport protocol may be employed. Accordingly, as used herein “RTP” is understood to include any standardized or non-standardized packet format for delivering audio and/or video information over a packet switched network. Allowable protocols may include any multicast and/or unicast protocols used in streaming media systems. The protocols may be designed for real-time applications like RTP or they may be designed for non-real-time application. Moreover, RTP as discussed herein can include any past, present, or future version of RTP including Secure RTP (SRTP) and those versions and derivatives of RTP not yet contemplated.
As can be appreciated by one of skill in the art, a contact is understood herein to include voice calls, emails, chat, video calls, fax, Instant Messages (IMs), conferences, and combinations thereof. Accordingly, a contact center may be equipped to handle any one or a number of the above-noted contact types.
These and other advantages will be apparent from the disclosure of the invention(s) contained herein. The above-described embodiments and configurations are neither complete nor exhaustive. As will be appreciated, other embodiments of the invention are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.
As used herein, “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram depicting a distributed communication system in accordance with embodiments of the present invention;
FIG. 2A is a block diagram depicting a publish data structure utilized in accordance with embodiments of the present invention;
FIG. 2B is a block diagram depicting a subscribe data structure utilized in accordance with embodiments of the present invention; and
FIG. 3 is a flow diagram depicting a method of sharing status and/or control information in accordance with embodiments of the present invention.
DETAILED DESCRIPTION
The invention will be illustrated below in conjunction with an exemplary communication system. Although well suited for use with, e.g., a system using a server(s) and/or database(s), the invention is not limited to use with any particular type of communication system or configuration of system elements. Those skilled in the art will recognize that the disclosed techniques may be used in any computing application in which it is desirable to share status/control information.
The exemplary systems and methods of this invention will also be described in relation to analysis software, modules, and associated analysis hardware. However, to avoid unnecessarily obscuring the present invention, the following description omits well-known structures, components and devices that may be shown in block diagram form, are well known, or are otherwise summarized.
For 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 the specific details set forth herein.
FIG. 1 shows an illustrative embodiment of a distributed communication system 100 in accordance with at least some embodiments of the present invention. The communication system 100 may comprise a plurality of communication endpoints or other types of distributed sites 108 connected to a common conference mechanism 104 . The conference mechanism 104 may be adapted to act as an information clearing house for each of the sites 108 a -N connected thereto. More specifically, the conference mechanism 104 may collect information that is published from various sites 108 and selectively share the published information with other sites 108 that have been given permissions to access the published information.
Permissions to access published information may be granted generically to any site 108 that is capable of connecting to the conference mechanism 104 (i.e., any site 108 that has connected to the appropriate conference number on the conference mechanism 104 and/or provided the conference mechanism 104 with a valid password). Alternatively, permissions to access published information may be granted selectively by the publishing site 108 . For instance, the publishing site 108 may identify other sites 108 that are allowed to receive published information or the publishing site 108 may identify certain requirements that another site 108 has to meet before that site 108 is allowed access to information sent to the conference mechanism 104 by the publishing site 108 . In accordance with at least some embodiments of the present invention, each site 108 may connect with the conference mechanism 104 at one of several different access permission levels (e.g., low, medium, or high access permission levels). A publishing site 108 may, for example, identify the minimum access permission level that is required for another site 108 to be eligible to receive information published by the publishing site 108 .
In accordance with at least some embodiments of the present invention, the conference mechanism 104 may comprise one or more data structures to help determine how published information should be distributed among the sites 108 connected thereto. Examples of the types of data structures that may be maintained at the conference mechanism 104 include a publisher list 112 and a subscriber list 116 . Although these lists are depicted as being separate lists, one skilled in the art will appreciate that a single publisher/subscriber list may be maintained on the conference mechanism 104 . The lists 112 , 116 may be dynamically updated as sites 108 connect to and disconnect from the conference mechanism 104 .
As can be seen in FIG. 1 , a plurality of sites 108 a - d , 108 g - 108 N may be connected directly to the conference mechanism 104 . Additionally, one or more sites 108 e , 108 f may be connected to the conference mechanism 104 through another site 108 . In accordance with at least some embodiments of the present invention, the multiple communication sites 108 may be connected to the conference mechanism 104 via a single communication port (e.g., an Ethernet port, a phone port, an RS-232 port, etc.). Alternatively, multiple sites 108 may be connected to the conference mechanism 104 via a plurality of different interfaces or ports. In the event that a single port is used to connect two or more sites 108 to the conference mechanism 104 , multiple separate RTP sessions may still be established with each communication site 108 .
In accordance with at least some embodiments of the present invention, the sites 108 may correspond to a single communication endpoint (e.g., a phone, laptop, computer, etc.), a collection of communication endpoints, a single communication device (e.g., a switch, a server, a gateway, or some other intermediate communication device), and/or a collection of communication devices. A contact center is one example of a site 108 that may be connected to the conference mechanism 104 in accordance with at least some embodiments of the present invention. The contact center may be adapted to share and receive status and/or control information from other contact centers and a contact center controller or call router via the conference mechanism 104 .
Referring now to FIGS. 2A and 2B exemplary data structures 112 , 116 utilized by the conference mechanism 104 will be described in accordance with at least some embodiments of the present invention. FIG. 2A depicts an exemplary publisher list 112 that is utilized to maintain identities of current publishing endpoints connected to the conference mechanism 104 .
The publisher list 112 may comprise a number of different data fields to facilitate the dissemination of information received from each publishing entity. Examples of such data fields include a publisher identification field 204 , an access permissions field 208 , and a backup conference mechanism(s) identifier field 212 . The publisher identification field 204 may be utilized to maintain identification information for each publishing entity that has created a secure connection (i.e., an RTP connection or SRTP connection) for sharing status and/or control information with the conference mechanism 104 . The types of identification information that may be maintained in the publisher identification filed 204 includes, but is not limited to, a network address associated with a publishing entity (e.g., an IP address, an extension, a phone number, etc.), a location identifier (e.g., an identifier of the physical location of the site 108 , an area code, or the like), a session identifier, a port identifier, or any other unique or semi-unique identifier for a communication site 108 .
The access permission field 208 may include information related to data access permissions granted by or otherwise associated with a publishing entity. In accordance with at least some embodiments of the present invention, a publishing entity may be adapted to define access permissions for the data that is published by the publishing entity to the conference mechanism 104 . Data, access permissions may be restricted in either a negative or positive manner. In a negative restriction, the publishing entity may identify security permissions or other requirements that must be met for another site 108 to be allowed access to information published by the publishing entity. In a positive restriction, the publishing entity may positively identify one or more sites 108 that are not allowed to access information published by the publishing entity. Thus, the access permission field 208 may include either identifiers of requirements needed to gain access to published information or identifiers of sites 108 that are allowed or not allowed to gain access to published information.
The backup conference mechanism(s) identifier field 212 may include information that can be used by the conference mechanism 104 to initiate and direct a re-connection of a publishing entity to another conference mechanism 104 . This may be particularly useful in the event that Quality of Service (QoS) falls below a predefined threshold for data transmissions to/from a conference mechanism 104 . In accordance with at least some embodiments of the present invention, if the conference mechanism 104 cannot support any further publishing entities, then the conference mechanism 104 may forward a request to connect to another conference mechanism 104 such that the publishing entity may still be able to connect with the status/control information clearing house. Information maintained in the backup identifier field 212 may include identifiers of potential backup conference mechanisms 104 , their associated capabilities, as well as thresholds (e.g., minimum QoS) that define when a site 108 should be transferred to a backup conference mechanism 104 identified in the field 212 .
FIG. 2B depicts an exemplary subscriber list 116 that may include a subscriber identifier field 216 , an access permissions field 220 , and a backup conference mechanism(s) identifier field 224 . The backup conference mechanism(s) identifier field 224 may be similar to the same field 212 in the publisher list 112 .
Referring now to FIG. 3 , an exemplary data sharing method will be described in accordance with at least some embodiments of the present invention. The method is initiated when a communication site 108 connects with a conference mechanism 104 (step 304 ). This particular step may involve the communication site 108 establishing a secure RTP stream with the conference mechanism 104 , a prerequisite of which is that the communication site 108 may need to provide authentication information to the conference mechanism 104 (step 308 ). The communication site 108 may also require some sort of authentication information from the conference mechanism 104 (i.e., mutual authentication). Once the authentication information has been validated, the RTP stream is established between the conference mechanism 104 and the communication site 108 (step 312 ). The RTP stream may be employed to transfer status and/or control information between the conference mechanism 104 and the communication site 108 . Additionally, the conference mechanism 104 may update its publishing list 112 and/or subscriber list 116 , depending upon whether the communication site 108 is acting as a publishing and/or subscribing entity.
After the connection between the communication elements has been established, the method continues with the communication site 108 providing the publish/subscribe parameters to the conference mechanism 104 (step 316 ). Examples of such parameters include, but are not limited to, the types of published information a particular site 108 wants to receive (i.e., control vs. status information) as well as publishing and subscription access permissions for allowing or gaining access to published information.
Thereafter, the method continues by waiting until a publish trigger occurs or until published information is received due to the site's 108 subscription to the conference mechanism 104 (step 320 ). Thus, the communication site 108 first determines whether a publish trigger has occurred (step 324 ). A publish trigger may include meeting or exceeding any threshold associated with making a decision to publish status and/or control information. In accordance with at least one embodiment of the present invention, a publish trigger may include any state change at the communication site 108 (e.g., when the entire communication site 108 has a global state change). Another publish trigger may include any state change of sub-entities within the communication site 108 . For instance, every time a resource (e.g., a contact center agent, IVR, voicemail, etc.) within the communication site 108 has a change in state, a publishing trigger may occur. Other publishing triggers may include the generation of a control signal. Still another publishing trigger may include receiving status information and/or control signals from another communication site 108 . This is particularly relevant to instances where once communication site 108 is in communication with a conference mechanism 104 via another communication site 108 .
In the event that a publishing trigger occurs, the method continues with the communication site 108 publishing the relevant status information and/or control signals to the conference mechanism 104 (step 328 ). If, however, a publishing event has not occurred, then the method continues by determining whether status information and/or control signals have been received at the conference mechanism 104 (step 332 ). This information may be received by a communication site 108 either connected directly to the conference mechanism 104 via an RTP stream or connected indirectly to the conference mechanism 104 though another communication site 108 . If not data has been received at the conference mechanism 104 from a publishing communication site 108 , then the method returns to step 320 .
Alternatively, if some sort of status information and/or control signals are received at the conference mechanism 104 , then the method continues with the conference mechanism 104 processing the received information and/or signals (step 336 ). In processing the receiving data, the conference mechanism 104 may utilize its publisher list 112 to determine if the received data has any access restrictions placed thereon as well as its subscriber list 116 to determine where the data can be sent. Depending upon this determination, the conference mechanism 104 may forward the received data to one or more subscribing entities allowed access to such data. Thus, the conference mechanism 104 operates as a conference bridge for status information and/or control signals for the communication sites 108 connected thereto. But rather than being a typical conference bridge, the conference mechanism 104 utilizes its various RTP streams with each communication site 108 to distribute such data. Moreover, the received data may include an identifier (e.g., that identifies the publishing entity) to help the conference mechanism 104 properly process the received data.
After the conference mechanism 104 has processed such data, the method continues by determining whether the conference quality is satisfactory with one or more of its RTP streams (step 340 ). This step may include performing a quality check on its connections with the communication sites 108 . This step may also include polling the subscriber communication sites 108 to determine if published information sent to such entities was, in fact, received by those subscribing entities.
If the quality is satisfactory, then the method returns back to step 320 . Conversely, if the quality of communications with one or more communication sites 108 is not up to quality thresholds, then the method continues with the conference mechanism 104 identifying a backup conference mechanism for one or more of the sites 108 connected thereto (step 344 ). This information may be retrieved from one or both lists 112 , 116 , depending upon whether the poor conference quality is associated with a publishing and/or subscribing entity. Thereafter, the method returns to step 304 where the communication site 108 attempts to connect with an alternative conference mechanism 104 .
While the above-described flowcharts have been discussed in relation to a particular sequence of events, it should be appreciated that changes to this sequence can occur without materially effecting the operation of the invention. Additionally, the exact sequence of events need not occur as set forth in the exemplary embodiments. The exemplary techniques illustrated herein are not limited to the specifically illustrated embodiments but can also be utilized with the other exemplary embodiments and each described feature is individually and separately claimable.
The systems, methods and protocols of this invention can be implemented on a special purpose computer in addition to or in place of the described communication equipment, 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, a communications device, such as a server, personal computer, any comparable means, or the like. In general, any device capable of implementing a state machine that is in turn capable of implementing the methodology illustrated herein can be used to implement the various communication methods, protocols and techniques 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 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 analysis systems, methods and protocols illustrated herein 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 communication arts.
Moreover, the disclosed methods may be readily implemented in software that can be stored on a storage medium, executed on a programmed general-purpose computer with the cooperation of a controller and memory, 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 an applet, JAVA® or CGI script, as a resource residing on a server or computer workstation, as a routine embedded in a dedicated communication system or system component, or the like. The system can also be implemented by physically incorporating the system and/or method into a software and/or hardware system, such as the hardware and software systems of a communications device or system.
It is therefore apparent that there has been provided, in accordance with the present invention, systems, apparatuses and methods for sharing status and/or control information among a number of different entities. 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.
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A distributed contact center and method of managing data transfers between the distributed parts of the contact center is provided. Distributed parts of the contact center are joined together through a known communications initiation protocol, then one or both of status information and control signals are transferred between the distributed parts using lossless communication protocols. The status information and/or control signals may be published to a large number of interested entities through the use of conference call facilities.
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BACKGROUND OF THE INVENTION
The present invention relates to a method of producing bleached wood pulp in which wood chips are digested and are then subjected to subsequent bleaching stages that are conducted in the presence of a sodium hydroxide. More particularly the present invention relates to such a method that includes an ozone bleaching stage in which a waste stream produced from an ozone bleaching stage is scrubbed to produce an oxygen containing stream useful in an oxygen delignification stage of the pulping process. Even more particularly, the present invention relates to such a method in which the waste stream is scrubbed by white liquor either in an external stage or during production of polysulfide liquor and then is separately reacted with white liquor to produce oxidized white liquor containing an appreciable amount of thiosulfate species of sulfur (thiosulfate liquor), and fully oxidized white liquor, containing almost no thiosulfate sulfur, to serve as sodium hydroxide in bleaching stages.
In the formation of bleached wood pulp, wood chips are digested in the presence of white liquor, which contains sodium sulfide and sodium hydroxide for such digestion, to produce brownstock pulp and weak black liquor. It is known that pulping with polysulfide liquor has advantages over conventional white liquor cooking in the wood chip digestion stage. The brownstock pulp is then washed and weak black liquor is extracted for reprocessing. The pulp is then subjected to oxygen delignification. The oxygen delignification is conducted in the presence of thiosulfate liquor, oxygen and steam. After the oxygen delignification, the wood pulp is sequentially subjected to an ozone bleaching stage, an extractive oxidation stage, which may be conducted in the presence of peroxide, and a final peroxide or chlorine dioxide bleaching stage. The extractive oxidation stage is conducted in the presence of thiosulfate liquor. Fully oxidized white liquor is a sodium hydroxide source for peroxide based bleaching stages and has advantages in such bleaching stages over thiosulfate liquor.
The ozone feed to the ozone bleaching stage is made in an ozone generator from air or more preferably oxygen. The end result is a mixture of ozone and oxygen containing about 5% ozone if air is used and anywhere from 10 to 14% ozone if the ozone is generated from oxygen. Not all of the feed to the ozone bleaching stage is consumed and as a result, a waste stream is produced that contains ozone, oxygen, carbon dioxide and water. This waste stream is further processed by an ozone destruct unit and a carbon dioxide scrubber to produce oxygen that can be used in an oxygen deliqnification stage. Ozone is destroyed so that the stream may be recycled to the ozone generator after CO 2 removal and drying. Also, some of the waste stream may be vented atmosphere and ozone must be destroyed for industrial hygienic reasons. Carbon dioxide must be removed, otherwise it would consume sodium hydroxide inside the oxygen delignification stage, limiting the extent of lignin removal.
As will be discussed, the present invention provides a method of producing bleached wood pulp in which a waste stream produced from an ozone bleaching stage is scrubbed and then used as a source of oxygen for oxygen delignification. Expensive ozone destruct units are not used and in fact oxygen requirements can be balanced with oxygen recovery from the waste stream. The implication of this is that an oxygen recycle involved in the utilization of the ozone destruct unit can be eliminated together with its attendant capital and power consumption. Additionally, there is no need to further purify the waste stream to remove carbon dioxide and water. Moreover, the present invention advantageously utilizes polysulfide liquor in the wood chip digestion stage, oxidized white liquor in oxygen delignification and extractive oxidation stages, and fully oxidized white liquor in the peroxide bleaching stage.
SUMMARY OF THE INVENTION
The present invention provides a method of producing bleached wood pulp. In accordance with the method, wood chips are digested in a digestion stage to produce brownstock pulp and weak black liquor. The brownstock pulp is washed and the weak black liquor is extracted. The brownstock pulp after having been washed is introduced into sequential bleaching stages, including oxygen delignification and ozone bleaching stages, to produce a bleached wood pulp product. The oxygen delignification stage utilizes an oxygen containing stream and the ozone bleaching stage utilizes an ozone/oxygen containing stream. The ozone bleaching stage produces a waste stream principally containing water vapor, carbon dioxide, ozone, and oxygen. The waste stream is recovered and scrubbed with an aqueous, sodium sulfide and sodium hydroxide containing solution to remove ozone and carbon dioxide from the waste stream and thereby form a scrubbed stream. The oxygen containing stream, used in the oxygen delignification stage, is formed from at least part of the scrubbed stream.
Residual ozone is consumed from the waste stream by oxidizing sodium sulfide to an oxygenated sulfur species such as sulfite, thiosulfate or sulfate. Sodium hydroxide reacts with carbon dioxide to form sodium carbonate. In this manner, the waste stream becomes a scrubbed stream to eliminate the need for an ozone destruct unit. Additionally, since carbon dioxide has been removed, it will not neutralize the alkalinity required in the oxygen deliqnification process. Furthermore, in another aspect of the present invention, that will be discussed hereinafter, the oxygen recovered from the waste stream can be balanced with oxygen usage by utilizing the waste stream as an oxidant in a polysulfide production stage. Such usage will scrub the waste stream and will produce polysulfide that can be advantageously used in the wood chip digestion stage. Furthermore, the resultant scrubbed stream can also be used in oxidizing and fully oxidizing the white liquor in oxidized white liquor and fully oxidized white liquor stages. The fully oxidized white liquor can also advantageously be used in a peroxide based bleaching stage.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims distinctly pointing out the subject matter that Applicants regard as their invention, it is believed that the invention will be better understood when taken in connection with the accompanying drawings in which:
FIG. 1 is a schematic representation of a method of producing bleached wood pulp in accordance with the present invention;
FIG. 2 is a schematic view of an alternative embodiment of a method of producing bleached wood pulp in accordance with the present invention; and
FIG. 3 is a schematic of a reactor used in producing fully oxidized white liquor.
DETAILED DESCRIPTION
With reference to FIG. 1, a process flow sheet of a method for producing bleached wood pulp is illustrated. Wood chips 10 and a polysulfide liquor stream 12 enter a digestion stage 14 , which can be provided by a known wood pulp digester, to produce brownstock pulp and weak black liquor. The brownstock pulp is introduced into a washing stage 16 , which can be a rotary washer, along with oxygen stage filtrate. The brownstock pulp is washed with the water and the weak black liquor is extracted as a weak black liquor stream 17 . Although not illustrated but as would be known to those skilled in the art that digestion and washing stages 14 and 16 could be integrated and generally could also include a knotting stage separating the digestion and washing stages 14 and 16 and a screening stage following washing stage 16 .
Weak black liquor stream can be processed in a manner well known in the art to produce white liquor. This is accomplished by introducing the weak black liquor into multiple effect evaporators and a recovery boiler to convert the weak black liquor to smelt. The smelt is then dissolved in a dissolving tank to produce green liquor. The green liquor is then causticized in a causticizing tank by the addition of lime from a lime kiln and is then subjected to a clarifying stage to produce the white liquor. All of these stages, which are known in the art, are designated by white liquor regeneration stage 18 . White liquor from white liquor regeneration stage 18 can be held for use within a holding tank 19 . It is to be noted that although not illustrated, washers would be placed between each of the stages with countercurrent flow of washer filtrate from washer to washer and then back to washing stage 16 . This is the manner in which oxygen stage filtrate is obtained for washing stage 16 . At the same time, the weak black liquor is being reprocessed to form white liquor which is in turn used throughout the bleaching process. It is to be noted that a mass balance can be maintained throughout the mill without the resort found in the prior art of adding sodium hydroxide. When sodium hydroxide is added, it can potentially build and thus be discharged from the mill.
The brownstock pulp is then introduced into an oxygen delignification stage 20 along with steam and a thiosulfate liquor stream 22 and a first oxygen containing stream 24 . The oxygen delignification stage 20 would be provided by a reactor, known in the art. The delignified wood pulp is then introduced into an ozone bleaching stage 26 along with an ozone/oxygen containing stream 28 to produce an ozone-bleached pulp and a waste stream 29 . The ozone-bleached pulp and a second oxygen-containing stream 28 is then introduced into a known extractive oxidation stage 30 along with a first fully oxidized white liquor stream 32 and a second oxygen containing stream 34 . The extractive oxidation stage is provided to remove soluble alkaline reaction products produced in ozone bleaching stage 26 . In the illustrated process, extractive oxidation stage 30 utilizes peroxide (the stream containing peroxide is not illustrated). It is to be noted that in some extractive oxidation processes peroxide is not utilized. In this regard, first fully oxidized white liquor stream 32 is optional because it is only required when peroxide is present within extractive oxidation stage 30 . When peroxide is not present, thiosulfate liquor may be substituted for fully oxidized white liquor. The ozone bleached pulp produced in extractive oxidation stage 30 is then introduced into a known peroxide bleaching stage 36 along with a second fully white oxidized liquor stream 38 to produce a bleached wood pulp product 39 . Alternatively, a chlorine dioxide bleaching stage could be used in place of the peroxide bleaching stage. In such case, second fully oxidized white liquor stream 38 would not be used.
Waste stream 29 from the ozone bleaching stage 26 is then introduced along with a subsidiary stream 40 composed of white liquor into a polysulfide reaction stage 42 . Polysulfide reaction stage 42 can be a stirred tank, a pipeline reactor or a device using counter-current contact devices such as structured packing. In any of these reactors, the white liquor serves to strip the carbon dioxide from the waste stream while the white liquor is oxidized by the oxygen contained within waste stream 29 to produce the polysulfide liquor. The sulfide reactions remove ozone. Thus, waste stream 29 is introduced into polysulfide reaction stage 42 as a third oxygen containing stream which becomes scrubbed with respect to carbon dioxide and ozone to become scrubbed stream 44 .
Scrubbed stream 44 is then compressed by a compressor 45 to an elevated pressure at which oxygen delignification stage 20 , white liquor and complete white liquor oxidizing stages, designated by reference numbers 46 and 48 , operate. These foregoing stages operate at an elevated pressure as compared with the remainder of the apparatus illustrated in FIG. 1 . After compression, scrubbed stream 44 is subdivided into first and second oxygen containing streams 24 and 34 and a forth and a fifth oxygen containing streams 50 and 52 which are then introduced into white liquor and complete white liquor oxidizing stages 46 and 48 , respectively, along with two other subsidiary streams 54 and 56 containing white liquor. Thiosulfate liquor is produced in white liquor oxidizing stage 46 and fully oxidized white liquor is produced in complete white liquor oxidizing stage 48 which in turn respectively serve as makeup for thiosulfate liquor stream 22 and first and second fully oxidized white liquor streams 32 and 38 .
As possible alternative embodiments, either thiosulfate liquor, white liquor, or fully oxidized white liquor could be used as an alkaline, aqueous solution to scrub carbon dioxide from waste stream 29 . In such alternative embodiments, waste stream 29 could be used as either the forth or fifth oxygen containing streams 50 and 52 to produce a scrubbed stream emanating from either white liquor and complete white liquor oxidizing stages 46 and 48 . Thereafter, such scrubbed stream would be subdivided into first and second oxygen containing streams 24 and 34 , a third oxygen containing stream to be introduced into polysulfide reaction stage 42 and either the remaining forth or fifth oxygen containing streams 50 and 52 which was not formed by waste stream 29 . As could be appreciated, in any of the foregoing embodiments in which waste stream 29 is used to directly form either fourth or fifth oxygen containing streams 50 and 52 , waste stream 29 must be compressed to the elevated operating pressure of white liquor and complete white liquor oxidizing stages 46 and 48 . For that matter, in any possible embodiment of the present invention, waste stream 29 could be compressed in lieu of compressing the scrubbed stream.
The oxygen requirements of a method in accordance with the present invention, such as outlined above, will depend upon whether the final bleaching stage is a peroxide bleaching stage or a chlorine dioxide bleaching stage. Chlorine dioxide bleaching is an acidic process that does not consume oxidized white liquor or oxygen and as such will not consume oxygen. Additionally, the amount of polysulfide produced will also effect oxygen consumption. On the supply side, the amount of oxygen produced will depend on the ozone requirements in the ozone bleaching stage. The greater the requirement for ozone, the greater will be the oxygen production. The following is a calculated chart of oxygen production versus usage is a process conducted in accordance with the present invention as set forth in FIG. 1 . In the first column, the term, “W % O 3 ” means the percentage by weight ozone in the ozone/oxygen containing stream produced by the ozone generator and used in ozone bleaching stage 26 . The term “O 3 charge on pulp” is the ozone requirement for the particular pulp being bleached. The next column, headed, “O 2 produced from O 3 gen” is the oxygen content in the ozone/oxygen containing stream. Under the grouping “oxygen Usage in Mill, the “%PS as S” is the percentage poly sulfide charge on the pulp expressed as sulfur. “PS-OZE op -P” indicates the use of a peroxide bleaching stage with an extractive oxidation stage using peroxide. “PS-OZE op -D” indicates a chlorine dioxide bleaching stage. For comparison purposes, the oxygen usage of a prior art pulp bleaching process that does not use polysulfide is labeled, “No PS”.
OXYGEN REQUIREMENTS FOR 1000 MFPD O.D. PULP
O 2
pro-
duced
O 3
from
Oxygen Usage in Mill
Wt.
charge
O 3
2% PS as S
1% PS as S
%
on pulp
gen
PS-
PS-
PS-
PS-
O 3
(% wt.)
mtpd
OZE OP -P
OZE OP D
OZE OP -P
OZE OP D
10
0.8
72
72
60
64
52
10
1.0
90
72
60
64
52
12
0.8
59
72
60
64
52
12
1.0
73
72
60
64
52
14
0.8
49
72
60
64
52
14
1.0
61
72
60
64
52
OXYGEN REQUIREMENTS FOR 1000 MTPD 0.D. PULP
Oxygen Usage in Mill
O 3 charge
O 2 produced
on pulp
from O 3 gen
No PS
Wt. % O 3
(% wt.)
mtpd
PS-OZE OP -P
PS-OZE OP D
10
0.8
72
57
45
10
1.0
90
57
45
12
0.8
59
57
45
12
1.0
73
57
45
14
0.8
49
57
45
14
1.0
61
57
45
As indicated by the charts, oxygen usage can be balanced. Also, under certain circumstances, the combination of ozone output and ozone charge required will not produce enough oxygen to sustain a process in accordance with the present invention. For instance, where the weight percent ozone in the ozone/oxygen containing stream 12 and the required ozone charge on the pulp is 0.8, then the 59 kg of oxygen per metric ton per day of oven dried pulp would only be sufficient to sustain a process in accordance with the present invention in which a chlorine dioxide bleaching stage were used and with a polysulfide stage that produced 1% sulfur in the polysulfide.
With reference to FIG. 2, waste stream 29 can be scrubbed within a scrubbing stage 58 by a partial stream 60 formed of thiosulfate liquor produced within white liquor oxidizing stage 46 to form a scrubbed stream 44 b which is then introduced into polysulfide reaction stage 42 as the third oxygen containing stream. The excess of scrubbed stream 44 b not used within polysulfide reaction stage 42 is then subdivided into first and second oxygen containing streams 24 and 34 and forth and fifth oxygen containing streams 50 and 52 . The thiosulfate liquor after having served its scrubbing function is returned as a recycled thiosulfate stream 61 which is added to the white liquor and used in forming subsidiary streams 54 and 56 .
Alternatively, partial stream 60 could be formed of fully oxidized white liquor from complete white liquor oxidizing stage 48 , white liquor, or polysulfide liquor from polysulfide reaction stage 42 . If fully oxidized white liquor is used, only carbon dioxide will be removed. No ozone destruct tubes place. As a result the residual ozone would eventually be consumed. This would not be preferred because the ozone would adversely effect conventional equipment and fittings. The resultant scrubbed stream could then again be introduced into polysulfide reaction stage 42 with the excess being subdivided into first and second oxygen containing streams 24 and 34 , the third oxygen containing stream, and forth and fifth oxygen containing streams 50 and 52 . A further alternate is that scrubbed stream 44 b could be compressed and introduced into either white liquor or complete white liquor oxidizing stage 46 or 48 and then, the excess subdivided into first and second oxygen containing streams 24 and 34 , the third oxygen containing stream, and either the forth or fifth oxygen containing stream 50 and 52 . As is apparent from the above discussion, in the embodiment of FIG. 2, the scrubbed stream is being used to form all oxygen containing streams.
With reference to FIG. 3, a preferred fully oxidized white liquor reactor 62 is illustrated. Reactor 62 consists of a liquid/vapor contacting column 64 of approximately 9.84 meters in height by about 0.9 meters in diameter. Column 64 is provided with an a white liquor inlet 66 and an oxygen inlet 68 to top and bottom regions 70 and 72 of column 64 , respectively. An oxygen stream is introduced into the column through inlet 66 and a white liquor stream is introduced into the column through inlet 68 .
The white liquor and oxygen are brought into intimate contact by contacting elements which are preferably formed by beds of structured packing designated by reference numeral 74 . As would be known by those skilled in the art, liquid distributors would be located between pairs of beds. The white liquor is introduced into structured packing 74 by a liquid distributor 76 and the oxygen rises through the open area of structured packing 74 . Structured packing is efficient and has a very low pressure drop. This allows the recycling of the gas stream with a blower or an eductor. It is to be noted that to preclude clogging of the packing by particulates, the packing type and crimp angle are important. In this regard, structured packing 74 can have a packing density of between about 500 m 2 /m 3 and is preferably Koch Type 1 X or 1 Y which can be obtained from Koch Engineering Company, Inc. of Wichita, Kansas. Random packing and trays could also be used with less effectiveness.
Column 64 should be operated at a pressure of no less than 9.2 atmospheres absolute. The oxygen should have a purity as high as is economical with 90% and above being preferred. The reaction should proceed at a total pressure of no less than about 9.2 atmospheres absolute and more preferably at least about 11.2 atmospheres absolute. Additionally, the reaction between the oxygen and the sodium sulfide should occur at a minimum temperature of about 110° C. A minimum reaction temperature of about 120° C. is more preferred and reaction temperatures at or above 150° C. are particularly preferred. A particularly preferred temperature and pressure is about 200° C. and about 18 atmospheres absolute.
The reaction of oxygen and sodium sulfide is an exothermic reaction. However, to start the reaction heat must be added to the white liquor to raise it to the requisite reaction temperature. To this end, a heat exchanger 78 can be provided before inlet 66 in which the incoming white liquor is heated by indirect heat exchange with steam. After the reaction progresses, heat exchanger 78 can be shut down.
The oxidized white liquor collects as a column bottom 80 within bottom region 72 of column 64 . A product stream 82 of the oxidized white liquor is removed from bottom region 70 of column 64 and divided into first and second fully oxidized white liquor streams 32 and 38 . At the same time, an oxygen containing tower overhead collects within top region 70 of column 64 .
Tower overhead stream is circulated by an eductor 82 having a low pressure inlet 84 , a high pressure outlet 86 , and a high pressure inlet 88 . A stream of in-process white liquor is pumped by a pump 90 through eductor 82 . Low pressure inlet 84 of eductor 82 draws the tower overhead stream from top region 70 of column 64 . The pumped oxidized white liquor is introduced into a high pressure inlet 88 of eductor 82 and a combined stream of tower overhead and oxidized white liquor is discharged from high pressure outlet 86 of eductor 82 . High pressure outlet 86 is connected by a conduit 92 to bottom region 70 of column 64 in order to circulate the oxygen-containing column overhead back into bottom region 70 .
Stripped gas impurities and reaction products which may serve to dilute the tower overhead stream and thereby lower oxygen partial pressure can collect at the top of column 64 . In order for such gas impurities and reaction products to not affect the reaction, they can be periodically or continually vented through the use of a small vent 94 provided for such purpose.
The following are examples of the method of the present invention as carried out in FIGS. 1 and 2.
EXAMPLE 1
The following is an example of a practice of the invention in accordance with the embodiment illustrated in FIG. 1 . For purposes of the examples set forth herein it is assumed that the white liquor has the following composition:
Unoxidized White Liquor (UWL) Composition
g/L as salt
g/L as sulfur
Na 2 S
40
16.4
NaOH
100
—
Na 2 CO 3
33.7
—
Na 2 S 2 O 3
1.3
0.5
Na 2 S x
0
—
Na 2 SO 4
1.0
0.2
Total
176
17.1
In the following discussion, the term “kg/mtpd pulp” means kilograms per metric ton per day of oven dried wood pulp being processed. In this Example 1, about 333 kg/mtpd pulp of white liquor is introduced into polysulfide reaction stage 42 . Additionally, 813 kg/mtpd pulp of white liquor is divided so that subsidiary stream 54 flows at about 250 kg/mtpd pulp and subsidiary stream 56 flows at approximately 563 kg/mtpd pulp to supply white liquor and complete white liquor oxidizing stages 46 and 48 . Polysulfide reaction stage 42 in this example operates at approximately 80° C. and at 1 atm and produces 20 kg/mtpd pulp of polysulfide expressed as sulfur.
The typical composition of the polysulfide liquor, expressed in grams/liter salt or grams/liter sulfur is as follows:
Grams/Liter as
Sulfur
Grams/Liter as Salt
Na 2 S x
5.0
—
NaOH
—
100
Na 2 CO 3
—
33.7
Na 2 SO 4
1.0
—
Na 2 S 2 O 3
2.0
—
The production of thiosulfate liquor and fully oxidized white liquor of partial and complete white liquor oxidizing stages 46 and 48 are roughly equal to the flow rates of white liquor entering these stages. The composition of the thiosulfate liquor and the fully oxidized white liquor is as follows when expressed in g/L as salt.
Thiosulfate
Fully Oxidized
Liquor
White Liquor
Na 2 S
0.0
0
NaOH
100
85
Na 2 CO 3
33.7
33.7
Na 2 SO 4
—
73
Na 2 S 2 O 3
—
<1.0
All of the thiosulfate liquor is utilized in oxygen delignification stage 20 while about 188 kg/mtpd pulp of the fully oxidized white liquor is used in extractive oxidation stage 30 with peroxide and about 375 kg/mtpd pulp of fully oxidized white liquor is used in a final peroxide bleaching stage 36 . An ozone generator (not illustrated) is required to produce a mixture of about 10 kg/mtpd pulp of ozone and 73 kg/mtpd pulp of oxygen. In ozone bleaching stage 26 , roughly 0.2% of the ozone is lost and waste stream 29 has the following approximate composition:
WL for Ozone Stage off-gas Cleaning
Typical composition on a weight percent basis
Oxygen
83%
O 3
0.2%
CO
30-40 ppm
CO 2
8-9%
H 2 O
satd at 40° C.
Organics
<10 ppm
All of waste stream is introduced into polysulfide reaction stage 42 which in turn uses about 14.9 kg/mtpd pulp of oxygen. Scrubbed stream 44 contains approximately 58 kg/mtpd pulp of oxygen, approximately 30 ppm carbon monoxide and water saturated at 80° C. Scrubbed stream 44 is compressed in compressor 45 to between about 100 and 150 psig and approximately 25 kg/mtpd pulp of oxygen is introduced into oxygen delignification stage 20 , about 5 kg/mtpd pulp of oxygen is introduced into the extractive oxidative stage 30 . Approximately 4.9 kg/mtpd pulp of oxygen is introduced into the partial white liquor oxidation stage 46 and about 22.2 kg/mtpd pulp of oxygen is introduced into the complete white liquor oxidizing stage 48 . The result of this is about 72 kg/mtpd pulp of oxygen is consumed and about 1 kg/mtpd pulp of oxygen is lost or vented from the process.
As can be seen from this example, a major advantage of the present invention is that most of the oxygen can be recycled back into the pulp bleaching apparatus and process if the waste stream 29 is first introduced into polysulfide reaction stage 42 . Polysulfide reaction stage 42 will scrub carbon dioxide from waste stream 30 while consuming some of the oxygen. This will produce a lesser volume to be compressed by compressor 45 which is an advantage to be realized in lower power consumption.
EXAMPLE 2
Example 1 has particular application to white liquor that does not have too high a sulfidity. When sulfidity is high, the carbonic acid formed in the polysulfide reactor due to the presence of carbon dioxide will tend to neutralize the alkalinity of the polysulfide. In such case, the waste stream is scrubbed by a scrubber as illustrated in FIG. 2 . In this example the flow rates of the various sodium hydroxide streams and oxygen containing streams will be the same as in the previous example. The main difference is that more white liquor will be needed to scrub waste stream 29 . In this regard, 1,266 kg/mtpd pulp of white liquor is consumed in this example as compared with 1146 kg/mtpd pulp of white liquor in Example 1 . The incoming white liquor is distributed so that about 933 kg/mtpd pulp of white liquor is used in white liquor oxidation (white liquor and complete white liquor oxidizing stages 46 and 48 ) and again, about 333 kg/mtpd pulp of white liquor is utilized in polysulfide reaction stage 42 . Approximately 370 kg/mtpd pulp of white liquor is introduced into partial white liquor oxidizing stage 46 and about 563 kg/mtpd pulp of white liquor is introduced again into complete white liquor oxidizing stage 48 . About 126 mtpd pulp of white liquor is used in forming scrubbing stream 60 .
While the invention has been illustrated with reference to a preferred embodiment, it will be understood by those skilled in the art that numerous additions, modifications, and omission may be made without departing from the spirit and scope of the present invention.
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A method for producing bleached wood pulp in which wood chips are digested in polysulfide liquor to produce brown stock pulp. The brown stock pulp is washed to produce washed brown stock wood pulp and weak black liquor and the washed wood pulp is then delignified in an oxygen delignification stage to produce oxygen delignified wood pulp. The delignified wood pulp is then ozone bleached in an ozone bleaching stage in which a waste stream principally containing ozone, carbon dioxide and oxygen is produced. The ozone-bleached pulp is introduced into an extractive oxidation stage which can include peroxide to further bleach the pulp and the product of the extractive oxidation stage is then either introduced into either a peroxide or chlorine dioxide bleaching stage. The waste stream is recovered and scrubbed with either white liquor, oxidized white liquor, or fully oxidized white liquor either in a separate scrubber or during oxidation reactions occurring in either polysulfide, white liquor or complete white liquor production stages. The scrubbing with white liquor or oxidized white liquor removes ozone and carbon dioxide so that the scrubbed stream can be utilized in the oxygen delignification stage. This eliminates the need for ozone destruct units. Moreover, the polysulfide liquor is utilized in the digestion of the wood pulp and the thiosulfate liquor is used in the oxygen delignification of the washed wood pulp. The fully oxidized white liquor can be utilized within the extractive oxidation stage and optionally can be used in a peroxide bleaching stage if present. The oxygen removed from the scrubbed stream can be balanced with oxygen demand of the foregoing stages.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a Continuation-In-Part of co-pending U.S. Non-Provisional patent application Ser. No. 11/622,674 filed Jan. 12, 2007, entitled “BAR CONNECTING APPARATUS” which is hereby incorporated by reference. This application and application Ser. No. 11/622,674 both claim the benefit of co-pending U.S. Provisional Patent Application Ser. No. 60/860,434 filed Nov. 21, 2006, entitled “CLIP APPLYING APPARATUS” which is hereby incorporated by reference. The present application also claims benefit of co-pending U.S. Provisional Patent Application Ser. No. 60/911,401 filed Apr. 12, 2007 entitled “BAR CONNECTING APPARATUS” which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and method for attaching clips to connect bars, wherein the bars are used to reinforce concrete. Reinforcing bars are commonly placed within a frame where cement is to be poured, so that the reinforcing bars will become encased in the poured cement. The reinforcing bars are placed in specified positions at specified heights within the frame, so the resulting concrete is strengthened. One method used to connect the reinforcing bars before the cement is poured is clips. These clips are attached at the intersection of two bars, so the bars are held together in a fixed position. The current invention provides an apparatus and a method for attaching clips to intersecting bars.
2. Description of the Related Art
Supporting bars are commonly used to reinforce concrete. The supporting bars are laid out in a grid where the cement is to be poured. To maximize the effectiveness of the supporting bars, they are placed at specified heights, usually between about 2 and 6 inches from the ground. The bars are then connected so the grid is stable and will not move when the concrete is poured.
Many methods have been used to connect the bars, and many are done by hand. Rebar is the type of supporting bar most commonly used. When the rebar is connected by hand, it requires a laborer to bend over and connect the rebar at many points within the grid. This is labor intensive, slow, and tends to cause injuries from the repeated bending. In some instances, the rebar grid can be prepared first, and then placed into a form where the concrete will be poured. This can reduce the bending required, but does not address the time and labor needed to connect the rebar. To reduce the time needed to connect rebar and to minimize the time a laborer is working in a stooped over position, several applicators for connecting the rebar have been developed.
For example, in U.S. Pat. No. 5,881,452 Nowell et al. describes an apparatus for applying deformable metal fastener clips to concrete reinforcement steel. The Nowell device is a hand held applicator. It applies generally U-shaped deformable metal clips at the intersection of pieces of reinforcing rebar or wire mesh sheets. The apparatus is used to place the U-shaped metal clip around adjacent metal bars and then deform and close the U, thus connecting the bars.
West, in U.S. Pat. No. 5,826,629, describes a pneumatic wire tying apparatus for tying crossed reinforcing bars together. This device has a guide member which opens to receive intersecting bars, and then closes onto the bars. In the closed position a length of wire is guided around the bars. A feed mechanism feeds a wire to the guide member, and a twist member engages and twists the wire around the reinforcing bars.
BRIEF SUMMARY OF THE INVENTION
The current invention relates to an apparatus for applying clips to connect reinforcing bar as is typically used in concrete structures. The bar connecting apparatus as described is designed to fasten plastic clips as defined in U.S. patent application publication number 2006-0248844 A1, which is incorporated herein by reference. The clips are inserted into a barrel, and the apparatus is positioned over transverse supporting bars. A hammer reciprocates longitudinally within the barrel and strikes the clip. The hammer propels the clip out of the distal end of the barrel, which is positioned over the transverse bars, such that the clip engages and connects the bars. An alignment head at the distal end of the barrel is utilized to position the bar connecting apparatus relative to the transverse bars.
The clips are provided in a clip string, which is a plurality of clips connected together. In one embodiment, the clips are connected directly to each other, and in another embodiment the clips are connected to a common feed rod. The clip string is inserted into a clip feed assembly, which directs a clip into a clip receiving cavity in the barrel each time the hammer reciprocates. The clip feed assembly engages the hammer through a cam guide, so the motion of the hammer as it reciprocates provides the drive to cycle the clip feed assembly. Therefore, each time the hammer propels a clip from the barrel, the clip feed assembly inserts another clip from the clip string into the barrel, so the bar connecting apparatus can connect several pairs of transverse bars in rapid succession.
The clip feed assembly utilizes at least one finger to engage and advance the clip string into the clip receiving cavity. The finger has a pivot point and a sloped side so the finger can ratchet backwards along the clip string before engaging and urging the clip string forward into the clip receiving cavity. The backwards ratcheting motion and forward engaging motion allows the finger to advance clips into the clip receiving cavity as the clip feed assembly reciprocates laterally with each cycle of the hammer.
The clip feed assembly includes a clip track, which supports the clip string outside of the clip receiving cavity. In one embodiment, the clip track engages the clip from the top, and the clip track extends through the clip receiving cavity. The hammer has an indentation with legs, so the clip track is received in the indentation with the hammer legs passing beside the clip track. The legs contact and drive the clip from the barrel. In a second embodiment, the clip track terminates before entering the clip receiving cavity, and a resilient retainer is utilized to hold the clip in place until it is driven from the bar connecting apparatus.
The hammer is reciprocated by a drive, which can be powered by many sources, including manual and pneumatic sources. The power source first biases the drive and the connected hammer distally to drive a clip from the barrel. Next, the drive and hammer are biased proximally to reposition the hammer for the next clip, and to complete the associated cycling of the clip feed assembly. A handle and a biasing spring are used for the manual embodiment, and a trigger is used to actuate a pneumatic or other power source.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a perspective view of the clip string.
FIG. 2 is a perspective view of a single clip engaged with transverse bars.
FIG. 3 is a perspective view of the clip string when the feed rod is utilized.
FIG. 4 is a perspective view of the clip string with teeth on the feed rod.
FIG. 5 is a side view of the manually driven embodiment of the bar connecting apparatus.
FIG. 6 is a side view of a distal portion of the bar connecting apparatus without the clip feed assembly.
FIG. 7 is a front view of a distal portion of the bar connecting apparatus without the clip feed assembly.
FIG. 8 is a side view of the manual drive portion of the bar connecting apparatus with an attached hammer.
FIG. 9 is a side view of the pneumatically driven embodiment of the bar connecting apparatus.
FIG. 10 is a side view of a distal portion of the bar connecting apparatus.
FIG. 11 is a top view of a finger of the clip feed assembly.
FIG. 12 is a top view of a clip string engaged by fingers of the clip feed assembly.
FIG. 13 is a side view of the hammer having an indentation.
FIG. 14 is a front view of a portion of the clip receiving cavity with resilient retainers.
FIG. 15 is a side view illustrating an alternate design for the cam plate.
FIG. 16 is a side view of an embodiment of the clip string.
FIG. 17 is a side view of an embodiment of the bar connecting apparatus showing the clip feed assembly.
FIG. 18 is a side view of an embodiment of the bar connecting apparatus with the barrel removed to display components within the barrel.
FIG. 19 is a side view of the distal portion of the bar connecting apparatus
FIG. 20 is a rear view of the distal portion of the bar connecting apparatus, with the clip feed assembly removed for clarity.
FIG. 21 is a side view of the hammer with the hammer plate.
FIG. 22 is a top view of the hammer with the hammer plate.
FIG. 23 is a top view of the cam plate for the hammer plate embodiment of the invention.
FIG. 24 is a side view of the cam plate for the hammer plate embodiment of the invention.
FIG. 25 is a rear view of the finger for the hammer plate embodiment of the invention.
FIG. 26 is a side view of the finger for the hammer plate embodiment of the invention.
FIG. 27 is a side view of the hammer plate embodiment of a manually actuated bar connecting apparatus with the safety plate removed for clarity.
DETAILED DESCRIPTION OF THE INVENTION
Clip String
The Bar Connecting Apparatus utilizes a clip string 2 as depicted in FIG. 1 . The clip string 2 is comprised of a plurality of connected individual clips 4 , wherein the last clip in the series is the terminal clip 6 . In the preferred embodiment, the clips 4 are comprised of plastic and each clip 4 has several components. Referring to FIG. 2 , the seat 8 is adapted to engage and position a first bar 9 . Below the seat 8 are a plurality of hooks 10 , preferentially four hooks 10 per clip 4 , which are adapted to engage and position a second bar 11 transverse to the first bar 9 . The first bar 9 is also positioned on top of the second bar 11 . The hooks 10 are joined by a joining portion 12 , and each hook 10 has an upper body 14 .
The upper body 14 combined with the upper portion of the joining portion 12 defines a cradle 15 for engaging and positioning another bar parallel to and above the second bar 11 . The clip 4 can position a bar parallel to the second bar 11 in the cradle 15 , or it can position a first bar 9 in the seat 8 , but not both at the same time because the seat 8 and the cradle 15 receive bars in areas which interfere with each other.
Each clip 4 in the clip string 2 is connected to at least one adjoining clip 4 at the connection point 16 , as seen in FIG. 1 . The connection point 16 can be defined anywhere on the portion of a clip that abuts an adjoining clip 4 , as long as the clips 4 are connected together. Each clip 4 has at least one connection point 16 , but multiple connection points 16 can be utilized if necessary. The clips 4 are connected such that every clip 4 in the clip string 2 has a consistent orientation. Preferably, the orientation is such that if a bar were received in the hooks 10 of the terminal clip 6 , the same bar could be simultaneously received in the hooks 10 of every other clip 4 in the clip string 02 . Therefore, there would be one axis defined by the hooks 10 of all of the clips 4 in a clip string 02 . Similarly, the cradles 15 defined by the upper bodies 14 of the clips 4 would also be aligned on a single axis.
In an alternative embodiment, the clips 4 as defined above are connected to a feed rod 18 , as depicted in FIG. 3 . If the feed rod 18 is utilized, the connection point 16 B connects each clip 4 to the feed rod 18 . The feed rod 18 can be positioned anywhere along the side of the clip string 2 B as long as the clips 4 are held in a consistent orientation as described above. It is possible for the feed rod 18 to have teeth 19 for advancing the clip string 2 B, as shown in FIG. 4 . Also, if the feed rod 18 is utilized, each individual clip 4 does not necessarily touch or directly contact the neighboring clip 4 . The clips 4 are connected to the feed rod 18 , and not to each other, so the clips 4 are not held in direct contact with other clips 4 in the clip string 2 B.
Every clip string 2 B has only one sized clip 4 , but every clip string 2 B does not necessarily have the same sized clip 4 . The clips 4 are sized to connect a certain size of reinforcing bar, and because there are several sizes of reinforcing bars, there are several sizes of clips 4 . Although the size of a clip 4 in different clip strings 2 B would vary, the feed rod 18 allows the spacing between neighboring clips 4 to be constant. That is, the distance from the front of a larger clip 4 to the front of a neighboring larger clip 4 in one clip string 2 B would be the same as the distance from the front of a smaller clip 4 to the front of a neighboring smaller clip 4 in another clip string 2 B. When a feed rod 18 is utilized, this consistent spacing is possible because the clips 4 do not have to touch to be connected together. The consistent spacing is desirable because it allows for a bar connecting apparatus to apply clips 4 of different sizes without having to adjust or change the clip feed mechanism.
A third embodiment of the clip string 2 C is shown in FIG. 16 . Similar components are given the same names, but the identification numbers are denominated by a “C,” for the sake of clarity. Every clip 4 C in a clip string 2 C is the same size, but the third embodiment allows for clips strings 2 C having different sized clips 4 C to maintain consistent spacing between the clips 4 C without the use of a feed rod.
The clip string 2 C has a length 3 C, with each individual clip 4 C having at least one adjacent clip. The terminal clip 6 C would only have one adjacent clip 4 C, whereas each clip 4 C in the middle of the clip string 2 C would have two adjacent clips 4 C. Each clip 4 C is oriented with the cradle 15 defined by the upper body 14 aligned perpendicular to the clip string length 3 C. When the cradle 15 is perpendicular to the clip string length 3 C, a bar received in the cradle 15 of the clip 4 C would be perpendicular to the length 3 C of the clip string 2 C. This orientation is ninety degrees from the orientation shown in FIG. 1 , where a bar received in the cradle 15 of each clip 4 would be parallel to the length of the clip string. In FIG. 16 each clip 4 C is still consistently oriented, but the orientation has shifted. It is also possible to orient each clip 4 C with the cradle 15 aligned parallel to the length 3 C of the clip string 2 C.
Consistent spacing between different sized clips 4 C in different clip strings 2 C is achieved by providing a connection point 16 C with a length 17 C. The connection point 16 C is also referred to as a tab 16 C, and the length 17 C of the tab 16 C varies between clip strings 2 C having clips 4 C of different size. By providing shorter tabs 16 C for clip strings 2 C with larger clips 4 C, the spacing between the clips 4 C can be kept consistent for clip strings 2 C having different sized clips 4 C. Therefore, the distance from the front of one clip 4 C to the front of an adjacent clip 4 C is the same for two different clip strings 2 C which have clips 4 C of different sizes. The length 17 C of the tab 16 C serves to hold adjacent clips 4 C apart, so they don't touch, with the adjacent clips 4 C separated by the tab length 17 C. When the clip string 2 C is flexed, adjoining clips 4 C may touch, but normally they would be apart.
The tab 16 C has an indent 13 C to facilitate breaking of the tab 16 C when the clip 4 C is applied to connect bars. The terminal clip 6 C becomes separated from the clip string 2 C when used to connect bars, and the indent 13 C provides a breaking point on the tab 16 C to aid in separating the terminal clip 6 C. Each clip 4 C is comprised of plastic, and preferably includes four hooks 10 , 4 upper bodies 14 , and two joining portions 12 which each connects two hooks 10 , as best seen in FIG. 2 . Each upper body 14 is connected to one other upper body 14 in each clip 4 .
Bar Connecting Apparatus
The clip string 2 is utilized in the bar connecting apparatus 20 as shown in FIG. 5 . Inside the bar connecting apparatus 20 is a barrel 22 with a clip receiving cavity 24 . The terminal clip 6 of the clip string 2 is received into the clip receiving cavity 24 of the barrel 22 , which can be seen more clearly in FIG. 6 . FIG. 6 does not include the clip feeding mechanism, to more clearly show the barrel 22 with the clip receiving cavity 24 . The clip receiving cavity 24 includes a hole in the side of the barrel 22 which is adapted to receive clips 4 from the clip string 02 . Inside the barrel 22 is a hammer 26 which reciprocates longitudinally within the barrel 22 . As the hammer 26 reciprocates distally, it contacts the terminal clip 6 and expels the terminal clip 6 out the distal end of the barrel 23 .
There is an alignment head 28 defined at the distal end of the barrel 23 , which aligns the clip applying apparatus 20 with the bars to be connected. When the terminal clip 6 is ejected from the barrel 22 , the alignment head 28 ensures the bar connecting apparatus 20 is properly aligned with the bars such that the terminal clip 6 connects the bars. After the terminal clip 6 is ejected the hammer 26 reciprocates proximally, the next clip 4 in the clip string 2 is advanced into the clip receiving cavity 24 and becomes the new terminal clip 6 , and the clip applying process is ready to be repeated.
The alignment head 28 has two pair of notches 30 , 30 B adapted to engage transverse bars, as seen in FIGS. 6 and 7 . For the sake of clarity, FIG. 7 also does not show the clip feeding mechanism. One pair of notches 30 is deeper than the other pair 30 B, so the first bar 9 , which is on top, is engaged in the deeper pair of notches 30 and the second bar 11 , which is underneath the first bar 9 , is engaged in the more shallow pair of notches 30 B. The notches 30 , 30 B in each pair are on opposite sides of the alignment head 28 , so the four points of contact between the notches 30 , 30 B and the transverse bars 9 , 11 prevent the bar connecting apparatus 20 from moving. The alignment head 28 , when engaged with the transverse bars, fixes the position of the bar connecting apparatus 20 in three dimensions.
The hammer 26 is reciprocated by a drive 32 , as seen in FIGS. 5 and 8 . FIG. 8 depicts the hammer 26 and the manual drive 32 , without the remainder of the bar connecting apparatus 20 . The drive 32 includes a drive rod 33 which is actuated either manual or automatically. The act of connecting the drive rod 33 to the hammer 26 can be aided by wrench flats in the drive rod 33 . In the manual embodiment, the drive 32 includes a handle 34 and a biasing spring 36 . The handle 34 is manually depressed to extend the hammer 26 distally for ejecting the terminal clip 6 from the barrel 22 . The biasing spring 36 then biases the handle 34 proximally and retracts the hammer 26 to a position such that the next terminal clip 6 can be introduced into the clip receiving cavity 24 .
FIG. 9 depicts the bar connecting apparatus 20 A with a trigger actuated automatic drive 32 A. For the sake of clarity, similar components in the manual and automatic embodiments are given the same name and number, but the component numbers in the automatic embodiment are designated with an “A.” The drive 32 A includes a trigger 38 for directing a power source to cycle the drive 32 A, such that the power source biases the drive 32 A distally when the trigger 38 is depressed and proximally when the trigger 38 is released. In the preferred embodiment, the power source is pneumatic; however, other power sources, such as an electric power source, could also be utilized. Additionally, an extension can be added to either the automatic or manual drive 32 , 32 A so an operator can stand upright while connecting bars.
The alignment head 28 includes two pair of notches 30 , 30 B, which are further designated as a first and second pair of notches 30 , 30 B, as seen in FIGS. 6 and 7 . The first pair of notches 30 are deeper than the second pair of notches 30 B. This allows the first transverse bar 9 , which is above the second bar 11 , to be engaged in the first pair of notches 30 , and the second, bottom transverse bar 11 to be engaged in the second pair of notches 30 B. The transverse bars 9 , 11 are perpendicular to each other, and the alignment head 28 C positions the barrel 22 C perpendicular to both bars 9 , 11 .
Clip Feed Assembly
The clip feed assembly 40 advances the clip string 2 into the clip receiving cavity 24 as the hammer 26 reciprocates, as seen in FIG. 10 . A cam guide 42 is connected to the side of the hammer 26 . The cam guide 42 passes through a straight slot and protrudes from the side of the barrel 22 . Therefore, the cam guide 42 reciprocates outside of the barrel 22 as the hammer 26 reciprocates inside of the barrel 22 . The cam guide 42 can include a bearing to make the motion of the cam guide 42 smoother.
The portion of the cam guide 42 which protrudes from the side of the barrel 22 is engaged in a slot type cam track 44 . The cam track 44 is defined in the cam plate 46 , and the cam plate 46 is pivotally connected to the bar connecting apparatus 20 at a pivot point 48 . The cam track 44 has an angled section such that as the hammer 26 and cam guide 42 cycle, the cam plate 46 pivots at the pivot point 48 and reciprocates laterally. The cam track 44 can also include straight sections, which are used for timing purposes to coordinate the clip feed assembly 40 operation with the cycling of the hammer 26 . The cam plate 46 reciprocates away from the barrel 22 as the hammer 26 reciprocates distally, and the cam plate 46 reciprocates towards the barrel 22 as the hammer 26 reciprocates proximally. With the slot type cam track 44 no return spring is needed for the cam plate 46 .
An alternate design for the cam plate, designated as 46 B is shown in FIG. 15 . Surrounding parts of apparatus 20 are not shown in FIG. 15 so as to aid in the ease of illustration of cam plate 46 B. The cam plate 46 B has an edge type cam track 44 B instead of the slot 44 of FIG. 10 . The edge type cam track 44 B is maintained in contact with the reciprocating cam guide 42 by a tension spring 47 , which is schematically illustrated in FIG. 15 . Any type of resilient return spring could be utilized in place of spring 47 to urge the cam track 44 B against cam guide 42 . With either the cam plate 46 of FIG. 10 or the cam plate 46 B of FIG. 15 the cam plate will reciprocate as the hammer 26 cycles.
A feed support block 50 can be positioned at the end of the cam plate 46 to facilitate the feeding of the clip string 2 into the clip receiving cavity 24 , as shown in FIG. 10 . At least one finger 52 , and preferably two fingers, is connected to the cam plate 46 through the feed support block 50 . Referring to FIGS. 10 , 11 , and 12 , the finger 52 has a flat end 51 for engaging the clip string 2 as the cam plate 46 reciprocates towards the barrel 22 , but the finger 52 also has a sloped side 53 for sliding past the clip string 2 as the cam plate 46 reciprocates away from the barrel 22 .
The finger 52 is pivotally connected to the feed support block 50 at a finger pivot point 57 , and a biasing spring 55 urges the finger 52 to engage an individual clip 4 of the clip string 2 as the cam plate 46 reciprocates towards the barrel 22 . The finger pivot point 57 allows the finger 52 to ratchet back past the clip string 2 as the cam plate 46 moves away from the barrel 22 . Therefore, the clip string 2 sits still as the cam plate 46 reciprocates away from the barrel 22 , but the clip string 2 is advanced into the clip receiving cavity 24 as the cam plate 46 reciprocates towards the barrel 22 . The clip feed assembly 40 does not utilize a spring or urging device at the back end of the clip string 2 to advance the clips 4 into the clip receiving cavity 24 . The above described mechanism engages the hammer 26 with the clip feed assembly 40 so the cycling of the hammer 26 provides the force to urge the clip string 2 into the clip receiving cavity 24 .
In one embodiment, the finger 52 has an angled back end 59 which can be pressed to disengage the finger 52 from the clip string 2 . When disengaged, the clip string 2 can be withdrawn from the clip receiving cavity 24 without the finger 52 retaining any of the individual clips 4 .
The clip string 2 is supported by a clip track 54 when inserted into the bar connecting apparatus 20 . The clip track 54 can engage the clip string 2 from either the top or the bottom. Referring now to FIGS. 1 , 9 , and 13 , the clip track 54 A can engage the clips 4 by the cradle 15 defined by the upper body 14 , or from the top. When the clip string 2 is engaged from the top, the clip track 54 A extends through the clip receiving cavity 24 A. The clips 4 are then released distally from the clip track 54 A. When the clip track 54 A extends through the clip receiving cavity 24 A, the hammer 26 A has an indentation 56 for receiving the clip track 54 A as the hammer 26 A reciprocates. The hammer 26 A has at least one, and preferably two, legs 58 on the side of the indentation 56 . The legs 58 contact the upper body 14 of the terminal clip 6 to propel the clip out of the barrel 22 A. As the legs 58 propel the terminal clip 6 out of the barrel 22 A, the clip track 54 A is received in the indentation 56 such that the legs 58 pass beside the clip track 54 A.
In the embodiment where the clip track 54 engages the clip string 2 from the bottom, the clip track 54 does not extend through the clip receiving cavity 24 , as shown in FIGS. 5 and 10 . The clip track 54 terminates at the clip receiving cavity 24 and the hammer 26 can be flat because there is no need to pass around the clip track 54 . Referring to FIGS. 5 , 10 , and 14 , because the clip track 54 does not hold the clip 4 in the clip receiving cavity 24 , at least one resilient retainer 60 can be used to secure the terminal clip 6 in the clip receiving cavity 24 . Preferably, four resilient retainers 60 comprised of ball bearing springs mounted in the clip receiving cavity 24 are used. The resilient retainer 60 releasably engages the terminal clip 6 in the clip receiving cavity 24 to prevent the terminal clip 6 from falling out of the barrel 22 before being expelled by the hammer.
Referring to FIGS. 1 and 9 , the clip track 54 A is further comprised of at least a first portion 62 and a second portion 64 . The second portion 64 is dimensioned to frictionally engage and lightly hold the clip string 2 . The first portion of the clip track 62 has smaller dimensions which do not frictionally engage or hold the clip string 2 , so the clips 4 will easily slide across the first portion of the clip track 62 . This allows the clips 4 to be easily engaged with the first portion of the clip track 62 , and yet still be frictionally engaged and held in position by a shorter second portion 64 . The second portion of the clip track 64 is between the barrel 22 A and the first portion 62 so that the clip string 2 is frictionally engaged when in a position to enter into the clip receiving cavity 24 A.
Clip Feed Assembly with a Hammer Plate
An alternate embodiment of the clip feed assembly is shown in FIGS. 17 , 18 , 19 and 20 . In the description of this embodiment, similar components are given the same name and number, but are denoted by the suffix “C.” In FIG. 18 , the barrel has been removed to better show the internal parts.
A barrel 22 C has a clip receiving cavity 24 C and a slot 25 C extending parallel to the length of the barrel 22 C. The hammer 26 C includes a hammer plate 27 C, which extends through the barrel slot 25 C. The hammer 26 C reciprocates longitudinally within the barrel 22 C, and the hammer plate 27 C reciprocates external and parallel to the barrel 22 C through the barrel slot 25 C. The hammer plate 27 C has an angled section 29 C, which is angled relative to the length of the barrel 22 C. This angled section 29 C works as an inclined plane. The hammer 26 C can be hollow and include holes to reduce weight, as better seen in FIGS. 21 and 22 . The cycling of the hammer 26 C provides the force to cycle the clip feed assembly 40 C, which urges a clip 4 C into the clip receiving cavity 24 C.
A cam plate 46 C is shown in isolation in FIGS. 23 and 24 . The cam plate has an inclined section 49 C, at least one running fit 66 C, and can include holes to reduce weight. The running fit 66 C has a spring pocket 68 C to receive and support a tension spring. The spring pocket 68 C has a larger diameter than the running fit 66 C. The inclined section 49 C faces the angled section 29 C of the hammer plate 27 C, as better seen in FIGS. 17 and 18 . The inclined section 49 C is positioned to be angled relative to the length of the barrel 22 C. A guide shaft 70 C is received in each running fit 66 C, and serves to guide the cam plate 46 C as the cam plate 46 C reciprocates. The guide shaft 70 C is fixed in one position, so the cam plate 46 C reciprocates parallel to the guide shaft 70 C. The running fit 66 C is dimensioned slightly larger than the guide shaft 70 C, so the cam plate 46 C will be held at a relatively constant angle to the guide shaft 70 C as the cam plate 46 C reciprocates up and down on the guide shaft 70 C. In this embodiment, the cam plate 46 C does not pivot on a pivot point.
As seen in FIG. 27 , a space 45 C between the hammer plate 27 C and the cam plate 46 C, when the hammer 26 C has reciprocated proximally, allows for the application of a smaller force to initiate the actuation motion of the hammer 26 C, as shown in FIG. 27 . This is because the hammer plate 27 C will have developed some momentum when contacting and initiating the cycling of the cam plate 46 C. This space 45 C between the hammer plate 27 C and cam plate 46 C is especially useful for a manually actuated bar connecting apparatus 20 D shown in FIG. 27 , because it requires less strength from the operator. Even though there is a space 45 C between the hammer plate 27 C and the cam plate 46 C, the angled section 29 C and the inclined section 49 C still face each other.
Referring again to FIGS. 17 and 18 , the guide shaft 70 C is received between the barrel 22 C and a guide shaft bracket 72 C. The guide shaft 70 C has a first end 74 C, which is connected and secured to the barrel 22 C, and a second end 76 C, which is secured to the guide shaft bracket 72 C. A compression spring 47 C is received about the guide shaft 70 C. The compression spring 47 C serves to urge the cam plate 46 C towards the hammer plate 27 C. The compression spring terminates on one end in the cam plate spring pocket 68 C, and on the other end in a guide shaft bracket spring pocket 78 C. The compression spring 47 C could be mounted in many alternative ways, and it could assume a form different than a coil spring, as long as it biases the cam plate 46 C towards the hammer plate 27 C.
As the hammer 26 C reciprocates distally, the angled section 29 C of the hammer plate 27 C pushes into the inclined section 49 C of the cam plate 46 C. The guide shaft 70 C forces the cam plate 46 C to only move parallel to the guide shaft 70 C, so the force of the hammer plate angled section 29 C on the cam plate inclined section 49 C is translated into a lateral motion of the cam plate 46 C along the guide shaft 70 C. Therefore, as the hammer 26 C reciprocates distally, the cam plate 46 C reciprocates laterally away from the barrel 22 C. When the hammer 26 C reciprocates proximally, the compression spring 47 C urges the cam plate 46 C towards the hammer 26 C, so the cam plate reciprocates laterally towards the barrel 22 C.
At least one safety plate 80 C is mounted to cover the workings of the hammer plate 27 C and the cam plate 46 C. Therefore, the safety plate 80 C is adjacent to the hammer plate 27 C and the cam plate 46 C. The safety plate 80 C is indicated by long and short dashed lines in FIGS. 17 and 19 , with the parts underneath the safety plate 80 C shown for clarity, even though the parts would not be visible underneath the safety plate 80 C. Preferably, there would be a safety plate 80 C on both sides of the bar connecting apparatus 20 C, to provide better protection from the workings of the hammer plate 27 C and the cam plate 46 C. The safety plate 80 C is connected to the barrel 22 C, and serves as a mount for the guide shaft bracket 72 C. It is also possible to connect a bracket 81 C between the safety plate 80 C and the handle 82 C of the bar connecting apparatus 20 C. The bracket 81 C can include a grip 83 C, if desired. The bracket 81 C and grip 83 C are shown in phantom lines in FIG. 17 .
A finger 52 C is pivotally connected to the cam plate 46 C at the distal end of the cam plate 46 C. The finger 52 C is for engaging and advancing a clip 4 C into the clip receiving cavity 24 C with each reciprocation of the cam plate 46 C. The finger 52 C is shown in isolation in FIGS. 25 and 26 . The finger 52 C has a flat end 51 C for engaging and advancing a clip. The finger 52 C also has a sloped side 53 C, to slide past a clip without engaging it. A catch portion 59 C serves to support the finger 52 C and prevent it from pivoting backwards, or towards the sloped side 53 C, when engaging a clip and advancing it forwards. An angled portion 61 C allows the finger to pivot forward, or towards the flat end 61 C, when the finger 52 C slides backwards past a clip to engage and advance a new clip forward. The finger 52 C has a pivot point 57 C, which is connected between two faces 69 C on the cam plate 46 C, as seen in FIGS. 23 and 26 . The catch 59 C abuts an edge of the cam plate faces 69 C as seen in FIG. 18 , which prevents the finger 52 C from pivoting backwards. The angled section 61 C abuts the edges of the cam plate faces 69 C after the finger 52 C has pivoted forward enough to allow the finger 52 C to slide away from barrel 22 C past a clip, so the forward pivoting of the finger 52 C is controlled by the angled section 61 C.
Referring now to FIG. 19 , the finger 52 C is received between finger brackets 84 C, which are mounted to the safety plate 80 C. When the hammer moves distally the cam plate 46 C moves away from the barrel 22 C, and the acceleration of the cam plate 46 C causes the finger 52 C to pivot towards the barrel 22 C on the finger pivot point 57 C. When the hammer moves proximally, the cam plate 46 C reverses direction and accelerates toward the barrel 22 C. This acceleration causes the finger 52 C to pivot away from the barrel 22 C on the pivot point 57 C. When the finger 52 C pivots away from the barrel 22 C, the flat end 51 C is positioned to engage and advance a clip 4 C towards the barrel 22 C.
A resilient catch 86 C is mounted in the finger bracket 84 C. The resilient catch 86 C is positioned to engage a clip 4 C received on the clip track 54 C and provide resistance to the clip 4 C sliding backwards, or away from the barrel 22 C. In particular, the resilient catch 86 C contacts a surface of a clip 4 C that is facing away from the barrel 22 C. The resilient catch 86 C is mounted in the finger bracket 84 C, but it could be mounted anywhere, as long as it is positioned adjacent to the clip track 54 C for contacting a surface of a clip 4 C that is facing away from the barrel 22 C. The resilient catch 86 C provides some resistance, but will allow motion past it if sufficient force is applied.
A clip track 54 C is connected to the barrel 22 C adjacent to the clip receiving cavity 24 C, but does not extend through the barrel 22 C. The clip track 54 C supports the clips 4 C in the seat 8 , so the connection point 7 between two upper bodies 14 is transverse to the clip track 54 C, as seen in FIGS. 19 , 2 , and 16 . The finger 52 C engages this connection point 7 , which provides a contact surface perpendicular to the motion of the finger 52 C. This broad contact surface facilitates the use of different sized clips 4 C in the same bar connecting apparatus 20 C, because different sized clips will still have the connection point 7 positioned above the clip track 54 C in the same manner. The finger 52 C moves a set distance with each reciprocation of the cam plate 46 C, so the consistent spacing of the clips 4 C in the clip string 2 C allows for different sized clips 4 C to be used in the bar connecting apparatus 20 C.
The clip track 54 C is parallel to the guide shaft 70 C, so the finger 52 C will move parallel to the clip track 54 C, as best seen in FIGS. 17 , 18 and 19 . The finger 52 C is connected to the cam plate 46 C, and the cam plate 46 C moves parallel with the guide shaft 70 C, so the finger 52 C also moves parallel with the guide shaft 70 C. The clip track 54 C can be perpendicular to the barrel 22 C, but it could also be at another angle, as long as it is parallel to the guide shaft 70 C.
Method of Connecting Bars
The current invention also includes a method of connecting bars, which is shown in FIGS. 1 , 5 , and 10 . The method includes providing a bar connecting apparatus 20 for applying clips 4 as described above. A clip string 2 is engaged with the clip track 54 of the bar connecting apparatus 20 , and then slid along the clip track 54 until at least one clip 4 is received in the clip receiving cavity 24 . The bar connecting apparatus 20 is then aligned with two transverse bars to be connected by an alignment head 28 . The alignment head 28 has two pair of notches 30 , so when the alignment head 28 is properly positioned each bar is engaged with one pair of the notches 30 . The bar connecting apparatus 20 is actuated, which reciprocates a hammer 26 in the barrel 22 . The hammer 26 contacts and expels the clip 4 received in the clip receiving cavity 24 such that the clip connects the bars. The cycling of the hammer 26 also cycles the clip feed assembly 40 to advance another clip 4 from the clip string 2 into the clip receiving cavity 24 for a subsequent clip application. The clip string 2 is advanced into the clip receiving cavity 24 in a direction transverse to the direction of reciprocation of the hammer.
The terminal clip 6 C of the clip string 4 C is inserted into the clip receiving cavity 24 C of the bar connecting apparatus 20 C, as seen in FIGS. 16 through 19 . After the terminal clip 6 C has been ejected to connect bars, the next clip 4 C becomes the new terminal clip 6 C, is advanced into the clip receiving cavity 24 C by the clip feed assembly 40 C, and the bar connecting apparatus is ready for a subsequent clip 4 C application.
The alignment head 28 C has two pair of notches 30 C, 30 D, wherein each pair of notches 30 C, 30 D has a different depth than the other pair, so the alignment head 28 C will engage two transverse bars 9 C, 11 C to be connected with one bar 9 C on top of the other 11 C. Each bar 9 C, 11 C is engaged in one pair of notches 30 C, 30 D.
The method includes the providing of at least a first and second clip string 2 C, wherein the size of the clips 4 C in each clip string 2 C is constant, but the clips 4 C in the first clip string 2 C are of a different size than the clips 04 C of the second clip string 2 C. The distance between the front ends of adjacent clips in the first and second clip string is the same. One clip string 2 C is selected such that the clips 4 C are sized properly for the bars to be connected. The selected clip string 2 C is then inserted into the clip receiving cavity 24 C for application of the clips 4 C.
Thus, although there have been described particular embodiments of the present invention of a new and useful BAR CONNECTING APPARATUS, it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims.
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A bar connecting apparatus applies clips to connect transverse bars used in reinforced concrete. A clip string is fed into the bar connecting apparatus by a clip feed assembly, so several pairs of transverse bars can be connected in rapid succession. A hammer reciprocates in the barrel of the bar connecting apparatus, and drives a clip from the barrel into engagement with the bars. An alignment head aligns the bar connecting apparatus with the transverse bars so the clips properly engage the bars.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is filed based upon and claims priority to Chinese Patent Application No. 201610427017.4, filed on Jun. 16, 2016, the entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The disclosure relates to the field of casting, in particular to a local extrusion device for high-pressure casting.
BACKGROUND
[0003] Dies are essential process equipment of the modern industry, particularly industries of automobiles, radio, aviation, instruments, articles of everyday use and the like. At present, because a die-casting fitting is complicated in structure, uneven in wall thickness and relatively short in solidification time, for ‘hot spot’ positions in the structure of the product, methods of feeding by high pressure boosting, optimizing a pouring gate structure, enhancing cooling and the like are frequently used, but feeding on the position of a far sprue is quite difficult to implement by adjustment of technological parameters, and porosity quite difficultly meets increasing requirements of customers of automobile companies.
SUMMARY
[0004] With regard to technical requirements of the aluminum alloy pressing casting, the disclosure provides a local extrusion structure and technology for high-pressure casting dies. The local extrusion structure and technology for high-pressure casting dies can be used for reducing the defect of shrinkage porosity at hot spot positions of the product, the internal quality of the product is improved, and the problems of porosity are reduced.
[0005] In one aspect of the disclosure, a local extrusion device for high-pressure casting is provided, the local extrusion device for high-pressure casting includes an extrusion core sleeve ( 03 ), an extrusion rod ( 04 ), an extrusion oil cylinder ( 05 ) and an extrusion oil cylinder piston ( 06 ), and is characterized in that the extrusion oil cylinder ( 05 ) includes the extrusion oil cylinder piston ( 06 ), the extrusion oil cylinder piston ( 06 ) is connected with the extrusion rod ( 04 ), the extrusion rod ( 04 ) is positioned in the extrusion core sleeve ( 03 ), and the extrusion core sleeve ( 03 ) and the extrusion oil cylinder ( 05 ) are fixed.
[0006] In a preferred aspect of the disclosure, the extrusion core sleeve ( 03 ) includes a cavity ( 12 ) in a direction facing a casting ( 01 ).
[0007] In a preferred aspect of the disclosure, the ratio of the cross sectional area of the extrusion oil cylinder piston ( 06 ) to the cross sectional area of the extrusion rod ( 04 ) is greater than 10.
[0008] In a preferred aspect of the disclosure, the ratio of the cross sectional area of the extrusion oil cylinder piston ( 06 ) to the cross sectional area of the extrusion rod ( 04 ) is 10-40.
[0009] In a preferred aspect of the disclosure, the ratio of the cross sectional area of the extrusion oil cylinder piston ( 06 ) to the cross sectional area of the extrusion rod ( 04 ) is 12.
[0010] In a preferred aspect of the disclosure, when the extrusion oil cylinder piston ( 06 ) is not extruded, a front end ( 08 ) of the extrusion rod is higher than an end surface ( 10 ) of the extrusion sleeve by 4-10 mm.
[0011] In a preferred aspect of the disclosure, a gap between a lower cavity inner wall ( 11 ) of the extrusion core sleeve and the extrusion rod ( 04 ) is 4-10 mm.
[0012] In a preferred aspect of the disclosure, the ratio of the cross sectional area of the extrusion oil cylinder piston ( 06 ) to the cross sectional area of the extrusion rod ( 04 ) is 12; when the extrusion oil cylinder piston ( 06 ) is not extruded, the front end ( 08 ) of the extrusion rod is higher than the end surface ( 10 ) of the extrusion sleeve by 10 mm; and the gap between the lower cavity inner wall ( 11 ) of the extrusion core sleeve and the outline of the extrusion rod ( 04 ) is 4 mm.
[0013] In another aspect of the disclosure, a local extrusion method in a high-pressure casting process is further disclosed, and is characterized in that the method includes the following steps: driving the extrusion oil cylinder piston ( 06 ) by using the local extrusion device for high-pressure casting; and driving the extrusion rod ( 04 ) to extrude the surface of the casting.
[0014] In a preferred aspect of the disclosure, the extrusion stroke of the extrusion rod ( 04 ) reaches 10-30 mm, and the distance from the front end ( 08 ) of the extrusion rod to the surface ( 07 ) of the casting is 2-5 mm after extrusion.
[0015] In a preferred aspect of the disclosure, timing is started at a two-speed transformation point, extrusion starting time is 0.5-3 s, and extrusion delay time is 3-15 s.
[0016] In a preferred aspect of the disclosure, a returned local extrusion core is pushed out again for spraying.
[0017] In another aspect of the disclosure, a local extrusion structure for high-pressure casting and a technological process are further provided, and the local extrusion structure for aluminum alloy high-pressure casting includes an extrusion boss ( 02 ), an extrusion core sleeve ( 03 ), an extrusion rod ( 04 ), an extrusion oil cylinder ( 05 ) and an extrusion oil cylinder piston ( 06 ). The ratio of the cross sectional area of the extrusion piston ( 06 ) to the cross sectional area of the extrusion rod ( 04 ) is greater than 10 to guarantee a big enough extrusion force. When the oil cylinder piston is not extruded (located at a zero position), a front end ( 08 ) of the extrusion rod is higher than an end surface ( 10 ) of the extrusion sleeve by 4-10 mm, and meanwhile, a cavity ( 12 ) is formed between the front end ( 08 ) of the extrusion rod and a lower cavity inner wall ( 11 ) of the extrusion core sleeve; and in an extrusion process of the extrusion rod, a gap between the lower cavity inner wall ( 11 ) of the extrusion core sleeve and the extrusion rod ( 04 ) is 4-10 mm (which is also the range of the wall thickness of the extrusion boss ( 02 )). In order to guarantee good extrusion effect of the local extrusion technology, local extrusion starting time and local extrusion delay time on a die-casting machine are adjusted, the extrusion stroke of the extrusion rod is enabled to reach 10-30 mm, the distance from the front end ( 08 ) of the extrusion rod to the surface ( 07 ) of a casting is 2-5 mm after extrusion, an X-ray flaw detection machine detects a thick and large part of the casting ( 01 ), and the result shows that the defect of shrinkage porosity does not exist. In the local extrusion technology, the extrusion starting time (timing is started at a two-speed transformation point) is 0.5-3 s, the extrusion delay time is 3-15 s, in a spraying cycle, the returned local extrusion core is required to be pushed out again for spraying to cool and lubricate the extrusion core well, jamming in an extrusion process is prevented, and the service life of the local extrusion core is prolonged.
[0018] The disclosure discloses a local extrusion structure and technology for high-pressure casting, the local extrusion structure for aluminum alloy high-pressure casting includes an extrusion boss ( 02 ), an extrusion core sleeve ( 03 ), an extrusion rod ( 04 ), an extrusion oil cylinder ( 05 ) and an extrusion oil cylinder piston ( 06 ). The local extrusion structure for aluminum alloy high-pressing casting is characterized in that the ratio of the cross sectional area of the extrusion oil cylinder piston ( 06 ) to the cross sectional area of the extrusion rod ( 04 ) is required to be greater than 10 to guarantee a big enough extrusion force. In a preferred aspect of the disclosure, when the oil cylinder piston is not extruded (located at a zero position), a front end ( 08 ) of the extrusion rod is higher than an end surface ( 10 ) of the extrusion sleeve by 4-10 mm, and meanwhile, a cavity ( 12 ) is formed between the front end ( 08 ) of the extrusion rod and a lower cavity inner wall ( 11 ) of the extrusion core sleeve; in an extrusion process of the extrusion rod, a gap between the lower cavity inner wall ( 11 ) of the extrusion core sleeve and the extrusion rod ( 04 ) is 4-10 mm (which is also the range of the wall thickness of the extrusion boss ( 02 ), the heat storage capacity of the extrusion cavity ( 12 ) can be guaranteed, and the circumstance that molten aluminum is solidified too early after entering the cavity and the adjustable range of the local extrusion technology is narrowed is prevented). In order to guarantee good extrusion effect of the local extrusion technology, local extrusion starting time and local extrusion delay time on a die-casting machine are required to be adjusted, the extrusion stroke of the extrusion rod is enabled to reach 10-30 mm, the distance from the front end ( 08 ) of the extrusion rod to the surface ( 07 ) of a casting is 2-5 mm after extrusion, an X-ray flaw detection machine detects a thick and large part of the casting ( 01 ), and the result shows that the defect of shrinkage porosity does not exist. In a preferred aspect of the disclosure, the extrusion starting time (timing is started at a two-speed transformation point) is 0.5-3 s, and the extrusion delay time is 3-15 s in the local extrusion technology. In a preferred aspect of the disclosure, the returned local extrusion core is required to be pushed out again for spraying to cool and lubricate the extrusion core well in a spraying cycle, jamming in an extrusion process is prevented, and the service life of the local extrusion core is prolonged.
[0019] The local extrusion device and method for high-pressure casting provided by the disclosure have the advantages that the structural design is reasonable, the extrusion stroke in the local extrusion technology can be guaranteed effectively, meanwhile, the defect of shrinkage porosity at the thick and large position of the product is reduced, production rejection rate is reduced, and the economic benefit of the enterprise is improved obviously.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The embodiment of the disclosure will be described in detail below with reference to the drawings, wherein:
[0021] FIG. 1 is a structural schematic view of a local extrusion device for high-pressure casting before extrusion;
[0022] FIG. 2 is a structural schematic view of a local extrusion device for high-pressure casting after extrusion;
[0023] before extrusion; right figure: after extrusion); and
LIST OF REFERENCE SYMBOLS
[0000]
01 casting
02 extrusion boss
03 extrusion core sleeve
04 extrusion rod
05 extrusion oil cylinder
06 extrusion oil cylinder piston
07 surface of casting
08 front end of extrusion rod
10 end surface of extrusion sleeve
11 lower cavity inner wall of extrusion core sleeve
12 cavity
DETAILED DESCRIPTION
[0035] Test Group 1
[0036] A local extrusion structure for aluminum alloy high-pressure casting includes an extrusion boss ( 02 ), an extrusion core sleeve ( 03 ), an extrusion rod ( 04 ), an extrusion oil cylinder ( 05 ) and an extrusion oil cylinder piston ( 06 ). The ratio of the cross sectional area of the extrusion oil cylinder piston ( 06 ) to the cross sectional area of the extrusion rod ( 04 ) is 12 to guarantee a big enough extrusion force. When the oil cylinder piston is not extruded (located at a zero position), a front end ( 08 ) of the extrusion rod is higher than an end surface ( 10 ) of the extrusion sleeve by 10 mm, and meanwhile, a cavity ( 12 ) is formed between the front end ( 08 ) of the extrusion rod and the lower cavity inner wall ( 11 ) of the extrusion core sleeve; in an extrusion process of the extrusion rod, a gap between the lower cavity inner wall ( 11 ) of the extrusion core sleeve and the outline of the extrusion rod ( 04 ) is 10 mm (which is also the range of the wall thickness of the extrusion boss ( 02 )). In order to guarantee good extrusion effect of the local extrusion technology, local extrusion starting time and local extrusion delay time on a die-casting machine are adjusted, the extrusion stroke of the extrusion rod is enabled to reach 15 mm, the distance from the front end ( 08 ) of the extrusion rod to the surface ( 07 ) of a casting is 2 mm after extrusion, an X-ray flaw detection machine detects a thick and large part of the casting ( 01 ), and the result shows that the defect of shrinkage porosity does not exist. In the local extrusion technology, the extrusion starting time (timing is started at a two-speed transformation point) is 3 s, the extrusion delay time is 3 s, in a spraying cycle, the returned local extrusion core is required to be pushed out again for spraying to cool and lubricate the extrusion core well, jamming in the extrusion process is prevented, and the service life of the local extrusion core is prolonged.
[0037] Test Group 2
[0038] A local extrusion structure for aluminum alloy high-pressure casting includes an extrusion boss ( 02 ), an extrusion core sleeve ( 03 ), an extrusion rod ( 04 ), an extrusion oil cylinder ( 05 ) and an extrusion oil cylinder piston ( 06 ). The ratio of the cross sectional area of the extrusion oil cylinder piston ( 06 ) to the cross sectional area of the extrusion rod ( 04 ) is 12 to guarantee a big enough extrusion force. When the oil cylinder piston is not extruded (located at a zero position), a front end ( 08 ) of the extrusion rod is higher than an end surface ( 10 ) of the extrusion sleeve by 4 mm, and meanwhile, a cavity ( 12 ) is formed between the front end ( 08 ) of the extrusion rod and the lower cavity inner wall ( 11 ) of the extrusion core sleeve; and in an extrusion process of the extrusion rod, a gap between the lower cavity inner wall ( 11 ) of the extrusion core sleeve and the outline of the extrusion rod ( 04 ) is 4 mm (which is also the range of the wall thickness of the extrusion boss ( 02 )). In order to guarantee good extrusion effect of the local extrusion technology, local extrusion starting time and local extrusion delay time on a die-casting machine are adjusted, the extrusion stroke of the extrusion rod is enabled to reach 10 mm, the distance from the front end ( 08 ) of the extrusion rod to the surface ( 07 ) of a casting is 3 mm after extrusion, an X-ray flaw detection machine detects a thick and large part of the casting ( 01 ), and the result shows that the defect of shrinkage porosity does not exist. In the local extrusion technology, the extrusion starting time (timing is started at a two-speed transformation point) is 0.5 s, the extrusion delay time is 8 s, in a spraying cycle, the returned local extrusion core is required to be pushed out again for spraying to cool and lubricate the extrusion core well, jamming in the extrusion process is prevented, and the service life of the local extrusion core is prolonged.
[0039] Test Group 3
[0040] A local extrusion structure for aluminum alloy high-pressure casting includes an extrusion boss ( 02 ), an extrusion core sleeve ( 03 ), an extrusion rod ( 04 ), an extrusion oil cylinder ( 05 ) and an extrusion oil cylinder piston ( 06 ). The ratio of the cross sectional area of the extrusion oil cylinder piston ( 06 ) to the cross sectional area of the extrusion rod ( 04 ) is 12 to guarantee a big enough extrusion force. When the oil cylinder piston is not extruded (located at a zero position), a front end ( 08 ) of the extrusion rod is higher than an end surface ( 10 ) of the extrusion sleeve by 10 mm, and meanwhile, a cavity ( 12 ) is formed between the front end ( 08 ) of the extrusion rod and the lower cavity inner wall ( 11 ) of the extrusion core sleeve; and in an extrusion process of the extrusion rod, a gap between the lower cavity inner wall ( 11 ) of the extrusion core sleeve and the outline of the extrusion rod ( 04 ) is 4 mm (which is also the range of the wall thickness of the extrusion boss ( 02 )). In order to guarantee good extrusion effect of the local extrusion technology, local extrusion starting time and local extrusion delay time on a die-casting machine are adjusted, the extrusion stroke of the extrusion rod is enabled to reach 10 mm, the distance from the front end ( 08 ) of the extrusion rod to the surface ( 07 ) of a casting is 5 mm after extrusion, an X-ray flaw detection machine detects a thick and large part of the casting ( 01 ), and the result shows that the defect of shrinkage porosity does not exist. In the local extrusion technology, the extrusion starting time (timing is started at a two-speed transformation point) is 2 s, the extrusion delay time is 10 s, in a spraying cycle, the returned local extrusion core is required to be pushed out again for spraying to cool and lubricate the extrusion core well, jamming in the extrusion process is prevented, and the service life of the local extrusion core is prolonged.
[0041] Test Result
[0042] Specific tests are carried out in a research and development workshop of Engineering Technology Institute of CITIC Dicastal Co., Ltd. according to the above arrangement. The test result shows that the occurrence rate of casting wastes caused by the defect of shrinkage porosity at the thick and large position of the product in the test group 1, the test group 2 and the test group 3 are reduced by 70.24%, 76.20% and 87.15% respectively.
[0043] Thus, by the local extrusion devices in the different test groups, the number of casting wastes caused by the defect of shrinkage porosity at the thick and large position of the product is reduced. Moreover, by the extrusion device in the test group 3, the defect of shrinkage porosity at the thick and large position of the product is greatly reduced unexpectedly, and therefore, the production cost is remarkably reduced.
[0044] The embodiments described above are for illustrative technical concept and features of the disclosure, the purpose is to allow those skilled in the art to understand the contents of the disclosure and implement, and not to limit the scope of the disclosure. Where under the equivalent changes or modifications made in the spirit of the disclosure shall fall within the scope of the disclosure.
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The disclosure provides a local extrusion device for high-pressing casting. The local extrusion device for high-pressure casting includes an extrusion core sleeve, an extrusion rod, an extrusion oil cylinder and an extrusion oil cylinder piston. The extrusion oil cylinder includes the extrusion oil cylinder piston, the extrusion oil cylinder piston is connected with the extrusion rod, the extrusion rod is positioned in the extrusion core sleeve, and the extrusion core sleeve and the extrusion oil cylinder are fixed.
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BACKGROUND
Many athletic activities, particularly team sports, utilize one of a variety of game ball types. For example, the game of soccer utilizes a soccerball, whereas the game of basketball utilizes a basketball. Other types of game balls that are commonly utilized include footballs, volleyballs, baseballs, and softballs, for example. The suitability of a type of game ball for a particular athletic activity depends upon a variety of characteristics, including dimensions, shape, materials, and weight.
When purchasing game balls, consumers generally prefer to inspect the game balls, which may include both a visual inspection and a tactile inspection (i.e., through touch) to ensure that the game balls possess the requisite characteristics. Moreover, inspection of the game balls permits the consumers to verify whether the game balls possess a requisite degree of quality, which is dependent upon workmanship and materials. Packaging, such a conventional box, may inhibit consumers' ability to inspect game balls. Accordingly, many manufacturers transport game balls to retail locations without packaging, and the game balls are displayed in bulk at the retail locations in a large bin or basket.
One drawback to displaying game balls without packaging is that information regarding the game balls may not be provided to the consumers. For example, when game balls are loosely displayed in a large bin or basket, information on materials used in the game balls, specifications of the game ball, and approval from governing athletic organizations may not be coupled with the game balls for use by the consumers when selecting between models or manufacturers. Another drawback relates to protection of the game balls. That is, damage to the game balls may occur during transport or while on display at the retail location.
SUMMARY
A container for receiving and displaying a game ball or a variety of other products is disclosed. The container may permit consumers to inspect a game ball by exposing a significant area of the game ball. The container may also provide an area for information on the game ball to be displayed, thereby providing the information to the consumers at a retail location. In addition, the container may impart protection to the game ball during transport and at the retail location.
The container may include various flaps with protrusions shaped to have a curvature that is approximately equal to the curvature of the game ball. In addition to supporting the game ball, the protrusions may contact the surface of the game ball along substantially all of the length of the protrusions. This configuration limits the degree to which the game ball rotates or otherwise moves during transport. In addition, the flaps of the container may have other protrusions and slits that mate and interlock to join the flaps together. In this configuration, the flaps may be folded inward to interlock the flaps and complete assembly of the container. Similarly, the flaps may be pressed further inward to disengage the protrusions and slits for purposes of removing the game ball from the container.
To gain an improved understanding of the advantages and features of novelty reference may be made to the following descriptive matter and accompanying drawings that describe and illustrate various embodiments and concepts related to the aspects of the invention.
DESCRIPTION OF THE DRAWINGS
The foregoing Summary, as well as the following Detailed Description, will be better understood when read in conjunction with the accompanying drawings.
FIG. 1 is a perspective view of a first display container in a closed configuration and in combination with a game ball.
FIGS. 2 and 3 are side elevational views of the first display container in the closed configuration and in combination with the game ball.
FIG. 4 is a top plan view of the first display container in the closed configuration and in combination with the game ball.
FIG. 5 is another perspective view of the first display container in the closed configuration and in combination with the game ball.
FIG. 6 is a perspective view of the first display container in the closed configuration.
FIGS. 7 and 8 are side elevational views of the first display container in the closed configuration.
FIG. 9 is a top plan view of the first display container in the closed configuration.
FIG. 10 is a perspective view of the first display container in an open configuration.
FIGS. 11 and 12 are side elevational views of the first display container in the open configuration.
FIG. 13 is a plan view of an element that forms the first display container.
FIG. 14 is a perspective view of a second display container in a closed configuration.
FIG. 15 is a side elevational view of the second display container in the closed configuration.
FIG. 16 is a top plan view of the second display container in the closed configuration.
FIG. 17 is a perspective view of a second display container in an open configuration.
FIGS. 18 and 19 are side elevational views of the second display container in the open configuration.
FIG. 20 illustrates a process for assembling the first display container.
DETAILED DESCRIPTION
The following discussion and accompanying figures disclose a container 10 for receiving and displaying a game ball. Although container 10 is depicted in combination with a soccerball 100 in FIGS. 1-5 , other configurations of container 10 may be utilized to receive and display a variety of other game balls, including a basketball, volleyball, football, baseball, or softball, for example. Container 10 may also be utilized to receive and display a variety of other products, in addition to game balls. Accordingly, container 10 is disclosed in a configuration suitable for receiving and displaying soccerball 100 for purposes of example, and may also be utilized to receive and display a variety of other products.
As discussed in the Background section above, packaging for game balls may inhibit the consumers' ability to inspect game balls. Furthermore, loosely displaying game balls without packaging limits the ability of manufacturers to convey information regarding the game balls to the consumers, and loosely displaying game balls may not provide adequate protection to the game balls. Container 10 , however, permits consumers to properly inspect soccerball 100 by exposing a significant area of soccerball 100 . Container 10 also provides an area for information on soccerball 100 to be displayed, thereby providing the information to the consumers. In addition, container 10 imparts protection to soccerball 100 during transport and at a retail location.
Container 10 is depicted in combination with soccerball 100 in FIGS. 1-5 . FIGS. 6-9 correspond with FIGS. 1-4 , but depict container 10 with soccerball 100 absent. Whereas FIGS. 1-9 depict container 10 in a closed configuration, FIGS. 10-12 depict container 10 in an open configuration, which may be utilized to place soccerball 100 within container 10 or remove soccerball 100 from container 10 . In addition, FIG. 13 depicts container 10 in an unassembled configuration. That is, FIG. 13 is a plan view of an element that forms container 10 . Although container 10 may be formed from a single element of material, as in FIG. 13 , some configurations of container 10 may be formed from two or more joined elements. A variety of materials may be utilized for display container 10 , including cardboard, paper, various polymers, or combinations of these materials, for example. Accordingly, the element depicted in FIG. 13 may be stamped or otherwise formed from a single cardboard element that is then folded and joined.
Container 10 has a generally cubic shape that defines six sides 12 a - 12 f and an interior void bounded by sides 12 a - 12 f for receiving soccerball 100 . Sides 12 a and 12 b respectively define apertures 14 a and 14 b through which soccerball 100 is visible. Sides 12 c and 12 d are not depicted as having apertures, which provides areas for information regarding soccerball 100 to be printed on the exterior of container 10 . In further configurations of container 10 , either of apertures 14 a and 14 b may be absent (i.e., the material of container 10 may extend across the areas of apertures 14 a and 14 b ) or sides 12 c and 12 d may also include apertures. Sides 12 e and 12 f , which respectively form a top and a bottom of container 10 , also expose areas of soccerball 100 . Accordingly, the configuration of container 10 in FIGS. 1-5 exposes soccerball 100 through four of the six sides 12 a - 12 f.
In addition to exposing portions of soccerball 100 , container 10 provides support to soccerball 100 . The support is provided by various flaps 16 a - 16 d that extend into the void in container 10 and contact soccerball 100 . For example, one of flaps 16 a extends from an upper area of side 12 a and is angled downward to contact soccerball 100 , and another of flaps 16 a extends from a lower area of side 12 a and is angled upward to contact soccerball 100 . Similarly, one of flaps 16 b extends from an upper area of side 12 b and is angled downward to contact soccerball 100 , and another of flaps 16 b extends from a lower area of side 12 b and is angled upward to contact soccerball 100 . As with sides 12 a and 12 b , each of sides 12 c and 12 d respectively have two flaps 16 c and 16 d that are angled downward and upward to contact soccerball 100 .
Each of flaps 16 a - 16 d respectively have a protrusion 18 a - 18 d that is approximately centered relative to sides of flaps 16 a - 16 d and contacts soccerball 100 . Protrusions 18 a - 18 d extend outward from ends of flaps 16 a - 16 d and have a concave configuration that contacts soccerball 100 . That is, protrusions 18 a - 18 d are shaped to have a curvature that is approximately equal to the curvature of soccerball 100 . Accordingly, protrusions 18 a - 18 d contact the surface of soccerball 100 along substantially all of the length of protrusions 18 a - 18 d . In some configurations of container 10 , protrusions 18 a - 18 d may not be shaped to have a curvature that is approximately equal to the curvature of soccerball 100 , or protrusions 18 a - 18 d may be absent from flaps 16 a - 16 d.
End portions of flaps 16 b and 16 d also respectively form a pair of other protrusions 20 b and 20 d . Similarly, end portions of flaps 16 a and 16 b respectively form a pair of slits 22 a and 22 c . When folded inward, protrusions 20 b and 20 d extend into and mate with slits 22 a and 22 c to interlock flaps 16 a - 16 d with each other. Referring specifically to FIG. 10 , one of protrusions 20 b from flap 16 b is immediately adjacent one of slits 22 a from flap 16 a . When flaps 16 a and 16 b are folded inward, protrusion 20 b will extend into slit 22 a to interlock flaps 16 a and 16 b . Similar concepts apply at other locations of container 10 . Slits 22 a and 22 c may also have the configuration of elongate apertures in some configurations.
An element that forms container 10 is depicted in FIG. 13 and the various sides 12 a - 12 d , apertures 14 a and 14 b , flaps 16 a - 16 d , protrusions 18 a - 18 d , protrusions 20 b and 20 d , and slits 22 a and 22 c are depicted. Note, however, that the element does not actually include specific portions that form sides 12 e and 12 f . When (a) the element is folded along various fold lines 24 and (b) a joining flap 26 extending from an edge of side 12 c is adhered or otherwise joined to side 12 d , sides 12 e and 12 f are defined by the upper and lower edges of sides 12 a - 12 d (i.e., the portions of sides 12 a - 12 d with flaps 16 a - 16 d ).
Based upon the above discussion, container 10 has a configuration suitable for receiving and displaying soccerball 100 . In other configurations, container 10 may also be utilized to receive and display a variety of other types of game balls or other products. Advantages of the configuration of container 10 are that (a) consumers may inspect soccerball 100 through apertures 14 a and 14 b and through sides 12 e and 12 f , (b) sides 12 c and 12 d provide an area for information regarding soccerball 100 to be displayed, and (c) soccerball 100 is protected by container 10 during transport and at a retail location. Another advantage of container 10 relates to protrusions 18 a - 18 d . As discussed, protrusions 18 a - 18 d are shaped to have a curvature that is approximately equal to the curvature of soccerball 100 , and protrusions 18 a - 18 d contact the surface of soccerball 100 along substantially all of the length of protrusions 18 a - 18 d . This configuration limits the degree to which soccerball 100 rotates or otherwise moves during transport. At the retail location, therefore, logos or other information printed on soccerball 100 may remain visible to the consumer if placed within container 10 such that the logos are visible. An additional advantage of container 10 relates to the interaction between protrusions 20 b and 20 d and slits 22 a and 22 c . When folded inward, protrusions 20 b and 20 d extend into and mate with slits 22 a and 22 c to interlock flaps 16 a - 16 d with each other. In this configuration, flaps 16 a - 16 d may be merely folded inward to interlock flaps 16 a - 16 d and complete the assembly of container 10 . That is, this configuration provides a relatively easy manner of securing soccerball 100 within container 10 .
Another configuration is depicted in FIGS. 14-19 as container 10 ′. As with container 10 , container 10 ′ is suitable for receiving soccerball 100 , other game balls, or a variety of other products. The primary elements of container 10 ′ are various sides 12 a ′- 12 f ′, a pair of apertures 14 a ′ and 14 b ′, and eight flaps 16 a ′- 16 d ′. Flaps 16 a ′ and 16 c ′ include various slits 22 a ′ and 22 c ′ that extend into various protrusions 20 b ′ and 20 d ′ on flaps 16 b ′ and 16 d ′ to interlock flaps 16 a ′- 16 d ′ with each other. Flaps 16 a ′ and 16 c ′ also include various wings 24 a ′ and 24 c ′ that fold inward to provide additional support for flaps 16 a ′- 16 d ′. In one or more configurations, wings 24 a ′- d ′ may extend longitudinally past the sides of container 10 ′. The longitudinal edges/sides of flaps 16 b ′ and 16 d ′ may further be sloped to facilitate joining with flaps 16 a ′ and 16 c ′. Wings 24 a ′- 24 d ′ may further extend in a lateral direction past a lateral edge of a remainder of flaps 16 a ′ and 16 c ′. Similarly, the longitudinal ends of flaps 16 b ′ and 16 d ′ may also protrude from the remainder of flaps 16 b ′ and 16 d ′ in a lateral direction. Each of wings 24 a ′- 24 d ′ may further include a crease between a portion extending beyond a side of container 10 ′ and the remainder of the wing. Additionally or alternatively, a longitudinal edge of each wing of wings 24 a ′- 24 d ′ may be angled or sloped.
With reference to FIG. 20 , a method of assembling container 10 is depicted. Initially, the element depicted in FIG. 13 is folded between sides 12 a - 12 d such that joining flap 26 contacts side 12 d , where joining flap 26 is adhered. Flaps 16 a - 16 d adjacent side 12 f are then folded inward so that protrusions 20 b and 20 d enter slits 22 a and 22 c . Soccerball 100 may then be placed within container 10 through side 12 e , and flaps 16 a - 16 d adjacent side 12 e are then folded inward so that protrusions 20 b and 20 d enter slits 22 a and 22 c . As an alternative, soccerball 100 may be placed within container 10 through the side 12 e after flaps 16 a - 16 d adjacent side 12 e are folded inward. This procedure secures soccerball 100 within container 10 .
In order to remove soccerball 100 from container 10 , two of flaps 16 a - 16 d may be pressed downward. By pressing two of flaps 16 a - 16 d further inward, protrusions 20 b and 20 d are disengaged from slits 22 a and 22 c and each of flaps 16 a - 16 d respectively extend adjacent to sides 12 a - 12 d , thereby opening side 12 e sufficiently for removal of soccerball 100 . Accordingly, the relatively easy action of pressing downward on two of flaps 16 a - 16 d is sufficient to remove soccerball 100 from container 10 .
The invention is disclosed above and in the accompanying drawings with reference to a variety of embodiments. The purpose served by the disclosure, however, is to provide an example of the various features and concepts related to aspects of the invention, not to limit the scope of aspects of the invention. One skilled in the relevant art will recognize that numerous variations and modifications may be made to the embodiments described above without departing from the scope of the invention, as defined herein.
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A structure configurable for holding and displaying a product (e.g., a game ball or sporting equipment) may include one or more sides having an aperture through which the contained product is visible. One or more sides of the structure may include flaps that are flexible inward toward an interior of the structure. The flaps may include a protrusion configured to contact and hold the product contained in the structure. A first flap may further include slits for receiving portions of a second flap to form a side of the structure. One or more sides of the structure may be void of an aperture to provide a surface on which information about the product may be displayed.
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This is a division of patent application Ser. No. 09/633,768, filing date Aug. 7, 2000 now U.S. Pat. No. 6,517,896 Spin Filter Bottom Spin Valve Head With Continuous Spacer Exchange Bias, assigned to the same assignee as the present invention.
FIELD OF THE INVENTION
The invention relates to the general field of GMR recording heads for magnetic disk systems with particular reference to design of the free layer.
BACKGROUND OF THE INVENTION
Read-write heads for magnetic disk systems have undergone substantial development during the last few years. In particular, older systems in which a single device was used for both reading and writing, have given way to configurations in which the two functions are performed by different structures. An example of such a read-write head is schematically illustrated in FIG. 1 . The magnetic field that ‘writes’ a bit at the surface of recording medium 15 is generated by a flat coil, two of whose windings 14 can be seen in the figure. The magnetic flux generated by the flat coil is concentrated within pole pieces 12 and 13 which, while being connected at a point beyond the top edge of the figure, are separated by small gap 16 . Thus, most of the magnetic flux generated by the flat coil passes across this gap with fringing fields extending out for a short distance where the field is still powerful enough to magnetize a small portion of recoding medium 15 .
The present invention is directed towards the design of read element 20 which can be seen to be a thin slice of material located between magnetic shields 11 and 12 ( 12 doing double duty as a pole piece, as just discussed). The principle governing the operation of read sensor 20 is the change of resistivity of certain materials in the presence of a magnetic field (magneto-resistance). Most magnetic materials exhibit anisotropic behavior in that they have a preferred direction along which they are most easily magnetized (known as the easy axis). The magneto-resistance effect manifests itself as a decrease in resistivity when the material is magnetized in a direction perpendicular to the easy axis, said decrease being reduced to zero when magnetization is along the easy axis. Thus, any magnetic field that changes the direction of magnetization in a magneto-resistive material can be detected as a change in resistance.
It is widely known that the magneto-resistance effect can be significantly increased by means of a structure known as a spin valve. The resulting increase (known as Giant magneto-resistance or GMR) derives from the fact that electrons in a magnetized solid are subject to significantly less scattering by the lattice when their own magnetization vectors (due to spin) are parallel (as opposed to anti-parallel) to the direction of magnetization of the solid as a whole.
The key elements of a spin valve structure are shown in FIG. 2 . In addition to a seed layer 22 on a substrate 21 and a topmost cap layer 27 , these key elements are two magnetic layers 24 and 26 , separated by a non-magnetic layer 25 . The thickness of layer 25 is chosen so that layers 24 and 26 are sufficiently far apart for exchange effects to be negligible (i.e. the layers do not influence each other's magnetic behavior at the atomic level) but are close enough to be within the mean free path of conduction electrons in the material. If, now, layers 24 and 26 are magnetized in opposite directions and a current is passed though them along the direction of magnetization (such as direction 28 in the figure), half the electrons in each layer will be subject to increased scattering while half will be unaffected (to a first approximation). Furthermore, only the unaffected electrons will have mean free paths long enough for them to have a high probability of crossing over from 24 to 26 (or vice versa). However, once these electrons ‘switch sides’, they are immediately subject to increased scattering, thereby becoming unlikely to return to their original side, the overall result being a significant increase in the resistance of the entire structure.
In order to make use of the GMR effect, the direction of magnetization of one of the layers 24 and 26 is permanently fixed, or pinned. In FIG. 2 it is layer 24 that is pinned. Pinning is achieved by first magnetizing the layer (by depositing and/or annealing it in the presence of a magnetic field) and then permanently maintaining the magnetization with an undercoat of a layer of antiferromagnetic material, or AFM, (layer 23 in the figure). Layer 26 , by contrast, is a “free layer” whose direction of magnetization can be readily changed by an external field (such as that associated with a bit at the surface 15 of a magnetic disk).
The structure shown in FIG. 2 is referred to as a bottom spin valve because the pinned layer is at the bottom. It is also possible to form a ‘top spin valve’ structure where the pinned layer is deposited after the pinning layer.
Ultra-thin free layers as well as MR ratio are very effective to obtain high output spin valve GMR heads for over 30 Gb/in 2 magnetic recording. In general, magneto-resistive devices have a characteristic response curve such that their sensitivity initially increases with the applied field, then is constant with applied field, and then decreases to zero for even higher fields. It is therefore standard to provide a biasing field to keep the sensor operating in the linear range where it is also at its most sensitive. However, as the free layer thickness decreases, it becomes difficult to obtain a controllable bias point, high GMR ratio and good magnetic softness all at the same time. Synthetic antiferromagnets (SyAF) are known to reduce magneto-static fields in a pinned layer, but a large bias point shift due to sense current fields remains a problem for practical use of an ultra-thin free layer. To overcome this problem, the spin-filter spin valve (SFSV) was invented.
In a SFSV, the free layer is placed between the Cu spacer and an additional high-conductance-layer (HCL). SFSV reduces sense current fields in the free layer by shifting the sense current center toward the free layer, resulting in a smaller bias point shift by sense current fields. High GMR ratio is maintained even in the ultra-thin free layer because the HCL improves the mean free path of a spin-up electron while maintaining the mean free path difference between spin-up and spin-down electrons.
As discussed earlier, spin valve GMR heads may be either top or bottom types. The GMR sensor track is defined by a patterned longitudinal biasing layer in the form of two bias stripes. These are permanently magnetized in a direction parallel to the surface. Their purpose is to prevent the formation of multiple magnetic domains in the free layer. The most commonly used longitudinal bias for the bottom spin valve is with contiguous (abutted) junction hard bias. The problem with the abutted junction is the existence of a “dead zone” at the sensor ends. A MR sensor track defined by continuous spacer exchange bias (similar to that for the DSMR) does not have the “dead zone”. This may be critical for a very narrow track for ultra-high density recording application.
A routine search of the prior art was performed. The following references of interest were found. U.S. Pat. No. 5,637,235(Kim et al.) shows a SV with a capping layer. U.S. Pat. No. 5,896,252 (Kanai) shows a SV with a free magnetic layer composed of a CoFe and NiFe sublayers. while U.S. Pat. No. 5,648,885 (Nishioka et al.) teaches a SV with CoFe free layer.
SUMMARY OF THE INVENTION
It has been an object of the present invention to provide a spin-filter synthetic antiferromagnetic bottom spin valve that is suitable for ultra-high density magnetic recording applications.
Another object of the invention has been to provide suitable longitudinal biasing leads for this structure.
A further object of the invention has been to provide processes for the manufacture of these structures.
These objects have been achieved in a structure made up the following layers:
NiCr/MnPt/CoFe/Ru/CoFe/Cu/(free layer)/Cu/Ta or TaO. A key feature is that the free layer is made of thin CoFe plus a CoFe/NiFe composite layer in which CoFe is thinner than NiFe. Experimental data confirming the effectiveness of this structure is provided, together with a method for manufacturing it and the longitudinal bias leads.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a read-write head for a magnetic disk system.
FIG. 2 shows the cross-sectional structure of a spin valve according to the teachings of the prior art.
FIG. 3 shows the cross-sectional structure of a spin-filter spin valve according to the teachings of the present invention.
FIG. 4 illustrates how the structure of FIG. 3 is modified in order to apply longitudinal bias leads to it.
FIG. 5 shows the structure of FIG. 3 after longitudinal bias leads have been added to it.
FIG. 6 shows a plan view of the structure of which FIG. 5 is a cross-section.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Relative to NiFe, sputter-etching of tantalum or tantalum oxide (TaO) is 3 times slower. In the present invention, the Ta or TaO capping layer of the bottom spin valve can be removed by using a carbon tetrafluoride reactive ion etching (RIE) process. The process for sputter etching the underlying Cu and partially etching of NiFe is controllable. These factors cause our process for forming an ultra-thin free layer bottom spin valve to be suitable for manufacturing.
Advantages of the processes and structures that we will disclose below include the following:
Bottom spin valves made by this invention have larger output signal amplitude.
The process for sputter-etching of the underlying Cu and (partially) etching NiFe for the continuous spacer exchange bias is controllable.
With the above design considerations in mind, we have worked out a structure and fabrication process to form a SF-SyAF bottom spin valve head with a very thin free layer. The GMR sensor track is defined by using a continuous exchange spacer bias.
Using the CVC GMR sputtering system, bottom SF-SyAF spin valves having: NiCr/MnPt/CoFe(I)/Ru/CoFe(2)/Cu/CoFe+NiFe(free layer)/Cu/Ta or TaO/ configuration were made. Free layers of the present work are made of a very thin CoFe/NiFe composite layer. TaO in the present structure is formed by first depositing a thin (e.g. 10–15 Å) Ta film on the NiFe free layer, and then oxidizing it by oxygen plasma ashing.
We now describe the process of the present invention for both spin valves and read heads. In the course of this description, the structure of the present invention will also become clear.
Referring now to FIG. 3 , the process for manufacturing a spin valve begins with the provision of substrate 21 onto which there is deposited magneto-resistance-enhancing seed layer 22 . Pinning layer 33 is then deposited onto layer 22 . This pinning layer is between about 100 and 200 Angstroms thick. Our preferred material has been MnPt but similar materials such as InMn, MnNi, of MnPtPd could also have been used. This is followed by pinned layer 34 , a synthetic antiferromagnetic material that is actually a laminate details not shown), deposited as follows:
first a layer of cobalt-iron, between about 12 and 25 Angstroms thick, then a layer of ruthenium, between about 6 and 9 Angstroms thick, and last a second layer of cobalt-iron, between about 12 and 25 Angstroms thick. It is a requirement that these two cobalt-iron layers differ in thickness by between about 2 and 10 Angstroms.
Next, non-magnetic copper spacer layer 25 , between about 18 and 25 Angstroms thick, is deposited onto layer 34 .
In a key feature of the invention, free layer 35 is then deposited. This free layer is actually a composite of a cobalt-iron layer, having a thickness between about 3 and 15 Angstroms and a nickel-iron layer that is between about 10 and 35 Angstroms thick, the CoFe being deposited first.
Next, high conductance copper layer 36 , between about 5 and 15 Angstroms thick, is deposited on free layer 35 . This is followed by the deposition of a specular reflection layer of either tantalum that may be left unchanged at a thickness between about 10 and 20 Angstroms or that is converted to tantalum oxide layer 37 through plasma oxidation, as discussed earlier. This tantalum oxide layer has a thickness between about 15 and 30 Angstroms. Then, capping layer of aluminum oxide 38 , between about 100 and 300 Angstroms thick, is deposited on layer 37 .
The process is then completed by annealing. This takes the form of heating in the presence a magnetic field of between about 5,000 and 10,000 Oe, in a transverse direction, at a temperature between about 250 and 280° C. for between about 5 and 10 hours.
The process for manufacturing a read head begins with the provision of a bottom spin valve structure that includes an ultra-thin specular free layer as described immediately above. First, capping layer 38 is removed by wet etching, thereby uncovering tantalum or tantalum oxide layer 37 onto which a layer of photoresist (comprising soluble underlayer 40 a and insoluble top layer 40 b ), suitable for later lift-off, is applied and then patterned to define the shape of a pair of conductor leads. This can be seen in FIG. 4 .
Then, all tantalum or tantalum oxide that is not protected by photoresist is removed by reactive etching in carbon tetrafluoride. This results in the uncovering of high conductance copper layer 15 , which layer serves as an effective etch stop layer. Etching, by sputter-etching, then continues until all uncovered high conductance copper 36 has been removed, as well as a certain amount of nickel iron from free layer 35 . The removed nickel iron is then refilled with a layer of ferromagnetic material such as NiFe or CoFe, to a slightly greater thickness than the removed material (because of some uncertainty in the thickness control). This is followed by deposition of a layer of antiferromagnetic material.
Continuing our reference to FIG. 4 , biasing layer 41 is then deposited on layer 35 (i.e. the refilled nickel-iron) to a thickness between about 100 and 150 Angstroms. The biasing layer may be either an exchange bias layer made of manganese-platinum or a similar material such as InMn, MnNi, or MnPtPd. This is followed by deposition of a layer of conductive material 42 . Our preferred material for the layer of conductive material has been Ta/Au/Ta, but similar materials, such as Cr/Rh/Cr could also have been used. It is deposited to a thickness between about 300 and 400 Angstroms.
At this point the liftoff process is invoked so that all photoresist, together with all material on the resist's surface, is removed, giving the structure the appearance shown in FIG. 5 . A plan view, of which FIG. 5 is a cross-section, is shown in FIG. 6 .
The process is completed by annealing. This involves heating in the presence a magnetic field of between about 100 and 200 Oe in the longitudinal direction, at a temperature between about 250 and 280° C. for between about 2 and 5 hours.
Experimental Verification of the Invention
For comparison purposes, SF-SyAF top spin valves having: NiCr/Cu/NiFe+CoFe (free layer)/Cu/CoFe1/Ru/CoFe2/MnPt/NiCr configurations with equivalent layer thicknesses were also made.
To characterize free layer anisotropy, free layer structures made of 55 NiCr/20 Cu/ 2 CoFe-34 NiFe/15 Cu/TaO/Al 2 O 3 and 55 NiCr/15 Cu/34 NiFe-2 CoFe/20 Cu/NiCr, respectively (where all numbers are thicknesses in Angstroms), for the bottom and top SFSV were also studied.
After forming free layer and GMR stacks, the deposited structures were first given a standard 6000 Oe transverse field 280° C.-5 hrs annealing. The high field annealing set up the pinned layer direction. After removing Al 2 O 3 capping by wet etching, the GMR and the free layer stacks, were further given a low field (100 Oe) 250° C.-5 hrs annealing to reset the free layer in the sensor direction. This low field annealing was used to simulate the exchange bias annealing process.
Comparisons of the top and bottom spin valve free layer magnetic properties are illustrated in Table I.
TABLE I
Free layer structure: 80.9% NiFe
B s
H c
H k
R s
Dr/r
Oe to close HA
CZB55/Cu15/NiFe32/CoFe3/Cu20/CZB50
Top
0.28
10.23
15.84
24.12
0.54
9 Oe
CZB55/Cu20/CoFe3/NiFe32/Cu15/TaO
Bottom
0.28
6.77
14.67
25.85
0.65
4 Oe
where B s = magnetic moment, H c = free layer coercivity (oe), H k = anisotropy field (oe), and R s = sheet resistance (ohm/sq.)
As illustrated in TABLE I, the free layer of the bottom spin valve shows softer magnetic properties (i.e. lower H c and H k than that of the top spin valve. To close the hard axis (HA) loops for the free layers, applied longitudinal fields of 9 and 4 Oe are needed for the top and the bottom spin valve respectively.
Magnetic performance properties of the top and bottom SF-SyAF spin valves are listed in TABLE II. For the top spin valve with (55 NiFe/5 CoFe) free layer, GMR ratio (Dr/r)=9.54% and output amplitude (Dr)=1.20 ohm/sq. Dr/r and Dr for the bottom spin valve are 10% higher. Also H c and H k are lower.
TABLE II
Structure: (80.9% NiFe/MP43%-2mt)
B s
H c
H e
H k
R s
Dr/r
Dr
FOM
CZB55/Cu15/NiFe55/CoFe5/Cu20/CoFe23/Ru
1
0.52
8.47
16.2
9.94
12.6
9.54
1.20
0.65
7.5/CoFe18/MP150/CZB30/Al 2 O 3
CZB55/MP150/CoFe18/Ru7.5/CoFe23/Cu20/
2
0.51
5.34
13.5
6.77
12.7
10.5
1.33
0.73
CoFe5/NiFe55/Cu15/Ta10/OL/Al 2 O 3
CZB55/Cu15/NiFe34/CoFe2/Cu19/CoFe23/Ru
3
0.28
7.20
13.5
7.44
14.6
9.74
1.42
1.33
7.5/CoFe18/MP150/CZB30/Al 2 O 3
CZB55/MP150/CoFe18/Ru7.5/CoFe23/Cu20/
4
0.29
6.05
4.56
2.20
15.5
10.7
1.66
1.45
CoFe2/NiFe34/Cu15/Ta10/OL/Al 2 O 3
CZB55/MP150/CoFel8/Ru7.5/CoFe23/Cu20/
5
0.27
5.92
8.53
4.07
15.9
12.8
2.03
1.89
CoFe10/NiFe20/Cu10/Ta10/Al 2 O 3
where B s = magnetic moment, H c = free layer coercivity (oe), H e = inter-layer coupling field (oe) H k = anisotropy field (oe), and R s = sheet resistance (ohm/sq.)
For ultra-high density recording, the free layer of the bottom spin valve is made of a very thin CoFe/NiFe composite layer having a magnetic moment equivalent to that of a 37 Å thick NiFe layer. See Cell 3 and Cell 4 /Cell 5 , respectively, for the top and the bottom spin valves with ultra-thin free layer. Figure-of-merit (FOM) for the (2 Å CoFe/34 Å NiFe) spin valves is about 2× greater than that with (5 Å CoFe/55 Å NiFe) free layer. The difference between Cell 4 and Cell 5 , is that the composite free layer in cell 5 has a thicker CoFe component. The FOM for the (10 Å CoFe/20 Å NiFe) spin valve with 10 Å Cu HCL is about 2.5× greater than that of the (5 Å CoFe/55 Å NiFe)spin valve with 15 Å Cdu HCL. Besides having greater FOM, the bottom spin valve has shown softer magnetic properties than the top spin valve. These results indicate that a bottom spin valve head gives higher sensor sensitivity to yield even higher output signal.
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.
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A high performance specular free layer bottom spin valve is disclosed. This structure made up the following layers: NiCr/MnPt/CoFe/Ru/CoFe/Cu/free layer/Cu/Ta or TaO/Al 2 O 3 . A key feature is that the free layer is made of a very thin CoFe/NiFe composite layer. Experimental data confirming the effectiveness of this structure is provided, together with a method for manufacturing it and, additionally, its longitudinal bias leads.
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BACKGROUND
[0001] 1. Field
[0002] This invention relates generally to reels for spooling linear material and, in particular, to a reel including an improved flow control mechanism for a reciprocating reel.
[0003] 2. Description of the Related Art
[0004] Reels for spooling linear material, such as a hose or wire, onto a rotating drum have incorporated reciprocating motion of a guide through which the linear material passes, to advantageously cause the linear material to be wrapped substantially uniformly around most of the surface area of the drum.
[0005] Several methods have been utilized in the past for achieving such reciprocating motion. One common approach is to use a rotating reversing screw which causes a guide to translate back and forth in front of a rotating drum. For example, such an approach is shown in U.S. Pat. No. 2,494,003 to Russ. However, such reversing screws tend to wear out quickly, degrading reel performance and necessitating frequent replacement. Further, such reversing screws are bulky and increase the size of the reel assembly.
[0006] Another approach for producing reciprocating motion of the guide is to use a motor to control a rotating screw upon which the guide translates. In this class of reels, the motor reverses the direction of rotation of the screw whenever the guide reaches an end of the screw. Unfortunately, the repeated reversing of the motor increases the spooling time and causes the motor to wear down sooner. Other reels have incorporated significantly more complicated gear mechanisms for achieving the reciprocating motion.
[0007] Many reel constructions include exposed moving parts, such as the reel drum, guide, and motor. Over time, such moving parts can become damaged due to exposure. For example, an outdoor reel is exposed to sunlight and rain. Such exposure can cause the moving parts of the reel to wear more rapidly, resulting in reduced performance quality. Additionally, many reel constructions include additional parts outside the reel assembly, which increases the number of steps that the user has to take to use the reel or the number of parts the user must interconnect to use the reel, which increases the complexity of using the reel and is inconvenient for the user.
[0008] Thus, there is a need for a compact reel assembly having a reel with an improved reciprocating mechanism for efficiently distributing linear material across the reel drum and having an improved flow control mechanism.
SUMMARY
[0009] Accordingly, it is a principle object and advantage of the present invention to overcome some or all of these limitations and to provide an improved reel incorporating a reciprocating mechanism and an improved flow control mechanism.
[0010] In accordance with another embodiment, a hose reel assembly is provided. The hose reel assembly comprises a rotatable member configured to rotate about a first axis to wind a hose onto the rotatable member or unwind the hose from the rotatable member. The rotatable member is also configured to rotate about a second axis that is substantially perpendicular to the first axis. The reel assembly further comprises a housing substantially enclosing the rotatable member, the housing comprising a first aperture configured to receive the hose therethrough and a second aperture spaced apart from the first aperture. The reel assembly further comprises a conduit assembly at least partially disposed within the housing and extending between a first end and a second end. The first end is configured to releasably and operatively couple with a liquid source, the first end being accessible through the second aperture and positioned substantially along the second axis. The second end is in fluid communication with a connector on the rotatable member that releasably couples to the hose, the conduit assembly further comprising a flow control valve coupled to a conduit portion of the conduit assembly. The flow control valve is configured to selectively allow fluid flow through the conduit assembly from the liquid source to the connector. The conduit assembly and the rotatable member are configured to move together about the second axis relative to at least a portion of the housing during operation of the rotatable member.
[0011] In accordance with another embodiment, a hose reel assembly is provided. The hose reel assembly comprises a rotatable member configured to rotate about a first axis to wind a hose onto the rotatable member or unwind the hose from the rotatable member. The rotatable member is also configured to rotate about a second axis that is substantially perpendicular to the first axis. The hose reel assembly further comprises a conduit assembly extending between a first end and a second end. The first end at least partially extends along the second axis and is configured to releasably and operatively couple with a liquid source. The second end is in fluid communication with a connector on the rotatable member that releasably couples to the hose. The conduit assembly further comprises a flow control valve coupled to a conduit portion of the conduit assembly, the flow control valve configured to selectively allow fluid flow through the conduit assembly from the liquid source to the connector. The hose reel assembly further comprises a housing substantially enclosing the rotatable member and conduit assembly. The housing comprises an upper housing portion and a lower housing portion, the upper housing portion being movable relative to the lower housing portion. The upper housing portion defines a first aperture configured to receive the hose therethrough, the housing comprising a second aperture aligned with the first end of the conduit assembly. The conduit assembly and the rotatable member are configured to rotate together about the second axis relative to at least a portion of the housing.
[0012] For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
[0013] All of these aspects are intended to be within the scope of the invention herein disclosed. These and other aspects of the present invention will become readily apparent to those skilled in the art from the appended claims and from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These and other features, aspects and advantages of the present invention will now be described in connection with a preferred embodiment of the invention, in reference to the accompanying drawings. The illustrated embodiment, however, is merely an example and is not intended to limit the invention. The drawings include the following figures.
[0015] FIG. 1 is a front perspective view of a disassembled reel, including a housing, in accordance with one embodiment.
[0016] FIG. 2 is a bottom perspective view of a drum assembly with reciprocating mechanism, in accordance with one embodiment disclosed herein.
[0017] FIG. 2A is a schematic illustration of a gear reduction between a motor and a gear of the reciprocating mechanism shown in FIG. 2 .
[0018] FIG. 3 is a top and side perspective view of one embodiment of a drum assembly.
[0019] FIG. 4 is bottom and side perspective view of the drum assembly in FIG. 3 .
[0020] FIG. 5 is a top partially cut-away perspective view of the reciprocating mechanism shown in FIG. 2 .
[0021] FIG. 6 is a bottom partially cut-away view of the reciprocating mechanism for a reel shown in FIG. 2 .
[0022] FIG. 7 is a bottom and side partially cut-away perspective view of reciprocating mechanism of FIG. 2 .
[0023] FIG. 8A is a top view of the drum assembly of FIG. 2 illustrating one position in the reciprocating rotation of the drum.
[0024] FIG. 8B is a top view of the drum assembly of FIG. 2 illustrating another position in the reciprocating rotation of the drum.
[0025] FIG. 8C is a top view of the drum assembly of FIG. 2 illustrating another position in the reciprocating rotation of the drum.
[0026] FIG. 8D is a top view of the drum assembly of FIG. 2 illustrating another position in the reciprocating rotation of the drum.
[0027] FIG. 8E is a top view of the drum assembly of FIG. 2 illustrating another position in the reciprocating rotation of the drum.
[0028] FIG. 9A is a top and front perspective view of the reel assembly of FIG. 1 illustrating one position in the reciprocating rotation of the drum.
[0029] FIG. 9B is a top and front perspective view of the reel assembly of FIG. 1 illustrating another position in the reciprocating rotation of the drum.
[0030] FIG. 10 is a top partially cut-away perspective view of another embodiment of a reciprocating mechanism.
[0031] FIG. 11 shows a partial bottom view of another embodiment of a drum assembly.
[0032] FIG. 12 shows a partial bottom view of the drum assembly of FIG. 11 , rotated 90 degrees.
[0033] FIG. 13 shows a partial perspective bottom view of the drum assembly of FIG. 11 .
[0034] FIG. 14 shows a partial bottom view of another embodiment of a drum assembly.
[0035] For ease of illustration, some of the drawings do not show certain elements of the described apparatus.
DETAILED DESCRIPTION
[0036] In the following detailed description, terms of orientation such as “top,” “bottom,” “upper,” “lower,” “front,” “rear,” and “end” are used herein to simplify the description of the context of the illustrated embodiments. Likewise, terms of sequence, such as “first” and “second,” are used to simplify the description of the illustrated embodiments. Because other orientations and sequences are possible, however, the present invention should not be limited to the illustrated orientation. Those skilled in the art will appreciate that other orientations of the various components described above are possible.
[0037] FIG. 1 illustrates one embodiment of a reel assembly 100 substantially enclosing a drum assembly 10 in a housing. In the illustrated embodiment, the housing includes an upper or top shell portion 22 and a lower or bottom shell portion 24 . Additionally, the upper and lower shell portions 22 , 24 have the shape of upper and lower domes 26 , 28 , respectively, so that the reel assembly 100 has a generally spherical shape. However, the upper and lower shell portions 22 , 24 can have any suitable shape, such as cylindrical and aspherical. As shown in FIG. 1 , the upper shell portion 22 includes a guide member 30 with an aperture (not shown), which preferably guides a linear material, such as a water hose, into and out of the housing of the reel assembly 100 as the linear material is wound onto or unwound from the drum assembly 10 . Additionally, the lower shell portion 24 is preferably supported by a plurality of legs 32 . However, other types of legs or support structures can be used. In one embodiment, a circumferential stand supports the lower shell portion 24 on a support surface. Preferably, the lower shell portion 24 is movably supported with respect to a lower support surface, so that the reel assembly 100 is capable of moving along the surface. For example, the legs 32 or support structure can have rollers.
[0038] As seen in FIGS. 1 and 2 , the drum assembly 10 defines a first or drum axis X about which the drum rotates. Additionally, a housing or second axis Y extends through the reel assembly 100 . In a preferred embodiment, the housing axis Y is generally vertical and the drum axis X is generally horizontal, so that the housing axis Y is generally orthogonal to the drum axis X. Further details on reel assemblies can be found in U.S. Pat. No. 6,279,848, the entire contents of which are hereby incorporated by reference and should be considered a part of this specification.
[0039] FIGS. 2-7 illustrate one embodiment of a reciprocating mechanism 200 for a reel assembly. In one embodiment, the reciprocating mechanism 200 can be used with the reel assembly 100 illustrated in FIG. 1 . The reciprocating mechanism 200 preferably includes a frame 210 comprising a top frame and a bottom frame. In the illustrated embodiment, the top frame includes an upper ring 212 and the bottom frame includes a lower ring 214 (see FIG. 1 ). In a preferred embodiment, the upper ring 212 is coextensive with and removably disposed on the lower ring 214 . In another embodiment, the upper ring 212 overlaps the lower ring 214 . The upper and lower rings 212 , 214 are preferably fastened to the upper and lower shell portions 22 , 24 , respectively, via any suitable method. In one embodiment, the shell portions 22 , 24 can be fastened to the rings 212 , 214 , respectively, using bolts or screws. In another embodiment, the shell portions 22 , 24 can be clamped, welded, or adhesively secured to the rings 212 , 214 .
[0040] In a preferred embodiment, the upper ring 212 can rotate relative to the lower ring 214 . For example, bearings (not shown) can be disposed between the upper and lower rings 212 , 214 . Preferably, the rings 212 , 214 are sized to enclose a drum assembly 220 , which consists of first and second endplates 222 , 224 and a drum 226 disposed between the endplates 222 , 224 . As shown in FIGS. 2 and 5 , a ring gear 230 is preferably attached to the first endplate 222 .
[0041] The ring gear 230 is coupled to a shaft 232 , which preferably extends into a hollow portion 228 of the drum 226 and rotatingly couples to a shaft support 234 disposed inside the hollow portion 228 (see FIG. 3 ). In one preferred embodiment, the shaft support 234 is disposed generally at the center of the upper ring 212 . In another embodiment, the shaft support 234 can be offset from the center of the upper ring 212 . Preferably, the shaft support 234 allows the shaft 232 to rotate freely therein. For example, in one embodiment, the shaft 232 can couple to the shaft support 234 via a bearing (not shown) disposed therein. As explained more fully below, the shaft 232 is preferably hollow so as to convey water. Additionally, the connection between the shaft 232 and the shaft support 234 preferably inhibits the leakage of fluid therebetween, as further discussed below. For example, in one embodiment, the connection between the shaft 232 and the shaft 234 includes a substantially water-tight seal.
[0042] The shaft 232 also connects to a fitting 236 . The fitting 236 couples to a conduit member 262 disposed within the lower shell portion 24 and disposed below the lower ring 214 . In the illustrated embodiment, the conduit member 262 is curved and has a first end 264 that connects to the fitting 236 , which in turn connects to the shaft 232 . The conduit member 262 has a second end 266 disposed generally along an axis Y2 extending generally perpendicular to the upper and lower rings 212 , 214 . In one embodiment, the shell axis Y and the axis Y2 are coaxial. Preferably, the second end 266 extends through an aperture (not shown) in the lower shell portion 24 . In one preferred embodiment, the fitting 236 is not coupled to the upper ring 212 . Further description of the fitting 236 and the conduit member 262 is provided below.
[0043] As shown in FIG. 5 , an upper ring support member 238 extends from a surface 240 of the upper ring 212 . In the illustrated embodiment, the upper ring support member 238 defines a slot 239 therein. Preferably, the slot 239 extends along the length of the support member 238 and is sized to slidingly receive one end 245 a of a support frame 245 coupled to the conduit member 262 . As shown in FIG. 5 , the support frame 245 has a horizontal portion and a vertical portion, and the end 245 a extends from the horizontal portion of the support frame 245 . In one embodiment, at least one bearing (not shown) is disposed in the slot 239 to facilitate the sliding of the end 245 a of the support frame 245 relative to the slot 239 . However, other suitable methods for facilitating the sliding of the support frame 245 in the slot 239 , such as, for example, applying a lubricant to at least one of the slot 239 and the end 245 a of the support frame 245 .
[0044] Preferably, the shaft 232 includes a worm gear section 242 , which extends along at least a portion of the shaft 232 . In one embodiment, the worm gear section 242 extends along substantially the entire length of the shaft 232 . The shaft 232 is preferably integrally formed with the worm gear section 242 . In another embodiment, the shaft 232 is removably coupled to the worm gear section 242 via, for example, a spline connection.
[0045] As shown in FIGS. 2 , 6 and 7 , the worm gear section 242 preferably meshingly engages a top or driven gear 244 mounted on and below the support frame 245 . As used herein, the “engagement” of two gears means that the teeth of one gear are engaged with the teeth of the other gear. The top gear 244 is in turn coupled to a lever 246 (see FIG. 5 ), for example, via a pin 246 a (see FIG. 8B ) that extends along an axis of rotation of the top gear 244 . As shown in FIG. 5 , the lever 246 defines an elongated slot 247 therein. In a preferred embodiment, the top gear 244 and lever 246 are lockingly coupled, so that rotation of the top gear 244 results in rotation of the lever 246 . In another embodiment, the top gear 244 and lever 246 are integrally formed. The lever 246 is preferably coupled to an elongate member 248 , so that a first end or portion 248 a of the elongate member 248 extends through and is adapted to slidingly move along the slot 247 , while a second end or portion 248 b of the elongate member 248 is pivotably secured to the support member 238 . In one embodiment, the first end 248 a of the elongate member 248 extends completely through the slot 247 of the lever 246 and at least partially or completely through the slot 252 of the guide member 250 (described below). In another embodiment, the lever 246 is below the guide member 250 , and the first end 248 a of the elongate member 248 extends completely through the slot 252 and at least partially or completely through the slot 247 of the lever 246 .
[0046] As best shown in FIG. 5 , a guide member or track 250 is disposed adjacent the lever 246 , so that the guide member 250 extends along a plane generally parallel to a plane within which the lever 246 rotates. In the illustrated embodiment, the guide member 250 defines an encircling slot 252 . In the illustrated embodiment, the enclircling slot 252 extends only partially through the guide member 250 , so as to define a groove or recess. In another embodiment, the encircling slot 252 can extend completely through the guide member 250 . In the illustrated embodiment, the first end 248 a of the elongate member 248 extends partially through and is adapted to move along the encircling slot 252 of the guide member 250 , so that the elongate member 248 pivots about an axis generally perpendicular to the plane of the encircling slot 252 . In another embodiment, the first end 248 a of the elongate member 248 can extend completely through the encircling slot 252 of the guide member 150 . In the illustrated embodiment, the guide member 250 is disposed between the support frame 245 and the lever 246 and is preferably secured to the support frame 245 . However, in another embodiment, the lever 246 can be positioned between the support frame 245 and the guide member 250 . As used herein, encircling means surrounding, but is not necessarily limited to a circular surrounding. In the illustrated embodiment, the guide member 250 is shaped somewhat in the form of a “D” (see FIG. 8A ). However, the guide member 250 can have other suitable shapes, such as circular, oval, triangular and trapezoidal.
[0047] As shown, for example in FIG. 2 , the reciprocating mechanism 200 includes a motor 254 mounted to the support frame 245 . In the illustrated embodiment, the motor 254 is disposed below the lower ring 214 and is housed in the lower shell portion 24 . Preferably, the motor 254 is an electric motor. The motor 254 preferably operatively connects to the ring gear 230 via a drive gear 256 . For example, the motor 254 can, through a gear reduction comprising multiple gears, drive the drive gear 256 , which can operatively drive the ring gear 230 at a desired speed. One example of a gear reduction is shown in FIG. 2A , which includes a motor gear 254 a that meshingly engages and drives the drive gear 256 . In the illustrated embodiment, another gear 257 (also shown in FIG. 6 ), which is preferably co-axial with the drive gear 256 , meshingly engages and drives the ring gear 230 . However, the gear reduction can include any number of gears and have other configurations for operatively coupling the motor 254 to the ring gear 230 . Additionally, any desired gear ratio can be used. In one embodiment, the gear reduction has a gear ratio of 2 to 1. In another embodiment, the gear reduction has a gear ratio of 4 to 1. In still another embodiment, the gear reduction has a gear ratio of between about 2 to 1 and about 25 to 1. One example of a gear reduction between the motor 254 and the ring gear 230 is schematically shown in FIG. 2A
[0048] The reel 100 can also employ an electronic motor controller and associated electronic componentry for controlling the speed and direction of the motor 254 . For example, while spooling the linear material 268 (see FIG. 9A ) onto the drum 226 , a motor-controller can be employed to vary the motor speed based upon the length of unwound linear material 268 . It will be appreciated that if the motor speed is constant, the inwardly pulled linear material 268 tends to move increasingly faster due to the increasing diameter of the spool itself. A motor-controller can adjust the motor speed to more safely control the motion of the linear material 268 during spooling. Also, a motor-controller can be used to slow or stop the motor 254 just before the linear material 268 becomes completely spooled onto the drum 226 . Otherwise, the linear material 268 would get pulled into the housing or, if there is an object at the end of the linear material 268 (e.g., a nozzle), the object may whip against or otherwise impact the housing or a person near the housing. In addition, a motor-controller can even be used to assist the user during unspooling of the linear material 268 (i.e., powered unspooling). One example of a motor-controller for a reel is disclosed in U.S. Pat. No. 7,350,736 to Caamaño et al., entitled Systems and Methods for Controlling Spooling of Linear Material, the entire contents of which are hereby incorporated by reference and should be considered a part of this specification. Also, the motor 254 and/or motor-controller can be operated via a remote control. An exemplary remote control system for a motorized reel is disclosed in U.S. Pat. No. 7,503,338 to Harrington et al., the entire contents of which are hereby incorporated by reference and should be considered a part of this specification. In a preferred embodiment, a remote control is engaged on the spooled linear material 268 at or near its outward end. The remote control can send signals wirelessly (e.g., via radio frequency signals) or through a wire within the linear material.
[0049] As shown in FIGS. 3-4 , the reciprocating mechanism 200 also has a platform 258 that extends between the shaft support 234 and the edge of the upper ring 212 . As shown in FIG. 8A , the platform 258 is disposed generally opposite the upper ring support member 238 . The platform 258 preferably extends into the hollow portion 228 of the drum 226 . In one embodiment, the platform 258 can support a battery (not shown) thereon so that the battery is disposed between the second endplate 224 and the upper ring 212 . Preferably, the battery provides power to the motor 254 . Details of one suitable battery for use with the reciprocating mechanism 200 can be found in U.S. Pat. No. 7,320,843 to Harrington, entitled Battery Assembly With Shielded Terminals, the entire contents of which are hereby incorporated by reference and should be considered a part of this specification.
[0050] As shown in FIGS. 3 and 4 , the platform 258 preferably supports the shaft support 234 thereon. In the illustrated embodiment, a pin 234 a of the shaft support 234 pivotably extends through an opening 258 a of the platform 258 , permitting the shaft support 234 to rotate with respect to the platform 258 about a vertical axis extending through the opening 258 a . This pivot connection advantageously allows the reciprocating mechanism 200 to reciprocatingly rotate the drum 226 about the shell axis Y, as further discussed below.
[0051] As discussed above, the fitting 236 couples to the conduit member 262 . In one embodiment, the second end 266 of the conduit 262 is configured to removably attach to a water hose (not shown). For example, the second end 266 can have a threaded surface for threaded engagement with a corresponding thread on the hose (e.g., a standard hose fitting). In another embodiment, the second end 266 can have a quick-disconnect portion configured to removably engage a corresponding quick-disconnect portion on the hose. Other mechanisms for connecting the hose and the conduit 262 are also possible. Preferably, water provided through the hose flows through the conduit 262 and through the fitting 236 and shaft 232 into the shaft support 234 . In one preferred embodiment, the shaft support 234 communicates, for example, via a second conduit (not shown), with a second fitting 268 (see FIGS. 2 and 8A ) disposed on the surface of the drum 226 . In this manner, water can be supplied to a hose that has been spooled on the drum 226 and has been removably fastened to the second fitting 268 . Any suitable mechanism for removably fastening the hose and the second fitting 268 can be used, such as a threaded engagement or a quick-disconnect connection. Further details on such an arrangement is shown, for example, in U.S. Pat. No. 6,981,670 to Harrington, entitled Reel Having Apparatus for Improved Connection of Linear Material, the entire contents of which are hereby incorporated by reference and should be considered a part of this specification.
[0052] The rings 212 , 214 and gears 230 , 242 , 244 , 256 of the reciprocating mechanism 200 are preferably made of a strong material resistant to breaking. In one embodiment, the rings 212 , 214 and gears, 230 , 242 , 244 , 256 can be made of a metal or metal alloy, such as stainless steel and aluminum. However, other materials can also be used. In another embodiment, the rings 212 , 214 and gears 230 , 242 , 244 , 256 of the reciprocating mechanism 200 can be made of a hard plastic. In still another embodiment, the gears 230 , 242 , 244 , 256 may be formed of acetyl, such as Delrin® sold by Dupont, headquartered in Wilmington, Del. Various combinations of these materials are also possible.
[0053] The use of the reciprocating mechanism 200 to reciprocatingly rotate the drum assembly 220 is illustrated in FIGS. 8A-8E . Actuation of the motor 254 preferably rotates the ring gear 230 in one direction via the drive gear 256 and, optionally, a gear reduction assembly (see e.g., FIG. 2A ) operatingly coupling the motor 254 to the drive gear 256 . Rotation of the ring gear 230 in turn rotates the reel drum 226 via the first endplate 222 . Rotation of the ring gear 230 also rotates the shaft 232 in the same direction, causing the worm gear section 242 to also rotate. Rotation of the worm gear section 242 rotates the top or driven gear 244 , which in turn rotates the lever 246 about the axis of the top gear 244 . As the lever 246 rotates, it guides the first end 248 a of the elongate member 248 about the axis of the top gear 244 and along the encircling slot 252 of the guide member 250 , thus moving the elongate member back and forth. As the lever 246 rotates and guides the first end 248 a of the elongate member 248 about the axis of the top gear 244 , the first end 248 a also slides along the slot 247 of the lever 246 . The movement of the elongate member 248 in turn reciprocatingly rotates the drum 226 relative to the upper ring 212 about the shell axis Y via the pivot connection 234 a , 258 a between the shaft support 234 and the platform 258 . In one embodiment (e.g., if the slot 252 is circular), the reciprocating mechanism 200 reciprocatingly rotates the drum 226 so that an angular velocity of the drum about the shell axis Y fluctuates generally sinusoidally.
[0054] In a preferred embodiment, the slot 247 on the lever 246 and the encircling slot 252 on the guide member 250 allow the drum 226 to reciprocate about the shell axis Y at a generally constant angular velocity between endpoints of the reciprocation for a given drum 226 rotation speed about the drum axis X. It is the general D-shape of the slot 252 that produces this outcome. It will be appreciated that other sizes and shapes of the slot 252 , slot 247 , lever 246 , and elongate member 248 can achieve the goal of a generally constant angular velocity between endpoints of the reciprocation.
[0055] In one embodiment, the upper shell portion 22 , which is preferably fixed with respect to the upper ring 212 , and the aperture guide 30 in the upper shell portion 22 , remain in a fixed position while the drum 226 reciprocatingly rotates inside the housing to spool and unspool the linear material 268 , as shown in FIGS. 9A-9B . In another embodiment, the reciprocating mechanism 200 reciprocatingly rotates the upper shell portion 22 about the shell axis Y, while the drum 226 is preferably in a substantially fixed angular position.
[0056] The substantially constant angular velocity of the drum 226 about the shell axis Y that is generated by the reciprocating mechanism 200 advantageously allows the spooling and unspooling of linear material onto the drum 226 with increased efficiency. Such increased efficiency allows the use of a drum 226 having a smaller width to spool the same amount of linear material, requires less power to spool the same amount of linear material, and allows for an overall reduction in the size of the reel assembly 100 . The reciprocating mechanism 200 according the embodiments discussed above also advantageously require about 30% less parts to operate than conventional reciprocating mechanisms.
[0057] FIG. 10 illustrates another embodiment of a reciprocating mechanism 200 ′. The reciprocating mechanism 200 ′ is similar to the reciprocating mechanism 200 , except as noted below. Thus, the reference numerals used to designate the various components of the reciprocating mechanism 200 ′ are identical to those used for identifying the corresponding components of the reciprocating mechanism 200 in FIG. 5 , except that a “′” has been added to the reference numerals.
[0058] The reciprocating mechanism 200 ′ includes a top or driven gear coupled to a lever 246 ′ via a pin 246 a ′ that extends along the axis of the top gear. The top gear and the lever 246 ′ are preferably lockingly coupled, so that rotation of the top gear about the top gear axis results in rotation of the lever 246 ′ in the same direction. In another embodiment, the top gear and the lever 246 ′ can be integrally formed. The lever 246 ′ is preferably pivotably coupled to an elongate member 248 ′ at a first pivot point 248 a ′. The elongate member 248 ′ is also pivotably secured to a support member 238 ′ at a second pivot point 248 b ′. The relative motion between the lever 246 ′ and the elongate member 248 ′ advantageously generates a reciprocating motion of the drum 226 ′ about a drum axis.
[0059] In a preferred embodiment, the gear ratio of the gear reduction and size of the ring gear 230 , worm gear 242 , drive gear 256 , and top gear 244 , as well as the lengths of the levers 246 and elongate member 248 , are selected to reciprocatingly rotate the drum 226 relative to the upper ring 212 about the shell axis Y so as to cause a linear material to be generally uniformly wound onto the reel drum. Thus, the reciprocating mechanism 200 advantageously allows a linear material to be uniformly wound onto the drum 226 .
[0060] As discussed above, the upper ring 212 and drum assembly 220 preferably rotate freely relative to the lower ring 214 , preferably through 360 degrees and more, as desired. Therefore, the upper shell portion 22 coupled to the upper ring 212 can advantageously rotate freely relative to the lower shell portion 24 , which is preferably fixed with respect to the lower ring 214 .
[0061] FIGS. 11-13 show another embodiment of a drum assembly 10 ′. The drum assembly 10 ′ is similar to the drum assembly 10 in FIGS. 2-7 and includes all of the components of the drum assembly 10 in FIGS. 2-7 , except as noted below. Thus, the reference numerals used to designate the various components of the drum assembly 10 ′ are identical to those used for identifying the corresponding components of the drum assembly 10 in FIGS. 2-7 and described above, except that a “′” has been added to the reference numerals.
[0062] With reference to FIGS. 11-13 , a flow control valve 270 is attached to the ring support member 238 ′. The flow control valve 270 is fluidly coupled to a proximal end 262 a ′ of a conduit member 262 ′ and to a distal end 267 b of a conduit section 267 . A distal end 262 b ′ of the conduit member 262 ′ is coupled to the conduit end portion 266 ′ (that extends along the axis Y2). In one embodiment, the conduit member 262 ′ and conduit end portion 266 ′ are a single piece. The conduit section 267 has a proximal end 267 a that can be in fluid communication with a hose fitting (not shown) on the drum 226 ′ to which a hose can be attached, the hose being wound and unwound about the drum. The conduit end portion 266 ′ can be coupled to a fluid source for providing a fluid flow from the fluid source, through the conduit end portion 266 ′, through the conduit member 262 ′, through the flow control valve 270 , through the conduit section 267 and through the hose fitting into the hose. The conduit member 262 ′ can be rigid or semi-rigid and be made of a hard plastic or other suitable material (e.g., metal). In the illustrated embodiment, the conduit member 262 ′ can be curved and have a curvature that generally corresponds to an inner curvature of one of the upper and lower shell portions 22 , 24 of the housing of the reel assembly 100 that defines a space into which the conduit member 262 ′ extends.
[0063] FIG. 14 shows another embodiment of a drum assembly 10 ″. The drum assembly 10 ″ is similar to the drum assembly 10 ′ in FIGS. 11-13 , except as noted below. Thus, the reference numerals used to designate the various components of the drum assembly 10 ″ are identical to those used for identifying the corresponding components of the drum assembly 10 ′ in FIGS. 11-13 , except that a “″” has been added to the reference numerals. With reference to FIG. 14 , the flow control valve 270 ″ can be disposed between the distal end 262 b ′ of the conduit member 262 ′ and the conduit end portion 266 ′. In still another embodiment, the flow control valve 270 ″ can be disposed at the distal end 262 b ′ of the conduit member 262 ′ and the drum assembly 10 ″ can exclude the conduit end portion 266 ′. Advantageously, mounting the flow control valve 270 , 270 ″ on the drum assembly 10 ′, 10 ″ allows for all components to be housed in a housing of the reel.
[0064] In one embodiment, the flow control valve 270 ″ can be mounted on a bottom portion (e.g. removable skid plate) of the lower dome 28 , which in one embodiment can be removably attached to the rest of the lower dome 28 to advantageously facilitate access to the flow control valve 270 ″ (e.g., to perform maintenance on the valve 270 ″ or replace the valve 270 ″) without having to detach the upper dome 26 from the lower dome 28 . The skid plate can be a circular portion (or other shaped circumference, such as square, oval, triangular) of the lower dome portion 28 that is removably attached to the rest of the lower dome portion 28 by one or more fasteners (e.g., screws or bolts), and that has an opening through which at least a connection portion of the conduit end portion 266 ′ extends, thereby allowing a water source to be fluidly coupled to the conduit end portion 266 ′. In one embodiment, the flow control valve 270 ″ can be mounted to the bottom portion of the lower dome 28 via one or more bearings and/or via a slip ring that allows rotation of the bottom portion (e.g., removable skid plate, slip ring) relative to the rest of the bottom dome 28 , to thereby allow rotation of the flow control valve 270 ″ about the axis Y2, as discussed above. In one embodiment, the one or more bearings can be interposed between the bottom portion and the rest of the bottom dome 28 (e.g., radially interposed between an outer edge of the bottom portion and an inner edge of the opening in the lower dome 28 that movably coupleably receives the bottom portion) to allow relative rotation between the bottom portion and the rest of the dome 28 .
[0065] Additionally, mounting the flow control valve 270 , 270 ″ on the drum assembly 10 ′, 10 ″ advantageously allows the valve 270 , 270 ″ to be powered by the power source (e.g., battery) that powers other components (e.g., motor 254 ′, controller) of the reel, so that the flow control valve 270 , 270 ″ need not have its own separate power source, thereby simplifying the construction of the reel and providing for more efficient operation of the reel. In one embodiment, the controller can be mounted on the ring support member 238 ′ and/or the support frame 245 , 245 ′ or platform 258 .
[0066] The valve 270 , 270 ″ can be an electrically actuated valve, such as a solenoid valve, and selectively permit or inhibit fluid flow therethrough. The valve 270 , 270 ″ can be electrically connected to a controller (not shown) of the reel assembly (e.g., the valve can be hardwired to the controller), and can be powered by a battery (not shown) that powers the reel assembly. Accordingly, the electrically actuated valve 270 , 270 ″ need not have its own power source.
[0067] The controller can have a wireless receiver configured to receive electromagnetic signals from a remote source (e.g., a remote control, such as remote control attached to the hose), and to translate those signals into signals that may open or close the electrically actuated valve 270 , 270 ″. In one embodiment, the flow control valve 270 , 270 ″ can be controlled wirelessly (e.g., with a remote control) as discussed above. In another embodiment, the flow control valve 270 , 270 ″ can be hard-wired to the controller. Additionally, the controller that controls the operation of the valve 270 , 270 ″ can be electrically connected to the motor 254 ′ that drives rotation of a reel drum 226 ′. Thus, the controller can send signals to control the operation of the motor 254 ′ for the reel, the motor command signals being conveyed to the motor via the wire connection. The wire connection can also convey power to one or both of the flow control valve 270 , 270 ″ and the motor 254 ′. In one embodiment, the motor 254 ′ can be powered by connection of an electrical plug to a power supply, the wire connection conveying power to the flow control valve 270 , 270 ″. Examples of communication methods include infrared (IR) and radio frequency (RF) communications.
[0068] Of course, the foregoing description is that of certain features, aspects and advantages of the present invention, to which various changes and modifications can be made without departing from the spirit and scope of the present invention. Moreover, the reel assembly need not feature all of the objects, advantages, features and aspects discussed above. Thus, for example, those skill in the art will recognize that the invention can be embodied or carried out in a manner that achieves or optimizes one advantage or a group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. In addition, while a number of variations of the invention have been shown and described in detail, other modifications and methods of use, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. It is contemplated that various combinations or subcombinations of these specific features and aspects of embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the discussed reel assembly.
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A reel assembly includes a rotatable member that rotates about a first axis to wind and unwind a hose from the rotatable member, where the rotatable member also rotates about a second axis that is substantially perpendicular to the first axis. A housing substantially encloses the rotatable member and has a first aperture that receives the hose therethrough and a second aperture spaced apart from the first aperture. A conduit assembly is at least partially disposed within the housing and extends between a first end and a second end, the first end being releasably and operatively coupleable with a liquid source, the first end being accessible through the second aperture and positioned substantially along the second axis. The second end is in fluid communication with a connector on the rotatable member that releasably couples to the hose. The conduit assembly also has a flow control valve coupled to a conduit portion of the conduit assembly and configured to selectively allow fluid flow through the conduit assembly from the liquid source to the connector. The conduit assembly and the rotatable member can move together about the second axis relative to at least a portion of the housing during operation of the rotatable member.
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BACKGROUND OF THE INVENTION
1. Background of the Invention
The present invention relates to a bobbin holding structure to house and hold a bobbin in a bobbin case holder.
2. Description of the Prior Art
FIG. 1 is a perspective view of a typical prior art structure. FIG. 2 is a perspective view of a bobbin 5. FIG. 3 is a perspective view of a bobbin case 6 where the bobbin case 6 is shown partially cut away.
A horizontal axis full rotary looptaker 1 provided in a lock stitch sewing machine includes a rotating hook 3 driven by a rotary shaft 2 to rotate around a horizontal axis and a bobbin case holder 4 housed in the rotating hook 3. Bobbin case 6 housing bobbin 5 fits in the bobbin case holder 4. The bobbin case holder 4 is prevented from rotating by a rotation stopper member 7. When the rotary shaft 2 is rotated, the rotating hook 3 rotates around the rotary axis while the bobbin case holder 4 remains stationary.
FIG. 4 is a perspective view of the horizontal axis full rotary looptaker 1 with the bobbin 5 and the bobbin case 6 removed therefrom. FIG. 5 is a partially enlarged perspective view of the bobbin case 6. With reference made also to FIG. 1 through FIG. 3, a stud 9 projects perpendicularly from a bottom 8 of the bobbin case holder 4 to an open end thereof. As shown in FIG. 3, a hollow shaft 10 of straight cylindrical shape is positioned within the bobbin case 6. The hollow shaft 10 is inserted through a central hole or passage 11 of the bobbin 5, and the bobbin 5 is housed in the bobbin case 6. The bobbin case 6 which houses the bobbin 5 is housed in the bobbin case holder 4 with the stud 9 inserted through the hollow shaft 10.
When the bobbin 5 is within the bobbin case holder 4, a locking piece 13 which is provided on the bobbin case 6 is locked in a locking groove 12 which is formed at a free end of the stud 9, thereby locking the bobbin case 6 in the bobbin case holder 4. Thus, the bobbin 5 is retained in the bobbin case holder 4 by the bobbin case 6. In order to remove bobbin 5 from the bobbin case holder 4, a pivotable flap 14 is operated to release the lock between the locking piece 13 and the stud 9, and the bobbin case 6 then is removed from the bobbin case holder 4 and the bobbin 5 is removed from the bobbin case 6.
In such a prior art structure as described above, it takes substantial time to replace the bobbin, thereby resulting in poor productivity. Moreover, the mechanism for holding the bobbin is complicated.
SUMMARY OF THE INVENTION
An object of the invention is to provide a bobbin holding mechanism which makes it possible to easily attach and detach a bobbin in and from a bobbin case holder, and which is capable of securely holding the bobbin in the bobbin case holder by means of a simple structure.
The invention provides a bobbin holding mechanism where a bobbin holding member which attracts the bobbin to the bobbin case holder is mounted in a freely detachable manner.
In a preferred embodiment of the invention, the bobbin holding member has a bobbin thread tensioning function.
In another preferred embodiment of the invention, the bobbin thread tensioning function is achieved by a bobbin thread tensioner spring attached to the bobbin holding member.
The bobbin holding member holds the bobbin securely within the bobbin case holder without allowing the bobbin to detach from the bobbin case holder during a sewing operation. Since the bobbin holding member is installed detachably on the bobbin case holder, the bobbin easily can be replaced and the efficiency of the sewing operation can be improved.
In accordance to the invention, the bobbin is housed in the bobbin case holder securely by the bobbin holding member without allowing the bobbin to detach from the bobbin case holder. Because the bobbin holding member is freely detachable from the bobbin case holder, the bobbin easily can be removed from the bobbin case holder. This enables quick and easy replacement of the bobbin, resulting in improved efficiency. The bobbin holding mechanism of the invention can be employed in a conventional rotating hook, thus making it possible to use the invention widely in existing sewing machines.
The invention provides a bobbin holding mechanism comprising a body extending along a diameter of a bobbin case holder at an end face of an open end thereof and made of a ferromagnetic material. The body has at ends thereof recesses or slots to enable the end face to fit therein. A shaft extends perpendicularly from the center of the body in an axial direction and has a tip end that extends to near a bottom of the bobbin case holder when the body is installed on the bobbin case holder. A bobbin thread tensioner spring has a base end attached to the body and a free end with a bobbin thread guide slot and making elastic contact with a side face of the body. A screw member is provided on the bobbin thread tensioner spring and displaces the same toward or away from the body, thereby changing the pressure of the free end against the side face of the body. An attraction member of magnetic material is installed at the tip end of the shaft. The shaft is inserted through a cylinder of the bobbin and the attraction member is magnetically attracted to the bottom of the bobbin case holder, thus retaining the bobbin in the bobbin case holder.
In accordance to the invention, when the bobbin holding member is installed in the bobbin case holder, the body is disposed in the direction of the diameter of the bobbin case holder and the free end of the bobbin case holder fits in the slot, thereby preventing displacement of the direction of the diameter and ensuring the position of the body with respect to the bobbin case holder. The tip of the shaft extends to adjacent the bottom of the bobbin case holder, and the attraction member provided at the tip magnetically adheres to the bottom, thus retaining the bobbin in the bobbin case holder. This construction makes it possible to change the bobbin easily and quickly, thereby minimizing the time taken to change the bobbin and improving efficiency of a sewing operation. Also, because the body is equipped with the bobbin thread tensioner spring, the bobbin thread lead extending from the bobbin and that is retained in the bobbin case holder can be properly tensioned, thereby enabling the formation of stitches of good quality without allowing slack in the thread.
In accordance with the invention, the bobbin housed in the bobbin case holder can be securely retained therein by the bobbin holding member. Because the bobbin holding member is installed in the bobbin case holder in a freely detachable manner, the bobbin easily can be removed from the bobbin case holder. This makes it possible to replace the bobbin quickly with improved operating efficiency. The bobbin holding mechanism of the invention is simpler in construction than the bobbin cases of the prior art and therefore provides for better productivity and lower cost of manufacture. Moreover the bobbin holding mechanism of the invention makes possible the replacement of only the bobbin case holder unlike the rotating hooks of the prior art, and therefore can be employed with a wide range of rotating hooks in existing sewing machines.
BRIEF DESCRIPTION OF THE DRAWINGS
Other and further objects, features and advantages of the invention will be apparent from the following detailed description, taken with reference to the drawings, wherein:
FIG. 1 is a perspective view of a typical prior art structure;
FIG. 2 is a perspective view of a bobbin;
FIG. 3 is a perspective view of a bobbin case;
FIG. 4 is a perspective view of a horizontal axis full rotary looptaker with the bobbin and the bobbin case removed therefrom;
FIG. 5 is a partially enlarged cross sectional view of the bobbin case;
FIG. 6 is a perspective view of a bobbin holding member illustrative of a first embodiment of the invention;
FIG. 7 is a perspective view of a horizontal axis full rotary looptaker equipped with the bobbin holding member;
FIG. 8 is a perspective view of a bobbin holding member illustrative of a second embodiment of the invention;
FIG. 9 is an enlarged perspective view of such bobbin holding member;
FIG. 10 is a partially enlarged perspective view of a bobbin thread tensioner spring;
FIG. 11 is a perspective view of a bobbin holding member illustrative of a third embodiment of the invention; and
FIG. 12 is a perspective view of a bobbin holding member illustrative of a fourth embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, preferred embodiment of the invention are described below.
FIG. 6 is a perspective view of a bobbin holding member 20 illustrative of an embodiment of the invention, and FIG. 7 is a perspective view of a horizontal axis full rotary looptaker 21 which is equipped with the bobbin holding member 20. In FIG. 6, the bobbin holding member 20 is shown partially cut away. The horizontal axis full rotary looptaker 21 to be installed in a lock stitch sewing machine is provided with a rotating hook 23 fixed to a rotary shaft 22 which is driven to rotate about a horizontal rotary axis. A bobbin case holder 24 made of a ferromagnetic material such as iron is housed in the rotating hook 23, and the bobbin holding member 20 with a bobbin 25 housed therein is installed in the bobbin case holder 24.
A rotation stopper 26 prevents the bobbin case holder 24 from rotating when the rotating hook 23 is rotated about the rotary axis thereof. In this embodiment, a bottom 27 of the bobbin case holder 24 is flat because it is not necessary to provide a stud 9 as required in the above described prior art structure.
The bobbin holding member 20 has a cylindrically shaped shaft 28 which extends along a center axis thereof. Formed at a tip of the shaft 28 is a recess 29 having fixed therein an attraction member 30 made of a magnetic material, e.g. a permanent magnet. By housing the bobbin 25 in such a bobbin holding member 20 and installing it in the bobbin case holder 24, the bobbin 25 can be retained securely in the bobbin case holder 24 by the magnetic attraction of the attraction member 30 to the bottom 27. The bobbin 25 easily can be removed from the bobbin case holder 24 by picking up the bobbin holding member 20 and removing it from the bobbin case holder 24.
In another embodiment, installation of a cylindrical attraction member in hollow shaft 10 of the conventional bobbin case 6 makes it possible to use the conventional bobbin case holder 4. As such, the invention widely may be employed with existing rotating hooks.
FIG. 8 is a perspective view of a bobbin holding member 40 installed in the horizontal axis full rotary looptaker 21 according to a second embodiment of the invention. FIG. 9 is an enlarged perspective view of the bobbin holding member 40. FIG. 10 is a partially enlarged perspective view of a bobbin thread tensioner spring 43. Parts which correspond to those of the embodiment mentioned above are designated by like reference numerals. The bobbin holding member 40 of the second embodiment includes a body 41 in the form of an elongated bar which is installed at an end face 24a of the bobbin case holder 24 at an axially open end thereof and extends in the direction of the diameter thereof, and a shaft 28 extending perpendicularly from the center of the body 41 in axial direction of bobbin case holder 24.
The body 41 has at opposite ends thereof fitting slots 42a, 42b to accommodate the end face 24a of the bobbin case holder 24. Thus, it is possible to install the bobbin holding member 40 in the bobbin case holder 24 so that the axis of shaft 28 is coaxial with the center axis of the bobbin case holder. Bobbin thread tensioner 43 has a curved plate shape and has a base end section thereof fixed to body 41 by a screw 44.
An adjustment screw 45 freely passes axially through the center of the bobbin thread tensioner spring 43 and is threaded into a screw hole formed in the body 41. Formed at a free end of the bobbin thread tensioner spring 43 is a pressurizing portion 47 which makes elastic contact with one side 41a of the body 41 and pressurizes a bobbin thread 46. A bobbin thread guiding slot 48 is formed in portion 47, as shown in FIG. 10. The bobbin thread 46 is passed through the bobbin thread guiding slot 48, and is elastically pressed against the side face 41a by the pressurizing portion 47.
By turning the adjustment screw 45 in opposite directions, the force acting on the bobbin thread can be adjusted. Therefore, it is possible to apply a proper tension, by the rotary action of the rotating hook 23, to the bobbin thread 46 removed from the bobbin 25, thereby ensuring a sewing operation conducted with a desired thread tension.
FIG. 11 is a perspective view of a bobbin holding member 60 illustrative of the third embodiment of the invention. A body 61 of the bobbin holding member 60 has integrally formed therewith a bobbin thread guiding member 62. The bobbin thread guiding member 62 has formed therein a notch 63 through which fits the bobbin thread 46. The bobbin thread 46 removed from the bobbin 25 passes through the bobbin thread guiding slot 48, is elastically pressed by the pressurizing portion 47 against a side face 61a of the body 61, and is passed through the notch 63. This constitution it is possible to retain the bobbin 25 in the bobbin case holder 24 and, by applying a desired tension to the bobbin thread 46, to remove the bobbin with the desired thread tension. Because the fitting slot 42b (FIG. 9) described in relation to the previous embodiment is not formed in this embodiment, the bobbin holding member 60 may be magnetically attracted to the end face 24a of the bobbin case holder 24 by magnetizing the body 61 adjacent a portion or end 64 thereof. By such arrangement, the bobbin holding member 60 can be installed securely without lateral displacement thereof relative to the end face 24a of the bobbin case holder 24 during a sewing operation.
FIG. 12 is a perspective view of a bobbin holding member 80 illustrative of the fourth embodiment of the invention. A bobbin thread tensioner spring 82 is installed by a set screw 83 on a base end section of a body 81 of the bobbin holding member 80. The body 81 is made of a magnetic material so that the bobbin thread tensioner spring 82 is magnetically attracted and thereby presses the bobbin thread 46 against a side face 81a. Formed at a free end of the bobbin thread tensioner spring 82 is a pressurizing portion 84 having formed therein a bobbin thread guiding slot 85. Formed between the base end section and the free end section of the bobbin thread tensioner spring 82 is a mounting section 87 through which is threaded an adjustment screw 86. A tip end of the screw 86 is in contact with a top face 81b of the body 81. By turning screw 86 in opposite directions, it is possible to displace bobbin thread tensioner spring 82 angularly about the set screw 83, thus changing the length of the bobbin thread 46 is interposed between the pressurizing portion 84 and the side face 81a of the body 81. When such length is increased a friction force applied to the bobbin thread is increased, and when such length is decreased the friction force is decreased. This makes it possible to apply a proper tension to the bobbin thread 465 to perform a sewing operation at a desired thread tension.
As described above, by means of the bobbin holding members 20, 40, 60 and 80 in accordance with the invention, it is possible to apply a proper tension to the bobbin thread removed from the bobbin 25 and perform a sewing operation at a desired thread tension.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and the range of equivalency of the claims are therefore intended to be embraced therein.
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A bobbin holding member magnetically adheres within a bobbin case holder which houses a bobbin. The bobbin is securely retained in the bobbin case holder without allowing the bobbin to be removed therefrom during a sewing operation. The bobbin holding member is installed in the bobbin case holder freely detachably, and thus the bobbin easily can be replaced.
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This is a division of Ser. No. 827,276, now abandoned, filed Aug. 24, 1977.
BACKGROUND OF THE INVENTION
In recent years a large and successful business has been developed which employs flexible plastic fasteners of a type designed to be inserted through hollow slotted needles for tagging or for joining two objects together. Such fasteners, together with apparatus for applying them, have been widely employed for the attachment of buttons to garments, for price tagging in retail establishments, for the pairing of items such as shoes, and in various industrial applications. Such fasteners and apparatus are shown in numerous references, including among others, U.S. Pat. Nos. 3,103,666; 3,399,432; 3,380,122; 3,444,597; 3,457,589; 3,470,834; 3,659,769; 3,733,657; 3,759,435; 3,875,648; 3,893,612; 3,895,753; and 3,948,128.
Most conveniently, plastic fasteners have been provided in assemblies for feeding sequentially through the dispensing apparatus. They have been supplied, as shown for example in U.S. Pat. No. 3,103,666, attached by means of severable necks to a runner bar, or, as described for example in U.S. Pat. No. 3,875,648, as a stock of continuous side members cross-coupled by a plurality of filaments, from which individual fasteners are severed. Fastener assemblies employing runner bars limit the number of fasteners which can be conveniently supplied in a single assembly and waste material since the runner bar is not put to productive end use. While these limitations are partially overcome by the fastener stock described in U.S. Pat. No. 3,875,648, a need has persisted for improvements in manufacture and in feeding and dispensing the fasteners, especially for applications such as price tagging where a single fastener end-bar is dispensed by means of a hand powered tool.
SUMMARY OF THE DISCLOSURE
Principle objects of the present invention are to provide improved methods and apparatus for feeding, servering and dispensing fasteners furnished in long lengths, and to provide fasteners of improved design suitable for economic manufacture and for use in the improved method and apparatus.
Fastener stock, as disclosed in U.S. Pat. No. 3,875,648, comprises two continuous elongated plastic side members cross-coupled by a plurality of filaments or cross-links, the stock being proportioned to be fed as a unit to a position where individual fasteners are separated therefrom within a machine, at least one of the side members being proportioned so that each separated fastener includes an end-bar formed from a portion of the side member and is configured for feeding through the bore of a hollow needle having a longitudinal slot for passage of the associated filament, and in which each filament is foldable toward the associated end-bar for feeding through the hollow needle. Preferably, and as shown, the filaments and end-bars are substantially circular in cross-section.
According to the present improvement, the cross-sections are modified such that one side of each filament is a substantially flat surface corresponding to the parting line of the mold in which they are formed. The filament cross-section is substantially D-shaped and provides draft on surfaces extending from the plane to facilitate removal from the mold. The side members are reduced in cross-sectional area between individual fasteners to provide severable connectors to facilitate separation. The connectors join the end-bars of adjacent fasteners end-to-end at a portion of their periphery, preferably having a flat face at said plane extending from side plane on either the same side as the filaments or the opposite side thereof. Preferably they extend from the same side and the joined end-bars are substantially D-shaped. Where the connectors extend from the opposite side, the section thereof is preferably continued across the joined end-bars to provide a more rounded cross-section for feeding through circular needle bores. The filaments may be stretched, if desired, after forming to reduce their size and increase their strength as previously disclosed. Filament stock so proportioned is adapted for continuous molding in endless lengths and is well adapted for feeding, severing and dispensing by the method and apparatus hereinafter described.
According to a further aspect of the present invention, the novel method of dispensing fasteners comprises advancing a fastener from a first position remote from the needle to a second position adjacent the rear portion of the needle bore with the end-bar transversely disposed thereto, aligning the end-bar with said bore, severing said connector and forcing said end-bar through said bore. Preferably the connector is restrained from substantial movement, and the end end-bar is rotated about said connector which acts as a hinge.
Apparatus for practicing the method comprises a casing, a dispensing hollow slotted needle mounted to the casing, means for advancing a fastener to a position adjacent the rear of the needle bore with its end-bar transversely disposed to the longitudinal axis of the bore, means for aligning the end-bar with the needle bore, and means for dispensing the end-bar through the bore. Preferably the apparatus comprises a feed wheel, an aligning means comprising a reciprocating cam slide which also actuates the feed wheel, a dispensing means comprising a plunger carried by a reciprocating support which also actuates the cam slide, and means for reciprocating the support. Preferred embodiments are more fully described hereinafter.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the accompanying drawings:
FIG. 1 is a plan view of a first embodiment of fastener stock according to this invention;
FIG. 2 is a rear view of the fastener stock of FIG. 1;
FIG. 3 is a side view of the stock of FIG. 1;
FIG. 4 is an end view of the stock of FIG. 1;
FIG. 4A is an enlarged view of one end of FIG. 4;
FIG. 5 is a perspective view of a portion of the fastener stock of FIG. 1 illustrating one end-bar and its associated connectors;
FIG. 6 is a perspective view of a portion of the other end of the fastener stock of FIG. 1;
FIG. 7 is a plan view of a second embodiment of fastener stock according to the present invention;
FIG. 8 is a side view of the embodiment of FIG. 7;
FIG. 8A is an enlarged view of one end of FIG. 8;
FIG. 9 is a plan view of a third embodiment of fastener stock;
FIG. 10 is a schematic view of continuous molding apparatus;
FIG. 11 is a section along the lines 11--11 of FIG. 10 illustrating molding apparatus to make the embodiment shown in FIG. 1;
FIG. 12 is an alternate section along the lines 11--11 of FIG. 10 illustrating molding apparatus for making the embodiment shown in FIG. 7;
FIG. 13 is a perspective view of the preferred embodiment of the dispensing apparatus of this invention, illustrating insertion of a fastener through woven material;
FIG. 14 is another perspective view of the apparatus of FIG. 13;
FIG. 15 is a plan view of the apparatus of FIG. 13 with portions of the casing broken away to show the operative interior mechanism, broken lines illustrating partial compression of the trigger to actuate the mechanism;
FIG. 16 is a view similar to FIG. 15 showing the trigger compressed;
FIG. 17 is a view similar to FIG. 15 showing the trigger return stroke;
FIG. 18 is a perspective view of the embodiment shown in FIGS. 13-17 showing the operative internal mechanism;
FIG. 19 is a perspective view of the cam slide of the apparatus of FIG. 18
FIG. 20 is a side view of a portion of the needle, feed wheel and aligning cam illustrating the alignment of a fastener end-bar with the needle bore;
FIG. 21 is a perspective view of a hollow slotted needle useful with the present invention; and,
FIG. 22 is a perspective view of a needle and needle retaining pin.
Referring to FIGS. 1-6, one embodiment of the fastener stock of the present invention is shown which comprises elongated, continuous side members 50 and 51 cross-coupled by a plurality of cross-links or filaments 52. Side member 50 comprises a plurality of tab or paddle end members 53 joined together by severable connectors 54, one face of the tabs 53 being optionally embossed at 55 for inclusion of identification or decorative matter. Side member 51 comprises a plurality of end-bars 56 joined together by severable connectors 57.
As shown for example in FIG. 5, the filaments 52 are approximately D-shaped in cross-section with the maximum width at a substantially flat plane 58 at one side thereof. The remainder of their cross-section decreases in width from the plane 58 to the other side thereof and may be of any suitable shape, including converging curves, lines or combinations thereof Preferably the end-bar 56, as shown for example in FIG. 4A, is larger in cross-section than the filament 52 and also has its widest parallel cross section dimension 60 in the plane 58. As shown in FIG. 6, tab ends 53 are also flat and have their greatest cross-sectional dimension at the plane 58.
In the embodiment of FIGS. 1-6, tab connectors 54 and end-bar connectors 57 have one face at the plane 58, are substantially thinner than either filament 58, cross-bar 56, or tab 53, and extend away from the plane 58 on the side thereof opposite to the body of filament 52. They also extend continuously not only between adjacent tabs 53 and adjacent end-bars 56, but also extend across end-bars 56 and tabs 53 respectively. Such extension provides a more rounded end-bar 56 (see FIG. 4A) and can be molded as continuous runners as hereinafter described.
As shown in FIGS. 1, 2 and 7, the filaments 52 may be molded somewhat wider and of greater circumferential dimension adjacent tabs 53 than at end-bars 56 to facilitate stretching adjacent the end-bars where the filaments are folded during dispensing through a hollow needle.
A second embodiment of fastener stock of the present invention is shown in FIGS. 7, 8 and 8A which is identical to the fastener stock shown in FIGS. 1-6 except that severable connectors 54a and 57a extend from the plane 58 in the same direction as the body of filament 52 and do not extend visibly across either end-bars 56a or tabs 53a. This embodiment is most preferred.
A third embodiment of fastener stock is shown in FIG. 9 in which two side members 51a are employed to provide end-bars at both ends of the filament 52a. In this embodiment, the filament 52a is molded somewhat wider at its mid-portion and is somewhat narrower or smaller in circumferential dimension adjacent each end-bar to facilitate stretching and strengthening of the filament 52 at those portions which are folded during dispensing. In all other respects, the embodiment of FIG. 9 is identical to the embodiment of FIG. 7.
Each of the foregoing embodiments of fastener stock are especially adapted for continuous molding and for feeding and dispensing as hereinafter described. Continuous molding of plastic parts is known and is disclosed for example in U.S. Pat. Nos. 3,085,292; 3,196,196; 3,515,778; and numerous others; and is schematically illustrated in FIGS. 10-12. Heated plastic is extruded from extruder 70 through orifices in platen 71 into cavities in the periphery of rotating molding wheel 72. After cooling, the continuously molded parts are removed from molding wheel 72 by take-off roller 73 and feed rolls 74, 75, stretched if desired at 76 by any suitable apparatus, and the stock 77 wound onto take-up roll 78. Stretching can be omitted or separately performed if desired.
As shown in FIG. 11, cavities 52', 56' and 53' are provided in the periphery of molding wheel 72 for the filaments 52, end-bars 56, and tabs 53, respectively. Connectors 54 and 57 are provided as continuous runner cavities 54' and 57' in the platen 71. Tabs 53 may be of the same or different thickness from the thickness of the filaments 52 as desired. As shown in FIG. 12, connectors 54a and 57a may be provided by grooves 54a' and 57a' in the periphery of molding wheel 72a between fastener cavities.
By comparing FIGS. 10-12 with FIGS. 1-9, it will be seen that the plane 58 is defined by the meeting surface of the platen 71 and the wheel 72. It should be understood that the dimensions previously described refer to the fastener assemblies as they are molded. If the filaments are thereafter stretched, as preferred and as described in the foregoing patents, the edges of the flat plane 58 may be rounded somewhat in stretching but the filaments will maintain their general cross-sectional shape. End-bars 56 and tabs 53 are generally not stretched. Some distortion from shrinkage and cooling may also be noted.
The preferred apparatus employing the method of the present invention is a hand-actuated dispensing gun as shown in FIGS. 13-22. The gun 100 comprises a hollow casing 102 preferably of molded plastic in two halves joined together in any suitable manner. Affixed to the casing 102 is vertical extension 104 to which is affixed a projecting rod 106 about which a spirally wound assembly of fasteners may be secured. The fastener stock may be retained on the rod 106 by means of spring loaded detents 108 and 110 which may be folded towards each other for insertion of the fastener stock and moved to a vertical disposition for retention. The free end of the fastener assembly stock, with the plane 58 facing upwardly as hereinafter described, is then fed over the periphery of feed wheel 112 which is journaled for rotation within the casing 102. Wheel 112 has means such as notches 114 about its periphery for receiving fastener filaments 52 and advancing them in an arcuate path about the wheel to a position adjacent the rear end of forwardly projecting needle 116. Wheel 112 is spaced from the inner wall of casing 102 to define a passageway for receiving and guiding fastener end-bars 56 as the wheel rotates. Casing 102 has a projection 115 over hanging wheel 112 to aid in restraining the end-bars for travel within the provided passageway. Detent pin 118 is mounted to casing 102 and is biased to restrain backward movement of wheel 112 by means of spring 120. Notches 114 are spaced about the periphery of the wheel 112 equal to the spacing between successive fastener filaments 52.
As shown for example in FIGS. 17 and 20, the end-most fastener end-bar 56e is indexed about the feed wheel 112 to a position transverse to the rear end of the bore 122 of the needle 116. A severing edge 124 may be secured to the needle or to the casing opposite the connector 57 connecting end-bar 56e with the end-bar of the next following fastener. As shown for example in FIG. 20, reciprocating cam means 126 is then advanced to rotate the end-most end-bar 56e about its connector as a hinge into alignment with the bore of the needle. A projecting tab 128 is provided in the casing in the vertical plane of wheel 122 forming an extension of the passageway about the wheel for the end-bars to guide the same during rotation. Tab 128 has a curved upper surface configured to guide the filament projecting from the wheel as the end-bar 56e is rotated into alignment.
After the end-bar is aligned with the needle bore 122, a plunger 130 is brought forward to contact the free rear end of aligned end-bar 56e to push it through the hollow needle bore, simultaneously breaking or cutting connector 57 at severing means 124. As illustrated in FIG. 13, the plunger drives the end-bar through the hollow needle which, if inserted through one or more layers of material 132 will secure them together or will secure a tag thereto. As the needle is withdrawn from the material 132, end-bar 56e will resiliently resume its transverse position with respect to the filament to prevent withdrawal of the filament from the material. Motion of the tool as it is removed from the material 132 will break the connector 54 joining tab 53 to the next following tab in the manner illustrated for example in U.S. Pat. No. 3,733,657. For this purpose, connector 54 should be relatively weak. Any other suitable means for severing may also be provided.
A knob or knurled wheel 134 is provided on the exterior of the casing 102 to turn the feed wheel 112 for feeding fastener stock into and out of the apparatus.
Plunger 130 is fixed at its rearward end to a rear slide or plunger support 136 which slides back and forth within slide grooves in the casing to reciprocate the plunger in and out of the needle bore 122. Slide 136 is pivotally joined to the upper end 138 of lever member 140 which extends downwardly into the hollow handle portion 141 of the casing 102. The lower end of lever member 140 is secured by means of slot 142 to a pin 144 carried by hollow trigger 145 which is pivotally joined at 148 to casing 102 for movement back and fourth within hollow handle 141. Pin 144 acts as a cam and the wall of slot 142 as a cam follower to impart motion to the lever member 140. Member 140 is joined intermediate its ends to a floating pivot 150 which is secured to one end of member 153, the opposite end of which is pivotally secured at 155 to the handle 141. Trigger 146 is biased in the open position by means of compression spring 156 described more fully hereinafter. Lever member 140 is biased by the spring 156 to retain the plunger support 136 in its rearward position. Upon squeezing the handle 141 and trigger 146, member 140 pivots about floating pivot point 150 to actuate support 136, causing it to slide from its rearward to its forward position, pushing the plunger through the needle bore 122 and ejecting a fastener end-bar through the needle. Plunger 130 is withdrawn from the needle bore by the energy stored in spring 156 when pressure on the trigger is released.
A forward slide 152 is mounted in the forward end of casing 102 and slides back and forth in slide grooves 154a and 154b in the casing. Slide 152 has a recess 159 which, together with the interior wall of the casing, houses a compression spring 158 which constitutes means for biasing the slide 152 in its forward position. Slide 152 has a rearwardly extending flexible arm 160 which has at its rearward end a detant surface 162 and an inclined cam surface 164. Plunger support 136 carries a cooperating cam surface 166 and detent surface 168 which actuates slide 152 as follows. When the trigger 146 is squeezed, and lever member 140 is actuated to advance plunger support 136, cam surface 166 rides up and over cam surface 164, deflecting flexible arm 160. On the return stroke of plunger support 136, detent surfaces 162 and 168 engage as shown for example in FIG. 17 and the plunger support 136 then moves slide 152 rearwardly, compressing biasing spring 158.
As the plunger support 136 approaches its rearward position, a fixed cam 170 mounted to the casing engages a rearward extension of cam surface 164 which deflects arm 160 downwardly until the detent surfaces 162 and 168 are disengaged. Upon such disengagement, compressed biasing spring 158 causes slide 152 to return to its forward position. Cam 126 is carried by the slide 152 and on its forward stroke rotates end-bar 56e into alignment with the needle bore 122.
Slide 152 has a second forwardly extending resilient arm 171 which as a rearwardly facing detent surface 172 and a forward cam surface 174. Feed wheel 112 is provided with cooperating index pins 176, one for each indexing position, each of which has a cam surface 178. As the slide 152 is drawn rearwardly by plunger support 136, cam surface 172 engages a pin 176 to rotate feed wheel 112 and feed the next fastener into position with its end-bar transverse to the longitudinal axis of the needle bore. On the return forward stroke of slide 152, cam surface 174 rides up and over cam surface 178 of the lower pin 176 to deflect arm 171 and allow its passage into its forward position ready for the next indexing stroke.
The needle 116 can be a hollow slotted needle of any known type suitable for feeding flexible fasteners, the fastener end-bar being dispensed through the hollow bore of the needle and the filament extending through and sliding within the communicating slot 180. Needle 116 is preferably removably secured to the forward end of the casing 102 by means of a pin 182 which engages a corresponding cut-out 184 in the needle 116. Pin 182 is also provided with cut-out slot 186 which provides a passageway for insertion and removal of the needle. Pin 182 is biased in its locking position by means of spring 188 mounted in the casing. When the pin is pushed toward spring 188 to compress it, slot 186 aligns with the needle to free it for removal. Preferably the portion of the pin 182 engaging needle cut-out 184 in locking position is rectangular or square in cross-section.
In a hand-actuated dispensing gun of the type described it is desirable that the actuating force to operate the device be as small as possible to avoid operator fatigue. The movable linkage disclosed in U.S. Pat. No. 3,893,612 is preferably employed for mechanical advantage as described. In addition, it is desirable that the compression force required decrease as the trigger is depressed. Such decreasing force is provided by the spring arrangement shown. The rear end of spring 156 is secured to a fixed pivot 157 in the handle 141. The forward end of the spring however is fixed to a movable pivot 190 which is secured to trigger 146 and moves therewith as the trigger is depressed. Movable pivot 190 is so located that in its normal extended position, an extension of the centerline or longitudinal axis of the spring 156 is located a substantial distance from the fixed pivot 148. As the trigger is depressed, this centerline moves with pivot 190 into a position closer to pivot pin 148 thereby decreasing the moment arm, the compressive force required and the extent of compressive motion of the spring, all in a smooth and continuous manner.
It should be noted that the apparatus described is readily assembled from molded or other easily fabricated parts, requires modest actuating force for hand operation, is positive in action, and is adapted to feed long lengths of fastener stock. It should be further noted, for example by reference to FIG. 20 that the coiled fastener stock has the connectors 57 or 57a facing outwardly at the free end for feeding over the periphery of the feed wheel. This places the connector during rotation of the end-bar 56e into alignment with the needle bore in position to act as a hinge, to engage the severing edge 124, and to expose the majority of the end-bar end-section to the plunger as the plunger is actuated to dispense the end-bar through the needle.
The operation of the apparatus described comprises the following sequence:
(1) A coil of fastener stock is placed over pin 106, or an alternative holder of fan-folded stock as shown in FIG. 12 of U.S. Pat. No. 3,875,648, connectors 57 and plane 58 at the free end facing upwardly. The free end is fed over feed wheel 112 and knob 134 is rotated until the end fastener 56e rests against the upper surface of cam 126.
(2) Trigger 146 is squeezed against handle 141 to rotate lever member 140 about pivot 150, thereby compressing return spring 156 and sliding plunger support 136 forward, cam surface 166 sliding over and deflecting cam surface 164.
(3) Trigger 146 is released, spring 156 causing support 136 to return to its rearward position. As support 136 returns, slide 152 is moved to its rear position and spring 158 is compressed until cooperating detents 162 and 168 are disengage by deflection of arm 160 by cam surfaces 170 and 164. On the rearward stroke of slide 152, detent 172 on arm 171 engages pin 176 of feed wheel 112 to index the wheel and feed end-bar 56e to the position shown in FIG. 17. As slide 152 returns to its forward position, cam surfaces 174 and 178 engage to deflect arm 170, and cam 126 rotates end-bar 56e about connector 57 into alignment with needle bore 122 as shown in FIG. 20.
(4) Trigger 146 is again squeezed to move plunger support 136 and plunger 130 forwardly to engage the exposed end of end-bar 56e and dispense it through the bore 122, edge 124 severing the connector 57.
(5) As trigger 146 is again released, the sequence described in (3) above is repeated to prepare the next end-bar for dispensing.
While the apparatus described is well adapted for hand operation, the operations may be powdered by any suitable means, for example, by means of electrical devices or fluid pressure. Such means are described for example in the aforementioned U.S. Pat. No. 3,875,658. And while the novel fastener stock herein described is well adapted for use in the method and apparatus described, other suitable fastener stock can be employed. The novel fastener stock may also be dispensed by mean of other suitable apparatus, for example as disclosed in U.S. Pat. No. 3,875,648.
It should be further understood that the present invention includes all modifications and equivalents within the scope of the appended claims.
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An improved system is described for attaching price tags to garments and for other joining applications using plastic fasteners dispensed through hollow, slotted needles. The system comprises a new method and tool for dispensing fasteners supplied in long lengths, together with improved fastener stock adapted for use therewith and for molding in continuous lengths.
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FIELD OF THE INVENTION
The present invention relates to optical sights, in particular to an optical gun sight with reticle patterns switchable for adaptation to various shooting conditions. More specifically, the invention relates to an optical sight, such as, e.g., a gunsight or a camera viewfinder, in which reticle patterns are switched electronically without mechanical movements.
BACKGROUND OF THE INVENTION
Optical sights are used in viewfinders for aiming photocameras or in firearms for accurate aiming of rifles, pistols, shotguns and the like. In firearms, these optical sights are typically mounted in an elongated tubular barrel or housing carrying conventional ocular and objective lens systems. An erector-lens system is provided between the ocular and objective systems to provide an erect target image for viewing by the shooter. Windage and elevation adjustments permit the sight to be compensated for targets at varying ranges.
For example, a conventional optical sight includes a reticle, typically of cross hair or post form, which is seen by the shooter in silhouette and superimposed over the target image. The position of the firearm is adjusted until the reticle is positioned on a target-image aiming point. The primary advantage of an optical sight is that the target image and reticle are in the same focal plane, eliminating any need for the shooter to shift eye focus between sight and target as must be done with conventional open sights on a rifle. The optical sight may provide fixed or variable magnification of the target image, but such magnification is not an essential feature and is subsidiary to the primary goal of providing a target image and aiming reticle in a single focal plane.
Conventional reticles are highly satisfactory during conditions of full daylight, but most hunting for game animals is done under restricted lighting conditions before sunrise or just before dark. This is because most game animals are nocturnal feeders, and their search for food is made in darkness or in the relatively short periods just before or after full darkness. A conventional optical sight is difficult to use in these conditions of subdued lighting because the reticle is seen in silhouette against a low-contrast dimly lit image of the target and target background. It is not uncommon for a hunter to lose sight of the reticle entirely while attempting to aim at a game animal standing or moving against a dark background of brush or trees. In such conditions, the firearm cannot be accurately sighted, and the animal will probably escape.
The “fading reticle” problem is solved by illuminating the reticle itself (e.g., electrically heated incandescent reticles have been proposed), or preferably by providing a luminous dot or other mark at the aiming point of the sight. Details of the latter solution are shown in U.S. Pat. No. 3,672,782 issued in 1972 to A. Akin. This patent shows a an optical sight with a battery-operated internal lamp, which projects a luminous reticle pattern (dot, cross hair, circle, etc.) on the sight field of view and centered on the sight aiming point. The optical sight of this patent is provided with multiple reticles, which can be selectively switched to a working position in compliance with the shooting conditions. This is achieved with the use of a flexible strip of a plastic material wound on extends between a pairs of shafts. The strip is generally opaque but defines specific transparent zones forming a plurality of reticles. Rotation of the shafts moves strips in certain fashion within a chamber in the mounting leg, and rotation is continued until a selected reticle is positioned for projection onto an ocular focal plane of the sight. Positions of the reticles are fixed with the use of spring-loaded knobs.
A disadvantage of the device of U.S. Pat. No. 3,672,782 consists in that the sight contains moveable parts and that the strip moves back and forth. Such a system, normally, has significant plays, which impair positioning of the reticles in the focal plane, and thus impairs accuracy of shooting.
U.S. Pat. No. 4,554,744 issued in 1985 to C. Huckenbeck is directed to an improved illuminated-reticle optical sight having a very compact battery-housing and actuating-switch assembly, which enhances the styling of the instrument, and is simple and convenient for the shooter to use. Though the optical sight of this device does not have moveable parts, it also does not have selectivity of reticles.
U.S. Pat. No. 4,618,221 issued in 1986 to R. Thomas describes an adjustable telescopic sight having objective lenses, intermediate lenses, and an eyepiece. The sight is provided with an adjustable reticle device, which is disposed in the second focal plane intermediate, the eyepiece and the intermediate lenses. The adjustable reticle device is provided with a fixed centerline reticle and two identical moveable reticles located on opposite sides of the centerline reticle. The moveable reticles are each supported by a carrier, which is moveable in two orthogonal directions by means of two threaded stems carried by the body of the adjustable reticle device. The stems are each provided with knurled knobs, each of which has two arrows thereon disposed at right angles to each other on the side of the knob facing the shooter so that the shooter can readily determine the direction of movement of bullet impact upon rotation of a knob in any specific direction.
Although this device is capable of adjusting position of a reticle with relatively high accuracy due to micrometric movements and of selecting reticles of a few types, the choice of reticles is very limited and the adjustment is carried out due to movement of reticle parts.
International Patent Publication WO 00/50836 of Aug. 31, 2000 issued to K. Gunnarsson, et al. describes an optical sight with a reticle produced by projecting a reticle image from a transparent media onto a concave semitransparent mirror. The source of light is a light emitting diode (LED), which is located on a sidewall within a tubular casing of the optical sight. The LED, the transparent media with the reticle image, the semitransparent concave mirror, and the eye of the viewer form an optical system, in which the reticle image is reproduced on the eye retina, while the image of the reticle is located on the optical axis of the optical system and is seen by the eye as if it is located in the infinity or in a very remote zone. During shooting, the reticle is aligned with the image of the target, which is also seen by the viewer's eye. Such a system ensures accurate aiming and is free of moveable parts. Furthermore, the sight of the type disclosed in WO 00/50836 is a sight of a collimating type, which does not have an optical eyepiece on the viewer's side and therefore has a not limited eye relief. An eye relief is a distance from the viewer eye to the sight. However, this system has only one reticle and cannot be adjusted for different shooting conditions.
In order to solve the above problem, American Technologies Network Corporation, South San Francisco, Calif., has developed an optical sight of the type described in WO 00/50836, but with a turret head that contains a plurality of reticle images, which can be selectively switched to a position aligned with the optical axis by rotating the turret head. Such a system makes it possible to select reticles in compliance with the shooting conditions, shooter's vision conditions, shooter's hunting habits, type of the target, etc. Nevertheless, the turret-type reticle switching mechanism has moveable parts and therefore has inevitable plays in the rotary mechanism. Since the image of the reticle is projected to the infinity and is seen as a virtual image, even slightest deviations of the reticle image projection from the optical axis will impair accuracy of shooting.
Thus, all known switchable optical sights of the types described above cannot ensure stability in positioning of the reticle with respect to the center of the partially transparent mirror or pellicle, and hence, with respect to the ballistic trajectory of the bullet. This is because the plays existing in the switching mechanisms with the moveable reticles or reticle elements cannot provide aforementioned positioning accuracy.
OBJECTS OF THE INVENTION
It is an object of the invention is to provide an optical sight for use in viewfinders of photocameras, or in aiming devices of fire arms, which is simple in construction, inexpensive to manufacture, has no moving parts, and ensures selection of reticle types and images in a wide range in compliance with the shooting conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general schematic side view of the optical sight of the invention.
FIG. 2A is a view of the LED in the direction of arrow A of FIG. 1 .
FIG. 2B is a sectional view along the line IIB—IIB of FIG. 2 A.
FIG. 3 is a more detailed image of the pattern of reticle elements with an electrical circuit.
FIGS. 4 and 5 illustrate examples of other patterns of reticle elements.
SUMMARY OF THE INVENTION
An optical sight for a photocamera viewfinder or for an aiming device of a firearm comprises a combination of a light emitting diode (LED) with a plurality of reticle patterns applied onto the surface of the LED and selectively illuminated by connecting various portions of the reticle patterns to the source of electric power supply. The switching from one reticle pattern to another is carried out electrically without the use of moving parts of the reticles or reticle images. This ensures high accuracy in positioning of reticle elements with regard to each other, e.g., with regard to the front sight center of the partially transparent mirror, and hence, with regard to the ballistic trajectory of the bullet.
DETAILED DESCRIPTION OF THE INVENTION
A general schematic side view of the optical sight of the invention is shown in FIG. 1 . In the embodiment shown in FIG. 1, the optical sight 20 of the invention is implemented as a firearm sight or a firearm-aiming device. The device consists of a mounting plate 22 , which is attachable to a firearm, e.g., with the use of a dovetail connection and locking screw (not shown). The mounting plate 22 has on its distal end 24 (which is the end nearest to the target) a vertically arranged partially transparent pellicle or mirror 26 with a red-light reflection coating 28 applied onto a slightly concave surface of the mirror 26 formed on the side of the mirror facing a viewer. In FIG. 1 the viewer is represented by an image of a human eye 30 . The aforementioned coating 28 may have properties of a narrow-band mirror which passes all wavelengths except for the wavelength of 650±10 nm, which is seen as a red light.
On the proximal side 32 , the mounting plate 22 supports a vertical bracket 34 with an opening 36 through which the viewer's eye 30 can see the target (not shown) through the partially reflecting mirror 26 . An eyepiece 38 can be attached to the rear side of the bracket 34 for convenience of the viewer.
A light-emitting diode (LED) 40 is installed on the mounting plate 22 in the proximal part of the optical sight 20 and in a position offset from the optical axis X—X. The LED 40 is spaced from the coating 28 at a distance equal to half the radius of the curvature on the concave surface of the mirror so that the light beam B 1 emitted from the LED 40 is reflected from the mirror coating 28 as a collimated beam B 2 . It is understood that the mirror coating 28 is perpendicular to beam B 2 . If beam B 2 carries an image (reticle), this image will be localized on the retina of the viewer'ss eye and will be seen as if it is located in the infinity. When the target appears in the vision field of the viewer, the latter moves the reticle image, and hence the rifle, to which the sight 20 is attached, and aims the weapon to the target by superposing the reticle image onto the target image. Reference numeral 42 designates a power source, e.g., a lithium battery, which supplies electric current to the LED 40 . To this point of the explanation, the optical sight is generally the same as the conventional optical sight with a reticle illuminated by a LED.
A distinguishing feature of the optical sight of the invention is a set of reticle elements and a method of generation of selected reticles, which can be aligned with the optical axis of the sight by using electric means, i.e., without moving any parts of reticles or reticle combinations.
More specifically, as shown in FIG. 2A, which is a view of the LED 40 in the direction of arrow A of FIG. 1, the reticle is formed on the outer surface of the LED 40 . FIG. 2B is a sectional view along the line IIB—IIB of FIG. 2 A. The arrangement of the LED shown in FIG. 2B is known as TO-CAN. This term is used for opto-electronic components mounted in closed containers with a transparent window. The LED unit consists of a metallic LED holder 41 which supports the LED 40 . The LED 40 is covered with a cup-shaped cover 43 . The upper electrodes (which will be described later) of the LED 40 are connected to output terminals 45 a , 45 b , 45 c which protrude outside the LED assembly through insulators 47 a , 47 b , 47 c (FIG. 2 A).
A more detailed image of the reticle and of the pattern of reticle elements is shown in FIG. 3 . As can be seen from FIG. 3, the reticle consists of a central light spot 46 and a plurality of luminous bars, in this case of four luminous bars 48 , 50 , 52 , and 54 . These luminous bars constitute the aforementioned upper electrodes of the LED 40 . The bars 50 and 54 are arranged symmetrically on both sides of the light spot 46 on a horizontal line X 1 —X 1 , while the bars 48 and 52 are arranged symmetrically on both sides of the light spot 46 on a vertical line Y 1 —Y 1 . Thus, the light spot 46 is located in the center of a cross formed by the luminous bars 48 , 50 , 52 , and 54 .
The luminous bars 48 , 50 , 52 , and 54 can be formed on the surface of the LED 40 , e.g., by a method of photolithography from a conductive material, e.g., from aluminum or chromium. In one model of the sight of the invention tested by the applicant, the LED 40 was a custom-made homo-transition type LED based on epitaxial structures of gallium arsenide phosphide alloy/gallium arsenide alloy (GaAsP/GaAs). The LED 40 was made with a large surface (with a diameter of about 2 to 3 mm) on which the radiation elements are formed so that it would be possible to perform the aforementioned photolithography. Each element of the reticle, i.e., a bar or a light point, is a closed-loop contour in the form of an elongated rectangle or a circle, so that the perimeter of the closed-loop contour determines the shape of the reticle element, i.e., rectangles, lines, circles, parts of the circle, dots, etc. As shown in FIG. 3, the upper electrodes or luminous bars 48 , 50 , 52 , and 54 and the light spot 46 are connected to a positive terminal 56 a of a source of power supply 56 , e.g., a lithium battery via an electric circuit with an electric switch 58 . A negative terminal 56 b of the power source 56 is connected to the metallic LED holder 41 (FIG. 2 B). Thus, a negative potential of the power source 56 is applied to the metallic holder 41 , which is in contact with the bottom of the LED 40 , while a positive potential is applied to the selected upper electrode which is represented by the selected elements of the reticle. The switch 58 can be a rotary type switch, a button-type switch, or an electronic switch. In the general view of the sight shown in FIG. 1, the control element of the switch 58 is shown as a rotary knob 59 which can be switched between four positions, i.e., a position “1”, a position “2”, a position “3”, and a position “OFF”. As shown in FIG. 3, the switch 58 has three switchable contacts SW 1 , SW 2 , and SW 3 , which can be closed or opened in various combinations determined by the aforementioned positions of the knob 59 . The light point 46 is connected to the switch 58 via a conductor 60 , a contact point 62 on the surface of the LED 40 , and a conductor 64 . The luminous bar 48 is connected to the switch 58 via a conductor 66 , a contact 68 on the surface of the LED 40 , and a conductor 70 . The luminous bars 50 , 52 , and 54 , which are connected parallel to each other via conductors 72 , 74 , and 76 , are connected to the switch 58 via a conductor 78 , a contact 80 on the surface of the LED 40 , and a conductor 82 .
At the maximum of its radiation, this LED generated red light of 65±10 nm. With the d.c. current of 20 μA, the LED 40 produced light with the brightness of not less than 150 μcd.
Operation temperature ranged from minus 60° C. to plus 70° C.
The reticle pattern shown in FIG. 3 makes it possible to select the following reticle shapes: a light point 46 , a light point 46 in the center of a cross formed by the luminous bars 48 , 50 , 52 , and 54 , a combination of the light point 46 with the luminous bars 50 , 52 , and 54 . It is understood that this simplified pattern was shown only as an example that illustrates the principle of the invention. It is understood that many other patterns and combinations of luminous elements are possible. Examples of other patterns are shown in FIGS. 4 and 5. The pattern of FIG. 4 consists of a central light spot 84 , two horizontal luminous bars 86 and 88 arranged symmetrically on both sides of the light spot 84 , and two arched elements 90 and 92 with outward radial projections. The elements 90 and 92 are also arranged symmetrically in a vertical direction with respect to the light point 84 . In the example of FIG. 5, the reticle is formed by a central light point 94 with two concentric luminous elements 96 and 98 , each consisting of arched portions separately connected to the power source via respective conductors (not shown). In this embodiment, the light point 94 can be combined with either of the circular reticles 96 and 98 , or can be combined with both of the at the same time.
OPERATION OF THE OPTICAL SIGHT OF THE INVENTION
In operation, when a hunter needs to select a specific reticle combination which to the most extent satisfies his/her needs with regard to the shooting conditions, shooting habits, type of a target, etc., he/she selects one position of the switch 58 . For example, when only a light spot 46 is needed in the reticle of FIG. 3, the switch 58 is installed to a position, in which the light point 46 is electrically connected to the switch 58 via a conductor 60 , a contact point 62 on the surface of the LED 40 , and a conductor 64 . In this selection, which corresponds, e.g., to the position “1” of the knob 59 , the switchable contact SW 1 is closed and the switchable contacts SW 2 and SW 3 are open. When it is necessary to illuminate a light point 46 and the cross formed by the luminous bars 48 , 50 , 52 , and 54 , all three switchable contacts SW 1 , SW 2 , and SW 3 are closed (position “2” of the knob 59 ), and when it is necessary to select a combination of the light point 46 with the luminous bars 50 , 52 , and 54 , the switchable contacts SW 1 and SW 3 are closed, while the switchable contact SW 2 is opened (position “3” of the knob 59 ). Position “OFF” of the knob 59 corresponds to the condition when all elements of the reticle are disconnected from the source of power supply 56 . It is understood that the switchable contacts are interlocked in such a manner that switching of contacts from one position to another automatically selects right position for the switchable contacts of the selected pattern and eliminates combination of the switchable contacts corresponding to the previous pattern.
Once the reticle pattern is selected, the shooter tries to find the target in the vision field of the optical sight 20 while constantly observing the reticle 44 as seen as if it is located in the infinity or in a very remote zone. The reticle 44 is aligned with the image of the target, which is also seen by the shooter's eye.
Thus, it has been shown that the invention provides an optical sight for use in viewfinders of photocameras, or in aiming devices of fire arms, which is simple in construction, inexpensive to manufacture, has no moving reticles or reticle elements, and ensures selection of reticle types and images in a wide range in compliance with the shooting conditions. Although the invention has been shown and described with reference to specific embodiments, it is understood that these embodiments should not be construed as limiting the areas of application of the invention and that any changes and modifications are possible, provided these changes and modifications do not depart from the scope of the attached patent claims. For example, the optical sight of the invention can be used in riflescopes, camcoders, telescopes, telescopic tubes, binoculars, surveying tools, navigation instruments, microscopes, optical micropositioning devices, etc. An unlimited variety of reticle patterns are possible, such as squares, triangles, ovals, hair lines, semi circles, or their combinations. The sight itself can be an open type or enclosed in a tubular housing. The brightness of the reticle image can be adjusted by changing the current supplied to the LED. The current adjustment control can be connected via a feedback line to an automatic exposure meter for automatically adjusting the reticle brightness in compliance with the environmental lighting conditions. The LED may emit light other than red.
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An optical sight for a photocamera viewfinder or for an aiming device of a firearm comprises a combination of a light emitting diode (LED) with a plurality of reticle patterns applied onto the surface of the LED and selectively illuminated by connecting various portions of the reticle patterns to the source of electric power supply. The switching from one reticle pattern to another is carried out electrically without the use of moving parts of the reticles or reticle images. This ensures high accuracy in positioning of reticle elements with regard to each other, e.g., with regard to the front sight center of the partially transparent mirror, and hence, with regard to the ballistic trajectory of the bullet.
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FIELD OF THE INVENTION
The invention relates to synthetic fibers and webs produced from polymer resins. In particular, the invention relates to fibers and webs containing ionomeric polymers or "ionomers."
BACKGROUND OF THE INVENTION
Salts of various compounds containing acid moieties, including ionomeric polymers, are known to be hydrophilic and have been used in a variety of applications where increased fluid absorbency is desirable, typically as super absorbent powders. Superabsorbent powders have been used to increase the absorbency of diapers, wipes, and cable wrapping strips for high voltage electrical cables, to name but a few uses for these compounds. For example, Buchwald et al. U.S. Pat. No. 4,820,560 discloses that a cross linked sodium salt of a polyacrylic acid serves as a super absorbent swellable powder for use in cable wrapping strips for high voltage electrical lines. The cable wrap is a nonwoven fabric containing the superabsorbent powder and swells upon exposure to moisture to seal the cable core from water and prevent the propagation of water lengthwise of the cable. Gross U.S. Pat. No. 3,966,679 discloses that cross linked salts of polymers containing carboxylic acid groups are useful as water swellable absorbent particles for incorporation in surgical sponges, diapers, tampons, meat trays, bath mats, and the like products.
Superabsorbent powders can be somewhat costly to prepare and their incorporation into fabrics and other articles for providing increased absorbency normally adds manufacturing and fabricating steps, increasing the cost of providing the fabric or article. Problems have also been encountered in keeping the powder fixed in the fabric or other article until use.
Another method for using hydrophilic compounds in fabrics and other articles that avoids some of the complications of powders is to form fibers and fibrous structures from fiber forming compositions that contain one or more hydrophilic compounds. For example, salts of acid containing copolymers, including ionomers, have been incorporated into the polymer resins from which fibers and various fibrous structures have been made, thus avoiding some of the problems associated with using superabsorbent powders. Bohme U.S. Pat. No. 3,801,551 discloses that acid polymers including salts of acid polymers may be converted to fibrillar masses by digesting structured solid granules of the compounds in aqueous alkaline media and applying shear forces by intensive stirring to convert the granules to fibrillar masses. The fibrillar masses are disclosed to be useful for mixing with other fibrous materials to make felted articles, paper-like products, filters, and the like, and for shaping into cups and other articles.
Le-Khac U.S. Pat. No. 4,731.,067 discloses dry spinning of fibers from copolymers including some ionomers to produce water-.absorbing compositions. The copolymers described by Le-Khac are blended with from about one to ten percent by weight (blended weight) of at least one monomer having a molecular weight less than 1000 and containing at least two hydroxyl groups. The monomer is said to serve as a cross linking agent for the copolymer, which results in the formation of covalent bonds upon curing at elevated temperatures of from, for example, 140° C. or higher to 200° C. or higher, depending upon the copolymer.
Dry spinning is characterized by extruding a solution of a fiber.-forming substance dissolved in a suitable solvent in a continuous stream and into a heated chamber to remove the solvent, leaving the solid filament, as is commonly used in the manufacture of acetate. Le-Khac U.S. Pat. No. 4,731,067 exemplifies a dry spinning method wherein fibers are spun from an aqueous solution of polymer and the water is then evaporated. Dry spinning sometimes is referred to in the technical literature as solvent spinning.
Dry spinning is distinguished from other methods of producing synthetic fibers, such as melt spinning. In melt spinning a molten fiber is extruded from a molten fiber forming substance through a die or spinneret in the absence of a solvent and at a constant rate under high pressure. The liquid polymer streams merge downward from the face of this spinneret, into air or other gas or into a suitable liquid. The polymer streams solidify and typically are used to form either meltblown or spunbonded webs, as described below, or drawn or attenuated mechanically after solidification using Godet rolls and are brought together to form threads and wound up on bobbins. In comparison to melt spinning, dry spinning is a more complicated, time consuming, and costly procedure and requires more careful treatment of the fibers produced therefrom.
Meltblowing, in particular, is an economical method for producing nonwoven products. In melt blowing, the extruded molten fibers are attenuated and then broken with a hot, high velocity air stream or steam to produce short fiber lengths. The short fibers are collected on a moving screen where they bond during cooling. Meltblowing is discussed in patent literature, e.g. Buntin, et al. U.S. Pat. No. 3,978.185; Buntin U.S. Pat. No. 3,972,759; and McAmish et al. U.S. Pat. No. 4,622,259. These patent disclosures are hereby incorporated by reference.
To form a spunbonded web, a molten polymer is extruded through a spinneret to form a multiplicity of continuous filaments, and the filaments of molten polymer are solidified and then drawn or attenuated, typically by a high velocity fluid, and then randomly deposited on a collection surface, such as a moving belt, to form a web. The filaments are then bonded to give the web coherency and strength.
European Patent Application Publication No. 0 351 318 describes meltblowing polymeric dispersions of incompatible thermoplastic resins, some of which include ionomers. The various polymeric dispersions include blends of polypropylene with ionomers that are sodium and calcium salts of copolymers of acrylic acid and ethylene. One thermoplastic resin forms a continuous phase, and one forms microfibrils dispersed as a separate phase. The multi-component fiber can be used to prepare nonwoven webs, or the continuous phase can be dissolved to yield microfibrils that can be made into various products. The webs and microfibrils may be used as wipes, napkins and personal care items; absorbents for drugs, urine, and similar fluids; for release of bactericides, drugs, fungicides, and insecticides; as filters, ionic exchange resins, and battery separators.
Although blends of ionomers with polyolefins, monomers, or other cross linking agents or incompatible polymers have been used to produce fibers and nonwoven webs, ionomers in the unblended state have not been used to produce fibers and nonwoven webs. Blending the ionomers with polyolefins, monomers, or other cross linking agents or incompatible polymers introduces complexity into the fiber spinning process and limits the properties available in fibers and webs produced from the blends.
SUMMARY OF THE INVENTION
The invention is directed to nonwoven webs of ionomeric fibers produced by extrusion of a molten polymer resin consisting essentially of one or more ionomers or one or more ionomers mixed with a compatible copolymer or terpolymer. Thus, the ionomers are not blended with polyolefins, monomers, or other cross linking agents or incompatible polymers. "Compatible" means that upon extruding fibers from one or more ionomers mixed with a copolymer or terpolymer, the cations can be evenly distributed over the fibers so that the fibers show substantially no heterogeneity.
The invention also includes a process for forming fibers from an unblended ionomer resin and products made from such fibers, such as hydrophilic wipes, absorptive liners, filters, and swellable wraps for high voltage electrical cables. Swelling and solubility of the fibers can be controlled by introducing cross linking in the ionomer through the use of various multivalent cations including Ca +2 , Mg +2 , Ba +2 , Al +3 , Ti +4 , and the like.
The invention can be used to prepare highly absorbent nonwoven webs by relatively inexpensive processes and using inexpensive starting materials. The commercially available ionomer resins typically are inexpensive and can be melt blown or extruded to produce spunbonded webs. The webs can be extremely hygroscopic and water-absorptive.
DETAILED DESCRIPTION OF THE INVENTION
The invention is directed to the production of fibers and nonwoven webs by extrusion of fibers from a molten ionomer resin not blended with polypropylene, polyethylene, or other typical polyolefins. The ionomers are salts of a copolymer or terpolymer that include a plurality of chemical groups derived from an ethylenically unsaturated sulfonic acid or carboxylic acid or anhydride precursor of an ethylenically unsaturated carboxylic acid. At least a portion of the carboxylic acid groups or acid anhydride groups are neutralized to form salts of univalent or multivalent cations or with ammonia or organic bases such as amines. Examples of some representative acid containing polymers that may be converted to ionomers are found in Bohme U.S. Pat. No. 3,801,551, which patent is incorporated by reference.
Typical acid polymers are addition polymers of ethylenically unsaturated monomers where the starting monomers include non-acid monomers and a plurality of monomers having an acid group or acid anhydride group capable of neutralization by aqueous base to form a salt. For example, suitable polymers are the copolymerization or terpolymerization products of one or more polymerizable ethylenically unsaturated sulfonic acids or carboxylic acids and one or more non-acid polymerizable monomers. The acids include acrylic acid, methacrylic acid, maleic acid and the anhydride, itaconic acid, fumaric acid, citraconic acid and the anhydride, methyl hydrogen maleate, and the like. The non-acid monomers include ethylene, propylene, butene-1, 1,3-butadiene, and other aliphatic olefins; styrene, α-methylstyrene, vinyltoluene, chlorostyrene, and other aromatic olefins; ethyl acrylate, methyl methacrylate, vinyl acetate and other unsaturated esters, vinyl and vinylidene chloride; vinyl ethers; acrylamide; acrylonitrile; and the like.
In general, the acid comonomer moiety is at least about 1% by weight of the copolymer. Preferably, the acid comonomer moiety is at least about 11% by weight of the copolymer when the remaining monomer moiety is non-polar, such as a hydrocarbon. The acid comonomer moiety preferably is at least about 8% by weight of the copolymer when the remaining monomer moiety is a polar monomer such as an ester comonomer, the acid comonomer moiety of the copolymer usually being not more than about 40% by weight of the copolymer.
Some of the ionomers may be derived from copolymers and terpolymers as set forth in Bohme U.S. Pat. No. 3,801,551 as follows. Suitable copolymers include:
(1) Copolymers of at least about 60% by weight ethylene and from at least about 11% to about 30% by weight of one or more ethylenically unsaturated acids such as acrylic acid, methacrylic acid, methyl hydrogen maleate, and others, as recited above.
(2) Copolymers of at least about 60% by weight of ethylene, from about 8 to about 30% by weight of one or more ethylenically unsaturated acids, and from about 5 to about 20% by weight of one or more other monomers such as ethyl acrylate, vinyl acetate, and others, as recited above.
(3) Copolymers of styrene (or other vinyl-aromatic compounds) and from about 11 to about 30% by weight of one or more ethylenically unsaturated acids such as acrylic acid, maleic anhydride, and others, as recited above.
Other carboxylic acid containing polymers are made from preformed and non-acid polymers by subsequent chemical reaction carried out thereon. For example, the carboxylic acid group may be supplied by grafting a monomer, such as acrylic acid or maleic anhydride, onto a polymer substrate; carboxylic anhydride, ester, amide, acyl halide, and nitrile groups can be hydrolyzed to carboxylic acid groups.
Specific examples and illustrations of representative organic acid copolymers that may be suitable for conversion to ionomers for use in the practice of the invention claimed herein, given for purposes of illuminating the description and not to limit the scope of the invention, are: ethylene/acrylic acid copolymers; ethylene/methacrylic acid copolymers; ethylene/itaconic acid copolymers; ethylene/methyl hydrogen maleate copolymers; ethylene/maleic acid copolymers; ethylene/acrylic acid/methyl methacrylate (ternary) copolymers; ethylene/acrylic acid/ethyl acrylate copolymers; ethylene/methacrylic acid/ethyl acrylate copolymers; ethylene/itaconic acid/methyl methacrylate copolymers; ethylene/methyl hydrogen maleate/ethyl acrylate copolymers; ethylene/acrylic acid/vinyl acetate copolymers; ethylene/methacrylic acid/vinyl acetate copolymers; ethylene/acrylic acid/vinyl alcohol copolymers; ethylene/propylene/acrylic acid copolymers, ethylene/acrylamide/acrylic acid copolymers; ethylene/styrene/acrylic acid copolymers; ethylene/methacrylic acid/acrylonitrile copolymers; ethylene/fumaric acid/vinyl methyl ether copolymers; ethylene/vinyl chloride/acrylic acid copolymers; ethylene/vinylidene chloride/acrylic acid copolymers; polyethylene/acrylic acid graft copolymers; polyethylene/methacrylic acid graft copolymers; polymerized ethylene/propylene/acrylic acid graft copolymers; styrene/acrylic acid copolymers; styrene/methacrylic acid copolymers; styrene/itaconic acid copolymers; styrene/methyl methacrylate/acrylic acid copolymers; styrene/maleic anhydride copolymers; styrene/citraconic anhydride copolymers; para-chlorostyrene/acrylic acid copolymers; para-t-butylstyrene/acrylate acid copolymers; and methyl methacrylate/isobutyl acrylate/acrylic acid copolymers.
The above carboxylic acid-containing polymers may be converted to ionomer resins by neutralization of at least a portion of the carboxylic acid groups with a salt-forming cation such as metal ions having valences of 1 or greater or with ammonia or organic bases such as amines. Generally, at least about 10% to 100% of the acid groups are neutralized for use in the practice of the invention.
Ionomers contemplated for use in the practice of the invention include those copolymers or terpolymers having cations of sodium, potassium, lithium, calcium, magnesium, barium, aluminum, titanium, and cations derived from ammonia or amines, and blends thereof, that include at least one chemical group derived from an ethylenically unsaturated sulfonic acid or carboxylic acid or anhydride precursor of an ethylenically unsaturated carboxylic acid. Ionomers commercially available for use in the practice of the invention include sodium, potassium, calcium, magnesium, and aluminum salts of ethylene and acrylic acid copolymers sold by Allied Signal Inc., Morristown, N.J., under the trade name AClyn. Specific ethylene and acrylic acid copolymers are 77% ethylene and 23% acrylic acid and 67% ethylene and 33% acrylic acid.
Olefin-maleic anhydride copolymers and terpolymers are available from S.C. Johnson & Son, Inc., Racine, Wis., and can be converted at least in part to salts by treatment of the resin with a base.
Mixtures of ionomers behave similarly to single ionomers. For example, fibers from a meltblown blend of ionomers can show no heterogeneity when examined by electron micrographs. A blend of sodium and magnesium ionomers of 90% neutralized salts of copolymers of 23% acrylic acid and 77% ethylene produce fibers in which the metal cations are intimately distributed throughout. While not wishing to be bound by theory, it is believed that either the ionomer resins blended intimately, or the cations interchanged between the two ionomers.
Also, if a mixture of an ionomer and its copolymer or terpolymer precursor, or other compatible copolymer or terpolymer, is melt extruded in accordance with the invention and under conditions of sufficient heat and mixing to promote redistribution of the cationic moieties, then a homogeneous composition is obtained.
The fibers and webs of the invention can be produced by extrusion of fibers from a molten ionomer resin by melt spinning methods that are documented in the art, including by meltblowing or spinning of continuous filaments, both of which techniques are documented in the art. Specifically, the fibers and webs of the invention can be produced by meltblowing ionomer resins using the controlled polymer degradation techniques set forth in Buntin U.S. Pat. No. 3,972,759, which is incorporated herein by reference. Webs can also be formed by spunbonding continuous filaments or by weaving continuous filaments that have been formed into threads and wound up on bobbins. However, with any of these techniques, special precautions may need to be taken with hygroscopic fibers and webs substantially to preclude absorption of water.
In the method of the Buntin patent, the thermoplastic resin is subjected to a controlled thermal degradation, optionally promoted by a free radical source compound. For higher molecular weight ionomers, it may be necessary to use a free radical source to obtain the desired thermal degradation of the polymer prior to meltblowing, but lower molecular weight ionomers typically will be used.
The fibers and webs produced therefrom are useful as absorbents for water, urine, blood and other bodily exudates and bases generally, as swellable cable wraps for moisture barriers for high voltage cables, as ion exchange resins, as adhesives, and the webs can be used for electrically conductive webs, to name but few uses. The absorbing capacity or solubility depends upon the content of carboxyl groups, the proportion of carboxyl groups converted to salts, and the type of salt, and these factors may be adjusted for particular requirements. For example, the use of various multivalent cations including Ca +2 , Mg +2 , Ba +2 , Al +3 , Ti +4 , and the like can be used to introduce cross linking in the fiber and to control the amount of cross linking, enabling fibers and webs produced therefrom to be customized with respect to water solubility and the absorption of water, salt solutions, urine, blood, or other bodily exudates, and bases generally.
The size of the fibers formed in accordance with the invention can be controlled to provide maximum surface area for absorption and to provide fibers that may be more easily handled for certain applications. For example, for some meltblown absorptive webs, such as webs used in diaper and personal care products, microfibers of from about 2 to 10 microns in diameter sometimes are preferred for maximum surface area and greatest absorption. For other applications, such as for cable wrap, somewhat larger fibers can be more easily handled and can be more practical. Typically, meltblown fibers are produced that range from microfiber size to about 50 microns or more, although meltblown fibers can be produced that are about 100 to 300 microns in diameter. At the larger sizes it may not be practical to meltblow the webs, and another melt spinning technique may be used and the web formed by weaving or spunbonding.
Fibers of the invention can be used alone or in composites. For example, fibers produced in accordance with the invention can be formed into a web with fibers of other compositions. Binder fibers can be incorporated into a web of the invention to provide support and strengthen the web or for lamination of the web to surfaces such as fabric surfaces. Other fibers with desirable characteristics can be used in a composite web to provide a web having characteristics of the individual fibers of the web.
Webs of the invention, including composites, can be used in laminates to provide structures having characteristics of the individual layers of the laminate. For example, a web of micro fibers made in accordance with the invention can be laminated to a nonporous outer layer and a porous inner layer to form an absorptive liner in a structure such as a diaper or other garment, dressing, or personal care item. Webs of the present invention can be laminated by the techniques documented in the art such as point bonding through the application of heat and pressure or through the use of adhesives.
The following working examples illustrate the invention claimed herein.
EXAMPLE 1
A sodium salt of ethylene acrylic acid (Na-EAA available from Allied-Signal Corp.) containing 77% ethylene and 23% acrylic acid by weight of the copolymer and having been 50% neutralized with NaOH, was meltblown into a continuous web using a method similar to that disclosed in Bohme U.S. Pat. No. 3,972,759. The web, wetted out and dissolved in water.
The web had a basis weight of 161 g/m 2 and a web thickness of 44 mils. Density was determined to be 0.144 g/cm 3 . The web had a Gurley permeability of 27 cfm/ft 2 .
The above physical characteristics were determined as follows. For determining basis weight, samples were cut using a razor blade and a metal template (50×200 millimeters) and the sample was weighed to the nearest 0.001 gram. The specimens were dried and equilibrated to ambient conditions before weighing. The basis weight is reported, in grams per square meter (g/m 2 ), as the weight of the sample ×100.
The caliper, or thickness of the web, was measured using an Ames gauge (Model 79-011; Ames Inc., Waltham, Mass.) with zero load.
The Gurley permeability of air through the web was determined using a Gurley Permeometer (Model 4301; Teledyne Gurley, Troy, N.Y.) for a two-inch-diameter disc of the web with an air pressure of 0.5 inch of water. Data are reported as the flow rate in cubic feet per minute (ft 3 /min) through one square foot of material.
EXAMPLE 2
A tumble-blended mixture of 5% of a magnesium salt of H-EAA by weight (Mg-EAA containing 77% ethylene and 23% acrylic acid by weight of the copolymer and being 90% neutralized with magnesium hydroxide) in a sodium ionomer of H-EAA (Na-EAA available from Allied-Signal Corp., containing 77% ethylene and 23% acrylic acid by weight of the copolymer and being 90% neutralized with NaOH) was melt blown into a continuous web using a method similar to that disclosed in Bohme U.S. Pat. No. 3,972,759. The web was readily wettable and swelled considerably on contact with water.
A sample of the web was frozen in a liquid nitrogen bath and fractured along the desired plane using a razor blade. The exposed fracture was sputter coated with gold-palladium (Model: Desk II; Denton Vacuum, Inc.) prior to analysis using a scanning electron microscope (JSM-840A, JEOL Instruments, Inc.). Photographs taken through the SEM of fiber cross-sections showed no discernable phase separation at a magnification of 10,000×.
It will be appreciated that various changes may be made in the details regarding the materials, processes, and products described herein without departing from the invention as defined in the appended claims.
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A process is disclosed for extruding fibers from ionomer resins that are not blended with polyolefins, monomers, solvents, or other conventional compounds typically used in connection with processing fibers that contain ionomers. The preferred ionomers are 90% neutralized metal salts of copolymers of from at least about 60 to 90% ethylene and from at least about 10 to 40% acrylic acid. Multivalent metal cations can be used to introduce cross linking for control of the solubility and swellability of the fibers. The fibers and webs produced therefrom can be produced by meltblowing and can be used to provide a less expensive alternative to superabsorbent powders.
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BACKGROUND OF THE INVENTION
The present invention relates to improvements in structures for forming a fibrous web from a suspension of fibers in a stock, and particularly to a headbox for handling a stock formed of a generated foam or a high consistency paper making stock.
In the manufacture of fibrous webs, particularly from synthetic fibers, one method which has been developed involves suspending the fibers in a foam suspension. The system for one such arrangement is disclosed in U.S. Pat. No. 3,716,449.
In handling the foam generated by the process taught in the aforesaid patent, a requirement is that the foam not be permitted to break down so that the fibers are uniformly carried and uniformly distributed. To accomplish this, the foam must be uniform and even in the bubble formation and this can be accomplished by continual regeneration of the foam in its flow through the system toward the forming surface.
In supplying the foam with the fibers suspended therein, its flow must be controlled so that the desired amount of fibers are fed to the forming surface at the speed desired. For the formation of a thicker web, a greater quantity of foam is supplied carrying a larger number of fibers onto the forming surface. The supply of fibers delivered to the forming surface also must be increased when the speed of the forming surface is increased. Likewise, for thinner web or a slower operating speed, the amount of foam fed to the forming surface is decreased.
The foam is generally supplied through a headbox arrangement. In the process the foam is first generated with the fibers distributed throughout the foam, and the foam is then flowed through a control headbox onto the forming surface. The control headbox optimumly must maintain uniformity of flow of the foam therethrough for uniform distribution of the foam out of the slice opening from the slice chamber. Also optimumly, a breakdown of the foam must be prevented and for a good procedure, foam regeneration should take place wherever possible throughout the system until the foam is delivered onto the forming surface.
It is accordingly an object of the present invention to provide an improved headbox for handling the flow of foam and delivering a uniform controlled supply of foam onto a forming surface where the flow can easily and readily be controlled.
A further object of the invention is to provide a foam flow headbox which provides for constant regeneration of the foam in the flow therethrough.
A still further object of the invention is to provide an improved foam supply headbox for the formation of a fibrous web in which the flow of foam is maintained uniform throughout the headbox and the quantity of foam flowing through the headbox can easily and quickly be controlled by the provision of a unique structure.
A further object of the invention is to provide a headbox of improved structure capable of handling a high consistency paper making stock.
Other objects, advantages and features, as well as equivalent structures which are intended to be covered herein will become more apparent with the teaching of the principles of the invention in connection with the disclosure of the preferred embodiment in the specification, claims and drawings, in which:
DRAWINGS
FIG. 1 is a side elevational view of a headbox with a vertical section taken through the headbox constructed and operating in accordance with the principles of the present invention;
FIG. 2 is a horizontal sectional view taken substantially along line II--II with portions of the mechanism omitted for clarity;
FIG. 3 is an enlarged fragmentary sectional view showing a shape of the surfaces within the headbox; and
FIG. 4 is an enlarged fragmentary sectional view showing a modified form of the structure of FIG. 3.
DESCRIPTION
As illustrated in FIGS. 1 and 2, the mechanism handles a fibrous foam suspension which flows out through a slice throat or nozzle 10 leading to a slice opening 11 to be deposited on a forming surface, not shown. On the porous forming surface, the stock is dewatered and if a foam stock is used, the foam is broken down to deposit the fibers suspended therein and form a web.
The headbox of the invention is particularly well adapted to use with a stock having fibers supported on a fine foam and is equally capable of handling a high consistency paper making stock. For convenience of description, the structure and operation will primarily be described in connection with the use of a foam stock, but it will be understood that these terms are used by way of description and not by way of limitation.
The foam carrying the fibers is delivered to the slice throat from a slice chamber 12 having a first flow passage 12a and a second flow passage 12b. These flow passages 12a and 12b extend diagonal toward the flow axis of the slice nozzle 10 and are defined by generally convergently related surfaces of a rectilinearly movable block or head 21 and complementary surfaces of walls defining the slice chamber 12. While in some arrangements a single flow passage could be employed, the utilization of two flow passages obtains better control and when foam is used, obtains increased surface for continual regeneration as the foam flows through the headbox. It is also contemplated that additional flow passages could be provided for supplementing the flow of the two flow passages shown, but the two flow passages are advantageous because with the unique constructions to be described, they permit change of the cross sectional size of each of the flow passages simultaneously to increase or decrease the volume of foam flow and to maintain the regenerative effect on the foam the same in each of the flow passages inasmuch as they narrow or widen uniformly with movement of the head block 21. When a high consistency paper making stock is used, the flow passages are shaped to create a tubulence which helps maintain the fibers in uniformly distributed and uniformly oriented pattern within the stock.
Inasmuch as both of the flow passages are essentially uniform in construction and size, only the flow passage 12a need be described in detail. The flow passage 12a contains an outer or stationary undulated area surface 13 and a lower or movable undulated flow area surface 14. The flow surfaces are made up in a preferred form of a plurality of smaller surfaces extending at right angles to each other. The slice chamber passage 12a has a plurality of small surfaces 16 which extend in a direction essentially parallel to the flow through the slice throat 10. That is, in the general direction of flow which is commonly termed the machine direction in the term of paper making art. The flow passages also comprise a plurality of inbetween flat surfaces 15 which extend at right angles to the flow passage surfaces 16 and at right angles to the direction of flow of the foam through the throat 10. These flat surfaces 15 and 16 extend continuously across the width of the headbox which is the cross-machine direction.
Similarly, the lower or movable area surface 14 includes a plurality of flat surfaces 20 which extend in the direction of flow through the throat 10. The area surface 14 also includes a plurality of flat surfaces 19 which extend at right angles to the direction of flow of the stock through the throat 10. These surfaces 19 and 20 join each other at right angles and extend continuously across the width of the machine. The first flow surfaces 16 and 20 which extend in the direction of flow are substantially parallel to each other and are substantially in alignment so that as the movable head 21 is brought up close to the stationary head portion, the surfaces tend to come together and the peaks between the surfaces throttle the flow. A projection 18 extends from the head 21 toward the throat in the direction of stock flow.
FIG. 3 illustrates a preferred form of structure wherein the flat surfaces 19 and 20 or the flat surfaces 15 and 16 join at a relatively sharp angle. In another form, as illustrated in FIG. 4, the surfaces 15 and 16, and the surfaces 19 and 20 may join each other at a small radius as illustrated at 15' and at 20' respectively. The arrangement of surfaces may be termed a modulated step configuration.
As shown in FIG. 3, the surfaces have been brought more closely together for purposes of illustration, and the flow will flow from a series of larger chambers 15a through their restriction portion shown at 15b into the larger chamber 16a. This throttling of the flow from a larger chamber through a throat and back to a larger chamber performs a constant regenerative effect as the foam bubbles are compressed and re-expanded and insures the maintenance of a uniform bubble size and a uniform distribution of fibers. As the miniature bubbles flow, they continually change direction and are swirled or tumbled to impact against the flat surfaces 15, 16, 19 and 20, and to then flow parallel to these surfaces only to again be forced to change direction by another right angle flat surface.
Where a high consistency stock is used instead of a foam, the structural relationship of the flat surfaces and the throttling of the flow performs a beneficial function similar to that on the foam. The continual compression and expansion chambers which are formed causes a fine scale turbulence in the high consistency stock maintaining the random orientation of the fibers and maintaining and improving the quality of the stock which flows out toward the throat and through the slice opening.
As the flow of stock passes down through the first and second flow passages 12a and 12b, it passes into a final merging flow portion 17 and 17a to merge at the throat 10.
The stock flows into upstream portions of the flow passages 12a and 12b of the slice chamber from tube banks 22 and 23 which provide supply passages extending through the head block 21, and which are a plurality of diverging tubes leading from a header 24 to discharge into the slice chamber flow passages. The tube banks comprise a plurality of tubes uniformly spaced extending across the movable head 21 of the headbox.
The header 24 leads from a larger end 25 and tapers down to a smaller end 26, FIG. 2. The foam is supplied through a supply conduit 27 to the larger end from a pump 28, and excess foam is recirculated through a line 29 leading from the smaller end.
An advantage of the mechanism is that the header 24 is carried with the movable sliding head 21 as it moves to increase or decrease the size of the legs of the slice chamber. For supporting the header on the movable head, it is mounted on blocks 36 and 37 which are bolted onto the head.
The headbox includes an upper plate 30 and a lower plate 31 which provide upper and lower guides for the movable head 21. The plates are provided with slots 32 and 33, through which extend guide bolts 34 and 35 which thread into the head 21 and slide in the slots. These bolts will guide the head and can be used to lock the head in an adjusted position.
For providing the power to move the head laterally, a Duff Norton screw jack 42 is provided with a reciprocating shaft 41 extending through an opening in a plate 43 and being connected to a plate 38. The plate 38 provides a drive, sliding between the upper and lower plates 30 and 31, and connects to drive rods 39 and 40 which connect to the movable head 21 and extend above and below the header 24. For movement of the head 21 to the right or left, the Duff Norton jack 42 is operated to slide the assembly including the plate 38 and the connecting rods 39 and 40 with the head 21 to the right or to the left, as shown in FIG. 1.
In some structural arrangements, it is advantageous to provide fluid supply lines such as 51 and 52 leading to the slice chamber in advance of the passages 12a and 12b. These supply lines are used to add a fluid to the liquid flowing through the slice chamber and where the slice chamber is conducting foam, additional air and/or detergent may be added, or additional pregenerated foam, which provides the desired consistency for the regeneration which occurs through the passages 12a and 12b. Where the headbox is used for water based stock, additional stock or additional fibers may be inserted through the lines 51 and 52. As illustrated for the line 51, a control valve 53 may be provided to balance the flows through lines 51 and 52 which are delivered from a pressure supply line 54 which may have a pump 55 therein.
In operation, the foam stock or high consistency stock is supplied to the header 24 and flows uniformly through the distributor tubes 22 and 23 into the flow passages 12a and 12b of the slice chamber. The width of these legs is determined by the lateral position of the head 21. As the stock flows through the two legs, it is continually regenerated by being forced through the constricted undulating passages by the compression and re-expansion and with uniform flow. The stock enters the throat 10 and exits through the slice throat opening 11 onto a forming surface.
The aqueous foam is continually treated to a regenerative action in accordance with the method of the invention, while it flows through the headbox. The high consistency stock is continuously maintained in fine scale turbulence. For this purpose the flow passages 12a and 12b include a plurality of projections extending toward each other, each formed by adjoining flat surfaces, with the apices, or the small radii, where the surfaces join being substantially opposite each other and being moved into opposing closer adjacency when the flow passage is restricted in size.
Thus, I have provided a simplified and compact headbox that is particularly well suited to the handling of foam stock and meets the objectives and advantages above set forth.
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A headbox for supplying a stock consisting of a generated liquid foam suspension of fibers or a high consistency paper making stock including a slice nozzle having a slice opening and a slice chamber having first and second slice flow passages arranged of a set of stepped surfaces leading to the slice nozzle with one set of the surfaces of the slice chamber mounted on a movable block to increase or decrease the size of the passages of the slice chamber, said stepped surfaces shaped to generate a turbulent expansion and shearing action on the foam for a regenerative process, and a tube bank and header chamber delivering foam to the slice chamber passages.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a Rule 60 Continuation of U.S. Pat. No. 5,699,157, filed Jul. 16, 1996, which application is incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
There has been a growing interest in the manufacture and use of microfluidic systems for the acquisition of chemical and biochemical information. Techniques commonly associated with the semiconductor electronics industry, such as photolithography, wet chemical etching, etc., are used in the fabrication of these microfluidic systems. The term, "microfluidic", refers to system or devices having channels and chambers are generally fabricated at the micron or submicron scale, e.g., having at least one cross-sectional dimension in the range of from about 0.1 μm to about 500 μm. Early discussions of the use of planar chip technology for the fabrication of microfluidic systems are provided in Manz et al., Trends in Anal. Chem. (1990) 10(5):144-149 and Manz et al., Avd. in Chromatog. (1993) 33:1-66, which describe the fabrication of such fluidic devices and particularly microcapillary devices, in silicon and glass substrates.
Application of microfluidic systems are myriad. For example, International Patent Appln. WO 96/04547, published Feb. 15, 1996, describes the use of microfluidic systems for capillary electrophoresis, liquid chromatography, flow injection analysis, and chemical reaction and synthesis. U.S. application Ser. No. 08/671,987 (Attorney No. 17646-400), entitled "HIGH THROUGHPUT SCREENING ASSAY SYSTEMS IN MICROSCALE FLUIDIC DEVICES", filed Jun. 28, 1996 by J. Wallace Parce et al. and assigned to the present assignee, discloses wide ranging applications of microfluidic systems in rapidly assaying compounds for their effects on chemical, and preferably, biochemical systems. The phase, "biochemical system," generally refers to a chemical interaction which involves molecules of the type generally found within living organisms. Such interactions include the full range of catabolic and anabolic reactions which occur in living systems including enzymatic, binding, signalling and other reactions. Biochemical systems of particular interest include, e.g., receptor-ligand interactions, enzyme-substrate interactions, cellular signalling pathways, transport reactions involving model barrier systems (e.g., cells or membrane fractions) for bioavailability screening, and a variety of other general systems.
As disclosed in International Patent Appln. WO 96/04547 and U.S. application Ser. No. 08/671,987 noted above, one of the operations which is suitable for microfluidic systems is capillary electrophoresis. In capillary electrophoresis charged molecular species, such as nucleic acids or proteins, for example, are separated in solution by an electric field. With very small capillary tubes as separation channels in a microfluidic system, resolution is enhanced because band broadening due to thermal convection is minimized. The requirement of only a small amount of sample material containing the molecular species is a further advantage of capillary electrophoresis in microfluidic systems.
Nonetheless, there is still room for improvement in capillary electrophoresis. One of the goals of microfluidic systems is high throughput. Presently capillary electrophoresis in microfluidic systems is performed by the observation of separating bands of species migrating in a separation channel under an electric field. The electrophoretic mobility of a species is determined by the time required from the entry of a test compound material into the separation channel for a species band from the test compound material to pass a detection point along the separation channel. The operation is completed after the last species band clears the detection point. See, for example, the above-cited International Patent Appln. WO 96/04547. While these operations are fast compared to macroscale electrophoretic methods, the operations fall short of a highly automated microfluidic system, such as disclosed in the above-mentioned U.S. application Ser. No. 08/671,987, for example.
In contrast, the present invention solves or substantially mitigates these problems. With the present invention, the electrophoretic mobility of each species is determined as the various species undergo electrophoresis in a microfluidic system. Identification of each species can be made automatically.
SUMMARY OF THE INVENTION
The present invention provides for a microfluidic system for high-speed electrophoretic analysis of subject materials for applications in the fields of chemistry, biochemistry, biotechnology, molecular biology and numerous other areas. The system has a channel in a substrate, a light source and a photoreceptor. The channel holds subject materials in solution in an electric field so that the materials move through the channel and separate into bands according to species. The light source excites fluorescent light in the species bands and the photoreceptor is arranged to receive the fluorescent light from the bands. The system further has a means for masking the channel so that the photoreceptor can receive the fluorescent light only at periodically spaced regions along the channel. The system also has an unit connected to analyze the modulation frequencies of light intensity received by the photoreceptor so that velocities of the bands along the channel are determined. This allows the materials to be analyzed.
In accordance with the present invention, the microfluidic system can also be arranged to operate with species bands which absorb the light from the light source. The absorbance of light by the species bands creates the modulation in light intensity which allow the velocities of the bands along the channel to be determined and the subject material to be analyzed.
The present invention also provides for a method of performing high-speed electrophoretic analysis of subject materials. The method comprises the steps of holding the subject materials in solution in a channel of a microfluidic system; subjecting the materials to an electric field so that the subject materials move through the channel and separate into species bands; directing light toward the channel; receiving light from periodically spaced regions along the channel simultaneously; and analyzing the frequencies of light intensity of the received light so that velocities of the bands along the channel can be determined for analysis of said materials. The determination of the velocity of a species band determines the electrophoretic mobility of the species and its identification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of one embodiment of a microfluidic system;
FIG. 2A is a representation of the details of a portion of the microfluidic system according to one embodiment of the present invention; FIG. 2B is a detailed representation of a portion of the separation channel of microfluidic system of FIG. 2A;
FIG. 3A represents an alternative arrangement of the portion of the microfluidic system according to another embodiment of the present invention; FIG. 3B is a detailed representation of a portion of the separation channel of microfluidic system of FIG. 3A; and
FIG. 4 represents still another arrangement of portion of the microfluidic system according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
General Description of Microfluidic Systems
FIG. 1 discloses a representative diagram of an exemplary microfluidic system 100 according to the present invention. As shown, the overall device 100 is fabricated in a planar substrate 102. Suitable substrate materials are generally selected based upon their compatibility with the conditions present in the particular operation to be performed by the device. Such conditions can include extremes of pH, temperature, salt concentration, and application of electrical fields. Additionally, substrate materials are also selected for their inertness to critical components of an analysis or synthesis to be carried out by the system.
Useful substrate materials include, e.g., glass, quartz and silicon, as well as polymeric substrates, e.g., plastics. In the case of conductive or semiconductive substrates, there should be an insulating layer on the substrate. This is particularly important where the device incorporates electrical elements, e.g., electrical fluid direction systems, sensors and the like, or uses electroosmotic forces to move materials about the system, as discussed below. In the case of polymeric substrates, the substrate materials may be rigid, semi-rigid, or non-rigid, opaque, semi-opaque or transparent, depending upon the use for which they are intended. For example, devices which include an optical or visual detection element, are generally fabricated, at least in part, from transparent materials to allow, or at least, facilitate that detection. Alternatively, transparent windows of, e.g., glass or quartz, may be incorporated into the device for these types detection elements. Additionally, the polymeric materials may have linear or branched backbones, and may be crosslinked or non-crosslinked. Examples of particularly preferred polymeric materials include, e.g., polydimethylsiloxanes (PDMS), polyurethane, polyvinylchloride (PVC) polystyrene, polysulfone, polycarbonate and the like.
The system shown in FIG. 1 includes a series of channels 110, 112, 114 and 116 fabricated into the surface of the substrate 102. As discussed in the definition of "microfluidic," these channels typically have very small cross sectional dimensions, preferably in the range from about 0.1 μm to about 100 μm. For the particular applications discussed below, channels with depths of about 10 μm and widths of about 60 μm work effectively, though deviations from these dimensions are also possible.
Manufacturing of these channels and other microscale elements into the surface of the substrate 102 may be carried out by any number of microfabrication techniques that are well known in the art. For example, lithographic techniques may be employed in fabricating glass, quartz or silicon substrates, for example, with methods well known in the semiconductor manufacturing industries. Photolithographic masking, plasma or wet etching and other semiconductor processing technologies define microscale elements in and on substrate surfaces. Alternatively, micromachining methods, such as laser drilling, micromilling and the like, may be employed. Similarly, for polymeric substrates, well known manufacturing techniques may also be used. These techniques include injection molding techniques or stamp molding methods where large numbers of substrates may be produced using, e.g., rolling stamps to produce large sheets of microscale substrates, or polymer microcasting techniques where the substrate is polymerized within a microfabricated mold.
Besides the substrate 102, the microfluidic system includes an additional planar element (not shown) which overlays the channeled substrate 102 to enclose and fluidly seal the various channels to form conduits. The planar cover element may be attached to the substrate by a variety of means, including, e.g., thermal bonding, adhesives or, in the case of glass, or semi-rigid and non-rigid polymeric substrates, a natural adhesion between the two components. The planar cover element may additionally be provided with access ports and/or reservoirs for introducing the various fluid elements needed for a particular screen.
The system 100 shown in FIG. 1 also includes reservoirs 104, 106 and 108, which are disposed and fluidly connected at the ends of the channels 114, 116 and 110 respectively. As shown, sample channel 112, is used to introduce a plurality of different subject materials into the device. It should be noted that the term, "subject materials," simply refers to the material, such as a chemical or biological compound, of interest. Subject compounds may include a wide variety of different compounds, including chemical compounds, mixtures of chemical compounds, e.g., polysaccharides, small organic or inorganic molecules, biological macromolecules, e.g., peptides, proteins, nucleic acids, or extracts made from biological materials, such as bacteria, plants, fungi, or animal cells or tissues, naturally occurring or synthetic compositions.
Many methods have been described for the transport and direction of fluids, e.g., samples, analytes, buffers and reagents, within microfluidic systems or devices. One method moves fluids within microfabricated devices by mechanical micropumps and valves within the device. See, published U.K. Patent Application No. 2 248 891 (Oct. 18. 1990), published European Patent Application No. 568 902 (May 2, 1992), U.S. Pat. Nos. 5,271,724 (Aug. 21, 1991) and 5,277,556 (Jul. 3, 1991). See also, U.S. Pat. No. 5,171,132 (Dec. 21, 1990) to Miyazaki et al. Another method uses acoustic energy to move fluid samples within devices by the effects of acoustic streaming. See, published PCT Application No. 94/05414 to Northrup and White. A straightforward method applies external pressure to move fluids within the device. See, e.g., the discussion in U.S. Pat. No. 5,304,487 to Wilding et al.
While these methods could be used to transfer the test compound materials to the separation channel for electrophoresis, a preferable method uses electric fields to move fluid materials through the channels of a microfluidic system. See, e.g., published European Patent Application No. 376 611 (Dec. 30, 1988) to Kovacs, Harrison et al., Anal. Chem. (1992) 64:1926-1932 and Manz et al. J. Chromatog. (1992) 593:253-258, U.S. Pat. No. 5,126,022 to Soane. Electrokinetic forces have the advantages of direct control, fast response and simplicity. Furthermore, the use of electrokinetic forces to move the subject materials about the channels of the microfluidic system 100 is consistent with the use of electrophoretic forces in the separation channel 110.
To provide such electrokinetic transport, the system 100 includes a voltage controller that is capable of applying selectable voltage levels, simultaneously, to each of the reservoirs, including ground. Such a voltage controller can be implemented using multiple voltage dividers and multiple relays to obtain the selectable voltage levels. Alternatively, multiple independent voltage sources may be used. The voltage controller is electrically connected to each of the reservoirs via an electrode positioned or fabricated within each of the plurality of reservoirs. See, for example, published International Patent Application No. WO 96/04547 to Ramsey, which is incorporated herein by reference in its entirety for all purposes.
Alternatively, rather than voltage, another electrical parameter, such as current, may be used to control the flow of fluids through the channels. A description of such alternate electrical parametric control is found in U.S. application Ser. No. 08/678,436, entitled "VARIABLE CONTROL OF ELECTROOSMOTIC AND/OR ELECTROPHORETIC FORCES WITHIN A FLUID-CONTAINING STRUCTURE VIA ELECTRICAL FORCES", filed Jul. 3, 1996 by Calvin Y. H. Chow and J. Wallace Parce and assigned to the present assignee. This application is incorporated herein by reference in its entirety for all purposes.
Stated more precisely, electrokinetic forces may be separated into electroosmotic forces and electrophoretic forces. The fluid control systems used in the system of the present invention employ electroosmotic force to move, direct and mix fluids in the various channels and reaction chambers present on the surface of the substrate 102. In brief, when an appropriate fluid is placed in a channel or other fluid conduit having functional groups present at the surface, those groups can ionize. For example, where the surface of the channel includes hydroxyl functional groups at the surface, protons can leave the surface of the channel and enter the fluid. Under such conditions, the surface possesses a net negative charge, whereas the fluid possesses an excess of protons or positive charge, particularly localized near the interface between the channel surface and the fluid.
By applying an electric field across the length of the channel, cations flow toward the negative electrode. Movement of the positively charged species in the fluid pulls the solvent with them. The steady state velocity of this fluid movement is generally given by the equation: ##EQU1## where v is the solvent velocity, ε is the dielectric constant of the fluid, ξ is the zeta potential of the surface, E is the electric field strength, and η is the solvent viscosity. Thus, as can be easily seen from this equation, the solvent velocity is directly proportional to the zeta potential and the applied field.
Besides electroosmotic forces, there are also electrophoretic forces which affect charged molecules as they move through the system 100. In the transport of subject materials from one point to another point in the system 100, it is often desirable for the composition of the subject materials to remain unaffected in the transport, i.e., that the subject materials are not electrophoretically differentiated in the transport until desired. To do so, the subject materials are transported in fluid slug regions 120 of predetermined ionic concentrations. The regions are separated by buffer regions of varying ionic concentrations and represented by buffer regions 121 in FIG. 1. A related patent application, U.S. application Ser. No. 08/671,986, entitled "ELECTROPIPETTOR AND COMPENSATION MEANS FOR ELECTROPHORETIC BIAS," filed Jun. 28, 1996 by J. Wallace Parce and Michael R. Knapp, and assigned to the present assignee, explains various arrangements of slugs, and buffer regions of high and low ionic concentrations in transporting subject materials with electrokinetic forces. The application is incorporated herein by reference in its entirety for all purposes. The application also explains how the channel 112 may be fluidly connected to a source of large numbers of separate subject materials which are individually introduced into the sample channel 112 and subsequently into the separation channel 110 for analysis.
Electrophoresis in Microfluidic System and Operation
As described in the above-cited International Patent Appln. WO 96/04547 and the previously mentioned U.S. Patent application Ser. No. 08/671,986, entitled "HIGH THROUGHPUT SCREENING ASSAY SYSTEMS IN MICROSCALE FLUIDIC DEVICES", the disclosures of which are incorporated herein by reference for all purposes, the slugs 120 of subject materials, separated by buffers 121, are moved through the sample channel 112 and into the separation channel 110. Each slug 120 is subjected to an electric field in the channel 110 so that the constituent species in each slug 120 separates into species bands 123, as shown in FIG. 1.
When the slugs 120 of subject materials are placed in the separation channel 110, the materials are subjected to an electric field by creating a large potential difference between the terminals in the reservoir 104 and 108. The species in the slugs separate according to their electric charges and sizes of their molecules. The species are subjected to electric fields in the range of 200 volts/cm. In accordance with one aspect of the present invention, the species are labeled with fluorescent label materials, such as fluorescent intercalating agents, such as ethidium bromide for polynucleotides, or fluorescein isothiocyanate or fluorescamine for proteins, as is typically done with conventional electrophoresis.
As shown in FIG. 2A, the arrangement has a light source 120, a first lens 124, a mask 122, the separation channel 110, a second lens 126, a filter 128, and a photoreceptor 130 connected to a frequency analyzer unit 134. The light source 120 emits light at wavelengths to energize the fluorescent labels of the species in the separation channel 110. Lamps, lasers and light-emitting diodes may be used for the source 120. The mask 122 is located between the light source 120 and the separation channel 110 and blocks light from reaching selected portions of the channel 110.
The projection of the mask 122 by the light source 120 onto the separation channel 110 results in a series of alternating illuminated and darkened regions which are equally spaced along the channel 110. Each darkened region 140 has the same width as another darkened region along the separation channel 110 and is approximately the same width as the species bands 123 in the separation channel 110, as shown in FIG. 2B. The illuminated regions 142 along the separation channel 110 are also approximately the same width as the darkened regions 140. For example, with a separation column approximately 10 μm deep and 60 μm wide, the illuminated and darkened regions 142 and 140 are approximately 50-500 μm along the separation channel 110.
As each species band from the sample slugs travel through the alternating darkened and illuminated regions 140 and 142 respectively, the species bands 123 are alternately fluorescent in the illuminated regions 142 and unlit in the darkened regions 140. As each species travels down the separating channel 110, the species fluoresces off and on with a characteristic frequency corresponding to its velocity along the channel 110. The velocity, v, of the particular species is directly related to the electrophoretic mobility, μ ep , of that species:
v=μ.sub.ep *E
where E is the electric field. Thus a plurality of different species moving through the separation channel 110 fluoresces at a plurality of frequencies, each corresponding to a particular species.
The light from the separation channel 110 is focussed by the lens 126 upon the photoreceptor 130. The light received by the photoreceptor 130, which may be a photomultiplier tube, a photodiode, a CCD array, and the like, is converted into electrical signals which are, in turn, sent to the frequency analyzer unit 134. The frequency analyzer unit 134, by straightforward Fourier analysis, breaks the electrical signals into their component frequencies. These electrical signal frequencies are the same as that of the modulated light intensities generated by the species undergoing electrophoresis in the separation channel 110. The frequency of light intensity is related to the electrophoretic mobility of each species band. Hence, a computer unit with a calibrated look-up table can automatically identify each species according to its electrical signal frequency from the frequency analyzer unit 134. The electrophoresis operation is entirely automated.
Note that each species band 123 need not pass completely through the separation channel 110. Identification occurs as soon as a characteristic optical modulation frequency is generated after the species passes through a predetermined number of alternating darkened and illuminated regions in the channel 110. Thus electrophoresis is performed in a matter of seconds.
As stated above, the mask 122 is arranged such that the alternating darkened and illuminated regions are approximately the same width along the separation channel 110 with respect to each other and to the widest species band. This ensures the largest possible variation between the maxima and minima of light intensity from the fluorescent species bands passing through the mask regions.
As symbolically shown in FIG. 2A, the photoreceptor 130 is placed along an axis formed with the light source 120, the mask 122 and the lens 126. An alternative arrangement has the light source 120 and the mask 122 off the axis so that light from the source 120 directed toward the separation channel 110 is also directed away from the photoreceptor 130. This arrangement allows the photoreceptor 130 to be illuminated only by the fluorescent light from the labeled species in the channel 110. Furthermore, to avoid contamination of the optical signals received by the photoreceptor 130, a filter 128 may be used for the photoreceptor 130. The filter 128 is a band-pass filter transmitting light only at wavelengths emitted by the fluorescent species, and blocking light at other wavelengths, i.e., light from the source 120. Alternatively, the filter 128 might be selective toward blocking light at the light source wavelengths. Typically, the fluorescent label materials fluoresce at longer wavelengths than those of the source 120. For example, for polynucleotides labeled with ethidium bromide as subject materials for electrophoresis, a light source emitting light at 540 nm is used and the species bands fluoresce at 610 nm. For proteins labelled with fluorescein, a light source at 490 nm works with species bands fluorescing at 525 nm.
As described above, the mask 122 is projected onto the separation channel 110. An alternative arrangement imposes the mask 122 onto the substrate itself so that a series of alternating darkened and light regions are created along the channel 110. Such an arrangement is illustrated in FIG. 3A. The light source 120 illuminates the species bands 122 in the separation channel 110 directly. On the side of the channel 110 toward the photoreceptor 120, a mask 150 of alternating darkened and transparent regions 154 and 152 respectively are placed on the substrate 152, as shown in FIG. 3B. The dimensions and spacing of the regions 154 and 152 are the same as the projection of the mask 122 in FIGS. 2A and 2B.
Still another arrangement projects the fluorescent species bands 123 in the separation channel 110 unto a mask 160, as shown in FIG. 4. After being collimated by a lens 164, light from the source 120 illuminates the species bands 123. Since light fluoresces from the bands 123 isotropically, the light is projected toward the mask 160 through a focussing lens 165. Light from the other side of the mask 160 is focused by the lens 126 onto the photodetector 120. As explained above, the elements of FIG. 4 illustrate a general relationship with each other. The lens 165, mask 160, lens 126, filter 128, and photoreceptor 130 need not be aligned with source 120, lens 164 and channel 110.
The arrangements above analyze the subject materials undergoing electrophoresis by the reception of fluorescent light from the moving species bands 123. The present invention also operates with the absorbance of light by the subject material. For example, using the arrangement of FIG. 2A, the light source 120 is selected to radiate light at wavelengths which are absorbed by the subject material. For proteins, the light source 120 may operate at wavelengths of 280 nm, for example. For polynucleotides, 260 nm is a suitable wavelength for the light source 120. The lens 126, filter 128 and photoreceptor are arranged to receive the light from the source 120 through the mask 122 and channel 120. The light source 120, lens 124, mask 122, channel 110, lens 126, filter 128 and photoreceptor 130 are optically aligned and the filter 128 is selected to pass light of the wavelength of interest from the source 120 to the photoreceptor 130. More typically for absorption measurements, the filter 128 is placed next to the source.
Rather than light from the species bands 123, darkness from the light-absorbing bands 123 moving in the channel 110 causes a varying signal to be received by the photoreceptor 130. Fourier analysis of the signal ultimately identifies the species in the channel 110. Similarly, the embodiments of the present invention illustrated in FIGS. 3A and 4 can be adapted to light absorbance by the species bands 123, rather than light fluorescence.
In another embodiment of the present invention, the mask 122 is eliminated. For example, a coherent light source, such as a laser, is used for the source 120 and a pair of slits are located between the source 120 and the channel 110. The slits are parallel to each other and perpendicular to the length of channel 110. By interference between the light emanating from the two slits, the light falls in intensities of alternating minima and maxima along the channel 110, like the operation of the mask 122 described previously. Light received from the periodically spaced locations of maxima allow the determination of the velocities of moving species bands 123 by the frequency analysis of the light intensity modulating in time, as described previously. This arrangement operates in either fluorescing or absorbing mode. Of course, other arrangements with one or more light sources 120 may also create light patterns of minima and maxima intensities along the channel 110 without a mask.
Speed and sensitivity of the present invention are much enhanced over previous systems which perform electrophoresis by the measurement of a species band past a detection point. The present invention has a higher signal-to-noise ratio since the light signals from the fluorescent bands 123 are averaged over time by the movement of the light signals past the mask regions, in contrast to a single observation at the detection point.
Of course, the present invention also has the other advantages of microfluidic systems, such as speed, low cost due to the low consumption of materials and the low use of skilled labor, and accuracy. The microfluidic system 100 has little or no contamination with high reproducibility of results.
While the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be clear to one skilled in the art from a reading of this disclosure that various changes in form and detail can be made without departing from the true scope of the invention. All publications and patent documents cited in this application are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication or patent document were so individually denoted.
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The present invention provides a microfluidic system for fast, accurate and low cost electrophoretic analysis of materials in the fields of chemistry, biochemistry, biotechnology, molecular biology and numerous other fields. Light from periodically spaced regions along a channel in the microfluidic system are received by a photodetector. The intensity of light received by the photodetector is modulated by the movement of species bands through the channel under electrophoretic forces. By Fourier analysis, the velocity of each species band is determined and the identification of the species is made by its electrophoretic mobility in the channel.
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[0001] The present application claims priority in U.S. Provisional Patent Application Ser. No. 60/709,347 filed Aug. 18, 2005 and entitled “Sonde Housing.”
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present application relates to drilling apparatus for directional drilling in utility installations and, more particularly, to housings for drill string instrumentation such as sonde transmitters and the like.
[0004] 2. Background Description of the Prior Art
[0005] Horizontal Directional Drilling (HDD) is a means of boring horizontally underground to provide utility installations and remediation of utility installations already in place. While most open areas are “open trenched” with various trenching equipment, the HDD boring rigs are used to “drill” a bore path under obstacles such as rivers, roads, railroads, other existing utilities etc.
[0006] An HDD drill rig consist basically of a boring machine and a drill string including drill pipe, locating electronics (aka transmitter, sonde or transmitter beacon, typically configured as an instrument assembly for being enclosed or packaged within a tubular housing), and a boring bit attached to the front of the drill string. A bore path is plotted and laid out for the contractors. The drilling crew then drills at an angle into the ground along the bore path until the desired depth is reached. The bore is then leveled out and advanced under the obstacle. During this time the locating electronics instrumentation is installed between the drill bit and the drill pipe for transmitting the drill bit's depth, pitch and clock location (e.g., at 12, 3, 6, or 9 o'clock) to the surface. Once the desired bore length is reached under and past the obstacle, the bit is steered toward the surface. The pilot tool is then removed and a reamer can be used to open the hole to a larger diameter while pulling the drill pipe back. If the pilot hole is the desired size, the tool is removed and the pipe, conduit or “product” is pulled back through the hole. During drilling, the drill pipe is fed into the bore 10 to 15 feet at a time. Attached to the front of the drill pipe just behind the drill bit (or, alternatively, a mud motor) is the instrumentation package such as a sonde housing which houses and protects the sonde (transmitter).
[0007] With respect to the instrumentation package, currently there are two types of prior art sonde housing designs on the market. The first type of prior art housing is known as an “end load” sonde housing. The sonde is loaded from one end of the housing and secured therewithin. With no “door” or “lid” access to the sonde this design requires “breaking” the connection between housing and drill stem to obtain access to the sonde within the housing. However, this design allows for a full set of “water ports” to be machined within the wall space surrounding the sonde cavity allowing a large volume of drilling fluids to be pumped through the drill pipe and tool. The volume and pressure capacity of this design allow drillers to drive hydro/mechanical drilling tools in the hole often called “mud motors”
[0008] The “end load” design is preferred for its flow capabilities and the security it offers for the electronics in the sonde. Secured inside the end load housing, the sonde is rarely lost during the coarse of boring. However, since the transmitter is powered by batteries, the process of disconnecting the drill string from the housing and removing the sonde can be cumbersome and difficult. This is especially true on shorter, smaller diameter “in & out” bores where the tool usually remains on the drill pipe from bore to bore.
[0009] The second type of prior art housing is known as a “side load” housing. It is more popular for use with smaller machines without the large pump capacity for mud motor drilling. These rigs use a variety of bits that drill by rotational force from the drill rig transferred through the drill pipe. The side load design allows easy access to the sonde for maintenance, battery changes and replacement of the sonde. On a side load housing the sonde is installed through an opening in the side of the housing that is long enough for the sonde to be inserted laterally, with its axis parallel to the axis of the sonde housing. The sonde is inserted parallel with the housing and secured in place. A housing door or “lid” is then attached to the housing to cover and protect the transmitter.
[0010] The side load feature is a time saving design but reduces the number of water ports that may be provided to direct fluid from one end of the housing to the other. This fluid restriction is the primary reason this housing design is not used with the larger machines.
[0011] Another drawback to the side load design is that, on occasion during the drilling process, due to deterioration or extreme rotational torque, the side lids or doors become dislodged from the housing. Once the door is dislodged from a closed position or removed the sonde is completely exposed and typically protrudes from the housing or even falls out of the housing. At that point the sonde is usually irretrievable or damaged beyond repair. The cost associated with this failure is usually the loss of the sonde ($2,000-$5,000) plus the added expense of “tripping” out of the hole, making repairs” and tripping back into the bore.
[0012] What is needed is an instrument housing for a drill string that provides full protection for the instrumentation, allows full capacity water ports for use with mud motors, provides for ease of assembly into a drill string, and provides an easily adjusted clocking mechanism for the instrument package, and is low in cost of manufacture.
SUMMARY OF THE INVENTION
[0013] Accordingly, an instrument housing for a drill string is described herein, comprising: a cylindrical housing having a centered axial bore forming a cavity for receiving an instrument assembly such as a transmitter sonde, the dimensions of the cross section of the cavity exceeding the diameter of the instrument assembly by a predetermined clearance; an elongated side load opening disposed parallel with the longitudinal axis of the cavity, formed through a side of the cylindrical housing and into the cavity opening, the side load opening having a length substantially less than the length of the instrument assembly; and an elongated side load door assembly, having first and second ends and configured to fit within the side load opening, for enclosing and securing the instrument assembly within the cylindrical housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates a side view of one embodiment of a sonde housing according to the present invention, having a sonde partially installed therewithin;
[0015] FIG. 2 illustrates an exploded side view of the embodiment of FIG. 1 including a clocking mechanism, a spacer assembly, and a side load door in position for assembly, and further having the sonde in place within the cavity of the sonde housing;
[0016] FIG. 3 illustrates a side view of the embodiment of FIGS. 1 and 2 following assembly;
[0017] FIG. 4 illustrates a cross section view of one embodiment of the sonde housing of FIG. 3 ; and
[0018] FIG. 5 illustrates a cross section view of an alternate embodiment of the sonde housing of FIG. 3 .
DETAILED DESCRIPTION OF THE INVENTION
[0019] Disclosed herein and illustrated in FIGS. 1 to 4 is one embodiment of a new side load housing for and instrument assembly called a transmitter sonde, sometimes referred to as a ‘beacon.’ While the specific embodiment describe herein is a sonde housing according to the present invention, the principles of the invention are applicable generally to cylindrical instrument housings having round or rectangular cross sections, that enclose a generally tubular instrumentation assembly, and that are typically used in harsh environments.
[0020] The sonde housing of the present invention illustrated in the appended figures provides a side-loaded sonde housing that is more resistant to damage to the side loading door assembly, and to the transmitter sonde (or, simply, sonde) itself, that may result from the torque applied to the drill string during drilling. The novel sonde housing design not only reduces the possibility of door loss but also protects and secures the sonde in the event the door does fail. As will be described, the clocking mechanism for use with the sonde is simplified, to reduce the time required to load and calibrate the sonde within the housing. This design also allows for an increased number (3 or 4 or 5) of water ports to accommodate the water flow capacity requirements of mud motors, as compared with prior art side load designs. In the description that follows, the reference numbers identifying the various structural features remain the same throughout the five figures when they refer to the same structures.
[0021] Referring to FIG. 1 , the side load sonde housing 10 of the present invention is made from either a tubular product or a solid material with a center bore or cavity 14 disposed along the longitudinal axis of the housing. The center cavity 14 may have a round cross section, or the cross section may be rectangular having interior wall surfaces 16 as in the illustrate embodiment shown in FIGS. 4 and 5 . In other embodiments the cross section may have other shapes. The housing is typically fabricated from a heat treated and hardened 4140 or 4340 alloy of stainless steel. Around the center cavity 14 of the housing 10 in the wall 12 (see FIG. 4 or 5 ) of the housing 10 , several water ports 110 may be drilled the length of the housing 10 . The size and number of these ports 110 is determined by the drill rig and pipe size and the type of tools being used. Typically there are at least 3 or 4 such water ports 110 , although in conventional side load sonde housings having a full length side load door, the number of such side ports is limited to one or two such ports.
[0022] The center cavity 16 may be “plugged” and welded to provide a seal on each end 18 , 20 . A side load door opening 30 is machined through the wall 12 of the housing 10 . The door opening 30 , which is shorter than conventional side load sonde housings, and disposed near one end of the cavity, is approximately 60% to 80% of the length of the sonde 40 . Also machined in the body 12 of the sonde housing 10 are a series of narrow antenna ports 22 that permit the transmitted signal from the sonde or beacon 40 to be radiated from the sonde 40 . There are typically five such ports (two are shown in FIG. 1 ), including one cut through the door 80 , shown in a longitudinal cross section. In some embodiments, the antenna ports 22 are cut using a circular saw blade and produce an antenna port cross section as shown by the arcuate lines 96 in FIG. 2 . Further, FIG. 1 illustrates a drilled, tapped, and countersunk hole called a “flush port” 24 for receiving a ¾ inch flush plug. The flush plug may be removed for cleaning the sonde housing 10 after use to remove mud, debris and other materials that accumulate in the housing 10 during drilling operations. At each end of the sonde housing 10 , the housing is machined to be coupled with other drill string components at the tapered and threaded tool joints 26 , 28 .
[0023] Continuing with FIG. 1 , the interior notches 34 , 36 are machined in each narrow end of the opening 30 to allow the tabs 86 , 88 machined on the door 80 to engage the housing 10 . An interior ledge 32 is also machined around the perimeter of the opening 30 to support the door 80 and to eliminate any deflection of the door 80 into the cavity 14 by forces occurring in the drill string path. The body 12 of the housing 10 further includes a drilled and tapped hole 54 for a third bolt 94 to secure the door 80 to the body of the housing 10 . A drilled and tapped hole 54 is also formed in the floor of the cavity in the housing to receive a second bolt 70 for securing the spacer 66 to the housing. The third bolt 94 and the second bolt 70 , as well as a first bolt 64 to be described may each preferably be, for example, a nylon pelleted, socket head shoulder bolt.
[0024] To install the sonde 40 into the housing 10 , the first end 42 of the sonde 40 is configured to be inserted into the center cavity 14 at an angle 50 relative to the longitudinal axis of the housing 10 . Before insertion, the sonde 40 may be oriented rotationally, so that, in the position illustrated in FIGS. 1, 2 , and 3 , the keyway or slot 46 is positioned at an initial position of “6 O'clock” and pushed into the enclosed portion of the housing 10 . Once fully inserted into the enclosed portion of the housing 10 , whereby the inside end 42 is positioned against the end 18 of the cavity 14 , and the indexing or exposed end 44 of the sonde 40 can be lowered into the cavity 14 and settled into position substantially inside the enclosed area of the housing 10 . Resilient collars 48 , such as O rings, are installed on the sonde 40 to center the sonde 40 within the cavity 14 and provide cushioning against mechanical shock. In the embodiment shown, for a typical sonde housing, approximately four inches of open space 100 (See FIG. 2 ) should remain in the open area of the cavity 14 after the sonde 40 is installed in the cavity 14 .
[0025] Referring to FIG. 2 , since the sonde 40 is to be “clocked” or indexed in respect to the drill bit's installed position, the sonde 40 may be rotated inside the cavity 14 to the desired position for indexing. In FIG. 2 , a two-piece “clocking mechanism” 60 is installed into the housing 10 and attached to the sonde 40 via the keyway or slot 46 formed in the end of the sonde 40 . This clocking mechanism 60 secures the sonde 40 in the proper rotational relationship (calibration) and partially secures the sonde 40 in the housing 10 . The clocking mechanism 60 itself may then be secured with a first bolt 64 . First bolt 64 may be a socket head shoulder bolt.
[0026] Continuing with FIG. 2 , once the clocking mechanism 60 is installed and secured with the first bolt 64 , the spacer 66 is inserted to fill the remaining open space 100 in the cavity 14 . The spacer 66 is designed with an extension or lip 67 that extends over the clocking mechanism 60 and a portion of the sonde 40 itself. The spacer 66 is secured to the bottom of the cavity 14 in the tapped hole 54 using the second bolt 70 and provides added measure of security for the sonde 40 should the door 80 (to be described) be lost. With the sonde 40 , clocking mechanism 60 and spacer 66 installed, somewhat less than about half the length of the sonde 40 is exposed if the door 80 is lost as compared to the exposure of the entire 18″ length of the sonde 40 when the prior art full length side load doors are lost.
[0027] The exploded view of the sonde housing 10 shown in FIG. 2 includes a door 80 for enclosing and securing the sonde 40 within the cavity 14 of the housing 10 . The door 80 includes an exterior surface 90 , a machined hole 92 for passage of the third bolt 94 therethrough, and an edge 98 on either side of the door 80 that fits along the interior ledges 32 of the sonde housing 10 when the door 80 is in place. After securing the spacer 66 , the first end 82 of the door 80 with machined tab 86 is slid at an angle completely into the first notch 34 in the housing 10 and then slid in the opposite direction along the supporting interior ledges 32 (See FIG. 1 ) within the bore 16 to engage the second tab 88 into the second notch 36 . The door 80 is then secured to the housing 10 using the third bolt 94 . The housing 10 may include tool joints 26 , 28 on either end, as previously described.
[0028] Continuing with FIG. 2 , a drill bit 102 having a threaded male end 104 is shown in an aligned position in preparation to be threaded into the female socket end of the tool joint 28 of the sonde housing 10 .
[0029] Referring to FIG. 3 , an instrument housing 10 for a transmitter sonde 40 according to the present invention is shown with the sonde 40 installed and indexed or “clocked” within the housing 10 in a proper orientation to correspond to the position of the drill bit (not shown) as described herein above. It will also be observed that once the door 80 is placed in its final position, a slight gap 106 remains between the end 82 of the door 80 and the end of the opening 30 that receives the door 80 . However, only part of the tab 86 is exposed, the rest (and most) of its length remaining within the housing 10 . Also shown in FIG. 3 is the ¾ inch (typically) “flush plug” 116 in place in the hole 24 provided. FIG. 3 further illustrates the drill bit 102 installed in position tool joint 28 .
[0030] Referring to FIGS. 4 and 5 there are illustrated cross sections of the sonde housing 10 with the transmitter sonde 40 installed, taken at the position indicated by the Roman Numerals IV and V respectively in FIG. 3 . FIGS. 4 and 5 depict respective embodiments of a sonde housing 10 having four water ports 110 disposed in the body 12 of the sonde housing 10 ( FIG. 4 ) and two water ports 110 disposed in the body 12 of the sonde housing 10 ( FIG. 5 ). The embodiment of FIG. 4 is especially suited for sonde housings used with mud motors, which require relatively large volumes of water be pumped through the body of the sonde housing. The embodiment of FIG. 5 is suited for drilling operations where a mud motor is not used.
[0031] While the invention has been shown in only one of its forms, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit thereof. For example, one version of the sonde housing 10 is available wherein the cross section may be any of three diameters adapted to 3.0″, 3.5″, and 4.5″ drill bits. The invention including its various component parts is readily scaled.
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An instrument housing for a drill string, comprising: a cylindrical housing having a cavity for receiving an instrument assembly such as a transmitter sonde; an elongated side load opening disposed parallel with and toward one end of the cavity and formed through a side of the cylindrical housing into the cavity. The side load opening is substantially shorter than the length of the instrument assembly; and an elongated side load door assembly is configured to fit within the side load opening, to enclose and secure the instrument assembly within the cylindrical housing such that the instrument is protected from loss or damage due to loss or damage to the side load door during operation.
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FIELD OF THE INVENTION
The present invention relates to a smear staining apparatus for staining a smear sample in which a sample such as blood is applied on a slide glass, a smear preparing apparatus, a smear processing system, and a method for determining the staining condition in staining the smear sample.
BACKGROUND
A smear staining apparatus for staining a smear sample is conventionally known (e.g., Japanese laid open patent application No. 2001-021468).
Japanese laid open patent application No. 2001-021468 discloses a smear staining apparatus for staining a smear sample by immersing the smear sample in a stain fluid bath. In the smear staining apparatus disclosed in this reference, the immersing time is determined by the user so as to stain the sample to a desired density.
The concentration of the concentrated stain fluid differs depending on the manufacturer and the manufacturing lot. Thus, an appropriate stain state may not necessarily be obtained after the concentrated stain fluid is replaced even if a constant immersing time is set. The immersing time thus needs to be re-determined if the concentrated stain fluid is replaced. However, although the operator determines the immersing time in the smear staining apparatus disclosed in the above document, the appropriate immersing time may not be determined at one time. Thus, the immersing time needs to be re-determined over and over until an appropriate stain state is obtained, which is a great load on the operator.
In view of the above situations, it is a main object of the present invention to provide a smear staining apparatus, a smear preparing apparatus, a smear processing system, and a method for determining the staining condition capable of easily determining an appropriate staining condition.
SUMMARY OF THE PRESENT INVENTION
A first aspect of the present invention is a smear staining apparatus comprising: a staining section which stains a smear sample with a quantity of stain fluid; and a controller, wherein the controller: receives information regarding a stain state on a smear sample which is stained according to a first staining condition by the staining section; and determines a second staining condition on the basis of the information and a target value which defines a targeted stain state.
A second aspect of the present invention is a smear preparing apparatus comprising: a smear preparing section for preparing a smear sample by smearing a sample on a slide glass; a staining section for staining the smear sample prepared by the smear preparing section using a quantity of stain fluid; and a controller, wherein the controller: receives information regarding a stain state on a smear sample which is stained according to a first staining condition by the staining section; and determines a second staining condition on the basis of the information and a target value which defines a targeted stain state.
A third aspect of the present invention is a smear processing system comprising: the smear staining apparatus of first aspect; and a smear imaging apparatus for imaging the smear sample stained by the smear staining apparatus to acquire an image, analyzing the obtained image, and outputting information regarding a stain state of the smear sample.
A fourth aspect of the present invention is a method of determining a staining condition including steps of: staining a smear sample according to a first staining condition by a staining apparatus for staining a smear sample using a quantity of stain fluid; acquiring information regarding a stain state of the smear sample stained by the staining apparatus according to the first staining condition from a smear imaging apparatus for imaging the stained smear sample and outputting information regarding the stain state; and determining a second staining condition of the staining apparatus based on the obtained information and a target value which defines a targeted stain state.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing an overall configuration of a smear processing system according to the embodiment;
FIG. 2 is a plan view showing an internal structure of the blood smear preparing apparatus according to the embodiment;
FIG. 3 is a perspective view showing the cassette and the slide glass used in the blood smear preparing apparatus according to the embodiment;
FIG. 4 is a perspective view showing the cassette and the slide glass used in the blood smear preparing apparatus according to the embodiment;
FIG. 5 is a perspective view showing a first aspirating and discharging unit of the staining section of the blood smear preparing apparatus according to the embodiment;
FIG. 6 is a fluid circuit diagram showing the supply path of the liquid supplied to the staining section of the blood smear preparing apparatus according to the embodiment;
FIG. 7 is a schematic view showing the configuration of the staining section of the blood smear preparing apparatus according to the embodiment;
FIG. 8 is a block diagram showing the configuration of the sample imaging apparatus according to the embodiment;
FIG. 9 is a perspective view showing one part of the configuration of the microscope unit of the sample imaging apparatus according to the embodiment;
FIG. 10 is a block diagram showing the configuration of the image processing unit of the sample imaging apparatus according to the embodiment;
FIG. 11 is a flowchart showing the flow of operation of changing the stain fluid of the blood smear preparing apparatus according to the embodiment;
FIG. 12 is a flowchart showing the flow of the blood cell imaging and the image analyzing operation of the sample imaging apparatus according to the embodiment;
FIG. 13 is a view showing an example of the blood cell image;
FIG. 14 is a view showing an input receiving screen according to the embodiment;
FIG. 15A is a flowchart showing the flow of the staining condition setting process of the blood smear preparing apparatus according to the embodiment (first half);
FIG. 15B is a flowchart showing the flow of the staining condition setting process of the blood smear preparing apparatus according to the embodiment (second half); and
FIG. 16 is a flowchart showing the flow of the smear sample preparing and staining process after changing the concentrated stain fluid by the blood smear preparing apparatus according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiment of the present invention will now be described with reference to the drawings.
[Configuration of Smear Processing System]
FIG. 1 is a perspective view showing an overall configuration of a smear processing system according to the present embodiment. As shown in FIG. 1 , a smear processing system 100 includes a blood smear preparing apparatus 1 and a sample imaging apparatus 3 . A transport device 2 for transporting a blood sample accommodated in a test tube is arranged on the front side of the blood smear preparing apparatus 1 , where the sample is transported to the blood smear preparing apparatus 1 by the transport device 2 so that the blood smear preparing apparatus 1 uses the relevant sample to prepare a smear sample. The prepared smear sample is imaged by the sample imaging apparatus 3 , and the blood cells are classified through image processing.
<Configuration of Blood Smear Preparing Apparatus>
The blood smear preparing apparatus 1 aspirates a blood sample and drops it on a slide glass, thinly stretches the blood sample on the slide glass and dries to prepare the smear sample, and then supplies the stain fluid to the smear sample to stain the blood on the slide glass. FIG. 2 is a plan view showing an internal structure of the blood smear preparing apparatus shown in FIG. 1 . The blood smear preparing apparatus 1 is connected with five containers 101 to 105 in which the fluid to be used in the staining process are accommodated. In the present embodiment, May-Grunwald stain solution (concentrated stain fluid), diluted solution (phosphate buffer solution in the present embodiment), Giemsa solution (concentrated stain fluid), methanol solution, and sample cleaning solution are accommodated in the containers 101 to 105 , respectively.
A shown in FIG. 2 , the blood smear preparing apparatus 1 includes a control unit 1 a having a function of controlling the operation for preparing the smear sample of the blood sample. The control unit 1 a includes a CPU 11 and a memory 12 consisting of a ROM and a RAM. As shown in FIG. 1 , the blood smear preparing apparatus 1 includes a display operation unit 2 a including a touch panel, an activation switch 2 b , a power switch 2 c , and a cover 2 d . The control unit 1 a displays various types of information on the display operation unit 2 a . The transport device 2 is arranged to automatically transport a sample rack 50 accommodating a test tube 51 accommodating the blood to the blood smear preparing apparatus 1 .
The overall configuration of the blood smear preparing apparatus 1 will now be described. First, as shown in FIG. 1 , the blood smear preparing apparatus 1 includes a hand member 1 b for transporting the test tube 51 accommodating the blood from the transport device 2 side to the blood smear preparing apparatus 1 side. As shown in FIG. 2 , the blood smear preparing apparatus 1 includes an aspirating and dispensing mechanism section 21 , a smearing section 22 , a resin cassette 23 , a cassette accommodating section 24 , a cassette transporting section 25 , a slide glass inserting section 26 , a staining section 27 , and a storage section 28 .
The aspirating and dispensing mechanism section 21 has a function of aspirating the blood from the test tube 51 transported to the blood smear preparing apparatus 1 side by the hand member 1 b (see FIG. 1 ) and dropping the aspirated blood on a slide glass 10 . As shown in FIG. 2 , the aspirating and dispensing mechanism section 21 includes a piazza (aspiration needle) 21 a for aspirating the blood from the test tube 51 , and a dispensing pipette 21 b for dispensing the aspirated blood on the slide glass 10 .
As shown in FIG. 2 , the smearing section 22 is arranged to supply the slide glass 10 to a dispensing/smearing position 90 , and to smear and dry the blood dropped on the slide glass 10 and print on the slide glass 10 . The resin cassette 23 is configured so as to be able to accommodate the smeared slide glass 10 and the liquid to be used in the staining step. FIG. 3 and FIG. 4 are perspective views showing the cassette and the slide glass used in the blood smear preparing apparatus shown in FIG. 2 . As shown in FIG. 3 and FIG. 4 , the cassette 23 includes a slide glass accommodating hole 23 a and a stain fluid aspirating and dispensing hole 23 b . The slide glass accommodating hole 23 a and the stain fluid aspirating and dispensing hole 23 b are connected inside.
Furthermore, as shown in FIG. 2 , the cassette accommodating section 24 is arranged to convey the cassette 23 into the cassette transporting section 25 , and includes a feed belt 24 a . The cassette transporting section 25 is arranged to transport the cassette 23 conveyed in from the cassette accommodating section 24 to the slide glass inserting section 26 and the staining section 27 . As shown in FIG. 2 , the cassette transporting section 25 includes a cassette transporting member 25 a movable in a horizontal direction (A direction in FIG. 2 ), and a transport path 25 b for transporting the cassette 23 supplied from the cassette accommodating section 24 . As shown in FIG. 2 , the slide glass inserting section 26 is arranged to accommodate the slid glass 10 performed with smearing and printing in the slide glass accommodating hole 23 a of the cassette 23 .
As shown in FIG. 2 , the staining section 27 according to the present embodiment is arranged to perform supply and discharge of the stain fluid and the cleaning solution to the stain fluid aspirating and dispensing hole 23 b of the cassette 23 transported by the cassette transporting member 25 a , and to lift up and dry the slide glass 10 accommodated in the cassette 23 to perform the staining process on the smeared slide glass 10 . The staining section 27 includes a sending member 71 for sending the cassette 23 transported by the cassette transporting member 25 a to the staining section 27 , a transport belt 72 for transporting the cassette 23 sent from the sending member 71 , first to fifth aspirating and discharging units 73 to 77 for performing supply and discharge of the stain fluid and the cleaning solution to the cassette 23 , a fan 78 a for drying the slide glass 10 at the second aspirating and discharging unit 74 , a fan 78 b for drying the stained slide glass 10 , and a send-out mechanism 79 for sending out the cassette 23 from the transport belt 72 to the transport belt 28 a side of the storage section 28 .
The first aspirating and discharging unit 73 will now be described. FIG. 5 is a perspective view showing a first aspirating and discharging unit of the staining section of the blood smear preparing apparatus shown in FIG. 2 . As shown in FIG. 5 , the first aspirating and discharging unit 73 includes a pipette 73 a for supplying the methanol solution to the cassette 23 , a pipette supporting member 73 b for supporting the pipette 73 a , and a drive mechanism 73 e with a motor 73 c and a drive belt 73 d for moving the pipette supporting member 73 b in the up and down direction. The relevant first aspirating and discharging unit 73 is configured to move the pipette 73 a downward by the drive mechanism 73 e to insert into the cassette 23 , and supply the methanol solution. The pipette supporting member 73 b of the first aspirating and discharging unit 73 is attached with a slide glass gripping member 73 f for gripping and lifting up the slide glass 10 from the cassette 23 .
The second aspirating and discharging unit 74 basically has a structure similar to the first aspirating and discharging unit 73 . The third aspirating and discharging unit 75 to the fifth aspirating and discharging unit 77 have a structure in which the slide glass gripping member 73 f is removed from the first aspirating and discharging unit 73 . As shown in FIG. 2 , the second aspirating and discharging 74 to the fifth aspirating and discharging unit 77 respectively includes a pipette 74 a , 75 a , 76 a , and 77 a for supplying May-Grunwald solution, May-Grunwald diluted solution, Giemsa diluted solution, and cleaning solution to the cassette 23 . The pipette 74 a is also used to aspirate (discharge) the methanol solution supplied by the pipette 73 a from the cassette 23 . Similarly, the pipette 75 a is used to aspirate (discharge) the May-Grunwald solution supplied by the pipette 74 a from the cassette 23 , the pipette 76 a is used to aspirate (discharge) the May-Grunwald diluted solution supplied by the pipette 75 a from the cassette 23 , and the pipette 77 a is used to aspirate (discharge) the Giemsa diluted solution supplied by the pipette 76 a from the cassette 23 .
The supply path of the liquid supplied from each pipette 73 a , 74 a , 75 a , and 76 a of the first aspirating and discharging unit 73 to the fourth aspirating and discharging unit 76 of the staining section 27 according to the present embodiment will now be described in detail. FIG. 6 is a fluid circuit diagram showing the supply path of the liquid supplied to the staining section shown in FIG. 2 . As shown in FIG. 6 , four containers 101 to 104 for accommodating the liquid to be supplied to the staining section are arranged on the supply path according to the present embodiment. Specifically, May-Grunwald solution serving as the concentrated stain fluid is accommodated in the container 101 , the diluted solution (phosphate buffer solution) is accommodated in the container 102 , the Giemsa solution serving as the concentrated stain fluid is accommodated in the container 103 , and the methanol solution is accommodated in the container 104 .
As shown in FIG. 6 , the container 101 accommodating the May-Grunwald solution serving as the concentrated stain fluid is connected to the pipette 74 a of the second aspirating and discharging unit 74 through a valve 111 , a valve 112 , a chamber 113 , and a valve 114 . An air pressure adjustor 115 is connected to the chamber 113 . The valve 114 is connected to a diaphragm pump 117 connected to an air pressure adjustor 116 .
The chamber 113 is arranged on the lower side of the blood smear preparing apparatus 1 (not shown). As shown in FIG. 6 , the chamber 113 is configured by a tank 113 b interiorly including a float switch 113 a . When the liquid in the tank 113 b reaches a defined amount, the float switch 113 a detects the same. The air pressure adjustor 115 has a function of pressurizing and depressurizing the interior of the chamber 113 , to which the air pressure adjustor 115 is connected. The diaphragm pump 117 has a function of aspirating and discharging a constant amount of solution. A plurality of air pressure adjustors and diaphragm pumps installed in the fluid path according to the present embodiment have functions similar to the air pressure adjustor 115 and the diaphragm pump 117 .
The container 101 is also connected to the pipette 75 a of the third aspirating and discharging unit 75 through the valve 111 , the valve 112 , the chamber 113 , a valve 121 , and a mixed chamber 122 , and a valve 123 . The valve 121 is connected with a diaphragm pump 125 connected to an air pressure adjustor 124 . The valve 123 is connected to a diaphragm pump 127 connected to an air pressure adjustor 126 . The container 102 accommodating the diluted solution (phosphate buffer solution) is connected to the mixed chamber 122 through a valve 131 . The valve 131 is connected with a diaphragm pump 133 connected to an air pressure adjustor 132 . The mixed chamber 122 is arranged to mix the May-Grunwald solution or the concentrated stain fluid accommodated in the container 101 and the diluted solution (phosphate buffer solution) accommodated in the container 102 .
The container 103 accommodating the Giemsa solution serving as the concentrated stain fluid is connected to the pipette 76 a of the fourth aspirating and discharging unit 76 through a valve 141 , a valve 142 , a chamber 143 , a valve 144 , a mixed chamber 145 , and a valve 146 . An air pressure adjustor 147 is connected to the chamber 143 . The valve 144 is connected to a diaphragm pump 149 connected to an air pressure adjustor 148 . The valve 146 is connected to a diaphragm pump 151 connected to an air pressure adjustor 150 . The chamber 143 has a structure similar to the chamber 113 and interiorly includes a float switch 143 a . The chamber 143 is arranged on the lower side of the blood smear preparing apparatus 1 (not shown). As shown in FIG. 6 , the container 102 accommodating the diluted solution is connected to the mixed chamber 145 through a valve 134 . The valve 134 is connected with a diaphragm pump 136 connected to an air pressure adjustor 135 . The mixed chamber 145 is arranged to mix the Giemsa solution or the concentrated stain fluid accommodated in the container 103 and the diluted solution accommodated in the container 102 .
The mixed chamber 122 is connected to a waste chamber 163 through a valve 161 , and the mixed chamber 145 is connected to the waste chamber 163 through a valve 162 . The waste chamber 163 is connected with an air pressure adjustor 164 . The waste chamber 163 has a structure similar to the chamber 113 and interiorly include a float switch 163 a . The float switch 163 a of the waste chamber 163 is arranged to detect whether or not the discharge of the waste solution stored in the waste chamber 163 is accurately carried out. The chamber 113 , the chamber 143 , and the waste chamber 163 are respectively connected to discharge ports 174 , 175 , 176 through valves 171 , 172 , and 173 .
The container 104 accommodating the methanol solution is connected at the middle of the supply path of the May-Grunwald solution from the container 101 , which accommodates the May-Grunwald solution, to the chamber 113 through a valve 181 . The container 104 accommodating the methanol solution is connected at the middle of the supply path of the Giemsa solution from the container 103 , which accommodates the Giemsa solution, to the chamber 143 through a valve 182 .
In the present embodiment, the container 104 accommodating the methanol solution is connected to the pipette 73 a of the first aspirating and discharging unit 73 through a valve 191 , as shown in FIG. 6 . The valve 191 is connected with the diaphragm pump 193 connected to the air pressure adjustor 192 . Thus, the methanol solution for cleaning accommodated in the container 104 can be supplied to the smear sample (slide glass 10 ) of the first aspirating and discharging unit 73 of the staining section 27 by arranging a path from the container 104 to the pipette 73 a of the first aspirating and discharging unit 73 through the valve 191 .
The storage section 28 shown in FIG. 2 is arranged to store the cassette 23 in which a stained slide glass 10 , which is stained by the staining section 27 , is accommodated. The storage section 28 includes a transport belt 28 a for transporting the cassette 23 .
FIG. 7 is a schematic view showing the configuration of the staining section 27 of the blood smear preparing apparatus 1 according to the present embodiment. The control unit 1 a is connected to the motors 73 c to 77 c arranged in the first to fifth aspirating and discharging units 73 to 77 , respectively, and drive controls such motors 73 c to 77 c . Each motor 73 c to 77 c is coupled to the pipette 73 a to 77 a respectively, so that the pipettes 73 a to 77 a move up and down by the operation of the motors 73 c to 77 c . Furthermore, the pipettes 73 a to 77 a perform the aspirating and discharging operation of the fluid by the fluid circuit described above. As described above, the methanol solution, the concentrated May-Grunwald solution, the diluted May-Grunwald solution, the diluted Giemsa solution, and the cleaning solution are respectively supplied to the pipettes 73 a to 77 a.
According to the above configuration, the staining of the smear sample in the blood smear preparing apparatus 1 is generally proceeded in the following manner. First, the immobilization step of immersing the smeared slide glass 10 in the methanol solution or May-Grunwald solution (undiluted solution) for a predetermined time (hereinafter referred to as “immobilization time”) is carried out, and then a first staining step of immersing the smeared and immobilized slide glass 10 in the diluted May-Grunwald solution (hereinafter referred to as “first stain fluid”) for a predetermined time (hereinafter referred to as “first staining time”) is carried out, a second staining step of immersing the slide glass 10 terminated with the first staining step in the Giemsa diluted solution (hereinafter referred to as “second stain fluid”) for a predetermined time (hereinafter referred to as “second staining time”) is carried out, and lastly, a cleaning step of cleaning the slide glass 10 is carried out.)
Such blood smear preparing apparatus 1 has a configuration in which the staining condition of the smear sample can be set. The staining condition here is the dilution magnification and the staining time of the concentrated stain fluid. The dilution magnification of the concentrated stain fluid can be set to one of five times, ten times, or twenty times, where the default value is ten times. The average nucleus G value is assumed to change by 30 if the dilution magnification of the concentrated stain fluid is changed one stage. That is, the average nucleus G value is assumed to increase by 30 if the dilution magnification is lowered one stage from ten times to five times or from twenty times to ten times, and the average nucleus G value is assumed to decrease by 30 if the dilution magnification is raised one stage from five times to ten times or from ten times to twenty times. The average nucleus G value is the average value of the G value of the region of the nucleus of the white blood cells in a plurality of blood cell images obtained by imaging the smear sample prepared by the blood smear preparing apparatus 1 with the sample imaging apparatus 3 .
The staining time can be set in 11 stages. The staining time that can be set includes the first staining time and the second staining time described above. The setting of the staining time is a combination of the first staining time and the second staining time, and one of the 11 ways of combinations can be set. That is, the first staining time and the second staining time cannot be independently setting changed, and the first staining time and the second staining time are both setting changed. The default value of the staining time is the combination of 5 minutes for the first staining time and 20 minutes for the second staining time, where the first staining time can be setting changed by 0.5 minutes and the second staining time can be setting changed by 2.5 minutes. The lower limit value of the staining time is a combination of 2.5 minutes for the first staining time and 7.5 minutes for the second staining time. The upper limit value of the staining time is a combination of 7.5 minutes for the first staining time and 32.5 minutes for the second staining time. If the staining time is changed one stage, the average nucleus G value is assumed to change by five. For instance, the average nucleus G value increases by five if the default value of “first staining time of 5 minutes and second staining time of 20 minutes” is changed to one stage higher or “first staining time of 5.5 minutes and second staining time of 22.5 minutes”, and the average nucleus G value decreases by five if changed to one stage lower or “first staining time of 4.5 minutes and second staining time of 17.5 minutes”.
<Configuration of Sample Transport Device>
As shown in FIG. 1 , the sample transport device 6 is arranged between the blood smear preparing apparatus 1 and the sample imaging apparatus 3 . The sample transport device 6 is arranged to transport the slide glass 10 accommodated in the cassette received from the blood smear preparing apparatus 1 to the sample imaging apparatus 3 . As shown in FIG. 1 , the sample transport device 6 includes a display unit 6 a and a power switch 6 b and a cover 6 c . The sample transport device 6 is configured to convey out the slide glass 10 to be imaged to the sample imaging apparatus 3 through the convey-out port 6 d.
<Configuration of Sample Imaging Apparatus>
FIG. 8 is a block diagram showing the configuration of the sample imaging apparatus according to the present embodiment. FIG. 8 schematically shows the configuration of the apparatus, where the arrangement of the sensor, the slide cassette, and the like is slightly different from the actual to facilitate the understanding. For instance, in FIG. 8 , the sensor for WBC detection and the sensor for autofocus are arranged above and below, but both sensors are actually arranged in substantially the same plane, as shown in FIG. 9 .
The sample imaging apparatus 3 includes a microscope unit 3 a for imaging an enlarged image of the blood smear sample focused by autofocus, and an image processing unit 3 b for processing the imaged image to classify the white blood cells in the blood and counting for every classification of the white blood cells. The sample transport device 6 is arranged near the sample imaging apparatus 3 , so that the blood smear sample prepared by the blood smear preparing apparatus 1 is automatically supplied to the microscope unit 3 a by the sample transport device 6 .
<Configuration of Microscope Unit 3 a>
FIG. 9 is a perspective view showing one part of the configuration of the microscope unit 3 a . The microscope unit 3 a includes an objective lens 32 configuring one part of the lens system of the microscope for enlarging the image of the blood thinly stretched and applied on the slide glass 10 mounted on the XY stage 31 . The XY stage 31 for holding the sample (slide glass 10 having the blood applied on the upper surface) is freely movable forward, backward, leftward, and rightward (X direction and Y direction) by a drive unit (not shown) drive controlled by the XY stage drive circuit 33 (see FIG. 8 ). The objective lens 32 is freely movable up and down (Z direction) by the drive unit (not shown) drive controlled by the objective lens drive circuit 34 .
A plurality of slide glasses 10 is accommodated in the slide cassette 35 in a stacked manner, and such slide cassette 35 is transported by the transport unit (not shown) drive controlled by the cassette transport drive circuit 36 . A chuck unit 37 (see FIG. 9 ) capable of gripping two areas near the ends in the longitudinal direction of the slide glass 10 is arranged on the XY stage 31 in a freely advancing and retreating manner with respect to the slide glass 10 accommodated in the slide cassette 35 stopped at a predetermined position. The slide glass 10 can be gripped by the chuck unit 37 , and the chuck unit 37 can be retreated to pull out the slide glass 10 from the slide cassette 35 and arrange it at a predetermined position of the XY stage 31 .
A lamp 38 or a light source is arranged on the lower side of the slide glass 10 , where the light from the lamp 38 passes the blood on the slide glass 10 , and then enters the line sensor 311 for autofocus in which a plurality of pixels is lined in a line, the sensor 312 for white blood cell (WBC) detection in which a plurality of pixels is lined in a line, and the CCD camera 313 through the half mirror 39 and the interference filter 310 arranged on the optical path. The white blood cell detection unit 314 configured by FPGA, ASIC, or the like is connected to the sensor 312 for white blood cell detection, so that the white blood cells are detected by the white blood cell detection unit 314 based on the output signal of the sensor 312 . The focus calculating unit 315 configured by FPGA, ASIC, or the like is connected to the sensor 311 for autofocus, so that the information used in the operation of the autofocus is calculated by the focus calculating unit 315 based on the output signal of the sensor 311 and the operation of the autofocus is carried out based on the relevant information.
The microscope unit 3 a includes a control unit 316 and communication interfaces 317 , 318 . The control unit 316 includes a CPU and a memory, where the control unit 316 executes the control program stored in the memory to control each mechanism described above.
The communication interface 317 is data communicably connected to the image processing unit 3 b through the communication cable. The communication interface 318 is connected to the CCD camera 313 through the A/D converter 313 a , and is also connected to the image processing unit 3 b through the communication cable. The image signal (analog signal) output from the CCD camera 313 is A/D converted by the A/D converter 313 a , and the image data (digital data) output from the A/D converter 313 a is provided to the communication interface 318 and transmitted to the image processing unit 3 b.
The microscope unit 3 a includes a two-dimensional barcode reader 319 . As described above, a two-dimensional barcode indicating the sample ID is printed on the frost part (not shown) of the slide glass 10 , and the two-dimensional barcode of the slide glass 10 introduced to the microscope unit 3 a is read by the two-dimensional barcode reader 319 .
<Configuration of Image Processing Unit 3 b>
The configuration of the image processing unit 3 b will now be described. FIG. 10 is a block diagram showing the configuration of the image processing unit 3 b . The image processing unit 3 b is realized by a computer 320 . As shown in FIG. 10 , the computer 320 includes a main body 321 , an image display unit 322 , and an input unit 323 . The main body 321 includes a CPU 321 a , a ROM 321 b , a RAM 321 c , a hard disc 321 d , a read-out device 321 e , an input/output interface 321 f , a communication interface 321 g , and an image output interface 321 j , where the CPU 321 a , the ROM 321 b , the RAM 321 c , the hard disc 321 d , the read-out device 321 e , the input/output interface 321 f , the communication interface 321 g , and the image output interface 321 j are connected by a bus 321 k.
The read-out device 321 e can read out the computer program 324 a for functioning the computer as the image processing unit 3 b from the portable recording medium 324 , and install the computer program 324 a in the hard disc 321 d.
The image processing unit 3 b stores the image transmitted from the microscope unit 3 a in the ROM 321 b or the hard disc 321 d . The CPU 321 a causes the image display unit 322 to display the stored image in accordance with the operation from the user. The CPU 321 a also analyzes the stored image and causes the image display unit 322 to display the analysis result in accordance with the operation from the user.
[Operation of Smear Processing System]
The operation of the smear processing system 100 according to the present embodiment will now be described. In the blood smear preparing apparatus 1 , the concentrated stain fluid or the diluted solution need to be replaced to a new one if the concentrated stain fluid or the diluted solution is gone or the expiration date for use is overdue. The concentration of the concentrated stain fluid differs depending on the manufacturer. The concentration also differs for every manufacturing lot even if the concentrated stain fluid is manufactured by the same manufacturer. Therefore, the degree of staining tends to differ if the sample is stained under the same staining condition (staining time and dilution magnification) before and after the concentrated stain fluid is replaced. In the blood smear preparing apparatus 1 according to the present embodiment, therefore, the staining conditions are set in the following manner when changing the stain fluid.
FIG. 11 is a flowchart showing the flow of operation of changing the concentrated stain fluid of the blood smear preparing apparatus 1 according to the present embodiment. First, the CPU 11 of the control unit 1 a of the blood smear preparing apparatus 1 determines whether or not the concentrated stain fluid needs to be replaced (step S 101 ). In this process, determination is made that the May-Grunwald solution needs to be replaced if the supply of the May-Grunwald solution to the chamber 113 is not detected by the float switch 113 a even though the valves 111 , 112 are opened, and determination is made that the Giemsa solution needs to be replaced if the supply of the Giemsa solution to the chamber 143 is not detected by the float switch 143 a even though the valves 141 , 142 are opened. The expiration date for use of the May-Grunwald solution and the Giemsa solution are respectively stored in the memory 12 of the control unit 1 a , so that the need to replace the concentrated stain fluid can be determined by having the CPU 11 determine whether the date for use has expired. If the concentrated stain fluid does not need to be replaced (NO in step S 101 ), the CPU 11 repeats the process of step S 101 . If determined that the concentrated stain fluid needs to be replaced (YES in step S 101 ), the CPU 11 displays an error message notifying that the concentrated stain fluid needs to be replaced on the display operation unit 2 a (step S 102 ).
The CPU 11 determines whether or not the concentrated stain fluid is replaced (step S 103 ). Determination is made that the concentrated stain fluid is replaced when the error message displayed on the display operation unit 2 a is closed by the operator. If the concentrated stain fluid is not replaced (NO in step S 103 ), the CPU 11 repeats the process of step S 103 . If determined that the concentrated stain fluid is replaced (YES in step S 103 ), the CPU 11 displays the OK button and the NO button on the display operation unit 2 a along with the message “Concentrated stain fluid is replaced. Perform test staining?”, and determines whether or not the execution of the test staining is instructed (step S 104 ). When the selection of the OK button is detected and the instruction to execute the test staining is made (YES in step S 104 ), the CPU 11 proceeds the process to step S 105 . When the selection of the NO button is detected, and the instruction not to execute the test staining is made (NO in step S 104 ), the CPU 11 terminates the process. In this case, the setting of the staining conditions is not replaced, and the staining conditions up to now are maintained.
In step S 105 , the CPU 11 executes the sample preparing process (step S 105 ). In the sample preparing process, the blood is aspirated by the aspirating and dispensing mechanism section 21 from the test tube 51 transported by the transport device 2 , and the aspirated blood is dropped on the slide glass 10 .
The blood used in the test staining is preferably a fresh blood collected from a healthy person. The fresh blood collected from the healthy person is preferably the blood which measurement value of each measurement item falls within a predetermined range when measured with respect to a plurality of measurement items in the blood cell analyzer and the blood collected within 24 hours.
As hereinafter described, the smear sample stained by the test staining is supplied to the sample imaging apparatus 3 , and the average nucleus G value indicating the stain state of the relevant smear sample is obtained. The average nucleus G value is obtained by acquiring the nucleus G value of the neutrophil cells of the white blood cells for a plurality of neutrophil cells, and obtaining the average value of the plurality of nucleus G values. The neutrophil cells are blood cells that occupy 60% of the white blood cells and are always contained in the blood collected from the healthy person, where barely any difference is recognized in the aspect of the neutrophil cells (e.g., easiness to stain) between the samples unless the blood is not degraded. Therefore, a stable average nucleus G value is always obtained only when the fresh blood collected from the healthy person is used in the test staining.
The blood dropped on the slide glass 10 is smeared on the slide glass 10 by the smearing section 22 and then dried. The smear sample obtained in such manner is inserted to the cassette 23 , and the test staining is carried out by the staining steps described above in the staining section 27 . In the test staining, the staining conditions of the default values are used. That is, the dilution magnification of the concentrated stain fluid is ten times, the first staining time is five minutes, and the second staining time is 20 minutes.
The test staining process will be described in detail. First, when the slide glass 10 that is smeared with the sample is sent to the staining section 27 , the immobilization step described above is carried out. In the immobilization step, the methanol solution or the concentrated May-Grunwald solution is discharged into the cassette 23 , to which the slide glass 10 is inserted, when the pipette 73 a of the first aspirating and discharging unit 73 or the pipette 74 a of the second aspirating and discharging unit 74 are operated. The slide glass 10 that is smeared with the sample is immersed in the methanol solution or the concentrated May-Grunwald solution until the immobilization time has elapsed from when the methanol solution or the May-Grunwald solution is supplied into the cassette 23 . After the immobilization time has elapsed from when the methanol solution or the May-Grunwald solution is supplied into the cassette 23 , the smeared slide glass 10 is lifted up from the slide glass accommodation hole 23 a of the cassette 23 by the second aspirating and discharging unit 74 , and the air is blown to the smear surface of the slide glass 10 by the fan 78 a to dry the fluid component on the smear surface. The immobilization process of the smear sample by the methanol solution is thereby terminated. The time (immobilization time) from when the smeared slide glass 10 is immersed in the methanol solution or the undiluted May-Grunwald solution until the slide glass 10 is lifted up by the second aspirating and discharging unit 74 is about 20 seconds to about 120 seconds. The methanol solution or the May-Grunwald solution inside the cassette 23 is discharged. This is carried out when the methanol solution is aspirated by the pipette 74 a if the methanol solution is supplied into the cassette 23 , and carried out when the May-Grunwald solution is aspirated by the pipette 75 a if the May-Grunwald solution is supplied into the cassette 23 . Thereafter, the slide glass 10 is returned to the slide glass accommodation hole 23 a of the cassette 23 .
The first staining step is then carried out. When supplying the diluted May-Grunwald solution (undiluted solution of first stain fluid) to the pipette 75 a of the third aspirating and discharging unit 75 , the flow path between the chamber 113 and the diaphragm pump 125 is in the open state by the valve 121 shown in FIG. 6 . The interior of the diaphragm pump 125 is depressurized by the air pressure adjustor 124 . A constant amount of the May-Grunwald solution of the chamber 113 is aspirated by the diaphragm pump 125 . Thereafter, the flow path between the diaphragm pump 125 and the mixed chamber 122 is in the opened state by the valve 121 . The interior of the diaphragm pump 125 is pressurized by the air pressure adjustor 124 . The May-Grunwald solution of the diaphragm pump 125 is moved to the mixed chamber 122 . Thereafter, the flow path between the diaphragm pump 125 and the mixed chamber 122 is in the shielded state by the valve 121 . The movement of the May-Grunwald solution of the chamber 113 to the mixed chamber 122 is thereby terminated.
The diluted solution (phosphate buffer solution) of the container 102 is then moved to the mixed chamber 122 to dilute the May-Grunwald solution of the mixed chamber 122 . Specifically, the flow path between the container 102 and the diaphragm pump 133 is in the opened state by the valve 131 . The interior of the diaphragm pump 133 is depressurized by the air pressure adjustor 132 . A constant amount of the diluted solution of the container 102 is aspirated by the diaphragm pump 133 . Thereafter, the flow path between the diaphragm pump 133 and the mixed chamber 122 is in the opened state by the valve 131 . The interior of the diaphragm pump 133 is pressurized by the air pressure adjustor 132 . The diluted solution of the diaphragm pump 133 is moved to the mixed chamber 122 . Thereafter, the flow path between the diaphragm pump 133 and the mixed chamber 122 is in the shielded state by the valve 131 . The movement of the diluted solution of the container 102 to the mixed chamber 122 is terminated. The first stain fluid of the dilution magnification of ten times, which is the default value, is prepared by controlling the repeating number of times of the constant amount supplying operation of the May-Grunwald solution and the diluted solution to the mixed chamber 122 .
After the flow path between the mixed chamber 122 and the diaphragm pump 127 is opened by the valve 123 , the interior of the diaphragm pump 127 is depressurized by the air pressure adjustor 126 . A constant amount of the first stain fluid of the mixed chamber 122 is thereby aspirated by the diaphragm pump 127 . Thereafter, the flow path between the diaphragm pump 127 and the mixed chamber 122 is shielded, and the flow path between the diaphragm pump 127 and the pipette 75 a of the third aspirating and discharging unit 75 is opened by the valve 123 . The interior of the diaphragm pump 127 is pressurized by the air pressure adjustor 126 . The first stain fluid in the diaphragm pump 127 is supplied from the pipette 75 a of the third aspirating and discharging unit 75 to the cassette 23 (see FIG. 2 ).
The slide glass 10 that is smeared with the sample is immersed in the first stain fluid while the cassette 23 is transported by the transport belt 72 and the staining of the sample by the first stain fluid is carried out until the first staining time has elapsed from when the first stain fluid is supplied into the cassette 23 . In the test staining, the first staining time is five minutes, which is the default value. After the elapse of the first staining time, the first stain fluid is aspirated by the pipette 76 a and the first stain fluid in the cassette 23 is discharged.
The second staining step is then carried out. When supplying the Giemsa diluted solution (undiluted solution of second stain fluid) to the pipette 76 a of the fourth aspirating and discharging unit 76 of the staining section 27 , the valves 141 and 142 shown in FIG. 6 are first opened from the initial state (all valves are shielded), and the interior of the chamber 143 is depressurized by the air pressure adjustor 147 . The Giemsa solution of the container 103 is thereby aspirated to the chamber 143 . The float switch 143 a installed in the chamber 143 is turned ON with the flow of the Giemsa solution to the chamber 143 . The valves 141 and 142 are then shielded, and the depressurization by the air pressure adjustor 147 is released. The movement of the Giemsa solution of the container 103 to the chamber 143 is then terminated.
The Giemsa solution of the chamber 143 is moved to the mixed chamber 145 . Specifically, the flow path between the chamber 143 and the diaphragm pump 149 is first opened by the valve 144 . The interior of the diaphragm pump 149 is depressurized by the air pressure adjustor 148 . A constant amount of Giemsa solution of the chamber 143 is thereby aspirated by the diaphragm pump 149 . Thereafter, the flow path between the diaphragm pump 149 and the mixed chamber 145 is in the opened state by the valve 144 . The interior of the diaphragm pump 149 is pressurized by the air pressure adjustor 148 . The Giemsa solution of the diaphragm pump 149 is moved to the mixed chamber 145 . Thereafter, the flow path between the diaphragm pump 149 and the mixed chamber 145 is in the shielded state by the valve 144 . The movement of the Giemsa solution of the chamber 143 to the mixed chamber 145 is then terminated.
The diluted solution (phosphate buffer solution) of the container 102 is then moved to the mixed chamber 145 to dilute the Giemsa solution of the mixed chamber 145 . Specifically, the flow path between the container 102 and the diaphragm pump 136 is in the opened state by the valve 134 . The interior of the diaphragm pump 136 is depressurized by the air pressure adjustor 135 . A constant amount of the diluted solution of the container 102 is aspirated by the diaphragm pump 136 . Thereafter, the flow path between the diaphragm pump 136 and the mixed chamber 145 is in the opened state by the valve 134 . The interior of the diaphragm pump 136 is pressurized by the air pressure adjustor 135 . The diluted solution of the diaphragm pump 136 is moved to the mixed chamber 145 . Thereafter, the flow path between the diaphragm pump 136 and the mixed chamber 145 is in the shielded state by the valve 134 . The movement of the diluted solution of the container 102 to the mixed chamber 145 is terminated. The Giemsa solution is mixed with the diluted solution in the mixed chamber 145 to become the Giemsa diluted solution (second stain fluid). The second stain fluid of the dilution magnification of ten times, which is the default value, is prepared by controlling the repeating number of times of the constant amount supplying operation of the Giemsa solution and the diluted solution to the mixed chamber 145 .
After the flow path between the mixed chamber 145 and the diaphragm pump 151 is opened by the valve 146 , the interior of the diaphragm pump 151 is depressurized by the air pressure adjustor 150 . A constant amount of the second stain fluid of the mixed chamber 145 is thereby aspirated by the diaphragm pump 151 . Thereafter, the flow path between the diaphragm pump 151 and the mixed chamber 145 is shielded, and the flow path between the diaphragm pump 151 and the pipette 76 a of the fourth aspirating and discharging unit 76 is opened by the valve 146 . The interior of the diaphragm pump 151 is pressurized by the air pressure adjustor 150 . The Giemsa diluted solution in the diaphragm pump 151 is supplied from the pipette 76 a of the fourth aspirating and discharging unit 76 to the cassette 23 (see FIG. 2 ).
The slide glass 10 is then immersed in the second stain fluid while the cassette 23 is transported by the transport belt 72 and the staining of the sample by the second stain fluid is carried out until the second staining time has elapsed from when the second stain fluid is supplied into the cassette 23 . In the test staining, the second staining time is twenty minutes, which is the default value. After the elapse of the second staining time, the second stain fluid is aspirated by the pipette 77 a and the second stain fluid in the cassette 23 is discharged.
The cleaning step is then carried out. After the cleaning solution is dispensed to the stain fluid aspirating and dispensing hole 23 b of the cassette 23 by the pipette 77 a , the stained slide glass 10 aspirated by the pipette 77 a is cleaned. The stained slide glass 10 is then dried with the fan 78 b . The staining process is thereby completed.
The cassette 23 accommodating the stained slide glass 10 is then sequentially sent to the transport belt 28 a of the storage section 28 from the transport 72 . The cassette 23 is transported by the transport belt 28 a of the storage section 28 .
After the relevant sample preparing process is completed, the stained smear sample that is prepared is automatically supplied from the blood smear preparing apparatus 1 to the microscope unit 3 a by the sample transport device 6 . FIG. 12 is a flowchart showing the flow of the blood cell imaging and the image analyzing operation of the sample imaging apparatus 3 according to the present embodiment. The sample imaging apparatus 3 detects the white blood cells in the blood applied to the slide glass 10 with the sensor 312 while moving the slide glass 10 in the X direction and the Y direction with the XY stage 31 (step S 201 ). The control unit 316 then executes the autofocus operation (step S 202 ), and images the stained blood cells (step S 203 ).
The control unit 316 transmits the obtained blood cell image to the image processing unit 3 b . The CPU 321 a of the image processing unit 3 b stores the received blood cell image in the ROM 321 b or the hard disc 321 d , and calculates various characteristic parameters of the white blood cells based on the blood cell image (step S 204 ). The characteristic parameter includes the area, the number of nucleus, the bumps, the color tone, and the concentration (unevenness) of the nucleus of the white blood cell that can be obtained based on the color signal (G, B, R) of the image, the area, the color tone, and the concentration (unevenness) of the cell cytoplasm of the white blood cells, as well as the area ratio and the concentration ratio of the nucleus and the cell cytoplasm.
The CPU 321 a then classifies the type of white blood cells based on the acquired characteristic parameter (step S 205 ). Specifically, for example, the types of white blood cells can be gradually narrowed down by sequentially comparing with the criterion value defined in advance for each parameter with respect to some of the characteristic parameters of the white blood cells. The imaged white blood cells is thus subjected to the classification of mature white blood cells such as lymphocytes, monocytes, acidocytes, basocytes, neutrophil cells (bacillary, lobulated), and the classificaiton of immature white blood cells such as gemmules, young granulocytes, and atypical lymphocytes, and the classification of erythoblasts.
FIG. 13 is a view showing an example of the blood cell image. A blood cell image 160 A of when the May Giemsa staining is performed includes a blood cell image 161 with a nucleus region 161 a and a cytoplasm region 161 b . The nucleus region 161 a of the blood cell image 160 A has different color shades depending on the concentration of the stain fluid and the staining time. The luminance value of the specific color component (green component in the present embodiment) of the nucleus region 161 a represents the characteristic of the nucleus region 161 a of the blood cell image and shows the stain state of the blood cell.
The image processing unit 3 b acquires the stain state information showing the stain state. This will be specifically described below. The CPU 321 a determines whether or not the white blood cells in the blood cell image is classified to the neutrophil cells based on the classification of step S 205 (step S 206 ). If the white blood cells are classified to the neutrophil cells (YES in step S 206 ), the luminance value (hereinafter referred to as G value) of the green component is acquired of the color components (red: R, green: G, blue: B) of each pixel in the nucleus region of the white blood cells in the blood cell image after the correction, the average value of the G values acquired for all the pixels of the nucleus region is calculated, and the obtained value (nucleus G value) is stored in the RAM 321 c (step S 207 ). The CPU 321 a then proceeds the process to step S 208 .
If the white blood cells in the blood cell image are not classified to the nuetrophil cells in step S 206 (NO in step S 206 ), the CPU 321 a proceeds the process to step S 208 . In step S 208 , the CPU 321 a determines whether or not the nucleus G value is calculated for a predetermined number (e.g., 100) of blood cell images (step S 208 ). If a predetermined number of nucleus G value is not obtained (NO in step S 208 ), the process returns to step S 201 , and the processes of steps S 201 to S 208 are again executed.
If a predetermined number of nucleus G values is obtained (YES in step S 208 ), the CPU 321 a calculates the average nucleus G value or the average value of the obtained nucleus G values (step S 209 ). The average nucleus G value becomes the information indicating the stain state of the smear sample stained according to the default staining condition in the staining section 27 . The CPU 321 a displays the obtained blood cell image and the average nucleus G value on the image display unit 322 (step S 210 ), and terminates the process.
Returning back to FIG. 11 , after the sample preparing process of step S 105 is completed, the CPU 11 of the blood smear preparing apparatus 1 displays an input receiving screen for receiving the input of the nucleus G value to become the target (hereinafter referred to as “target nucleus G value”) and the average nucleus G value displayed on the image processing unit 3 b on the display operation unit 2 a (step S 106 ). FIG. 14 is a view showing the input receiving screen. The input receiving screen 200 includes an input area 201 for inputting the target nucleus G value, an input area 202 for inputting the average nucleus G value, and a software key 203 for inputting numbers and the like. The target nucleus G value and the average nucleus G value are respectively a numerical value in the range of 0 to 125. Thus, the numerical value in the range of 0 to 125 can be input to the input areas 201 , 202 . The user operates the software key 203 displayed on the display operation unit 2 a to input the target nucleus G value showing the nucleus G value of the appropriately stained smear sample to the input area 201 , and to input the average nucleus G value displayed on the image processing unit 3 b to the input area 202 , and selects the enter key. The CPU 11 determines whether or not the inputs of the target nucleus G value and the average nucleus G value are received (step S 107 ), and repeats the process of step S 107 until input if the target nucleus G value and the average nucleus G value are not input (NO in step S 107 ). If the target nucleus G value and the average nucleus G value are input (YES in step S 107 ), the CPU 11 executes the following staining condition setting process (step S 108 ). If the target nucleus G value is not input and the average nucleus G value is input, the target nucleus G value of default value (e.g., 70) is automatically set.
The nucleus G value indicating the stain state of the appropriately stained smear sample is input for the target nucleus G value. The nucleus G value of the stained smear sample subjected to staining before changing the concentrated stain fluid can be used for such nucleus G value. Such operation is carried out in the following manner.
A plurality of blood cells images of the neutrophil cells obtained by imaging the stained smear sample stained before changing the concentrated stain fluid is stored in the image processing unit 3 b of the sample imaging apparatus 3 . The user operates the image processing unit 3 b to display the stored blood cell images on the image display unit 322 , and selects a plurality of blood cell images stained to the desired stain state. The blood cell image selected here is preferably the blood cell image obtained by imaging the smear sample prepared using a fresh blood collected from a healthy person and then stained. The plurality of blood cells images to be selected may be obtained from one stained smear sample or may be respectively obtained from different stained smear samples, and are not particularly limited.
The user instructs the image processing unit 3 b to execute the process (process of step S 207 of FIG. 12 ) for obtaining the average nucleus G value of the plurality of selected blood cell images. The image processing unit 3 b obtains the nucleus G value for each of the plurality of blood cell images, and displays the average value thereof on the image display unit 322 . The user inputs the displayed value in the input receiving screen as the target nucleus G value.
The staining condition capable of realizing substantially the same stain state as the desired stain state obtained before changing the concentrated stain fluid can be set by inputting the target nucleus G value and setting the staining conditions.
FIG. 15A and FIG. 15B are flowcharts showing the flow of the staining condition setting process. The CPU 11 performs a calculation to subtract the average nucleus G value from the input target nucleus G value to calculate a difference A (step S 111 ). The CPU 11 then determines whether or not the difference A is zero (step S 112 ), and sets the dilution magnification and the staining time (first staining time and second staining time), which are the staining conditions, to default values (step S 113 ) if the difference A is zero (YES in step S 112 ), and returns the process to the call-out address of the staining condition setting process in the main routine.
If the difference A is not zero (NO in step S 112 ), the CPU 11 determines whether or not the difference A is greater than zero (positive) (step S 114 ), and determines whether or not the difference A is greater than or equal to 30 (step S 115 ) if the difference A is positive (YES in step S 114 ). If the difference A is greater than or equal to 30 (YES in step S 115 ), the CPU 11 determines whether or not the difference A is greater than 55 (step S 116 ). If the difference A is greater than 55 (YES in step S 116 ), abnormality that cannot be handled by changing the staining condition is assumed to have occurred, and hence the CPU 11 causes the display operation unit 2 a to display the error message (step S 117 ) and returns the process to the call-out address of the staining condition setting process in the main routine.
If the difference is greater than or equal to 30 and smaller than or equal to 55 (NO in step S 116 ), the CPU 11 performs a calculation of subtracting 30 from the difference A and dividing the result thereof by five (step S 118 ). If there is a remained in the process of step S 118 , such remained is cut off. That is, an integer in the range of 0 to 5 is obtained in the process of step S 118 . The CPU 11 then sets the staining conditions (step S 119 ). In the process of step S 119 , the dilution magnification is lowered by one stage and the staining time is raised by the number obtained in the process of step S 118 . That is, the dilution magnification is set to 5 times, which is one stage lower than the default value of ten times, and the staining time is set to a value higher than the default value of five minutes for the first staining time and twenty minutes for the second staining time by the number obtained in the process of step S 118 , and the set values are stored in the memory 12 . After the setting of the staining conditions is completed, the CPU 11 returns the process to the call-out address of the staining condition setting process in the main routine.
If the difference A is smaller than 30 in step S 115 (NO in step S 115 ), the CPU 11 performs a calculation of dividing the difference A by five (step S 120 ). If there is a remained in the process of step S 120 , such remained is cut off. That is, an integer in the range of 0 to 5 is obtained in the process of step S 120 . The CPU 11 then sets the staining conditions (step S 121 ). In the process of step S 121 , the dilution magnification is not changed and the staining time is raised by the number obtained in the process of step S 120 . That is, the dilution magnification is set to the default value of ten times, and the staining time is set to a value higher than the default value of five minutes for the first staining time and twenty minutes for the second staining time by the number obtained in the process of step S 120 , and the set values are stored in the memory 12 . After the setting of the staining conditions is completed, the CPU 11 returns the process to the call-out address of the staining condition setting process in the main routine.
If the difference A is negative in step S 114 (NO in step S 114 ), the CPU 11 determines whether or not the difference A is smaller than or equal to −30 (step S 122 ). If the difference A is smaller than or equal to −30 (YES in step S 122 ), the CPU 11 determines whether or not the difference A is smaller than −55 (step S 123 ). If the difference A is smaller than −55 (YES in step S 123 ), abnormality that cannot be handled by changing the staining condition is assumed to have occurred, and hence the CPU 11 causes the display operation unit 2 a to display the error message (step S 124 ) and returns the process to the call-out address of the staining condition setting process in the main routine.
If the difference is smaller than or equal to −30 and greater than or equal to −55 (NO in step S 123 ), the CPU 11 performs a calculation of adding 30 to the difference A and dividing the result thereof by five (step S 125 ). If there is a remained in the process of step S 125 , such remained is cut off. That is, an integer in the range of 0 to −5 is obtained in the process of step S 125 . The CPU 11 then sets the staining conditions (step S 126 ). In the process of step S 126 , the dilution magnification is raised by one stage and the staining time is lowered by the number obtained in the process of step S 125 . That is, the dilution magnification is set to twenty times, which is one stage higher than the default value of ten times, and the staining time is set to a value lower (value lower by one stage if −1) than the default value of five minutes for the first staining time and twenty minutes for the second staining time by the number obtained in the process of step S 125 , and the set values are stored in the memory 12 . After the setting of the staining conditions is completed, the CPU 11 returns the process to the call-out address of the staining condition setting process in the main routine.
If the difference A is smaller than −30 in step S 122 (NO in step S 122 ), the CPU 11 performs a calculation of dividing the difference A by five (step S 127 ). If there is a remained in the process of step S 127 , such remained is cut off. That is, an integer in the range of 0 to −5 is obtained in the process of step S 127 . The CPU 11 then sets the staining conditions (step S 128 ). In the process of step S 128 , the dilution magnification is not changed and the staining time is lowered by the number obtained in the process of step S 127 . That is, the dilution magnification is set to the default value of ten times, and the staining time is set to a value lower (value lower by one stage if −1) than the default value of five minutes for the first staining time and twenty minutes for the second staining time by the number obtained in the process of step S 127 , and the set values are stored in the memory 12 . After the setting of the staining conditions is completed, the CPU 11 returns the process to the call-out address of the staining condition setting process in the main routine.
After the staining condition setting process is terminated, the CPU 11 terminates the process.
After the staining conditions are set, the set values are stored in the memory 12 of the control unit 1 a , and used in the subsequent staining process of the smear sample.
FIG. 16 is a flowchart showing the flow of the smear sample preparing and staining process after changing the concentrated stain fluid by the blood smear preparing apparatus 1 according to the present embodiment. The CPU 11 determines whether or not the preparing and the staining of the smear sample are instructed from the user (step S 301 ). If not instructed (NO in step S 301 ), the process of step S 301 is repeated until instruction is made. The CPU 11 determines that the instruction is made when the test tube 51 accommodating the blood is set in the transport device 2 by the user, and the preparing and the staining of the smear sample are instructed from the display operation unit 2 a (YES in step S 301 ), and reads out the set values of the staining conditions stored in the memory 12 (step S 302 ). The CPU 11 then executes the sample preparing and staining process (step S 303 ). In the sample preparing process, the blood is aspirated by the aspirating and dispensing mechanism section 21 from the test tube 51 transported by the transport device 2 , and the aspirated blood is dropped on the slide glass 10 . The blood dropped on the slide glass 10 is smeared on the slide glass 10 by the smearing section 22 and then dried. The smear sample obtained in such manner is inserted to the cassette 23 , and the staining is carried out by the staining section 27 . In the staining process, the smear sample is stained according to the set values of the staining conditions read from the memory 12 in step S 302 using the undiluted solution of the stain fluid same as the concentrated stain fluid used in the test staining. Specifically, the new concentrated stain fluid that was replaced is diluted according to the set dilution magnification to prepare first and second stain fluids. The smear sample is subjected to staining by the first stain fluid in the set first staining time, and to staining by the second stain fluid in the set second staining time. After the smear sample preparing and the staining process is terminated, the CPU 11 terminates the process.
According to such configuration, the operator inputs the target nucleus G value and the average nucleus G value, and can set the staining conditions with which the nucleus G value close to the target nucleus G value can be expected to be obtained according to the difference A of the input target nucleus G value and the average nucleus G value. Therefore, the operator can easily set the appropriate staining conditions. Skilled training is not required to set the staining conditions, and the setting of the staining conditions can be prevented from varying for every operator.
Furthermore, the staining state can be greatly changed by changing the dilution magnification and the staining state can be finely tuned by changing the staining time by individually setting the dilution magnification and the staining time. Therefore, the operator can finely and accurately set the desired staining conditions.
Other Embodiments
In the embodiment described above, the average nucleus G value displayed on the image processing unit 3 b is input to the blood smear preparing apparatus 1 by the user, but this is not the sole case. The blood smear preparing apparatus 1 and the sample imaging apparatus 3 may be communicably connected, the average nucleus G value may be obtained by the sample imaging apparatus is provided to the blood smear preparing apparatus by communication, and the blood smear preparing apparatus 1 automatically may set the staining condition using the average nucleus G value.
In the embodiment described above, a configuration of performing the test staining and the setting of the staining conditions when changing the undiluted solution of the stain fluid has been described, but is not limited thereto. The test staining and the setting of the staining conditions may be performed in an arbitrary period, and for example, the test staining and the setting of the staining conditions may be carried out in the maintenance task of the blood smear preparing apparatus 1 .
In the embodiment described above, a configuration of setting the staining conditions of the blood smear preparing apparatus 1 using the average nucleus G value related to the G value of the region of the nucleus of the blood cell image has been described, but is not limited thereto. The value (average nucleus B value or average nucleus R value) obtained by averaging the B values or the R values of the region of the nucleus of the blood cell image for every sample may be obtained instead of the average nucleus G value, and the staining conditions may be set using the average nucleus B value or the average nucleus R value. The blood cell image of the density image may be obtained, and the staining conditions may be set using the average value of the brightness (luminance) of the region of the nucleus of the blood cell image. The staining conditions may be set using the nucleus G value (or the nucleus B value or the nucleus R value) calculated from one blood cell image instead of the average value of the nucleus G value calculated from each of the plurality of blood cell images, or the blood cell image or one density image may be obtained and the staining conditions may be set using the average value of the brightness of the region of the nucleus of the blood cell image. Furthermore, the G value (or B value, R value, or brightness of density image) of one pixel in the region of the nucleus of the blood cell image may be used as a representative value, and the staining conditions may be set using such value.
In the embodiment described above, the input of the target nucleus G value and the average nucleus G value is received, and the staining conditions are set based on the input target nucleus G value and the average nucleus G value, but this is not the sole case. The target nucleus G value may be stored as a fixed value, the input of only the average nucleus G value may be requested, and the staining conditions may be set based on the input average nucleus G value and the stored target nucleus G value. The user may set the target nucleus G value, the input of the target nucleus G value may not be requested when requesting for the input of the average nucleus G value, and the staining conditions may be set using the input average nucleus G value and the target nucleus G value stored as the set value.
In the embodiment described above, the dilution magnification is determined by the magnitude of the difference A between the target nucleus G value and the average nucleus G value, and the staining time is determined by performing a predetermined calculation using the difference A, but this is not the sole case. The set value may be changed from a default value by the amount of change of the staining condition corresponding to the difference A with reference to a table storing the relationship of the difference A, and the amount of change from the default value of the staining condition (dilution magnification, first staining time, and second staining time).
In the embodiment described above, the staining conditions are reset to the default setting uniformly at the time of test staining, but this is not the sole case. For instance, the test staining may be carried out based on the setting of immediately before the test staining.
In the embodiment described above, the configuration in which the blood smear preparing apparatus for preparing the smear sample sets the staining conditions has been described, but this is not the sole case. The smear staining apparatus, which does not have a function of preparing a smear sample but has a function of staining the smear sample, may receive the input of the target nucleus G value and the average nucleus G value, and set the staining conditions based on the input target nucleus G value and the average nucleus G value.
INDUSTRIAL APPLICABILITY
The smear staining apparatus, the smear preparing apparatus, the smear processing system, and the method of determining the staining conditions of the present invention are useful as a smear staining apparatus for staining a smear sample in which a sample such as blood is smeared on a slide glass, a smear preparing apparatus and a smear processing system, as well, as a method of determining the staining conditions in the staining of the smear sample.
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A smear staining apparatus comprising: a staining section which stains a smear sample with a quantity of stain fluid; and a controller, wherein the controller: receives information regarding a stain state on a smear sample which is stained according to a first staining condition by the staining section; and determines a second staining condition on the basis of the information and a target value which defines a targeted stain state, is disclosed. A smear preparing apparatus, a smear processing system and method for determining staining condition are also disclosed.
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BACKGROUND
In many gas wells, inflowing fluid passes through a sand screen which filters out particulates from the inflowing gas. Generally, the flow rate of the inflowing gas is very high such that any sand production can cause substantial erosion of components in a gas well completion. The sand production is controlled with sand screens employed either as stand-alone screens or in combination with a surrounding gravel pack. However, the velocity of the inflowing gas often can exceed an erosion velocity which causes erosion of the sand screen and ultimate failure of the sand screen. Once the sand screen fails, the risk of erosion arises with respect to other elements of the completion. Use of gravel packing may limit the velocity of particulates; however gravel packs are not necessarily uniform along the entire sand screen, resulting in high, erosive flow rates through poorly packed regions.
SUMMARY
In general, the present invention provides a technique for filtering sand; distributing a flow of fluid; e.g. distributing an inflow of gas or condensate; and limiting the potential for erosion of completion components in a wellbore. By way of example, the technique is useful in production applications, but the technique also can be used in fluid injection applications, e.g. gas injection applications. The technique employs a base pipe and a sand screen surrounding the base pipe. The base pipe comprises a plurality of flow restriction elements deployed in a selected pattern along the base pipe to provide a desired distribution of flowing fluid. The pattern of flow restriction elements also maintains a flow rate of the flowing fluid below an erosive flow rate across the entire sand screen.
BRIEF DESCRIPTION OF THE DRAWINGS
Certain embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
FIG. 1 is a schematic illustration of one example of a sand screen assembly deployed in a well, according to an embodiment of the present invention;
FIG. 2 is a partial cross-sectional view of the sand screen assembly taken generally across an axis of the sand screen assembly, according to an embodiment of the present invention;
FIG. 3 is a partial cross-sectional view taken generally in an axial direction through a wall of the sand screen assembly, according to an embodiment of the present invention;
FIG. 4 is a partial cross-sectional view of an alternate example of the sand screen assembly taken generally across an axis of the sand screen assembly, according to another embodiment of the present invention;
FIG. 5 is a partial cross-sectional view taken generally in an axial direction through a wall of an alternate example of the sand screen assembly, according to another embodiment of the present invention;
FIG. 6 is a schematic illustration of one embodiment of the flow restriction elements, according to an embodiment of the present invention;
FIG. 7 is a partial cross-sectional view of an alternate example of the sand screen assembly taken generally across an axis of the sand screen assembly, according to another embodiment of the present invention;
FIG. 8 is a partial cross-sectional view taken generally in an axial direction through a wall of an alternate example of the sand screen assembly, according to another embodiment of the present invention; and
FIG. 9 illustrates one example of a flow profile along a sand screen when fluid inflow is controlled by flow restriction elements, according to an embodiment of the present invention.
DETAILED DESCRIPTION
In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
The present invention generally relates to a system and methodology for filtering sand from flowing fluid, such as from inflowing gas in a gas production well. As explained in greater detail below, the system and methodology also enable a desired distribution of the flowing fluid across the sand screen while keeping the flow rate of the flowing fluid below an erosion flow rate to protect the sand screen from degradation.
According to one embodiment, a well system is provided with one or more sand screen assemblies coupled into a completion and deployed downhole into a gas well. Each sand screen assembly comprises a base pipe surrounded by a sand screen which filters particulates from an inflowing stream of gas during gas production. The base pipe beneath the sand screen is equipped with a plurality of flow restriction elements through which the inflowing gas moves to an interior of the base pipe after passing through the sand screen.
The flow restriction elements are sized and distributed to provide a controlled pressure drop and to eliminate regions of high flow velocity along the sand screen. The flow velocity is restricted to a rate below an erosion rate of the sand screen to prevent degradation and failure of the sand screen during gas production. The flow restriction elements may be arranged in a variety of patterns to provide the controlled pressure drop and thus the controlled flow rate through the sand screen. For example, multiple flow restriction elements may be evenly distributed along the base pipe to provide an evenly distributed inflow of gas and a consistent pressure drop along the sand screen. However, other patterns of the flow restriction elements also may be selected to create a desired flow control, e.g. a desired variation in pressure drop and/or flow rate along the sand screen.
Referring generally to FIG. 1 , one schematic example of a well system 20 for use in a well 22 is illustrated. Well 22 may comprise a production well for producing a desired fluid, e.g. gas or oil; or well 22 may comprise an injection well for injecting a desired fluid, e.g. gas or water. The well system 20 is designed to enable filtering of flowing fluid during production (or injection) of fluid from the well 22 . In this particular example, well system 20 may comprise a well completion 24 , e.g. a gas production well completion, deployed downhole into a wellbore of well 22 . The completion 24 may be deployed downhole via a conveyance 26 , such as coiled tubing, production tubing, or another suitable conveyance. Depending on the specific application, well 22 may comprise a wellbore 28 which is cased or lined with a casing 30 having perforations 32 to enable fluid communication between a surrounding reservoir/formation 34 and the wellbore 28 . However, completion 24 may be employed in open wellbores or in a variety of other wellbores, environments and wellbore configurations designed to maximize retrieval of the desired hydrocarbon based fluid, e.g. gas. The completion 24 also may be designed for fluid, e.g. gas, injection applications.
Well completion 24 potentially includes many types of devices, components and systems. For example, the well equipment may comprise a variety of artificial lift systems, sensor systems, monitoring systems, and other components designed to facilitate production operations, servicing operations, and/or other well related operations. In the example illustrated, well completion 24 further comprises a sand screen assembly 36 .
The sand screen assembly 36 has a sand screen 38 designed to filter sand from gas or other fluid flowing across the sand screen 38 . During gas production, for example, gas flows into wellbore 28 from formation 34 and passes through sand screen 38 which filters out sand while allowing the remaining gas to pass into completion 24 . The sand screen 38 may be used in cooperation with and/or be positioned between other components of the well completion 24 . Additionally, the sand screen assembly 36 may comprise a base pipe 40 positioned such that the sand screen 38 is mounted to surround the base pipe 40 .
Completion 24 also may comprise one or more isolation devices 42 , e.g. packers, positioned to enable selective isolation of a specific well zone associated with the sand screen assembly 36 . It should be noted that well completion 24 may further comprise additional sand control assemblies 36 and isolation devices 42 to isolate and control fluid flow, e.g. gas flow, from (or to) other well zones of the reservoir/formation 34 .
In FIG. 1 , wellbore 28 is illustrated as a generally vertical wellbore extending downwardly from a surface location 44 . Additionally, completion 24 is illustrated as deployed downhole into the generally vertical wellbore 28 beneath surface equipment 46 , such as a wellhead. However, the design of wellbore 28 , surface equipment 46 , and other components of well system 20 can be adapted to a variety of environments. For example, wellbore 28 may comprise a deviated, e.g. horizontal, wellbore or a multilateral wellbore extending from surface or subsea locations. The well completion equipment 24 also may be designed for deployment into a variety of vertical and deviated wellbores drilled in a variety of environments.
Referring generally to FIG. 2 , one embodiment of sand screen assembly 36 is illustrated. In this embodiment, base pipe 40 comprises a plurality of flow restriction elements 48 , and sand screen 38 is mounted around base pipe 40 and the plurality of flow restriction elements 48 . The flow restriction elements 48 are designed to allow gas flow through a sidewall 50 of base pipe 40 and into an interior 52 of the base pipe for production to a desired location. The plurality of flow restriction elements 40 are arranged in a desired, predetermined pattern to provide a controlled pressure drop across the base pipe 40 , and thereby to provide a controlled flow rate of inflowing gas through sand screen 38 . The flow restriction elements 48 also may be employed for use with other fluid, e.g. condensates, oil or water, flowing at a high flow rate into or out of the base pipe 40 during production or injection applications.
Various sizes, densities and patterns of flow restriction elements 48 may be located along the base pipe 40 which is positioned radially beneath the surrounding sand screen 38 . The sizes, densities and patterns of flow restriction elements 48 are selected according to the environment, downhole pressures, quality of the formation, presence of a surrounding gravel pack, and other environmental parameters. The size, density and arrangement of the flow restriction elements 48 establish the desired pressure drop along the base pipe 40 and also serve to sufficiently reduce the flow velocity of the gas or other fluid below an erosion flow rate. In specific applications, the arrangement of flow restriction elements 48 is selected to reduce the flow rate of inflowing gas (and particulates carried with the inflowing gas) to a rate which does not cause erosion along any region of the surrounding sand screen 38 . In many applications, the flow restriction elements 48 are evenly distributed along the base pipe 40 to provide a constant pressure drop along the base pipe 40 and an evenly distributed inflow of gas. However, the size, density and pattern of the restriction elements 48 also may be varied along the base pipe 40 in a predetermined manner to provide a controlled variation of pressure drop and/or flow rate of, for example, inflowing gas.
In FIGS. 2 and 3 , cross-sectional views of portions of one specific embodiment of the sand screen assembly 36 are illustrated. In this embodiment, the flow restriction elements 48 comprise small holes or orifices 54 extending in a generally radial direction through sidewall 50 of base pipe 40 . The orifices 54 have a diameter selected according to the parameters of the downhole application, e.g. gas production application, so as to sufficiently reduce the rate of flowing fluid below an erosion rate of sand screen 38 . In many applications, the size of orifices 54 is in the range of one to five times the size of the slot openings/passages through the surrounding sand screen 38 . For example, if sand screen 38 is designed with screen openings, e.g. pore or slot openings, approximately 0.25 mm in diameter, the diameter of orifices 54 may be selected in the 0.3 mm to 1.0 mm range. However, formation parameters, e.g. particle size, and other downhole factors may encourage use of smaller or larger orifices 54 . The pattern of orifices 54 can be used to significantly reduce flow area through the base pipe 40 and to spread the flowing fluid over a desired perforation pattern. Consequently, the desired pressure drop occurs as fluid moves through sidewall 50 of base pipe 40 . The total inflow area created by the sum of flow restriction elements 48 is calculated to give the desired pressure drop and flow rate reduction along the base pipe.
The inflow area provided by flow restriction elements 48 is a function of perforation/orifice diameter and the number of orifices 54 . To achieve an even distribution of the flowing fluid, e.g. inflowing gas, as desired in some embodiments, many small holes may be created through sidewall 50 of base pipe 40 in a consistent or even pattern. This type of pattern through the base pipe 40 creates an even gas inflow pattern toward and through the sand screen 38 .
In the embodiment illustrated, sand screen 38 comprises a plurality of layers 56 designed to facilitate both filtering and flow through the sand screen 38 . Depending on the well environment and other downhole factors, the actual type and number of layers can vary substantially. However, several types of sand screens 38 comprise an internal drainage layer 58 surrounded by a filter media layer 60 . Alternate and/or additional layers also may be provided.
In FIGS. 4 and 5 , another embodiment of sand screen assembly 36 is illustrated as having sand screen 38 positioned over base pipe 40 . In this embodiment, each flow restriction element 48 comprises a nozzle 62 in the form of an insert which is inserted into a corresponding perforation or opening 64 formed radially through sidewall 50 . The nozzle inserts 62 may be secured in their corresponding openings 64 by a variety of mechanisms. For example, the nozzle inserts 62 may be threaded into or press fit into corresponding openings 64 . The nozzle inserts 62 also may be tapered or conical to facilitate frictional engagement when press fit into corresponding opening 64 . It should be noted that in other embodiments, the nozzles 62 may be formed in sidewall 50 without creating separate inserts received in corresponding openings.
In the embodiment illustrated, each nozzle insert 62 comprises a passage 66 through which inflowing gas is routed through sidewall 50 and into the interior 52 of base pipe 40 . As described with respect to the previous embodiment, the size of each passage 66 as well as the number and pattern of inserts 62 may be calculated to achieve the desired pressure drop across the base pipe 40 and also the desired reduction in velocity of flowing fluid, e.g. inflowing or outflowing gas, to a flow rate below an erosion rate of the sand screen 38 . The nozzle inserts 62 also may be formed from an erosion resistant material, such as a hardened material, carbide material, or other suitable material.
Referring generally to FIG. 6 , the nozzles 62 may be designed with flow passages 66 each having an expanded portion 68 downstream of a passage entry opening 70 . By way of example, the expanded portion 68 may be designed as a tapered region with a taper having an increasing diameter in the direction of flowing fluid. The expanded portions 68 help prevent plugging of passages 66 if particles pass through screen openings 72 , e.g. slots or pores, of sand screen 38 . In this design, the entry opening 70 provides the desired flow area, but this region only extends a short length to help prevent plugging.
By choosing nozzles 62 having passages equal to or slightly larger than screen openings 72 of the sand screen 38 , a self-healing effect is achieved. If the sand screen 38 undergoes any erosion, as illustrated by the widened screen opening 72 on the right side of FIG. 6 , a particle 74 is able to pass through and plug the corresponding nozzle 62 . The plugged passage 66 reduces the fluid flow flux in this area and reduces or eliminates any further erosion. Consequently, the diameter/area of passages 66 may be selected based on formation particle size to make sure the particles are able to plug the passage 66 in the event of regional failure of sand screen 38 . In some applications, passages 66 may be smaller than screen opening 72 but then the nozzles are subject to unwanted plugging due to fines passing through the sand screen 38 .
To further improve this self-healing effect, the drainage layer 58 of the sand screen 38 may be separated into several compartments. The compartmentalization may be achieved by placing inserts or other types of flow blocking members in the axial flow channels of the drainage layer 58 to prevent movement of particles 74 in an axial direction along an exterior of the base pipe 40 . Preventing particles 74 from flowing axially or tangentially along an outer surface of the base pipe 40 ensures that a significant portion of the sand screen will not fill with sand even if a small part of the sand screen 38 is eroded. By way of example, the inserts or flow blocking members may comprise a ring in the drainage layer, a segment between structural members, e.g. between axial rods, of the sand screen, a shim placed between wrappings of the screen, or other suitable members designed to compartmentalize the screen and thus prevent any substantial transverse flow of fluid and particulates.
Referring generally to FIGS. 7 and 8 , another embodiment of sand screen assembly 36 is illustrated as having sand screen 38 positioned around base pipe 40 . In this embodiment, each flow restriction element 48 comprises a small tube 76 disposed between an outer surface of the base pipe 40 and the surrounding sand screen 38 . In one example, multiple tubes 76 are oriented generally longitudinally between a drainage layer of the sand screen 38 and the outer surface of base pipe 40 , as best illustrated in FIG. 8 . Additionally, each tube 76 is routed to and coupled with the corresponding hole 54 extending through sidewall 50 .
With respect to embodiments of the present erosion prevention system, such as those embodiments discussed above, the size of the passages/flow areas through the flow restriction elements is designed for optimal flow performance. However, various embodiments also may be constructed to provide the self-healing effects discussed above. Generally, each flow restriction element 48 provides a flow connection to the interior 52 of base pipe 40 and acts as a drain for inflowing fluid, e.g. gas, entering the sand screen 38 . As a result, the gas flow approaching sand screen assembly 36 tends to converge towards these drainage points.
The focusing effect of the flow may be controlled, at least somewhat, by the slot/opening density of the sand screen 38 and/or by the cross-sectional configuration of the drainage layer 58 , as illustrated schematically in FIG. 9 which provides an example of a flow profile 78 across the sand screen 38 . With relatively small areas open to flow through the sidewall 50 of base pipe 40 versus a relatively large cross-sectional area of the drainage layer 58 /sand screen 38 , a more even flux is achieved with respect to fast flowing fluid, e.g. inflowing gas, approaching the sand screen assembly 36 . As the fluid enters the slot opening 72 of the sand screen 38 , a small pressure drop occurs. Additionally, a small pressure drop occurs as a fluid flows longitudinally/transversely within the sand screen 38 toward a flow restriction element 48 of base pipe 40 . To achieve a small flux variation, the sand screen assembly 36 may be designed so the pressure drop through the screen opening 72 is of a similar order of magnitude as the pressure drop along the drainage layer 58 over the distance between distant flow restriction elements 48 .
Desired patterns of flow restriction elements 48 may be selected and designed based on optimization of peak flow velocity versus average flow velocity. Knowledge of the peak flow velocity and the average flow velocity is used to design flow restriction element density and flow area to ensure the velocity approaching sand screen 38 stays below an erosion velocity, thereby reducing or preventing erosion of the sand screen 38 .
The overall well system 20 may be constructed to accommodate a variety of flow filtering applications in a variety of well environments while limiting or preventing erosion of the screen and other completion components. Accordingly, the number, type and configuration of components and systems within the overall system may be adjusted to accommodate different applications. For example, the size, number and configuration of the sand screen assemblies may vary from one application to another along the completion equipment. Additionally, many types of flow restriction elements and arrangements of those elements may be employed as dictated by the overall design of gas production equipment and by downhole environmental conditions. The base pipe configuration and the sand screen configuration also may be adjusted according to the specific application and environment. The sand screen assemblies and their erosion control elements may be combined into many types of well completions utilized in production and/or servicing operations. Also, the types and arrangements of other downhole equipment used in conjunction with the one or more sand screen assemblies may be selected according to the specific well related application in which the sand screen assemblies are employed.
Although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this invention. Accordingly, such modifications are intended to be included within the scope of this invention as defined in the claims.
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A technique enables an improved filtering of sand, a desired distribution of produced or injected fluid, and a reduction in erosion of completion components positioned in a production or injection well. The technique employs a base pipe and a sand screen surrounding the base pipe. The base pipe comprises a plurality of flow restriction elements arranged in a selected pattern along the base pipe to provide a desired distribution of the fluid flowing into or out of the sand screen. The pattern of flow restriction elements also maintains a flow rate of the flowing fluid below an erosive flow rate across the entire sand screen.
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BACKGROUND OF THE INVENTION
In most room humidifiers in many areas, the container for the water and the media unit become encrusted with mineral deposits from the water supply. To applicant's knowledge there have been several prior attempted solutions to eliminate this problem in room humidifiers, one of which is periodic addition of anti-liming tablets, and another is addition of a liquid anti-liming solution which can be poured into the water reservoir but those are not wholly satisfactory because they require the home owner to periodically obtain the material from storage and either place a tablet or manually pour a certain amount of solution from a bottle into the water reservoir. A somewhat better arrangement is shown in U.S. Pat. No. 3,323,784 to P. A. Fazio, who discloses in a room humidifier, the use of a second reservoir fixed internally of the humidifier and used to continuously meter an additive liquid such as a deodorant or medicated liquid to the water reservoir. For obvious reasons, continuous metering of an anti-mineral material to a console humidifier would be wasteful and unsatisfactory.
The same problem occurs in the water reservoir of central humidifier apparatus and evaporative cooler installations and, again, solutions to the problem include adding anti-mineral tablets either directly to the water reservoir or to a water supply line as in U.S. Pat. No. 3,191,915 to G. Goettl; or dissolving such tablets in an auxiliary unit and metering the concentrated liquid additive to the reservoir as shown in U.S. Pat. Nos. 3,094,134 to G. C. Curries and 3,430,823 to V. L. Hunsaker both of whom show progressive automatic introduction of tablets to the dissolving container; or by dissolving dry material in a container through which the water supply passes as shown in U.S. Pat. Nos. 2,709,522 to S. C. Osborne, 2,874,032 to R. L. Kuehner, and 3,126,427 to L. N. Broughton; or by automatically periodically introducing liquid anti-mineral chemicals from large storage tanks or carboys as taught by U.S. Pat. Nos. 2,859,766 to H. L. Shuldener and 3,196,892 to R. H. Savage et al. Most of the central units require an automatic water supply and controls and apparatus not found in room humidifiers and, while satisfactory for central units, often require dismantling or adjustments in fixed equipment and are relatively expensive.
The present invention was developed to provide a convenient and easy way to dispense a water treatment liquid such as liquid "LIME OUT" or other desired water treatment liquids to the water reservoir of a room humidifier and to do so in a manner which will be acceptable to and used by the owner of such humidifiers.
As a solution to the problem, this present invention incorporates, in a humidifier assembly, a readily removable and refillable unit with an auxiliary supply of liquid water treatment within its own convenient dispensing container. The unit is incorporated as an auxiliary attachment to a humidifier with its operating portion accessible from the exterior of the top wall of the humidifier housing. The preferred way to accomplish the desired function and convenient utilization is to provide a simple refillable dispensing bottle with a cap carried poppet valve, the unit being inverted and slipped vertically into the humidifier and having provisions enabling an operator, by a simple depression on the accessible end of the inverted bottle, to cause operation of the dispensing valve to dispense a desired portion of the liquid treatment material into the humidifier water container.
This same type of simple hand manipulated dispenser unit while developed specifically for room console type room humidifiers can be readily incorporated in central heating system and other humidifiers.
SUMMARY OF THE INVENTION
A primary object of the present invention resides in the provision of a readily removable and refillable dispenser unit enabling a convenient and easy method of dispensing a liquid water treatment material such as an anti-lime agent or other material to the water supply bucket or reservoir of a humidifier.
A further object of this invention resides in the provision of a refillable dispenser unit for humidifiers consisting of an elongate bottle, the base of which is shaped to aid in mounting the dispenser and is so constructed to enable ease of removal of the dispenser and the neck of which includes threads to which is removably fastened a cap carrying a spring loaded poppet type dispensing valve.
In conjunction with the foregoing object, still another object resides in the combination in a humidifier of such a dispenser mounted in inverted relationship through the top wall of the humidifier so that the operating stem of the cap carried poppet valve has an operative engagement with an abutment component mounted on an interior support section of the humidifier housing and so located that the valve dispenses fluid into the humidifier water bucket. The valve operation can be accomplished by rigidly affixing the abutment component and depressing the bottle to open the valve or by rigidly affixing the bottle to the humidifier structure and moving the abutment to depress the poppet valve. In conjunction with the foregoing combination, the abutment component can be an apertured funnel shaped abutment unit secured to an interior portion of the humidifier providing a drain into the water reservoir and serving as a support for the dispenser unit.
In further conjunction with the combinations denoted in the foregoing objects, additional objects reside in the provision of structure on the base or bottom of the bottle which includes side lugs enabling cooperation with structure in the top wall of the humidifier which permits vertical sliding movement of the bottle or, upon rotation of the bottle, blocking or locking the bottle against vertical shift in at least in one direction; such structure made with a finger grip for rotating and or raising and removing the dispenser from its assembled location in the humidifier.
Further novel features and other objects of this invention will become apparent from the following detailed description, discussion and the appended claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred as well as an alternate structural embodiment of this invention is disclosed in the accompanying drawings in which:
FIG. 1 is a front top quarter view partially illustrating a console room humidifier having provision for a removable dispenser unit to be mounted in the left rear corner, the dispenser unit being illustrated out of and placed on the top grid of the humidifier;
FIG. 2 is a partial perspective rear upper quarter view of the humidifier shown in FIG. 1, illustrating the dispenser in its assembled location in the humidifier;
FIG. 3 is a partial elevation view, with a portion sectioned, looking at the right upper rear of the humidifier;
FIG. 4 is a partially broken section view taken on line 4--4 of FIG. 3 to illustrate further relationship between the dispenser and the other humidifier components;
FIG. 5 is an enlarged detail top view showing the base end of the dispenser flush with and accessible at the top surface of the humidifier cabinet;
FIG. 6 illustrates the manner in which dispensing can be accomplished by pressing on the base end of the dispenser;
FIG. 7 is an exploded and partially sectioned elevation view of components of the dispenser unit including the poppet valve in the bottle cap, the unit being illustrated in its operative inverted position;
FIGS. 8 and 9 are detail views of the special base end cap to be secured on the base of the bottle shown in FIG. 7;
FIG. 10 is a section taken on line 10--10 of FIG. 11 to illustrate the guide slot and abutment formations in the special dispenser panel;
FIG. 11 is a plan view of the dispenser panel;
FIG. 12 is a detail view of one of the internal guide slot and abutment formations in the dispenser panel, looking in the direction of line 12--12 in FIG. 11;
FIG. 13 is a top view of the funnel shaped dispenser abutment unit;
FIG. 14 is a section view taken on line 14--14 of FIG. 13; and
FIG. 15 is a diagrammatic view illustrating an alternative manner of mounting the dispenser so its valve can be manipulated by a push button and linkage arrangement.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The removable dispenser unit for introducing a liquid water treatment fluid into a humidifier water reservoir can be adapted for installation in conjunction with the water reservoir of most humidifiers, however it was developed for use with and is described in combination with a room type console humidifier, an example of which can be seen in application Ser. No. 790,012 now U.S. Pat. No. 4,112,015 to T. E. Tinsler for Humidifier Drive System.
Such a console humidifier 20, FIGS. 1 through 4, consists of an open back cabinet 22 having front, side, bottom and top walls. The illustrated cabinet 22 can be molded from plastic as a unit whose bottom wall or shelf 24 supports the water reservoir 26. Its top wall 28 provides suitable panels, usually toward the rear, where humidifier controls 30 are located, and a large access opening 32 across its forward portion. Opening 32 provides access to the rotating media member for removal and replacement and also serves as an outlet for air flow, being covered by one or more open grill panels 34 to permit outlet passage of humidified air with deflection control as desired.
Within the cabinet (FIGS. 3 and 4) is a relatively large diameter media wheel 36 carrying a porous media belt 38 and suspended on grooved rollers, one of which is ordinarily a friction drive roller, as shown at 40. Media wheel 36 is arranged to rotate with a lower sector always disposed within the water reservoir 26. The grooved rollers are disposed on the front side of and are mounted on an upright panel 42 of an interior support housing 44 which may also support idler rollers (not shown) to maintain the media wheel in a vertical attitude, as it rotates.
A central opening or plenum 46 is provided in panel 42, surrounding a fan 48 driven by electric motor 50 which, in turn, is mounted via support members 52 to the housing 44. The media wheel 36 is slowly rotated by drive roller 40 driven by motor 50 through a high speed reduction belt and pulley drive system, generally denoted at 54. Motor 50 is powered and controlled via leads from a power source and suitable controls 30, which may include multi-speed controls, an automatic humidistat and an on-off control. In addition, the controls may include a water level indicator or refill indicator light for signalling the amount of water in the reservoir.
During operation, the fan draws air in from the rear of the unit, passes the air through the plenum opening to the interior of and directed against the inner surface of the media wheel, which diverts the air flow through the porous media belt 38 which is continuously wetted as it rotates through the water reservoir 26. The air becomes moisture laden as it passes through belt 38 and thence through the top wall which directs the humidified air into the room or enclosure where the humidifier is placed.
With reference to FIGS. 2, 3 and 4, interior support housing 44 is a separate intermediate section usually made from sheet metal with peripheral top 56, side 58, and bottom 60 walls which, with the main panel 42, provide a rigid box like structure. The edges of the side and top walls of the support housing 44 have bent attachment flanges which rest against and are secured, as by screws, to the rear edges of the console cabinet. So assembled the top wall of the support housing is under the rear portion of and close to the under surface of the cabinet top wall 28. Its lower horizontal wall 60 is located intermediate the top and bottom of the cabinet and the water reservoir 26, which is a plastic tray or bucket, can be slid into place on the bottom shelf 24 of the cabinet and under the lower wall 60 of the interior housing.
Most room humidifiers have basic components somewhat similar to those described in the foregoing paragraphs and many of the central home humidifiers have somewhat equivalent components such as the housing, interior support structure and a water reservoir located at or near the lower part of the humidifier. In such humidifiers there is usually space and existing structure which can accommodate and be utilized for receiving a removable liquid water treatment dispenser in accord with the present invention.
In the humidifier structure illustrated in FIGS. 1-4 the liquid water treatment dispenser 70 is an elongate bottle 72 with a base unit 74 and a cap 76 which includes a spring loaded poppet valve 78 (see FIG. 7) having a projecting stem 79. As seen in FIG. 1, a small panel insert 80, securely mounted in a cutout at the rear corner of the console top wall 28, has an opening 82 into which the dispenser unit can be inserted, cap end down. The inverted dispenser 70 fits with a free sliding fit through the insert opening 82, through a second opening 84 (FIG. 4) in the top wall 56 of the interior housing and will slide down to its assembly location where the end of the valve stem 79 abuts a special shaped drain unit 86 (to be described hereinafter) secured in the lower wall 60 of the interior housing above the reservoir tray 26. As shown in FIGS. 2-4, so inserted, the weight of the dispenser is supported on its valve stem 79 and is maintained in vertical disposition by its cooperative fit through the panel insert opening 82. The length of the dispenser will be such that, in assembly, its base end surface will be flush with the upper surface of the console top rear panel. The bias force of the spring in poppet valve 78 is sufficient to support a filled dispenser unit without causing unintentional opening of the poppet valve. So positioned, fluid can be dispensed by pressing down on the base of the dispenser unit (FIG. 6) causing the poppet valve 78 to open and permit fluid to pass from the dispenser through the drain 86 into the reservoir 26. Releasing the downward pressure permits the dispenser to move, under valve spring bias force, up to its rest position and the valve will close.
FIG. 7 shows the components of the dispenser 70 in exploded view and partially sectioned. The bottle 72 is preferably transparent or semi-transparent and can be made from glass or plastic and is tubular with a threaded neck 90 at one end and a closed base end 92, circumferentially stepped at 94 and including a short integral projecting lug 96.
The cap 76 is internally threaded at 98 to mate with and fit the threaded neck 90 on bottle 72 and carries a flat washer-like seal 100 which is clamped and provides a seal between the cap 76 and the bottle neck. The hole 102 in the washer seal 100 is aligned with a central aperture 104 in cap 76 permitting the stem 70 of the poppet valve to be inserted through the openings from within the cap. Stem 79 has an integral flanged head 106 which can abut the washer seal and provide a sealed valving closure of the cap aperture 104. To bias the poppet valve 78 to a closed position, a coil compressor spring 108 is placed over the valve stem 79 with one end abutting the outside of the cap 76 and is held in place on the stem by contact with a C-clip 110 fitted into a groove adjacent the end of the valve stem. Poppet valve 78 may be moved to an open position by moving the stem 79 inward against the force of spring 108. To permit a free flow of liquid from the bottle, stem 79 can be longitudinally grooved as at 112 (FIG. 7). The cap and valve can be removed as a unit to permit filling the bottle through its neck.
A base unit 74 is secured to the bottle 72 to provide several functions, i.e., it serves as a guide, provides locking or blocking and includes a small handle to aid in rotary manipulation as well as removal of the dispenser unit. Base 74 (FIGS. 7, 8 and 9) is preferably molded from plastic and is essentially cylindrical with a mid-wall 118 and an external cross bar 120 providing a finger grip handle for rotating and lifting the dispenser. The underside of cross bar 120 is hollow providing a recess 122 into which the projected bottle base lug 96 and a U-clip 124 are fitted with the skirt 126 of base unit disposed over the stepped bottom end 94 of bottle 72. So assembled, the cylindrical configuration of the base unit 74 provides a continuation of the cylindrical contour of the bottle. Metal U-clip 124 fits over the lug 96 and into depressions 128 in the sides of the lug so when the lug and clip are pressed into the base unit recess 122, friction force will hold the components in assembly. To assure secure assembly, an adhesive can be placed on the lug or in the recess before the base unit is forced onto the bottom of the bottle.
Looking at FIGS. 5, 6, 8 and 9, dispenser base unit 74 has two diametrical side lugs 130 and 132. As will become apparent, the lugs are utilized in conjunction with formations in the dispenser panel insert 80 to provide a means in one position for blocking (locking) the dispenser against inadvertent dispensing and in another position to enable depression of the dispenser to permit flow of a desired small amount of water treatment material into the humidifier reservoir.
As was hereinbefore described, the dispenser 70 is vertically supported by abutment of the end of poppet valve stem 79 on a drain component 86 located in or on the lower wall 60 of the interior humidifier housing. In the preferred embodiment, the drain 86 is made from plastic as a separate unit attached to and providing a fluid flow passage through the lower interior housing wall 60. The drain has an apertured wall 138, a short depending circular sleeve portion 140 and an upper section formed as a divergent frustum or funnel section 142. Integrally molded on the exterior are several triangular abutments 144 which, when unit 86 is mounted with the depending cylindrical sleeve fitting through a circular opening 146 in wall 60 above the reservoir space, will abut the top surfaces of wall 60. Drain unit 86 can be secured in assembly by use of a circular star clip on sleeve 140 or the bottom edge of the plastic skirt or sleeve 140 can be deformed outward, as by heat, to engage the underside of wall 60 around the opening 146. Alternatively, the drain can be made structurally integral with the lower wall, e.g., lower wall 60 if made from sheet metal could be deformed (not shown) at the desired drain location into a small funnel-like depression with pierced openings similar to the drain openings 148 in the drain unit 86.
The upper funnel shaped skirt 142 helps to guide and locate the dispenser valve stem to an abutment over the drain openings as well as assuring that dispensed liquid will be trapped by and directed through the drain to the reservoir.
As illustrated, panel insert 80 is a separately made escutcheon-like part fastened to the console cabinet, as by adhesive or other suitable means, and cooperates with the special dispenser base unit 74 to provide two dispenser conditions, a locked condition and an operative condition. Panel insert 80 is molded with an integral top plate 152 and a dependent, essentially cylindrical receptacle sleeve 154 and formed in the internal surface of the sleeve 154 are diametrically located recesses 156 shaped as shown in layout drawing FIG. 12. Each of the recesses have two vertical grooves 158 and 160, groove 158 being longer than groove 160 and each groove having a lower end abutment 162 and 164 respectively. The dispenser 70 is slipped into sleeve 154, the poppet valve stem will abut the drain 86 when the two base unit side lugs 130 and 132 slip into the diametrical recesses 156. The dispenser can be rotated through an approximate 45° whereupon to align the base unit side lugs 130 and 132 either with the set of long grooves 158 or the set of short grooves 160. Viewing FIG. 12, when the lugs are positioned in alignment with the long grooves 158 of the recesses they will normally be disposed as illustrated by position A, their rest disposition determined by abutment of the poppet valve stem on drain unit 86. In this position the dispenser can be physically depressed until the base unit side lugs engage the bottom abutments 162 of long grooves 158 whereat the poppet valve spring is compressed and the poppet valve opens to permit liquid to flow from the dispenser into the reservoir. Releasing pressure on the base of the dispenser permits the poppet valve spring to move the dispenser upward to a valve closed condition. To prevent inadvertent dispenser operation, the dispenser 70 can be rotated by finger handle 120 to place base unit side lugs into the phantom line position B of FIG. 12, whereat they are aligned with and will abut the bottom abutments 164 of the short grooves 160. In this condition dispenser 70 cannot be pressed downward, it is blocked from or locked against dispensing operation.
An alternate manner of removably mounting a refillable dispenser unit in a humidifier is illustrated in FIG. 15. In such embodiment, the dispenser unit 170 can be constructed essentially the same as unit 70 but is inserted in the humidifier cabinet 172 through a different panel insert 180 which will include bayonet type lock formations 182 under which the lugs on the dispenser base unit 174 will rotate to lock the dispenser against up and down vertical movement. The valve unit 178 will be oriented immediately above a funnel like abutment 184 located on one arm of a double arm lever 186 pivoted at 188 on fixed humidifier structure 190 above the reservoir 192. The other arm of lever 186 is pivotally connected to the lower end of a plunger rod 194 which projects up through the top wall of the humidifier cabinet and terminates in an actuator push knob 196. The inactive condition of the operating linkage can rely on the bias of the valve spring 198 or a supplemental compression coil spring 200 can be included between knob 196 and the top wall of the humidifier. The funnel abutment 184 will be situated adjacent and aligned above an opening in humidifier structure to permit through flow of liquid from the dispenser to the reservoir whenever the knob 196 is depressed.
The invention may be embodied in other specific forms without departing from the scope, spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope and spirit of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.
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A humidifier unit with a water supply reservoir, a media unit which passes through the reservoir and picks up moisture, a motor and fan unit together with drive mechanism for rotating the media unit and for blowing air through the media unit and into the surrounding area, and a removable, refillable liquid water treatment dispenser. As depicted, the humidifier is a console room humidifier with the water reservoir accessible from the rear. The removable dispenser is an auxiliary unit consisting of an elongate bottle, the cap of which carries a spring biased poppet valve with a projecting stem. The bottle is inverted and received through an opening in the top wall of the humidifier with its valve operating stem resting on an abutment above a flow passage funnel unit mounted on structure within the humidifier above the water reservoir. The dispenser, when in place, can be pressed down against the biasing force of the spring biased poppet valve, causing the valve to open and dispense a selected amount of treatment fluid such as an anti-liming composition into the water reservoir.
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TECHNICAL FIELD
[0001] This invention relates to friction damping elements and, more particularly, to friction damping elements disposed within a planetary gear arrangement.
BACKGROUND OF THE INVENTION
[0002] Planetary systems have a plurality of meshing gear interfaces. Each of these gear meshes has a lash quantity built in for manufacturing purposes mostly. Therefore, during operation, the lash, which is the distance between the meshing gear teeth while they are in mesh, can reverse from being a driving tooth engagement to a driven tooth engagement. For example, the sun gear therein provides a driving arrangement to the planet pinions, which then provide a driving arrangement to the ring gear. However, should the torque or driving force at the sun gear be reversed and/or allowed to coast, the driving connection between the gear teeth will be reversed. That is, the ring gear will begin to drive the pinion gear and the pinion gear will drive the sun gear. Thus, the side of the tooth of each respective gear has reversed and has driving and driven capabilities.
[0003] It is known to put an active friction type damper between two shafts in a countershaft type transmission to reduce the gear rattle or lash change between the gear members on the input shaft, the output shaft, and the countershaft. In these arrangements, it is proposed to put the damper between the input shaft and the output shaft, which are coaxially aligned and supported one within the other. Such an arrangement is shown in U.S. Pat. No. 6,477,909 issued to Gilbert et al. on Nov. 12, 2002. This patent is assigned to the assignee of the present application.
SUMMARY OF THE INVENTION
[0004] It is an object of the present invention to provide an improved planetary gear arrangement having a friction damping interface between two members of the planetary gearset.
[0005] In one aspect of the present invention, an active damper mechanism is placed between the sun gear member of the planetary gearset and the ring gear member of the planetary gearset.
[0006] In another aspect of the present invention, a selectively active damper is placed between the ring gear member of a planetary gearset and the carrier member of a planetary gearset.
[0007] In yet another aspect of the present invention, an active damper is disposed within an all wheel drive transfer planetary gear arrangement.
[0008] In yet still another aspect of the present invention, the all wheel drive planetary gear arrangement has an input carrier member, a front output sun gear, a rear output sun gear, and pinion gears intermeshing with each other and with respective ones of the sun gears, and wherein an active damper mechanism is disposed between the input carrier and the front output sun gear.
[0009] In a yet still another aspect of the present invention, an active damper is disposed within the all wheel drive transfer planetary gear arrangement between the input carrier and the rear output sun gear.
[0010] In a further aspect of the present invention, active damper mechanisms can be positioned between the intermeshing planet pinion gears and/or between the output sun gear and one of the pinion gears meshing therewith.
DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is an elevational view of a planetary gearset incorporating the present invention.
[0012] FIG. 2 is an exploded view of the planetary gearset shown in FIG. 1 depicting an active damper mechanism between various members of the planetary gearset.
[0013] FIG. 3 is a schematic representation of a planetary gearset used in an all wheel drive transfer planetary gear arrangement and incorporating the present invention.
[0014] FIG. 4 is a view taken along line 4 - 4 of FIG. 3 .
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0015] Referring to the drawings, wherein like characters represent the same or corresponding parts throughout the several views, there is seen in FIG. 1 a planetary gear arrangement 10 including a sun gear member 12 , a ring gear member 14 , and a planet carrier assembly member 16 . The planet carrier assembly member 16 includes a planet carrier member 18 having rotatably mounted thereon a plurality of pinion gears 20 , which are disposed in meshing relationship with both the sun gear member 12 and the ring gear member 14 .
[0016] As is well known, when the sun gear member 12 rotates in the direction of Arrow A, the ring gear member 14 will rotate in the direction of Arrow B. Also, when the ring gear member 14 rotates in the direction of Arrow C, the sun gear member 12 will rotate in the direction of Arrow D. During normal transmission operation, the sun gear member 12 will be rotating in the direction of Arrow A to drive the ring gear member 14 in the direction of Arrow B. At sometime during the operation, the planetary gear arrangement 10 may change from a driving planetary gearset to a coasting planetary gearset in which case the ring gear member 14 may rotate in the direction of Arrow C and thereby driving the sun gear member 12 in the direction of Arrow D.
[0017] During this interchange of rotational torque transmission, the intermeshing gear teeth between the sun gear member 12 and the pinion gears 20 and also between the ring gear member 14 and the pinion gears 20 will be transferred from one side of the teeth to the other. Since the teeth of meshing gears cannot be continuously in contact with both sides, some lash is built into the system to permit the reversal of torque through the planetary gearset. However, the lash condition can produce a noise relationship, which is not desirable.
[0018] To accommodate this situation in the present invention, an active friction damper 22 is disposed, as seen in FIG. 2 , to engage the sun gear member 12 and the ring gear member 14 . When the torque reversal or drive reversal occurs within the planetary gear arrangement 10 , the friction damper 22 is activated such that the ring gear member 14 and sun gear member 12 have a slipping frictional component generated therebetween, which reduces the speed or the velocity at which the lash condition changes from a sun gear drive condition to a ring gear drive condition thereby reducing the noise which might otherwise occur.
[0019] Also shown in FIG. 2 is an active friction damper 24 , which is disposed between the ring gear member 14 and the planet carrier member 18 . The damper in this position can also be activated during a torque reversal within the system to eliminate the gear interface noise that might be generated during such torque reversal. It is possible in assemblies to use one of the friction dampers either 22 or 24 , or to incorporate both of the friction dampers 22 and 24 . Preferably, the friction dampers are controlled by a conventional electronic control unit (ECU), not shown, which is sensitive to the operating condition of the transmission and also the operating condition of the engine.
[0020] During certain operating conditions, the ECU will issue electronic signals to the damper 22 and/or the damper 24 to cause energization of the dampers just during the time period that a noise is most likely to occur. These conditions might occur with engine throttle position change, gear ratio change within the transmission, or a number of other conditions. Each of these conditions is known to the ECU, which generally includes a conventional programmable digital computer to provide the speed necessary for the actuation of the devices within the transmission. The construction and operation of these mechanisms, such as the ECU, is well known within the art of transmission design and construction.
[0021] The active dampers 22 and 24 are operable to apply a frictional drag torque between the two components that they contact. The level or amount of drag torque applied is not capable of rendering the two components to rotate in unison, it merely retards any rapid relative rotational changes between the two, which eliminates the lash noise that might otherwise occur.
[0022] FIGS. 3 and 4 depict schematically and diagrammatically a planetary differential generally designated 40 . The planetary differential 40 includes an input planet carrier assembly member 42 , a first output sun gear 44 , and a second output sun gear 46 . The planet carrier assembly member 42 includes a planet carrier assembly member 47 having side plates 48 and 50 that are interconnected through extensions 52 . A pair of meshing pinion gears 54 and 56 is rotatably supported on pins 58 and 60 , respectively. The pins 58 and 60 are secured to the side plates 48 and 50 . The pinion gears 54 and 56 mesh with the sun gears 44 and 46 , respectively.
[0023] The side plate member 48 can be operatively connected with the sun gear member 44 through an active damper 62 and the side plate member 50 can be operatively connected with the sun gear member 46 through an active damper 64 . The active damper 62 is effective to control rapid speed changes between the sun gear 44 and the planet carrier assembly member 47 , which will, of course, reduce gear lash noise between the pinion gears 54 and the sun gear 44 .
[0024] The active damper 64 is effective when operated to reduce rapid velocity changes between the side plate 50 and the sun gear 46 thereby reducing the gear lash noises between the sun gear 46 and the pinion gear 56 . It is also possible to position active dampers between the pinion gears 54 and 56 and the planet carrier side plates 48 and 50 . Activation of these friction dampers will reduce or eliminate lash noise between the meshing pinion gears 54 and 56 .
[0025] In view of the above description, it will now be evident to those skilled in the art that the active dampers may be placed either singularly or in combination between various members of the planetary gear arrangement to accommodate the reduction in lash noise which can occur during various operating conditions such as throttle changes of the engine or ratio changes at the transmission.
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A planetary gear arrangement having at least three rotatable members with intermeshing gears and a primary torque path defined therein. At least one active friction damper is disposed between two of the planetary gear members, for example, a sun gear and a ring gear. The active damper is selectively operable to apply frictional engagement between the two members with which it is interconnected to establish a controlled secondary torque path therebetween. The active damper is effective to reduce gear lash changes between the gear members of a planetary assembly.
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FIELD OF THE INVENTION
[0001] The invention relates to supramolecular polymers. i.e. polymers having quadruple hydrogen bonding units (4H-units) within their structure, that also contain covalently attached ionic or ionogenic groups. These so-called supramolecular ionomers (or ionomeric supramolecular polymers) can be dispersed or solubilized in water at high solids contents while maintaining low viscosities, facilitating easy use and processing of the resulting aqueous formulations. The aqueous ionomer mixtures have excellent film-forming properties. Moreover, the polymer materials have good mechanical properties after drying, as they are not tacky, show high elasticity and low or no creep. The beneficial properties of the introduced polymer materials arise from the unprecedented action of both (i) ionic groups in the polymer structure and (ii) physical interactions between the polymer chains that are based on multiple hydrogen bonding interactions (supramolecular interactions based on 4H-units).
BACKGROUND OF THE INVENTION
[0002] This invention relates to supramolecular polymers that comprise self-complementary quadruple hydrogen bonding units (4H-units) that are capable of forming (at least) four H-bridges with other of such units leading to physical interactions between different polymer chains. Self-complementary hydrogen bonding units having at least four hydrogen bonds in a row, and thus capable of forming at least four hydrogen bonds, are in this patent application abbreviated as quadruple hydrogen bonding units, quadruple hydrogen bonding sites, 4H bonding units, 4H-units, 4H-elements or structural elements (4H) and are used in this patent application as interchangeable terms. Sijbesma et al. (U.S. Pat. No. 6,320,018; Science, 278, 1601; incorporated by reference herein) discloses such self-complementary units which are based on, particularly, 2-ureido-4-pyrimidones.
[0003] Telechelic polymers or trifunctional polymers have been modified with 4H-units (Folmer, B. J. B. et al., Adv. Mater. 2000, Vol. 12, 874; Hirschberg et al., Macromolecules 1999, Vol. 32, 2696; Lange, R. F. M. et al, J. Polym. Sci, Part A, 1999, 37, 3657-3670). However, these polymers have the 4H-unit coupled at the termini of the polymers, so the number of end groups is therefore limited to two, and the functional units are always located at the periphery of the polymer. Moreover, these polymers are not, or only poorly, water-soluble.
[0004] WO 02/46260 discloses polyurethane based polymers with 4H-bonding units as end-cappers and, optionally, with grafted 4H-bonding units; the disclosed polymers can be used as hot melt adhesive or TPU-foam. WO 03/099875 discloses polyurethane based polymers with 4H-bonding units as end-cappers that can be used as TPU-foam. Both patent applications use comparable or the same chemistry as described in Lange, R. F. M. et al, J. Polym. Sci, Part A, 1999, 37, 3657-3670, and are not water-soluble or dispersible.
[0005] WO 04/016598, incorporated by reference herein for the US patent practice, discloses polymers with grafted quadruple hydrogen bonding units. For example, polyacrylates and polymethacrylates with grafted 4H-units have been produced using different kinds of polymerization techniques. However, the 4H-units are not integrated in the backbone, and more importantly, no water soluble or water dispersible ionomers are disclosed.
[0006] WO 04/052963, incorporated by reference herein for the US patent practice, disclose polysiloxanes comprising 4H-units in the polymer backbone. However, these polymers do not contain ionic groups and are not water-soluble/dispersible.
[0007] WO 05/042641, incorporated by reference herein for the US patent practice, discloses polymers comprising 4H-units in the polymer backbone. However, these polymers do not contain ionic groups and are not water-soluble or dispersible.
[0008] US 2004/023155, incorporated by reference herein for the US patent practice, discloses a supramolecular polymer having the structure A-L-B, wherein A and B are polymers comprising a 4H-unit (in US 2004/023155 the 4H-unit is indicated by “QHB”) which are linked by joining group L. The preparation of polymers A and B is said to be possible by reacting an appropriate polymer with a 4H-unit precursor having a terminal isocyanate group (in US 2004/023155 indicated by “QHBE”). According to US 2004/023155, an appropriate polymer would be a carboxyl substituted acrylic polymer such as a (co)polymer of acrylic acid. According to the examples (Examples 12 and 13), the 4H-units are grafted in a post modification step onto the carboxyl substituted acrylic polymers so that the 4H-units do not constitute an integral part of the polymer structure and are not present as terminal groups. US 2004/023155 further discloses that the appropriate polymer may be a polyurethane made from carboxyl functional diols, e.g. dimethylol propionic acid, and diisocyanates. Such polyurethanes comprising anionic groups would have a terminal OH-group that can me postreacted with the 4H-unit precursor having a terminal isocyanate group thereby providing a polyurethane comprising anionic groups which has a terminal 4H-unit. However, US 2004/023155 does not provide an enabling disclosure of such modified polyurethanes.
[0009] Because of environmental regulations governing the emission of volatile organic compounds (VOCs) into the atmosphere, the need for waterborne systems is emerging. General ways to obtain polyurethane ionomers, i.e. polyurethanes containing ionic groups that are dispersible or soluble in water, are for example described by Dieterich, D. et al., Angew. Chem., 1970, Vol. 2, page 53. In U.S. Pat. No. 3,480,592 and U.S. Pat. No. 3,388,087, polyurethanes are disclosed that are water dispersible by the incorporation of cationic-groups in the polyurethane chain. In order to obtain elastic materials, however, these polyurethanes need to be chemically cross-linked or of high molecular weight. Especially the cross linked materials can hardly be processed, if at all.
[0010] The present invention discloses polymers that not only contain 4H-units in their molecular structure, but also ionic or ionogenic groups. It has surprisingly been found that the presence of cationic or anionic groups in the polymer chain does not disturb the supramolecular hydrogen-bonding interactions between different 4H hydrogen bonding units. Nor does the presence of the apolar 4H-units hinder the water solubility or dispersibility of the resulting polymers. Even more surprising is the fact that the possible remaining water molecules in the dried materials do not corrupt the hydrogen-bonding interactions and that therefore the resulting waterborne materials still display unique material properties, because of the reversible nature of the H-bonding interactions between the polymer chains. Thus, the present invention enables the manufacture of elastic, non-tacky polymers with excellent film-forming properties that can easily be processed or applied, by for example spraying, from high solid content—yet still low viscosity—water dispersions (or solutions). The described polymers are of relatively low molecular weight, thereby circumventing the use of hardly processable high molecular weight or cross-linked materials.
SUMMARY OF THE INVENTION
[0011] The present invention provides supramolecular ionomers comprising (i) a quadruple hydrogen bonding unit (4H-unit) and (ii) an ionic group within the polymer structure. The present invention also provides a process for the preparation of supramolecular ionomers, aqueous formulations comprising a supramolecular ionomer and the use of such ionomers in a wide variety of applications.
DETAILED DESCRIPTION OF THE INVENTION
[0012] In this patent applications, ionic groups are to be understood as organic groups that are positively or negatively charged, i.e. that they can be cationic or anionic in nature. Precursors of the supramolecular ionomers according to the invention include monomers that can be polymerized to the supramolecular ionomers per se, but also monomers that can be polymerized to a supramolecular polymer comprising a quadruple hydrogen bonding units and an ionogenic group, wherein the ionogenic group is to be understood as a group being capable of the formation of an ionic group. As will be apparent to the person skilled in the art, the conversion of ionogenic groups into ionic groups may be performed during polymerization, but also after the termination of the polymerization in a subsequent step. Consequently, when in this patent application reference is made to a “supramolecular ionomer”, this term also includes supramolecular polymers wherein the ionic group or ionic groups are still in a “protected form”, i.e. that they are present as ionogenic groups.
[0013] According to the invention, the supramolecular ionomers have a relatively low number average molecular weight of about 2000 to about 200000, preferably about 5000 to about 60000, most preferably about 7000 to about 30000. The number average molecular weights of the supramolecular ionomers (e) according to the present invention are determined by size-exclusion chromatography (SEC) also known in the art as gel permeation chromatography (GPC) and are relative to polystyrene standards.
[0014] According to the invention, the supramolecular ionomers (e) have the following general structure:
[0000] -[( a ) p -( b ) q -( c ) r -( d ) s ]-
[0000] wherein (a) is a monomeric unit comprising at least one quadruple hydrogen bonding unit (4H-unit); (b) a macromonomeric unit; (c) a monomeric unit comprising an ionic group; (d) is a reactive monomeric unit, wherein (a), (b), (c), and (d) are covalently bonded in the polymer structure, or more preferably, in the polymer backbone. Additionally, p, q, r and s indicate the total number of units of (a), (b), (c) and (d), respectively, in the polymer backbone, wherein: p is 1 to 200, preferably 2 to 50 and most preferably 3 to 20; q is 0 to 200, preferably 2 to 50 and most preferably 3 to 20; r is 1 to 200, preferably 2 to 75 and most preferably 4 to 30; and s is 0 to 200, preferably 2 to 75 and most preferably 4 to 30. That is that according to a preferred embodiment the supramolecular ionomer comprises a monomeric unit (a), a monomeric unit (c) and a component selected from the group consisting of macromonomeric unit (b) and reactive monomeric unit (d). According to a more preferred embodiment of the invention, the supramolecular ionomer comprises a monomeric unit (a), a macromonomeric unit (b), a monomeric unit (c) and a reactive monomeric unit (d).
[0015] According to the present invention, the preparation of the supramolecular ionomers involves a chain extension reaction of a monomeric unit (a) comprising a (precursor of a) 4H-element, with a monomeric unit (c) comprising an ionic and/or ionogenic group. As explained above, the ionogenic group may be converted into the ionic group during this chain extension reaction or after the chain extension reaction in a separate step. Likewise, monomeric unit (a) may comprise a precursor of a quadruple hydrogen bonding unit that is converted into the 4H-unit during polymerization or afterwards in a separate step. In this patent application the precursor of a quadruple hydrogen bonding unit is denoted as a 4H*-unit. Consequently, where in this patent application reference is made to a 4H-unit, this term generally and where appropriate also includes a precursor of a 4H-unit, said precursor being indicated as 4H*-unit.
[0016] The molecular structure of the supramolecular ionomer according to the present invention may vary considerably. At one extreme, components (a), (c) and optionally (b) and (d), preferably (a)-(d), can be randomly distributed along the polymer chain. However, at the other extreme, these components can also be alternating—so that a strictly segmented polymer is obtained—in any permutation thinkable. Examples of such structures are:
[0000] -[( a )-( b )-( c )-( d )] n -
[0000] -[( a )-( b )-( d )-( c )] n -
[0000] -[( a )-( c )-( b )-( d )] n - etc.,
wherein n is the number of repeats of the component sequence. Other sequences of components (a), (b) (c) and (d), that are not strictly random or not strictly alternating are obviously also possible as will be apparent to the polymer scientist skilled in the art.
[0018] The supramolecular ionomers according to the present invention comprise self-complementary quadruple hydrogen bonding units (4H-elements or 4H-units) in the polymer structure as well as ionic groups. The amount of 4H-units incorporated in the polymer structure, as calculated by dividing the employed total amount of moles of (a) by the employed total amount of moles of (a), (c) and (b) plus (d) if (b) and (d) are present, is preferably about 5 to about 50 mol %, more preferably about 10 to about 40 mol %, and most preferably about 15 to about 30%.
[0019] The amount of ionic groups incorporated in the polymer structure, as calculated by dividing the employed total amount of moles of (c) by the employed total amount of moles (a), (c) and (b) plus (d) if (b) and (d) are present, is preferably about 5 to about 50 mol %, more preferably about 10 to about 40 mol %, and most preferably about 20 to about 35 mol %.
[0020] The supramolecular ionomer (e) of this invention comprises as many ionic or ionogenic groups as is necessary to make the polymer processable (dispersible or soluble) in water or in aqueous mixtures. The dispersions or solutions can be made by any method known in the art, such as for example the acetone process, the pre-polymer mixing process, the melt emulsification process, or the ketimine-ketazine process (see Ullmann's Encyclopedia of Industrial Chemistry, Volume A21, pages 677-680, 5 th Ed., VCH, Weinheim—Polyurethanes for more information on such processes).
Description of the Reactive Groups (F i )
[0021] As explained above, the preparation of the supramolecular ionomers according to the present invention proceeds by a chain extension reaction of a monomeric unit (a) comprising a (precursor of a) 4H-element, with a monomeric unit (c) comprising an ionic and/or ionogenic group. However, it is preferred that the supramolecular ionomers are prepared from (a), (b) and (c) or (a), (c) and (d). It is even more preferred that the supramolecular ionomers are prepared from (a)-(d).
[0022] Components (a)-(d) are coupled to each other via reactive groups that are denoted as reactive groups (F i ), wherein i denotes the number of reactive groups. The reactive group (F i ) that is present in the components (a)-(d) can be any functional group that is reactive towards another (complementary) functional group, as is evident for persons skilled in the art of polymer or organic chemistry.
[0023] In this patent application the terms “reactive group” and “complementary reactive group” are denoted as (F i ) and are used interchangeably to indicate the reactive groups that are present in (a)-(d). Complementarity of two or more reactive groups is to be understood as reactive groups that are capable to form covalent bonds with each other under conventional reaction conditions, as will be apparent to a person skilled in the art. Preferred examples of (sets of) reactive groups that are complementary are:
hydroxyl groups and isocyanate groups that can form urethanes; amino groups and isocyanate groups that can form ureas; hydroxyl groups, amino groups and isocyanate groups that can form urethanes and ureas; carboxyl derivatives and hydroxyl groups that can form esters; carboxyl derivatives and amino groups that can form amides; and carboxylic acids and isocyanate groups that can form amides.
[0029] The reactive groups (F i ) and preferences for these groups will be further specified in this patent application further below. Preferably, the reactive group (F i ) is a functional group that comprises an active hydrogen atom. In particular, preferred functional groups (F i ) are selected from the group consisting of hydroxyl, thiol, carboxylic acid, (activated) carboxylic ester, carboxylic acid halide, (blocked) isocyanate, (blocked) thioisocyanate, (activated) primary or secondary amine, vinyl, (meth)acrylate, or halogen groups.
[0030] More preferred reactive groups (F i ) are selected from the group consisting of hydroxyl, thiol, carboxylic acid, (activated) carboxylic ester, (blocked) isocyanate, (blocked) thioisocyanate, and (activated) primary or secondary amine groups.
[0031] Even more preferably, the reactive groups (F i ) are selected from the group consisting of hydroxyl, primary amine, isocyanate, carboxylic acid, and carboxylic ester groups.
[0032] Most preferably, the reactive groups (F i ) are selected from the group consisting of hydroxyl, primary amine and isocyanate groups.
[0033] In this patent application, “hydroxy” denotes a —OH group.
[0034] A “thiol” denotes a —SH group.
[0035] A “carboxylic acid” denotes a —C(O)OH group.
[0036] A “carboxylic ester” denotes a —C(O)OR group, wherein R is selected from the group consisting of C 1 -C 6 alkyl, C 6 -C 12 aryl, C 7 -C 12 alkaryl and C 7 -C 12 alkylaryl groups, wherein the alkyl groups may be linear, branched or cyclic.
[0037] A “carboxylic acid halide” denotes a —C(O)X group, wherein X is a chlorine atom, a bromine atom or an iodine atom.
[0038] An “isocyanate” denotes a —NCO group.
[0039] A “blocked isocyanate” denotes a —NHC(O)R* group, wherein R* is a leaving group. Suitable examples of leaving groups are halides, phenol and thiophenol derivatives, cyclic groups such as caprolactam groups, heterocyclic five or six membered rings comprising 1-3 heteroatoms selected from O, S and N such as for example imidazole, hydroxy-succinimide groups, ester derivatives such as the methyl ester of hydroxy-benzoic acid, alcohol derivatives such as 2-ethyl-hexyl-alcohol and t-butyl-alcohol, oxime derivatives such as methyl-ethyl ketoxime.
[0040] A “thioisocyanate” denotes a —NCS group.
[0041] An “blocked thioisocyanate” denotes a —NHC(S)R* group, wherein R* is a leaving group as indicated for “blocked isocyanate”.
[0042] A “primary amine” denotes a —NH 2 group.
[0043] A “secondary amine” denotes a —NHR group, wherein R is selected from the group consisting of C 1 -C 6 alkyl, C 6 -C 12 aryl, C 7 -C 12 alkaryl and C 7 -C 12 alkylaryl groups, wherein the alkyl groups may be linear, branched or cyclic [as described above for the “carboxylic ester” group].
[0044] An “activated amine” denotes a —C(R)═NOH group (that can be converted into an amine group via the Beckmann rearrangement), a —C(O)N 3 group (that can be converted into an amine group via the Curtius rearrangement), a —C(O)NH 2 group (that can be converted into an amine group via the Hofmann rearrangement), a —NHC(O)R* group wherein R is a leaving group as defined above for “blocked isocyanate”. According to the present invention, the “activated amine” preferably denotes a —NHC(O)R* group with R* being an imidazole, caprolactam or hydroxy succinimide group.
[0045] As explained above, the supramolecular ionomer according to the present invention may have different structures. In practice, the sequence of the components (a)-(d) will be governed by the complementarity of the reactive groups (F i ) in the respective components, and thus a somewhat segmented polymer may be obtained. For example, if components (b) and (c) are diols and components (a) and (d) are diisocyanates, the resulting supramolecular ionomer (e) will have the structure: [(a) or (d)] v −[(b) or (c)] w with v and w the number of components (a)+(d) and (b)+(c) in the ioniomeric material, respectively.
[0046] According to the invention, all four components (a)-(d) have preferably two reactive groups (F i ) that enable coupling to one or more of the other components—i.e. the reactive groups in the four components (a)-(d) are complementary—to produce the supramolecular ionomers (e) of this invention.
[0047] However, other numbers of reactive groups (e.g. 1, 3, 4) in either of the components (a), (b), (c) and/or (d) are part of this invention as well, as this allows for branched and/or capped ionomeric materials. A component bearing only one reactive group also gives the opportunity to control and tune the molecular weight of the ionomeric material. Different types of monomeric units (a), macromolecular units (b), monomeric units (c), and reactive compounds (d) can be used in one synthetic procedure. For example, several macromolecular units (b) can be employed wherein the macromolecular units (b) are of a different chemical nature and/or of a different molecular weight, or different monomeric units (c) can be employed wherein the monomeric units (c) are of a different chemical nature and/or bear opposites charges, or different reactive compounds (d) can be used wherein the reactive groups in these compounds are of a different chemical nature.
Description of the Monomeric Unit (a)
[0048] Monomeric unit (a) comprises a 4H-unit and several reactive groups linked to or part of this unit, wherein these reactive groups can form covalent bonds upon reaction with one or more of the other components (b)-(d). In general, monomeric unit (a) can be represented by the formulae (I) or (II),
[0000] (4H) k —(F i ) l (I)
[0000] (4H*) k —(F i ) l (II)
[0000] wherein 4H represents a structural element (4H); 4H* represents a precursor of the structural element (4H); F i represents a reactive group that is linked to the structural element (4H) or it represents a reactive group that is linked to or part of the precursor of the structural element (4H), i.e. (4H*); k represents the number of (precursors of) structural elements (4H) that is present in monomeric unit (a); and l represents the number of reactive groups that is present in monomeric unit (a). According to the invention, k is 1 to 4 and l is 1 to 4.
[0049] Preferably, k is 1 and l is 1 or 2. More preferably k is 1 and l is 2 and monomeric unit (a) is then represented by formulae (III) or (IV):
[0000] F 1 -4H—F 1 or F 1 -4H—F 2 (III)
[0000] F 1 -4H*—F 1 or F 1 -4H*—F 2 (IV)
[0050] According to this preferred embodiment of the invention, monomeric unit (a) contains only one (precursor of a) structural element (4H), and it contains two reactive groups that are of the same (F 1 ) or of a different type (F 1 and F 2 ). The reactive groups F 1 and F 2 are linked to the structural element (4H) or are linked to or part of the precursor of the structural element (4H).
[0051] The reactive groups (F i ) are described and defined in the previous section, and are in this case of monomeric unit (a) most preferably a hydroxyl, primary amine, isocyanate, carboxylic acid or carboxylic ester derivative, and most preferably a hydroxyl, primary amine or isocyanate group.
[0052] In general, the structural element that is capable of forming at least four hydrogen bridges (4H) has the general form (1′) or (2′):
[0000]
[0053] If the structural element (4H) is capable of forming four hydrogen bridges, which is preferred according to the invention, the structural element (4H) has preferably the general form (1) or (2):
[0000]
[0054] In all general forms shown above the C—X i and C—Y i linkages each represent a single or double bond, n is 4 or more and X 1 . . . X n represent donors or acceptors that form hydrogen bridges with the H-bridge-forming unit containing a corresponding structural element (2) linked to them, with X i representing a donor and Y i an acceptor or vice versa. Properties of the structural element having general forms (1′), (2′), (1) or (2) are disclosed in U.S. Pat. No. 6,320,018 which for the US practice is incorporated herein by reference.
[0055] The structural elements (4H) have at least four donors and/or acceptors, preferably four donors and/or acceptors, so that they can form in pairs at least four hydrogen bridges with each another. Preferably, the structural elements (4H) have at least two successive donors, followed by at least two successive acceptors, preferably two successive donors followed by two successive acceptors, preferably structural elements according to general form (1′), or more preferably according to (1) with n=4, in which X 1 and X 2 both represent donors or acceptors, respectively, and in which X 3 and X 4 both represent acceptors or donors, respectively. According to the invention, the donors and acceptors are preferably O, S, and N atoms.
[0056] Molecules that can be used to construct the structural element (4H) are nitrogen containing compounds that are reacted with isocyanates, thioisocyanates or activated amines, or that are activated to give an activated amine that is then reacted with primary amines, to obtain a urea or thiourea moiety that is part of the quadruple hydrogen bonding site. Methods of preparing such structural units are well known in the art. The nitrogen containing compound is preferably a pyrimidine or a triazine derivative. More preferably, the nitrogen containing compound is an isocytosine or a thio-isocytosine derivative (i.e. a 2-amino-4-hydroxy-pyrimidine or a 2-amino-4-mercapto-pyrimidine derivative) or a triazine derivative, or a tautomer and/or enantiomer of these derivatives. More preferably, the nitrogen containing compound is an isocytosine derivative having a proton or aliphatic-substituent containing a functional group in the 5-position and an alkyl-substituent in the 6-position, most preferably 2-hydroxy-ethyl or a 3-propionic acid ester in the 5-position and methyl in the 6-position, or hydrogen in the 5-position and methyl in the 6-position. The isocyanates or thioisocyanates that are reacted with the nitrogen containing compound can be monofunctional or bifunctional (for example alkyl or aryl (di)(thio)isocyanate(s)), and are preferably bifunctional. The primary amine can be of any kind (aromatic, aliphatic) and may contain other functional groups in its structure, such as another amine function, an alcohol, an ester or a carboxylic acid function.
[0057] According to the invention, monomeric unit (a) comprising the structural element (4H) is particularly suitably represented by the compounds having the general formulae (3) or (4), and tautomers and/or enantiomers thereof (see below). Monomeric unit (a) comprising a precursor of the structural element (4H), i.e. (4H*), is particularly suitably represented by the compounds having the general formulae (5) or (6). The X in formulae (4) and (6) is preferably a nitrogen atom, but it can also be a carbon atom with an attached R4-group.
[0000]
[0058] R1, R2, R3 and R4 may independently be a hydrogen or all kinds of shorter or longer chains, for example, saturated or unsaturated, branched, cyclic or linear alkyl chains, aryl chains, alkaryl chains, alkylaryl chains, ester chains, ether chains and any chain of atoms used in traditional (polymer) chemistry, whether or not substituted with one or more functionalities, such as (thio)ureas or thio(urethanes), and whether or not substituted with one or more reactive group(s) (F i ), such as (blocked) isocyanates, (blocked) thio-isocyanates, primary, secondary or tertiary hydroxyl groups (i.e. alcohols), primary, secondary, tertiary or quaternary amines, activated amines, (thio)phenols, thiols, (activated) esters and carboxylic acids. R1, R2, R3 and R4 may also directly constitute one of these or other functionalities or reactive groups (F i ).
[0059] Preferably, “saturated or unsaturated, branched, cyclic or linear alkyl chains” denote a C 1 -C 10 alkylene group.
[0060] “Aryl chains” preferably denote a C 6 -C 12 arylene group.
[0061] “Alkaryl chains” and “alkylaryl chains” preferably denote a C 7 -C 12 alkaryl group and a C 7 -C 12 alkylaryl group, respectively.
[0062] “Ester chains” preferably denote a polyester obtained by ring opening polymerisation of C 4 -C 8 lactones or dilactides or glycolides having the general formula:
[0000]
[0000] wherein the R groups are independently selected from the group consisting of linear or branched C 1 -C 6 alkyl groups. However, it is preferred that for “ester chains” the R groups are independently selected from hydrogen atoms and methyl groups.
[0063] “Ether chains” preferably denote a polyether chain comprising ethylene oxide and/or propylene oxide, wherein the polyether chain is represented by the formula:
[0000] —(CR*H—CR*H—O) w —
[0000] wherein R* can be a hydrogen atom or a methyl group and w is in the range of 1-100, preferably 1-20.
[0064] Preferably, if any one of R1, R2, R3 and R4 is part of or constitutes a reactive group (F i ) or if it comprises one or more reactive group(s) (F i ), and it therefore links the (precursor of the) structural element (4H) to the reactive group(s) (F i ), said linking moiety is a hydrogen, a chemical bond or a C 1 -C 12 straight chain, a branched alkylene group, a C 6 -C 12 arylene, a C 7 -C 12 alkarylene or a C 7 -C 12 arylalkylene group, wherein the alkylene, arylene, alkarylene or arylalkylene group may be substituted with other groups or may contain cyclic groups as substituent or in the main chain. Examples of such groups are methylene, ethylene, propylene, tetramethylene, pentamethylene, hexamethylene heptamethylene, octamethylene, nonamethylene, 1,6-bis(ethylene)cyclohexane, 1,3,3-trimethyl-1-methylene-cyclohexane, 1,6-bismethylene benzene, etc. The alkylene, arylene, alkarylene or arylalkylene groups may be interrupted by heteroatoms, in particular heteroatoms selected from the group consisting of oxygen, nitrogen, and sulphur.
[0065] However, according to the invention, it is even more preferred that the structural elements (4H) or (4H*) in the compounds (3) and (4) or (5) and (6), respectively, are connected to two reactive groups (F i ) via one or two R groups of the series R1, R2, R3, R4 with the other R-group(s) representing independently random side chains or hydrogen atoms. According to the invention, the random side chain is preferably a C 1 -C 12 alkyl group, most preferably methyl, 1-ethylpentyl or 2-ethylhexyl. According the present invention, the term “alkyl” when used in connection with the random side chain encompasses linear, branched and cyclic alkyl groups, but the random side chain is preferably a linear alkyl group.
[0066] Hence, for formula (3), the structural element (4H) is preferably connected to a reactive group (F 1 ) via R1 and to a reactive group (F 1 ) or (F 2 ) via R2, whereas R3 is a random side chain or a hydrogen atom; or the structural element (4H) is connected to a reactive group (F 1 ) via R1 and to a reactive group (F 1 ) or (F 2 ) via R3, whereas R2 is a random side chain or a hydrogen atom; or the structural element (4H) is bonded to two reactive groups (F i ) both via R1, whereas R2 and R3 are independently random side chains or hydrogen atoms. To indicate that the reactive groups (F i ) may be of a different type, they are specified as (F 1 ) or (F 2 ). Most preferably, for formula (3), one reactive group (F 1 ) is connected via R1 and one reactive group (F 1 ) or (F 2 ) is connected via R3, while R2 is a hydrogen or a random side chain as defined above.
[0067] Preferably, for formula (5), the structural element (4H*) is connected to a reactive group (F 1 ) via R1 and a reactive group (F 1 ) or (F 2 ) via R2, whereas R3 is a random side chain as defined above or a hydrogen atom, or the structural element (4H*) is connected to a reactive group (F 1 ) via R1 and to a reactive group (F 1 ) or (F 2 ) via R3, whereas R2 is a random side chain as defined above or a hydrogen atom. Most preferably, for formula (5), one reactive group (F 1 ) is connected via R1 and one reactive group (F 1 ) or (F 2 ) is connected via R3, while R2 is a random side chain as defined above or a hydrogen atom.
[0068] Preferred embodiments of monomeric unit (a) are,
[0000]
[0000] and tautomers or enantiomers thereof, wherein X is a linear, branched or cyclic C 1 -C 16 alkyl group, a C 6 -C 16 aryl group, a C 7 -C 16 alkaryl or a C 7 -C 16 alkylaryl group. Examples are: butyl, hexyl, 1-methylene-1,3,3-trimethyl-cyclohexane, 2,2,4-trimethylhexyl, 2,4,4-trimethylhexyl, 2,2,5-trimethylhexyl, toluoyl, methylene diphenyl or methylene dicyclohexyl. Preferably, n=0, 1 or 2, R is hydrogen, methyl or ethyl, Y is a short linear, branched or cyclic alkylene, arylene or alkylarylene spacer containing two to sixteen carbon atoms and that may contain heteroatoms such as N, S and O, F 1 and F 2 are reactive groups that are defined above and that preferably and independently selected from the group consisting of hydroxyl, primary amine, carboxylic acid and carboxylic ester groups. R2 is a random side chain as defined above.
Description of the Macromonomeric Unit (b)
[0069] Macromonomeric unit (b) can be any functional polymer or oligomer and can be represented in the following schematic form:
[0000] P—(F i ) l (V)
[0000] where P represents the polymer chain, F i represents the reactive groups in the macromonomeric unit (b) and l represents the number of reactive groups (F i ) in macromonomeric unit (b). In formula (V), l is 1 to 30, preferably 1 to 6. More preferably, l is 1 to 3, most preferably l is 2 so that (VII) can be written as:
[0000] F 3 —P—F 3 or F 3 —P—F 4 (VI)
[0070] According to this preferred embodiment, macromonomeric unit (b) comprises two reactive groups (F i ) that can be of the same (F 3 ) type or that can be of a different type (F 3 and F 4 ). The reactive or functional groups (F i ) have been described and defined above, and are in this case of macromonomeric unit (b) preferably hydroxyl, primary amine or isocyanate groups. P represents any polymer backbone, such as a polyether, polyester, polyamide, polyacrylate, polymethacrylate, polyolefin, hydrogenated polyolefin, polycarbonate, polysiloxane, perfluorinated polyether, or the like. P can also represent co-polymers of any kind. According to a preferred embodiment of the invention, P is selected from the group consisting of polyether, polyester, polycarbonate, polysiloxane or hydrogenated polyolefin. Most preferably, P is a polyester, a polyether or a hydrogenated polyolefin and even most preferably, P is a polyester. The number average molecular weight of the polymer P is in the range from about 100 to about 100000, more preferably from about 300 to about 50000, even more preferably from about 400 to about 20000, most preferably from about 500 to about 5000.
[0071] The macromonomeric unit (b) has therefore preferably a number average molecular weight of about 100 to about 100000, preferably about 300 to about 50000 and more preferably about 400 to about 20000 and most preferably about 500 to 5000.
[0072] Preferably, macromonomeric unit (b) is a polymer with hydroxyl groups as reactive groups, more preferably, a polymer with two hydroxyl end groups. Examples are α,ω-dihydroxy polyethers having a polyoxyalkylene chain and hydroxyl end-groups, such as α,ω-dihydroxy polyethylene glycol, α,ω-dihydroxy polypropylene glycol, α,ω-dihydroxy poly(ethylene-co-propylene)glycol, α,ω-dihydroxy poly(ethylene-co-propylene-co-ethylene)glycol, α,ω-dihydroxy polytetramethylene glycol, or α,ω-dihydroxy polyesters, such as α,ω-dihydroxy polycaprolactones, α,ω-dihydroxy polyadipates (e.g. hydroxy terminated poly(1,2-ethylene adipate), hydroxy terminated poly(1,4-butylene adipate), hydroxy terminated poly-(2-methyl-1,3-propylene adipate)), α,ω-dihydroxy polyglutarates (e.g. hydroxy terminated poly(1,4-butylene glutarate, hydroxy terminated poly(2-methyl-1,3-propylene glutarate)), α,ω-dihydroxy polyterephthalates, α,ω-dihydroxy polyphthalates (e.g. hydroxy terminated copolymers of phthalic acid (the term “phtalic acid” is to be understood as to include also the regioisomers of phtalic acid, i.e. homophtalic acid and terephtalic acid) and diethyleneglycol, hydroxy terminated copolymers of phthalic acid and 1,6-hexanediol or 1,4-butanediol), α,ω-dihydroxy polycarboxylates wherein the carboxylates are derived from aliphatic dicarboxylic acids containing 1-12 carbon atoms, the aliphatic moiety being linear, branched or cyclic and the aliphatic moiety optionally containing one or more unsaturated carbon carbon bonds, α,ω-dihydroxy polyisophthalates (e.g. hydroxy terminated copolymers of 5-NaSO 3 -isophtalic acid, isophthalic acid, diethyleneglycol and bis-hydroxymethylene-cyclohexane, hydroxy terminated copolymers of isophtalic acid and 1,4-butanediol, hydroxy terminated copolymers of 5-NaSO 3 -isophthalic acid, adipic acid, phthalic acid and 1,6-hexanediol), α,ω-dihydroxy polylactides, α,ω-dihydroxy polyglycolides, α,ω-dihydroxy poly(hydroxybutyrates), or α,ω-dihydroxy (hydrogenated) polyolefines, such as hydroxyl functionalized polybutadiene, hydroxyl functionalized poly(ethylene-butylene), or α,ω-dihydroxy polycarbonates such as poly(1,3-propanediol carbonate)glycols or poly(1,6-hexanediol carbonate)glycols, or α,ω-dihydroxy polysiloxanes, such as α,ω-bis(6-hydroxy hexyl)polydimethylsiloxanes, α,ω-bis(oligo-ethyleneoxide) polydimethylsiloxanes, or α,ω-dihydroxy-hydroxy polyamides.
[0073] Another preferred macromonomeric unit (b) is a polymer with primary amine reactive groups. Examples are Jeffamines® (polyoxyalkylene amines produced and marketed by Huntsman), or amino terminated polysiloxanes, such as α,ω-bis(3-amino propyl)polydimethylsiloxanes, or amino terminated aliphatic polyamides.
[0074] Another preferred macromonomeric unit (b) is a polymer with isocyanate reactive groups. These type of macromonomeric units (b) are usually derived from hydroxyl or amine functionalized polymers (see above for examples of these polymers) by reaction of these polymers with diisocyanates. Examples of and preferences for such diisocyanates are described below in the description of the reactive compound (d).
Description of the Monomeric Unit (c)
[0075] Monomeric unit (c) can be any functional molecule that comprises at least one ionic group, and can be represented by the following general formula:
[0000] (I) k —(F i ) l (VII)
[0000] wherein I represents the ionic group, F i represent the reactive groups, k represents the number of ionic groups and l represents the number of reactive groups (F i ). Preferably, k is 1 to 3 and 1 is 1 to 5, and more preferably, k is 1 and 1 is 2, so that monomeric unit (c) is represented by formula (VIII):
[0000] F 5 —I—F 5 or F 5 —I—F 6 (VIII)
[0076] According to this preferred embodiment of the invention, the monomeric unit (c) comprises two reactive groups (F i ) that can be of the same (F 5 ) type or that can be of a different type (F 5 and F 6 ). The reactive or functional groups (F i ) are described and defined before, and are in this case of monomeric unit (c) preferably an hydroxyl or a primary amine group, most preferably a hydroxyl group.
[0077] As explained above, an ionogenic group is a precursor for an ionic group. Suitable ionogenic groups are for example (tertiary) amine, pyridine, carboxylic acid or carboxylic ester groups whereas suitable ionic groups are for example quarternary amine (ammonium derivatives which may be linear, branched or cyclic including compounds having a nitrogen atom in the ring, e.g. piperidinium), pyridinium, carboxylate, sulfonate and phosphate groups. Conversion from an ionogenic group to an ionic group is typically achieved by protonation or deprotonation. Alternatively, conversion is achieved by alkylation or saponification of the ionogenic group. Preferably, the ionic groups are selected from the groups that are derived from —N + (R 1 ) 4 X − , —S(O)OH; —S(O) 2 OH; —P(O)(R 1 )(OH); —P(O)(OH) 2 , wherein R 1 is independently selected from the group consisting of linear, branched or cyclic C 1 -C 16 alkyl groups, C 6 -C 16 aryl groups, C 7 -C 16 alkaryl groups or C 7 -C 16 alkylaryl groups and wherein X is the counter ion Y − defined below.
[0078] Monomeric units (c) comprising one or more nitrogen atoms can be used to obtain cationic ionomers (e). Monomeric units (c) comprising one or more nitrogen atom that can be used, are, for example, compounds of the following general molecular formulae:
[0000]
[0000] in which R5 and R6 are independently selected from the group consisting of linear, branched or cyclic C 2 -C 8 alkyl groups, R7, R10, and R11 are independently selected from the group consisting of linear or branched C 1 -C 6 alkyl groups, phenyl groups or (C 1 -C 4 )alkyl phenyl groups, R8 and R9 are independently selected from the group consisting of H or linear or branched C 1 -C 6 alkyl groups, and R12 is selected from the group consisting of H, linear or branched C 1 -C 6 alkyl groups, phenyl groups or (C 1 -C 4 )alkyl phenyl groups.
[0079] Preferably, p is 1, 2 or 3.
[0080] Y − can be any counter anion, but is preferably a chloride, bromide, iodide, phosphate (PO 4 3− /3), sulfate (SO 4 2− /2), [C 1 -C 6 ]alkyl sulfate, [C 1 -C 6 ]alkyl phosphate or [C 1 -C 6 ]carboxylate.
[0081] Monomeric units (c) comprising sulfonate or carboxylate groups can be used to obtain anionic ionomers (e). Monomeric units (c) with sulfonate or carboxylate groups that can be used, are, for example, 2,2-bis(hydroxymethyl)-propionic acid, or compounds of the general formulae:
[0000]
[0000] in which m and n are, independently an integer from 1 to 8, in particular from 1 to 6, M+represents a metal cation with any positive charge (i.e. 1 + , 2 + , 3 + , 4+etc.), preferably a cation derived from an alkaline metal or an alkaline earth metal, more preferably Li + , Na + , or K + , p and q are independently an integer from 0 to 50, with the proviso that p+q>0. The order of the alkylene oxide units is arbitrary, the molecular weight of the polyether-copolymers is preferably from about 400 to about 3000. R14 is preferably a C 2 -C 18 linear, branched or cyclic alkylene group.
[0082] In a preferred embodiment of this invention, monomeric unit (c) is N-methyl-di-2-ethanolamine, 2,6-bis-(hydroxymethyl)-pyridine, 2,2-bis(hydroxymethyl)-propionic acid, or diesters of diols with the alkali salt of 5-sulfo isophthalic acid. More preferably, monomeric unit (c) is N-methyl-diethanolamine, 2,6-bis-(hydroxymethyl)-pyridine or 2,2-bis(hydroxymethyl)-propionic acid, most preferably monomeric unit (c) is N-methyl-diethanolamine.
Description of the Reactive Compound (d)
[0083] Reactive monomeric unit (d) is used in the polymerization reaction to balance or control the molar amounts of the complementary reactive groups in the reaction, such that the desired structure and molecular weight of polymer (e) is achieved. Although the use of reactive monomeric unit (d) is often required, its use is optional. The use of reactive monomeric unit (d) gives the opportunity to introduce extra functions or properties in ionomer (e). For example, reactive monomeric unit (d) may be a reactive (fluorescent) dye, a surface active ingredient, a UV-stabilizer, an anti-oxidant or any other chemical compound having a function.
[0084] Reactive monomeric unit (d) can be any functional compound and is represented by the general formula (IX):
[0000] J-(F i ) l (IX)
[0085] wherein J is an organic moiety, F i is a reactive group as defined above and l is 1 to 5. More preferably, l is 1 or 2, most preferably 2. According to this preferred embodiment, reactive compound (d) is then represented by the general formula (X):
[0000] F 7 -J-F 7 or F 7 -J-F 8 (X)
[0000] wherein J is an organic moiety and F 7 and F 8 are reactive groups as defined above. Most preferably, J is a linear, branched, or cyclic alkylene group having 2 to 24 carbon atoms, preferably 4 to 18 carbon atoms.
[0086] The reactive groups (F i ) are preferably isocyanate, thioisocyanate, hydroxyl, primary amine, carboxylic acid or carboxylic ester groups. Most preferably, the reactive monomeric units (d) are diisocyanates. The diisocyanates most preferred in this invention, are those which are commonly used in polyurethane-synthesis and that are known in the art. Examples of suitable diisocyanates that can be used in this invention are:
1,4-diisocyanato-butane (BDI), 1,4-diisocyanato-4-methyl-pentane, 1,6-diisocyanato-2,2,4-trimethylhexane, 1,6-diisocyanato-2,4,4-trimethylhexane, 1,5-diisocyanato-5-methylhexane, 3 (4)-isocyanatomethyl-1-methylcyclohexyl isocyanate, 1,6-diisocyanato-6-methyl-heptane, 1,5-diisocyanato-2,2,5-trimethylhexane, 1,7-diisocyanato-3,7-dimethyloctane, 1-isocyanato-1-methyl-4-(4-isocyanatobut-2-yl)-cyclohexane, 1-isocyanato-1,2,2-trimethyl-3-(2-isocyanato-ethyl)-cyclopentane, 1-isocyanato-1,4-dimethyl-4-isocyanatomethyl-cyclohexane, 1-isocyanato-1,3-dimethyl-3-isocyanatomethyl-cyclohexane, 1-isocyanatol-n-butyl-3-(4-isocyanatobut-1-yl)-cyclopentane. 1-isocyanato-1,2-dimethyl-3-ethyl-3-isocyanatomethyl-cyclopentane, 3(4)-isocyanatomethyl-1-methylcyclohexyl isocyanate (IMCI), toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), methylene dicyclohexane 4,4-diisocyanate (HMDI), isophorone diisocyanate (IPDI), α,α,α′,α′-tetramethyl-1,3-xylylene diisocyanate (TMXDI), and hexane diisocyanate (HDI).
[0109] More preferably, the diisocyanate is IPDI, HDI, BDI, MDI, TDI, TMXDI, 1,6-diisocyanato-2,2,4-trimethylhexane, 1,6-diisocyanato-2,4,4-trimethylhexane or methylene dicyclohexane 4,4-diisocyanate (HMDI).
[0110] Most preferably, the diisocyanate is IPDI, HDI, MDI, TMXDI or methylene dicyclohexane 4,4-diisocyanate (HMDI).
Description of the Preparation of Supramolecular Ionomer (e)
[0111] The polymers presented in this invention are obtainable by reacting monomeric unit (a) with monomeric unit (c) and optionally macromonomeric unit (b) and/or (d), most preferably by reacting monomeric unit (a) with (c)-(d). Obviously, the various reactive groups in the respective components must enable reaction with one or more of the other components to form covalent bonds (i.e. the reactive groups in the set of components are complementary). Thus, ionomer product (e) is preferably a co-polymer of the components (a)-(d) and has a quadruple hydrogen bonding unit (4H-unit) and an ionic group within the polymer structure.
[0112] According to the present invention, the components (a), (c), and optionally (b) and/or (d), preferably (a)-(d), are brought together and reacted in any desired ratio, fashion, or sequence to produce ionomer (e). The molar ratio in which the components are used, can be varied to a large extent, so that the structure and the molecular weight of the supramolecular ionomer (e) can be predetermined and controlled.
[0113] The polymerization reaction of the components (a), (c), and optionally (b) and/or (d), preferably (a)-(d), that produces ionomer (e) may be any kind of (polymerization) reaction known in the art, but preferably it involves reactions that are typical for the production of polyurethanes (PUR-chemistry) or polycondensates (polycondensations). For example, the four components have only hydroxyl or isocyanate reactive groups (F i ), or hydroxyl, primary amine and isocyanate groups, or hydroxyl, primary amine, carboxylic acid and isocyanate groups (PUR-chemistry), or have only hydroxyl and carboxylic acid or carboxylic ester groups, or hydroxyl, primary amine and carboxylic acid or carboxylic ester groups (polycondensation chemistry).
[0114] The production of polymer (e) may involve any kind of polymerization procedure or process known in the art of polymerization chemistry. Solution, bulk, suspension, and other types of polymerizations may be used; one-pot procedures or procedures involving a sequence of (polymerization) reactions may be used to produce polymers (e). Polymers (e) may also be produced in extrusion processes, in which the components are mixed in any desired sequence. The reaction temperature is in the range from about 20° to about 250° C., preferably from about 60° to about 150° C. The reaction can be carried out without solvent or in a suitable inert solvent or solvent mixture. Suitable solvents are aprotic polar solvents, such as tetrahydrofuran, dioxane, ethyl acetate, toluene, N-methylpyrrolidone, DMSO, and, preferably, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone (MIBK). The reaction is preferably carried out under an inert-gas atmosphere such as nitrogen. The reaction is preferably carried out in the presence of a suitable catalyst known in the art in order to achieve the desired product; examples are dibutyltindilaurate, DABCO or Ti(IV)-alkoxides, such as Ti(IV) tetra-n-butoxide.
[0115] According to the invention, more than one type of monomeric unit (a) and/or type of macromonomeric unit (b) and/or type of ionic or ionogenic unit (c) and/or type of reactive monomeric unit (d) can be used in the polymerization reaction. Examples of this inclusion are:
1. The use of two or more types of macromonomeric units (b) that for example differ in number average molecular weight, in the structure of the main-chain and/or in the nature of the reactive groups; 2. The use of monofunctional species (‘stopper’-molecules) of any one of the components (a), (b) (c) or (d); in formulae these ‘stopper’-molecules can for example be denoted as: 4H—F 1 , 4H*—F 1 , P—F 3 or as I—F 5 (see the previous sections for an explanation of these formulae). The procedure of adding ‘stopper’ molecules is well known in the art (cf. for example Flory, P. J.; J. Am. Chem. Soc. 1942, Vol. 64, p. 2205), and enables the control of the molecular weight and of the end-groups in the polymer product (e). A particular ‘stopper’ molecule 4H—F 1 is for example 2-(3-(6-isocyanato-hexyl)-ureido-6-methyl-isocytosine. Other particular examples involve monofunctional reactive monomeric unitrs (d) that bear an extra function or property, such as for example color (e.g. a hydroxy functionalized dye, a thioisocyanate fluorescent dye, etc.); 3. The use two or more monomeric units (c) that differ in structure, charge and/or type of reactive groups, enabling, in particular, the charge distribution in the polymer product (e). In one embodiment of this invention, polymer (e) can have both acid groups and amino groups. The difference in number of acid groups and amino groups is preferably from about 15 to 150, more preferably from 30 to 100.
Aqueous Compositions
[0119] The aqueous compositions according to the invention comprises about 0.5 to about 40.0%, preferably about 1.0 to about 35.0% by weight of ionomer (e), based on the total weight of the aqueous composition. The ionomer (e) may me molecularly dissolved or be present as dispersed, charged nano-sized particles, preferably having an average size between about 10 and about 250 nm.
[0120] The ionomers (e) comprising acidic groups, i.e. anionic ionomers, can be neutralized partially or completely by using a base. As a rule, the resulting salts of the polymers have better dispersibility or solubility in water than the non-neutralized polymers. Bases that can be used for the neutralization of polymers (e) containing acidic groups are for example (aqueous solutions of) alkali metal bases, such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate and alkaline earth metal bases, such as calcium hydroxide, calcium oxide, magnesium carbonate, magnesium hydroxide, ammonia and amines. Amines suitable for (partial) neutralization are for example C 1 -C 6 -alkylamines, dialkylamines, trialkylamines, dialkylalkanolamines, such as di-C 1 -C 6 -alkylethanolamines, alkyldialkanolamines, such as C 1 -C 6 -alkyldiethanolamines, preferably methyl- or ethyl diethanolamine, trialkanolamines, such as triisopropanolamine, or a diamine like lysine. Obviously, the alkyl groups may be linear, branched or cyclic. More preferably, the amines are 2-amino-2-methyl-1-propanol (AMP), 2-amino-2-methyl-1,3-propanediol (AMPD), diethylaminopropyl amine, and triisopropanol amine. Neutralization of acid containing polymers (e) can also take place using mixtures of two or more bases, such as a mixture of sodium hydroxide and triisopropanolamine. Depending on the intended use, neutralization can be partial, for example up to 40%, or complete, for example up to 100%.
[0121] The polymers (e) containing neutral, protonated or quaternized amino groups are generally readily soluble in water without the aid of emulsifiers. Charged cationic groups can be obtained from (tertiary) amine nitrogens by protonation, for example by using carboxylic acids, such as lactic acid, or mineral acids, such as phosphoric acid, sulphuric acid and hydrochloric acid, or by quaternization, for example by using alkylating agents, such as C 1 -C 4 -alkyl halides or sulfates. Examples of such alkylating agents are methylchloride, methylbromide, ethylchloride, ethylbromide, dimethylsulfate and diethylsulfate. Preferably, charged cationic species are obtained by protonation.
[0122] The use of different monomeric units (c) in the preparation of ionomer (e) allows for tuning of the solubility and dispersibility of the ionomer as function of the pH of the aqueous solution in which the polymer is dispersed or solubilized. Ionic groups with pK a 's in the range of 7 are soluble in neutral aqueous solution, whereas ionic groups with pKa's lower than 6 preferably need acidified water and ionic groups with pKa's greater than 8 preferably need alkaline water. Consequently, a person skilled in the art can convert clear aqueous solutions or dispersions of (e) to gels or turbid dispersions simply by changing the pH.
[0123] Aqueous formulations of the ionomers (e) can be applied to a substrate via spraying or any other method known in the art to apply a solution or dispersion to a substrate. In general, when the macromonomeric unit (b) has a glass transition temperature below 10° C., the resulting ionomers (e) have excellent film-forming properties. Optionally, plasticizers known in the art, such as aqueous dispersions of elastomeric polyethers or hydrophobic non-polymeric plasticizers, may be added to improve film forming at room temperature. Moreover, although the inventors do not wish to be bound by any scientific theory, it has been unexpectedly found that the presence of ionic groups in ionomer (e) results in a strong increase in adhesive properties of these polymers when compared to polymers consisting of only components (a), (b), and (d).
Applications
[0124] The (waterborne) ionomers according to the invention are in particular suitable for applications related to surface coatings used in applications with leather, leather imitates, textile, optical fibers, glass, paper and paint formulations, imaging technologies such as printing, stereo lithography, photography and lithography, biomedical applications, such as (biodegradable) materials for controlled release of drugs, hydrogels for wound-dressings or tissue-engineering, tablet formulations, sizing agents, (thermo)reversible coatings, adhesive and sealing compositions, thickening agents, gelling agents, binders, and surfactant compositions.
EXAMPLES
[0125] The following examples further illustrate the preferred embodiments of the invention. When not specifically mentioned, chemicals are obtained from Aldrich.
Example 1
Preparation of Polymers (e) of this Invention
[0126] Table I shows examples of polymer materials (e) that have been prepared on a ca. 5 to 10 gram scale by reacting the components (a), (b), (c) and (d) in the given molar ratios, e.g. material B has been prepared by using a molar ratio of 0.86 (=ca. 6/7): 1:1:1 for components (a):(b):(c):(d). The polymers (e) have been obtained by reaction in dry chloroform in the presence of dibutyltindilaurate catalyst at an oil bath temperature of 60° C. under an argon atmosphere. The reaction was maintained for as long as NCO-groups were detected, as determined by FT-IR, but typically reactions were executed overnight with stirring. After completion, ethanol was added to the reaction mixture to scavenge traces of unreacted isocyanates. Polymers were isolated by precipitation into hexane and drying. The materials were analyzed with size exclusion chromatography (SEC) to assess their molecular weight relative to polystyrene standards using THF as eluent.
[0127] For component (a), IUI, a ureido-pyrimidone derived from 5-hydroxy-ethyl-isocytosine and 2 equivalents of isophorone diisocyanate (IDPI) was used. IUI is a mixture of (stereo)isomers, because IPDI exists in different (regio)isomers and because both isocyanate groups in IPDI are reactive towards to the amine and hydroxyl functions in 5-hydroxy-ethyl-isocytosine. Therefore, the structure shown below is just one of the possible isomers of component (a). For the preparation of polymer I, in addition to IUI, also the stopper molecule IU was applied (see one of its isomers below).
[0000]
[0128] For component (b) have been used: poly-(2-methyl-1,3-propylene)adipate with hydroxy end groups and a molecular weight M n of 2000 (Poly-(2-MePr-Adp)-2000); poly-(2-methyl-1,3-propylene)glutarate with hydroxy end groups and a M n of 1020 (Poly-(2-MePr-Glu)-1000); poly-(diethyleneglycol)adipate with hydroxy end groups and a M n of 2500 (Poly-(DEG-Adp)-2500); all purchased from Aldrich. These polymers were dried before use by three-fold co-evaporation with dry toluene.
[0129] For components (c), N-methyl-diethanolamine (MDEA), 1,4-bis-(2-hydroxyethyl)piperazine (BHEPip) or 2,2-bis(hydroxymethyl)-propionic acid (DMPA) have been used. For component (d), IPDI was optionally used.
[0000]
TABLE I
Preparation of polymers (e) by reaction of the components in the given molar ratios.
Component (a)
Component (b)
Component (c)
Component (d)
mol
Telechelic OH-functional
mol
ionogenic
mol
reactive
mol
M n
Material
4H-unit
ratio
Polymer
ratio
Group
ratio
group
ratio
(kD) 1
A
IUI
1.60
Poly-(2-MePr-Adp)-2000
1.00
BHEPip
1.00
IPDI
0
8.1
B
IUI
0.86
Poly-(2-MePr-Adp)-2000
1.00
BHEPip
1.00
IPDI
1.00
18.2
C
IUI
1.00
Poly-(2-MePr-Adp)-2000
1.00
MDEA
1.00
IPDI
1.00
17.2
D
IUI
0.86
Poly-(2-MePr-Adp)-2000
1.00
MDEA
1.00
IPDI
1.00
15.0
E
IUI
1.00
Poly-(2-MePr-Adp)-2000
1.00
MDEA
2.00
IPDI
2.00
19.4
F
IUI
0.86
Poly-(2-MePr-Adp)-2000
1.00
MDEA
2.00
IPDI
2.00
24.6
G
IUI
0.86
Poly-(2-MePr-Glu)-1000
1.00
MDEA
2.00
IPDI
2.00
8.7
H
IUI
0.86
Poly-(DEG-Adp)-2500
1.00
MDEA
2.00
IPDI
2.00
9.7
I 2
IUI
0.80
Poly-(2-MePr-Adp)-2000
1.00
DMPA
0.60
IPDI
0.60
10.1
J 3
IUI
0.86
Poly-(2-MePr-Adp)-2000
1.00
—
—
—
—
16.5
K 3
—
—
Poly-(2-MePr-Adp)-2000
1.00
MDEA
1.00
IPDI
1.86
23.2
1 molecular weight in kiloDalton as determined with SEC relative to PS-standards
2 for this polymer also 0.4 mol ratio of IPDI-UPy stopper component (a) was used
3 examples for comparison
[0130] For components (c), N-methyl-diethanolamine (MDEA), 1,4-bis-(2-hydroxyethyl)piperazine (BHEPip) or 2,2-bis(hydroxymethyl)-propionic acid (DMPA) have been used.
[0131] For component (d), IPDI was optionally used.
Example 2
Preparation of Aqueous Mixtures of Polymers (e)
[0132] Materials A, B, C, D, E, F, G, and H, can be dispersed in water by first dissolving them in THF, or alternatively, by directly using the reaction mixture with the polymers (e) when the solvent for reaction is THF or a ketone. To this THF solution, an HCl-solution in water is added in such a way that 0.95 equivalents of the tertiary amines become protonated; the protonation yields polymers A(H + )—H(H + ). Evaporating the THF for a prolonged time at 40° C., and applying such a vacuum that the water is not evaporated, gives aqueous mixtures that are low viscous, when containing up to at least 20 w/w % polymer material. Transparent, milky blue or milky white dispersions can be obtained. For example, polymers F(H + ) and G(H + ) give low viscous blueish mixtures at a 20 w/w % concentration in water, while polymer H(H + ) gives a low viscous and more transparent mixture and polymer D(H + ) gives a low viscous more milky-white mixture at the same concentration levels in water. Homogeneous aqueous mixtures of polymers (e) prepared at 30 w/w % concentration levels are also transparent, milky blue or milky white, but these mixtures show increased viscosities when compared to the 20 w/w % solutions.
[0133] The above described aqueous mixtures, possibly with added ingredients wanted for the specific application that are solubilized or dispersed in water, can be used directly in formulations that can be sprayed and applied on surfaces of choice.
Example 3
Properties of the Prepared Polymers (e)
[0134] The polymers (e) A-I in Table I have excellent film-forming properties when casted or sprayed on a surface from organic solvents. Also the aqueous mixtures of the protonated polymers, designated with A(H + )—H(H + ), as prepared by the procedure given in Example 2 can be casted or sprayed to give films. Some films have been examined with respect to their mechanical properties and their thermal properties. Results are shown in the Table II; given are the Young's modulus (E mod ), the yield stress (σ yield ) and the elongation at break (ε break ), that is defined as (L atbreak −L 0 )/L 0 *100%, with L 0 being the length of the narrow middle part of the dog-bone-shaped testing bar before elongation and L atbreak being the length of the narrow part of the dog bone at the elongation of break.
[0000]
TABLE II
Mechanical testing data and thermal properties
of several polymer materials (e).
Mechanical Properties (average
Thermal
values of more tests)
Properties
E mod
σ yield
ε break
Tensile Set
Tg
Tm
Material
(MPa)
(MPa)
(%)
(TS in %)
(° C.)
(° C.)
A
15.7
2.1
290
n.d.
n.d.
n.d.
A(H + )
51
4.1
180
n.d.
n.d.
n.d.
B
4.9
0.7
790
n.d.
−32
—
B(H + )
14
2.0
700
n.d.
−37
—
D
2.7.
1.1.
1150.
17
−32
—
D(H + )
6.5
1.1
570
34
−39
—
F
5.3
0.6
800
33
−31
—
F(H + )
37
2.5
700
51
−37
71
G
13
1.0
430
14
−4
—
G(H + )
179
9.5
300
34
−25
68
K a
soft/sticky
soft/sticky
soft/sticky
Soft/sticky
−43
n.p.
K(H + ) a
soft/sticky
soft/sticky
soft/sticky
Soft/sticky
−42
n.p.
a Comparative polymer, mechanical properties too poor to be determined
(n.d. = not determined; n.p. = not present).
[0135] Per polymer material, 3 to 5 dog bones have been prepared and average measured values are given in Table II. The tensile set (TS) is determined after break of the dog bones, and is thus defined here as (L afterbreak −L 0 )/L 0 *100%, with L 0 defined as before and L afterbreak being the length of the narrow middle part of the broken dog bone after the test and after piecing the testing bar together.
[0136] Table II shows that the prepared polymers (e), i.e. A, B, D, F, G and their protonated equivalents, are quite elastic, especially given their relatively low molecular weights (given in Table I). The tensile set is measured after break (>300% elongation), so the TS-values will be significant lower when determined after lower elongations of for example 50% or 100%. The Young's moduli show that the polymers (e) are real materials that are not sticky (E mod >1 MPa). Moreover, the Young's modulus can be tailored by changing the (ratio between) the components (a), (b), (c) and (d). All polymers (e) give transparent films that are not or hardly hygroscopic.
Comparative Example 4
Polymer J
[0137] Applying the same procedure as mentioned in example 2 to material J, resulted in the formation of a precipitate. Hence, material J, lacking ionogenic or ionic groups, can not be dispersed or solubilized in water, as opposed to the polymers A(H + )—H(H + ) given in Example 2.
Comparative Example 5
Polymers K and K(H + ) Versus Polymers D and D(H + )
[0138] Applying the procedure as mentioned in example 2 to material K, resulted in the formation of a clear low viscous solution of polymer K(H + ). However, the material properties of materials K and K(H + ), respectively, are much poorer as those of, for example, materials D and D(H + ), respectively, that have incorporated 4H-units. Polymers K and K(H + ) are so soft and sticky that they do not allow the formation of a testing bar for mechanical testing; in contrast, polymers D and D(H + ) are non-sticky materials with very elastic properties.
Comparative Example 6
[0139] Generally, polymers (e)—for example those given in Tables I and II—adhere much better to various surfaces than comparable polymers without ionic or ionogenic groups such as polymer J. This latter polymer J can be peeled off surfaces easily or more easily than the polymers (e) of this invention.
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The invention relates to supramolecular ionomers. i.e. polymers having quadruple hydrogen bonding units (4H-units) and ionic groups or ionogenic groups within their structure. The supramolecular ionomers can be dispersed or solubilized in water at high solids contents while maintaining low viscosities, facilitating easy use and processing of the resulting aqueous formulations. The aqueous supramolecular ionomer compositions have excellent film-forming properties. Moreover, the polymer materials have good mechanical properties after drying, as they are not tacky, show high elasticity and low or no creep.
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The present invention relates to the production of mercapto alcohols and more particularly to the production of mercapto alcohols in which the --SH and --OH groups are in alpha-beta relationship to each other, by reacting a vicinal epoxide with H 2 S.
Typically when mercapto alcohols are made in this manner excess H 2 S is employed to maximize conversion of the epoxide and to minimize the production of thiodiglycol. In the past the unreacted, excess H 2 S was simply flashed to the atmosphere. However, for ecological and economical reasons it is more desirable to recover the H 2 S for recycling in the process. The recycling operation generally involves compression and purification of the unreacted H 2 S.
In practicing the recycling of the unreacted H 2 S, it was observed that mercapto alcohol built up in the H 2 S system knockout pots, compressors, and columns. This in turn led to numerous valve failures in the H 2 S compressors. Upon investigation it was surprisingly found that the mercapto alcohol buildup was the result of formation of the mercapto alcohol in the compressors rather than entrainment of the mercapto alcohol in the H 2 S stream. The excess H 2 S stream coming from the reaction zone was found to contain significant amounts of the epoxide rather than significant amounts of the mercapto alcohol product. The mercapto alcohol was apparently forming as a result of the heat developed during the compression of the H 2 S.
An object of the present invention is to provide a method for removing the unreacted epoxide from the excess H 2 S so that the H 2 S can be compressed and purified for reuse without the inconvenience noted in the past.
SUMMARY OF THE INVENTION
In accordance with the present invention a process is provided in which a mercapto alcohol is produced by the reaction of H 2 S with a vicinal epoxide under suitable reaction conditions, excess H 2 S is separated from the mercapto alcohol and the thus separated excess H 2 S prior to being compressed is subjected to reaction conditions sufficient to cause entrained epoxide to be converted to the mercapto alcohol.
DETAILED DESCRIPTION
The reaction of the hydrogen sulfide with the epoxide can be carried out using generally any of the techniques known in the art. Typically examples of such procedures are disclosed in U.S. Pat. Nos. 3,574,768 and 3,462,496, the disclosures of which are incorporated herein by reference. Generally this reaction involves the commingling of a liquid mixture of the epoxide with or without inert diluent with excess H 2 S.
The epoxides often used in such reactions are alkyl or cycloalkyl epoxides, which can be substituted with halogen groups, alkoxy groups, hydroxyl groups, aromatic groups, such as phenyl, naphthyl, tolyl or hydrocarbon substituted hydrocarbon rings, halo-aromatic groups, and phenoxy and ring-halogenated phenoxy groups.
Specific representative compounds which can be reacted include ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, isobutylene oxide, glycidol, butyl glycidyl ether, cyclohexene oxide, styrene oxide, and ring-substituted derivatives thereof, including halogenated and alkylated styrenes, epichlorohydrin, epibromohydrin, epifluorohydrin, epiiodohydrin, diglycidyl ether, and the diglycidyl ether of Bisphenol A.
The present invention is particularly of importance for the reactions using the more volatile epoxides, particularly the alkyl epoxides containing 2 to 6 carbons per molecule, more especially for ethylene oxide and 1,2-propylene oxide.
The temperature and pressures employed in the reaction between the H 2 S and the epoxide can vary widely and depend to some extent upon the epoxide employed. Generally, however, the pressure will be in the range of 50 to 1000 psig or more. Generally the temperature is in the range of about 20° C. to about 160° C., more typically in the range of 50° C. to 120° C.
It is generally preferable to employ a catalyst for the reaction between the H 2 S and the epoxide. Examples of known catalysts include the activated alumina of U.S. Pat. No. 3,574,768 and those such as alkali metal hydroxides, alkaline earth metal hydroxides, hydrated forms of alkaline earth metal hydroxides, trialkylamines, quaternary amines, and chromium salts of lower saturated aliphatic organic acids having 1 to 4 carbon atoms per molecule.
The amount of the H 2 S is as noted greater on a molar basis than the amount of epoxide employed. The mole ratio of H 2 S to epoxide can be as high as 10/1 or more.
The unreacted H 2 S can be separated from the reaction product in any suitable manner. Typically the separation simply involves venting the H 2 S from the first reaction vessel into another vessel or conduit.
Epoxide contained in the separated unreacted excess H 2 S can be converted to the mercapto alcohol by heating the mixture to a suitable temperature.
Here again the temperature needed to effect the reaction will vary somewhat depending upon the particular epoxide employed. For H 2 S containing entrained ethylene oxide a temperature of at least about 110° F. (43° C.) would generally be desirable. Most typically a temperature of about 140° F. would be preferred.
One preferred technique for effecting the conversion of entrained epoxide to mercapto alcohol involves contacting the H 2 S with a heated fluid which is substantially inert, that is to say, a fluid which does not react significantly with the H 2 S or epoxide and which does not result in the formation of undesirable byproducts. A particularly preferred fluid for such an embodiment is the mercapto alcohol which results from the reaction of the H 2 S and the epoxide. Another example would be suitable thioether, particularly those having no more than about 10 carbon atoms per molecule.
A typical application of the present invention would be in a process wherein ethylene oxide and H 2 S are continuously fed into a loop reactor while the mercapto alcohol product is continuously removed. In such a process the pressure in the loop reactor is maintained so that a liquid phase is present and excess H 2 S is separated by being flashed to a lower pressure.
Ethylene epoxide entrained in the thus separated H 2 S can be converted into additional beta mercapto alcohol by countercurrent contact with the beta mercapto alcohol that had been heated to preferably about 140° F. This can readily be done by passing the H 2 S up through a column, preferably containing liquid-gas contacting means or packing, while passing heated mercapto alcohol downward through the column. H 2 S substantially free of epoxide can be recovered from the column. Typically, the H 2 S would then be passed through a condenser and a mercapto alcohol accumulator, and then to a compression/purification sytem. The end result is a H 2 S stream that can be sent through a compression/purification system without causing the problems heretofore observed. A side benefit is additional mercapto alcohol which can be recovered from the overhead accumulator.
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A process for the production of mercapto alcohols wherein an epoxide is reacted with excess H 2 S, the excess H 2 S is separated from the mercapto alcohol, and the thus separated H 2 S is subjected to reaction conditions sufficient to cause entrained epoxide to be converted to mercapto alcohol before the H 2 S is compressed.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to the field of mobile communication devices and deals more particularly with a package and housing design that combines the mechanical design considerations for the RF, acoustic and image capture functionalities to reduce the overall physical size of the device and at the same time enhance the RF, accoustic and optics performance.
[0002] The growth in the use of portable electronic devices such as, for example mobile communication devices, cellular telephones and the like, has driven the design of such devices to become smaller and more convenient and include further features and functionalities. These newer feature and functionality laden mobile communication devices have led to a new product category in the mobile phone industry as multi-media phones. Multi-media phones are highly desirable and are characterized by some type of camera or image capturing feature and a wide range or diversity of audio features and functionality, such as, music playback, which may or may not be combined with some type of video or graphics.
[0003] Consumers have become accustomed to the convenience and portability of cellular telephones and have demanded that those cellular telephones become even more convenient and even more portable. The constant thrust in cellular telephone design is to make them as small as possible and the same demands are placed on multi-media mobile phones.
[0004] Conventional multi-media mobile communication devices such as for example, of the type shown by the prior art in FIG. 1 and FIG. 2 and generally designated 100 typically include an internal antenna 102 , a speaker or audio transducer component 104 to provide audio functionality and a camera system or other similar imaging sensor 106 to provide image capture functionality. The multi-media mobile communication device may be, for example, a cellular telephone and include a display such as an LCD or other visual display panel generally designated 110 and include keys 112 , 112 which are used for dialing the desired telephone number or for activating and utilizing features of the multi-media cellular telephone 100 . The internal antenna 102 includes an RF-emitter that is generally held or located in a spaced separation with respect to a ground plate mounted in a chassis or sub-assembly within the housing of the device 100 . The RF-emitter electrically connects to the operational electronic circuitry of the mobile communication device. The spaced separation between the RF-emitter and the ground plate area defines the mechanical outline of an antenna chamber volume generally designated 120 , that is, the area or space beneath or under the antenna profile outline is clear of interference.
[0005] The audio functionality for the multi-media phone is typically provided by an audio transducer 104 , such as, a loud speaker, earpiece and microphone which are located separate and away from the antenna RF-emitter to prevent interference with the emitter. Typically, the transducer or speaker 104 is mounted in an enclosure of some sort defining a chamber generally designated 130 . The chamber 130 functions as an acoustic resonator and the physical size or volume of the chamber 130 influences the audio quality, and a larger volume generally results in better audio quality.
[0006] The image capture functionality of the multi-media phone is typically provided or carried out by a camera system or other similar sensor 106 , such as an optics package or module that is also located separate and apart from the antenna functionality and audio functionality to prevent interference. The image capture functionality is also enclosed within the housing of the multi-media phone in an area or enclosure of a desired configuration defining a chamber generally designated 140 to accommodate the camera system. The camera system may include but is not limited to the camera lens, focus and image capturing components including any of the optic and electronic components necessary to carry out the intended function. As illustrated in the schematic functional block diagram shown in side elevational view in FIG. 2, the internal antenna 102 , speaker component 104 and image capture unit 106 are maintained in a spaced relationship with respect to one another and typically consuming a large amount of space and volume within the housing thus adding to the overall size of the multi-media mobile communication device. The camera system or image capture functionality specifically, the size of the camera optics package or module 106 has been forced to be reduced in size and volume to accommodate the demand for smaller and more convenient mobile phones. To obtain the size reduction, lenses have been made smaller and accordingly the focal length of the camera system made shorter. As a consequence, the captured image quality (aberrations, brightness and other image quality characteristics) worsens and is less than desirable due to fundamental optics laws, manufacturing problems and tolerances and lens purity. In order to improve the captured image quality, the size of the camera optics package or module 106 must be made larger or high precision optics made of glass must be used. Accordingly, the internal antenna 102 , audio transducer 104 and camera optics 106 impose separate mechanical design requirements and operational considerations that must be taken into account to insure the proper operation of each functionality to obtain the desired results. These functionality design and operational considerations add to the overall physical size of the multi-media mobile communication device 100 , and each requires a relatively large air volume cavity within the mobile communication device to provide the desired and acceptable performance level.
[0007] U.S. patent application Ser. No. 10/099,476 titled, “Mobile Communication Device and Related Construction Method” and assigned to the same assignee as the present invention discloses a possible structure and method for sharing at least a portion of the volume required to provide the RF functionality and the acoustic functionality to further reduce the size of the mobile communication device while maintaining acceptable performance levels. In the referenced application, which is incorporated herein by reference, a common shared chamber provides sufficient air volume for the RF antenna functionality and required back cavity air volume for the audio transducer. However, the image capture functionality remains physically separate in its own space or area within the housing.
[0008] Consequently, there is a need to identify further construction methods and designs that provide the desired overall physical size reduction and yet provide a chamber having a sufficient air volume to accommodate RF antenna, acoustic and image capture functionalities while overcoming the disadvantages of known multi-media mobile communication devices.
[0009] Therefore, it is a general object of the present invention to provide a mechanical design that reduces the size of the multi-media mobile communication device.
[0010] It is a further object of the present invention to provide a design method to combine the RF functionality, accoustic functionality and image capture functionality without increasing the size of the multi-media mobile communication device.
[0011] It is another object of the present invention to provide a reduced size multi-media mobile communication device by sharing a common physical volume for the RF antenna, the audio transducer and the camera system that accommodates the mechanical and operational design requirements of the RF antenna, speaker and camera system, respectively.
[0012] It is a yet further object of the present invention to provide a reduced size multi-media mobile communication device wherein the RF antenna common shared volume chamber provides the required back cavity air volume for the audio transducer and image capture camera optics.
SUMMARY OF THE INVENTION
[0013] In accordance with a first aspect of the invention, a multi-media mobile communication device of the type having a RF transmitter and receiver, a RF antenna, a speaker component and imaging functionality includes a housing for carrying subassemblies comprising an operational communication device. The housing itself is generally a contoured case that has an exterior surface and an interior surface. In one embodiment, the interior surface forms and defines a shared interior cavity within the housing for carrying a speaker component and a RF antenna with the further improvement of carrying the imaging functionality. Preferably, the imaging functionality further comprises camera optical means, which may further include camera sensor means. The camera sensor means may be located within or outside the shared interior cavity.
[0014] Preferably, the camera optical means includes a camera lens carried within the shared interior cavity and located intermediate of the camera sensor means and an aperture in a wall of the interior cavity and defining an optical path having a first focal length.
[0015] Preferably, the multi-media mobile communication device includes one or more lenses defining a lens system being located intermediate the camera lens and the aperture along the optical path and defining a second focal length to improve the quality of an image being captured.
[0016] Preferably, the lens system includes means for varying the focal length along the optical path to improve the quality of an image being captured.
[0017] Preferably, the housing includes a window in optical alignment with the camera sensor means whereby an image is captured when the housing is held in an orientation with the window pointed in the direction of the image.
[0018] Preferably, a further lens is located in the housing window.
[0019] Preferably, the RF antenna is an internal planar antenna located in a spaced relationship to and with the audio component and the camera means.
[0020] Preferably, the shared interior cavity provides a suitable air volume to simultaneously accommodate RF antenna functionality, audio functionality and imaging functionality.
[0021] Preferably, the shared interior cavity carrying the antenna, audio and imaging functionality is a substantially sealed acoustic cavity.
[0022] In accordance with a further aspect of the invention, a multi-media mobile communication device has antenna functionality, speaker functionality and imaging functionality and includes a housing for carrying subassemblies of the operational communication device. The housing has an interior cavity of a predetermined volume for accommodating the antenna functionality, speaker functionality and imaging functionality.
[0023] In another aspect of the invention, a multi-media mobile communication device includes a housing for carrying subassemblies defining the operational communication device. Speaker mean 6 are provided for producing audible signals, and antenna means are provided for transmitting and receiving RF signals and camera means are provided for capturing image signals. Cavity means defining a substantially sealed chamber within the housing carry the speaker means, the antenna means and the camera sensor means. Additionally, the cavity means defines a common shared chamber that functions as an acoustic resonator chamber, an antenna-ground plate separation chamber and imaging capture chamber.
[0024] A yet further aspect of the invention relates to a method for construction of a multi-media mobile communication device having combined RF antenna, audio and imaging functionalities. The method for construction comprises the steps of: locating the RF antenna means, audio transducer means and camera sensor means in a combined shared chamber within the multi-media mobile communication device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Other objects, features and benefits of the present invention will become readily apparent from the following written detailed description taken together with the drawings forming a part thereof, wherein
[0026] [0026]FIG. 1 is a schematic functional block diagram of a conventional multi-media phone representative of the prior art;
[0027] [0027]FIG. 2 is a schematic functional block diagram in a side elevation view of the conventional multi-media phone illustrated in FIG. 1 representative of the prior art;
[0028] [0028]FIG. 3 is a schematic representation of a portion of a mobile communication device showing the construction of a prior art combined common shared antenna-speaker chamber;
[0029] [0029]FIG. 4 is a schematic functional block diagram representation of a portion of a multi-media mobile communication device showing the combined common shared antenna-speaker-image capture chamber embodying the present invention;
[0030] [0030]FIG. 5A is a schematic functional block diagram representation of a portion of a multi-media mobile communication device showing another embodiment of the combined common shared antenna-speaker-image capture chamber of the present invention wherein an additional optics system is located between the aperture and the camera sensor;
[0031] [0031]FIG. 5B is a schematic functional block diagram representation of a portion of a multi-media mobile communication device showing another embodiment of the combined common shared antenna-speaker-image capture chamber of the present invention wherein an aperture is located in oppositely disposed walls and the camera sensor is located outside the chamber;
[0032] [0032]FIG. 5C is a schematic functional block diagram representation of a portion of a multi-media mobile communication device showing another embodiment similar to FIG. 5C wherein an additional lens system is located in the chamber between the apertures located in oppositely disposed walls and with the camera sensor located outside the chamber;
[0033] [0033]FIG. 6 is a schematic representation of an exemplary cover of a multi-media mobile communication device illustrating the combined common shared antenna-speaker-image capture chamber embodying of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0034] In order to gain a better understanding of the present invention, a discussion of a prior art combined common shared antenna-speaker chamber is illustrated in FIG. 3 as a schematic representation of a portion of a mobile communication device and is generally designated 60 . As illustrated in FIG. 3, the planar antenna 70 and audio transducer or speaker component 80 share a common cavity or chamber 90 with a portion 92 of the chamber 90 located in the area beneath the antenna 70 . The antenna and audio transducer are combined into a single mechanical configuration that meets both the acoustic requirements and the RF requirements of the mobile communication device. The planar antenna 70 may be carried on a surface 50 of the cover 52 forming a part of the chamber 60 when the cover is in place. The cover 52 provides rigidity to the planar antenna which may be printed or deposited thereon on the upper surface 50 or on the inner surface 56 disposed opposite the outer surface 50 and facing inwardly toward the chamber cavity 90 . The planar antenna 70 is printed in a manner well known to those skilled in the art of mobile communication devices and is connected in a normal manner to the operational electronic circuitry defining the mobile communication device.
[0035] The antenna 70 or the surface carrying the antenna is held or otherwise mounted in a generally fixed and spaced relationship with respect to an inner surface or plane 62 of the chamber or with respect to a substrate, such as an electrical printed circuit board (not shown) carried within the chamber 60 . The printed circuit board is well known to those skilled in the art and may take on many different forms and shapes to accommodate the packaging of the mobile communication device. A ground plane or plate 64 such as metallized paint or other conductive materials to carry out the intended function is carried on at least a portion of the cavity surface 62 and in a spaced relation to the planar antenna 70 . To operate properly, the RF-emitter of the antenna 70 is mechanically placed or constructed such that there are no electrical conductors or dielectric materials near the emitter. In the prior art combined common shared antenna-speaker chamber design shown in FIG. 3, the ground plane 64 prevents the inadvertent or unintentional placement of electrically conducting material such as circuit paths and electrical components in the vicinity of or beneath the RF-emitter of the antenna 70 . The chamber is a substantially sealed chamber to provide the desired acoustic characteristics and audio passes through “leak” holes in the chamber wall.
[0036] Although the antenna chamber volume can be a part of the speaker chamber volume, and thus the total combined volume for the speaker and antenna is less than the two separate volumes of the antenna and the speaker, an additional volume or space is required within the housing of a multi-media mobile communication device having a prior art combined common shared antenna-speaker chamber.
[0037] Now considering the invention in further detail, a schematic functional block diagram representation of a portion of a multi-media mobile communication device embodying the combined common shared antenna-speaker-image capture chamber embodying the present invention is illustrated in FIG. 4 and generally designated 200 . The combined common shared chamber 200 may be formed as an integral portion of the device housing or may be a separate structural component part or module located within the housing. The combined common shared chamber 200 includes an internal planar antenna generally designated 202 and an audio transducer, for example, a speaker generally designated 204 . The combined common shared chamber 200 also includes the imagining capture functionality and comprises in the illustrated embodiment, a camera sensor generally designated 206 carried on the interior surface generally designated 210 of a wall 222 of the chamber 200 . An aperture or opening 212 is located in a wall 208 in an oppositely disposed and spaced relation with the wall 222 . The aperture 212 is aligned opposite the camera sensor 206 so that arrows 220 , 220 which are representative of light paths of an image pass through the aperture 212 along an optical path having a first focal length and impinge on the surface 214 of the camera sensor 206 . The term “aperture” as used herein defines the optical opening through which light paths of an image pass along an optical path. It will be noted that the aperture is not a physical opening allowing communication between the outside and inside of the chamber because the desired acoustic characteristic achieved by the sealed chamber would be affected. Therefore, as a practical matter, the aperture 212 contemplates a physical window barrier 228 in the wall to maintain the chamber substantially sealed while admitting light paths. An optically clear window may form the aperture 212 . It should be apparent that a sealing means 236 may be utilized between the edges of the window and chamber wall to maintain the desired sealed chamber 200 . The internal volume of the combined common shared chamber 200 is determined by the dimensions of height and width and depth of the chamber 200 and is calculated to provide the necessary mechanical design requirements for the antenna and camera optics and satisfy the acoustic transducer volume requirements to insure the desired acoustic resonator performance for the characteristics of the audio transducer 204 .
[0038] The walls 208 , 216 , 218 , 222 and the bottom cover 224 and oppositely disposed upper cover 226 are preferably made of a strong, light-weight plastic material to provide the necessary mechanical rigidity to carry the audio transducer 204 and the camera optics 206 without adding any appreciable weight to the multi-media mobile communication device. Alternately, the aperture 212 may include an additional camera lens or lens system in addition to or in place of the window barrier 228 to further enhance or improve image quality. The choice of plastic or other desirable material to carry out the intended function is dependent on the actual construction and fabrication techniques employed to manufacture the combined common shared chamber and such materials are well known to those skilled in the art. The material of the combined common shared chamber is not restricted to plastic or presently known materials and contemplates the use of other currently known or future developed materials.
[0039] The walls, bottom and upper covers can be glued or otherwise sealed or can be sonically welded to provide the substantially sealed combined common shared chamber 200 . Other methods including molding the combined common shared chamber 200 with the antenna, audio transducer and camera optics in place are likewise suitable methods for construction and are well known to those skilled in the art. The physical appearance or configuration of the combined shared chamber 200 is not restricted to any given shape, but may be contoured and shaped to accommodate the size and shape of a multi-media communication device housing with which it is used. The important aspects to take into account are the mechanical design considerations to achieve the desired performance levels of the RF-antenna, acoustic and image capture functionalities. It should also be apparent that a corresponding window lens or opening must be located in a wall of the multi-media communication device to admit the image.
[0040] Turning now to FIGS. 5A, 5B and 5 C an alternate embodiments of the combined antenna-speaker-image capture chamber of the present invention are illustrated as a schematic functional block representation therein and generally designated 250 . The embodiments shown in FIGS. 5A, 5B and 5 C are similar in appearance to that shown in FIG. 4 and like reference numbers refer to like parts. In FIG. 5A, the combined common shared chamber 250 includes an additional optics system including a lens or lens system 230 physically located within the chamber intermediate the camera sensor 206 and the aperture 212 . The lens system 230 may include one or more lenses as required to provide the desired optical focus and focal length, for example, a wide angle capture of an image or a smaller angle capture of an image. Although not shown, the lens system 230 may have a telescopic capability controllable by suitable electronics carried in the multi-media mobile phone. Arrows 220 , 220 which are representative of light paths of an image pass through the aperture 212 and lens system aperture 232 along an optical path having a second focal length compared to the embodiment of FIG. 4 to impinge on the surface 214 of the camera sensor 206 . Optionally, the aperture 212 may include an additional lens 234 to provide further enhanced image capture quality. Since the focal length of the system is longer than that available with prior art multi-media phones, the lens may be of an optical grade plastic and achieve, at a lesser cost of components or construction, similar or better image quality than that of glass lenses used in prior art multi-media mobile phones.
[0041] Additional combinations of camera optics, lenses and sensor placements are also possible and contemplated by the present invention as illustrated in FIGS. 5B and 5C. For example, and not by way of limitation, it may be desired to locate a lens system 234 a , 234 b in apertures 212 a , 212 b respectively in oppositely disposed walls 208 , 222 of the chamber 250 with the camera sensor 206 located outside the chamber. It may also be desired to include one or more lens systems 230 inside the chamber located along the optical path between the apertures 212 a , 212 b in the oppositely disposed walls 208 , 222 of the chamber 250 .
[0042] It will be recognized and appreciated by those skilled in the art that the above schematic functional block representations are provided for illustrative purposes only to explain the features and benefits of the present invention. It will be recognized that the mechanical structural elements forming the common shared antenna-speaker-image capture chamber can be integral with the interior of the multi-media mobile communication device housing and produced as a part of the plastic injection molding process or other manufacturing process techniques employed either now known or future-developed. The important idea to be carried away from the above disclosure is the combination of the otherwise separate common shared antenna-speaker chamber with the image capture functionality to reduce the overall size of the multi-media mobile communication device.
[0043] The construction method of the present invention includes providing a common shared antenna-speaker-image capture chamber or cavity within the interior of the housing of the multi-media mobile communication device and locating the camera system within the chamber such that the camera system does not interfere with the operation of the RF-emitter of a planar antenna carried on a surface of a covering substrate enclosing the speaker within the common shared antenna-speaker-image capture chamber and the antenna and speaker do not interfere with the operation of the camera system.
[0044] Turning now to FIG. 6, a partially cut-away portion of an opened cover of a reduced size multi-media mobile communication device showing an alternate embodiment of a combined common shared antenna-speaker-image capture chamber embodying the present invention is illustrated therein and generally designated 300 . The cover, generally designated 302 , includes a housing structure 310 for carrying subassemblies, generally designated 312 , which make up the operational multi-media communication device. A ground plate 320 is carried in a spaced relationship with respect to the base wall 308 . A printed circuit board generally designated 330 is held in a spaced relationship with respect to the ground plate 320 and which circuit board 230 carries various electronic components and printed circuit paths for power and signal distribution and for other uses and functions well known to those skilled in the art of multi-media mobile communication devices.
[0045] A supporting structure generally designated 340 carries the planar antenna 342 on a face surface 344 of the structure 340 it being understood and that the planar antenna can also be carried on the interior face surface opposite 344 . The speaker, generally designated 332 , is mounted such that the cone or sound emitting portion is in facing relationship with the base 308 and sound or audio generated by the speaker is communicated through apertures or openings through the base surface in any well-known manner.
[0046] A wall 350 carries on its interior surface 352 , a camera or image capture sensor 360 . An aperture or opening generally designated 362 is located in a wall 354 and is aligned with or otherwise positioned with respect to the camera sensor 360 so that light rays pass through the aperture 362 and impinge on the capture surface 370 of the camera sensor 360 .
[0047] A multi-media mobile communication device having a common shared antenna-speaker-image capture chamber and related construction method has been presented above in several preferred embodiments. Numerous changes and modifications may be made to the above embodiments without departing from the spirit and scope of the present invention. For example, the cover of the common shared antenna-speaker-image capture chamber may be provided by a complementary mating surface of another portion of the housing for the multi-media mobile communication device. Accordingly, the present invention has been disclosed by way of example rather than limitation.
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Mechanical and operational design considerations for the antenna, speaker and image capture functionalities, in a multi-media mobile communication device are combined and carried in a common shared antenna-speaker-image capture chamber. The common shared chamber permits greater focal lengths and larger optics packages compared to conventional multi-media communication devices with separate, individual chambers within the device.
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TECHNICAL FIELD
The invention relates to a vacuum brake booster for motor vehicles.
BACKGROUND OF THE INVENTION
One vacuum brake booster of this general type is, for example, known from DE-OS 42 27 479 A1. The valve body of this known brake booster, which is prestressed in the direction of the sealing seats by means of a valve spring, is provided with passages within the region of its sealing surface. These passages originate at an annular chamber that is connected to the work chamber and end in the pneumatic chamber, namely on the side of the valve body that faces away from the sealing seats. Consequently, a continuous pressure compensation takes place between this chamber and the work chamber. In this case, the valve body has two pneumatically effective surfaces. The first effective surface or annular surface is limited by the radially inner sealing seat (atmospheric sealing seat) of the control valve as well a radially inner sealing lip of the valve body which cooperates with the guide part that limits the pneumatic chamber. Consequently, this effective surface or annular surface is subjected to a pneumatic differential pressure between the atmospheric pressure and the vacuum that exists in the pneumatic chamber in the release position. This results in a force component that is directed opposite to the force generated by the valve spring and decreases during the actuation of the brake booster as the degree of ventilation of the pneumatic chamber increases, namely until said force component is reduced to zero once the control point of the brake booster is reached or the work chamber is entirely ventilated, i.e., the first annular surface is pressure-compensated.
The second effective surface or annular surface is limited by the radially outer sealing seat (vacuum sealing seat) of the control valve as well as a radially outer sealing lip of the valve body which cooperates with the inner wall of the valve gear casing which limits the pneumatic chamber, i.e., this effective surface or annular surface is pressure-compensated in the release position of the brake booster and subjected to a pneumatic differential pressure when the brake booster is actuated. Consequently, a vacuum-dependent force component that boosts the effect of the aforementioned valve spring is generated.
However, one disadvantage associated with previously disclosed vacuum brake boosters is that constructive modifications in the valve gear casing are required for minimizing the vacuum-dependent sealing force component that occurs when higher actuation forces are applied.
The present invention make it possible to minimize the aforementioned sealing force component without requiring constructive modifications of the valve gear casing.
According to the invention, this objective is attained by forming the radially outer limitation of the pneumatic chamber by the guide part.
According to one additional advantageous development of the invention in which the valve body comprises a radially outer sealing lip as well as a radially inner sealing lip, and in which the radially inner sealing lip cooperates with an inner, tubular region of the guide part, it is proposed that the radially outer sealing lip cooperates with a radially outer region of the guide part, which is realized as a cylinder and radially adjoins the valve gear casing.
One additional advantageous embodiment of the invention in which the valve body comprises a first annular surface that is limited by the radially inner sealing lip and the radially inner sealing seat as well as a second annular surface that is limited by the radially outer sealing lip and the radially outer sealing seat is characterized by the fact that both annular surfaces have the same size. Due to this measure, the vacuum brake booster according to the invention behaves in a pressure-compensated fashion, in particular, in its moderate operating range, namely because the forces that act in opposite directions are neutralized.
Another advantageous embodiment of the object of the invention is characterized by the fact that the first annular surface is larger than the second annular surface. This embodiment is particularly advantageous in the realization of control valves that can be controlled proportionally and, for example, are used in brake boosters that are actuated independently or electromechanically.
In this case, it is advantageous if the guide part is made of plastic or metal.
A simplification in the assembly of the control components in which the guide part is sealed relative to the valve gear casing by means of a ring seal can be attained with one additional embodiment in which the ring seal is arranged in a radial groove in the guide part.
A reduction of the axial length, in particular, the axial length of the brake booster control components in which an air filter, as well as a readjusting spring that prestresses the radially inner sealing seat (atmospheric sealing seat) opposite the actuating direction, is arranged within the air intake region of the valve gear casing, can be attained if the air filter axially adjoins the guide part and the readjusting spring is realized as a cylinder and arranged radially outside as well as coaxial to the air filter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial longitudinal section through the vacuum brake booster of the present invention.
FIG. 2 is and enlarged, partial cross sectional view of the control components of the vacuum brake booster of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The schematically illustrated booster housing 1 of the vacuum brake booster according to the invention shown in FIG. 1 is divided into a work chamber 3 and a vacuum chamber 4 by means of an axially movable wall 2 . The axially movable wall 2 consists of a deep-drawn diaphragm disk 8 and a flexible membrane 18 that adjoins the diaphragm disk. This flexible membrane forms a roll-type membrane seal between the outer circumference of the diaphragm disk 8 and the booster housing 1 .
A control valve 12 that is actuated by means of an actuating rod 7 is accommodated in a valve gear casing 5 that carries the movable wall 2 and is guided in the booster housing 1 in a sealed fashion. This control valve consists of a first sealing seat 15 that is arranged on the valve gear casing 5 , a second sealing seat 16 that is arranged on a valve piston 9 that is connected to the actuating rod 7 , as well as an annular valve body 10 that cooperates with both sealing seats 15 , 16 . This valve body is guided in a guide part 21 that is arranged in the valve gear casing 5 in a sealed fashion and pressed against the sealing seats 15 , 16 by means of a valve spring 22 that is supported on the guide part 21 . The work chamber 3 can be connected to the vacuum chamber 4 by way of channels 28 that extend laterally in the valve gear casing 5 .
The brake force is transmitted to the actuating piston of a master cylinder (not shown) of the brake system by way of an elastic reaction disk 6 that adjoins the base of the valve gear casing 5 as well as a plunger rod 14 that comprises a top flange 23 . The master cylinder of the brake system is arranged on the vacuum side of the vacuum brake booster. The force introduced by way of the actuating rod 7 is transmitted to the reaction disk 6 by means of the valve piston 9 .
A readjusting spring 26 that is schematically illustrated in FIG. 1 and supported on the face wall of the booster housing 1 on the vacuum side, namely on a flange (not shown), holds the movable wall 2 in the normal position shown. In addition, a piston rod pull-back spring 27 that is arranged between the actuating rod 7 and the guide part 21 such that it radially encompasses an air filter 33 that axially adjoins the guide part 21 is provided. The force of this piston rod pull-back spring ensures a certain prestress of the valve piston 9 or its sealing seat 16 relative to the valve body 10 .
In order to connect the work chamber 3 to the atmosphere during the actuation of the control valve 12 , a channel 29 that approximately extends radially is arranged in the valve gear casing 5 . The return movement of the valve piston 9 at the end of a brake maneuver is limited by a transverse element 11 that, in the release position of the vacuum brake booster shown in the figures, adjoins a sliding ring seal 13 which guides the valve gear casing 5 in the booster housing 1 in a sealed fashion.
The figures also show that the valve body 10 limits a pneumatic chamber 17 in the guide part 21 . This pneumatic chamber is connected to an annular chamber 24 that is limited by the sealing seats 15 , 16 by way of passages 19 ( FIG. 2 ) arranged in the valve body 10 . The aforementioned pneumatic channels 29 end in this annular chamber such that the pneumatic chamber 17 formed on the side of the valve body 10 that faces away from the sealing surface 20 is continuously connected to the work chamber 3 , i.e., the valve body 10 is pressure-compensated.
FIG. 2 shows that the valve body 10 comprises a radially outer first sealing lip 31 that adjoins a cylindrical, radially outer region 25 of the guide part 21 in a sealed fashion as well as a radially inner second sealing lip 32 that cooperates with a tubular, radially inner region 30 of the guide part 21 . A ring seal 34 that is arranged in a circumferential radial groove 35 of the guide part 21 effectively seals the guide part 21 relative to the valve gear casing 5 .
In the release position shown in FIG. 2 , the pressure in the vacuum channels 28 , the annular chamber 24 , and the pneumatic pressure compensation chamber 17 is approximately identical or corresponds to the vacuum that exists in the vacuum chamber 4 . The valve spring 22 generates the force required for pressing the valve body 10 against the sealing seats 15 , 16 . Since atmospheric pressure exists in the chamber that is limited by the valve piston 9 , as well as the radially inner region of the valve body 10 , a pneumatic differential pressure acts upon the first annular surface A 1 of the valve body 10 between an imaginary circle corresponding to points opposite the second (atmospheric) sealing seat 16 and the radially inner sealing lip 32 . Consequently, a force component which counteracts the sealing force generated by the valve spring 22 and depends on the vacuum in the pressure compensation chamber 17 is generated.
During the actuation of the brake booster, i.e., when the second sealing seat 16 is lifted off the valve body 10 and the work chamber 3 is ventilated, the pressure compensation chamber 17 is simultaneously ventilated such that a pneumatic differential pressure acts upon the second annular surface A 2 of the valve body 10 between an imaginary circle corresponding to points opposite the first (vacuum) sealing seat 15 and the radially outer sealing lip 31 . Consequently, a force component that is directed toward the sealing seats 15 , 16 and boosts the effect of the valve spring 22 is generated. During the continued ventilation of the pressure compensation chamber 17 , the force component that acts upon the first annular surface A 1 decreases until it is reduced to zero once the control point of the brake booster is reached or the brake booster is entirely ventilated.
The previous description indicates that the behavior of the vacuum brake booster according to the invention can be influenced by suitably adapting the two annular surfaces A 1 and A 2 . For example, if both annular surfaces A 1 and A 2 have the same size, a pressure-compensated behavior of the brake booster is attained within the moderate range of the actuating forces, namely due to the fact that both force components are neutralized. However, if the radially outer annular surface A 2 is larger than the first annular surface A 1 , a proportional control of the control valve 12 , which is particularly practical in independently or electromagnetically actuated brake boosters, can be attained.
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In order to minimize the vacuum-dependent force component acting upon the valve body of a vacuum brake booster that is equipped with a pneumatically pressure-compensated control valve without requiring constructive modifications of the valve gear casing that accommodates the control valve, the invention includes a radially inner limit as well as the radially outer limit of a pressure compensation chamber in the valve gear casing, which is limited by the valve body, is formed by a guide part that guides the valve body.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to hydraulic fracturing treatments. More particularly, the present invention relates to methods and compositions for carrier fluids comprising water-absorbent fibers.
[0002] Servicing fluids comprising suspended or slurried particulates are used in a variety of operations and treatments performed in oil and gas wells. Such operations and treatments include, but are not limited to, well completion operations such as fracturing, gravel packing, and frac-packing.
[0003] An example of a production stimulation operation using a servicing fluid having particles suspended therein is hydraulic fracturing. That is, a type of servicing fluid referred to in the art as a fracturing fluid is pumped through a well bore into a subterranean zone to be stimulated at a rate and pressure such that fractures are formed and extended into the subterranean zone. The fracture or fractures may be horizontal or vertical, with the latter usually predominating, and with the tendency toward vertical fractures generally increasing with the depth of the formation being fractured. Generally, fracturing fluids are viscous fluids in the form of gels, emulsions, or foams. The particulate materials used in these operations are often referred to as proppant. The proppant is deposited in the fracture and functions, inter alia, to maintain the integrity of the fracture open while maintaining conductive channels through which such produced fluids can flow upon completion of the fracturing treatment and release of the attendant hydraulic pressure.
[0004] Suspended or slurried particulates also are used in well completion operations such as gravel packing. Gravel packing treatments are used, inter alia, to reduce the migration of unconsolidated formation particulates into the well bore. In gravel packing operations, particulates, often referred to in the art as gravel, are carried to a well bore in a subterranean producing zone by a servicing fluid that acts as a gravel carrier fluid. That is, the particulates are suspended in a carrier fluid, which may be and usually is viscosified, and the carrier fluid is pumped into a well bore in which the gravel pack is to be placed. As the particulates are placed in or near the zone, the carrier fluid leaks off into the subterranean zone and/or is returned to the surface. The resultant gravel pack acts as a sort of filter to prevent the production of the formation solids with the produced fluids. Traditional gravel pack operations involve placing a gravel pack screen in the well bore before packing the surrounding annulus between the screen and the well bore with gravel. The gravel pack screen is generally a filter assembly used to support and retain the gravel placed during the gravel pack operation. A wide range of sizes and screen configurations is available to suit the characteristics of a well bore, the production fluid, and any particulates in the subterranean formation. Gravel packs are used, among other reasons, to stabilize the formation while causing minimal impairment to well productivity.
[0005] In some situations, hydraulic fracturing and gravel packing operations may be combined into a single treatment. Such treatments are often referred to as “frac pack” operations. In some cases, the treatments are completed with a gravel pack screen assembly in place with the hydraulic fracturing treatment being pumped through the annular space between the casing and screen. In this situation, the hydraulic fracturing treatment ends in a screen-out condition, creating an annular gravel pack between the screen and casing. In other cases, the fracturing treatment may be performed prior to installing the screen and placing a gravel pack.
[0006] Previously, fibrous, non-degradable materials, such as glass, aramide, nylon, ceramic, and metal, have been added to carrier fluids to help decrease, or eliminate, the flowback of proppant both during and after the fracturing treatment. In addition to decreasing proppant flowback, these fluids also offered the additional benefits of decreasing the required polymer loadings of viscosifier and lowering the amount of fluid loss during the fracturing treatment. Unfortunately, many of these fluids exhibit limited usefulness, due ate least in part to the fact that after the placement of proppant inside the fracture, the fibers remain within the proppant pack, plugging the pore spaces between the proppant particulate, and causing the fracture conductivity to be significantly diminished under closure stresses.
[0007] One area where degradable fibers are commonly used is in the field of disposable absorbent products. Water-absorbent degradable fibers have been used in a variety of applications, including disposable diapers, feminine hygiene products, surgical drapes, and wound dressings. These materials retain their integrity and strength during use, but after such use, may be disposed of more efficiently. Such products typically use woven fibers, and, to date, have not been subjected to widespread use in the oilfield industry.
SUMMARY OF THE INVENTION
[0008] The present invention relates to hydraulic fracturing treatments. More particularly, the present invention relates to methods and compositions for carrier fluids comprising water-absorbent fibers.
[0009] One embodiment of the present invention provides a method of treating a portion of a subterranean formation, comprising providing a slurry wherein the slurry comprises a servicing fluid, particulates, and a degradable, water-absorbent material wherein the degradable, water-absorbent material acts to help keep the particulates from settling out of the slurry; and, introducing the slurry into the portion of the subterranean formation.
[0010] Another embodiment of the present invention provides a method of placing proppant into a fracture within a portion of a subterranean formation, comprising providing a slurry wherein the slurry comprises a servicing fluid, particulates, and a degradable, water-absorbent material wherein the degradable, water-absorbent material acts to help keep the particulates from settling out of the slurry; and, introducing the slurry into the fracture within a portion of a subterranean formation.
[0011] Another embodiment of the present invention provides a slurry suitable for use in subterranean operations comprising a servicing fluid, particulates, and a degradable, water-absorbent material wherein the degradable, water-absorbent material acts to help keep the particulates from settling out of the slurry.
[0012] The features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the description of the preferred embodiments that follows.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] The present invention relates to hydraulic fracturing treatments. More particularly, the present invention relates to methods and compositions for carrier fluids comprising water-absorbent fibers.
[0014] In accordance with the present invention, a carrier fluid comprising degradable, water-absorbent material (preferably in the form of fibers) may be used to effectively transport particulates down hole. The use of degradable, water-absorbent material to increase a fluid's ability to transport proppant in place of or in addition to conventional gelling agents (such as guars) may allow the fluid to carry the particulates with less sensitivity to well conditions (e.g., permeability, fluid loss, temperature). After the transport and placement of the particulates in a fracture or a well bore, the water-absorbent fibers are allowed to degrade. In some embodiments, the degradation of the water-absorbent fibers occurs relatively quickly such that the degradation products are returned to the surface when the carrier fluid reverts to a thin fluid. In other embodiments, the degradation of the water-absorbent fibers occurs more slowly and may continue during the production of the well.
[0015] The addition of degradable, water-absorbent fibers to a carrier fluid offers numerous benefits. The addition of fibrous material to a carrier fluid has been proven to decrease the need of polymer loadings of viscosifier and to decrease fluid loss during subterranean operations such as fracturing. The degradable, water-absorbent fibers also act to increase the ability of a carrier fluid to suspend particles (such a proppant or gravel) by, inter alia, creating a chemical and/or a crosslinked network or providing a mechanical network. Such networks may also act to lessen the effects temperature may have on the viscosity of a carrier fluid comprising degradable, water-absorbent fibers. This allows for enhanced carrier fluid performance at moderate or high temperatures. Particular embodiments of the present invention also help enhance the clean-up and/or removal of the carrier fluid from a proppant pack that has been deposited in a subterranean fracture.
[0016] Moreover, where the chosen degradable, water-absorbent fibers of the present invention is a hydrolysable ester or another material that degrades to produce an acid, the degradation of the fibers may facilitate the breakdown of polymerized guar-based gelled fluids that may be used in accordance with the present invention by lowering the pH of the fluids. In particular embodiments, this lower pH may cause the fluids to de-crosslink, reducing their viscosity.
[0017] Generally, any know subterranean servicing fluid (such as those commonly used in fracturing and gravel packing operations) may be used as a carrier fluid in accordance with the teachings of the present invention, including aqueous gels, emulsions, and foams. Suitable aqueous gels are generally comprised of water and one or more gelling agents. Suitable emulsions can be comprised of two immiscible liquids such as an aqueous gelled liquid and a liquefied, normally gaseous, fluid, such as carbon dioxide or nitrogen. In exemplary embodiments of the present invention, the servicing fluids are aqueous gels comprised of water, a gelling agent for gelling the water and increasing its viscosity, and, optionally, a crosslinking agent for crosslinking the gel and further increasing the viscosity of the fluid. The increased viscosity of the gelled, or gelled and cross-linked, servicing fluid, inter alia, reduces fluid loss and allows the servicing fluid to transport significant quantities of suspended particulates. The water used to form the servicing fluid may be salt water, brine, or any other aqueous liquid that does not adversely react with the other components.
[0018] A variety of gelling agents may be used, including hydratable polymers that contain one or more functional groups such as hydroxyl, carboxyl, sulfate, sulfonate, amino, or amide groups. Particularly useful are polysaccharides and derivatives thereof that contain one or more of the monosaccharide units galactose, mannose, glucoside, glucose, xylose, arabinose, fructose, glucuronic acid, or pyranosyl sulfate. Examples of natural hydratable polymers containing the foregoing functional groups and units that are particularly useful in accordance with the present invention include guar gum and derivatives thereof, such as hydroxypropyl guar, and cellulose derivatives, such as hydroxyethyl cellulose. Hydratable synthetic polymers and copolymers that contain the above-mentioned functional groups can also be used. Examples of such synthetic polymers include, but are not limited to, polyacrylate, polymethacrylate, polyacrylamide, polyvinyl alcohol, and polyvinylpyrrolidone. The gelling agent used is generally combined with the water in the fracturing fluid in an amount in the range of from about 0.01% to about 2% by weight of the water.
[0019] Examples of crosslinking agents that can be used to further increase the viscosity of a gelled servicing fluid are alkali metal borates, borax, boric acid, and compounds that are capable of releasing multivalent metal ions in aqueous solutions. Examples of multivalent metal ions include chromium, zirconium, antimony, titanium, iron, zinc, or aluminum. When used, the crosslinking agent is generally added to the gelled water in an amount in the range of from about 0.01% to about 5% by weight of the water.
[0020] The gelled or gelled and cross-linked servicing fluids may also include internal delayed gel breakers such as enzyme, oxidizing, acid buffer, or temperature-activated gel breakers. The gel breakers cause the viscous carrier fluids to revert to thin fluids that can be produced back to the surface after they have been used to place particulates in subterranean operations. The gel breaker used is typically present in the servicing fluid in an amount in the range of from about 1% to about 5% by weight of the gelling agent. The servicing fluids may also include one or more of a variety of well-known additives, such as gel stabilizers, fluid loss control additives, clay stabilizers, bactericides, and the like.
[0021] Generally, degradable, water-absorbent materials suitable for use in the present invention readily absorb water when exposed to an aqueous environment and slowly degrade or dissolve depending on the ambient temperature. Examples of degradable, water-absorbent materials suitable for use with the present invention include poly(lactic acid) polymers, which may be prepared by the polymerization of lactic acid and/or lactide. By modifying the stereochemistry of the poly(lactic acid) polymer, the physical properties of the polymer, such as melting temperature, melt rheology, crystallinity, and degree of absorbance, may be modified as well. Other degradable, water-absorbent materials suitable for use in the present invention include, but are not limited to, poly(ortho esters), polybutylene succinate, polybutylene succinate-co-adipate, polyhydroxybutyrate-valerate, polyhydroxybutyrate-covalerate, polycaprolactone, polyester amide, starch-based polymers, and mixtures and co-polymers thereof. Other suitable polymers include, but are not limited to, polyethylene terephthalate-based polymers, sulfonated polyethylene terephthalate, polyethylene oxide, polyethylene, polypropylene, polyvinyl alcohol, and aliphatic aromatic copolyester. Additional information on degradable, water-absorbent fibers suitable for use in increasing a fluid's ability to transport particulates may be found in U.S. Pat. No. 5,698,322 issued to Tsai, et al., and U.S. Pat. No. 6,135,987 issued to Tsai, et al., the relevant disclosures of which are herein incorporated by reference.
[0022] Typically, the water-absorbent materials are present in an amount of from about 0.01% to about 10% by weight of the carrier fluid. In particular embodiments, the water-absorbent materials may be present in an amount of from about 0.1% to about 2% by weight of the carrier fluid. Any suitable method mixing the water-absorbent materials with the carrier fluid may be used in accordance with the teachings of the present invention. In particular embodiments, these may include batch blending or adding the water-absorbent materials directly to the flow stream as the carrier fluid is being pumped down hole (i.e., on-the-fly).
[0023] In some embodiments of the present invention, the degradable, water-absorbent particulate material is used in the form of fibers (i.e., materials having a length-to-diameter ratio greater than about 10). Generally, the degradable, water-absorbent materials may range in length from about 50 microns to about 50,000 microns, provided the selected length of the fibers does not interfere with the mixing and pumping of the carrier fluid. In particular embodiments of the present invention, the water-absorbent materials may be the only material used to increase a fluid's ability to carry particulates. In other embodiments, the water-absorbent materials may be combined and mixed with viscosifiers (such as guar gums, or viscoelastic surfactants) to increase the ability of a fluid to transport particulates.
[0024] Particular embodiments of the present invention also further comprise super-absorbent fibers that may be combined with the aforementioned degradable, water-absorbent fibers of the present invention. Preferably, these super-absorbent fibers are water-swellable, delayed-degradable polymers having a high liquid absorption capacity. In exemplary embodiments, these super-absorbent fibers include fibers prepared from a mixture of poly(vinylamine) polymer and polyacrylic acid. Other examples of suitable super-absorbent fibers include, but are not limited to, modified cellulose, modified lignocellulose, and modified polysaccharide. In particular embodiments, these “modified” polymers are modified by sulfating the polymers. Furthermore, in particular embodiments of the present invention, the modified polymers may be crosslinkable.
[0025] Generally, super-absorbent fibers are made by applying a super-absorbent polymer to a fiber substrate fibers by surrounding fibers in the substrate or by bonding the super-absorbent polymer to itself or to substrate fibers with, for example, crosslinkers in a super-absorbent polymer or pre-polymer solution. Crosslinking may, for example, form bonds which range from highly ionic to highly covalent types of bonds or the like. These bonds can be further augmented with hydrogen bonds and/or induced polar bonds. Suitable methods of applying the super-absorbent polymer to the fiber substrate include saturation, printing, coating, and spraying. Examples of suitable application methods are taught in U.S. Pat. No. 4,500,315 issued Feb. 19, 1985, PCT Publication No. WO 00/50096 published Aug. 31, 2000, European Patent Application No. 0 947 549 A1 published Oct. 6, 1999, U.S. Pat. No. 6,417,425 issued Jul. 9, 2002, and in U.S. Pat. No. 5,962,068 issued Oct. 5, 1999. In one particular method, namely an in-situ polymerization super-absorbent coating process, a super-absorbent monomer solution containing monomer, crosslinkers and initiators is sprayed onto the substrate, the sprayed substrate is exposed to UV radiation and/or other radiation in order to polymerize and crosslink the monomer, and the irradiated substrate is then exposed to heat to remove any remaining moisture. In another method, the nonwoven is coated on one or both sides, with the super-absorbent polymer either completely covering the nonwoven or covering the nonwoven only in discreet areas with the super-absorbent polymer containing activatable cross-linkers which are activated to cross-link the super-absorbent polymer.
[0026] Suitable super-absorbent polymers may include, for example, alkali metal salts of polyacrylic acids; polyacrylamides; polyvinyl alcohol; ethylene maleic anhydride copolymers; polyvinyl ethers; hydroxypropylcellulose; polyvinyl morpholinone; polymers and copolymers of vinyl sulfonic acid, polyacrylates, polyacrylamides, polyvinyl pyridine; and the like. Other suitable polymers include hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, and isobutylene maleic anhydride copolymers and mixtures thereof. Other suitable super-absorbent polymers may comprise inorganic polymers such as polyphosphazene and the like. Further details on super-absorbent materials may be found in U.S. Pat. No. 4,500,351 issued Feb. 19, 1985 to Peniak et al, using ISOBAM 18 available from the Kuraray America, Inc. of New York, N.Y., and diethylene triamine cross-linker, or the emulsion method of PCT Publication No. WO 00/50096 published Aug. 31, 2000 by Gartner et al., or using a suitable mixture of monomer, cross-linker, and initiators per the teachings in U.S. Pat. No. 6,417,425 to Whitmore et al., or the method of U.S. Pat. No. 5,962,068 issued Oct. 5, 1999 wherein the redox initiated polymerizing superabsorbent is applied to the fibers.
[0027] Generally, the carrier fluids of the present invention are suitable for use in hydraulic fracturing, frac-packing, and gravel packing applications. In exemplary embodiments of the present invention where the carrier fluids are used to carry proppant, the proppant particles are generally of a size such that formation fines that may migrate with produced fluids are prevented from being produced from the subterranean zone. Any suitable proppant may be used, including graded sand, bauxite, ceramic materials, glass materials, nut shell, composite polymer beads, and the like. Generally, the proppant particles have a size in the range of from about 4 to about 400 mesh, U.S. Sieve Series. In some embodiments of the present invention, the proppant is graded sand having a particle size in the range of from about 10 to about 70 mesh, U.S. Sieve Series.
[0028] In particular embodiments of the present invention, the proppant may be at least partially coated with a curable resin. In particular embodiments, this resin-coated proppant (“RCP”) may comprise proppant that has been pre-coated by a commercial supplier. Suitable commercially available RCP materials include, but are not limited to, pre-cured resin-coated sand, curable resin-coated sand, curable resin-coated ceramics, single-coat, dual-coat, or multi-coat resin-coated sand, ceramic, or bauxite. Some examples available from Borden Chemical, Columbus, Ohio, are “XRTTM® CERAMAX P,” “CERAMAX I,” “CERAMAX P,” “ACFRAC BLACK,” “ACFRAC CR,” “ACFRAC SBC,” “ACFRAC SC,” and “ACFRAC LTC.” Some examples available from Santrol, Fresno, Tex., Are “HYPERPROP G2,” “DYNAPROP G2,” “MAGNAPROP G2,” “OPTIPROP G2,” “SUPER HS,” “SUPER DC,” “SUPER LC,” and “SUPER HT.”
[0029] Particular embodiments may also include proppant that is coated on-the-fly with a curable resin. The term “on-the-fly” is used herein to mean that a flowing stream is continuously introduced into another flowing stream so that the streams are combined and mixed while continuing to flow as a single stream as part of the on-going treatment. Coating the proppant particles with the curable resin composition and mixing the resin-treated proppant particles with the fracturing fluid may all be performed on-the-fly. Such mixing may also be described as “real-time” mixing. On-the-fly mixing, as opposed to batch or partial batch mixing, may reduce waste and simplify subterranean treatments. This is due, in part, to the fact that if the components are mixed and then circumstances dictate that the subterranean treatment be stopped or postponed, the mixed components may quickly become unusable. By having the ability to rapidly shut down the mixing of streams on-the-fly, unnecessary waste may be avoided, resulting in, inter alia, increased efficiency and cost savings.
[0030] Suitable curable resin compositions include those resins that are capable of forming a hardened, consolidated mass. Suitable resins include, but are not limited to, two-component epoxy-based resins, novolak resins, polyepoxide resins, phenol-aldehyde resins, urea-aldehyde resins, urethane resins, phenolic resins, furan/furfuryl alcohol resins, phenolic/latex resins, phenol formaldehyde resins, polyester resins and hybrids and copolymers thereof, polyurethane resins and hybrids and copolymers thereof, acrylate resins, and mixtures thereof. Some suitable resins, such as epoxy resins, may be of the two-component variety mentioned above and use an external catalyst or activator. Other suitable resins, such as furan resins generally require a time-delayed catalyst or an external catalyst to help activate the polymerization of the resins if the cure temperature is low (i.e., less than 250° F.), but will cure under the effect of time and temperature if the formation temperature is above about 250° F. preferably above about 300° F. Selection of a suitable resin coating material may be affected by the temperature of the subterranean formation to which the fluid will be introduced. By way of example, for subterranean formations having a bottom hole static temperature (“BHST”) ranging from about 60° F. to about 250° F. two-component epoxy-based resins comprising a hardenable resin component and a hardening agent component containing specific hardening agents may be preferred. For subterranean formations having a BHST ranging from about 300° F. to about 600° F. a furan-based resin may be preferred. For subterranean formations having a BHST ranging from about 200° F. to about 400° F. either a phenolic-based resin or a one-component HT epoxy-based resin may be suitable. For subterranean formations having a BHST of at least about 175° F. a phenol/phenol formaldehyde/furfuryl alcohol resin also may be suitable. It is within the ability of one skilled in the art, with the benefit of this disclosure, to select a suitable resin for use in embodiments of the present invention and to determine whether a catalyst is required to trigger curing.
[0031] Proppant used in accordance with the present invention may also be at least partially coated with a tackifying agent, in addition to any resin that may or may not be present. The tackifying agent may act, inter alia, to enhance the grain-to-grain contact between individual proppant particles and is believed to soften any partially cured resin that may be on the proppant particles. This dual action of the tackifying agent may improve the final consolidation strength of a proppant pack made in accordance with the present invention.
[0032] Similar to the application of a curable resin, the tackifying agent may be applied either on-the-fly or as a pre-coat. When used in conjunction with RCP, the tackifying agent is typically applied subsequent to the application of the resin. Compositions suitable for use as tackifying agents in accordance with the present invention comprise any compound that, when in liquid form or in a solvent solution, will form a non-hardening coating upon a proppant particle. In particular embodiments, tackifying agents may include polyamides that are liquids or in solution at the temperature of the subterranean formation such that they are, by themselves, non-hardening when introduced into the subterranean formation. One such compound is a condensation reaction product comprised of commercially available polyacids and a polyamine. Such commercial products include compounds such as mixtures of C 36 dibasic acids containing some trimer and higher oligomers and also small amounts of monomer acids produced from fatty acids, maleic anhydride, and acrylic acid, and the like. Such acid compounds are commercially available from companies such as Witco Corporation, Union Camp, Chemtall, and Emery Industries. The reaction products are available from, for example, Champion Technologies, Inc., and Witco Corporation. Additional compounds which may be used as tackifying agents include liquids and solutions of, for example, polyesters, polycarbonates and polycarbamates, natural resins such as shellac, and the like. Suitable tackifying agents are described in U.S. Pat. No. 5,853,048 issued to Weaver, et al., and U.S. Pat. No. 5,833,000 issued to Weaver, et al., the relevant disclosures of which are herein incorporated by reference.
[0033] Tackifying agents suitable for use in the present invention may be either used such that they form non-hardening coating or they may be combined with a multifunctional material capable of reacting with the tackifying compound to form a hardened coating. A “hardened coating” as used herein means that the reaction of the tackifying compound with the multifunctional material will result in a substantially non-flowable reaction product that exhibits a higher compressive strength in a consolidated agglomerate than the tackifying compound alone with the particulates. In this instance, the tackifying agent may function similarly to a hardenable resin. Multifunctional materials suitable for use in the present invention include, but are not limited to, aldehydes such as formaldehyde, dialdehydes such as glutaraldehyde, hemiacetals or aldehyde releasing compounds, diacid halides, dihalides such as dichlorides and dibromides, polyacid anhydrides such as citric acid, epoxides, furfuraldehyde, glutaraldehyde or aldehyde condensates and the like, and combinations thereof. In some embodiments of the present invention, the multifunctional material may be mixed with the tackifying compound in an amount of from about 0.01 to about 50 percent by weight of the tackifying compound to effect formation of the reaction product. In some preferable embodiments, the compound is present in an amount of from about 0.5 to about 1 percent by weight of the tackifying compound. Suitable multifunctional materials are described in U.S. Pat. No. 5,839,510 issued to Weaver, et al., the relevant disclosure of which is herein incorporated by reference.
[0034] Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. While numerous changes may be made by those skilled in the art, such changes are encompassed within the spirit of this invention as defined by the appended claims.
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The present invention relates to methods and compositions for carrier fluids comprising water-absorbent fibers. One embodiment of the present invention provides a method of treating a portion of a subterranean formation, comprising providing a slurry wherein the slurry comprises a servicing fluid, particulates, and a degradable, water-absorbent material wherein the degradable, water-absorbent material acts to help keep the particulates from settling out of the slurry; and, introducing the slurry into the portion of the subterranean formation. Another embodiment of the present invention provides a slurry suitable for use in subterranean operations comprising a servicing fluid, particulates, and a degradable, water-absorbent material wherein the degradable, water-absorbent material acts to help keep the particulates from settling out of the slurry.
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FIELD OF THE INVENTION
The present invention relates to plumbing fixtures and more particularly relates to a urinal for use by both men or we, men which urinal provides significant water savings.
BACKGROUND OF THE INVENTION
The conventional toilet when flushed discharges approximately between 1.6 and 5 gallons of water into tile toilet bowl to flush and wash the contents down the sewer. Recently, consistent with the recognition of the need for water conservation, toilets have been provided which utilize less volume of water by incorporating devices such as valves which achieve negative buoyancy and close prior to the discharge of the entire contents of the toilet tank, thus saving water. Nevertheless, even with such lower water consumption devices, the normal flush will discharge over one gallon of water per flush. While this quantity of water may be necessary for flushing some materials such as fecal matter and paper, this quantity of water is in excess of that normally required for proper flushing of urine.
Apart from the problem of water conservation, the conventional toilet design does not provide the convenience and expediency of a urinal. It is not uncommon that at public events, long lines form at the rest room, particularly women's rest rooms because women's rest rooms do not provide urinals of the type generally found in men's rest rooms.
THE PRIOR ART
The prior art discloses a number of urinal attachments for toilet bowls. For example. U.S. Pat. No. 3,412,408 discloses a bowl-like urinal adjustably positionable and attachable to the toilet. The device has a flexible, disposable drain duct which discharges into the toilet bowl. While the device shown in this patent facilitates male urination, it is not generally suitable for use by females and does not result in water savings since the contents are discharged into the toilet bowl requiring a full cycle flushing operation.
U.S. Pat. No. 4,145,768 discloses a water conserving urinal having an open top funnel which can be mounted on a wall adjacent the toilet with a flexible hose which is connectable to the U-shaped gas trap section of adjacent sink or wash basin. While the device does serve to conserve water to some extent, there are certain sanitary objections to having a urinal located adjacent a wash basin or sink. Further, the device requires special installation such as soldering and does not have a cover.
U.S. Pat. No. 4,282,611 discloses a urinal adapted for attachment to a toilet bowl which has a bracket arm connected to the toilet seat anchor bolts and which extends laterally of the toilet bowl. A swing arm is pivotally connected to the bracket arm and supports a funnel. In the use-position, the funnel and stem are in registry with the toilet bowl and in a non-use position they are pivoted or swung out of registry. Again, the device while providing the convenience of a urinal, does not result in water savings and would also have certain sanitary objections in that in the non-use position, urine not drained from the device could easily drip onto the floor, wall or toilet.
U.S. Pat. No. 4,985,940 shows a plumbing fixture for installation in women's rest rooms. An elongate, flexible hose has a funnel at its top and communicates with a water-holding bowl that is flushed by a siphoning action. A sanitary cuff extends around the rim of the funnel so that the funnel does not contact the user. The cuff is removed from the funnel after use by an ejector arm when the funnel is placed between the arms of a hanger member. The urinal device of the '940 patent requires special plumbing fixtures.
U.S. Pat. No. 5,153,947 shows a urinal attachment for a floor-mounted toilet. The urinal has a bowl adjacent the toilet and the outlet of the bowl connects to a drain line fitting which attaches to tile toilet base. The drain line of the urinal bowl is connected to the drain tilting so that it bypasses the toilet bowl and yet is periodically rinsed by a water line. Again, this device requires special plumbing adaptation and could result in noxious odors from the drain pipe being communicated to the rest room via the device.
Therefore, while the above devices and others found in the prior art do to some extent provide the convenience of a urinal and also in some cases provide water saving features, there nevertheless exists a need for an improved urinal which results in water savings and which is adaptable for use by both men and women.
SUMMARY OF THE INVENTION
Accordingly, it is a broad object of the present invention to provide a water-conserving urinal assembly which is convenient to use by either men or women.
It is another object of the present invention to provide a urinal which may be conveniently mounted to existing toilet bowls.
Another object of the present invention is to provide a urinal which can be used in either private residential or public rest rooms.
It is another primary object of the present invention is to provide a urinal which use results in substantial savings of water.
Another object of the present invention is to provide a urinal which is flexibly and pivotally mounted to the toilet so as to provide convenience of use and permits the device to be moved to a convenient out-of-the-way position.
Another object of the present invention is to provide a urinal which may be plumbed to a conventional toilet and which discharges waste directly into the sewer through the toilet establishing a water seal through the toilet bowl.
Another object of the present invention is to provide a urinal having a disposable sanitary cover.
Briefly, in accordance with a preferred embodiment of the present invention, the urinal includes a funnel-shaped bowl having a cover which is hinged to close when the device is not in use. The bowl is supported on a vertical, flexible support member which at its lower end is pivotally mounted to the toilet bowl at the bolt holes at the rear of the toilet lid. A flush ring in the bowl distributes water around the upper, interior area of the tunnel and is connected by a flexible water line to the water line communicating with the toilet tank. A flexible waste or drain line extends from the bowl, through the toilet bowl and into the waste or sewer line and accordingly drains directly into the sewer when flushed without the necessity of flushing tile toilet. This arrangement also provides a water seal to prevent sewer gases and odors from being released through the urinal waste line.
The bowl is attached at tile upper end of a support member which comprises a spring which encloses the drain line and allows the bowl to be moved forward to the proper height for comfortable urination. When urination is completed, the support member will return the urinal bowl to the storage position adjacent the toilet tank. The pivotal mounting at the lower end of the flexible support also allows the device to be moved forwardly as well as flexed at the support. A universal joint may be provided at the bottom connection of the bowl to the waste line.
In another embodiment, the urinal bowl is a narrow, elongated trough which may be used both by men and women. Sanitary covers may be provided which may be placed over the top of the bowl and around the edges so the user's body does not come into contact with the urinal. The cover may then be disposed of after use in a separate waste container.
The device may also be installed independent of a toilet, as for example in a public rest room, and connected directly to the sewer line which installation would require less space than conventional toilets and allow more convenient, rapid use of these facilities by women.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages of the present invention will become more apparent from the following description, claims and drawings in which:
FIG. 1 is a side view, partly cut away, showing a preferred form of the urinal of the present invention attached to a conventional toilet;
FIG. 2 is an enlarged exploded view showing the urinal bowl;
FIG. 3 is a detail view partly cut away, of a portion of the urinal bowl:
FIG. 4 is a detail view showing the lower end of the support attached to a toilet bowl;
FIG. 4A shows a hose clamp that retains the waste line in place;
FIG. 5 is a cross sectional view showing another embodiment in which the bowl is elongated for use by men and women;
FIG. 6 is a perspective view of another embodiment in which a sanitary paper dispenser is attached to the bowl;
FIG. 7 is a sectional view taken along line 7--7 of FIG. 6;
FIG. 8 is a sectional view taken along line 8--8 of FIG. 6; and
FIG. 9 is a plan view of a section of a sanitary cover.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings, FIGS. 1 to 4 shows a preferred form of the present invention which is generally designated by the numeral 10 and is shown in conjunction with a conventional toilet which has a toilet bowl 12 and a tank 14. The toilet tank 14 is supplied with water by means of water line 16 and filler line 18. A conventional shut-off valve 20 is provided in the water line 16. The water in tank 14 may be selectively discharged into the toilet bowl by operation of a trip handle 15 which will lift a ball or other valve member from the valve seat allowing the water from the tank to be discharged into the toilet bowl and ultimately across the trap section 22 of the toilet into the sewer line 26. The toilet is typically secured to the floor by a plurality of hold-down nuts 28 provided in the flange 29 at the base of the toilet. The toilet tank and bowl are typically ceramic and a lid assembly 30 is secured to the toilet bowl by bolts 32 which extend through bores 34 provided at the rear of the toilet bowl. The above construction is conventional and is described to facilitate an understanding of the present invention as the present invention 10 may be attached to conventional toilets of the type described.
The urinal 10 includes a bowl 50 which is seen in detail in FIG. 2. The bowl is preferably molded from a suitable rigid and chemically resistant plastic material such as PVC, ABS or the like and has a side wall 52 terminating at an upper rim 54. The bowl as shown is square but may be any suitable shape such as rectangular or round. The bowl downwardly converges in a funnel portion 55 terminating at a lower outlet 56. A cover 60 is secured to the rear of the bowl by one or more hinges 62. In the open position, the cover 60 assumes a vertical or past vertical position to remain open. A flush ring 66 is shaped to conform to the shape of the interior of the bowl and is mounted at the upper edge or rim 54 as seen in FIG. 3. The flush ring is preferably molded plastic tubing and has a plurality of spaced-apart outlets 68 on the underside of the tubing which will serve to direct water downwardly along the interior walls of the bowl. The flush ring may be fabricated as an integral part of the bowl. The inlet 70 to the flush ring extends through an aperture 72 in the rear of the bowl and a suitable seal is provided around the inlet to prevent leakage from the bowl at this point. A filtering screen 75, which may be plastic or wire mesh, is seated in the lower interior portion of the bowl. A suitable deodorizer cake 76 may be placed on the screen 75.
The flush ring is connected to the water line 16 by means of a tee 80 interposed in the filler line 18. One outlet of the tee connects to water line 82 which is flexible tubing. Water line 82 extends upwardly adjacent the rear and side of the toilet tank 14. The upper end of the tubing 82 is connected to a flush valve 84 via conventional fitting 86. The flush valve 84 has a handle 88 which when operated will allow water to flow to the flush ring to be discharged downwardly along the interior surface of the bowl. The outlet of the flush valve is connected by means of an elbow 90 and fitting 92 to the inlet 70 of the flush ring. The flush valve 84 is shown as manually operable but may also be automatic which either periodically flushes or flushes when it is used by infra red or other conventional sensing devices.
The bowl 50 is mounted on the upper end of a flexible support 108 which, in turn, is attached to the toilet at a pivotal support 110 at its lower end. The pivot support includes a fixed bracket 90 secured to the toilet at bore 32 provided in the toilet bowl. The bracket 90 extends rearwardly along the tank and a pivot arm 102 is pivotally secured to the bracket 90 by means of pivot pin 104. The fixed bracket 90 and the pivot arm 102 comprise a pivot assembly which, as will be explained hereafter, permits the bowl to be pivoted forwardly to a use-position and pivoted rearwardly to the stored position shown in FIG. 1 when not in use. The stored position shown in FIG. 1 places the bowl conveniently out of the way so it will not interfere with the normal use, maintenance and cleaning of the toilet.
The vertical flexible support 108 allows the bowl to be pulled forwardly and lowered to the appropriate elevation convenient for use. The vertical flexible support in conjunction with the pivotal support 110 provides a wide range of positions for the comfort and convenience of users.
The flexible vertical support 108 includes vertical spring 115 which has a cup-shaped connector 116 at its bottom end. A threaded bolt 118 depends from the connector 116 so that the connector and attached spring 115 may be secured to the outer end of the pivot arm 102 by means of nut 119. A fitting 120 is provided in the side of the connector 116 to facilitate connection of the lower drain line section 130 of the drain line. The upper end of spring 115 is secured about the neck of the outlet 56 of the bowl at clamp 128. Drainage of the bowl is accommodated by upper drain line section 132 which has its upper end clamped or otherwise secured to the distal end of the outlet 56 of the bowl at 129. Drain line 132 is a flexible tubing member and extends downwardly enclosed within the interior of the spring 115 to the coupling 116 where it is attached to a fitting 120. The remaining section 130 of the drain line is connected to fitting 120. The lower drain line section 130 extends beneath the toilet seat lid 30 at the rear of the toilet.
As seen in FIG. 4 and 4A, a clamp 140 which is generally U-shaped may be positioned on the horizontal surface of the toilet beneath the seat and serves to hold the drain tubing in place at loop 142. The lower section of drain line 130 extends along the rear of the toilet bowl 12 and upwardly over the interior dam 135 in the toilet terminating at the sewer 26. Preferably the distal end of the drain line section 130 is slightly bent inwardly so that it will better resist, it being unintentionally pulled or dislodged from the waste line 26. The lower drain section 136 is flexible and follows the interior configuration of the toilet forming an inverted U-section 140 which creates a water seal to prevent noxious gases and odors from escaping upwardly through the drain line.
When installed, the urinal is in the normal non-use position shown in FIG. 1 which places it out of tile way but convenient for use. In use, the user will grasp the urinal bowl 50 on the flexible support and pull tile device forward causing the urinal bowl 50 to be moved forward or laterally and also lowered to the desired position. This movement is due to the flexibility of the support 100 and the forward pivotal movement of arm 102.
The urinal is flushed after each use by means of flush valve 84 which is actuated by operating tile lever 88. A small quantity of water, typically a pint or so, is discharged through tile spaced-apart holes 68 in the flush ring 60 which water flows down along tile interior sides of the urinal. The waste along with the water passes across the deodorizer 76 and screen 75 to the upper and lower drain lines and is ultimately discharged into tile sewer 26. Odors are prevented from flowing from the waste line through the drain line by the water seal that is maintained in the lower section 130 of the drain line as it passes across the trap 22. After use, release of the bowl will allow the urinal to return to its normal out-of-the-way position adjacent the toilet tank at the rear of the toilet. An important aspect of the invention is that the urinal does not require that the toilet tank 15 be flushed, but rather only a small quantity of rinse water from flush valve 86 is required. Thus, in contrast to normal toilet operation, a very small amount of water is utilized. It is estimated that between about 11/2 to 5 gallons of water per flush are saved, using the urinal of the present invention.
The device will mount to either side of the toilet bowl at the preference of the user. The device is flexible and adjustable to accommodate users of all ages and physical sizes. The construction, being mostly plastic, is durable, rust-resistant and inexpensive either as an OEM product or as an aftermarket modification.
Other significant benefits result from the invention. Use of the urinal will help to avoid the male "seat-down" controversy and will accordingly maintain the toilet seat in a dry, condition. Soiling of carpet, flooring and clothing is less likely than when using the toilet for urination. Embarrassing noise is also reduced.
The urinal shown in FIGS. 1 to 4, is designed primarily for use by men. FIG. 5 shows an alternate embodiment of the present invention in which the urinal may be used by either men or women, although the design is primarily adapted to accommodate use by women.
The embodiment shown in FIG. 5 is generally designated by the numeral 200. The device is again attachable to a conventional toilet having a toilet bowl 12 and tank 14. The construction of the device with the exception of the bowl 250 is as has been described above. Accordingly, detailed description of the other elements described above is not believed necessary. It is sufficient to say the device is connected in the same manner as shown in FIG. 4 to water line 16 by means of flexible tubing 82 across manual or automatic flush valve 88. A vertical, flexible support 108 maintains the bowl 250 adjacent the toilet. The vertical support 108 is attached to the toilet at its lower end to a pivot assembly 110. Drain line 130 connects to the bowl 250 and extends within the toilet bowl to the sewer line 26.
The bowl 250 is adapted for use by either men or women. The bowl is shown having a front vertical wall 252, rear wall 254 and opposite side walls 256. Rear wall 254 is deeper than the front wall 252. A bottom section 260 extends downwardly and forwardly to an intermediate location and from there bottom wall 268 slopes upwardly intercepting the lower edge of front wall 252. As viewed from the top, the bowl has a generally rectangular configuration having a width of approximately 2" to 3" and an overall length of 6" to 14". The depth of the front wall is approximately 1" to 2" and the depth of the rear wall 254 is approximately 3" to 4". Again, the bowl 250 may be molded of a plastic material of suitable strength and chemical resistance.
The flexible water line 82 connects to the rear wall 254 at fitting 270. A discharge pipe or outlet 275 depends from the bowl.
In some instances, it may be desirable, particularly when used by women, to provide a sanitary cover on the urinal. Accordingly, referring to FIG. 9, a sanitary cover is fabricated of paper which preferably is treated to have some frictional characteristics so the cover will properly adhere to the bowl in use. The cover is designated by the numeral 300 and is adapted for use with the type of bowl designated 250 as shown in FIG. 5. The paper cover 300 has a top section which is generally rectangular having opposite edges 302 and 304, front edge 306 and rear edge 308. Fold lines 310 and 312 extend from the rear edge and intercept transverse fold line 314. Sections 320 and 322 are attached to the center section 325 along fold lines defined at edges 302 and 304. A front flap or skirt 324 is formed at the front and is provided with a pull tab for user convenience. Center section 325 is provided with a longitudinal aperture 330. In use, the sanitary cover will rest on the bowl extending across the opening with the aperture 330 above the bowl. The skirts or flaps 320, 322 will depend or hang at the opposite sides of the bowl and skirt 324 depends across the front 306.
The sanitary covers may be provided in roll form and separable at transversely extending perforations or can be provided in individual packages which would be preferably provided at the tab 330 such as on the upper surface of the toilet tank adjacent the urinal. When use of the urinal is completed, the user would simply grasp the cover at a convenient location such as at one of the sides and deposit the used sanitary cover in a convenient waste container or in the toilet.
FIGS. 6 to 8 show a modified form of the urinal of FIG. 3 having an attached dispenser 400 secured to the bowl 250. The dispenser has a roller 302 secured to the bowl by rearwardly extending bracket arms 402 for holding a roll 410 of covers 300 of the type shown in FIG. 4. The covers are separable and may be severed from the roll and placed over the bowl and temporarily held in place by a clip 425 at the front of bowl 250
A coupling 480 as seen in FIGS. 6 and 7 may be provided to allow both rotative and pivotal movement of the bowl 250 with respect to the flexible support 100. The remaining structure of the device is has been described above as is the operation. The principal advantage of the embodiment shown in FIGS. 6 and 7 is that the coupling or universal joint 480 has both pivotal and rotative movement of the bowl to further facilitate use by both men and women. The vertical, flexible support along with the pivotal support facilitates further positioning of the bowl. The elongated shape of the bowl accommodates use by men as well as by women when standing. While the bowl of the urinal has been shown as having a rectangular configuration, it could similarly be fondled in an elongated oval shape.
While the urinal of the present invention has been described as an after market attachment or accessory which can be easily adapted to toilets of most conventional designs. The urinal may also be used as a fixture independent of a toilet. In this case, the device would be constructed as shown in FIGS. 1 or 2 with the fixed bracket 90 secured to a suitable location such as the wall of a men's or women's rest room. The lower waste tubing line would be directly connected to a sewer line plumbed to the wall preferably through a suitable trap to prevent odors from the sewer emanating into the rest room area.
Thus, it will be seen from the foregoing, that the present invention provides a unique, new and novel low water volume urinal. The device is easy and convenient to use and may be mounted at either side of conventional toilets. The pivot arm and support structure make the device easily flexible and adjustable to the physical requirements of the user. The device is provided with a flush valve which may be manually operated or may be an automated flush valve. When used with a conventional toilet, the waste tubing connects directly to the drain making it unnecessary to waste large volumes of water in the conventional flushing process as a low volume of water will adequately flush the bowl. The device can be made from various materials but is preferably manufactured with the primary components such as the urinal, brackets, tubing and fittings being fabricated from plastic. The device is also easy to install.
The device provides the user benefits in addition to convenience and conservation. Wet toilet seats are avoided and carpet and clothes are less apt to become soiled.
It is understood that the present embodiments described above are to be considered as illustrative and not restrictive. It will be obvious to those skilled in the art to make various changes, alterations and modifications to the invention described herein. To the extent that these variations, modifications and alterations do not depart from the scope and spirit of the appended claims, they are intended to be encompassed therein.
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A water conserving urinal for male and female use attachable to a toilet. The urinal includes a urinal bowl which is supported on a flexible member secured at its lower end to a pivot member. Water is supplied to the bowl from the toilet water supply line via a flexible supply line. A flush valve is provided in the water line and distributes a low volume of water around the interior of the bowl through an interiorly extending flush ring. A waste line extends from discharge of the urinal bowl through the center of the flexible support and through the toilet bowl to the sewer. Fluid waste is thus discharged directly to the sewer line without the necessity of a full flush of the toilet resulting in substantial water savings. The pivot support and flexible support permit the urinal to be moved forward to the desired position and height to accommodate the physical requirements of the user.
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BACKGROUND OF THE INVENTION
Prior semi-automatic pneumatic feeders for advancing strip stock into the work station of a punch press have been relatively expensive and have required relatively complex apparatus and procedures for interfacing the feeder with the press. For example, the press itself has in some instances been modified by the installation of a rotary feeder control cam that is adapted to be rotatably driven by the main crankshaft of the press so that the feeder valves and associated control circuits may be synchronized with the operation of the press. This type of interfacing is expensive and is relatively cumbersome in terms of set-up time and timing adjustment. Furthermore, these known types of semi-automatic pneumatic feeders may each utilize several control valves that are serially operated during each feeder cycle, and this serial action tends to cause the feeder to be slower in effective speed.
SUMMARY OF THE INVENTION
The present feeder is provided with a control valve that is adapted to be shifted between two predetermined operative positions by means of a relatively simple mechanical triggering and reversing linkage that acts directly on the valve in response to two feeder input motions; one input motion being from a feeder cycle triggering plunger, while the other is from a feed slide reversing trip bar. This relatively inexpensive mechanical linkage affords not only a simple direct arrangement for interfacing the feeder with the press but also provides a very fast valve control action.
The primary object of this invention is to provide an improved semi-automatic punch press feeder that is less expensive to make, is much easier to interface with the press, and is faster acting than prior pneumatic feeders.
Other objects will become apparent as the disclosure progresses.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are diagrammatic views illustrating the nature of the operation of certain prior art punch press feeders.
FIGS. 3 and 4 are diagrammatic views illustrating the nature of the operation of the present feeder.
FIG. 5 is a plan view of the stock transport portion of the present feeder.
FIG. 6 is a front elevational view, in partial axial section, of the apparatus of FIG. 5.
FIG. 7 is a sectional view of the feed slide taken along the transverse section line 7--7 of FIG. 6.
FIG. 8 is a plan view in partial section illustrating the feeder valve means and associated controls therefor and the construction and arrangement of the parts at the head end of the main cylinder of the feeder.
FIG. 9 is a front elevational view illustrating the valve control apparatus of FIG. 8.
FIG. 10 is a left side elevational view (with certain parts broken away) of a portion of the apparatus shown in FIG. 9.
FIG. 11 is a sectional view of the control valve unit as taken along section line 11--11 of FIG. 8.
FIG. 12 is a rear elevation view of the valve unit taken in the opposite direction as that of FIG. 9.
FIGS. 13, 14 and 15 are front elevational fragmentary views diagrammatically illustrating the sequence of operation of the feeder cycle triggering and reversing means that operatively shift the control valve during each cycle of operation of the present feeder.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 diagrammatically illustrate a conventional type of control for feeders which are adapted to be controlled by the operation of the punch press. In such conventional feeders a valve control plunger 20 is adapted to be vertically displaced by the press ram, and a stock advancing feed slide 22 is adapted to be reciprocated between two fixed stops 23 and 24. When the feeder valve control plunger 20 is moved downwardly as indicated by arrow 21 the feed slide 22 will be displaced through a non-feed stroke as illustrated by arrow 25 of FIG. 1. Thereafter during the following upward movement of the press ram the feeder valve control plunger moves upwardly as indicated by arrow 26 of FIG. 2 whereby the feed slide 22 will be displaced through a feed stroke as illustrated by arrow 27 of FIG. 2. In this type of control there is a feed slide movement in response to each downward movement of plunger 20 and in response to each upward movement of said plunger.
FIGS. 3 and 4 illustrate the control sequence for the present stock advancing feed slide means. Here when the press ram moves downwardly the control plunger 30 of the feeder will be thereby moved downwardly as indicated by arrow 31 of FIG. 3; however during this plunger movement the stock advancing slide 32 will remain in a normal rearward or indexed position as illustrated in FIG. 3. When the control plunger 30 is permitted to move upwardly, as indicated by arrow 33 of FIG. 4, in response to the upward movement of the press ram the feed slide 32 will be displaced first through a feed stroke and then automatically returned through a non-feed stroke to said normal indexed position, as indicated by arrow 34, and will remain there until the feeder is triggered again during the next upward stroke of the press ram. The FIGS. 3-4 type control thus provides for the semi-automatic sequencing of the feeder in response to each cycle of operation of the press ram.
Referring primarily to FIGS. 5, 6 and 7 the transport portion of the present improved semi-automatic feeder will be described first. The feeder frame may take any suitable form such as that shown in my U.S. Pat. No. 3,329,327 or may for example comprise a U-shaped frame member 38, FIG. 5, having a main body portion 40, an end block portion 41 and a plate like portion 42 interconnecting the lower regions of said main body and end block portions 40 and 41. Slidably mounted on the flat upper surfaces of said plate like portion 42 is a stock advancing feed slide 43 that is formed with a central depending key portion 44 that slidably engages a T-slot guideway 45 centrally formed in said plate like portion 42; the key portion 44 being vertically retained in said guideway by any suitable means such as a headed screw and washer arrangement 46 as is illustrated in FIGS. 6 and 7. A stock gripping means is carried by said feed slide 43 and comprises a grip bar 50 which is biased upwardly to a normal stock releasing position shown in FIG. 7 by suitable springs 51 and which is adapted to be moved downwardly by two similar single acting fluid motors that are carried by said feed slide. Each such fluid motor includes a piston 52 that is slidably disposed in a cylinder 53 formed in the feed slide and an integral piston rod 54 that extends upwardly through the top of the feed slide and through a suitable hole formed in said stock grip bar 50. A suitable ring fastener 55 secures the bar 50 against a shoulder 56 of each piston rod 54. Any suitable sliding O-rings seals 57 are provided where and as needed. As will be apparent when fluid pressure is admitted to the top portions of the two fluid cylinders 53 and the bar 50 will be moved downwardly against the action of springs 51 from its said stock release position to a stock gripping position.
The effective length of the feed stroke of feed slide 43 may be varied by means of a stroke adjusting screw 60 which threadedly extends through the said end block portion 41 and which may be secured in selected adjusted position by means of a lock nut 61 as is well understood in the art. The top of the end block 41 is formed with a transverse slot 62 in which a stock braking spring 63 is at least partially disposed, said spring having hooked ends that engage suitable holes such as 64, FIG. 6, formed in the two end faces of said end block portion 41. This spring-groove arrangement is adapted to laterally guide and apply a light braking force to the stock that is being fed through the feeder and between the spring 63 and the upper surface of said end block frame portion 41.
A fluid motor means is provided for reciprocating the feed slide 43; such means comprising a main cylinder 70 formed in the said main body portion 40 and a piston 71 slidably disposed therein. A tubular piston rod 72 integrally connected to said piston 71 extends axially through a collar 73 that is press fitted or otherwise secured in the end of cylinder 70. The shouldered outer end of the piston rod is received in a similarly shaped hole formed through the feed slide, as is best illustrated in FIG. 6, and a headed screw 74 which threadedly engages the outer end of the piston rod serves to secure said feed slide in fluid tight and fixed relation on and with respect to the said outer end of piston rod 72. The headed screw 74 and the outer end of the piston rod 72 are provided with suitable static fluid seals 75 as and where needed as illustrated in FIG. 6, while the piston 71 and collar 73 are provided with suitable sliding fluid seals 76 where and as needed as is also illustrated in FIG. 6. The opposite or forward end of the main cylinder 70 is closed by means of a plug 80, FIGS. 5 and 8, that is secured in the position shown by any suitable means such as a roll pin 81. As illustrated in FIG. 8 the plug 80 is formed with passages that deliver pressure fluid to and from the main cylinder and the grip cylinder, respectively and to this end a tube 82 is provided which is secured by any suitable means in a similarly shaped axially extending cylindrical recess formed in the inner end of plug 80 and which telescopically cooperates with the tubular piston rod 72. The plug is also formed with a first right angled fluid conducting passage 83 that communicates at one end thereof with the inside of tube 82 and at the other end thereof with a first annular groove 84 formed in the outer cylindrical surfaces of said plug. Plug 80 is formed with a second similar annular groove 85 and a second right angled passage 86 that provides communication between said annular groove 85 and an annular recess 90 formed in the inner face of said plug. An annular projection 88 formed on the inner face of piston 71 is adapted to cooperate with said recess 90 so as to thereby afford a buffer or cushioning effect for the terminal portion of each feed stroke of the instant feeder. As will be seen pressure fluid may flow to and from the head end of the main cylinder 70 through the annular groove 85, passage 86 and recess 90, and to and from the said grip fluid motors carried by the feed slide through said annular groove 84, passage 83, and tube 82. The fluid conducting line for the said gripper fluid motors is completed through the serially communicating passages defined by the tubular piston rod 72, FIG. 6, the radially extending holes 91, FIGS. 6 and 7, and an annular groove 92 formed in the outer cylindrical wall of the end of said piston rod 72, and passages 93, 94 and 95, FIGS. 5, 6 and 7 formed in the feed slide 43. Three suitable static seals 100, 101 and 102, FIG. 8, are provided on the plug 80 so as to insure the mutual isolation of the pressure fluid which flows through the annular grooves 85 and 84, respectively, and which actuates the main and gripper fluid motors respectively. The main body portion 40 of the feeder frame is formed with horizontally extending passages 103 and 104, FIG. 5, which respectively communicate with the said annular plug grooves 84 and 85 and with two vertical fluid conducting passages 105 and 106 respectively, FIGS. 5 and 6, that extend upwardly through the top surface of said main body portion 40. A third similar vertical passage 107 communicates with a lower horizontal passage 108 that in turn communicates with a fluid pressure supply line 109. The inner end of line 109 communicates with the rod end of the main cylinder 70 while the outer end thereof is enlarged and threaded as indicated at 109a of FIGS. 5 and 9.
A mono-stable rotary four-way valve unit 110, FIGS. 8 and 11, is provided to control the flow of pressure fluid from supply lines 107-109 into and out of the said passages 105 and 106 so as to thereby properly sequence the operation of said main and gripper fluid motors. The valve 110 comprises a valve block 111 that is secured to the said main body portion 40 by any suitable fastening means such as screws 112. Rotatably mounted in valve block 111 is a rotary valve core 113 that is formed with two coplanar right angle passages 114, 115 as illustrated in FIG. 11. The four ends of passages 114, 115 are effectively spaced 90 degrees apart around the periphery of valve core 113. The valve block is drilled horizontally so as to form passages 116 and 117 having coextensive axes that are disposed diametrally with respect to the valve block aperture that receives said valve core 113; and is drilled vertically so as to form passages 120, 121 having vertical coextensive axes that are also disposed diametrally with respect to said valve block aperture. The inner ends of said passages 116, 117, 120 and 121 are effectively spaced 90 degrees apart. A vertical passage 122 formed in the valve block communicates with said passage 117, while a similar passage 123 communicates with said passage 116. As is shown in FIG. 11 when the valve block 110 is secured in place on the main body portion 40 the lower ends of passages 121, 122 and 123 will communicate with the upper ends of said passages 107, 105 and 106 respectively. The valve core 113 is adapted to be oscillated through 90 degrees between two predetermined positions. In the normal clockwise position illustrated in FIG. 11, pressure fluid will be supplied to and exhausted from the main fluid motor means and the gripper fluid motor means respectively, and the reverse is true when valve core 113 is turned counterclockwise 90 degrees. Any suitable restriction may be provided in one of the lines between the valve and the head end of the main cylinder so as to control the speed and timing of the actuation of the said fluid motor means as is well understood in the art. The fluid conductive lines 103, 104, 108, 93 and 116 are plugged at their respective outer ends so as to prevent leakage from the fluid circuit.
FIGS. 8-10 illustrate the mechanical means for oscillating or shifting the position of the valve core 113; which means includes a vertically reciprocable feeder cycle triggering plunger 130 that is slidably mounted on two spacer studs 131, 132 that are fixedly secured to the valve block 111 and frame body portion 40 respectively, the plunger being slidably retained on said studs by any suitable type fastener rings. A tension spring 133, FIGS. 9 and 10, secured between said stud 131 and a pin 134 carried by the plunger serves to bias plunger 130 to its normal upper position shown in FIGS. 9 and 10 as determined by engagement of said studs 131, 132 with the respective lower ends of the vertical slots 135 formed in said plunger 130. A latching means or driver pawl 136 is pivotally mounted on the inner side of plunger 130 by any suitable means such as a pin 137. A suitable torsion spring 140 serves to yieldably bias said pawl in a counter clockwise direction as seen in FIG. 9 so that the lower edge thereof is urged into engagement with a pin 141 extending out from the end of the valve core 113 as is best seen in FIGS. 9 and 10. The driver pawl or latching means 136 is formed with a shoulder 142, FIG. 9, that is adapted to cooperate with said valve core pin 141 during reciprocation of plunger 130. The inner end of the valve core 113 is provided with two diametrically opposed and inwardly extending pins 143 and 144. A tension spring 145, FIG. 12, is connected between said pin 143 and a pin 146 secured to the valve block 111 so as to normally rotatably bias said valve core in a counter clockwise direction as seen in FIG. 12 and in a clockwise direction as seen in FIG. 9 so that valve core 113 assumes the normal position shown in FIGS. 9, 11 and 12 as determined by engagement of the valve core pin 144, FIG. 12, with a suitable stop 147 that is secured by any suitable means to the valve block 111.
When the plunger 130 is in its normal upper position illustrated in FIG. 9 the lower end of the driver pawl or latch means 136 is disposed immediately in front of and substantially coplanar with respect to the adjacent end of a horizontal slide bar or trip reverse means 150 that is slidably carried on the side of the main body portion 40 by means of suitable pins 151 and 152 and associated fasteners rings on the latter. The slide bar is yieldably biased to a normal right hand position seen in FIG. 9 by means of a spring 153 that is secured between said pin 152 and a pin 154 fixed on said slide bar 150; this normal position being determined by the engagement of the said pins 151, 152 with the left ends of the respectively associated slots 156 formed in said slide bar 150. The outer or right end 157 of slide bar 150 as seen in FIG. 9 is adapted to be engaged and displaced to the left as seen in FIG. 9 by a pin 160, FIGS. 5 and 7, fixed to the side of feed slide 43 during the terminal portion of each feed stroke of the said feed slide 43; this leftward movement of the bar 150 serving to displace the said pawl 136 in a clockwise direction, as seen in FIG. 9, against the action of said spring 140. It will be noted that the time required for valve core 113, once released, to be spring returned to its feed normal position in FIG. 12, affords a short time delay which insures that a feed stroke is fully completed before a non-feed stroke commences.
The operation of the feeder will now be described. When pressure fluid is supplied to the said air line 109 the rod end of the main cylinder will be continuously biased by said pressure fluid and thus the feed slide 43 will be continuously urged in the feed direction as indicated by arrow 165 of FIG. 5. In the normal FIG. 11 position of the valve core 113 pressure fluid may flow from said supply line 109 through lines 108, 107, 121, 115, 116, 123, 106, 104, 85, 86 and 90 to the head end of the main cylinder whereby the feed slide will be displaced in a non-feed direction as indicated by arrow 166 of FIG. 5 to a normal indexed position determined by engagement of the slide 43 with the inner end of the stroke adjustment screws 60 as seen in FIG. 5. As will be apparent from FIG. 11 the valve core will simultaneously permit the exhaust of fluid pressure from the gripper motors on the feed slide 43 through lines 95, 94, 93, 92, 91, piston rod 72, tube 82 lines 83, 84, 103, 105, 122, 117, 114 and finally to the valve exhaust hole 120; thus the grip bar 50 will be moved by springs 51 to its upper or stock releasing position shown in FIG. 7. In this normal indexed position of the feed slide 43 the stock to be fed (generally indicated by arrow 5 of FIG. 6) is yieldably held stationary by the light frictional braking action of spring 63, FIGS. 5 and 6. The vertically reciprocable plunger 130 is adapted to be actuated by the vertical motion of the press ram whereby during the downward movement of said ram the plunger 130 will be displaced downwardly, against the action of spring 133, from its normal upper FIG. 9 position as indicated by arrow 167 of FIG. 13 until the pawl shoulder 142 swings underneath the valve core pin 141 as is diagrammatically illustrated in FIG. 13. During this downward movement of plunger 130 there is no resulting shift in the rotary position of valve core 113 and hence the feed slide 43 remains in its indexed position shown in FIG. 5.
During the ensuing upward movement of the press ram plunger spring 133 will cause the plunger 130 to move upwardly, as indicated by arrow 168 of FIG. 14, to its said normal upper position thereby causing the pawl 136 to displace the valve core 113 in a counter clockwise direction through 90 degrees as indicated by arrow 170 of FIG. 14. The spring 133 is effectively stronger than spring 145, FIG. 12. The 90 degree shift of the valve core position from its normal FIG. 11 position will now cause pressure fluid to be supplied to the said stock gripper fluid motors carried by the feed slide and to be exhausted from the head end of the main cylinder 70 whereby the feed slide is displaced through a feed stroke in said feed direction 165 of FIG. 5. During the terminal portion of this feed stroke the feed slide pin 160 will engage and displace the trip slide bar 150 to the left as seen in FIG. 9 so that the slide bar displaces the driver pawl 136 in a clockwise direction as seen in FIG. 9. This displacement of pawl 136 will move the pawl shoulder 142 out from under the valve core pin 141, as is diagrammatically illustrated in FIG. 15, so that the spring 145, FIG. 12, is now free to return the now released valve core 113 through 90 degrees to its said normal position as indicating by arrow 175 of FIG. 15. When the valve core thus snaps back to its said normal FIG. 11 position the feed slide will again partake of a non-feed stroke and return to its said normal FIG. 5 position, and the trip slide bar 150 and pawl 136 will also return to their respective normal FIG. 9 positions under the action of springs 153 and 140 respectively. The feed slide 43 will remain in said normal indexed or FIG. 5 position until the next operative cycle of the press produces the next semi-automatic cycling of the instant feeder in a manner similar to that just described.
The principal advantages of the present construction and arrangement are, first no complex interfacing is required between the present semi-automatic feeder and the press; the only requirement here being that the press ram simply operate the plunger 130. Secondly the relatively simple feeder cycle triggering action of the upward motion of driver pawl 136, as illustrated in FIG. 14, and the equally simple and direct reversing or valve tripping action afforded by the leftward motion of the trip slide bar 150, as illustrated in FIG. 15, permits a reliable fast acting control for oscillating the valve means so as to produce a more efficient semi-automatic control means for the feed slide movement as described in connection with FIGS. 3 and 4. Thirdly the construction and operation of the present valve and valve control linkage is such as to afford a semi-automatic action for the feeder at only a minor increase in cost over that for a feeder that operates in the conventional manner described in connection with FIGS. 1 and 2.
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An improved pneumatic feeder for a punch press or the like wherein the operation of the feeder is adapted to be slaved in a semi-automatic manner to the operation of the punch press. The feeder is provided with a stock advancing feed slide and a control valve therefor whereby the stock advancing slide is normally positioned in a rearward or indexed position, and is adapted, when the feeder is triggered in response to the operation of the press, to execute a feed stroke and immediately thereafter automatically execute a non-feed stroke so as to return to said normal indexed position where it will remain until said feeder is again triggered in response to the next operation of said press. This semi-automatic action is obtained by the provision of an improved simple, relatively inexpensive and fast acting mechanical linkage for controlling the shifting action of the said feeder control valve; which linkage not only affords a much simpler mode of interfacing the feeder with the press, but requires no significant modification of the press.
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This is a divisional of co-pending application Ser. No. 06/677,151 filed on Nov. 30, 1984.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to liquid propellant guns utilizing a differential piston to provide continued or regenerative injection of propellant into the combustion chamber.
2. Prior Art
This invention is an improvement of the invention disclosed in Ser. No. 840,074, filed Oct. 6, 1977, now abandoned, by M. Bulman, which discloses a liquid propellant gun system having an annular differential piston journaled for telescopic movement with respect to an annular control valve and to the chamber of the firing bore.
The invention is furthermore an improvement of the invention disclosed in Ser. No. 178,254, filed Aug. 7, 1980, by M. Bulman, which in an annular piston, annular control valve, liquid propellant gun, discloses a check valve to permit liquid propellant under relatively low pressure to flow from the supply system into the combustion chamber and to preclude the pulse of pressure generated in the combustion chamber from feeding back to the supply system.
Reference should be made to Ser. No. 840,074 and Ser. No. 178,254, hereby incorporated by reference, for structure not shown in this disclosure.
SUMMARY OF THE INVENTION
An object of this invention is to simplify the injection mechanism for an annular piston, annular control valve gun system.
A feature of this invention is the provision in an annular piston, annular control valve, liquid propellant gun system, of a dual angle injection mechanism to provide both bore and chamber injection, which employs a single injection control valve. A flexible lip on the projectile is used in conjunction with the dual angle injection mechanism to positively eliminate backflow of propellant through the injection mechanism during the ignition phase of the gun cycle.
BRIEF DESCRIPTION OF THE DRAWING
These and other features and advantages of the invention will be apparent from the following description of the invention taken in conjunction with the accompanying drawing in which:
FIG. 1 is a view in elevation, in longitudinal cross-section, of a gun system embodying this invention. The upper half of the view shows the assembly during the filling with liquid propellant, while the lower half shows the assembly after filling and during firing.
DESCRIPTION OF THE INVENTION
The gun system includes a gun barrel assembly 8 which is fixed within a housing 10. The barrel assembly has a rifled firing bore 20, a projectile receiving chamber 22 having an intermediate forcing cone 23 and a cylindrical surface 24. A round of ammunition comprising a projectile 25 with a rotating band 26 having an aftwardly-outwardly projecting deflectible annular lip 26a. The projectile is fixed by a frangible threaded tube 27 to a stub cartridge case 28 which has a percussion primer 29 and a booster charge 30. The round is chambered, locked and extracted by a conventional bolt 32, or, in a large caliber gun, a breech block. The booster has a plurality of gas vents 31 for the booster charge, which is ignited by the primer 29 via a bore 33.
The barrel assembly and the housing 10 define a substantially hollow cylindrical cavity 34 in which are telescopically disposed a substantially hollow cylindrical valve 36 and a substantially hollow cylindrical piston 38.
The valve 36 includes a forward annular portion 40 having an inner wall surface 42 providing an annular gap or passageway 44 adjacent the outer wall surface 46 of the barrel. The annular portion 40 is integral with an intermediate tubular portion 52 having an inner wall surface 54 providing an annular cavity 56 adjacent the outer wall surface 46, and an outer wall surface 58 providing an annular cavity 60 adjacent the inner wall surface 50 of the housing. The intermediate portion 52 is integral with an aft annular portion 62 having an inner wall surface 64 journaled on the outer wall surface 66 of the barrel and substantially sealed thereto, a transverse aft surface 68, a transverse forward surface 70, an inner annular cavity 72, a plurality of longitudinal bores or passageways 74 extending between the surfaces 68 and 70, and a ring seal 76 disposed in an annular groove in the outer wall surface 58. A plurality of longitudinal bores 77 provide passageways between the cavity 56 and the cavity 72 when the valve 36 is aft of its forwardmost position. Two rods 78 have their aft ends respectively fixed to the forward annular portion 40, and pass through bores in the housing. The rods are each biased aftwardly by a respective helical compression spring 210 captured between a cross pin on the rod and a plug in the housing. Each rod may have a respective seal as shown in Ser. No. 840,074, and has a detent mechanism to preclude aftward movement of the valve beyond that shown in the upper part of FIG. 1.
The piston 38 includes a forward annular portion 90 having an inner wall surface 92 journaled on the surface 58 of the valve and an outer wall surface 94 spaced from the surface 50 of the housing. The annular portion 90 is integral with an intermediate tubular portion 96 having an inner surface 92 bearing against the ring seal 76 in the valve, and an outer surface 100 bearing against a pair of ring seals 102a and 102b respectively disposed in a pair of annular grooves in the inner surface 104 of the housing. The intermediate portion 96 is integral with an aft annular portion 106 having mounted thereon a ring seal 108, which may be a discrete seal as shown or simply a tight clearance, which is biased to journal on and seal against the aftmost portion 66a of the outer surface 66 of the barrel. It will be seen that the effective cross-sectional area of the forward surface 114 of the aft annular portion 106 is less than the effective cross-sectional area of the aft-surface 112, providing the piston sleeve 38 with a differential piston action.
The barrel 8, the valve 36 and the piston 38, depending on their mutual positioning, may be considered to define a liquid propellant fill cavity 56, a valve cavity 72, a pumping cavity 118, and a combustion cavity 120. The barrel 8 has a first plurality of bores 126 disposed in an annular row and angled aftwardly from the surface 66 in the pumping chamber 118 to the surface 24 in the projectile chamber 22. The barrel 8 has a second plurality of bores 128 disposed in an annular row and angled forwardly from the surface 66 in the pumping chamber 118 to bore 20. The bores 126 and 128 are herein shown at an angle of 45°.
A supply means 151 for supplying liquid propellant under pressure is coupled to a cam controlled valve 152 which is coupled to an inlet in the housing which leads to an annular passageway 154 in the housing, from which a plurality of radial bores 156 lead to and through the forward portion of the surface 50. A radial bore 158 leads through and from the surface 50 aft of the annulus 90 of the piston 38 to a vent.
Two rods 170 and 172 have their aft ends respectively fixed to the forward annular portion 90 of the piston 38, and pass through bores with seals in the housing. The forward ends of the rods respectively terminate in an enlargement. A drum cam, such as is shown in U.S. Pat. No. 3,763,739, issued Oct. 9, 1973, to D. P. Tassie, has a helical control track in which rides a cam follower which has an arm which terminates in a rod follower. The rods are free to move forwardly free of the follower, but are controlled in their movement aftwardly by the cam track via the followers. The cam track is also able to pull the rods forwardly via the followers, all as shown in Ser. No. 840,074.
The barrel 8 has an enlarged portion 200 with an outer surface 201 which rides on and serves to seal against the inner surface 54 of the valve 36. A plurality of substantially longitudinal bores 77 are disposed in an annular row through the enlargement to serve as passageways from the fill annular cavity 56 to the valve cavity 72. The plurality of longitudinal bores 74 serve as passageways from the valve cavity 72 to the pumping cavity 118.
A belleville washer 206 is seated in the valve cavity 72 on the barrel adjacent the bores 77 and retained by a retaining ring 208. The washer is normally conical in shape and permits the flow of liquid propellant from the fill cavity 56, through the passageways 77, around the washer 206, through the valve cavity 72, and through the passageways 74 into the pumping cavity 118. Prior to firing, the differential valve 36 is held in the position shown in the upper portion of FIG. 1 by means of external compression springs 210 coupled to the rods 78, so that the surface 66 of the valve head 62 closes both rows of bores 126 and 128 and precludes the flow of liquid propellant from the pumping cavity 118 into these bores. At the beginning of firing, the liquid pressure in the pumping cavity 118 will rise and be communicated to the valve cavity 72. This increase in pressure on the aft face of the belleville washer 206 over the pressure on the forward face of washer will force the washer flat against its inherent spring force to close the passageways 77, to thereby isolate the fill cavity 56 and its anterior system from the ballistic fluid pressures generated during the firing. During firing, because the forward face 70 of the head of the valve 36 has less transverse area than the aft face 68, the differential pressure generated thereby will progressively force the valve 36 forward, against the bias of the springs 210, to progressively reduce the volume of the valve cavity 72 to substantially zero and to progessively uncover the aftwardly directed bores 126 and the forwardly directed bore 128.
In the embodiment here shown, firing is initiated by a mechanical firing pin in the gun bolt 32 impacting the primer 29 to generate and pass hot gas under high pressure through the passageway 33 to the booster charge 30, which in turn generated hot gas under pressure which is passed through the vents 31 into the combustion cavity 120. This gas under pressure will act on the aft face 112 of the head 106 of the piston 38 to force the piston forwardly, increasing the pressure in the pumping cavity 118 on the aft face 68 of the head 62 of the valve 36, and in the valve cavity 72. The belleville washer 206 closes the passageways 77 and the valve 36 commences to move forwardly. As the valve 36 moves forwardly it uncovers the bores 126 which pass liquid propellant into the annular cavity defined by the projectile, the surface 24, the forcing cone 23 and the lip 26a of the rotating band 26. The lip seals the annular cavity, blocking back pressure developed in the combustion cavity 120 from entering this annular cavity and the upstream liquid propellant supply system. As the pressure increases in the pumping cavity 118, the lip 26a is deflected to pass liquid propellant aftwardly of the projectile into the combustion cavity 120. Because the forward face 114 of the piston head has less transverse area than the aft face 112, the differential pressure generated will force the piston forwardly continuing the flow of liquid propellant through the bores 126. At a predetermined gas pressure in the combustion chamber 120, e.g., 5,000 psi, the frangible tube 27 will break and the projectile will be free to ride forwardly into the gun barrel bore to uncover the bores 128. Since the valve head 62 has already uncovered these bores, liquid propellant is now free to pass from the pumping cavity 118 through these bores forwardly into the gun barrel bore to provide a spray of liquid propellant into the gun barrel which then burns due to contact with hot combustion gasses. Throughout the injection phase, chamber gas flow is provided by the aft angled holes and bore gas flow is provided by the forward angled holes.
The dual angle feature of this injector dispurses the separate injection streams and avoids the accumulation of an unstable quantity of unburned propellants.
In the event of a misfire, both the differential valve 36 and the belleville washer valve will remain in their initial, open dispositions, to permit the liquid propellant in the pumping cavity 118 to be returned to the supply system 151 by the process of moving the differential piston forwardly via the rods 170 and 172.
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This invention provides an annular piston, annular control valve, liquid propellant gun system, having a dual angle injection mechanism to provide both bore and chamber gas requirements with a single injection control valve. The dual angle feature assures a stable combustion zone. A flexible lip on the projectile is used in conjunction with the dual angle injection mechanism to positively eliminate backflow of propellant through the injection mechanism during the ignition phase of the gun cycle.
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FIELD OF THE INVENTION
[0001] This invention relates in general to shoe accessories and more specifically to a shoe tree.
BACKGROUND OF THE INVENTION
[0002] When shoes, in particular (but not limited to) women's dress shoes, are worn they will automatically begin to fall out of shape and appear ruffled, often wrinkled from spending the majority of their life off a person's feet and unsupported by a firm substitute. When a shoe is exposed to elements such as rain, heat, dryness and normal wear and tear, the shoe will degrade over time until it must be thrown away.
[0003] Shoe trees were invented primarily to tackle this problem by becoming a substitute for the foot when the shoe is not being worn. While a shoe tree is in the shoe, it is providing support which is needed to allow the shoe to maintain its form and to remain in as close to a “new” condition as possible. Common designs of shoe tree are usually in the form of a foot-shaped wooden insert, sometimes adjustable in various directions.
[0004] However, the shoe trees which are currently available do not generally address the problems found with very pointed shoes and boots. If a pointed pair of shoes is outfitted with a conventional shoe tree, only the back of the shoe (where the heel sits) and part of the foot (where the arch and forefoot end at the beginning of the toes) are preserved by the shape of the shoe tree. The very end point of the shoe where it is too narrow for toes to actually fit into when worn has no off-foot protection from the elements and from the normal wear and tear of being worn. The condition of the shoe can deteriorate relatively quickly.
SUMMARY OF THE INVENTION
[0005] It is an object of the present invention to provide a shoe tree which addresses the problems associated with wear and tear on particularly pointed shoe types.
[0006] In one broad aspect of the present invention there is provided a shoe tree for use with a shoe including a main body with a narrow forward end adapted to fill a cavity in a shoe beyond where, in use, toes are accommodated.
[0007] This invention creates off-foot support for not only the main body of the shoe but also for the extended pointed toe of the shoe and/or boot. This added dimension for the shoe tree allows for the protection of a pointed toe of a shoe or boot which is often the most affected by the lack of any off-foot support because it is the smallest part of the body of a shoe or boot. Even while being worn, it does not have any support since it is too narrow for any part of the toes to fit into. Because of this fact, it is the most flexed and therefore vulnerable part of a shoe or boot.
[0008] In a preferred form the narrow forward end is removable/detachable and/or replaceable from the main body. This gives the clear advantage of being able to tailor a shoe tree to the individual needs of the toe of the shoe it fits into. Small variations such as a flat end can be addressed by a suitably shaped or malleable detachable end. In various embodiments the forward end is attached to the main body by a dove-tail (tongue-in-groove) joint, screw or bolt, magnet, Velcro®, hooks or a snap-on mechanism or like arrangement.
[0009] The general shape of the assembled shoe tree will hold it together while in place in a shoe, however, the attachment means provides a convenient coupling when the shoe tree is removed from the shoe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows an overhead plan view of a “pointed” shoe tree according to the present invention,
[0011] FIG. 2 shows a side view of the invention illustrated in FIG. 1 ,
[0012] FIG. 3 shows alternative side views,
[0013] FIG. 4 shows a plan view of a further embodiment of a shoe tree according to the invention with three different variations,
[0014] FIG. 5 shows the separated pointed toe in three different attachment methods,
[0015] FIG. 6 shows two toe ends to be used separately as toe supports,
[0016] FIG. 7 shows a further embodiment of a shoe tree according to the invention,
[0017] FIG. 8 shows a rear perspective view of the shoe tree illustrated in FIG. 2 , and
[0018] FIG. 9 shows a side view of the shoe tree illustrated in FIG. 2 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] FIG. 1 shows an overhead plan view of a solid single extended toe piece 1 “pointed” shoe tree according to the present invention, with a levered metal separating center rod 2 and an adjustable heel piece 3 . Also shown in FIG. 1 is a flexible spring coil center rod 4 attached to a stationary ball shaped heel 5 as an alternative to the center rod 2 /heel 3 .
[0020] In FIG. 1 a pointed, narrow ended, single main body 1 will typically be made out of wood, however many different materials will suffice such as plastic, rubber or metal. The general shape of main body 1 (apart from the pointed end) will generally resemble the dimensions of a foot, or the front part of a foot.
[0021] Also shown in FIG. 1 is a levered metal center rod 2 that adjusts to fit a particular shoe size. As an alternative to the levered center rod 2 FIG. 1 illustrates a flexible spring/coil 4 that would extend from a rearward end of the main body 1 in the same way. At the right end of the spring coil center rod 4 rests an oval ball 5 which, when the flexible spring/coil 4 is bent to fit the shoe, allows the ball 5 to fit snugly into the heel of the shoe, thus applying pressure to the front of the shoe tree and extending the pointed toe into the tip of the shoe and filling the shoe with all of the necessary support. The ball end 5 may be designed to fit the entire heel section of the shoe 3 and not resemble a ball at all.
[0022] In a yet further embodiment (not illustrated) these structures could be replaced by a telescopic metal rod able to adjust to fit many different shoe sizes. The adjustable rods 2 , 4 may be made of different materials like plastic or wood to achieve the same effect.
[0023] In FIG. 2 the invention is seen from a side view demonstrating the lever action of the center rod 2 . FIG. 3 shows close-up of alternatives: levered center rod 2 and flexible spring center rod 4 .
[0024] FIG. 4 shows a plan view of a further embodiment of a shoe tree according to the invention with three different variations of the solid single extended toe: very pointed 1 , an extended small square tip 6 and a extended wider square toe 7 . Reference numerals 6 and 7 represent solid single extended toe pieces as in FIG. 1 but with a square and wider point respectively in order to fit squared shaped extended toe shoes and or boots.
[0025] FIG. 5 shows the separated pointed toe in three different attachment methods: magnet/tongue-in-groove 8 , screw or bolt 9 and dove tail 10 .
[0026] The three variations of a removable pointed tip 8 may be made of different material to the main body 9 . For example, the body 9 may be of wood and the pointed tip 8 may be made of a firm but malleable foam rubber which allows it to be deformed for use separately with another conventional shoe tree, and therefore somewhat molded into both the tip of the shoe or boot as well as into the toe of the conventional shoe tree, allowing a nice snug fit. FIG. 5 demonstrates a plug-type attachment means 10 (which could in some embodiments be magnetized), a screw or bolt 11 and dove-tail (jig-saw) attachment means 12 to enable coupling to the body 9 .
[0027] As illustrated, the tip 8 generally conforms with the contours of the main body 9 and should enable a smooth transition between the components.
[0028] FIG. 6 shows two toe ends 11 and 12 to be used separately as toe supports with strings 13 attached for easy withdrawal. In FIG. 6 the pointed toe pieces 13 and 14 are demonstrated separately by having a stringed attachment 15 to be used by itself or in combination with a conventional shoe tree. This unit may be manufactured separately and used as a separate toe piece and not necessarily sold separately with the rest of the invention.
[0029] The present invention enables a user to protect pointed toe shoes from deterioration in a way that has not been possible with conventional designs. Conventional designs may include means to expand the shoe tree laterally (to simulate a wider foot) and sometimes longitudinally but do not extend to the cavity of a pointed toe end to maintain a desirable shape.
[0030] A kit set could be provided where a user can mould their own extended toe end (from a material that sets in shape or cut from a template) to tailor the shoe tree to their own shoes and can be incorporated detachably (or not) with the main body of the shoe tree.
[0031] The present invention is intended to extend the life of pointed shoe types by a simple insertion means. The ability to interchange toe points on a shoe tree according to one aspect of the present invention enables it to be tailored to the requirements of the user and many types of men's and women's shoes/boots.
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A shoe tree for use with a shoe including a main body with a narrow forward end adapted to fill a cavity in a shoe beyond where, in use, toes are accommodated. The narrow forward end is removable, so it can be replaced or tailored to fit into a variety of different shoe types, primarily shoes with pointed toes that are otherwise prone to damage.
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FIELD OF THE INVENTION
The present invention is directed towards a hose. Specifically, the hose is reinforced with ebonite to provide the hose with the desired physical characteristics.
BACKGROUND OF THE INVENTION
Ebonite is a known rubber compound containing a high sulfur content, typically compounded with 30 to 50% by weight sulfur, having a high Shore A hardness. Ebonite compounds have been used in tank linings for chemical products and in other applications where hardness and impermeability are desired. For example, U.S. Pat. No. 4,469,729 discloses that in the past, for flexible articles such as belts, hoses, and diaphragms, the inner surface of the article was harden by ebonite formation. This was done to improve wear resistance, reduce friction, and provide for a barrier effect.
U.S. Pat. No. 5,222,770 discloses a high-pressure hydraulic hose. The multi-layered hose has an inner layer, an intermediate insulation layer, and an outer layer. Between the layers are several conductive layers. The inner, intermediate, and outer layers may be rubber or ebonite.
While ebonite has been used as an alternative to rubber layers in various articles, the presently disclosed invention is directed towards previously unappreciated benefits of ebonite in an article.
SUMMARY OF THE INVENTION
The present invention is directed to a light weight, inexpensive hose and a method of forming such a hose.
The inventive hose is comprised of at least a cover layer, an innermost layer, and at least one intermediate reinforcing layer. The reinforcing layer is formed from an ebonite rubber.
In one aspect of the invention, the ebonite rubber comprising the at least one reinforcing layer has a Shore D hardness in the range of 75 to 100, preferably 90 to 100.
In another aspect of the invention, the ebonite rubber comprising the at least one reinforcing layer has a sulfur content of 10 to 50% by weight.
In another aspect of the invention, the hose is formed with an integral flange formed at at least one end of the hose. The hose is formed with the integral flange being comprised of a central disc of ebonite rubber.
Also disclosed in a method of forming a hose comprising an inner layer, at least one intermediate reinforcing layer, and an outer layer. The method is comprised of forming an inner layer, applying a reinforcing layer of uncured ebonite rubber over the inner layer, and applying a cover layer to form a hose assembly. The hose assembly is cured to form the hose.
In another aspect of the disclosed method of forming a hose, the ebonite rubber is applied until it reaches the thickness required to achieve a desired strength in the cured hose.
In another aspect of the disclosed method of forming a hose, an ebonite disc is applied to at least one end of the hose assembly prior to curing the hose assembly to form an integral flange on the hose.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described by way of example and with reference to the accompanying drawings in which:
FIG. 1 is a hose formed in accordance with the present invention;
FIG. 2 is another embodiment of the present invention;
FIG. 3 is hose with an integral flange; and
FIG. 4 illustrates the assembly method for forming the hose with an integral flange.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a hose 10 . The hose 10 has the simplest construction that is in accordance with the present invention. The hose 10 has an inner layer 12 , an intermediate reinforcing layer 14 , and a cover layer 16 . The inner layer 12 and the cover layer 16 are formed of conventional hose materials, including thermoplastic and thermoelastic materials. The material selection will vary depending upon the application and desired properties of the hose. The inner layer 12 is selected to be resistant to the material to be conveyed by the hose 10 . The intermediate reinforcing layer 14 , instead of being the conventional textile or metallic reinforcement layer, is an ebonite layer. The reinforcing ebonite layer 14 is built up to a thickness to accomplish the desired strengthening of the hose to replace the various conventional reinforcement layers typically found in a hose. In forming the ebonite reinforced hose, after the inner layer 12 is formed, either by extrusion about a mandrel or form or by winding unvulcanized rubber about a mandrel, the ebonite rubber is extruded over the uncured inner layer or sheets of uncured ebonite rubber is wound over the uncured inner layer until the desired thickness to obtain the required strength in the cured hose is achieved.
The ebonite rubber has a base rubber of any sulfur vulcanizable rubber, and a sulfur content of 10 to 50% by weight, preferably 10 to 20% by weight. The ebonite rubber has a Shore D hardness of 75 to 100, preferably 90 to 100 Shore D.
The hose may be formed with more than the three specified layers. The hose may also have an intermediate rubber layer, see FIG. 2 . The hose 20 has an inner layer 22 , a reinforcing layer 24 , an intermediate rubber layer 26 , a second reinforcing layer 28 , and a cover layer 30 .
A hose may be formed in any lay-up construction known to those in the art. For example, the inner layer 12 or 22 may be several layers, including a barrier layer, a friction layer, and an adhesive layer. Whatever construction is chosen for the hose, the main reinforcing layer of the hose is formed from an ebonite rubber material.
The hoses 10 , 20 formed in accordance with the present invention are most suitable for use as suction and discharge hoses, since such hoses do not require a high degree of flexibility. Such hoses 10 , 20 are used for transporting ore slurry, water, chemical products, and other such flowable materials. It is desired that suction and discharge hoses be highly durable since the hose is subject to extreme working conditions, including being dragged and pulled along rough surfaces. Because an operator may carry the hose around, it is also desired to reduce the weight of the hose. The use of the ebonite in the hose provides the hose with the desired strength needed for such a hose, while reducing the weight and the cost of the hose.
To further reduce the weight of the discharge hose, the hose may be formed such that the conventional iron flanges attached to the ends of the hose are eliminated, as disclosed in a further embodiment of the present invention.
FIG. 3 illustrates a hose 30 formed with an integral flange 32 . The body 34 of the hose 30 is formed in accordance with the simplest hose construction, as disclosed previously. The hose 30 has an inner layer 36 , an intermediate reinforcing layer 38 , and a cover layer 40 . A flange 32 is formed at at least one end of the hose 30 .
FIG. 4 illustrates a hose being formed with integral flanges 32 at both ends of the hose 30 ; however, if desired, the flange 32 may be formed at only one end of the hose 30 . The desired inner layer 36 is first applied to a mandrel (not illustrated). Over the inner layer 36 , the necessary layers of ebonite 38 are applied until the specified thickness to achieve the desired reinforcement of the hose 30 is achieved. The cover layer 40 is then applied to form a hose assembly. Nylon tape (not illustrated) is then applied over the hose assembly.
Two-part flanges 42 are placed near the ends of the hose assembly. The ends 44 of the cover layer 40 are turned up over the two-part flanges 42 . The ends 46 of the ebonite layers 38 are then also turned up, adjacent the ends 44 of the cover layer 40 . Discs of ebonite 48 are placed against the turn up ends 44 ; each ebonite disc 48 preferably has the same thickness as the conventional steel flange that the disc 48 is replacing. The ends 50 of the inner layer 36 are turned up adjacent the discs 48 . Curing flanges 52 are then placed over the turned up ends 44 , 46 , 50 and discs 48 . The final hose assembly is cured, after which the two-part flanges 42 , the cure flanges 52 , and the nylon tape are removed. Following curing the ebonite disc 48 and the turned up ends 44 , 46 , 50 of the hose layers 36 , 38 , 40 are transformed into the integrally formed rigid flanges 32 .
The above formed method is one method of constructing the integral flanges 32 . In an alternative method, instead of turning up the ends of the various hose layers 36 , 38 , 40 to sandwich the ebonite disc 48 , layers of material corresponding to the material of each layer may instead be applied to the ends of the hose assembly. After the hose assembly is prepared on a mandrel, the two-part flanges 42 are placed at the ends of the hose assembly. If it is desired to form only one flange 32 , than a two-part flange 42 is located at only one end of the hose assembly.
Rubber layers of the same material as the cover layer 40 are applied over the flanges 42 . Discs of ebonite are applied. Ebonite rubber layers corresponding to the layer 38 may be applied to the ebonite discs. If no such additional ebonite layers are applied, than the ebonite disc has the same composition as the layer 38 . Rubber layers corresponding in material to the material of the inner layer 36 are placed over either the ebonite discs or the additional ebonite layers, encapsulating the ebonite between the two different non-ebonite rubber layers. Curing flanges 50 are than placed over the built up layers and the final hose assembly is cured.
The flange 32 may be provided with passageways 54 for bolts or other mechanical mechanism to be inserted into the flange for securing the hose 30 to other hoses, couplings, or fittings when the hose 30 is in use. These passageways 54 are formed when the hose 30 is cured.
By forming the inventive hose with integral ebonite flanges, the conventional hose constructed from tire cord plies, steel wires, and metal flanges is replaced by a light weight, rigid, and less expensive hose.
Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is therefore to be understood that changes can be made in the particular embodiments described which will be within the full intended scope of the invention as defined by the following appended claims.
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The present invention is directed to a rubber hose wherein the reinforcing layers are formed from ebonite rubber. The ebonite rubber has a thickness sufficient to provide the desired reinforcing characteristics to the hose. The hose may be formed with integral hose flanges wherein the hose flanges are also formed from ebonite rubber.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to German Patent Application No. 10 2012 220 652.3, filed Nov. 13, 2012, and International Patent Application No. PCT/EP2013/072546, filed Oct. 29, 2013, both of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
The present invention relates to a camshaft having a tubular outer shaft and an inner shaft, which is arranged coaxially thereto and can be rotated at least to a limited extent with respect to the outer shaft, according to the preamble of the independent claims.
BACKGROUND
EP 1 963 625 B1 discloses a generic camshaft having an outer shaft and an inner shaft arranged coaxially thereto, the inner shaft being supported directly against a stepless inner lateral face of the outer shaft by means of at least one securing device arranged on an axial end region of the shaft.
Owing to the necessary freedom of movement between the inner shaft and the outer shaft in an adjustable camshaft and/or owing to a necessary oil duct for a phase adjuster and/or bearing lubrication, a sufficient annular gap of between 0.2 and 2 mm in radial height is usually required between the inner shaft and the outer shaft. Sealing is therefore needed at the end of the two shafts to be able to build up the oil pressure necessary for the phase adjuster between the inner shaft and the outer shaft. With inner shafts known from the prior art, they are usually thickened in the region of a sealing ring, which can be achieved for example by removing material from almost the entire length of the inner shaft adjacent to the annular seal. This is however very expensive and requires an initially unmachined inner shaft with a comparatively large amount of material.
SUMMARY
The present invention is therefore concerned with the problem of specifying an improved embodiment for a camshaft of the generic type, which in particular has a different mounting of an inner shaft in relation to an outer shaft.
This problem is solved according to the invention by the subject matter of the independent claims. Advantageous embodiments form the subject matter of the dependent claims.
The present invention is based on the general concept of, in a camshaft known per se having a tubular outer shaft and an inner shaft, which is arranged coaxially thereto and can be rotated at least to a limited extent with respect to the outer shaft, providing at least one annular step, which projects radially inwards and by means of which the inner shaft can be mounted on the outer shaft. In contrast, the inner shaft has a constant outer diameter and does not need further post-machining, for example after drawing of same. The minimum diameter of the inner shaft is thus limited only by the required torsion resistance and the pinning of cams coupled to the inner shaft (pin diameter). It is also of particular advantage in the camshaft according to the invention that the inner shaft does not have to be post-machined, in particular turned, over most of its outer circumferential face as previously customary, as a result of which the inner shaft can be produced comparatively simply and cost-effectively. The outer shaft is partially thickened only in the region of the bearing point and in the region of the sealing point by the radially inwardly projecting annular step, the effort for producing said radial annular step during production of the outer shaft being very low. The annular step can for example be produced by means of a forming process, in particular by upsetting or forming under combined tensile and compressive conditions during drawing of the outer shaft. Depending on the radial thickness of the annular step according to the invention, said step can even hold or mount a sealing ring.
In a further advantageous embodiment of the solution according to the invention, the inner shaft has an outwardly open groove, in particular a circumferential groove, in which a sealing ring is arranged, which is arranged at the axial height of the annular step when the camshaft is assembled. Additionally or alternatively to the sealing ring arranged in the region of the annular step of the outer shaft, a sealing ring can thus be arranged in an outwardly open groove in the inner shaft, in particular if the inner shaft is formed as a solid profile. If the inner shaft is formed as a tube, the sealing ring is preferably arranged in the inwardly open groove in the outer shaft. The radially inwardly projecting annular step can be arranged on the longitudinal end of the outer shaft, but purely theoretically can also be arranged at a plurality of positions spaced apart axially on the outer shaft.
In an advantageous development of the solution according to the invention, the at least one annular step has chamfered edges. Such chamfered edges make it easier to insert the inner shaft and thus to assemble the camshaft. Additionally or alternatively, the inner shaft has on at least one end an oblique introduction face, which likewise makes it easier to insert the inner shaft into the outer shaft when assembling the camshaft.
The annular gap expediently has a radial thickness of 0.2 to 2.0 mm. In order to be able to keep a sufficient oil volume in the annular gap, for example for lubricating sliding bearings or for actuating a phase adjuster, the described annular gap is provided between the inner shaft and the outer shaft. The annular gap is used in particular as an oil guide.
In general, the camshaft according to the invention can be assembled comparatively simply. To this end, for example, a sealing ring is first placed into an outwardly open groove in the inner shaft, then an assembly sleeve is pushed over the sealing ring. The assembly sleeve causes the sealing ring to be pressed into the groove on the inner shaft side. Then the inner shaft is inserted into the outer shaft and the camshaft is assembled thereby. The assembly sleeve is then withdrawn, as a result of which the sealing ring that is pressed into the groove in the inner shaft bears against an inner lateral face of the outer shaft and thereby seals off the annular gap between the inner shaft and the outer shaft. If, however, the sealing ring is arranged in a groove in the outer shaft in an alternative embodiment, the sealing ring is first placed into the inwardly open groove in the outer shaft and then the inner shaft is inserted into the outer shaft. The oblique introduction face at the front end of the inner shaft, as seen in the insertion direction, can prevent damage to the sealing ring during insertion. Comparatively simple assembly of the camshaft is thus possible in the last-mentioned embodiment.
Further important features and advantages of the invention can be found in the subclaims, the drawings and the associated description of the figures using the drawings.
It is self-evident that the above-mentioned features and those still to be explained below can be used not only in the combination given in each case but also in other combinations or alone without departing from the scope of the present invention.
Preferred exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the description below, the same reference symbols referring to the same or similar or functionally equivalent components.
BRIEF DESCRIPTION OF THE DRAWINGS
In the figures,
FIG. 1 schematically shows a sectional diagram through a first possible embodiment of a camshaft according to the invention,
FIG. 2 schematically shows a diagram as in FIG. 1 , but with a sealing ring mounted on an inner shaft,
FIG. 3 schematically shows a diagram as in FIG. 2 , but with a differently formed radial annular step,
FIG. 4 schematically shows a sectional diagram through a camshaft according to the invention with a phase adjuster arranged at the end,
FIG. 5A-D schematically show individual method steps for assembling the camshaft according to the invention.
DETAILED DESCRIPTION
According to FIGS. 1 to 4 , a camshaft 1 according to the invention has a tubular outer shaft 2 and an inner shaft 3 , which is arranged coaxially thereto and can be rotated at least to a limited extent with respect to the outer shaft 2 . An annular gap 4 is provided at least in some regions between the inner shaft 3 and the outer shaft 2 , to conduct oil for the lubrication of sliding bearings and/or for actuating a phase adjuster 5 (compare FIG. 4 ). Such a phase adjuster 5 is used in a known manner for the relative rotation of the inner shaft 3 with respect to the outer shaft 2 , the inner shaft 3 being connected in a rotationally fixed manner to first cams 6 , and the outer shaft 2 being connected in a rotationally fixed manner to second cams 7 . The rotationally fixed connection between the inner shaft 3 and the first cams 6 takes place by means of a pin arrangement 8 , which in each case has a pin 9 , which is inserted into the inner shaft 3 and at the same time is connected in a rotationally fixed manner to the first cam 6 . A slot, which extends in the circumferential direction, is provided in the outer shaft 2 at the axial height of the pin 9 , in which slot the pin 9 can be moved during a relative rotation of the inner shaft 3 with respect to the outer shaft 2 .
In order to be able to seal off the annular gap 4 in the axial direction of the camshaft 1 , the outer shaft 2 has according to the invention at least one radially inwardly projecting annular step 10 , by means of which the inner shaft 3 is mounted and sealed off with respect to the outer shaft 2 . The annular step 10 arranged on an inner lateral face of the outer shaft 2 can be produced comparatively simply and cost-effectively, for example by a forming process, in particular by upsetting or by forming under combined tensile and compressive conditions during drawing of the outer shaft 2 . The annular step 10 offers the great advantage that the inner shaft 3 can be configured with a constant outer diameter and as a result can be produced in a comparatively cost-effective manner. A previously complex and expensive post-machining of the inner shaft 3 can also usually be omitted.
If FIGS. 1 and 4 are viewed, it can be seen that the outer shaft 2 has an inwardly open annular groove 11 in the region of the annular step 10 , in which groove a sealing ring 12 is arranged. In contrast to this, the inner shaft 3 according to FIGS. 2, 3 and 5 has an outwardly open annular groove 11 , in which a sealing ring 12 ′ is arranged, the sealing ring 12 ′ being arranged at the axial height of the annular step 10 when the camshaft 1 is assembled. When the groove 11 is provided in the region of the annular step 10 , no reduction in the cross section of the inner shaft 3 is necessary, so the shaft can be restricted to the minimum required diameter, which is only limited by the necessary torsion resistance and the pin arrangement 8 of the first cams 6 (diameter of the pins 9 ). The sealing ring 12 mounted in the outer shaft 2 also provides advantages in particular during assembly of the camshaft 1 , as is explained below. Since the inner shaft 3 in this case has a much smaller diameter overall, which is limited only by the torsion resistance and the pin arrangement 8 , said shaft can also be made much lighter than inner shafts known previously from the prior art. The inner shaft 3 shown is formed as a solid profile, a hollow inner shaft 3 of course also being conceivable.
The sealing ring 12 , 12 ′ can be formed from a plastic, in particular from an elastomer or a polytetrafluoroethylene (PTFE), metallic sealing rings of course also being conceivable. The sealing ring 12 , 12 ′ can withstand the chemical environment inside the camshaft 1 , as well as the temperatures occurring during operation of an internal combustion engine containing the camshaft 1 , for a long time. The plastics mentioned for the sealing ring 12 , 12 ′ should be understood as mere examples; other plastics are also conceivable.
If FIGS. 1 to 5 are viewed, it can be seen that the at least one annular step 10 has at least one chamfered edge 13 , even two chamfered edges 13 , 13 ′ depending on the embodiment, which make it easier to insert the inner shaft 3 into the outer shaft 2 . Similarly, an oblique introduction face 14 can be provided on at least one end of the inner shaft 3 , which face makes it easier to introduce the inner shaft 3 into the outer shaft 2 and thus to assemble the camshaft. If the annular step 10 is situated on the axial end region of the outer shaft 2 , as is shown for example in FIGS. 3 to 5 , the annular step 10 usually only has one chamfered edge 13 .
FIGS. 5 a to 5 d show a possible assembly of the camshaft 1 according to the invention; in the first method step according to FIG. 5 a , an assembly sleeve 15 is first aligned coaxially to the inner shaft 3 . In this case the inner shaft 3 bears the sealing ring 12 ′ in its groove 11 ′. In the method step shown in FIG. 5 b , the assembly sleeve 15 is then pushed over the sealing ring 12 ′ and thus over the inner shaft 3 , then, in the method step according to FIG. 5 c , the inner shaft 3 is inserted into the outer shaft 2 of the camshaft 1 . When the assembly aid 15 is placed over the inner shaft 3 , the assembly aid 15 presses the sealing ring 12 ′ into the groove 11 ′ on the inner shaft side. Once the final position of the inner shaft 3 in the outer shaft 2 is reached, the assembly sleeve 15 is withdrawn according to the method step in FIG. 5 d , whereupon the sealing ring 12 ′ rises at least partially out of the groove 11 ′ in the inner shaft 3 and bears against an inner lateral face of the outer shaft 2 , that is, against the inner lateral face of the annular step 10 .
If, however, the sealing ring 12 is arranged in the groove 11 in the outer shaft 2 , to assemble the camshaft 1 , the sealing ring 12 is first positioned in the groove 11 , whereupon the inner shaft 3 is then inserted into the outer shaft 2 , and, because of the continuous outer diameter of the inner shaft 3 , no damage to the sealing ring 12 occurs even when the inner shaft is inserted into the outer shaft 2 , so in this case an assembly aid 15 can be omitted entirely.
With the camshaft 1 according to the invention, not only the assembly thereof can be simplified, but also the weight thereof can be much reduced, which is of great advantage in particular in internal combustion engines used in motor vehicles. In addition, the radial annular step 10 is comparatively simple and cost-effective to produce, which constitutes a clear advantage compared with an inner shaft that was previously post-machined in a complex manner over almost its entire axial length.
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A camshaft may include a tubular outer shaft and an inner shaft arranged coaxially thereto. The inner shaft may be rotatable at least partially with respect to the outer shaft. An annular gap may be disposed between the inner shaft and the outer shaft. The outer shaft may include at least one radially inwardly projecting annular step facing the inner shaft. The at least one annular step may mount the inner shaft with respect to the outer shaft.
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The present application is a divisional of and claims priority of U.S. patent application Ser. No. 11/066,133, filed Feb. 24, 2005, the content of which is hereby incorporated by reference in its entirety.
The present application is based on and claims the benefit of U.S. provisional patent application Ser. No. 60/547,966, filed Feb. 26, 2004, the content of which is hereby incorporated by reference in its entirety.
FIELD OF INVENTION
This invention relates to methods for generating T-cells with enhanced immunostimulatory capabilities for use in cell therapy treatment protocols.
BACKGROUND OF THE INVENTION
Cell therapy methods have been developed in order to enhance the host immune response to tumors, viruses and bacterial pathogens. Cell therapy methods often involve the ex-vivo activation and expansion of T-cells. Examples of these type of treatments include the use tumor infiltrating lymphocyte (TIL) cells (see U.S. Pat. No. 5,126,132 issued to Rosenberg), cytotoxic T-cells (see U.S. Pat. No. 6,255,073 issued to Cai, et al.; and U.S. Pat. No. 5,846,827 issued to Celis, et al.), expanded tumor draining lymph node cells (see U.S. Pat. No. 6,251,385 issued to Terman), and various other lymphocyte preparations (see U.S. Pat. No. 6,194,207 issued to Bell, et al.; U.S. Pat. No. 5,443,983 issued to Ochoa, et al.; U.S. Pat. No. 6,040,177 issued to Riddell, et al.; U.S. Pat. No. 5,766,920 issued to Babbitt, et al.).
For maximum effectiveness of T-cells in cell therapy protocols, the ex vivo activated T-cell population should be in a state that can maximally orchestrate an immune response to cancer, infectious diseases, or other disease states. For an effective T-cell response, the T-cells first must be activated. For activation, at least two signals are required to be delivered to the T-cells. The first signal is normally delivered through the T-cell receptor (TCR) on the T-cell surface. The TCR first signal is normally triggered upon interaction of the TCR with peptide antigens expressed in conjunction with an MHC complex on the surface of an antigen-presenting cell (APC). The second signal is normally delivered through co-stimulatory receptors on the surface of T-cells. Co-stimulatory receptors are generally triggered by corresponding ligands or cytokines expressed on the surface of APCs.
Due to the difficulty in maintaining large numbers of natural APC in cultures of T-cells being prepared for use in cell therapy protocols, alternative methods have been sought for ex-vivo activation of T-cells. One method is to by-pass the need for the peptide-MHC complex on natural APCs by instead stimulating the TCR (first signal) with polyclonal activators, such as immobilized or cross-linked anti-CD3 or anti-CD2 monoclonal antibodies (mAbs) or superantigens. The most investigated co-stimulatory agent (second signal) used in conjunction with anti-CD3 or anti-CD2 mAbs has been the use of immobilized or soluble anti-CD28 mAbs.
The combination of anti-CD3 mAb (first signal) and anti-CD28 mAb (second signal) immobilized on a solid support such as paramagnetic beads (see U.S. Pat. No. 6,352,694 issued to June, et al.) has been used to substitute for natural APCs in inducing ex-vivo T-cell activation in cell therapy protocols (Levine, Bernstein et al. 1997; Garlie, LeFever et al. 1999; Shibuya, Wei et al. 2000). While these methods are capable of achieving therapeutically useful T cell populations, the use of paramagnetic beads makes the ease of preparation of T-cells less than ideal. Problems include the high cost of the beads, the labor-intensive process for removing the beads prior to cell infusion, and the inability of the beads to activate CD8 T-cell subsets (Deeths, Kedl et al. 1999; Laux, Khoshnan et al. 2000). In addition, the T-cell populations resulting from this method, and other prior art T-cell stimulation methods, lack the type of robustness required for eliciting effective immune stimulation when infused into patients. As a consequence, no prior art cell therapy protocols have demonstrated significant efficacy in clinical settings.
This has motivated the search for more effective methods for activating T-cells for use in cell therapy protocols. One such method is the use of APC tumor cell lines that have been genetically modified to express receptors that bind mAbs. These modified APC can be loaded with anti-CD3 and anti-CD28 mAbs (Thomas, Maus et al. 2002) or additionally modified to express the ligand for 4-1BB (Maus, Thomas et al. 2002) and then used to activate T-cells for use in cell therapy protocols. It was found that these modified APCs resulted in more effective activation of T-cell populations than the use of CD3/CD28-coated paramagnetic beads. However, the use of genetically-manipulated tumor cell lines in cell therapy protocols raises safety concerns which limit the commercial application of this technique.
SUMMARY OF THE INVENTION
In this situation, biodegradable supports coated with a first material that is capable of cross-linking second materials with reactivity to moieties on the surface of T-cells are utilized. The coated biodegradable supports are then mixed with second material labeled T-cells. The signals delivered by the cross-linked second materials are enhanced by centrifugation of the mixture. The signals are further enhanced by the culture of the mixture at high cell densities.
The present invention also includes biodegradable devices that have a biodegradable support with one or more agents that are reactive to T-cell moieties. Such agents deliver signals to T-cells to enhance immunostimulatory or immunoregulatory capabilities.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
There is a need for improved T-cell stimulation methods capable of increasing the robustness of T-cells for use in cell therapy protocols that are more suitable for use in human therapy.
In order to improve the robustness of T-cells, it is also desirable that the improved stimulation methods as closely as possible mimic the stimulatory effects of natural APCs. The improvement in T-cell activation observed with the CD3/CD28-coated APC cell lines discussed above (Thomas, Maus et al. 2002); (Maus, Thomas et al. 2002), was attributed to the availability of ligands to co-stimulatory molecules naturally expressed on the APC cell line that worked in concert with the CD3/CD28 stimulation. These ligands included B7-H3, PD-L1, PD-L2 and IL-15.
Therefore, it is desired to have a method for improved T-cell stimulation capable of presenting a multiplicity of co-stimulatory ligands without the requirement for use of a tumor cell line.
Natural APCs, however, not only provide multiple simultaneous stimuli to T-cells, they provide different arrays of multiple stimuli at different times and/or stages in the T-cell response to T-cell stimulation. No prior art T-cell stimulation methods are capable of mimicking this natural process.
The ability to mimic this natural process would provide a means to control not only the expansion of T-cells, but also the differentiation of T-cells. In the process of T-cell differentiation into regulatory or effector cells, different signals are required at different times and/or stages in the T-cell response to APC stimulation. Thus, it would be desirable to be able to create ex-vivo conditions that mimic this natural process in order to provide a greater variety of differentiated cells for use in cell therapy, including cells which could either stimulate immunity or suppress immunity.
The maintenance of the high density cell cultures used in the present invention require special care, as the degradation of the biological supports causes a fall in the media pH and the higher cell densities result in rapid accumulation of metabolic waste products and consumption of nutrients in the culture medium. For these reasons, media changes are required at least daily and preferably at least twice daily after the cells obtain a cell density in excess of 1 million per ml.
Frequent media changes can remove endogenous cytokines that are important for the maintenance and growth of the T-cell cultures. Therefore, in preferred embodiments, the removed culture media is filtered through a dialysis membrane in order to remove metabolic waste products, but retain endogenous cytokines. The retained media is then supplemented with fresh nutrient media and returned to the mixed culture. This enables the cells to be exposed to fresh nutrient media without dilution of the endogenous cytokines.
As the T-cells grow and mature in the cultures, various arrays of second materials can be added to the cultures at any time as required and subsequently cross-linked by mixing with additional coated biodegradable supports. Alternatively, the second materials can be added to the biodegradable supports and the coated supports added at various times to the cultures. Centrifugation of the mixture each time after adding additional second materials and coated biodegradable supports provides added benefit. In preferred embodiments, the centrifugation step is conducted daily to coincide with the media dialysis step.
Biodegradable Spheres
Aliphatic polyesters, such as polylactic acid) (PLA), poly(glycolic acid) (PGA), copolymers of PLA and PGA (PLGA) or poly(carprolactone) (PCL), and polyanhydrides are preferred materials for use as biodegradable polymers for the supports. The polymers can be formulated as various shapes, such as films, strips, fibers, gels, nanospheres or microspheres, and then coated with a first material. Microspheres are a preferred formulation because they can be reproducibly manufactured into small microsphere particle sizes of 1.to.500 microns, preferably 1 to 10 microns and most preferably 1 to 5 microns. Microspheres of this size range are capable of direct injection into the body by conventional methods. It is preferred that the coated microspheres be formulated to degrade in culture media or physiological fluids within 14 days, more preferably within 7 days, and most preferably within 3 days. In other preferred methods, nanospheres are formulated. These devices are preferred in applications where very rapid degradation, for example 3 days or less is required.
One preferred first material for coating on the biodegradable microspheres is polyclonal goat (or sheep) anti-mouse polyclonal antibodies. By way of example, this preferred first material can be used to cross-link mouse-derived monoclonal antibodies, or fragments or genetically engineered derivatives thereof, that have specificity for T-cell surface moieties. Thus, for example, the mixing of goat anti-mouse coated microspheres (or nanospheres) with human T-cells labeled with mouse anti-human CD3 and mouse anti-human CD28 mAbs will cause the cross-linking of the mouse mAbs on the human T-cells through the binding of the goat anti-mouse polyclonal antibody with the mouse mAbs. The cross-linking of the mAbs causes the activation and proliferation of the T-cells. Many combinations of first materials and second materials can be used to accomplish the objective of cross-linking second agents attached to T-cell surface moieties in order to initiate signal transduction and activation of T-cells. Alternatively, the second materials can be added to the biodegradable supports prior to addition to the T-cells.
The coated biodegradable microspheres (or nanospheres) used in the present invention provide many advantages for preparation of T-cells for use in cell therapy protocols over prior art methods where mitogenic agents are immobilized on a solid surface, such as paramagnetic beads:
First, since the devices are biocompatible and naturally degrade into non-toxic substances, there is no need to institute a bead removal process.
Second, because the devices have a low density, they can be used with cells being subjected to a centrifugal force. Prior art devices, such as paramagnetic beads, cause damage to cells when subjected to centrifugation. The ability to centrifuge cells with the beads permits the use of centrifugal force to enhance the quality of signals provided to the T-cells by stimulatory ligands cross-linked on the surface of the T-cells and also provides a means to wash and otherwise process the T-cells for preparation for infusion.
Third, in one use of the present invention, rather than immobilizing T-cell stimulatory and co-stimulatory ligands to a solid surface to present signals to T-cells, the use of a coated biodegradable microspheres (or nanospheres) permits the ligands to be first applied to the T-cells and then the labeled T-cells to be mixed with the coated biodegradable microspheres (or nanospheres). In this manner, the coated microspheres (or nanospheres) act as a universal cross-linking agent.
Fourth, as a universal cross-linking agent, a multiplicity of stimulatory and co-stimulatory ligands can be applied to T-cells and be cross-linked by the coated beads and the composition of the multiplicity of stimulatory and co-stimulatory ligands to be cross-linked can be varied over time.
Fifth, the ability to vary the composition of the array of stimulatory and co-stimulatory signals provided to T-cells over time permits the practice of methods designed to mimic natural presentation of T-cell proliferation, differentiation and functional signals.
Sixth, the ability to mimic the natural signal presentation to T-cells permits the development of T-cells with a multitude of functional characteristics for use in cell therapy protocols.
Seventh, the ability to control the sequence and variety of signals delivered to T-cells over time permits a means to control the differentiation pathways of T-cells ex-vivo. This will permit experimentation with novel combinations and sequencing of signals delivered to T-cells. Such methods will lead to T-cell products with novel effector functions both stimulatory and suppressive for use in cell therapy protocols.
For the purposes of the present invention, all references to T-cells includes a population of cells with at least a portion of the cells containing T-cells. T-cells are cells which express TCR, including α/β and γ/δ TCRs. T-cells include all cells which express CD3, including T-cell subsets which also express CD4 and CD8. T-cells include both naĩve and memory cells and effector cells such as CTL. T-cells also include regulatory cells such as Th1, Tc1, Th2, Tc2, Th3, Treg, and Tr1 cells. T-cells also include NKT-cells and similar unique classes of the T-cell lineage.
Increased Signal Transduction
One aspect the present invention provides methods for enhanced stimulation of a population of T-cells by the concentration of a mixture of first material coated biodegradable microspheres (or nanospheres) and second material labeled T-cells. In order to increase the efficacy of the signal transduced to the T-cells, it is important to both increase the quantity of second agents cross-linked and the quality of the cross-linking.
In order to assure the highest quantity of second materials that are associated with the corresponding surface moieties on the surface of the T-cells, the labeling of the T-cells should be conducted with excess second materials. In a preferred embodiment where mouse mAbs to human T-cell surface antigens are the second materials, the mAbs are preferably mixed with a T-cell suspension whereby the T-cells are at a concentration of 1×10 6 to 1×10 7 per ml and each mAb is at a concentration of 0.5 μl/ml to 10 μl/ml, preferably 1 μl/ml. The labeled T-cells should be mixed with the coated biodegradable spheres at a ratio of at least one sphere per cell, and preferably at a ratio of 3 spheres per cell.
In order to assure the highest quality of cross-linking, the labeled cells and the coated biodegradable spheres are preferably first mixed thoroughly and then concentrated together under centrifugal force. The centrifugation is preferably conducted every 3 days, more preferably at least once daily. It is also preferable that the T-cells be kept at 4° C. from the time new mAbs are added through the completion of the centrifugation. Keeping the cells at refrigeration temperature prevents the capping and shedding of the ligated T-cell surface receptors prior to being cross-linked.
Cell Culture Methods
It is preferable to maintain processive and sustained TCR signal transduction and co-simulation in order to provide the most robust T-cells for use in cell therapy protocols. For this reason, the methods of the present invention work best when the cultured T-cells are maintained at high cell densities, such as greater than 10 6 cells/ml, or more preferably greater than 10 7 cells/ml, or most preferably greater than 10 8 cells/ml. The high cell densities increase the cell:cell interaction and the interaction with the biodegradable spheres.
The increased cell:cell interaction has a beneficial effect that is separate from the cross-linking effect of the biodegradable spheres. The beneficial effect comes from the expression of stimulatory ligands which upregulate on the surface of T-cells in response to maximal activation conditions. These ligands interact with the corresponding receptors on other T-cells. For example, T-cells will express one or more of the following TNFR co-stimulatory ligands such as LIGHT, CD70, OX40L, 4-1BBL and CD30L after maximal activation.
Maintaining cells at high densities in culture with biodegradable spheres requires the frequent changing of the culture media. The high cell densities result in a high rate of build up of metabolic waste products and consumption of available nutrients. In addition, the hydrolysis of the biodegradable spheres causes the pH of the culture media to become acidic. Too rapid media replacement, however, can be detrimental to cultures where exogenous cytokines are not utilized. It is preferable not to use exogenous cytokines when processing cells for use in cell therapy protocols, as exogenous cytokines can be toxic when infused into humans and can make the cultured cells dependant upon the presence of the exogenous cytokines for viability. Therefore, the methods of the present invention include a dialysis step in the cell processing.
Dialysis of the culture medium with membrane pore size of 10,000 dalton or less will enable retention of endogenous cytokines while allowing passage of metabolic waste. In preferred embodiments, half the culture medium of a culture is removed daily and 90% passed through a dialysis filter. The media passed through the filter is discarded, while the retained media is brought up to the original volume with fresh culture media.
According to the method of the present invention, a process is described for producing T-cells with robustness and enhanced function for use in cell therapy protocols involving: (1) the labeling of a population of T-cells with one or more agents that have reactivity to cell surface moieties; (2) mixing of the population of labeled T-cells with coated biodegradable spheres capable of cross-linking the agents attached to cell surface moieties on the T-cells causing a signal to be transduced to the T-cells; (3) concentrating of the mixture by centrifugation; (4) continued culture of the T-cells at high cell density; and (5) removal of media from the cultures at least daily and the dialysis of the media for retention of endogenous cytokines and replacement with fresh media; and (6) repeat of the process as necessary with the same or different agents for labeling of the T-cells in order to generate both the quantities of T-cells necessary for infusion and the optimal function of the T-cells for clinical effect.
Choice of T-Cell Ligating Targets
The ability to design more efficient and effective T-cell activation, expansion and differentiation methods will be a direct result of the selection and timing of application of second materials. Second materials are agents which are capable of ligating T-cell surface moieties and delivering a signal to the T-cell upon cross-linking. These materials are preferably monoclonal antibodies, or fractions or genetically manipulated versions thereof, such as fusion proteins. The selection of second materials will be as a result of understanding of the T-cell activation, expansion and differentiation process and the requirements for the type and duration of signals at any one time in the life of the responding T-cells.
It is known that at least two type of receptors need to be engaged for T-cell activation, the TCR and a co-stimulator (Chambers and Allison 1999). In response to natural APC engagement with antigenic peptide and co-stimulatory ligands, the contact site of the APC and T-cell forms an “immunological synapse”. The synapse assembles into topologically and spatially distinct regions. The initial TCR engagement occurs at the periphery of the synapse (Grakoui, Bromley et al. 1999) after which ligand engagement of co-simulating molecules such as CD28, CD2, CD48 and LFA-1 facilitates the sorting and re-arrangements of receptors at the synapse. The content of molecules at the synapse can be specifically enriched in a subset of proteins and can selectively exclude proteins. This selective movement of proteins is facilitated by structures known as “lipid rafts”.
Lipid raft membrane partitioning is known to be crucial for optimal TCR signal transduction (Moran and Miceli 1998; Janes, Ley et al. 1999) and co-stimulators to TCR signaling cause the synapse formation and the re-organization and clustering of lipid rafts at the synapse. These events provide a natural mechanism for integrating spatial and temporal information provided to T-cells from the environment.
Accordingly, knowledge of the types of receptors available at the synapse in response to defined stimuli can provide the information for deciding the various types of co-stimulators to utilize over a period of time. Lipid rafts function as platforms for the concentration and juxtaposition of TCR associated signal transducers and assembly of an organized TCR signaling complex. Thus, by a process of first providing a defined array of signals to a population of T-cells and next analyzing the proteins assembled in lipid rafts that were induced by the first array, a second array of possible signals can be determined. The process can be repeated with second array stimulators. After application of the second array, the process can be repeated with a third array and so on. At each step in the process, the response of the T-cells can be monitored in order to optimize for the desired function, such as proliferation, the types and quantities of selected cytokine production, the expression of effector molecules and other functional surface molecules.
For example, both CD2 and LFA-1 are raft associated proteins that can stimulate initial T-cell activation in the absence of CD28 engagement (Yashiro-Ohtani, Zhou et al. 2000). The engagement of these molecules is known to upregulate and increase avidity for receptors for ICAM-1 which could then be engaged in a second array. CD2/LFA-1 engagement are know to facilitate T-cell activation by increasing the number of TCRs engaged over time, whereas CD28 functions by increasing the potency of those TCRs that are engaged, thus lowering the number of TCRs that need to be engaged in order to effect a response (Bachmann, McKall-Faienza et al. 1997).
In preferred embodiments, a first array including CD3 and other co-stimulatory molecules selected from one or more of the following: CD2, CD28, CD48, LFA-1, CD43, CD45, CD4, CD8, CD7, GM1, LIGHT (HVEM fusion protein) is utilized. A second array including CD3 and one or more of the first array co-stimulators with the additional choices of the following inducible co-stimulatory ligands: CD27, OX40, 4-1BB and CD30.
Also in preferred embodiments, T-cell counter receptors to various adhesion molecules can be engaged during the process. Examples of adhesion molecules on T-cells are: CD44, CD31, CD18/CD11a (LFA-1), CD29, CD54 (ICAM-1), CD62L (L-selectin), and CD29/CD49d (VLA-4). Other suitable second array agents include non-cytokine agents which bind to cytokine receptors and deliver a signal when cross-linked. Examples of these type of agents are mAbs to cytokine receptors including: IL-2R, IL-4R, IL-10R, Type II IFNR1 and R2, Type I IFNR, IL-12Rbeta1 and beta2, IL-15R, TNFR1 and TNFR2, and IL-1R. Also any agents capable of binding to chemokine receptors on T-cells and delivering a signal when cross-linked, including those in the C—C and C—X—C categories. Examples of chemokine receptors associated with T-cell function include CCR1, CCR2, CCR3, CCR4, CCR5, and CXCR3
EXAMPLE METHODS
Examples of optimized processes for producing a T-cell population with enhanced ability to stimulate the immune system follow. All examples utilize goat anti-mouse coated biodegradable microspheres and T-cells labeled with mouse mAbs specific for T-cell surface antigens:
Example #1
Set-up (Day 0)
(1) collection of leukocytes by leukapheresis;
(2) purification of 10 8 CD4+ T-cells by positive selection;
(3) labeling of purified CD4+ cells with anti-CD3, anti-CD28 and anti-IL-12Rbeta2 mAbs;
(4) mixing the labeled cells with coated microspheres in gas permeable bags (3:1 sphere:cell);
(5) suspension of the mixture at a cell density of 1×106/ml in 100 ml;
(6) centrifugation of the mixture at 500×g for 8 min at 4° C.;
(7) gently resuspend and culture in humidified atmosphere at 37° C. with 5% CO 2 ;
Day 3
(8) remove 80 ml of culture media by syringe aspiration using a 0.45 micron filter so as not to remove any cells;
(9) pass 70 ml of the removed media through a dialysis filter of 6,000 dalton cut-off size;
(10) add 70 ml of fresh culture media to the retained 10 ml and add back to the culture bag;
(11) add 100 μg each of anti-CD3, anti-CD28, anti-IL-12Rbeta2 and anti-4-1BB mAbs to the culture bag;
(12) mix coated microspheres at a sphere:cell ratio of 1:1;
(13) centrifuge mixture at 500×g for 8 min at 4° C.;
(14) gently resuspend and culture in humidified atmosphere at 37° C. with 5% CO 2 ;
Day 4
(15) repeat steps 8-10
Day 5
(16) repeat steps 8-10
Day 6
(17) repeat steps 8-14
(18) after 12 h repeat steps 8-10
Day 7
(19) repeat steps 8-10
(20) after 12 h repeat steps 8-10
Day 8
(21) repeat steps 8-10
(22) after 12 h repeat steps 8-10
Day 9
(23) harvest T-cell population and formulate for infusion
Results
This method results in a population of T-cells with enhanced proliferation and production of IFN-gamma and TNF-alpha compared to cells activated with CD3/CD28-coated immunomagnetic beads alone. N=6
Fold
IFN-gamma
TNF-alpha
IL-4
Method
Expansion
ng/ml
ng/ml
pg/ml
Example #1
830 +/− 77
970 +/− 160
180 +/− 38
<20
3/28-beads +
80 +/− 20
3 +/− 2.2
0.5 +/− .2
80 +/− 16
IL-2
Example #2
Set-up (Day 0)
(4) collection of leukocytes by leukapheresis;
(5) purification of 10 8 CD4+ T-cells by positive selection;
(6) labeling of purified CD4+ cells with anti-CD3, anti-CD28 mAbs;
(4) mixing the labeled cells with coated microspheres in gas permeable bags (3:1 sphere:cell);
(5) suspension of the mixture at a cell density of 1×106/ml in 100 ml;
(6) centrifugation of the mixture at 500×g for 8 min at 4° C.;
(7) gently resuspend and culture in humidified atmosphere at 37° C. with 5% CO 2 ;
Day 3
(8) remove 80 ml of culture media by syringe aspiration using a 0.45 micron filter so as not to remove any cells;
(9) pass 70 ml of the removed media through a dialysis filter of 6,000 dalton cut-off size;
(15) add 70 ml of fresh culture media to the retained 10 ml and add back to the culture bag;
(16) add 100 μg each of anti-CD3, anti-CD28, mAbs to the culture bag;
(17) mix coated microspheres at a sphere:cell ratio of 1:1;
(18) centrifuge mixture at 500×g for 8 min at 4° C.;
(19) gently resuspend and culture in humidified atmosphere at 37° C. with 5% CO 2 ;
Day 4
(15) repeat steps 8-10
Day 5
(16) repeat steps 8-10
Day 6
(24) repeat steps 8-14
(25) after 12 h repeat steps 8-10
Day 7
(26) repeat steps 8-10
(27) after 12 h repeat steps 8-10
Day 8
(28) repeat steps 8-10
(29) after 12 h repeat steps 8-10
Day 9
(30) harvest T-cell population and formulate for infusion
Results
This method results in a population of T-cells with enhanced proliferation and production of IFN-gamma and TNF-alpha compared to cells activated with CD3/CD28-coated immunomagnetic beads alone, as well as enhanced expression of CD40L. N=6
Fold
IFN-gamma
TNF-alpha
Method
Expansion
ng/ml
ng/ml
CD40L %
Example #2
630 +/− 77
90 +/− 16.7
8.8 +/− 1.3
78.5 +/− 10
3/28-beads +
80 +/− 20
3 +/− 2.2
0.5 +/− .2
15 +/− 6
IL-2
Example #3
Set-up (Day 0)
(7) collection of leukocytes by leukapheresis;
(8) purification of 10 8 CD4+ T-cells by positive selection;
(9) labeling of purified CD4+ cells with anti-CD3, anti-CD28 and anti-HVEM mAbs;
(4) mixing the labeled cells with coated microspheres in gas permeable bags (3:1 sphere:cell);
(5) suspension of the mixture at a cell density of 1×106/ml in 100 ml;
(6) centrifugation of the mixture at 500×g for 8 min at 4° C.;
(7) gently resuspend and culture in humidified atmosphere at 37° C. with 5% CO 2 ;
Day 3
(8) remove 80 ml of culture media by syringe aspiration using a 0.45 micron filter so as not to remove any cells;
(9) pass 70 ml of the removed media through a dialysis filter of 6,000 dalton cut-off size;
(20) add 70 ml of fresh culture media to the retained 10 ml and add back to the culture bag;
(21) add 100 μg each of anti-CD3, anti-CD28, anti-CD27 and anti-4-1BB mAbs to the culture bag;
(22) mix coated microspheres at a sphere:cell ratio of 1:1;
(23) centrifuge mixture at 500×g for 8 min at 4° C.;
(24) gently resuspend and culture in humidified atmosphere at 37° C. with 5% CO 2 ;
Day 4
(15) repeat steps 8-10
Day 5
(16) repeat steps 8-10
Day 6
(31) repeat steps 8-14
(32) after 12 h repeat steps 8-10
Day 7
(33) repeat steps 8-10
(34) after 12 h repeat steps 8-10
Day 8
(35) repeat steps 8-10
(36) after 12 h repeat steps 8-10
Day 9
(37) repeat steps 8-10;
(38) after 12 h repeat steps 8-10;
(39) add 100 μg each of anti-CD3, anti-CD28, and HVEM-Fc to the culture bag;
(40) mix coated microspheres at a sphere:cell ratio of 1:1;
(41) centrifuge mixture at 500×g for 8 min at 4° C.;
(42) gently resuspend and culture in humidified atmosphere at 37° C. with 5% CO 2 ;
Day 10
(43) repeat steps 8-10;
(44) after 12 h repeat steps 8-10;
Day 11
(45) harvest T-cell population and formulate for infusion.
Results
This method results in a population of T-cells with enhanced proliferation and production of IFN-gamma LIGHT and FasL compared to cells activated with CD3/CD28-coated immunomagnetic beads alone. N=6
Fold
IFN-gamma
Method
Expansion
ng/ml
LIGHT (%)
FasL %
Example #3
290 +/− 21
44 +/− 6.2
38.4 +/− 3.3
61.4 +/− 10
3/28-beads +
80 +/− 20
3 +/− 2.2
6.1 +/− 5
4 +/− 1.3
IL-2
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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T-cells are generated with enhanced immunostimulatory capabilities for use in self therapy treatment protocols, by utilizing a biodegradable device with a biodegradable support that has one or more agents that are reactive to T-cell surface moieties. The biodegradable devices are mixed with the T-cells sufficiently so that the one or more agents cross-link with the T-cells' surface moieties and deliver a signal to the T-cells to enhance immunostimulatory capabilities.
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FIELD OF THE INVENTION
[0001] This invention relates to the field of immunology and more specifically to monoclonal antibodies, immunoassay methods, including ELISA and immunostrip assays, for detection of phytase, specifically Aspergillus niger (phyA2) derived phytase, in genetically modified organisms, such as corn. The invention includes monoclonal antibodies capable of detecting glycosylated phytase. The invention further includes hybridoma cell lines that produce anti-phytase monoclonal antibodies and its application in various detection methods and assays.
BACKGROUND OF INVENTION
[0002] Phytase (myo-inositol hexakisphosphate phosphohydrolase) EC 3.1.3.8 is part a class of phosphatases which can catalyze the sequential hydrolysis of phytate to lower phosphorylated inositol and inorganic phosphates. Phytate is the main storage form of phosphorus in livestock feed such as seeds and cereal grains, representing nearly 90% of their total phosphorus content. The digestive microbial fauna of monogastric animals lack the necessary phosphorus hydrolyzing enzymes and as a result much undigested phytate-associated phosphorus is lost into the environment. This can lead to excessive phosphorus loading in soil and water and the ensuing pollution can affect other ecosystems. Inorganic phosphorus or phytase as feed supplements and the subsequent development and application of transgenic phytase plants has been shown as possible solutions to greatly improve the phytate antinutrient factor, prompting the search for more temperature and pH tolerant phytases and propelled phytase optimization technology through genetic and protein engineering.
[0003] This has precipitated a growing need for accurate verification and increased awareness regarding the distribution of genetically modified phytase organisms and products, particularly those pertaining to agriculture and in the development of food nutritional and environmental management strategies wherein concerns of phytate mineral availability and environmental issues need to be assessed. Development of a rapid diagnostic test (RDT), which is a qualitative immunoassay (consisting of target specific antibodies to phytase) used in point-of-care testing, for transgenic A. niger (phyA2) phytase would offer an efficient and convenient method of detection.
[0004] Phytases can be glycosylated and the level of glycosylation is known to be highly variable, between different expression systems and individuals within a given expression system. Glycosylation can have many effects on the properties of a protein, such as on stability, solubility, and metabolic energy. Glycosylation of phytase have been shown to increase thermostability which would be an invaluable feature when there are concerns regarding enzyme activity loss due to heat such as that from feed pelleting. Phytases for commercial use have been isolated mainly from fungi and bacteria and selection for efficacious products is greatly dependent on the source, tolerance to processing factors, digestive resistance and production costs. Aspergillus niger phytase (phyA2) which has 10 potential glycosylation sites was cloned and expressed in a methylotrophic yeast, Pichia pastoris . Phytase expressed from yeast is known to be glycosylated and the said yeast-expressed A. niger phytase had facilitated the invention to include the ability to detect glycosylated phytase.
[0005] The present invention can fulfil the need for a rapid diagnostic test for an efficient detection of phytase by production of anti-phytase monoclonal antibodies, of which the phytase antigen may be glycosylated, hybridoma cell lines, and the construction of immunological assays that would deliver immediate results, requiring little skill or additional equipment.
SUMMARY OF THE INVENTION
[0006] The immunoassay for detecting for the presence of phytase in a sample is supplied. This would include the monoclonal antibodies which can detect a phytase, specifically an A. niger (phyA2) phytase that resulted in the production of EH10a, FA7, AF9a and CC1. Phytase can be found in various microorganisms, fungi and plants. The invention can be used to detect the phytase protein in genetically modified (GM) plants which encode the transgenic phytase gene. The genetically modified phytase plants can be used for human and non-human consumption in the form of agricultural plants or plant by-products.
[0007] The phytase (phyA2) protein may be purified from A. niger and grown in the methylotrophic yeast, Pichia pastoris . This protein is then introduced into animals to produce polyclonal or monoclonal antibodies.
[0008] The monoclonal antibodies have a high specificity and sensitivity for phytase that is distinguishable from plant- and yeast-expressed phytase and can be applied to immunoassay methods for detection of phytase in genetically modified organisms. The specificity of the phytase monoclonal antibody pairs EH10a-FA7 and AF91-CC1 (where one of the pair is immobilized on the surface of the capture membrane and the other conjugated to gold particles near the sample pad) in an antibody-coated lateral test strip were constructed and tested with different seed varieties of commercial plants. Phytase could not be detected in any of the non-GM phytase seed varieties tested using either of the antibody pairs. Detection limit of the immunolateral test strip to recombinant phytase using the EH10a-FA7 antibody pair was 5 ng/ml whereas the detection limit to GM phytase corn using the AF9a-CC1 antibody pair was as low as 2 ng/ml. The strips were confirmed to be stable when kept at RT for at least 1 year.
[0009] Analyses of the protein detected from the plant- and yeast-expressed phytase showed that different sizes were detected. Monoclonal antibody pairs EH10a and FA7 which had detected the larger-sized protein may be able to recognize glycosylated phytase. This suggests that the epitope binding sites of one or both of the monoclonal antibody pairs EH10a and FA7 may consist of a carbohydrate moiety. Correct detection of glycosylation within transgenic phytase plants may be essential when a marketable product with a more thermostable enzyme is required. A rapid diagnostic test in the form of an immunochromatographic capillary flow assay consisting of specific and sensitive monoclonal antibodies allows for an efficient and sensitive point-of-care testing method that would deliver immediate results, requiring little skill or additional equipment. Here we present the development of such a said rapid diagnostic test that is able to detect phytase from genetically modified crops.
BRIEF DESCRIPTION OF THE FIGURES
[0010] FIGS. 1A and B show that the monoclonal antibodies target phytase. FIG. 1A shows that all seed samples tested contains protein using a 15% polyacrylamide protein gel. Fifty micrograms of plant seeds were ground in 500 μl Laemmli buffer of which 20 μl were loaded into each lane. The lanes are as follows: (1) water, (2) 10 mM Tris-HCl, pH 8.0, (3) Marker, (4) 1 μg recombinant phytase, (5) GM phytase corn, (6) corn 1, (7) green bean, (8) white bean, (9) Pickseed2733 corn, (10) WCS F1 corn, (11) GM corn 1, (12) GM corn 2, (13) GM corn 3, (14) GM corn 4 and (15) GM soybean. FIG. 1B show that Western blot analyses were conducted on the samples used in (A), except that 5 μg of recombinant phytase and 100 mg of ground plant seeds were used and probed with an equal mixture of monoclonal antibodies AF9a, CC1, EH10a and FA7. The protein marker sizes kilodaltons (kD) are indicated on the left of the blot. GM=genetically modified; WCS=West Coast Seeds. Unless stipulated, GM corn samples are not GM phytase corn.
[0011] FIGS. 2A and B show that both match pair EH10a-FA7 and AF9a-CC1 antibodies show high specificity to phytase using lateral flow test strips. FIG. 2A show that phytase specificity analysis was conducted using lateral flow strips containing the EH10a gold-conjugated antibody and the FA7 capture membrane antibody. Strips 1-4 were immersed in a 10 ml solution consisting of (1) 200 μg/ml recombinant phytase, (2) 200 μg/ml transgenic phytase corn, (3) 10 mM Tris-HCl and (4) distilled water. Strips 5-28 were immersed in the supernatant of 2 g of seeds ground in 10 ml of 10 mM Tris-HCl for 1-5 minutes. The strips were tested using the following seeds: (5) corn 1, (6) corn 2, (7) corn 3, (8) corn 4, (9) GM corn 1, (10) GM soybean, (11) Pickseed2733 corn, (12) GM corn 2, (13) GM corn 3, (14) GM corn 4, (15) WCS F1 corn 1, (16) WCS F1 corn 2, (17) WCS P corn 1, (18) WCS P corn 2, (19) WCS DF1 corn, (20) green soybean, (21) WCS corn, (22) green bean, (23) white bean, (24) corn 5, (25) corn 6, (26) corn 7, (27) GM corn 5 and (28) GM corn 6. For each strip the upper line is the control (C) line containing antibodies to goat anti-mouse IgG and the lower line (if present) is the test (T) line with the FA7 capture antibody. The corn used in strips 5 to 8 and 24 to 26 were generic (non-GM) varieties. FIG. 2B show that phytase specificity analysis was conducted using lateral flow strips containing the AF9a gold-conjugated antibody and the CC1 capture membrane antibody. Each strip was prepared and tested with the same samples as described in FIG. 2A except the lower T line (if present) contains the CC1 capture antibody.
[0012] FIGS. 3A and B show that both match pair EH10a-FA7 and AF9a-CC1 antibodies show high sensitivity to phytase using lateral flow test strips. FIG. 3A shows that phytase sensitivity analysis of the EH10a-FA7 antibodies was conducted, using concentrations from 0.002 to 200 μg/ml of recombinant phytase applied to lateral flow strips containing the EH10a gold-conjugated antibody and the FA7 capture membrane antibody. FIG. 3B shows that phytase sensitivity analysis of the AF9a-CC1 antibodies was conducted, using concentrations from 0.001 to 400 μg/ml of the GM phytase corn applied to lateral flow strips containing the AF9a gold-conjugated antibody and the CC1 capture membrane antibody. The strips were immersed in a 10 ml solution of recombinant phytase in FIG. 3A and GM phytase corn in FIG. 3B in the various concentrations indicated above the strips. The arrangement of the control (C) and test (T) lines along the strips are as described in FIG. 2 .
[0013] FIGS. 4A and B reveal the nature of phytase epitopes using the monoclonal antibodies match-pair EH10a-FA7 and AF9a-CC1 over time. FIG. 4A indicates that 10 μl of (200 μg/ml) purified recombinant phytase (phy2A) expressed from yeast (top row) and (200 μg/ml) phytase expressed from GM corn (bottom row) were prepared and evaluated every 2 weeks over a period of 10 weeks using western blot analysis. Each blot was probed with a mixture of monoclonal antibodies EH10a, FA7, AF9a and CC1 (in equal 1:400 concentrations). Record dates are indicated above the blot with the protein marker sizes kilodaltons (kD) to the left. FIG. 4B shows that purified recombinant phytase (phy2A) expressed from yeast (top row) and phytase expressed from GM corn (bottom row) were prepared and tested along immunolateral flow strips. Test strips containing the EH10a gold-conjugated antibody and the FA7 capture membrane antibody (green coloured) and AF9a conjugate antibody and the CC1 capture antibody (brown coloured) were immersed in a solution of the prepared phytase and detection was recorded on the dates indicated above the strips. The arrangement of the control (C) and test (T) lines along the strips are as described in FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION EMBODIMENTS
[0014] Anti-phytase monoclonal antibodies, hybridomas, and the immunoassays, for the detection of phytase in a sample are described.
[0015] The methodology of the invention may be used to detect enzymes in samples, such as those in agricultural crops and food by-products. Many enzymes have been detected in such a manner by those experienced in the art. Specificity is important in the proper construction of immunoassays to detect phytase in genetically modified organisms and their products. Therefore, to ensure the manufacture of successful commercial products, highly specific monoclonal antibodies to phytase were developed. Described is an immunoassay which employs a test kit strip format and consists of sensitive and specific monoclonal antibodies for the detection of phytase in genetically modified organisms, such as those in agricultural products.
Recombinant Phytase Protein
[0016] Preparation of antigenic recombinant protein, such as Aspergillus niger phytase, was cloned into an appropriate DNA vehicle with a suitable promoter, transformed into an suitable host strain, e.g., a bacterial, insect or yeast host, such as Pichia pastoris , by means of heat or chemical inducement whereby cells are incubated until sufficient concentrations are reached after which cells are cultured for an additional period to yield recombinant enzyme protein. The protein is subsequently purified from pelleted cells that were subjected to physical or chemical disruption by methods known to those skilled in the art.
Antibodies
[0017] The antibodies produced in this invention may be made using a rabbit, chicken, mouse or a goat. For example, mice were immunized with multiple subcutaneous or intraperitoneal injections of recombinant phytase over a set period. The immunization protocol can be selected by one skilled in the art. Each mouse was immunized with a mixture of the recombinant phytase and an immunizing agent, such as complete Freund's adjuvant. Subsequent booster injections were given with another immunizing agent, such as incomplete Freund's adjuvant, over a set period. After which the immune response was assessed by measuring polyclonal antibody titer in immunized animal sera using indirect ELISA. Such techniques are known to those skilled in the art. Immunized mice with the highest titers are selected for hybridoma production and given a final booster injection before their spleen cells were to be harvested. The harvested spleen cells were fused with myeloma cells, usually of mouse or rat origin, producing hybridoma cells that are suspended in an enriched medium, such as RPMI 1640.
Hybridoma Cell Lines
[0018] The hybridoma cells were seeded in tissue culture plates in a suitable medium, such as hypoxanthine-aminopterin-thymidine (HAT), which contains one or more substances that inhibit the growth or survival of the unfused, immortalized cells. Cell lines which showed the strongest positive signals were selected for using indirect ELISA and processed to maximize monoclonality and stability. Supernatants from these clones were retested using indirect ELISA and positive candidates were selected for large scale production in a nonselective medium and stored in liquid nitrogen until required.
[0019] The hybridoma cell lines are assigned as EH10a, FA7, AF9a and CC1.
Monoclonal Antibodies
[0020] The anti-phytase antibodies were monoclonal antibodies. Monoclonal antibodies raised against proteins, such as the recombinant A. niger phytase, were produced using a standard ascitic fluid method as described in the EXAMPLE below. The production and purification protocol can be selected by one skilled in the art. The said hybridomas produced in this invention may involve a mouse, hamster, or other appropriate host animal, which is typically immunized with an immunizing agent to elicit lymphocytes that produce or are capable of producing monoclonal antibodies that will specifically bind to the said immunizing agent. For example, mice could be injected intraperitoneally with the said hybridoma cells for a set time. The ascitic fluid would be drained and purified, for example, by a protein A affinity chromatography, protein A-Sepharose, hydroxylapatite chromatography, gel electrophoresis, dialysis, or affinity chromatography, method to obtain high quality monoclonal antibodies. The titer was determined by methods known to those skilled in the art, for example, indirect ELISA.
[0021] Monoclonal antibodies of the invention using the hybridoma cell lines are as follows:
[0000] Cell culture line EH10a deposited as EH10a
Cell culture line FA7 deposited as FA7
Cell culture line AF9a deposited as AF9a
Cell culture line CC1 deposited as CC1
Immunoassay
[0022] The antibodies described above may be used in a various assays to determine the presence of the phytase in a sample. The antibodies may be used in any quantitative or qualitative immunoassay.
[0023] A typical quantitative in entail the following steps: a phytase-containing sample, for example from a genetically modified corn seed, is captured onto a solid phase using a primary antibody. In one embodiment, the primary antibody is a mouse anti-phytase antibody, coated onto the solid carrier. A secondary anti-phytase antibody is further added. In one embodiment, the secondary antibody is labelled or unlabelled goat anti-phytase antibody. After washing to remove unbound antibody, the label on the bound secondary antibody is detected. In one embodiment, the label is horse radish peroxidise (HRP). A substrate to detect the label is added and colour development is measured by reading the absorbance.
[0024] A typical protocol entails:
[0000] 1. Coat and incubate a solid carrier, such as wells in a 96-well plate, with primary anti-phytase antibody.
2. Wash the carrier to remove unbound with primary anti-phytase antibody
3. Prepare the phytase-containing sample and apply to prepared solid carrier
4. Wash the carrier to remove unbound sample
5. Apply labelled secondary anti-phytase antibody which will bind to the sample
6. Wash the carrier to remove unbound secondary anti-phytase antibody
7. Add a substrate which binds to the label of the secondary anti-phytase antibody to form primary anti-phytase antibody-phytase sample-secondary anti-phytase antibody complex
8. Measure the amount of labelled secondary anti-phytase antibody
[0025] In one embodiment, the phytase is a fungal phytase, more particularly, an Aspergillus niger phytase.
[0026] The antibodies can be used a qualitative immunoassay for the detection of a transgenic enzyme, such phytase in genetically modified organisms. This invention utilizes a test strip immunoassay whereby antibodies are coated on a membrane attached to a solid support strip. As a liquid sample (or solid sample mixed in a liquid, such as water) is placed on the sample pad at one end of the strip, it will be drawn up by capillary action and migrates toward the distal end of the strip. In one embodiment if the antigen within the sample reacts with the antibodies that are labelled directly with a detectable label for identification and visualization of the antigen, such as phytase protein, in the sample pad and further reacts with antibodies, also anti-antigenic, on the capture line on the solid membrane backing as it moves the length of the strip, a positive signal will be detected on the said capture line. Labels for use in immunoassays are generally known to those skilled in the art and include, but are not limited to enzymes, radioisotopes, paramagnetic nanoparticles, fluorescent, luminescent, and chromogenic substances including colored particles such as colloidal gold and latex beads. In a preferred embodiment, colloidal gold is the visualization particle means of detection. Methods of labelling antibodies and assay conjugates are well known to those skilled in the art.
[0027] In one embodiment the phytase is a fungal phytase. In a more particular embodiment, the phytase (phyA2) is from Aspergillus niger . In another embodiment, the phytase is a transgenic protein found in genetically modified organism, such as corn. In other embodiments, the solid membrane backing is usually made up of cellulose acetate, cellulose, nitrocellulose or nylon. In a preferred embodiment, the solid phase format is nitrocellulose. In another preferred embodiment, the solid support strip further comprises a sample absorption pad at one end. In a more preferred embodiment, the immunoassay further comprises a strip comprising a labelled anti-phytase antibody at the sample absorption pad end and a distal wicking pad to draw the liquid forward at the other end. Methods for coupling antibodies to solid phases are known to those skilled in the art.
[0028] A highly sensitive immunoassay employing the antibodies described above is provided. The assay is useful for detection of phytase protein in genetically modified organisms that have been engineered to include a gene encoding a phytase gene. The immunoassay is capable of detecting low concentrations of the protein in samples, such as in genetically modified crop samples. As described above, the antibodies are highly specific and sensitive as to react with epitopes on the phytase protein, thus providing for an accurate determination of the presence of the phytase protein in a genetically modified phytase organism, such as corn.
[0029] The sample may be obtained from any portion of any genetically modified phytase organism, for example, the sample may be any plant tissue or extract including root, stem, stalk, leaf, or seed or products derived from such crops, such as food products.
[0030] The least amount of reaction time that results in binding of the phytase to the antibodies is desired to minimize the time required to complete the assay. An appropriate reaction time period for an immunoassay test strip is between one second and ten minutes. A reaction time of less than five minutes is preferred.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] The immunoassay methods described above will be further understood with reference to the following, but not limited to, examples. The examples below show typical experimental protocols and reagents that can be used in the detection of phytase in samples such plants or plant materials. 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, and any change and/or modification of the invention will be at the discretion of those skilled in the art from these detailed descriptions and examples.
EXAMPLES
[0032] These methods and materials describe the general procedure for preparing the corn seed samples for testing and the production of the polyclonal and monoclonal antibodies used in the examples described below.
Materials and Methods
[0033] Corn Sample: The corn seed protein was genetically modified phytase corn seed sample. Corn kernels were ground in a blender. The resulting corn flour was suspended in 5 ml distilled water to solubilize the proteins. The supernatant was tested in either the ELISA or with the immunoassay test strips.
Recombinant phytase protein: The antigenic Aspergillus niger recombinant phytase protein was cloned into a DNA plasmid with a suitable promoter and transformed into the Pichia pastoris yeast host.
Production of Monoclonal Antibodies
[0034] Female mice were immunized with four intraperitoneal injections of recombinant phytase (expressed from yeast Pichia pastoris ) over a period of 2 weeks. Prior to immunization, blood was collected from the inner canthus of mice to be used as a negative control. Each mouse was immunized with 1:1 mixture (v/v) of the recombinant phytase and complete Freund's adjuvant. After the two weeks, three separate booster injections were given in the same proportion of immunogen emulsified using incomplete Freund's adjuvant over a period of 2 weeks. A second round of booster injections was given over an additional 2 weeks, after which the immune response was assessed by measuring the titer of polyclonal antibody in mice sera using indirect ELISA. Immunized mice with the highest titers were selected for hybridoma production and given a final booster injection via the tail vein 3 days before their spleen cells were to be harvested and used just prior to cell fusion. The other sera were pooled and used as a positive control.
[0035] Three days after the last intravenous booster injection, the immunized mice were eye-bled (to verify high antibody production), had splenocytes removed and were subsequently euthanized. The harvested spleen cells were fused with myeloma cells and the resulting hybridoma cells were suspended in enriched RPMI 1640 media. The cells were centrifuged at 500 g for 10 min and the subsequent pelleted cells were suspended in HAT media and incubated for 2 weeks. Cells were then seeded into 96-well tissue culture plates and kept in a hypoxanthine thymidine media for a further 2 weeks. Using indirect ELISA, cell lines which showed the strongest positive signals were recloned three times by limiting dilution using spleen cells from non-immunized mice to maximize monoclonality and stability. Supernatants from these clones were retested using indirect ELISA and positive candidates were selected for large scale production in a nonselective medium and stored in liquid nitrogen until required.
[0036] Monoclonal antibodies (MAbs) raised against the said recombinant A. niger phyA2 phytase were produced using a standard ascitic fluid method. Each mouse, primed with liquid paraffin, was injected intraperitoneally with 1×10 6 hybridoma cells. One to two weeks later, the ascitic fluid was drained and centrifuged at 4000 rpm at 4° C. for 10 min. The collected supernatants were precipitated in 50% saturated ammonium sulfate (pH 7.4), followed by extensive dialysis with 0.02 M phosphate solution (pH 7.4) at 4° C. The solution was purified by protein A affinity chromatography to obtain high quality MAbs. The flow through was collected in 4-5 ml fractions whereby the OD 280 of each fractions was monitored until the reading dropped below 0.05 to ensure that there was no more unbound protein in the solution. The column was then eluted by loading 5 ml, 1 ml at a time, of elution buffer (pH 3.0). To neutralize the pH, the eluants were collected in tubes containing 300 μl of 1 M Tris-HCl (pH 9.0). Eluant fractions of 1 ml were collected and monitored until an OD 280 reading of 0.05 was reached.
[0037] The purity of the eluted products was assessed by 10% SDS-PAGE. The titer of MAbs was determined by indirect ELISA. The extensive screening process yielded MAbs which showed the highest detection response for large scale production.
Example 1
Phytase Indirect ELISA
[0038] This example describes the detection and quantitative measurement of phytase antigen in culture supernatant samples using the enzyme-linked immunosorbent assay (ELISA) immunological technique.
Procedure
[0039] Each well of various 96-well microplates was coated with 100 μl of (yeast expressed) recombinant phytase antigens, which included positive and negative controls, in 0.1 M NaHCO 3 at a concentration of 10 μg/ml and incubated overnight at 4° C. After blocking for 2 h with 1×PBS and 1% BSA, 100 μl of hybridoma culture supernatants, immunized mouse serum (positive control) and SP2/0 (negative control) were added to respective wells and incubated at 37° C. for 1 h. Plates were washed three times with PBST and each well was incubated with 100 μl horseradish peroxidise conjugated goat anti-mouse immunoglobulin (IgG-HRP) in blocking buffer (at 1:1000) for 30 min at 37° C. Finally the plates were washed five times with 1×PBST and developed with 3,3′,5,5′-tetramethylbenzidine (TMB) liquid substrate system for ELISA. The reaction was terminated by supplementing per well with 50 μl of 1 M sulfuric acid (H 2 SO 4 ). The absorbance values of the wells from the ELISA were recorded at 450 nm. The titer of the antibody preparation was defined as the highest dilution that could give a reading of 0.05. One indirect ELISA unit was defined as the smallest amount of antibody which can detect a positive antigen signal.
[0040] The titer of the antibodies in the supernatant culture of hybridomas and ascites indicated high activity (all >10 −6 ).
Example 2
ELISA to Characterize Anti-Phytase Epitopes (Antibody Binding Sites)
[0041] This example describes the quantitative measurement of the epitopes of the purified MAbs to phytase characterized by ELISA and the additivity index (AI) described by Friguet et al. [(J. Immunol. Methods, 60:351(1983)].
Procedure
[0042] The wells of a 96-well plate were coated with 100 μl of 2 μg/ml (yeast expressed) recombinant phytase and incubated overnight at 4° C. The following day, the wells were blocked then incubated with 100 μl of antibodies, EH10a, FA7, AF9a, CC1 individually or in paired combinations (50 μl each) of equivalent concentrations at 1:1000 overnight at 4° C. For each treatment there were three replicate wells. The following day, the wells were incubated with 100 μl of a goat anti-mouse IgG-HRP secondary antibody at 1:1000 for 30 min at 37° C. The wells were developed and the reaction terminated by addition of an equal volume of 1 M H 2 SO 4 . Similar treatment sample wells were combined and the absorbance value for each treatment was recorded at 450 nm. The AI was calculated using the following equation: {[2A 1+2 /(A 1 +A 2 )]−1}×100%, where A 1 , A 2 and A 1+2 are the absorbance values for the individual antibodies and the respective combined pairs. If the two antibodies are directed against different epitopes (no competition), A 1+2 should be equal to the sum of A 1 and A 2 and the AI value should approach 100%. If the two antibodies are directed against the same epitope (competition), A 1+2 should be equal to the mean value for A 1 and A 2 and AI should be close to 0%. The threshold in this study was determined by AI≧40%.
[0000] TABLE 1 AI values of the epitopes of the monoclonal antibodies to phytase Antibody pairs Additive Index (AI) (%) FA7 + AF9a 67.7 FA7 + CC1 91.4 AF9a + EH10a 57.7 EH10a + CC1 69.7 FA7 + EH10a 59.6 AF9a + CC1 ≧99
As shown in Table 1, the AI data indicate that if any pair of these monoclonal antibodies would result in the targeting of a different phytase epitope.
Example 3
Detection of Phytase Protein in Plant Seeds
[0043] This example describes the detection of phytase protein in plant seeds using western blot analysis and anti-phytase monoclonal antibodies (EH10a, FA7, AF9a and CC1).
Procedure
[0044] Protein and western blot analysis on the specificity of the MAbs was evaluated by 15% SDS-PAGE. Sodium dodecyl sulfate-polyacrylamide gel or SDS-PAGE was prepared as a two layered gel whereby the lower, resolving gel layer consists of 15% acrylamide/bis-acrylamide, 390 mM Tris, pH 8.8, 0.1% SDS (w/v), 0.1% ammonium persulfate (w/v) and 0.1% TEMED and the upper, stacking gel consists of 4% acrylamide/bis-acrylamide, 125 mM Tris, pH 6.8, 0.1% (w/v) SDS, 0.1% (w/v) ammonium persulfate and 0.1% tetramethylethylenediamine (TEMED). The upper, stacking gel was prepared to accommodate a 15-well sample loading comb.
[0045] Samples evaluated consisted of 1 μg of (yeast expressed) recombinant phytase and 50 mg of ground seeds from genetically modified phytase corn, generic corn, green bean, white bean, Pickseed2733 corn, WCS F1 corn, four varieties of GM corn and one GM soybean variety. The phytase was released from the genetically modified phytase corn by homogenizing the corn in a modified Tris buffer [50 mM Tris-HCl (pH 8.0), 10 mM KCl, 3 mM MgCl2, 1 mM EDTA, 1 mM β-mercaptoethanol, 0.1% BSA, 13% sucrose and SigmaFAST™ Protease inhibitor cocktail (Sigma-Aldrich, St. Louis, Mo.) at 400 μl per 100 mg tissue] after which the sample was centrifuged at 4500 g for 10 min. Laemmli buffer was then added to the supernatant and incubated at 65° C. for 20 min. The remaining seeds were ground were homogenized in 500 μl of Laemmli buffer, boiled for 10 min, and centrifuged for 2 min at 12,000 g. To improved western blot detection, 5 μg of recombinant phytase and 100 mg of ground seeds were used. Twenty microlitres of each prepared seed supernatant was used for protein and western blot analysis. The recombinant phytase, 20 μl of water, and 10 mM Tris (the latter two serving as negative controls) were also boiled in Laemmli buffer as described above.
[0046] Twenty microlitres of each supernatant sample is loaded onto the stacking gel into separate wells. The gels were run at a voltage of 200 V for 45 min in a running buffer consisting of 25 mM Tris, 200 mM glycine and 0.1% (w/v) SDS. For the purpose of evaluating total protein, SDS-PAGEs are stained with Coomassie Brilliant Blue stain [9.375% (w/v) trichloroacetic acid and 0.0625% (w/v) Brilliant Blue stain] whereas SDS-PAGEs for western blot analysis are transferred to a nitrocellulose membrane using semi-dry transfer blot apparatus running at a voltage of 20 V for 2 h with a transfer buffer consisting of 25 mM Tris, 192 mM glycine and 20% (w/v) methanol. After which the blot is blocked in 5% milk power and 1×PBST (phosphate buffered saline-Tween 20) or 1×TBST (tris buffered saline-Tween 20) for 1 h and probed with a combined mixture of the monoclonal antibodies (EH10a, FA7, AF9a, and CC1) at 1:400 each] overnight. The following day the blot is washed with 1×PBST or 1×TBST and incubated with horseradish peroxidise conjugated goat anti-mouse immunoglobulin (IgG-HRP at 1:1000) for 90 min at RT. Proteins on the blot were developed using the DAB (3,3′-diaminobenzidine tetrahydrochloride; Sigma-Aldrich, St. Louis, Mo.) method with 0.1% hydrogen peroxide.
[0047] As shown in FIG. 1 , the results indicate that the monoclonal antibodies (EH10a, FA7, AF9a and CC1) were able to only detect protein phytase from the recombinant phytase protein and GM phytase corn but none from the non-GM seed varieties. The size of the detected phytase protein is of different between the (yeast expressed) recombinant protein and GM corn.
Example 4
Anti-Phytase Immunoassay Test Strips (A)
[0048] This example describes the use of immunoassay strips to test the specificity of anti-phytase antibodies by comparison with seeds from other plant varieties.
Procedure
[0049] Seeds from various plants [six varieties of genetically modified corn, one variety of a genetically modified soybean, corn (2733) from Pickseed, six corn varieties from West Coast Seeds (=WCS; two of F1, two of P, one of DF1 and one unknown), green bean, white bean and seven generic varieties of corn (purchased from local markets)]. Two grams of each seed variety was ground in 10 mM Tris-HCl. The absorption pad end of a prepared test strip was immersed in seed supernatant. In addition, test strips were also immersed in 200 μg/ml of (yeast expressed) recombinant phytase, 200 μg/ml of transgenic corn, distilled water and 10 mM Tris-HCl (the latter two serving as negative controls). A response was observed after 1-5 min. Two bands that appeared at both the test and control site represent a positive test result. Only one band at the control site represents a negative test result. The absence of a line at the control site indicates the test is invalid.
[0050] The phytase lateral flow test strips consisted of a sample binding area called an analyte absorption pad, followed by a conjugate pad, a nitrocellulose membrane and a terminal wicking pad. The detection phytase antibody (the test line antibody consisting of either FA7 or CC1) and the goat anti-mouse IgG (the control line antibody, placed in parallel above the test line antibody) were diluted to a standard concentration of 1.5 mg/ml with 10 mM Tris-HCl (pH 8.0) and applied in a thin line onto a nitrocellulose membrane, allowed to dry for 2 h, then blocked with 5% milk powder and dried at 37° C. for 24 h. The colloidal gold conjugated phytase capture antibody was prepared using 100 ml of 0.01% (w/v) chloroauric acid (HAuCl 4 ) in a 250 ml siliconized flask which was heated to boiling in a microwave oven. After which 1.4 ml 1% trisodium citrate was added. After the colloidal gold solution was allowed to cool gradually, the pH was adjusted to 8.4 with 1% (w/v) potassium carbonate. Colloidal gold to be conjugated with either the EH10a or AF9a antibody was prepared individually by adding the antibody dropwise into 10 ml of colloidal gold solution while being stirred for 30 min using a magnetic stirrer. After the solution was stabilized at 4° C. for 30 min, 1 ml of 10% (w/v) bovine serum albumin (BSA) was added to block access reactivity of the gold colloid. The mixture was then stirred for an additional 30 min and incubated at 4° C. for 2 h. After which the mixture was centrifuged at 3000 g for 4° C. for 30 min; the supernatant was further centrifuged at 14,000 g at 4° C. for 45 min and the resulting conjugate pellet was suspended in 10 mM borax buffer (pH 8.0) containing 2% (w/v) BSA and 0.05% sodium azide (NaN 3 ). The prepared conjugate phytase antibody (either EH10a or AF9a) was sprayed twice onto fibreglass (0.5-1.5 cm×25 cm) and dried at 37° C. The optimal concentration of the conjugate antibody is with an OD of 50.
[0051] The components were assembled as a unit wherein the phytase capture membrane was placed on the solid support plastic backing board with the phytase antibody capture line exposed in the middle with the goat anti-mouse IgG control line in parallel above the phytase antibody capture line. The gold-conjugated phytase antibody is placed ahead of the absorbent sample pad which is at one end and the wicking pad at the other end. The monoclonal antibody pairs (conjugate-capture) EH10a-FA7 and AF9a-CC1 were prepared on respective strip tests. The assembled unit was then sliced into 4-mm wide strips.
[0052] As shown in FIG. 2 , the results indicate that the monoclonal antibody match pairs EH10a-FA7 and AF9a-CC1 was able to detect the (yeast expressed) recombinant phytase and the GM corn phytase, respectively, but none of the non-GM seed varieties.
Example 5
Anti-Phytase Immunoassay Test Strips (B)
[0053] This example describes the use of immunoassay strips to test the sensitivity of the anti-phytase antibodies (AF9a, CC1, EH10a and FA7) to phytase samples.
[0054] In photos which illustrate embodiments of the invention, FIG. 2 reveals the sensitivity of the antibodies to phytase. Immunolateral flow test strips were prepared by testing the (yeast expressed) recombinant phytase diluted in concentrations from 200 to 0.002 μg/ml by 10 mM Tris-HCl (pH 8.0) using the EH10a-FA7 MAb match pairs whereas the GM phytase corn was tested in concentrations from 400 to 0.001 μg/ml using the AF9a-CC1 match pairs. The immunolateral flow test strips were assembled and processed in a manner as described above in which the recombinant phytase and GM phytase corn samples in the said concentrations were tested and evaluated as described above.
[0055] As shown in FIG. 3 , the results indicate that the monoclonal antibody match pairs EH10a-FA7 and AF9a-CC1 were able to detect concentrations as low as 5 ng of the (yeast expressed) recombinant phytase and as low as 2 ng of the GM corn phytase, respectively.
Example 6
Role of Glycosylation in Anti-Phytase Antibody Epitopes
[0056] This example characterizes the role of glycosylation in anti-phytase antibody epitopes using western blot analysis and phytase immunoassay test strips with the anti-phytase monoclonal antibodies (EH10a, FA7, AF9a and CC1).
Procedure
[0057] To evaluate the role of glycosylation in the MAbs epitope binding sites for (yeast expressed) recombinant phytase and the GM corn phytase, an additional western blot analysis was performed. Ground GM phytase corn was reconstituted to a concentration of 200 μg/ml and stored at 4° C. until required. Every 2 weeks for a period of 10 weeks, 10 μl from each of the recombinant phytase and GM phytase corn was boiled with 10 μl of loading buffer for 5 min and loaded onto a 10% SDS-PAGE. The SDS-PAGE and western blot were prepared as described above. Each transferred membrane blot was incubated overnight at 4° C. with a combined mixture of MAbs (EH10a, FA7, AF9a, and CC1) as described above. The subsequent steps are as described above, except the concentration of the IgG-HRP secondary antibody was 1:5000 with an incubation time of 30 min.
[0058] The role of glycosylation on the MAbs epitope binding sites for (yeast-expressed) recombinant phytase and the GM corn phytase was evaluated along immunolateral flow test strips. Individual test strips consisting of either the EH10a-FA7 or the AF9a-CC1 MAb match pairs were prepared as described above. The samples were stored at 4° C. until required. The prepared strips were immersed in the reconstituted recombinant or GM corn phytase samples every 2 weeks for a period of 10 weeks. With the “MAX” line on the test strip positioned above the liquid level, a sample was allowed to migrate halfway up the strip after which the strip was removed. The results were obtained within 30 min and the strips were evaluated as above.
[0059] As shown in FIG. 4 , the results indicate that the monoclonal antibody match pairs EH10a-FA7 and AF9a-CC1 were able to detect a prominent protein band of 75 kD and 60 kD, respectively. This difference in size may be attributed to a larger-sized glycosylated phytase detected by match pairs EH10a-FA7 from the (yeast-expressed) recombinant phytase. Over time, the detection of the 75 kD protein by monoclonal antibody match pair EH10a-FA7 decreased and its ability to detect the 60 kD increased. In contrast, the ability of the monoclonal antibody match pair AF9a-CC1 to detect the 60 kD protein decreased over time from the GM corn phytase. This suggests that the anti-phytase antibodies can be used to distinguish a (yeast-expressed) glycosylated recombinant phytase (using the EH10a-FA7 match pair) from a lesser glycosylated GM corn phytase (using the AF9a-CC1 match pair). Further, this provides evidence that the epitope binding sites for monoclonal antibodies, EH10a and FA7, to phytase may be glycosylated.
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This invention relates to the field of immunology and more specifically relates to antiphytase monoclonal antibodies and immunoassay methods for the detection of a phytase from or derived from Aspergillus niger (phyA2) phytase, in particular, EH10a, FA7, AF9a and CC1 antiphytase antibodies. The invention further relates to hybridoma cell lines that produce antiphytase monoclonal antibodies.
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TECHNICAL FIELD AND BACKGROUND
[0001] The invention relates to a gas hearth including a combustion chamber, a gas supplier for supplying combustible gas into the combustion chamber to a firebed-simulator positioned in the combustion chamber, an ignitor for igniting the combustible gas in the combustion chamber and a flue-gas discharge duct connected to the combustion chamber for discharging combustion flue gases from the combustion chamber.
[0002] Various types of hearths, in particular decorative hearths, are known and can be used as built-in hearths or as hearth stoves. Such decorative hearths are suitable for burning gas, wood or other natural fuels. A decorative hearth which is known from, for example, from EP1659340A2, tries to produce a fire image which is as realistic as possible and is characterized by firebed-simulating means which are made up as imitation logs which are provided with lighting elements.
[0003] The lighting elements which are present in the imitation logs emit light which gives the impression that the imitation log is burning. However, such decorative hearths in which the fire image is only based on lighting elements do not give a realistic impression of a fire.
[0004] Other decorative hearths are known, wherein firebed-simulating means in the form of imitation logs positioned over a real firebed have been placed in the combustion chamber. This firebed is produced by means of gas supply means which extend into the combustion chamber and by means of which gas along and around the imitation logs is ignited. This creates the impression as if the imitation logs are actually burning. The combustible flue gases are then discharged via a flue-gas discharge duct which is connected to the combustion chamber.
[0005] However, the problem associated with these gas hearths is that a relatively high supply of gas is required to achieve a firebed or flame bed which is sufficiently large as to create a realistic impression of a fire. As a result thereof, a significant amount of heat and energy is lost. Since the primary aim of a decorative hearth is to imitate a firebed and thereby to create an impression of a fire, producing heat is a secondary aim, thus it is desirable for a gas hearth to have a gas and energy consumption which is as minimal as possible.
BRIEF SUMMARY OF THE INVENTION
[0006] It is therefore an object of the present invention to provide a gas hearth according to the abovementioned preamble that provides a realistic impression of a fire while using a minimal amount of natural fuel.
[0007] To this end, the gas hearth is provided with metering means arranged in the combustion chamber for metering a pyrotechnical additive into the flames of the burning combustible gas during operation. This makes it possible to produce an additional fire impression, for example, sparks which also occur with the burning of real wooden logs.
[0008] More specifically, the metering means includes a reservoir for the pyrotechnical additive which is provided with at least one metering opening, and furthermore at least one supply line which is connected to the metering opening and ends near the firebed simulator. To this end, it is possible to install the metering means elsewhere in the gas hearth and not necessarily in the combustion chamber, which is not desirable from an aesthetic and safety point of view.
[0009] According to a further aspect, the metering means includes at least one pump which is placed near the at least one metering opening for passing a certain amount of pyrotechnical additive through the supply line in the direction of the firebed simulator by means of a pressurized medium.
[0010] More particularly, the metering means includes a valve arranged for closing the at least one metering opening and for dispensing a certain amount of pyrotechnical additive from the reservoir and the metering means includes control means for actuating the valve and the pump, in particular, for sequentially actuating the valve and the pump. In this way, it is possible to add the pyrotechnical additive to the flame bed in a quick and safe manner by means of a simple actuation in order to produce an additional, more realistic impression of a fire.
[0011] In one aspect, the valve is a magnetic coil-actuated valve and the pump is a compressed air pump.
[0012] The metering means may be arranged under or above the firebed simulator.
[0013] In the latter embodiment, the reservoir can be attached to a shaft, and the metering means can include drive means for rotatably driving the shaft.
[0014] In one aspect, the drive means can be configured as a chain drive.
[0015] In a further embodiment, the reservoir can be provided with a filling opening which can be closed with a closure, which closure, in the embodiment wherein the metering means have been arranged under the firebed simulator means, forms part of the firebed simulator.
[0016] In particular, the reservoir can be configured to pass the pyrotechnical additive to the at least one metering opening. Thus, the metering means can require very little, if any, maintenance and the risk of failures and/or blockages is minimal.
[0017] In this case, the reservoir may be provided with one or more walls which run at an angle in the direction of the at least one metering opening.
[0018] Furthermore, the pyrotechnical additive may include granules, for example a pulverulent or granular material, in particular a carbon-containing additive.
[0019] Embodiments of the invention can include one or more or any combination of the above features and configurations.
[0020] Additional features, aspects and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein. It is to be understood that both the foregoing general description and the following detailed description present various embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] These and other features, aspects and advantages of the present invention are better understood when the following detailed description of the invention is read with reference to the accompanying drawings, in which:
[0022] FIG. 1 shows a diagrammatic view of a gas hearth according to the prior art with a metering means according to the present invention;
[0023] FIG. 2 is a perspective view of a metering means and hearth according to an embodiment of the invention;
[0024] FIG. 3 is an elevation view of the metering means;
[0025] FIG. 4 is a cross-sectional view of the metering means;
[0026] FIG. 5 is a perspective view showing the metering means, pump, and controller;
[0027] FIG. 6 is an exploded view of another embodiment of a metering means;
[0028] FIG. 7 is an assembled perspective view of the metering means of FIG. 6 ; and
[0029] FIG. 8 is a detailed view of a portion of the hearth according to an embodiment of the invention.
DETAILED DESCRIPTION
[0030] For a better understanding of the invention, the similar components shown in the various figures are denoted by identical reference numerals in the following description of the figures.
[0031] FIG. 1 diagrammatically shows an embodiment of a gas hearth according to the prior art. In particular, the burner system of a hearth is shown in the way in which it is arranged in the combustion chamber of the gas hearth.
[0032] In general, a decorative hearth is composed of a housing comprising side walls, a bottom wall, a front wall and a rear wall. The front wall is often transparent and can also be rotated away or slid away for maintenance. The front, bottom, rear and side walls enclose a combustion chamber 10 in which the firebed-simulating means, denoted here, for example, by reference numerals 12 a - 12 d, are accommodated. The firebed-simulating means 12 a - 12 d are configured to simulate a fire image and all respective components are fitted to a bottom panel which forms part of the bottom wall of the combustion chamber 10 .
[0033] As is illustrated in FIG. 1 , the hearth 1 is provided with gas supply means (gas supply line) 13 which are connected to a main supply line (not shown). The gas supply line 13 branches off into branch lines 13 a - 13 d, each of which extend into the combustion chamber 10 , and which, in particular, each end at the location of the firebed-simulating means 12 a - 12 d. A control valve 14 is incorporated in the gas supply line 13 which can be controlled by suitable control means (not shown) via the control line 15 and can be closed off in order to close off the gas supply into the combustion chamber 10 .
[0034] The firebed-simulating means 12 a - 12 d may be configured, for example, as imitation logs, which may, for example, be made of a fireproof ceramic material. Such imitation logs are often also porous, so that the gas supplied via the respective branch line 13 a - 13 d may flow through or leak into the porous imitation logs and can be made to ignite locally on the surface using suitable, gas ignition means (not shown). In this way, a fire image may be simulated which is similar to that of a conventional fire of burning wooden logs.
[0035] The combustion flue gases can be discharged from the combustion chamber 10 via the flue-gas discharge duct 11 .
[0036] As one objective of a decorative hearth is to produce a realistic fire image, and is not intended, unlike conventional hearths, to emit heat to the surroundings, it is desirable for a decorative hearth to produce as realistic a fire image as possible while using a minimal amount of gas.
[0037] However, a lower gas consumption (i.e. gas supply to the combustion chamber via the gas supply 13 ) also leads to fewer flames, as a result of which the fire image is less realistic. However, the firebed-simulating means 12 a - 12 d aim to enhance the fire image by simulating burning logs.
[0038] In order to be able to also produce a realistic fire image with an improved fire impression in the case of reduced gas consumption, metering means 20 are arranged in the combustion chamber 10 which, during operation, meter a pyrotechnical additive into the flames of the burning combustible gas. In particular, the metering means are arranged above the firebed-simulating means 12 a - 12 d, as is illustrated in FIG. 1 , in such a way that, when metering the pyrotechnical additive being contained in reservoir 22 via the metering opening 22 b, this additive ends up in the air stream of the rising combustible flue gases and is ignited by the flames when it flutters down in the direction of the firebed created by the firebed-simulating means 12 a - 12 d . Upon ignition, the pyrotechnical additive generates additional fire and light effects, such as sparks, which also occur during burning of natural wooden logs.
[0039] In another embodiment, such as illustrated, for example, in FIG. 5 , the metering means 20 are arranged at the bottom of the combustion chamber 10 and more particularly under the firebed-simulating means 12 a - 12 d.
[0040] The metering means 20 are composed of a mounting panel 21 to which, and on which, all relevant components are attached. Reference numeral 22 indicates a reservoir wherein a certain amount of pyrotechnical additive is stored. The reservoir 22 is sufficiently fire-resistant and heat-resistant in order to ensure that the heat which is produced in the combustion chamber during operation does not result in an undesirable and premature spontaneous combustion of the pyrotechnical additive which is held in the reservoir 22 .
[0041] The reservoir 22 is provided with a top side 22 a which is provided with an opening which may be closed off by a closure, in particular a closing lid 23 . The reservoir 22 can be filled with a certain amount of pyrotechnical additive via the opening which is provided in the top side 22 a. Furthermore, the reservoir 22 is provided with a metering opening 22 b for supplying a certain amount of pyrotechnical additive from the reservoir 22 to a supply line 25 which runs from the metering opening 22 b through the combustion chamber and the free end 25 a of which ends at one of the firebed-simulating means 12 a - 12 d, as is illustrated in FIG. 1 .
[0042] The reservoir 22 is constructed in such a way that it promotes or facilitates the supply of the pyrotechnical additive from the reservoir 22 in the direction of the metering opening 22 b and the supply line 25 . In particular, the reservoir 22 is provided with oblique walls 22 c and 22 d which thus form a funnel in the direction of the metering opening 22 b.
[0043] According to the invention, the metering opening 22 b can be closed off by means of a controllable shut-off valve 24 . By briefly opening and closing the closable valve 24 , a certain amount of pyrotechnical additive can leave the reservoir 22 via the metering opening 22 b closed off by the valve 24 and be received in the line 25 . At the location of the closable valve 24 , the line 25 is connected to an air line 27 which is connected to a pump 26 . By means of the pump 26 , the amount of pyrotechnical additive held in the line 25 by means of a pressurized medium, for example air, can be blown in the direction of the outlet opening 25 a.
[0044] When the pyrotechnical additive leaves the outlet opening 25 a, which, as has already been mentioned, is positioned at the location of the firebed-simulating means 12 a - 12 d, it will come into contact with the burning gas and thus create additional flame and fire effects, such as sparks.
[0045] To this end, the metering means 20 also comprise control means 28 (see FIG. 3 ) which pass control signals to the closable control valve 24 or the pump 26 , respectively, via suitable control lines 29 a and 29 b. More specifically, the control means 28 are configured in such a way that the control means actuate the control valve 24 and the air pump 26 sequentially. Sequentially means firstly that the closable control valve 24 is actuated by the control means 28 , resulting in the control valve 24 being opened briefly. As a result thereof, a certain amount of pyrotechnical additive can be poured or metered into the line 25 from the reservoir 22 via the metering opening 22 b which has been opened in this way.
[0046] Subsequently, the control valve 24 is closed by the control means 28 and the air pump 26 is actuated which blows this metered amount of pyrotechnical material through the supply line 25 in the direction of the outlet opening 25 a by means of a short air pressure pulse via the air line 27 and the supply line 25 . Upon leaving the outlet opening 25 a on account of the air pulse delivered by the pump 26 , the dispensed pyrotechnical additive will be brought to ignition at the location of the firebed-simulating means 12 a - 12 d (see FIG. 1 ) by the burning gas and thus produce the additional flame and fire effects.
[0047] The air pump 26 is in each case actuated briefly by the control means 28 for delivering an air pressure pulse in the air line 27 in the direction of the control valve 24 and the supply line 25 . To this end, the air pump 26 takes air from elsewhere and preferably from outside the combustion chamber 10 (see FIG. 1 ) via the inlet opening 27 a. Thus, the air line 27 has such a length, as a result of which the air pump 26 and preferably the inlet opening 27 a are arranged at some distance from and outside the combustion chamber 10 . This prevents hot combustion flue gases from being introduced into the air line 27 via the inlet opening 27 a, which could possibly cause the pyrotechnical additive metered into the supply line 25 to ignite spontaneously. The position of the inlet opening 27 a of the air line 27 as far as outside the combustion chamber 10 is thus a safety aspect of the present gas hearth.
[0048] In this embodiment, a non-return valve has to be incorporated in the inlet line 27 a which extends to the outside of the combustion chamber in order to prevent combustion flue gases from escaping from the combustion chamber 10 via the air line 27 and the inlet opening 27 a instead of via the flue-gas discharge duct 11 .
[0049] In a preferred embodiment, the inlet opening 27 a of the air line 27 and the outlet opening 25 a of the outlet line 25 are both in the combustion chamber 10 . This results in a closed system, so that combustion flue gases cannot escape from the combustion chamber except via the flue-gas discharge duct 11 . However, the inlet opening 27 a has to be arranged in the combustion chamber 10 in such a way, for example at some distance from the firebed-simulating means, so as to prevent an undesired inflow of combustion flue gases.
[0050] In yet another embodiment, the air pump is not switched on or off by the control means 28 , but the air pump is actuated continuously and an air stream is continuously blown in the direction of the supply line 25 and the outlet line 25 a by the air line 27 .
[0051] As is illustrated in FIG. 4 , the closable control valve 24 is, in particular, a magnetic valve (also referred to as a magnet-coil actuated valve). To this end, the control valve 24 is provided with a bore hole 24 b in which a reciprocating plunger 24 a is accommodated. The plunger 24 a is movable into a closed position, such as illustrated in FIG. 4 , in which it closes the metering opening 22 b and closes it off from the air line 27 and the supply line 25 , and into an open position, in which the metering opening 22 b is briefly connected with the supply line 25 , so that pyrotechnical additive which is situated in the reservoir 22 can be metered out.
[0052] The reciprocating plunger 24 a is provided with grooves wherein coil windings 24 c are wound. In addition, the valve 24 is provided with a magnet 24 e which is arranged around the bore hole 24 b and the part of the plunger 24 a where the coil windings 24 c are situated. By means of suitable control signals which are emitted by the control means 28 to the magnetic valve 24 via the control line 29 a, the plunger 24 a can be moved to and fro in the bore hole 24 b between the closed position and the open position on account of the coil/magnet interaction.
[0053] In this way, it is possible to transfer a small amount of pyrotechnical additive from the reservoir and the open metering opening 22 b to the supply line 25 by in each case briefly opening the magnetic valve 24 . Closing the magnetic valve 24 again first and then actuating the air pump 28 to deliver an air pulse into the air line 27 prevents the air pulse from blowing the pyrotechnical additive which has just been metered back into the reservoir 22 . By contrast, the closed magnetic valve 24 causes the metered pyrotechnical additive which is present in the supply line 25 to be blown in the direction of the outlet opening 25 a by the air pulse through the supply line 25 .
[0054] Preferably, the actuation of the magnetic valve 24 by the control means 28 is random, so that the supply of the pyrotechnical additive via the outlet opening 25 a to the burning firebed-simulating means 12 a - 12 d is also random and unpredictable. The random unpredictable actuation of the magnetic valve 24 and the resulting random supply of pyrotechnical additive to the firebed-simulating means 12 a - 12 d also contributes to a more realistic fire image, since this also produces random flame and fire effects, similar to the fire image of a conventional burning log fire.
[0055] The time period of the brief opening of the magnetic valve 24 may also be set randomly within a certain range, so that the amount of pyrotechnical additive during each metering from the reservoir 22 in the supply line 25 also varies. Consequently, the intensity of the resulting flame and fire effects vary with each dose. This also helps to create an improved simulation of the random and chaotic fire image of a conventional burning log fire.
[0056] The pyrotechnical additive preferably includes granules, in particular a pulverulent or granular material. In particular, the pyrotechnical additive is a carbon-containing additive, in which the granules have a grain size of between 0.05 mm-2.5 mm.
[0057] In a further embodiment, such as illustrated in FIG. 5 , wherein the metering means 20 are positioned under the firebed-simulating means 12 a - 12 d of the gas hearth, as is illustrated in FIG. 1 , the closure 23 is formed in such a manner that it fauns part of the firebed-stimulating means. In FIG. 5 , the closure is denoted by reference numeral 230 and is formed as an imitation log. In this way, the metering means 20 can be fitted at a small distance below the level of the firebed-simulating means 12 a - 12 d in the gas hearth, thus achieving a further reduction in the installation space.
[0058] It should be noted that although the sealing cap 230 is formed as an imitation log, it does not actively contribute to the play of flames and fire during operation. The sealing cap 230 will therefore not be porous and will also not be provided with a connection to the gas supply means 13 , as illustrated in FIG. 1 .
[0059] FIGS. 6-8 show another embodiment of a gas hearth according to the invention.
[0060] In this embodiment, the metering means 40 are positioned at the top of the combustion chamber 10 and in particular above the firebed-simulating means 12 a - 12 d. The reservoir 42 is provided with a top side 42 a in which an opening 42 a ′ is provided which can be closed off by a closure, in particular a closing lid or cap 43 . The reservoir 42 can be filled with a certain amount of pyrotechnical additive via the opening 42 a ′ which is provided in the top side 42 a.
[0061] Furthermore, the reservoir 42 is provided with one or more metering openings 42 b for supplying or scattering a certain amount of pyrotechnical additive at the top of the combustion chamber 10 (and above the burning firebed-simulating means 12 a - 12 d ) from the reservoir 42 . In this case, the reservoir 42 is placeable in a holder 41 which is supported by shafts 45 which are rotatably accommodated in the combustion chamber 10 (see FIG. 8 ). In this case, reservoir 42 is retained in the holder 41 by means of a retaining pawl 44 a which can be fixed to the threaded end 41 c of the holder 41 by means of a swivel or screw 44 b.
[0062] Analogous to the reservoir 22 as shown in FIGS. 2-6 , the reservoir 42 has oblique walls 42 c and 42 d which thus form a funnel in the direction of the metering opening 42 b in order thus to assist or facilitate the supply of the pyrotechnical additive to the combustion chamber 10 .
[0063] Furthermore, the metering means 40 comprise drive means 50 for rotatably driving the shaft 45 . The drive means 50 are placed on one side of the combustion chamber 10 and in this embodiment comprise a drive motor 51 (electric motor) provided with a first gear wheel 53 a by means of which the shaft 45 is rotatably driven via a chain transmission. To this end, a chain 52 is placed over the first gear wheel 53 a and also runs across a second gear wheel 53 b. The second gear wheel 53 b is placed on the shaft 45 . On the other side of the combustion chamber 10 , the shaft 45 is mounted in a bearing 46 which is accommodated in the wall of the combustion chamber 10 .
[0064] In operation, the drive motor 51 will rotate the shaft 45 , as a result of which the holder 41 with the reservoir 42 in the combustion chamber 10 and above the firebed-simulating means 12 a - 12 d co-rotate. With each rotation, the pyrotechnical additive in the reservoir 42 will be displaced in the direction of the metering opening(s) 42 b (partly assisted by the oblique side walls 42 c and 42 d ) and will be released into the top of the combustion chamber 10 and above the burning firebed-simulating means 12 a - 12 d (see FIG. 1 ) via the metering opening(s) 42 b on account of the force of gravity.
[0065] The pyrotechnical additive will enter the air stream of the rising combustible flue gases and will be ignited by the flames when it drifts down in the direction of the firebed created by the firebed-simulating means 12 a - 12 d. Upon ignition, the pyrotechnical additive creates additional fire and light effects, such as sparks, which also occur during burning of natural wooden logs.
[0066] Instead of performing a complete rotation, the reservoir 42 may also be rotated to and fro by the drive motor 51 . Upon each rotation or reciprocating movement, the pyrotechnical additive in the reservoir 42 will be disturbed and will be released in the form of a small dose of a random amount of additive via the metering opening 42 b.
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A gas hearth including a combustion chamber, a gas supplier for supplying combustible gas into the combustion chamber to a firebed simulator disposed in the combustion chamber, an ignitor for igniting the combustible gas in the combustion chamber, a flue-gas discharge duct connected to the combustion chamber for discharging combustion flue gases from the combustion chamber, and a metering means disposed in the combustion chamber for metering a pyrotechnical additive into the flames of the burning combustible gas during operation.
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FIELD OF THE INVENTION
The invention relates to prostheses, and more particularly an acetabular cup and femoral component configured for a hip replacement system to reduce the likelihood of dislocation.
BACKGROUND OF THE INVENTION
Artificial joints provide patients having arthritic or otherwise dysfunctional skeletal features with an alternative treatment for the chronic pain and discomfort often associated with such problems. Correction of the condition generally involves surgically replacing one or more of the natural components making up the joint with an artificial equivalent.
One of the more widely implemented artificial joints serves as a substitute for hips. A typical hip replacement system generally includes a femoral prosthesis implanted in the upper end of the femur when the femoral head requires replacement. The replacement is formed with a spherically shaped head and an elongated narrow neck extending from the head and connected to a stem which can be attached to the femur. The femoral head is pivotally nested within the socket of an acetabular cup. The cup includes a hemispherical base for mounting to the pelvis, and an outwardly opening socket to receive the femoral head. The prosthesis components are implanted during a surgical procedure well known to those skilled in the art.
While the typical hip replacement system described above provides a moderate range of mobility, the acetabular cup generally has limited clearance with respect to the neck of the femoral prosthesis. As a result, attempts by the patient to forcefully move the joint beyond the designed range of motion may cause the femoral head to pop out of the cup, resulting in dislocation that ultimately may require subsequent surgery for correction.
One attempt to expand the range of movement is disclosed in U.S. Pat. No. 5,387,244. The joint includes an acetabular cup with a bevelled edge for anchoring to the pelvis and a femoral prosthesis configured with a spherical head and a neck formed in lateral offset relation away from the medial side to the longitudinal axis of the femoral prosthesis. The neck includes a formed contact surface to complementally engage the bevelled edge of the cup to define a maximum degree of flexion.
While the design above may provide a relatively moderate range of mobility, the problem of dislocation remains unresolved. Dislocation typically occurs when the neck of the femoral component contacts the acetabular liner and rotates about that contact point. For the modified hip replacement system described above, the resultant contact point defined by the beveled edge and the contact surface occurs near the head center to create a fixed fulcrum that cooperates with the bulk of the prosthesis length to generate a relatively large moment. Under some circumstances, this moment is capable of dislodging or dislocating the head out of the cup. Moreover, continuous impact between these components can cause wear debris to accumulate in the joint.
Therefore, the need exists for a hip replacement system configured to minimize the occurrence of dislocation of the femoral component and the cup. The hip replacement of the present invention satisfies these needs.
SUMMARY OF THE INVENTION
The hip replacement of the present invention provides patients the capability of carrying out everyday tasks with the reduced likelihood of component dislocation. This reduces the complications and expense arising from reassembling the joint through subsequent surgery or the like. It also reduces the accumulation of wear debris caused by impacts between the hip components. Additionally, the design of the hip replacement expands the range of flexion for the joint to correspondingly create a wider range of mobility for the patient.
To realize the advantages described above, the present invention, in one form, comprises an acetabular cup for mating to a femoral component comprising a ball-shaped head and a reduced-diameter neck, i.e. a neck having a diameter less than the diameter of the head. The component neck extends from the head and has a contact surface. The cup includes a socket adapted to pivotally retain the femoral component head. The socket is bounded peripherally by a rim which forms an engagement surface to define a stop which engages the contact surface to establish an initial contact point corresponding to a predetermined motion limit for the femoral component. As the hip joint moves beyond this motion limit, the contact point shifts radially outwardly along the surface to reduce the likelihood of dislocation.
Other features and advantages of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a lateral sectional view of a conventional hip replacement system;
FIG. 2 is a view similar to FIG. 1 showing a maximum degree of deflection before dislocation;
FIG. 3 is a lateral sectional view of the present invention according to a first embodiment;
FIG. 4 is a view similar to FIG. 3;
FIG. 5 is a lateral sectional view of the present invention according to a second embodiment; and
FIG. 6 is a view similar to FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
A human hip joint typically comprises a socket portion formed in the pelvis to rotatably capture a ball-shaped head portion projecting inwardly from the femur bone. Severe dysfunction of the joint often requires hip arthroplasty, involving a surgical substitution of the socket portion, the head portion, or both.
Referring now to FIGS. 1 and 2, a conventional hip replacement system for substituting a human hip joint, generally designated 10, includes an acetabular cup 12 and a femoral element 18. The acetabular cup is configured with a curved (for example, hemispherical) shape and is formed with a central cavity 14 (FIG. 2) that opens radially outwardly to define a socket. The socket is bounded radially by a chamfered anterior rim 16 that extends radially outwardly to define a flat surface. During the arthroplasty procedure, the cup is typically implanted in the pelvis.
Further referring to FIGS. 1 and 2, the femoral component 18 is typically implanted into the femur bone and includes a formed mushroom shaped head 20 for rotatably nesting in the cup socket 14. Projecting outwardly from the head is a formed neck that angles radially outwardly to define a shaft 22. The neck forms an engagement surface for impinging on the surface of rim 16 during extreme movement of the joint.
Dislocation of the components comprising a conventional hip replacement system typically results from an overabundance of leverage caused by extreme movement. FIG. 1 illustrates the cup 12 and the femoral element 18 oriented with the neck initially impinging on the anterior rim, but with the head 20 still securely nested in the socket 14. Continued flexure of the joint beyond the orientation shown in FIG. 1 results in the head popping out of the socket, as shown in FIG. 2, due to the fixed leverage created at the contact point.
Referring now to FIGS. 3 and 4, the hip replacement system of the present invention, according to a first embodiment, and generally designated 30, reduces the dislocation problem described above by providing an acetabular cup 32 that cooperates with a femoral component 40 to establish decreasing leverage on the femoral component during extreme movement of the joint.
With continuing reference to FIG. 3, the acetabular cup 32 may be C shaped in cross-section, with a centrally formed cavity 34 (FIG. 4) defining a hemispherical socket (for example) and bounded radially by a rim has a convex surface which 38. The rim extends radially outwardly at an angled orientation to from point 36.
The femoral component 40, which may be the same as the femoral component shown in FIGS. 1 and 2, comprises a ball-shaped head 42 and a reduced-in-diameter neck 44 extending from the head and having a formed contact surface 46. As shown in FIGS. 3-6, the opening of the socket formed by the acetabular cup is slightly larger than the diameter of the femoral head and, therefore, the socket itself does not prevent withdrawal of the head from the socket.
During an arthroplasty procedure, the acetabular cup 32 is implanted into the pelvis (not shown), while the femoral component 40 is implanted into a surgically modified femur bone (not shown). Following the surgical procedure, the joint is fully operative to allow relative rotation between the two components.
As shown in FIG. 3, operation of the hip replacement 30 will often involve movement to an orientation such that the contact surface 46 of the neck 44 abuts the rim surface 38 at an initial contact point 50 corresponding to a predetermined motion limit for the femoral component. The initial contact orientation, according to a first embodiment, comprises fifty seven degrees of deflection as compared to a socket central axis 52. Further flexing of the joint places an increased load on the femoral component resulting from leverage being exerted at the initial contact point.
However, as shown in FIG. 4, due to the unique declining angular convex configuration of the rim liner 38, as the hip joint moves beyond this motion limit, the contact point shifts radially outwardly along the rim to a peripheral contact point 54 allowing a maximum deflection of sixty nine degrees, while reducing the dislocation leverage acting on the femoral component. Additionally, by decreasing the dislocation leverage acting on the femoral component, an oppositely directed restoring moment is increased to maintain the component within the socket.
Referring now to FIG. 5, a second embodiment of the present invention, generally designated 60, implements an acetabular cup 62 formed substantially similar to that of the first embodiment, but having a less pronounced angular decline for the convex surface 64. A femoral component 66 is also included which is formed substantially similar to that of the first embodiment.
It has been discovered that by making the angle of decline less pronounced for the surface 64 with respect to the angle implemented for the surface according to first embodiment of the present invention, during operation, the contact point shifts radially outwardly, unexpected allowing an unexpected advantage in relative mobility from sixty nine degrees to seventy three degrees. On the other hand, the steeper angle of decline of FIGS. 3 and 4 will produce a higher restoring moment during subluxation.
In the illustrated embodiments, the rim surface 38 is convex and the contact surface 46 of neck 44 concave. Other shapes for these surfaces are also contemplated. For example, the surface 38 may be curved and the surface 46 straight, i.e. not curved in cross section, or surface 46 may be curved and surface 38 straight. Possibly, surface 38 may be concave and surface 46 convex. The invention contemplates any surface configurations which enable the contact point between the neck and the rim to move outwardly or toward the periphery of the rim as motion of the femoral component increases.
It is also envisioned that the present invention may be individually packaged and sold as a kit of unassembled components to reduce any unnecessary costs associated with purchasing an entire system, should only the need for one component of the system arise.
Those skilled in the art will appreciate the many benefits and advantages realized by the present invention. Of paramount importance is the shifting contact point feature that reduces leverage acting upon the femoral component to pop it from the cup socket. As a direct result, severe dislocations that may degrade the performance of the joint are substantially reduced. Moreover, by greatly reducing the number of dislocations between the hip joint components, subsequent costly surgical corrections are dramatically minimized.
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
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A hip replacement for reducing the likelihood of joint dislocation and including a femoral component having a head and an elongated neck and an acetabular cup formed with a socket to capture the head. The socket includes a formed annular liner defining a stop to engage the neck during extreme motion. The neck contact surface and annular liner cooperate to shift the resultant contact point radially outwardly from the head to minimize dislocation resulting from the moment acting upon the femoral component.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to the cell structure, device configuration and fabrication process of power semiconductor devices. More particularly, this invention relates to an improved cell configuration and processes to manufacture trench MOSFET device with junction barrier Schottky rectifier in the same cell so that integrated cells with spacing savings and lower capacitance and higher performance are achieved.
[0003] 2. The Prior Arts
[0004] Normally for high efficiency DC/DC application, a Schottky rectifier is externally added in parallel with a MOSFET device. FIG. 1 is a circuit diagram that illustrates the implementation of a Schottky diode with a power MOSFET device. Once the parasitic P/N diode is turned on, both the electron and hole carriers are generated thus require longer time to eliminate the carriers by electron-hole combination. In order to achieve higher speed and efficiency, the Schottky diode (SKY) is connected in parallel to the MOSFET device with the parasitic PN body diode to function as a clamping diode to prevent the body diode from turning on. The Schottky Diode is single carrier, i.e., electron carrier only and that can be drawn simply by the drain Electrode. The requirement for the clamping effect is that the Forward Voltage of the Schottky diode Vf is less than the parasitic PN diode (˜0.7V). As the electronic devices become more miniaturized, there is requirement to integrate the Schottky diode as part of the semiconductor power device as an IC chip to reduce the space occupied by the Schottky diode instead of connecting the Schottky diode as an external electronic component.
[0005] In U.S. Pat. No. 6,351,018, a trenched MOSFET device integrated with trench Schottky diodes with common trench gates is disclosed as that shown in FIG. 2 . In U.S. Pat. No. 6,593,620 discloses another trench MOSFET device with a trench Schottky diode with separated trench gates as shown in FIG. 3 . In U.S. Pat. No. 6,987,305 (not shown) discloses another trench MOSFET device which is similar to U.S. Pat. No. 6,593,620 except thick gate oxide on trench bottom. The configurations as disclosed in the patented invention have a disadvantage that the Schottky diodes occupy additional space for planar contact that is about the same space as the MOSFET. The Trench Schottky diodes further suffer from a high leakage between drain and source due to phosphorus increase at channel region during the sacrificial and gate oxidation processes. Furthermore, the device as shown has a higher capacitance due to the presence of the trench MOS-Schottky structure which has inherent parasitic capacitance from trench sidewall and bottom in trench MOS-Schottky.
[0006] In U.S. Pat. No. 6,433,396, a trench MOSFET device with a planar Schottky diode is disclosed as that shown in FIG. 4 . The configuration again has disadvantages that the Schottky diode occupies additional space for planar contact and reverse leakage current Ir between anode and cathode is high. Also, the formation process requires additional contact mask for the Schottky diode thus increases the cost and processes complications for producing the MOSFET power device with Schottky diode.
[0007] In U.S. Pat. No. 6,998,678 discloses another trench semiconductor arrangement as shown in FIG. 5 with a MOS transistor which has a gate electrode, arranged in a trench running in the vertical direction of a semiconductor body, and a Schottky diode which is connected in parallel with a drain-source path (D-S) and is formed by a Schottky contact between a source electrode and the semiconductor body. The configuration has disadvantage that it is difficult to optimize both performance of the Schottky diode and the trench MOSFET when they share same mesa space between two adjacent trenches and same source trench contact. Furthermore, the manufacturing cost is increased due to the requirement that an additional P+ mask is required to form the trench Schottky diodes.
[0008] Therefore, there is still a need in the art of the semiconductor device fabrication, particularly for design and fabrication of the trenched power device, to provide a novel cell structure, device configuration and fabrication process that would resolve these difficulties and design limitations. Specifically, it is desirable to provide more integrated trench MOSFET with embedded Schottky diode that can accomplish space saving, process simplification and capacitance reduction such that the above discussed technical limitations can be resolved.
SUMMARY OF THE INVENTION
[0009] It is therefore an aspect of the present invention to provide improved semiconductor power device configuration and manufacture processes for providing semiconductor power devices with trench junction barrier Schottky rectifier in single chip with trench Schottky contact instead of planar contact as shown in above prior arts so that space occupied which is one of the major technical limitations discussed above can be reduced.
[0010] Another aspect of the present invention is to provide improved semiconductor power device configuration and manufacture processes for providing semiconductor power devices with trench junction barrier Schottky rectifier in single chip wherein no additional mask is required to integrated the trench junction barrier Schottky rectifier with trench MOSFET compared with the planar Schottky contact and that leads to a cost-down of the production.
[0011] Another aspect of the present invention is to provide improved semiconductor power device configuration and manufacture processes for providing semiconductor power devices with trench junction barrier Schottky rectifier in single chip so that the devices with trench contact are able to be shrunk to achieve low specific on-resistance for trench MOSFET, and low Vf and reverse leakage current for trench junction barrier Schottky rectifier.
[0012] Briefly, in a preferred embodiment, the present invention discloses a semiconductor power device comprising a trenched MOSFET and a trenched junction barrier Schottky rectifier in single chip. Wherein the trench MOSFET device comprises a trenched gate surrounded by a source region encompassed in a body region above a drain region disposed on a bottom surface of a substrate. The semiconductor power device further includes an insulation layer covering the trenched semiconductor power device with a source-body contact trench opened through and extending into the source and body regions and filled with Tungsten plugs therein. Said Tungsten plugs contact all said source region with a metal of Aluminum alloy or Copper serving as source metal by a layer of Ti, or Ti/TiN deposited along top surface of the insulator layer. A region underneath said contact trench is more heavily doped than the body region to reduce the resistance between said trench contact metal plug and said body region. The trenched junction barrier Schottky rectifier further includes junction barrier Schottky contact trench and more heavily doped region at the bottom of each contact filled with a layer of Ti silicide/TiN or Co silicide/TiN along each trench contact sidewall and Tungsten plug connected to said source metal serving as anode of said Schottky rectifier; other contact trenches formed in the P-body adjacent to said junction barrier Schottky contact trench for said P-body contact to said source metal.
[0013] In an exemplary embodiment, the structure disclosed is the same as the structure mentioned in the first embodiment except that there is no heavily doped region underneath junction barrier Schottky trench contact.
[0014] In an exemplary embodiment, the structure disclosed is the same as the structure mentioned in the first embodiment except that the trench MOSFET has double gate oxides with thick oxide on trench bottom to reduce the gate charge for power saving.
[0015] In an exemplary embodiment, the structure disclosed is the same as the structure mentioned in the second embodiment except that the trench MOSFET has double gate oxides to reduce the gate charge for power saving.
[0016] In an exemplary embodiment, the structure disclosed is the same as the structure mentioned in the first embodiment except that there is another N2 doped epitaxial layer above the N1 drift region according to the doping concentration relationship N2<N1 and said junction barrier Schottky trench contact is formed in the N2 doped epitaxial layer to optimize a trade-off between Vf and Ir.
[0017] In an exemplary embodiment, the structure disclosed is the same as the structure mentioned in the fifths embodiment except that there is no heavily doped region underneath junction barrier Schottky trench contact.
[0018] These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment, which is illustrated in the various drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a conventional application circuit of diode in parallel with the MOSFET power device.
[0020] FIG. 2 is a side cross-sectional view of an integrating method of prior art.
[0021] FIG. 3 is a side cross-sectional view of another integrating method of yet another prior art.
[0022] FIG. 4 is a side cross-sectional view of another integrating method of yet another prior art.
[0023] FIG. 5 is a side cross-sectional view of another integrating method of yet another prior art.
[0024] FIG. 6 is a cross-section of an integrated trench MOSFET with junction barrier Schottky rectifier structure of the first embodiment for the present invention.
[0025] FIG. 7 is a cross-section of an integrated trench MOSFET with junction barrier Schottky rectifier structure of another embodiment for the present invention.
[0026] FIG. 8 is a cross-section of an integrated trench MOSFET with junction barrier Schottky rectifier structure of another embodiment for the present invention.
[0027] FIG. 9 is a cross-section of an integrated trench MOSFET with junction barrier Schottky rectifier structure of another embodiment for the present invention.
[0028] FIG. 10 is a cross-section of an integrated trench MOSFET with junction barrier Schottky rectifier structure of another embodiment for the present invention.
[0029] FIG. 11 is a cross-section of an integrated trench MOSFET with junction barrier Schottky rectifier structure of another embodiment for the present invention.
[0030] FIGS. 12A to 12D are a serial of side cross sectional views showing the processing steps for fabricating a MOSFET device as shown in FIG. 7 of this invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0031] Please refer to FIG. 6 for a preferred embodiment of this invention where the MOSFET power device with junction barrier Schottky rectifier in one cell are formed in a N epitaxial layer 200 above the a heavily N+ doped substrate 201 coated with back metal on rear side as drain. A trenched gate 211 surrounded by a source region 212 encompassed in a body region 213 formed in a P-well. An insulation layer 202 covering the trenched semiconductor power device with a source-body contact trench 210 opened through and extending into the source and body regions and filled with tungsten plugs therein. A layer of Al Alloys or Copper 203 serves as source metal by a layer of Ti, or Ti/TiN 214 deposited along the top surface of the insulation layer 202 . The region 215 is more heavily doped to reduce the resistance between said trench contact metal plug 210 and said body region. The junction barrier Schottky contact trench 216 and more heavily doped region 217 at the bottom of each contact is formed in said N epitaxial layer and other contact trench 218 formed in the P-well 219 adjacent to said junction barrier Schottky contact trench filled with a layer of Ti silicide/TiN or Co silicide/TiN along each trench contact sidewall and Tungsten plug connected to said source metal serving as anode of said Schottky rectifier.
[0032] FIG. 7 shows another embodiment of the present invention. The only difference between the structure of FIG. 7 and FIG. 6 is that there is no P+ region underneath the contact trench of junction barrier Schottky rectifier by using additional P+ mask to block P+ Ion Implantation during diffusion process.
[0033] For the purpose of further reduction of the gate charge for power saving, a double gate oxide structure is used, as shown in FIG. 8 . The structure illustrated is the same as that in FIG. 6 except the bottom of gate oxide layer 250 .
[0034] FIG. 9 shows another embodiment of the present invention. The only difference between the structure of FIG. 9 and FIG. 8 is that there is no P+ region underneath the contact trench of junction barrier Schottky rectifier by using additional P+ mask to block P+ Ion Implantation during diffusion process.
[0035] FIG. 10 shows another embodiment of the present invention, the structure is the same as the structure illustrated in FIG. 6 except that there is another N2 doped epitaxial layer 207 above the N1 drift region 200 according to the doping concentration relationship N2<N1 and said junction barrier Schottky trench contact 219 is formed in the N2 doped epitaxial layer 207 .
[0036] FIG. 11 shows another embodiment of the present invention. The only difference between the structure of FIG. 11 and FIG. 10 is that there is no P+ region underneath the contact trench of junction barrier Schottky rectifier by using additional P+ mask to block P+ Ion Implantation during diffusion process.
[0037] FIGS. 12A to 12D are a series of exemplary steps that are performed to form the inventive device configuration of FIG. 7 . FIG. 12A shows that an N doped epitaxial layer 200 is grown on an N+ doped substrate 201 . A trench mask (not shown) is applied to open a plurality of trenches by employing a dry silicon etch process. An oxidation process is then performed to form an oxide layer 214 covering the entire structure after a sacrificial oxide is grown and removed. After the formation of the gate oxide, doped poly is filled into the trenches and then etched back, serving as the gate material.
[0038] In FIG. 12B , a P-body mask is employed in the P-body Ion Implantation and followed by diffusion process to form the body region 213 and P-body 219 , and a N+ source mask is employed in the N+ Ion Implantation and followed by diffusion process to form the source region 212 . In FIG. 12C , a layer of insulation 202 is formed by oxide deposition above the whole structure. Followed by employing a contact mask, contact trenches 210 are formed by Dry Oxide Etch through oxide layer 202 and Dry Silicon Etch through source region 212 into the body region 213 , while contact trenches 216 extend into the N epitaxial layer 200 , and contact trenches 218 extend into the P-body 219 . Next, a P+ mask is employed to form the P+ region underneath trenches 210 and 218 in the process of BF2 Ion Implantation.
[0039] In FIG. 12D , a layer of Ti/TiN or Co/CoN 220 is deposited along the sidewall of each trench. Then the RTA process (730˜900° C. for 30 seconds) is applied to form Ti silicide or Co silicide. To fill the contact trenches, tungsten is deposited serving as plug metal. Then, deposited Ti/TiN/W or Co/TiN/W is etched back to expose the portion to deposit a layer of Ti or Ti/TiN 214 acting as a contact metal to short all source regions and anodes of junction barrier Schottky rectifier. Last, a layer of front metal Al Alloys or Copper 203 is deposited above the entire structure while a layer of back metal such as Ti/Ni/Ag is deposited on the rear side of N+substrate after back grinding to connect the drain of the MOSFET power device and the cathode of the junction barrier Schottky rectifier.
[0040] Although the present invention has been described in terms of the presently preferred embodiments, it is to be understood that such disclosure is not to be interpreted as limiting. Various alternations and modifications will no doubt become apparent to those skilled in the art after reading the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alternations and modifications as fall within the true spirit and scope of the invention.
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A trench MOSFET in parallel with trench junction barrier Schottky rectifier with trench contact structures is formed in single chip. The present invention solves the drawback brought by some prior arts, for example, the large area occupied by planar contact structure and high gate-source capacitance. As the electronic devices become more miniaturized, the trench contact structures of this invention are able to be shrunk to achieve low specific on-resistance of Trench MOSFET, and low Vf and reverse leakage current of the Schottky Rectifier.
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BACKGROUND OF THE INVENTION
The present invention provides novel compounds, novel compositions, methods of their use and methods of their manufacture, such compounds pharmacologically useful in the treatment of cardiac arrhythmias. More specifically, the compounds of the present invention are class III antiarrhythmic agents which, by effectively prolonging repolarization of a cardiac cell action potential, can be used effectively to treat certain cardiac arrhythmias.
Antiarrhythmic drugs have been grouped together according to the pattern of electrophysiological effects that they produce and/or their presumed mechanisms of action. Thus, Class I antiarrhythmic agents are characterized by being sodium channel blockers, Class II antiarrhythmic agents are beta-adrenergic blockers, Class III antiarrhythmic agents prolong repolarization, and Class IV antiarrhythmic agents are calcium channel blockers.
Currently, there are very few Class III antiarrhythmic agents available for therapeutic use. Among them is bretylium. Bretylium's usefulness is limited, however, and currently its therapeutic use is reserved for life-threatening ventricular arrhythmias that are refractory to other therapy. Thus, bretylium's use is generally confined to intensive care units. It is an object of this invention to provide Class III antiarrhythmic agents of broader therapeutic use than existing Class III antiarrhythmic agents.
SUMMARY OF THE INVENTION
The invention relates to novel compounds of the general formula I: ##STR1## and the pharmaceutically acceptable salts thereof, wherein R 1 is unsubstituted aryl, substituted aryl, or alkyloxyaryl, in which alkyl is one to ten carbon atoms and wherein R 2 is cycloalkyl of three to eight carbon atoms, phenyl, phenyl substituted by alkyl of one to ten carbon atoms, fused polycycloalkyl, fused cycloalkylphenyl, fused cycloalkylphenyl wherein phenyl is substituted by alkyl of one to ten carbon atoms, or naphthalenyl or naphthalenyl substituted by alkyl of one to ten carbon atoms.
The compounds and pharmaceutical compositions thereof are useful in the antiarrhythmic methods of the invention. The invention further provides dosage unit forms adapted for oral, topical and parenteral administration. Also provided for in this invention are the pharmaceutically acceptable salts of the compounds.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the expression "aryl" is defined as phenyl. The term "substituted aryl" shall include phenyl substituted by alkyl of one to ten carbon atoms. The term "alkyloxyaryl" is defined to include alkyl of one to ten carbon atoms and aryl which may be unsubstituted phenyl or phenyl substituted by alkyl of one to ten carbon atoms. The term "alkyl" is defined to include straight or branched carbon-carbon linkages of one to ten carbon atoms. The term "fused polycycloalkyl" is defined to include two or more cycloalkyl rings fused together, each independently of three to eight carbon atoms. The term "fused cycloalkyl phenyl" is defined to mean phenyl fused to a cycloalkyl of five to eight carbon atoms.
The term "cardiac arrhythmia" is defined to mean any variation from the normal rhythm of the heartbeat, including, without limitation, sinus arrhythmia, premature heartbeat, heartblock, fibrillation, flutter, pulsus alternans, tachycardia, paroxysmal tachycardia and premature ventricular contractions.
The term "repolarization of cardiac cells" is defined as those phases of a cardiac action potential during which time a depolarized cardiac cell is reverting to normal pre-polarization transmembrane voltage.
The term "pharmaceutically acceptable salts" refers to non-toxic salts of the compounds of this invention which are generally prepared by reacting the free base with a suitable organic or inorganic acid. Representative salts include the hydrochloride, hydrobromide, sulfate, bisulfate, acetate, oxalate, valerate, oleate, palmitate, stearate, laurate, borate, benzoate, lactate, phosphate, tosylate, citrate, maleate, fumarate, succinate, tartrate, napsylate, clavulanate and the like salts.
Compounds of the invention can be prepared readily according to the following reaction scheme or modifications thereof using readily available starting materials, reagents and conventional synthesis procedures. In these reactions, it is also possible to make use of variants which are in themselves known, but are not mentioned in greater detail. ##STR2## The compounds of the present invention can be administered in such oral dosage forms as tablets, capsules, pills, powders, granules, elixers, tinctures, suspensions, syrups and emulsions. Likewise, it can also be administered in intravenous, intraperitoneal, subcutaneous or intramuscular form, all using forms known to those of ordinary skill in the pharmaceutical arts. In general, the preferred form of administration is oral. An effective but non-toxic amount of the compound is employed in the treatment of arrhythmias of the heart. The dosage regimen utilizing the compound of the present invention is selected in accordance with a variety of factors including the type, species, age, weight, sex and medical condition of the patient; with the severity of the condition to be treated; the route of administration; the renal and hepatic function of the patient; and the particular compound employed or salt thereof. An ordinarily skilled veterinarian or physician can readily determine and prescribe the effective amount of the drug required to prevent, treat or arrest the progress of the condition.
Oral dosages of the compounds of the present invention, when used for the indicated cardiac effects, will range between about 0.1 mg per kilogram of body weight per day (mg/kg/day) to about 1000 mg/kg/day and preferably 1.0 to 100 mg/kg/day. Advantageously, the compounds of the present invention can be administered in a single daily dose or the total daily dosage can be administered in divided doses of two, three or four times daily.
In the pharmaceutical compositions and methods of the present invention, the compounds described in detail below will form the active ingredient that will typically be administered in admixture with suitable pharmaceutical diluents, excipients or carriers (collectively referred to herein as "carrier" materials) suitably selected with respect to the intended form of administration, that is, oral tablets, capsules, elixers, syrups and the like, and consistent with conventional pharmaceutical practices.
For instance, for oral administration in the form of tablets or capsules, the active drug component can be combined with an oral non-toxic pharmaceutically acceptable inert carrier such as lactose, starch, sucrose, glucose, methylcellulose, magnesium stearate, dicalcium phosphate, calcium sulfate, mannitol, sorbitol and the like; for oral administration in liquid form, the active drug components can be combined with any oral non-toxic pharmaceutically acceptable inert carrier such as ethanol, glycerol, water, and the like. In the case of oral administration and in liquid form, suitable flavoring carriers can be added such as cherry syrup and the like. Moreover, when desired or necessary, suitable binders, lubricants, disintegrating agents and coloring agents can also be incorporated into the mixture. Suitable binders include starch, gelatin, natural sugars such as glucose or beta-lactose, corn sweeteners, natural and synthetic gums such as acacia, tragacanth, or sodium alginate, carboxymethylcellulose, polyethylene glycol and various waxes. Lubricants for use in these dosage forms include magnesium stearate, sodium benzoate, sodium acetate, sodium stearate, sodium chloride, sodium oleate and the like. Disintegrators include, without limitation, starch, methylcellulose, agar, bentonite, xanthan gum and the like.
The compounds of this invention can also be administered by intravenous route in doses ranging from 0.01 to 10 mg/kg/day.
Furthermore, it is also contemplated that the invention can be administered in an intranasal form topically via the use of suitable intranasal vehicles, or via transdermal routes, using those forms of transdermal skin patches well known to those of ordinary skill in that art. In the case of transdermal skin patch administration, daily dosage is continuous via the transdermal delivery system rather than divided, as in an oral delivery system.
The compounds of this invention exhibit antiarrythmic activity useful in the treatment of various cardiac arrhythmias. The test procedures employed to measure this activity of the compounds of the present invention are described below.
EXAMPLE 1
Guinea pigs, of either sex weighing between 200-350 g, are acutely sacrificed and the right ventricular papillary muscle is isolated. A sample of a given test compound is added using an in vitro tissue bath. Concentrations used are generally 3×10 -5 M, but may also be as low as 3×10 -7 M. Changes in refractory period are measured before and after adding 1 concentration (usually 3×10 -5 M, as noted above) of a test compound to the bath. One hour is allowed for drug equilibration. A compound is considered active (Class III) if an increase in ventricular refractory period is 25 msec or more (at 3×10 -5 M).
______________________________________ ResultsCompound Concentration (M) Change (msec)______________________________________H.sub.2 O -- 8Disopyramide 3 × 10.sup.-5 20Clofilium 3 × 15.sup.-5 24Sotalol 3 × 10.sup.-5 35Example 2 3 × 10.sup.-5 75Example 3 3 × 10.sup.-6 35______________________________________
The following non-limiting examples further illustrate details for the preparation of the compounds of the present invention. Those skilled in the art will readily understand that known variations of the conditions and processes of the following preparative procedures can be used to prepare these compounds. All temperatures are degrees Celsius unless otherwise noted. Melting points were determined on a Thomas-Hoover Unimelt Capillary Apparatus and are not corrected. Unless otherwise noted, I.R. and NMR spectra were consistent with the assigned structure.
EXAMPLE 2
8-4[(4-methoxyphenyl)methyl]-8-azabicyclo[3.2.1]-octan-3-one oxime (VI, R 1 =(4-methoxyphenyl)methyl). ##STR3## Following the general procedure previously described (P. Dostert, T. Imbert, M. Langlois, B. Bucher, and G. Mocquet, Eur. J. Med. Chem. Chim. Ther. 1984, 19, 105.), a mixture of 2,5-dimethoxy-tetrahydrofuran (8.22 g, 62.2 mmol) in 75 mL of 0.1 N HCl was heated at 80 ° C. for 1 h then cooled to 10 ° C. in an ice bath. Acetone 1,3-dicarboxylic acid (10.0 g, 68.4 mmol), 4-methoxybenzylamine (9.40 g, 68.5 mmol), 5.7 mL concentrated hydrochloric acid, and sodium acetate trihydrate (10.17 g, 74.7 mmol) were added and the reaction mixture was allowed to stir 18 h at room temperature. The solution containing the crude ketone V (R 1 =(4-methoxyphenyl)methyl) was filtered through a pad of diatomaceous earth, treated with hydroxylamine hydrochloride (4.76 g, 68.5 mmol), stirred for 40 min, and brought to pH 8 with 50% aqueous NaOH solution. The gummy precipitate was partitioned between ethyl acetate and water, affording after removal of solvent 13.7 g of crude oxime VI (R 1 =(4-methoxyphenyl) methyl) as a tan solid (85%). An analytical sample was recrystallized from acetonitrile to afford a white powder: mp 128°-131 ° C. (corr). Anal. calcd. for C 15 H 20 N 2 O 2 : C, 69.21; H, 7.74; N, 10.76. Found: C, 69.16; H, 7.79; N, 10.93. 1 H NMR δ (CDCl 3 ) 3.80 (s,3, OCH 3 ), 3.58 (s, 2, CH 2 N).
EXAMPLE 3
exo-8-[(4-methoxyphenyl)methyl]-8-azabicyclo[3.2.1]octan-3-amine (VII, R 1 =(4-methoxyphenyl)methyl). ##STR4## Following the general procedure previously described (P. Dostert, T. Imbert, M. Langlois, B. Bucher, and G. Mocquet, Eur. J. Med. Chem. Chim. Ther. 1984, 19, 105.), oxime VI (10.0 g, 38.4 mmol, R 1 =(4-methoxyphenyl) methyl) was dissolved in 125 mL n-pentanol at 120 ° C. in a 500 mL three-necked round-bottom flask equipped with a mechanical stirrer. The flask was removed from the heat and sodium metal (7.80 g, 0.339 g-atom) was added in small pieces at a rate sufficient to maintain the reaction temperature at 120°-130 ° C. After the addition was complete the flask was heated to maintain this temperature until all the sodium had been consumed. The reaction mixture was cooled then poured onto 100 g of ice in a separatory funnel. After shaking the mixture, the pentanol layer was extracted thrice with 50 mL portions of 10% HCl. The combined acid washes were made basic with aq. NaOH and extracted thrice with 50 mL portions of ethyl acetate. The organic layer was washed with 50 mL water, 50 mL saturated brine, dried over sodium sulfate, and concentrated to afford the amine VII (R 1 =(4-methoxyphenyl)methyl) as a clear light golden oil 8.73 g (92% crude) which was used without further purification: 1 H NMR δ (CDCl 3 ) 3.78 (s, 3, OCH 3 ), 3.48 (s, 2, CH 2 N), 2.93 (m, 1,-CHNH 2 ).
EXAMPLE 4
Preparation of exo-N-[8-[(4-methoxyphenyl)methyl)]-8-azabicyclo[3.2.1]oct-3-yl]benzamide ##STR5## A solution of amine VII (0.975 g, 3.96 mmol) and triethylamine (0.7 mL, 5.0 mmol) in 10 mL CH 2 Cl 2 was cooled in an ice bath and treated dropwise with benzoyl chloride (0.5 mL, 4.3 mmol). After 1 h the solution was washed with 10 mL 1 N NaOH, 10 mL water, dried over sodium sulfate, and concentrated to afford amide I (R 1 =(4-methoxyphenyl)methyl, R 2 =phenyl) as a solid.
Recrystallization from ethyl acetate gave the product as a white powder, 0.71 g (51%): mp 159.5°-161.0 ° C. (corr). Anal. calcd. for C 22 H 26 N 2 O 2 : C, 75.40; H, 7.48; N, 7.99. Found: C, 75.37; H, 7.63; N, 7.97. 1 H NMR δ (CDCl 3 ) 3.78 (s, 3, OCH 3 ), 3.47 (s, 2, CH 2 N), 4.35 (cm, 1, CHNHCOPh).
EXAMPLE 5
exo-1,2,3,4-tetrahydro-N-[8-[(4-methoxyphenyl)-methyl)]-8-azabicyclo [3.2.1]oct-3-yl]-2-naphthalenecarboxamide ##STR6## Following the procedure outlined in Example 4 and substituting 1,2,3,4-tetrahydro-2-naphthalenecarbonyl chloride as the acylating reagent, amine VII (1.30 g, 5.28 mmol, R 1 =(4-methoxyphenyl)methyl) afforded I (1.33 g, 62%, R 1 =(4-methoxyphenyl)methyl, R 2 =phenyl) after recrystallization of the crude product from ethyl acetate: mp 189.5°-191.5 ° C. (corr). Anal. calcd. for C 26 H 32 N 2 O 2 : C, 77.19; H, 7.97; N, 6.92. Found: C, 76.95; H, 8.02; N, 6.85. 1 H NMR δ (CDCl 3 ) 3.79 (s, 3, OCH 3 ), 3.45 (s, 2, CH 2 N), 4.18 (cm, 1, CHNHCOR 2 )
While the invention has been described and illustrated with reference to certain preparative embodiments thereof, those skilled in the art will appreciate that various changes, modifications and substitutions can be made therein without departing from the spirit and scope of the invention. For example, effective dosages other than the preferred range as set forth herein above may be applicable as a consequence of variations in the responsiveness of the mammal being treated for severity of cardiac arrhythmia, dosage-related adverse effects, if any, and analogous considerations. Likewise, the specific pharmacological responses observed may vary according to and depending upon the particular active compounds selected or whether there are present certain pharmaceutical carriers, as well as the type of formulation and mode of administration employed, and such expected variations for differences in the results are contemplated in accordance with the objects and practices of the present invention. It is intended, therefore, that the invention be limited only by the scope of the claims which follow, and that such claims be interpreted as broadly as is reasonable.
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N-benzyl tropane amides, which have activity as Class III antiarrhythmic agents, acting by prolonging cardiac action potential repolarization. The invention further provides for compositions incorporating the compounds and methods of their use, as well as providing for pharmaceutically acceptable salts of the compounds.
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CLAIM FOR PRIORITY
The present application claims priority under 35 U.S.C. §119( e ) to U.S. Provisional Application No. 60/840,974, filed Aug. 30, 2006, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to aircraft landing systems and more particularly to a device for measuring the pressure inside a landing gear shock strut. This invention is particularly useful for retrofit applications where drilling a new hole or changing the volume of the shock strut by the addition of a normal pressure transducer is not acceptable.
BACKGROUND OF THE INVENTION
Shock strut pressure is measured during maintenance of landing gear and other pressure vessels to ensure proper performance. The physical geometry of these pressure vessels (such as landing gear shock absorbers) determine (along with fluid and gas volumes) the behaviour and performance of the vessel. Measuring the pressure of the gas within the shock absorber is a critical task that must be performed regularly to ensure safe operation of the aircraft. This is presently performed by attaching a gauge to the external port of the charging valve, then opening the valve. This action is suboptimal because it requires a manual operation to connect and read the system, and because it involves the opening and closing of the valve (with the attendant loss of a small amount of fluid or gas).
In order to reduce the amount of required maintenance, an automatic means of measuring the pressure of fluid within the shock strut is desired. Conventional approaches to this problem would involve the mounting of a pressure transducer either directly into the body of the shock strut, or the fitting of a manifold to the existing port to allow both a pressure measurement and a facility to charge (alter the quantity of fluid and gas). Both of these solutions present problems when they are applied to existing shock strut designs. Fitting a transducer into the body of the shock strut involves drilling a hole in the structure of the strut—which is generally not acceptable from a strength or fatigue perspective. Adding a manifold to the shock strut changes the amount of internal working volume, which changes the energy absorbing properties of the landing gear—which is not desirable.
Many landing gears have a poppet charging valve conforming to MS28889-2/MIL-PRF-6164F. This valve allows the introduction or removal of fluid and gas from the pressure vessel. The present invention modifies this valve to include a pressure-sensing means and electrical contact means such that measurements may be made of the working fluid without interfering with the normal operation of the valve or significantly altering the volume within the pressure vessel.
This modified valve can be retrofitted to any landing gear to allow pressure measurements to be made without altering the landing gear. A change in military standards from MS28889-2 to the newer performance based specification—MIL-PRF-6164F allows the certification of a modified valve to act as a replacement for existing valves.
SUMMARY OF THE INVENTION
At the base, the design involves introducing a pressure sensitive element on one end of the valve and providing a route for the measurement wires to a connector that is mounted internally in the valve stem. The connector is configured in such a manner that it does not interfere with normal pressure charging apparatus, but a specially designed electrical connector can connect to the valve for determining the pressure either in flight or on the ground.
In one aspect the present invention provides a charging valve for use in a pressure vessel in an aircraft landing gear comprising a valve stem having a first and second end and a channel extending therebetween, a pressure-sensing device received within the channel at the first end and operable to measure the pressure of the pressure vessel, and a receptacle received within the channel between the pressure-sensing device and the second end and operable to be in communication with the pressure-sensing device and configured to allow fluid to flow through the valve.
In another aspect the present invention provides a charging valve for use in a pressure vessel in an aircraft landing gear comprising a valve stem having a first and second end and a channel extending therebetween, a pressure reading means connected to the first end of the valve body for reading the pressure in the pressure vessel and a receptacle received within the channel between the pressure reading means and the second end and operable to be in communication with the pressure reading means and configured to allow fluid to flow through the valve.
In a further aspect the present invention provides a method of modifying a charging valve having a main body including a channel therethrough, to include a pressure measuring device for use in a pressure vessel comprising the steps of (i) placing a pressure-sensing device within the channel at the end of the valve that is in communication with the pressure vessel to allow the pressure-sensing device to measure the pressure within the vessel; (ii) connecting the pressure-sensing device to a receptacle or connector to allow for communication therebetween, the receptacle being located within the channel of the valve at the opposite end of the pressure-sensing device from the measurement end and being operable to allow for fluid to flow through the valve. The pressure-sensing device may be a pressure transducer or may include a modification to the end of the valve to form a pressure sensitive diaphragm that is gauged.
In another aspect, the present invention provides a retrofit kit for use in a charging valve used with a pressure vessel comprising a pressure-sensing device sized to be received within the channel of the valve at the first end and operable to measure the pressure of the pressure vessel and a receptacle sized to be received within the channel of the valve and operable to be in communication with the pressure-sensing device and configured to allow fluid to flow through the valve. The pressure-sensing device and receptacle are as described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described in further detail with reference to the following figures:
FIG. 1 is a schematic diagram of the standard geometry of a charging valve;
FIG. 2 is an exploded perspective view showing the valve stem of the present invention in two portions and the pressure-sensing device, connector and plug to be used with the valve;
FIG. 3 is a perspective view of one embodiment of the receptacle of the present invention;
FIG. 4 is a perspective view of an alternate embodiment of the receptacle and the second portion of the modified valve stem of the present invention;
FIG. 5 is a perspective view of a further alternative embodiment of the receptacle and the second portion of the modified valve stem of the present invention;
FIG. 6 is a perspective view of a further embodiment of the receptacle of the valve of the present invention;
FIG. 7 is a perspective view of a further embodiment of the receptacle and the second part of the modified valve stem of the present invention;
FIG. 8 is a perspective exploded view of the receptacle and plug of the valve of the present invention according to the embodiment illustrated in FIG. 3 ;
FIG. 9 a is a perspective exploded view of the mating orientation of the receptacle and plug of the present invention;
FIG. 9 b is a perspective view illustrating the mating connection of the plug and the receptacle of FIG. 9 a;
FIG. 10 is an exploded perspective view of one embodiment of the plug construction of the present invention;
FIG. 11 is a schematic showing the stem machining modifications for one embodiment of the valve of the present invention;
FIG. 12 is a side cross-sectional view of the placement and connection of the pressure-sensing device of the present invention;
FIG. 13 is a side cross-sectional view illustrating the welding of the pressure-sensing device during installation according to one embodiment;
FIG. 14 is an exploded perspective view illustrating the plug, and the assembly of the receptacle, the pressure-sensing device, and the valve stem according to one embodiment of the present invention;
FIG. 15 is a perspective view of one embodiment of the fully assembled valve of the present invention with the cap off;
FIG. 16 is a cross-sectional view of an alternative embodiment of the valve of the present invention wherein the valve is modified to form a pressure sensitive diaphragm that is gauged; and
FIG. 17 is a cross-sectional view of a further embodiment of the valve of FIG. 16 in which the valve stem has been modified to include a cavity in its end.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a modified charging valve having a pressure sensitive element at one end and a connector or receptacle mounted within it. The receptacle is configured to determine pressure within the valve either in flight or on the ground with minimal interference with the normal pressure charging apparatus.
The modified valve of the present invention utilises the structure of known valves used in the art and incorporates within it a pressure-sensing device and a receptacle or connector that allows for pressure measurements to be made as desired without interfering with the normal operation of the valve and with minimal alteration of the volume of the working fluid within the pressure vessel. Pressure vessels and charging valves are known in the art and therefore are not described in detail herein. In an alternative embodiment, the existing end of the valve can also be modified to form a pressure sensitive diaphragm and then be gauged.
The valve of the present invention will now be described in further detail with reference to the accompanying figures.
FIG. 1 provides a schematic diagram of the standard valve geometry. As stated above, the present invention utilises the structure of valves known in the art. As will be described, the valve is modified to accommodate, for example, the pressure-sensing device, the receptacle and a measuring device. Generally such known valves include a main body (also referred to as a valve stem herein), that has a central channel, or bore, that extends from one end of the body to the other. The present invention incorporates the use of a pressure-sensing device and receptacle within the channel of the body, as described below.
Referring to FIG. 2 , one embodiment of the modified valve of the present invention will be described in further detail. FIG. 2 is an exploded perspective view illustrating the components of the modified valve, indicated in the Figures at numeral 18 , which includes a valve stem 20 which is illustrated in two portions, a first portion 22 and a second portion 24 . It will be understood that the modified valve 18 of the present invention may comprise one main body that does not consist of two separate parts, however in a preferred embodiment the valve main body comprises two portions to assist in the assembly of the modified valve. The description of the modified valve will make reference to a two part valve body, however a person skilled in the art will understand that a one part valve body may also be used. The stem 20 includes an elongate channel 26 that extends through the stem 20 from one end to the other, i.e. through the first and second portions 22 , 24 .
The modified valve 18 also includes a pressure-sensing device 28 and a receptacle 30 . The modified valve 18 may optionally include a plug 32 or the plug 32 may be a separate component that is used in combination with the modified valve 18 when a pressure reading is required, discussed in further detail below.
The pressure-sensing device 28 may be any pressure-sensing device or transducer that is operable to measure pressure and is sized to be received within the first portion 22 of the stem 20 . In an alternative embodiment, the channel 26 may be widened, for example by boring, to incorporate the pressure-sensing device 28 . The pressure-sensing device 28 is fixedly attached to the end of the first portion 22 by any means known in the art, for example welding, using a laser or other means, fixed using an adhesive or mechanically retained within the channel 26 . The connection of the pressure-sensing device 28 within the channel 26 may be by any means that allows the pressure-sensing device 28 to measure the pressure in the pressure vessel to which the valve 18 is attached.
Examples of the type of a pressure-sensing device 28 that may be used include, but is not limited to resistive strain gauges and capacitive gauges. The modified valve 18 of the present invention may also include a temperature sensitive element (not shown). Examples of the type of temperature sensitive elements that may be used include a thermocouple and a resistance temperature detector (RTD). As will be understood by a person skilled in the art, the pressure sensing device 28 and the temperature sensing device may be an integrated piece operable to measure the pressure and temperature of the fluid within the pressure vessel. That is, the integrated pressure and temperature sensing device is preferably sized to be received within the first portion 22 of the valve stem 20 . Alternatively, the channel 26 may be widened to receive the integrated pressure and temperature sensing device.
In the illustrated embodiment of FIG. 2 , the pressure-sensing device 28 includes a series of wires 38 extending from one end which allow the pressure measurement to be communicated to an external, or internal, measuring device or plug 32 via receptacle 30 . As will be understood, if an integrated temperature and pressure sensing device are used, the combined pressure and temperature measurements may be communicated to an external, or internal, measuring device or plug 32 via the receptacle 30 .
Located within the channel 26 in the second portion 24 of the stem 20 is the receptacle 30 . The receptacle 30 is operable to be in communication with the pressure-sensing device 28 and is also operable to be electrically connected to a measuring device or plug 32 at the opposite end from the connection to the pressure-sensing device 28 . The receptacle 30 is operable to communicate with the pressure-sensing device 28 , and in the illustrated embodiment, the wires 38 of the pressure-sensing device 28 are connected to the receptacle 30 . The connection of the wires 38 may be made by any means known in the art, including soldering. Thus, since the receptacle 30 is electrically connected to the pressure-sensing device 28 and the plug or measuring device 32 , it facilitates communication of a pressure reading from the pressure sensing device 28 to the plug or measuring device 32 .
FIG. 3 illustrates one embodiment of the receptacle 30 , comprising a hollow cylindrical shell portion 40 within which a series of strips 42 are received. The strips 42 are connected to the interior surface of the shell portion 40 at spaced intervals. The strips 42 are attached to the shell portion 40 by any means known in the art that will withstand the environment of the valve and maintain the strips 42 in their position. The strips 42 are made from a conductive material and allow for communication between the wires 38 of the pressure-sensing device 28 and a measuring device or plug 32 . As can be seen more clearly in FIG. 8 , the strips 42 extend outwardly past the shell portion 40 in the direction of the pressure-sensing device 28 . The wires 38 of the pressure-sensing device 28 are connected to the strips 42 by any means known in the art, for example soldering.
The conductive material that is used is preferably inert to the fluid environment of the valve 18 . The illustrated embodiment shows the receptacle 30 having four spaced strips 42 within it, however the number of strips and their size and configuration may vary provided that a conductive pathway is provided from the pressure-sensing device through the receptacle 30 .
As stated above, the modified valve 18 allows for pressure measurements to be taken when desired with minimal interference with the valve operation and working fluid. Therefore, it will be understood that although variations to the number and positioning of the strips 42 may be made it is preferable to minimise the obstruction of the fluid through the receptacle 30 .
Referring to FIGS. 3-7 , alternative embodiments of the receptacle 30 are illustrated. Other variations of the receptacle 30 may be used to provide an electrical connection between the pressure-sensing device 28 , and in particular the wires 38 , and the plug or measuring device 32 . As will be understood referring to FIGS. 3-7 , the strips 42 are positioned on the receptacle 30 such as to provide sufficient separation therebetween so as to allow separation between the electrical connections on the strips 42 . FIGS. 4 through 7 provide perspective drawings of other embodiments of the receptacle 30 . In each of these figures it will be understood that the receptacle 30 is viewed from the end that is operable to connect to plug 32 . The opposite end is connected to the wires 38 as described above.
Referring to FIGS. 4 to 7 , at the end of each of the illustrated receptacles 30 a series of apertures, indicated generally at 44 , are shown that are operable to connect to the plug 32 . In these embodiments, the plug 32 will include protrusions, not shown, that will be sized and configured to be received within the apertures 44 to provide a connection there between.
Each alternative embodiment of the receptacle 30 will now be described in more detail. FIG. 4 illustrates a receptacle 30 having a rectangular body with curved sides such as to be fittedly received within the channel 26 . This involves machining grooves in the valve stem 20 (preferably the second portion 24 ) to accommodate the receptacle 30 . In this embodiment illustrated, the apertures 44 are located within the rectangular body in a parallel line. Each aperture 44 is sized to receive a conductive strip 42 . Fluid is operable to flow on either side of the rectangle through the valve body.
FIG. 5 illustrates a circular or cylindrical embodiment of the receptacle 30 that includes a pair of locking tangs 46 for holding the connector 34 within the second portion 24 of the valve stem 20 . The circular embodiment of the receptacle 30 is centrally located within the channel 26 and allows for fluid flow around the exterior circumference of the receptacle 30 .
FIG. 6 illustrates a circular or cylindrical receptacle 30 that is suspended within the channel 26 by a cover 48 . It will be understood that in this embodiment the cover 48 , that extends around the connector 34 and is held within the valve shell 40 by a tab like attachment point, is preferably made from a thin metal to minimise interference with fluid flow around the connector and also to allow the minimum fluid flow rate in which the metal is susceptible to fatigue from twisting due to high fluid pressures.
FIG. 7 includes an alternate embodiment of the receptacle 30 . According to the embodiment illustrated, the receptacle 30 is circular or cylindrical shaped and sized to fit within the channel 26 . The illustrated circular receptacle 30 includes a hollow passageway therefore to allow for fluid flow. The apertures 44 are located within the walls of the receptacle 30 .
The plug 32 and its use will now be described in further detail. As stated above, the plug 32 may form part of the valve 18 or may be a separate unit that is used only when required. The plug 32 is operable to connect with the receptacle 30 at the opposite end from the pressure-sensing device 28 . In the illustrated embodiment, as can be seen in FIG. 8 , the plug 32 includes a contact end that includes a series of connectors 52 having contact strips 54 that are operable to mate with the strips 42 on the receptacle 30 . The connection, or mating, of these two components can be clearly seen in FIGS. 9A and 9B . The connection of the two parts allows for electrical contact between the pressure-sensing device 28 , the receptacle 30 and the plug 32 and therefore allows a pressure reading to be taken and communicated to a user.
It will be understood that the connection point between the receptacle 30 and the plug 32 may be made by other means. For example, and as described above, in the alternative embodiments of the receptacle 30 a series of apertures 44 were provided for receiving protrusions on the plug 32 to allow for a connection between the pressure-sensing device, the receptacle 30 and the plug 32 .
FIG. 10 provides an exploded perspective view of the embodiment of the plug described above, including contact strips 54 received in the connectors 52 sized to engage with the strips 42 on the receptacle 30 .
As can be seen in FIGS. 9A and 9B the contact strips 54 of the plug 32 and the strips 42 of the receptacle 30 may be slightly curved to ensure a secure lock between the components when mated. The insulation between each mating set of contact strips is the shell portion 40 of the receptacle 30 shown in FIG. 9A . The shell portion 40 that mounts the conductive strips is preferably a dielectric plastic material such as Delrin or PEEK. The conductive strips are therefore mounted on an insulating mount, i.e. the shell portion, when located in the conductive stainless steel of the valve stem.
To ensure that the plug 32 and receptacle 30 mate in the appropriate orientation (to ensure that the correct electrical connections are made), the strips 42 and contact strips 54 may be offset radially as shown in FIG. 10 to ensure that only one mating orientation works. Furthermore, one of the strips 42 of the receptacle 30 may be made deeper than the other strips to provide a mechanical guideway—the plug 32 would not fit into the hole in receptacle 30 unless rotated to the appropriate position.
An example of the machining requirements for one embodiment of the present invention is provided in FIG. 11 . However, it will be understood that these are merely provided as an example and are not meant to be limiting in any way. The machining requirements may be changed depending on the valve size and the configuration of the connector and pressure sending device and plug to be utilised within the valve.
The valve main body or stem 20 may be modified as follows: carve a 0.04″ wide groove around the circumference of the stem 0.8″ from the left and cut the stem in half at 0.84″ starting from left of stem. As discussed above, this provides a two-part valve stem 20 that assists in the positioning and securing of the receptacle 30 to the wires 38 of the pressure-sensing device 28 . However, this is not required and the receptacle 30 may be placed within the valve body/stem 20 while the stem 20 comprises one unitary piece.
Once the valve stem 20 has been divided into two pieces the first piece of the stem may be adapted to include a hole in the end facing the second stem piece with diameter 0.1170″ offset from centre with a depth of 0.6450″ using standard drill size 0.1142″+0.004/−0.001. A second hole at the opposite end (where the pressure-sensitive face of the transducer will be) may be drilled with diameter of 0.126″ and a depth of 0.1750″, using standard drill size 0.1260″+0.005/−0.001.
The second half of the stem may be hollowed out to a diameter of 0.2000″ along the length of the piece. This could be done using a standard drill size 0.2008″+0.005/−0.001.
In addition a cylindrical end piece 72 is machined with a diameter of 0.395″ and length 0.180″ with an offset through hole with diameter 0.15″, using a standard drill size 0.1496″+0.005/−0.001. This hole would align with the hole through the first stem piece 22 .
The installation of the pressure-sensing device 28 will now be described with reference to FIGS. 12 and 13 .
In the illustrated embodiment, there were two methods that may be used to secure the pressure transducer or pressure sensing device 28 in place. Either: (i) Using Room Temperature Vulcanized rubber 56 potting compound & epoxy 58 , shown in FIG. 12 or (ii) micro laser welding 60 it in place, shown in FIG. 13 .
When following the method illustrated in FIG. 12 , i.e. RTV 56 potting and epoxy 58 , the end piece 72 of the stem must be hermetically laser welded 62 onto the first half of the stem. The pressure-sensing device 28 is then put in place using the epoxy 58 near the lower portion of the transducer and potting 56 surrounding the head. This is to prevent residual stress caused by the epoxy curing from affecting the strain and pressure readings on the pressure-sensitive face of the transducer.
If using a laser weld, as illustrated in FIG. 13 , to install the pressure-sensing device, insert the transducer 28 into the end piece 72 until the pressure-sensitive face is flush with the surface of the end piece. Then weld 60 the two parts together around the circumference of the transducer over the existing weld left from the construction of the transducer where it protrudes from the other side of the end piece. Place the assembled end piece and transducer at the end of the first stem piece with the transducer wires extending through the stem hole. Weld 62 the end piece 72 to the first stem piece 22 around the circumference where the two parts meet.
The assembly of the modified valve 18 of the present invention will now be described with reference to FIGS. 14 and 15 .
To assemble the system, the pressure-sensing device 28 should first be connected to the first portion 22 of the valve main body 20 , as described above. The wires 38 from the pressure-sensing device 28 , which protrude from the first portion of the main body 20 may be formed into one wire. The wires or wire, may then be soldered onto the receptacle 30 (e.g. onto the strips 42 ). The receptacle 30 is then placed within the second portion 24 of the main body 20 and the first and second portions are connected together. Preferably the first and second portions ( 22 , 24 ) are hermetically laser welded together. The modified valve 18 can then be reassembled with the unmodified valve housing 74 and locking nut 76 to make the valve functional.
The valve 18 may also include a cap 64 , shown in FIG. 15 . The cap 64 fits on the end of the second portion of the valve body and provides a dust cap or seal. In one embodiment, the cap 64 may include the plug 32 which may be operable to be in communication with the receptacle 30 during the operation of the aircraft, i.e. pressure readings may be taken during operation of the aircraft whenever required. Alternatively, the cap 64 may be manually removed and the plug 32 be contained as a separate unit, for example a handheld unit, and connected to the receptacle 30 if and when a pressure reading is required.
The present invention provides a modified valve according to the above description that includes a pressure-sensing means and a receptacle or connector that allows for periodic or continual communication with the pressure-sensing means. In another aspect the present invention provides a method for retrofitting a valve within a pressure vessel to incorporate a pressure-sensing device within it. In a further aspect the present invention provides a pressure-sensing retrofit device that includes a connector that may be installed in a valve to allow for pressure measuring with minimal interference with the valve.
The present invention provides a standard charging valve modified to add a pressure transducer with the active diaphragm subjected to the pressure within the charged vessel. The present invention further provides an arrangement to allow the wires and connector to not interfere with the flow of gas or oil so as to not interfere with normal servicing.
In a further embodiment of the present invention the existing end of the valve may be modified to form a pressure sensitive diaphragm, which is then gauged. The gauges are indicated at numeral 70 and may be attached directly into the valve stem. FIG. 16 illustrates the inclusion of a gauge 70 in the valve stem with wires 38 extending from the gauge. The wires are as described herein and may connect in a similar manner as described above.
FIG. 17 illustrates a further embodiment of the valve including the gauge in which the stem of the valve is modified to include a cavity that has been formed in one end of the valve. The cavity may be formed by machining and then welding the stem or by electro discharge machining (EDM). The strain gauge 70 may then be adhered in the cavity and the wires extend therefrom as described above. It will be understood that the gauge and wires may replace the pressure-sensing device described in the above embodiments.
While this invention has been described with reference to illustrative embodiments and examples, the description should not be construed in a limiting sense. Thus, various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments. Further, all of the claims are hereby incorporated by reference into the description of the preferred embodiments.
Any publications, patents and patent applications referred to herein are incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety.
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The present invention is a device that allows the pressure inside an aircraft landing gear shock strut to be measured. A charging valve is modified by integrating a small pressure sensing device into the stem of the part such that the active diaphragm is subjected to the pressure within the charged vessel. The wires from the pressure sensing device are connected to a receptacle or connector in the bore of the stem such that a corresponding electrical receptacle may be mated for the purposes of making a measurement. The internal receptacle is designed such that the flow of air or oil is not excessively impeded and normal servicing tools do not interfere with the receptacle.
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BACKGROUND OF THE INVENTION
In electro-optical document-reading apparatus such as facsimile apparatus, light is directed onto a printed document, and light is reflected from each elemental area of the printed document, in accordance with the color or blackness of the elemental area. The reflected light is fed through an optical system, usually including a spherical lens system, to electrical apparatus in which the reflected light is converted to electrical signals which are used to perform a printing operation which reproduces the document. One characteristic of a spherical lens is that there is a fall-off in light intensity at the ends of the lens so that a line of light which passes through the lens is reduced in intensity at its ends and is more intense at the center. This results in imperfect reproduction of a document.
Briefly, this problem is avoided in the present invention by the provision of means for flooding a document with light having a distribution of intensity which compensates for the fall-off in the lens to provide a substantially uniform light intensity distribution at the input to the electronic circuit portion of the system.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the invention;
FIG. 2 is a side, elevational view, partly in section, of the apparatus of FIG. 1;
FIG. 3 is a side elevational view of a portion of the apparatus of FIG. 2 showing a modification thereof;
FIG. 4 is a rear elevational view of a portion of the apparatus of FIG. 1;
FIG. 5 is a side, elevational view of a modification of the invention;
FIG. 6 is a plan view of apparatus illustrating another modification of the invention;
FIG. 7 is a side elevational view of still another modification of the invention;
FIG. 8 is a plan view of a modification of the invention,
FIG. 9 is a plan view of another modification of the invention;
FIG. 10 is a front view of a portion of the apparatus of FIG. 9;
FIG. 11 is a front view of a modified light source used with the invention;
FIG. 12 is a schematic representation of another modification of a light source used with the invention;
FIG. 13 is a side view of apparatus using the apparatus of FIG. 12; and
FIG. 14 is a side elevational view of another modification of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In general terms, the apparatus 10 embodying the invention includes a light guide 20 having a generally rectangular inlet end 22 and a generally rectangular outlet end 24. At the outlet end of the light guide is positioned means for supporting a document to be illuminated with light, line-by-line. At the inlet end of the light guide is positioned light source means for generating light to be directed through the light guide onto the document disposed across the outlet end of the light guide. The apparatus 10 also includes optical and electronic circuit means for receiving light reflected from the document, line-by-line, and converting such reflected light to electrical signals which are used to reproduce the document at a remote location.
One embodiment of the light guide 20 used in practicing the present invention is a hollow duct which is relatively long and wide but has small height and has a rectangular cross-section. In addition, the duct enlarges from the inlet end to the outlet end so that the outlet end 24 has a larger area than the inlet end 22. The light guide includes relatively large-area top and bottom plates 30 and 40 and trapezoidal side plates 50 and 60, all of which have highly reflective inner surfaces. The light guide has a width which is somewhat larger than the width of a document to be "read" in order to avoid edge effects in the light guide.
At the outlet end of the light guide and spaced a suitable distance therefrom is a rotatable cylinder 110 which carries a document 120 to be read, line-by-line, by the system. The document is positioned to receive light transmitted through the light guide and to transmit light in accordance with the reflectance of unit areas of each line of the message printed thereon, as is well known in the art. For most uses, the cylinder 110 should be as close as possible to the outlet end 24 of the light guide.
For a number of reasons, including the need to avoid reflection problems or to control the path of reflected light to pickup apparatus, the angular relationship between the optical axis of the light guide and the surface of the document may be varied, from perpendicular as illustrated in FIG. 2 to some suitable angle as illustrated in FIG. 3.
According to the invention, the apparatus 10 is provided with light source means positioned to compensate for the cosine fourth power drop-off of the reading lens system normally employed with apparatus of the type under consideration, one embodiment of which is described below. In one arrangement, the compensating light source means comprises two incandescent lamps 70 and 80 disposed close to the rear opening 22 of the light guide and positioned to direct light into the light guide and toward the document. In order to provide the desired compensation, the lamps are spaced apart, with each being disposed between the center of the rear opening and one of the side walls 50 or 60. Some of the light rays from the lamp strike the document directly, and some strike the document through reflections from the side walls and the top and bottom plates of the light guide, and the total light which reaches the document has the desired distribution of light intensity along the document. As noted, the desired light intensity distribution shows greater intensity toward the left and right edges of the document than at the center thereof. The exact positioning of the lamps to obtain the desired distribution of intensity depends on a number of mechanical and optical factors and can be readily determined by those skilled in the art.
It is further noted that, in one mode of operation of the apparatus 10 wherein light reflected from the document is directed back through the light guide to pick up or reading apparatus to be described, the lamps 70 and 80 must be spaced apart sufficiently to permit all useful light up to and including the limiting rays R (FIG. 1) to exit from the end 22 of the light guide.
In order to improve the efficiency of the lamps 70 and 80 and increase the flexibility of adjustment thereof, adjustable concave reflectors 90 and 100 are positioned one behind each lamp. The reflectors should be properly positioned and angled with respect to the lamps so that light reflected therefrom is not obstructed by the lamp filaments or other parts thereof. Of course, the reflectors are also positioned to assist in achieving the desired distribution of light intensity along the document.
In one embodiment of the invention wherein light reflected from the document is fed back through the light guide, the pickup portion of the apparatus 10 includes a spherical, aberration-free lens system 130 mounted behind and between the lamps 70 and 80 to receive light reflected from the document 120. Behind the lens 130, is positioned a photoelectric sensor 140 for converting light reflected from each unit area of a line of print on the document to electrical signals, as is well known in the art. One suitable photoelectric device comprises an integrated dircuit chip having a large number of tiny photosensitive elements arranged in a line, each element receiving light from a unit area of each line of print.
It is noted that the light distribution along the document generated by the lamp (and reflectors) combines with the distribution generated by the lens 130 to provide a substantially uniform light distribution at the input to the electronics of the system.
A modification of the apparatus 10 shown schematically in FIG. 5, provides a longer optical path than the apparatus of FIG. 1, if such is required. The apparatus in FIG. 5 includes a folding mirror 150 which is disposed rearwardly of the lamps to receive light reflected from the document along a first axis 160, this light being reflected on a second axis 170 disposed at a suitable angle to the first. This light is directed through the lens 130 to the photoelectric sensor 140.
Those skilled in the art will appreciate that the mechanical parameters selected for the light guide are determined by, among other things, the size of the light guide, the spacing of the document from the outlet end of the light guide, the intensity of the light which reaches the document, the size of the document, the lamp filament size, the lamp bulb size, and the like. In one embodiment of the invention wherein the spacing of the document from the guide opening 24 was about four inches and the light guide had a length of about eleven inches., the top and bottom plates of the light guides were disposed at an angle to the horizontal of about 1° to about 1.5°.
In a modification of the apparatus described above, each of the lamps 70 and 80 is replaced by two or more lamps 70' and 80', as illustrated in FIG. 6. The lamps 70' and 80' are positioned to satisfy all of the requirements spelled out for lamps 70 and 80.
In another modification of the apparatus of the invention, light reflected from the document 120 does not return through the light guide but travels along a path disposed outside the light guide. Thus, as illustrated in FIG. 7, the light guide 20 is disposed at such an angle to the document that light is reflected from the document on an axis 180 which is disposed above the light guide to suitable optical apparatus and electro-optical pickup mechanism (not shown). With this type of reading arrangement, the lamps 70 and 80 can be replaced by two separate spaced-apart fluorescent bulbs 190 and 192 or by a single fluorescent bulb 194 (FIG. 9) suitably masked by an opaque coating 196 (FIG. 10) to provide greater output at its ends than at its center. With this arrangement, a single source of light is provided, which represents economies while the desired light distribution is achieved. On of the important advantages of using one or more fluorescent bulbs resides in the fact that the bulbs can be placed directly against the open end of the light guide to provide optimum optical efficiency.
In still other modifications of the invention, the light sources might comprise electroluminescent panels, or they might be light-emitting diodes 200 shaped and disposed to achieve the desired light distribution as shown schematically in FIG. 11, wherein there is a greater concentration of light-emitting devices at the ends than at the center.
Alternatively, a single row of separate light-emitting devices 200 might be connected to current control means 203 whereby different light output is obtained from the devices at the ends than at the center of the series. This is illustrated in FIG. 12. In this arrangement, in addition, the devices 200 are narrow, line-like devices which allow light R to return back through the light guide 20 from the document to the reading lens 130 and electronic pickup apparatus (not shown) as illustrated in FIG. 13.
In another modification of the invention illustrated in FIG. 14, an assembly of optical fibers 210 is disposed between the outlet end of the light guide 20 and the document 120. Each optical fiber may be of the order of one to two inches in length. The assembly provides improved optical efficiency.
It is clear that the principles of the invention may be applied, not just to facsimile, but to photography in general or to other optical fields which have the problems solved by the invention.
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The disclosure is of apparatus including a duct-like light guide having an inlet end and an outlet end, light source means at the inlet end, a document at the outlet end, an optical reading system for receiving light reflected from the document, and electronic circuit means for converting the reflected light to electrical signals. Typically, the optical reading system has non-uniform light transmission characteristics, and, with one type of lens system, there is fall-off in intensity at the ends of the system. To compensate for this fall-off, the light source means is designed and positioned to provide a corresponding non-uniform light distribution so that the net effect is a uniform light distribution at the output of the lens system.
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BACKGROUND OF THE INVENTION
The present invention relates to a digital to analog converter and, more particularly, to a converter and a method of conversion that accomplishes the conversion by duty cycle modulation.
In the design of interfaces for digital or microprocessor-based electronic circuits, it is often necessary to convert a binary number to an equivalent voltage or current. This is accomplished by a circuit commonly referred to as a digital to analog ("D/A") converter which divides a precision reference voltage into a ratio proportional to the binary number. The division is accomplished either by a ladder of precisely ratioed resistors or by duty cycle modulation. The present invention relates to a D/A converter using duty cycle modulation.
A circuit for this type of D/A conversion generates a wavetrain having a duty cycle proportional to the binary input and an amplitude equal to the reference voltage (V r ). The duty cycle, D, is the ratio of time "on" to time "off" for one cycle of a wavetrain. A common approach to generating the wavetrain is to load the binary input into a counter. The output of the counter is held high while the counter counts down to zero. When the counter reaches zero, the output is set back to low until it is time for the cycle to be repeated. The cycle time or wavetrain period, T, is equal to the product of the number, 2 n , and the period of a clock cycle, where n is the number of bits comprising the binary number. For example, a wavetrain for a three-bit D/A converter could be in one of eight forms, 2 3 , wherein the pulse width [("PW"), where PW×(T)(D)] ranges from 1/8 to 7/8 of the wavetrain period, T, and has an amplitude equal to the reference voltage (V r ). Thus, for the binary number 011. The D/A converter provides a wavetrain having a duty cycle corresponding to the binary number, i.e., a duty cycle of D=3/8. The wavetrain is applied to the input of a low pass filter which derives an average value. The average value of the wavetrain is equal to the product of its amplitude, the reference voltage (V r ), and its duty cycle (D), in this case 3/8.
The low-pass filter can be, for example, a single-pole RC circuit. The problem with such a filter is that the time constant of the filter must be long relative to the wavetrain period (T) in order to reduce the output ripple to a value smaller than one least significant bit, lsb, i.e., a number equal to 1/2 n , where n is the number of bits comprising the binary number. This requirement seriously limits the speed of response of the D/A converter. Furthermore, a D/A converter for larger binary numbers requires filter components having correspondingly larger values. As a result, the necessary filter components are too large in size for integrated circuit designs. For example, when the time constant of the filter is longer than the wavetrain period (T), the wave shape of the output will be triangular, rising during the high pulse time and falling during the low pulse time. The rising portion of the ripple, R, is defined as follows:
Equation 1: R=(V.sub.r -V.sub.0) (PW/τ)
where:
V.sub.r =reference voltage
V.sub.0 =output voltage
PW=pulse width of the waveform
τ=time constant of the filter
Since V 0 =(V r ) (D) and PW=(T) (D), the ripple percentage, R% (=R/V r ), becomes:
Equation 2: R%=(1-D) (D)(T)/τ
Since the function (1-D) (D) has a maximum value of 0.25 when D is equal to 0.5 (i.e., a 50% duty cycle), the maximum ripple percentage, R% max, is equal to 0.25(T)/τ. As mentioned above, R% max must be less than one lsb or 1/2 n . Substituting this value for R% max, the time constant of the filter can be defined as follows:
Equation 3: τ=0.25(T)2.sup.n
Assuming that the frequency, f, is equal to 2 MHz, the filter's time constant for a 3-bit digital number would be equal to 3 ms, which is an acceptable design value. However, the filter's time constant for a 14-bit word would be greater than 33 seconds, which is not acceptable.
Accordingly, there is a need for a D/A converter using duty cycle modulation and, more specifically, one that is capable of converting a large binary number to an analog signal while still using reasonably sized filter components that can be used in conjunction with the design of integrated circuits.
SUMMARY OF THE INVENTION
The present invention meets these needs by providing a circuit and method for converting a binary number having a plurality of bits, D 0 to D n , to a signal having aproportionally equivalent characteristic.
The circuit comprises a parallel input for receiving each bit, D 0 to D n , of the binary number and means for generating wavetrains, W 0 to W n , having frequencies decreasing by powers of two from the least significant wavetrain, W 0 , to the most significant wavetrain, W n . Each wavetrain comprises pulses having a pulse width equal to the inverse of twice the frequency of the least significant wavetrain, W 0 , so that the duty cycle of each of the wavetrains is proportional to the corresponding frequency thereof. The pulses of each of the wavetrains are nonoverlapping with the pulses of the other wavetrains. The circuit also codmprises logic means, connected to the input and the generating means, for logically multiplying each wavetrain taken in an order from the least significant to the most significant, W 0 to W n , by a corresponding bit of the binary number taken in a reverse order from the most significant to the least significant, D n to D 0 , and logically summing all of the products of each, the sum thereof being a composite waveform. The circuit also comprises output means, connected to the logic means, for receiving the composite waveform. Thus, the composite waveform has a duty cycle proportionally equivalent to the binary number.
The output means may further comprises means for smoothing the composite waveform to provide an analog signal equivalent to the duty cycle of the composite waveform, whereby the analog signal is proportionally equivalent to the binary number. The output means may further comprise referencing means for referencing the composite waveform by setting a logic one level of the composite waveform to a precise reference voltage and a logic zero level of the composite waveform to a ground level, whereby the referencing means provides the composite waveform to the smoothing means.
The method comprises the steps of receiving each bit, D 0 to D n , of the binary number and providing downcounting signals, N 0 to N n , each comprising a series of pulses where in the frequencies decrease by powers of two from the least significant downcounting signal, N 0 , to the most significant downcounting signal, N n . The method further comprises the step of inverting each downcounting signal, N 0 to N n , and logically multiplying each inverted downcounting signal by all of the corresponding less significant downcounting signals, the products thereof forming wavetrains, W 0 to W n , each wavetrain having pulses of the same width and not overlapping with the pulses of the other wavetrains and having frequencies decreasing by powers of two from the least significant wavetrain, W 0 , to the most significant wavetrain, W n . The method further comprises the step of logically multipling each wavetrain taken in an order from the least significant to the most signicant, W 0 to W n , by a corresponding bit of the binary number taken in a reverse order from the most significant to the least significant, D n to D 0 , and logically summing all the products of each, the sum thereof being a composite waveform. The composite waveform consists of each wavetrain enabled by the corresponding bit thereof and having a peak amplitude equal to that of the pulses of the wavetrains and a duty cycle proportionally equivalent to the binary number.
The method may further comprise the step of smoothing the composite waveform to provide an analog signal being proportionally equivalent to the binary number and equal to the product of the amplitude and the duty cycle of the composite waveform.
Accordingly, it is an object of the present invention to provide a circuit and method for converting a binary number having any number of bits to a signal having a proportionally equivalent characteristic; to provide a D/A converter and method for D/A conversion using such circuit; to provide an analog signal having a proportionally equivalent voltage or current; and to provide such a D/A converter and a method for D/A conversion that is capable of converting a large binary number to an analog signal while still using reasonably sized filter components that can be used in conjunction with the design of integrated circuits.
Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an electrical schematic of the D/A converter which comprises a wavetrain generator and a sum of the products (SP) circuit constructed in accordance with the invention.
FIG. 2 is an electrical schematic of the wavetrain generator shown as a block diagram in FIG. 1.
FIG. 3 is an electrical schematic of the SP circuit shown as a block in FIG. 1.
FIG. 4 is a series of time graphs illustrating the relative timing sequence of signals existing within the wavetrain generator and the SP circuit of FIG. 1 to generate a composite waveform signal (CW) in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a D/A converter is indicated generally at 10 for converting a binary number at its input along a parallel bus 12 to an analog signal at its output along a wire 14 having an output voltage, V 0 , proportionally equivalent to the binary number. The D/A converter 10 further comprises a latch 16 having parallel inputs connected to the parallel bus 12 for receiving the binary number and a load terminal LD connected to a data clock. When the data clock causes the load terminal LD to go high, the latch 16 transmits the binary number to its parallel outputs connected to the parallel data bus 18. Each binary data signal or bit, D.sub. to D 13 of the binary number is held at the output of the latch 16 when the load terminal LD goes low.
The D/A converter 10 further comprises a wavetrain generator 20 which consists of a down counter 22, providing 14 downcounting signals, N 0 to N 13 , along a parallel bus 24 and a decoder 26 providing 14 wavetrains, W 0 to W 13 , along a parallel bus 28. The D/A converter 10 further comprises a sum of products, SP, circuit 30 which is connected to the parallel buses 18, 28 for receiving the binary data signals, D 0 to D 13 , and the wavetrains, W 0 to W 13 , and for providing a composite waveform, CW, at its output along a wire 32. The down counter 22 provides a timing signal, TS, at its output along a wire 34. The D/A converter 10 further comprises a D-type flip flop 36, a precision reference voltage source 38 and a low-pass filter 40. The D-terminal of the flip flop 36 is connected to the wire 32 for receiving the composite waveform (CW) and the toggle terminal of the flip flop 36 is connected to the wire 34 for receiving the timing signal (TS). The Q-output of the flip flop 36 is connected by a wire 42 to the precision reference voltage source 38 having an output connected via a wire 44 to the low-pass filter 40. The output of the low pass flter 40 provides the analog signal along the wire 14.
Referring to FIG. 2, the wavetrain generator 20 comprises the downcounter 22 and the decoder 26 as described above. The downcounter 22 has fourteen output terminals, 0 to 13, which provide the downcounting signals, N 0 to N 13 , to the decoder 26 and are connected to the decoder 26 as follows. Output terminal O is connected to the input of an inverter 50 and the first inputs of three NAND gates 51, 52, 53, the outputs of which are connected respectively to the first inputs of four NOR gates 54, 55, 56, 57. The output of the inverter 50 provides the wavetrain W 0 and the outputs of the NOR gates 54, 55, 56, 57 respectively provide the four wavetrains W 1 to W 4 . Output terminal 1 of the downcounter 22 is connected to the second inputs of the NOR gate 54 and the NAND gates 51, 52, 53; output terminal 2 is connected to the second inputs of the NOR gate 55 and third inputs of the NAND gates 52, 53; and, output terminal 3 is connected to the second input of the NOR gate 56 and a fourth input of the NAND gate 53. The output of the NAND gate 53 is also connected to the first input of an OR gate 58.
Output terminal 4 of the downcounter 22 is connected to the input of an inverter 60 and the first inputs of three NAND gates 61, 62, 63, the outputs of which are connected respectively to the first inputs of four NOR gates 64, 65, 66, 67. Output terminal 4 is also connected to the second input of the NOR gate 57. The outputs of the NOR gates 64, 65, 66, 67 respectively provide the four wavetrains, W 5 to W 8 . Output terminal 5 of the downcounter 22 is connected to the second input of the NOR gate 64 and the NAND gates 61, 62, 63; output terminal 6 is connected to the second input of the NOR gate 65 and third inputs of the NAND gates 62, 63; and, output terminal 7 is connected to the second input of the NOR gate 66 and a fourth input of the NAND gate 63.
Output terminal 8 of the downcounter 22 is connected to the input of an inverter 70 and the first inputs of three NAND gates 71, 72, 73, the outputs of which are connected respectively to the first inputs of four NOR gates 74, 75, 76, 77. Output terminal 8 is also connected to the second input of the NOR gate 67. The outputs of the NOR gates 74, 75, 76, 77 respectively provide the four wavetrains, W 9 to W 12 . Output terminal 9 of the downcounter 22 is connected to the second input of the NOR gate 74 and the NAND gates 71, 72, 73; output terminal 10 is connected to the second input of the NOR gate 75 and third inputs of the NAND gates 72, 73; and, output terminal 11 is connected to the second input of the NOR gate 76 and a fourth input of the NAND gate 73.
Output terminal 12 is connected to the second input of the NOR gate 77 and the input of an inverter 78, the output of which is connected to the first input of a NOR gate 79. Finally, output terminal 13 of the downcounter 22 is connected to the second input of the NOR gate 79, the output of which provides the wavetrain W 13 . The output of the NAND gate 53 is also connected to third inputs of the NOR gates 64, 65, 66, 67, 74, 75, 76, 77. The output of the NAND gate 63 is also connected to fourth inputs of the NOR gates 74, 75, 76, 77 and the second input of the OR gate 58 having a third input connected to the output of the NAND gate 73. The output of the OR gate 58 is connected to a third input of the NOR gate 79.
Essentially, the decoder 26 derives each wavetrain, W 0 to W n , by logically multiplying each of the corresponding negagated downcounting signals, N 0 to N 13 , from the counter 22 and all of the lower order output signals from the counter 22. Thus, each wavetrain is defined by the following logic formulas: ##EQU1##
Referring also to FIG. 4, the wavetrain clock signal, the first four least significant downcounting signals, N 0 to N 3 , and the first four least significant wavetrains, W 0 to W 3 , are shown in the time domain over a period from t 0 to t 16 as an example. All of the following discussion applies equally to all the higher order wavetrains from W 4 to W 13 to W n . The corresponding truth table for this logic circuit is as follows (certain logic zero being indicated by a blank space for illustration):
TABLE A______________________________________Time N.sub.3 N.sub.2 N.sub.1 N.sub.0 W.sub.3 W.sub.2 W.sub.1 W.sub.0______________________________________t.sub.150 0 0 0 1t.sub.140 0 0 1 1 0t.sub.130 0 1 0 1t.sub.120 0 1 1 1 0 0t.sub.110 1 0 0 1t.sub.100 1 0 1 1 0t.sub.90 1 1 0 1t.sub.80 1 1 1 1-- 0-- 0-- 0t.sub.71 0 0 0 1t.sub.61 0 0 1 1-- 0t.sub.51 0 1 0 1t.sub.41 0 1 1 1-- 0-- 0t.sub.31 1 0 0 1t.sub.21 1 0 1 1-- 0t.sub.11 1 1 0 1t.sub.01 1 1 1 0______________________________________
As can be seen in FIG. 4, the frequencies of the wavetrains, W 0 to W 3 , decrease by powers of 2 from the least significant wavetrain, W 0 , to the most significant wavetrain, W 3 . Assuming that the frequency of the wavetrain clock is equal to 2 MHz, the frequencies of the wavetrains, W 0 to W 3 , would be respectively 1.0, 0.5, 0.25 and 0.125 MHz; the frequency for the most significant wavetrain W 13 would be equal to about 122 Hz. Additionally, the pulse-width (PW) of each wavetrain is equal to the inverse of twice the frequency of the least significant wavetrain, W 0 . This results because each wavetrain is derived by ANDing the corresponding negated output signal from the counter 22 and with all of the lower order output signals. This is illustrated by the shading in FIG. 4 for the wavetrain W 3 at time t 8 and by the corresponding dashed lines at time t 8 in the truth table, Table A.
Assuming again that the wavetrain clock frequency is equal to 2 MHz, the pulse width (PW) for the pulses of all the wavetrains, W 0 to W n , is equal to 500 nanoseconds. Since the wavetrains comprise pulses having the same width, the duty cycle (D) of each wavetrain is proportional to its frequency. Therefore, the duty cycle (D) of the wavetrains, W 0 to W 3 , would be respectively 1/2, 1/4, 1/8and 1/16; the duty cycle (D) for the most significant wavetrain (W 13 ) would be equal to 1/16384, i.e. 1/2 n , where n=14.
The wavetrains are also nonoverlapping, i.e., the pulses of one wavetrain do not overlap the pulses of any other wavetrain in time as shown by the shading in FIG. 4 for the wavetrains, W 1 and W 2 , at times t 2 , t 4 and t 6 and by the corresponding dahsed lines at the same times in the truth table, Table A. The wavetrains are nonoverlapping because a downcounter causes only one bit to go to 0 at a time as shown in the truth table, Table A. The nonoverlapping feature is important because any combination of the wavetrains can be logically ORed to produce an equivalent composite duty cycle for the binary number being converted.
Referring to FIG. 3, the wavetrains, W 0 to W 13 , are provided to the SP circuit 30 by the parallel bus 28 which provides each wavetrain via a separate wire to the first inputs, respectively, of fourteen NAND gates 100 to 113. The binary bits, D 13 to D 0 , of the binary number are also provided to SP circuit by the parallel bus 18 which provides each bit via a separate wire to the second inputs, respectively, of the NAND gates 100 to 113. The outputs of the NAND gates 100 to 103 are connected to the inputs of an AND gate 121; the outputs of the NAND gates 104 to 107 are connected to the inputs of an AND gate 122, the outputs of the NAND gates 108 to 111 are connected to the inputs of an AND gate 123; and, the outputs of the NAND gates 112 and 113 are connected to the inputs of an AND gate 124. The outputs of the AND gates 121 to 124 are connected to the inputs of an AND gate 125, the output of which provides the composite waveform signal (CW) on the wire 32 which has a duty cycle (D) proportional to the binary number.
Essentially, the SP circuit 30 is a sum-of-products circuit. When viewing the operation of the gates 100 to 113 as AND gates, they form the logical products, W 0 D 13 to W 13 D 0 . Associating the inversion of the NAND gates, 100 to 113, with the inputs of the AND gates, 121 to 124, transforms them into NOR gates which function as OR gates when their inverted outputs are applied to the AND gate 125. Thus, the products, W 0 D 13 to W 13 D 0 , are logically ORed or summed by gates 121 to 125 to form the logical expression for the composite waveform (CW) as follows:
CW=W.sub.0 D.sub.13 +W.sub.1 D.sub.12 + . . . +W.sub.13 D.sub.0
Each wavetrain, W 0 to W 13 , is ANDed with the corresponding binary bit, D 13 to D 0 , and the resulting products are ORed together.
The wavetrains to be included in the composite waveform (CW) are selected by the corresponding binary bits, i.e., a positive pulse enables the transmission of the corresponding wavetrain. The enabled wavetrains are logically summed to form the composite waveform (CW) which has a duty cycle (D) proportional to the binary word. For example, if the D/A converter 10 is designed to convert a three-bit binary number, the composite waveform (CW) is defined as follows:
CW=W.sub.0 D.sub.2 +W.sub.1 D.sub.1 +W.sub.2 D.sub.0
Referring to this logical equation and the wavetrains W 0 , W 1 and W 2 in FIG. 4, the duty cycle (D) corresponding to each binary number can be determined as shown in the following truth table:
TABLE B______________________________________W = W.sub.0 W.sub.1 W.sub.2D = D.sub.2 D.sub.1 D.sub.0 CW D______________________________________0 0 1 W.sub.2 1/80 1 0 W.sub.1 2/80 1 1 W.sub.1 + W.sub.2 3/81 0 0 W.sub.0 4/81 0 1 W.sub.0 + W.sub.2 5/81 1 0 W.sub.0 + W.sub.1 6/81 1 1 W.sub.0 + W.sub.1 + W.sub.2 7/8______________________________________
As can be seen in both Table B and FIG. 4, the duty cycle (D) increases in direct proportion to the binary number being converted because the wavetrain having the highest frequency W 0 , is selected if the most significant bit, D 2 , is set, the wavetrain having the second highest frequency, W 1 , is selected if the second most significant bit, D 1 , is set, and the wavetrain having the third highest frequency, W 2 , is selected if the third most significant bit, D 0 , is set. The same explanation applies to a D/A converter for converting a 14-bit word where the duty cycle (D) of the composite waveform (CW) will vary by increments of 1/16,384 (1/2 n ).
The composite wave form (CW) is then clocked by the timing signal (TS), in this case 2 MHz, through the flip flop 36 to synchronize precisely the edges to the wavetrain clock, thus eliminating the effects of varying propagation delays. The output from the flip flop 36 is provided via the wire 42 to the precision reference voltage source 38 which comprises a discrete CMOS transistor package including an NMOS FET and a PMOS FET. A positive reference voltage, V r , is applied to the drain terminal of the PMOS FET and the source of the NMOS FET is grounded. The wire 42 is connected to the gate terminals of both FETS. The source terminal of the PMOS FET and the drain terminal of the NMOS FET are connected and provide an output signal via the wire 44 to the low-pass filter 40. The CMOS transistor package insures that the logic one and zero levels are accurately set to the reference voltage (V r ) and to the analog ground level. The low-pass filter 40 is a single-pole RC filter comprising a resistor 39 having one end connected to the wire 44 and a capacitor 41 connected between the other end of the resistor 39 and ground. the low-pass filter 40 integrates the composite waveform output signal provided via the wire 44 to obtain the average DC value which is the analog output signal provided via the wire 14 across the capacitor 41. The analog signal is equal to the product of the reference voltage (V r ) and the duty cycle (D) of the composite waveform (CS), and is therefore proportional to the binary number being converted.
The D/A converter 10 just described drastically reduces the requirement of earlier devices for filters having time constants that were too large for practical design in order to insure that the ripple percentage (R%) is less than one least significant bit. The ripple at the output of the filter 40 is determined by adding the individual ripple due to each wavetrain comprising the composite waveform (CW). Therefore, Equation 2 must be solved for each composite wavetrain.
As previously defined, the time period (T) is equal to 2 n wavetrain clock cycles. For the D/A converter 10, it is also the time period of the wavetrain, W 13 , having the lowest frequency that is associated with the least significant bit, D 0 , of the binary number. Therefore, the period, T n , of all the other wavetrains, W 0 to W 12 , is equal to T/2 where b is the bit number ranging from 0 to the number, n-1 or 12, for the most significant bit. The duty cycle, D n , also varies for each component wavetrain and is equal to 2 b /2 n . When T n and D n are substituted into Equation 2, the ripple percentage is defined as follows:
Equation 4: R%=(1-2.sup.b /2.sup.n) (1/2.sup.n) (T/τ)
For the most significant bit, D 13 , the duty cycle of the corresponding wavetrain, W 0 , is 0.5, which makes the ripple percentage (R%) half that of the lower significant bits, D 0 to D 12 (2 b /2 n approaches 0.5). The maximum ripple percentage (R% max) is for the least significant bit, D 0 , where the duty cycle is nearly 1.0 (2 b /2 n approaches 0). Therefore, if all the composite wavetrain components, W 0 to W 13 , are selected and were in phase, the maximum ripple percentage (R% max) is equal to n times the ripple percentage of the least significant bit or n(1/2 n ) (T/τ). Hence, if the ripple percentage is to be less than one least significant bit, 1/2 n , and substituting into the immediately preceding equation, then the time constant for the RC filter 40 is defined as:
Equation 5: τ=2T=2(2.sup.n /f)=2.sup.n+1 /f
Thus, for a 14-bit D/A converter having a wavetrain clock operating at 2 MHz, the time constant must be no smaller than 16 ms which is substantially smaller than the 33 seconds required by previous D/A converters. In the specific embodiment of the present invention, the resistor 39 has a value of 200 K ohms and the capacitor 41 has a value of 0.01 microfarads which provides a time constant of 20 ms that satisfies the above requirement. Filter components having these values are much less expensive and very much smaller than what would be required for previous D/A converters.
Having described the invention in detail and by reference to preferred embodiments thereof, it will be apparent that other modifications and variations are possible without departing from the scope of the invention defined in the appended claims.
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A circuit and method for converting a binary number having a plurarity of bits, D o to D n , to a signal having a proportionally equivalent characteristic. The circuit comprises a parallel input for receiving each bit, D o to D n , of the binary number and means for generating a plurarity of wavetrains, W o to W n , having frequencies decreasing by powers of two from the least significant wavetrain, W o , to the most significant wavetrain, W n . Each wavetrain comprises pulses having a pulse width equal to the inverse of twice the frequence of the least significant wavetrain, W o , so that the duty cycle of each of the wavetrains is proportional to the corresponding frequency thereof. The pulses of each of the wavetrains are not overlapping with the pulses of the other wavetrains. The circuit also comprises logic means, connected to the input and the generating means, for logically multiplying each wavetrain taken in an order from the least significant to the most significant, W o to W n , by a corresponding bit of the binary number taken in reverse order from the most significant to the least significant, D n to D o , and logically summing all of the products of each, the sum thereof being a composite waveform. Thus, the composite waveform has a duty cycle proportionally equivalent to the binary number.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a nonprovisional application claiming priority from U.S. Provisional Patent Application No. 60/824,759, filed on Sep. 6, 2006, the contents of which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] The field of the invention generally relates to an improved tubal cannulator for cannulating the fallopian tubes and facilitating tubal reconnection after, for example, tubal ligation.
BACKGROUND
[0003] Referring to FIGS. 1 and 2 , the female reproductive system includes the fallopian tubes 100 , the uterus 105 , the uterine corneal 107 , the ovary 110 , the cervix 115 and the vagina 120 . The fallopian tube 100 is a narrow muscular organ connecting the uterus 105 to the ovary 110 . The inner tubal lining of the fallopian tube 100 is rich in cilia, microscopic hair-like projections that beat in waves and move the egg to the uterus. The fallopian tube is about 10 cm (4 inches) in length and is made up of several segments. The interstitial segment 125 arises from the uterus 105 at the tubal ostium 127 and passes through the uterine muscle to the isthmic segment 130 . The isthmic segment 130 is a narrow muscular segment by the uterus 105 that is between the interstitial segment 125 and the ampullary segment 135 . The ampullary segment 135 is a wider middle segment that is between the isthmic segment 130 and the infundibular segment 140 . The infundibular segment 140 is a funnel shaped segment near the ovary. Extending from the infundibular segment 140 , the fimbrial segment 145 has a ciliary lining that faces the ovary.
[0004] There are a number of different medical conditions that can result in damage to the fallopian tubes. These conditions include tubal blockage and tubal scarring. Physicians treat medical conditions of the fallopian tubes using a number of procedures. For example, in patients with fallopian tubes occluded near the origin (i.e., a proximal occlusion) and resulting infertility, physicians cannulate the fallopian tubes. Physicians also facilitate tubal reconnection due to complete obstruction of the tubal lumen after tubal ligation or pathologic process. These interventions occur when the patients seek reversal of sterilization and/or treatment of “tubal factor infertility.”
[0005] Tubal obstructions are divided into those that are a result of mucous plugs and those with true obstructions that are secondary to scar tissue and have total obliteration of the tubal lumen. The first type of tubal obstruction can be overcome by pushing or flushing the tubal plug, or by advancing a stent and dislodging the plug. The second type of tubal obstruction typically necessitates surgery to resect the occluded portion and reconnect the tube by microsurgery.
[0006] Currently, tubal cannulation is typically performed by either hysteroscopy or fluoroscopy. With hysteroscopy, a telescope is introduced into the uterine cavity under local or general anesthesia. With fluoroscopy, a stent is guided into the tube under radiographic control. Of the two types of procedures, hysteroscopy is a more involved procedure both because the patients generally require some kind of sedation as well as the need to distend the uterus with gas or fluid in order to visualize the tubal ostium. This degree of involvement makes the procedure more expensive and subject to a greater potential for complications such as fluid overload, pulmonary edema, and potentially fatal embolism.
[0007] Physicians prefer the fluoroscopic procedure because the procedure is easier to perform and does not require anesthesia or uterine distension, therefore reducing the potential for complications as well having a lower cost. The cannulators presently available are rigid instruments with a predetermined curvature that is intended to accommodate the majority of tubal ostium locations within the uterus. The inventors, however, have determined that this “one size fits all” approach is unsuitable for all patients and a need exists for a more accommodating instrument.
[0008] Others have developed various instruments for accessing the uterine cavity for various medical purposes. U.S. Pat. No. 4,585,438 discloses a semi-rigid tubular member for injecting material, such as sperm, into the uterine cavity. The tubular member is characterized as being semi-rigid and flexible enough to bend with the natural curvature of the uterus while yet being rigid enough to maintain its shape.
[0009] U.S. Pat. No. 5,195,964 discloses a catheterization cannula for sealing the uterine cavity to allow injection of a radiopaque dye in the cavity. The catheter shaft portion is characterized as being flexible. The catheter shaft portion has an inner tuber 58 and an outer tube 60 described in reference to FIG. 3a as being made from a flexible material such as nylon. The purpose of the outer tube is to increase the rigidity of the cannula while still allowing some flexibility.
[0010] U.S. Pat. No. 6,007,478 is directed to tubes used with blood pumps, for example, during cardiovascular surgeries. The specification describes the tubes as having different degrees of flexibility along the length of the tube. This varying flexibility is achieved by using sections of tube joined in butt joints rather than step joints. The sections of tube are made using layers of plaster with different degrees of flexibility. By varying the thickness of the layer of one plastic versus another, the flexibility can be varied. The tubes may include spiral springs to prevent the collapse of the tube in use and radial deformation. The spring material may be subject to significant deformation but still regain its shape.
[0011] U.S. Pat. No. 6,491,645 is directed to a uterine tissue collector. The device is disclosed as being in the form of a cannula with a distal portion. The distal portion can be flexed or bent in different directions by using guide wires attached to a handle at a proximal end of the device. The cannula is characterized as preferably being formed from a flexible material and optionally including a portion with a low bending moment to allow for easy flexing of the distal portion. This may be accomplished by using notches in the wall of the cannula. The flexing or bending of the distal portion does not appear to be permanent but instead is subject to continued force applied by the guide wires.
[0012] US Patent Publication No. 2004/0054322 is directed to a shape-transferring cannula that includes two parallel rigidizing sections that alternatingly stiffen and relax with respect to one another and alternatingly transfer the path shape traced-out by the articulating tip to one another. A steerable articulated tip is attached to one of the rigidizing sections. The cannula's custom shape is formed by guiding the articulated tip along a desired path direction, stiffening the attached rigidizing section, and advancing the other rigidizing section along the stiffened section. The cannula, however, does not appear to be malleable and have its shape permanently altered.
SUMMARY
[0013] In one general aspect, a cannulator has an adjustable shape for conforming to an anatomy to reach the tubal ostium of a patient. The cannulator includes a body segment, a tip section, and a handle. The body segment is made of a malleable material having a malleable characteristic with a degree of resistance to lateral deflection until sufficient force is applied to cause permanent bending thereby imparting a shape to the body segment. The tip section is positioned at a distal end of the body segment and the handle is positioned at a proximal end of the body segment.
[0014] Embodiments of the cannulator may include one or more of the following features. For example, the handle may be made of a plastic. The handle may include a visual reference to indicate an orientation of the tip section. The handle may include a circular shaft and the visual reference may include a first reference on the circular shaft and a second reference on the circular shaft, the positions of the first reference and the second reference defining the diameter of the circular shaft. The visual reference may include text that includes right and left directions. The handle may include two or more ports. The ports may be used for one or more of injecting a fluid, inserting a medical device, and withdrawing a fluid.
[0015] The body segment may include a wall defining a lumen within the body segment, the lumen passing between the handle and the tip section. The lumen may have an inner diameter of between 4 F and 6 F. The malleable material may be one or both of a malleable metal material and a malleable plastic material. The malleable metal material may be one or more of aluminum and stainless steel.
[0016] The tip section may have a smooth and rounded end. The tip section may include a cone that tapers from a proximal end to a distal end. The tip section may be a rounded plastic piece.
[0017] The body segment and/or the tip section may be coated with a coating.
[0018] In another general aspect there is provided a method of cannulating a fallopian tube. The method includes providing a tubal cannulator, adjusting a shape of the tubal cannulator and inserting the tubal cannulator into the uterine cavity and guiding the tip section to the tubal ostium. The tubal cannulator includes a body segment, a tip section, and a handle. The body segment is made of a malleable material having a malleable characteristic with a degree of resistance to lateral deflection until sufficient force is applied to cause permanent bending thereby imparting a shape to the body segment. The tip section is positioned at a distal end of the body segment and the handle is positioned at a proximal end of the body segment.
[0019] Embodiments of the method may include one or more of the following features or those described above. For example, the method may further include advancing a medical device through a lumen of the cannulator into the proximal tubal lumen. The method may further include removing the cannulator, modifying the shape of the cannulator, and reinserting the tubular cannulator. The malleable material may be one or both of a malleable metal material and a malleable plastic material. The malleable metal material may be one or more of aluminum and stainless steel.
[0020] In the method, adjusting a shape of the cannulator may include adjusting the shape of the body segment and/or the tip section.
[0021] The cannulator advantageously can be used under either laparoscopic or fluoroscopic control. It can eliminate the need for hysteroscopy to selectively cannulate each fallopian tube. This reduces operating time, the need for uterine distention, expensive monitoring/video equipment, and the possibility of major complications, such as fluid overload, pulmonary edema, and death. The cannulator also may permit most anastomoses to be performed laparoscopically rather than through a significantly more invasive laparotomy. In addition, while malleable, the cannulator nonetheless has enough strength to allow it to be advanced against the cervix adjacent to the tubal ostium, thus permitting easier visualization of that region during laparoscopy.
[0022] The details of various embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the description, drawings, and claims.
DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a plan view of the female reproductive system.
[0024] FIG. 2 is a close up plan view of a fallopian tube.
[0025] FIG. 3 is a perspective view of a first implementation of a malleable cannulator.
[0026] FIG. 4 is a perspective view of a second implementation of a malleable cannulator.
DETAILED DESCRIPTION
[0027] The inventors have determined that the current cannulators used in fallopian tube cannulation do not permit universal fallopian tube cannulation because the cannulators are constructed from overly rigid plastics. To address this limitation, the inventors have developed a radiopaque malleable cannulator. The cannulator is constructed with a malleable material that allows the operator to adjust the cannulator's curvature in the procedure room to best fit the instrument to the patient's anatomy. Advantageously, the malleable material may be metal, plastic and or a composite of the two that is visible under x-ray (i.e., radiopaque) so that it can be utilized not only during surgery but also during fluoroscopic (i.e., x-ray) procedures as well. As used herein, the term malleable means the physical property of a material that allows the material to be deformed without cracking or at least without destructive cracking that causes the cannulator to be unusable for the intended purpose.
[0028] Referring to FIG. 3 , a cannulator 200 includes a handle 205 , a body segment 210 , and a tip section 215 . The body segment 210 is connected at a proximal end to the handle 205 and at a distal end to the tip section 215 . The cannulator 200 has a lumen 220 that passes between a proximal opening 225 in the handle and a distal opening 230 in the tip section. The handle 205 includes a funnel luer lock 235 at the proximal end and a side injection luer lock 240 includes a lumen 245 that connects to the lumen 220 . The handle 205 also includes an indicator 250 . The indicator 250 can be, for example, a letter indicating the orientation of the handle 205 relative to the tip section 215 . Specifically, the indicator on the handle can be for the orientation of the tip with respect to the patient. Thus, an indicator of “RIGHT” on the handle would be for a tip section oriented to the left with respect to the handle but oriented to the right with respect to the patient.
[0029] In some embodiments, the tip section 215 has a length, A, of between approximately 30 to 50 mm and, more particularly, approximately 40 mm. The tip section may have a radius, r, of between approximately 20 and 60 degrees, and more particularly, approximately 30 degrees. It should be noted that the radius of the tip section may be adjusted during use of the cannulator 200 to better fit an individual's anatomy. It is expect that most patients' anatomy will match a radius of approximately 30 degrees, the vast majority of patients' anatomy will match a radius of approximately 20 degrees to 60 degrees, and essentially all patients' anatomy will be matched with the ability to adjust the cannulator's curvature. It also should be noted that the tip section refers to the distal end of the cannulator and may not be a separate piece from the body segment. Thus, references to a tip section should be understood to have a meaning that includes a separate tip attached to the body segment, a region of the distal end of the cannulator and a section of the cannulator that extends from the body segment.
[0030] The body segment 210 has a length, B, of between approximately 120 mm and 160 mm and, more particularly, approximately 140 mm. The body segment 210 can have its shape adjusted as well. The handle 205 can have a length, C, of between approximately 50 mm and 70 mm and, more particularly, approximately 60 mm.
[0031] The lumen 220 has an inner diameter that is approximately 4-9 French (F) or approximately 1.5 mm to 3 mm inner diameter (where 1 F is equivalent to 0.33 mm). More particularly, the lumen 220 may have an approximately 5-6 F inner diameter. The outer diameter of the body segment 210 may be approximately three to five mm and the outer diameter of the tip 215 may be tapered and have an outer diameter of approximately three to five mm or smaller. The funnel luer lock 235 may have an inner diameter of approximately 2.5 mm and an outer diameter of approximately 3 mm. It should be noted that the dimensions for diameters of the luer lock are exemplary and other dimensions for the luer lock may be used.
[0032] The tip section 215 is configured to be atraumatic with a rounded, blunt or cone-shaped end that fits easily within the uterine corneal. The tip section can be formed by shaping the distal end of the body segment or by attaching a preformed tip to the body segment. For example, the tip section 215 can be made of an injection molded plastic that either is injection molded onto the cannulator, screwed onto the cannulator, or otherwise affixed to the cannulator. Alternatively, the tip section 215 can be integral with the cannulator and coated to make the tip section less traumatic.
[0033] The handle is configured to be easily gripped by the physician and optionally marked on opposite sides with an indicator 250 that may be a letter R or L, or the like. As noted above, the indicator 250 is used to indicate the orientation of the handle 205 relative to the tip section 215 with respect to the patient's anatomy. Such indicators are designed to be reference points to the physician using the cannulator. For example, if the physician has the tip section bent to the right while the handle side marked with an L is facing the physician, the physician can be aware during the procedure of the orientation of the tip relative to the handle by merely looking at the handle. Thus, if the cannulator is inserted into the patient and the handle side marked L is facing the physician, if the physician has followed the convention described above, the physician will know that the tip section is bent to the right relative to the handle and is therefore oriented to the patient's left.
[0034] The handle can be made of, for example, any biocompatible plastic. In particular, the plastic can be one that is easily injection molded, such as polyethylene and polypropylene, and injection molded onto the proximal end of body segment, screwed onto the proximal end of the body segment, or affixed to the proximal end of the body segment.
[0035] The body segment 210 and/or tip section 215 are made of any biocompatible, malleable metal, plastic or composite of the two. Examples of malleable metals include but are not limited to aluminum, stainless steel, silver, gold, silver-coated copper, and other alloys and composites. An example of a malleable composite is an extruded plastic tube in which part of the wall, either within the plastic or external to the plastic, includes a malleable metal portion. For example, a mesh of a malleable aluminum wire can be formed within the plastic wall using common extrusion techniques. The cannulator then can be bent and its bent shape retained during the procedure. The malleability of the body segment and/or tip section should be such that they can be bent by the physician yet not bend during insertion and advancement in the patient. The body segment 210 and tip section 215 may be made by one of several fabrication methods. For example, the body segment and tip section may be extruded separately and then attached or extruded as a single piece with the body segment integral with the tip section. To assemble the device, the body segment and/or tip section can be coated and then attached to a molded handle. Alternatively, the body segment and/or tip section may be coated after assembly. The tip section should be blunt and/or have extra coating or blunt tip attachment to be atraumatic.
[0036] The cannulator 200 may used by a physician in a variety of medical procedures, and, in particular, in the types of procedures described above, namely, tubal obstructions caused by mucous plugs and tubal obstructions classified as true obstructions. In either type of procedure, the cannulator first is shaped to provide a radius of curvature that the physician determines to be a suitable starting point. The cannulator may shaped at either or both of the tip section and the body segment. Then the cannulator is introduced into the uterine cavity through the cervix and the tip guided to the tubal ostium. If the curvature of the tip section is not correct, the physician removes the cannulator, modifies the shape of the body segment 210 , reinserts the cannulator, and advances the cannulator to the tubal ostium.
[0037] Once the tip section of the cannulator is successfully advanced to the immediate proximity of the tubal ostium, a medical device, such as a stent or wire guide, is then pushed through the lumen of the cannulator and into the proximal tubal lumen. One example of the stent or wire guide that can be used is the Cook Medical Road Runner PC Wire Guide available from Cook Medical of Bloomington, Ind. The physician then can use the injection luer lock to inject a contrast agent or dye to verify patency or placement, or alternatively or in addition, inject a flushing solution to clear the lumen of debris, and withdraw a fluid or debris. It should be noted that the medical device used may be a stent or wire guide but may also be another type of medical device, such as a balloon, a laser fiber, a fiber optic device, or other device for visualizing the tubal site or opening the tubal site.
[0038] In cases of soft obstructions, referred to above as mucous or tubal plugs, the stent or wire guide dislodges the plug and opens the tube. In the true obstructions, also known as hard obstructions, the stent or wire guide stops at the level of the obstruction and the obstructed segment must be surgically removed, which leaves the tube separated into two segments apart from each other. The physician then advances the stent or wire guide from the first, or proximal, segment of the tube to the other, distal segment. The physician then can use the stent/wire guide as both a guide and a stable platform to visualize the tubal lumen and facilitate the placement of stitches to reconnect the tubal segments by forming an anastomosis of the two severed ends of the fallopian tube. The physician then can use the injection luer lock to flush the tubal segments and/or visualize the patency.
[0039] The cannulator can be used in other applications as well. For example, the cannulator can be used in selective chromotubation to check the tubal patency of each fallopian tube. The cannulator can be used to remove or flush amorphous material, such as tubal mucoid plugs, from the tubal lumen using the injection luer lock. This injection luer lock can be used to inject a contrast agent or dye to assist in visualizing the anatomy of the patient and the patency of the tubal lumen. The injection luer lock also can be used to inject fluids to flush the tubal lumen or assist in opening the lumen. Simultaneously, the funnel luer lock can be used to advance a medical device through the tubal cannulator. Advantageously, the cannulator 200 can be used in place of a number of devices and their various functions by opening the lumen, visualizing the lumen, etc., such that multiple devices do not need to be inserted and withdrawn.
[0040] Referring to FIG. 4 , in a second implementation of a cannulator, a cannulator 300 includes a handle 305 , a body segment 310 , a tip section 315 and a tip attachment 320 . The handle, body segment and tip section are similar to the corresponding components in the cannulator 200 . However, the cannulator 300 differs from the cannulator 200 by the inclusion of a tip attachment 320 attached to the tip section 315 . The tip attachment 320 may be made of a biocompatible plastic that can be molded, screwed, affixed, or otherwise attached to the tip section 315 to cause the distal end of the cannulator 300 to be atraumatic. In this manner, the cannulator 300 does not need to be coated with an atraumatic coating. Nonetheless, one or more of the tip attachment 320 , tip section 315 and body segment 310 may be coated to reduce any trauma with the tissue.
[0041] The cannulators 200 or 300 also can be used with an optional set of shaping mandrils. The shaping mandrils may be rigid metal rods that are configured to fit within the lumen 220 of the cannulator and impart a preset shape to the cannulator. For example, the shaping mandrils may be configured such that a set of, for example, up to three mandrils will provide the curves that will be needed in the vast majority of the procedures. The physician may initially insert the cannulator and determine that the initially selected shape forms too tight of a radius and that a looser radius is needed. By comparing the initially selected shape to the mandrils, the physician can easily make a minor adjustment to the curvature and reinsert the cannulator.
[0042] While several particular forms of the invention have been illustrated and described, it will be apparent that various modifications and combinations of the invention detailed in the text and drawings can be made without departing from the spirit and scope of the invention. For example, references to methods of construction, specific dimensions, shapes, utilities or applications are also not intended to be limiting in any manner and other materials and dimensions could be substituted and remain within the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims.
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The invention relates to a cannulator that has an adjustable shape for conforming to an anatomy to reach the tubal ostium of a patient. The cannulator includes a body segment, a tip section, and a handle. The body segment is made of a malleable material having a malleable characteristic with a degree of resistance to lateral deflection until sufficient force is applied to cause permanent bending thereby imparting a shape to the body segment. The tip section is positioned at a distal end of the body segment and the handle is positioned at a proximal end of the body segment.
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[0001] Priority to U.S. Provisional Patent Application Ser. No. 60/962,734, filed Jul. 31, 2007, is claimed, the entire disclosure of which is hereby incorporated by reference herein.
[0002] The present invention relates generally to hydraulic torque converters, and more particularly to hydraulic torque converters having bridging clutches.
BACKGROUND OF THE INVENTION
[0003] U.S. Pat. No. 7,011,196, hereby incorporated by reference herein, describes a hydraulic torque converter with a bridging clutch.
[0004] In FIG. 1 , a prior art torque converter 10 contains a cover 12 , an impeller 14 , a turbine 16 , and a bridging clutch 18 . Torque converter 10 is driven by an engine connected at hole 20 . Cover 12 has a front cover 22 and a back cover 24 , secured and sealed together, for example welded. Impeller 14 is rigidly attached to back cover 24 . Turbine 16 is rigidly attached to a turbine hub 26 with, for example, rivets 28 . Turbine hub 26 is non-rotatably attached to a shaft 30 with, for example, splines 32 . Shaft 30 may be the input shaft of a transmission, for example.
[0005] Leaf springs have been known to connect the piston of bridging clutch 18 to a separate piece later welded to front cover 22 . Alternately, the piston, which can be in the form of a plate, splines to front cover 22 which can cause a rattle or noise complaint. Another method is to attach the piston to front cover 22 with leaf springs, typically positioned radially outside of friction surfaces.
SUMMARY OF THE INVENTION
[0006] The present invention provides a torque converter comprising a cover; and a bridging clutch for selective connection to the cover, the bridging clutch including a clutch plate fixed to the cover and having an inner radial surface and having a piston having an outer radial surface opposite the inner radial surface.
[0007] The present invention also provides a method for assembling a torque converter comprising: providing a cover, connecting a clutch plate to the cover, the clutch plate having an inner radial surface, and pressing the piston into the inner radial surface.
[0008] The present invention advantageously can simplify the connection of the piston and clutch plate to the cover.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 shows a prior art torque converter.
[0010] One embodiment of the present invention is shown with respect to the drawings in which:
[0011] FIG. 2 shows one embodiment of a torque converter according to the present invention.
DETAILED DESCRIPTION
[0012] FIG. 2 describes a torque converter 110 for connection to a shaft 130 , which may be the input shaft of a transmission for example, according to the present invention. Torque converter 110 has a front cover 122 , a bridging clutch 118 , and a cover flange 162 . An engine, attached to front cover 122 , rotates front cover 122 about center axis CA. Torque from front cover 122 is transmitted in one mode hydraulically using an impeller and turbine to a turbine hub non-rotatably connected to shaft 130 . Cover flange 162 is rigidly attached to front cover 122 and may be supported for example via a bearing on shaft 130 (shown schematically) located within cover flange 162 .
[0013] Bridging clutch 118 includes a piston 134 , a clutch plate 164 , and a friction surface carrier 140 . Cover 122 can have a friction surface 174 , friction surface carrier 140 can have friction surfaces 176 , 178 and clutch plate 164 can have a friction surface 180 . In an assembly step, annular friction surface carrier 140 can be placed against cover 122 , and then the pot-shaped clutch plate 164 can be attached to cover 122 with, for example, leaf springs 173 . Clutch plate 164 can be riveted to cover 122 , for example by rivets 175 through leaf springs 173 . Clutch plate 164 has an axially-extending inner radial surface 170 .
[0014] Piston 134 is an annular piston plate and has a base 144 supported by cover flange 162 and sealed with a seal 166 . An axially-extending outer radial surface 168 of piston 134 is centered within surface 170 of clutch plate 164 . The region between surfaces 168 and 170 is sealed with a seal 172 . Because piston 134 , cover flange 162 , and clutch plate 164 have the same angular velocity, seals 166 , 172 are rotationally static seals. By contrast, because cover flange 162 and shaft 130 do not necessarily have the same angular velocity, cover flange 162 seals to shaft 130 with a dynamic seal.
[0015] Piston 134 and clutch plate 164 can move axially within torque converter 110 according to a controlled pressure difference between regions 148 and 150 . By sealing piston 134 and clutch plate 164 with seal 172 , the area of clutch plate 164 as well as piston 134 becomes the effective area in applying the clutch.
[0016] Bridging clutch 118 can be engaged by introducing a higher pressure in region 150 than in region 148 . This pressure difference moves piston 134 and clutch plate 164 axially towards cover 122 to compress springs 173 and engage friction surfaces 174 , 176 , 178 , 180 . Engagement of friction surfaces 174 , 176 , 178 , 180 engages bridging clutch 118 . When bridging clutch 118 is engaged, torque from the engine is transmitted by torque converter 110 to shaft 130 through a direct mechanical connection. By contrast, when bridging clutch 118 is not engaged, torque from the engine is transmitted by torque converter 110 to shaft 130 through hydraulic fluid using an impeller and a turbine.
[0017] Piston 134 advantageously can be assembled by pressing the piston within the already assembled pot-shaped clutch plate 164 . No further connections in this embodiment are necessary.
[0018] Centering piston 134 between cover flange 162 and clutch plate 164 also avoids problems associated with using splines and welding. Assembly is simplified.
[0019] Rivets 175 are radially positioned between cover flange 162 and axially-extending surface 168 . The radial locations of rivets 175 , an axially-extending outer surface 163 of cover flange 162 , and axially-extending surface 168 are R 1 , R 2 , and R 3 , respectively, in FIG. 2 .
[0020] By positioning rivets 175 at location R 3 radially inside friction surfaces 174 , 176 , 178 , 180 , the radial location R 4 of friction surfaces 174 , 176 , 178 , 180 can be maximized, thus advantageously maximizing friction surface area.
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A torque converter including a cover and a bridging clutch for selective connection to the cover, the bridging clutch including a clutch plate fixed to the cover and having an inner radial surface and having a piston having an outer radial surface opposite the inner radial surface. A method for assembling a torque converter is also provided.
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FIELD OF THE INVENTION
[0001] This application is related to the field of cryptography, and more specifically to a system and device that operates to generate and/or validate digital signatures using a Diffie-Hellman based algorithm.
BACKGROUND
[0002] Digital signature technologies that verify whether or not a file has come from an authorized or trusted source are well known in the art. For example, using a public/private key encryption system, a sender may electronically sign a document by scrambling or encrypting the contents of an associated file using a locally available, and secretly held, private key. The receiving party may, using the sender's public key, decrypt the received file. The ability of the receiving party to properly descramble or decrypt the received file validates that the file was sent by an authorized or trusted sender.
[0003] FIG. 1 illustrates a block diagram 100 of a system for creating a digital signature. As shown, file 110 is provided to a “hashing” algorithm 120 that generates and associates a value with the file. For example, SHA-1 (Secure Hashing Algorithm) can create a 160-bit hash value for any file. It can be further shown that it is computationally infeasible to create two files that have the same hash value. The hashed value is then encrypted or scrambled using, for example, an RSA private encryption key of the sending party, at block 130 . In this case, the encrypted or scrambled hash value is representative of a digital signature. The file and the signature are transmitted over network 150 .
[0004] A receiving party receives the file 160 and the encrypted hash value, i.e., digital signature, decrypts or descrambles the digital signature using the associated RSA public key, at block 180 , and hashes the file, at block 170 , to generate a re-calculated hash value. A comparison is made, at block 190 , to determine whether the decrypted hash value is the same as the calculated hash value.
[0005] While the use of the above-described public/private key system provides a certain measure of security, such a system may be vulnerable to intensive mathematical computational attack. Furthermore, existing digital signature techniques may have somewhat limited usability, as encryption technologies are subject to certain export restrictions. Alternative validation techniques are desired.
SUMMARY
[0006] A method and associated devices for generating and decoding digital signatures to validate the source of received information items is disclosed. The receiving device is operable to determine a first comparator value in relation to a first value associated with an information item received over a network and a Diffie-Hellman public key, determine a second comparator value in relation to a digital signature received, wherein the digital signature is determined in association with a second value associated with the information item prior to transmission over the network, compare the comparator values and validate that the information was sent by the source based on the comparison. The key generating device is operable to generate a first and second Diffie-Hellman public key from a plurality of large numbers randomly selected, wherein at least one of the numbers is a prime number and further determine a public key as a Diffie-Hellman transpose of one of the generated Diffie-Hellman public keys.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 illustrates a block diagram of a process for conventional RSA digital signature processing;
[0008] FIG. 2 illustrates a block diagram of a process for validating a user's identity in accordance with an aspect of the present invention;
[0009] FIG. 3 illustrates a flow chart of an exemplary process for generating a digital signature in accordance with an aspect of the present invention;
[0010] FIG. 4 illustrates a flow chart of an exemplary process for decoding a digital signature in accordance with an aspect of the invention; and
[0011] FIG. 5 illustrates a device for executing the processing shown herein.
[0012] It is to be understood that these drawings are solely for purposes of illustrating the concepts of the invention and are not intended as a definition of the limits of the invention. The embodiments shown in FIGS. 2-5 and described in the accompanying detailed description are to be used as illustrative embodiments and should not be construed as the only manner of practicing the invention. Also, the same reference numerals, possibly supplemented with reference characters where appropriate, have been used to identify similar elements.
DETAILED DESCRIPTION
[0013] The use of a Diffie-Hellman algorithm in encryption technology has been expanded to three parties as is more fully explained in “ Applied Crytography 2 nd edition” Bruce Schneier (Ed.), p. 514. In this encryption technology, each party transfers elements of a key that are provided by another party. A common encryption key is determined for the session by each party based on the information provided. For example, assuming that the encryption variables g and n, where n is a large prime number, are known to each party, it can be shown that a three party key exchange can be formed using the following process:
[0014] “A” randomly selects a large integer x, forms X=g x mod(n) and transmits X to “B”;
[0015] “B” randomly selects a large integer y, forms Y=g y mod(n) and transmits Y to “C”; and
[0016] “C” randomly selects a large integer z, forms Z=g z mod(n); and transmits Z to “A”;
[0017] “A” then creates a transform of Z as Z′=Z x mod(n) and transmits Z′ to “B”;
[0018] “B” then creates a transform of X as X′=X y mod(n) and transmits X′ to “C”; and
[0019] “C” then creates a transform of Y as Y′=Y z mod(n) and transmits Y′ to “A”.
[0020] “A” then determines key value, k, as k=Y′ z mod(n);
[0021] “B” then determines key value, k, as k=Z′ y mod(n); and
[0022] “C” then determines key value, k, as k=X′ z mod(n).
[0023] The ability of “A,” “B,” and “C” to each determine common key value, k, may be shown mathematically as:
g x mod(n) y mod(h) z mod(n)=g xyz mod(n)= z, 900 g y mod(n) z mod(n) x mod(n) [1]
[0024] FIG. 2 illustrates a block diagram of an exemplary operation 200 for generating a digital signature in accordance with an aspect of the present invention. A first party “A”, represented as block 205 , generates encryption values, n, g, x, and z at block 210 . Encryption values, n, g, x, and z preferably are each randomly selected large numbers and n is a prime number. Values n and z are transmitted over network 202 . Values g and x are maintained in confidence by party “A.” At block 220 a first key value is generated as X=g x mod(n) and is representative of party “A”'s private key, for use by second party “B”. In a preferred embodiment, private key X is transmitted to party “B” via a secure link, such as physical delivery, represented by dashed line 222 . In another aspect of the invention, private key X may be transmitted from party “A” to party “B” over network 202 using secure aspects of network 202 between parties “A” and “B”. Such secure aspects include secure communication provisions, such as passwords and shared keys, for example.
[0025] At block 215 a second key value is generated as Z=g z mod(n) and at block 225 second key value Z is transformed into a public key as Z′=Z x mod(n). Public key Z′ is then delivered to third party “C”. In the example shown, public key Z′ is transmitted over network 202 . Although not shown, it would be recognized by those skilled in the art that when public key Z′ is transmitted over a public network, provisions are included, for example, signatures, certificates and the like, that are used to assure a receiving party that public key Z′ is transmitted from a trusted source. Hence, independent means for validating public key Z′ are needed when distribution is made over a public network, such as the Internet. In another aspect of the invention, public key Z′ is a known, preloaded or predetermined value at the site representative of third party “C”.
[0026] Second party “B”, represented as block 230 , hashes an information item or a file 235 at block 240 to produce a hash value, referred to as “y”. The hash value y is then used to determine a digital signature, X′, using private key X and encryption variable, n, as x′=X y mod(n) at block 245 . File 235 and signature X′ ate then transmitted over network 202 .
[0027] Third party, “C”, represented as block 250 , receives file 235 , shown as block 260 , and computes a hash value of the received file at block 265 using methods comparable to those used for determining a hash value as previously discussed. The computed hash value is referred to as “y′”. A first comparator value is then formulated using public key Z′ and computed hash value y′ as:
K b =Z′ y mod(n). [2]
[0028] Third party “C” further generates a second comparator value (K a ) at block 275 from the received digital signature X′ and the encryption variable z as:
K a =X′ z mod(n). [3]
[0029] At block 280 a comparison is performed to validate the source of the transmission. The validity of the source of the information item or file transmitted, i.e., second party “B”, is assured when the value of the hash value of the file before transmission (y) equals the hash value of the received file (y′). In this case, the comparator values, K a and K b , can be shown to be equal as:
K a =X′ z mod(n)=(X y mod(n)) z mod(n)=((g x mod(n)) y mod(n)) z mod(n)=g xyz mod(n); [4]
K b =Z′ y′ mod(n)=(Z x mod(n)) y′ mod(n)=((g z mod(n)) x mod(n)) y′ mod(n)=g xy′z mod(n); [5]
[0030] FIG. 3 illustrates a flow chart of a process 300 for generating key values in accordance with an aspect of the present invention. In this illustrative process, key variables g, n, x and z are generated at block 310 . At block 320 , two keys are generated as:
X=g x mod(n) and Z=g z mod(n); [6]
[0031] At block 330 , one of the generated keys is transformed into a public key as:
Z′=Z x mod(n). [7]
[0032] At block 340 , selected ones of the encryption variables, e.g., n and z, are transmitted over the network. In one aspect, a first key, X, and public key, Z′, may be transmitted over a secure portion of a network. In another aspect, first key X and public key Z′ may be preloaded or predetermined and hence, known, by parties “B” and “C.”
[0033] FIG. 4 illustrates a flow chart of a process 400 for validating the digital signature in accordance with an aspect of the present invention. In this exemplary process, the key values and encryption variables are obtained at block 410 . As previously discussed, the keys and variables may be transmitted over secure networks, electronically or-physically, or reloaded or prestored. At block 420 , a hash value is determined for the received file. At lock 430 , a first comparator value is determined based upon the determined hash value. At lock 440 , a second comparator value is determined. At block 450 , a determination is made whether the determined first and second comparator values are the same. If the answer is in the affirmative, then at block 460 , an indication is generated that indicates that second party “B” sent the received file.
[0034] Although not shown, it would be recognized by those skilled in the art that encryption variables n, g, x and z may be predetermined and known by respective parties. Hence, these values need not be transmitted over the network. In this case, in a system wherein first party “A” is a factory producing set-top boxes, each set-top box or device may be preloaded or preset with the generated encryption key, Z′, and variables n and z. In this case, each set-top box would be representative of party “C”. Similarly, second party “B” may be a transmission device, such as a cable company or other media content service, referred to as a “head-end”. In this case, first party A need provide only a minimum amount of information to second party B for party B to create a digital signature, X′.
[0035] FIG. 5 illustrates a system 500 for implementing the principles of the invention as depicted in the exemplary processing shown in FIGS. 2-4 . In this exemplary system embodiment 500 , input data is received from sources 505 , such as over network 550 , and is processed in accordance with one or more programs executed by processor 520 of processing system 510 . The results of processing system 510 may then be transmitted over network 570 for viewing on display 580 , reporting device 590 and/or a second processing system 595 .
[0036] Specifically, processing system 510 includes one or more input/output devices 540 that receive data from the illustrated source devices 505 over network 550 . The received data is then applied to processor 520 , which is in communication with input/output device 540 and memory 530 . Input/output device 540 , processor 520 and memory 530 may communicate over a communication medium 525 . Communication medium 525 may represent a communication network, e.g., ISA, PCI, PCMCIA bus, one or more internal connections of a circuit, circuit card or other device, as well as portions and combinations of these and other communication media. Processor system 510 or processor 510 may be representative of a handheld calculator, special purpose or general purpose processing system, desktop computer, laptop computer, palm computer, or personal digital assistant (PDA) device, etc., as well as portions or combinations of these and other devices that can perform the processing illustrated.
[0037] Processor 520 may be a central processing unit (CPU) or dedicated hardware/software, such as a PAL, ASIC, FGPA, operable to execute computer instruction code or a combination of code and logical operations. In one embodiment, processor 520 may include code which, when executed, performs the operations illustrated herein. The code may be contained in memory 530 or may be read or downloaded from a medium such as a CD-ROM or floppy disk represented as 583 , or provided by manual input device 585 , such as a keyboard or a keypad entry, or read from a magnetic or optical medium (not shown) which is accessible by processor 520 , when needed. Information items provided by input device 583 , 585 and/or magnetic medium may be accessible to processor 520 through input/output device 540 , as shown. Further, the data received by input/output device 540 may be immediately accessible by processor 520 or may be stored in memory 530 . Processor 520 may further provide the results of the processing shown herein to display 580 , recording device 590 or a second processing unit 595 through I/O device 540 .
[0038] As one skilled in the art would recognize, the terms processor, processing system, computer or computer system may represent one or more processing units in communication with one or more memory units and other devices, e.g., peripherals, connected electronically to and communicating with the at least one processing unit. Furthermore, the devices illustrated may be electronically connected to the one or more processing units via internal busses, e.g., serial, parallel, ISA bus, microchannel bus, PCI bus, PCMCIA bus, USB, etc., or one or more internal connections of a circuit, circuit card or other device, as well as portions and combinations of these and other communication media, or an external network, e.g., the Internet and Intranet. In other embodiments, hardware circuitry may be used in place of, or in combination with, software instructions to implement the invention. For example, the elements illustrated herein may also be implemented as discrete hardware elements or may be integrated into a single unit.
[0039] As would be understood, the operation illustrated in FIGS. 24 may be performed sequentially or in parallel using different processors to determine specific values. Processor system 510 may also be in two-way communication with each of the sources 505 . Processor system 510 may further receive or transmit data over one or more network connections from a server or servers over, e.g., a global computer communications network such as the Internet, Intranet, a wide area network (WAN), a metropolitan area network (MAN), a local area network (LAN), a terrestrial broadcast system, a cable network, a satellite network, a wireless network, or a telephone network (POTS), as well as portions or combinations of these and other types of networks. As will be appreciated, networks 550 and 570 may also be internal networks or one or more internal connections of a circuit, circuit card or other device, as well as portions and combinations of these and other communication media or an external network, e.g., the Internet and Intranet. As would be recognized by those skilled in the art, processing system 510 maybe representative of a device suitable for operation as second party “B” or third party “C”.
[0040] While there has been shown, described, and pointed out fundamental novel features of the present invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the apparatus described, in the form and details of the devices disclosed, and in their operation, may be made by those skilled in the art without departing from the spirit of the present invention. For example, it would be recognized by those skilled in the art that a 160 bit hash value may not be large enough to provide sufficient security. In this case, it may be advantageous to further extend the range of the hash value by performing an expanding function on the value. For example, in one aspect, a larger hash value may be determined by raising the 160 bit hash value obtained from the SHA-1 algorithm noted above to a known power, i.e. (hash value) a . In a preferred embodiment, a is selected greater than 7.
[0041] It is expressly intended that all combinations of those elements that perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Substitutions of elements from one described embodiment to another are also fully intended and contemplated.
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In one embodiment, a device for decoding digital signatures to validate the source of received information items is disclosed. The device is operable to determine a first comparator value in relation to a first value associated with information items received over a network and a Diffie-Hellman public key, determine a second comparator value in relation to a digital signature received, wherein the digital signature is determined in association with a second value associated with the information items prior to transmission over said network, and com paring the first and second comparator values to validate the source based on the comparison. In another embodiment, a key generating device is operable to generate a first and second Diffie-Hellman key from a plurality of large numbers randomly selected, wherein at least one of the numbers is a prime number, and further determine a public key as a Diffie-Hellman transpose of one of the generated first and second Diffie-Hellman keys.
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BACKGROUND OF THE INVENTION
The present invention relates to means for fastening two members together and more particularly to such fastening means having provision for causing a plurality of fastening means to create equal compression forces on the two members being held together thereby.
There are numerous instances wherein two members having mating surfaces must be releasably held together in such a manner that the compressive forces holding the members together are substantially equal over the entire mating surfaces thereof. One well-known example of such an application is the mounting of cylinder heads on reciprocating piston engines and compressors. In such apparatus it is sufficient to have threaded studs passing through bores within the cylinder head to be fastened down by nuts equally tensioned by measured forces such as available with a torque wrench.
Underwater drilling apparatus poses a similar problem but one increased in scale. In such sub-sea drilling apparatus, a riser pipe extends from the ocean floor to a floating platform or vessel on the ocean's surface. Because of the extreme depths involved, the riser cannot be made in one single section. Therefore, the riser comprises a plurality of conduit sections coupled together. Contrary to the cylinder head of the foregoing example which usually remains fastened together for months or years on end, the marine riser conduit sections must be taken apart and reassembled as the marine riser conduit is raised and lowered from the ocean's floor.
Even more important, however, the structure of the conduit and the forces exerted thereon created problems not present in less stringent applications. To prevent damage to and/or loss of valuable equipment, the marine riser conduit section couplings must resist tension and bending loads created therein. In particular, they must be designed to resist "stress concentrations" which are defined as stresses greater than two times the average stress present in the linear riser conduit sections. Since the average stress present in the linear riser conduit sections may be as high as 25,000 pounds per square inch, it can be seen that great care must be taken to assure uniform tensioning of the connectors in the coupling sections.
In the copending patent application Ser. No. 783,636, now U.S. Pat. No. 4,183,562, entitled "Marine Riser Conduit Section Coupling Means" by Bruce J. Watkins and A. Michael Regan, assigned to the common assignee of this application, a coupling for such marine riser conduits is described incorporating a design whereby an optimum curve is employed transferring from a portion adapted for mating with the riser casing to a horizontally disposed flange having the mating surface disposed thereon such that stresses created within the coupling are optimally transferred. In the coupling described in said application, the flanges are connected together by a plurality of radially equally spaced bolts passing through bores in the flange of the coupling upper member threaded into a threaded bore in the flange of the coupling lower member. In particular, in the example as shown in the application there are twelve bolts connecting the upper flange to the lower flange. Because of the critical nature of the fastenings of the two members together, the aforementioned technique employed in engines and pumps whereby the threaded connections are tightened by torque measuring apparatus, cannot be employed to achieve equal compression from each bolt. Variations in threads and the smoothness of mating surfaces rotated relative to one another as well as the presence of friction-producing agents within the threads of the mating parts make torque measurement an inaccurate means of determining the compressive force being created by the connecting bolts. Thus, the standard bolt tightening technique is to grip the bolts individually and apply an extending force thereto as the bolts are snuggly tightened down against the upper flange. Upon release of the external extending force, the restorative forces of the material of the bolt will cause it to contract thereby exerting a compression force against the upper flange equal to the extension force applied thereto. Such a method is time consuming and still prone to inaccuracies inasmuch as all the bolts cannot be simultaneously extended by a common extending force. Thus, in most such tightening operations either by the extension method or the torque wrench method it is common practice to partially tighten the bolts in steps according a preset pattern whereby the members are drawn into equal compressive loading throughout.
Wherefore, it is the objective of the present invention to provide method and apparatus for replacing the bolts employed in such prior art apparatus by fasteners which can be extended simultaneously by a common internal extending force to allow a one-step fastening and unfastening of two members requiring such equalized compressive holding together thereof.
SUMMARY
The objectives of the present invention have been incorporated in apparatus for connecting together two members having mating surfaces by means of a plurality of fasteners causing equal compression forces to be exerted on the members along force lines normal to a common plane by having one of the members including an integral manifold adapted for connection to a source of fluid under pressure, the member also including a plurality of bores extending into the member from the side thereof having the mating surface along lines normal to the common plane to connect into the integral manifold, and further including means for releasably and sealably engaging pins inserted into the bores; the other of the members including a plurality of bores concentrically aligned with the bores in the one member; a plurality of hollow, cylindrical, fluid-filled pins inserted into respective ones of the bores of the one member, each of the pins having a deformable diaphragm on the end thereof inserted into the bores and means for engaging the engaging means of the one member whereby the pins are held in the bores with the deformable diaphragms in sealed communication with the integral manifold, the pins each also being non-deformable on the end not inserted into the bores and having means adjacent the last-named end for releasably and adjustably engaging a stop, the portion of the pins not inserted into the bores of the one member being adapted to pass through the bore in the other member having sidewalls between the two ends of a thickness so as to resist lateral deformation while allowing maximum longitudinal extensibility in response to pressurization of the internal fluid; and, a plurality of stops adapted for mounting adjacent the non-deformable end of respective ones of the pins, the stops being unable to pass through the bores in the other member and including means for engaging the stop engaging means on the pins whereby the stops can be releasably positioned longitudinally on the pins close adjacent the other member opposite the mating surface thereof with the pins longitudinally extended through the application of fluid pressure through the internal manifold and the deformable diaphragm to the internal fluid so that the pins will subject the two members to identical compression forces through the stop by the restorative force of the pins when the fluid pressure is released from the manifold.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cut-away elevation through the area of one connector pin of the present invention as employed in a marine riser conduit coupling with the connector pin in its disconnected position.
FIG. 2 is a detailed, enlarged, cut-away view of the area II of FIG. 1.
FIG. 3 is the apparatus of FIG. 1 with the connector pin in its connected position in an untightened state whereby no compressive force is created on the coupling.
FIG. 4 is a detailed, enlarged, cut-away view of the area IV of FIG. 3.
FIG. 5 is the apparatus of FIG. 1 with the connector pin conected and tightened to create a compressive force on the coupling.
FIG. 6 is a cut-away plan view of the apparatus of FIG. 5 in the plane VI--VI.
FIG. 7 is a detailed view of the fitting of FIG. 6 with a stab connector inserted for the application of fluid pressure to the apparatus through the internal manifold incorporated therein.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The conduit section coupling of the present invention is generally indicated as 10 in FIGS. 1, 3 and 5. The coupling 10 comprises an upper portion referred to as the "pin flange" 12 adapted to be connected to an upper riser casing 14 such as by weld 16 and a lower section referred to as the "box" 18 adapted for connection to a lower riser casing 20 such as by weld 16'. With the bores of upper riser casing 14 and lower riser casing 20 in axial alignment, the pin flange 12 and box 18 have mating surfaces 22 and 24 respectively machined to meet in a common plane circumferentially about the coupling 10. Thus, it is desired to create compressive forces as indicated by the arrows 26 which are normal to a plane parallel to the mating surfaces 22, 24 such as that labeled P--P in FIG. 1. In the preferred embodiment of the present invention as applied to the conduit coupling section of a marine riser, the plane P--P is parallel to the mating surfaces 22, 24 having the longitudinal axis passing through upper riser casing 14 and lower riser casing 20 normal thereto. As can be seen from FIG. 1, other secondary mating surfaces can be provided within the conduit section coupling 10 not in a plane parallel to the plane P--P. Such an example are the angled mating surfaces 28, 30. Having picked the plane P--P as the plane to which all compressive forces will be made normal, it can be seen that the forces through the secondary mating surfaces 28, 30 will pass angularly therethrough.
As can be seen by reference to FIGS. 6 and 7, the box 18 is provided with an integral manifold 32 having a fitting 34 communicating therewith adapted for insertion of a "stab connector" 35 providing a source of fluid 37 under pressure. Box 18 is further provided with a plurality of radially equally spaced bores generally indicated as 36 extending from mating surface 24 concentrically with an axis 38 normal to the plane P--P to the internal manifold 32. The lower portion of each bore 36 has a rubber washer 40 disposed therein. Integral manifold 32 is filled with hydraulic fluid 42 which is prevented from exit therefrom by the self-sealing fitting 34 and the plurality of rubber washers 40 blocking the bottom of the bores 36. When a connector 35 is connected to fitting 34 as shown in FIG. 7, pressurized fluid 37 applies equal force throughout the fluid 42 in manifold 32 as indicated by the arrows 39. The upper portion of each bore 36 is provided with internal threads 44. In between the internal threads 44 and rubber washer 40 there is an unthreaded portion generally indicated as 46 including a " seat" portion 48 adjacent rubber washer 40. The reason for the foregoing will become apparent from the description which follows hereinafter. An internally and externally threaded sleeve 50 is threaded into the upper portion of each bore 36. Threaded sleeves 50 are provided for the usual reason, that is, in the event of the galling of internal threads 52 thereof, sleeve 50 can be replaced as opposed to requiring the complete replacement or complicated re-threading of box 18. Threaded sleeves 50 also have the lower portion thereof unthreaded and of reduced wall thickness to provide additional benefits to be described hereinafter. The unthreaded lower portion of each sleeve 50 is provided with a plurality of circumferentially spaced holes 54 passing between the inside and outside the threaded sleeve 50.
The pin flange 12 is provided with a plurality of bores 56 in concentric alignment with the bores 36 of box 18. Bores 56 are of a diameter so as to be a clearance fit for threads suited for engagement with the internal threads 52 of the threaded sleeves 50.
The compressive force holding pin flange 12 against box 18 is provided by a plurality of hollow pins generally indicated as 58. Hollow pins 58 are cylindrical in shape having threads 60 on the bottom thereof suited for engagement with threads 52 of sleeves 50 and threads 62 on the top thereof. The bottom of each pin 58 is closed by a thin deformable diaphragm 64 and the top is closed by a non-deformable end including a hexagon-shaped protrusion 66 by which the pins 58 can be screwed into and out of the threaded sleeves 50. The bottom of hollow pins 58 is also provided with a seating portion 68 adapted to sealably mate with the seat portions 48 of bores 36. With pins 58 screwed into threaded sleeves 50 as shown in FIG. 3, seating portion 68 is sealably mated with seat portion 48 and deformable diaphragm 64 is tight against rubber washer 40. Additionally, an internal chamber 70 is created circumferentially between the bottom of hollow pins 58 and the inside of threaded sleeve 50 and an external chamber 72 is created circumferentially between the outside of threaded sleeve 50 and bore 36 because of the thin-walled unthreaded portion 46 of threaded sleeve 50 having holes 54 therein discussed hereinbefore. Thus, the holes 54 communicate between each internal chamber 70 and its associated external chamber 72. A pressure relief passage 74 is provided between the atmosphere and each external chamber 72. Chambers 70, 72 and passages 74 provide a passageway for the egress of trapped air and fluid as the pins 58 are threaded into the sleeves 50.
As can be seen in FIG. 5, the sidewalls 76 of hollow pins 58 are thinner than any other portion of hollow pins 58 with the exception of the deformable diaphragm 64. In like manner to integral manifold 32, the hollow interior of pins 58 is filled with hydraulic fluid 78. As can now be seen, if a source of pressurized fluid is connected to fitting 34, the pressure will be transmitted into hydraulic fluid 42 within integral manifold 32 as discussed with reference to FIG. 7. Rubber washer 40 will be forced by the pressure in hydraulic fluid 42 against diaphragm 64. Being deformable, diaphragm 64 will be deformed into the interior of hollow pin 58 to exert pressure against hydraulic fluid 78. By being thinner, the sidewalls 76 are made the weakest point of the pressurized container formed by pins 58. The sidewalls 76 are made thick enough that, being a cylinder, they will resist lateral deformation but will tend to stretch in response to the increased pressure within pins 58. Thus, an internal force can be created within pins 58 tending to longitudinally extend them. To aid in preventing lateral deformation of sidewalls 76, a pair of raised ridges 80 are provided substantially midway between the threaded ends which are adapted to remain in sliding contact with the internal walls of bores 56. Ridges 80 also provide an additional benefit to be described hereinafter.
The top threads 62 of each hollow pin 58 has a nut 82 threaded thereon. Nuts 82 thus provide longitudinally adjustable stops on pins 58. To prevent loss of the nuts 82, it is preferred that the top end of pins 58 be provided with a shoulder 84 as shown. In such case, top threads 62 and bottom threads 60 are made identical whereby nuts 82 are first threaded across bottom threads 60 and thence onto top threads 62 before pins 58 are threaded into sleeves 50. As a further safety measure, each bore 56 is provided with an internal groove 86 containing a snap ring 88. As can be seen in FIGS. 1 and 2, each pin 58 can be withdrawn to a point where its respective snap ring 88 is disposed between the two ridges 80 previously described to thus hold pins 58 in disengagement from box 18 while simultaneously preventing the loss of pins 58.
To connect the two casings 14, 20 by the conduit section coupling 10 of the present invention, pins 58 are first withdrawn to the disengaged position shown in FIGS. 1 and 2. Nuts 82 are backed off against shoulders 84 as shown in FIG. 1. Pin flange 12 and box 18 are brought into proper alignment by aligning means (not shown) with mating surfaces 22, 24 in contact. By so doing, bores 36 and 56 are in concentric alignment along axes 38. All the pins 58 are threaded into the threaded sleeves 50 of respective adjacent bores 36 in sealed engagement with the rubber washers 40. A source of pressurized fluid at a pressure equal to the desired compressive pressure to be exerted by pins 50 on mating surfaces 22, 24 is connected to fitting 34 in the manner described in relation to FIG. 7. The pins 58 are simultaneously longitudinally extended thereby to a point wherein each pin 58 has the restorative force thereof equal and opposite to the longitudinally extending force of the hydraulic fluid 78 interior thereof. At such point, all the nuts 82 are snuggly tightened down against the top of pin flange 12 an equal amount. The source of external pressure then is removed from fitting 34 causing the pins 58 to simultaneously attempt to restore themselves to their unextended position. Nuts 82 now being firmly against the top of pin flange 12, the pins 58 are unable to retract to their unextended position and, thereby, all exert equal compressive forces on the pin flange 12 and box 18.
While the present invention as hereinbefore described is designed primarily for use in the connection of marine riser conduit sections as employed in undersea drilling operations, it will be understood by those skilled in the art that the present invention can be adapted for implementation in any application wherein the benefits attendant thereto are desired.
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The present invention discloses method and apparatus for connecting together two members having mating surfaces by means of a plurality of fasteners such that equal compression forces are exerted on the members along force lines normal to a common plane. To accomplish the foregoing objectives, a plurality of pins are carried by one member and pass through bores in the opposite member. The pins are longitudinally extended simultaneously with a common internal extending force and stops are affixed to the ends extending through the second member snugly against the surface thereof. Upon release of the common extending force, all the pins attempt to restore to their original positions with equal restorative forces being equal and opposite to the common extending force applied thereto.
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[0001] This application claims the priority of a provisional U.S. patent application Ser. No. 61/737,739 filed on 15 Dec., 2012. The disclosure of the prior related application is hereby fully incorporated by reference herein.
FIELD OF INVENTION
[0002] This invention relates to mobile communication devices, more specifically to accessories for handheld smartphones.
DESCRIPTION OF PRIOR ART
[0003] Smart telephones became more and more versatile. Nowadays in their versatility, smart telephones resemble a Swiss Army Knife—a multi-function and multi-purpose item. Most wireless communication devices (cellular or mobile telephones, e.g.) incorporate additional non-communication features, such as imaging (photo and video), personal planners, games, navigation, etc. There are numerous inventions that attempt to include more features for measurement and/or monitoring external signals such as temperature and air pressure. An example is the electromagnetic radiation sensors as taught by the U.S. Pat. No. 8,275,413 issued to Fraden et al. and incorporated herein as reference. Especially of interest for practical applications are medical uses of the smartphones for patient monitoring, self-diagnostic and treatment.
[0004] For a chemical analysis and material composition a mass-spectrometry can be employed. A recent advancement in the MEMS technology allowed a construction a miniature sensor responsive to a single molecule as described in A. K. Naik et al. “Towards single-molecule nanomechanical mass spectrometry”. Nat. Nanotechnol. 4, 445-450 (2009). This chip can be incorporated in a mobile communication device or a carrying case.
[0005] Certain medical monitoring detectors can be imbedded directly into a smartphone and become an integral part of such. Yet, many more shouldn't be integrated into mobile communication devices (smart phones, e.g.) for various reasons. The key reason why all smartphones should not comprise a multitude imbedded sensors is a pure practicality. At least in a foreseeable future, many sensors would take a valuable space and increase cost—often this makes not much sense for a generic smartphone that is intended for a general population. Being “smart’ is good and beneficial, but being “too smart” is not always useful. For example, an air pressure or noncontact infrared temperature measurements may be very useful features during activities of certain phone owners (in a work place, hospital, travel, e.g.), yet they would not be needed at all for many other users that are not engaged in such activities. Incorporating monitors and sensors into smartphones while technically feasible, would increase cost, cause larger overall dimensions and reduce reliability. Further, numerous smartphone models being already in service, can't be retrofitted for adding the extra sensing features. One approach to this issue would be a use of an external attachment to a conventional telephone. However, such attachments may not be convenient for carrying around (and most consumers would never do that), are relatively bulky and require extra efforts for attaching and maintenance. Another and more practical approach is to imbed additional sensors and detectors into a conventional everyday accessory that is routinely used with a smartphone. Such a commonly used accessory is a protective jacket or case that envelops the exterior surface of a phone and absorbs impact forces if dropped on a floor. Most of such covers are designed just for a mechanical protection of the phone. However, the phone covers that in addition to their protective properties incorporate extra electronic circuitry are known in art and exemplified herein by the following. The U.S. Pat. No. 5,517,683 issued to Collett teaches an extension system that implements the additional electronic functions in a case attachable to an external surface of the cellular phone to form a physically integral unit with a connector to couple the extension electronics to the cellular phone electronics. U.S. Pat. No. 8,086,285 issued to McNamara et al. teaches a sound enhancing feature in a protective case. A phone case with electrical lights is taught by the U.S. Publication No. 20120302294 issued to Hammond et al. The U.S. Publication No. 20120285847 issued to Ollson teaches use of an electronic devices inside a protective case. U.S. Publication No. 20120088558 issued to Song et al. teaches an extra battery incorporated inside a protective case. A US company AliveCor (www.alivecor.com) developed the ECG screening monitor incorporated into a protective smartphone jacket. All foregoing patents, publications and the company are incorporated herewith as references. These devices and other inventions on record and known commercial products fail to address sensing a variety of external signals by a smartphone protective case.
[0000] Generally, there are two types of sensors that can be either imbedded into a smartphone or protective jacket. The sensors of the first type are responsive to external electrical signals, like voltage or charge, as exemplified by the above referenced the ECG screening monitor from AliveCor. The second type sensors are responsive to non-electrical external stimuli, for instance: pressure, chemical composition, temperature, light, as exemplified by the above referenced U.S. Pat. No. 8,275,413. The latter sensor type is characterized by a complex sensor design comprising at least one transducer of non-electrical energy to electrical signal, for example, a thermopile that converts the absorbed infrared light to heat, then coverts heat to electrical signal.
[0006] Thus, it is an object of the present invention to provide a protective cover for a smartphone that incorporates additional sensors and/or actuators.
[0007] It is another object of the present invention to increase versatility of a smartphone by adding sensors for electromagnetic radiation, chemical composition, ECG, pressure and other external factors of either electrical or non-electrical in nature.
[0008] And another goal of the invention is to develop a smartphone protective cover that can sense ECG signals with no physical contact with the patient body.
[0009] Further and additional objects and goals are apparent from the following discussion of the present invention and the preferred embodiments.
SUMMARY OF THE INVENTION
[0010] A protective case for holding a smartphone incorporates at least one sensor for detecting signals caused by the stimuli external to the smartphone. The stimuli may be electrical or non-electrical. The case and the phone form an integral unit that possess the sensing features that the phone alone doesn't have. The sensor is supplemented by a signal conditioning and interface electronic circuit for communicating the sensed information to the inner processor of the smartphone. The communication may be via a wired connection to the smartphone connector or wirelessly via a radio wave or optical link. For expanding versatility of a smartphone, specific sensors imbedded into a protective sensing case may be adapted for detecting non-contact temperature, light, ECG, smell, chemical composition, ultrasonic and other external stimuli.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 illustrates isometric views of the back and front sides of a sensing case;
[0012] FIG. 2 is an illustration of a coupling of an internal connector to a sensing module;
[0013] FIG. 3 presents a diagrammatical view of mutual dispositions of the components;
[0014] FIG. 4 shows a top positioning of a sensing module;
[0015] FIG. 5 is a block-diagram of a module for sensing thermal radiation;
[0016] FIG. 6 is a block diagram of a sensing case for sensing thermal radiation and ECG;
[0017] FIG. 7 is a cross-sectional view of a capacitive dry ECG electrode;
[0018] FIG. 8 illustrates a ground electrode;
[0019] FIG. 9 illustrates an isometric view of a smartphone case with a removable top;
[0020] FIG. 10 is an isometric view of a case with a folding flap, containing a sensor;
[0021] FIG. 11 is a case with a feedback component;
[0022] FIG. 12 illustrates incorporation of a optical sensor into a phone case;
[0023] FIG. 13 shows a sensor protected by a lid.
[0024]
[0000]
Parts List for FIGS. 1-13
1
back side
2
front side
3
camera opening
4
back wall exterior
5
back wall interior
6
connector
7
IR sensor lens
8
side extension
9
module
10
wiring harness
11
upper part
12
receptacle
13
slots
14
flat battery
15
smartphone
16
phone connector
17
link
18
ECG converter
19
openings
20
top extension
21
sensing jacket (case)
22
thermopile detector
23
signal conditioner
24
encoder
25
back wall
26
first ECG electrode
27
second ECG electrode
28
amplifier
29
signal conditioner
30
signal converter
31
electrode plate
32
isolator
33
follower
34
driven shield
35
electrode housing
36
follower output
37
bottom part
38
upper part
39
coupler one
40
coupler two
41
joint
42
back case
43
flap
44
flap thickness
45
pivot
46
mating portion
47
ground electrode
48
ground amplifier
49
output means
50
sensor
51
lid
52
axis
53
directions
54
wireless module
55
1 st LED
56
2 nd LED
57
photo detector
58
filter
DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] In the following description, the words “smartphone”, “cell phone”, “phone” and “mobile communications device” are used interchangeably and generally have the same meaning. Likewise, words “case”, “cover” and “jacket” refer to the same item.
[0026] FIG. 1 illustrates the back, 1 , and front, 2 , sides of a protective case, 21 , for holding a mobile communication device (a smartphone, e.g.). The case is designed for a snag fit over the exterior of a phone and not to interfere with its normal functions. Toward this goal, the case, 21 , has one or more slots and openings, 13 and 19 , for the phone controls, switches, microphone/speaker, etc. To protect the phone against damage, if dropped, the case is fabricated of an impact resistant and stress absorbent material. Example are polyurethane, phenolics and polycarbonate. Such materials are well known in art and not described herein. A front side of the case, 21 , is open for providing an access to the phone display and controls, while the rear side preferably (but not necessarily) is protected by a wall having the back side, 4 , and front side, 5 . The connector, 6 , may be incorporated inside the case, 21 , for coupling to the inner electronic components and battery of the smartphone. On the upper side of the case, there is a side extension, 8 , for housing certain components that will be described below. A shape and location of the side extension, 8 , is arbitrary and depends on the ergonomic, esthetic and engineering requirements to the device.
[0027] FIG. 2 shows the case, 21 , that inside the side extension, 8 , incorporates a module, 9 , that may comprise one or more sensors of the external stimuli and supporting electronic circuits to perform additional functions for the phone. Examples of such components are: a thermopile detector for sensing thermal (infrared) radiation, air pressure sensor, UV light detector, signal converter, electromagnetic field detector, blood pulse oximeter, blood glucose meter, detector of a chemical composition, and many others. A spectrum of the electromagnetic field may range from UV to long waves to static electrical and magnetic fields. The module, 9 , communicates with the smartphone (not shown in FIG. 2 ) through the connector, 6 , that is attached to the module via a wiring harness, 10 , such as a flexible circuit board, e.g. The connector, 6 , may be directly attached to a receptacle, 12 , that allows electrical connection of the smartphone to a peripheral equipment, for example, a battery charger or computer. Optionally, an additional battery, 14 , may be incorporated inside the case, 21 , for example, inside the back wall, 25 .
[0028] Before operation, smartphone, 15 , in positioned inside the case, 21 , with the phone inner connector, 16 , being coupled to the case connector, 6 , as illustrated in FIG. 3 . For clarity only, the smartphone, 15 , is shown outside of the case, 21 while the coupling is shown by a broken line, 17 .
[0029] Alternatively, the smartphone, 15 , may communicate with the module, 9 , by a wireless means, for example by using a bidirectional radiofrequency or optical coupling. In that case, the module, 9 , and smartphone, 15 , must incorporate the appropriate coupling components that are well known in art and thus not described here. As a result, the connector, 6 , and the wiring harness, 10 , will not be required for a wireless communication between the case and the smartphone.
[0030] Optionally, module, 9 , may be positioned in other areas of the case, 21 , for example, inside the back wall, 25 , or at the upper part, 11 , as shown in FIG. 4 . The latter placement will require a top extension, 20 . Positioning of the module, 9 , (or 10 ) depends on particular applications. For example, for a noncontact temperature measurement, lens, 7 , of the IR detector should be positioned close to the digital camera lens protruding through the opening, 3 .
[0031] If the jacket comprises a module that for operation requires certain disposable or reusable components, the jacket my be appended with a pocket for storing such components (not shown). An example is a set of disposable test strips for a glucometer. Likewise, certain actuators, either manual or electrical, also can be imbedded into the jacket. An example is a piercing blade (a blood lancet) for puncturing the patient skin to obtain a blood sample for a glucometer.
[0032] Most of the sensors imbedded into the case, 21 , can't be directly coupled to the connector, 6 , and thus require intermediate (interface) electronic circuits, such as signal conditioners, amplifiers, analog-to-digital converters, encoders, etc. As an illustration, FIG. 5 shows module, 9 , incorporating the thermopile detector, 22 , with the infrared lens, 7 . The detector receives the incoming IR radiation and converts it into electric voltage that is fed to the signal conditioner, 23 , that in turn is connected to the encoder, 24 . Typically, the signal conditioner, 23 , is comprised of an amplifier and filter, while the encoder, 24 , is comprised of an analog-to-digital converter and a code adapter for matching a signal format in wiring harness, 10 , with the signal format compatible with a particular model of a smartphone for which the case, 21 , is intended. The sensor (a thermopile, e.g.) not necessarily should be part of the module, 9 . For practical reasons, it may be external to the module, comprising a signal conditioning, encoding and communicating functions.
[0033] In this example of FIG. 5 , a non-electrical stimulus (IR radiation) is converted by a thermopile detector, 22 , first to heat and subsequently heat is converted to a small electrical voltage that is substantially proportional to the intensity of IR radiation received by the detector, 22 . In other embodiments, a stimulus may be of an electrical nature, for example, electro-cardiographic (ECG) voltage naturally appearing over the patient's chest.
[0034] To illustrate operation of a sensor responsive to the ECG electrical stimuli, FIG. 6 shows the case, 21 , that on the back wall exterior, 4 , incorporates three non-contact ECG electrodes, 26 , 27 and 47 . The electrodes may be simple metal plates or they can be designed in a more complex form as shown below. For clarity, module, 9 , and the electrodes are shown as removed from the case, 21 , although in reality they are incorporated into the case. Note that more than one type of sensors may be incorporated into the same case, 21 . This is illustrated by a thermopile detector, 22 , (for thermal radiation) being part of the module, 9 , with the IR lens, 7 , protruding through the case, 21 . The thermopile detector is in addition to the ECG electrodes and electronics.
[0035] Electrical signals from the ECG electrodes are amplified by the amplifier, 28 , processed by the signal conditioner, 29 and converted to a digital format by the signal converter, 30 . The same converter may be used to convert signals from the thermopile detector, 22 . The digital signals pass to the connector, 6 , and subsequently appear at receptacle, 12 , for connecting to the external peripheral devices, if needed for calibration, e.g.
[0036] During operation, the non-contact active electrodes 26 and 27 and the ground electrode, 47 , are pressed against the patient chest. Here term “non-contact” means that the conductive portions of the electrodes make no direct electrically conductive contact with the patient skin. Fundamentals of such an electrode system can be found in: Yu M. Chi et al. “Wireless Non-contact Cardiac and Neural Monitoring.” Wireless Health 2010, Oct. 5-7, 2010, San Diego, USA.
[0037] A more detailed schematic of an active non-contact capacitive electrode ( 26 or 27 ) is illustrated in FIG. 7 . Word “active” here means having an imbedded electronic circuit. The electrode is comprised of an electrode plate, 31 , that is made of a conductive material (metal or conductive polymer, e.g.), isolator, 32 , voltage follower, 33 , driven shield, 34 , and the electrode housing, 35 . Note that isolator, 32 , should be thin (on the range of 1-10 mkm) and composed of an electrically non-conductive material having as high dielectric constant as practical, preferably more than 20. A high dielectric constant increases a capacitance between the patient skin (not shown) and the electrode plate, 31 , thus improving quality of the recorded ECG signals at the lower part of the frequency spectrum. Examples of suitable materials for the isolator, 32 , are certain ceramics, such as titanium dioxide (rutile) deposited on the electrode plate, 31 . Thus, the electrode plate, 31 , and isolator, 32 , forms a unitary two-layer structure. Input of the voltage follower, 33 , is connected to the electrode plate, 31 , while the follower's output, 36 , is connected to the electrically conductive driven shield, 34 , and preferably to the electrode housing, 35 , which also should be made of the electrically conductive material. The voltage follower, 33 , has a very high input impedance on the order of several Gigohm and a very low output impedance in the ohm range. This assures a to sufficiently low cut-off frequency of the electrode and lower interferences. Note that driven shield, 34 , is well isolated from the electrode plate, 31 , but both are at substantially the same voltage (potential), thanks to a unity gain of the voltage follower, 33 . “Substantial” here means be within 1% from one another. As a result, any stray capacitance between the driven shield and electrode plate becomes immaterial and makes no effect on the recorded signal.
[0038] A capacitance between the electrode plate, 31 , and the patient body provides a capacitive coupling for the ECG varying voltage. A voltage difference between the electrodes, 26 and 27 , is amplified and in a digital format is fed to the smartphone inner electronics for processing. Note that the ground electrode, 47 , is driven by a ground amplifier, 48 . The ground electrode construction is shown in FIG. 8 . Like an active electrode of FIG. 7 , it also contains a conductive electrode plate, 21 , and insulator, 32 .
[0039] Note that thanks to very high input impedance of the voltage follower, 33 , it may take a long time for an ECG signal to settle down for a normal recording after the case, 21 , being placed onto the patient chest. This transition time can be significantly reduced by a momentary shorting together the electrode plates, 21 , of both active electrodes, 26 and 27 , to the electrode plate of the ground electrode, 47 . This can be accomplished by a set of additional solid-state switches that are not shown in the drawings because details of the capacitive electrode design go beyond the scope of this disclosure.
[0040] Even though the mobile communication device (smartphone, e.g.) usually has a means for communication with the user, it may be beneficial to supplement the sensing case, 21 , with an additional output means, 49 ( FIG. 11 ), comprising one or more of the following: LCD, LED, speaker, vibrator. One example of the functionality of such an output means is providing a feedback to the user in case when communication with the smartphone can't be established.
[0041] Case, 21 , can be designed in many modifications without departing from the key principles and spirit disclosed herein. As an illustration, FIGS. 9 and 10 illustrate two other embodiments of the invention. The embodiment of FIG. 9 shows a two-part case, 21 , comprising the bottom part, 37 and the upper part, 38 , where one part is fully detachable from another. During operation, both parts are slid over the smartphone housing and joined together. A sensor (or several sensors) can be positioned either in one part or both parts. If necessary, to assure continuity of the wiring harness, 10 , at a mating portion, 46 , of the case, 12 , a coupler one, 39 , is mated with a coupler two, 40 . The couplers are the interconnecting devices. Note that the receptacle, 12 , may be separated from connector, 6 , and linked to it by an electrical joint, 41 . The embodiment of FIG. 10 also shows a two-part case, 21 , where both parts are joined together and can mutually rotate around pivot, 45 . The back case, 42 , envelops a portion of the body of a smartphone, 15 , while flap, 43 , may carry one or more sensors as illustrated by an optical sensor having the IR lens, 7 . The receptacle, 12 , may be located on the either part of the case, like on the flap, 43 , as shown in FIG. 10 . The flap thickness, 44 , should be sufficient for housing all needed sensors and supporting electronic components.
[0042] FIG. 12 illustrates another embodiment of this invention comprising an optical sensor, 50 . Note that the optical sensor can have a multitude configurations and applications and may operate in various portions of the optical spectral range—from UV to far infrared. As an example, FIG. 12 shows an optical sensor, 50 , adapted for measuring percentage of a human hemoglobin oxygenation by a method of a pulse oxymetry. It incorporates a near IR light emitting diode−1 st LED, 55 , a red light−2 nd LED, 56 , and a photo detector, 57 . These components are protected by an optical filter, 58 , that is transparent in the near IR and red portions of the light spectrum. For measuring a hemoglobin oxygenation, the filter, 58 , is pressed against a portion of the patient body, a finger tip, e.g. The method of pulse oxymetry is well known in art and thus not further described herein. Note that in this illustration, the case, 21 , has no wired connection to a mobile communication device, but is connected to it via a wireless module, 54 (a “Bluetooth”, e.g.). Since there is no wired connection to a mobile communication device, electric power to the components incorporated into the case, 21 , may be provided by a flat battery, 14 , imbedded into the back wall, 25 .
[0043] An optical sensor as described herein can be adapted for monitoring a heart rate of a human or animal subject by detecting a variable (modulated) light by the photo detector, 57 . Alternatively, a heart rate me be computed from an R-wave of the ECG signal as detected by the embodiment shown in FIG. 6 .
[0044] Some sensors after being incorporated into case, 21 , may be quite delicate, thus requiring an additional protection from environment. This can be accomplished by appending case, 21 , with a protective lid, 51 , shown in FIG. 13 . The lid, 52 , can swing in directions, 53 , around axis, 52 to an open and closed positions. If needed, the lid, 52 , may incorporate certain additional components, like a photo detector, e.g. (not shown in FIG. 13 ).
[0045] While the present invention has been illustrated by description of various preferred embodiments and while these embodiments have been described in some detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The various features of the invention may be used alone or in numerous combinations depending on the needs and preferences of the user. This has been a description of the present invention, along with the preferred methods of practicing the present invention as currently known. However, the invention itself should only be defined by the appended claims.
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A protective case for enveloping a smartphone incorporates at least one sensor for detecting stimuli arriving from outside of the smartphone. The case and the phone form an integral unit that possess extra features than the phone alone wouldn't have. The sensor is supplemented by a signal conditioning and interface electronic circuit for communicating the sensed information to the smartphone inner processor. The communication is via a wired connection to the smartphone's connector or wireless via a radio waves or optical link. For expanding versatility of the smartphone, the sensors may be adapted for detecting non-contact temperature, light, ultrasonic, smell, material composition, human vital signs, and other signals.
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FIELD OF THE INVENTION
The present invention refers to an improved method of excavating tunnels wherein friction stresses between the casing and the walls of the excavation are avoided and, more particularly, it is related to an improved method of excavating tunnels by the so called casing or tube pushing system, wherein the pushed-in casing is floated in a drilling mud within the excavation to avoid friction and to provide a fluid support for the walls of the excavation.
BACKGROUND OF THE INVENTION
It is well known that for building tunnels, particularly when the excavation of the tunnel is to be effected in soft soils which walls are not self supporting and must be provided with a casing during excavation, and still more particular when excavating through non cohesive soils or sands both above or below subsurface water and through muddy soils or soft clays of any type, as well as soils formed by gravel or boulders, excavation methods are used in which a casing or supporting tube is arranged within the excavation in order to prevent collapsing of the walls of the tunnel, inasmuch as the latter are not self supporting.
A vast plurality of methods to accomplish the above have been deviced and are very well known in the art. Some typical processes comprise, inter alia, the provision of pneumatic chambers and the use of compressed air to fill the excavation and avoid collapsing thereof, but the above so called pressure systems have not gained popularity because they are unsafe, costly and require the use of highly sophisticated equipment. Other typical and more widely used processes are those using the so called "push-casing" systems, wherein a casing is arranged to be pushed by means of jacks or the like, with its outer surface in direct contact with the excavation and with the application of a suitable lubricating agent to facilitate displacement of the casing by reducing the friction between the outer surface of the casing and the surface of the excavation.
As lubricating agents for the above purpose, bentonite paste type lubricants are generally used, but these lubricants are simply applied in very thin layers between the sliding parts, which merely serve to avoid as much as possible the friction stresses, but without achieving the goal of reducing friction forces to an extent suitable to enable pushing inwardly of the excavation large lengths of casing or large diameter casings.
Therefore, prior art processes, particularly those which are effected by pushing a casing inwardly of the excavation, have not been adequate to permit insertion of a casing having a length or a diameter sufficiently large and, therefore, such excavation methods are restricted to relatively small tunnels, inasmuch as the pushing forces become excessively large when the length or the diameter of the excavation are large.
In view of the above, for excavating tunnels of considerable length or diameter, the pushing method has proven to be quite impractical, whereby other processes for supporting the walls of the excavation must be used, with the consequent increase in the costs of operation. The fact that the most economical method presently known for excavating tunnels, that is, the push-casing method, is impractical for excavating large tunnels, represents a serious drawback in the tunnel excavating art, but the fact is that said push-casing methods have not been sufficiently developed to reduce the friction forces between the casing and the walls of the excavation to an extent sufficient to permit pushing a large casing inwardly of said excavation.
Therefore, for long a process has been sought that, having the economical characteristics and advantages of the push-casing method, may also provide for the possibility of easily pushing large casings inwardly of straight or curved excavations, without the need of having resort to other costly methods for supporting the walls of the excavation.
BRIEF SUMMARY OF THE INVENTION
Having in mind the defects of the prior art tunnel excavation methods, it is an object of the present invention to provide a method of excavating tunnels by the use of the push-casing system, which will reduce in a practically complete manner the friction forces generated between the outer surface of the pushed-in casing and the surface of the excavation and thus will permit excavating tunnels having considerable length and diameter.
It is another object of the present invention to provide a method of excavating tunnels, of the above mentioned character, which will be of simple execution and entail considerable economies, and which however will be highly efficient for excavating curved or straight tunnels of considerable length.
A still more particular object of the present invention is to provide a method of excavating tunnels, of the above mentioned character, which will overcome all the problems of the prior art methods and will permit pushing very long and large casings into the excavation without generating excessive friction forces throughout the length of the excavation.
A more particular object of the present invention is to provide a method of excavating tunnels, of the above mentioned characteristics, which will permit placing of the final casing in a simple and economical manner, without the need of introducing special machinery and equipment in the tunnel.
A still further object of the present invention is to provide a method of excavating tunnels, of the above described character, which will permit the prefabrication of all the members utilized for assemblying the casing sections, will permit the fabrication of said casing in a factory and will allow a thorough inspection of said casing.
A still further object of the present invention is to provide a method of excavating tunnels, of the above specified character, which will prevent collapsing of the soil throughout the length of the tunnel as the excavation proceeds.
Another and more particular object of the present invention is to provide a method of excavating tunnels, of the above characteristics, which will permit floating of the casing in a fluid within the excavation and will provide for a leakproof sealing of the chamber containing such fluid.
A still other object of the present invention is to provide a method of excavating tunnels, of the above mentioned character, which will prevent water leakage into the excavation and will therefore avoid the necessity of pumping out subsurface water.
The foregoing objects and other ancillary thereto are preferably accomplished as follows:
A tunnel is excavated starting from a well or a portal, by any suitable method known in the art, such that the cross-sectional area of the excavation be slightly larger than the outer cross-sectional area of the casing to be pushed inwardly of the excavation, in order to permit the insertion of the casing into the excavation leaving an annular chamber between the casing and the excavation, thereafter filling said annular chamber with a drilling mud under a suitable pressure, to thereby effectively support the walls of the excavation and at the same time float the casing pushed into the excavation, whereby excessive friction forces throughout the tunnel will be prevented. In order to prevent leakage of drilling mud from the annular chamber between the excavation and the casing, at least one seal is provided at the outer end or entrance of the excavation between the walls of the excavation and the outer walls of the casing, and at least a further seal is provided at the inner end of the casing whereby to form a drilling mud containing chamber which may be maintained at a constant pressure to suitably support the walls of the excavation and float the casing. The casing may be maintained in a centered position spaced from the walls of the excavation by means of adjustable supports which generally only add minimum friction forces, inasmuch as the casing is actually floating in the drilling mud which is injected under pressure into the annular space or chamber between the excavation and the casing.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features that are considered characteristic of the present invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments, when read in connection with the accompanying drawings, in which:
FIG. 1 is a diagrammatic cross-sectional elevational view of a tunnel excavation which is initiated from a well and wherein the method of the present invention is used;
FIG. 2 is a diagrammatic fragmentary cross-sectional elevational view of the excavation front of the tunnel, showing the excavation apparatus and its relation with the tunnel and casing;
FIG. 3 is a diagrammatic fragmentary cross-sectional elevational view taken along lines 3--3 of FIG. 1 and looking in the direction of the arrows, in order to illustrate the supporting devices for maintaining the casing centered in the excavation;
FIG. 4 is a view similar to FIG. 2 but showing another embodiment of the invention wherein no mud chamber is used at the excavating front;
FIG. 5 is a view similar to FIG. 4 but showing the excavating front provided with a perforate plate through which the excavating material is removed from the excavation
FIG. 6 is a fragmentary cross-sectional elevational view of the entrance section of the excavated tunnel and well, showing a preferred embodiment of a seal which is used to prevent leakage of the drilling mud out of the annular space between the casing and the walls of the excavation;
FIG. 7 is a diagrammatic cross-sectional view taken along lines 7--7 of FIG. 6 and looking in the direction of the arrows, in order to show the arrangement of the pressurizing chambers for the packing or stuffing material of the seal;
FIG. 8 is a cross-sectional detailed view of one of the individual pressurizing chambers of the seal illustrated in FIG. 7; and
FIG. 9 is a cross-sectional view of one of the pressurizing chamber of the seal, taken along lines 9--9 of FIG. 8 and looking in the direction of the arrows.
DETAILED DESCRIPTION
The improved tunnel excavation method in accordance with the present invention permits an economical excavation of tunnels having any practical diameter and through any type of soil, particularly through soft soils which walls are not self supporting and therefore need the introduction of a casing during the excavation process. This method is particularly useful in non cohesive soils or sands, both above or below the sub-surface water. It is also highly useful for muddy soils or soft clays, as well as for gravels and boulders and it may even be used to excavate through rocky soils of any type, as well as through intermediate soils, for reducing subsidence. The method in accordance with the present invention also finds application in tunnels drilled through soft altered rock or medium quality rock as well as in cemented soils or in healthy rock, wherein it is applied merely as a method of inserting the casing in place.
The method in accordance with the present invention comprises initiating the excavation of a tunnel 2 from a well 1 of from a portal as is well known in the art. Well 1, as is clearly shown in the particularly preferred embodiment of FIG. 1 of the drawings, is vertically excavated through soil 3 and to said well the usual casing 4 is applied in accordance with well known techniques. The excavation front of tunnel 2 may be worked by any type of well known machinery or also by hand. However, in the embodiment illustrated in FIG. 1 of the drawings, said excavation method is effected using a machine in accordance with what will be described in more detail hereinafter, but it must be understood that this embodiment is not restrictive of the scope and spirit of the present invention. The excavation of the tunnel is effected by giving the tunnel a diameter slightly larger than the outer diameter of the casing, with the purpose of leaving an annular space 8 around casing 6 which is pushed inwardly of the excavation 2, so as to space a casing 6, which may be prefabricated from concrete or steel, from the soil 7. In order to prevent this empty space 8 to be occupied by the loose soil, inasmuch as the latter is not self-supporting, a drilling mud or any other fluid is injected thereinto, which injection is commenced as soon as practicable after the excavation itself is initiated.
The mud used in accordance with the present invention may be any type of mud such as that used for drilling wells, as well as muds containing barite, attapulgite, cement, bentonite, clays of any type and it may also contain additives to form better lattices in order to control the viscocity or in order to control leakage. The mud injection may be made at one or more points of the annular chamber 8 by means of pipes which may run within or outside the well but, in the illustrative embodiment represented in FIG. 1, the drilling mud is injected through pipe 9 which may be installed at the entrance of the excavation 2 but which may also be distributed into several pipes along the lenght of the tunnel, said pipe being able to run within or outside the casing 6, and the mud being pumped in by means of a pump 10 which takes the drilling mud from a suitable deposit 11.
The drilling mud is injected into chamber 8 under a suitable pressure which may be maintained by means of a column contained in a vertical pipe within the well or aside the same, as well as by varying its density. The pressure may also be maintained by means of the pump 10 itself, by a pressurized deposit, or by any other suitable means, without any of these means representing restriction in connection with the present invention.
The casing 6 is introduced concentrically along the tunnel excavation 2 and is generally formed by tube sections 5 which may be selected from steel sections, in which case the joints may be welded, and prefabricated concrete tube sections, in which case the joints may be effected by the provision of tensors or by any other known means. Tube sections 5 are lowered into the well 1 by means of a suitable crane 12 suspended from a cable 13 in accordance with what is illustrated in FIG. 1 of the drawings, and the complete casing 6 is pushed inwardly of the excavation 2 by means of a plurality of jacks 17, bearing on the opposite wall of the well or on a suitable structure.
In order to form a pressure chamber 8 for the drilling mud, at least a seal 14 is provided at the entrance of the excavation 21, that is, at the well 1 and at least one other seal 15 is provided at the inner end of the casing 6, whereby a leakproof chamber 8 is formed to contain the mud under pressure and such that the said pressure may be controlled to balance the vertical forces extant in the soil at the roof of the tunnel and, therefore, the horizontal forces as well, said pressure being able to be modified during the excavation operation in accordance with the movements observed in the walls of the excavation.
In accordance with the particular preferred embodiment of the invention illustrated in FIG. 1 of the drawings, several additional intermediate seals 16 may be distributed along the length of the excavation 2 for the purpose of forming annular chambers for containing pressurized mud, in order to enable the pressurization of said mud under different pressures and thus to provide test chambers to periodically test the mud for leakage and the like or in order to provide for the minimum possible detrimental effect of said leakage. As is well known in the art, when mud leakage exists, agents for controlling the loss of water are injected through suitable bores left or made through the walls of the casing.
An additional chamber 21 may be provided at the excavation front 24, such as clearly illustrated in FIGS. 1 and 2 of the drawings, in order to also contain drilling mud under a suitable pressure for preventing at least in part leakage from the annular chamber 8. This chamber 21 may be kept at a pressure sufficient to balance the pressure of the mud within chamber 8, in which case the use of the seal 15 at the end of the casing is avoided. Chamber 21 is built by including a plate 20 having the form of the cross-section of the excavation and attached to the innermost extremity of the casing 6. As the excavation is being effected by the use of a machine, the shaft 22 of motor 19 is passed through plate 20 through a suitable packing gland 28 in order to actuate a mechanical cutter 18 which is used to penetrate into the excavation front 24. Chamber 21 also serves as a deposit to receive the excavated material forming a thick slurry that may be pumped out from the tunnel by any suitable slurry pumping means (not shown). However, as it may be seen in schematical FIGS. 4 and 5, the excavation front 24 may not contain the pressure chamber 21, particularly when the excavation is effected by hand or, as an alternative, the excavation front may be partially open by the provision of a plate 29 having regulatable openings 28 so that the excavated material may enter into the casing 6 through the openings 28. In this latter cases, of course, the annular chamber 8 is maintained as much as possible under a leakproof condition by providing the seal 15 at the extremity of casing 6.
The casing 6 is maintained centered within the excavation 2 by means of a number of supports clearly illustrated in FIG. 3 of the drawings and identified by the reference character 25. These supports may be controlled in order to vary the distance of the casing 6 from the walls of the excavation 2 by means of the threaded stems 26 and heads 27, which may be rotated to increase or decrease the spacing and to change the excentricity of the total assembly.
The supports 25, 26, 27 may also be raised or lowered or moved aside or they may be bent at the curves of the tunnel if sufficient flexibility is provided in casing 6.
The cross-section of the tunnel may have any shape, either circular, square, rectangular, elyptical, oval, or horseshoe shaped, etc., without therey requiring a change in the system used in accordance with the present invention.
The casing 6 may also be loaded to control flotation thereof during the process of insertion of said casing.
In order to regulate the mud pressure within the annular chamber 8, a plurality of gages 23 such as that illustrated in FIG. 2 of the drawings, may be connected through the wall of the casing 6, so as to measure the mud pressure and permit control thereof in accordance with the varying needs of the soil, particularly when the multiple seal embodiment illustrated in FIG. 1 of the drawings is used.
Casing 6, in accordance with the above, is generally formed by means of a plurality of prefabricated sections 5. Said sections 5 may have the form of precast lengths of concrete tube that may be manufactured in a plant or cast within the well. Said lengths may be thereafter joined by means of prestressing cables, rods, adhesives or any other fastening device in order to provide a monolithic and impermeable casing.
The seals used in accordance with the present invention are preferably provided using a pasty or plastic injectable material such as a putty or mastic, stored between a pair of flanges, and thus as it may be more clearly seen in FIGS. 1, 2, 4 and 5 of the drawings, the seal 15 provided at the inner end of the casing 6 may be formed by injecting a putty or mastic through a pipe 32 into a chamber formed between a flange 31 provided at the periphery of plate 20 and a flange 30 provided as an integral part of the corresponding tube section 5 of casing 6, whereas the intermediate seals 15 may be formed by injecting the sealing material through pipes such as 33 into chambers formed between a pair of spaced flanges 30 integrally formed in the casing 6. As the casing 6 is displaced inwardly of the excavation 2, some loss of the putty or mastic sealing material from the seals is experienced, but additional material may be injected through pipes 32 and 33 in order to replenish said losses and maintain a suitable pressure of the mastic or putty which will provide for a sufficient mud leakproof characteristic of the system of the present invention.
As to the seals such as seal 14 used at the entrance of the excavation tube, these seals must be such that they permit an absolute leakproof characteristic of chamber 8 and, thus, while the preferred embodiment of the invention is also to provide a seal operating on the basis of a plurality of chambers filled with a putty or mastic material, the structure of said seal must be quite different from the structure of the intermediate and the inner seals, whereby having reference to FIGS. 6 through 9 of the drawings, it will be seen that the outer seal 14 in accordance with a preferred embodiment of the invention is built such that a plurality of chambers 35 are arranged around the circumference formed by the outer surface of the casing 6, each said chamber 35 having a piston 36 actuated by means of a linear fluid motor 37 which controlledly presses against a body of plastic material such as the putty or mastic 38, the chambers 35 being supported by means of a suitable metallic structure 39 fastened to a cylindrical flange 40 which is attached to the casing 4 of the well 1. As the casing 6 is advanced inwardly of the excavation tube, some of the putty 38 is lost and therefore it must be replenished, for which purpose each one of the individual chambers 35 is provided with a feed pipe 41 to inject therethrough additional amounts of the mastic material to maintain a suitable pressure on the seal. Also, the linear motors or piston-cylinder assemblies 38, permit certain flexibility in view of the fact that the pressure may be maintained constant without feeding additional amounts of the mastic material for a certain time of operation, by merely pressing the mastic 38 with the piston 36 in order to compensate for the loss of material from the seal.
The individual chambers 35 are arranged around the circumference of the seal as clearly indicated in the diagrammatic representation of FIG. 7, in the manner of radial gear teeth, so that each individual pressurizing chamber 35 is arranged with its axis along a radius of the circumference having as its center the geometrical center of casing 6. Therefore, each individual piston 36 of each chamber 35 presses radially inwardly of the seal, so as to permit a uniform pressurization of the mastic material against the outer walls of the casing 6, whereby an absolutely leakproof joint is obtained.
FIGS. 8 and 9 illustrate in more detail the structure of each individual pressurizing chamber 35 and it will be seen that each individual chamber is formed by means of a pair of plates 42 and 43 which form a rectangular chamber 35. Each plate 42 and 43 is reinforced by means of U-shaped reinforcements 44 and 45 and a pair of annular plates such as 46 is arranged, one at each side of plates 42 and 43 of all the individual chambers, in order to close said chambers along their sides. Plates 42 and 43 of each adjacent chamber 35 join at a vertex which is separate from the outer surface of the casing 6 as clearly illustrated by the reference character 60 in FIG. 8 of the drawings, in order that a common annular continuous chamber 47 is formed at the bottom of the pressurizing chambers 35 to transmit a uniform pressure to the putty material in contact with the outer wall of casing 6.
Each individual chamber is provided, as more particularly illustrated in FIG. 9 of the drawings, and as mentioned above, with a pair of annular plates 46 and 51 which close the chambers along and throughout the circumference of the seal, and within each chamber a piston 36 is arranged having a pusher member 50 which is actuated by means of a piston rod 49 actuated in turn by the fluid operated cylinder 37 by means of the injection of fluid through a hose 48 or the like. The space 54 of each individual chamber 35 is filled with a putty or mastic material which flows down to the common annular chamber 47 which is bounded by means of an inclined annular wall 52 and a straight flange 53, thus forming a complete annular packing for the entrance of the chamber 8, around the casing 6 as mentioned above. By these means, coordinated actuation of the cylinders 37 will maintain the pressure of the putty or mastic material for a length of time and, when replenishment of the material becomes necessary, then additional material is injected through pipes or hoses such as 41, as more clearly illustrated in FIGS. 6 and 9 of the drawings.
From the above it will be seen that a simple process for excavating tunnels has been provided, in which the casing is fully spaced from the walls of the excavation, whereby the friction between the casing 6 and the soil 7 is practically eliminated, inasmuch as casing 6 is floating on a drilling mud contained in chamber 8. Therefore, very long casings 6 may be advanced inwardly of the excavation 2 with minimum efforts on the material forming the casing. In the process in accordance with the present invention, the drilling mud is used as a flotation medium for the casing and also as a supporting element for the soil and not merely as a lubricating agent as was the case of the prior art lubricated push-casing method, whereby it constitutes a remarkable improvement over said prior art, inasmuch as in the known method the casing is directly supported on the soil, regardless of the fact that a certain lubricating agent is injected to reduce the friction forces. Said prior art lubricating agent, on the other hand, is generally a drilling mud of a very thick consistency, such as a concentrated bentonite type mud, which renders handling thereof very difficult, whereas in accordance with the present invention the floating muds may be prepared with a much more fluid consistency, in view of the fact that they are to serve merely as a floating medium, with the consequent advantages in the handling thereof.
As there is practically no friction between the soil and the wall of the casing when the method of the present invention is used, the thrust necessary to inwardly displace the casing is relatively small, whereby the jacks 17 may be regulated to merely compensate for the displacement of the excavation front in the tunnel in accordance with the excavation process and with the pressures exerted by the soil, without the need of providing for overcoming any measurable friction stress.
It will be clearly apparent to anyone skilled in the art that the gap occupied by the mud may have any dimension, that is, from a few inches up to several feet if necessary, in order to provide for curvatures in the tunnel or in order to correct alignments. It will also be apparent that it is possible to temporarily shore the interior of the casing 6 when very high mud pressures need to be handled.
The process of the present invention is completed by injection into chamber 8 previously filled with the drilling mud and once the required length of the casing has been introduced into the excavation, of mortars, concretes, soils, cements and the like, in order to suitably and permanently support and join the walls of the excavation 2 with the walls of the casing 6, whereby this method of injection prevents any subsidence, because no void is ever left and because the mortar, when injected, will displace the mud from chamber 8 instantaneously taking its place, whereby the excavation made through the soil 7 will be preserved unaltered.
It will be seen from the above that for the first time an excavation method has been provided which, by means of the simple injection of drilling muds into an annular chamber between the casing and the inner surface of the excavation, floats said casing avoiding all types of friction stresses, whereby the introduction of a fully completed and prefabricated casing inwardly of a horizontal or inclined excavation is possible if desired, regardless of the fact that said excavation may have a straight or curved shape, while the excavation walls are at the same time supported by said drilling mud, thus maintaining atmospheric pressure in the interior of the casing which permits free access to workers. Also, the system of the present invention avoids the carrying of concrete or additional materials inwardly of the tunnel, inasmuch as the casing sections may be prefabricated outside the tunnel and therefore may undergo a perfect inspection prior to their installation. Also, the method of the present invention permits the injection of mortars to fill the space originally occupied by the mud, with the latter being displaced by the former whereby collapsing of the walls of the excavation is prevented, because no single part of the excavation is ever left without support.
Although I have shown and described certain specific embodiments of the invention, I am fully aware that many modifications thereof are possible. The invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.
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A method of excavating tunnels comprises digging an excavation to form a tunnel, gradually pushing a casing inwardly of the excavation as the excavation proceeds, the cross-sectional area of the excavation being larger than the outer cross-sectional area of the casing in order to provide a hollow annular chamber between the same; arranging at least a seal at the inner end of the casing to seal the annular section between said casing and the excavation; arranging a seal at the entrance of the excavation to seal the annular section between the casing and the entrance to the excavation; and injecting under pressure a drilling mud to completely fill the annular space between the casing and the excavation as the excavation front advances, in order to provide a fluid support for the walls of the excavation and to float the casing within the excavation, whereby friction contact between said casing and the excavation is prevented as the casing is pushed inwardly of the excavation. The excavation front is preferably worked within an end chamber to which drilling mud is also injected to avoid leakage of the drilling mud from the annular space between the casing and the excavation and to permit removal of the excavating material suspended in the drilling mud, by pumping out the same.
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The present invention relates to a surface-modified, pyrogenically produced aluminum oxide.
BACKGROUND OF THE INVENTION
It is known to use powdery toners containing pyrogenically produced surface-modified silicon dioxide in electrostatic developing processes. Various silanes, especially dimethyldichlorosilane are used for surface modification (See U.S. Pat. No. 3,720,617).
It is also known that pyrogenically produced silicon dioxide waterproofed with compounds of the general formula ##STR1## can be added to positively chargeable resin powders in order to increase their flowability (See published European Patent Application EP-A 0,293,009).
Published German Patent Application DE-A 12 09 427 discloses aluminum oxide whose surface has been modified with halogen silanes can be added to electrographic developing powders.
Published German Patent Application DE-A 34 26 685 (Canon) teaches the addition of aluminum oxide to positively chargeable toners in which the aluminum oxide has been treated simultaneously with the adhesion promoter γ-aminopropyltriethoxy-silane and trimethylethoxysilane.
A similarly treated aluminum oxide is described in Published Japanese Patent Application JP-OS 31442 (Nippon Aerosil Corporation).
The known method has the disadvantage that it must use an organic solvent system. Alcohols, hydrocarbons and halogenated hydrocarbons are used as solvents which cannot be completely removed from the reaction product.
SUMMARY OF THE INVENTION
The object of the present invention is to avoid these problems and produce a solvent-free, waterproofed aluminum oxide.
The present invention provides a surface-modified, pyrogenically produced aluminum oxide which is surface modified with a silane mixture consisting of silane A (trimethoxyoctylsilane) and silane B (3-aminopropyltriethoxysilane) having the chemical formulas: ##STR2## The surface-modified, pyrogenically produced aluminum oxide has the following physico-chemical properties:
______________________________________Surface (m.sup.2 /g) 50 to 150Stamping density (g/l) 50 to 90Drying loss (%) <5Annealing loss (%) 0.5 to 15C content (%) 0.5 to 12pH 4 to 8.______________________________________
The present invention also provides a method of producing the surface-modified, pyrogenically produced aluminum oxide in which the pyrogenically produced aluminum oxide is placed in a mixer and sprayed, with the mixer running, with the mixture of silane A and silane B. The silane and aluminum oxide are mixed after the addition of the silane mixture and the resulting mixture is tempered at 100° to 150° C., preferably at 115° to 125° C.
The ratio of aluminum oxide to silane mixture can be 0.5 to 40 parts by weight silane mixture per 100 parts by weight aluminum oxide.
The silane mixture can consist of 1 to 99 parts by weight silane A and 99 to 1 parts by weight silane B.
A mixture can be used with preference consisting of 50±20 parts by weight silane A and 50±20 parts by weight silane B.
A particularly suitable aluminum oxide is Aluminum Oxide C which is produced pyrogenically from aluminum trichloride by flame hydrolysis in an oxyhydrogen flame and which has the following physico-chemical characteristics:
______________________________________ Al.sub.2 O.sub.3 C______________________________________AppearanceSurface according to BET m.sup.2 /g 100 ± 15Average size of the 20primary particles nanometerStamping density.sup.1) g/l --Drying loss.sup.2) <5(2 hours at 105° C.) %Annealing loss.sup.2)6) <3(2 hours at 1000° C.) %pH.sup.3) (in 4% aqueous dispersion) 4-5SiO.sub.2 .sup.5) % <0.1Al.sub.2 O.sub.3 .sup.5) % >99.6Fe.sub.2 O.sub.3 .sup.5) % <0.02TiO.sub.2 .sup.5) % <0.1HCl.sup.5)7) % <0.5Sieve residue.sup.4) <0.05according toMocker (45 m)packing drum size (net)normal goods kg 5compressed goods(additive "V) kg______________________________________ Technical data of the AEROSIL standard types .sup.1) according to DIN 53 194 .sup.2) according to DIN 55 921 .sup.3) according to DIN 53 200 .sup.4) according to DIN 53 580 .sup.5) relative to the substance annealed 2 hours at 1000° C. .sup.6) relative to the substance dried 2 hours at 105° C. .sup.7) HCl content is a component of the annealing loss
The waterproofed aluminum oxide of the invention has the advantage that it has no solvent components. It can be used in toners for copiers,
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The following examples illustrate the invention.
Example 1
2 kg Al 2 O 3 C produced pyrogenically from aluminum trichloride in an oxyhydrogen flame and having the properties given above are placed in a 135 liter Lodige mixer and sprayed with 100 g of a silane mixture consisting of 50 g trimethoxyoctylsilane and 50 g 3-aminopropyltriethoxysilane with the mixer running. The mixture is mixed for 15 minutes more. The silanized oxide is tempered 2 hours at 120° C.
Physico-chemical properties of the surface-modified aluminum oxide
______________________________________Carrier Al.sub.2 O.sub.3 CSurface (m.sup.2 /g) 92Stamping density (g/l) 70Drying loss (%) 0.9Annealing loss (%) 5.3C content (%) 2.9pH 5.7______________________________________
Example 2
The aluminum oxide waterproofed according to Example 1 is tested in a positive toner system. The toner system consists of the following components:
______________________________________Pigment black Printex 35 7%Copy-Blau PR (Hoechst AG) 3%Toner resin 90%______________________________________
The repeated activation was tested with this toner and a high charge stability in comparison to the raw toner was determined (see FIG. 1).
Copy-Blau PR is a charge regulating agent for positive toners. It is characterized as follows:
Area of Application
1. Charge regulating agents for positive toners (1- or 2-component toners for copiers or laser printers)
2. Clearing agents for black toners
Chemical characterization: triphenylmethane derivative
Thermal resistance: >200° C.
Solubility: insoluble in water slightly soluble in organic solvents
The toner resin used is characterized as follows:
______________________________________ Unit Theoretical value______________________________________Melt flow Index.sup.1) g/10 min 5-10(150° C./2, 16 kp)Viscosity number.sup.2) cm.sup.3 /g 37-43Weight loss.sup.3) % by weight <1Residual monomers.sup.4) % by weight <0.35Styrene <0.25n-BMA <0.10Other product properties:Monomer composition 70% by weight styrene 30% by weight n-butylmethacrylateGlass transition 60-65° C.temperature Tg.sup.5)Average grain diameter.sup.6) 0.200-0.314 mm(d 50% RS)______________________________________ .sup.1) DIN 53 735, 2/88 edition Specimen pretreatment: Drying at 50° C. oil pump vacuum, 1 hour or 4 hours drying oven, 50° C. .sup.2) DIN 7745, 1/80 edition .sup.3) IR drier until weight constancy .sup.4) Gas chromatography .sup.5) DSC method, ASTM D 3418/75 .sup.6) DIN 53 734, 1/73 edition, evaluation according to DIN 66 141, 2/7 edition
__________________________________________________________________________RCF (regular color furnace)density: (g/cm.sup.3) 1.8-1.9__________________________________________________________________________ Product specifications DBP Adsorption Extract Depth of Color (mg/100 g) Volatile contents Sieve Color Strength powder beads Components toluene ResiduePrintex 35 RCF Class M.sub.γ -value IRB 3 = 100 Powder Beads (%) pH (%) (%)__________________________________________________________________________Furnace Blacks RCF 236 100 42 42 0.9 9.5 <0.1 0.05Printex 35__________________________________________________________________________ Further technical data BET Ashing Stamping Density Particle Surface Printex 35 RCF Residue Powder Beads Size (nm) (m.sup.2 /g)__________________________________________________________________________ Furnace Blacks 0.3 420 550 31 65 Printex 35__________________________________________________________________________
The q/m measurement takes place under the following conditions:
98% carrier (spherical ferrite (80-100 m))
2% aluminum oxide according to Example 1
Activation: Rolling fixture, 360 rpms in 40 ml glass bottle, weighed portion 40 g, developer
BRIEF DESCRIPTION OF FIGURES OF DRAWING
In the drawing, the FIGURE is a graph of q/m versus activation time.
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Surface-modified, pyrogenically produced aluminum oxide which has the following physico-chemical properties:
______________________________________
Surface (m 2 /g) 50 to 150Stamping density (g/l) 50 to 90Drying loss (%) <5Annealing loss (%) 5.0 to 15C content (%) 0.5 to 12pH 4 to 8.______________________________________
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FIELD OF THE INVENTION
The invention is directed to an artificial fishing lure that attracts fish by motion and sound as it is drawn through the water.
BACKGROUND OF INVENTION
Fish have a lateral line running along each side of their bodies. Each line is a small canal extended along the length of a side of the fish. The canal is filled with a thick liquid. Numerous pores along the length of the canal are open to the outside in the skin or between the fish scales. Nerve endings joined to the canal are part of the nervous system of the fish. The lateral lines allow the fish to monitor information about its surroundings. The fish senses the changes in current, temperature and direction of the water flow. The lateral lines also function to monitor balance and operate as a sonar system. As the fish swims it produces motion that sends out vibrations that are reflected off of objects. The reflected vibrations or signals are picked up by the sensitive lateral lines. The nerve endings sense the signals picked up by the lateral lines and transmit the signals to the nervous and control/command systems of the fish. It has been observed that fish respond to sound by swimming to the source of the sound vibrations.
A fishing lure that utilizes sound to attract fish is described by Lowes in U.S. Pat. No. 3,397,478. The Lowes fishing device produces pulse vibrations as it is drawn through the water. These vibrations are produced by a pair of bladed rotatable members mounted on a single shaft. A helical cam interposed between the rotatable members causes forward and reverse movements of one rotatable member to produce intermittent sounds.
An audible fishing lure for producing chirping and clicking sounds to attract fish disclosed by Tay in U.S. Pat. No. 3,112,576. The Tay lure has a pair of oppositely pitched spinners rotatably mounted on a single rigid shaft attached to a fish line. The spinners strike each other during their rotation to produce clicking sounds.
SUMMARY OF INVENTION
The invention relates to a fishing lure that produces sound signals or vibrations as it is retrieved in the water. The lure has body means having a forward eye adapted to accommodate a fish line or leader connected to a conventional fishing tackle. A hook is joined to the rear of the body means. A pair of bendable arms are attached to the forward end of the body means. The arms extend upwardly and outwardly from the body means. Rod members joined to the outer ends of the arms extend generally parallel to the body means. Rotatable spinners are mounted on the rod members. The spinners rotate in opposite directions and have portions that hit each other on rotation of the spinners which generates fish attracting intermittent sounds. A first weight is mounted on the body means adjacent to hook means. A flexible skirt surrounds the hook means adjacent the first weight means to provide a camoflage for the weight means and the hook. The skirt has a plurality of flexible bands surrounding the weight means and hook. A second weight means is joined to the body means adjacent the forward eye. The arms are connected to the second weight means. The arms are bendable elongated linear wire members. Each of the arms is selectively bendable toward or away from each other to alter the lateral space relationship between the spinners to change the sound generating characteristics of the rotating spinners.
Each of the spinners has a generally V-shaped body and oppositely turned ears located on opposite end portions of the body. The ears of the second spinner extend in directions opposite to the direction of extension of the corresponding ears in the first spinner whereby the first and second spinners turn in opposite rotational directions as the lure is moved forwardly in the water. The rotating spinners contact each other and produce clicking sounds and motion that attracts fish.
DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the audible fishing lure of the invention;
FIG. 2 is a top view of the lure of FIG. 1; and
FIG. 3 is a front elevational view of the lure of FIG. 1.
DETAILED DESCRIPTION OF INVENTION
Referring to FIGS. 1 to 3, there is shown the audible fishing lure of the invention indicated generally at 10. Lure 10 has an elongated linear body 11 normally extended in generally horizontal direction. Body 11 is an elongated wire or rod having a rear end attached to a hook 12. Hook 12 extends in an upward direction and terminates in a forwardly projected barb 13. Hook 12 is normally located in the vertical plane of body 11. A first sinker or weight 14 surrounds the rear of body 11 and the shank of hook 12. Hook 12 is connected to the rear end of body 11. Weight 14 is a molded lead body located around the connection of the hook 12 to body 11. Weight 14 has a general conical or tear-drop shape which tapers in a rearward direction toward hook 12.
A flexible camoflage skirt 15 is mounted on hook 12 adjacent weight 14. As shown in FIG. 2, a cord or band 16 wrapped around the mid-portion of skirt 15 retains the skirt on the hook 12 adjacent weight 14. Skirt 15 comprises a plurality of flexible members or bands that project from opposite sides of cord 16 to provide camoflage for hook 12 and weight 14. The flexible members are elongated plastic or rubber bands. The bands can have one or more colors, such as red and white, black and white, and the like.
The forward end of body 11 is an upwardly turned loop 18 forming an eye 19. A line or a leader (not shown) can be attached to loop 18 whereby the lure 10 is pulled in the forward direction by conventional fishing tackle. A second sinker, weight or head 21 is mounted on the forward end of body 11 adjacent loop 18. Head 21 is a general cone-shaped weight, such as a lead body molded on the body 11 and upper end of loop 18.
Extended upwardly from head 21 are a pair of bendable linear arms 22 and 23. Arms 22 and 23 are wires extended upwardly in opposite outward directions from head 21. The angle between arms 22 and 23 is less than 90 degrees. This angle can be changed by bending the arms toward or away from each other. The lower ends of arms 22 and 23 are anchored to head 21. Head 21 is a rigid connector for arms 22 and 23. Arm 22 has a first linear rod end 24 rotatably supporting a first spinner indicated generally at 26. Arm 23 has a second rod end 28 rotatably supporting a second spinner indicated generally at 29. Rod ends 24 and 28 are linear wires extended generally parallel to each other and parallel to body 11.
The upper end of arm 22 has a right angle corner 31 joined to the forward end of rod 24. A cylindrical bead 32 spaces spinner 26 from corner 31. Spinner 26 has a pair of end tabs 33 and 34 having holes accommodating rod 24. The rear end of rod 24 supports a bead 35. A right angle finger 36 of rod 24 retains bead 35 and spinner 26 in rotating relationship on rod 24. Spinner 26 has a generally flat V-shaped body 37 with a central hole 40 and a pair of curved blades or ears 38 and 39 located on the opposite rear edges of body 37. Body 37 has rearwardly diverging linear side edges. Blades 38 and 39 each have generally U-shaped outer edges that merge with the linear side edges of body 37. Rod 24 extends through hole 40. Blades 38 and 39 project in opposite directions and cause a rotation of spinner 26 in a counter-clockwise direction as indicated by the arrow 41 when the lure is pulled in the forward direction.
Second arm 23 has an outer right angle corner 42 joined to the forward end of rod 28. A bead 43 rotatably mounted on rod 28 spaces spinner 29 from corner 42. Spinner 29 has a pair of tabs 44 and 45 containing aligned holes for accommodating rod 28. The rear end of rod 28 rotatably supports a spherical bead 45. A turned finger 47 on the end of rod 28 maintains bead 45 and spinner 29 in rotating assembled relation on rod 28. Spinner 29 has a V-shaped body 48 with a central hole 50 and rear end blades or ears 49 and 51 projected in opposite directions. Spinner 29 has the same size and shape as spinner 26 except that blades 49 and 51 extend in opposite directions from corresponding blades 38 and 39 whereby spinner 29 rotates in a clockwise direction as indicated by arrow 52. Rod 28 extends through hole 50. An example of lure 10 has the following dimensions. The body 11 is a linear stiff wire having a length of 6 cm. Weight 14 surrounds one end of the wire and adjacent end of hook 12. Hook 12 is turned upwardly with the point projected in the forward direction. Body 11 and hook 12 are located in the same vertical plane direction. Skirt 15 comprises a plurality of flexible plastic strings having a length of 8 cm. The strings are disposed around weight 14 and retained on the hook shank with plastic cord 16. Arms 22 and 23 are linear bendable wires that project upwardly. The angle between the arms 22 and 23 is less than 90 degrees. Each arm has a length of 3 cm. Each rod end 24 and 28 has a length of 4 cm. and extends rearwardly generally parallel to body 11. The beads 32 and 33 rotatably mounted on ends 24 and 28 have elongated general oval shapes and length of 5 cm. Spinners 26 and 29 are one-piece sheet metal members rotatably mounted on ends 24 and 28. Spinners 26 and 29 can be made of sheet aluminum. An example of a suitable rotatable spinner is disclosed by Sparkman in U.S. Pat. No. 4,201,008.
In use, spinners 26 and 27 rotate in opposite directions as indicated by arrows 41 and 52 as the lure is moved in a forward direction as indicated by arrow 54. The rotating spinners 26 and 29 intermittently contact or hit each other thereby produce sounds and motion. Outer portions 53 of spinners 26 and 29, as shown in FIG. 2, hit each other and thereby produce sounds or vibrations. The vibrations are transmitted through the water. Fish in the vicinity of the lure will sense the sound vibrations and make an inquisitive investigation.
The sound producing characteristics of lure 10 can be altered by the fisherman. As shown in FIG. 3, arms 22 and 23 can be bent in opposite outward directions as indicated by the broken lines. This laterally spaces spinners 26 and 29 from each other so only outer edges of the ears 38, 39 and 49, 51 will intermittently engage each other as the spinners 26 and 29 rotate in opposite directions as indicated by arrows 41 and 52. This changes the sound vibration intensity and frequency of lure 10 as it is drawn through the water. The fisherman, with the use of intermittent retrieval can further alter the sound generating characteristics of the lure to attract fish. Alternations in the retrieval speed of lure 10 also causes changes in the sound signals caused by the rotating spinners 26 and 29.
While there has been shown and described a preferred embodiment of the audible fishing lure of the invention, it is understood that changes in any shape, materials, and size of the lure can be made by those skilled in the art without departing from the invention. The invention is defined in the following claims.
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A sound producing fishing lure having an elongated body secured to a hook and a pair of bendable arms. Rod members attached to the arms rotatably support spinners that intermittently hit each other to produce fish attracting sounds. The arms are bendable to change the relative lateral positions of the spinners thereby change the sounds producing characteristics of the lure.
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CROSS REFERENCE TO RELATED APPLICATION
Reference is made to commonly assigned, co-pending U.S. patent application Ser. No. 10/020443 by Sadasivan et al., filed of even date herewith entitled “Ink Jet Recording Element”.
FIELD OF THE INVENTION
This invention relates to an ink jet printing method using an ink jet recording element. More particularly, this invention relates to an ink jet printing method using an ink jet recording element containing a multiplicity of particles.
BACKGROUND OF THE INVENTION
In a typical ink jet recording or printing system, ink droplets are ejected from a nozzle at high speed towards a recording element or medium to produce an image on the medium. The ink droplets, or recording liquid, generally comprise a recording agent, such as a dye or pigment, and a large amount of solvent. The solvent, or carrier liquid, typically is made up of water, an organic material such as a monohydric alcohol, a polyhydric alcohol or mixtures thereof.
An ink jet recording element typically comprises a support having on at least one surface thereof an ink-receiving or image-forming layer, and includes those intended for reflection viewing, which have an opaque support, and those intended for viewing by transmitted light, which have a transparent support.
It is well known that in order to achieve and maintain photographic-quality images on such an image-recording element, an ink jet recording element must:
Be readily wetted so there is no puddling, i.e., coalescence of adjacent ink dots, which leads to non-uniform density
Exhibit no image bleeding
Exhibit the ability to absorb high concentrations of ink and dry quickly to avoid elements blocking together when stacked against subsequent prints or other surfaces
Exhibit no discontinuities or defects due to interactions between the support and/or layer(s), such as cracking, repellencies, comb lines and the like
Not allow unabsorbed dyes to aggregate at the free surface causing dye crystallization, which results in bloom or bronzing effects in the imaged areas
Have an optimized image fastness to avoid fade from contact with water or radiation by daylight, tungsten light, or fluorescent light
An ink jet recording element that simultaneously provides an almost instantaneous ink dry time and good image quality is desirable. However, given the wide range of ink compositions and ink volumes that a recording element needs to accommodate, these requirements of ink jet recording media are difficult to achieve simultaneously.
Ink jet recording elements are known that employ porous or non-porous single layer or multilayer coatings that act as suitable image receiving layers on one or both sides of a porous or non-porous support. Recording elements that use non-porous coatings typically have good image quality but exhibit poor ink dry time. Recording elements that use porous coatings typically contain colloidal particulates and have poorer image quality but exhibit superior dry times.
While a wide variety of different types of porous image-recording elements for use with ink jet printing are known, there are many unsolved problems in the art and many deficiencies in the known products which have severely limited their commercial usefulness. A major challenge in the design of a porous image-recording layer is to be able to obtain good quality, crack-free coatings with as little non-particulate matter as possible. If too much non-particulate matter is present, the image-recording layer will not be porous and will exhibit poor ink dry times.
U.S. Pat. No. 5,912,071 relates to a recording medium comprising a substrate and a porous layer formed on the substrate wherein the porous layer comprises water-insoluble resin particles preferably having a core/shell structure. However, there is no disclosure in this reference of the use of a combination of water-insoluble, cationic, polymeric particles and particles having a core/shell structure. An element with an image-receiving layer that does not contain water-insoluble, cationic resin particles would not have good image quality. An element with an image-receiving layer that does not contain particles having a core/shell structure would exhibit cracking.
U.S. Pat. No. 6,099,956 relates to a recording medium comprising a support with a receptive layer coated thereon. The receptive layer comprises a water insoluble polymer, which is preferably, a copolymer comprising a styrene core with an acrylic ester shell. However, there is no disclosure in this reference of the use of a combination of water-insoluble, cationic, polymeric particles and particles having a core/shell structure. An element with an image-receiving layer that does not contain water-insoluble, cationic resin particles would not have good image quality. An element with an image-receiving layer that does not contain particles having a core/shell structure would exhibit cracking.
It is an object of this invention to provide an ink jet printing method employing a porous ink jet recording element that has instant dry time when used in ink jet printing. It is another object of this invention to provide an ink jet printing method employing a porous recording element that has good coating quality, especially reduced cracking. It is another object of this invention to provide an ink jet printing method employing an ink jet recording element that exhibits good image quality after printing.
SUMMARY OF THE INVENTION
These and other objects are achieved in accordance with the invention, which comprises an ink jet printing method comprising the steps of:
A) providing an ink jet printer that is responsive to digital data signals;
B) loading the printer with ink jet recording element comprising a substrate having thereon a porous image-receiving layer comprising
a) organic particles encapsulated with an organic polymer having a Tg of less than about 100° C.; and
b) water-insoluble, cationic, polymeric particles;
C) loading the printer with an ink jet ink composition; and
D) printing on the image-receiving layer using the ink jet ink composition in response to the digital data signals.
By use of the invention, an ink jet recording element is obtained that has good coating and image quality when used in ink jet printing.
DETAILED DESCRIPTION OF THE INVENTION
Any organic particle may be used to prepare the encapsulated particles employed in the invention. In a preferred embodiment, the organic particles are polymeric particles, such as particles made from poly(methylmethacrylate), poly(styrene), poly(p-methylstyrene), poly(t-butylacrylamide), poly(styrene-co-methylmethacrylate), poly(styrene-co-t-butylacrylamide), poly(methylmethacrylate-co-t-butylacrylamide), and homopolymers derived from p-cyanophenyl methacrylate, pentachlorophenyl acrylate, methacrylonitrile, isobornyl methacrylate, phenyl methacrylate, acrylonitrile, isobornyl acrylate, p-cyanophenyl acrylate, 2-chloroethyl acrylate, 2-chloroethyl methacrylate, 2-naphthyl acrylate, n-isopropyl acrylamide, 1-fluoromethyl methacrylate, isopropyl methacrylate, and 2-hydroxypropyl methacrylate. In a preferred embodiment of the invention, the core polymer is derived from a styrene-containing monomer or an acrylate-containing monomer, such as poly(methylmethacrylate), poly(styrene), poly(p-methylstyrene), poly(t-butylacrylamide) or poly(styrene-co-methylmethacrylate). In another preferred embodiment of the invention, the particle size of the inorganic particles is from about 5 nm to about 1000 nm. In yet another preferred embodiment of the invention, the Tg of the organic particle is at least about 60° C., preferably from about 60° C. to about 150° C.
The encapsulated particles used in the invention may be prepared in a preferred embodiment by polymerizing one or more monomers in the presence of the organic particles. Useful polymerization techniques can be found in “Emulsion Polymerization and Emulsion Polymers”, edited by P. A. Lovell and M. S. El-Aassar, John Wiley and Sons, 1997. Another embodiment relates to preparing the encapsulated particles by adsorbing polymer onto the surface of the organic particles. Another embodiment relates to preparing the encapsulated particles by forming chemical bonds between the organic particles and the polymer either before or after it is formed from the monomer.
The organic polymer used for encapsulation of the organic particles employed in the invention has a Tg of less than about 100° C., preferably from about −50° C. to about 65° C. Methods for determining Tg values of organic polymers are described in “Introduction to Physical Polymer Science”, 2nd Edition by L. H. Sperling, published by John Wiley & Sons, Inc., 1992. For each of the organic polymers in Table 1 below, the Tg value was calculated as the weighted sum of the Tg values for homopolymers derived from each of the individual monomers, i, that make up the polymer: Tg = ∑ i W i X i
where W is the weight percent of monomer i in the organic polymer, and X is the Tg value for the homopolymer derived from monomer i. Tg values for the homopolymers were taken from “Polymer Handbook”, 2nd Edition by J. Brandrup and E. H. Immergut, Editors, published by John Wiley & Sons, Inc., 1975.
In a preferred embodiment of the invention, monomers used to prepare the organic polymers of the encapsulated particles include acrylate and styrene monomers that may have a cationic, anionic, or nonionic functionality such as quaternary ammonium, pyridinium, imidazolium, sulfonate, carboxylate or phosphonate groups. Examples of useful monomers include: n-butyl acrylate, n-ethylacrylate, 2-ethylhexylacrylate, methoxyethylacrylate, methoxyethoxy-ethylacrylate, ethoxyethylacrylate, ethoxyethoxyethylacrylate, 2-ethylhexyl-methacrylate, n-propylacrylate, hydroxyethylacrylate, etc. and cationic monomers such as a salt of trimethylammoniumethyl acrylate and trimethylammoniumethyl methacrylate, a salt of triethylammoniumethyl acrylate and triethylammoniumethyl methacrylate, a salt of dimethylbenzylammoniumethyl acrylate and dimethylbenzylammoniumethyl methacrylate, a salt of dimethylbutylammoniumethyl acrylate and dimethylbutylammoniumethyl methacrylate, a salt of dimethylhexylammoniumethyl acrylate and dimethylhexylammoniumethyl methacrylate, a salt of dimethyloctylammoniumethyl acrylate and dimethyloctylammoniumethyl methacrylate, a salt of dimethyldodeceylammoniumethyl acrylate and dimethyldocecylammoniumethyl methacrylate, a salt of dimethyloctadecylammoniumethyl acrylate and dimethyloctadecylammoniumethyl methacrylate, etc. Salts of these cationic monomers that can be used include chloride, bromide, methylsulfate, triflate, etc.
Examples of the organic polymers which can be used in the invention to prepare the encapsulated particles include poly(n-butylacrylate-co-vinylbenzyltrimethylammonium chloride), poly(n-butylacrylate-co-vinylbenzyltrimethylammonium bromide), poly(n-butylacrylate-co-vinylbenzyldimethylbenzylammonium chloride) and poly(n-butylacrylate-co-vinylbenzyldimethyloctadecylammonium chloride). In a preferred embodiment of the invention, the polymer can be poly(n-butyl acrylate), poly(2-ethylhexyl acrylate), poly(methoxyethylacrylate), poly(ethoxyethylacrylate), poly(n-butylacrylate-co-trimethylammoniumethyl acrylate methylsulfate), poly(n-butylacrylate-co-trimethylammoniumethyl methacrylate methylsulfate) or poly(n-butylacrylate-co-vinylbenzyltrimethylammonium chloride).
Any weight ratio of organic particle to organic polymer in the encapsulated particles may be used. In a preferred embodiment, the weight ratio is 0.2:1 to 20:1. In another preferred embodiment, the weight ratio is 0.5:1 to 10:1.
Following are examples of organic particles encapsulated with an organic polymer which can be used in the invention:
TABLE 1
Encapsulated
Organic
Tg of
Ratio
Particle
Particle, A
Organic Polymer, B
B(° C.)
of A/B
1
Poly
Poly(n-butyl methacrylate-
40
1:1
(styrene)
co-ethyl methacrylate) (1:1)
2
Poly
Poly(ethyl methacrylate)
60
1:1
(styrene)
3
Poly
Poly(ethyl methacrylate-co-
82
1:1
(styrene)
methyl methacrylate) (1:1)
4
Poly
Poly(n-butylacrylate-co-
12
1:1
(styrene)
trimethylammoniumethyl
methacrylate methylsulfate)
(1:1)
5
Poly
Poly(n-butylacrylate-co-
1
10:1
(methyl
trimethylammoniumethyl
meth-
methacrylate methylsulfate)
acrylate)
(2:1)
6
Poly
Poly(ethyl methacrylate-co-
58
0.5:1
(methyl
trimethylammoniumethyl
meth-
methacrylate methylsulfate)
acrylate)
(2:1)
In a preferred embodiment of the invention, additional particles may be added to the image-receiving layer such as inorganic particles, e.g., metal oxides or hydroxides, such as alumina, boehmite, hydrated aluminum oxide, titanium oxide or zirconium oxide; clay; calcium carbonate; calcined clay; inorganic silicates; or barium sulfate. Organic particles such as polymeric beads may also be used. Examples of organic particles useful in the invention are disclosed and claimed in U.S. patent application Ser. No.: 09/458,401, filed Dec. 10, 1999, now U.S. Pat. No. 6,364,477; Ser. No. 09/608,969, filed Jun. 30, 2000, now U.S. Pat No. 6,492,006; Ser. No. 09/607,417, filed June 30, 2000, now U.S. Pat. No. 6,390,280; Ser. No. 09/608,466 filed Jun. 30, 2000, now U.S. Pat. No. 6,475,602; Ser. No. 09/607,419, filed Jun. 30, 2000, now U.S. Pat. No. 6,376,599; and Ser. No. 09/822,731, filed Mar. 30, 2001, now U.S. Pat. No. 6,541,103; the disclosures of which are hereby incorporated by reference. In still yet another preferred embodiment, the mean particle size of these additional particles is up to about 5 μm.
The water insoluble, cationic, polymeric particles useful in the invention can be in the form of a latex, water dispersible polymer, beads, or core/shell particles wherein the core is organic or inorganic and the shell in either case is a cationic polymer. Such particles can be products of addition or condensation polymerization, or a combination of both. They can be linear, branched, hyper-branched, grafted, random, blocked, or can have other polymer microstructures well known to those in the art. They also can be partially crosslinked. Examples of core/shell particles useful in the invention are disclosed and claimed in U.S. patent application Ser. No. 09/772,097, of Lawrence et al., Ink Jet Printing Method, filed Jan. 26, 2001, now U.S. Pat. No. 6,619,797, the disclosure of which is hereby incorporated by reference. Examples of water dispersible particles useful in the invention are disclosed and claimed in U.S. patent application Ser. No. 09/770,128, of Lawrence et al., Ink Jet Printing Method, filed Jan. 26, 2001, now U.S. Pat. No. 6,454,404; and U.S. patent application Ser. No. 09/770,127, of Lawrence et al., Ink Jet Printing Method, filed Jan. 26, 2001, now U.S. Pat. No. 6,503,608; the disclosures of which are hereby incorporated by reference. In a preferred embodiment, the water insoluble, cationic, polymeric particles comprise at least about 20 mole percent of a cationic mordant moiety.
In another preferred embodiment of the invention, the water insoluble, cationic, polymeric particles which may be used in the invention are in the form of a latex which contains a polymer having a quaternary ammonium salt moiety. In yet another preferred embodiment, the water-insoluble, cationic, polymeric particles comprises a mixture of latexes containing a polymer having a (vinylbenzyl)trimethyl quaternary ammonium salt moiety and a polymer having a (vinylbenzyl)dimethylbenzyl quaternary ammonium salt moiety.
The water insoluble, cationic, polymeric particles useful in the invention can be derived from nonionic, anionic, or cationic monomers. In a preferred embodiment, combinations of nonionic and cationic monomers are employed. In general, the amount of cationic monomer employed in the combination is at least about 20 mole percent.
The nonionic, anionic, or cationic monomers employed can include neutral, anionic or cationic derivatives of addition polymerizable monomers such as styrenes, alpha-alkylstyrenes, acrylate esters derived from alcohols or phenols, methacrylate esters, vinylimidazoles, vinylpyridines, vinylpyrrolidinones, acrylamides, methacrylamides, vinyl esters derived from straight chain and branched acids (e.g., vinyl acetate), vinyl ethers (e.g., vinyl methyl ether), vinyl nitriles, vinyl ketones, halogen-containing monomers such as vinyl chloride, and olefins, such as butadiene.
The nonionic, anionic, or cationic monomers employed can also include neutral, anionic or cationic derivatives of condensation polymerizable monomers such as those used to prepare polyesters, polyethers, polycarbonates, polyureas and polyurethanes.
The water insoluble, cationic, polymeric particles employed in this invention can be prepared using conventional polymerization techniques including, but not limited to bulk, solution, emulsion, or suspension polymerization. In a preferred embodiment of the invention, the water insoluble, cationic, polymeric particles employed have a mean particle size of from about 10 to about 500 nm.
Examples of water insoluble, cationic, polymeric particles which may be used in the invention include those described in U.S. Pat. No. 3,958,995, the disclosure of which is hereby incorporated by reference. Specific examples of these polymers include:
Polymer A. Copolymer of (vinylbenzyl)trimethylammonium chloride and divinylbenzene (87:13 molar ratio)
Polymer B. Terpolymer of styrene, (vinylbenzyl)dimethylbenzylamine and divinylbenzene (49.5:49.5:1.0 molar ratio)
Polymer C. Terpolymer of butyl acrylate, 2-aminoethylmethacrylate hydrochloride and hydroxyethylmethacrylate (50:20:30 molar ratio)
Polymer D. Copolymer of styrene, dimethylacrylamide, vinylbenzylimidazole and 1-vinylbenzyl-3-hydroxyethylimidazolium chloride (40:30:10:20 molar ratio)
Polymer E. Copolymer of styrene, 4-vinylpyridine and N-(2-hydroxyethyl)-4-vinylpyridinium chloride (30:38:32 molar ratio)
Polymer F. Copolymer of styrene, (vinylbenzyl)dimethyloctylammonium chloride), isobutoxymethyl acrylamide and divinylbenzene (40:20:34:6 molar ratio)
In a preferred embodiment of the invention, the encapsulated organic particles comprise up to about 50 wt. % of the image-receiving layer.
The amount of water insoluble, cationic, polymeric particles used should be high enough so that the images printed on the recording element will have a sufficiently high density, but low enough so that the interconnected pore structure formed by the aggregates is not filled. In a preferred embodiment of the invention, the water-insoluble, cationic, polymeric particles are present in an amount of from about 5 to about 30 weight % of the image-receiving layer.
The image-receiving layer employed in the invention may also contain a polymeric binder in an amount insufficient to alter its porosity. In a preferred embodiment, the polymeric binder is a hydrophilic polymer, such as poly(vinyl alcohol), poly(vinyl pyrrolidone), gelatin, cellulose ethers, poly(oxazolines), poly(vinylacetamides), partially hydrolyzed poly(vinyl acetate/vinyl alcohol), poly(acrylic acid), poly(acrylamide), poly(alkylene oxide), sulfonated or phosphated polyesters and polystyrenes, casein, zein, albumin, chitin, chitosan, dextran, pectin, collagen derivatives, collodian, agar-agar, arrowroot, guar, carrageenan, tragacanth, xanthan, rhamsan and the like; or a low Tg latex such as poly(styrene-co-butadiene), a polyurethane latex, a polyester latex, poly(n-butyl acrylate), poly(n-butyl methacrylate), poly(2-ethylhexyl acrylate), a copolymer of n-butylacrylate and ethylacrylate, a copolymer of vinylacetate and n-butylacrylate, etc. The polymeric binder should be chosen so that it is compatible with the aforementioned particles.
The amount of binder used should be sufficient to impart cohesive strength to the ink jet recording element, but should also be minimized so that the interconnected pore structure formed by the aggregates is not filled in by the binder. In a preferred embodiment of the invention, the weight ratio of the binder to the total amount of particles is from about 1:20 to about 1:5.
In addition to the image-receiving layer, the recording element may also contain a base layer, next to the support, the function of which is to absorb the solvent from the ink. Materials useful for this layer include inorganic particles and polymeric binder.
In addition to the image-receiving layer, the recording element may also contain a layer on top of the image-receiving layer, the function of which is to provide gloss. Materials useful for this layer include sub-micron inorganic particles and/or polymeric binder.
The support for the ink jet recording element used in the invention can be any of those usually used for ink jet receivers, such as resin-coated paper, paper, polyesters, or microporous materials such as polyethylene polymer-containing material sold by PPG Industries, Inc., Pittsburgh, Pa. under the trade name of Teslin®, Tyvek® synthetic paper (DuPont Corp.), impregnated paper such as Duraform®, and OPPalyte® films (Mobil Chemical Co.) and other composite films listed in U.S. Pat. No. 5,244,861. Opaque supports include plain paper, coated paper, synthetic paper, photographic paper support, melt-extrusion-coated paper, and laminated paper, such as biaxially oriented support laminates. Biaxially oriented support laminates are described in U.S. Pat. Nos. 5,853,965; 5,866,282; 5,874,205; 5,888,643; 5,888,681; 5,888,683; and 5,888,714, the disclosures of which are hereby incorporated by reference. These biaxially oriented supports include a paper base and a biaxially oriented polyolefin sheet, typically polypropylene, laminated to one or both sides of the paper base. Transparent supports include glass, cellulose derivatives, e.g., a cellulose ester, cellulose triacetate, cellulose diacetate, cellulose acetate propionate, cellulose acetate butyrate; polyesters, such as poly(ethylene terephthalate), poly(ethylene naphthalate), poly(1,4-cyclohexanedimethylene terephthalate), poly(butylene terephthalate), and copolymers thereof; polyimides; polyamides; polycarbonates; polystyrene; polyolefins, such as polyethylene or polypropylene; polysulfones; polyacrylates; polyetherimides; and mixtures thereof. The papers listed above include a broad range of papers, from high end papers, such as photographic paper to low end papers, such as newsprint. In a preferred embodiment, Ektacolor paper made by Eastman Kodak Co. is employed.
The support used in the invention may have a thickness of from about 50 to about 500 μm, preferably from about 75 to 300 μm. Antioxidants, antistatic agents, plasticizers and other known additives may be incorporated into the support, if desired.
In order to improve the adhesion of the image-receiving layer to the support, the surface of the support may be subjected to a corona-discharge treatment prior to applying the image-receiving layer. The adhesion of the image-receiving layer to the support may also be improved by coating a subbing layer on the support. Examples of materials useful in a subbing layer include halogenated phenols and partially hydrolyzed vinyl chloride-co-vinylacetate polymer.
The coating composition can be coated either from water or organic solvents, however water is preferred. The total solids content should be selected to yield a useful coating thickness in the most economical way, and for particulate coating formulations, solids contents from 10-40 wt. % are typical.
Coating compositions employed in the invention may be applied by any number of well known techniques, including dip-coating, wound-wire rod coating, doctor blade coating, gravure and reverse-roll coating, slide coating, bead coating, extrusion coating, curtain coating and the like. Known coating and drying methods are described in further detail in Research Disclosure no. 308119, published December 1989, pages 1007 to 1008. Slide coating is preferred, in which the base layers and overcoat may be simultaneously applied. After coating, the layers are generally dried by simple evaporation, which may be accelerated by known techniques such as convection heating.
The coating composition may be applied to one or both substrate surfaces through conventional pre-metered or post-metered coating methods such as blade, air knife, rod, roll coating, etc. The choice of coating process would be determined from the economics of the operation and in turn, would determine the formulation specifications such as coating solids, coating viscosity, and coating speed.
The image-receiving layer thickness may range from about 1 to about 60 μm, preferably from about 5 to about 40 μm.
After coating, the ink jet recording element may be subject to calendering or supercalendering to enhance surface smoothness. In a preferred embodiment of the invention, the ink jet recording element is subject to hot soft-nip calendering at a temperature of about 65° C. and a pressure of 14000 kg/m at a speed of from about 0.15 m/s to about 0.3 m/s.
In order to impart mechanical durability to an ink jet recording element, crosslinkers which act upon the binder discussed above may be added in small quantities. Such an additive improves the cohesive strength of the layer. Crosslinkers such as carbodiimides, polyfunctional aziridines, aldehydes, isocyanates, epoxides, polyvalent metal cations, and the like may all be used.
To improve colorant fade, UV absorbers, radical quenchers or antioxidants may also be added to the image-receiving layer as is well known in the art. Other additives include pH modifiers, adhesion promoters, rheology modifiers, surfactants, biocides, lubricants, dyes, optical brighteners, matte agents, antistatic agents, etc. In order to obtain adequate coatability, additives known to those familiar with such art such as surfactants, defoamers, alcohol and the like may be used. A common level for coating aids is 0.01 to 0.30 wt. % active coating aid based on the total solution weight. These coating aids can be nonionic, anionic, cationic or amphoteric. Specific examples are described in MCCUTCHEON's Volume 1: Emulsifiers and Detergents, 1995, North American Edition.
Ink jet inks used to image the recording elements employed in the present invention are well-known in the art. The ink compositions used in ink jet printing typically are liquid compositions comprising a solvent or carrier liquid, dyes or pigments, humectants, organic solvents, detergents, thickeners, preservatives, and the like. The solvent or carrier liquid can be solely water or can be water mixed with other water-miscible solvents such as polyhydric alcohols. Inks in which organic materials such as polyhydric alcohols are the predominant carrier or solvent liquid may also be used. Particularly useful are mixed solvents of water and polyhydric alcohols. The dyes used in such compositions are typically water-soluble direct or acid type dyes. Such liquid compositions have been described extensively in the prior art including, for example, U.S. Pat. Nos. 4,381,946; 4,239,543 and 4,781,758, the disclosures of which are hereby incorporated by reference.
The following examples are provided to illustrate the invention.
EXAMPLES
Synthesis of Encapsulated Particle 1 Employed in the Invention
200 g of deionized water and 2 g of cetyltrimethylammonium bromide (CTAB) were mixed in a 2 L 3-neck round bottom flask equipped with a mechanical stirrer, condenser and nitrogen inlet. The flask was immersed in a constant temperature bath at 80° C. and purged with nitrogen for 20 min. 0.5 g of 2,2′-azobis(2-methylpropionamidine) hydrochloride (AMA) was then added.
A monomer emulsion comprising 200 g of styrene, 2 g of AMA, 20 g of CTAB and 200 g of deionized water was added over one hour with constant agitation. The reaction mixture was stirred for an additional 30 minutes. A second monomer emulsion comprising 100 g of n-butyl methacrylate, 100 g of ethyl methacrylate, 2 g of AMA, 20 g of CTAB and 200 g of deionized water was added over one hour. The reaction mixture was stirred for an additional hour and then cooled to 60° C. 4 mL of 10 wt. % t-butyl hydroperoxide and 10 wt. % formaldehyde-sulfite were added and the resulting reaction mixture stirred for 30 minutes at 60° C. The reaction mixture was then cooled to room temperature and filtered. The resulting dispersion was 40 wt. % solids and the particle size was 68 nm.
Synthesis of Encapsulated Particle 2 Employed in the Invention
200 g of deionized water and 2 g of CTAB were mixed in a 2 L 3-neck round bottom flask equipped with a mechanical stirrer, condenser and nitrogen inlet. The flask was immersed in a constant temperature bath at 80° C. and purged with nitrogen for 20 min. 0.5 g of AMA was then added.
A monomer emulsion comprising 200 g of styrene, 2 g of AMA, 20 g of CTAB and 200 g of deionized water was added over one hour with constant agitation. The reaction mixture was stirred for an additional 30 minutes. A second monomer emulsion comprising 200 g of ethyl methacrylate, 2 g of AMA, 20 g of CTAB and 200 g of deionized water was added over one hour. The reaction mixture was stirred for an additional hour and then cooled to 60° C. 4 mL of 10 wt. % t-butyl hydroperoxide and 10 wt. % formaldehyde-sulfite were added and the resulting reaction mixture stirred for 30 minutes at 60° C. The reaction mixture was then cooled to room temperature and filtered. The resulting dispersion was 41 wt. % solids and the particle size was 72 nm.
Synthesis of Encapsulated Particle 3 Employed in the Invention
200 g of deionized water and 2 g of CTAB were mixed in a 2 L 3-neck round bottom flask equipped with a mechanical stirrer, condenser and nitrogen inlet. The flask was immersed in a constant temperature bath at 80° C. and purged with nitrogen for 20 min. 0.5 g of AMA was then added.
A monomer emulsion comprising 200 g of styrene, 2 g of AMA, 20 g of CTAB and 200 g of deionized water was added over one hour with constant agitation. The reaction mixture was stirred for an additional 30 minutes. A second monomer emulsion comprising 100 g of ethyl methacrylate, 100 g of methyl methacrylate, 2 g of AMA, 20 g of CTAB and 200 g of deionized water was added over one hour. The reaction mixture was stirred for an additional hour and then cooled to 60° C. 4 mL of 10 wt. % t-butyl hydroperoxide and 10 wt. % formaldehyde-sulfite were added and the resulting reaction mixture stirred for 30 minutes at 60° C. The reaction mixture was then cooled to room temperature and filtered. The resulting dispersion was 39 wt. % solids and the particle size was 70 nm.
Element 1 of the Invention
A coating solution for a base layer was prepared by mixing 254 dry g of precipitated calcium carbonate Albagloss-s® (Specialty Minerals Inc.) as a 70% solution, 22 dry g of silica gel Gasil® 23F (Crosfield Ltd.), 2.6 dry g of poly(vinyl alcohol) Airvol® 125 (Air Products) as a 10% solution, 21 dry g of styrene-butadiene latex CP692NA® (Dow Chemical Co.) as a 50% solution and 0.8 g of Alcogum® L-229 (Alco Chemical Co.). The solids of the coating solution was adjusted to 35 wt. % by adding water. The base layer coating solution was bead-coated at 25° C. on Ektacolor Edge Paper (Eastman Kodak Co.) and dried by forced air at 60° C. The thickness of the base layer was 25 μm or 27 g/m 2 .
A coating solution for the image receiving layer was prepared by mixing 15.0 dry g of alumina Dispal® 14N4-80 (Condea Vista) as a 20 wt. % solution, 2.4 dry g of fumed alumina Cab-O-Sperse® PG003 (Cabot Corp.) as a 40 wt. % solution, 0.6 dry g of poly(vinyl alcohol) Gohsenol® GH-17 (Nippon Gohsei Co. Ltd.) as a 10 wt. % solution, 1.2 dry g of Polymer A as a 20 wt. % solution, 1.2 dry g of Polymer B as a 20 wt. % solution, 0.9 dry g of Encapsulated Particles 1 as a 40 wt. % solution, 0.1 g of Silwet® L-7602 (Witco. Corp.), 0.2 g of Silwet® L-7230 (Witco. Corp.) and water to total 153 g.
The image-receiving layer coating solution was bead-coated at 25° C. on top of the base layer described above. The recording element was then dried by forced air at 60° C. for 80 seconds followed by 38° C. for 8 minutes. The thickness of the image-receiving layer was 8 μm or 8.6 g/m 2 .
Element 2 of the Invention
This element was prepared the same as Element 1 except that 0.9 dry g of Encapsulated Particles 2 as a 41 wt. % solution was used instead of Encapsulated Particles 1.
Element 3 of the Invention
This element was prepared the same as Element 1 except that 0.9 dry g of Encapsulated Particles 3 as a 39 wt. % solution was used instead of Encapsulated Particles 1.
Synthesis of Comparative Encapsulated Particles 1 (Tg of Encapsulating Polymer is greater than 100° C.)
200 g of deionized water and 2 g of CTAB were mixed in a 2 L 3-neck round bottom flask equipped with a mechanical stirrer, condenser and nitrogen inlet. The flask was immersed in a constant temperature bath at 80° C. and purged with nitrogen for 20 min. 0.5 g of AMA was then added.
A monomer emulsion comprising 200 g of styrene, 2 g of AMA, 20 g of CTAB and 200 g of deionized water was added over one hour with constant agitation. The reaction mixture was stirred for an additional 30 minutes. A second monomer emulsion comprising 200 g of methyl methacrylate, 2 g of AMA, 20 g of CTAB and 200 g of deionized water was added over one hour. The reaction mixture was stirred for an additional hour and then cooled to 60° C. 4 mL of 10 wt. % t-butyl hydroperoxide and 10 wt. % formaldehyde-sulfite were added and the resulting reaction mixture stirred for 30 minutes at 60° C. The reaction mixture was then cooled to room temperature and filtered. The resulting dispersion was 40 wt. % solids and the particle size was 70 nm. The Tg of the encapsulating organic polymer is about 105° C.
Synthesis of Comparative Encapsulated Particles 2 (Tg of Encapsulating Polymer is greater than 100° C.)
200 g of deionized water and 2 g of CTAB were mixed in a 2 L 3-neck round bottom flask equipped with a mechanical stirrer, condenser and nitrogen inlet. The flask was immersed in a constant temperature bath at 80° C. and purged with nitrogen for 20 min. 0.5 g of AMA was then added.
A monomer emulsion comprising 200 g of styrene, 2 g of AMA, 20 g of CTAB and 200 g of deionized water was added over one hour with constant agitation. The reaction mixture was stirred for an additional 30 minutes. A second monomer emulsion comprising 190 g of methyl methacrylate, 10 g of ethylene glycol dimethacrylate, 2 g of AMA, 20 g of CTAB and 200 g of deionized water was added over one hour. The reaction mixture was stirred for an additional hour and then cooled to 60° C. 4 mL of 10 wt. % t-butyl hydroperoxide and 10 wt. % formaldehyde-sulfite were added and the resulting reaction mixture stirred for 30 minutes at 60° C. The reaction mixture was then cooled to room temperature and filtered. The resulting dispersion was 40 wt. % solids and the particle size was 76 nm.
The Tg of the encapsulating organic polymer is about 110° C. The presence of a small amount of the ethyleneglycol dimethacrylate increases the Tg value of the homopolymer derived from methyl methacrylate by about 5° C.
Comparative Element 1
This element was prepared the same as Element 1 except that 0.9 dry g of Comparative Encapsulated Particles 1 as a 40 wt. % solution was used instead of Encapsulated Particles 1.
Comparative Element 2
This element was prepared the same as Element 1 except that 0.9 dry g of Comparative Encapsulated Particles 2 as a 40 wt. % solution was used instead of Encapsulated Particles 1.
Coating Quality
The above dried coatings for visually evaluated for cracking defects. Results are tabulated in Table 2 below.
Image Quality & Dry Time
An Epson Stylus Color 740 printer for dye-based inks using Color Ink Cartridge S0201911/IC3CL01 was used to print on the above recording elements. The image consisted of adjacent patches of cyan, magenta, yellow, black, green, red and blue patches, each patch being in the form of a rectangle 0.4 cm in width and 1.0 cm in length. Bleed between adjacent color patches was qualitatively assessed. A second image was printed, and immediately after ejection from the printer, the image was wiped with a soft cloth. The dry time was rated as 1 if no ink and was smudged on the image. The dry time was rated as 2 if some ink smudged, and 3 if a lot of ink smudged. Results are shown in Table 2 as follows:
TABLE 2
Recording
Coating
Element
Quality
Image Quality
Dry Time
1
No cracking
Little bleeding
1
2
No cracking
Little bleeding
1
3
No cracking
Little bleeding
1
Comparative 1
Cracking
Severe Bleeding
2
Comparative 2
Cracking
Severe Bleeding
2
The above table shows that the recording elements employed in the invention have good coating quality, image quality and instant dry time as compared to the comparative recording elements.
This invention has been described with particular reference to preferred embodiments thereof but it will be understood that modifications can be made within the spirit and scope of the invention.
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An ink jet printing method having the steps of: A) providing an ink jet printer that is responsive to digital data signals; B) loading the printer with ink jet recording element having a substrate having thereon a porous image-receiving layer of a) organic particles encapsulated with an organic polymer having a Tg of less than about 100 ° C.; and b) water-insoluble, cationic, polymeric particles; C) loading the printer with an ink jet ink composition; and D) printing on the image-receiving layer using the inkjet ink composition in response to the digital data signals.
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BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates generally to attitude determination systems and, more particularly, to a method and apparatus for autonomous attitude acquisition for a stellar inertial attitude determination system.
(b) Description of Related Art
The term attitude is used to describe the orientation of an object with respect to a reference orientation. Attitude is of particular interest in satellite operations. For example, if a satellite is to be used in a communications application, it is necessary that the satellite be oriented in the proper direction to receive and/or transmit relevant information for the communication link. The attitude of a satellite is determined by computations based on the output of attitude sensors located on the satellite. Attitude sensors monitor the position of reference objects, which may include the sun, the earth, stars and/or star constellations, or radio frequency beacons. For example, a spacecraft may have two or more sensors, one monitoring the sun and one monitoring the earth. However, sun sensors are ineffective when the sun cannot be observed (i.e., when the earth is between the satellite and the sun). Better availability of multiple stars in the sky makes star trackers the preferred attitude measurement devices in many spacecraft applications.
A spacecraft may use two or more star trackers to monitor the position of constellations or stars with respect to the spacecraft. Attitude is determined by comparing information from the star trackers to information in an on-board star catalog (OSC). An OSC includes information such as direction to the stars (right ascension or declination) in the ECI frame and the magnitude of brightness of certain stars. Stars observed by the star trackers that are located in the OSC are commonly referred to as OSC stars. A comparison between where stars are sensed, with respect to the satellite, by the star tracker and the stars in the OSC enables the satellite to determine its attitude.
Comparisons between sensed stars and OSC stars may be made in two different ways: pattern matching and direct matching. When a satellite or spacecraft has no information about its attitude, the spacecraft is "lost in space." When a spacecraft is lost in space, it must acquire its attitude in order to begin its mission. Attitude acquisition is typically performed through pattern matching. To perform pattern matching, the lost spacecraft observes constellations and compares the constellations observed using its star trackers to the stars in the OSC. Various pattern matching methods are disclosed in several U.S. patents. For example, U.S. Pat. Nos. 4,621,329 and 4,944,587 to Jacob and Harigae, respectively, disclose pattern matching methods based on processing a single snap-shot of the sky taken by star trackers. Some pattern matching approaches use a priori information of spacecraft position to reduce the size of the OSC needed. Exemplary systems are disclosed in U.S. Pat. Nos. 4,658,361 and 5,177,686 to Kosaka et al. and Boinghoff et al., respectively.
Once attitude acquisition is performed, spacecraft attitude is basically known within some tolerance. Once this a priori information is known, a direct match procedure may be used to fine-tune and maintain the attitude of the spacecraft. Direct matching uses star trackers to observe stars and examines the observed stars to find a direct match between the observed stars and the OSC stars. When a direct match is found, a reference vector to the star in the ECI frame is calculated and spacecraft attitude is precisely determined.
Star trackers vary in both sensitivity and field-of-view (FOV). Field-of-view is a measure of how broad an area of sky a tracker can monitor. The sensitivity of a star tracker determines how bright a star must be before it can be detected by the tracker. The FOV and sensitivity of a star tracker dictate how many stars that tracker can observe at a given instant in time. To acquire attitude using star trackers and a pattern matching method, at least three OSC stars must be observed at one time. The use of narrow FOV sensors or sensors with reduced sensitivity lowers the probability that sufficient number of OSC stars will be observable by the star trackers. If sufficient OSC stars are not available in the tracker FOV, attitude cannot be acquired using pattern matching.
Disclosed prior systems, which use only a single snap-shot of the sky, require a sufficient number of stars in the star tracker FOV in order to acquire spacecraft attitude. Therefore, in many instances, spacecraft attitude may not be acquired due to insufficient OSC stars in the star tracker FOV. Accordingly, there is a need for a star-based attitude acquisition method that provides attitude information when insufficient OSC stars are present in the star tracker field-of-view in a single measurement.
SUMMARY OF THE INVENTION
The present invention is embodied in a method of autonomous determination of spacecraft attitude. The method includes the steps of using a star tracker to observe a first set of stars at a first instant in time, forming a set of candidate star triplets from the first set of stars, and pattern matching each candidate star triplet to an on-board star catalog to determine a set of pattern matches. The method of the present invention further includes the steps of forming a set of candidate spacecraft attitudes based on the pattern matches and performing a rejection method on the set of candidate spacecraft attitudes to eliminate certain candidate spacecraft attitudes from the set of candidate spacecraft attitudes.
In one embodiment, the rejection method includes the steps of using the star tracker to observe a second set of stars at a second instant in time and eliminating certain candidate spacecraft attitudes from the set of candidate spacecraft attitudes if a number of the stars in the observed second set of stars do not match the on-board star catalog.
In another embodiment the rejection method includes the steps of designating each candidate spacecraft attitude with a propagated attitude at an instant in time and the time at which the propagated attitude was measured, computing the difference between a past attitude measurement and a current propagated attitude measurement, and determining a largest string of consistent measurements based on the computed difference. The method further includes the step of terminating the rejection method when the largest string reaches critical length.
The present invention also proposes a method of calibrating an inertial sensor. The method includes the steps of observing a star at a first time, determining if the observed star has been measured previously, retrieving reference measurements if the observed star has been measured previously, and computing a bias estimate based on the observed position of the star and previous measurements of the star.
The present invention is also embodied in a spacecraft including star trackers for observing stars in the sky, inertial sensors for detecting body rates of the spacecraft, and a spacecraft control processor that receives attitude-related position information from the star trackers and the inertial sensors. The spacecraft control processor is programmed to manipulate the star trackers to observe a first set of stars at a first instant in time, form a set of candidate star triplets from the observed stars, and pattern match each candidate star triplet to an on-board star catalog to determine a set of pattern matches. The spacecraft control processor of the present invention is further programmed to form a set of candidate spacecraft attitudes based on the pattern matches and perform a rejection method on the set of candidate spacecraft attitudes to eliminate certain candidate spacecraft attitudes from the set of candidate spacecraft attitudes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a satellite system in which the present invention may be implemented;
FIG. 2 is a block diagram of the satellite control processor portion of the satellite system shown in FIG. 1;
FIG. 3 is a block diagram showing detail of the spacecraft attitude determination function shown in FIG. 2;
FIG. 4 is a flow chart representation of the functionality of the present invention;
FIG. 5 is a flow chart representation of the calibration method of the present invention;
FIG. 6 is a flow chart representation of a rejection method shown in FIG. 4; and
FIG. 7 is an alternative flow chart representation of the rejection method shown in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a satellite system 10 in which the present invention may be implemented is shown. The satellite system 10 includes a satellite 15, which further includes star trackers 20, 25, a spacecraft control processor 30, an antenna 33, thrusters 35, and inertial sensors 36. The star trackers 20, 25 may be embodied in digital cameras based on charge coupled devices (CCDs) The star trackers 20, 25 have fields-of-view 21, 26, which are used to monitor stars and/or celestial constellations 22, 27. The star trackers 20, 25 and are used to determine the attitude of the satellite 15. The outputs from the star trackers 20, 25 are fed to the spacecraft control processor 30, which is responsible for attitude acquisition, determination, and adjustment. Attitude determination may be critical, for example, for a satellite 15 to maintain proper attitude in order to keep the earth footprint 50 of the antenna 33 in a desired location to provide satellite coverage to a particular geographical area 50 on the earth 40.
The satellite 15 also includes inertial sensors 36, which are used to monitor the body rates of the satellite 15. Information from the inertial sensors 36 is used in conjunction with the star trackers 20, 25 to acquire the attitude of the satellite in conjunction with the present invention. The thrusters 35 are used to propel and steer the satellite 15. The steering of the satellite 15 is critical to the attitude acquisition method of the present invention.
FIG. 2 is a block diagram of a spacecraft attitude determination and control function 55 embodying the present invention. The spacecraft attitude determination and control function 55 includes the star trackers 20, 25, the inertial sensors 36, and the spacecraft control processor 30. The functions, which will be subsequently described as residing within the spacecraft control processor 30, may be software functions. Alternatively, the functions within the spacecraft control processor 30 may be hardware implementations of the described functions, which reside outside of the spacecraft control processor 30. Hardware implementations of the functions may utilize technology such as application specific integrated circuits (ASICs). The spacecraft control processor includes a attitude reference source 70, a spacecraft attitude determination function 75, a spacecraft attitude control function 80 and a steering command function 85.
The star trackers 20, 25 employed by the present invention are capable of measuring the position of stars or constellations in the star tracker reference frame. The position of two stars may be sufficient to acquire spacecraft attitude. However, three stars is a practical minimum for star pattern identification due to star positions, magnitude uncertainties, and required computational burden. The output of the star trackers 20, 25 is either pixel information representative of the image that is observed by the star tracker or horizontal and vertical information regarding the position of stars in the star tracker FOV. Additionally, star tracker output may include magnitude information based on the the stars observed. The inertial sensors 36 may be gyroscopes or any other mechanisms capable of measuring inertial acceleration and body rates. The sensors 20, 25, and 36 are mounted in a conventional manner to a satellite structure. The star trackers 20, 25 outputs and the inertial sensor outputs are fed to the spacecraft control processor 30 and, more specifically, to the spacecraft attitude determination function 75.
The attitude reference source 70 of the spacecraft control processor 30 may be embodied in an on-board star catalog (OSC), which includes a listing of stars within the sensitivity range of the star tracker and star retrieval functions. The OSC is created on the ground prior to satellite launch. The OSC may include star pattern features that are spacecraft orientation independent, such as star separations. The attitude reference source 70 is in communication with the spacecraft attitude determination function 75.
The spacecraft attitude determination function 75 outputs an estimated spacecraft attitude measurement expressed in terms of a directional cosine matrix C m and an estimated spacecraft body rate ω m to the spacecraft attitude control function 80. The spacecraft attitude control function 80 uses estimated attitude and body rate inputs together with steering commands to generate a set of spacecraft torque commands which are fed to actuators, such as thrusters 35. The thrusters 35 are used to alter the attitude of the spacecraft in response to torque commands. Alternatively, actuators may be embodied in devices such as reaction wheels or magnetic torquers. While the spacecraft attitude control function 80 uses estimated attitude and body rate inputs to correct attitude, the steering command function 85 issues steering commands to alter the desired attitude in a manner consistent with the spacecraft mission. In the case of star acquisition, which is the object of the present invention, the steering command function 85 commands the satellite to various positions to allow the star trackers 20, 25, and the spacecraft control processor 30 to take attitude measurements. The spacecraft attitude control function 80 processes the steering commands, the estimated body rates, and the estimated spacecraft attitude to produce a set of torque commands that are coupled to thrusters or other torque devices.
FIG. 3 is a software functional block diagram showing further detail of the spacecraft attitude determination function 75 of FIG. 2. The spacecraft attitude determination function 75 includes, star tracker output combining circuitry 90, a star identification function 92, an attitude acquisition function 93, an attitude processing function 95, a gyro calibration function 100, and an attitude propagation function 105.
The star tracker output combining circuitry 90, combines the various outputs of the star trackers 20, 25 into an array of measurements. The array of measurements is coupled to the star identification function 92, which compares the output of the star trackers 20, 25 to the attitude reference source 70. The star identification function 92 performs a dual function in the present invention. While the spacecraft is "lost in space," the star identification function 92 is used to calibrate the inertial sensors 36. However, after attitude is acquired, the star identification function 92 performs the function of direct matching star tracker output to the OSC in the attitude reference source 70.
In accordance with the present invention, the attitude acquisition function 93 is employed when the satellite is "lost in space" and is disabled once satellite attitude is acquired. As will be explained in greater detail in conjunction with FIG. 4, the attitude acquisition function 93 receives a pseudo reference attitude from the attitude propagation function 105 when the satellite has not acquired its attitude. The pseudo reference attitude is any attitude that the attitude propagation function 105 is producing. This attitude is merely used for reference and will be updated at a later time with the proper, acquired attitude. The attitude acquisition function 93 examines the output of the star tracker combining function 90 to determine if sufficient stars are visible and if attitude may be acquired from a first position. If sufficient stars are not available, the satellite steers to a second position where it can observe new stars. The attitude acquisition function 93 correlates the stars observed from the first and second positions with the output from the attitude propagation function 105 to acquire attitude. If, again, sufficient stars are not available, the satellite steers to a third position and correlates the stars observed in all three positions with information from the attitude propagation function 105. In accordance with the present invention, the operation of repeatedly maneuvering the satellite and observing stars while correlating all observed stars using inertial information allows the satellite to acquire its attitude in an efficient manner. After attitude is acquired, the attitude acquisition function 93 transfers the acquired attitude to the attitude propagation function 105, which replaces the pseudo reference attitude with the newly acquired attitude. Once attitude is acquired, the attitude acquisition function 93 is disabled and the attitude processing function 95 performs the function of maintaining satellite attitude through star tracker 220, 25 and inertial sensor 36 information.
The attitude processing function 95 may be embodied in an extended Kalman filtering function. The gyro calibration function 100 processes and calibrates outputs from the inertial sensors 36. This calibration is performed in conjunction with the attitude processing function 95 and the attitude propagation function 105. The attitude propagation function 105, which integrates corrected gyro rates to determine attitude is also in communication with the attitude processing function 95.
FIG. 4 is a block diagram representation of the functionality that is carried out by the software representing the spacecraft attitude determination function 75 according to the present invention. Generally, the attitude determination function 75 matches star tracker outputs to OSC patterns from the attitude reference source 70 and rejects certain previously matched patterns to acquire satellite attitude. According to the present invention, inertial rate information is used in conjunction with star tracker output to accurately and efficiently acquire satellite attitude. The method of the present invention is executed by the spacecraft attitude determination function 75. The star tracker output combining circuitry 90, the attitude processing function 95, the gyro calibration function 100, and the attitude propagation function 105 of the spacecraft attitude determination function 75 collectively perform the functionality represented in FIG. 4.
Referring again to FIG. 4, a step 150 initializes the method of the present invention. Step 150 begins steering the spacecraft according to the requirements of the spacecraft mission, initializes spacecraft attitude, and initializes a gyroscope calibration method.
Step 155 performs the functions of propagating spacecraft attitude based on gyroscope outputs and calibrating the gyroscopes. FIG. 5 is a flow chart representing a method by which gyroscope calibration may be performed. First, step 157 selects a star to track, which is done using the star trackers 20, 25. After a star has been selected, control is passed to step 159. Step 159 determines if the current measurement corresponds to a previously measured star. If the current measurement does not correspond, control is passed to step 161. Step 161 stores the current information for later use as reference for the next measurement of the current star. After step 161 is complete, control passes to step 170 of FIG. 4.
If, however, the current measurement information does correspond to a previously measured star, control is passed from step 159 to step 163. Step 163 retrieves any reference measurements made for the current star that is being measured. The retrieved information is used by step 165 to calculate updates to gyro bias and attitude error. After step 165 calculates the updates, control is returned to step 170 of FIG. 4. The functionality of 155 may be performed by the star identification function 92. Steps 157 to 165 are performed for every star measurement and every attitude update time of the satellite spacecraft control processor 30.
After step 155 of FIG. 4 is complete, control is passed to step 170, which performs the function of manipulating the star trackers 20, 25 to take a picture of the sky, such that the picture has at least three stars present. After the picture is taken, step 170 performs the function of forming a set of candidate star triplets. A star triplet is any three-star combination of stars observed by the star trackers 20, 25. For example, if three stars are present in the picture, there is only one star triple that may be formed. However, if five stars are in the picture, ten star triplets may be formed from the five stars.
After all of the triplets have been formed by step 170, step 175 performs a pattern match by comparing each star triplet to the OSC. This step uses all patterns to form a candidate set of spacecraft attitudes. That is, if matches are found, any match is classified into a candidate set of spacecraft attitudes. After step 175 has completed, step 180 determines if any candidates have been found. If no candidates have been found, control passes to step 185, which waits for new sky to come into the view of the star trackers 20, 25. Because the spacecraft is moving, step 185 effectively widens the FOV of the star trackers. That is, because the spacecraft is being steered, new stars are constantly coming into the view of the star trackers. Therefore, if no matches are found at a particular time, at some later time it is possible that matches will come into view of the star trackers. In an alternative implementation, star observed in different time frames may be combined using gyro-propagated attitude estimates to be processed by the pattern match algorithm.
If step 180 determines that matches are found, control passes to step 190, which uses all pattern matches to form a set of candidate spacecraft attitudes. After the set of a candidate spacecraft attitudes have been selected, control passes to step 192, which waits for new sky. New sky may be observed through spacecraft steering and reorientation to allow the star trackers 20, 25 to observe new sky. After new sky is available, control passes to step 195, which performs a pattern rejection on the spacecraft candidate attitudes. A flow chart of an exemplary pattern rejection method is shown in FIG. 6. Referring to FIG. 6, step 200 makes star observations until six new stars are observed by the star trackers. Once six new stars are observed, control passes to step 205. Step 205 compares position and magnitude of the newly observed stars to the OSC for each attitude candidate. If less than three stars match the OSC for a given attitude candidate, that candidate is removed from consideration. The functionality of step 205 continues until all attitude candidates are evaluated on the basis of the newly observed stars in comparison to the OSC.
FIG. 7 is a flow chart illustrating an alternative pattern rejection method in accordance with the present invention. The method is based on the consistency between gyro propagated attitudes and attitude candidates. The method will be explained in conjunction with Table 1 below.
TABLE 1______________________________________ C.sub.1 C.sub.2 C.sub.3 C.sub.4______________________________________C.sub.1 -- C I IC.sub.2 -- -- C IC.sub.3 -- -- -- IC.sub.4 -- -- -- --______________________________________
Table 1 is a convenient way to represent the consistency checks that are used in one embodiment of the rejection method. The terms along the top and right side of the table represent four attitude candidates that were produced by step 190 of FIG. 4. Each cell in the top right hand corner of the table is filled with either a C indicating that there is consistency or I indicating that there is inconsistency between the attitude candidates in the corresponding row and column.
Referring again to FIG. 7, step 210 performs the function of stamping each attitude candidate with its propagated attitude and the time at which the attitude was taken. After each attitude candidate has been stamped, step 215 compares all past attitude measurements with the current propagated attitude of each attitude candidate. This comparison includes computing the difference between past attitudes of an attitude candidate and current propagated attitude. All differences should be equal, within a tolerance. The tolerance is a function of time between when attitude candidates were taken and the rate at which the spacecraft move in that time. The comparison is used to determine the consistency of the attitude candidates. Consistency or inconsistency is determined using the matrix equation shown in Equation 1.
∥(C.sub.1.sup.T ·C.sub.2).sup.T (C.sub.1.sup.T ·C.sub.2)-I.sub.3×3 ∥<Threshold Equation 1
In Equation 1, all the directional cosine matrices C represent attitude candidates and all "C hat" terms represent corresponding gyro propagated attitudes. The first parenthetical term represents the difference between the two gyro propagated attitudes. Likewise, the second parenthetical term represents the difference between two attitude candidates. If two candidates are consistent, the multiplication of the transpose of the first parenthetical term with the second parenthetical term will yield a small result. The identity matrix of Equation 1 represents no attitude rotation. Therefore, when the parenthetical terms are combined as shown in Equation 1 and the identity matrix is subtracted from the product, the normalized result will be below a selected threshold if the attitude candidates correlate. The threshold is chosen based on the application of the method of the present invention. Equation 1 represents an equation that would be used to check the correlation between the first and the second attitude candidates. Appropriate modifications to the subscripts may be made to check the correlation of other attitude candidates. Computations using equations similar to Equation 1 are made for each attitude candidate and the corresponding results (C or I) are filled into Table 1. Once Table 1 is filled, control is passed to step 220.
Step 220 finds the largest string of consistent measurements with respect to attitude candidates. For example, as shown in Table 1 attitude candidate 1 (C 1 ) has the longest string of consistent measurements. Step 225 performs the function of evaluating the number of consistent measurements to determine when the rejection algorithm has either rejected all of the candidates or converged on a single candidate. Again, referring to Table 1 attitude candidate C 1 would be accepted and all other attitude candidates would be rejected.
Returning to FIG. 4, after the pattern rejection is complete, step 230 tests to see if a single attitude measurement has been identified. If a single measurement has not been identified, control passes back to step 185, which waits for new sky and further passes control to step 170 to start the attitude acquisition process again. If a single attitude measurement is identified by step 230, control is passed to step 235, which indicates that the attitude of the spacecraft has been acquired. At this time the spacecraft will go into normal mode processing phase. That is, normal mode steering and normal mode star identification will be employed in place of acquisition mode functions.
Of course, it should be understood that a range of changes and modifications can be made to the preferred embodiment described above. For example, spacecraft rate propagated by a spacecraft dynamics model may be used instead of the gyros to propagate spacecraft attitude. The star pattern algorithm may be embodied in many possible algorithms, which include algorithms that use three stars for pattern match or any other number of stars, and have arbitrary memory storage formats and contents. A direct pattern match algorithm can be one of many possible algorithms, which include a scheme where an attitude candidate is rejected or accepted after comparison to new or previously sampled stars or attitude candidates. Additionally, the gyroscope compensation method can be one of many possible methods, which use star measurements and their corresponding reference vectors to compute adjustments to the gyroscope outputs. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting and that it be understood that it is the following claims, including all equivalents, which are intended to define the scope of this invention.
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A method and apparatus for autonomous acquisition of attitude in a stellar inertial spacecraft attitude system is disclosed. The present invention uses star trackers, an on-board star catalog, spacecraft steering and inertial sensors to determine spacecraft attitude. The present invention utilizes pattern match and pattern rejection methods and uses multiple stellar snap-shots in conjunction with spacecraft steering and spacecraft inertial measurements to acquire spacecraft attitude. Spacecraft inertial measurements are used to connect multiple stellar snap-shots to provide adequate star information that can be used to acquire spacecraft attitude. In an attitude determination system using star trackers, the star trackers may have a narrow field-of-view or few stars may be available for viewing. The present invention uses pattern matching and pattern rejection on different sets of stars, thereby allowing attitude acquisition when the number of stars in view is small.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a lumbar support of a car seat.
[0003] 2. Description of the Related Art
[0004] In general, a car seat is to be provided so as to safely and comfortably support a passenger in the limited space of the vehicle room and in a limited range of weight. Therefore, the car seat includes a seat back having a seat back frame and a seat back pad so as to support the waist and back portions of a driver or a passenger, wherein the driver and a passenger who seat in the front seats can control the angles of the seat backs by pulling or pushing the same forwards or backwards according to the driving habit of the driver or the body conditions of the driver or the passenger.
[0005] However, there are difficulties to respond to the change of the seating posture of the driver or the passenger just by the seat back frame and the seat back pad in the case of long time driving. Therefore, a lumbar support is provided in the seat back so as to comfortably surround and support the back and the lumbar vertebra regions of the driver, wherein the lumbar support includes a support plate which comes in contact with the lumbar vertebra region of the driver and a controller for controlling the movement of the support plate.
PRIOR ART DOCUMENT
Patent Documents
[0000]
Korean Reg. Patent Publication No. 10-1122980—Lumbar support of a car seat, registered on 24 Feb. 2012
Korean Reg. Patent Publication No. 10-1085154—Actuator system for controlling a lumbar support, registered on 14 Nov. 2011
Korean Reg. Patent Publication No. 10-0781018—Lumbar support system for a vehicle, registered on 23 Nov. 2007
SUMMARY OF THE INVENTION
[0009] In view of the prior art with respect to the lumbar support as above, a lumbar support as disclosed in Korean Reg. Patent Publication No. 10-1122980 comprises a pair of coupling means to be coupled to traversal fixing bars which are provided to the upper and lower portions in a seat back, a pair of support plates, each having a plurality of support wings provided at both right and left sides between the coupling means and the coupling means, a support member formed at the lower portions of the support plates and having a sacral region, and a support height control means for steplessly controlling the protruding height of the support plates which can selectively protrude to be curved at one side portion of each of the support plates, wherein a lumbar vertebra region is further provided to be integrated into the sacral region of the support member.
[0010] The prior art lumbar support as above can differ the bending degree of the support plate by manually operating a rotary lever which is mounted on the side wall portion of the seat. However, for the promotion of the convenience of a driver, the bending degree control by any other method rather than the inconvenient manual operation of the rotary lever has been required.
[0011] As a prior art for resolving the inconvenience of the manual operation and providing automatic controlling of the lumbar support, Korean Reg. Patent Publication No. 10-1085154 discloses a technique, wherein a deceleration part includes a worm, a worm gear and a screw so as to connect a wire of which one end is fixed to a lumbar support to a driving motor such that a slider which is screw-coupled to the screw moves in a housing by the operation of the deceleration part so as to pull or push the wire, thereby controlling the bending degree of support plates.
[0012] However, the prior art as above still has a problem that the wire snaps due to the load which is continuously applied thereto even though the bending degree can be controlled using the wire which is fixed at the upper and lower portions of the support plates.
[0013] The present invention is derived in consideration of the problems and disadvantages of the prior art and has an objective to provide a lumbar support of a car seat, of which bending degree can be automatically controlled by power while stably pressing support plates so as to improve the safety of the product.
[0014] In order to achieve the above and any other objectives of the present invention, provided is a lumbar support of a car seat, comprising: support plates made from a synthetic resin material in the shape of a plate and having a plurality of support wings at both sides and fixing hooks on top of the rear surface thereof; support frame positioned at the rear portions of the support plates and having a support rod engaged with the fixing hooks and a pair of guide rods connected to the support rod in parallel to each other; slider member provided to move in the vertical direction by the guide of the guide rods and having a spiral hole formed in the center thereof; vertically driving means having a driving motor driven by an external input signal and a screw which is coupled in the spiral hole of the slider member so as to move the slider member by the operation of the driving motor; and a biasing force control means positioned between the support plates and the support frame and controlling the pressing degree of the support plates according to the operation of a user, wherein the biasing force control means includes; an upper member coupled to the slider member; a lower member guided to move in contact with the guide rods of the support frame; and coil springs having both end portions which are respectively fitted and fixed into the upper member and the lower member and a shaft fitted into a coil portion in the center thereof; wherein a wire which passes through an insertion hole of the lower member so as to be held by the upper member is pulled and released by an actuator such that the central coil portion of the coil springs presses the support plates.
[0015] According to another aspect of the present invention, the rollers may be mounted on the shaft by being fitted between the coil springs at both sides of the shaft.
[0016] Further, hinge parts may be formed at both end portions of the slider member so as to surround the hinge shafts which are formed at both ends of the upper member, and guide protrusions may be respectively formed by protruding from the both sides of the lower member so as to prevent the movement of the lower member in the right and left directions when the lower member moves in the vertical direction along the guide of the guide rods.
[0017] According to another aspect of the present invention, provided is a lumbar support of a car seat comprising: a support plate to support user's back and made of elastic material; a support frame to which the support plate is rotatably engaged; a slider member mounted on the support frame in a movable manner in a vertical direction; a vertically driving means to move the slider member on the support frame; a biasing force control means including an upper member moving together with the slider member, a lower member disposed below the upper member, a biasing member connecting the upper and lower members to each other and having a controllable biasing force acting on the support plate depending on a distance between the upper and lower members, and an actuating means to control the distance between the upper member and the lower member.
[0018] Here, fixing hooks may be formed in one end of the support plate which is hingedly engaged to the support frame.
[0019] Further, the support frame may include: a supporting member to which the fixing hooks are engaged; and a pair of guides rod fixed to the supporting member.
[0020] Further, the slider member may be guided by a pair of guide rods provided to the support frame, and the vertically driving means is fixed to the support frame.
[0021] Here, the vertically driving means may include: a driving motor; a screw driven by the driving motor and engaged with the slider member via a threaded hole formed in the slider member.
[0022] Further, each end of the biasing member may be respectively engaged to the upper member and the lower member.
[0023] Here, the biasing member may be configured to be protruded toward the support plate as the distance between the upper member and the lower member decreases.
[0024] Here, the biasing member may include: coil springs extended between the upper member and the lower member; and a shaft inserted into the coil springs.
[0025] Here, the biasing member may include a pair of coil springs and the shaft inserted into both of the pair of coil springs.
[0026] Here, the actuating means may include: a wire engaged to the upper member through the lower member; and an actuator pulling or releasing the wire such that the central coil portion of the coil springs presses the support plate.
[0027] According to the present invention in the above structure, the central coil portion presses the support plates by coming in or out by the operation for decreasing or increasing a distance between the upper member 50 and the lower member 60 which are coupled to the both ends of the coil springs 70 . Therefore, the pressing operation can be smoothly carried out.
[0028] Further, the pressing portion which comes in contact with the support plates is pressed in the coil portion which is positioned in the center of the coil springs 70 . Therefore, the support plates which supports a human body is applied with elasticity even in the case of collisions or the like during driving. Therefore, it is possible to more safely protect a driver.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a perspective view showing the entire configuration of a lumbar support according to an embodiment of the present invention.
[0030] FIG. 2 is a front view of the lumbar support of FIG. 1 .
[0031] FIG. 3 is a plane view of the lumbar support of FIG. 1 .
[0032] FIG. 4 is a perspective view showing the principal construction of a pressing device which presses support plates according to the present invention.
[0033] FIG. 5 is a rear view showing the principal construction of the pressing device according to the present invention.
[0034] FIG. 6 is a side view showing a state before that the support plates are pressed according to the present invention, and
[0035] FIG. 7 is a side view showing a state after that the support plates are pressed according to the present invention.
[0036]
[0000]
Brief Description of Reference Numerals
10 - support plate
12 - support wings
20 - support frame
22 - guide rods
30 - slider member
31 - spiral hole
32 - hinge parts
40 - vertically driving means
41 - driving motor
42 - screw
50 - upper member
51 - hinge shafts
60 - lower member
61 - guide protrusions
70 - coil springs
72 - shaft
80 - actuator
81 - wire
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] Hereinafter, the present invention will be described in greater detail by reference to the drawings. However, the present invention should not be construed as being limited thereto.
[0038] Now, the configuration of the present invention to achieve the above objective will be described.
[0039] According to the present invention, a lumbar support of a car seat is provided in a seat back and controlled to move forwards or backwards with respect to the lumbar vertebra region of a passenger by power so as to support the lumbar vertebra region of a passenger such that the contact and comfort of a passenger in a seat can be improved and an overload is prevented from being applied to the lumbar region of the passenger due to the improper seating posture of the passenger.
[0040] A lumbar support according to the present invention mainly includes support plates 10 in the shape of a general plate, a support frame 20 formed of a support rod 21 and a pair of guide rods 22 which are in parallel to each other and connected to the support rod 21 , a slider member 30 provided so as to move in the vertical direction by the guide of the guide rods 22 , a vertically driving means 40 for reciprocatingly moving the slider member 30 , and a biasing force control means for controlling the degree to press the support plates 10 by the operation of a user.
[0041] The support plates 10 is, as shown in FIG. 1 , made from a synthetic resin material which has excellent elasticity and provided with a plurality of support wings 12 at both sides, wherein fixing hooks 13 in the shape of a hook are formed at the upper portion of the rear surface thereof.
[0042] The support plates 10 as above have through holes penetrated in the shape of a rectangle in the center and both side portions. The support wings 12 provided at both sides of the support plates 10 are formed to be slightly larger than the support wings 12 provided in the center of the support plates 10 . The support wings 12 are provided at an interval so as to increase the elasticity.
[0043] Further, the fixing hooks 13 which are formed at the upper portions of the rear surface are formed in the shape of a hook such that the fixing hooks 13 are prevented from being separated from the horizontal support rod 21 of the support frame 20 in the state that the fixing hooks 13 are fitted on the horizontal support rod 21 of the support frame 20 as described below.
[0044] The support frame 20 is formed by folding a metal rod and coupled to the rear surface of the support plates 10 , and has the support rod 21 which horizontally extends at the upper portion thereof and the guide rods 22 which are in parallel to each other and connected to the support rod 21 in the vertical direction.
[0045] The slider member 30 has a spiral hole 31 formed in the center of the body part thereof and is provided to be slidable along the guide of the guide rods 22 in the state that the slider member 30 is screw-coupled to the screw 42 of the vertically driving means 40 .
[0046] As for the operations of the slider member 30 , the screw 42 rotates by the driving motor 41 which rotates in the clockwise direction or the counterclockwise direction according to a signal by the selection of a user such that the slider member 30 carries out sliding motion in the vertical direction according to the rotation direction of the driving motor 41 .
[0047] Meanwhile, the vertically driving means 40 preferably includes a worm gear 43 and a worm gear 44 which are engaged with each other and provided to the screw 42 of the driving motor 41 so as to obtain a deceleration ratio as desired.
[0048] Further, the vertically driving means 40 is provided with a hall sensor (not shown) for sensing the rotation number of the driving shaft of the driving motor 41 and a motor control circuit for stopping the operation of the driving motor 41 as the rotation number of the driving shaft of the driving motor 41 reaches a preset rotation number.
[0049] In addition, the biasing force control means is positioned between the support plates 10 and the support frame 20 so as to control the degree to press the support plates 10 by the operation of the user.
[0050] The biasing force control means according to the present invention includes an upper member 50 which is hinge-coupled to the slider member 30 , a lower member 60 which is guided to move in contact with the guide rods 22 of the support frame 20 , coil springs 70 which are fixed to the upper member 50 and the lower member 60 by respectively fitting the both end portions into the upper member 50 and the lower member 60 , a shaft 72 which is inserted into the coil portions of the coil springs 70 , and an actuator 80 , wherein a wire 81 which is held by the upper member 50 by passing through an insertion hole 42 a of the lower member 60 is pulled or released such that the coil portions in the center of the coil springs press the support plates 10 .
[0051] At this time, rollers 73 are fitted between the coil springs 70 at both sides of the shaft 72 so as to reduce the frictional resistance when the support plates 10 are pressed.
[0052] The operations of the biasing force control means according to the present invention structured as above will now be described in reference with FIG. 4 to FIG. 7 .
[0053] First, a user who seats in the driver's seat or the passenger's seat operates an operation part (not shown) for the control of the lumbar support, an operation signal is transmitted to a controller (not shown) such that power is supplied to the driving motor 41 via the controller.
[0054] As the screw 42 rotates by the power of the driving motor 41 , the slider member 30 which is coupled to the spiral hole 31 lifts or lowers in the vertical direction by the screw 42 .
[0055] At this time, the slider member 30 is hinge-coupled to the upper member 50 and the upper member 50 is connected to the lower member 60 through the one pair of coil springs, such that the above constituent elements move together in the vertical direction.
[0056] In this way, the pressing position of the support plates 10 can be controlled in the vertical direction.
[0057] Further, the degree for pressing the support plates 10 is determined by the biasing force control means.
[0058] As the user manipulates a switch in order to operate the biasing force control means in the case of automatic power control, the actuator 80 pulls or releases the wire 81 .
[0059] In addition, the wire 81 can be pulled or released if the user rotates a lever in a desired direction in the case of manual control.
[0060] The end portion 81 of the wire 81 is held by a holding hook 82 on the upper member 50 which is hinge-coupled to the slider member 30 .
[0061] Hinge parts 32 are formed at both end portions of the slider member 30 so as to surround the hinge shafts 51 which are formed at both ends of the upper member 50 .
[0062] Therefore, the slider member 30 is placed in position in the state that the slider member 30 and the upper member 50 are lifted or lowered together, and the upper member 50 can rotate at an inclination together with the coil springs 70 with respect to the hinge shafts 51 as shown in FIG. 7 .
[0063] Further, the both end portions 71 of the coil springs 70 are fitted between the upper member 50 and the lower member 60 . Therefore, the distance between the upper member 50 and the lower member 60 decreases as the wire 81 is pulled such that the coil portions which are positioned in the centers of the coil springs 70 protrude forwards and press the support plates 10 .
[0064] Therefore, a press part which comes in contact with the support plates is supported by the coil springs 70 so as to maintain the elasticity of the springs. Thus, the support plates which support the body of the driver can be applied with elasticity and absorb shocks so as to more safely protect the driver even in the case of a collision during driving.
[0065] At this time, the coil springs 70 have elasticity such that the both end portions 71 of the coil springs 70 are maintained in a straight line in the free state of the coil springs 70 and the coil springs 70 are restored to the straight line state if tension is applied thereto while the center coil portions protrude forwards by the wire 81 .
[0066] At this time, it is preferable to provide the rollers 73 between the coil springs 70 at both sides of the shaft 72 by fitting so as to reduce the frictional resistance which is applied when the support plates 10 are pressed.
[0067] Further, it is preferable to respectively provide guide protrusions 61 at both sides of the lower member 60 so as to prevent the lateral movement of the lower member 60 when the lower member 60 moves along the guide rods 22 in the vertical direction.
[0068] If the user operates the actuator 80 so as to release the wire 81 , the support plates which have protruded towards the lumbar vertebra region are restored as shown in FIG. 6 , and the pressing degree can be controlled by stopping the operation at a desired position.
[0069] Therefore, the lumbar support according to the present invention can stably and comfortably support the protruding motion of the support plates 10 and absorb the shock at the time of a vehicle collision, thereby safely protecting the driver.
[0070] The embodiments described above are to be understood as a few illustrative examples of the present invention and the invention is not to be limited by any of the embodiments and drawings of the description. It will be understood by those skilled in the art that various modifications, combinations and changes may be made to the embodiments without departing from the scope of the present invention.
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A lumbar support of a car seat according to the present invention includes: a support plate to support user's back and made of elastic material; a support frame to which the support plate is rotatably engaged; a slider member mounted on the support frame in a movable manner in a vertical direction; a vertically driving means to move the slider member on the support frame; a biasing force control means including an upper member moving together with the slider member, a lower member disposed below the upper member, a biasing member connecting the upper and lower members to each other and having a controllable biasing force acting on the support plate depending on a distance between the upper and lower members, and an actuating means to control the distance between the upper member and the lower member.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a thermal stencil plate making method. More particularly, the invention relates to a thermal stencil plate making method using a thermal stencil original sheet in which a thermoplastic resin film and a porous support are laminated to each other. Further, the invention relates to a thermal stencil plate making method using a thermal stencil original sheet substantially made only of a thermoplastic resin film.
2. Description of the Related Art
The screen printing method is conventionally widely used as a simple and easy printing method. This method employs a thermal stencil original sheet in which a thermoplastic resin film is layered on the surface of an appropriate ink-transmissive support. The thermoplastic resin film is heated to fuse by a thermal head or the like to form image-like perforations. Printing ink is introduced from the ink-transmissive support side to effect printing on a printing object such as paper. Alternatively, using a thermal stencil original sheet substantially only of a thermoplastic resin film, the thermoplastic resin film is heated to fuse by a thermal head to form image-like perforations and printing ink is forced through the single thermoplastic resin film to effect printing on a printing object such as paper (in the case of support-less stencil).
The thermal heads for thermal color development recording or for thermal transfer recording have been divertedly used heretofore as the thermal head for the above thermal stencil plate making method. The thermal heads for thermal recording are designed to form a record image of continuous pixels connected to each other. If such thermal heads were used for thermal stencil plate making, the image of perforations would be continuous, which results in increasing offset or in increasing plate wear. Meantime, the diameter of image perforations can be changed by adjusting the energy applied to the thermal head. The perforation diameter becomes larger as the applied energy increases; conversely, it becomes smaller as the applied energy decreases. Employing such technique, there is a method to assure the independency of image perforations. However, the most suitable application energy is to be in the energy range in which the dispersion of perforations in a perforation image is smallest. This condition is generally also to select the maximum application energy in the range in which the durability of the thermal head is increased. Decreasing the applied energy below the suitable value increases the dispersion of image perforations, while increasing the applied energy is not preferable in respect of the durability of the thermal head. Further, a new problem of support-less thermal stencil original sheet appeared such as an abnormal image (especially wrinkles) arisen from plate shrinkage due to thermal shrinkage of a non-image portion.
To solve the above problems in the thermal stencil original sheet with support, there is means of reducing only the thickness of the protection layer of heating elements, proposed in Japanese Patent Application Laying Open (KOKAI) No. 63-191654. However, since the thickness of the protection layer is made extremely thin as 0.5 to 3.5 μm, there are a lot of pin holes in the protection layer. When the humidity is high, an antistatic agent enters the pin holes to cause corrosion of the electrode. Even if the humidity is not so high, the pin holes could cause lack of abrasion resistance. In addition, in case that the thickness of the protection layer is 0.5 μm, the image perforations are liable to be connected to each other if a distance between heating elements is below 2.5 μm (d/T<5). Further in this case, especially with the support-less thermal stencil original sheet, the new problem of abnormal image for example of wrinkles is liable to arise from plate shrinkage. Conversely, if the thickness of protection layer is 3.5 μm and if a distance between heating elements is longer than 35 μm (10<d/T), the image perforations are separate too far from each other. Especially in case of support-less thermal stencil original sheet, a printed image will lose its continuity, because an ink transfer amount is small because of the property thereof.
Proposed in Japanese Patent Application Laying Open (KOKAI) No. 2-67133 is means to make the secondary scan length of each heating element in the thermal head shorter than the dot pitch in the primary scan direction. It was, however, insufficient, because the master, to which the invention was directed, was the thermal stencil original sheet with support. Wrinkles due to plate shrinkage sometimes appeared especially in making a stencil plate from a support-less stencil original sheet. The degree of wrinkle appearance increases as the film thickness of support-less stencil original sheet becomes thicker. Further, even with a general thermal stencil original sheet, the communication between perforations occurred if the dot pitch in the primary scan direction is made different from that in the secondary scan direction. Especially with support-less thermal stencil original sheet, too far image perforations were sometimes made for the same reason as described above.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a thermal stencil plate making method excellent in plate wear, little in offset, and free from the abnormal image due to plate shrinkage which is the new problem especially in support-less thermal stencil original sheet.
The above object of the present invention can be achieved by a thermal stencil plate making method by which a perforation image is formed on a thermal stencil original sheet comprising a thermoplastic resin film and a porous support laminated on each other or a thermal stencil original sheet composed substantially only of a thermoplastic resin film by applying thermal energy to the thermal stencil original sheet by means of a thermal head, wherein a distance between heating elements in said thermal head: d (μm) and a thickness of a heating element protection layer: T (μm) satisfy the following condition of Equation (1) and wherein a secondary scan direction heating element spacing between heating elements in said thermal head: D (μm) and the thickness of the heating element protection layer: T (μm) satisfy the following condition of Equation (2):
5≦d/T (1);
4.5≦D/T (2).
The distance between heating elements in the thermal head herein: d (μm) is a value obtained by subtracting the primary-scan-direction length of heating elements: Lm (μm) from the distance between the heating element centers in the primary scan direction: Pm (μm) (d=Pm-Lm; see FIG. 1a).
Also, the secondary-scan-direction heating element spacing of heating elements in the thermal head: D (μm) is a value obtained by subtracting the secondary-scan-direction length of heating elements: Ls (μm) from the feed amount per dot in the secondary scan direction upon plate-making: Ps (μm) (D=Ps-Ls; see FIG. 1b).
Further, the above object of the present invention can also be achieved preferably by a thermal stencil plate making method by which a perforation image is formed on a thermal stencil original sheet comprised substantially only of a thermoplastic resin film by applying thermal energy to said film by means of a thermal head, wherein a distance between heating elements in said thermal head: d (μm) and a thickness of a heating element protection layer: T (μm) satisfy the following condition of Equation (3) and wherein a secondary scan direction heating element spacing between heating elements in said thermal head: D (μm) and the thickness of the heating element protection layer: T (μm) satisfy the following condition of Equation (4):
5≦d/T≦10 (3):
4.5≦D/T (4).
The present invention enables the plate making little in offset on a print, excellent in plate wear of master plate, and further free from the abnormal image on the print due to plate shrinkage, because image perforations are formed independent of each other, Also with support-less thermal stencil original sheet, there is no support, so that all perforations made by heating elements become ink-transmissive regions, reducing the dispersion of image density among pixels.
Since the distance between hearths elements: D (μm) and the heat element spacing in the secondary scan direction between heating elements: D (μm) are sufficiently large as compared with the thickness of protection layer: T (μm), heat from individual heating elements is transmitted to the perforations can be attained. Namely, the independency of image perforations can be assured be, satisfying following Equations (1) and (2) the present invention.
5≦d/T (1)
4.5-D/T (2)
When above Equations (1) and (2) are satisfied, there is no plate shrinkage caused, in addition to the improvement of independency of image perforations. If the thickness of the protection layer exceeds 7.0 μm so as not to satisfy above Equations (1) and (2), the independency of image perforations will be negatively affected and the thermal response of the thermal head will be lowered (because of increase of heat capacity of the protection layer). Then the line speed of plate-making cannot be increased, and especially the plate shrinkage appears outstanding. If the thickness is below 3.5 μm, the thermal head cannot have sufficient durability. If the distance in the primary scan direction between heat elements in the thermal head and the heating element spacing in the secondary scan direction between heating elements are simultaneously shorter than 17.5 μm so as not to satisfy above Equations (1) and (2), a non-perforated portion is insufficient in a solid print portion even with the independency of image perforations being assured, which especially results in reducing the plate wear.
Especially in case of the support-less thermal stencil original sheet, the gap between image perforations is made suitable in addition to the above effect.
5≦d/T≦1O (3)
4.5≦D/T (4)
In more detail, when Equations (3) and (4) are satisfied, the continuity of printed image (solid evenness) becomes especially excellent even with a small ink transfer amount because of the property of support-less thermal stencil original sheet.
The difference of range between Equations (1), (2) and Equations (3), (4) is due to the characteristics of the thermal head. In more detail, the heating elements are not aligned in the secondary scan direction of the thermal head, so that when two perforations adjacent to each other are made in the secondary scan direction, heating of the thermal head for the two perforations are not simultaneous. Accordingly, the heat distribution for two perforations adjacent to each other in the secondary scan direction is different from that for two perforations adjacent to each other in the primary scan direction. Therefore, the ranges of two corresponding equations are different from each other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is a schematic plan view of a thermal head;
FIG. 1b is a schematic plan view to show heating locations of heating elements in a thermal head; and
FIG. 2 is a cross sectional view of a thermal head.
The thermal head employed in the present invention is of the same type of structure as the thin-film type thermal head usable in thermal printers. The thermal head is constructed as follows. As shown in FIG. 2, a thermal resistance layer 7 made of glass is formed on an insulating base 8, and an electrode layer 9 of metal material such as NiCr, Ta, etc. is formed by the vapor deposition method through a heating resistor layer 8 over the thermal resistance layer. In a heating portion, a non-oxidizable layer 10 is directly formed on the heating resistor layer, forming a concave heating portion 12. There are two types of thin-film type thermal heads, i.e., completely glazed thermal head as shown in FIG. 2 and partially glazed thermal head (not shown), either of which satisfies the same equations.
The present invention is effective to make independent perforation dots whereby excellent prints can be provided with superior image reproducibility, with minimum offset, and with no wrinkle on image which could be caused by the plate shrinkage especially liable to occur in the support-less thermal stencil original sheet. Further, the durability of the plate-making machine, specifically of the thermal head, is excellent.
The thermoplastic resin film may be any of general thermoplastic resin films formed by the extrusion process, the casting process or another process. The thermoplastic resin film may be selected from the group consisting of polyester (preferably copolymer polyester) type, polyamide (preferably copolymer polyamide) type, polyolefin type, polystyrene type, polyvinyl chloride type, acrylic acid derivative type, ethylene-vinyl alcohol type and polycarbonate type copolymers. The film preferably has a high perforation sensitivity. For that reason, the thermoplastic resin should preferably have a degree of crystallinity ranging from the substantially amorphous level to 15% in the state of film. More preferably, the film is substantially amorphous. The film of substantially amorphous level means that the raw material shows little melting point by the DSC method, or that the film is made while suppressing the crystallization by the processing method (for example by quench). If the degree of crystallinity is high, the energy from the thermal head is dissipated as energy for crystal melting, affecting the perforation property.
The degree of crystallinity is determined by the X-ray method, but it can also be obtained by the DSC method, using an area ratio of fusing energy.
More preferably, the film mainly contains a copolymer polyester and is of substantially amorphous level. Most preferably, the copolymer polyester as raw material is substantially amorphous. The substantially amorphous polyester is different from the commercially available resin mainly containing so-called highly crystalline polyethylene terephthalate having a crystalline melting point (measured by the DSC method) in the range of 245° to 260 ° C., but is a composition comprising a polymer or polymer blend and having a degree of crystallinity of not more than 10%, preferably not more than 5%, more preferably one with a melting point scarcely observed by the DSC method. The measurement of crystallinity degree is carried out using the above composition fully annealed into an equilibrium state and fixed in degree of crystallinity by the X-ray method as a reference. Using the thermoplastic film of such low crystalline type, the energy loss as crystal melting energy may be reduced, so that the thermal perforation may be fully effective with a small amount of energy applied to the thermal head.
The thickness of the thermoplastic resin film employed in the present invention is preferably in the range of 0.5 μm to 30 μm, more preferably in the range of 0.7 to 20 μm. If the thickness is too thin, the plate wear will be degraded in particular because of the low mechanical strength, though the perforations are sufficiently independent of each other. Conversely, if the thickness is too thick, the perforation becomes hard and the plate-making wrinkles readily appear.
The melting start temperature should be in the range of 50° C. to 300° C., preferably in the range of 70 ° C. to 290 ° C. A too low melting start temperature makes the production of film difficult and lowers the shelf stability as a product of thermal stencil original sheet. A too high melting start temperature causes the energy necessary for perforation from the thermal head to the thermal stencil original sheet to increase, whereby the perforation becomes difficult.
The raw material for the porous support may be natural fibers such as kozo (paper mulberry), mitsumata and Manila hemp; semisynthetic fibers such as rayon; synthetic fibers such as polyester, vinylon, polyamide and polypropylene, used alone or in combination of at least two thereof at weight of 8 to 15 g/m 2 . An additive such as an antistatic agent may be added in the porous support. Further, the support may be a porous resin film which can transmit ink.
The adhesive for laminating the thermoplastic resin film to the porous support may be one selected from the group comprising acrylic resins, vinyl acetate resins, vinyl acetate resins containing rosin resin, methoxypolyamides, vinyl chloride copolymers, chlorinated polypropylene resins, urethane adhesives of reaction prepolymers from di-isocyanate and polyether diol, mixture adhesives from active hydrogen containing resin and polyisocyanate, ultraviolet curing adhesives, and electron radiation curing adhesives.
An anti-fusion-bonding treatment may be effected on the thermoplastic resin film on the side thereof to contact with the thermal head, if the perforating means is the thermal head. The anti-fusion-bonding treatment can be done by the method of uniformly applying an anti-fusion-bonding agent selected from fatty acid metal salts, phosphate surface active agents, fluid lubricants such as silicone oil, and fluorine compounds having a perfluoroalkyl group.
An amount of coating is in the range of 0.001 to 2 g/m 2 preferably in the range of 0.005 to 1 g/m 2 . A too small amount of coating cannot reveal the anti-fusion-bonding effect, while a too large amount of coating negatively affects the perforation function.
The method of providing the thermoplastic resin film with the antistatic effect may be a method of uniformly coating the thermoplastic resin film with an antistatic agent or a method of mixing an antistatic agent into the thermoplastic resin film.
The antistatic agent used in the method of coating may be, one of general antistatic agents such as metal salts of organosulfonic acids, polyalkylene oxides, esters, amines, polyethoxy derivatives, carboxylates, amine guanidine salts quarternary ammonium salts, and alkyl phosphates.
A coating amount of the antistatic agent is in the range of 0.001 to 2.0 g/m 2 , preferably in the range of 0.01 to 0.5 g/m 2 . A too small coating amount cannot present the sufficient antistatic effect especially in the environment of low humidity; conversely, a too large coating amount will negatively affect the perforation function as well as the effect of the anti-fusion-bonding agent.
The antistatic agent used in the method of mixing it in the thermoplastic resin film may be selected from metal salts of organosulfonic acids, polyalkylene oxides, or one or more mixtures of quarternary ammonium salts.
The metal salts of organosulfonic acids compounds represented by the formula of RSO 3 X (where R is an alliphatic group, an alicyclic group or an aromatic group and X is a metal, for example Na, K, Li), specifically, metal salts of alkylsulfonic acids or metal salts of alkylbenzenesulfonic acids for example. The alkyl may be octyl, decyl, dodecyl (lauryl), tetradecyl (myristyl), hexadecyl, octadecyl (stearyl) and the like, for example. Further specific compounds may be laurylsulfonic acid sodium salt, laurylsulfonic acid potassium salt, laurylsulfonic acid lithium salt, stearylsulfonic acid sodium salt, stearylsulfonic acid potassium salt, stearylsulfonic acid lithium salt, dodecylbenzenesulfonic acid sodium salt, dodecylbenzenesulfonic acid potassium salt, dodecylbenzenesulfonic acid lithium salt or the like for example. The content of organosulfonic acid metal salt is in the range of 0.1 to 2% by weight relative to the thermoplastic resin film, preferably in the range of 0.2 to 1.5% by weight. If the content of organosulfonic acid metal salt is less than 0.1% by weight, the antistatic effect appears little; if over 2% by weight, the surface of thermally perforated sheet undesirably becomes rough.
Also, the polyalkylene oxides to be contained in the thermoplastic resin film may be polyethylene oxides, polypropylene oxides, polyethylene-propylene oxide polymers, polytetramethylene oxides, or the like for example, and the molecular weight thereof is in the range of 400 to 500,000, preferably 1,000 to 50,000.
The content of polyalkylene oxide is in the range of 0.1 to 5% by weight relative to the thermoplastic resin film, preferably in the range of 0.2 to 4% by weight. If the content of polyalkylene oxide is less than 0.1% by weight, the antistatic effect is not enough; if over 5% by weight, the mechanical properties of film will be undesirably degraded.
The electrically conductive agents to be contained in the thermoplastic resin film may be one or more of quarternary ammonium salts represented by the formula of [R--N (CH 3 ) 2 --R']X (where R is an alkyl group having a carbon number of 12 to 18, R' is an alkyl or methyl group having a carbon number of 12 to 18, and X is Cl or Br, or HSO 4 or C 2 H 5 SO 4 ).
The content of the ammonium salt should be preferably in the range of 1 to 50% by weight based on the thermoplastic resin film, more preferably in the range of 2 to 30% by weight.
Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.
Reference numerals and symbols in the drawings represent the following elements or portions;
1: electrode;
2: heating element;
Ps: feed amount per dot;
Lm: length of heating element in the primary scan direction;
Ls: length of heating element in the secondary scan direction;
3: thermal head;
6: insulating base;
7: thermal resistance layer;
8: heating resistor layer;
9: electrode layer;
10: non-oxidizable layer;
11: wear-resistant layer;
12: heating portion;
13: electrode portion;
14 : protection layer;
20: hypothetical position of conventional heating element;
30: heating position of heating element of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be further described in detail with the following embodiments, but it should be noted that the present invention is not intended to be limited by these examples.
EXAMPLE 1
Used as the thermoplastic resin film was a substantially amorphous film (the degree of crystallinity of 1.0%) with thickness of 1.8 μm and melt temperature of 160° C. mainly containing a copolymer polyester. The film was laminated to a porous support of 11 g/m 2 made of 15% of polyester fibers and 85% of Manila hemp. The laminate was coated on the side thereof to contact with the thermal head with a phosphate surface active agent (GAFAX RL210 with mp. 54° C. manufactured by TOHO CHEMICAL INDUSTRY) at 0.1 g/m 2 to form an anti-fusion-bonding layer, whereby a thermal stencil original sheet was obtained with the porous support.
A stencil plate including a black solid image portion was made from the thermal stencil original sheet, using a thin-film type thermal head of 16 dots/mm (heating element primary scan length Lm: 42 μm; secondary scan length Ls: 32 μm; thickness of heating element protection layer T: 4.0 μm; feed amount in the secondary scan direction upon plate-making Ps: 62.5 μm) with energy enough to produce perforations at the probability of not less than 90% being applied to the thermal head. The thermoplastic resin film after the plate-making was set in PRIPORT SS 955 manufactured by RICOH Co., LTD., and printing was carried out. Images obtained were excellent in solid evenness and little in offset. No wrinkles due to the plate shrinkage were observed on the images. The plate wear was also satisfactory.
In this example, d/T=5.1 and D/T=7.6.
EXAMPLE 2
Used as the thermoplastic resin film was a substantially amorphous film (the degree of crystallinity of 1.0%) with thickness of 1.8 μm and melting temperature of 160° C. mainly containing a copolymer polyester. The film was coated on the side thereof to contact with the thermal head with a phosphate surface active agent (GAFAX RL210 with mp. 54° C. manufactured by TOHO CHEMICAL INDUSTRY) at 0.1 g/m 2 as anti-fusion-bonding layer.
A stencil plate including a black solid image portion was made from the thermoplastic resin film, using a thin-film type thermal head of 16 dots/mm (heating element primary scan length Lm: 45 μm; secondary scan length Ls: 45 μm; thickness of heating element protection layer T: 3.5 μm; feed amount in the secondary scan direction upon plate-making Ps: 62.5 μm) with energy enough to produce perforations at the probability of 100% being applied to the thermal head. The thermoplastic resin film after plate-making was set in PRIPORT SS 955 manufactured by RICOH Co., LTD. and printing was carried out. Images obtained were excellent in solid evenness and little in offset. There were no wrinkles due to the plate shrinkage observed on the images. Also, the plate wear was satisfactory.
In this example, d/T=5.0 and D/T=5.0.
EXAMPLE 3
Used as the thermoplastic resin film was a film with thickness of 2.5 μm and the degree of crystallinity of 20% mainly containing polyethylene terephthalate. The film was coated on the side thereof to contact with the thermal head with a phosphate surface active agent (GAFAX RL210 with mp. 54° C. manufactured by TOHO CHEMICAL INDUSTRY) as anti-fusion-bonding layer and a quarternary ammonium salt of dodecyltrimethylammonium chloride [C 12 H 25 N (CH 3 ) 2 CH 3 Cl] as antistatic agent at the weight ratio of 1:1 at 0.2 g/m 2 .
A stencil plate including a black solid image portion was made from the thermoplastic resin film, using a thin-film type thermal head of 16 dots/mm (heating element primary scan length Lm: 31 μm; secondary scan length Ls: 38 μm; thickness of heating element protection layer T: 4.0 μm; feed amount in the secondary scan direction upon plate-making Ps: 62.5 μm) with energy enough to produce perforations at the probability of 100% being applied to the thermal head. The thermoplastic resin film after plate-making was set in PRIPORT SS 955 manufactured by RICOH Co., LTD. and printing was carried out. Images obtained were excellent in solid evenness and little in offset. There were no wrinkles due to the plate shrinkage observed on the images. Also, the plate wear was satisfactory.
In this example, d/T=7.9 and D/T=6.1
EXAMPLE 4
Used as the thermoplastic resin film was a substantially amorphous film (the degree of crystallinity of 1.0%) with thickness of 7.5 μm and melting temperature of 160° C. mainly containing a copolymer polyester. The film was coated on the side thereof to contact with the thermal head with a phosphate surface active agent (GAFAX RL210 with mp. 54° C. manufactured by TOHO CHEMICAL INDUSTRY) as anti-fusion-bonding layer and a quarternary ammonium salt of dodecyltrimethylammonium chloride [C 12 H 25 N (CH 3 ) 2 CH 3 Cl] as antistatic agent at the weight ratio of 1:1 at 0.2 g/m 2 .
A stencil plate including a black solid image portion was made from the thermoplastic resin film, using a thin-film type thermal head of 12 dots/mm (heating element primary scan length Lm: 45 μm; secondary scan length Ls: 50 μm: thickness of heating element protection layer T: 4.0 μm; feed amount in the secondary scan direction upon plate-making Ps: 83.3 μm) with energy enough to produce perforations at the probability of 100% being applied to the thermal head. The thermoplastic resin film after plate-making was set in PRIPORT SS 955 manufactured by RICOH Co., LTD. and printing was carried out. Images obtained were excellent in solid evenness and little in offset. There were no wrinkles due to the plate shrinkage observed on the images. Also, the plate wear was satisfactory.
In this example, d/T=9.6 and D/T=8.3.
EXAMPLE 5
Used as the thermoplastic resin film was a substantially amorphous film (the degree of crystallinity of 1.0%) with thickness of 5.5 μm and melting temperature of 160° C. mainly containing a copolymer polyester. The film was coated on the side thereof to contact with the thermal head with a phosphate surface active agent (GAFAX RL210 with mp. 54° C. manufactured by TOHO CHEMICAL INDUSTRY) as anti-fusion-bonding layer and a quarternary ammonium salt of dodecyltrimethylammonium chloride [C 12 H 25 N (CH 3 ) 2 CH 3 Cl] as antistatic agent at the weight ratio of 1:1 at 0.2 g/m 2 . A stencil plate including a black solid portion was made from the thermoplastic resin film, using a thin-film type partially glazed thermal head of 12 dots/mm (heating element primary scan length Lm: 45 μm; secondary scan length Ls: 50 μm; thickness of heating element protection layer T: 7.0 μm; feed amount in the secondary scan direction upon plate-making Ps: 83.3 μm) with energy enough to produce perforations at the probability of 100% being applied to the thermal head. The thermoplastic resin film after plate-making was set in PRIPORT SS 955 manufactured by RICOH Co., LTD. and printing was carried out. Images obtained were excellent in solid evenness and little in offset. There were no wrinkles due to the plate shrinkage observed on the images. Also, the plate wear was satisfactory.
In this example, d/T=5.5 and D/T=4.8.
Comparative Example 1
A stencil plate including a black solid portion was made from the same thermal stencil original sheet as that in Example 1, using a thin-film type completely glazed thermal head of 16 dots/mm (heating element primary scan length Lm: 45 μm; secondary scan length Ls: 58 μm: thickness of heating element protection layer T: 3.5 μm; feed amount in the secondary scan direction upon plate-making Ps: 62.5 μm). When energy enough to produce perforations at the probability of not less than 90% was applied to the thermal head, numerous communications were made between perforations in the secondary scan direction, which extremely lowered the plate wear. On the other hand, if the applied energy is within the range not to cause the communications between perforations in the secondary scan direction, the probability to produce perforations becomes lower, degrading the solidness of solid image.
In this example d/T=5.0 and D/T=1.3.
Comparative Example 2
Used as the thermoplastic resin film was a substantially amorphous film (the degree of crystallinity of 1.0%) with thickness of 5.5 μm and melting temperature of 160° C. mainly containing a copolymer polyester. The film was coated on the side thereof to contact with the thermal head with a phosphate surface active agent (GAFAX RL210 with mp. 54° C. manufactured by TOHO CHEMICAL INDUSTRY) as anti-fusion-bonding layer and a quarternary ammonium salt of dodecyltrimethylammonium chloride [C 12 H 25 N (CH 3 ) 2 CH 3 Cl] as antistatic agent at the weight ratio of 1:1 at 0.2 g/m 2 . A stencil plate including a black solid portion was made from the thermoplastic resin film, using a thin-film type completely glazed thermal head of 16 dots/mm (heating element primary scan length Lm: 45 μm; secondary scan length Ls: 58 μm; thickness of heating element protection layer T: 3.5 μm; feed amount in the secondary scan direction upon plate-making Ps: 62.5 μm). When the energy enough to produce perforations at the probability of 100% was applied to the thermal head, numerous communications were made between perforations, which extremely lowered the plate wear. The thermal shrinkage was observed locally especially in the secondary scan direction or totally depending upon the image on the stencil master plate after plate-making, which caused wrinkles on printed images.
In this example d/T=5.0 and D/T=1.3.
Many widely different embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.
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A thermal stencil plate making method, by which a perforation image is formed on a thermal stencil original sheet comprising a thermoplastic resin film and a porous support laminated on each other or a thermal stencil original sheet composed substantially only of a thermoplastic resin film by applying thermal energy to the thermal stencil original sheet by means of a thermal head, is characterized in that a distance between heating elements in the thermal head: d (μm) and a thickness of a heating element protection layer: T (μm) satisfy the following condition of Equation (1) and that a secondary scan direction heating element spacing between heating elements in the thermal head: D (μm) and the thickness of the heating element protection layer: T (μm) satisfy the following condition of Equation (2):
5≦d/T (1);
4.5≦D/T (2).
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a National Stage of International Application No. PCT/CH2011/000045, filed on Mar. 9, 2011, which claims priority from Swiss Patent Application No. 1943/10, filed on Nov. 19, 2010, the contents of all of which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
The present invention relates to a bowl for the mixing of food, for example for the mixing of dough, puddings, etc.
PRIOR ART
Bowls for the mixing of food, in a wide variety of forms, are sufficiently known in the prior art. In the mixing of food, it can be advantageous to the user to hold the bowl in an oblique position or even to tilt it back and forth during the mixing. The circulation and stirring of a food present in the bowl can thereby be aided.
In order to enable such holding in an oblique position or a tilting of the bowl back and forth, it is known from the prior art to configure a bowl with a curved bottom and to provide a stand on which the bowl rests with its curved bottom. Within certain limits, the bowl is here freely pivotable in relation to the stand. Such a bowl with stand is described, for instance, in EP 0 384 197. Devices of this type have the drawback, however, that they consist of at least two separate parts.
It is additionally known to place structures on the outer side of bowls in order to enable an obliquely held bowl to rest on a plane surface. In U.S. Pat. No. 5,169,023, two parallelly running ribs, for example, are attached to the outer side of the bowl in order to allow guided rolling of the bowl on a work surface. U.S. Pat. No. 5,423,452 describes a bowl which in the transition region between the bottom and the side wall is of stepped configuration, so that it is possible to hold the bowl in an oblique position. In these bowls, further tilting out of their oblique position is prevented, however, only in one motional direction. The danger exists that the bowl will nevertheless accidentally slide away or roll during mixing.
The bowls which are shown in GB 491,517 and U.S. Pat. No. 2,121,165 have in the region of their curved outer sides respectively one or more plane bearing surfaces.
The bowl is thereby prevented from accidentally sliding away or rolling when held in oblique orientation to the work surface such that it is supported with one of the plane bearing surfaces.
In U.S. Pat. No. 1,394,540 is described a bowl which in the transition region between a flat bottom and a circumferential side wall has a circumferential thickening in the form of a bead. In an upper region of the side wall, outwardly projecting bosses are also configured. The bowl can be placed in an inclined orientation laterally onto a plane surface, in that it rests on this with respectively two adjacent bosses as well as with the circumferential thickening. Resting of the bowl with the bosses and the thickening on a plane surface is only possible, however, at a predetermined inclination relative to the surface.
REPRESENTATION OF THE INVENTION
One object of the present invention is to define a bowl for the mixing of food, which bowl is configured to rest in an inclined position on a plane surface, wherein the bowl is prevented from accidentally sliding away from this position. This bowl is designed to be able to be produced as easily and as cheaply as possible.
Below, location references such as at the bottom, at the top, above and below relate to a bowl which with an upward-facing removal opening, in relation to the gravitational direction, stands upright on a plane surface. The bowl has an interior which is accessible via the removal opening.
The present invention thus provides a bowl for the mixing of food. The bowl comprises a curved base having a convex outer surface. Preferably, this outer surface is substantially smooth. The term “smooth” should here be understood in the mathematical sense, which means that the outer surface of the base, apart from its marginal region, forms a surface which is continuously differentiable at all points and which, in particular, has no abrupt corners or edges. Preferably, the outer surface is partially spherical or forms a partial ellipsoid.
According to the invention, on the outer surface of the base are configured at least three knobs, which respectively all project outward as far as a common plane, so that the bowl can be placed onto a plane surface, in an orientation inclined with respect to the gravitational direction, such that it rests with all knobs of this group on the plane surface. In other words, the free ends of the knobs of this group lie all in a common plane.
Since the bowl, with the projecting knobs of, respectively, a group, can be placed in an inclined orientation onto a plane surface, the processing of the food received by the bowl is made considerably easier for the user. Hence the user does not necessarily have to introduce a mixer into the bowl from above, for example, but instead he can also thrust it under the content of the bowl from the side. The bowl is here prevented from sliding away or rolling out of this inclined position by the knobs which rest on the surface.
A knob constitutes a pronounced, local elevation of a surface. The knob here clearly stands out from the surface by which it is circumferentially surrounded at the sides. In contrast to a bar, which has substantially larger dimensions in one direction than in a direction perpendicular thereto, a knob has similar dimensions in all directions perpendicular to its longitudinal axis. A knob can have a substantially cylindrical form. However, it can also, for example, be of frustoconical, semispherical or partially semispherical configuration, or can have the form of a straight prism, preferably with a base area in the form of a regular polygon, for example a regular hexagon. The free end of the knob can form a plane surface or can be curved.
The knobs preferably have a diameter which corresponds to no more than the distance between respectively two adjacent knobs, preferably to no more than half the distance, frequently even to just one-tenth to one-fifth of the distance.
The groups of knobs are preferably respectively configured and arranged such that the bowl, when it rests with the knobs of a group on a plane surface, is movable into a different orientation with respect to the gravitational direction only when a certain tilting force is surmounted. It is here preferred that the empty bowl can be placed stably in an inclined position onto a plane surface without it having to be held by the user.
The bowl preferably has a multiplicity of knobs, which form a plurality of groups of respectively at least three knobs, wherein the knobs of each group respectively all project outward as far as a common plane. Sometimes these groups can mutually overlap, i.e. have common knobs, yet they can also be disjunctive, so that each group fully consists of different knobs. Advantageously, the knobs are evenly distributed over a large part of the outer surface of the base, in particular over a region of the base which is circumferential with respect to the direction of opening of the bowl. The bowl hence has a large number of options for resting in an inclined position with a group of knobs on a plane surface. At the same time, it is possible for a central bottom region having no knobs to be provided on the base.
The knobs can respectively have in the outward direction a rounded end. Advantageously, each of the knobs of a common group has an end, however, whose end face forms a plane, outward facing, preferably circular bearing surface. The bearing surfaces of all knobs of a group preferably respectively form a common plane. The knobs of a group can hence rest with their bearing surfaces all respectively flat on a plane surface, whereby the stability of the bowl in the inclined position is enhanced. It is also conceivable, however, that although the end faces of the knobs have plane surfaces, these surfaces do not form a common plane but form a certain angle to one another. In this case it is only important that the knobs of a group project as far as a common plane, so that they can all rest on a plane surface. The knobs can also rest only in a marginal region on the surface. Between the knobs of a group, which, by definition, all project as far as a common plane, can be disposed further knobs, which do not belong to this group and which project less far than the knobs of the group concerned. Although these knobs are unnecessary for the functionality of the present invention, they may be desirable for other reasons, for example to produce a more uniform appearance.
In a preferred embodiment, the knobs of each group respectively all extend parallel to one another outward from the outer surface of the base. The knobs of a group are here generally of different length. When resting on a plane surface, the knobs of a common group hence all extend in perpendicular direction relative to the surface. The result of this is that the forces acting on the knobs are optimally absorbed.
Advantageously, the bowl has a multiplicity of groups, which respectively all have an equal number of knobs. Preferably, the knobs within each group are similarly arranged.
The knobs of, respectively, a group are advantageously arranged such that they jointly form a regular polygon. The knobs can here respectively form the corner points of the polygon. Further knobs can be distributed along the sides and/or over the surface of the polygon. An embodiment in which each group respectively has precisely three knobs is, however, particularly preferred. Advantageously, the knobs are here arranged in the form of an equilateral triangle. In a particularly preferred embodiment, the knobs are arranged such that they form the grid points of a grid of equilateral triangles.
The bowl can be provided, in particular in the region of the base, at least partially with a plastics coating, on which the knobs are integrally configured.
The plastics coating can be sprayed onto the bowl in particular by injection molding or can be otherwise connected to the bowl. Where such a plastics coating of this type is present, it advantageously has a lower Shore A-hardness than the base. The plastics coating can here in particular have a Shore A-hardness of less than 70, though preferably of less than 60, and particularly preferably of around 50. Suitable materials are, for example, silicone rubber or thermoplastic elastomers (TPE) such as Santoprene™ (a TPE on an EPDM/polypropylene base). The knobs can then, when resting on the surface, better adapt thereto, so that, in particular, the forces acting on the knobs are more evenly distributed over the various knobs of a group and the outer side of the base thus becomes more slip-proof. The plastics coating can cover the entire outer surface of the bowl or be provided only in the region of the base. It can also, however, be provided only substantially in the region of the base and extend upward at a certain point, in particular in the region of a handle.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are described below with reference to the drawings, which serve merely for illustration and should not be interpreted restrictively. In the drawings:
FIG. 1 shows a perspective view of an inventive bowl according to a preferred, first embodiment;
FIG. 2 shows a view of the bowl of FIG. 1 from the side;
FIG. 3 shows a view of the bowl of FIG. 1 from below;
FIG. 4 shows a central sectional view of the plane IV-IV through the bowl of FIG. 1 ;
FIG. 5 shows a perspective view of the bowl of FIG. 1 , resting on a surface in an oblique position;
FIG. 6 shows a partial sectional view of the bowl of FIG. 1 ;
FIG. 7 shows a partial sectional view of an inventive bowl according to a second embodiment;
FIG. 8 shows a partial sectional view of an inventive bowl according to a third embodiment;
FIG. 9 shows a perspective view of an inventive bowl according to a fourth embodiment; and
FIG. 10 shows a central sectional view through an inventive bowl according to a fifth embodiment; and
FIG. 11 shows a view of the bowl of FIG. 10 from the side.
DESCRIPTION OF PREFERRED EMBODIMENTS
An inventive bowl for the mixing of food according to a preferred, first embodiment is shown in FIGS. 1 to 6 .
The bowl has a base 10 having a curved, convex, smooth outer surface, on which knobs 12 are configured. As in the present illustrative embodiment, the base 10 can be of substantially semispherical configuration. Other forms of the base 10 are also conceivable, however. Thus they could also be designed, for example, only partially semispherical or as an ellipsoid or partial ellipsoid. In its lowermost region, the base 10 has a central bottom region 13 ( FIG. 3 ) without knobs, which here is likewise curved outward. In contrast to the present embodiment, this bottom region 13 could alternatively, however, also be configured flat in order to serve as a standing surface of the bowl when this is placed upright on a surface 70 . The base 10 is adjoined in the upward direction by a circumferential, here cylindrical side wall 20 .
The base 10 and the side wall 20 jointly delimit with their inner surfaces an interior 30 , which serves to receive foods, such as, for example, baking products. The side wall 20 has an upper rim 21 , which delimits a removal opening of the bowl. The interior 30 is accessible through this removal opening.
The bowl has a multiplicity of knobs 12 , which are configured on the outer surface of the base 10 . In the present illustrative embodiment, the knobs 12 of cylindrical design and have a diameter which is smaller by a factor of about three than the distance between respectively two adjacent knobs 12 . The length of the knobs 12 , which here project radially outward, in each case perpendicular to the outer surface of the base 10 , is slightly smaller than their diameter. The knobs 12 respectively have ends which have a plane outer surface. These outer surfaces of the knobs 12 respectively point outward in a perpendicular direction in relation to the outer surface of the base 10 .
Each knob 12 respectively forms a part of a group. A group of knobs 12 is characterized in that it respectively has at least three knobs 12 , wherein all knobs 12 of a group respectively project outward as far as a common plane. As shown in FIG. 5 , the bowl can thus be placed in an oblique position onto a plane surface 70 such that it rests on this with all the knobs 12 of a group. The knobs do not necessarily have to rest with the whole of their end face on the plane surface, but rather it is sufficient if the knobs, as in the present example, rest only with a marginal region of their free end on the plane surface. The bowl can, but does not have to, additionally rest on the surface 70 with a point located between the knobs 12 . The knobs 12 resting on the plane surface 70 prevent the bowl from accidentally sliding or tilting away when it rests in this position on a surface 70 .
In the present case, precisely three knobs 12 respectively form a common group. The knobs 12 of a group are here respectively arranged such that they form the corner points of an equilateral triangle. Other arrangements of the knobs 12 of a common group are also conceivable, however. Thus the knobs 12 of a group could be arranged in the form of a polygon of choice, in particular a regular polygon. The knobs 12 do not here necessarily have to be positioned only at the corner points of the triangle or polygon, but could also, for example, be arranged along the sides or regularly distributed over the surfaces of the triangle or polygon. The bowl can also, of course, have any chosen combination of differently configured groups of knobs.
In the present case, the knobs 12 are distributed circumferentially and regularly over almost the entire outer surface of the base 10 . The knobs 12 here form a multiplicity of groups of respectively three knobs 12 , which are arranged in the form of an equilateral triangle. Only in the uppermost region of the base 10 and in the central bottom region 13 are there no knobs present. The knobs 12 arranged around the bottom region 13 , which in the present case jointly form a pentagon, can serve, in particular, to hold the bowl stable in its position when it is resting in an upright position on a plane surface 70 . Between the central bottom region 13 and the uppermost region of the base 10 , the knobs 12 are preferably distributed, as here, regularly over the entire outer surface of the base 10 . In the present embodiment, not only are the knobs 12 arranged in groups in the form of equilateral triangles, but they also, moreover, form the grid points of a grid of equilateral triangles. Due to this regular arrangement of the knobs 12 , an individual knob 12 can respectively form a part of several, here from four to six groups. The various groups of knobs can thus, as is here the case, also overlap.
The knobs 12 can jointly be configured integrally with the base 10 . Preferably, however, the knobs 12 , as can be seen for example in FIG. 4 , are configured integrally on a plastics coating 11 . This plastics coating 11 can cover a part or even the whole of the outer surface of the base 10 . Advantageously, the plastics coating 11 is here applied to the base 10 in such a way that its outer side, as is shown in FIG. 4 , is arranged flush with the rest of the outer side of the bowl. In the present illustrative embodiment, the outer side of the plastics coating 11 is arranged flush with the outer side of the side wall 20 . The plastics coating 11 can here, in particular, be sprayed onto the base 10 , which is made, preferably integrally with the side wall 20 , of a plastic. Advantageously, the plastics coating 11 is made, in comparison to the base 10 , of a softer material, i.e. of a material having a lower Shore A-value, for example of silicone rubber. Due to this softness of the plastics coating 11 , the knobs 12 , when resting on a surface, can better adapt thereto, so that the forces are better distributed amongst the various knobs 12 of the corresponding group. Moreover, the outer side of the base becomes in this way more slip-proof.
According to the embodiment represented in FIG. 7 , the knobs 12 ′ do not necessarily have to have plane end faces, but can also be of rounded configuration on their outward facing free ends.
A particularly advantageous embodiment is shown in FIG. 8 . The knobs 12 ″ of a common group here respectively all extend outward parallel to one another. A group here respectively has five knobs 12 ″, wherein more or less than five, yet at least three, knobs 12 ″ per group could naturally also be provided. In the present illustrative embodiment, the knobs 12 ″ of a common group are respectively configured with different length such that they end with their here preferably plane outer surfaces on a common plane. Due to this particular design of the knobs 12 ″ within a group, the bowl can rest in an oblique position with all knobs 12 ″ of respectively a group on a plane surface 70 such that all knobs 12 ″ stand perpendicularly on the surface 70 and the outer surfaces of the knobs 12 ″ rest flat on the surface 70 .
A further embodiment of an inventive bowl is represented in FIG. 9 . The bowl here additionally has in the region of its side wall 20 a spout 40 for pouring out of the bowl content. The spout 40 can be disposed, as here, within the side wall. It is also conceivable, however, to arrange the spout in the region of the upper rim 21 of the side wall 20 . Moreover, in the present illustrative embodiment, the interior 30 of the bowl is closed off to the top by a lid 60 . The lid 60 has a handle 61 . In order that the lid 60 , in an inclined position of the bowl, does not slip away from this, it can have, in particular, a downwardly extending casing, which, adjacent to the side wall 20 , juts into the interior 30 . Furthermore, in this illustrative embodiment, a handle 50 is attached to the bowl, which handle makes the bowl easier to handle for the user. Of course, it is also possible, however, to dispense with the spout, the handle and the lid. Even the side wall 20 can be fully dispensed with in order to obtain a flat bowl.
Yet another embodiment of an inventive bowl is shown in FIGS. 10 and 11 . The bowl here has a spout 40 ′ on the upper rim 21 of the side wall 20 , and a diametrically opposing handle 50 ′. As can be seen, in particular, in FIG. 11 , the plastics coating 11 here extends upward in the region of the handle 50 ′ and both over the bottom side and over the top side of the handle 50 ′. It can here cover the handle fully or else only partially. In a central region, the base 10 is of flattened design. Moreover, the plastics coating 11 , as here, can have in this flattened region a circular opening, into which the base 10 can extend with a downwardly jutting region. In the region around this central opening, the plastics coating 11 is configured slightly thickened in order to form a bearing region for improved stability of the bowl in its upright position. The knobs 12 ′ are here attached to the plastics coating 11 only in the region where the base 10 is curved, and not in the region where it is flattened.
REFERENCE SYMBOL LIST
10 base
11 plastics coating
12 , 12 ′, 12 ″ knobs
13 central bottom region
20 side wall
21 upper rim
30 interior
40 , 40 ′ spout
50 , 50 ′ handle
60 lid
61 handle
70 surface
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The invention relates to a bowl for mixing food. At least one group of at least three knobs ( 12; 12′; 12″ ) is attached to the outside of the base ( 10 ) of said bowl. All the knobs of a group protrude outwards to a common plane so that the bowl can be placed onto an even surface ( 70 ) in an orientation that is inclined with respect to the direction of gravity in such a manner that said bowl lies on the even surface ( 70 ) with all the knobs ( 12; 12′; 12″ ) of said group.
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BACKGROUND OF INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a method for introducing and implanting an embryo into the uterus.
[0003] 2. Prior Art
[0004] Human In Vitro Fertilization (IVF) is the extracorporeal (outside the body) fertilization of a human egg thereby producing an embryo. To optimize pregnancy potential, the fertilized egg(s), i.e., embryo(s) must be accurately and smoothly placed in the uterine (endometrial) cavity and then retained in that location. Typically one or more embryos are transferred into the uterine cavity after culturing for two to six days. The process of placing the embryo(s) is called Embryo Transfer (ET).
[0005] An embryo is normally transferred into the uterus by means of a polytetrafluoroethylene or Teflon® catheter. The embryo is suspended in a fluid medium in the catheter. The catheter is passed through the cervical opening, via the cervical canal into the endometrial cavity. Conventional means such as ultrasound and fiber optics may be used to guide and position the catheter in the uterus. Upon entrance into and proper placement in the cavity, the fluid containing the embryo is flushed through the catheter and the embryo is carried into the uterus.
[0006] Less than one third of the embryos so transferred result in a live birth. A successful outcome following the in vitro fertilization and embryo transfer is in a large part dependent upon the appropriate placement of the transferred embryo in the uterine cavity. Descent or reflux of transferred embryos into the cervical canal during withdrawal of the ET catheter results in their sequestration and renders such embryos unavailable for implantation.
[0007] Attempts have been made to reduce the incidence of embryo reflux by a number of methods including:
[0008] 1. Use of a flexible ET catheter to avoid inducing uterine irritability.
[0009] 2. Use of fibrin as a sealant (glue) to “attach” the transferred embryos to the uterine wall.
[0010] 3. Careful measurement of the uterine depth and ultrasound and/or fiberoptic guidance to promote accurate placement of embryos in the uterine cavity.
[0011] 4. Use of uterine tocolytics such as β-adrenergic and anti-prostaglandin agents to relax the uterus in preparation for ET.
[0012] For example, U.S. Pat. No. 6,010,448, to Thompson, issued on Jan. 4, 2000 discloses the use of an adhesive carried by the distal end of the catheter to glue the embryo to the uterine wall and a balloon to position and hold the embryo in place against the uterine wall.
[0013] However, any one, or the combination, of these techniques fail to sufficiently increase the pregnancy rate. The present invention relates to a method for promoting proper embryo placement and retention, thereby increasing the likelihood of the embryo(s) being available for subsequent implantation into the uterine lining (endometrium), further reducing embryo reflux.
SUMMARY OF INVENTION
[0014] We have found that the interaction of the catheter with the mucus plug in the cervical canal (the entrance to the uterus) is a major cause of IVF/ET failure. The cervical mucus adheres to the transferred catheter and is carried into the uterus during insertion. This not only leads to inadvertent introduction of bacterial and cellular debris into the normally sterile endometrial cavity, but mucus at the catheter tip may also engulf the embryo, diminishing its ability to implant or act to adhere the embryo to the catheter causing it to be pulled down into the cervical canal and /or vagina as the catheter is removed. Thus, in many cases, implantation failure is due to embryo sequestration within the cervical mucus.
[0015] The present invention is designed to overcome this effect of the mucus plug on the ET transfer through the use of phospholipid, a non-embryotoxic surface tension lowering substance, as a coating on the catheter. In accordance with the present invention, the embryo is protected from the mucus plug and the likelihood of the embryo being actually removed from the uterus upon withdrawal of the ET catheter is reduced by the application of a the phospholipid, Phosphatidylcholine, to the exterior surfaces of the ET catheter and its outer sheath (canula). The phospholipid lowers the surface tension on and at and in the tip of the catheter. Such reduction in surface tension improves the easy passage of the ET catheter through the cervical canal, minimizes the risk of introducing mucus and cellular debris into the uterine cavity, promotes proper discharge of the embryo(s) into the uterine cavity by reducing the likelihood of an embryo adhering to the catheter, and thereby enhances embryo availability for implantation. Naturally occurring phospholipids in general and, phosphatidylcholine in specific, are not harmful to (and may even enhance) embryo development and/or implantation. Some Examples of other acceptable phospholipids for such use are: phosphatydil glycerol, sphingomyelin and phosphatydil ethanolamine.
[0016] Immediately before use, the surfactant phospholipid is liberally applied both to the outer surfaces of the ET catheter and its sheath (canula). Such application has a number of positive effects including elimination of an embryo's attachment to the outer surface of the ET catheter, reducing the likelihood of the embryo-containing culture medium sticking to the ET catheter tip and being drawn back into the cervical canal at the time of the catheter withdrawal. As a result, there is improved uterine retention of transferred embryos and higher embryo implantation (pregnancy) rates following ET.
DETAILED DESCRIPTION
[0017] The present invention is an improvement of embryo transfer technology to eliminate the adverse effects of the ET catheter passing through the cervical canal and its mucus plug. When the ET catheter passes through the mucus plug, it is often coated, in at least part, with mucus including mucus at and near the tip of the catheter. Such mucus and other “debris”, derived from the cervix may act as a barrier to the correct implantation of the embryo(s) into the endometrium, by 1) causing their adherence to the catheter and thus allowing the embryo(s) to be dragged into the cervical canal when the catheter is removed and, 2) by acting as a physical barrier that interfaces between the embryo and the endometrial lining, thus interfering with attachment (implantation) of the embryo(s) to the endometrium. In the present invention, a non-embryotoxic phospholipid surfactant acts as a surface tension lowering agent, which coats the ET catheter and canula. The surfactant acts to lessen the accumulation of mucus and other “debris” on the catheter as it passes through the cervical canal, into the uterus and lessens the ability of any mucus, which does remain on the catheter from causing the embryo(s) to stick to the catheter. One acceptable surfactant phospholipid is presently offered by Abbott Laboratories under the trademark SURVANTA. The Survanta is a solution containing a natural bovine lung extract comprising 25 mg/ml of phospholipids, with 11-15 mg/ml of phosphatidylcholine suspended in 0.9% saline. It is normally vaporized and sprayed into the lungs of neonates with Respiratory Distress Syndrome (Hyaline membrane disease). Mouse embryos toxicity assays found a 1:3 dilution of Survanta with Human tubular fluid to have no adverse effect on fertilization, embryo development and blastocyst formation.
[0018] The present invention can be used with any ET catheter. The sterile catheter may be flushed with a diluted phospholipid prior to loading the embryo(s). Immediately prior to the ET, a phospholipid is liberally applied along the distal 5 cm of the outer surface of both the ET catheter and its sheath (canula). Such application of human tubal fluid prevents cervical mucus, blood and cellular debris from adhering to the ET catheter, thereby reducing the possibility of embryo retention. Given this coating, an embryo is less likely to be blocked on its passage from the catheter to the uterine wall and less likely to adhere to the exterior of the catheter and thus be dragged out of position with the catheter's removal.
[0019] The invention is further illustrated by the following example:
EXAMPLE 1
[0020] A group of 32 women under 39 years of age, with a normal uterine cavity and normal ovarian reserve, were stimulated for IVF/ET standard protocols. Embryos were cultured in P 1 (Irvine Scientific embryo growth media) until day 3. Some embryos were then allowed to continue in culture in a blastocyst medium (Irvine Scientific) for an additional 2-3 days. Embryo transfer was performed on day 3, 5 or 6, Embryo transfer was performed using a Wallace catheter under ultrasound-guidance after flushing and cleansing the cervical canal with culture media. The patients were randomized to receive standard ET (Group A, n=15) or ET in accordance with the present invention (Group B, n=17). After the embryo(s) were drawn up into the distal end of the catheter the ET catheters in Group B were coated with dilute 1:3 Survanta to the outer surfaces of the distal 5 cm of both the catheter and canula. ET was performed within 2 minutes thereof thereafter under abdominal ultrasound guidance.
[0021] Each woman received between one and 3 embryos during a single procedure session. The woman of Group A received a total of 40 embryos transferred and Group B received a total of 49 embryos transferred. In Group A, there were 13 embryos successfully implanted, (i.e., viable conceptii confirmed by ultrasound examination after the twelfth week of pregnancy) in 9 women while in Group B, there were 27 embryos successfully implanted in 12 women. Thus, the implantation rate of successful embryo transfers for Group A was 33% and Group B was 55% percent. Several woman were carrying more than one child as it is common to transfer multiple embryos during implantation. As seen from the data, the rate of successful implantation was substantially higher per embryo transfer in Group B.
[0022] While the invention has been described in detail and with reference to the specific embodiment thereof, it will be apparent that various changes and modifications can be made therein without varying from the spirit and scope thereof, such as the use of alternative non-embryo toxic human tubal fluid.
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An enhanced method of in vitro fertilization by coating an embryo transfer catheter with a non-embryotoxic phospholipid. The phospholipid reduces or eliminates the collection of mucus on an ET catheter as it passes through the mucus plug in the cervical cannel and thus elimininating its detrimental effect in, engulfing the embryo and preventing implantation.
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RELATED APPLICATIONS
There are currently no applications co-pending with the present application.
FIELD OF THE INVENTION
The presently disclosed subject matter is directed towards games. More particularly the subject invention is directed to an illuminated electronic beanbag toss game.
BACKGROUND OF THE INVENTION
Older people often remember with great fondness the games of their youth. Neighborhood children would often play tag, board games, baseball, bad mitten, horseshoes, and darts. While some of those games are still popular they are not as popular as they once were.
One (1) reason for the decline in popularity of older games is that today's children are influenced by fast action computer games, movies, and other such activities that incorporate sound and light effects. However, some of the older games combined elements of both competition and skill that are difficult to replicate on a computer. One (1) such game is the much loved game of beanbag toss. In beanbag toss, a bag filled with a material such as beans, corn kernels, shells, or other filler material is tossed from a toss line toward one or more targets, usually a hole in a board. A successful toss, when the bag passes through the hole, results in a score. By placing multiple different sized scoring holes through the board, different points can be awarded. Then, like in the game of darts, different ways to determine who won a game can be implemented: high score, first to a score, or the first to accumulate a given score are all possible.
The challenge of simply tossing a bag through a hole in a board should not be underrated. It can be remarkably challenging, and if it becomes too easy the challenge can be increased simply by moving the line further from the board. Since beanbag toss can be played in teams, using two (2) boards makes team play easier and the game overall faster.
In view of the foregoing a more modern version of the old bean bag toss game that incorporates lights and sounds would be beneficial.
SUMMARY OF THE INVENTION
The principles of the present invention provide for a modern version of the beanbag toss game and which incorporates lights and sounds to make the game more interesting and player friendly.
A toss game that is in accord with the principles of the present invention includes a target board having a flat surface with a target opening. The target board is illuminated by a plurality of board perimeter illumination lamps, while the target opening is illuminated by target perimeter illumination lamps. The target board is supported by a hinged rear support leg and by a hinged front support frame that fold under the target board. The toss game also includes a speaker, a game piece (preferably illuminated), and a detector that senses when the game piece enters the target opening. The first target perimeter illumination lamp signals when the game piece enters that target opening.
Beneficially, the target board includes a centerline hinge and a carrying handle, and the flat surface further includes a second target opening illuminated by a second target perimeter illumination lamp. Also beneficially, the first target perimeter illumination lamp and the second target perimeter illumination lamp have different colors.
In practice, the target board is supplied with a battery storage compartment that houses a first replaceable battery that selectively powers the board perimeter illumination lamps, and a first ON/OFF switch that controls the application of power from the first replaceable battery. Additionally, the toss game includes an audio ON/OFF switch that controls a signal that is applied to the speaker. The first target perimeter illumination lamp lights and/or flashes whenever a game piece passes through the first target opening while the board perimeter illumination lamps are lit during game play.
Detecting when a game piece enters the target opening is performed by a detector having an emitter and a receiver, beneficially photoelectric that form a detection field that spans the target opening. The detector provides an electric signal whenever a game piece passes through the target opening.
As noted, the game piece is beneficially illuminated. If so, the game piece includes an internal battery, a battery switch, and a fill media.
The toss game further includes a software operated controller module that controls the board perimeter illumination lamps and the target perimeter illumination lamps in response to the electric signal from the detector. The controller module can also drive an audio processor that is connected to the speaker and can control the board perimeter illumination lamps to illuminate and/or flash.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings in which like elements are identified with like symbols and in which:
FIG. 1 is an isometric view of a beanbag toss game 10 that is in accord with the principles of the present invention;
FIG. 2 is a sectional view of the target board 15 of the beanbag toss game 10 illustrated in FIG. 1 ;
FIG. 3 is a sectional view of the game pieces 20 taken along line II-II of FIG. 1 ;
FIG. 4 is an electrical block diagram of the target board 15 shown in FIG. 2 ; and,
FIG. 5 is an electrical block diagram of the game pieces 20 shown in FIGS. 1 and 3 .
DESCRIPTIVE KEY
10 beanbag toss game
15 target board
20 game pieces
25 flat surface
30 target opening
35 centerline hinge
40 carrying handle
45 rear support legs
50 first hinge mechanism
55 front support frame
60 second hinge mechanism
65 travel path arrows
70 speakers
75 board perimeter illumination lamps
80 target perimeter illumination lamp
85 battery storage compartment
90 first replaceable batteries
95 first ON/OFF switch
96 audio ON/OFF switch
100 detector
105 emitter
110 receiver
115 detection field
120 outer cloth covering
125 fill media
130 light-emitter
135 light rays
140 adhesive
145 control enclosure
150 zipper
155 second replaceable battery
160 second ON/OFF switch
165 controller module
170 audio processor
175 audio file memory module
180 perimeter illumination driver
185 target illumination driver
190 driver circuit
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within FIGS. 1 through 5 , and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention, and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope.
The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.
The principles of the present invention are presented in terms of a beanbag toss game 10 embodiment depicted in FIGS. 1 through 5 .
FIG. 1 presents an isometric view of the beanbag toss game 10 , a game that includes elements of both skill and strategy and which is preferably played outdoors. The beanbag toss game 10 is played on two (2) identical target boards 15 , only one (1) of which is shown for purposes of illustration, and a set of game pieces 20 . While the game pieces 20 are shown and described as being beanbag-shaped that is not intended to be a limiting factor of the present invention as other shapes may also be used.
Still referring to FIG. 1 each target board 15 comprises a flat surface 25 having at least one (1) target opening 30 (four (4) are shown in FIG. 1 ). The flat surface 25 has a centerline hinge 35 and a carrying handle 40 that enable the target board 15 to be folded in half, carried and transported. The flat surface 25 is envisioned as being made from weather-resistant materials such as molded plastic, plastic-coated plywood, or the like.
The target board 15 is provided with two (2) rear support legs 45 (only one (1) of which is shown due to limitations of illustration) which are supported by first hinge mechanisms 50 . The target board 15 is also provided with a front support frame 55 which is supported by a second hinge mechanism 60 . The rear support legs 45 and the front support frame 55 fold inward as depicted by travel path arrows 65 .
The front support frame 55 is provided with a series of speakers 70 which emit pre-recorded verbal announcements that are intended to enhance game enjoyment, such as during initial activation of power, as well as each scoring success. Additional details on the functionality of the speakers 70 are provided below. The target board 15 is also provided with a plurality of board perimeter illumination lamps 75 such as incandescent lamps, LED lamps, Neon lamps or the like. Additionally, the target board 15 is provided with target perimeter illumination lamps 80 around each of the target openings 30 . As before, the target perimeter illumination lamps 80 can be from incandescent lamps, LED lamps, neon lamps or the like. It is envisioned that each target opening 30 is provided with a unique color perimeter illumination such as green, blue, red, or the like, so as to communicate which target opening 30 a user has scored through.
Still referring to FIG. 1 , the front support frame 55 includes a battery storage compartment 85 for housing first replaceable batteries 90 (not shown in FIG. 1 , but see FIG. 4 ) that supply operating power for elements attached to the target board 15 . The first replaceable batteries 90 enable portable operation of the beanbag toss game 10 without reliance on outside power.
Referring now to both FIG. 1 and FIG. 4 , the beanbag toss game 10 includes a first ON/OFF switch 95 that is located on the rear of the target board 15 to allow a user to control the game power. When the first ON/OFF switch 95 is OFF or when the first replaceable batteries 90 are depleted or not installed, the beanbag toss game 10 functions as a conventional beanbag toss game. The beanbag toss game 10 also includes an audio ON/OFF switch 96 that is adjacent the first ON/OFF switch 95 . The audio ON/OFF switch 96 enables a user to turn off sound to operate the beanbag toss game 10 in a silent mode if desired.
Still referring to both FIG. 1 and FIG. 4 , each target opening 30 includes a detector 100 for detecting when a game piece 20 enters the target opening 30 . Further description of the detectors 100 is provided below. The detectors 100 enable enhanced playing enjoyment of the beanbag toss game 10 by causing the target perimeter illumination lamps 80 to light and flash whenever a game piece 20 passes through a target opening 30 . It is also envisioned that the board perimeter illumination lamps 75 and the target perimeter illumination lamps 80 would illuminate in a continuous or a sequential flashing manner during game play.
Referring now to both FIG. 1 and FIG. 5 , the game pieces 20 are also provided with internal illumination as described subsequently. Such illumination in conjunction with the audio sounds provide more interesting and attractive game play and are particularly beneficial should the beanbag toss game 10 be played at night or during other periods of low ambient light. Indeed, at night the illumination provided by the board perimeter illumination lamps 75 , the target perimeter illumination lamps 80 , and the game pieces 20 can serving as the only illumination and such is envisioned as increasing the level of fun and excitement.
FIG. 2 is a sectional view of the target board 15 taken along line I-I of FIG. 1 and which is particularly helpful in understanding the detector 100 and its relationship to the flat surface 25 and the target opening 30 . The detector 100 comprises a photoelectric emitter 105 and a photoelectric receiver 110 . However, the emitter 105 and receiver 110 may operate on other principles such as ultrasonic, radioactive, and capacitive and the like can be used with equal effectiveness. The emitter 105 and the receiver 110 form a detection field 115 which spans the opening of the target opening 30 and which provides an electric signal whenever an object such as the game pieces 20 (see FIG. 1 and FIG. 3 ) passes through. The emitter 105 and the receiver 110 should be located so as not to impede or assist the passage of the game pieces 20 through the target opening 30 .
FIG. 3 presents a sectional view of the game pieces 20 taken along line II-II of FIG. 1 . As shown, the game pieces 20 have an outer cloth covering 120 of a heavy duty material such as nylon, canvas, denim or the like. Most of the interior space is filled with a fill media 125 such as corn kernels, beans, sand, small pebbles or the like. A series of light-emitters 130 such as light-emitting diodes (LED's) are located inside the outer cloth covering 120 so as to shine through the outer cloth covering 120 to produce exterior light rays 135 . The light-emitters 130 are held in place with adhesive 140 or secured by another means such as sewing. The light-emitters 130 are connected to a control enclosure 145 located inside the outer cloth covering 120 and near a zipper 150 . The control enclosure 145 houses a second replaceable battery 155 and a second ON/OFF switch 160 . The user can control the operation of the light-emitters 130 , as well as replace the second replaceable battery 155 without upsetting the aerodynamic and exterior characteristics of a conventional bean bag.
Referring now to FIG. 4 , which is an electrical block diagram of the target board 15 . Operating power for the target board 15 is derived from the first replaceable batteries 90 as controlled by the first ON/OFF switch 95 . Switched power is routed to a controller module 165 . The controller module 165 includes a microcontroller such as a basic stamp module that operates in accord with software programs, such as an Arduino-based platform that uses the Arduino programming language. The controller module 165 further includes hard wiring, glue logic, a relay or the like. Such various control based themes are well known in the art and are not intended to be a limiting factor of the present invention.
Inputs to the controller module 165 include the detector 100 and its emitter 105 and the receiver 110 . The number of detectors 100 correspond to the number of target openings 30 (see FIG. 1 ). Outputs from the controller module 165 drive an audio processor 170 , which connect both to speakers 70 as well as to an audio file memory module 175 . Example content of the audio file memory module 175 may include files for tunes such as “LET'S PLAY”, “GOOD SHOT”, “RIGHT DOWN THE MIDDLE”, “CHEERING SOUNDS”, “THAT'S A WINNER”, and the like.
Another output from the controller module 165 powers a perimeter illumination driver 180 which drives the board perimeter illumination lamps 75 . The perimeter illumination driver 180 provides steady state illumination, random flashing, steady state flashing, sequential flashing and the like. The controller module 165 also provides outputs to a series of target illumination drivers 185 for each of the target openings 30 (see FIG. 1 ). It is envisioned that each target illumination driver 185 provides illumination to a respective target opening 30 which in turn comprises a unique color perimeter illumination such as green, blue, red, or the like, so as to communicate which target opening 30 the user has scored through. The activation of the target illumination driver 185 is controlled by the detector 100 within each target opening 30 . As such, the light from the target perimeter illumination lamps 80 correspond to passage of a throwing game piece 20 through a target opening 30 .
Referring now to FIG. 5 , an electrical block diagram of the game pieces 20 , power from the second replaceable battery 155 is routed through the second ON/OFF switch 160 and into a driver circuit 190 . The output of the driver circuit 190 drives the light emitters 130 . The driver circuit 190 beneficially provides for continuous illumination, random illumination, sequential illumination and the like.
It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention. While only one particular configuration is shown and described, such is for purposes of clarity and disclosure and not by way of limitation of scope.
The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. It is envisioned that the bean bag game 10 would be constructed in general accordance with FIG. 1 through FIG. 5 . It is also envisioned that the target board 15 would be made of weather-resistant plywood or plastic using well known forming and manufacturing methods. The various electronic components as aforementioned described would be placed on or in the target board 15 or the game pieces 20 respectively and wired together in accord with the block diagrams of FIG. 4 and FIG. 5 . The target board 15 and the game pieces 20 would be supplied with first replaceable batteries 90 and a second replaceable battery 155 . A pair of target boards 15 would be located in an outdoor or other appropriate environment a suitable distance apart. The first ON/OFF switch 95 , the audio ON/OFF switch 96 , and the second ON/OFF switch 160 would be activated. At this point in time, the bean bag game 10 is ready for use.
During actual use of the bean bag game 10 , teams of player(s) would take turns trying to throw the game pieces 20 through the target openings 30 . Various points are awarded for successful attempts. Scoring continues for a predetermined number of rounds or until a predetermined point level is reached thus determining a winner or winning team. During such play, the bean bag game 10 provides illumination via the board perimeter illumination lamps 75 and the target perimeter illumination lamps 80 while also provided special scoring illumination via the detector 100 and target perimeter illumination lamps 80 and audible sounds via the speakers 70 . When finished with play, the target board 15 and the game pieces 20 are deactivated. The rear support legs 45 and the front support frame 55 are folded inward and the target board 15 is folded in half and transported via the carrying handle 40 to a suitable storage location.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention and method of use to the precise forms disclosed. Obviously many modifications and variations are possible in light of the above teaching. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application, and to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions or substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but is intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.
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Provided is an illuminated toss game having at least one (1) game piece that is tossed into at least one (1) scoring hole located in a top surface of a playing platform. The toss game further includes a speaker and various lighting devices that are activated when a game piece is tossed through a scoring hole. To sense when a game piece passes through a scoring hole the toss game also includes a detector that emits an electrical signal that causes lights near the scoring hole to signal that a point has been scored. The toss game further includes an on-board battery, power and audio ON/OFF switches, and a controller that causes various lighting and sound effects to occur. Additionally, the game piece includes illumination lights.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part application of a U.S. patent application, Ser. No. 07/060,606, filed on June 11, 1987 entitled "COMPOUND SEMICONDUCTOR STRUCTURE HAVING GRADED MOLE FRACTION AND PROCESS FOR PREPARATION THEREOF".
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a compound semiconductor structure and a process of making the same, and more particularly to a compound semiconductor structure having a graded composition or mole fraction adapted for reducing the source resistance in a hetero-junction field effect transistor and a process of making the same.
2. Description of the Related Art
Applications of compound semiconductors involve the hetero-junction field effect transistor (HJ-FET). An example of the prior art of HJ-FET is shown in FIG. 6.
An undoped GaAs layer 2 is formed on a semi-insulating GaAs substrate 1. An undoped Al 0 .3 Ga 0 .7 As layer 3 is formed on the undoped GaAs layer 2 to form a hetero-junction. Due to the difference in the electron affinity in the materials GaAs and Al 0 .3 Ga 0 .7 As, there are formed steps ΔE c and ΔE v in the conduction band energy and the valence band energy, respectively, at the Al 0 .3 Ga 0 .7 As/GaAs hetero-junction interface. A quantum potential well originating in the gap of the conduction bands, ΔE c , is formed in the undoped GaAs layer 2 adjacent the hetero-junction interface and results in the yielding of a two dimensional electron gas (2DEG), that is supplied from the donor in n-Al 0 .3 Ga 0 .7 As layer, by means of ionizing. 2 DEG in its quantum potnntial well should contribute as a channel of the HJ-FET.
On the channel region constituted by the undoped Al 0 .3 Ga 0 .7 As layer 3 and the undoped GaAs layer 2, are formed graded mole fraction layers 22 and 23 of Al x Ga 1-x As sandwiched between uniform composition layers 21 and 24 of undoped GaAs and n type doped Al 0 .3 Ga 0 .7 As. The graded mole fraction layers 22 and 23 have a composition distribution in which the Al mole fraction x of Al x Ga 1-x As changes from 0 to 0.3 as the position goes from the upper surface of the layer 22 to the lower surface of the layer 23, as shown at right hand side portion of FIG. 6. Thus, with respect to the Al mole fraction, the graded composition layers 22 and 23 connect the undoped GaAs layer 21 and the undoped Al 0 .3 Ga 0 .7 As layer continuously.
The layers 21 and 22 disposed below the gate electrode 9 are undoped to prevent the excessive increase in the field intensity, which may lead to avalanche breakdown.
Electrons are supplied from the source electrode 8 to the channel region 2, 3 through the layers 21, 22, 23 and 24. Electrons are transported through the channel formed by the hetero-junction layers 2 and 3 in the form of a two dimensional electron gas, whose electron number could be controlled by the voltage of a gate electrode. And those are derived through the layers 21, 22, 23 and 24 to the drain electrode 10. The source and drain electrodes 8, 10 may be formed of Au/Ni/AuGe and makes an Ohmic contact with the alloy under the condition of 400° C. for 2 minutes. The gate electrode 9 may be formed of Al and established using the usual lift-off process.
FIG. 7 shows a band diagram in the HJ-FET of FIG. 6 in a direction perpendicular to the substrate surface (i.e. in the depthwise direction). The left end, i.e. outer left, region represents the surface GaAs region 21. The flatness of the diagram in this region means the state under the no electric field. In the case of the flowing electrons, of course, the band diagram should be inclined to right hand side. The inner left region, next to the surface GaAs region 21, represents the graded composition regions 22 and 23. The region 22 is undoped for providing a high breakdown voltage, as described above.
When the source electrode 8 is biased slightly negatively with respect to the channel region 2, electrons will flow from the source 8 to the channel 2 with a low resistance. The inner right region represents the n-type Al 0 .3 Ga 0 .7 As region 24 and the undoped Al 0 .3 Ga 0 .7 As region 3. In the right-hand side of these region 24, 3, the bands are bent upward due to the ionization of donor in n-type Al 0 .3 Ga 0 .7 As region 24. The right end i.e. the outer right region, represents the undoped GaAs region 2. Due to the differences in the energy of the conduction band and the valence band with respect to the vacuum level, there are generated gaps ΔE c and ΔE v in the bottom of the conduction band E c and in the top of the valence band E v , respectively.
If the graded composition region 22 and 23 is not provided that is, Al mole fraction of x is 0.3 in the regions, similar gaps may be formed at the interface between the surface GaAs region 21 and the Al 0 .3 Ga 0 .7 As above said region in the case of no graded one. The graded composition region 22, 23 serves to connect the bottom of the conduction band E c continuously, thereby enhancing transport of the charge carrier, electrons. This structure is reported, for example, in IEEE Transactions on Electron Devices, Vol. ED-33, No. 5 (1986) pp. 601-607.
Conventionally, the graded composition layer as described was formed through crystal growth by the molecular beam epitaxy (MBE), by changing the temperature of an aluminum cell during the growth to vary the Al mole fraction x of Al x Ga 1-x As from 0.3 to 0.0.
Generally, one of the features of the MBE epitaxial growth of a compound semiconductor crystal is that the vapor pressures of atoms, and hence the rate of crystal growth, are regulated by controlling the temperatures of molecular beam sources. In the MBE epitaxial growth of a compound semiconductor, the constituent atoms of the compound are fed in the form of vapor into an ultrahigh vacuum space from two or more molecular beam sources and are solidified, in the form of an epitaxial crystal, on a semiconductor substrate crystal placed on a temperature-controlled susceptor, wherein the axes of the grown crystal follow those of the substrate crystal. The composition or mole fraction of the crystal to be grown, for example, x of Ga x Al 1-x As, is determined by setting each vapor pressure of the molecular beam sources, Ga, Al and As. The vapor pressure of each source only depends upon the cell temperature of above said source. Thus, for making a crystal having a graded mole fraction x, it is necessary to vary the cell temperature of source to be varied. Conventionally, for grading a mole fraction x from a higher value toward a lower value, natural cooling has been utilized by switching off the electric power source which is the heat source for the cell of the atom concerned. Vapor pressure changes exponentially with temperature. Stable temperature control (for example of the order of ±0.1° C.) is required for providing an accurate vapor pressure. For realizing a smooth composition distribution, it is preferable to gradually change the temperature. Thus, natural cooling has been adopted. FIG. 3 represents the relationship between the Al mole fraction of an Al x Ga 1-x As crystal and the film thickness of the crystal grown under natural cooling of the Al cell. Initially, the respective cell temperatures are set to grow Al 0 .3 Ga 0 .7 As. The heater of the Al cell is turned off to allow the Al cell to be cooled naturally. As the temperature of the Al cell decreases, the Al vapor pressure decreases, after the relation P Al α exp (-ΔE Al /kT Al ), where ΔE Al is the activation energy of Al and T Al is the Al cell temperature, resulting in gradual decrease in the composition x of the grown Al x Ga 1-x As layer. As the value of x becomes small, the variation becomes gentle.
When the quantity of As vapor is sufficient, the composition x of the grown layer Al x Ga 1-x As is determined by the vapor pressures of aluminum P Al and gallium P Ga . The growth rates are set, for example, ##EQU1## Here, the well temperatures of Ga and Al are set at T Ga =983° C. and T Al =1090° C. The growth rate of Al 0 .3 Ga 0 .7 As is the sum of the growth rates of GaAs 1 μm/hr, and of AlAs, 0.43 μm/hr. Letting the growth rate of AlAs be y μm/hr, the composition x will be ##EQU2## The growth rate of AlAs is ##EQU3## When the Al cell temperature is 1090° C. (=1363° K.) in the growth of Al 0 .3 Ga 0 .7 As, the growth rate of AlAs can be expressed as
y=0.429 exp [(-ΔE.sub.Al /k) (1/T.sub.Al -1/1363)].
Ordinary natural cooling requires about 30 seconds for lowering the Al cell temperature T Al by 100 degrees. For allowing the composition x to change from 0.3 to 0.0, it is necessary to grow a graded layer of the order of 400 Å thick.
The crystal growth by MBE as described above is discussed in K. Takahashi, "Molecular Beam Epitaxy Technique" (1984) published by Kogyo Chosakai.
This conventional technique utilizing the natural cooling is useful for varying the mole fraction of an epitaxial crystal within a thickness of several hundreds of nm. Because of a relatively long growth time, the temperature can be lowered sufficiently. Thus, it was possible to vary, for example, the Al mole fraction x of Al x Ga 1-x As from x=0.3 to x=0. However, in forming a thin film of around several tens of nm, the change in mole fraction from x=0.3 to x=0 was difficult owing to a too small growth time to cause sufficient temperature lowering.
It is indeed possible, to forcedly control the cell temperature by heating, etc. For example in the growth of Al x Ga 1-x As by MBE, when the temperature of the Al cell is raised, the pressure of Al vapor varies in accordance with the instantaneous temperature of the Al cell, and hence the growth rate of the Al x Ga 1-x As crystal varies. In such cases, control of the film thickness and the doping concentration becomes very difficult. This is because rapid temperature changes in a practical cell is hardly monitored accurately even when a thermo-couple thermometer is disposed near the cell for detecting the temperature and effecting temperature control. Thus, reproducibility and stability have been problematic.
A kind of superlattice structure as shown in FIG. 4 was proposed. The film thickness A of one kind of layer containing the element (Al in this case) and the film thickness B of another kind of layer which does not contain the element (Al) are set equal to each other (A=B). The sum of the thicknesses of adjacent pair of films (A+B) is increased. In FIG. 4, there is shown the relationship between the Al mole fraction and the epitaxial crystal thickness (proportional to the time of growth). The solid line represents the Al mole fraction of the grown film and the broken line represents the average mole fraction. This technique is described in Electronics Letters, 21, pp. 882-884 (1985).
U.S. Pat. No. 4,620,206 to Ohta et al (corresponding to JP-A-60-28268) discles a negative resistance device formed with a superlattice. Typically, a superlattice layer C is formed between material A layer and material B layer. In the superlattice, one end portion contacting the material A layer has properties substantially identical to material B and the other end portion contacting the material B layer has properties substantially identical to material A. A negative resistance phenomenon is exhibited, using above said structure involving homogeneous materials A and B and super-lattice. Here, if material A is exchanged by material B, and also B by A, the negative resistance phenomenon can not be observed in principle.
SUMMARY OF THE INVENTION
An object of this invention is to provide a compound semiconductor structure having a layer of effectively graded composition, using superlattice layers.
Another object of this invention is to provide a hetero-junction field effect transistor having a structure for reducing the source resistance.
Further object of this invention is to provide a process for growing a crystal layer of an effectively graded composition without any problem in reproducibility and stability.
According to one aspect of this invention, a crystal layer of an effectively graded composition is realized by a superlattice layer formed of ultrathin films of two kinds of material, one having a composition larger than a desired composition and the other having a composition smaller than the desired composition.
When the interval of the superlattice is smaller than the quantum mechanical spreading of the wave function of an electron in the semiconductor, the potential which an electron senses is an average of the potential distribution over those layers of the superlattice which are located within the spreading of the wave function of the electron. In such a case, approximation can be made that the average composition will mainly control the average potential which the electron senses. Then, a superlattice structure having a graded average composition can be equivalent to a continuous layer having a graded composition for an electron. This holds true when there is no intense field in the superlattice structure and no influence of the forbidden band of the superlattice on the electrons.
In the superlattice structure comprising repeated pairs of superthin films, there can be established sub-band structure which extends throughout the superlattice, when the thickness of each pair of superthin layers is less than the dimension of an electron cloud.
It is possible to connect two layers of different composition with a superlattice which has an average composition distribution changing from one to the other of the different compositions of the two layers, to realize a gradual change of the potential for an electron in the band structure, as the sub-band of superlattice. More specifically, ratio A/B of the thickness A of the ultrathin film of a first composition material to the thickness B of the ultrathin film of a second composition material, is varied stepwise along with the successive deposition of the ultrathin films for forming a superlattice structure. The average composition at each end of the superlattice is approximately equal to the composition of the neighboring homogeneous layer. Thus, there can be provided a compound semiconductor structure including a pair of outer layers and an intervening superlattice layer and having an effectively graded composition from one outer layer to the other outer layer.
According to another aspect of this invention, there is provided a process for making a compound semiconductor structure by MBE, which structure contains at least three constituent elements and has a graded composition distribution with respect to at least two of said constituent elements. Two or more sets of molecular beam sources having different mole fractions of elements are used to alternately laminate superthin epitaxial layers while successively varying the thickness ratio of the pair of adjacent superthin layers to establish effectively graded mole fraction. According to another aspect of this invention, there is also provided a compound semiconductor structure having effectively smoothly graded mole fraction produced by the above process. In this process, while varying the ratio (A/B) of the thickness A of a layer containing the element whose mole fraction is being varied to the thickness B of another layer not containing said element, superthin layers are grown one upon another to construct a superlattice structure of compound semiconductor having effectively graded mole fraction.
In an embodiment, a first sub-band of the superlattice layer where electrons can exist smoothly connects the conduction bands of the two materials of the layers sandwiching the superlattice layer.
In another embodiment, after a superlattice structure has been made, the superlattice structure is subjected to annealing, in which the films constituting the superlattice cause mutual diffusion, thereby transforming the superlattice into a continuous layer.
A compound semiconductor structure of a thin layer shape of the order of tens of microns and having an effectively largely varying composition can be made utilizing the MBE technique. When such a semiconductor structure is adopted in a hetero-junction semiconductor device such as a hetero-junction field effect transistor, reduction in the parasitic source resistance and hence an improvement in performance can be attained.
Since a semiconductor structure capable of reducing the source resistance of a hetero-junction field effect transistor can be made by the MBE with all the cell temperatures kept constant, good controllability and stability in the film thickness and the doping level can be provided to enable easy fabrication of a high performance semiconductor device.
When natural cooling is combined with the above-mentioned technology, further rapid and smooth change in the effective composition or the effective band structure can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing a composition distribution in a superlattice structure in the direction of film thickness, according to an embodiment of this invention.
FIG. 2 is a graph showing a composition distribution in a superlattice structure in the direction of film thickness, according to another embodiment of this invention.
FIG. 3 is a graph showing a composition distribution in a grown crystal layer in the direction of film thickness, according to the prior art utilizing natural cooling.
FIG. 4 is a graph showing a composition distribution in a superlattice structure in the direction of film thickness, according to the prior art.
FIG. 5A is a cross-sectional view of a heterojunction field effect transistor according to embodiment of this invention.
FIG. 5B is a graph of the Al composition x and the thickness ratio of one kind of film in each pair of films, with respect to the depth or thickness in a main part of the HJ-FET of FIG. 5A.
FIG. 6 is a cross-sectional view of a heterojunction field effect transistor according to the prior art.
FIG. 7 is a band diagram in a main part of the HJ-FET of FIG. 6.
FIG. 8A is a diagram illustrating a superlattice structure sandwiched between a pair of uniform composition semiconductor layers.
FIG. 8B is a graph showing the distribution of Al composition y in the direction of the film thickness in the superlattice structure and two kinds of uniform composition semiconductor layers of FIG. 8A.
FIG. 8C is a band diagram showing the subbands in the superlattice structure and the bands in the uniform composition semiconductor layers sandwiching the superlattice structure of FIG. 8A.
FIG. 9 is a cross-sectional view of a heterojunction field effect transistor according to another embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 represents the relation between the mole fraction and the thickness of the film having a superlattice structure formed by depositing superthin layers while gradually decreasing the thickness ratio d A /d B , where d A is a thickness of each material A film and d B is a thickness of each material B film, and the superlattice is constituted in a form of (ABAB . . . AB). Materials A and B are exemplified to have compositions x=0.3 and x=0.0. For example, A is Al 0 .3 Ga 0 .7 As and B is Al 0 .0 Ga 1 .0 As. The solid line represents the mole fraction distribution in the as-grown film. The thickness ratio d A /d B and the average composition may be defined by considering each material A film and a succeeding material B film as a pair. As shown by the broken line, the average mole fraction decreases with the increase in film thickness, resulting in graded mole fraction.
In a superlattice formed of a lamination of ultrathin films, a sub-band structure is established, which extends over the lamination, depending on the properties of the materials constituting the superlattice, the thicknesses of the respective films, etc. By selecting the conditions appropriately, an electronic state similar to that of a continuous bulk crystal having a graded composition can be obtained in a superlattice region having a average composition within the region of spreading of an electron wave function to be graded.
The superlattice structure can be subjected to annealing, e.g. rapid annealing which is a high temperature annealing in such a short period as several tens of seconds or below, to cause thermal diffusion of the constituent elements. By the diffusion of the element or elements which establish the repeatedly varying composition distribution of the superlattice, the composition distribution can be smoothened. The superlattice structure can be transformed to a continuous structure of a graded composition. By such diffusion of constituent element or elements, the composition itself will have a distribution as shown by a broken line in FIG. 1, to provide a layer having an actually smoothly varying graded composition.
This invention is a course adaptable widely to polyatomic compounds such as, for example, In x Ga 1-x As, InAs x P 1-x , In x Ga 1-x As y P 1-y , In x Al 1-x As, In x Al 1-x P and others, by selecting the number of cells and appropriate source materials.
The epitaxial crystal growth by MBE can control the film thickness on the order of monoatomi layer. Thus, it is possible to grow an Al compound crystal with Al mole fraction being varied. When the composition is constant, continuous growth can be carried out in a usual manner on a lattice-matched underlie crystal. Here, description will be made on a case in which, between an Al x Ga 1-x As layer and an Al y Ga 1-y As layer, a graded composition layer having a composition varying from x to y (1≧y≧0) is formed. As a specific case, a case of x=0.3 and y=0, as shown in FIG. 1, will be described.
The MBE apparatus to be used may be an ordinary one having a crystal growth chamber of ultrahigh vacuum. The semiconductor compound exemplified in this Example is Al x Ga 1-x As. Four cells of Ga, As, Al and Si are used as molecular beam sources.
After a substrate is accommodated on a receptor, the temperatures of the substrate and cells of Al, Ga and As are set at such levels that the Al mole fraction x of an Al x Ga 1-x As crystal to be grown is 0.3, i.e. Al 0 .3 Ga 0 .7 As.
For example, the As cell is kept at a sufficiently high temperature to supply sufficient As vapor, the Al cell and the Ga cell are kept at 1090° C. and 983° C. respectively to supply Al/Ga vapors which will form a mixed crystal Al 0 .3 Ga 0 .7 As. The growth rate is, for example 1.43 μm/hr. The growth is initiated by opening the shutters of the cells, after the substrate is heated to a predetermined temperature. A layer of uniform composition Al 0 .3 Ga 0 .7 As is first grown.
Then, a first layer of the superlattice, i.e., Al 0 .3 Ga 0 .7 As of a controlled thickness (FIG. 1, left end layer) is grown. Up to this point, the shutter of the Al cell has been kept open. In the stage of growing a region having a varying effective Al mole fraction from 0.3 to 0, the shutter of the Al cell is closed for successively longer periods to decrease the Al composition. Taking a unit time span to be 20 seconds, for instance, the Al cell is open for 19 seconds during the first period of 20 seconds, then for 18 seconds during the second period of 20 seconds, and so on so that the quantity of Al, and hence the average Al mole fraction in the pair of layers grown in 20 seconds shall steadily decrease. Finally, the shutter of the Al cell is closed for the full period of 20 seconds.
In FIG. 1, unit time interval is selected to grow a pair of layers with a sum thickness of 4 nm. The pair of layers have compositions x=0.3 and x=0.0. The average composition is determined by the thickness ratio of the two layers.
Under a certain schedule, the thickness ratio of layers is gradually changed to realize gradual decrease of the average composition.
Under consideration of the dimension of an electron cloud, the thickness of a monoatomic layer and the rate of crystal growth, the time span may be adjusted so as to obtain gradually varying graded average mole fraction, distribution of which is equivalent to a really smoothly graded composition distribution.
The spreading of an electron wave function in semiconductors is of the order of 80 Å, although it depends on the kind of semiconductor, the degree of crystallinity, etc. The interval of the superlattice structure is preferably small for avoiding variations in the potential which may cause scattering from the state moving the electron in a direction perpendicular to the superlattice to other states.
In the regions wherein the time length of open shutter and that of closed shutter become approximately equal, it is effective for making the potential of the sub-band to change smoothly as possible to decrease the unit time span.
For growing doped films, the Si cell is kept at a constant temperature with the shutter kept open so as to achieve a prescribed doping level.
The shutter can of course be closed when an undoped Al x Ga 1-x As layer with graded Al mole fraction is to be grown.
Now, an example of a semiconductor device will be described referring to FIGS. 5A and 5B. As shown in FIG. 5A, on a semi-insulating GaAs substrate 1, an undoped GaAs layer 2 having a thickness of 5000 Å, an undoped Al 0 .3 Ga 0 .7 As layer 3 having a thickness of 20 Å, an n + -type Al 0 .3 Ga 0 .7 As layer 4 having a Si concentration of 2.3×10 18 cm -3 and a thickness of 100 Å, an n + -type-Al 0 .3 Ga 0 .7 As/n + -type GaAs superlattice layer 5 having a Si concentration of 2.3×10 18 cm -3 and a thickness of 150 Å, an undoped Al 0 .3 Ga 0 .7 As/undoped GaAs superlattice layer 6 having a thickness of 100 Å, and an n + -type GaAs layer 7 having an impurity concentration of 3.5×10 18 cm -3 and a thickness of 1600 Å are successively epitaxially grown. Similar to the conventional device shown in FIG. 6, the heterojunction between the Al 0 .3 Ga 0 .7 As layer 3 and the GaAs layer 2 establishes a two-dimensional electron gas channel.
In forming the superlattice structures, the cell temperatures of Al, Ga and As are kept respectively constant. Doping is controlled by opening or closing the shutter of Al cell. Thus, the stability and the controllability of the growth rate and the doping level are very good, as being similar to the usual bulk growth by MBE.
The GaAs/AlGaAs superlattice is formed by alternately growing Al y Ga 1-y As (y>0) layers and GaAs layers. As shown in FIG. 8A, taking adjacent layers of Al y Ga 1-y As and GaAs as a unit, m units of Al y Ga 1-y As/GaAs layers are laminated to form a superlatice. The thickness of the Al y Ga 1-y As layer in the j-th unit is denoted as d jA , and the thickness of the GaAs layer in the j-th unit is denoted as d jB . FIG. 8B schematically illustrates the actual variation of the Al composition in the superlattice structure. The sum of the layer thicknesses in each unit, d j =d jA +d jB , is kept constant, and the ratio of the Al y Ga 1-y As layer thickness d jA to the sum thickness d j is gradually changed from 1 to 0, between uniform composition layers of Al y Ga 1-y As and GaAs. FIG. 8C illustrates the relation of the sub-band structure in the superlattice and the conduction band structures of Al y Ga 1-y As and GaAs uniform composition layers. Thus, it is made possible to set the energy of the first sub-band in the superlattice structure to smoothly vary from the conduction band energy of Al y Ga 1-y As to the conduction band energy of GaAs. For making a superlattice structure of small resistance, the sum thickness d j of layers in each unit is selected preferably not more than about 4 nm.
In an example, the sum thickness of layers in each unit was set at 2.5 nm, d j =d jA +d jB =2.5 nm, and the ratio of the Al 0 .3 Ga 0 .7 As layer to the unit thickness, d jA /d j was gradually varied from 1 to 0 as schematically illustrated in FIG. 5B. In FIG. 5B, crystal growth proceeds from the right hand side to the left hand side.
After the crystal growth, an ordinary mesaetching process for an electric isolation, formation of source and drain electrodes by lift-off process, and formation of a gate electrode are carried out to form a hetero-junction field effect transistor as shown in FIG. 5A.
The two dimensional electron gas channel formed in the GaAs layer 2 adjacent the hetero-junction is connected to the source/drain electrodes through the superlattice layer 5 and 6 sandwitched between uniform composition layers 4 and 7. The uniform composition layer 7 is heavily doped to form low resistance Ohmic contacts with the source/drain electrodes 8 and 10. A latter part of the superlattice layer is undoped to relax the field intensity below the gate electrode 9.
Although the superlattice structure was formed of Al y Ga 1-y As layers where y=0.3 and GaAs layers in the above description, the end composition is not limited to 0.3. In ordinary cases, the end composition may be selected from the range from 0.2 to 0.32 in case of the Al x Ga 1-x As/GaAs HJ-FET.
A HJ-FET having an Al 0 .3 Ga 0 .7 As/GaAs superlattice structure according to the above embodiment was made with a gate length 0.3 μm, and a gate width 200 μm. The device performances of this HJ-FET were measured. The source resistance was 0.5 Ω.mm. The mutual conductance was 350 mS/mm. As the characteristics at high frequencies, the noise figure NF was 0.7 dB and the gain G was 13 dB at 12 GHz, and NF=1.0 dB and G=10 dB at 18 GHz.
Although the above embodiment has been described on the Al x Ga 1-x As/GaAs superlattice, the embodiment is not limited to this combination and may be similarly applied to other combination of materials such as In x Ga 1-x As/GaAs, In x Ga 1-x As/Al y Ga 1-y As, etc. In case of using In x Ga 1-x As, the channel layer which forms a two-dimensional electron gas is preferably formed of an In z Ga 1-z As (0<Z<0.2) layer, instead of the undoped GaAs layer 2 of the above-described structure. Further high performance of the device can be expected due to the higher electron mobility and the higher saturation velocity which are ascribed to a smaller effective mass of electron compared to the case of using GaAs.
Another embodiment will be described, referring to FIG. 9. In this embodiment, the recess etching for forming a gate electrode is performed through selective dry etching. In case of GaAs/Al x Ga 1-x As system, the selective dry etching can be performed through the use of CCl 2 F 2 +He gas. An undoped Al x Ga 1-x As stopper layer 11 (x=0.2-0.32) having a thickness of not less than 1.5 nm and not more than 5 nm is inserted between the superlattice layer 6 and the n + -type GaAs layer 7 to serve as an etching stopper for the dry etching process. Other details of this embodiment may be similar to those of FIG. 5A.
Cases where the cell temperatures of the molecular beam sources are kept constant have been described hereinabove. The cell temperature for an element or elements, the composition of which is to be varied, can also be varied. Namely, the cell temperature of a particular molecular beam source or sources can be lowered by natural cooling, while the film thickness ratio is also varied by controllably closing the cell shutter. A steeper or finer composition variation can be achieved by epitaxially growing a superlattice structure through thus combining two kinds of composition control.
FIG. 2 shows, as an example, the relation between the Al mole fraction and the film thickness of a semiconductor epitaxial crystal of Al x Ga 1-x As having a superlattice structure prepared by lowering the temperature of molecular beam source for the element whose mole fraction is to be varied and controlling the time interval of opening and closing the shutter of the Al molecular beam source.
The cell temperatures of the Al, Ga, and As sources are initially set to grow Al 0 .3 Ga 0 .7 As. First, an Al 0 .3 Ga 0 .7 As layer is grown as an underlie.
Then, a superlattice is grown. Selecting the unit interval of the superlattice similar to that of FIG. 1, each pair of a composition A layer containing Al and a composition B layer not containing Al is grown. The thickness ratio of the A layer to the sum thickness in the unit interval is gradually varied and the temperature of Al cell was lowered by natural cooling to reduce the Al vapor pressure.
By repeating the above procedure for twelve times, there is obtained a thin film, about 50 nm in thickness, of Al x Ga 1-x As with gradually varying average Al mole fraction. Subsequently, a continuous crystal growth with the Al cell shutter being closed is done to form a GaAs layer. The solid line represents Al mole fraction in the as-grown crystal. It is shown that, owing to the decrease in Al vapor pressure from the Al molecular beam source due to temperature lowering of the Al cell, the Al mole fraction in Al x Ga 1-x As in the state where Al cell shutter is opened, decreases. A more rapidly graded composition distribution than that of FIG. 1 is obtained by lowering the cell temperature of the Al cell in addition to increasing the closed-shutter time period for the Al cell. The average composition in the superlattice structure is shown by a broken line.
An Al x Ga 1-x As layer with a graded Al composition where x varies from 0.3 to 0.0 was obtained in a thin layer of 50 nm through the above process. In producing a thinner film with similarly graded Al mole fraction, it becomes necessary to reduce the rate of growth. Then, it may be required to decrease the cell temperatures. It is to be noted, however, that the grown layer becomes more sensitive to the residual gas such as oxygen and that it is necessary for forming a high quality film to increase the vacuum in the growth chamber in proportion to the decrease in growth rate.
Further, short time or rapid annealing may be done to cause Al atom to diffuse and distribute as shown by broken line, resulting in really smoothly and continuously graded Al mole fraction. Here, the "short time" or "rapid" annealing is the annealing at an increased temperature in a reduced time period, i.e. within about several tens of seconds, compared to the usual annealing, e.g. for tens of minutes.
In a rapid annealing, the superlattice film containing Si as dopant is subjected to heat treatment at 800° C. for 30 seconds. After annealing the Al mole fraction itself becomes smoothly graded, as shown by the broken line in FIG. 2.
For smoothing the Al composition itself, it is necessary to diffuse Al atoms from the Al-containing films to Al-not-containing films sufficiently. The annealing time can be curtailed by decreasing the unit time span of shutter operation, shorter than the above-described described 30 seconds.
Further, it has been found that the Al diffusion is facilitated by the diffusion of the conductivity-affording impurity such as Si or Ge.
In forming an undoped layer with graded mole fraction, there is no diffusion of dopant during annealing in the above said condition and, hence, the diffusion of Al by annealing becomes more difficult. In this case, it is necessary to anneal at 900° C. for 10 minutes or more.
As described above, annealing conditions differ depending on whether a dopant is present or not. In a selectively doped heterojunction device, the distribution of a doped region can be made smoothly graded by annealing, while an undoped portion may remain in a superlattice state which has a gradually graded average composition.
As described above, it is possible to form a compound semiconductor superthin film with an effectively graded mole fraction by MBE and, when desired, to make the mole fraction itself to be smoothened to realize a really smoothly graded distribution by annealing.
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A compound semiconductor structure in the form of a superlattice film with effectively graded average composition, comprising an alternating lamination of two kinds of layers of different composition to form pairs of layers, the ratio of the thickness of one layer to the thickness of the other in said pairs of layers being gradually varied in the direction of thickness throughout successive pairs, thereby the average composition being effectively graded throughout the pairs. In a hetero-junction field effect transistor, the layer of effectively graded composition is used between a semiconductor layer making low resistance contact with a current-supplying electrode and a semiconductor layer where a two dimensional channel is to be formed. In case of AlGaAs/GaAs system, the Al composition is varied. When the superlattice film is heat-treated, Al in the AlGaAs layer diffuses into the GaAs layer, yielding a film with actually smoothly graded Al mole fraction.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/430,818 (Atty. Docket No. PU020470), entitled “DYNAMIC RANGE AND CONTRAST ENHANCEMENT FOR MICRODISPLAY”, filed Dec. 4, 2002, which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a light valve system and, more particularly, to a light valve system with a microdisplay for use in a rear projection television.
BACKGROUND OF THE INVENTION
[0003] In a conventional light valve system for, example in displays such as, rear projection televisions (RPTVs), digital cinema, etc., white light output from a lamp is directed to a microdisplay such as a liquid crystal display (LCD), liquid crystal on silicon (LCOS), or digital light processing (DLP) system, through a series of integrating and collimating optics. In the LCD or LCOS systems, white light is separated into its component red, green, and blue (RGB) bands of light, polarized by a polarizing beam splitter (PBS) in the case of LCOS, and directed onto the microdisplay. The microdisplay has a matrix of pixels. The microdisplay operates to modulate each of the pixels of the component RGB bands of incident light by a gray-scale factor control output from a controller based on a video input signal to form a light matrix of discrete modulated light signals or pixels. The light matrix is reflected or output from the microdisplay and directed to a system of projection lenses that projects the modulated light onto a display screen, combining the pixels of light to form a video image.
[0004] In the DLP system, the white light is separated into its component RGB bands of light, and reflected onto a DLP microdisplay. The microdisplay is a semiconductor device containing an array of hinge-mounted microscopic mirrors. Each of the mirrors corresponds to one pixel in a video image input to the microdisplay. When the semiconductor is driven by the video input signal, the mirrors are tilted or switched on and off to reflect all or some of the incident light. The array of pixels reflected from the mirrors form a light matrix corresponding to the video-input signal. The light matrix is reflected or output from the microdisplay and directed to a projection lens system that projects the modulated light onto a display screen to form a video image.
[0005] A disadvantage of these display systems is that the video images projected in a dark state scene are inferior in quality to the video images that are projected in a bright state scene. In the LCD or LCOS systems, the difference in quality occurs because the amount of light directed onto the microdisplay remains constant regardless of the brightness of the video image input to the microdisplay. Gray-scale variation from pixel to pixel is thereby limited by the number of bits used to process the video-input signal. Because the video input signal is a fixed number of bits, which corresponds to the full scale of light, there tend to be very few bits available for subtle differences in darker areas of the video image. For example, if the microdisplay is capable of reproducing 1024 gray shades (10-bit output digital to analog converter (DAC)) when the program contains only 0 to 64 gray shades, the net effect is that contrast appears poor and the video image appears to have a severe level of noise and contouring due to quantization effects and truncation effects. The DLP system suffers from more severe contouring effects than the LCOS or LCD systems due to the intrinsically linear response of the semiconductor.
[0006] To alleviate the differences in quality occurring between the light and dark video images, it is known to increase the contrast of the microdisplay itself. Increasing the contrast of the microdisplay, however, leads to very high data rates, very high resolution DAC'S, and very critical optical and liquid crystal performance requirements. It is, therefore, desirable to develop a light valve system that enhances the contrast ratio for the video images, particularly in dark video images, and reduces contouring artifacts.
SUMMARY OF THE INVENTION
[0007] The invention relates to a light valve system that comprises a color selection device configured to temporally attenuate component color bands of light to correspond with a video input signal. A first polarizing beam splitter configured to polarize the component color bands into oppositely polarized components, and a microdisplay configured to receive at least one of the oppositely polarized components for forming a projected light matrix.
[0008] The invention further relates to a light valve system that comprises a color selection device configured to temporally separate light into its component color bands to correspond with a video input signal. A first polarizing beam splitter configured to polarize the component color bands into a first set of oppositely polarized components. First and second liquid crystal displays. Each of the first and second liquid crystal displays configured to receive one of the first set of oppositely polarized components for forming first and second light matrices, respectively. A second polarizing beam splitter configured to receive the first and second light matrices for separating the first and second light matrices into a second set of oppositely polarized components, and a microdisplay configured to receive at least one of the second set of oppositely polarized components for forming a projected light matrix.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention will be described in greater detail with reference to the following figures, wherein:
[0010] FIG. 1 is block diagram of a light valve system according to a first embodiment of the invention;
[0011] FIG. 2 is block diagram of a light valve system according to a second embodiment of the invention; and
[0012] FIG. 3 is a schematic diagram of a polarizing beam splitter arrangement for use in the system of FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] FIG. 1 shows a light valve system 1 according to a first embodiment of the invention. The system 1 includes a lamp 10 . The lamp 10 generates white light 4 and projects the white light 4 toward a set of illumination optics 11 . The illumination optics 11 may include, for example, a polarizer and/or an integrator. In this embodiment a polarizer is included to rotate incident light to an s-polarization. The illumination optics 11 directs a telecentric beam of the white s-polarized light 4 toward a color selection device 5 . In the illustrated embodiment, the color selection device 5 is a color switching device, which is an optical device having several layers of liquid crystal displays stacked together. Examples of such a color selection device 5 include the COLORSWITCH® made by ColorLink, Inc. of Boulder, Colo. and the Application Specific Integrated Lens (ASIL) made by DigiLens, Inc. of Sunnyvale, Calif. The white light 4 enters the color selection device 5 , and the color selection device 5 temporally filters the white light 4 incident thereon into sequential component red, green, and blue (RGB) bands of light 12 . A selected band of light is transmitted or reflected depending on a digital control signal voltage applied to the color selection device by a display controller 3 . The color selection device 5 also has an on/off state voltage input for receiving a control signal from the display controller 3 . When the voltage level from the display controller 3 is high, it drives the color selection device 5 to an off state and when the voltage level from the display controller 3 is low, it drives the color selection device 5 to an on state in which light is transmitted therethrough. The display controller 3 , by virtue of its processing of the video-input signal to the microdisplay 7 , performs analysis on the video signal to determine its content. In this analysis, the display controller 3 analyzes the video-input signal on a pixel-by-pixel basis for the frame to be displayed. If none of the pixel input values exceed half of full scale, then the voltage level controlling attenuation in the color selection device 5 is set at 50% of full scale. If on the other hand the input pixel values are all zero thus indicating a full black screen, the voltage level controlling a color selection device is reduced to the full on state voltage. This attenuation control enhances contrast especially in frames containing mostly dark content. Since ultimate contrast is the product of contrast achieved through the optical components in the system, if for example the color selection device 5 has a contrast of 50:1 and the microdisplay 7 has a contrast of 600:1 then the measured sequential contrast is 30000:1 allowing for improved contrast levels especially in the dark state.
[0014] The display controller 3 is programmed with the transfer function of the microdisplay 7 . To program the display controller 3 the microdisplay 7 may be calibrated at a factory level or auto-calibrated by photosensors in a cabinet or a projection light path, e.g., behind a folding mirror. Because the calibration may be performed in binary steps, the calibration would take no more than a few seconds and may be performed during normal operation after the video-input signal is known. As a result, the dynamic contrast of the system 1 is improved without the cost of any additional hardware, and a customer has the option of reducing the peak brightness of the video image as she chooses without producing undesired contouring effects.
[0015] The sequential component RGB bands of light 12 exit the color selection device 5 and are directed toward a polarizing beam splitter 8 (PBS). Incident s-polarized components 19 of the incident light 12 are reflected from the polarizing surface 17 to a third surface 15 . A microdisplay 7 is disposed beyond the third surface 15 of the PBS 8 , and the s-polarized component 19 of the light 12 is incident thereon.
[0016] In the illustrated embodiment, the microdisplay 7 is a liquid crystal on silicon (LCOS) imager. Alternatively, a liquid crystal display (LCD) may be used and the optical system adjusted accordingly. The LCOS microdisplay 7 serves to modulate incident light with video signal coming from the display controller 3 . Each of the pixels of the projected light matrix 18 has an intensity or luminance proportional to the individual gray scale value provided for that pixel in the microdisplay 7 . As a result of the modulation, the LCOS microdisplay 7 reflects a light matrix 18 comprising a matrix of pixels or discreet dots of p-polarized light back through the third surface 15 of the PBS 8 . The p-polarized components of the projected light matrix 18 pass through the polarizing surface 17 and out of the PBS 8 through a fourth surface 16 . The projected light matrix 18 is directed from the fourth surface 16 to a projection lens system 9 . The projection lens system 9 projects the light matrix 18 onto a display screen 6 , combining the pixels of light to form the video image corresponding to the video input signal 2 .
[0017] FIG. 2 shows a light valve system 20 according to a second embodiment of the invention. The system 20 includes a lamp 35 . The lamp 35 generates white light 23 and projects the white light 23 toward illumination optics 31 . The illumination optics 31 may include, for example, an integrator, such as, a sequential color recapture (SCR) integrator. The integrator 31 directs a telecentric beam of the white light 23 toward a color selection device 24 . In the illustrated embodiment, the color selection device 24 is a color wheel, which has a disc with fan-shaped sectors uniformly disposed along a circumference of the disk. The sectors filter the white light 23 incident thereon into its component RGB bands of light 25 in a timed sequence corresponding to color wheel rotation. The color selection device 24 is rotated by a motor (not shown) and is controlled by a display controller 22 to transmit corresponding component RGB bands of light 25 in synchronization with a video input signal 21 to transmit the respective component RGB bands of light 25 on a frame-by-frame basis.
[0018] The component RGB bands of light 25 are directed toward a PBS arrangement 50 . The PBS arrangement 50 includes first and second PBSs 46 , 49 , first and second mirror prisms 47 , 48 , and first and second LCDs 26 , 28 . Alternatively, the first and second LCDs 26 , 28 may be arranged before the integrator 31 . As shown in FIG. 3 , the component RGB bands of light 25 enter a first face 42 of the first PBS 46 and are polarized by a first polarizing surface 43 to have an s-polarized component 27 and a p-polarized component 45 . The path of the s-polarized component 27 of the RGB bands of light 25 through the PBS arrangement 50 will first be described in greater detail, and then, the path of the p-polarized 45 component will be described in greater detail.
[0019] The s-polarized component 27 is reflected through a second face 56 of the first PBS 46 and is received in the first mirror prism 47 . The s-polarized component 27 is reflected by a first mirror surface 59 out of the first mirror prism 47 and toward the first LCD 26 . The first LCD 26 is for example, a single cell panel containing a matrix of liquid cells coupled to an electrical signal from the display controller 22 ,. The electrical signal controls the LCD 26 to have it either rotate polarization of light passing therethrough or pass the light without rotation.
[0020] As a result the first LCD 26 transmits a first light matrix 38 comprising a matrix of pixels or discreet dots of light with s-polarized and p-polarized components. The first light matrix 38 enters a first face 44 of the second PBS 49 and is polarized by a second polarizing surface 53 . The s-polarized component (not shown) of the first light matrix 38 is reflected through a second face 57 of the second PBS 49 and is discarded while, the p-polarized component 60 of the first light matrix 38 passes through the second polarizing surface 53 and out of the second PBS 49 through a third face 52 toward illumination lens 33 .
[0021] The p-polarized component 27 of the component RGB band of light 25 passes through the first polarizing surface 43 and through a third face 51 of the first PBS 46 toward the second LCD 28 . The second LCD 28 is identical to the first LCD 26 in structure and function and, as such, further description thereof has been omitted. The second LCD 26 transmits a second light matrix 55 comprising a matrix of pixels or discreet dots of light with s-polarized and p-polarized components. The second light matrix 55 enters the second mirror prism 48 and is reflected by a second mirror surface 58 out of the second mirror prism 48 and toward the second PBS 49 . The second light matrix 55 enters a fourth face 54 of the second PBS 49 and is polarized by the second polarizing surface 53 . The p-polarized component (not shown) of the second light matrix 55 passes through the second polarizing surface 53 and is discolored through second face 57 of the second PBS 49 . The s-polarized component 61 of the second light matrix 55 is reflected out of the second PBS 49 through the third face 52 and is received in a light stop (not shown) in combination with the s-polarized component 45 , so that there is a fairly low loss of total brightness.
[0022] As shown in FIG. 2 , the s-polarized component 61 of the second light matrix 55 and the p-polarized component 60 of the first light matrix 38 are simultaneously focused by illumination lenses 33 into a third mirror prism 34 for high-through-put efficiency. The third mirror prism 34 may be, for example, a total internal reflection (TIR) prism or off axis optics. The s-polarized component 61 of the second light matrix 55 and the p-polarized component 60 of the first light matrix 38 pass through a first surface 36 of the third mirror prism 34 . The s-polarized component 61 of the second light matrix 55 and the p-polarized component 60 of the first light matrix 38 are reflected at an angle away from a reflection surface 41 of the third mirror prism 34 and through a third surface 37 the third mirror prism 34 . A DLP microdisplay 30 is disposed beyond the third surface 37 of the mirror prism 37 , and the combined s-polarized and p-polarized components 60 , 61 are incident thereon.
[0023] The DLP microdisplay 30 may be any suitable digital light processor (DLP), such as the DLP made by Texas Instruments Incorporated of Dallas, Tex. The microdisplay 30 has an optical semiconductor (not shown), such as the DIGITAL MICROMIRROR DEVICE made by Texas Instruments Incorporated of Dallas, Tex. The semiconductor contains an array of hinge-mounted microscopic mirrors. Each of the mirrors corresponds to one pixel in a video image (not shown) of the video-input signal 21 . When the semiconductor is driven by the controller 22 based on video input signal 21 , the mirrors are tilted or switched on or off to reflect all or some of the first and second light matrices 51 , 49 . The array of pixels reflected from the switched mirrors forms a projected light matrix 40 corresponding to the video-input signal 21 from the display controller 22 .
[0024] Operation of the LED's 26 , 28 serve as attenuation control whereby some p-polarized and some s-polarized light is discarded before recombination. For example, as described above in the first embodiment if none of the video input pixel values exceeds half of full-scale, then the first and second LCDs 26 , 28 control fifty percent of incident light. In an instance where the video input signal 21 indicates a full black screen, the first and second LCDs 26 , 28 are set by the display controller 22 to maximum, and the microdisplay 30 is driven with zeros to achieve very high sequential contrast. Thus, if the first and second LCD's 26 , 28 have a peak attenuation of 50:1, and the microdisplay 30 has a sequential contrast of at least 600:1, then the measured sequential contrast is 30,000:1.
[0025] The projected light matrix 40 is reflected from the microdisplay 30 back through the third surface 37 of the TIR prism 34 . The projected light matrix 40 passes through the reflecting surface 41 of the TIR prism 34 and out of the TIR prism 34 through a fourth surface 39 . The projected light matrix 40 is directed from the fourth surface 39 to a system of projection lenses 32 . The projection lenses 32 project the projected light matrix 40 onto a display screen 29 , to form the video image corresponding to the video input signal 21 .
[0026] The system 20 has the benefit of allowing the microdisplay 30 to be illuminated with alternating polarizations of light, which allows for polarization-based stereographic imaging.
[0027] The foregoing illustrates some of the possibilities for practicing the invention. Many other embodiments are possible within the scope and spirit of the invention. It is, therefore, intended that the foregoing description be regarded as illustrative rather than limiting, and that the scope of the invention is given by the appended claims together with their full range of equivalents.
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The invention relates to a light valve system that enhances the contrast ratio for light and dark video images and reduces contouring artifacts. The light valve system comprises a color selection device configured to temporally attenuate component color bands of light to correspond with a video input signal. A first polarizing beam splitter configured to polarize the component color bands into oppositely polarized components, and a microdisplay configured to receive at least one of the oppositely polarized components for forming a projected light matrix.
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REFERENCE TO RELATED APPLICATION
This patent application claims priority of U.S. provisional patent application Ser. No. 60/535,867, filed Jan. 12, 2004, and entitled “Candle Warmer.”
FIELD OF THE INVENTION
This invention relates generally to heating devices. More specifically, the invention relates to a heating device which is operable to receive and retain a scented candle and to maintain it at an elevated temperature relative to an ambient temperature so as to facilitate the dispersal of scent therefrom.
BACKGROUND OF THE INVENTION
Scented candles release an aroma into the ambient atmosphere when burned, and are increasing in popularity. Such candles are often used for enhancing the ambience or mood in the home or workplace. Despite their popularity, there are some perceived problems associated with the burning of scented candles. The presence of an open flame can present hazards to children and pets, and burning candles present a fire hazard and should not be left unattended. Also, the smoke produced by burning candles can present a health or a nuisance hazard, and can complicate respiratory problems for particular individuals. Furthermore, smoke from the burning candle can damage or discolor furniture, walls and fabrics. Thus, it will be seen that while the effects of scented candles are desirable, there are problems associated with the open flame attendant upon their use.
Consequently, the prior art has sought to implement solutions whereby a candle's scent may be released without the requirement of utilizing an open flame. Toward that end, the prior art has investigated various designs of candle warming devices which allow scented candles to flamelessly disperse their aroma. The previous implementation of such a candle heater comprised the use of miniature hotplates, of the type employed for heating individual beverage cups; and in such instance, the candle, which is typically contained in a glass vessel, is placed onto the hotplate. In some instances, these hotplate-type candle warmers have a collar which surrounds a portion of the length of the candle; but they are not designed to enclose the entire length of the candle. This approach is less than satisfactory since only the bottom portion of the candle is heated. As a consequence, it takes a relatively long time to melt the upper surface of the candle wax so as to release the scent. This lag time can be shortened if the heat level of the hotplate is raised to a fairly high value; however, these high heat levels can pose a burn hazard once the candle is fully warm. Also, high heat levels can start to vaporize the candle wax thereby generating unwanted odors and damaging fumes. In addition, the heated wax fumes can present a significant fire hazard. Hotplate-type candle warmers are shown, for example, in U.S. Pat. No. 6,627,857. Another prior art approach to warming scented candles involves the use of a radiant heater which projects infrared light onto an upper surface of the candle. Devices of this type are relatively complicated and energy inefficient. Radiant candle heaters are shown in U.S. Pat. No. 6,354,710.
As will be explained hereinbelow, the present invention is directed to a flameless candle heating device which efficiently and safely retains scented candles and the like and warms them to a uniform temperature optimized for safety and release of scent. These and other advantages of the invention will be apparent from the drawings, discussion and description which follow.
BRIEF DESCRIPTION OF THE INVENTION
There is disclosed herein a device for retaining and heating a scented candle or other body of scented hydrocarbon material. The device includes a housing which is fabricated from a body of a low thermal conductivity material. The housing has a substantially open top and comprises at least one sidewall and a base, which cooperate to define a partially enclosed interior volume which is configured to receive and retain the entire length of a candle therein. The device further includes an electrical heater which is in thermal conductivity with the housing. The heater is operable to warm the body of scented hydrocarbon material so that its scent exits through the open top of the housing.
The housing may, in some instances, be a unitary body, while in other instances it may comprise an assembly of multiple pieces. The housing has a relatively low thermal conductivity, as defined herein, and may, in some instances, be fabricated from a body of ceramic material. In other instances, it may comprise a relatively high thermal conductivity material such as a metal combined with a body of insulating material.
In specific embodiments, the device can include a temperature controller for regulating its operation, as well as other features, such a pilot light, an on/off switch, and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one embodiment of a candle warming device structured in accord with the principles of the present invention;
FIG. 2 is a cross-sectional view of the device of FIG. 1 taken along section line A—A;
FIG. 3 is a cross-sectional view of another embodiment of a heating device of the present invention; and
FIG. 4 is a schematic depiction of one circuit which may be used to energize the electrical heater in warming devices of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention comprises a device for uniformly heating a scented candle so as to release its aroma, without the necessity of employing an open flame. The device of the present invention includes a housing which is fabricated from a body of low thermal conductivity material, as will be explained and defined hereinbelow. The low thermal conductivity housing encloses a scented candle. The device further includes an electrical heater which is in thermal communication with the housing. The housing operates to retain heat and allows the heater to uniformly heat the entire body of the candle without generating large temperature extremes. Since the housing shields the heated candle, it provides additional safety.
Referring now to FIG. 1 , there is shown a perspective view of one embodiment 10 of a candle heater structured in accord with the principles of the present invention. As will be seen, the warming device 10 includes a body 12 which includes a base portion 14 which is integral therewith. The body 12 has a generally cylindrical sidewall 15 which cooperates with the base portion thereof 14 to define and enclose an interior volume. In specific embodiments, this interior volume is sufficiently large so as to contain substantially all of the length of a candle disposed therein. The configuration of the body 12 is such that its top is substantially open so as to permit the insertion of a candle 16 thereinto. The substantially open top also facilitates the dispersal of aroma from the candle 16 in the operation of the device. It is to be understood that the top is shown as completely open in these figures; however, the top may be partially covered by a perforated plate, a mesh, or other such covering, provided that the covering has significant open space therethrough to permit dispersal of the aroma. As such, the presence of top members of this type does not preclude the top from being defined as “substantially open.”
The device of FIG. 1 includes a power cord 20 for connecting its heater (not shown in this drawing) to a source of electrical power. As illustrated, the power cord includes an on/off switch 22 ; although, this item is an option in the present invention. The warmer 10 of FIG. 1 also includes an indicator light 24 which is lit when the heater is energized so as to provide a visual indication of the operation of the device. This is also an optional feature of the present invention. Another optional feature of the present invention is a temperature control device such as the dial control 26 shown in FIG. 1 . This control allows the user of the device to regulate the temperature of the heater. In other embodiments, this temperature controller may be eliminated. In yet other embodiments, temperature control may be automatic, by means of a thermostat, thermistor, or similar device.
Referring now to FIG. 2 , there is shown a cross-sectional view of the warming device 10 of FIG. 1 taken along line A—A. As will be seen, the device 10 includes a body portion 12 which further includes a base 14 integral therewith. The body portion is fabricated, at least in part, from a material having a low thermal conductivity. In general, a low thermal conductivity is understood to be a thermal conductivity less than that of steel. Steel and other iron alloys typically have a thermal conductivity in the range of 0.16 (cal/sec)/(cm 2 ° C./cm). Most typically, the low thermal conductivity materials of the present invention have a thermal conductivity which is less than 0.01 (cal/sec)/(cm 2 ° C./cm), and in particular instances, have a thermal conductivity which is less than 0.005 (cal/sec)/(cm 2 ° C./cm). Ceramics are one low thermal conductivity material which may be utilized in the present invention, and a typical thermal conductivity for such ceramic materials is in the approximate range of 0.005–0.001 (cal/sec)/(cm 2 ° C./cm). Other low thermal conductivity materials include various polymers, which term also encompasses polymer-based composites, such as glass or mineral filled polymers, or polymer coated materials such as metals, provided that such structures fall within the definition of low thermal conductivity.
Shown in the FIG. 2 embodiment is an electrical heater 28 which is disposed at the bottom of the interior volume enclosed by the housing 12 . Although not shown in this view, it is understood that this heater is in electrical communication with a source of electrical power via a power cord or the like, as is better shown in FIG. 1 .
As can be seen from FIG. 2 , a scented candle 16 is disposed within the body 12 so as to be heated by the heater 28 . As shown, the candle 16 includes a wick 30 and a body of scented wax 32 . Since the heater of the present invention eliminates the need for burning the candle, the wick 30 may be eliminated. It is also to be understood that the body of wax 32 may be replaced by an oil or other such hydrocarbon material which will dissolve and retain a scent agent. Accordingly, it is to be understood that within the context of this disclosure, the term “scented candle” is to be interpreted very broadly so as to include all bodies of scented hydrocarbon material, both liquid and solid, whether they include a wick or not.
The present invention may be implemented in various embodiments, and FIG. 3 illustrates one other embodiment of candle warmer 40 structured in accord with the present invention. The FIG. 3 embodiment includes a two-part housing comprised of a sidewall member 42 disposed upon a base 44 which has an electrical heater 46 supported thereupon. As in the previous embodiment, the housing defines an interior volume 48 which is substantially open at its top and which is configured to receive and retain a candle (not shown) therein.
The FIG. 3 embodiment also differs from the FIGS. 1 and 2 embodiment insofar as the sidewall portion of the housing 42 is fabricated from a relatively high thermal conductivity material such as sheet metal; but, it is further configured to define an insulating air space 50 between opposed wall portions 52 . This enclosed space 50 may be left empty, or may be filled with an insulating material such as a glass or a mineral fiber. The thermal conductivity of the material (air or insulating fiber) in the enclosed space 50 is very low. Hence, the overall thermal conductivity of the sidewall member 42 is low, within the definitions established herein. Yet other variations of the present invention may be likewise implemented.
Referring now to FIG. 4 , there is shown a schematic diagram of one circuit which may be employed for energizing the electrical heater used in the device of the present invention. Shown in FIG. 4 is an electrical heater 28 which is electrically energized, in this case, by a source of alternating current 54 . An electrical switch 22 allows for the selectable energization of the heater 28 . A pilot light 24 is also electrically connected to the generator 54 via the switch 22 so that the light will be lit whenever the heater 28 is energized.
Also shown in FIG. 4 is a temperature controller 56 which is associated with the heater 28 . The temperature controller 56 operates to regulate the flow of electrical energy to the heater 28 , thereby controlling the temperature of the heater. In some instances, the temperature controller may comprise a thermostat having a preset temperature point, and will operate to maintain the heater at a preselected temperature. In one embodiment, the temperature of the heater is regulated so that the body of hydrocarbon material in the device of the present invention does not exceed 75° C. In other instances, the temperature controller may comprise a thermostat which can be user-set to a desired temperature. In yet other instances, the temperature controller may comprise a variable resistor which a user can set to control the temperature of the heater. In yet other instances, the temperature controller may comprise a temperature responsive electronic device such as a thermistor.
In one mode of operation of the present invention, the temperature controller 56 may operate to initially energize the heater at a fairly high power level to provide for a rapid initial temperature rise in the heating device; and, the controller will further operate so that when a target temperature is reached, the power to the heater will be stepped-down to a lower level sufficient to maintain a desired temperature. Yet other modifications and variations of the power circuit will be readily apparent to those of skill in the art.
It is to be understood that the foregoing drawings, discussion and description are illustrative of specific embodiments of the present invention, but are not meant to be limitations upon the practice thereof. In view of the teaching presented herein, numerous modifications and variations of the invention will be apparent to those of skill in the art. It is the following claims, including all equivalents, which define the scope of the invention.
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Disclosed herein is a device for heating a scented candle so as to release scent therefrom in the absence of an open flame. The device includes a housing for retaining the candle. The housing is fabricated from a material having a low thermal conductivity. The device further includes an electrical heater in thermal communication with the housing. The heater warms the candle, and the low thermal conductivity housing aids in retaining heat in the candle thereby causing scent to be released therefrom.
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[0001] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/106,475 filed on Oct. 30, 1998, which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present disclosure relates generally to fabrication of nanostructures and in particular to high density nanostructure fabrication using nanoimprint lithography.
BACKGROUND OF THE INVENTION
[0003] Nanostructures are used for a variety of application areas, including, among other things, optical and magnetic data storage. One form of data storage is a low-cost information storage media known as Read Only Memory (ROM). One way to make ROM disks is by injection molding. Such disks may have a data storage density of ˜0.68 Gbit/in 2 , and are read using a focused laser beam. To meet the future demand for ROM disks with increasing information storage densities, methods must be developed for low-cost manufacturing of such disks with replicated data patterns, and for inexpensive read-back techniques suitable for retrieving high-density information.
[0004] One attempt is to develop ROM disks with ultrahigh-density topographical bits and to use proximal-probe based read-back. ROM disks of topographic bits with 45 Gbit/in 2 storage density have recently been reported by a group from IBM (B. D. Terris, H. J. Mamin, and D. Rugar, 1996 EIPBN, Atlanta, Ga., 1996; B. D. Terris, H. J. Mamin, M. E. Best, J. A. Logan, D. Rugar, and S. A. Righton, Apply. Phys. Lett., 69, 4262 (1996)). This group reports that features as small as 50 nm were produced by electron beam lithography and replicated on a glass substrate using a photopolymerization (2P) process. However, a smaller the feature size is needed to increase the storage density of the medium.
[0005] What is needed in the art is an improved method and apparatus for high density nanostructures. There is also a need for smaller feature size storage to enhance storage density.
SUMMARY OF THE INVENTION
[0006] The present disclosure teaches methods and apparatus which address the needs in the art mentioned above and addresses several other needs not mentioned expressly herein, but appreciated by those skilled in the art.
[0007] Method and apparatus for producing nanostructures is provided. The nanostructures are useful in the production of high density and ultra-high density storage media. The method and apparatus are demonstrated in the application to nano-compact disks, however, the method and apparatus are suitable for other applications, and the nano-compact disk application is not intended in an exclusive or limiting sense.
[0008] In particular nano-compact disks with 400 Gbit/in 2 storage density containing 10 nm minimum feature sizes have been fabricated using nanoimprint lithography. Furthermore, method and apparatus relating to the reading and wearing of Nano-CDS using scanning proximal probe techniques are described. This storage density is nearly three orders of magnitude higher than commercial CDS (0.68 Gbit/in 2 ). Other embodiments are possible with different feature sizes and different storage densities using the method and apparatus provided herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a schematic of one nanoimprint lithography process for production of nanostructures according to one embodiment of the present system.
[0010] [0010]FIG. 2 is a SEM micrograph of a 50 nm track with Nano-CD daughter mold fabricated using nanoimprint lithography, according to one embodiment of the present system.
[0011] [0011]FIG. 3 is a SEM micrograph of a 40 nm track width Nano-CD fabricated with nanoimprint lithography and liftoff, according to one embodiment of the present system.
[0012] [0012]FIG. 4 is a SEM micrograph of a Nano-CD consisting of 10 nm metal dots with a 40 nm period fabricated using nanoimprint lithography and liftoff, according to one embodiment of the present system.
[0013] [0013]FIG. 5 is an initial tapping mode AFM image (a) and 1000th image (b) of a Nano-CD consisting of 50 nm period gold dots fabricated using nanoimprint lithography and liftoff, according to one embodiment of the present system.
[0014] [0014]FIG. 6 shows cross sections of contact mode AFM images showing wear of chrome grating after various applied forces using a silicon scanning probe tip, according to one embodiment of the present system. The images are for (a) initial, (b) 11 μN, (c) 15 μN, and (d) 19 μN applied force. Only at the 19 μN force the tip removes the Cr grating.
DETAILED DESCRIPTION OF THE INVENTION
[0015] In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that the embodiments may be combined, or that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents. In the drawings, like numerals describe substantially similar components throughout the several views.
[0016] One embodiment of the present system uses a nanostructure fabrication process incorporating nanoimprint lithography (NIL) to create high density storage media, such as optical disks, for example compact disks. Other high density or ultra high density storage formats, such as magnetic, are possible without departing from the scope of the present system.
[0017] NIL is a high-throughput and low-cost nonconventional lithography technology with sub-10 nm resolution. One embodiment of the technology is provided in FIG. 1, and is discussed in U.S. Pat. No. 5,772,905 by S. Y. Chou, and the articles by S. Y. Chou, P. R. Krauss, and P. J. Renstrom, in Applied Physics Letters, 67, 3114 (1995); and Science, 272, 85 (1996), all of which are incorporated herein by reference in their entirety. Other embodiments and applications are described in copending U.S. patent application Ser. No. 09/107,006, entitled Release Surfaces, Particularly for Use in Nanoimprint Lithography, and in U.S Pat. No. 5,820,769, Ser. No. 08,448,807 entitled Method for Making Magnetic Storage Having Discrete Elements With Quantized Magnetic Moments, and copending U.S. patent application Ser. No. 08/762,781, entitled Quantum Magnetic Storage, all of which are incorporated by reference in their entirety. Applicant also incorporates by reference in its entirety the article entitled Nano-compact disks with 400 Gbit/in 2 storage density fabricated using nanoimprint lithography and read with proximal probe by P. R. Krauss and S. Y. Chou in Applied Physics Letters. 71 (21), Nov. 24, 1997.
[0018] In one embodiment, NIL patterns a resist through deformation of resist physical shape by embossing rather than through modification of resist chemical structure by radiation or by self-assembly. The nanoscale topographical bits on a Nano-CD can be made with a variety of materials such as polymers, amorphous materials, crystalline semiconductors, or metals. Here, we focus our discussion on one embodiment of Nano-CDS consisting of metal bits. Other embodiments and applications are possible, and the description herein is not intended in a limiting or exclusive sense.
[0019] In this embodiment, the first step of the Nano-CD fabrication process uses a SiO 2 mold on a silicon substrate with a CD-like data pattern fabricated using high-resolution electron beam lithography and reactive ion etching. The SiO 2 was selected because it has a low atomic number to reduce the backscattering and proximity effects during the electron beam lithography, thereby extending the lithography resolution down to features as small as 10 nm with a 40 nm period, in one embodiment. Other embodiments having different feature sizes are possible without departing from the present system. Although high-resolution electron beam lithography is a relatively expensive and low-throughput process, the master mold may be used to replicate many Nano-CDS using inexpensive and high-throughout NIL. Furthermore, the master mold may be used to fabricate daughter molds, thereby increasing the total number of disks that can be fabricated per master mold, and lowering the cost per disk. The daughter molds may be composed of the same material as the master mold, or other materials (such as high atomic number materials) that are optimized for better durability performance. A daughter mold with 13 nm minimum feature size and 40 nm pitch fabricated using NIL is shown in FIG. 2. Other feature sizes with different minimum feature sizes are possible without departing from the present system.
[0020] The second step in the Nano-CD fabrication process, according to this embodiment, was to imprint the mold into a polymer resist film on a disk substrate using NIL. The 75-nm-tall SiO 2 master Nano-CD mold was imprinted into a 90-nm-thick polymethyl-methacrylate (PMMA) film on a silicon disk. During the imprint step, both the mold and resist coated disk were heated to 175° C., however, other temperatures are possible without departing from the present system. The mold and wafer were compressed together with a pressure of 4.4 MPa for 10 minutes at this temperature, followed by being cooled down to room temperature. The mold was then separated from the disk resulting in duplication of the Nano-CD data pattern in the PMMA film. A mold release agent, as described in U.S. patent Ser. No. 09/107,006, entitled Release Surfaces, Particularly for Use in Nanoimprint Lithography, which was incorporated by reference in its entirety, may be used to improve the resolution of the imprinting and improve the minimal feature size. Furthermore, it has been demonstrated that using a single molecular layer of release agent or agents may provide a minimal feature size of 10 nanometers or less.
[0021] At this point, it is possible to directly use the disk with the patterned PMMA for data read-back, such as done with acrylate-based 2P processes. One advantage of NIL over the 2P process is that it can produce smaller feature sizes. Another advantage is that the substrate choice in NIL is not limited to UV transparent materials such as glass, but can be silicon, aluminum, or other opaque substrates.
[0022] The third step of the Nano-CD fabrication process, according to this embodiment, was to transfer the imprinted pattern into metal bits, which have much better durability than polymers during read-back. An anisotropic O 2 RIE pattern transfer step was used to transfer the imprinted pattern through the entire PMMA thickness. The resulting PMMA template was used to transfer the Nano-CD pattern into metal using a liftoff process where Ti/Au (5 nm/10 nm thick) were deposited on the entire disk and lifted off. FIG. 3 shows a section of a Nano-CD with a 40 nm track width and 13 nm minimum feature size, fabricated using the mold shown in FIG. 2. Other minimal feature sizes are possible without departing from the present system. This track width corresponds to a storage density of 400 Gbit/in 2 . FIG. 4 shows another 400 Gbit/in 2 Nano-CD with 10 nm minimum feature size and 40 nm pitch. Gold was chosen due to it high contrast on the silicon substrate in the scanning electron microscopy (SEM). Other materials may also be used which offer better wear properties than gold, as discussed later.
[0023] In one embodiment, rather than deposit material on substrate the PMMA can be used as the etch mask to directly etch the substrate.
[0024] It is noted that the fabrication process described herein is not intended in an exclusive or limiting sense. Other materials may be used and temperatures and processes may be employed which are within the scope of the present system.
[0025] A high-resolution and nondestructive technique is needed to read data stored in the nanoscale topographical bits of a Nano-CD. The bits are too small to be read by current laser beams as used in CDS. In one embodiment, information stored on Nano-CDS was read back using an atomic force microscope (AFM) with commercial silicort scanning probes. Both tapping mode and contact mode AFM were demonstrated. FIG. 5( a ) shows a tapping mode AFM image and a cross-section profile of a Nano-CD consisting of a uniform array of gold dots with a 50 nm period. Tapping mode AFM images show the gold dots are wider than the 10 nm measured by SEM. The discrepancy is attributed to the scanning probe's tip size. The cross-section profile indicates that the probe tip can resolve individual nanoscale dots and the flat silicon substrate between the 50 nm period dots. However, for 40 nm period dot arrays with the same diameter, the probe tip could not always reach the substrate, making the dot height measured by AFM smaller than that for 50 nm period dots. This problem can be avoided by using a sharper probe.
[0026] The wear of Nano-CDS and the scanning probe during read-back process was investigated. Tapping mode AFM (a force range of 0.1-1.0 nano-Newtons) was used to scan the same location of the Nano-CD 1000 times as shown in FIG. 5( b ). We did not observe any discernible change in the AFM image. This indicates that neither the silicon proximal probe nor the Nano-CD exhibited significant wear during the tapping mode AFM imaging.
[0027] To accelerate the wear test of the tips and the disks, contact mold AFM and large tip forces were used. Moreover, the gold dots were replaced by a 15-nm-thick chrome grating of a 3 μm spacing and linewidth fabricated using photolithography and liftoff. Chrome has a Mohs hardness of 9, making it more resistant to wear than gold, which has a hardness of 2.5. The magnitude of the applied forces depends upon the spring constant of the proximal probe cantilever. The AFM tips used were 125-μm-long commercial silicon cantilevers which had spring constants ranging from 20 to 100 N/m. Since the spring constant of the cantilevers was not accurately known, the approximate forces were calculated using a spring constant of 60 N/m.
[0028] [0028]FIG. 6 shows 10-μm-wide cross-section profiles from contact mode AFM images of the chrome grating after various forces were applied to the center 5-μm-wide section. The AFM tip force can be increased to 15 μN without creating immediate noticeable change in the AFM image. However, at 19 μN force, the silicon tip will remove the chrome line during scanning. This indicates that in tapping mode, where the AFM tip force can be over four orders of magnitude smaller than the damage threshold, both the Nano-CD and silicon probe tip should have a lifetime that is at least four orders of magnitude longer than that at the damage threshold (although the exact relation between the wear and the force is unknown). High data retrieval rates may be obtained by using arrays of scanning probe tips operating in parallel.
[0029] In one embodiment, another method of reading the data is to use a near field probe. A near field probe is a special type of optical tip with sub 100 nanometer resolution. In one embodiment, the data can also be read by using a capacitance probe. In such an embodiment, different spacing gives different capacitances. Other embodiments are possible without departing from the present system.
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A method and apparatus for high density nanostructures is provided. The method and apparatus include Nano-compact optical disks, such as nano-compact disks (Nano-CDS). In one embodiment a 400 Gbit/in 2 topographical bit density nano-CD with nearly three orders of magnitude higher than commercial CDS has been fabricated using nanoimprint lithography. The reading and wearing of such Nano-CDS have been studied using scanning proximal probe methods. Using a tapping mode, a Nano-CD was read 1000 times without any detectable degradation of the disk or the silicon probe tip. In accelerated wear tests with a contact mode, the damage threshold was found to be 19 μN. This indicates that in a tapping mode, both the Nano-CD and silicon probe tip should have a lifetime that is at least four orders of magnitude longer than that at the damage threshold.
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FIELD OF THE INVENTION
The present invention relates to a paint composition for automotive weather strips and glass runs, as well as processes for producing automotive weather strips and glass runs.
BACKGROUND OF THE INVENTION
Most automotive weather strips and glass runs (which are hereunder sometimes referred to simply as “automotive weather strips”) are coated with curable urethane-based paints on the surface of the substrate to impart it special functions such as wear resistance and slip property (sliding property) or provide it with better appearance.
Conventionally, curable urethane-based paints of a solvent type have been used in the manufacture of automotive weather strips; however, with the recent concern over the global environment and the health of working personnel, a need has arisen for a shift toward aqueous and other paints of a non-solvent type.
However, water which is the medium for paints of the aqueous type have more latent heat of evaporation than solvents, so the aqueous paints require more heat than paints of the solvent type in order to dry up the water after application. In addition, unlike solvent-type paints that allow adjustment of volatilization temperature and rate by combining several kinds of solvents, aqueous-type paints require preliminary drying in order to prevent “flashing” due to nearly instantaneous volatilization of water. As a result, longer drying times are required by the aqueous paints and in order to deal with this low productivity problem, it becomes necessary to build a new drying oven for shifting from the solvent-type paint to the aqueous type.
Most automotive weather strips use substrates that are made of thermosetting elastomers such as EPDM rubber (ethylene propylene rubber) or thermoplastic elastomers such as TPO (thermoplastic polyolefins).
If thermoplastic elastomers are used as the substrate, drying should be carried out at a low temperatures of 150° C. or below to prevent thermal deformation that would otherwise occur during post-application drying; however, if the paint applied is of the aqueous type, the drying operation is not highly productive since water is very difficult to dry.
The EPDM rubber as an exemplary thermosetting elastomer is nonpolar and has low sticking property and it is also hydrophobic; hence, aqueous paints cannot produce a more adhesive coat than solvent-type paints.
With a view to solving this problem, pretreatments such as corona discharge and primer application are conventionally applied to the substrate surface but problems still remain, such as high initial cost and the difficulty involved in performing positive pretreatments on complexly shaped articles.
SUMMARY OF THE INVENTION
Therefore, a first object of the invention is to provide a paint for automotive weather strips that is free from the above-mentioned defects of the prior art and which can achieve strong adhesion to the EPDM rubber without corona discharge, primer application or other pretreatments on the substrate surface while exhibiting high wear resistance.
A second object of the invention is to provide a process for producing automotive weather strips which does not require the as-applied coat to be cured completely in a drying oven but which permits it to be cured completely by the heat inertia of the drying step and which can also shorten the length of the drying oven or lower the drying temperature.
A third object of the invention is to provide a process by which automotive glass runs having high wear resistance in the bottom portion while exhibiting high softness and flexibility in the lip portions can be produced efficiently and with minimum impact on the global environment.
As a result of the extensive studies made in order to attain the above-mentioned objects, the present inventors found that the first object of the invention could be attained by adding at least two specified silane coupling agents or a product of premixing reaction between said at least two silane coupling agents to a curable urethane-based emulsion paint.
Thus, in a first aspect, the present invention relates a paint composition for automotive weather strips comprising a curable urethane-based emulsion paint having added thereto either at least two silane coupling agents selected from the group consisting of a silane coupling agent having an amino group, a silane coupling agent having an epoxy group, a silane coupling agent having a methacryloxy group and a silane coupling agent having an acryloxy group, or a reaction product obtained by previously mixing said at least two silane coupling agents.
The second object of the invention can be attained by a process for producing automotive weather strips which comprises the steps of extruding a semi-finished product of automotive weather strip while it is continuously coated with a urethane-based aqueous paint, then drying and curing the product in a heating furnace, or comprises extruding a semi-finished product of automotive weather strip, heating it, immediately followed by continuous application of a urethane-based aqueous paint, then drying and curing the product in a heating furnace, or comprises unrolling a semi-finished extruded product of automotive weather strip while it is continuously coated with a urethane-based aqueous paint, then drying and curing the extruded product in a heating furnace, wherein a silicone compound having an amino group is applied to the coated surface of the semi-finished product or extruded product after it leaves the heating furnace, or wherein a silicone compound having an amino group is incorporated in the urethane-based aqueous paint.
The third object of the invention can be attained by a process for producing automotive glass runs which comprises the steps of extruding a semi-finished product of automotive glass run as while is continuously coated with a silane-crosslinkable polyethylene, then drying and curing the product in a heating furnace, or comprises the steps of extruding a semi-finished product of automotive glass run, heating it, immediately followed by continuous coating with a silane-crosslinkable polyethylene, then drying and curing the product in a heating furnace, or comprises the steps of unrolling a semi-finished extruded product of automotive glass run while it is continuously coated with a silane-crosslinkable polyethylene, each of which processes further comprises applying an urethane resin-based aqueous paint containing a silicone compound having an amino group or a silicone compound having an amino group or a solution thereof onto the silane-crosslinkable polyethylene coat, then heating the applied product in a heating furnace to dry and cure the applied aqueous paint, silicone compound or solution and to crosslink the silane-crosslinkable polyethylene.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of an abrasion tester according to a method specified by the Japan Society for Promotion of Scientific Research;
FIG. 2 is an illustration of a glass run product;
FIG. 3 is an illustration of another type of glass run product; and
FIG. 4 illustrates how a glass run product is subjected to an abrasion test or a sliding resistance test.
DETAILED DESCRIPTION OF THE INVENTION
The following is the description of a mode for carrying out the invention as it relates to a paint composition for automotive weather strips.
The curable urethane-based emulsion paint which is used as the base of the paint composition is a urethane-based emulsion paint which typically uses an isocyanate-, melamine-, epoxy- or carbodiimide-based curing agent.
Examples of the silane coupling agent having an amino group include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane.
Examples of the silane coupling agent having an epoxy group include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.
Examples of the silane coupling agent having a methacryloxy group include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldiethoxysilane and 3-acryloxypropylmethoxysilane.
At least two of the silane coupling agents listed above or their reaction product is preferably added in an amount of 10 to 40 parts by weight per 100 parts by weight of the involatile content in the base curable urethane-based emulsion paint.
The following is the description of a mode for carrying out the invention as it relates to a process for producing automotive weather strips.
The substrate of automotive weather strips is not limited in any particular way but thermoplastic elastomers are preferably used.
The urethane-based aqueous paint may be a urethane-based emulsion paint which typically uses an isocyanate-, melamine-, epoxy- or carbodiimide-based curing agent.
Preferred examples of the silicone compound having an amino group include aminosilane coupling agent such as γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, as well as amino-modified silicone oils.
If the silicone compound having an amino group is to be applied to the coated surface of the substrate as it emerges from the drying oven, it may be diluted with water. The application method is in no way limited and spraying and brushing may be mentioned as typical examples.
The following is the description of a mode for carrying out the invention as it relates to a process for producing automotive glass runs.
The urethane-based aqueous paint may be a urethane-based emulsion paint which typically uses an isocyanate-, melamine-, epoxy- or carbodiimide-based curing agent.
The silane-crosslinkable polyethylene which is to be applied to the bottom portion of a semi-finished extruded product of automotive glass run is as easily processable as common polyethylenes before crosslinking but, once processed, exhibits better sliding and wear-resistant properties than ultrahigh molecular-weight polyethylenes; hence, the silane-crosslinkable polyethylene is suitable for use as a sliding member in the bottom portions of glass runs that require high wear resistance.
The silane-crosslinkable polyethylene reacts with water and condenses through the removal of alcohol to thereby become crosslinked. If the aqueous paint containing the silicone compound having an amino group is applied to the silane-crosslinkable polyethylene coat, which is then dried and cured in a heating furnace, the water in the aqueous paint and the silicone compound having an amino group which has a catalytic action in the condensation of silane crosslinks by removal of alcohol work together to cause rapid crosslinking and curing of the applied silane-crosslinkable polyethylene coat. The silicone compound having an amino group offers the added advantage of promoting the curing of the as-applied aqueous paint film, thereby increasing its adhesion to the EPDM rubber or silane-crosslinkable polyethylene.
The lip portions of glass runs do not require as high wear resistance as their bottom portions. On the other hand, they should have better sealing and handling properties, higher ability to prevent rattling sound and dust scratching, and more attractive appearance; therefore, the sliding member to be used in the lip portions should not impair the softness and flexibility of the substrate rubber and is suitably based on polyurethane resins.
Preferred examples of the silicone compound having an amino group include aminosilane coupling agents such as γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, as well as amino-modified silicone oils. The silicone compound having an amino group is preferably incorporated in amounts ranging from 2 to 15 parts by weight per 100 parts by weight of the involatile content of the aqueous paint.
Coating with the silane-crosslinkable polyethylene may be accomplished by coextrusion with rubber or it may be applied after vulcanization while the rubber is still hot.
The present invention will now be described by way of reference to the Figures, which should in no way be construed as limiting the present invention. FIG. 1 is a schematic representation of an abrasion tester according to a method specified by the Japan Society for the Promotion of Scientific Research, in which D is an abrading glass plate (t=3.5 mm) and E is a coated sample. FIG. 2 is an illustration of a glass run product, in which F is a coated site, G is crosslinked PE, and H is EPDM rubber. FIG. 3 is an illustration of another glass run product, in which F is a coated site and H is EPDM rubber. FIG. 4 illustrates how a glass run product is subjected to an abrasion test or a sliding resistance test.
EXAMPLES
The present invention is illustrated in greater detail below with reference to the following Examples, but the invention should not be construed as being limited thereto.
Examples 1 and 2 and Comparative Example 1
The data in Table 1 demonstrates the advantages of the paint composition according to the invention. Two samples of a curable urethane polymer were mixed with two silane coupling agents to prepare two paint compositions, which were tested for adhesion, wear resistance and dynamic friction coefficient. The results are shown in Table 1 together with those of a comparative paint composition.
TABLE 1
Comp.
Ex. 1
Ex. 2
Ex. 1
Amount
Curable
100.0
100.0
100.0
(parts by
urethane
wt.)
polymer
Silane A
8.0
8.0
8.0
Silane B
8.0
—
—
Silane C
—
8.0
8.0
Adhesion (N/cm)
7.0
7.0
4.0
Wear resistance
30,000
20,000
10,000
(cycles) 1
Dynamic friction
≦0.1
≦0.1
0.2
coefficient (μK)
Silance coupling agent A: γ-glycidoxypropyltrimethoxysilane (KBM-403 of Shin-Etsu Chemical Co., Ltd.; TSL 8350 of GE Toshiba Silicone; SH-6040 of Toray Dow Silicone)
Silane coupling agent B: 3-acryloxypropyltrimethoxysilane (KBM-5103 of Shin-Etsu Chemical Co., Ltd.)
Silane coupling agent C: γ-aminopropyltrimethoxysilane (KBM-903 of Shin-Etsu Chemical Co., Ltd.; TSL 8330 of GE Toshiba Silicone)
1 Wear resistance: The coated surface was rubbed with a glass plate (see FIG. 1) until the substrate became exposed. The wear resistance of the sample was evaluated in terms of the number of cycles the glass plate was reciprocated before the substrate showed.
Examples 3 and 4 and Comparative Examples 2 and 3
The data in Table 2 demonstrates the advantages of the process for producing an automotive weather strip according to the invention. Extruded, heated and later cooled automotive weather strips were coated with two samples of urethane-based aqueous paint containing γ-aminopropyltrimethoxysilane as a silicone compound having an amino group, thereby preparing weather strip products, which were tested for wear resistance. The results are shown in Table 2 together with those of two comparative products.
TABLE 2
Ex. 3
Ex. 4
Comp. 2
Comp. 3
Treatment with
yes
yes
no
no
silicon compound 1)
Drying/curing
200° C. ×
80° C. ×
200° C. ×
80° C. ×
conditions
10 min
10 min
10 min
10 min
Wear
EPDM
20,000
20,000
10,000
5,000
resistance
rubber
(cycles) 2)
TPO
5,000
5,000
2,000
100
1) Silicone compound: Gamma-aminopropyltrimethoxysilane (KBM-903 of Shin-Etsu Chemical Co., Ltd.; TSL 8330 of GE Toshiba Silicone) was processed into a 10% solution by means of ion-exchanged water.
2) Wear resistance: The coated surface was rubbed with a glass plate (see FIG. 1) until the substrate became exposed. The wear resistance of the sample was evaluated in terms of the number of cycles the glass plate was reciprocated before the substrate showed.
Examples 5-7 and Comparative Examples 4-6
The data in Table 3 demonstrates the advantages of the process for producing a glass run according to the invention. Glass run products made using γ-aminopropyltrimethoxysilane as a compound having an amino group were tested for wear resistance, resistance to sliding and adhesion to EPDM rubber and crosslinked polyethylene (PE). The results are shown in Table 3 together with those of comparative products.
TABLE 3
Ex. 5
Ex. 6
Ex. 7
Comp. 4
Comp. 5
Comp. 6
Amount
Curable urethane
100.0
—
100.0
100.0
—
100.0
(parts by
polymer
wt.) in
Silane coupling
10.0
10.0
10.0
—
—
—
coating film
agent 1)
(F)
Ion-exchanged water
—
90.0
—
—
—
—
Wear resistance (cycles) 2)
40,000
—
40,000
10,000
—
10,000
Sliding resistance
3.0
3.0
5.0
—
5.0
(N/100 mm) 3)
Adhesion to EPDM rubber_(H) 4)
◯
—
◯
Δ
—
Δ
Adhesion to cross-linked PE (G) 4)
◯
◯
—
X
X
—
Glass run product
FIG. 1
FIG. 1
FIG. 2
FIG. 1
FIG. 1
FIG. 2
1) Silane coupling agent: Gamma-aminopropyltrimethoxysilane (KBM-903 of Shin-Etsu Chemical Co., Ltd.; TSL 8330 of GE Toshiba Silicone).
2) Wear resistance: A glass run product (see FIG. 2 or 3) was set on a test jig (see FIG. 4) and a glass plate (100 × 70 mm; t = 3.5 mm) was allowed to slide back and forth until the substrate became exposed in the coated lip portions and the bottom portion. The wear resistance was evaluated in terms of the number of cycles the glass plate was reciprocated before the substrate showed.
3) Sliding resistance: A glass run product (see FIG. 2 or 3) was set on a test jig (see FIG. 4) and a glass plate (100 × 70 mm, t = 3.5 mm) was allowed to slide for a distance of 70 mm; the resulting resistance was measured.
4) Adhesion: The coated surface was rubbed with a calico cloth under a load of 1 kg until either the coat transferred to the cloth or the substrate became exposed. (The criteria for rating were: ◯, neither transfer to the cloth nor exposure of the substrate; X, the substrate became exposed).
As described on the foregoing pages, the paint composition for automotive weather strips according to the present invention can achieve strong adhesion to the EPDM rubber without corona discharge, primer application or other pretreatments on the substrate surface while exhibiting high wear resistance.
The processes for producing automotive weather strips according to the present invention do not require the as-applied coat to be cured completely in a drying oven but they permit it to be cured completely by the heat inertia of the drying step and they can also shorten the length of the drying oven or lower the drying temperature. The improvement in productivity is particularly noticeable if thermoplastic elastomers such as TPO are used as the substrate of automotive weather strips.
The processes for producing automotive glass runs according to the present invention are such that by using these processes, automotive glass runs having high wear resistance in the bottom portion while exhibiting high softness and flexibility in the lip portions can be produced efficiently and with minimum impact on the global environment.
While the present invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
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A paint composition for automotive weather strips and glass runs which comprises a curable urethane-based emulsion paint having added thereto either at least two silane coupling agents selected from the group consisting of a silane coupling agent having an amino group, a silane coupling agent having an epoxy group, a silane coupling agent having a methacryloxy group and a silane coupling agent having an acryloxy group, or a reaction product obtained by previously mixing said at least two silane coupling agents. Also discloses are processes for producing automotive weather strips.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority pursuant to 35 U.S.C. Sec 119(e) to U.S. Provisional Application No. 61/265,121, filed Nov. 30, 2009, entitled “METHOD OF OPPORTUNITY-BASED TRANSMISSION OF WIRELESS VIDEO,” the subject matter thereof being fully incorporated herein by reference.
[0002] The subject matter of this application is related to the subject matter of the commonly owned U.S. patent application Ser. No. 12/702,722, filed Feb. 9, 2010,entitled “SYSTEM AND METHOD OF WIRELESS UPLINK VIDEO TRANSMISSION”.
[0003] The subject matter of this application is related to the subject matter of the commonly owned U.S. application Ser. No. 12/793,213, filed Jun. 3, 2010, entitled “METHOD OF PRIORITY BASED TRANSMISSION OF WIRELESS VIDEO.”
ART BACKGROUND
[0004] Wireless access links, such as those provided by 3G and 4G networks, are shared, limited resources and as such may become scarce as demand outstrips supply. As a consequence, contention will arise when too many users attempt to transmit data from their mobile devices within the same sector. Until recently, users predominantly uploaded considerably less data than they would download. However, the recent introduction of video-enabled mobile devices is likely to stimulate rapidly growing demand for uplink bandwidth.
[0005] For this and other reasons, there is a growing need for mechanisms to reduce bandwidth requirements for over-the-air video transmission and effectively manage transmission resources, particularly the uplink resource. In particular, there is a need for flexible methods of video transmission that can provide enough quality to satisfy user needs while consuming relatively little bandwidth during times when resources are scarce, and can provide higher quality when resources are more plentiful.
SUMMARY OF THE INVENTION
[0006] The H.264 Scalable Video Codec (SVC) provides a mechanism to encode video in multiple layers, including a base layer and one or more additional layers. Transmitting the base layer is sufficient to allow the receiver to decode a viewable video signal, but each additional layer adds to the quality of the decoded signal. For example, the different layers may represent video that has been coded at different levels of quality in such a way that data and decoded samples of lower qualities can be used to predict data or samples of higher qualities.
[0007] We have developed a method to efficiently transport video signals that can be used when resources are scarce, for example when a wireless network is experiencing peak demand. In accordance with implementations of our approach, a user's mobile terminal codes the video in multiple layers, as described above. If it is not expected that all the layers can be transmitted from the mobile device because of resource limitations over-the-air, the mobile terminal acting according to our method reduces current bandwidth requirements by streaming a subset, i.e., one or more of the lower coded video layers only. This streamed video can be viewed by peers and saved on a server. Meanwhile, the higher layers that were not sent are saved on the mobile device. When network resources eventually become available, the saved higher layers only are sent to the destination server that saved the lower layers. The entire video can then be reconstructed on the destination server. The user will then have the entire video saved at high quality.
BRIEF DESCRIPTION OF THE DRAWING
[0008] FIG. 1 is a block diagram of an Evolved Packet Core network including an Intelligent Video Masher (IVM) as described below.
[0009] FIG. 2 is a conceptual block diagram of a mobile phone or other user terminal useful for practicing the invention in at least some embodiments.
[0010] FIG. 3 is a conceptual block diagram of a wireless communication network in which the user terminal of FIG. 1 may be an element.
[0011] FIG. 4 is a conceptual block diagram of a mobile phone or other user terminal useful for practicing the invention in at least some embodiments. In contrast to FIG. 1 , where features useful for the transmission of video are emphasized, FIG. 3 emphasizes features useful for the reception of video. The features of FIGS. 1 and 3 may of course be combined in one device.
DETAILED DESCRIPTION
[0012] As will be apparent from the foregoing discussion, our method can be used in a video streaming application. The user can stream video from a mobile device to peers in real time at lower quality when the network is experiencing high usage. The remaining video layers that are not sent in real time are sent later so that the reconstructed high quality video can be stored in the recipients' personal storage.
[0013] Accordingly, the later-sent video layers are transmitted at a time which is at least partially independent of the time of the initial transmission. That is, the timing of the later transmission is not completely determined by the timing of the initial transmission, as would be the case if, e.g., the transmissions were required to be concurrent or juxtaposed in time. Instead, the timing of the later transmission is determined, at least in part, by at least one factor that is independent of the timing of the initial transmission. Such a factor may be, for example, an indication of more favorable network conditions. One example of “partially independent timing” would be a policy to transmit the further layers at the earliest indication, subsequent to the initial transmission, that network conditions have surpassed a threshold.
[0014] Limiting the number of layers that are transmitted can ensure that the over-the-air interface is utilized most efficiently. It should be noted in this regard that as an alternative to sending over a wireless network such as a WiMax or LTE network, it would also be possible to send the higher layers over WiFi or other technologies to similarly reduce bandwidth on the over-the-air interface. This would not only save bandwidth consumption for the network operator but this could save the user streaming video from charges associated with metered billing for bandwidth usage.
[0015] It should also be noted that our method promotes efficiency in bandwidth utilization because it obviates the need to retransmit entire video signals. That is, as noted above, after the lower layer or layers have been sent, it is sufficient if only the higher layers are sent in subsequent transmissions.
[0016] Software, e.g. client software running on the mobile phone, determines how many layers to transmit at a given time. To make this determination, the client software may use information about channel quality received from the base station. Channel quality information may include, without limitation, any of channel quality indices, signal to interference and noise ratios, error rates, and power levels. (In other implementations, the software that schedules the transmission of layers may run on a device external to the mobile phone, such as a server at the base station, elsewhere in the radio access network, or in the core network. In one particular example, the software that schedules the transmission of layers runs on an Intelligent Video Masher, as described below.)
[0017] The mobile station identifies the various video streams to the receiver, so that they can be correlated and recombined. (In some cases, earlier-received video streams will need to be combined with higher-layer streams that arrive after a significant delay.) For example, the Session Description Protocol (SDP) can provide the mobile terminal with a message format for notifying the receiver of the type of media being transmitted. Thus, for example, the mobile can notify the receiver that instead of conventional video streams under H.264 SVC, the media being transmitted include multiple video layers that are transmitted at different times and are to be combined as described here. SDP is described in the Internet Engineering Task Force (IETF) publication RFC 5583, which is discussed in greater detail below.
[0018] Additionally, SVC, for example, includes a feature referred to as a Network Abstraction Layer (NAL) header. The NAL headers can be used to identify and correlate the individual video layers to which each respective bitstream belongs. A decoder as prescribed under the H.264 SVC standard is able to use the information in the NAL headers for combining the various video streams so that the video content can be rendered at a higher quality.
[0019] In an example scenario, a user streams video from his mobile phone, which may for example be a smartphone. The phone includes a video encoder. The video encoder applies H.264 SVC to produce multiple coded layers, which may, e.g., be assigned a port number for streaming to their destination.
[0020] As will be understood by those skilled in the art, the TCP and UDP protocols may apply if the video streaming is conducted according to the IP suite of protocols. At least in such cases, the port numbers will typically be TCP port numbers or UDP port numbers.
[0021] The receiver rebuilds a composite coded video signal from the various video layers that have been received. (The receiver can use SDP, for example, to identify those incoming video streams that are related.) For example, the composite signal may be rebuilt by jointly decoding the individual video layers according to well-known standards such as H.264 SVC. The rebuilt, coded signal may then be conditioned for rendering of the video content. (The output of the rendering process is a signal capable of driving a video display.)
[0022] As noted above, SDP is described in RFC 5583, “Signaling Media Decoding Dependency in the Session Description Protocol (SDP),” July 2009, http://tools.ietf.org/html/rfc5583.
[0023] Very briefly, RFC 5583 provides a signaling method by which the nodes in an IP network using the Real-Time Transport Protocol (RTP) can inform each other of the decoding dependencies of media bitstreams that are to be transmitted. (A media bitstream is a valid, decodable stream that conforms to a media coding standard.) In particular, RFC 5583 describes the signaling of such decoding dependencies for layered media bitstreams. It should be noted in this regard that an. SDP session description may contain one or more media descriptions. Each media description may identify one media stream. A layered media bitstream includes one or more media partitions, each conveyed in its own media stream.
[0024] A media partition is part of a media bitstream which is intended for independent transportation, and which may represent one or more layers that are to be handled as a unit. A decoding dependency is a type of relationship between media partitions. In the case of a layered decoding dependency, each media partition can be decoded only when the media partitions on which it depends are also available.
[0025] Various types of devices may serve as the receiver that is the destination for the streamed video. Of course one such entity is the fixed or mobile terminal belonging to a network user. Another example is a video server that receives the various layers and caches them until it can reconstitute the full transmission and retransmit it to the ultimate destinations. Such a video server may reside at any of various locations in the wireless network, including in the core network.
[0026] It should be noted in this regard that cacheing is only one type of storage that is useful in this regard. Cacheing is a short-term type of storage useful, e.g., to hold partial content until it is feasible to retransmit it in the full transmission. On the other hand, longer-term storage may be used, e.g., to hold the various layers until there is a request to retransmit them on-demand. Furthermore, the various coded video layers may be jointly decoded or transcoded to create a non-layered representation of the video content, and that non-layered representation may be held in cache, or in longer-term storage, until retransmission is feasible or until it is requested.
[0027] It should be noted further that instead of decoding, the various coded video layers may be jointly transcoded to create a coded video representation that is non-layered. For example, techniques for transcoding from a layered SVC representation to a non-layered AVC representation are well known. Transcoding is particularly useful because in many instances, it may be more efficient to transmit non-layered coded video than it is to transmit layered coded video.
[0028] It should also be noted that in a receiver, a video signal may be rendered at the time of receipt of the initial transmission, containing the base layer, and that further coded video layers may be received subsequently. In such a case, if the initially received layers have been stored, e.g. in a cache memory, they can be decoded or transcoded a second (or further) time, as inputs to the joint decoding or transcoding of the full video signal.
[0029] One example of a video server residing in the core network is the entity that we refer to as an Intelligent Video Masher (IVM). For example, the IVM may be included in the core network of a wireless communication system the supports LTE. LTE is a Fourth Generation enhancement to UMTS telecommunication that includes an all-IP networking architecture. LTE is being introduced through a series of releases by the 3rd Generation Partnership Project (3GPP). In LTE, the GPRS core network is replaced by the System Architecture Evolution (SAE), which is a flat, IP-based network architecture. Because LTE is all-IP from end to end, the mobile handsets and other terminal devices for LTE have embedded IP capabilities, and the base stations, referred to as Evolved NodeBs (eNodeBs), are IP-based. The IVM will typically be implemented as a server running on an appropriate host machine, and in particular it will be able to perform video processing, such as H.264 SVC processing, so that it can process the video bitstreams.
[0030] FIG. 1 illustrates the Evolved Packet Core (EPC) 170 , which is the main architectural component of SAE. It will be seen from the figure that the EPC comprises four elements: the Serving Gateway (SGW) 100 , the Packet Data Network Gateway (PGW) 110 , the Mobility Management Entity (MME) 120 , and the Policy and Charging Rules Function (PCRF) 130 . The SCW, PGW, and MME were introduced in 3GPP Release 8, and the PCRF was introduced in 3GPP Release 7.
[0031] The SGW is a data plane element. Its primary function is to manage user-plane mobility and to act as a demarcation point between the radio access network (RAN) and the core networks. The SGW maintains data paths between eNodeBs 140 and the PGW.
[0032] The PGW is the termination point of the packet data interface toward the packet data networks. As such, it is the entry and exit point for traffic for the UEs 150 , i.e., for the user terminals. The PGW supports operator-defined policy for resource allocation and usage, packet filtering, and charging.
[0033] The MME performs the signaling and control functions to manage the UE access to network connections, the assignment of network resources, and the management of the mobility states to support tracking, paging, roaming, and handovers, as well as all other control-plane functions related to subscriber and session management.
[0034] The PCRF supports service data flow detection, policy enforcement, and flow-based charging. (In LTE, a service data flow—SDF—is the virtual connection that carries data-plane traffic.)
[0035] With further reference to FIG. 1 , it will be seen that the IVM 160 is situated, for example, just outside the EPC 170 , where it can intercommunicate with the various EPC elements. More particularly, the IVM may be situated just outside the PGW 110 , with which it communicates using known protocols of the Internet protocol suite. Higher protocol layers are used for the signaling and messaging that set up the video streaming. The IVM may reside on any of various hardware platforms, such as an ATCA platform.
[0036] Communication between the IVM and the various user terminals is effectuated by a protocol layer added on top of LTE. Such a protocol layer is readily added using known protocols, and need not be described here in detail.
[0037] Accordingly, as shown in FIG. 2 , a mobile phone or other user terminal includes a video camera 210 . The video stream from the camera enters a processor or processors, some of whose various functionalities are indicated in the figure as coder 220 , payload processor 230 , and header processor 240 . This representation is meant to be purely conceptual, and it may have many different practical realizations in hardware and software, none of which are meant to be excluded. In general, however, at least one hardware processing device, such as a digital signal processor, will carry out the illustrated operations or their equivalent under appropriate control, which may be provided, e.g., by a program implemented in hardware, software, or firmware.
[0038] Coder 220 processes the video stream according, for example, to the H.264 SVC specification or other multilayer video protocol. This results in multiple outputs, each of which corresponds to one of several coding layers, as described above. The various coding layers are indicated in the figure as Packet Layer 1 , Packet Layer 2 , etc.
[0039] Payload Processor 230 assembles the coded data into packet payloads 233 . Header information 235 must be appended to each of the packets. This header information is provided by Header Processor 240 .
[0040] Storage of the individual coded video layers as discussed above is provided by memory 250 .
[0041] In an example scenario as illustrated in FIG. 3 , a user 350 streams video from his mobile phone, which may for example be a smartphone. The phone includes a video encoder. The video encoder applies H.264 SVC to produce multiple coded layers. A processor in the phone assigns port numbers to the coded packets.
[0042] Packets 361 , 362 , 363 corresponding to the respective coded layers are transmitted, possibly at different times, to base station 370 . (In particular, an initial transmission may include at least the base layer, and at least one further layer may be transmitted later.) Base station 370 transmits the packets to its core network 380 , from which the packets are transmitted toward their destination through public network 390 , which may, e.g., be the Internet. The public network delivers the packets to core network 400 , which serves the user for whom the packets are destined. Core network 400 transmits the packets to base station 410 , which transmits them to destination user 420 .
[0043] The receiver reconstructs the video signal. The receiver is responsible for recombining these flows for input to the decoder. Ultimately, the decoder determines the structure of the layers based on the coding method, e.g., H.264 SVC.
[0044] In some embodiments, the video signal is reconstructed at a receiving user terminal, such as a mobile terminal. In other embodiments, the various video layers are saved at a device in the core network or in the access network, and when all layers are available, the device retransmits them together toward the final destination. The various layers may be retransmitted in the layered representation, or they may, for example, be transcoded for transmission in a non-layered representation.
[0045] Accordingly, as shown in FIG. 4 , a mobile phone or other user terminal includes a video display device 430 . The video stream to the display device is output from a processor or processors, some of whose various functionalities are indicated in the figure as decoder 440 , payload processor 450 , and header processor 460 . This representation is meant to be purely conceptual, and it may have many different practical realizations in hardware and software, none of which are meant to be excluded. In general, however, at least one hardware processing device, such as a digital signal processor, will carry out the illustrated operations or their equivalent under appropriate control, which may, be provided, e.g., by a program implemented in hardware, software, or firmware.
[0046] Header processor 460 extracts the header information from the received packets 465 . Payload Processor 450 converts the packet payloads 470 into coded video streams in each respective layer. The various coded layers are indicated in the figure as Video Layer 1 , Video Layer 2 , etc. Decoder 440 processes the video streams according, for example, to the H.264 SVC specification or other multilayer video protocol in order to render the video signal that is provided to display device 430 .
[0047] Storage of the individual coded video layers as discussed above is provided by memory 480 .
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A method is provided to efficiently transport video signals on a wireless network when resources are scarce. In an embodiment, a user's mobile terminal codes the video in multiple layers. If resources are scarce, the mobile terminal reduces current bandwidth requirements by streaming a subset, i.e., one or more of the lower coded video layers only. This streamed video can be viewed by peers and saved on a server. Meanwhile, the higher layers that were not sent are saved on the mobile device. When network resources eventually become available, the saved higher layers only are sent to the destination server that saved the lower layers. The entire video can then be reconstructed on the destination server.
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BACKGROUND OF THE INVENTION
This invention relates to the detection of chemical vapors distributed in a region of the atmosphere. More specifically, the present invention is a system for the detection of chemical vapors in the atmosphere that directly exploits, in a novel manner, the basic physical principles of quantum mechanical absorption and emission by molecular structures at fixed frequencies determined by the physics of the particular molecular structure. Molecules exhibit the absorption of energy at discrete electromagnetic frequencies due to the quantum effect. Likewise, molecules exhibit emission of energy at discrete frequencies due to the quantum effect. In both absorption and emission, the energy absorbed or emitted is related to the frequency of the absorbed energy or the emitted energy by the fundamental physical constant known as Planks constant, denoted h;
Energy=h×(frequency)
Because of the quantum effect, a particular molecule in isolation will absorb energy at a limited number of fixed discrete frequencies only. These frequencies are known as absorption bands or absorption frequencies. A large number of chemicals have molecular structures having a multiplicity of absorption bands in the microwave frequency region from approximately one Gigahertz (10 9 Hertz) to 100 Gigahertz (10 11 Hertz). It is to these chemicals which may exist as a vapor distributed in the atmosphere that this present invention is addressed. National Bureau of Standards Monograph No. 70, entitled "Microwave Spectral Tables", Volume I through Volume 5, 1968, lists several hundred chemicals having absorption bands in the above mentioned region along with a tabulation of the absorption bands for each of the listed chemicals.
As background to the present invention, the following references are hereby cited:
In 1939, U.S. Pat. No. 2,165,214 was issued to Blau, et al. Blau et al teaches a method for the direct use of absorption band measurements in geophysical prospecting. Blau et al teaches the use of various portions of the electromagnetic spectrum, including light as well as the aforementioned microwave region, to directly measure the absorption frequencies.
In 1972, U.S. Pat. No. 3,651,395 was issued to Owen et al. Owen et al teaches the use of a system which exploits the frequency of radiation from excited hydrocarbon molecules to locate oil and gas deposits. Owen et al teaches the use of the frequency shift that results from highly exciting molecules causing them to emit at a frequency shifted by an amount determined by physics of the molecules from that of the frequency of the exciting energy. This frequency shift physical phenomena is known in the art as Raman Spectroscopy, see "Raman Spectroscopy" by D. A. Long, McGraw Hill, 1977 and, in general, do not correspond to the absorption frequencies.
In 1974, U.S. Pat. No. 3,803,595 was issued to McMillin. McMillin teaches the use of a poly-static system to locate molecules derived from petroleum.
In 1978, U.S. Pat. No. 4,100,481 was issued to Gournay. Gournay teaches a system for detecting and locating hydrocarbon gasses by the means of transmission and reception devices coupled with wide bandwidth and multiple channel narrow band processing devices.
In 1979, U.S. Pat. No. 4,132,943 was issued to Gournay, et al. Gournay, et al teaches an improvement over Gournay to determine the magnitude of the concentration of the hydrocarbon gas.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts graphs of the absorption and emission bands for a typical chemical vapor and reveals the basic system approach of this invention for exploiting the physical phenomena.
FIG. 2 depicts the block diagram of the invention for the detection of chemical vapors in the atmosphere.
FIG. 3 depicts a detailed block diagram for a preferred embodiment of the invention.
FIG. 4 depicts an alternative embodiment for the present invention.
FIG. 5 depicts an alternative embodiment of the invention for use with continuous wave transmission.
SUMMARY OF THE INVENTION
In order to adequately summarize the present invention, it is necessary to examine the physical theory that underpins the invention. In FIG. 1(A), a graph of a typical absorption frequency for a given molecule in isolation is shown. For example, if the chemical is Ketene, the frequency of absorption, denoted FA, shown in FIG. 1(A), can be either 8521.5 MHz, 9188.2 MHz or 9562.7 MHz. In general, a predetermined chemical will have a multiplicity of absorption bands. In the present invention one of the multiplicity of absorption bands is selected for use. In effective isolation (i.e., at low pressure and with molecules from no other chemicals present), the bandwidth of the absorption frequency as show is extremely narrow. In other words, the molecules will absorb energy only if it is almost exactly at the absorption frequency, FA. However, if the molecules are under pressure (such as that of the normal atmosphere) in the presence of other vapors (such as the Oxygen and Nitrogen of the normal atmosphere), the absorption band broadens as shown in FIG. 1(B). The broadened absorption band shape can be interpreted as a probability density function showing the proportion of molecules of the given chemical under pressure that will absorb energy in any given frequency region F' to F'+ΔF'.
Once the energy is absorbed, the normal energy distribution of the molecules, determined in part by the ambient pressure and temperature, is changed. The excited molecules will then tend to redistribute themselves into their normal ambient energy levels. In doing so, they will also radiate the absorbed energy in a band of frequencies according to the distributions shown in FIG. 1(B). Notice that the bulk of the energy will be emitted in the frequency region around FA, the absorption frequency of the isolated molecule.
The present invention provides a system to take maximum advantage of the basic physical laws described above. Transmission of energy is provided at a frequency F t , offset from FA, one of the absorption frequencies of the chemical vapor selected for detection, by an amount F o . The offset frequency F o is selected to place the transmission frequency F t as close to FA as possible, to maximize absorption, without causing the transmitted spectrum to unduly overlap the receiver bandwidth (see FIG. 1(C)). The exact value of F o is not critical in that it does not control or affect the value of FA; that is to say, FA has a fixed value determined by the molecular structure of the selected chemical vapor and is not a shift in frequency as in Raman spectroscopy. The bandwidth of the receiver is established to be wide enough to span the peak of the broadened absorption band to maximize the received energy. The receiver bandwidth spans the frequency region around FA as shown in FIG. 1(C).
An object of the present invention is to provide a controlled, tunable system for the selective detection of each of a multiplicity of predetermined chemical vapors in the atmosphere.
A further object of the present invention is to provide a novel and improved means to remotely detect the presence of a given chemical vapor in a region of the atmosphere.
A further object of the present invention is to provide an improved means to detect the presence of gas and oil deposits through the detection of hydrocarbons in the atmosphere indicative of subsurface deposits of oil or gas.
A further object of the present invention is to provide a novel means to detect leaks in the transmission and distribution systems for natural gas.
A further object of the present invention is to provide a means to detect predetermined polluting chemical vapors in the atmosphere.
The key advantages of the present invention are the single means for tuning control and the direct measurement of the selected absorption frequency by means of a single channel, narrowband device.
The foregoing and other objects, features and advantages of the invention will be better understood from the following detailed description.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The function and operation of the present invention can be understood by reference to FIG. 2. Before beginning a detailed description of the function and operation of the invention, however, the following terms require definition:
FA is the frequency of the selected absorption band of the predetermined chemical vapor to be detected
Fif is the tuned frequency of narrowband IF 23 in FIG. 2, a design parameter normally in the convenient range 1 to 80 MHz
Flo is the local oscillator frequency and is tuned to Flo=FA-Fif, therefore Fif=FA-Flo (alternatively Flo can be Fif+FA; the firm requirement is that Fif=|FA-Flo|)
Ft is the transmit frequency and is selected so that Ft=FA+Fo (Ft will later be further defined)
Fo is the offset frequency and is defined by Fo=Fd-Fif
Fd is the transmitter delta frequency such that Ft=Flo+Fd=FA+Fo, i.e., Fd=Fo+Fif
In operation, an absorption band of the chemical vapor to be detected is selected (for example, from NBS monograph 70) and the frequency of the selected absorption band, now denoted FA, is inserted into Frequency Control 17. Frequency Control 17 causes Tunable Local Oscillator 15 to produce a signal on Conductor 29 having a frequency Flo, the difference between FA and Fif. The signal on Conductor 29 is coupled to Tunable Transmitter 13, causing it to produce a pulsed output signal having a frequency Ft on Conductor 33. The signal on Conductor 33 is coupled to Antenna 11 and from there radiated into the atmosphere. Antenna 11 is a directional antenna capable of directing the radiated signal in a desired direction and consequently causing the emitted energy to be directed to the region of the atmosphere to be investigated. Transmit-Receive Switch 19 prevents the high energy pulse produced by Transmitter 13 from entering Mixer 21. The action of Transmit-Receive Switch 19 is well known in the art and is discussed in "Introduction to Radar Systems" by M. Skolnik, McGraw Hill, 1962. The pulsed signals produced by Transmitter 13 are normally periodic in nature; however, periodicity is not a necessary condition for the operation of the invention; the pulses may occur in an aperiodic fashion. Further, the pulse rate may be established by an external timing control without deviating from the intent of the invention. The function of an exterior timing control will be discussed herein in a later portion of this specification. Tunable Local Oscillator 15, Tunable Transmitter 13, Antenna 11, and the action of TR Switch 19 in conjunction with their indicated interconnections form a tunable transmitting means for directing transmitted energy at the region of the atmosphere to be investigated.
During the periods in which pulsed signals are not being transmitted, Antenna 11 receives electromagnetic energy from the region of the atmosphere upon which it is directed. These signals are coupled to Transmit-Receive Switch 19 and are thereby passed to Mixer 21. The action of Mixer 21 is to produce an output signal on Conductor 31 whose frequency is the difference between the frequency FA of the received signal and the frequency Flo of the output of Local Oscillator 15 which is coupled on Conductor 29 to Mixer 21. Said signal on Conductor 31 is coupled to Narrow Band IF 23. Narrow Band IF 23 is a tuned amplifier having a pass band around the tuned frequency such as to pass only signals in the frequency region of a signal resulting from signals with frequency in the region of FA received at Antenna 11. In other words, if the predetermined chemical vapor is present in a region of space upon which the transmitted energy is directed, the chemical vapor will emit signals in the region around the frequency FA as shown in FIG. 1(C). In this case, the signals appearing on Conductor 31 are, as defined herein above, in the region around, FA - Flo. Consequently, signals resulting from the reception at Antenna 11 of signals in the frequency region indicative of the presence of the predetermined chemical vapor will be amplified by Narrow Band IF 23. The output of Narrow Band IF 23 is coupled to Detector 25. The function of Detector 25 is to produce a signal indicative of the power contained in the received signal. The design of detectors of this type, such as square law detectors, is well known in the electronic art. There are a number of different, conventional and well known detectors which can be used without deviating from the spirit or intent of this invention. The signal produced by Detector 25 is then coupled in Conductor 27 to one of a number of appropriate display devices. Any number of conventional display devices, such as an oscilloscope, strip recorder, voltage meter, audible indicator or other well known displays can be used. One such conventional display can be the well known Planned Position Indicator, or as it is called in the art, "The PPI Radar Display". Displays of this type require synchronization with the transmitting function to produce a coherent display. In cases where such displays are to be used, the timing control indicated in FIG. 2 would be used for synchronization.
Antenna 11, Transmit-Receive Switch 19, Mixer 21, Narrow Band IF 23, Detector 25, Tunable Local Oscillator 15, and their associated inter-connections form a tunable receiving means which can be directed at the desired region of the atmosphere to be investigated for the presence of the predetermined chemical vapor.
Frequency Control 17 provides a simple and direct means to tune the system of FIG. 2 to detect the presence of the desired predetermined chemical vapor. Frequency control 17 is coupled to the Transmitting means and to the Receiving means by its control of Tunable Local Oscillator 15, a component of both the transmitting and the receiving means.
The present invention has several advantages over the prior art as can be readily understood from the description of the system as depicted in FIG. 2. The following are some of the key advantages of the present invention: The system as depicted in FIG. 2 directly detects the presence of a chemical vapor in accordance with the established laws of Physics from a single location. A single means is provided for tuning control of the transmitting and receiving means so that the system can be quickly and directly tuned to detect the presence of the desired predetermined chemical vapor. The present invention provides a means to detect the predetermined chemical vapor by exciting and detecting an absolute frequency emission, FA, of the chemical vapor and does not depend upon detection of relative frequencies or frequency shifts as taught by Owens et al. The receiving means of the present invention directly detects signals in the frequency region of the absorption band and does not require wide band and multiple, narrow band processing for detection as taught by Gournay.
FIG. 3 shows the details of a specific embodiment of the system depicted in FIG. 2, for use when a large number of chemical vapors are of interest. Antenna 11, Transmit-receive Switch 19, Mixer 21, Narrow Band IF 23, and Detector 25 function and provide the same operational features as described in conjunction with FIG. 2. As shown in FIG. 3, Tunable Transmitter 13 comprises Transmitter Pulse Amplifier 47, Voltage Control Oscillator 45, Low Pass Filter 43, Phase Detector 41, Delta Oscillator 39, and Image Rejection Mixer 37. The theory and practice of image rejection mixers is discussed in "Radar Handbook" by M. Skolnik, McGraw Hill, 1970 (see page 10 of Chapter 5). An image rejection mixer is required to prevent the incorrect sideband from causing the transmitter to tune to the wrong value of frequency. Image Rejection Mixer 37, Phase Detector 41, Low Pass Filter 43 and Voltage Coantrol Oscillator 45 along with their associated interrconnections form a phase locked loop. The action of the phase locked loop and the associated Delta Oscillator 39 are as follows. Local Oscillator signal Flo on Conductor 29 is mixed in Mixer 37 with the signal on Conductor 49 produced by Voltage Control Oscillator 45. The output of Mixer 37 on Conductor 53 is the difference between the frequency of the output of Voltage Control Oscillator 45 and Local Oscillator signal Flo on Conductor 29. This difference signal on Conductor 53 is coupled to Phase Detector 41. The output of Delta Oscillator 39 is also coupled to Phase Detector 41. The frequency of the signal produced by Delta Oscillator 39 is Fd, as defined previously herein. The output of Phase Detector 41 which appears on Conductor 51 is a voltage proportional to the phase difference between the local oscillator signal Flo on Conductor 29 and the Voltage Control Oscillator signal on Conductor 49. The signal on Conductor 51 is passed through Low Pass filter 53 which acts as a leaky integrator to smooth the phase difference signal produced by Phase Detector 41. The output of Low Pass Filter 43 is used to control Voltage Control Oscillator 45. The frequency of the signal produced by Voltage Control Oscillator 45, under control of the signal of Low Pass Filter 43, is proportional to the voltage of the output of Low Pass Filter 43. The action of the phase locked loop is similar to a servo mechanism loop in that when the phase of the signal on Conductor 53 produced by Mixer 37 and the phase of the output of Delta Oscillator 39 are equal, the loop is in the lock condition and the frequency of the signal produced by Voltage Control Oscillator 45 is equal to Flo+Fd. As defined previously herein, Flo+Fd is equal to FA+Fo which is in turn equal to Ft, the desired transmitting frequency. The output of Voltage Control Oscillator 45 is coupled to Transmitter Pulse Amplifier 47. Transmitter Pulse Amplifier 47 uses the Voltage Control Oscillator 45 output on Conductor as its transmitting reference signal and produces amplified pulses of the same frequency on Output Conductor 33. The timing of the pulses can be controlled either through an external timing control as shown in FIG. 3 or by means of an internal oscillator control.
The function of Tunable Oscillator 15 and Frequency Control 17 depicted in FIG. 2 are provided in the embodiment of FIG. 3 by a Digital Frequency Synthesizer 35 and its control input. There are commercially available frequency synthesizers such as the Hewlett-Packard Model HP8672A which will perform the function required by Digital Frequency Synthesizer 35. When using a direct frequency synthesizer, such as the HP8672A, the frequency is inserted by means of the device's input control panel, thereby providing the function of Frequency Control 17 of FIG. 2.
FIG. 4 depicts a detailed block diagram of an alternate embodiment of the present invention. This alternate embodiment as depicted in FIG. 4 is particularly useful when there are a limited number of predetermined chemical vapors of interest. Again, Antenna 11, Transmit-Receive Switch 19, Mixer 21, Narrow Band IF 23, and Detector 25 serve the same functions as previously described herein. Tunable Local Oscillator 15 comprises Combiner 55 and a multiplicity of individual local oscillators 57. Since the utility of the system depicted in FIG. 4 is in cases where there are a limited number of chemical vapors of interest, a limited number of local oscillators set at the appropriate Flo suffice; therefore, there will be one local Oscillator 57 for each of the chemical vapors of interest, tuned to the appropriate frequency for detecting the appropriate absorption band associated with the given chemical vapor. The outputs of Local Oscillators 57 are coupled to Combiner 55 which produces the selected output Flo on Conductor 29.
Tunable Transmitter 13 comprises Transmitter Amplifier 65, Modulator 63, Combiner 61 and Oscillators 59. Each of the multiplicity of Oscillators 59 is tuned to produce the required frequency Ft for the individual chemical vapors of interest. The outputs from Oscillators 59 are coupled to Combiner 61 which produces as its output the selected signal from the selected one of Oscillators 59. The output from Combiner 61 is coupled to Modulator 63 which in conjunction with the timing control input produces pulses of frequency Ft. The output of Modulator 63 is coupled to Transmitter Amplifier 65 which amplifies the pulses produced by Modulator 63 and couples these to Antenna 11 on Conductor 33.
Multiple-ganged Switch 67 provides the function of Frequency Control 17 described in FIG. 2. Thus, through the use of Switch 67 the system can be controlled to produce the desired transmit frequency Ft and to receive and to detect signals at the desired frequency FA.
It is possible to have an alternate definition of Ft consistent with the functioning of the invention as defined herein above in relation to FIG. 1, FIG. 2, FIG. 3, and FIG. 4. The alternate definition for Ft is that Ft is equal to FA minus Fo. It can be readily seen from FIG. 1 that the transmit frequency Ft can also be lower in frequency than Fa and still cause absorption of energy by the molecules of the chemical vapor. Again, according to the Physical Laws of absorption and emission of chemical vapors under pressure, the emission of energy will be distributed in frequency according to the curve shown in FIG. 1(B). In other words, the significant portion of defining Fo is that its magnitude be such that Ft is close to FA, but sufficiently displaced such that Ft does not overlap the frequency region set by the receiving means bandwidth shown in FIG. 1. Thus, given the magnitude of Fo, the value of Ft can be now defined as FA±Fo or in mathematical terms as the algebraic sum of FA and Fo; where the magnitude of Fo is set but its sign can be arbitrarily selected.
The system embodiments of the present invention as depicted in FIG. 2 and described in detail in FIG. 3 and FIG. 4 all employ pulsed emissions to excite the molecules of the predetermined chemical vapor. The advantage of using pulsed emissions is that greater transmitted power can be achieved and consequently greater detection ranges can be achieved than those possible if continuous waves or CW transmissions were used.
However, there are disadvantages associated with pulse transmissions. The ideal frequency power spectrum of a periodic train of rectangular RF pulses has the form
sin π
fT/πft
where f is the RF frequency and T is the width of the pulse. Examination of this function reveals that as T, the width of the pulse becomes smaller (i.e., narrow pulse width) the spectrum emitted spreads in frequency around the transmitted frequency f. Spreading of the spectrum causes interference with the detection of emission from the chemical vapor under investigation (refer to FIG. 1(c)). Therefore, wider pulses are desired to reduce the spread of transmitted energy into the receiver passband. In general, pulses with widths in the order of one to two microseconds are desirable to allow a small value of Fo without creating large interference at FA. Transmit-receive Switch 19 closes off the receiving function during the pulse transmission. Thus, it can be seen that a blind zone exists for a minimum of one-half the pulse width. Further, after the cessation of the pulse, Transmit-receive Switch 19 has a recovery period before reception can begin that is generally in the order of one to two microseconds. The resulting blind region for a one microsecond pulse is a radius around the antenna of approximately one quarter of a nautical mile or about 1500 feet. In high power pulse systems intended for wide areas (i.e., long ranges) use, this is a minor disadvantage. However, in some applications (e.g., searching for leaks in natural gas distribution systems, or analyzing pollution vapors in a confined area) this can be a serious disadvantage. This disadvantage can be overcome some what in a pulse system through the use of a circulator to couple Tunable Transmitter 13 and Mixer 21 to Antenna 11. The use of circulators in this application are well known in the art and is adequately discussed in "Radar Handbook" by M. Skolnik, McGraw-Hill, 1970, Chapter 8. This approach does limit, however, the peak power that can be emitted and therefore limits the range of the system. The embodiment of the present invention depicted in FIG. 5 overcomes the disadvantage of a blind region by the use of continuous wave, referred to as C.W., transmission rather than pulse transmission. The use of a C.W. mode of operation as an alternative embodiment of the present invention requires further definitions. In the C.W. embodiment of FIG. 5,
Fif=fo
Flo=Ft
and as before,
Ft=FA+Fo
or
Ft=FA-Fo
(i.e., Ft is the algebraic sum of FA and Fo).
The following description of the embodiment depicted in FIG. 5 will assume Ft=FA+Fo, however, either the sum or the difference (i.e., the algebraic sum) is within the scope of the present invention.
With reference to FIG. 5, Antenna 11, Narrowband IF 23, and Detector 25 serve the same functions as described above herein. Tunable Oscillator 73 provides a C.W. signal at frequency Ft as defined by frequency Control 17. Tunable Oscillator 73 produces output signal on Conductor 77. Conductor 77 couples output of Tunable Oscillator 73 to Circulator 69. The action of Circulator 69 is to couple the signal on Conductor 77 to Conductor 79 but not to Conductor 81. Conductor 79 couples the signal produced by Tunable Oscillator 73 to Antenna 11. Thus, Tunable Oscillator 73, Circulator 69, and Antenna 11, together with conductors 77 and 79 comprise a tunable transmitting means. Signals received by Antenna 11 are coupled to Circulator 69 by means of Conductor 79. The action of Circulator 69 is to couple signals from Antenna 11 on Conductor 79 to Conductor 81, but not to Conductor 77. Conductor 81 couples the received signals to Mixer 71. To perform the mixing function, Mixer 71 requires not only the signal to be heterodyned but a local oscillator signal. Because small missmatches of impedance always occur at junctions, some of the signal at frequency Ft produced by Tunable Oscillator 73 is reflected from the junction of Antenna 11 and Conductor 79. In practice, it is often necessary to deliberately increase the impedance missmatch to provide sufficient reflection. The reflected signal is coupled by Circulator 69 to Mixer 71 by way of Conductor 81, thereby providing the second signal needed for the heterodying operation. The output of Mixer 71 is coupled to Narrowband IF 23 by means of Conductor 31. If a signal having energy in the region around FA is received by Antenna 11, Narrowband IF 23 will produce an output in the pass band of Narrowband IF 23. This output of Narrowband IF 23 is coupled to Detector 25 as described hereinabove.
By the functions described in the previous paragraphs, it can be seen that Antenna 11, Circulator 69, Tunable Oscillator 73, Mixer 71, Narrowband IF 23, and Detector 25 along with their interconnections comprise a tunable receiving means. Frequency Control 17 is coupled to the tunable transmitting means and to the tunable receiving means through its effect on Tunable Oscillator 73.
The output of Detector 25 maybe be coupled to one or more forms of display devices by means of Conductor 27 without departing from the intent of the present invention.
While specific embodiments of the present invention have been shown and described, other modifications are within the spirit and scope of the invention; therefore, the invention is limited only by the following claims.
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The present invention is a system for the detection of chemical vapors in the atmosphere based on detecting radiation from the molecules of the vapor. The radiation is induced by energy transmitted from the system at a frequency close to an absorption frequency of the molecules of the vapor to be detected. The system provides a easily used means for the excitation and detection of the vapor by virtue of the common tuning control of the system and the direct detection of radiation at the absorption frequency excited by the transmitted energy.
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BACKGROUND AND SUMMARY OF THE INVENTION
The present invention is directed to an implantable dental fixture. The fixture is preferably made of a biomechanical material such as titanium or a titanium alloy. This fixture is designed to be implanted in the maxilla or mandible of a patient and becomes the base, or root, for an artificial tooth or denture to be mounted thereon. This invention relates to the implant fixture itself and the drill tool geometry that is used to remove bone to form a pilot hole for the fixture. Commonly assigned U.S. patent application Ser. No. 07/964,747 filed Oct. 22, 1992, now U.S. Pat. No. 5,302,125, which is directed to attachment and adjustability features between the fixture and the abutment, is hereby incorporated by reference.
In some other implant fixture designs, specifically other self-tapping versions, a hole is bored into the bone at a diameter approximating the minor or base diameter of the thread. The top portion of the hole is counterbored or otherwise pre-enlarged to the major diameter of the implant fixture so that a relatively wide unthreaded portion of the implant can be placed into the enlarged hole with a precise fit in order to prevent any bacterial leakage (known as micro-leakage) into the surgical site. The fit between the implant fixture and hole is very important to the healing of and integration of the implant fixture into the bone tissue. This procedure, although somewhat effective, does not take advantage of the hard cortical bone layer that surrounds the perimeter of the mandible and maxilla as a medium in which to anchor.
The present invention uses the very dense cortical bone layer to support the implant fixture with integral self-tapping screw threads. The hole diameter for the self-tapping implant fixture is approximately the pitch diameter of the thread. Pre-enlarging of the top portion of the hole is not necessary with the system of the present invention. The surgical drill has a smaller diameter tip to penetrate the inferior border of cortical bone for support. This design does not simply rely just upon the use of cancellous (soft spongy) bone for mechanical stability. Rather, the present implant engages in the cortical bone by having an increased thread height, a smaller lead-in angle on the bottommost portion, an outwardly tapered minor thread diameter so that all the threads end at least approximately 0.015" below the uppermost portion of the fixture, and a 0.010" highly polished collar above the threads that is approximately 0.010" larger in diameter than the major thread diameter. In a first embodiment, the implant fixture preferably has three equally spaced cutting flutes that run the length of the threaded portion and taper outwardly to match the taper angle of the minor diameter of the threads and stop below the 0.010" highly polished collar. With this configuration, the total threaded portion of the implant fixture mechanically grabs both cortical and cancellous bone giving it maximum mechanical stability without risking any bacterial leakage into the upper region of the bone. As the implant fixture is screwed into the bone, it compresses and cuts bone at three points separated by 120° as a result of engagement of the three cutting flutes and the outwardly tapered minor diameter of the thread.
In an alternative second embodiment, similar results are provided by a first cutting flute on the tapered entry portion of the threaded implant fixture and a second cutting flute on the portion of the screw containing the major diameter threads. This secondary cutting flute extends at least partially into the region of the fixture where the minor diameter of the threads is increasing.
Various other features, advantages and characteristics of the present invention will become apparent after a reading of the following detailed description thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The Figures depict the preferred embodiments of the present invention with like parts bearing like reference numerals, in which
FIG. 1 is a side view of a first embodiment of the self-tapping dental implant of the present invention;
FIG. 2 is a bottom view of the embodiment shown in FIG. 1;
FIG. 3 is a cross-sectional side view as seen along line 3--3 of FIG. 2;
FIG. 4 is a side view of the stepped drill bit used in the installation process of the present invention;
FIG. 4a is a perspective view of an end portion of the drill bit shown in FIG. 4;
FIG. 5a is a cross-sectional end view of a mandible drilled using the stepped drill bit of the present invention and awaiting installation of the fixture;
FIG. 5b is a cross-sectional end view of the mandible shown in FIG. 5a with the implant installed;
FIG. 6 is a break away cross-sectional side view showing an implant with fixture attached;
FIG. 7a is a side view of a second embodiment of the fixture of the present invention;
FIG. 7b is a top view of the second embodiment of the fixture;
FIG. 8a is a side view of a third embodiment of the implant fixture of the present invention;
FIG. 8b is a schematic side view of that third embodiment with a drive element attached; and
FIG. 8c is a top view of the drive element shown in FIG. 8b.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first preferred embodiment of the self-tapping dental implant fixture of the present invention is depicted in FIGS. 1-3 generally at 10. A thread 12 is formed on the external periphery of fixture 10 for advancing and anchoring into an appropriate portion of a patient's jaw bone (this term shall be used herein to collectively refer to both mandibular and maxillary bone needing dental prosthetic implants). There are four zones A-D of fixture 10: zone A is the entry region having blunt end 21, a uniform minor or base diameter d 1 and a tapering major thread diameter or height h 1 ; zone B which has a uniform base diameter d 1 and a uniform major thread diameter h 2 ; zone C which has a tapering base diameter d 2 and a uniform thread height h 2 ; and, zone D which has a maximum diameter d 4 having an axial length or thickness t 1 on an uppermost region and is threadless throughout its thickness t 1 .
Preferably three thread-cutting grooves 14 are cut diametrically (see FIG. 2) into threads 12 at 120° intervals about the periphery of fixture 10. In this embodiment, grooves 14 are continuous and each extends through at least portions of each and, preferably, through substantially all of zones A-C. Grooves 14 extend below the base diameter d 1 in zones A and B and taper in zone C at a rate which is most preferably substantially the same rate as outwardly tapering base diameter d 2 . Grooves 14 do not extend into zone D so that maximum diameter d 4 of zone D can serve as a seal to prevent micro-migration into the bone around the implant 10. Because of the narrow profile of zone D, the threads of zone C can engage in the upper cortical bone as discussed below.
A longitudinal bore 16 formed in fixture 10 has a thread portion 18, an undercut 20, and a beveled counterbored region 22. Threaded portion 18 can be utilized to both attach the abutment (not shown) to fixture 10 and to attach a drive element 50 (FIG. 8b) utilizing a securement fastener 60 to permit drive rotation of the fixture 10 into the patient's jaw bone. A hex drive socket (not shown) engages external hex 52 to rotate fixture 10 into jaw bone 11 (FIG. 5b) with thread-cutting grooves 14 removing the bone tissue necessary to form female grooves for receiving threads 12. The method of installing implant 10 will be detailed in connection with FIGS. 4, 4a, 5a and 5b.
FIGS. 4 and 4a depict a stepped drill bit 30 useful in the installation process. Drill bit 30 has a tip 32 having a large included angle β. β is preferably in the range of between 110° and 125° and most preferably is an angle of 118°. This large included angle minimizes the amount of cortical bone 13 (FIGS. 5a and 5b) on the inferior border 15 that must be removed to accommodate the tapered entry region A of thread 12. The cortical bone 13 surrounding the spongier cancellous bone 17 in the center, is harder and the key to the present installation process is to maximize surface contact between the fixture 10 and cortical bone 13 to ensure optimum locking to reduce the possibility of loosening or thread backout. Chip removal slot 34 extends over a substantial portion of the drill bit's length to promote removal of debris. Tip 32 has a smaller diameter d 5 than the diameter d 6 of the main body 36 of drill bit 30. This also reduces the amount of cortical bone 13 removed from the inferior border 15. Leading edge 38 of drill tip 32 is hooked to increase its bite and to encourage chips to curl and breakoff. While FIGS. 4a and 4b depict the drill bit as having a single flute, bit 30 may have two or even three equally spaced flutes about its periphery.
As seen in FIG. 5a, stepped drill bit 30 is used to form a stepped hole 19 in jaw bone 11. The deepest portion 23 of hole 19 leaves adequate thickness of cortical bone 13 underlying (or overlying, in the case of maxilla) the implant fixture 10 to avoid breakthrough under maximum jaw pressure. Then a hex tool (not shown) is fitted upon external hex 52 (FIGS. 8b and 8c) and the self-tapping implant fixture 10 is rotated into the pre-drilled hole. By using a stepped drill, a second counterboring procedure is made unnecessary. Further, unlike some implant systems, the implant fixture 10 of the present invention taps its own threads in jaw bone 11 as it is rotated. This makes unnecessary an additional step of tapping a thread into the jaw bone prior to implant fixture insertion.
As seen in FIG. 5b, the tapered leading thread having diameter d 1 anchors in cortical bone 13 in inferior (or superior, in the case of maxilla) border 15. The highly polished threadless region of zone D which has a height of 0.010", engages superior cortical bone 15'. Implant 10 effectively maximizes the peripheral surface area in engagement with the higher density cortical bone and significantly reduces the possibility of loosening. Further, the maximum dimension d 4 at the upper reaches of the implant fixture 10 is threadless and exceeds the diameter d 5 by at least 0.010" reducing the risk of micromigration into the surgical region. As the implant fixture 10 is permitted 4-6 months for the bone to grow around and capture it, the outward pressure exerted over substantially the entire length of the implant fixture 10 is believed to accelerate restorative bone growth.
FIG. 6 depicts implant 10 having an abutment 40 being initially installed in jaw bone 11 and secured thereto by securement fastener 62. The position of skin cover over bone 11 is shown at 11'. Tapered surface 44 on member 62 engages tapered surfaces 46 on abutment 40 forcing rear surfaces 48 of fingers 49 (as taught in U.S. Pat. No. 5,302,125) underneath undercut 20 creating mechanical interlock between fixture 10 and abutment 40 making it impossible for these elements to be separated without removal of threaded member 62. Following tightening of threaded member 62, the upper protruding portion 43 may be ground off to match the slope of surface 47 on abutment 40. A dental prosthesis (not shown) is then attached to abutment 40, as by casting it in place from a moldable material.
FIGS. 7a and 7b depict a second embodiment 10' of the present invention. In this embodiment, thread-cutting grooves 14' are formed in two portions. First portion 14a' begins in zone A which has uniform minor diameter d 1 and tapering major thread diameter h 1 and extends into zone B which has the uniform minor thread diameter d 1 and uniform major thread height h 2 . Second thread-cutting groove portion 14b' extends substantially the entire length of zone C. This second thread-cutting groove 14b' tapers outwardly substantially at the same rate as minor thread diameter of zone C. These tapers serve to expand the diameter of the tapped hole in the proximal corticular bone 15' as well as the cancellous bone 17 while the tapered zone A is tapping and anchoring in distal corticular bone 15. Because diameter d 4 of highly polished segment of zone D is the maximum diameter of implant 10', this region can serve to seal the bone region around the implant 10' against micro-migration. Further, it is believed the larger compressive pressure exerted by threads 12' induces more rapid bone growth following installation of the implant 10'. As shown in FIG. 7b, grooves 14' may be limited to two diametrically opposed thread-cutting grooves, although the three equally spaced grooves of the first embodiment is actually preferred.
FIGS. 8a, 8b, and 8c depict a third embodiment of the invention. The embodiments of FIGS. 1-7b depict systems in which flexible fingers 49 are formed on abutment 40. However, it may be desirable in certain applications to form the flexible fingers 49" directly on the top portion of implant 10", thereby reversing the undercut/locking roles performed by the interengaged portions of implant 10" and abutment (not shown). While this embodiment is shown with the split groove configuration (14a" and 14b") of the second embodiment, it will be understood a single continuous groove of the type utilized in the FIG. 1 embodiment could be used, as well. As has previously been discussed, FIGS. 8b and 8c show attachment of an external hex drive element 50 by securement fastener 60. This provides an enlarged, and therefore, superior drive surface in the form of hex surfaces 52 so the drive force can be more widely distributed than if an internal hex is used. Further, by providing the driver 50 on a separate element, the surfaces can be more robust since element 50 can be made of a higher strength material and need not be of a biomechanical material since it shall be removed once implant 10" has been installed.
Various changes, alternatives, and modifications to the specific embodiments discussed above will become apparent to one of ordinary skill in the art following a reading of the foregoing specification. It is intended that all such changes, alternatives, and modifications as come within the scope of the appended claims be considered part of the present invention.
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A self-tapping dental prosthetic implant has a blunt leading end, a tapered first section which has a uniform minor diameter and a uniformly increasing major diameter, a second section having uniform minor and major thread diameters, a third section with a uniform major thread diameter and a outwardly tapering minor diameter and a fourth section which has a diameter larger than any other segment and a relatively low profile (i.e., short axial length). A thread-cutting groove extends over a substantial portion of the threaded length of the implant. A stepped drill with a tip having a large included angle is used to drill a pilot hole permitting anchoring in the proximate and distal portions of cortical bone by the threaded implant.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of application Ser. No. 09/017,137, filed Feb. 2, 1998 now U.S. Pat. No. 6,144,049.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a field effect transistor and a method of fabricating the same, and more particularly to a field effect transistor as a highly reliable, high-performance chemical compound electronic device operating in a range of microwaves and millimeter waves, and a method of fabricating the same.
2. Description of the Related Art
In these days, ternary and quaternary mixed crystal semiconductor such as InGaAs and InGaAsP have attracted attention. Among them, InGaAs matching in lattice to an InP substrate is in particular suitable to optical devices and material of which field effect transistors are made. In particular, a field effect transistor employing two-dimensional electron gas at a hetero-interface between InP and InAlAs has been much studied. The reasons why InGaAs is promising as an electron transfer device in comparison with GaAs and so on are as follows:
(a) a peak value at electron drift velocity is greater;
(b) mobility of an electron at a low intensity electric field is greater;
(c) it is easier to form ohmic electrodes with the result of smaller contact resistance;
(d) greater overshoot in an electron speed can be expected;
(e) smaller noise caused by root scattering; and
(f) better characteristics with respect to an interface with insulating materials. In addition, it is one of major reasons to be able to accomplish a two-dimensional electron gas device.
A field effect transistor employing two-dimensional electron gas at an interface between InGaAs and InAlAs is presently considered promising as a high performance microwave milliwave device, and is researched and developed. In particular, the above-mentioned field effect transistor has been confirmed to be effective as a low-noise device in experiments. For instance, as reported by K. H. G. Duh et al. in “A Super Low-Noise 0.1 μm T-Gate InAlAs-InGaAs-InP HEMT”, IEEE MICROWAVE AND GUIDED WAVE LETTERS. Vol. 1, No. 5, May 1991, pp. 114-116, noise figure of 1.2 dB and associated gain of 7.2 dB at 94 GHz in room temperature have been confirmed. The device having been reported by Duh was made of material accomplishing lattice match on an InP substrate, that is, In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As, and material defining In composition. In the device, two-dimensional electron gas is formed in the In 0.53 Ga 0.47 As layer.
In order to enhance performance of the device, for instance, an attempt was made by G. I. NG et al. in “Improved Strained HEMT Characteristics Using Double-Heterojunction In 0.65 Ga 0.35 As/Ino 0.52 Al 0.48 As Design”, IEEE ELECTRON DEVICE LETTERS, Vol. 10, No. 3, March 1989, pp. 114-116, where In composition in an InGaAs layer constituting a channel was arranged to have a figure greater than 0.53.
Recently, various high performances of a device have been reported in the field of InAlAs/InGaAs family hetero-junction field effect transistor. On the other hand, thermally unstable factors have been also reported. That is, impurities such as fluorine which is not a constituent of a device enter an epitaxial layer from outside to thereby inactivate donor in an impurity containing InAlAs layer usually used as a donor layer.
For instance, Hayafuji has reported degradation of a device caused by fluorine in “Thermal stability of AlInAs/GaInAs/InP heterostructure”, Applied Physics Letters, Vol. 66, No. 7, February 1995, pp. 863-865. For another instance, Takahashi has reported degradation of a device caused by oxygen in “Thermal Stability of Al 0.48 In 0.52 As/Ga 0.47 In 0.53 As/InP Heterostructure and its Improvement by Phosphidization”, Proceedings of 7th International Conference of InP and Related Materials, 1995, pp. 597-600.
Fujihara et al. reported in Technical Report of IEICE ED95-105, pp. 13-20 that impurities entering an epitaxial layer are reduced in an amount by decreasing a composition rate of Al in an InAlAs Schottky layer formed on an InAlAs donor layer. That is, when a donor layer is composed of InAlAs, the thermal instability may be eliminated by forming a barrier layer on the donor layer for preventing impurities from entering to the donor layer. Fujihara reported conducting experiment in which there were formed samples of InAlGaAs Schottky layers containing no impurities and having different composition rates between Al and Ga, and the samples stood in heated condition. The result of the experiment was that as a composition rate of Al was decreased, fluorine entering an epitaxial layer was reduced in an amount and further a reduction of a sheet electron density was stopped.
As an example for enhancing reliability of a device in a similar manner, Fujihara et al. suggested a field effect transistor in “Thermally stable InAlAs/InGaAs heterojunction FET with AlAs/InAs superlattice insertion layer”, ELECTRONICS LETTERS, May 23, 1996, Vol. 32, No. 11, pp. 1039-1041. In the suggested field effect transistor, a superlattice layer composed of AlAs and InAs is inserted between a donor layer and a gate forming layer. It is reported that the field effect transistor can prevent intrusion of fluorine thereinto, and stop thermal degradation.
As an example of an InP layer used as a barrier layer, Enoki et al. has suggested a structure in “0.1−μm InAlAs/InGaAs HEMTS WITH AN InP-RECESS-ETCH STOPPER GROWN BY MOCVD”, Proceedings of 7th International Conference of InP and Related Materials, 1995, pp. 81-84. It is reported that an InP layer as a gate contact layer is formed on an InAlAs layer to thereby enhance uniformity of device characteristics in a wafer.
As mentioned above, when a donor layer is composed of InAlAs, inactivation of donor caused by intrusion of impurities thereinto is a major problem significantly reducing reliability of a device. In most of heterojunction field effect transistors to be formed on an InP substrate, a donor source layer is generally composed of an InAlAs layer. To the contrary, a transistor which does not employ InAlAs, but employs InP for a donor layer has been suggested by A. M. Küsters et al. in IEEE ELECTRON DEVICE LETTERS, Vol. 16, No. 9, 1995, pp. 396-398. The suggested transistor avoids inactivation of donor caused by intrusion of impurities such as fluorine by not employing InAlAs for a donor source layer, to thereby ensure thermal reliability.
As mentioned earlier, a major problem for reducing reliability in an InALAs/InGaAs heterojunction transistor is that impurities such as fluorine present in an atmosphere or fluorine adhered to a surface of a sample in a process enters an epitaxial layer while a device is held in heated condition, resulting in that donor in an InAlAs layer containing n-type impurities therein is inactivated.
One of objects of the present invention is to solve this problem by providing a highly reliable high performance InAlAs/InGaAs family heterojunction transistor. One of solutions to the problem is to insert a barrier layer between an InAlAs donor layer and a gate electrode for preventing intrusion of impurities into an epitaxial layer. Up to now, it has been found out by experiments that intrusion of impurities into an epitaxial layer can be prevented by employing material other than InAlAs and AlGaAs, as having been reported by Hayafuji, Fujihara and Enoki.
However, the use of a barrier layer is accompanied with other problems. If a barrier layer had positive conduction band discontinuity to material of which a cap layer is composed, since an ohmic electrode is formed on the barrier layer, a source resistance would be increased with the result of deterioration of performance of a device. Since a cap layer is usually composed of InGaAs, the barrier layers employed in the above-mentioned prior art are accompanied with another problem of an increased source resistance.
In addition, since crystal quality of a barrier layer exerts a major influence on crystal quality of a layer to be formed on the barrier layer, it would be absolutely necessary to determine crystal growth conditions each time when a device is fabricated.
Apart from the above-mentioned prior art, various InAlAs/InGaAs family heterojunction transistors have been suggested as follows.
In “Double-Heterojunction Lattice-Matched and Pseudomorphic InGaAs HEMT with δ-Doped InP Supply Layers and p-InP Barrier Enhancement Layer Grown by LP-MOVPE”, IEEE ELECTRON DEVICE LETTERS, Vol. 14, No. 1, January 1993, A. M. Küsters et al. have suggested a LP-MOVPE-grown double-hetrojuction HEMT (DH-MEMT) with InP as carrier-supplying and barrier layers that avoid the kink effect due to Al-containing layers.
Japanese Unexamined Patent Publication No. 4-180240 has suggested a field effect transistor including an InP substrate and an InGaAs layer formed on the InP substrate, wherein the InGaAs layer has an In composition rate greater than 0.53 at which the InGaAs layer is lattice-matched with the InP substrate.
Japanese Unexamined Patent Publication No. 6-232175 has suggested In X Al 1−X As/In Y Ga 1−Y As heterojunction type field effect transistor lattice-matched with an InP substrate, wherein pseudo-morphic undoped Al Z Ga 1− As layer is inserted below a gate electrode, and an n-type GaAs layer is formed on the undoped Al Z Ga 1−Z As layer in source/drain regions.
Japanese Unexamined Patent Publication No. 6-236898 has suggested a field effect transistor, in which an I-type In 0.52 Al 0.48 As buffer layer, an I-type In 1−X Ga X As Y P 1−Y channel layer, an In 0.52 Al 0.48 As spacer layer, an n-type In 0.52 A 0.48 As electron supply layer, an I-type In 0.52 Al 0.48 As Schottky layer, and n-type Ino 0.53 Ga 0.47 As cap layer are grown on a semi-insulating InP substrate. A gate electrode is formed on a recess formed in the n-type In 0.53 Ga 0.47 As cap layer, and source and drain electrodes are formed at opposite sides of the gate electrode.
Japanese Unexamined Patent Publication No. 6-302625 has suggested a field effect transistor including n-In 0.49 Ga 0.51 P etching stopper layer, n-Al X Ga 1—X As layer, and a GaAs cap layer on an operation layer. A gate electrode is formed on the n-In 0.49 Ga 0.51 P etching stopper layer.
Japanese Unexamined Patent Publication No. 7-111327 has suggested a heterojunction field effect transistor wherein a non-doped In 0.52 Al 0.48 As buffer layer, a non-doped In 0.80 Ga 0.20 As channel layer, a non-doped In 0.52 Al 0.48 As spacer layer, an n-type In 0.52 Al 0.48 As doped layer, a non-doped In 0.52 Al 0.48 As gate contact layer, a non-doped In 0.80 Ga 0.20 As resistance reducing layer, and an n-type In 0.53 Ga 0.47 As cap layer are formed in this order on a semi-insulating InP substrate. The field effect transistor is characterized by the non-doped In 0.53 Ga 0.20 As inserted between the non-doped In 0.52 Al 0.48 As gate contact layer and the n-type In 0.53 Ga 0.47 As cap layer.
Japanese Unexamined Patent Publication No. 7-312421 has suggested a field effect transistor wherein an InGaAs active layer, an InAlAs layer, a GaAs layer, and an InGaAs cap layer are formed on an InP substrate. A gate electrode is formed on the GaAs layer. A layer made of metal having a melting point at 1600° C. or greater is sandwiched between the gate electrode and the GaAs layer. N-type impurities are implanted into a part of the InAlAs layer.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a field effect transistor as a microwave milliwave compound device capable of avoiding thermal instability caused by impurities entering a donor layer to thereby cause donor to be inactivated, and also provide a method of fabricating the same.
In one aspect of the present invention, there is provided a field effect transistor including (a) a semi-insulating semiconductor substrate formed with a recess at a region in which a gate is to be formed, (b) a gate base layer formed on the recess and composed of one of an InP layer and a plurality of layers including an InP layer, and (c) a gate electrode formed on the gate base layer.
There is further provided a field effect transistor including (a) a semi-insulating semiconductor substrate formed with a recess at a region in which a gate is to be formed, (b) a gate base layer formed on the recess and composed of one of an InGaP layer and a plurality of layers including an InGaP layer, and (c) a gate electrode formed on the gate base layer.
There is still further provided a field effect transistor including (a) a semi-insulating semiconductor substrate formed with a recess at a region in which a gate is to be formed, (b) a gate base layer formed on the recess and composed of one of an Al X Ga 1−X As (0≦X≦1) layer and a plurality of layers including an Al X Ga 1−X As (0≦X≦1) layer, and (c) a gate electrode formed on the gate base layer.
There is yet further provided a field effect transistor including (a) a semi-insulating semiconductor substrate formed with a recess at a region in which a gate is to be formed, (b) a gate base layer formed on the recess and composed of one of an In X Ga 1− As (0≦X≦1) layer and a plurality of layers including an In X Ga 1−X As (0≦X≦1) layer, and (c) a gate electrode formed on the gate base layer.
There is still yet further provided a field effect transistor including (a) a semi-insulating semiconductor substrate formed with a recess at a region in which a gate is to be formed, (b) a gate base layer formed on the recess and composed of one of an In X Al 1−X As (0≦X<0.4 or 0.6<X≦1) layer and a plurality of layers including an In X Al 1−X As (0≦X<0.4 or 0.6<X≦1) layer, and (c) a gate electrode formed on the gate base layer.
The above-mentioned field effect transistor may further include an InAlAs or AlGaAs layer containing no impurities therein, formed between the gate base layer and the gate electrode. For instance, the semi-insulating semiconductor substrate may be composed of GaAs or InP.
In another aspect of the present invention, there is provided a method of fabricating a field effect transistor, including the steps of (a) forming a recess with a semi-insulating semiconductor substrate at a region in which a gate is to be formed, (b) forming a gate base layer on the recess, the gate base layer being composed of one of an InP layer and a plurality of layers including an InP layer, and (c) forming a gate electrode on the gate base layer.
There is further provided a method of fabricating a field effect transistor, including the steps of (a) forming a recess with a semi-insulating semiconductor substrate at a region in which a gate is to be formed, (b) forming a gate base layer on the recess, the gate base layer being composed of one of an InGaP layer and a plurality of layers including an InGaP layer, and (c) forming a gate electrode on the gate base layer.
There is still further provided a method of fabricating a field effect transistor, including the steps of (a) forming a recess with a semi-insulating semiconductor substrate at a region in which a gate is to be formed, (b) forming a gate base layer on the recess, the gate base layer being composed of one of an Al X Ga 1−X As (0≦X≦1) layer and a plurality of layers including an Al X Ga 1−X As (0≦X≦1) layer, and (c) forming a gate electrode on the gate base layer.
There is yet further provided a method of fabricating a field effect transistor, including the steps of (a) forming a recess with a semi-insulating semiconductor substrate at a region in which a gate is to be formed, (b) forming a gate base layer on the recess, the gate base layer being composed of one of an In X Ga 1−X As (0≦X≦1) layer and a plurality of layers including an In X Ga 1−X As (0≦X≦1) layer, and (c) forming a gate electrode on the gate base layer.
There is still yet further provided a method of fabricating a field effect transistor, including the steps of (a) forming a recess with a semi-insulating semiconductor substrate at a region in which a gate is to be formed, (b) forming a gate base layer on the recess, the gate base layer being composed of one of an In X Al 1−X As (0≦X<0.4 or 0.6<X≦1) layer and a plurality of layers including an In X Al 1−X As (0≦X<0.4 or 0.6<X≦1) layer, and (c) forming a gate electrode on the gate base layer.
The above-mentioned method may further include the step (d) of forming an InAlAs or AlGaAs layer containing no impurities therein, between the gate base layer and the gate electrode, the step (d) being to be carried out between the steps (b) and (c).
One of keys of the present invention is to form a barrier layer below a gate electrode. The barrier layer is composed of material which does not allow impurities to pass therethrough in order to prevent InAlAs and AlGaAs layers, to which n-type impurities are implanted and which are readily contaminated with impurities such as fluorine, from being exposed outside. However, when the InAlAs and AlGaAs layers are crystal-grown in usual planar state, the formation of a barrier layer below a gate electrode may be accompanied with problems such as an increase of a source resistance and gate leakage. In addition, if a barrier layer is formed directly below a gate electrode, crystal growth conditions have to be determined in detail and/or a barrier layer may have a thickness limitation in order to avoid degradation in quality of a cap layer to be formed on a barrier layer. Hence, in accordance with the present invention, a recess is first formed, then a barrier layer and a gate contact layer are selectively grown within the recess, and finally a gate electrode is formed on the barrier layer.
The field effect transistor in accordance with the present invention prevents thermal instability thereof caused by impurities such as fluorine entering a donor layer to thereby inactivate donor. As a result, there is presented a highly reliable compound field effect transistor to be formed on an InP substrate.
The above and other objects and advantageous features of the present invention will be made apparent from the following description made with reference to the accompanying drawings, in which like reference characters designate the same or similar parts throughout the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a cross-sectional view of a field effect transistor in accordance with the first embodiment of the present invention.
FIG. 1B is a cross-sectional view of a field effect transistor in accordance with the second embodiment of the present invention.
FIG. 1C is a cross-sectional view of a field effect transistor in accordance with the third embodiment of the present invention.
FIG. 2A is a graph showing thermal fluctuation in a drain current in a storage test in heated condition in field effect transistors in accordance with the first, second and third embodiments.
FIG. 2B is a graph showing thermal fluctuation in a mutual conductance in a storage test in heated condition in field effect transistors in accordance with the first, second and third embodiments.
FIG. 3A is a cross-sectional view of a field effect transistor in accordance with the fourth embodiment of the present invention.
FIG. 3B is a cross-sectional view of a field effect transistor in accordance with the fifth embodiment of the present invention.
FIG. 3C is a cross-sectional view of a field effect transistor in accordance with the sixth embodiment of the present invention.
FIG. 4A is a graph showing thermal fluctuation in a drain current in a storage test in heated condition in field effect transistors in accordance with the fourth, fifth and sixth embodiments.
FIG. 4B is a graph showing thermal fluctuation in a mutual conductance in a storage test in heated condition in field effect transistors in accordance with the fourth, fifth and sixth embodiments.
FIG. 5A is a cross-sectional view of a field effect transistor in accordance with the seventh embodiment of the present invention.
FIG. 5B is a cross-sectional view of a field effect transistor in accordance with the eighth embodiment of the present invention.
FIG. 5C is a cross-sectional view of a field effect transistor in accordance with the ninth embodiment of the present invention.
FIG. 6A is a graph showing thermal fluctuation in a drain current in a storage test in heated condition in field effect transistors in accordance with the seventh, eighth and ninth embodiments.
FIG. 6B is a graph showing thermal fluctuation in a mutual conductance in a storage test in heated condition in field effect transistors in accordance with the seventh, eighth and ninth embodiments.
FIG. 7A is a cross-sectional view of a field effect transistor in accordance with the tenth embodiment of the present invention.
FIG. 7B is a cross-sectional view of a field effect transistor in accordance with the eleventh embodiment of the present invention.
FIG. 7C is a cross-sectional view of a field effect transistor in accordance with the twelfth embodiment of the present invention.
FIG. 8A is a graph showing thermal fluctuation in a drain current in a storage test in heated condition in field effect transistors in accordance with the tenth, eleventh and twelfth embodiments.
FIG. 8B is a graph showing thermal fluctuation in a mutual conductance in a storage test in heated condition in field effect transistors in accordance with the tenth, eleventh and twelfth embodiments.
FIG. 9 is a cross-sectional view of a conventional field effect transistor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[First Embodiment]
FIG. 1A illustrates a field effect transistor in accordance with the first embodiment of the present invention. The illustrated field effect transistor includes a semi-insulating InP substrate 101 , and an epitaxial-layered structure formed on the InP substrate 101 . The epitaxial-layered structure is comprised of an InALAs layer 102 containing no impurities therein and having a thickness of 20 nm, an InGaAs layer 103 containing no impurities therein and having a thickness of 20 nm, an InAlAs layer 104 containing no impurities therein and having a thickness of 5 nm, an InAlAs layer 105 implanted at a dose of 3−10 18 cm −3 silicon and having a thickness of 150 nm, an InAlAs layer 106 containing no impurities therein and having a thickness of 20 nm, and an InGaAs layer 107 implanted at a dose of 3×10 18 cm −3 silicon and having a thickness of 20 nm, all of which are deposited one on another in this order.
Ohmic electrodes 108 a and 108 b as source and drain electrodes are formed on the uppermost layer or InGaAs layer 107 . The ohmic electrodes 108 a and 108 b are composed of alloy of AuGe, Ni and Au. By thermal annealing, these alloy layers reach the InGaAs layer 103 corresponding to a channel.
Between the ohmic electrodes 108 a and 108 b is formed a recess which reaches an intermediate depth of the InAlAs layer 106 . The recess is covered with an InP layer 110 a containing no impurities and having a thickness of 10 nm. A gate electrode 108 c is formed on the InP layer 110 a . The gate electrode 108 c has a multi-layered structure including Ti, Pt and Au layers deposited one on another in this order, and has a gate length of 1 μm.
The gate electrode 108 c and the InP layer 110 a are entirely covered with a protection film 111 composed of SiN and deposited by plasma-enhanced chemical vapor deposition (PECVD).
In the illustrated field effect transistor in accordance with the first embodiment, a mutual conductance of 500 mS/mm was obtained as device initial characteristics. In addition, there were also obtained Schottky barrier height of 0.5 eV and a gate inverse breakdown voltage of 7V.
[Second Embodiment]
FIG. 1B illustrates a field effect transistor in accordance with the second embodiment. In the illustrated field effect transistor, an InGaP layer 110 b containing no impurities is formed in place of the InP layer 110 a in the first embodiment, illustrated in FIG. 1 A. The field effect transistor in accordance with the second embodiment provides the same advantages as those of the field effect transistor in accordance with the first embodiment.
In the illustrated field effect transistor in accordance with the second embodiment, a mutual conductance of 490 mS/mm was obtained as device initial characteristics. In addition, there were also obtained Schottky barrier height of 0.5 eV and a gate inverse breakdown voltage of 7V.
[Third Embodiment]
FIG. 1C illustrates a field effect transistor in accordance with the third embodiment. In the illustrated field effect transistor, a superlattice layer 110 c composed of AlAs and InAs and containing no impurities is formed in place of the InP layer 110 a in the first embodiment, illustrated in FIG. 1 A. The superlattice layer 110 c has a four-cycled multi-layered structure including four AlAs atom layers and four InAs atom layers deposited one on another. The field effect transistor in accordance with the third embodiment provides the same advantages as those of the field effect transistor in accordance with the first embodiment.
In the illustrated field effect transistor in accordance with the second embodiment, a mutual conductance of 510 mS/mm was obtained as device initial characteristics. In addition, there were also obtained Schottky barrier height of 0.5 eV and a gate inverse breakdown voltage of 6V.
FIGS. 2A and 2B show a drain current and a mutual conductance both obtained when a storage test in heated condition was conducted to the field effect transistors in accordance with the above-mentioned first to third embodiments, respectively. As mentioned later in detail, the field effect transistors in accordance with the above-mentioned first to third embodiments show less degradation both in a drain current and a mutual conductance than a conventional field effect transistor represented with solid circles ().
[Fourth Embodiment]
FIG. 3A illustrates a field effect transistor in accordance with the fourth embodiment of the present invention. The illustrated field effect transistor includes a semi-insulating InP substrate 201 , and an epitaxial-layered structure formed on the InP substrate 201 . The epitaxial-layered structure is comprised of an InAlAs layer 202 containing no impurities therein and having a thickness of 500 nm, an InGaAs layer 203 containing no impurities therein and having a thickness of 20 nm, an InAlAs layer 204 containing no impurities therein and having a thickness of 5 nm, an InAlAs layer 205 implanted at a dose of 3×10 18 cm −3 silicon and having a thickness of 150 nm, an InAlAs layer 106 containing no impurities therein and having a thickness of 20 nm, and an InGaAs layer 207 implanted at a dose of 3×10 18 cm −3 silicon and having a thickness of 20 nm, all of which are deposited one on another in this order.
The epitaxial-layered structure is formed at an upper surface thereof with a recess which reaches an intermediate depth of the InAIAs layer 206 . The recess is covered with an InP layer 210 a containing no impurities and having a thickness of 10 nm. A gate electrode 208 c is formed on the InP layer 210 a . The gate electrode 208 c has a multi-layered structure including Ti, Pt and Au layers deposited one on another in this order, and has a gate length of 1 μm.
Ohmic electrodes 208 a and 208 b as source and drain electrodes are formed on the InP layer 210 a . The ohmic electrodes 208 a and 208 b are composed of alloy of AuGe, Ni and Au. By thermal annealing, these alloy layers reach the InGaAs layer 203 corresponding to a channel.
The gate electrode 208 c and the InP layer 210 a are entirely covered with a protection film 211 composed of SiN and deposited by PECVD.
In the illustrated field effect transistor in accordance with the fourth embodiment, a mutual conductance of 500 mS/mm was obtained as device initial characteristics. In addition, there were also obtained Schottky barrier height of 0.6 eV and a gate inverse breakdown voltage of 7V.
[Fifth Embodiment]
FIG. 3B illustrates a field effect transistor in accordance with the fifth embodiment. In the illustrated field effect transistor, an InGaP layer 210 b containing no impurities is formed in place of the InP layer 210 a in the fourth embodiment, illustrated in FIG. 3 A. The field effect transistor in accordance with the fifth embodiment provides the same advantages as those of the field effect transistor in accordance with the fourth embodiment.
In the illustrated field effect transistor in accordance with the fifth embodiment, a mutual conductance of 510 mS/mm was obtained as device initial characteristics. In addition, there were also obtained Schottky barrier height of 0.65 eV and a gate inverse breakdown voltage of 6.5V.
[Sixth Embodiment]
FIG. 3C illustrates a field effect transistor in accordance with the sixth embodiment. In the illustrated field effect transistor, a superlattice layer 210 c composed of AlAs and InAs and containing no impurities is formed in place of the InP layer 210a in the fourth embodiment, illustrated in FIG. 3 A. The superlattice layer 210 c has a four-cycled multi-layered structure including four AlAs atom layers and four InAs atom layers deposited one on another. The field effect transistor in accordance with the sixth embodiment provides the same advantages as those of the field effect transistor in accordance with the fourth embodiment.
In the illustrated field effect transistor in accordance with the sixth embodiment, a mutual conductance of 540 mS/mm was obtained as device initial characteristics. In addition, there were also obtained Schottky barrier height of 0.65 eV and a gate inverse breakdown voltage of 6V.
FIGS. 4A and 4B show a drain current and a mutual conductance both obtained when a storage test in heated condition was conducted to the field effect transistors in accordance with the above-mentioned fourth to sixth embodiments, respectively. As mentioned later in detail, the field effect transistors in accordance with the above-mentioned fourth to sixth embodiments show less degradation both in a drain current and a mutual conductance than a conventional field effect transistor represented with solid circles ().
[Seventh Embodiment]
FIG. 5A illustrates a field effect transistor in accordance with the seventh embodiment of the present invention. The illustrated field effect transistor includes a semi-insulating InP substrate 301 , and an epitaxial-layered structure formed on the InP substrate 301 . The epitaxial-layered structure is comprised of an InAlAs layer 302 containing no impurities therein and having a thickness of 500 nm, an InGaAs layer 303 containing no impurities therein and having a thickness of 20 nm, an InAlAs layer 304 containing no impurities therein and having a thickness of 5 nm, an InAlAs layer 305 implanted at a dose of 3×10 18 cm −3 silicon and having a thickness of 150 nm, an InAlAs layer 306 containing no impurities therein and having a thickness of 20 nm, and an InGaAs layer 307 implanted at a dose of 3×10 18 cm −3 silicon and having a thickness of 20 nm, all of which are deposited one on another in this order.
Ohmic electrodes 308 a and 308 b as source and drain electrodes are formed on the uppermost layer or InGaAs layer 307 . The ohmic electrodes 308 a and 308 b are composed of alloy of AuGe, Ni and Au. By thermal annealing, these alloy layers reach the InGaAs layer 303 corresponding to a channel.
Between the ohmic electrodes 308 a and 308 b is formed a recess which reaches an intermediate depth of the InAlAs layer 306 . The recess is covered with an InP layer 310 a containing no impurities and having a thickness of 10 nm, and the InP layer 310 a is covered with an InAlAs layer 312 containing no impurities and having a thickness of 5 nm. A gate electrode 308 c is formed on the InAIAs layer 312 . The gate electrode 308 c has a multi-layered structure including Ti, Pt and Au layers deposited one on another in this order, and has a gate length of 1 μm.
The gate electrode 308 c and the InAlAs layer 312 are entirely covered with a protection film 311 composed of SiN and deposited by PECVD.
In the illustrated field effect transistor in accordance with the seventh embodiment, a mutual conductance of 500 mS/mm was obtained as device initial characteristics. In addition, there were also obtained Schottky barrier height of 0.6 eV and a gate inverse breakdown voltage of 7V.
[Eighth Embodiment]
FIG. 5B illustrates a field effect transistor in accordance with the eighth embodiment. In the illustrated field effect transistor, an InGaP layer 310 b containing no impurities is formed in place of the InP layer 310 a in the seventh embodiment, illustrated in FIG. 5 A. The field effect transistor in accordance with the eighth embodiment provides the same advantages as those of the field effect transistor in accordance with the seventh embodiment.
In the illustrated field effect transistor in accordance with the eighth embodiment, a mutual conductance of 450 mS/mm was obtained as device initial characteristics. In addition, there were also obtained Schottky barrier height of 0.6 eV and a gate inverse breakdown voltage of 6V.
[Ninth Embodiment]
FIG. 5C illustrates a field effect transistor in accordance with the ninth embodiment. In the illustrated field effect transistor, a superlattice layer 310 c composed of AlAs and InAs and containing no impurities is formed in place of the InP layer 310 a in the seventh embodiment, illustrated in FIG. 5 A. The superlattice layer 310 c has a four-cycled multi-layered structure including four AlAs atom layers and four InAs atom layers deposited one on another. The field effect transistor in accordance with the ninth embodiment provides the same advantages as those of the field effect transistor in accordance with the seventh embodiment.
In the illustrated field effect transistor in accordance with the ninth embodiment, a mutual conductance of 480 mS/mm was obtained as device initial characteristics. In addition, there were also obtained Schottky barrier height of 0.6 eV and a gate inverse breakdown voltage of 7V.
FIGS. 6A and 6B show a drain current and a mutual conductance both obtained when a storage test in heated condition was conducted to the field effect transistors in accordance with the above-mentioned seventh to ninth embodiments, respectively. As mentioned later in detail, the field effect transistors in accordance with the above-mentioned seventh to ninth embodiments show less degradation both in a drain current and a mutual conductance than a conventional field effect transistor represented with solid circles ().
[Tenth Embodiment]
FIG. 7A illustrates a field effect transistor in accordance with the tenth embodiment of the present invention. The illustrated field effect transistor includes a semi-insulating InP substrate 401 , and an epitaxial-layered structure formed on the InP substrate 401 . The epitaxial-layered structure is comprised of an InAIAs layer 402 containing no impurities therein and having a thickness of 500 nm, an InGaAs layer 403 containing no impurities therein and having a thickness of 20 nm, an InAlAs layer 404 containing no impurities therein and having a thickness of 5 nm, an InAlAs layer 405 implanted at a dose of 3×10 18 cm −3 silicon and having a thickness of 150 nm, an InAlAs layer 406 containing no impurities therein and having a thickness of 20 nm, and an InGaAs layer 407 implanted at a dose of 3×10 18 cm −3 silicon and having a thickness of 20 nm, all of which are deposited one on another in this order.
The epitaxial-layered structure is formed at an upper surface thereof with a recess which reaches an intermediate depth of the InAlAs layer 406 . The recess is covered with an InP layer 410 a containing no impurities and having a thickness of 10 nm, and the InP layer 410 a is covered with an InAlAs layer 412 containing no impurities and having a thickness of 5 nm.
A gate electrode 408 c is formed on the InAlAs layer 412 . The gate electrode 408 c has a multi-layered structure including Ti, Pt and Au layers deposited one on another in this order, and has a gate length of 1 μm.
Ohmic electrodes 408 a and 408 b as source and drain electrodes are formed on the InAlAs layer 412 . The ohmic electrodes 408 a and 408 b are composed of alloy of AuGe, Ni and Au. By thermal annealing, these alloy layers reach the InGaAs layer 403 corresponding to a channel.
The gate electrode 408 c and the InAlAs layer 412 are entirely covered with a protection film 411 composed of SiN and deposited by PECVD.
In the illustrated field effect transistor in accordance with the tenth embodiment, a mutual conductance of 500 mS/mm was obtained as device initial characteristics. In addition, there were also obtained Schottky barrier height of 0.6 eV and a gate inverse breakdown voltage of 7V.
[Eleventh Embodiment]
FIG. 7B illustrates a field effect transistor in accordance with the eleventh embodiment. In the illustrated field effect transistor, an InGaP layer 410 b containing no impurities is formed in place of the InP layer 410 a in the tenth embodiment, illustrated in FIG. 7 A. The field effect transistor in accordance with the eleventh embodiment provides the same advantages as those of the field effect transistor in accordance with the tenth embodiment.
In the illustrated field effect transistor in accordance with the eleventh embodiment, a mutual conductance of 500 mS/mm was obtained as device initial characteristics. In addition, there were also obtained Schottky barrier height of 0.55 eV and a gate inverse breakdown voltage of 6V.
[Twelfth Embodiment]
FIG. 7C illustrates a field effect transistor in accordance with the twelfth embodiment. In the illustrated field effect transistor, a superlattice layer 410 c composed of AlAs and InAs and containing no impurities is formed in place of the InP layer 410 a in the tenth embodiment, illustrated in FIG. 7 A. The superlattice layer 410 c has a four-cycled multi-layered structure including four AlAs atom layers and four InAs atom layers deposited one on another. The field effect transistor in accordance with the twelfth embodiment provides the same advantages as those of the field effect transistor in accordance with the tenth embodiment.
In the illustrated field effect transistor in accordance with the twelfth embodiment, a mutual conductance of 520 mS/mm was obtained as device initial characteristics. In addition, there were also obtained Schottky barrier height of 0.5 eV and a gate inverse breakdown voltage of 5V.
FIGS. 8A and 8B show a drain current and a mutual conductance both obtained when a storage test in heated condition was conducted to the field effect transistors in accordance with the above-mentioned tenth to twelfth embodiments, respectively. As mentioned later in detail, the field effect transistors in accordance with the above-mentioned tenth to twelfth embodiments show less degradation both in a drain current and a mutual conductance than a conventional field effect transistor represented with solid circles (i).
[Comparison between the Invention and Prior Art]
FIG. 9 illustrates a conventional field effect transistor including an InAlAs donor layer. The illustrated conventional field effect transistor includes a semi-insulating InP substrate 501 , and an epitaxial-layered structure formed on the InP substrate . The epitaxial-layered structure is comprised of an InAlAs layer 502 containing no impurities therein, an InGaAs layer 503 containing no impurities therein, an InAlAs layer 504 containing no impurities therein, an InAlAs layer 505 containing impurities such as silicon therein, an InAlAs layer 506 containing no impurities, and an InGaAs layer 507 containing impurities such as silicon therein, all of which are deposited one on another in this order.
Source and drain electrodes 508 a and 508 b are formed on the uppermost layer or InGaAs layer 507 . The InGaAs layer 507 is formed with a recess between the source and drain electrodes 508 a and 508 b . A gate electrode 508 c is formed on the InAlAs layer 506 within the recess of the InGaAs layer 507 .
The gate electrode 508 c and the recess are entirely covered with a protection film 511 composed of SiN and deposited by PECVD.
The inventor conducted the experiment where the field effect transistors in accordance with the first to twelfth embodiments and the conventional field effect transistor illustrated in FIG. 9 were kept heated in a furnace at 300° C. FIGS. 2A, 4 A, 6 A, and 8 A illustrate fluctuation in a drain current with the lapse of time in the experiment in the field effect transistors in accordance with the first to twelfth embodiments, and FIGS. 2B, 4 B, 6 B and 8 B illustrate fluctuation in a mutual conductance with the lapse of time in the experiment in those field effect transistors.
In the conventional field effect transistor, both a drain current and a mutual conductance were gradually degraded with the lapse of time. After 100 hours had passed, a drain current was degraded by 25% or greater relative to the initial drain current, and a mutual conductance was degraded by 15% or greater relative to the initial mutual conductance.
On the other hands, in the field effect transistors in accordance with the first to twelfth embodiments, even after 100 hours had passed, a drain current was degraded by 10% or less relative to the initial drain current, and a mutual conductance was degraded by 5% or less relative to the initial mutual conductance. Thus, it was confirmed that the field effect transistors in accordance with the embodiments provided superior thermal stability.
In addition, SIMS analysis was conducted to the field effect transistors having been kept heated for 100 hours to thereby examine whether impurities entered the field effect transistors. It was confirmed that impurities, that is, foreign materials other than constituents of the field effect transistor, did not exist in the transistors, and that there was no fluctuation in profiles of constituents of he transistors.
Apart from the field effect transistors in accordance with the third, sixth and ninth embodiments illustrated in FIGS. 1C, 3 C and 5 C, respectively, in which the superlattice composed of AlAs and InAs is employed, the inventor had fabricated field effect transistors including an Al X Ga 1×X As (0≦X≦1) layer, an In X Ga 1×X As (0≦X1) layer, and an In X Al 1×X As (0≦X≦0.4 or 0.6<X≦1) in place of the above-mentioned superlattice, and tested them. When those layers had a thickness of 3 nm, the same thermal stability was obtained as thermal stability which would be obtained when the superlattice is used.
Though the above-mentioned embodiments employ specific material and dimensions, it is for ease of understanding the invention. For instance, thickness of the layers in the crystal structure and doping concentration may be varied from those shown in the embodiments. It should be noted that the field effect transistor in accordance with the present invention may be advantageously designed to have an InAlAs donor layer into which silicon or other impurities is(are) planar-doped. Any material other than silicon may be employed as donor impurity unless it enables n-type doping. For instance, sulfur (S) and selenium (Se) may be employed in place of silicon.
In the above-mentioned embodiments, the ohmic electrodes are composed of alloy of AuGe, Ni and Au, however, it should be noted that the ohmic electrodes might be composed of non-alloy metal such as Ti, Pt or Au. The gate electrode may be composed of a single metal layer or deposited metal layers such as WSi, W, Ti/Al, Pt/Ti/Pt/Au, Al, or Mo/Ti/Pt/Au.
In the superlattice composed of AlAs and InAs, employed in the field effect transistors in accordance with the third, sixth and ninth embodiments, the number of atomic layers and the number of cycles of superlattice are not to be limited to the numbers exemplified in those embodiments.
While the present invention has been described in connection with certain preferred embodiments, it is to be understood that the subject matter encompassed by way of the present invention is not to be limited to those specific embodiments. On the contrary, it is intended for the subject matter of the invention to include all alternatives, modifications and equivalents as can be included within the spirit and scope of the following claims.
The entire disclosure of Japanese Patent Application No. 9-22989 filed on Feb. 5, 1997 including specification, claims, drawings and summary is incorporated herein by reference in its entirety.
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There is provided a field effect transistor including a semi-insulating semiconductor substrate formed with a recess at a region in which a gate is to be formed, a gate base layer formed on the recess and composed of one of an InP layer and a plurality of layers including an InP layer, and a gate electrode formed on the gate base layer. The InP layer may be replaced with an InGaP layer, an Al X Ga 1−X As (0≦X≦1) layer, an In X Ga 1−X As (0≦X≦1) layer, or an In X Al 1−X As (0≦X<0.4 or 0.6<X≦1) layer. The above-mentioned field effect transistor prevents thermal instability thereof caused by impurities such as fluorine entering a donor layer to thereby inactivate donor. As a result, there is presented a highly reliable compound field effect transistor.
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BACKGROUND
This invention relates generally to digital signal processing and in particular aspects to architectures for digital signal processors.
Digital signal processors generally modify or analyze information measured as discrete sequences of numbers. Digital signal processors are used for a wide variety of signal processing applications such as television, multimedia, audio, digital image processing and telephony as examples. Most of these applications involve a certain amount of mathematical manipulation, usually multiplying and adding signals.
A large number of digital signal processors are available from a large number of vendors. Generally, each of these processors is fixed in the sense that it comes with certain capabilities. Users attempt to acquire those processors which best fit their needs and budget. However, the user's ability to modify the overall architecture of the digital signal processor is relatively limited. Thus, these products are packaged as units having fixed and immutable sets of capabilities.
In a number of cases, it would be desirable to have the ability to create a digital signal processor that performs complex functions that are specifically adapted to particular problems to be solved. Thus, it would be desirable that the hardware and software of the digital signal processor be adapted to a particular function. However, such a digital signal processor might enjoy a relatively limited market. Given the investment in silicon processing, it may not be feasible to provide a digital signal processor, which has been designed to meet relatively specific needs. However, such a device would be highly desirable. It would provide the greatest performance for the expense incurred, since only those features that are needed are provided. Moreover, those features may be provided that result in the highest performance without unduly increasing cost.
Multiprocessing digital signal processors or media processors generally use a hierarchical or a peer-to-peer processor array. The timing between instructions and data is invariable, known and fixed in hardware. The assembler or programmer uses the delay information to ensure that timing dependencies are met. When new processing elements are added to the overall architecture, they tend to require that preexisting code be rewritten. Moreover, the software that runs the digital signal processor is dependent on hardware timing and thus is not portable across different silicon process technologies. Binary or assembly code written on one version of these processors may not be portable to other versions that have different processing elements.
These architectures may also use a master control processor that does not contribute to the data processing work because it is busy directing the slave processors. The assembler or programmer is involved in predicting the clock-to-clock timing dependencies on variables stored in memories.
Thus, there is a need for digital signal processors that are adaptable to the addition of new processing elements, independent of hardware timing, more communication efficient or less timing dependent.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of one embodiment of the present invention;
FIG. 2 is a depiction of a register configuration in accordance with one embodiment of the present invention; and
FIG. 3 is a flow chart for one embodiment of the present invention.
DETAILED DESCRIPTION
A digital signal processor 10 may include a plurality of processing elements 12 a , 12 b , 12 c , 12 d and 12 e each having their own instruction sets. The individual processing elements 12 need not communicate directly with one another but instead may communicate through storage registers associated with a general purpose register (GPR) 32 that is part of the register 16 . Thus, the results of an operation performed by one of the processing elements 12 may be stored in the GPR 32 for access by another processing element 12 .
Each of the processing elements 12 may be separately programmed with its own set of codes. The instruction sets for each processing element 12 may provide the logic for operating the particular functions for that processing element 12 , avoiding the need for separate hardware logic for implementing the subprocessor functions, in one embodiment of the invention.
A programmable input processor (PIP) 12 a receives inputs from a receive buffer such as a first in first out (FIFO) register 14 . The PIP 12 a may, in some embodiments of the present invention, provide a precision change or a scaling of an input signal. The PIP 12 a may be advantageous since it may provide for input data processing when input signals are available and may provide mathematical operations at other times.
The programmable output processor (POP) 12 b provides outputs to a transmit buffer 22 such as a first in first out (FIFO) register. The POP 12 b may also do mathematical operations when no output data is available for transmission to the transmit buffer 22 .
The programmable random access memory (RAM) processor (PRP) 12 c basically stores and retrieves data. It may be particularly advantageous in storing intermediate results, in a cache-like fashion. This may be particularly applicable in two-dimensional image processing.
Some embodiments of the present invention may use normal length words but other embodiments may use the so-called very long instruction word (VLIW). VLIW may be advantageous in some embodiments because the logic may be in effect contained within the instructions and glue logic to coordinate the various subprocessors may be unnecessary.
A number of mathematical processors 12 may be provided within the unit 26 based on the particular needs in particular applications. In the illustrated embodiment, a pair of identical add and subtract programmable mathematical processors (PMP) 12 d are combined with a pair of multiply and accumulate (MAC) programmable mathematical processors (PMP) 12 e . However, a variety of other mathematical processors may be plugged into the digital signal processor 10 in addition to or in place of any of those illustrated.
Each of the processing elements 12 may be programmable, contain its own random access memory and decode the random access memory contents into instructions, in one embodiment of the invention.
The register 16 contains general purpose registers for storing data and allowing the accessing of data by the programmable processing elements 12 . The inclusion of a programmable random access memory processor 12 c , programmable input processor 12 a and the programmable output processor 12 b allows very flexible input, output and data manipulation/storage operations to take place in parallel with mathematical operations.
The register 16 includes a bus interface 34 and N general purpose registers 32 configured to allow independent read and write operations that can occur from a number of processing elements 12 at the same time. The GPR 32 allows independent data transfers from any of the other processing elements 12 and to any of the other processing elements 12 . The GPR 32 includes registers for each of the processing elements 12 that can be written to by any processing element 12 . If two processing elements 12 try to write to the same register, an error flag is set.
Each of the general purpose registers 32 may include the configuration shown in FIG. 2 in one embodiment. As one example, the general purpose register zero may include a data section 34 including a predetermined amount of data such as one word, in one embodiment. Appended to that data section 34 are a plurality of bits, one bit for each of the processing elements 12 included in the digital signal processor 10 . Thus, there may be a data valid bit 1 (DV- 1 ) for the input processing element 12 a , as indicated at 36 a , a data valid bit (DV- 2 ) for the processing element 12 b as indicated at 36 b and a data valid bit (DV- 3 ) for the processing element 12 c as indicated at 36 c and so on.
The data section 34 may be written to or read out from the register 32 without necessarily changing the data valid bits 36 . The bits 36 are not read out during a read or overwritten during a write of the data section 34 . Thus, the bits 36 indicate a state relative to each of the processing elements 12 making up the digital signal processor 10 and a particular data section 34 .
The architecture shown in FIG. 1 is simply an example of on potential architecture. The number of input processors 12 a and output processors 12 b may vary from on e to several. The number of memory processors 12 c is also considerably variable. Likewise, the number and arrangement of the MAC processors 12 e , or add and subtract processors 12 d may likewise be subject to considerable variability. Other processing elements 12 (not illustrated) may be combined as well.
All data inputs and outputs to the processing elements 12 take place through the general register 32 . The processing elements 12 have direct read and write access through registers 32 through a full cross bar connection bus 11 . The processing elements 12 use the semaphore illustrated in FIG. 2 for reading or writing data to or from the registers 32 .
Instructions are executed by any given processing elements 12 when all the necessary data is currently available in a general purpose register 32 as indicated by the data valid bits 36 . Storage of the result of instruction execution by a given processing element 12 occurs when space is available in a general purpose register 32 (unless the results of the instruction do not target a register 32 ). Thus, the multi-processing environment is data driven, shared register with a peer-to-peer architecture using a multiple instruction, multiple data type digital signal processor 10 .
Each of the processing elements 12 , executing instructions that require data from a register 32 , wait until the corresponding data valid bits 36 are set active. That is, a given processor 12 does not read a data section 34 from a given register until the corresponding data valid bit for that processing element 12 is set active. Once all of the data valid bits 36 are set, an instruction may execute and may (or may not) reset the data valid bits as the data section 34 is read from the register 32 .
A processing element 12 waits until all data valid bits (except for the data valid bit for that processing element) are inactive before writing into the data section 34 . When all data valid bits are clear (except for the processing element's own bit), the result of a processing element's operation may be written to a register 32 . If any data valid bits are active (except for the processing element's data valid bit), then the processing element's pipeline stalls. When data is written into a register 32 , the intended destination processing element 12 for the data is indicated by setting the corresponding data valid bit for the destination processing element 12 .
All data valid bits can be set by any processing element 12 to indicate a constant variable is stored in the data section 34 that may be used by all processing elements. In this case, a processing element 12 does not reset its data valid bit when reading the data section 34 from a register 32 until access to the constant by all processing elements 12 is complete. Each processing element 12 is responsible for resetting its data valid bit on its last access of the constant to free up the general purpose register 32 for additional use by other waiting processing elements needing available register space.
Referring to FIG. 3 , initially, an instruction written by a programmer is fetched as indicated at block 40 . The instruction is decoded as indicated in block 42 . If the instruction requires data, a check at diamond 44 determines whether the data valid bit for a given processing element 12 executing the instruction is active for each data section 34 that is needed to execute the instruction. If not, the flow awaits the situation when all the data valid bits for all the needed data sections 34 are valid.
When that situation occurs, the instruction may be prepared for execution by routing or sending all the necessary data and controller information to the execution unit of the appropriate processing element 12 . If appropriate, the processing element 12 may then reset its data valid bit for that data section 34 if the data section 34 is not needed anymore by that particular processing element, as indicated in block 46 .
After the instruction is executed, as indicated in block 48 , if there is an instruction execution result to store, the destination register 32 is checked to determine if it is available. Its availability may be determined, at diamond 50 , by checking that all other data valid bits are unasserted except for the data valid bit for the processor which wishes to store data in the data section 34 of the register 32 .
If this is not the case, because another data valid bit is asserted, the flow simply awaits the deassertion of the data valid bit. If there are no results to store as indicated at line 54 , the flow terminates. If there is a result to store and other data valid bits are unasserted, the results are stored in the destination general purpose register 32 as indicated in block 52 . The data valid bits are then set for the next recipients of the data. The bit is set pursuant to the instructions that were executed.
As a simple example, suppose a first processing element 12 is to execute the operation C=A×B and a second processing element 12 is going to execute E=C×D. The second processing element 12 cannot execute the instruction until the first processing element 12 stores C in the general purpose register 32 . The instruction for E=C×D has two data dependency bits that indicate which asserted data valid bits 36 to look for. In this case, C in GPR X and D in GPR Y must be checked. Only when both data valid bits are asserted is the data available allowing instruction execution. When data sections for C and D are read from the general purpose register 32 , the associated data valid bits 36 for the second processing element 12 may be cleared, indicating that the data is no longer needed by the second processing element 12 .
Before the first processing element 12 can store C into the specified general purpose register 32 , all data valid bits 36 must be deasserted. When all data valid bits 36 are deasserted, the general purpose register 32 no longer has valid data intended for other processing elements 12 . As a result, one may write to the general purpose register 32 . When the first processing element 12 stores C in a GPR X, the first processing element also asserts that the data valid bit that the data in this case C, is intended for the second processing element, so the data valid bit (DV- 2 ) associated with the second processing element is asserted. This process and protocol may be maintained throughout interactions with the general purpose register 32 , providing self-timed, data dependent instruction execution.
The advantages over a non-data driven architecture may include, in some embodiments, providing an architecture that can adapt to the addition of new processing elements without affecting preexisting code. Expanding the number of data valid bits may have no affect, in some embodiments, because the data valid bits that do not get set do not get used. This assumes that the encoding of the instruction is such that the old instruction fits inside the new instruction space and the new data valid control bits are not utilized. A purely data driven instruction execution model, in one embodiment, allows software to be functional, hardware timing independent and thus portable across different silicon processing technologies. Binary assembly code written on one version of the digital signal processor 10 may be portable across other processors that have different types or versions of the same processing elements.
A peer-to-peer multi-processor interconnect and communication method may be more efficient than a hierarchical multiprocessing method. The use of a master control processor in a hierarchical style system does not contribute to the data processing work because the master control processor is too busy directing the slave processors.
The assembler or programmer may be detached from having to predict the clock-to-clock timing dependencies on variables stored in registers. Post analysis can be performed when the data dependent delays are back annotated and then instructions can be rearranged by the assembler to increase performance.
Different pipelining depths that are mode dependent can be changed on the fly, can be of any depth and can still provide software compatibility and correct functionality.
While the present invention has been described with respect to a limited number of embodiments, those skilled in the art 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.
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A digital signal processor may include a plurality of processing elements that are coupled together to accomplish a specialized function. Each processing element may utilize the same shared storage in a form of a plurality of general purpose registers. Each of these registers may be accessed by any of the processing elements. Each register may include a data storage section and a plurality of storage areas for data valid bits that indicate whether the data is valid or not for each of the plurality of processing elements.
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This application is a continuation-in-part of U.S. application Ser. No. 10/664,518 filed Sep. 17, 2003, now abandoned, this application is a continuation-in-part of U.S. application Ser. No. 10/794,387 filed Mar. 5, 2004, now abandoned and this application is a continuation-in-part of U.S. application Ser. No. 10/872,139 filed Jun. 18, 2004, now abandoned.
BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates in general to papermaking, and in particular relates to the manufacture of paper suitable for use as ticket stock used for making redemption tickets of the type commonly dispensed from automated machines in game arcades and the like.
Game arcades often have electronic games that dispense redemption tickets as a reward for having played the game well. Depending on the game score achieved by the player, the game machine dispenses a different number of tickets. The tickets typically can be redeemed for prizes such as toys, stuffed animals, candy, and the like. The game machines generally employ an automated ticket dispenser that dispenses a number of tickets based on the game score. The tickets are supplied in the form of a roll of interconnected tickets separated from one another by perforations. The tickets usually have a printed bar code on one side and may have other indicia and/or graphics on the opposite side. The automated ticket dispenser includes an optical sensor that detects the bar code or other printed marking on each ticket, and in that manner the dispenser is able to count how many tickets are dispensed. Arcades sometimes also include ticket counting machines that operate on a similar principle, such that tickets to be redeemed are fed into the counting machine, which counts the tickets by using an optical sensor.
For proper functioning of the ticket dispensers and ticket counters, and for good aesthetics of the tickets, it is important that the paper or stock making up the tickets have a high opacity so that printed ink on one side of the tickets does not show through to the other side. At the same time, it is desirable for the tickets to have a soft feel in the hand, to have edges that are not so sharp as to pose a risk of cutting the users' hands, to have relatively high strength so they are not easily torn, and to have a highly smooth surface for good printability. Currently available ticket stocks do not always achieve all of these desirable characteristics.
The majority of ticket stocks currently being produced are formed on multiply paper machines, and have a thickness or caliper of about 9.5 to 13 points (i.e., 0.0095 to 0.013 inch). Some ticket stock is also produced as a coated solid bleached sulfate (SBS) sheet with a caliper as low as 7 points, but the coating is essential for achieving sufficient opacity to enable proper functioning of the automated ticket dispensers. Such coated SBS ticket stock generally does not have a desirable soft feel in the hand.
Ticket stock of lower caliper is desirable for improving the ticket yield per unit weight of the papermaking furnish, and for increasing the number of tickets per roll of a given diameter. However, reducing the caliper generally has an adverse impact on some of the other desirable characteristics. For instance, a thinner paper, all other things being equal, has a reduced opacity, a reduced stiffness, and a reduced strength. There is also a certain caliper threshold below which the tickets do not have a good “feel” in the hand, as being too flimsy or insubstantial. It is generally thought that the practical lower limit is about 6.5 to 7 points, as tickets below this caliper level generally feel flimsy and are not favored by consumers.
Additionally, although some ticket stocks are colored, there is a sizeable market for white ticket stock. Such white ticket stock must have a high brightness.
Accordingly, it would be desirable to provide a white ticket stock of relatively low caliper, such as about 7 to 9 points, more preferably about 7 points, having a high opacity, a soft feel, and a highly smooth surface for good printability.
BRIEF SUMMARY OF THE INVENTION
Tickets are widely used for prize redemption in family entertainment centers, arcades, location-based entertainment centers, amusement parks, and similar establishments. Tickets may also be used to conduct drawings, raffles and give-a-ways.
Organizers of events and companies that dispense tickets typically order tickets by the tens of thousands, and often by the truckload. Beyond the expense of purchasing the actual ticket, ticket-purchasing organizations may expect to pay shipping and storage fees.
The present invention relates to one or more of the following features, elements or combinations thereof. A ticket is illustratively formed from a sheet or strip of a substrate. The substrate is illustratively reply card stock paper. The substrate may have a caliper characteristic in the range of 5 and 11 points. The opacity of the substrate may be below 98%. The substrate may be manufactured and formed into rolls of tickets, or may be manufactured and formed into decks of tickets. Alternatively, the substrate may be manufactured and formed into sheets of tickets or individual tickets. A roll of 2000 tickets may have a diameter of less than 6.5 inches. The roll of 2000 tickets may have a weight of less than one pound. The rolls may be packaged in a container that has smaller dimensions than the previously-known shipping container. A container holding four rolls across may have a smaller side dimension than 13.5 inches.
In another embodiment, a ticket is illustratively formed from a sheet or strip of a substrate. The substrate is illustratively high opacity ticket stock. The substrate has a caliper characteristic in the range of 5 to 7.5 points. The opacity of the substrate is above 98%. The substrate may be manufactured and formed into rolls of tickets, or may be manufactured and formed into decks of tickets. Alternatively, the substrate may be manufactured and formed into sheets of tickets or individual tickets. A roll of 2000 tickets may have a diameter of less than 6.5 inches. The roll of 2000 tickets may have a weight of less than one pound. The rolls may be packaged in a container that has smaller dimensions than the previously-known shipping container. A container holding four rolls in a two-by-two fashion may have a smaller side dimension than 13.5 inches.
The invention addresses the above needs and achieves other advantages, by providing a ticket stock and manufacturing process wherein a pulp is formulated from a blend of recycled furnishes, with added starch for enhancing sheet stiffness and reducing linting and dusting on cut edges of the stock, and with added clay or other opacifier for enhancing opacity of the stock. A preferred pulp comprises a blend of recycled solid bleached sulfate plate stock, recycled coated soft white, and recycled ground wood furnish such as newsprint or the like. In one embodiment, the blend comprises about 25-50 wt. % recycled solid bleached sulfate plate stock, about 25-50 wt. % recycled coated soft white, and about 15-25 wt. % recycled ground wood furnish. Starch can be added in the amount of about 25 to 35 pounds per ton of the finished stock. Clay can comprise about 80 to 120 pounds per ton of the finished stock.
The ticket stock preferably has a caliper of about 7 to 9 points, more preferably about 7 points. The formulation of the pulp leads to an opacity (measured according to the TAPPI 519 method) of at least about 98 percent. The ticket stock has a Parker Smoothness not substantially exceeding about 8 microns, more preferably not substantially exceeding about 6 microns, and still more preferably not substantially exceeding about 5 microns.
A process for making a ticket stock in accordance with the invention entails formulating a pulp from a mixture of recycled furnishes as noted above, and adding starch and clay or other opacifier to the pulp. The recycled furnishes are repulped with minimal mechanical refining or fiber shortening. The pulp is then processed at elevated temperature to hydrate and soften the fibers; this can be accomplished, for example, in a unit that injects steam into the pulp while the pulp is at a high consistency. In the case where the recycled furnish includes some printed furnish, this treatment is also effective to break up ink and other contaminants into very fine particles.
Next, the pulp is fed at a suitable consistency level to a former, which forms a wet web. The former can comprise any of various formers known in the art, including single-ply and multi-ply formers. In one embodiment, a fourdrinier former is employed to form a single-ply web.
The wet web is then dewatered and pressed in a press section. The press section can comprise various types and numbers of presses. In one embodiment, the press section comprises two sequentially arranged presses such as roll presses equipped with dewatering fabrics. The web is then advanced through a drying section. The drying section can be of various configurations. In one embodiment of the invention, the drying section comprises a series of heated drying cylinders that the web is brought into contact with in turn. The web can be urged into firm contact with the cylinders by fabrics.
After drying, the web is fed through a soft nip calendar. The calendaring of the web imparts a smooth surface to the web for good printability and enhances the soft feel of the web.
Additional features of the disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
FIG. 1 is a schematic depiction of a papermaking machine and process in accordance with one embodiment of the invention;
FIG. 2 is a schematic illustration of one cylinder group of the drying section in accordance with one embodiment of the invention; and
FIG. 3 shows a roll of redemption tickets formed of a stock in accordance with an embodiment of the invention.
FIG. 4 shows a perspective view of a prior art roll of tickets and the smaller, new roll of tickets made according to the present disclosure;
FIG. 5 shows a front elevation view of an end of a prior art ticket and an end of a ticket made according to the present disclosure;
FIG. 6 shows a perspective view of a portion of a double roll;
FIG. 7 shows a perspective view of a deck of folded tickets;
FIG. 8 shows a top view of a container packed with the prior art rolls of tickets;
FIG. 9 is a top view similar to that of FIG. 5 , showing a container packed with rolls of tickets made according to the disclosure; and
FIG. 10 is a top view of the space formed between four rolls, showing the space saved when the rolls are made according to the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some but not all embodiments of the invention are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
With reference to FIG. 1 , an apparatus and process for making a paper suitable for use as a ticket stock is illustrated. The process begins by placing a mixture of furnishes into a pulper, or repulper, 10 along with a quantity of water and agitating the mixture to break the furnishes down into a pulp. The mixture of furnishes comprises a blend of recycled furnishes. A preferred mixture comprises a blend of recycled solid bleached sulfate plate stock, recycled coated soft white, and recycled ground wood furnish such as newsprint or the like. In one embodiment, the blend comprises about 25-50 wt. % recycled solid bleached sulfate (SBS) plate stock, about 25-50 wt. % recycled coated soft white, and about 15-25 wt. % recycled ground wood furnish. A particularly advantageous blend comprises about 30 wt. % SBS plate stock, about 50 wt. % coated soft white, and about 20 wt % newsprint. The furnishes advantageously are blank or unprinted, but alternatively one or more can be printed. The pulper 10 preferably repulps the furnishes without any substantial degree of mechanical refining or fiber shortening. In this regard, the pulper preferably comprises a large open metal vessel with a high shear agitator in the bottom. A slurry of pulp at a consistency of 4%-6% solids is formed by feeding dry paper bales along with process white water into the pulper and agitating until the slurry can be extracted through a perforated plate and pumped to a receiving chest for further processing.
After the furnishes are pulped in the pulper 10 , the resulting pulp is cleaned using suitable cleaning equipment 12 to remove certain undesirable contaminants such as plastic, metal, glass, wood splinters, and dirt. The cleaning equipment comprises liquid cyclone cleaners which continuously remove particles of high specific gravity and contaminant materials such as sand, glass, paper clips, and staples, and also includes barrier screens which are designed to continuously remove oversized particles from the pulp stream prior to refining and formation.
The pulp is then fed into a disperser 14 that injects steam into the pulp while the pulp is at a high consistency (e.g., approximately 12%-20%). The disperser is a horizontally oriented, pressurized cylindrical vessel with a screw type feeder designed to keep slurry moving continuously through the vessel. The injected steam softens and hydrates the fibers of the pulp. Additionally, if any of the furnish used is printed, the steam injection breaks the inks down into very small particles which remain in the finished product but can barely be seen with the naked eye. Pigment in the form of high-brightness clay can be added later in the process to offset the loss of brightness caused by the presence of ink.
The pulp is fed from the disperser into a machine chest 16 where additional water is added to the pulp to reduce the consistency to a level suitable for paper forming. Additionally, one or more additives can be added to the pulp at this stage. For example, advantageously an amount of clay, liquid opacifier, or other opacifying agent can be added to the machine chest 16 for enhancing the opacity of the finished paper. In one embodiment, clay is added in an amount of about 80 to 120 pounds per ton of the finished paper stock.
Next, a process of fiber refining 18 can be performed using suitable equipment such as fractionating units or the like, to achieve a pulp having fiber lengths in a desired range. Such fractionating units and processes are known in the art and hence need not be described in detail herein. Advantageously, the pulp after the refining step 18 has developed sufficient bonding sites on the fiber cell walls for strength development with minimum fiber length reduction. Following the refining step, a size agent such as starch can be added to the pulp as shown. Starch can be added in the amount of about 25 to 35 pounds per ton of the finished stock.
The pulp advantageously is then subjected to a thin stock cleaning process 20 . This process consists of pumping dilute slurry (<1% solids) through a bank of multiple high velocity centrifugal cleaners to remove a large percentage of remaining fine particle contaminant materials (approx. 70%-90% removal rate).
The pulp is then fed into a headbox 22 of a fourdrinier former 24 . The headbox injects a stream of pulp onto a traveling wire 26 of the former. Dewatering elements 28 beneath the wire drain some of the water from the web formed on the wire. Advantageously, a Dandy roll 30 (i.e., essentially a roll with a wire screen wrapped about it) contacts the upper surface of the formed web to assist in web formation.
The web formed in the fourdrinier former 24 is advanced to a press section 32 for further dewatering. The press section can comprise various types and numbers of press devices, including roll presses, extended-nip or shoe presses, or the like. In the illustrated embodiment, the press section comprises a first roll press 34 and a second roll press 36 . Each of the roll presses includes a pair of dewatering fabrics (not shown) between which the wet web is sandwiched. The fabrics with the web therebetween are passed through the nip between the two rolls of the press. The pressure exerted on the fabrics and web causes water to be transferred from the web into the fabrics, as known in the art. The linear nip load exerted on the fabrics and web is generally higher in the second press 36 than in the first press 34 . For example, the nip load in the first press advantageously can be about 400 lb/linear inch (PLI) while the load in the second press can be about 1400 PLI.
The web can be treated by a steam box 38 prior to the press section 32 in order to heat the wet sheet and improve pressing and drying efficiency.
After pressing, the web is fed through a dryer section 40 for thermally drying the web to a desired low moisture content. The dryer section is made up of a first group of heated drying cylinders 42 and a second group of heated drying cylinders 44 . Each group of cylinders includes a pair of fabrics for urging the web against the cylinders. FIG. 2 shows the first group of cylinders 42 in greater detail. The cylinders are arranged so that the web W passes in serpentine fashion about each cylinder in turn, whereby one side of the web contacts the first cylinder, the other side of the web contacts the next cylinder, and this alternate cycle repeats for the next two cylinders, etc. A first fabric 46 is arranged to pass around a first set of the cylinders 42 . Guide rolls 48 guide the first fabric 46 from one cylinder to the next and allow the fabric to wrap about a substantial proportion of the circumference of each cylinder. The web W is arranged so that it is between the first fabric 46 and each cylinder 42 . A second fabric 50 is arranged to pass around a second set of the cylinders 42 , and guide rolls 52 guide the second fabric from one cylinder to the next and allow the fabric to wrap about a substantial proportion of the cylinder circumferences.
The second group of drying cylinders 44 likewise has a pair of fabrics that operate in the way described above.
With reference again to FIG. 1 , after the web exits the drying section 40 , it can optionally be coated on one or both sides in a coating applicator 54 . The applied coating(s) can then be dried in a dryer 56 . Advantageously, however, a ticket stock in accordance with preferred embodiments of the invention does not have any coating.
Next, the web is passed through a calender 58 . The calender advantageously comprises a soft nip calender wherein one of the calender rolls has a surface that is deformable so that the nip formed between the deformable roll and the opposing roll is somewhat elongated rather than being a single tangent point between two rigid rolls. The calender is preferably heated. A suitable calendering temperature is between about 400.degree. F. and about 500.degree. F. Calendering of the web in the soft nip calender imparts a smooth surface to the web for good printability, and enhances the soft feel of the web.
Finally, the finished web is wound into a roll in a reel-up 60. The roll of finished stock typically is shipped to a converter where it is converted into redemption tickets or other products. In the case of redemption tickets, the stock is unwound from the roll, slit, perforated, printed, and wound into individual rolls of redemption tickets such as the roll 70 shown in FIG. 3 .
The stock in accordance with preferred embodiments of the invention is manufactured to have a caliper of about 7 to 9 points, more preferably about 7 points. The formulation of the pulp leads to an opacity (measured according to the TAPPI 519 method) of at least about 98 percent for the finished stock, more preferably at least about 99 percent. The stock preferably has a Parker Smoothness, on at least one of its surfaces, not substantially exceeding about 8 microns, more preferably not substantially exceeding about 6 microns, and still more preferably not substantially exceeding about 5 microns.
As an example of a stock made in accordance with one embodiment of the invention, a white ticket stock was manufactured from 30 wt. % SBS plate stock, 50 wt % coated soft white, and 20 wt. % blank newsprint. Clay was added to the pulp in the amount of about 100 pounds per ton of the finished stock. Starch was added in the amount of about 28 to 31 pounds per ton of finished stock. The stock was manufactured using the above-described process, without the optional coating. Five rolls of the stock were prepared, and three samples from each roll were tested for various properties. The average of all samples was computed for each measured property. The average properties are listed below:
Caliper: 6.84 points
Basis Weight: 32.65 lbs/1000 ft.sup.2
Density: 4.78 lbs/point (per 1000 ft.sup.2)
Tensile Modulus (MD): 47 lbs.
Water Drop (TAPPI RC-70): 103 secs. (back), 85 secs. (top)
Taber Stiffness: 18.9 g-cm (MD), 10.2 g-cm (CD)
Parker Smoothness: 5.97.mu. (top), 4.29.mu. (back)
Minolta Color (avg. of top and back): 84.72 (L), 1.77 (A), 2.51 (B)
Opacity (TAPPI 519): 99.61%
The finished stock was clean and bright, with little or no specs or particles that could pick off the surface when printed. The stock had a matte finish and a generally soft feel in the hand. Slit edges were clean and substantially free of linting or dusting.
A ticket 100 , as can be seen in FIG. 4 , may be illustratively used for admission to or for point of purchase applications at any of the following: social events, festivals, carnivals, amusement places, parking lots, academic functions, religious functions, and athletic events, among others. Such a ticket 100 may be available in a wide variety of sizes, shapes, and colors, and may or may not have markings relating to the event. Ticket 100 may be punched, perforated, numbered, or die cut. Ticket 100 can be specifically designed for hand issue, machine issue, mechanical collection, collection and accounting by weight, and/or collection and accounting by audit.
The illustrative tickets 100 may be provided on a roll 120 of 2000 continuous tickets, commonly called “roll tickets” in the industry, as can be seen in FIG. 4 . In such an embodiment, tickets 100 are configured to be unrolled from the roll 120 and separated along perforations 280 in increments desired by the dispensing party. Alternatively, tickets 100 may be formed in groups of two or more, and can be dispensed two or more at a time from a “double roll” 140 , as can be seen in FIG. 6 . A double roll comprises 2000 sets of two tickets, and can be used, for example, in a raffle or lottery scenario. However, it should be understood that other configurations and embodiments are within the scope of the disclosure, and multiple tickets may be rolled adjacent each other. Furthermore, any number of tickets may be provided on a roll, and the tickets could alternatively be grouped in strips or sheets, or may be presented individually or in any other manner known in the industry.
The common ticket 200 , which has been known in the art for years, uses a substrate of “common ticket stock” paper having a caliper characteristic of approximately 9.5. Typically, the common ticket stock is comprised of ticket bristol paper, and has an illustrative thickness B, as can be seen in FIG. 5 . In contrast, ticket 100 is illustratively printed on a stock of paper that is considered “return postcard” or “reply card” stock paper. Such reply card stock having the same length and width dimensions may have a thickness A (as can be seen in FIG. 5 ). The caliper range may be between 5 and 11 points. The illustrative reply card stock has a caliper of 7. Common ticket stock is comprised of ticket bristol paper, and has an illustrative thickness B, as can be seen in FIG. 5 . In contrast, ticket 100 is illustratively printed on a stock of paper that is considered high opacity ticket stock paper. Such high opacity ticket stock having the same length and width dimensions may have a thickness A (as can be seen in FIG. 5 ). The caliper range may be between 5 and 7.5 points. The illustrative high opacity ticket stock has a caliper of 7. Tickets are illustratively formed to have a width of one inch and a length of two inches, although other dimensions are within the scope of the disclosure.
Additionally, the opacity of a paper may be considered. Common ticket stock typically has an opacity of 99% or greater. The illustrative reply card stock has an opacity of less than 98%. Such reply card stock having a caliper between 5 and 11 points and/or having an opacity below 98% can be ordered from paper supply companies such as International Paper, headquartered in Stamford, Conn., and Boise Cascade headquartered in Boise, Id. The common ticket stock is much thicker and heavier than the high opacity ticket stock presently disclosed. The illustrative high opacity ticket stock has an opacity of greater than 98%, while having a caliper range of between 5 and 7.5 points. Such high opacity ticket stock can be specially ordered from paper supply companies using the characteristics discussed herein.
It should be understood that while the illustrative substrates are reply card stock paper and high capacity ticket stock paper, other substrates providing the opacity and caliper characteristics suggested are within the scope of the disclosure. For example, the substrate may be a polymer-based material.
Use of the reply card stock and high capacity ticket stock described provides a ticket 100 having a substantially smaller thickness A than the thickness B of common ticket 200 constructed of common ticket stock, as demonstrated in FIG. 5 . The smaller thickness also provides a ticket roll 120 of 2000 tickets that has a substantially smaller diameter than the common ticket roll 220 of 2000 tickets, as can be seen in FIG. 4 . Illustratively, a common ticket roll 220 has a diameter of approximately seven (7) inches, and the ticket roll 120 according to specification has a diameter of approximately six (6) inches. The smaller diameter of ticket roll 120 compared to ticket roll 220 allows a box or container 160 of ticket rolls 120 to be shipped and stored in a smaller container 160 than a box or container 240 of ticket rolls 22 , as can be seen by comparing the dimensions of containers 160 and 240 , shown in FIGS. 8 and 9 . The smaller dimension of container 160 allows more containers 160 to be shipped in a given amount of space, i.e. a truckload, and allows more ticket rolls 120 to be stored in a given amount of storage space. Illustratively, container 16 has side dimensions of less than 13.5 inches.
The high opacity of greater than 98% prevents bleeding or burn-through of ticket dispensing sensors. Such sensors are typically optical sensors and misreadings can occur when lower opacity stock paper is used. A typical optical sensor is used for ticket-counting purposes by utilizing the combination of a light beam and sensor positioned on opposite sides of the strip of tickets being dispensed, the light sensor “reading” when the light shines through an aperture or notch 38 formed in the strip of tickets 10 . In lower opacity and/or caliper characteristics, such ticket-counting by light sensors may be impaired.
A container 160 shipping ticket rolls 120 made according to the present disclosure is also a more efficient means of shipping ticket rolls because the space 320 between rolls 120 is of smaller dimension than the space 340 between rolls 220 . By shipping less air and the same number of tickets, the shipping is more efficient. FIG. 10 illustrates the space saved by using rolls 120 of the present disclosure. The cross-hatched area 360 of FIG. 10 illustrates the shipping space saved when utilizing the presently disclosed rolls 120 .
Use of reply card stock or high capacity ticket stock can also provide a ticket 100 having less weight. A common single-ticket roll 220 of 2000 tickets, as shown in FIG. 4 , weighs approximately 1.10 pound. A ticket roll 120 of 2000 tickets according to the specification weighs approximately 0.65 pound. Because shipping costs are commonly calculated at least partially based on the weight of the shipment, the lighter weight of the ticket rolls 120 permits a savings on shipping costs to a consumer. Single-ticket rolls 220 , such as those shown in FIG. 4 , are illustratively shipped in containers 240 having 40 ticket rolls 220 . When such single-ticket rolls 220 are manufactured from common ticket stock, the approximately weight of container 240 is forty-seven (47) pounds. When single-ticket rolls 120 are manufactured from the illustrative reply card stock, the approximate weight of container 160 is twenty-eight (28) pounds. Common double-ticket rolls of 2000 tickets weigh approximately 2.35 pounds each, and double rolls 140 according to the disclosure weigh approximately 1.35 pound each.
It is within the scope of the disclosure to provide rolls of any number of tickets. For example, a double roll of 1000 tickets may be provided (not shown). If such a double roll were manufactured from common ticket stock, the diameter would be approximately five (5) inches and the weight would be approximately 1.1 pound. If the double roll were manufactured from the illustrative reply card stock, the diameter would be approximately 4.375 inches and the weight would be approximately 0.65 pound. If the double roll were manufactured from the illustrative high opacity ticket stock, the diameter would be approximately 4.375 inches and the weight would be approximately 0.90 pound.
The present disclosure is not limited to tickets on rolls, but can also be applied to sheet tickets, folded decks 180 of tickets (as can be seen in FIG. 7 ), and any other type of ticket known in the art. One use of folded decks 180 is that of redemption tickets, wherein the tickets are dispensed from a game of skill or chance for redemption of a prize. When decks 180 of tickets 100 are used in such a format, it may be necessary to reconfigure the ticket-counting device associated with the ticket dispenser. For example, a typical ticket-counting device (not shown) uses the combination of a light beam and sensor positioned on opposite sides of the strip of tickets being dispensed, the light sensor “reading” when the light shines through an aperture or notch 380 formed in the strip of tickets 100 . In some opacity and caliper characteristics disclosed herein, such ticket-counting by light sensors may be impaired. In the alternative, the light sensor may be configured to read a “dark” spot on the ticket 100 , rather than a light shining through a notch 380 . In such an embodiment, a dark line may be printed across a ticket where the ticket passes under the ticket-counting device, and the notch 380 may be omitted from the ticket 100 . However, it should be understood that the described embodiment is merely one example of how a ticket-counting device may be configured, and other examples are within the scope of the disclosure.
It is within the scope of the disclosure to provide a ticket with a light-sensor-triggering marking imprinted thereon. Such a light sensor could be used as a ticket counter.
A method of manufacturing tickets is also disclosed. The method includes the steps of unwinding a portion of a roll of reply card stock paper, feeding the unrolled portion through a printer, cutting the paper to form strips of paper, and perforating the strips of paper to form separable tickets therebetween. The method may include rolling tickets 100 on a tube 260 (visible in FIGS. 4 and 9 ) in a roll 120 of 2000 tickets 100 . Alternatively, the method may include forming decks 180 of tickets, typically accordion-folded with five tickets 10 disposed between each fold line 30 , as can be seen in FIG. 7 . Decks 180 are illustratively packaged in sets of 3000 tickets, although it is within the scope of the disclosure to combine any number of tickets to form a deck.
A method of shipping tickets is also provided by the disclosure. The method includes the steps of providing rolls of 2000 in a container measuring less than 14 inches on each side.
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A ticket stock and manufacturing process wherein a pulp is formulated from a blend of recycled furnishes, with added starch for enhancing sheet stiffness and reducing linting and dusting on cut edges of the stock, and clay or other opacifier for enhancing opacity of the stock. A preferred pulp comprises a blend of recycled solid bleached sulfate plate stock, recycled coated soft white, and recycled ground wood furnish such as newsprint or the like. In one embodiment, the blend comprises about 25-50 wt. % recycled solid bleached sulfate plate stock, about 25-50 wt. % recycled coated soft white, and about 15-25 wt. % recycled ground wood furnish. The furnish blend is repulped with minimal mechanical refining, is treated with steam injection for hydrating and softening the fibers, and is formed into a web that is pressed, dried, and soft calendered. The caliper of the resulting stock is about 7 to 9 points and provides a ticket for use in prize redemption in family entertainment centers, arcades, location-based entertainment centers, amusement parks, and similar establishments. The ticket may also be used to conduct drawings, raffles and give-a-ways. The ticket may be formed from a sheet of reply card stock paper having a caliper characteristic in the range of 5 and 11 points.
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BACKGROUND
[0001] The present invention regards a card for storage of coins, pogs and the like. More specific the invention concerns a card preferably of common bank and credit card size for fastening of coins, pogs or the like.
[0002] In connection with the present invention the terms token and pog will be used interchangeable and are synonymous with coins and circular articles.
[0003] The background for the present invention is the steady increasing use of bank cards and payment cards, and the simultaneous decreasing use and availability of coins. Despite this fact, there are still many fields where coins have to be used. Coins are e.g. used during shopping and retail purchasing in kiosks and shops, parking meter, toll roads and the like.
[0004] Another important field is for using a shopping trolley (cart) in a shopping center. To ensure that the customer carries the shopping trolley back to the shop after use, some shopping centers have introduced a kind of deposit on the trolley. To utilize a shopping trolley, the customer has to insert a coin (10-kr or 20-kr) into a particular lock mounted on the shopping trolley. This coin is refunded to the customer when the trolley is brought back to the shop.
[0005] A frequently occurring problem is that the customers often do not have the relevant coins and have to ask the employees of the shop to exchange another monetary unit. This can sometimes be irritating for the customer and disturbing for the employee.
[0006] The present invention is also directed to another field, where today coins are used. This is in connection with luggage trolleys (carts) to be used by the passengers for transportation of suitcases and bags on airports, railway stations and other traffic junctions.
[0007] The prior art describes different cardholders for fastening of coins, keys and the like items.
[0008] U.S. Pat. No. 4,037,716 describe a card with a die-cutted area for insertion of keys and coins. An adhesive transparent layer covers the die-cutted area with a gripping edge along one side for opening and closing.
[0009] U.S. Pat. No. 4,402,398 describe a card with a magnetic strip and a hole for mounting coins. It is important that the die-cutted hole has an exact dimension to remove the coin or secure it in the hole.
[0010] U.S. Pat. No. 5,022,247 describe a card with die-cutted areas for spare keys, which is mounted in the areas by means of friction between the key and the card. On the backside of the card is an adhesive layer of the same size as the card, with possibility for advertising or information.
[0011] These US patents have in common that they are complicated regarding manufacturing and structure, with peculiar pockets for keys and complex closing mechanisms.
SUMMARY OF THE DISCLOSURE
[0012] The present invention has a simpler configuration and consists of fewer components and is thus simpler and thus inexpensive in production.
[0013] The primary object of the present invention is to increase the availability of coins, pogs and tokens especially for use in connection with shopping trolleys and luggage trolleys. The object of the invention is preferably achieved with a card of common credit card or bank card size, wherein there are one or more die-cutted holes for insertion of coins, pogs or tokens.
[0014] More specific, the invention is directed to a device comprised of a card for keeping tokens, pogs or coins wherein the storage card has at least one hole, area or die-cutting to receive and fasten at least a token, pog or coin, wherein the token, pog or coin is circular and shaped with a groove, in a way that the token can be picked out and inserted into the hole several times.
[0015] The card is intended to every day use. The card will be produced according to methods and technique of prior art. The card according to the invention may be made of one or more layers of PVC, the layers together constitute the required thickness, preferably 0.7-1 mm. PVC is used as it is a very applicable plastic which is well known from a plurality of products.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention will be further explained with the aid of drawings, wherein
[0017] [0017]FIG. 1 is a view of a card with an oval hole,
[0018] [0018]FIG. 2 is a view of token/pog with a groove which runs circular along the edge seen from above and from one side,
[0019] [0019]FIG. 3 is a view of a card with a cutted side for mounting of a token/coin,
[0020] [0020]FIG. 4 is a view of a token/pog to be fastened to the card in FIG. 4,
[0021] [0021]FIG. 5 is a view of a card with hole and a transverse groove for mounting of a token/coin,
[0022] [0022]FIG. 6 is a view of the card according to FIG. 5 with a mounted pog/token,
[0023] [0023]FIG. 7 is a view of a card with a hole which is exact adjusted to a token/pog to be mounted by means of frictional forces.
DETAILED DESCRIPTION
[0024] As can be seen from the drawings the card according to the invention preferably has a size as the known payment, credit or bankcards. The well known dimension of the card is: height 5.40 cm and length 8.57 cm, with tolerance limits in both directions +/−0.040 cm. The thickness of the card is 0.7-1 mm. The cards are produced in a suitable flexible material, preferably plastic as e.g. PVC.
[0025] [0025]FIG. 1 is a card 10 with an oval hole 12 . The hole can be provided during production e.g. by die cutting. The hole 10 is located in the lower part of the card, but it can have an arbitrary placing on the card. It is also possible to have more than one hole in the card.
[0026] [0026]FIG. 2 displays the circular token/pog 11 with the groove 14 running circular along the edge. The groove is extending continuously around the circumference of the token and has a thickness that corresponds to the thickness of the card 10 , that is about 0.7-1 mm. The depth of the groove is also about 1 mm. The token with the groove 14 seen from one side, and the token seen from above is not depicted in the same scale.
[0027] The oval hole is adjusted to fit the token 11 . The hole 12 in the card has an oval shape, as the smallest diameter is equal the diameter of the circular groove 14 of the token, and the larger diameter is larger than the diameter of the token. The token 11 is fitted in the card by pressing into the oval hole in a way that the groove gets in contact with the edges 15 , 16 of the card. When the token is to be removed, the card is carefully bent and the token is picked out with a finger grip. The token is thus ready for use for instance in connection with a shopping- or luggage trolley. The empty card is then put into the wallet or other storage, to be used again when the utilization of the token is terminated. In this way the user will always have a token to be used during shopping or transportation.
[0028] The token is preferably manufactured in plastic, but it can also be manufactured in another material as for instance a metal or an alloy.
[0029] [0029]FIG. 3 depicts a card 10 with a cutted or die-cutted side section 17 . The section is in the figure provided along one short side 18 , but an equivalent section can also be placed along the long side 19 , or both on the short side and the long side.
[0030] The token/pog which is adjusted to this shaping is shown in FIG. 4. The circular token is provided with a center groove 20 extending from the outside towards the center of the diameter of the token. The depth of the groove 20 equals the radius of the token, and the width of the groove is in such a way that the token and the card is connected by means of frictional forces. The adjustment between token and card shall be such that the token can be removed and mounted without any problems. FIG. 5 depicts an embodiment wherein the hole 12 is divided with a transverse pole 21 . This embodiment of the card uses a token/pog as shown in FIG. 6, that includes a transverse groove, preferably being diametrical. To further ensure that the token does not fall off, this diametrical groove has a cut with a wide bottom and a narrow top. In this way it is possible to obtain a snap locking between token and card. The hole 12 in FIG. 5 is depicted circular, but can be oval as well.
[0031] [0031]FIG. 7 depicts a card provided with a pressed-out hole 25 for perfect adjustment for a token. The hole 25 is not through and is dependent on friction forces between the token and the card in a secure manner.
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The device comprises a card ( 10 ) for storage of coins ( 12 ), characterised by that the storage card ( 10 ) is shaped with at least one hole ( 12 ) or area to receive and fasten at least a coin ( 12 ) in a way that the coin ( 12 ) can be repeatedly taken out and fixed in the hole.
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BACKGROUND OF THE INVENTION
This application relates generally to photography and more particularly to photographic products, processes and compositions which include cyclic crown ether ligands as silver halide solvents.
Photographic processing compositions capable of forming water-soluble complex silver salts are known to be useful in many types of silver halide photography. In conventional or "tray" development, it is customary to fix the developed silver halide emulsion by applying a solution of silver halide solvent, i.e., silver halide complexing agent which forms a water-soluble silver complex with the residual silver halide. The water-soluble silver complex thus formed and excess silver halide solvent are then removed from the developed and fixed emulsion by washing with water.
Silver halide solvents also have been employed in monobaths where a single processing composition containing a silver halide developing agent in addition to the silver halide solvent is utilized for both developing and fixing an exposed photosensitive silver halide layer. Silver halide solvents also have been employed in diffusion transfer photographic processes. Such processes are now well known in the art; see for example, U.S. Pat. Nos. 2,543,181; 2,647,056; 2,983,606; etc. In processes of this type, an exposed silver halide emulsion is treated with a processing composition whereby the exposed silver halide emulsion is developed and an imagewise distribution of diffusible image-forming components is formed in the unexposed and undeveloped portions of the silver halide emulsion. This distribution of image-forming components is transferred by imbibition to an image-receiving stratum in superposed relationship with the silver halide emulsion to provide the desired transfer image. In diffusion transfer processes where a silver transfer image is formed, processing is effected in the presence of a silver halide solvent which forms a diffusible complex with the undeveloped silver halide. The soluble silver complex thus formed diffuses to the superposed image-receiving layer where the transferred silver ions are deposited as metallic silver to provide the silver transfer image. In preparing silver prints in this manner, the image-receiving element preferably includes a silver precipitating agent, for example, heavy metal sulfides and selenides as described in U.S. Pat. No. 2,698,237.
The present invention is concerned with new photographic compositions, processes and products as well as novel silver halide solvents.
SUMMARY OF THE INVENTION
It is therefore the object of this invention to provide photographic products, processes and compositions wherein cyclic crown ether ligands are utilized as silver halide solvents.
It is another object to provide novel cyclic crown ether ligands.
BRIEF SUMMARY OF THE INVENTION
These and other objects and advantages of the invention are accomplished by providing photographic products, processes and compositions which include, as silver halide solvents, at least one silver complexing compound which is represented by the structural formula ##STR1## wherein
X may be selected from the group consisting of oxygen, nitrogen, sulfur, phosphorous and selenium;
R 1 and R 2 may be the same or different and may be H, alkyl, hydroxyalkyl, alkoxyalkyl or aminoalkyl, preferably having from two to six carbon atoms, ##STR2## wherein
R 4 may be H, alkyl, alkoxy, or --NO 2 and R 5 may be H, alkyl, alkoxy or alkoxyalkyl; and
when X is --N--, R 3 may be H, alkyl, hydroxyalkyl, alkoxyalkyl or aminoalkyl, preferably having from two to six carbon atoms, ##STR3## wherein R 6 may be H, alkyl, cyano or ##STR4## wherein R 7 may be H or alkyl.
The compound wherein X is oxgyen and R 1 and R 2 are both hydrogen is disclosed in Tetrahedron Letters, Pelissard and Louis page 4589 (1972). The other compounds which are within the general formula are per se novel compounds.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One class of specific preferred silver complexing compounds which are suitable for use according to the invention is represented by the general formula ##STR5## wherein R 1 and R 2 are as described in Table I
TABLE I______________________________________Compound R.sub.1 R.sub.2______________________________________A H HB CH.sub.3 CH.sub.3 ##STR6## HD ##STR7## ##STR8##E ##STR9## HF ##STR10## ##STR11##G ##STR12## ##STR13##H ##STR14## H______________________________________
Other specific preferred silver complexing compounds which are suitable for use according to the invention are represented by the following formulas: ##STR15##
Compounds A, B, I, J and L are stable in an alkaline environment, have a melting point less than about 50° and the log of the stability constant (β) for a 1:1 complex of the complexing agent with silver is at least about 10.5. By "stable in an alkaline environment" is meant that the silver complexing agent retains at least 75% of its silver complexing ability after being in a 1 N sodium hydroxide solution for twenty-four hours at room temperature. These preferred complexing agents can be used in a diffusion transfer photographic method for making positive transparencies, without washing, which are substantially completely free of crystals. The method is described and claimed in applicants' copending application Ser. No. 080,349, filed on even date herewith. Accordingly, these compounds are the preferred silver complexing agents of the invention.
Compound A may be synthesized according to the method described in Tetrahedron Letters, 45, pp 4589-4592 (1972). The pentadentate macrocyclic ligands B, I, J and L can be prepared by reacting N,N'-dimethyl-N,N'bis(2-mercaptoethyl) ethylenediamine [for its preparation see J. Amer. Chem. Soc., 98, page 6951 (1976)] with (Cl CH 2 CH 2 ) 2 X (where X may be O, N--Me, NH or S) in a suspension of sodium hydride in tetradydrofuran. Compounds such as C--H may be prepared from compound A by reaction with appropriate acyl halides. Similarly, compound K may be prepared from compound J by reaction with p-nitrophenyl chloroformate. The desired ligands can be separated from the crude reaction products by first treating their methanol solution with silver thiocyanate to form the 1:1 ligand-silver thiocyanate complex which preferentially crystallizes from solution while the impurities remain in the filtrate. Recrystallization of the complex followed by precipitation of silver as silver sulfide with hydrogen sulfide and liberation of the free ligand by passing an aqueous solution of the resulting thiocyanic acid complex through an anion exchange column provides essentially pure samples of the ligands. Alternatively purification can be effected by chromatography of the crude product mixture on silica gel, a more time consuming procedure.
As mentioned previously, the compounds represented by the general formula are useful as silver complexing agents in photography. The log of the stability constant (β) for the 1:1 complex of various preferred compounds is shown in Table II. The stability constants were determined by potentiometry, i.e, by titrating the ligand with a standardized solution of silver perchlorate in mildly alkaline, constant pH, constant ionic strength medium (0.05 M NaOH, 0.10 M NaClO 4 ). All solutions and titrants were prepared carbonate free and with an ionic strength of 0.1 (NaClO 4 ) except when the perchlorate salt of the complex was found to be insoluble. In those cases perchlorate was omitted from the system. An argon atmosphere was used throughout. The indicating electrode was a silver specific ion type used in conjunction with a sleeve type double junction Ag/AgCl reference electrode.
TABLE II______________________________________Compound Log β______________________________________A 11.37 ± .01B 11.84 ± .01I 12.30 ± .01 J* 11.98 ± .02L 11.84 ± .02______________________________________ *No perchlorate was added
In formulating photographic processing compositions utilizing the above-described compounds, the compounds may be used singly or in admixure with each other or with other silver halide solvents. The total amount employed may vary widely depending upon the particular photographic system and should be used, for example, in a quantity sufficient for fixing a developed negative in conventional "tray" processing or in a quantity sufficient to give a satisfactory transfer print in diffusion transfer processes under the particular processing conditions employed.
Though the silver halide solvents of the present invention are broadly useful in a variety of photographic processes of the type in which water-soluble silver complexes are formed from the unreduced silver halide of a photoexposed and at least partially developed silver halide stratum, they find particular utility in diffusion transfer processes. A composition embodying the present invention specifically suitable for use in the production of transfer images comprises, in addition to the silver complexing agents of the above-described type, a suitable silver halide developing agent. Examples of developing agents that may be employed include hydroquinone and substituted hydroquinones, such as tertiary butyl hydroquinone, 2,5-dimethyl hydroquinone, methoxyhydroquinone, ethoxyhydroquinone, chlorohydroquinone, pyrogallol and catechols, such as catechol, 4-phenyl catechol and tertiary butyl catechol; aminophenols, such as 2,4,6-triamino-orthocresol; 1,4-diaminobenzenes, such as p-phenylenediamine, 1,2,4 triaminobenzene and 4-amino-2-methyl-N,N-diethylaniline; ascorbic acid and its derivatives, such as ascorbic acid, isoascorbic acid and 5,6-isopropylidene ascorbic acid, and other enediols, such as tetramethyl reductic acid; and hydroxylamines, such as N,N-di-(2-ethoxyethyl)hydroxylamine and N,N-di(2-methoxyethoxyethyl)hydroxylamine.
In diffusion transfer processes, the processing composition, if it is to be applied to the emulsion by being spread thereon in a thin layer, also usually includes a viscosity-imparting reagent. The processing composition may comprise, for example, one or more silver halide solvents of the present invention, one or more conventional developing agents such as those enumerated above, an alkali such as sodium hydroxide or potassium hydroxide and a viscosity-imparting reagent such as a high molecular weight polymer, e.g., sodium carboxymethyl cellulose or hydroxyethyl cellulose.
In one such transfer process, the processing solution is applied in a uniformly thin layer between the superposed surfaces of a photoexposed photosensitive element and an image-receiving element, for example, by advancing the elements between a pair of pressure-applying rollers. The elements are maintained in superposed relation for a predetermined period, preferably for a duration of 15 to 120 seconds, during which exposed silver halide is reduced to silver and unreduced silver halide forms a water-soluble, complex salt which diffuses through the layer of solution to the image-receiving element, there to be reduced to an argental image. At the end of this period, the silver halide element is separated from the image-receiving element. Materials useful in such a transfer process are well known in the art.
The photosensitive element may be any of those conventionally used in silver diffusion transfer processes and generally comprises a silver halide emulsion carried on a base, e.g., glass, paper or plastic film. The silver halide may be a silver chloride, iodide, bromide, iodobromide, chlorobromide, etc. The binder for the halide, though usually gelatin, may be a suitable polymer such as polyvinyl alcohol, polyvinyl pyrrolidone and their copolymers.
The image-receiving element preferably includes certain materials, the presence of which, during the transfer process has a desirable effect on the amount and character of silver precipitated on the image-receiving element. Materials of this type are known in the art.
Separating of the silver halide element from the image-receiving element may be controlled so that the layer of processing composition is removed from the image-receiving element or the layer of the processing composition is caused to remain in contact with the image-receiving element, e.g., to provide it with a protective coating. Techniques which enable such results to be accomplished as desired are described in U.S. Pat. No. 2,647,054. In general, the processing reagents are selected so that traces remaining after the solidified processing layer has been separated from the silver image or which remain in said layer adhered as a protective coating on the silver image, as indicated above, are colorless or pale, so as not to appreciably affect the appearance of the image and to have little or no tendency to adversely react with the silver image.
The silver halide solvents of the present invention also may be employed in diffusion transfer processes adapted to provide positive silver transfer images which may be viewed as positive transparencies without being separated from the developed negative silver image including such processes adapted for use in forming additive color projection positive images. Diffusion transfer processes of this type are known in the art. See, for example, U.S. Pat. Nos. 3,536,488, 3,615,428, and 3,894,871. The subject compounds also find utility in silver halide solvents in diffusion transfer processes utilizing the properties of the imagewise distribution of silver ions in the soluble silver complex made available in the undeveloped and partially developed areas of a silver halide emulsion to liberate a reagent, e.g., a dye in an imagewise fashion, as described in U.S. Pat. No. 3,719,489.
As noted above, in diffusion transfer film units the negative component comprising at least one photosensitive layer and the positive component comprising an image-receiving layer may be in separate sheet-like elements which are brought together during processing and thereafter either retained together as the final print or separated following image formation.
Rather than the photosensitive layer and the image-receiving layer being in separate elements, they may be in the same element. In one such film unit, the image-receiving layer is coated on a support and the photosensitive layer is coated on the upper surface of the image-receiving layer. The liquid processing composition is applied between the combined negative-positive element and a second sheet-like element or spreading sheet which assists in spreading the liquid composition in a uniform layer adjacent to the surface of the photosensitive layer.
Still other film units are those where the negative and positive components together may comprise a unitary structure wherein the image-receiving layer carrying the transfer image is not separated from the developed photosensitive layer(s) after processing but both components are retained together as a permanent laminate. Such film units include those for providing positive silver transfer images which may be viewed as positive color transparencies, such as, those described in U.S. Pat. No. 3,894,871. Other integral film units also include those adapted for forming a transfer image, in color or in black and white, viewable by reflected rather than by transmitted light. In addition to the aforementioned photosensitive layer(s) and image-receiving layer, such film units include means for providing a reflecting layer between the image-receiving and photosensitive layer(s) in order to mask the developed photosensitive layer(s) and to provide a white background for viewing the transfer image. This reflecting layer may comprise a preformed layer of a reflecting agent included in the film unit or the reflecting agent may be provided subsequent to photoexposure, for example, by including the reflecting agent in the processing composition. In addition to these layers, the laminate usually includes dimensionally stable outer layers or supports, at least one of which is transparent so that the resulting transfer image may be viewed by reflection against the background provided by the light-reflecting layer. Integral negative-positive film units wherein the photosensitive and image-receiving layers are retained as a permanent laminate after processing are described, for example, in U.S. Pat. Nos. 3,415,644; 3,647,437 and 3,594,165.
It will be appreciated that in the formation of color transfer images, a dye image-providing material such as the compounds of U.S. Pat. No. 3,719,489 may be associated with the photosensitive silver halide layer or layers of the negative component.
The diffusion transfer film units described above are employed in conjunction with means, such as, a rupturable container containing the requisite processing composition and adapted upon application of pressure of applying its contents to develop the imagewise exposed film unit.
To illustrate the utility of the above-described compounds as photographic silver halide complexing agents, certain of the compounds were incorporated in photographic processing composition which were then employed in a photographic method. In one such illustrative showing a film unit was prepared comprising a transparent polyester film base carrying on one surface an additive color screen of approximately 1000 triplets per inch of red, blue and green filter screen elements in repetitive side by side relationship; an approximately 4 micron thick polyvinylidene chloride barrier layer; a nucleating layer comprising 0.23 mg/ft 2 of palladium nuclei (as metal), 0.29 mg/ft 2 of gelatin, 0.35 mg/ft 2 of tin (as metal) and 0.47 mg/ft 2 of total chloride (associated with Pd and Sn); an interlayer of 2.21 mgs/ft 2 of deacetylated chitin, 0.645 mg/ft 2 of copper acetate (dihydrate), 0.178 mg/ft 2 of sodium acetate and 0.194 mg/ft 2 of alkyl phenoxy polyoxy ethylene glycol; a hardened gelatino silver iodobromo emulsion coated at a coverage of about 85 mgs/ft 2 of silver, 114 mgs/ft 2 of gelatin, 50 mgs/ft 2 of Dow 620 carboxylated styrene butadiene latex, 4.56 mgs/ft 2 of propylene glycol alginate and 0.55 mg/ft 2 of chrome alum (coverage as K 2 Cr(SO4) 2 . 12 H 2 O); and an antihalo top coat of 300 mgs/ft 2 of gelatin, 175 mgs/ft 2 of Dow 620 carboxylated styrene butadiene latex, 8.8 mgs/ft 2 of propylene glycol alginate, 1.2 mgs/ft 2 of dioctyl ester of sodium succinic acid, 5.6 mgs/ft 2 of pyridinium bis-1,5(1,3-diethyl-2-thiol-5-barbituric acid) pentamethine oxanol, 7.0 mgs/ft 2 of 4-(2-chloro-4-dimethyl-amino benzaldehyde)-1-(p-phenyl carboxylic acid)-3-methyl pyrazolone-5 and 5.0 mgs/ft 2 of benzimidazole-2-thiol gold Au -1 complex (as gold).
A film unit as identified above was exposed through the additive color screen to a step wedge. After a polyester cover sheet was superposed over the film unit it was processed, while being retained intact, by spreading a layer of processing composition less than about 1.2 mils thick between the anti-halo top coat layer and the cover sheet. The processing composition was prepared by adding 0.4 ml of compound A to 10 ml of the following formulation:
______________________________________Water 79.02 g.Hydroxyethyl cellulose 0.84 g.Sodium hydroxide 10.04 g.Tetramethyl reductic acid 8.38 g.Sodium sulfite 0.97 g.Potassium bromide 0.73 g.4-aminopyrazolo (3,4-d)pyrimidine 0.019 g.______________________________________
After an imbibition period of about one minute the cover sheet was stripped away and the maximum and minimum densities of the resultant image were determined with a transmission densitometer. The values were as follows:
______________________________________ Red Green Blue______________________________________D Max 1.83 2.31 3.33D Min 0.80 0.98 1.45______________________________________
In another illustrative showing, a film unit was prepared as follows: the light sensitive element comprised a transparent polyester film base carrying on one surface an additive color screen of approximately 1500 triplets per inch of red, blue and green filter screen elements in repetitive side by side relationship; a composite barrier structure made up of an approximately 0.7 micron thick layer of polyvinylidene chloride coated from a solvent, an approximately 1.0 micron thick layer of polyvinylidene chloride coated from water emulsion and an approximately 0.3 micron thick layer of polyvinyl formal; a nucleating layer as described in the previous example; an interlayer of 1.94 mgs/ft 2 of gelatin, and 0.194 mg/ft 2 of alkyl phenoxy polyoxy ethylene glycol; a hardened gelatino silver iodobromo emulsion coated at a coverage of about 85 mgs/ft 2 of silver, 85 mgs/ft 2 of gelatin, 7.5 mgs/ft 2 of propylene glycol alginate, 0.41 mg/ft 2 of chrome alum (coverage as K 2 Cr(SO 4 ) 2 , and 0.61 mg/ft 2 of alkyl phenol polyglycol ether (average 9.5 mols ethylene oxide) surfactant; and an antihalo top coat as described in the film unit of the previous example with the exception that 22 mgs/ft 2 of propylene glycol alginate were present.
The cover sheet comprised a 4 mil thick polyester support having a thin coating on one surface to prepare the support for coating. Coated on the support in the following order were:
(A) An acid providing layer formed by combining 60 parts by volume of a 30% solution of the half butyl ester of ethylene maleic anhydride in methyl ethyl ketone and 40 parts by volume of a solution of 5.7% Butvar B-72 (available from Monsanto), 63.3% ethyl acetate and 31% n-butanol and coating the mixture on the support to provide a dry coverage of about 2.45 mgs/ft 2 ; and
(B) A gelatin layer formed by coating a water solution containing 10% deionized gelatin, and 0.05% Emulphor ON-870 (available from Antara Chemical Co.) to provide a dry coverage of about 1 mg/ft 2 .
The film unit as identified above was exposed through the additive color screen to a step wedge and processed while being retained intact, by spreading a layer of a processing composition less than about 3 mils thick between the cover sheet and the light sensitive element. The processing composition was prepared by adding 0.5 ml of compound (B) to 10 ml of the following formulation:
______________________________________Water 82.36 g.Sodium hydroxide 7.265 g.Hydroxyethyl cellulose 2.811 g.Sodium sulfite 2.54 g.Tetramethyl reductic acid 3.17 g.Dodecyl-N,N-dipyridiniumdibromide 1.78 g.4-aminopyrazolo (3,4-d)pyrimidine 0.016 g.5-bromo-6-methyl-4-azabenzimidazole 0.016 g.Thiazololidine-2-thione 0.035 g.______________________________________
After an imbibition period of about one minute the maximum and minimum densities of the image were determined on a transmission densitometer. The values were as follows:
______________________________________ Red Green Blue______________________________________D Max 1.58 1.69 1.64D Min 0.29 0.31 0.38______________________________________
When examined visually 17 days after processing no crystals were apparent in the transparency. The image was stored under ambient conditions during the interim.
It will be apparent that the relative proportions of the subject silver halide solvents and of the other ingredients of the processing compositions may be varied to suit the requirements of a given photographic system. Also, it is within the scope of this invention to modify the formulations set forth above by the substitution of alkalies, antifoggants and so forth other than those specifically mentioned. Where desirable, it is also contemplated to include in the processing compositions, other components as commonly used in the photographic art.
The invention will now be described further in detail with respect to specific preferred embodiments by way of examples, it being understood that these are illustrative only and the invention is not intended to be limited to the materials, conditions, process parameters, etc., recited therein. All parts and percentages are by weight unless otherwise indicated.
EXAMPLES
Preparation of N,N'-dimethyl-N,N'-bis(2-mercaptoethyl)-ethylene diamine
A 250 ml three-neck flask, equipped with a magnetic stirrer, addition funnel, thermometer and argon inlet was charged with a solution of 18.3 g. (0.208 mol) of N,N'-methylethylenediamine in 70 ml of benzene. A solution of 25.1 g. (0.417 mol) of ethylene sulfide in 10 ml of benzene was added with stirring to the solution in the flask under argon while maintaining the temperature of the solution in the flask at 50°-55° C. The resulting clear solution was allowed to remain overnight at ambient temperature, washed with two 5 ml portions of water and dried over magnesium sulfate. The solvent was removed under reduced pressure and 39.9 g. (97% yield) of a colorless oil was obtained.
The material is susceptible to air oxidation and therefore further purification was not carried out. The material can be stored up to a week under argon in a freezer without any significant deterioration. Since the compound has an extremely unpleasant odor and can cause severe skin allergy careful handling is necessary.
EXAMPLE I
Preparation of Compound B
A three neck liter flask equipped with an overhead stirrer, addition funnel and argon inlet, and an oil bath was charged with 14.5 g. of a 50% sodium hydride dispersion in oil (0.26 molar in NaH). Most of the oil was removed by repeated washings with petroleum ether carried out under argon. In each washing about 15-20 ml of petroleum ether were added to the dispersion, the dispersion stirred briefly and allowed to settle and supernatant liquid removed with a syringe. 520 ml of spectrograde dimethylformamide were then introduced into the dispersion and the reaction flask was heated with the oil bath maintained at about 95° C. When the internal temperature of the flask reached about 75° C. there was begun the dropwise addition, with vigorous stirring, of a mixture of 27.08 g. (0.13 mole) of N,N'-dimethyl-N,N'-bis(2-mercaptoethyl)ethylenediamine and 18.6 g. (0.13 mole) of bis-2-chloroethylether in 40 ml dimethylformamide. Addition of the mixture was completed in about 2 1/2 hours. The temperature was maintained at about 80°-85° C. throughout the addition of the mixture and for about 16 hours thereafter. Most of the solvent was removed in vacuo with the bath temperature at about 70°-75° C. The resulting thick light brown oil was dissolved in 300 ml of ethylacetate, washed with three 20 ml portions of water and dried over magnesium sulfate. Removal of the solvent under reduced pressure gave 34 g. of a light brown syrup. 13 C NMR and chromatographic analysis showed this to be a complex mixture of products.
A solution of 18 g. of the crude product in 200 ml of methanol was formed and to it there were added 10.9 g. of silver thiocyanate in portions. Toward the end of the silver thiocyanate addition dissolution of the silver salt became slow and a sticky material separated from solution. The mixture was stirred for about 15 minutes after which the soluble portion was removed, diluted with 100 ml of methanol and filtered through Celite 542 (a diatomaceous earth material available from Johns Manville Co.). The filtrate was concentrated to 120 ml under reduced pressure and stored for two days in a refrigerator. Light yellow crystals deposited during storage and these were collected, washed with methanol and recrystallized from methanol twice at low temperature by first dissolving the crystals in excess solvent at 40° C. and then concentrating to about one-half the initial volume. The crystals were then dried under high vacuum. A total of 8.5 g. of 1:1 compound B - silver thiocyanate complex, m.p. 147°-149° C. was recovered. Recrystallization of a small sample of this material gave essentially colorless crystals, m.p. 149°-150° C. C 13 H 26 N 3 OS.Ag requires 35.13%C, 5.895%H, 9.46%N, 21.64%S and 24.27%Ag. Elemental analysis of this material gave 35.03%C, 5.91%H, 9.50%N, 21.60%S and 24.43%Ag. Also NMR spectral data were consistent with a compound B - silver thiocyanate complex.
8.3 g. (18.7 moles) of the complex were dissolved in 100 ml of a 70:30 (vol/vol) mixture of dichloromethane and ether and treated with hydrogen sulfide gas to precipitate silver as silver sulfide. Bubbling of hydrogen sulfide was continued until an aliquot of the supernatant solution gave no precipate with hydrogen sulfide. The mixture was then stirred for about 15 minutes, filtered through Celite 542 and the filtrate was concentrated to a thick colorless syrup, presumably a thiocyanic acid complex of ligand B. The free ligand, compound B, was obtained from this material by the following alternative procedures:
(A) A column of a strongly basic, quaternary ammonium (polystyrene) type, anion exchange resin (Amberlite IRA-400) was prepared in carbonate-free water, washed with dilute sodium hydroxide and then thoroughly with water until the eluent was not basic. An aqueous solution of the above colorless syrup was passed through the column and washing with carbonate-free water was continued until most of the material had been eluted. The combined washings were concentrated under reduced pressure. The residual syrup was dissolved in absolute ethanol, filtered through Celite 542 and the filtrate concentrated to provide about 5 g. of compound B as a clear colorless syrup. The sample was dried at 50° C. by pumping under high vacuum.
(B) Alternatively, the aqueous solution of the bisthiocyanic acid complex was treated with a stoichiometric amount of a 10% aqueous tetramethylammonium hydroxide solution and extracted with ethylacetate or dichloramethane. The organic layer was washed with water and dried over anhydrous sodium sulfate. Removal of the solvent gave compound B as a colorless syrup.
C 12 H 26 N 2 S 2 O requires 51.75%C, 9.41%H, 10.06%N, 23.03%S and 5.74%O. Elemental analysis gave 51.74%C, 9.39%H, 10.02%N and 22.84%S.
EXAMPLE II
Preparation of Compounds C and D
A solution of 0.25 g. of compound A in 5 ml of tetrahydrofuran was formed, cooled in an ice bath and to it was added dropwise over a period of about 15 minutes a solution of 0.186 g. of p-nitrobenzoyl chloride in 5 ml tetrahydrofuran. The solution was stored overnight in a refrigerator, warmed to 0° C. and then stirred at room temperature for about four hours. The solvent was removed and the residue triturated with ice. A semi-solid was obtained and extracted with dichloromethane. The extract was washed with dilute sodium hydroxide until the aqueous layer was slightly basic and then dried over sodium sulfate. Examination of the product by thin layer chromatography on silica gel using a 20:1 (vol/vol) ethylacetate-ethanol mixture as the eluent showed the product to be a mixture of the mono-(compound C) and diacylation (compound D) product as well as starting material.
The diacylation product, m.p. 196°-197° C. was separated by recrystallization from absolute ethanol. The filtrate, upon removing the diacylation product, was concentrated. Examination of the concentrate by thin layer chromatography on silica gel using a 85:15 (vol/vol) benzene-methanol mixture showed it to contain primarily the monoacylation product (compound C) and the starting material along with minor impurities. The monoacylation product was isolated as a thick syrup by chromatographing the product two additional times under the same conditions. The NMR spectrum of the product was consistent with compound C.
EXAMPLE III
Preparation of Compound D
A suspension of 0.322 g. of the dihydrochloride salt of compound A in 5 ml of benzene was treated with 2 ml of dimethylformamide to dissolve most of the solid, followed by the addition of 0.28 ml triethylamine. Then a solution of 0.186 g. of p-nitrobenzoyl chloride in 2 ml tetrahydrofuran was added dropwise and the mixture stirred overnight at room temperature. The mixture was concentrated, diluted with 15 ml of ice water, extracted with three 15 ml portions of dichloromethane and dried over magnesium sulfate. The product was concentrated to give a thick syrup which solidified when triturated with methanol at ice bath temperature. The solid was filtered, washed with methanol and dried under reduced pressure to give a white solid, m.p. 195°-198° C. The NMR spectrum was consistent with compound D.
EXAMPLE IV
Preparation of Compounds E and F
A solution of 0.38 g. of compound A in 10 ml dry ether was formed and cooled in an ice bath. The solution was treated with ethereal hydrochloric acid (HCl gas dissolved in ether at 0° C.) until the supernatant liquid showed no turbidity upon additional treatment with ethereal hydrochloric acid. A white solid (the dihydrochloride salt of compound A) separated from solution, was removed by filtration and washed with ether.
To a stirred suspension of 0.32 g. of the dihydrochloride salt of compound A in 2 ml of 6% potassium hydroxide solution there was added 0.23 g. of tosyl chloride. The mixture was warmed to a temperature of 50°-60° C. for about 15 minutes and then cooled in an ice bath. The solid which formed was removed by filtration, washed with water and crystallized from ethanol to provide colorless, needlelike crystals, m.p. 170°-172° C. The NMR spectrum of the material was consistent with the ditosylate (compound F).
After removing the ditosylate the aqueous filtrate was extracted with dichloromethane and the extract dried and concentrated. The material was then chromatographed on silica gel using an 80:20 mixture of ethylacetate-ethanol as the eluent to separate the monotosylate (compound E) as a colorless syrup which solidified on standing at room temperature, m.p. 71°-73° C. The NMR spectrum of the material was consistent with the monotosylate.
EXAMPLE V
Preparation of Compounds G and H
125 mg of compound A were dissolved in 1.5 ml of dichloromethane and to the solution were added dropwise, with stirring, 0.05 ml of acetic anhydride. The mixture was heated under reflux for 6 hours and then stirred overnight at room temperature. The solvent was removed and the residue taken up in 25 ml of dichloromethane, washed sequentially with 0.5 N hydrochloric acid, 3% sodium bicarbonate and water. The extract was dried over magnesium sulfate and concentrated under reduced pressure to give the crude product mixture as a semi-solid. Crystallization from absolute ethanol gave colorless crystals, m.p. 145°-146° C. The NMR spectrum was consistent with compound G.
EXAMPLE VI
Preparation of Compound I
To a suspension of 0.24 g. of a 50% sodium hydride dispersion in oil (which had previously been washed free of oil with petroleum ether) in 15 ml of dimethylformamide was added 0.95 g. of mechlorethamine hydrochloride. To the resulting free amine were added 1.05 g. of N,N'-dimethyl-N,N'-bis(2-mercaptoethyl) ethylenediamine in 5 ml of dimethylformamide.
To a separate three neck flask there was added 0.5 g of a 50% sodium hydride dispersion in oil and this was washed free of oil with petroleum ether under argon. To this were added 50 ml of dimethylformamide and the suspension was heated to 80°-90° C. The mixture of the two reactants prepared above was then added dropwise with vigorous stirring over a period of about 25 minutes and stirring was continued at that temperature overnight. The solvent was then removed under reduced pressure, the residue taken up in 25 ml of ethyl acetate, washed twice with two 5 ml portions of water and dried over sodium sulfate. Removal of the solvent gave 1.4 g of a slightly colored syrup. 13 C NMR and thin layer chromatographic analysis on silica gel using a 50:50 (vol/vol) mixture of ethylacetate-hexane showed this to be a mixture of products. Purification by column chromatography on silica gel gave 0.5 of compound I which was characterized by 13 C NMR and mass spectrum (m/e=291, parent ion and 292 P+1).
A stirred solution of 116 mg of compound I in 5 ml methanol was treated with 66.4 mg of silver thiocyanate. After 10 minutes the mixture was filtered to remove traces of suspended material and the solvent removed under reduced pressure to give a white crystalline solid, m.p. 160°-162° C. The product was crystallized from methanol by storing for several days in a refrigerator. Needle-like crystals formed and these were collected by filtration and washed to give colorless needles, m.p. 164°-165° C.
C 14 H 29 N 4 S 3 AG requires 36.75%C, 6.39%H, 12.25%N, 21.03%S and 23.58%AG. Elemental analysis of the product gave 36.70%C, 6.35%H, 12.29%N, 21.03%S and 23.74%AG.
EXAMPLE VII
Preparation of Compound J
In a two-neck flask 0.24 g. of a 50% sodium hydride dispersion in oil was washed free of oil with petroleum ether under argon atmosphere and then 15 ml of dimethylformamide were introduced with a syringe. The suspension was stirred for 5 minutes and 0.89 g. of bis-chloroethylamine hydrochloride was added with stirring followed by the addition of 1.5 g. of N,N'-dimethyl-N,N'-bis(2-mercaptoethyl) ethylenediamine.
In a separate 3-neck flask equipped with an addition funnel there was added 0.5 g. of a 50% sodium hydride dispersion in oil which was then washed free of oil with petroleum ether under argon. Then 45 ml of dimethylformamide were added and the suspension was stirred at a temperature of 80°-90° C. To the suspension was added dropwise over a period of 1.5 hours the reactant mixture described above. Stirring was continued overnight at that temperature and then for an additional period at room temperature. Most of the solvent was removed under reduced pressure and the residue was taken up in 30 ml ethyl acetate, washed twice with 5 ml portions of water and dried over sodium sulfate. Removal of the solvent gave a clear light brown syrup.
The product was purified by column chromatography on silica gel using an ethyl acetate-ethanol mixture for elution. NMR spectra of the product were consistent with compound J.
EXAMLE VIII
Preparation of Compound K
To a solution of 138 mg of compound J in 10 ml dichloromethane there was added dropwise, with stirring under argon at 5°-10° C., a solution of 120 mg of p-nitrophenyl-chloroformate in 2 ml dichloromethane. Stirring was continued overnight at room temperature after which it was diluted with 10 ml of dichloromethane, washed with dilute sodium carbonate solution, then with water and dried over magnesium sulfate. Evaporation of the solvent under reduced pressure gave a light yellow syrup which solidified on standing.
The solid was chromatographed on a silica gel plate using a 90:10 (vol/vol) ethyl acetate-ethanol mixture. The major band was removed and eluted with methanol. Removal of the solvent gave a solid which was then dissolved in ether, filtered through Celite 542, the filtrate concentrated and the last traces of ether removed under reduced pressure. A pale solid m.p. 103°-107° C. was obtained. This solid was recrystallized twice from methanol to give a pale yellow crystalline solid m.p. 109°-110° C., which was dried under reduced pressure.
C 19 H 30 N 4 O 4 S 2 requires 51.56%C, 6.83%H, 12.66%N, 14.49%S and 14.46%O. Elemental analysis of the product gave 51.63%C, 6.62%H, 12.56%N and 14.39%S.
EXAMPLE IX
Preparation of Compound L
In a 250 ml three neck flask equipped with an addition funnel, reflux condenser and a serum cap there were added 1.01 g. of 50% sodium hydride dispersion in oil. The dispersion was washed free of oil by repeated treatments of petroleum ether under argon. Most of the petroleum ether was removed with a syringe and the last traces removed by blowing with argon. Dimethylformamide (70 ml) was added and the suspension heated to 70°-80° C. To the stirred suspension there was slowly added dropwise over a period of 2 hours at a temperature of 85°-90° C., a mixture of 2.1 g. of N,N'-dimethyl-N,N'-bis(2-mercaptoethyl) ethylenediamine and 1.58 g. of bis-2-chloroethylsulfide in 15 ml dimethylformamide. Stirring was continued overnight at 85°-90° C. after which the solvent was removed under reduced pressure. The residue was extracted with ethyl acetate, washed three times with 5 ml portions of water and dried over magnesium sulfate. The residue was concentrated to give a brown syrup and the last traces of solvent removed under reduced pressure. The product was purified by chromatography with silica gel using ethyl acetate as the eluent to furnish compound L as a pale-colored syrup which solidified under refrigeration.
C 12 H 26 N 2 S 3 requires 48.93%C, 8.89%H, 9.51%N and 32.66%S. Elemental analysis of the product gave 48.88%C. 8.80%H, 9.38%N and 32.51%S.
Although the invention has been described with respect to various preferred embodiments thereof, it is not intended to be limited thereto but rather those skilled in the art will recognize that modifications and variations may be made therein which are within the spirit of the invention and the scope of the claims.
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There are described photographic products, processes and compositions wherein cyclic crown ether ligands are utilized as silver halide solvents. Also disclosed are novel cyclic crown ether ligands.
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TECHNICAL FIELD
The present invention is directed to data categorization, and more particularly to a method for detecting incorrectly categorized data that is used in directories, such as telephone directories.
BACKGROUND ART
Phone directories and other information sources containing large amounts of data often provide the data into two formats: a general listing that simply lists business names and phone numbers alphabetically (often called “white pages”) and a grouped listing that lists business names and phone numbers under selected categories (often called “yellow pages”). The grouped listings usually include business names and telephone numbers that are grouped by business category so that the phone numbers for similar types of businesses are found in the same location in the phone directory.
Problems occur, however, if the category information, such as the business category of a business phone listing, is incorrect. More particularly, failure to thoroughly check the category assignment data or process for accuracy and timeliness may cause data miscategorization or categorizing of incorrect or outdated data. Categorization of telephone data is usually conducted by scanning telephone directories and using optical character recognition and/or human labor to match the data in the general listing with an appropriate category in the grouped listing. Errors may occur if, for example, the information in the general listing and the grouped listing does not match or is otherwise defective (e.g., if a phone number in the general listing belongs to a party that has gone out of business, if the same phone number is assigned to two different businesses due to irregularities in the change history of the phone number, or if a given phone number is reassigned to a business that is different than the business who previously had the same phone number). Failure to detect incorrectly categorized data may result in directories that list multiple phone numbers for the same business or assign unrelated businesses to the same category. Also, failure to delete outdated entries may further add to categorization errors.
Although manual review of the entries and categories can detect categorization assignment errors, applying the same level of review to all of the assignments is inefficient and cumbersome, particularly if the data being checked includes a large number of pairs and a relatively small number of errors.
There is a need for a method or system that can detect the existence of incorrectly categorized data so that the incorrectly categorized data can be located and fixed efficiently.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a method for determining the reliability of a data category assignment, and more particularly for determining the accuracy of an assignment of an entry to a given category. The method includes the steps of obtaining a database containing a plurality of entry-category pairs and calculating a score for each entry-category pair, wherein the score corresponds to a likelihood that the entry is correctly assigned to the category. The score itself can be calculated based on the relative probability between the occurrence of a particular entry-category pair and the number of occurrences of the entry and the category, separately, in the database.
In one embodiment, the method includes sorting the pairs according to the scores and generating a curve based on the calculated scores to indicate the likelihood that a given portion of the sorted pairs will contain accurately or inaccurately categorized data and/or to estimate the number of inaccurate data categorizations. The method may also include checking the pairs against an existing reference database. Once a data region having a higher likelihood of errors has been identified via the inventive system, any manual review of the data can be more efficiently targeted toward error-prone data rather than correctly categorized data.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram illustrating one embodiment of the invention;
FIG. 2 is a flow diagram illustrating one embodiment of a score calculation process in the invention;
FIG. 3 is an example of a curve generated by the invention in accordance with the process shown in FIG. 2 to estimate the likelihood of incorrectly categorized data;
FIG. 4 is a flow diagram illustrating a score calculation process according to another embodiment of the invention; and
FIG. 5 is an explanatory diagram corresponding to the process shown in FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates one embodiment of the inventive method 100 for detecting incorrectly categorized data. Generally, the inventive method 100 includes obtaining a database of categorized data containing a plurality of entry-category pairs 102 and calculating a score for each entry-category pair 104 , wherein the score corresponds to a likelihood that the entry is correctly assigned to the category. The entries and categories in the entry-category pairs can be, for example, individual business names assigned to “yellow pages”-type business categories to form a plurality of business name-category pairs. Note that the database may contain multiple category assignments per entry and that there may be multiple entries with the same name. Also note that multiple entries with the same name may be assigned to the same category or to different categories. These factors are taken into account in the invention in determining whether entries are assigned to the correct category. Once scores are assigned to the entry-category pairs, the entry-category pairs can be reviewed at step 106 to verify the correctness of the category assignments. Each of thee steps in the method 100 will be explained in greater detail below.
The method begins by obtaining one or more databases at step 102 . If a single database is used, the invention checks for internal consistencies within the database, assuming that the majority of the data is correctly categorized into entry-category pairs in the first place. More particularly, in the single database case, the method acts as an internal consistency test by checking for assignments that do not look like other assignments within the same database. Alternatively, the obtaining step 102 can test the data categorization in a test database against another database acting as a reference database. The reference database can contain information about additions or changes (e.g., a change history) to the test database.
Next, the invention generates a score at step 104 corresponding to the likelihood that the entry is assigned to the correct category. There are various ways in which the score can be generated, but generally the score should reflect the probability that a given entry, such as a business name/number, is assigned to a correct category. Two possible options will be described below.
One option for generating a score indicating the probability of a correct or an incorrect assignment is shown in FIGS. 2 and 3. Referring to FIG. 2, the score calculation process 200 according to this embodiment first involves counting a total number of times that a given entry-category pair occurs in the database at step 202 . In this specific example, the entries are referred to as “words”, but the invention can evaluate any combination of letters and/or numerals in its score computation. The categories can be, for example, business categories and the entries/words can be, for example, words in a business name. The total number of times that a given category-word combination appears in the database is referred to as J(c,w).
The process also counts the number of pairs in which the given category and given word appear, regardless of whether the given category and word appear in the same pair, at steps 204 and 206 , respectively. The total number of times that the given category appears is referred to as C(c), and the total number of times that the given word appears is referred to as W(w). Note that according to this counting process, categories having associated entries with more words will have a higher count. Similarly, words that appear in more categories will also have a higher count.
The total number of category-word pairs in the database is then counted at step 208 . This total number of pairs is referred to as N. From all of these counts, the score for a given pair (c,w), which corresponds to the likelihood that the entry/word is incorrectly assigned to the category, is calculated at step 210 as: ∑ w = w1 → wn log [ J ( c , w ) C ( c ) W ( w ) ]
Once the scores for a plurality of category-word pairs have been calculated at step 210 , the scores can be used to rank the pair assignments according to the likelihood that, according to the score, each assignment is correct. Sampling techniques and/or manual evaluation can then be conducted on the ordered data at step 212 to generate a curve that indicates the likelihood that a given portion of the ordered data will contain correctly categorized data, incorrectly categorized data, or marginal data (where it is unclear whether the categorization is correct or incorrect).
An example of a curve indicating the likelihood that a given portion of the ordered data will contain correctly categorized data is shown in FIG. 3 . FIG. 3 illustrates an example of categorization results from various groups of samples. Note that the numbers used in FIG. 3 are for illustrative purposes only; there are no restrictions as to the sample size and depth in the inventive method. In this example, the numbers on the x-axis correspond to the depth of the sample group (for example, given 100 pairings in the ordered data, a bar graph with a position of 46 would correspond to samples that are taken from positions 1 through 46), while the y-axis corresponds with the percentage of the pairings in the sample that have correct, incorrect, or unclear category assignments. The curve corresponds to the score which, in this case, indicates the likelihood that a given portion of the data will contain correctly categorized data. In each group of bar graphs, the leftmost bar 300 indicates the percentage of clearly correct pairings in the sample, the center bar 302 indicates the percentage of clearly incorrect pairings, and the rightmost bar 304 indicates the percentage of pairings that are unclear and that may require additional examination.
The generated curve can also be used to estimate the number of incorrect assignments in a given set of data by calculating the area under the portion of the curve to be evaluated. This calculation is helpful in cases where the number of incorrect assignments is small compared to the total number of assignments. By pinpointing the data regions in which there is a greater likelihood of pairs containing incorrect assignments, any manual evaluation or examination of the data can concentrate on correcting the incorrect assignments rather than attempting to locate them among a large number of correctly assigned pairs. To help determine which data areas require closer scrutiny, the process may include selecting a threshold or cutoff point beyond which there is a high likelihood of incorrect assignments based on a predetermined level of accuracy.
Another way in which the score can be calculated is explained with reference to FIGS. 4 and 5. The process 400 in this embodiment generally counts the frequencies of occurrence and co-occurrence of the words and categories of interest, scans existing categorizations, and uses the frequency counts obtained from the counting process to compute a relevant logodds as the score corresponding to the likelihood that any given pair will contain an incorrect category assignment. In one embodiment, if the logodds (score) indicate that certain pairs have a higher likelihood of incorrect category assignment, the affected pairs can be sorted by their logodds (e.g., listing the pairs having the most negative scores first) for further review. These steps will be described in greater detail below with reference to FIG. 4 .
The process 400 shown in FIG. 4 begins by determining the probability that a business name contains a particular word, assuming that the business is of a given category. This probability, notated P(w|c) and referred to as the “maximum likelihood estimate”, is calculated by counting the total number of listings in the given category at step 402 , counting the number of listings in the given category that contain the particular word at step 404 , and dividing this number by the total number of listings at step 406 . Note that other conditional probabilities P(w|˜c), P(˜w|c) and P(˜w|˜c) (i.e., the probabilities of a business having a word given that it is not of the category, etc) can also be calculated in a similar manner. Also, the corresponding joint probability P(w,c), which corresponds to the probability that a given word-category pair appears in the database, and the marginal probabilities P(w) and P(c), which correspond to the probability that a given word or category, respectively, appears in the database, can be computed at step 408 so that P(w|c)=P(w,c)/P(w).
FIG. 5 is an explanatory diagram that illustrates the basic concept used in the process of FIG. 4 . FIG. 5 is a contingency table, which is often used in categorical data analysis. Each word-category pair of interest has an associated two-by-two contingency table corresponding to whether or not the entry contains a given word and whether or not the entry is in a target category. Each of the four cells of the table contains the count of entries with those combinations of features, such that the sum of the four quantities in the cells is the total number of entries in the database, such as a reference database.
Referring back to FIG. 4, a G 2 statistic, or “Wilk's statistic” can be generated for each word-category pair of interest as the score associated with that pair at step 410 . The Wilk's statistic is effectively the logodds ratio of the best multivariate model of the data (estimating each cell count as generated by an independent probability) compared with the best independent model of the data (where the word marginal probability and category marginal probability may explain the data as well as the multivariate model). More particularly, the Wilk's statistic characterizes the degree to which the data is better described by treating the word and category as statistically dependent. The Wilk's statistic itself is calculated as follows: G 2 = ∑ c , w NP ( w , c ) log P ( w , c ) P ( w ) P ( c )
Where N is the total data size and c and w range over {c, ˜c} and {w, ˜w}, that is, all of the data ranging from data having category/not having catgeory and word/not word (in essence, the entire data table). Note that this quantity can be computed directly from the information in the contingency table shown in FIG. 5, where NP(w,c) is the count in the upper-right cell in the table of FIG. 5, and the ratio in the log expression is the ratio between the actual cell count P(w,c)as the numerator and the expected cell count, given word-category independence, as the denominator P(w)P(c).
Once the Wilk's statistic has been calculated for a given word-category pair, the Wilk's statistic can be used directly as a way to filter out coincidences in the data that do not help in evaluating whether a category assignment is correct. The specific amount of filtering can be set by selecting a threshold for the Wilk's statistic after reviewing the rules to be used to evaluate the entry-category pairs. More particularly, the Wilk's statistic can be used as a threshold to determine the degree to which a supposedly incorrect pairing is a chance mistake or an actual categorization error.
Components of the Wilk's statistic can also be used to evaluate word-category pairs. For instance, the “positive” diagonal pair of the contingency table which includes the cells,(has word, is category) and (does not have word, is not category) may represent positively associated words and categories (i.e., proper assignment is more likely than not), whereas the other two cells may represent a negative association (i.e., proper assignment is less likely than not).
One method currently in use is to construct the logodds of P(word|category)/P(word|not category) for each word, and to sum them for the words that occur in the business name. This can be conducted particularly efficiently for existing category assignments because only the rules relevant to that category assignment need to be considered. Effectively the invention computes the logodds of P(contains all the words|is category)/P(contains all the words|not category), so the result can be positive (i.e., proper assignment is more likely than not) or negative (i.e., proper assignment is less likely than not). A negative logodds value indicates that the data is more likely than not to be improperly categorized. Once this data is identified at step 412 , the process may include further verification of the specific pair at step 414 , either manually or through some other means, to confirm whether the category assignment for that pair is correct.
The result of the score calculation processes described above is a number that can be used to rank the list of entry category assignments according to the likelihood that they contain incorrect assignments. For evaluation purposes the entries having negative scores are of particular interest because it indicates likelihood that the category assignment is incorrect. Variations on the embodiment described above may include using different values for the G 2 cutoff using a different base logarithm (such as base 2 instead of natural log) or discarding incorrectly categorized entries based solely on the calculated score, without any separate verification step. Other variations contain the scope of the invention will be apparent to those skilled in the art.
As a result, the present invention identifies data portions that are more likely to contain inaccurate assignments, allowing user to focus on the pairs that are more likely to contain incorrectly categorized data rather than attempting to focus on all of the pairs equally. This approach will increase efficiency in checking the data, particularly in cases where there are a large number of pairs that have a relatively small number of pairs with incorrect assignments. The method can be embodied in a computer system or in a computer-readable storage medium as software.
It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby.
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A method for detecting incorrect categorization of data includes obtaining a database containing a plurality of entry-category pairs, calculating a score for each entry-category pair that corresponds to a likelihood that the pair contains an incorrect category assignment, and verifying the correctness of the assignment based on the score. The verification step can be conducted manually. The score assists users in focusing any manual verification efforts on data that may actually contain incorrect category assignments, thereby making the verification process more efficient. The method can be used to review and correct business name and phone number listings in telephone directories.
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BACKGROUND OF THE INVENTION
This invention relates to the twine wrapping mechanism commonly found in a crop roll forming machine and, more particularly, to the wrapping means employed to place a desired binding material about the periphery of a completed crop roll by the twine wrapping mechanism.
Recently the practice of harvesting crop materials, such as hay, alfalfa, or corn stover, by forming such crop materials into large cylindrically shaped rolls using large roll forming machines has become increasingly popular and economically advantageous in the agricultural industry. The formation of crop materials into large, compact cylindrical rolls, rather than rectangular bales as formerly done, permitted the crop material to be deposited in roll form and left in fields for extended periods of time since the rolled material tended to provide a self-shedding protective covering from inclement weather. The ability to leave these rolled bales in fields thus obviated the formerly required additional steps of gathering the rectangular bales and transporting them to a storage area protected from the elements.
The forming of crop material into compact rolls itself is not new. The origins can be traced back 30 or 40 years to the small cylindrical bale of hay or other fiberous material produced by the type of machine illustrated in U.S. Pat. No. 2,336,491, dated Dec. 14, 1943. The rolls of crop material produced by this type of machine, in the context of the current agricultural marketplace factors, suffered from the principal disadvantage of producing rolls of such small diameter that excessive spoilage from weathering occurred around the periphery of the roll in comparison to the overall diameter of the roll when such rolls were stored in the field.
A later type of machine produced generally cylindrically shaped rolls of crop material by rolling the material along the ground until a roll of desired size was obtained. Crop rolls of this type, produced by machines of the type disclosed in prior U.S. Pat. No. 3,110,145, dated Nov. 12, 1963, suffered several inherent disadvantages because of the technique that was used to form them. This technique permitted an undesirable amount of crop material to be left upon the ground without being included in the crop roll. Additionally, dirt, clods of earth, stones and the like were picked up by the roll and included therein.
The latest and currently most successful type of machine forming crop rolls picked up a swath or windrow of crop material from the field and deposited it onto a lower conveyor. The conveyor then transported the material to a roll forming region where an apron or flight of belts, usually positioned above and adjacent the conveyor, moved in a suitable direction to rotate the crop material and form a large, compact cylindrical bale. Variations of the type of machine utilizing this principle are illustrated in U.S. Pat. No. 3,859,909 to Mast dated Jan. 14, 1975, and U.S. Pat. No. 3,722,197 dated Mar. 27, 1973.
All of the above-cited crop roll forming machines utilized in some form crop material binding means to wrap the various sized compact crop rolls. The binding material commonly took the form of twine and the binding means, accordingly, became known as twine wrapping means or apparatus. The wrapping means was used in a twine wrapping cycle that included the steps of feeding the twine, wrapping the completed roll or bale and severing the twine prior to ejecting the roll or bale from the machine. Generally, the twine wrapping means employed by these machines included an elongated tube which oscillated in a predetermined path across the bale forming region to dispense the binding material as the material was wrapped about the bale. Automatic twine wrapping means that serially undertook the previously mentioned three steps without any operator involvement have been used in the art on machines used to form cylindrical rolls of crop material, as well as hydraulically or electrically powered means requiring manual activation and completely manually operated twine wrapping means. Operators and manufacturers of the more recent large roll forming machines quickly realized that the less time required for the twine wrapping cycle, the more time there would be for gathering crop material from the field to form completed crop rolls.
The current increasing popularity of large crop roll forming machines has seen their use broaden from merely rolling wintering forage for livestock to rolling high protein crops. Therefore, these machines have been the focal point of many ideas for developing twine wrapping means or apparatus that will appreciably decrease the amount of time required for the twine wrapping cycle, as well as active operator involvement in the cycle. Regardless of whether the twine wrapping means is manual, powered or automatic, the time required to complete the cycle is directly a function of the amount of time it takes to dispense the binding material about the periphery of the completed crop roll and then cut the material. When only a single dispensing means is used to oscillate across the bale forming region to dispense binding material, the time required will necessarily be longer than if multiple dispensing means of some type are used to bind the full length of a completed crop roll. Accordingly, it was found, as will be shown and described in detail hereafter, that the use of multiple elongated dispensing tubes that oscillate simultaneously across distinct portions of the entire length of a completed crop roll substantially decrease the length of time required for the twine wrapping cycle to be completed. It also was found that to obtain the optimum benefit from the instant invention. These multiple dispensing tubes require the corresponding use of multiple binding material severing means.
The multiple dispensing tubes, as well as the severing means, must be synchronized in operation so that the strands of binding material dispensed from the elongated dispensing tubes are wrapped about the completed crop roll and severed at approximately the same instant in time so that the twine wrapping cycle may be promptly terminated and the completed roll ejected from the crop roll forming machine. The multiple dispensing tubes and the multiple severing means are optimally employed with any type of a powered twine wrapping means that can easily drive the multiple dispensing tubes and activate the multiple severing means. In the context of the present invention they have been specifically designed to function with automatic twine wrapping means to effect the binding of the completed crop roll in the least amount of time possible.
The foregoing problems are solved in the design of the apparatus comprising the present invention by providing multiple twine dispensing tubes that are center pivoted and driven by an appropriate power source to dispense a binding material across the entire periphery of a completed crop roll.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved binding material dispensing means that utilizes a plurality of elongated tubes which move in predetermined and generally oscillatory paths to cause the binding material to be dispensed about the periphery of a completed crop roll.
It is another object of the present invention to provide an improved binding material dispensing means that utilizes a plurality of elongated dispensing tubes which are driven in synchronization across the length of a completed crop roll.
It is a further object of the present invention to provide an improved binding material dispensing means that utilizes a plurality of elongated dispensing tubes, the first one of which is driven through a predetermined generally oscillatory path and which serves to drive any additional elongated dispensing tubes through corresponding predetermined paths.
These and other objects and advantages are obtained by providing a center pivoted binding material dispensing means that upon actuation of the wrapping means causes a first dispensing means to be driven across a bale forming region in a first predetermined path and correspondingly drives a second dispensing means in a second predetermined path, the predetermined paths being adjacent the completed crop roll to effect the binding of the crop roll across its entire length with the binding material while crop roll is rotated by bale forming means.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages of this invention will become apparent upon consideration of the following detailed disclosure of the invention, especially when it is taken in conjunction with accompanying drawings wherein:
FIG. 1 is a side elevation of a crop roll forming machine illustrating the general location of the instant invention in its operational environment.
FIG. 2 is a fragmentary top plan view of the front portion of a roll forming machine showing the center pivoted dispensing means.
FIG. 3 is a front elevation of a crop roll forming machine having a partial cutaway to show the center pivoted dispensing means.
FIG. 4 is a side elevation taken along the lines 4--4 of FIG. 2.
FIG. 5 is a side elevation of the breakaway 70 and the associated elements of the center pivoted dispensing means.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring generally to FIG. 1 there is shown a crop roll forming machine 10 of the type generally shown in U.S. Pat. No. 3,859,909 to Mast, dated Jan. 14, 1975, connected to a towing vehicle, such as tractor 11, by an appropriate hitch 12 and roll forming machine tongue 14. A power take-off shaft 15 connects the tractor power take-off 16 with the mechanically driven operational components of the crop roll forming machine 10. Hydraulic lines 18 connect the tractor hydraulic power source (not shown) with the hydraulically operable components of the roll forming machine 10. The roll forming machine 10 has a crop pickup, indicated generally by the numeral 19, which gathers the crop material from the field and delivers it to a lower apron, indicated generally by the numeral 20, which conveys the material rearwardly into contact with the upper bale forming means 21. Upper bale forming means 21 is mounted to an upper and lower frame, indicated generally by the numerals 22 and 24, respectively by means of a series of sprockets and guide rollers shown generally by the numeral 25. Upper bale forming means 21 is extensible by means of a pair of takeup arms 26 mounted on both sides of the machine 10 by brackets 27 which permit the upper bale forming means 21 to be fed out around the ever expanding periphery of the crop roll as it is formed within a bale forming region defined generally by the upper bale forming means 21 and the lower apron 20. Upper frame 22 is pivotably raisable at the completion of the twine wrapping cycle for ejection of the completed crop roll R by a pair of hydraulic cylinders 28, only one of which is shown. The crop roll forming machine 10 is mounted on a pair of wheels 29, only one of which is shown.
Twine wrapping apparatus, indicated generally by the numeral 30, is mounted to the side of lower frame 24 in a suitable manner. The binding material 31 is dispensed from binding material storage and dispensing containers 32 suitably affixed to the side of lower frame 24. The binding material 31 is guided by a suitable number of eyelets 34 through guide rings 33, only one of which is shown, to the twine dispensing tubes 35 and 36 of FIG. 2. The cutting blades 37 of twine wrapping apparatus 30 sever the binding material at the conclusion of the twine wrapping cycle, only one blade of which is shown in FIG. 2. A detailed description of the operation and structure of the cutting blades 37 is given in the concurrently filed co-pending application Ser. No. 894,456, entitled "Independently Controlled Twine Knives" of J. S. Richardson, assigned to the assignee of the present invention.
The twine or binding material dispensing means is shown in greatest detail in FIG. 2 and partially in FIG. 3 where a portion of the drive means for the crop roll forming machine 10 has been cut away. Referring specifically then to FIG. 2, it is seen that a drag link 38 is connected to a pivotable plate 39 with a roller 40 at the end nearest the control means (not shown) of the twine wrapping apparatus 30, shown and described in detail in concurrently filed co-pending application Ser. No. 894,457, entitled "Improved Automatic Twine Wrapping Apparatus" of Freimuth et al, assigned the assignee of the present invention and hereby specifically incorporated by reference herein. Pivotable plate 39 rotates about a stub shaft 41, which extends through the underside of housing plating 42, as the roller 40 traverses the curvilinear periphery of the rotatable cam plate of the twine wrapping apparatus 30 (not shown). Drag link 38 is secured to the end of the cam follower link 39 by a retaining bolt 44 and appropriate washers and lock nuts (not shown). Drag link 38 is adjustable by means of adjusting nuts 45 fitted over threaded end portions indicated generally by the numeral 46 at both ends of the drag link 38.
At the end opposite pivotable link 39, drag link 38 connects with the wrapping means indicated generally by the numeral 48. That opposing end of drag link 38 is rotatably fastened to driven link 49 by means of retaining bolt 50, lock washers and locking nuts (both of which are not shown) or other suitable rotatable fastening means. Driven link 49 is rotated about retaining bolt 50 in response to the movement of drag link 38 as cam follower roller 40 traverses the curvilinear surface of the cam plate (not shown). Driven link 49 is connected to the twine dispensing tubes 35 and 36 by means of tube mounting plates 51 and intermeshing involute spur gears 52. The rotation of the driven link 49 about retaining bolt 50 allows the intermeshing involute gears 52 to be driven to cause journals, indicated generally by the numerals 53 and 54, to rotate and thereby jointly force the dispensing tubes 35 and 36 downwardly in an arcuate path across the path of the bale forming region.
Journals 53 and 54 include shafts 55, bushings 56 and snap rings 58, as shown in FIG. 2. Spur gears 52 are held on shafts 55 by retaining collars 57, one of which is seen in FIG. 4. As best shown in FIG. 2, journal 53 is rotated by the action of drag link 38 and driven link 49, thereby causing twine dispensing tube 35, fastened to its mounting plate 51, to follow a generally oscillatory predetermined path across the bale forming region defined generally by the sides of lower frame 24 and upper bale forming means 21. Twine dispensing tube 35 transfers its oscillatory motion to twine dispensing tube 36 through involute spur gears 52, which are intermeshed in a fashion that permits the twine dispensing tubes 35 and 36 to follow generally corresponding oscillatory paths in synchronized movement to dispense binding material 31.
Journal 53, best seen in FIG. 4, has a spacer bushing 59 between driven link 49 and breakaway link 60. Breakaway link 60 is fastened to a biasing link 61 by a bolt 62 and retaining nut 64 in a manner that allows the biasing link to pivot thereabout. The opposite end of biasing link 61 has a spring 65 connected through an aperture 66, as shown in FIG. 2. Spring 65 is connected at its other end to housing plating 42 through aperture 68. Spring 65 serves to supply the proper predetermined amount of tension through biasing link 61 to the driven link 49 and finally dispensing tubes 35 and 36 as the tubes oscillate across the bale forming region.
Breakaway link 61 has a bracketing link 69 fixedly fastened to an end of breakaway link 60 in a suitable fashion, such as by welding, as seen in FIG. 4. Bracket 69 has affixed thereto a breakaway, indicated generally by the numeral 70, which maintains the cooperative functional integrity of the components of the wrapping means 48 and thus prevents any damage from occurring to the wrapping means 48 should the twine dispensing tubes 35 and 36 encounter any impassable obstacles during their travel along their predetermined paths. The breakaway 70, shown in FIG. 5, is not described in further detail at this time since it is old in the art and is described in detail in U.S. Pat. No. 4,072,095 to Campbell et al, assigned to the assignee of the present invention.
Twine dispensing tubes 35 and 36 are fastened to tube mounting plates 51 by means of welded brackets 71, best seen in FIG. 2. Binding material guide rings 33, only one of which is shown, are mounted to each of the tube mounting plates 51. The entire wrapping means 48 is mounted to a mounting plate 72, which is in turn fastened to a transverse support frame beam 74 by fastening bracket 75, best seen in FIG. 4. Wrapping means mounting plate 72 has a shielding 76 affixed to it to protect the wrapping means 48 from the elements and to prevent any undesirable foreign matter from accumulating thereon. Mounting plate 72 also has mounted thereon a tensioning means 78 to apply the proper amount of tension to the binding material 31 as it is fed across the bale forming region by the twine dispensing tubes 35 and 36. Tensioning means 78 is not described any further at this point since the operation and structure is wholly conventional and well known in the art. The mounting plate 72, tensioning means 78 and shielding 76 are secured to their respective supporting structures by appropriate fastening means, such as bolts and nuts. The fastening bracket 75 is fixedly fastened to transverse support beam 74 by welding. As shown in FIG. 4, the shielding 76 is fastened at its forwardmost portion to gearbox shielding 79 which covers a gearbox (not shown) mounted on transverse support beam 74.
Cutting blades 37, only one of which is shown in detail in FIG. 2, are part of severing means 80. Severing means 80 is shown and described in detail in the concurrently filed, co-pending application Ser. No. 894,456, entitled "Independently Operated Twine Knives" of J. S. Richardson, assigned to the assignee of the present invention and hereby specifically incorporated by reference herein. Briefly, cutting blades 37 are mounted to rotatable brackets 81 in a suitable fashion, such as by bolts or rivets. Brackets 81 are suitably fastened to rotatable sleeves 82 which are concentrically mounted about elongated rod 84. A striker plate 85 is fastened by means of bolts 86 to a side frame bracket 88. Bracket 88 is fixed to the side of lower frame 24 by a mounting plate 89 and bolts 90. Sleeves 82 have an L-shaped guide bracket 91 to prevent the binding material 31 from overrunning the ends of the completed crop roll R as the binding material is dispensed from dispensing tubes 35 and 36 about the periphery of the crop roll R. The binding material 31 is wrapped about the periphery of the completed crop roll R when the end of each strand of binding material 31 is brought into frictional contact with the rotating crop roll R as the twine dispensing tubes 35 and 36 are brought to their lowest position, shown in phantom in FIG. 2. This frictional contact causes the binding material 31 to be pulled from the twine dispensing tubes 35 and 36 as the tubes oscillate generally along their predetermined path across the length of the completed crop roll R.
In operation, the wrapping means 48 are activated by the control means of the twine wrapping apparatus when the cam follower roller 40 of pivotal plate 39 traverses the curvilinear periphery of the rotatable cam plate of the control means. This action causes the drag link 38 to drive driven link 49 which is journalled to the lead twine dispensing tube 35. The twine dispensing tube 35 is thereby started in motion and permits the biasing spring 65 through biasing link 61 to cause the tube 35 to be quickly snapped generally downwardly from a home position to its phantomed lowest position in a predetermined path. At the same time, through the transfer of power via intermeshing spur gears 52, the twine dispensing tube 36 is correspondingly driven from its home position. The twine tubes 35 and 36 are thus spring assisted until they reach their fully downwardly extended position from which they started their return along their predetermined and generally oscillatory paths to the home position. During this return portion of the oscillating cycle, the binding material 31, having been released from between the cutting blades 37 and striker plates 85, is fed out along the periphery of the rotating crop roll R and wrapped thereabout. Upon the return of the twine dispensing tubes 35 and 36 to their respective home positions, the severing means 80 is activated to cause the cutting blades 37 to be rotated into cutting engagement with the striker plates 85, thereby severing the binding material.
It has been previously stated that the multiple twine dispensing tubes 35 and 36 are equally well employed with any type of a power source that has the capacity to drive them. Alternative power sources that are entirely self contained units, such as electrical motors or hydraulic cylinders, as opposed to having power being supplied through the upper blade forming means 21 from the power takeoff shaft 15, can be connected to the drag link 38 at the aperture for retaining bolt 44 and either automatically or manually controlled. Examples of such alternative power sources previously utilized on round balers are shown in U.S. Pat. No. 4,022,120, dated May 10, 1977 to McAllister, illustrating an electrical motor, and U.S. Pat. No. 4,072,095, dated Feb. 7, 1978 to Campbell et al., illustrating an hydraulic cylinder. Other suitable drive connections to the driven link 49 easily can be employed to utilize these alternative power sources.
While the preferred structure in which the principles of the present invention have been incorporated is shown and described above, it is to be understood that the invention is not to be limited to the particular details thus presented, but, in fact, widely different means may be employed in the practice of the broader aspects of this invention. The scope of the appended claims is intended to encompass obvious changes in the details, materials and the arrangement of parts which will occur to one of skill in the art upon a reading of this disclosure.
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In a crop roll forming machine which forms large cylindrically shaped bales in a bale forming region and wraps the bales with a binding material and which further has a wrapping means for controlling the wrapping of the completed bale there is provided at least a first and a second binding material dispensing means adjacent the bale forming region connected to the wrapping means so that upon actuation of the wrapping means the first dispensing means is driven across a portion of the bale forming region in a first predetermined path and the second dispensing means is driven in a second predetermined path. The predetermined paths are adjacent the completed bale to effect the wrapping of the bale substantially across its length as the bale is rotated by the bale forming means of the crop roll forming machine.
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SEQUENCE LISTING
[0001] This application contains a sequence listing in paper format and in computer readable format, the teachings and content of which are hereby incorporated by reference. The sequence listing is also identical with that incorporated in WO06/072065.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The present invention relates to the use of an immunogenic composition comprising a porcine circovirus type 2 (PCV2) antigen for the prevention, reduction in severity of clinical signs, reduction in the incidence of infection and/or clinical signs, and treatment of several clinical manifestations (diseases) in animals having anti-PCV2 specific antibodies. Preferably, those anti-PCV-2 specific antibodies are maternal antibodies.
[0004] Description of the Prior Art
[0005] Porcine circovirus type 2 (PCV2) is a small (17-22 nm in diameter), icosahedral, non-enveloped DNA virus, which contains a single-stranded circular genome. PCV2 shares approximately 80% sequence identity with porcine circovirus type 1 (PCV1). However, in contrast with PCV1, which is generally non-virulent, infection of swine with PCV2 has recently associated with a number of disease syndromes which have been collectively named Porcine Circovirus-Associated Diseases (PCVAD) (also known as Porcine Circovirus Diseases (PCVD)) (Allan et al, 2006, IPVS Congress). Postweaning Multisystemic Wasting Syndrome (PMWS) is generally regarded to be the major clinical manifestation of PCVAD. (Harding et al., 1997, Swine Health Prod; 5: 201-203; Kennedy et al., 2000, J Comp Pathol; 122: 9-24). PMWS affects pigs between 5-18 weeks of age. PMWS is clinically characterized by wasting, paleness of the skin, unthriftiness, respiratory distress, diarrhea, icterus, and jaundice. In some affected swine, a combination of all symptoms will be apparent while other affected swine will only have one or two of these symptoms. (Muirhead, 2002, Vet. Rec.; 150: 456) During necropsy, microscopic and macroscopic lesions also appear on multiple tissues and organs, with lymphoid organs being the most common site for lesions. (Allan and Ellis, 2000; J Vet. Diagn. Invest., 12: 3-14) A strong correlation has been observed between the amount of PCV2 nucleic acid or antigen and the severity of microscopic lymphoid lesions. Mortality rates for swine infected with PCV2 can approach 80%. In addition to PMWS, PCV2 has been associated with several other infections including pseudorabies, porcine reproductive and respiratory syndrome (PRRS), Glasser's disease, streptococcal meningitis, salmonellosis, postweaning colibacillosis, dietetic hepatosis, and suppurative bronchopneumonia. However, research thus far has not confirmed whether any of these clinical symptoms are in fact, the direct result of a PCV2 infection. Moreover, it is not yet known whether any of these clinical symptoms can be effectively reduced or cured by an active agent directed against PCV2.
[0006] Approaches to treat PCV2 infections based on a DNA vaccine are described in U.S. Pat. No. 6,703,023. In WO03/049703 production of a live chimeric vaccine is described, comprising a PCV-1 backbone in which an immunogenic gene of a pathogenic PCV2 strains replaces a gene of the PCV-1 backbone. WO99/18214 has provided several PCV2 strains and procedures for the preparation of a killed PCV2 vaccine. However, no efficacy data have been reported. An effective ORF-2 based subunit vaccine has been reported in WO06/072065 and in WO2007/028823. Any of such vaccines are intended to be used for the vaccination/treatment of swine or pigs older than 3 weeks of age. None of these vaccines have been described for use in young piglets, younger than 3 or 2 weeks of age.
[0007] Maternally derived immunity has been shown to confer a certain degree of protection against PCV2 infection and clinical diseases associated with PCV2 infections. This protection has been shown to be titer dependent: higher titers are generally protective whereas lower titers are not (McKeown et al., 2005; Clin. Diagn. Lab. Immunol.; 12: 1347-1351). The mean antibody half-life in weanlings has been estimated to be 19.0 days and the window for PCV2-passive antibody decay within a population is relatively wide (Opriessnig et al. 2004, J. Swine Health Prod. 12:186-191). Low titers of PCV2 passively acquired antibodies present at 10-12 days of age were found to decay by approximately 4.9±1.2 weeks of age, moderate levels of antibodies were found to decay by approximately 8.1±1.9 weeks of age and high levels of antibodies were found to decay by approximately 11.1±2.5 weeks of age (Opriessnig et al., 2006, 37 th Annual Meeting of the American Association of Swine Veterinarians). In a timely close correlation with the waning antibody titer stands the occurrence of first clinical signs of PCVAD which occur when piglets are approximately 5 and 12 weeks old (Allan et al, 2000, Vet. Diagn. Investigation, 12: 3-14). Furthermore, PCV2 has also been isolated out of lymphnodes of neonatal piglets (Hirai et al, 2001, Vet. Record; 148:482-484) indicating that even younger piglets may be affected from PCVAD in the absence of protective maternal antibody titers. The obvious correlation between the antibody titer and protection has been proven in a Spanish Field study: Pigs with low antibody titers at 7 weeks of age (mean antibody titer 1:100, range 0 to 1:320) had a significantly higher mortality rate over the following 5 weeks than animals with higher antibody titers (Rodriguez-Arrioja et al., 2002, Am. J Vet. Res. 63:354-357).
[0008] The presence of maternally-derived antibody not only may confer a certain degree of protection against viral infections, which however is not predictable, but also be known to impair the efficacy of immunization. For example higher titers of maternally-derived antibodies to classical swine fever virus (CSFV) inhibit both cell-mediated and humoral immune response to a CSFV vaccine, but lower titers have no significant influence (Suradhat and Damrongwatanapokin, 2003, Vet. Microbiol; 92: 187-194). Also, for live PCV2 vaccines, it has been predicted that they will work most efficiently when given to piglets older than 7 or 8 weeks of age, because the maternal antibodies have mostly waned at that time. Maternal antibody interference is influenced by the type of elicited immune response (Th1 versus Th2) which is dependent (beyond others) on the type of vaccine, type of antigen, type of adjuvant as well as on the amount of administered antigen. Consequently, possible maternal antibody interference may differ for vaccines even if they protect against the same pathogen. Altogether, maternally-derived anti-PCV2 antibodies may confer a certain degree of protection against PCV2, but on the other hand those antibodies may impair the efficacy of any PCV2 vaccine.
[0009] The protection of animals by active immunization is further complicated by the fact that a) the time for the decay of maternally derived antibodies (MDA) varies from animal to animal and b) many diseases occur shortly after the decay of antibodies. To face this problem several vaccination strategies foresee a two shot vaccination regime for young animals: The first vaccination is given early in life in order to protect those animals with low MDA. It is accepted that this first vaccination may not be effective in animals with high MDA titers due to an interference with the vaccine antigen. In order to also protect these animals, a second vaccination is required, when high MDA levels are expected to have declined. This kind of vaccination schedule is used for many small animal vaccines (against e.g. canine parvovirosis, canine hepatitis, etc.), equine vaccines (against e.g. equince influenza vaccines) and porcine vaccines (against e.g. Actinobacillus pleuropneumoniae, Haemophilus parasuis ). As the onset of PCVAD in animals 5 weeks of age or older seems to be linked to the decay of PCV2 antibodies, which is reported to occur in animals aged 4-11 weeks, several vaccine approaches against PCVAD have been described using a two shot vaccination regime in order to circumvent a possible maternal antibody interference. In WO 2007/028823 vaccination of piglets having maternally-derived anti-PCV2 antibodies with more than 20 μg/dose antigen using a two shot vaccination regime is described. Initial vaccination was administered between 1 and 4 weeks of age. All animals were re-vaccinated three weeks after the initial vaccination, when the maternally-derived antibodies in animals with high MDA levels at the time of first vaccination had declined or ceased. Thus, yet no information exist which describes the exact influence of maternally-derived anti-PCV2 antibodies on degree of protection or interference. For that reason, it is recommended not to vaccinate piglets prior to three (3) weeks of age at least with a single shot vaccine regime. Vaccination prior to weeks 3 of age is connected with a certain degree of uncertainty with respect to immunization efficacy. On the other hand, piglets with lower levels of maternally-derived anti-PCV2 antibodies, whereas yet nobody knows what lower levels exactly means, are not sufficiently protected against PCV2 infection prior to week 3 of age. In other words, herds with low MDA titers which are not vaccinated before 3 weeks of age have an immanent risk of PCV2 infections due to lack of a sufficient immune status.
[0010] Moreover, such vaccines have not been described to confer protective immunity against PCV2 infection or reducing, lessening the severity of, lessening the incidence of, or curing any clinical symptoms associated therewith in pigs already having anti-PCV2 antibodies, preferably having maternal anti-PC2 antibodies.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a graph of anti-PCV2 antibody titer classes at the time of vaccination;
[0012] FIG. 2 is a graph comparing the live body weight in vaccinated animals with low (<1:100) and high (>1:1000) anti-PCV2 antibodies; and
[0013] FIG. 3 is a graph illustrating body weight difference in vaccinated (IVP) as compared to placebo-treated control animals (CP).
DISCLOSURE OF THE INVENTION
[0014] The present invention overcomes the problems inherent in the prior art and provides a distinct advance in the state of the art. According to general aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in animals having anti-PCV2 antibodies, comprising the step of administering an effective amount of PCV2 antigen or an immunogenic composition comprising an PCV2 antigen to that animal in need of such treatment. It was an unpredictable and surprising finding, that the presence of anti-PCV2 antibodies, and in particular of maternal origin, does not impair the efficacy of vaccine comprising PCV2 antigen.
[0015] The terms “vaccine” or “immunogenic composition” (both terms are used synonymously) as used herein refer to any pharmaceutical composition containing a PCV2 antigen, which composition can be used to prevent or treat a PCV2 infection-associated disease or condition in a subject. A preferred immunogenic composition can induce, stimulate or enhance the immune response against PCV2. The term thus encompasses both subunit immunogenic compositions, as described below, as well as compositions containing whole killed, or attenuated and/or inactivated PCV2.
[0016] Thus according to another aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in animals having anti-PCV2 antibodies, in particular maternally-derived anti-PCV2 antibodies, comprising the step of administering an effective amount of PCV2 antigen or an immunogenic composition comprising an PCV2 antigen to that animal in need of such treatment, wherein the immunogenic composition is a subunit immunogenic composition, a compositions containing whole killed, or attenuated and/or inactivated PCV2.
[0017] The term “subunit immunogenic composition” as used herein refers to a composition containing at least one immunogenic polypeptide or antigen, but not all antigens, derived from or homologous to an antigen from PCV2. Such a composition is substantially free of intact PCV2. Thus, a “subunit immunogenic composition” is prepared from at least partially purified or fractionated (preferably substantially purified) immunogenic polypeptides from PCV2, or recombinant analogs thereof. A subunit immunogenic composition can comprise the subunit antigen or antigens of interest substantially free of other antigens or polypeptides from PCV2, or in fractionated from. A preferred immunogenic subunit composition comprises the PCV2 ORF-2 protein as described below. Most preferred are immunogenic subunit compositions, which comprise any of the PCV2 antigens provided in WO06/072065, which are all incorporated herein by reference in their entirety.
[0018] An “immune response” means but is not limited to the development in a host of a cellular and/or antibody-mediated immune response to the composition or vaccine of interest. Usually, an “immune response” includes but is not limited to one or more of the following effects: the production or activation of antibodies, B cells, helper T cells, suppressor T cells, and/or cytotoxic T cells, directed specifically to an antigen or antigens included in the composition or vaccine of interest. Preferably, the host will display either a therapeutic or a protective immunological (memory) response such that resistance to new infection will be enhanced and/or the clinical severity of the disease reduced. Such protection will be demonstrated by either a reduction in number or severity of, or lack of one or more of the symptoms associated with PCV2 infections, in delay of onset of viremia, in a reduced viral persistence, in a reduction of the overall viral load and/or a reduction of viral excretion.
[0019] The terms “antigen” as used herein refers to an amino acid sequence which elicits an immunological response as described above. An antigen, as used herein, includes the full-length sequence of any PCV2 proteins, analogs thereof, or immunogenic fragments thereof. The term “immunogenic fragment” refers to a fragment of a protein which includes one or more epitopes and thus elicits the immunological response described above. Such fragments can be identified using any number of epitope mapping techniques, well known in the art. See, e.g., Epitope Mapping Protocols in Methods in Molecular Biology, Vol. 66 (Glenn E. Morris, Ed., 1996) Humana Press, Totowa, N.J. For example, linear epitopes may be determined by e.g., concurrently synthesizing large numbers of peptides on solid supports, the peptides corresponding to portions of the protein molecule, and reacting the peptides with antibodies while the peptides are still attached to the supports. Such techniques are known in the art and described in, e.g., U.S. Pat. No. 4,708,871; Geysen et al. (1984) Proc. Natl. Acad. Sci. USA 81:3998-4002; Geysen et al. (1986) Molec. Immunol. 23:709-715. Similarly, conformational epitopes are readily identified by determining spatial conformation of amino acids such as by, e.g., x-ray crystallography and 2-dimensional nuclear magnetic resonance. See, e.g., Epitope Mapping Protocols, supra.
[0020] Synthetic antigens are also included within the definition, for example, polyepitopes, flanking epitopes, and other recombinant or synthetically derived antigens. See, e.g., Bergmann et al. (1993) Eur. J. Immunol. 23:2777-2781; Bergmann et al. (1996), J. Immunol. 157:3242-3249; Suhrbier, A. (1997), Immunol. and Cell Biol. 75:402-408; Gardner et al., (1998) 12th World AIDS Conference, Geneva, Switzerland, Jun. 28-Jul. 3, 1998.
[0021] According to further aspect, the immunogenic composition as used herein most preferably comprises the polypeptide, or a fragment thereof, expressed by ORF-2 of PCV2. PCV2 ORF-2 DNA and protein, used herein for the preparation of the compositions and within the processes provided herein is a highly conserved domain within PCV2 isolates and thereby, any PCV2 ORF-2 would be effective as the source of the PCV ORF-2 DNA and/or polypeptide as used herein. A preferred PCV2 ORF-2 protein is that of SEQ ID NO: 11 herein and of WO06/072065. A further preferred PCV ORF-2 polypeptide is provided as SEQ ID NO: 5 herein and in WO06/072065. However, it is understood by those of skill in the art that this sequence could vary by as much as 6-10% in sequence homology and still retain the antigenic characteristics that render it useful in immunogenic compositions. The antigenic characteristics of an immunological composition can be, for example, estimated by the challenge experiment as provided by Example 4 of WO06/072065. Moreover, the antigenic characteristic of a modified antigen is still retained, when the modified antigen confers at least 70%, preferably 80%, more preferably 90% of the protective immunity as compared to the PCV2 ORF-2 protein, encoded by the polynucleotide sequence of SEQ ID NO:3 or SEQ ID NO:4 as provided herein and in WO06/072065.
[0022] Thus according to a further aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in animals having anti-PCV2 antibodies, in particular maternally-derived anti-PCV2 antibodies, comprising the step of administering an effective amount of PCV2 antigen or an immunogenic composition comprising a PCV2 antigen to that animal in need of such treatment, wherein the PCV2 antigen is an antigen of PCV2 ORF-2 protein that has at least 70%, preferably, 80% even more preferably 90% of the protective immunity as compared to compared to the PCV2 ORF-2 protein, encoded by the polynucleotide sequence of SEQ ID NO:3 or SEQ ID NO:4 as provided herein and in WO06/072065. Preferably said PCV2 ORF-2 sequences have the sequence of SEQ ID NO: 11 or SEQ ID NO: 5 as provided herein and in WO06/072065.
[0023] In some forms, immunogenic portions of PCV2 ORF-2 protein are used as the antigenic component in the immunogenic composition, comprising PCV2 antigen. The term “immunogenic portion” as used herein refers to truncated and/or substituted forms, or fragments of PCV2 ORF-2 protein and/or polynucleotide, respectively. Preferably, such truncated and/or substituted forms, or fragments will comprise at least 6 contiguous amino acids from the full-length ORF-2 polypeptide. More preferably, the truncated or substituted forms, or fragments will have at least 10, more preferably at least 15, and still more preferably at least 19 contiguous amino acids from the full-length PCV ORF-2 polypeptide. Two preferred sequences in this respect are provided as SEQ ID NO: 9 and SEQ ID NO:10 herein and in WO06/072065. It is further understood that such sequences may be a part of larger fragments or truncated forms.
[0024] As mentioned above, a further preferred PCV2 ORF-2 polypeptide is any one encoded by the nucleotide sequences of SEQ ID NO: 3 or SEQ ID NO: 4. However, it is understood by those of skill in the art that this sequence could vary by as much as 6-20% in sequence homology and still retain the antigenic characteristics that render it useful in immunogenic compositions. In some forms, a truncated or substituted form, or fragment of this PCV2 ORF-2 polypeptide is used as the antigenic component in the composition. Preferably, such truncated or substituted forms, or fragments will comprise at least 18 contiguous nucleotides from the full-length PCV2 ORF-2 nucleotide sequence, e.g. of SEQ ID NO: 3 or SEQ ID NO: 4. More preferably, the truncated or substituted forms, or fragments, will have at least 30, more preferably at least 45, and still more preferably at least 57 contiguous nucleotides of the full-length PCV2 ORF-2 nucleotide sequence, e.g. SEQ ID NO: 3 or SEQ ID NO: 4.
[0025] “Sequence Identity” as it is known in the art refers to a relationship between two or more polypeptide sequences or two or more polynucleotide sequences, namely a reference sequence and a given sequence to be compared with the reference sequence. Sequence identity is determined by comparing the given sequence to the reference sequence after the sequences have been optimally aligned to produce the highest degree of sequence similarity, as determined by the match between strings of such sequences. Upon such alignment, sequence identity is ascertained on a position-by-position basis, e.g., the sequences are “identical” at a particular position if at that position, the nucleotides or amino acid residues are identical. The total number of such position identities is then divided by the total number of nucleotides or residues in the reference sequence to give % sequence identity. Sequence identity can be readily calculated by known methods, including but not limited to, those described in Computational Molecular Biology, Lesk, A. N., ed., Oxford University Press, New York (1988), Biocomputing: Informatics and Genome Projects, Smith, D. W., ed., Academic Press, New York (1993); Computer Analysis of Sequence Data, Part I, Griffin, A. M., and Griffin, H. G., eds., Humana Press, New Jersey (1994); Sequence Analysis in Molecular Biology, von Heinge, G., Academic Press (1987); Sequence Analysis Primer, Gribskov, M. and Devereux, J., eds., M. Stockton Press, New York (1991); and Carillo, H., and Lipman, D., SIAM J. Applied Math., 48: 1073 (1988), the teachings of which are incorporated herein by reference. Preferred methods to determine the sequence identity are designed to give the largest match between the sequences tested. Methods to determine sequence identity are codified in publicly available computer programs which determine sequence identity between given sequences. Examples of such programs include, but are not limited to, the GCG program package (Devereux, J., et al., Nucleic Acids Research, 12(1):387 (1984)), BLASTP, BLASTN and FASTA (Altschul, S. F. et al., J. Molec. Biol., 215:403-410 (1990). The BLASTX program is publicly available from NCBI and other sources (BLAST Manual, Altschul, S. et al., NCVI NLM NIH Bethesda, Md. 20894, Altschul, S. F. et al., J. Molec. Biol., 215:403-410 (1990), the teachings of which are incorporated herein by reference). These programs optimally align sequences using default gap weights in order to produce the highest level of sequence identity between the given and reference sequences. As an illustration, by a polynucleotide having a nucleotide sequence having at least, for example, 85%, preferably 90%, even more preferably 95% “sequence identity” to a reference nucleotide sequence, it is intended that the nucleotide sequence of the given polynucleotide is identical to the reference sequence except that the given polynucleotide sequence may include up to 15, preferably up to 10, even more preferably up to 5 point mutations per each 100 nucleotides of the reference nucleotide sequence. In other words, in a polynucleotide having a nucleotide sequence having at least 85%, preferably 90%, even more preferably 95% identity relative to the reference nucleotide sequence, up to 15%, preferably 10%, even more preferably 5% of the nucleotides in the reference sequence may be deleted or substituted with another nucleotide, or a number of nucleotides up to 15%, preferably 10%, even more preferably 5% of the total nucleotides in the reference sequence may be inserted into the reference sequence. These mutations of the reference sequence may occur at the 5 or 3′ terminal positions of the reference nucleotide sequence or anywhere between those terminal positions, interspersed either individually among nucleotides in the reference sequence or in one or more contiguous groups within the reference sequence. Analogously, by a polypeptide having a given amino acid sequence having at least, for example, 85%, preferably 90%, even more preferably 95% sequence identity to a reference amino acid sequence, it is intended that the given amino acid sequence of the polypeptide is identical to the reference sequence except that the given polypeptide sequence may include up to 15, preferably up to 10, even more preferably up to 5 amino acid alterations per each 100 amino acids of the reference amino acid sequence. In other words, to obtain a given polypeptide sequence having at least 85%, preferably 90%, even more preferably 95% sequence identity with a reference amino acid sequence, up to 15%, preferably up to 10%, even more preferably up to 5% of the amino acid residues in the reference sequence may be deleted or substituted with another amino acid, or a number of amino acids up to 15%, preferably up to 10%, even more preferably up to 5% of the total number of amino acid residues in the reference sequence may be inserted into the reference sequence. These alterations of the reference sequence may occur at the amino or the carboxy terminal positions of the reference amino acid sequence or anywhere between those terminal positions, interspersed either individually among residues in the reference sequence or in the one or more contiguous groups within the reference sequence. Preferably, residue positions which are not identical differ by conservative amino acid substitutions. However, conservative substitutions are not included as a match when determining sequence identity.
[0026] “Sequence homology”, as used herein, refers to a method of determining the relatedness of two sequences. To determine sequence homology, two or more sequences are optimally aligned, and gaps are introduced if necessary. However, in contrast to “sequence identity”, conservative amino acid substitutions are counted as a match when determining sequence homology. In other words, to obtain a polypeptide or polynucleotide having 95% sequence homology with a reference sequence, 85%, preferably 90%, even more preferably 95% of the amino acid residues or nucleotides in the reference sequence must match or comprise a conservative substitution with another amino acid or nucleotide, or a number of amino acids or nucleotides up to 15%, preferably up to 10%, even more preferably up to 5% of the total amino acid residues or nucleotides, not including conservative substitutions, in the reference sequence may be inserted into the reference sequence. Preferably the homolog sequence comprises at least a stretch of 50, even more preferably at least 100, even more preferably at least 250, and even more preferably at least 500 nucleotides.
[0027] A “conservative substitution” refers to the substitution of an amino acid residue or nucleotide with another amino acid residue or nucleotide having similar characteristics or properties including size, hydrophobicity, etc., such that the overall functionality does not change significantly.
[0028] “Isolated” means altered “by the hand of man” from its natural state, i.e., if it occurs in nature, it has been changed or removed from its original environment, or both. For example, a polynucleotide or polypeptide naturally present in a living organism is not “isolated,” but the same polynucleotide or polypeptide separated from the coexisting materials of its natural state is “isolated”, as the term is employed herein.
[0029] Thus, according to a further aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in animals having anti-PCV2 antibodies, in particular maternally-derived anti-PCV2 antibodies, comprising the step of administering an effective amount of PCV2 antigen or an immunogenic composition comprising a PCV2 antigen to that animal in need of such treatment, wherein said PCV2 ORF-2 protein is any one of those, described above. Preferably, said PCV2 ORF-2 protein is
i) a polypeptide comprising the sequence of SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 9, SEQ ID NO: 10 or SEQ ID NO: 11 herein or of WO06/07065; ii) any polypeptide that is at least 80% homologous to the polypeptide of i), iii) any immunogenic portion of the polypeptides of i) and/or ii) iv) the immunogenic portion of iii), comprising at least 10 contiguous amino acids included in the sequences of SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 9, SEQ ID NO: 10 or SEQ ID NO: 11 herein or of WO06/072065, v) a polypeptide that is encoded by a DNA comprising the sequence of SEQ ID NO: 3 or SEQ ID NO: 4 herein or of WO06/072065. vi) any polypeptide that is encoded by a polynucleotide that is at least 80% homologous to the polynucleotide of v), vii) any immunogenic portion of the polypeptides encoded by the polynucleotide of v) and/or vi) viii) the immunogenic portion of vii), wherein polynucleotide coding for said immunogenic portion comprises at least 30 contiguous nucleotides included in the sequences of SEQ ID NO: 3, or SEQ ID NO: 4 herein or of WO06/072065.
[0038] Preferably any of those immunogenic portions have the immunogenic characteristics of PCV2 ORF-2 protein that is encoded by the sequence of SEQ ID NO: 3 or SEQ ID NO: 4 herein or of WO06/07065.
[0039] According to a further aspect, PCV2 ORF-2 protein is provided in the immunogenic composition at an antigen inclusion level effective for inducing the desired immune response, namely reducing the incidence of, lessening the severity of, or preventing or reducing one or more clinical symptoms resulting from or associated with a PCV2 infection. Preferably, the PCV2 ORF-2 protein inclusion level is at least 0.2 μg antigen/ml of the final immunogenic composition (μg/ml), more preferably from about 0.2 to about 400 μg/ml, still more preferably from about 0.3 to about 200 μg/ml, even more preferably from about 0.35 to about 100 μg/ml, still more preferably from about 0.4 to about 50 μg/ml, still more preferably from about 0.45 to about 30 μg/ml, still more preferably from about 0.5 to about 18 μg/ml, even more preferably from about 0.6 to about 15 μg/ml even more preferably from about 0.75 to about 8 μg/ml, even more preferably from about 1.0 to about 6 μg/ml, still more preferably from about 1.3 to about 3.0 μg/ml, even more preferably from about 1.4 to about 2.5 μg/ml, even more preferably from about 1.5 to about 2.0 μg/ml, and most preferably about 1.6 μg/ml.
[0040] According to a further aspect, the PCV ORF-2 antigen inclusion level is at least 0.2 μg/PCV2 ORF-2 protein as described above per dose of the final antigenic composition (μg/dose), more preferably from about 0.2 to about 400 μg/dose, still more preferably from about 0.3 to about 200 μg/dose, even more preferably from about 0.35 to about 100 μg/dose, still more preferably from about 0.4 to about 50 μg/dose, still more preferably from about 0.45 to about 30 μg/dose, still more preferably from about 0.5 to about 18 μg/dose, even more preferably from about 0.6 to about 15 μg/ml, even more preferably from about 0.75 to about 8 μg/dose, even more preferably from about 1.0 to about 6 μg/dose, still more preferably from about 1.3 to about 3.0 μg/dose, even more preferably from about 1.4 to about 2.5 μg/dose, even more preferably from about 1.5 to about 2.0 μg/dose, and most preferably about 1.6 μg/dose. It has been surprisingly found, that a PCV2 ORF-2 protein inclusion level (antigen content) of less than 20 μg/dose, preferably of about 0.5 to 18 μg/dose is suitable to confer immunity in young animals and/or in animals which are positive for PCV2 antibodies, in particular which are positive for anti-PCV2 maternally-derived antibodies. Thus, according to a further aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in animals having anti-PCV2 antibodies, in particular maternally-derived anti-PCV2 antibodies, comprising the step of administering less than 20 μg/dose, preferably of about 0.5 to 18 μg/dose of PCV2 antigen or an immunogenic composition comprising an PCV2 antigen to that animal in need of such treatment. Said PCV2 antigen is any one described in this patent application. Preferably, said PCV2 antigen is any PCV2 ORF-2 protein, more preferably, any PCV2 ORF-2 protein described herein.
[0041] The PCV2 ORF-2 polypeptide used in the immunogenic composition in accordance with the present invention can be derived in any fashion including isolation and purification of PCV2 ORF2, standard protein synthesis, and recombinant methodology. Preferred methods for obtaining PCV2 ORF-2 polypeptide are provided in WO06/072065, the teachings and content of which are hereby incorporated by reference in their entirety. Briefly, susceptible cells are infected with a recombinant viral vector containing PCV2 ORF-2 DNA coding sequences, PCV2 ORF-2 polypeptide is expressed by the recombinant virus, and the expressed PCV2 ORF-2 polypeptide is recovered from the supernatant by filtration and inactivated by any conventional method, preferably using binary ethylenimine, which is then neutralized to stop the inactivation process.
[0042] The immunogenic composition as used herein also refers to a composition that comprises i) any of the PCV2 ORF-2 protein described above, preferably in concentrations described above, and ii) at least a portion of the viral vector expressing said PCV2 ORF-2 protein, preferably of a recombinant baculovirus. Moreover, the immunogenic composition can comprise i) any of the PCV2 ORF-2 proteins described above, preferably in concentrations described above, ii) at least a portion of the viral vector expressing said PCV2 ORF-2 protein, preferably of a recombinant baculovirus, and iii) a portion of the cell culture supernatant.
[0043] Thus, according to a further aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in animals having anti-PCV2 antibodies, in particular maternally-derived anti-PCV2 antibodies, comprising the step of administering an effective amount of PCV2 antigen or an immunogenic composition comprising an PCV2 antigen to that animal in need of such treatment, wherein the PCV2 antigen is recombinant PCV2 ORF-2, preferably a baculovirus expressed PCV2 ORF-2. Preferably those recombinant or baculovirus expressed PCV2 ORF-2 having the sequence as described above.
[0044] The immunogenic composition as used herein also refers to a composition that comprises i) any of the PCV2 ORF-2 proteins described above, preferably in concentrations described above, ii) at least a portion of the viral vector expressing said PCV2 ORF-2 protein, preferably of a recombinant baculovirus, and iii) a portion of the cell culture; wherein about 90% of the components have a size smaller than 1 μm.
[0045] The immunogenic composition as used herein also refers to a composition that comprises i) any of the PCV2 ORF-2 proteins described above, preferably in concentrations described above, ii) at least a portion of the viral vector expressing said PCV2 ORF-2 protein, iii) a portion of the cell culture, iv) and inactivating agent to inactivate the recombinant viral vector preferably BEI, wherein about 90% of the components i) to iii) have a size smaller than 1 μm. Preferably, BEI is present in concentrations effective to inactivate the baculovirus, preferably in an amount of 2 to about 8 mM BEI, preferably of about 5 mM BEI.
[0046] The immunogenic composition as used herein also refers to a composition that comprises i) any of the PCV2 ORF-2 proteins described above, preferably in concentrations described above, ii) at least a portion of the viral vector expressing said PCV2 ORF-2 protein, iii) a portion of the cell culture, iv) an inactivating agent to inactivate the recombinant viral vector preferably BEI, and v) a neutralization agent to stop the inactivation mediated by the inactivating agent, wherein about 90% of the components i) to iii) have a size smaller than 1 μm. Preferably, if the inactivating agent is BEI, said composition comprises sodium thiosulfate in equivalent amounts to BEI.
[0047] The polypeptide is incorporated into a composition that can be administered to an animal susceptible to PCV2 infection. In preferred forms, the composition may also include additional components known to those of skill in the art (see also Remington's Pharmaceutical Sciences. (1990). 18th ed. Mack Publ., Easton). Additionally, the composition may include one or more veterinary-acceptable carriers. As used herein, “a veterinary-acceptable carrier” includes any and all solvents, dispersion media, coatings, adjuvants, stabilizing agents, diluents, preservatives, antibacterial and antifungal agents, isotonic agents, adsorption delaying agents, and the like. In a preferred embodiment, the immunogenic composition comprises PCV2 ORF-2 protein as provided herewith, preferably in concentrations described above, which is mixed with an adjuvant, preferably Carbopol, and physiological saline.
[0048] Those of skill in the art will understand that the composition used herein may incorporate known injectable, physiologically acceptable sterile solutions. For preparing a ready-to-use solution for parenteral injection or infusion, aqueous isotonic solutions, such as e.g. saline or corresponding plasma protein solutions, are readily available. In addition, the immunogenic and vaccine compositions of the present invention can include diluents, isotonic agents, stabilizers, or adjuvants. Diluents can include water, saline, dextrose, ethanol, glycerol, and the like. Isotonic agents can include sodium chloride, dextrose, mannitol, sorbitol, and lactose, among others. Stabilizers include albumin and alkali salts of ethylendiamintetracetic acid, among others.
[0049] “Adjuvants” as used herein, can include aluminium hydroxide and aluminium phosphate, saponins e.g., Quil A, QS-21 (Cambridge Biotech Inc., Cambridge Mass.), GPI-0100 (Galenica Pharmaceuticals, Inc., Birmingham, Ala.), water-in-oil emulsion, oil-in-water emulsion, water-in-oil-in-water emulsion. The emulsion can be based in particular on light liquid paraffin oil (European Pharmacopea type); isoprenoid oil such as squalane or squalene oil resulting from theoligomerization of alkenes, in particular of isobutene or decene; esters of acids or of alcohols containing a linear alkyl group, more particularly plant oils, ethyl oleate, propylene glycol di-(caprylate/caprate), glyceryl tri-(caprylate/caprate) or propylene glycol dioleate; esters of branched fatty acids or alcohols, in particular isostearic acid esters. The oil is used in combination with emulsifiers to form the emulsion. The emulsifiers are preferably nonionic surfactants, in particular esters of sorbitan, of mannide (e.g. anhydromannitol oleate), of glycol, of polyglycerol, of propylene glycol and of oleic, isostearic, ricinoleic or hydroxystearic acid, which are optionally ethoxylated, and polyoxypropylene-polyoxyethylene copolymer blocks, in particular the Pluronic products, especially L121. See Hunter et al., The Theory and Practical Application of Adjuvants (Ed. Stewart-Tull, D. E. S.). JohnWiley and Sons, NY, pp51-94 (1995) and Todd et al., Vaccine 15:564-570 (1997).
[0050] For example, it is possible to use the SPT emulsion described on page 147 of “Vaccine Design, The Subunit and Adjuvant Approach” edited by M. Powell and M. Newman, Plenum Press, 1995, and the emulsion MF59 described on page 183 of this same book.
[0051] A further instance of an adjuvant is a compound chosen from the polymers of acrylic or methacrylic acid and the copolymers of maleic anhydride and alkenyl derivative. Advantageous adjuvant compounds are the polymers of acrylic or methacrylic acid which are cross-linked, especially with polyalkenyl ethers of sugars or polyalcohols. These compounds are known by the term carbomer (Phameuropa Vol. 8, No. 2, June 1996). Persons skilled in the art can also refer to U.S. Pat. No. 2,909,462 which describes such acrylic polymers cross-linked with a polyhydroxylated compound having at least 3 hydroxyl groups, preferably not more than 8, the hydrogen atoms of at least three hydroxyls being replaced by unsaturated aliphatic radicals having at least 2 carbon atoms. The preferred radicals are those containing from 2 to 4 carbon atoms, e.g. vinyls, allyls and other ethylenically unsaturated groups. The unsaturated radicals may themselves contain other substituents, such as methyl. The products sold under the name Carbopol; (BF Goodrich, Ohio, USA) are particularly appropriate. They are cross-linked with an allyl sucrose or with allyl pentaerythritol. Among them, there may be mentioned Carbopol 974P, 934P and 971P. Most preferred is the use of Carbopol, in particular the use of Carbopol 971P, preferably in amounts of about 500 μg to about 5 mg per dose, even more preferred in an amount of about 750 μg to about 2.5 mg per dose and most preferred in an amount of about 1 mg per dose.
[0052] Further suitable adjuvants include, but are not limited to, the RIBI adjuvant system (Ribi Inc.), Block co-polymer (CytRx, Atlanta Ga.), SAF-M (Chiron, Emeryville Calif.), monophosphoryl lipid A, Avridine lipid-amine adjuvant, heat-labile enterotoxin from E. coli (recombinant or otherwise), cholera toxin, IMS 1314, or muramyl dipeptide among many others.
[0053] Preferably, the adjuvant is added in an amount of about 100 μg to about 10 mg per dose. Even more preferably, the adjuvant is added in an amount of about 100 μg to about 10 mg per dose. Even more preferably, the adjuvant is added in an amount of about 500 μg to about 5 mg per dose. Even more preferably, the adjuvant is added in an amount of about 750 μg to about 2.5 mg per dose. Most preferably, the adjuvant is added in an amount of about 1 mg per dose.
[0054] Additionally, the composition can include one or more pharmaceutical-acceptable carriers. As used herein, “a pharmaceutical-acceptable carrier” includes any and all solvents, dispersion media, coatings, stabilizing agents, diluents, preservatives, antibacterial and antifungal agents, isotonic agents, adsorption delaying agents, and the like. Most preferably, the composition provided herewith, contains PCV2 ORF-2 protein recovered from the supernatant of in vitro cultured cells, wherein said cells were infected with a recombinant viral vector containing PCV2 ORF-2 DNA and expressing PCV2 ORF-2 protein, and wherein said cell culture was treated with about 2 to about 8 mM BEI, preferably with about 5 mM BEI to inactivate the viral vector, and an equivalent concentration of a neutralization agent, preferably sodium thiosulfate solution to a final concentration of about 2 to about 8 mM, preferably of about 5 mM.
[0055] The present invention also relates to an immunogenic composition that comprises i) any of the PCV2 ORF-2 proteins described above, preferably in concentrations described above, ii) at least a portion of the viral vector expressing said PCV2 ORF-2 protein, iii) a portion of the cell culture, iv) an inactivating agent to inactivate the recombinant viral vector (preferably BEI), and v) a neutralization agent to stop the inactivation mediated by the inactivating agent, preferably sodium thiosulfate in equivalent amounts to BEI; and vi) a suitable adjuvant, preferably Carbopol 971 in amounts described above; wherein about 90% of the components i) to iii) have a size smaller than 1 μm. According to a further aspect, this immunogenic composition further comprises a pharmaceutical acceptable salt, preferably a phosphate salt in physiologically acceptable concentrations. Preferably, the pH of said immunogenic composition is adjusted to a physiological pH, meaning between about 6.5 and 7.5.
[0056] The immunogenic composition as used herein also refers to a composition that comprises per one ml i) at least 1.6 μg of PCV2 ORF-2 protein described above, preferably less than 20 μg ii) at least a portion of baculovirus expressing said PCV2 ORF-2 protein iii) a portion of the cell culture, iv) about 2 to 8 mM BEI, v) sodium thiosulfate in equivalent amounts to BEI; and vi) about 1 mg Carbopol 971, and vii) phosphate salt in a physiologically acceptable concentration; wherein about 90% of the components i) to iii) have a size smaller than 1 μm and the pH of said immunogenic composition is adjusted to about 6.5 to 7.5.
[0057] The immunogenic compositions can further include one or more other immuno-modulatory agents such as, e.g., interleukins, interferons, or other cytokines. The immunogenic compositions can also include Gentamicin and Merthiolate. While the amounts and concentrations of adjuvants and additives useful in the context of the present invention can readily be determined by the skilled artisan, the present invention contemplates compositions comprising from about 50 μg to about 2000 μg of adjuvant and preferably about 250 μg/ml dose of the vaccine composition. Thus, the immunogenic composition as used herein also refers to a composition that comprises from about 1 ug/ml to about 60 μg/ml of antibiotics, and more preferably less than about 30 μg/ml of antibiotics.
[0058] The immunogenic composition as used herein also refers to a composition that comprises i) any of the PCV2 ORF-2 proteins described above, preferably in concentrations described above, ii) at least a portion of the viral vector expressing said PCV2 ORF-2 protein, iii) a portion of the cell culture, iv) an inactivating agent to inactivate the recombinant viral vector preferably BEI, and v) an neutralization agent to stop the inactivation mediated by the inactivating agent, preferably sodium thiosulfate in equivalent amounts to BEI; vi) a suitable adjuvant, preferably Carbopol 971 in amounts described above; vii) a pharmaceutical acceptable concentration of a saline buffer, preferably of a phosphate salt, and viii) an anti-microbiological active agent; wherein about 90% of the components i) to iii) have a size smaller than 1 μm.
[0059] The immunogenic composition as used herein also refers to Ingelvac® CircoFLEX™, (Boehringer Ingelheim Vetmedica Inc, St Joseph, Mo., USA), CircoVac® (Merial SAS, Lyon, France), CircoVent (Intervet Inc., Millsboro, Del., USA), or Suvaxyn PCV-2 One Dose® (Fort Dodge Animal Health, Kansas City, Kans., USA).
[0060] Thus according to a further aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in animals in animals having anti-PCV2 maternal antibodies, comprising the step of administering an effective amount of a PCV2 antigen to that animal in need of such treatment, wherein the immunogenic composition is CircoFLEX®, CircoVac®, CircoVent or Suvaxyn PCV-2 One Dose®. Most preferably, the immunogenic composition is Ingelvac® CircoFLEX™, and/or the PCV2 antigen is PCV2 ORF-2, preferably, baculovirus expressed PCV2 ORF-2, most preferably as included in Ingelvac® CircoFLEX™.
[0061] For investigation of a possible interference of PCV2 antigen with the maternal antibody a study was conducted in which the antibody titers of study animals were determined at the time of vaccination which were then grouped into a low, moderate and high antibody class: Geometric mean titers of <1:100 were considered as low antibody titers, titers of 1:100 to 1:1000 were considered as moderate antibody titers and titers of >1:1000 were considered as high antibody titers. This grouping pattern is comparable to that done in a Canadian field study where antibody titers of 1:80 were considered as low, antibody titers of 1:640 as moderate and antibody titers of >1:1280 as high (Larochelle et al., 2003, Can. J. Vet. Res.; 67: 114-120). In order to analyze the impact of low, medium and high antibody titers at the time of vaccination on viremia, vaccinated and placebo-treated animals were compared with regard to the onset, end, duration of viremia, the number of positive sampling days and the virus load. It was surprisingly found, that the presence of anti-PCV2 antibodies, in particular of maternally-derived antibodies, had no significant impact of any of those parameters. In other words, it was surprisingly found that the efficacy of the PCV2 antigen in prevention and treatment of a PCV2 infection or in reduction of clinical symptoms caused by or associated with a PCV2 infection in animals was not affected at the day of vaccination by the presence of anti-PCV2 antibodies, preferably by anti-PCV2 antibody titers of up to 1:100, preferably of more than 1:100, even more preferably of more than 1:250, even more preferably of more than 1:500, even more preferably of 1:640; even more preferably of more than 1:750, most preferably of more than 1:1000. This effect could be shown in a one shot vaccination experiment, which means that the PCV2 antigen was administered only once and without any subsequent administration of PCV2 antigen.
[0062] Methods for detection and quantification of anti-PCV2 antibodies are well known in the art. For example detection and quantification of PCV2 antibodies can be performed by indirect immunofluorescence as described in Magar et al., 2000, Can. J. Vet Res.; 64: 184-186 or Magar et al., 2000, J. Comp. Pathol.; 123: 258-269. Further assays for quantification of anti-PCV2 antibodies are described in Opriessnig et al., 2006, 37 th Annual Meeting of the American Association of Swine Veterinarians. Moreover, example 2 also describes an indirect immunofluorescence assay that can be used by a person skilled in the art. In cases of controversial results and in any question of doubt, anti-PCV2 titers as mentioned herein, refer to those which are/can be estimated by the assay as described in Example 2.
[0063] Thus according to a further aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in animals having anti-PCV2 antibodies, in particular maternal antibodies, comprising the step of administering an effective amount of a PCV2 antigen to that animal in need of such treatment, preferably of less than 20 μg/dose wherein said animal has a detectable anti-PCV2 antibody titer of up to 1:100, preferably of more than 1:100, even more preferably of more than 1:250, even more preferably of more than 1:500, even more preferably of 1:640, even more preferably of more than 1:750, most preferably of more than 1:1000. Preferably, such an anti-PCV2 antibody titer is detectable and quantifiable in a specific anti-PCV2 immune assay, preferably in the assay as described in Example 2. More preferably, those anti-PCV-2 antibodies are maternally-derived antibodies. Most preferably, the PCV2 antigen is only administered once, preferably with a dose of less than 20 μg/dose.
[0064] Piglets with only low titers (<1:100) or moderate titers (<1:1000) of maternally-derived anti-PCV2 antibodies are not sufficiently protected against PCV2 infections which occur prior to week 3 of age. Therefore, vaccination at a very early stage of life is desirable. Due to the unpredictable and unexpected results provided herein and demonstrating the lack of interference of anti-PCV2 antibodies with PCV2 antigen, vaccination/treatment of animals before 3 weeks of age becomes realistic. Moreover, it has been surprisingly found that anti-PCV2 antibody titers of more than 1:1000 had no influence on the efficacy of the PCV2 vaccine regardless of the level of the existing initial antibody titer. For example, vaccination of high-titer animals (anti-PCV2 antibody titer >1:1000) resulted in a 9.5 day shorter duration of viremia, a 11.9 days earlier end of viremia, 1.9 days less viremic sampling days and an approximately 2-fold reduction of the sum of genomic equivalents/ml as compared to non vaccinated control animals. Upon comparison of vaccinated “high” “moderate” and “low titer animals” no significant differences were observed with regard to the different parameters of PCV2 viraemia. These results indicate that also in the presence of high anti-PCV2 antibody titers, the PCV2 antigen used for vaccination can still significantly reduce viremia in blood (end of viremia, duration of viremia, virus load). In line with this finding, no differences could be found with regard to the live body weight when comparing low and high titer animals of the vaccinated group. Furthermore vaccinated animals with a high anti-PCV2 antibody titer at the time of vaccination/treatment (>1:1000) also showed a significantly higher body weight after the onset of viremia compared to placebo-treated animals with initial high antibody titers (see FIG. 3 ). Consequently, vaccination/treatment of animals of 1 day of age or older with PCV2 antigen is possible. However, vaccination should be done within the first 8, preferably within the first 7 weeks of age. Thus according to a further aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in animals, comprising the step of administering to that animal in need of such treatment at day 1 of age or later, preferably but not later than at week 8 of age an effective amount of a PCV2 antigen. According to a preferred embodiment, less than 20 μg/dose PCV2 antigen are required to confer immunity in such animal. According to a more preferred embodiment, the PCV2 antigen, preferably less than 20 μg/dose thereof is only administered once to the animal in need of such treatment.
[0065] According to a further, more general aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in young animals, comprising the step of administering an effective amount of a PCV2 antigen to that animal in need of such treatment.
[0066] The term “young animal” as used herein refers to an animal of 1 to 22 days of age. Preferably, by the term young animal, an animal of 1 to 20 days of age is meant. More preferably, the term young animal refers to an animal of 1 to 15 days of age, even more preferably of 1 day of age to 14 days of age, even more preferably of 1 to 12 days of age, even more preferably of 1 to 10 days of age, even more preferably of 1 to 8 days of age, even more preferably of 1 to 7 days of age, even more preferably of 1 to 6 days of age, even more preferably of 1 to 5 days of age, even more preferably of 1 to 4 days of age, even more preferably of 1 to 3 days of age, even more preferably of 1 or 2 day(s) of age, and most preferably to an animal of 1 day of age. Thus according to a further aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in young animals, comprising the step of administering an effective amount of a PCV2 antigen to an animal of 1 to 22 days of age, preferably of 1 to 20 days of age, more preferably of 1 to 15 days of age, even more preferably of 1 to 14 days of age, even more preferably of 1 to 12 days of age, even more preferably of 1 to 10 days of age, even more preferably of 1 to 8 days of age, even more preferably of 1 to 7 days of age, even more preferably of 1 to 6 days of age, even more preferably of 1 to 5 days of age, even more preferably of 1 to 4 days of age, even more preferably of 1 to 3 days of age, even more preferably of 1 or 2 day(s) of age, most preferably at 1 day of age in need of such treatment. For example, evidence is given that vaccination/treatment on 19 to 22 days of age shows high efficacy of vaccination. Moreover, vaccination/treatment at 12 to 18, preferably 12 to 14 days of age has also be shown to be very effective in the reduction of clinical symptoms associated with PCV2 infections, reduction of overall viral load, reduction of duration of viremia, delay in onset of viremia, and weight gain. Moreover, vaccination at 1 week of age has also been shown to be very effective in reduction of clinical symptoms associated with PCV2 infections, reduction of overall viral load, reduction of duration of viremia, delay in onset of viremia, weight gain. Preferably less than 20 μg/dose PCV2 antigen are required to confer immunity in those young animals. According to more preferred embodiment, the PCV2 antigen, preferably less than 20 μg, is only administered once to that young animal in need of such treatment.
[0067] Due to the ubiquity of PCV2 in the field, most of the young piglets are seropositive in respect to PCV2. Thus according to a further aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in young animals having anti-PCV2 antibodies at the day of vaccination, comprising the step of administering an effective amount of a PCV2 antigen to an animal of 1 to 22 days of age, preferably of 1 to 20 days of age, more preferably of 1 to 15 days of age, even more preferably of 1 to 14 days of age, even more preferably of 1 to 12 days of age, even more preferably of 1 to 10 days of age, even more preferably of 1 to 8 days of age, even more preferably of 1 to 7 days of age, even more preferably of 1 to 6 days of age, even more preferably of 1 to 5 days of age, even more preferably of 1 to 4 days of age, even more preferably of 1 to 3 days of age, even more preferably at 1 or 2 day(s) of age, and most preferably at 1 day of age in need of such treatment. Preferably, said young animals, at the day of vaccination/treatment, have a detectable anti-PCV2 antibody titer of up to 1:100, preferably of more than 1:100, even more preferably of more than 1:250, even more preferably of more than 1:500, even more preferably of 1:640, even more preferably of more than 1:750, most preferably of more than 1:1000 at the day of vaccination/treatment. Preferably less than 20 μg/dose PCV2 antigen are required to confer a sufficient immunity in those young animals. According to more preferred embodiment, the PCV2 antigen, preferably less than 20 μg, is only administered once to that young animal in need of such treatment.
[0068] As described above, vaccination/treatment of young animals with PCV2 antigen resulted in a shortening of viremic phase as compared to non vaccinated control animals. The average shortening time was 9.5 days as compared to non vaccinated control animals of the same species. Therefore, according to a further aspect, the present invention also provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in young animals, comprising the step of administering an effective amount of a PCV2 antigen to that animal in need of such treatment, wherein the treatment or prophylaxis results in shortening of the viremia phase of 5 or more days, preferably 6 or more day, even more preferably of 7 or more days, even more preferably of 8 or more days, even more preferably of 9, even more preferably of 10, even more preferably of 12, even more preferably of 14, and most preferably of more than 16 days as compared to animals of a non-treated control group of the same species. In some cases viremic phase is shortened by more than 20 days. In general, the vaccination of young piglets resulted in a reduction in the loss of weight gain, a shorter duration of viremia, an earlier end to viremia, and a lower virus load. Therefore, according to a further aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in young animals, comprising the step of administering an effective amount of a PCV2 antigen to that animal in need of such treatment, wherein said treatment or prophylaxis of PCV2 infection results in an improvement in comparison to animals of a non-treated control group of the same species in a vaccine efficacy parameter selected from the group consisting of a reduction in the loss of weight gain, a shorter duration of viremia, an earlier end to viremia, a lower virus load, or combinations thereof. Preferably less than 20 μg/dose PCV2 antigen are required to cause any of the improved vaccine efficacy parameters mentioned above. Moreover such improved vaccine efficacy parameter(s) are achieved by a single administration of only one dose.
[0069] The term “an effective amount” as used herein means, but is not limited to, an amount of antigen, that elicits or is able to elicit an immune response in an animal, to which said effective dose of PCV2 antigen is administered. Preferably, an effective amount is defined as an amount of antigen that confers a duration of immunity (DOI) of at least 10 weeks, preferably at least 12 weeks, more preferably at least 15 weeks, and most preferably at least 20 weeks.
[0070] The amount that is effective depends on the ingredients of the vaccine and the schedule of administration. Typically, when an inactivated virus or a modified live virus preparation is used in the combination vaccine, an amount of the vaccine containing about 10 2.0 to about 10 9.0 TCID 50 per dose, preferably about 10 3.0 to about 10 8.0 TCID 50 per dose, and more preferably, about 10 4.0 to about 10 8.0 TCID 50 per dose is used. In particular, when modified live PCV2 is used in the vaccines, the recommended dose to be administered to the susceptible animal is preferably about 10 3.0 TCID 50 (tissue culture infective dose 50% end point)/dose to about 10 6.0 TCID 50 /dose and more preferably about 10 4.0 TCID 50 /dose to about 10 5.0 TCID 50 /dose. In general, the quantity of antigen will be between 0.2 and 5000 micrograms, and between 10 2.0 and 10 9.0 TCID 50 , preferably between 10 3.0 and 10 6.0 TCID 50 , more preferably between 10 4.0 and 10 5.0 TCID 50 , when purified antigen is used.
[0071] Sub-unit vaccines are normally administered with an antigen inclusion level of at least 0.2 μg antigen per dose, preferably with about 0.2 to about 400 μg/dose, still more preferably with about 0.3 to about 200 μg/dose, even more preferably with about 0.35 to about 100 μg/dose, still more preferably with about 0.4 to about 50 μg/dose, still more preferably with about 0.45 to about 30 μg/dose, still more preferably with about 0.5 to about 18 μg/dose, still more preferably with about 0.6 to about 16 μg/dose, even more preferably with about 0.75 to about 8 μg/dose, even more preferably with about 1.0 to about 6 μg/dose, and still more preferably with about 1.3 to about 3.0 μg/dose.
[0072] Unexpectedly, it was found that the prophylactic use of the immunogenic compositions described supra, is effective for the reduction of clinical symptoms caused by or associated with PCV2 infections, preferably in young animals and/or in animals having passive immunity against PCV2 at the day of treatment. In particular, it was discovered that the prophylactic use of the immunogenic compositions as described herein, and specifically of compositions comprising PCV2 ORF-2 antigen, is effective for reducing lymphadenopathy, lymphoid depletion and/or multinucleated/giant histiocytes in animals infected with PCV2 and having maternal anti-PCV-2 antibodies at the day of treatment/vaccination. Furthermore, it was discovered that the prophylactic use of the immunogenic compositions as described herein, and specifically of compositions comprising PCV2 ORF-2 antigen, is effective for reducing (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc, (7) Pia like lesions, normally known to be associated with Lawsonia intracellularis infections (Ileitis), (8) lymphadenopathy, (9) lymphoid depletion and/or (10) multinucleated/giant histiocytes (11) Porcine Dermatitis and Nephropathy Syndrome (PDNS), (12) PCVAD associated mortality, (13) PCVAD associated weight loss, (14), reduced growth variability (15), reduced frequency of ‘runts’ (16), reduced co-infections with Porcine Reproductive and Respiratory Disease Complex (PRRSV). Such an immunogenic composition is also effective in improving economical important growth parameters such as time to slaughter, carcass weight, and/or lean meat ratio. Thus the term “clinical symptoms” as used herein, means, but is not limited to (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc, (7) Pia like lesions, normally known to be associated with Lawsonia intracellularis infections (Ileitis), (8) lymphadenopathy, (9) lymphoid depletion and/or (10) multinucleated/giant histiocytes (11) Porcine Dermatitis and Nephropathy Syndrome (PDNS), (12) PCVAD associated mortality, (13) PCVAD associated weight loss, (14) reduced growth variability (15) reduced frequency of ‘runts’ and (16) reduced co-infections with Porcine Reproductive and Respiratory Disease Complex (PRRSV). Moreover, the antigenic composition described herein reduces the overall circovirus load including a later onset, a shorter duration, an earlier end of viremia, and a reduced viral load and its immunosuppressive impact in young animals, in particular in those having anti-PCV2 antibodies at the day of vaccination, thereby resulting in a higher level of general disease resistance and a reduced incidence of PCV2 associated diseases and symptoms.
[0073] Thus, according to a further aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in young animals and/or in animals having anti-PCV2 antibodies, comprising the step of administering an effective amount of PCV2 antigen or an immunogenic composition comprising an PCV2 antigen to that animal in need of such treatment, wherein those clinical symptoms are selected from the group consisting of: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc, (7) Pia like lesions, normally known to be associated with Lawsonia intracellularis infections (Ileitis), (8) lymphadenopathy, (9) lymphoid depletion and/or (10) multinucleated/giant histiocytes (11) Porcine Dermatitis and Nephropathy Syndrome (PDNS), (12) PCVAD associated mortality, (13) PCVAD associated weight loss, (14) reduced growth variability (15) reduced frequency of ‘runts’ and (16) reduced co-infections with Porcine Reproductive and Respiratory Disease Complex (PRRSV). According to a further aspect, the present invention provides a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in young animals, comprising the step of administering an effective amount of a PCV2 antigen to that animal in need of such treatment, wherein those clinical symptoms are selected from the group consisting of: (1) interstitial pneumonia with interlobular edema, (2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis (6) reproductive disorders, e.g. abortion, stillbirths, mummies, etc, (7) Pia like lesions, normally known to be associated with Lawsonia intracellularis infections (Ileitis), (8) lymphadenopathy, (9) lymphoid depletion and/or (10) multinucleated/giant histiocytes (11) Porcine Dermatitis and Nephropathy Syndrome (PDNS), (12) PCVAD associated mortality, (13) PCVAD associated weight loss, (14) reduced growth variability (15) reduced frequency of ‘runts’ and (16) reduced co-infections with Porcine Reproductive and Respiratory Disease Complex (PRRS V).
[0074] The composition according to the invention may be administered or applied, orally, intradermally, intratracheally, or intravaginally. The composition preferably may be administered or applied intramuscularly or intranasally, most preferably intramuscularly. In an animal body, it can prove advantageous to apply the pharmaceutical compositions as described above via an intravenous or by direct injection into target tissues. For systemic application, the intravenous, intravascular, intramuscular, intranasal, intraarterial, intraperitoneal, oral, or intrathecal routes are preferred. A more local application can be effected subcutaneously, intradermally, intracutaneously, intracardially, intralobally, intramedullarly, intrapulmonarily or directly in or near the tissue to be treated (connective-, bone-, muscle-, nerve-, epithelial tissue). Depending on the desired duration and effectiveness of the treatment, the compositions according to the invention may be administered once or several times, also intermittently, for instance on a daily basis for several days, weeks or months and in different dosages.
[0075] Preferably, one dose of the immunogenic composition as described above is intramuscularly administered to the subject in need thereof. According to a further aspect, the PCV2 antigen or the immunogenic composition comprising any such PCV2 antigen as described herein is bottled in and administered at one (1) mL per dose. Thus, according to a further aspect, the present invention also provides a 1 ml immunogenic composition, comprising PCV-2 antigen as described herein, for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in young animals, comprising the step of administering an effective amount of a PCV2 antigen to that animal in need of such treatment. According to a further aspect, the present invention also provides a 1 ml immunogenic composition, comprising PCV-2 antigen as described herein, treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in animals having anti-PCV2 antibodies, comprising the step of administering an effective amount of PCV2 antigen or an immunogenic composition comprising an PCV2 antigen to that animal in need of such treatment.
[0076] According to a further aspect, at least one further administration of at least one dose of the immunogenic composition as described above is given to a subject in need thereof, wherein the second or any further administration is given at least 14 days beyond the initial or any former administrations. Preferably, the immunogenic composition is administered with an immune stimulant. Preferably, said immune stimulant is given at least twice. Preferably, at least 3 days, more preferably at least 5 days, even more preferably at least 7 days are in between the first and the second or any further administration of the immune stimulant.
[0077] Preferably, the immune stimulant is given at least 10 days, preferably 15 days, even more preferably 20, and even more preferably at least 22 days beyond the initial administration of the immunogenic composition provided herein. A preferred immune stimulant is, for example, keyhole limpet hemocyanin (KLH), preferably emulsified with incomplete Freund's adjuvant (KLH/ICFA). However, it is herewith understood, that any other immune stimulant known to a person skilled in the art can also be used. The term “immune stimulant” as used herein, means any agent or composition that can trigger the immune response, preferably without initiating or increasing a specific immune response, for example the immune response against a specific pathogen. It is further instructed to administer the immune stimulant in a suitable dose.
[0078] The “animal” as used herein means swine, pig or piglet.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0079] The following examples set forth preferred materials and procedures in accordance with the present invention. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods, devices, and materials are now described. It is to be understood, however, that these examples are provided by way of illustration only, and nothing therein should be deemed a limitation upon the overall scope of the invention.
Example 1
Preparation of PCV2 ORF-2 Antigen
[0080] Initial SF+ cell cultures from liquid nitrogen storage were grown in Excell 420 media (JRH Biosciences, Inc., Lenexa, Kans.) in suspension in sterile spinner flasks with constant agitation. The cultures were grown in 100 mL to 250 mL spinner flasks with 25 to 150 mL of Excell 420 serum-free media. When the cells had multiplied to a cell density of 1.0-8.0×10 6 cells/mL, they were split to new vessels with a planting density of 0.5-1.5×10 6 cells/mL. Subsequent expansion cultures were grown in spinner flasks up to 36 liters in size or in stainless steel bioreactors of up to 300 liters for a period of 2-7 days at 25-29° C.
[0081] After seeding, the flasks were incubated at 27° C. for four hours. Subsequently, each flask was seeded with a recombinant baculovirus containing the PCV2 ORF-2 gene (SEQ ID NO: 4). The recombinant baculovirus containing the PCV2 ORF-2gene was generated as described in WO06/072065. After being seeded with the baculovirus, the flasks were then incubated at 27±2° C. for 7 days and were also agitated at 100 rpm during that time. The flasks used ventilated caps to allow for air flow.
[0082] After incubation, the resulting supernatant were harvested, filtered in order to remove cell debris and inactivated. The supernatant was inactivated by bringing its temperature to 37±2° C. and binary ethlylenimine (BEI) is added to the supernatant to a final concentration of 5 mM. The samples were then stirred continuously for 72 to 96 his. A 1.0 M sodium thiosulfate solution to give a final minimum concentration of 5 mM was added to neutralize any residual BEI. After inactivation, PCV2 ORF-2 buffered with phosphate buffer and Carpopol was added to about 0.5 to 2.5 mg/dose. The final dose comprises about 16 μg PCV2 ORF-2 antigen.
Example 2
Anti PCV-2 Immuno Assay
[0083] PK15 (e.g. ATCC CCL-33) or VIDO R1 cells described in WO 02/07721, are seeded onto a 96 well plate (about 20.000 to 60.000 cells per wells). Cells are infected with a PCV2 isolate, when monolayers are approximately 65 to 85% confluent. Infected cells are incubated for 48 hours. Medium is removed and wells are washed 2 times with PBS. The wash buffer is discarded and cells are treated with cold 50/50 methanol/acetone fixative (˜100 μl/well) for about 15 mm at about −20° C. The fixative is discarded and the plates are air tried. Serial dilutions of porcine serum samples are prepared in PBS, added to the plates and incubated to allow antibodies to bind if present in the serum samples for about 1 hr at 36,5 1° C. In addition, serial dilutions of an anti-PCV2 positive and negative control sample (Positive Control and Negative Control Samples) are run in parallel. The plates are then washed three times with PBS. The PBS is discarded. Plates are then stained with an commercial Goat anti-Swine FITC conjugate diluted 1:100 in PBS and incubated for about 1 hr at 36.5±1° C., which allows detection of antibodies bound to infected cells. After incubation is complete, the microplates are removed from incubator, the conjugate is discarded and the plates are washed 2 times with PBS. The plates were read using UV microscopy and individual wells reported as positive or negative. The Positive Control and Negative Control samples are used to monitor the test system. If the controls are within expected ranges the test results are acceptable in regard to test method parameters. The serum antibody titers were calculated using the highest dilution showing specific IFA reactivity and the number of wells positive per dilution, or a 50% endpoint is calculated using the appropriate Reed-Muench formula.
Example 3
Efficacy of PCV2 ORF-2 (Ingelvac® CircoFLEX™) in Young Animals Having Low or High Anti-PCV2 Antibodies
[0084] For investigation of a possible interference of the vaccine with the maternal antibody a study was conducted in which the antibody titers of all study animals were determined at the time of vaccination which were then grouped into a low, moderate and high antibody class: Geometric mean titers of <1:100 were considered as low antibody titers, titers of 1:100 to 1:1000 were considered as moderate antibody titers and titers of >1:1000 were considered as high antibody titers.
Study Performance
[0085] Approximately 500 animals were included into the study. The study animals were balanced and equally distributed among both treatment groups with regard to initial body weight and litter assignment. At 20 days of age all study animals received a single dose (1 ml) of the PCV2 vaccine (Investigational Veterinary Product, IVP) or a single (1 ml) dose of a placebo containing adjuvanted cell culture supernatant (Control Product, CP) by intramuscular injection in the right side of the neck. Study animals were followed until the end of fattening. Blood samples from all study animals were collected and subsequently analyzed by IFAT in order to determine the antibody titers at the time of vaccination. Following this, the initial antibody titers were correlated with the weight gain. In addition, dependent on the initial antibody titer, animals were grouped into three classes (low, moderate and high initial antibody titers) and ‘high titer’ animals of both treatment groups were then compared for possible differences with regard to weight gain and viremia.
Results
Initial Antibody Titers
[0086] At the time of vaccination the majority of animals had either moderate antibody titers (defined as 1:100 to 1:1000) or high antibody titers (defined as >1:1000). Only approximately 13% percent of animals had low antibody titers (defined as <1:100). Due to the absence of PCV2 infection at the time of study initiation it can be concluded that the antibody titers on study day 0 were possibly maternally derived. No significant differences in the antibody titers of study day 0 were observed between the two treatment groups. An overview about the percentage of animals per titer class is given in FIG. 1 .
[0000] Correlation of Antibody Titers at the Time of Vaccination with Viremia in Blood
[0087] In order to determine whether a high antibody titer at the time of vaccination (>1:1000) had an impact on viremia, vaccinated and placebo-treated animals with high initial antibody titers were compared with regard to the onset, end, duration of viremia, the number of positive sampling days and the virus load. Table 1 summarizes the comparison of viremia parameters of the ‘high-titer animals’ from both treatment groups.
[0000]
TABLE 1
Comparison of viremia in ‘high titer animals’
from both treatment groups
Investigated
Treatment
Number
Parameter
Group
of pigs
Mean
Median
P
Onset of
CP
38
111.90
days
113.00
days
0.7843
Viremia
IVP
36
109.50
days
113.00
days
ns
CP-IVP
2.4
days
Duration of
CP
38
27.00
days
27.50
days
<0.0001***
Viremia
IVP
36
17.50
days
6.50
days
CP-IVP
9.50
days
End of
CP
38
138.90
days
141.00
days
0.0033**
Viremia
IVP
36
127.00
days
122.50
days
CP-IVP
11.9
days
Positive
CP
39
3.70
days
3.00
days
0.0082**
Sampling
IVP
47
1.80
days
1.00
days
days
CP-IVP
1.9
days
Mean Sum gE
CP
39
18.79
gE
17.21
gE
<0.0001***
(log10)
IVP
47
9.12
gE
5.38
gE
CP-IVP
9.67
gE
gE: sum of genomic equivalents per ml
P: p-value of the Wilcoxon Mann-Whitney test for comparisons between groups;
ns: not significant, p > 0.05;
**significant, p ≦ 0.01;
***significant, p < 0.001
[0088] Compared to the placebo-treated high-titer animals, vaccinated high-titer animals had a 9.5 day shorter duration of viremia, a 11.9 days earlier end of viremia, 1.9 days less viremic sampling days and an approximately 2-fold reduction of the sum of genomic equivalents/ml over the course of the study. These results indicate that also in the presence of high maternal antibody titers the IVP can still significantly reduce viremia in blood (end of viremia, duration of viremia, virus load).
[0000] Correlation of Antibody Titers at the Time of Vaccination with Weight Gain
[0089] It was next investigated, whether the initial antibody titer had any effect on the weight gain over the course of the study. Table 2 presents the correlation of the initial antibody titer with the weight gain at different time intervals as determined by the calculation of the Spearman rank coefficient and the p-value.
[0090] A statistically significant negative correlation between the antibody titer and the weight gain was found for both treatment groups at study weeks 0 to 7 indicating that a high maternal antibody titer negatively influences the weight gain development in the rearing phase. No other statistically significant correlations between the initial antibody titer and the weight gain during different time intervals were observed. It can therefore be concluded that the level of maternal antibody titer did not have an influence on the weight gain from 10 weeks of age (study week 7) onwards for neither the vaccinated or for the placebo-treated animals.
[0000]
TABLE 2
Correlation of the PCV2 antibody titer at the time of vaccination
with body weight gain over the course of the study
Correlation of antibody titer at the time
of vaccination with weight gain
Study week
Study week
Study week
Study week
0-7
7-12
12-17
17-22
CP
r
−0.09623
0.03501
−0.00521
−0.02774
P
0.0086**
0.3425 ns
0.8884 ns
0.4617 ns
n
744
737
728
706
IVP
r
−0.09748
0.04309
−0.00954
0.02694
P
0.0077**
0.2440 ns
0.7974 ns
0.4710 ns
n
746
733
727
718
r: Spearman rank correlation coefficient
P: p-value of test on r = 0:
ns: not significant, p > 0.05;
**significant, p ≦ 0.01
n: Number of animals
[0091] In line with this finding, no differences could be found with regard to the live body weight when comparing low and high titer animals of the vaccinated group. FIG. 2 shows that the body weight after the onset of viremia (study week 17 and 22) was comparable irrespective of the level of initial antibody titer ( FIG. 2 ).
[0092] Furthermore vaccinated animals with a high antibody titer at the time of vaccination (>1:1000) also showed a significantly higher body weight after the onset of viremia compared to placebo-treated animals with initial high antibody titers. As can be seen in FIG. 3 the body weight (LSMean) at study week 17 and at study week 22 was indeed significantly higher in vaccinated ‘high titer animals’ (study week 17: 1.55 kg, p=0.0328; study week 22: 3.06 kg, p=0.0007) than in placebo-treated ‘high titer animals’. Together these findings demonstrate that there is no interference of the IVP with the antibody titer at the time of vaccination.
Conclusion
[0093] For analysis of a possible maternal antibody interference the initial antibody titer was correlated with the two efficacy parameters viremia in blood and live body weight. Compared to the placebo-treated ‘high titer animals’ the following statistical significant findings were noted for the vaccinated ‘high titer animals’:
reduction in loss of weight gain shorter duration of viremia and earlier end of viremia lower virus load
Example 4
Efficacy of PCV2 ORF-2 (Ingelvac® CircoFLEX™) in Young Animals Having Anti-PCV2 Antibodies with Respect to Lymphoid Depletion, Lymphoid Inflammation, and Lymphoid Immunohistochemistry (IHC)
[0097] The objective of this blinded vaccination-challenge study was to evaluate at what age pigs vaccinated with Porcine Circovirus Vaccine, Type 2, Killed Baculovirus Vector established immunity in the presence of Porcine Circovirus Type 2 (PCV2) maternally-derived antibodies. Three primary parameters were analyzed following challenge. These three parameters included lymphoid depletion, lymphoid inflammation, and lymphoid immunohistochemistry (IHC). To demonstrate immunity in the presence of PCV2 maternally-derived antibodies, conventionally raised pigs vaccinated with PCV2 vaccine at 3 weeks of age or at 8 weeks of age, must demonstrate statistically significant differences (p<0.05) for lymphoid depletion, lymphoid inflammation, and lymphoid IHC, compared with challenge control pigs treated with Control Product at 3 weeks of age.
Study Performance
[0098] One hundred twenty (120) conventionally raised pigs, 21 days of age on Day 0 (DO), were assigned completely at random to one of five treatment groups. On DO, blood samples were collected from all pigs,
Group 1a was treated with Investigational Veterinary Product (IVP; PCV2 reference vaccine) at 3 weeks of age. Group 1b was treated with Investigational Veterinary Product (IVP; PCV2 reference vaccine) at 8 weeks of age. Group 2 was treated with Control Product (CP) at 3 weeks of age.
[0102] Pigs were observed for clinical assessments post-vaccination from D-1 to D59. Additional pre-challenge blood samples were collected on D14, D28, D42, D56 and D63. A summary of Group PCV2 serological Geometric Mean Titers (GMT) pre-challenge are shown below in Table 3.
[0000]
TABLE 3
Group PCV2 Serological Geometric Mean Titers Pre-challenge
PCV2 Serology—GMT
Group—Treatment
D0
D14
D28
D42
D56
D63
Group 1a
556.5
252.8
142.0
56.2
32.0
51.3
IVP administered
3 weeks of age
Group 1b
476.2
308.2
151.6
36.2
29.3
48.3
IVP administered at
8 weeks of age
Group 2
513.8
310.7
134.3
36.9
16.9
24.5
CP administered at
3 weeks of age
[0103] All remaining pigs received 2.0 mL of keyhole limpet hemocyanin (KLH) emulsified in incomplete Freund's adjuvant (ICFA) IM on D60 (Day Post-Challenge (DPC) −3) and D66 (DPC 3). On D63 (DPC 0), remaining pigs received 1.0 mL of PCV2 Iowa State University Veterinary Diagnostic Laboratory (ISUVDL) challenge material (4.75 log 10 TCID 50 /mL) IM and 1.0 mL of the same material IN. Body weights, rectal temperatures, clinical observations, blood samples and nasal swabs were collected on the day of challenge and periodically post-challenge. At necropsy for each pig, gross lesions were noted and lung and lymphoid tissue samples were collected. Lung and lymphoid tissues were examined microscopically by ISUVDL for lesions and for the presence of PCV2 antigen by IHC testing. A general description of the challenge phase of the study is shown below in table 4.
[0000]
TABLE 4
Challenge Phase of Study
KLH/
PCV2
KLH/
ICFA
Challenge
ICFA
On D60
on D63
On D66
Day of
Group - Treatment
Number
(DPC-3)
(DPC 0)
(DPC 3)
Necropsy
Group 1a
20
Yes
Yes
Yes
D87 (DPC 24) or
IVP administered
D88 (DPC 25)
3 weeks of age
Group 1b
21
Yes
Yes
Yes
D87 (DPC 24) or
IVP administered
D88 (DPC 25)
at 8 weeks of age
Group 2
20
Yes
Yes
Yes
D87 (DPC 24) or
CP administered
D88 (DPC 25)
at 3 weeks of age
[0104] On D86, the geometric mean titers were 906.6, 2447.1, 2014.9, respectively.
Results
[0105] Following PCV2 challenge exposure on D63 and subsequent necropsy, Group 1a had a statistically significant lower proportion of pigs positive for lymphoid depletion (p=0.0084), a lower proportion of pigs positive for lymphoid inflammation (p=0.0079), and a lower proportion of pigs with IHC lymphoid-positive tissues (p=0.0031), all in comparison to Group 2. Following PCV2 challenge, Group 1b had a statistically significant lower proportion of pigs positive for lymphoid depletion (p=0.0148), a lower proportion of pigs positive for lymphoid inflammation (p=0.0036), and a lower proportion of pigs with IHC lymphoid-positive tissues (p=0.0013), all in comparison to Group 2. A summary of primary efficacy parameter results for Groups 1a, 1b and 2 are shown below in table 5.
[0000]
TABLE 5
Summary of Primary Efficacy Parameter Results
for Groups 1a and 1b compared with Group 2
PCV2
Lymphoid
Lymphoid
Lymphoid
Group -
Serological
Depletion
Inflammation
IHC
Treatment
status on Day 0
(+/total)
(+/total)
(+/total)
Group 1a
Seropositive
1/20 (5%)
3/20 (15%)
3/20 (15%)
IVP at 3 weeks
*p = 0.0084
*p = 0.0079
*p = 0.0031
of age
Group 1b
Seropositive
2/21 (9.5%)
3/21 (14.3%)
3/21 (14.3%)
IVP at 8 weeks
*p = 0.0148
*p = 0.0036
*p = 0.0013
of age
Group 2
Seropositive
9/20 (45%)
12/20 (60%)
13/20 (65%)
CP at 3 weeks
of age
*p value compared with Group 2 - Fisher's Exact Test
[0106] There were significant differences between Groups 1a and 1b compared with Group 2 for microscopic lung inflammation (p≦0.0407), but no significant differences between these groups for lung tissue testing positive for PCV2 antigen by IHC testing (p≧0.2317). There were no significant differences between Groups 1a and 1b compared with Group 2 for clinical assessments post-vaccination, ADG, clinical signs post-challenge, pyrexia, nasal shedding of PCV2, % total lung scores and lymphadenopathy.
[0107] In conclusion, Group 1a, vaccinated at 3 weeks of age and having a GMT of 556.6 at the time of vaccination, was significantly protected from lymphoid depletion, lymphoid inflammation, and lymphoid tissues testing positive for PCV2 antigen by IHC testing, compared with Group 2. Group 1b, vaccinated at 8 weeks of age and having a GMT of 151.6 one week prior to vaccination, was significantly protected from lymphoid depletion, lymphoid inflammation and lymphoid tissues testing positive for PCV2 antigen by IHC testing, compared with Group 2. Pigs with PCV2 maternally-derived antibodies were protected from Porcine Circovirus Associated Disease (PCVAD) when vaccinated as early as 3 weeks of age.
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The present invention relates to a method for the treatment or prophylaxis of a PCV2 infection or for reduction of clinical symptoms caused by or associated with a PCV2 infection in animals a) having anti-PCV2 antibodies and/or b) being young piglets of 1 to 22 days of age, comprising the step of administering an effective amount of a PCV2 antigen to that animal in need of such treatment. Preferably, those animals are pigs or young piglets.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to deck systems, and more particularly, to a deck system having unique columns, rails and planks that provide an easy to install, weatherable and attractive deck.
2. Description of the Related Art
Deck systems and railings are well known in the art. However, existing deck systems and railings have drawbacks which can make the already labor-intensive job of deck installation time-consuming and expensive. For example, the balusters or pickets used in most existing systems require tools at the work site for installation. Thus, U.S. Pat. Nos. 5,340,087 to Turner, 4,146,212 to Lermer, 3,918,686 to Knott et al., 3,596,880 to Greenberg and 3,506,243 to Seiler all disclose railing systems requiring screws, pins or rods to hold the balusters or pickets in place. Denmark Patent No. 92088 discloses a similar type of railing system. Use of such fasteners adds expense to a project, requires use of tools by the installer to fasten the balusters in place and is time consuming.
Similarly, U.S. Pat. No. 3,620,505 to Murdock uses a pair of wedges to lock a baluster into place within a top and bottom rail. However, once again, a tool is required on site to drive the wedges to the proper location through a hole in the rail. The system disclosed in U.S. Pat. No. 3,955,799 to Lauzier takes a different approach to solving this problem. Rather than requiring that the installer use a tool and fasteners to fasten the balusters into place, Lauzier discloses doing more pre-installation work on the balusters themselves. In particular, Lauzier teaches machining the otherwise uniformly shaped balusters to create four notches or grooves in each baluster to be used in the installation of the balusters. These notched balusters then are inserted into the rails on site without the use of an additional tool. Because this approach requires specially designed balusters which themselves have now become labor intensive, this is a less than optimal solution to the problem.
Thus, it would be desirable to have a railing system wherein easy-to-manufacture (e.g., uniform throughout their length) balusters are inserted into the top and bottom rails without requiring that the installer have additional tools for the installation. Ideally, the installation would be relatively quick and easy.
In addition, none of the aforementioned systems are shown to be used in the railing for a deck and to house electrical wiring to provide power to electrical components housed, e.g., in the columns for the railing system.
Problems also exist with the deck planks used to form the surfaces of decks. For example, when deck planks are made of wood or a wood fiber composite, such as Strandex® wood fiber composite available from Strandex Corporation of Madison, Wisconsin (a compound of wood fiber, polyethylene, thermoset resins and other minor additives--see U.S. Pat. No. 5,516,472, the contents of which are hereby incorporated by reference), these planks can expand in their widths over time due to moisture absorption. Thus, for example, where tongue-in-groove type planks are used, neighboring planks may expand into one another. The expansion can be large enough to cause damage or even ruin a deck. This is an expensive problem. Therefore, it would be desirable to have a deck system that uses deck planks that reduce or eliminate this problem.
SUMMARY OF THE INVENTION
The deck system of the present invention reduces or eliminates many of the aforementioned problems. A deck in accordance with the present invention can include a railing system that has balusters that are easy to manufacture and easy to install on site without any additional tools. This can lead to significant time and cost savings. In addition, the railing system can be used to house electrical wiring for electrical components, such as lights or stereo equipment, which can be built right into the deck, e.g., in the columns. A deck in accordance with the present invention also includes deck planks made with a novel tongue-in-groove structure that reduces or eliminates the damage caused by expansion of the deck planks.
A deck system in accordance with the present invention generally includes a plurality of columns, at least one top rail segment, a top rail support means, a bottom support means, a means for attaching the top rail segment to two of the columns, a means for attaching the bottom support means to two of the columns and a plurality of deck planks. The columns can be hollow and each column can have at least one recessed flute on its exterior. Each column also can have a plurality of internal bosses extending inwardly from the exterior and can have a support tube centrally located between the internal bosses. The column can have a plurality of exterior walls, each of which can define a recessed flute. A top rail segment extends between two of the columns. The top rail segment includes a top rail cap and a body defining a top rail upper channel. Wiring can be housed within the top rail upper channel and can be fed to an electronic component housed within one of the columns. The top rail cap is dimensioned to fit over the body along the top rail upper channel.
Means can be provided for attaching or removably attaching the top rail cap to the body. The body of the top rail segment also can define a top rail lower channel and can have a generally H-shaped perimeter. A top rail support means is provided for supporting the top rail segment. The top rail support means can be, e.g., a plurality of balusters extending from the top rail segment to the bottom support means. The balusters may be hollow or solid. A bottom support means is provided for supporting the top rail support means. A spacer can be inserted in the bottom support means between successive balusters. A spacer also can be inserted in the top rail lower channel between successive balusters. The bottom support means can include a bottom rail segment extending between successive columns. The bottom rail segment can define a bottom rail upper channel and a bottom rail lower channel. Finally, the deck system includes means for attaching the top rail segment to two of the columns and means for attaching the bottom support means to two of the columns.
The means for attaching the top rail segment can include a top angle bracket and a bottom angle bracket, each of which has a plate for attachment to one of the columns and a flange for attachment to the body. The plates and flanges can be substantially planar. The plate and the flange of each bracket can be substantially perpendicular. The plate for the top angle bracket can define an opening adjacent the top rail upper channel. The means for attaching the bottom support means can include a bottom angle bracket that can be identical to the bottom angle bracket used with the top rail segment.
The planks used in the deck can have an elongated body defining a groove on one side and can have a tongue protruding from the body on a side opposite from the groove. The tongue and the groove can extend throughout the length of the plank. The groove receives the tongue from an adjacent plank. A tab extends into the groove to abut the tongue upon initial insertion. A cavity can be provided behind the tab. When the planks expand, the tongue can crack the tab and force it into the cavity. In this way, the plank can maintain the tongue from an adjacent plank in a first initial position and then, after expansion, in a second position.
Thus, the deck system of the present invention provides a deck that is relatively easy to install. The deck system also reduces or eliminates many of the problems associated with existing deck systems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a portion of a deck in accordance with the present invention;
FIG. 2 is a section view along line 2--2 of FIG. 1;
FIG. 3 is a section view along line 3--3 of FIG. 2;
FIG. 4 is a section view along line 4--4 of FIG. 3;
FIG. 5 is a perspective view of a top angle bracket for use in the present invention;
FIG. 6 is a perspective view of a bottom angle bracket for use in the present invention;
FIG. 7 is a section view of a spacer forming part of the present invention; and
FIG. 8 is a section view of a plank forming part of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, there is shown a portion of a deck system 10 generally comprising a railing system 12 and deck planks 14. Railing system 12 comprises columns 18, top rail segments 20, balusters 22 for supporting top rail segment 20, spacers 23 for aligning and maintaining proper spacing of balusters 22, and bottom rail segments 24. Columns 18, top rail segments 20, balusters 22, spacers 23 and bottom rail segments 24 preferably are made of Strandex wood fiber composite. As shown in FIG. 4, column 18 can have a substantially square cross-section formed by exterior walls 26a-d. Each of exterior walls 26a-d preferably defines a recessed flute 28a-d along the length of column 18. Of course, columns 18 also could be made with fewer recessed flutes, if desired. As shown in FIG. 4, column 18 preferably is hollow. Column 18 preferably includes internal bosses 30. Optionally, a support tube 32 is positioned between internal bosses 30. Support tube 32 can be made of steel and can be used, if desired, e.g., to provide additional support where a second story deck is being constructed. The top of column 18 can be closed off with a suitable cap 34, as shown in FIG. 2.
Referring now to FIG. 2 in more detail, top rail segment 20 is shown. Top rail segment 20 actually comprises a body 36 that preferably is H-shaped and a top rail cap 38. Body 36 defines a top rail upper channel 40. Body 36 preferably also defines a top rail lower channel 42 which receives balusters 22. Top rail lower channel 42 preferably includes a pair of receiving grooves 41 for receiving spacers 23 between successive balusters 22. Body 36 preferably defines an opening 43 throughout its length to facilitate the extrusion of body 36.
As shown in FIG. 2, bottom rail segment 24 defines a bottom rail upper channel 44 and a bottom rail lower channel 46. Bottom rail upper channel 44 receives balusters 22. Bottom rail upper channel 44 preferably includes a pair of receiving grooves 41 for receiving spacers 23 between successive balusters 22. Bottom rail lower channel 46 is used in attaching bottom rail segment 24 to column 18 as described below. Alternatively, balusters 22 can be attached to the trim or fascia in which case bottom rail segment 24 is not necessary. Optionally, a piece of blocking made, e.g., of a baluster can be placed in the space between the deck and bottom rail lower channel 46.
Turning to FIG. 7, there is shown a section view of a spacer 23. As noted above, spacers 23 preferably are used in both top rail lower channel 42 and bottom rail upper channel 44, although alternatively spacers 23 may be omitted from one, or both, of these locations. Spacer 23 is placed between successive balusters 22 to properly align and space balusters 22. Thus, once the first baluster is inserted into top rail lower channel 42 and bottom rail upper channel 44 and plumbed, the remaining balusters 22 are easily installed by simply alternately inserting spacers 23 and balusters 22. Spacer 23 has a central portion 25 and two legs 27 extending outwardly therefrom. Each leg 27 has a rounded foot portion 29 to be received in receiving grooves 41. Spacers 23 are snapped into place without tools. Spacers 23 have flat ends perpendicular to their lengths in order to properly align balusters 22.
Bottom rail segment 24 is attached to column 18 using a bottom angle bracket 58 as shown in FIGS. 3 and 6. Bottom angle bracket 58 generally includes a plate 60 and a flange 62. Plate 60 and flange 62 preferably are substantially planar with flange 62 substantially perpendicular to plate 60 when bottom rail segment 24 is to extend substantially perpendicular to column 18. Flange 62 is attached in bottom rail lower channel 46 of bottom rail segment 24 by screws or other suitable means. Then, plate 60 is attached to column 18 using screws or other suitable means.
Top rail segment 20 is attached to column 18 via a top angle bracket 48 and a second bottom angle bracket 58 as shown in FIGS. 3, 5 and 6. Bottom angle bracket 58 is attached to column 18. Then, body 36 is placed over bottom angle bracket 58 such that bottom angle bracket 58 can be attached in top rail lower channel 42. Top angle bracket 48 includes a plate 50 for attachment to column 18 and a flange 52 for attachment to body 36. Plate 50 and flange 52 preferably are substantially planar. Plate 50 and flange 52 preferably are substantially perpendicular when body 36 is to extend substantially perpendicular to column 18. Plate 50 defines an opening 54.
Flange 52 of top angle bracket 48 is attached in top rail upper channel 40 of body 36 by screws or other suitable means known to those in the art prior to attachment of top angle bracket 48 to column 18. Then, plate 50 of top angle bracket 48 is attached to column 18 using screws or other suitable attachment means.
Turning now to FIG. 8, there is shown a section view across the width of a plank 14 that can be used to construct a deck in accordance with the present invention. Plank 14 can include a number of apertures 21 extending throughout its length. Plank 14 can be a tongue-in-groove type plank. Thus, plank 14 generally includes a tongue 15 and a groove 17 extending throughout its length. Tongue 15 is inserted into groove 17 of the adjacent plank 14 while groove 17 receives a tongue 15 from a plank 14 adjacent on the opposite side. It has been found that when plank 14 is made of Strandex wood fiber composite or wood, plank 14 may expand in its width due to, e.g., absorption of moisture. When this happens, plank 14 may expand into the surrounding planks 14 which also are expanding. Such expansion can damage the deck.
Plank 14 of FIG. 8 has a novel structure to eliminate such damage. Plank 14 includes a small sacrificial tab 19 extending throughout the length of plank 14 into groove 17. In the FIG. 8 embodiment, a cavity 31 extends throughout the length of plank 14 above and behind tab 19. Tab 19 is spaced and sized such that tongue 15 from an adjacent plank initially snugly abuts tab 19. As planks 14 expand in their widths, tongue 15 cracks tab 19 and moves tab 19 out of the way to allow expansion of the planks 14. Tab 19 can be forced into cavity 31. In this way, planks 14 can expand without damaging the deck. Of course, numerous other spatial relationships are possible for groove 17, tab 19 and cavity 31. All that is suggested here is that tongue 15 be maintained initially in groove 17 in one position and also allow for the expansion of plank 14 such that tongue 15 is maintained in a second position.
Having described the various elements of deck system 10, a brief overview of the construction of deck system 10 now will be provided. First, columns 18 are placed into the ground and/or into conventional timber framing structure and conventional structure for supporting deck planks 14 is provided. Deck planks 14 and appropriate trim and fascia are then added. Bottom angle brackets 58 are attached to bottom rail lower channel 46 of bottom rail segment 24. Bottom angle brackets 58 then are attached to columns 18. Additional bottom angle brackets 58 are attached to columns 18 for supporting body 36 of top rail segment 20. Then, body 36 is placed on bottom angle brackets 58 such that bottom angle brackets 58 are placed into top rail lower channel 42. Bottom angle brackets 58 are then attached to body 36. Next, top angle brackets 48 are placed in top rail upper channel 40 of body 36 and attached thereto. Finally, top angle brackets 48 are attached to columns 18.
The first baluster 22 then is placed in bottom rail upper channel 44 and top rail lower channel 42. The installer then plumbs baluster 22. Once baluster 22 is plumbed, spacers 23 are inserted preferably into both top rail lower channel 42 and bottom rail upper channel 44 between baluster 22 and column 18. Spacers 23 also are placed on the other side of baluster 22 to define the distance to the next baluster 22. The next baluster 22 is inserted and placed flush with spacers 23 in top rail segment 20 and bottom rail segment 24. Because the ends of spacers 23 are flat and extend in a vertical plane, the next baluster 22 is automatically properly oriented. The remaining balusters 22 and spacers 23 are inserted in this fashion.
The installer now has an open channel in top rail segment 20 to run wiring to suitable electrical components which can be placed in columns 18 as desired. Once the electrical work is complete, top rail cap 38 can be attached over body 36 either permanently or in a way providing for removal if an electrical problem were to develop.
Thus, a new deck system has been provided which provides a weatherable and attractive way to integrate electronic components into the deck while simultaneously providing a convenient method of construction.
Whereas the present invention has been described with respect to specific embodiments thereof, it will be understood that various changes and modifications will be suggested to one skilled in the art and it is intended that the invention encompass such changes and modifications as fall within the scope of the appended claims.
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A deck system provides an easy to install deck by using unique columns, rails and planks. The columns can house electrical components. The rails enable quick assembly because they do not require additional fasteners or tools to install the balusters. The planks include a novel tongue-in-groove assembly that allows the planks to expand without damaging the deck.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Application No. PCT/SE00/01647 filed Aug. 28, 2000, which designated the United States and was published in English under PCT Article 21, and which claims priority from provisional application Ser. No. 60/159,281, filed Oct. 13, 1999.
FIELD OF THE INVENTION
The present invention relates to a board machine and method for manufacturing a multilayer cardboard web with a printable surface layer, comprising a wet section and a press section, which wet section includes a first forming unit for forming a first layer, which first forming unit has at least one forming wire, running in an extended loop up to the press section to form a pick-up point for the multilayer cardboard web, and one or more further forming units for forming one or more further layers and for couching the same with said first layer on said extended forming wire of the first forming unit to form the multilayer cardboard web, which press section includes at least one double-felted press, having an upper press element, a lower press element in the shape of a press roll, which press elements create a press nip with each other, an upper press felt, running in a loop around a plurality of guide rolls and a pick-up roll, arranged at said pick-up point for transferring the multilayer cardboard web to the upper press felt, and a lower press felt, running in a loop around a plurality of guide rolls.
As used herein, the expression “the 0 line of the press” is defined, for a roll press, as the tangent perpendicular to a straight line intersecting the centers of the press rolls and, for a shoe press, as the tangent of the transition from the concave curvature to the convex curvature of the shoe at the exit of the press nip.
BACKGROUND OF THE INVENTION
One side of a multilayer cardboard web is often used for printing. This side, denoted the front side of the finished cardboard product, is formed by a surface layer that must have a high degree of surface smoothness to provide good printability. Special pulps are used for manufacturing the surface layer. Short-fiber pulps result in surface layers with improved printability. The pulp intended for the printable surface layer is preferably, but not necessarily, bleached. It may consist of a mixture of short-fiber and long-fiber pulps, in which the short-fiber proportion of the pulp may constitute 50-70 per cent by weight of the mass. However, the short-fiber proportion may constitute 100 per cent. The layer to be printed may also be made of 100 per cent bleached long-fiber pulp. Short-fiber pulp can be pulp from birch or eucalyptus, for instance, while long-fiber pulp can be pulp from pine, for instance.
A number of methods and machines for manufacturing multilayer cardboard webs are described in patent literature and the following are mentioned by way of example: EP-0 511 186, WO 92/06242, U.S. Pat. No. 4,961,824, EP-0 511 185, U.S. Pat. No. 5,074,964, EP-0 233 058 and SE-506 611.
U.S. Pat. No. 5,639,349 (corresponding to DE-4401761) describes a method for improving the quality of multilayer papers in the wet section of a paper machine by recirculating the drainage water within each forming unit. The outer layer of the paper web is made of stock of higher quality than the stock for the core. The patent specification does not mention cardboard or board and the problem associated with providing a printable surface layer on a multilayer cardboard web. Neither does the patent specification touch upon the problem relating to the press section and the web run in the same, and in particular does not address the problem of pressing of a multilayer cardboard web with a printable surface layer.
U.S. Pat. No. 4,957,778 describes a paper machine for manufacturing two-layer carbonless copy paper. The paper machine has upper and lower fourdrinier formers, the layers of which are combined by couching to form a coherent paper web, which is pressed in a press with two single-felted press nips, created by two press rolls and a counter roll shared by the same. Multilayer cardboard webs are not touched upon in this patent specification and, consequently, neither are the problems associated with pressing a multilayer cardboard web.
In practice, the predominant technique for manufacturing a multilayer cardboard web is to manufacture the surface layer with a forming unit, for instance an upper fourdrinier former, arranged relative to at least one other forming unit, for instance a lower fourdrinier former, in such a way that the surface layer is couched with a subjacent layer and the cardboard web emerges from the wet section with the surface layer facing upwards. This in turn dictates the configuration of the press section. In accordance with conventional techniques, a double-felted roll press is employed as the first press. It is also known to use a double-felted shoe press with the shoe in a top or bottom position as the first press. A first double-felted press of known kind has an upper felt acting as a pick-up felt to transfer the cardboard web to the press nip, while the lower felt is intended to carry the cardboard web subsequent to its passage through the press nip. The surface layer of the cardboard web thus comes into direct contact with the upper felt. Accordingly, to be able to satisfy the requirement of high surface smoothness of the surface layer, the structure of the web-contacting surface of the upper felt must not be too rough. If, on the other hand, the structure of the web-contacting surface of the lower felt were to be too smooth or fine to ensure the correct web run after the press nip, the lower felt will not be sufficiently open to allow permeation of water and will relatively quickly become clogged with fibers, which means that reconditioning of the lower felt cannot be accomplished with the desired result and that the service life of the lower felt becomes relatively short. In practice, the two contradictory requirements for the properties of the upper felt and the lower felt result in the requirement that the differences between their surfaces structures with respect to roughness or smoothness become relatively small and there is, therefore, a risk of the cardboard web sometimes having a tendency to accompany the upper felt after the press nip instead of the lower felt as intended, even if the lower felt has the smoother surface. To ensure the correct web run in a shoe press with the shoe in the bottom position the lower felt must be passed over the downstream edge of the shoe and the upper felt passed approximately in the direction of the so-called 0 line, but this is not an acceptable solution as the web is then subjected to detrimental shear forces during its passage over the shoe edge.
SUMMARY OF THE INVENTION
The object of the present invention is to provide an improved board machine and an improved method of manufacturing a multilayer cardboard web. The invention thus enables the manufacture of a multilayer cardboard web having a printable surface layer with a desired high degree of surface smoothness and maximum dry-solids content after the press section, while safeguarding the web run in the press section.
The board machine, in accordance with the invention, is characterized in that the first forming unit is arranged to form the printable surface layer and arranged with its extended forming wire to transfer the multilayer cardboard web to the upper press felt of the press with the printable surface layer facing downwards to contact the lower press felt in the press nip. The lower press felt has a finer web-contacting surface to exert a greater adhesion force on the multilayer cardboard web than the upper press felt, and the lower press felt at the discharge side of the nip is arranged to encompass the lower press roll by a pre-determined minimum sector angle α measured from a point in the press nip intersected by the 0 line of the press, as defined herein for a roll press and a shoe press, respectively.
The method, in accordance with the invention, is characterized in that the printable surface layer is formed in the first forming unit and the extended forming wire transfers the multilayer cardboard web to the upper press felt of the press with the printable surface layer facing downwards so that it is in contact with the lower press felt in the press nip. The lower press felt exerts a greater adhesion force on the multilayer cardboard web than the upper press felt by virtue of its finer web-contacting surface, and the lower press felt is caused to encompass the lower press roll by a pre-determined minimum sector angle α measured from a point in the press nip intersected by the 0 line of the press, as defined herein for a roll press and a shoe press, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features, and advantages of the invention will become more apparent from the following description of certain preferred embodiments thereof, when taken in conjunction with the accompanying drawings in which:
FIG. 1 shows schematically parts of a board machine for manufacturing a multilayer board web in accordance with a first embodiment of the invention.
FIG. 2 shows schematically parts of a board machine for manufacturing a multilayer cardboard web in accordance with a second embodiment of the invention.
FIG. 3 is a cross section along the line III—III in FIG. 1 .
FIG. 4 shows schematically a part of a shoe press used in the board machines shown in FIGS. 1 and 2.
FIG. 5 shows schematically a roll press in a board machine for manufacturing a multilayer cardboard web in accordance with a third embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
FIGS. 1 and 2 show schematically parts of a board machine for manufacturing a cardboard web 1 , consisting of a first layer 2 and a further layer 3 . In the embodiment shown and in accordance with the present invention, the first layer 2 forms a surface layer in the finished two-layer cardboard web, while the further layer 3 forms its core. Alternatively, a cardboard web is manufactured, consisting of said first layer and several further layers, one of which is said core.
The board machines comprise a wet section 4 , a press section 5 and a drying section 6 .
The wet section 4 comprises a first forming unit 7 for manufacturing the first layer 2 and a second forming unit 8 for manufacturing the second layer 3 .
In the embodiment shown in FIG. 1, the two forming units 7 , 8 consist of a first fourdrinier former, located upstream, and a second fourdrinier former, located downstream, while in the embodiment in accordance with FIG. 2, they consist of a first twin-wire former or gap former located upstream, and a second twin-wire former or gap former located downstream. In this context, the expressions “upstream” and “downstream” indicate the relative locations of the forming units viewed in the machine direction.
The first fourdrinier former 7 , located upstream according to FIG. 1, is extended in the machine direction and has a fourdrinier wire 9 , running in a loop around an upstream breast roll 10 , a downstream suction couch 11 , a wire turning roll 12 and a plurality of other types of guide rolls 13 , such as alignment rolls and tension rolls. The upper part 14 of the fourdrinier wire 9 , dewatering the stock and forming the layer and web, between the breast roll 10 and the suction couch 11 is plane and horizontal. The first fourdrinier former 7 , located upstream, further comprises a headbox 15 , arranged close to the breast roll 10 to emit a jet of stock onto the upper part 14 of the fourdrinier wire 9 , and dewatering members 16 for dewatering the stock to form the first layer 2 .
The second fourdrinier former 8 , located downstream according to FIG. 1, has a fourdrinier wire 17 , running in a loop around a breast roll 18 , an upper guide roll 19 and two lower guide rolls 20 , which lower guide rolls are arranged in close proximity to the upper part 14 of the fourdrinier wire 9 of the first fourdrinier former 7 for couching the formed second layer with the formed first layer. The second fourdrinier former 8 comprises a headbox 21 , arranged close to the breast roll 18 to emit a jet of stock onto the upper, plane part 22 of the fourdrinier wire 17 , and dewatering members 23 for dewatering the stock to form the second layer.
The first twin wire former, located upstream according to FIG. 2, has first and second forming wires 25 , 26 , which run together in a forming zone. The first forming wire 25 runs in an upper loop around a plurality of guide rolls 27 . The second forming wire 26 runs in a lower loop around an upstream forming roll 28 and a downstream suction couch 29 , a wire turning roll 30 and a plurality of other guide rolls 31 , comprising alignment rolls and tension rolls. The lower forming wire 26 is extended up to the press section so that the suction couch 29 is located downstream of the second twin wire former 8 . In the loop of the first forming wire 25 , dewatering means 32 are arranged within said forming zone. A headbox 33 is arranged to emit a jet of stock into a gap defined by the forming roll 28 and a guide roll 27 located adjacently to the same in the upper wire loop 25 .
The second twin wire former 8 , located downstream according to FIG. 2, has first and second forming wires 34 , 35 , which run together in a forming zone. The first forming wire 34 runs in a loop around a plurality of guide rolls 36 and has a lower, linear part 37 , passing along the lower forming wire 26 of the first twin wire former 7 to create a couching zone. The second forming wire 35 runs in a loop around a forming roll 38 and, two guide rolls 39 . In the loop of the first forming wire 34 , dewatering means 40 are arranged within said forming zone. A headbox 41 is arranged to emit a jet of stock into a gap defined by the forming roll 38 and a guide roll 36 located adjacently to the same in the first wire loop 34 .
The first forming unit 7 , located upstream, is arranged to create a surface layer 2 suitable for printing in the finished cardboard web, while the second forming unit 8 , located downstream, is arranged to create a core 3 , which encounters the surface layer so that the two layers are couched together with each other to a coherent two-layer cardboard web, see FIG. 3, which leaves the forming wire 9 , 26 of the first forming unit 7 with the surface layer facing downwards.
The press section 5 in the board machines shown in FIGS. 1 and 2 comprises a first double-felted press 45 and a second double-felted press 46 , which presses 45 , 46 are arranged directly one after the other. The first press 45 comprises an upper press element 47 and a lower press element 48 , which press elements create a press nip with each other. The first press 45 further comprises an upper press felt 49 , which runs in a loop around a plurality of guide rolls 50 , comprising a pick-up suction roll 51 for transferring the multilayer cardboard web 1 to the upper press felt 49 , and a lower press felt 52 , which runs in a loop around a plurality of guide rolls 53 , and which together run through the press nip with the web 1 enclosed therebetween in a sandwich construction. The second press 46 comprises an upper press element 54 and a lower press element 55 , which press elements create a press nip with each other. The second press 46 further comprises an upper press felt 56 , which runs in a loop around a plurality of guide rolls 57 , comprising a pick-up suction roll 58 for transferring the multilayer cardboard web 1 to the upper press felt 56 , and a lower press felt 59 , which runs in a loop around a plurality of guide rolls 60 , and which together run through the press nip with the web 1 enclosed therebetween in a sandwich construction.
The lower press felt 52 , 59 of each press 45 , 46 has a finer surface structure than the upper press felt 49 , 56 with the purpose of ensuring that the web 1 adheres to the lower press felt 52 , 59 and not to the upper press felt 49 , 56 after the press nip. This difference in surface structure or adhesive capability is a first parameter to assist in safeguarding the correct web run.
The lower press element 48 , 55 in each press is a press roll, around which the lower press felt 52 , 59 runs in contact with the envelope surface of the press roll after the press nip by a pre-determined minimum sector angle α measured from a certain point in the press, depending on which type of press is used, as explained below. The web has a tendency to accompany the one of the two press felts that has the greater part in contact with the press roll after the press nip. This circumstance is a second parameter to assist in safeguarding the correct web run. At least the first parameter, and preferably both the first and second parameters, are utilized in the press, while the printable surface layer 2 simultaneously faces downwards. This enables an increased difference between the degrees of surface smoothness of the lower and upper felts. At the same time, the lower press felt is caused to maintain contact with the lower press roll downstream of the nip for a predetermined sector angle. Thus, the proper web run is facilitated.
The press sections 5 shown in FIGS. 1 and 2 are alike and their presses consist of a first shoe press 45 with a press shoe 63 and a subsequent, second shoe press 46 with a press shoe 64 . Each shoe press 45 has a shoe roll 47 , 54 in the upper position and a counter roll 48 , 55 in the lower position. Each counter roll 48 , 55 can have a blind-drilled, grooved or smooth envelope surface. Each shoe roll or one of the shoe rolls has an envelope surface 65 , see FIG. 4, in the shape of a press belt that is smooth, blind-drilled or grooved. From the point of view of operability, a blind-drilled or grooved press belt 65 is preferable, as this provides a large open volume behind the upper press felt 49 , 56 so that the cardboard web acquires a high dry-solids content while the upper press felt simultaneously remains open towards the open surface behind the upper press felt to enable ventilation of the same. Such high dry-solids content is further improved by employing a blind-drilled or grooved counter roll, thus providing a large open volume behind the lower press felt 52 , 59 . In especially difficult operating conditions, such as high web speed and low surface weight, a counter roll with a smooth envelope surface is used because the large open volume is not required, as smaller quantities of water (low surface weight) need to be removed and an extra great vacuum pulse is created in the lower press felt, which results in the “attraction” of the web to the lower felt being increased still further. Placing the shoe rolls in a top position creates enhanced possibilities for guiding the cardboard web to the lower press felt by arranging the lower felt to encompass the counter roll to a greater extent.
The lower press felt 52 is arranged to encompass the counter roll 48 with a pre-determined minimum sector angle α of 10° measured from a point (denoted a 0 point herein) on the periphery of the shoe 63 at which the concave curvature of the shoe transitions into a convex curvature, the tangent of this point being denoted the 0 line 61 of the shoe. The part of the upper press felt 49 surrounding the counter roll 48 is adjustable within a range from +5° to −5° measured as an angle β between the upper press felt 49 and the 0 line 61 , positive angle values being located below and negative angle values above this 0 line 61 .
Alternatively, the first press 45 can consist of a roll press as shown in FIG. 5 . The second press 46 in such a press section can be a similar roll press or a shoe press as described above. The upper and lower press rolls 47 , 48 of the roll press can have smooth, blind-drilled or grooved envelope surfaces. The lower press felt 52 , see FIG. 5, is arranged to encompass the lower press roll 48 by a pre-determined minimum sector angle α of 10° measured from a 0 point on the periphery of the lower press roll 48 that is tangent to the periphery of the upper press roll. Stated differently, the 0 point is located on the periphery of the lower press roll 48 at a point intersected by a straight line connecting the centers of the press rolls 48 , 47 . The tangent to this 0 point is perpendicular to the straight line intersecting the centers of the press rolls, which tangent is denoted as the 0 line 62 of the roll press. The sector angle α is normally in the range 10°-25° for a roll press. The part of the upper press felt 49 surrounding the lower press roll 48 is adjustable within a range from +10° to −5° measured as an angle β between the upper press felt 49 and the 0 line 62 , positive angle values being located below and negative angle values above this 0 line 62 .
Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
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A board machine and method for making a multilayer cardboard web, in which a first layer of the web having a printable surface is formed in a first forming unit and carried on an extended forming wire thereof through a couching unit where the first layer is couched with one or more additional layers, the multilayer web then being carried on the extended wire to a pick-up point. An upper press felt of a double-felted press picks up the web at the pick-up point such that the printable surface faces downward and contacts the lower press felt through the nip of the press. The lower felt is smoother than the upper felt, and the lower felt contacts the lower press roll for a minimum sector angle beyond an exit of the nip to ensure that the web follows the lower felt.
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The present invention relates to the art of clamping and more particularly to a clamp designed to join a cylindrically shaped object in a cylindrically shaped recess.
BACKGROUND OF THE INVENTION
Clamping sets designed to clamp cylindrical bodies in cylindrical recesses are known in the art. One such clamping set is disclosed in DE 27 34 784 C2. The known clamping set has proven itself in the creation of high radial clamping forces with automatic disconnection after loosening of the tightening screws. However, it was observed in some cases at low friction coefficients on the cone surfaces that the center cone ring, which under some circumstances experiences plastic deformation at high torques, is forced out between the neighboring cone elements in the axial direction toward the apex of the cone surfaces.
Due to the problems associated with clamping in environments with a low friction coefficient, there has developed a need for a clamping set that provides high radial clamping forces in low friction coefficient arrangements and resists deformation of the clamping set components when high torques are applied to the components.
SUMMARY OF THE INVENTION
The present invention pertains to an improvement over prior clamping sets and incorporates a design and arrangement which overcomes the past deficiencies of prior clamping sets. The present invention pertains to a clamping set for joining of an outer component having a cylindrical recess, such as a hub, to an inner component, such as a shaft, having a cylindrical outer peripheral surface and arranged concentrically to the recess. The clamping set includes an inner cone element having an outer peripheral surface formed as a cone surface, an outer cone element having an inner peripheral surface formed as a cone surface, and a center cone ring with inner and outer peripheral surfaces formed as cone surface. The center cone ring is designed to have the same taper angle with the outer and inner cone surfaces of the inner and outer cone elements. The inner and outer cone elements and the center ring cooperate by axial sliding and form with them a cone surface pair in which the vertices of the cone surfaces of the center cone ring are positioned axially on the same side of cone ring and the taper angle of one cone surface pair with an angular distance from the self-locking angle lies in the self-locking range, while the taper angle of the other cone surface pair lies above the self-locking range. Axial set screws are preferably used to axially tighten the center cone against the inner and outer cone element. At least one recess is provided in at least one of the cone surfaces. The recess is preferably edged completely around the cone surface.
The edged recess should therefore not be a slit passing through the plane running through the axis, as is often encountered in cone clamping arrangements to facilitate deformation of the cone rings. The recess should instead have at least one, but normally two walls extending in the peripheral direction or arched wall parts extending essentially in the longitudinal direction. This has the effect that the cone surface neighboring the recess, which has no recess, is forced slightly into the recess under the very high radial pressures so that increased friction resistance occurs on the edges of the recess running essentially in the peripheral direction, which prevents displacement of the center cone ring in the axial direction relative to the cone element having the neighboring cone surface.
It has been shown that squeezing out of the center cone ring between the two neighboring cone elements can be reliably prevented with the clamping arrangement according to the invention even in cone surface pairs having low friction coefficients.
In order to create definite force conditions the clamping set is designed to include an axial stop for the end of center cone ring. The axial stop is designed to have a more limited wall thickness on the cone element and has a taper angle lying above the self-locking range and the radii of the cone surfaces with the larger taper angle dimensioned so that a point during the tightening of the set screws, the center cone ring lies against the stop with ends and at the same time lies against the opposite cone surface with the cone surface. The center cone ring is initially positioned during tightening against the stop on the cone element with the larger taper angle. This cone element and the center cone ring act from then on as a unit, against which the cone element having the smaller taper angle is then moved only in the axial direction.
In the preferred variant the recess is provided in at least one of the cone surfaces of the center cone ring.
The recess can be formed, in particular, by an edged radial opening of the center cone ring that goes all the way around, which is simple to produce and can be formed by a radial hole of the center cone ring or a milled groove radially positioned in the center cone ring.
A significant effect is already achieved if only a recess is present in the center cone ring.
In particular, for reasons of uniform distribution of forces and deformations, however, it can be advisable to provide several recesses evenly distributed around the periphery.
In summary, the present invention pertains to a clamping set for joining of an outer component having a cylindrical recess to an inner component having a cylindrical outer peripheral surface and arranged concentrically to the recess. The clamping set preferably includes an inner cone element with an outer peripheral surface formed as a cone surface, an outer cone element with an inner peripheral surface formed as a cone surface, and a center cone ring with inner and outer peripheral surfaces formed as cone surfaces. The center cone ring is preferably designed to have the same taper angle with the outer and inner cone surfaces of the inner and outer cone elements. The cone elements and cone ring preferably cooperate by axial sliding and form a cone surface pair in which the vertices of the cone surfaces of the center cone ring are positioned axially on the same side of cone ring and the taper angle of one cone surface pair and having an angular distance from the self-locking angle lies in the self-locking range, while the taper angle of the other cone surface pair lies above the self-locking range. Preferably, axial set screws are used to axially tighten the center cone against the inner and outer cone element. At least one recess is preferably provided in at least one of the cone surfaces. The recess is preferably edged completely around the cone surface. Preferably, the clamp set includes an axial stop for the center cone ring. The axial stop preferably is positioned at the end of center cone ring. The axial stop is designed to preferably have a more limited wall thickness on the cone element, have a taper angle lying above the self-locking range. The radii of the cone surfaces with the larger taper angle are dimensioned so that at a point during tightening of the set screws, the center cone ring lies against the stop with ends and at the same time lies against the opposite cone surface with the cone surface. Preferably, the recess is provided in at least one of the cone surfaces of the center ring. Preferably, the recess is formed by a radial opening of the center cone ring edged all the way around. Preferably, the recess is formed by a radial hole of the center cone ring. Alternatively, the recess is formed by a radial groove of the center cone ring. Preferably, several recesses are provided uniformly distributed over the periphery of the center ring.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference may now be made to the drawings, which illustrate various embodiments that the invention may take in physical form and in certain parts and arrangements of parts wherein:
FIG. 1 illustrates a sectional view of the clamping set of the present invention;
FIG. 2 illustrates a sectional view of an alternative embodiment of the present invention; and,
FIG. 3 shows an enlarged depiction of the region III shown with the dash-dot line in FIG. 2.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, wherein the showings are for the purpose of illustrating the preferred embodiments of the invention only and not for the purposes of limiting the same, FIGS. 1 and 2 illustrate two embodiments of the invention. In both embodiments the outer component is designated 1. It can be the hub of a gear or other wheel, also the wall of a drive pulley for conveyor belts or the like. The outer component 1 is attached to a shaft 2 or 42 by means of different versions of the clamping set. The outer component has a cylindrical recess 3, the shaft a cylindrical peripheral surface 4 or 44. In the variant according to FIG. 1 a space exists between them in which a clamping set 10 is accommodated. In FIG. 2 shaft 42 is a hollow shaft in which clamping set 40 is arranged and which lies with its outside periphery 44 in the cylindrical recess 3 of the outer component 1.
The clamping set of FIG. 1 denoted overall as 10 comprises an inner cone element in the form of an internal cone ring 11, which lies with its cylindrical inside peripheral surface 12 on the outside peripheral surface 4 of shaft 2. Cone ring 11 has on the outside a cone surface 13 with a taper angle 14 of about 12°, i.e., above the self-locking angle of about 7°. On the thick-walled end cone ring 11 has a radial flange 15 that projects far enough radially that it overlaps the edge of the outer component 1 at 16.
An outer cone element lies against the cylindrical recess 3 of the outer component 1 with the cylindrical outer peripheral surface 17 in the form of an outer cone ring 18 whose inner peripheral surface 19 is a cone surface with a taper angle 20 of about 3° lying within the self-locking range.
A center cone ring 21 carrying cone surfaces 22 and 23 on both peripheral sides corresponding to the cone surfaces 13 and 19, i.e., having the same taper angle and lying flat against them, is situated between cone rings 11 and 18. The cone surfaces 13, 22 and 19, 23 are arranged so that the vertices of the cone surfaces are situated on the same side of cone ring 10 (namely, the right side in FIG. 1).
Cone ring 18 has a threaded hole 24 on the side facing radial flange 15 into which a headed screw 5 can be screwed from the outside of radial flange 15 by passing through this in a hole 25. Several headed screws 5 are distributed evenly over the periphery. For the most part the headed screws are arranged as closely together as they can be.
As long as screws 5 are loose, the clamping set 10 forms a unit whose parts are intimately connected. After insertion into the space between space 2 and the outer component 1 fastening begins by tightening of set screws 5. To achieve centering it can be expedient if the radial flange 15 has a cylindrical projection 26 that precisely fits into cylindrical recess 3. In this fashion slumping of outer component 1 on shaft 2 is avoided, which inhibits uniform concentric fastening.
During tightening of set screws 5 the cone ring 18 moves axially against radial flange 15 and in so doing entrains center cone ring 21. The radial flange 15 forms with its surface positioned against cone rings 18, 21 and directly perpendicular to the axis a stop 27 against which after a certain displacement of center cone ring 21 in the axial direction its end 28 stops. The dimension of the radii of cone surfaces 13, 22 is such that these cone surfaces then also lie against each other. From this clamping point the cone rings 11 and 21 form a unit whose parts are undisplaceable against each other during further tightening of set screws 5.
Since the set screws 5 act between cone rings 11 and 18, subsequent clamping occurs as if only a two-part clamping set were involved with a taper angle 20 lying in a self-locking range. Cone ring 18 can therefore be tightened up to achievement of a significant radial pressing force on the center cone ring 21.
To loosen the clamping set 10 the set screws 5 are loosened. Owing to the taper angle 14 lying above the self-locking range, the cone rings 21 and 18 loosen as a unit without requiring forcing screws with corresponding dimensioning.
In order for cone rings 11, 18, 21 not to exhaust the clamping force of set screws 5, it is recommended that all cone rings be notched in a plane passing through the axis.
If the set screws 5 are very strongly tightened and the cone surfaces 13, 22 and 19, 23 are provided with a highly effective lubricant, it can happen that the center cone ring 21 is forced out between the outer cone rings 11 and 18 rightward according to FIG. 1, i.e., in the direction of the vertex of cone surfaces 13, 22 and 19, 23 between cone rings 11, 18.
In order to prevent this, the center cone ring 21 has a radially continuous groove 31, but edged all the way around in the peripheral surface, whose longer extent can run in the peripheral direction or also parallel to the axial direction. Under significant radial forces the cone surfaces 13 and 19 adjacent to groove 31 are forced somewhat into the clear cross section of groove 31.
It was surprisingly found that in this fashion the center cone ring 21 can be blocked in the axial direction so that undesired squeezing out rightward according to FIG. 1 does not occur.
To the extent that parts functionally corresponding to FIG. 1 are present in FIG. 2 the reference numbers are the same.
While the clamping set 10 is arranged in the radial space between outside periphery of shaft 2 and the inside periphery of outer component 1, shaft 42 in FIG. 2 is a hollow shaft that lies in the cylindrical recess 3 of outer component 1 with its cylindrical outer periphery 44. For this reason, there is no intermediate space between shaft 42 and outer component 1. The clamping set 40 is rather arranged in the interior of hollow shaft 42 and widens it radially in order to produce friction closure between the outer periphery 44 of hollow shaft 42 and the outer component 1.
The clamping set 40 is designed as a double-cone clamping set and has two oppositely arranged inner cone elements in the form of cone disks 30 having on their outer periphery cone surfaces 13 with the angle lying below the self-locking range, these disks being pulled toward one another in the axial direction by set screws 5. The cone surfaces 13 face each other with the smaller radii. Two double-cone rings 32 corresponding to the cone ring 21 in FIG. 1 are arranged on cone disks 30. The outer cone element is a double-cone ring with a taper angle 14 lying above the self-locking range, having two cone surfaces 19 arranged so that the greatest wall thickness of the double-cone ring 33 lies in the center.
The cone rings 32 have radial holes 41 closed all the way around with hole axes passing through the axis of the cone elements perpendicular to them, two of which are shifted by 180° one relative to the other. The holes 41 have the same blocking effect as the holes 31 in FIG. 1.
The grooves 31 or holes 41 need not absolutely pass through the entire wall thickness of the center cone ring 21 or 32. To achieve the intended effect it would also be theoretically sufficient if only flat recesses were provided, as indicated by the dash-dot line in FIG. 2 at 43. However, it is understood that use of a through-hole 41 is much simpler than machining of a flat recess 43, especially on the inside of cone ring 32.
The action of the invention is indicated schematically in FIG. 3, which depicts the region III shown in the upper right of FIG. 2 in enlarged fashion. It is apparent that the cone surface 13 is forced into the clear cross section of radial hole 41 under the prevailing high pressure. The depiction in FIG. 3 is exaggerated for clarity. At position 45, at which the hole wall runs roughly in the peripheral direction, blocking that prevents squeezing out of cone ring 32 rightward occurs by the formed elevation of cone surface 13.
The double-cone ring 33 has a peripheral groove 34 on its internal peripheral surface 19, 19 in the center that reduces the cross section and this peripheral groove leads to an additional blocking effect when clamping set 40 is tightened at the position 46 corresponding in action to position 45.
The smaller front sides 47 of center cone ring 32 positioned in the region of groove 34 lie against each other axially and form mutual stops corresponding to stop 27 in FIG. 1.
The invention has been described with reference to a preferred embodiment and alternates thereof. It is believed that many modifications and alterations to the embodiments disclosed will readily suggest themselves to those skilled in the art upon reading and understanding the detailed description of the invention. It is intended to include all such modifications and alterations insofar as they come within the scope of the present invention.
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A clamping arrangement designed to join an outer component having a cylindrical recess to an inner component having a cylindrical outer peripheral surface which is concentrically arranged in the cylindrical recess. The clamping arrangement includes an inner cone element, an outer cone element and a center cone ring which cooperates with one another to clamp the inner component in the cylindrical recess.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a gas-turbine engine combustor capable of burning both gas and liquid fuels and in particular, but not exclusively, a combustor operating under a lean-burn combustion process.
[0002] Lean-burn combustor designs, in which very little if any combustion air is introduced into the combustor downstream of the location of the burner air-fuel mixing arrangement, are currently prevalent. The great advantage of lean-burn systems is the reduction of the levels of harmful emissions under high engine-load conditions. A drawback, however, is the difficulty that is experienced in maintaining the integrity of the combustor flame during low-load conditions, so that “flame-out”, i.e., the simple extinction of the flame, does not occur.
[0003] To avoid flame-out at low engine-load conditions, prior-art designs have used techniques such as fuel-rich pilot-flame systems and staged fuel systems. The former are inclined to increase emission levels and the latter generally result in a complicated and expensive design.
SUMMARY OF THE INVENTION
[0004] The present invention aims to combine a reduction in harmful emissions with a reduction in complexity and consequently cost.
[0005] In its broadest aspect, the present invention provides a gas-turbine engine combustion system of the lean-burn type, having a combustor comprising a burner, a combustion pre-chamber and a combustion main chamber disposed in flow series, the burner comprising a burner head having a burner face including fuel injection means for the injection of fuel from the burner face into the pre-chamber, the combustor being arranged such that during operation of the combustor, a front face of a combustion flame burns closely adjacent the burner face, the burner further comprising fuel directing means for directing fuel towards the burner face during a first mode of operation of the combustor, and cooling air directing means for directing a flow of cooling air towards the burner face during a second mode of operation of the combustor.
[0006] According to a preferred embodiment of the present invention, a gas-turbine engine combustion system of the lean-burn type has a combustor comprising a burner, a combustion pre-chamber and a combustion main chamber disposed in flow series, the burner comprising
[0007] a burner head,
[0008] a burner face of the burner head, the burner face defining an up-steam extremity of the pre-chamber,
[0009] gas fuel injection means for the injection of gas-fuel from the burner head into the pre-chamber, and
[0010] liquid-fuel injection means separate from the gas-fuel injection means for the injection of liquid-fuel from the burner head into the pre-chamber,
[0011] the combustor being arranged such that during operation of the combustor a front face of a combustion flame burns closely adjacent a central part of the burner face, the combustion system further having
[0012] means for enabling changeover from gas fuel operation of the combustor to liquid fuel operation of the combustor, and
[0013] means operable during liquid-fuel operation of the combustor to prevent injection of gas fuel and enable injection of cooling air from the burner head into the pre-chamber,
[0014] the burner further comprising directing means, whereby gas-fuel is directed towards the central part of the burner face during gas-fuel operation of the combustor and cooling air is directed towards the central part of the burner face during liquid-fuel operation of the combustor.
[0015] It is convenient, but not essential, that the same directing means be utilized to direct both the gas fuel and the cooling air towards the central part of the burner face.
[0016] The gas-fuel injection means may include duct means adapted to inject the gas-fuel and the cooling air in an annular configuration towards the central part of the burner face.
[0017] The directing means may comprise lip means provided on the burner face and extending towards the central part of the burner face, the lip means being disposed relative to the injector means such as to deflect gas-fuel and air exiting the injector means towards the central part of the burner face.
[0018] The liquid-fuel injection means may be disposed between the gas-fuel injection means and the central part of the burner face. Preferably, the liquid-fuel injection means comprises a liquid-fuel duct means communicating with the burner face. An igniter may be disposed between the gas-fuel injection means and the liquid-fuel injection means, or between adjacent liquid-fuel injection means.
[0019] The liquid-fuel and gas-fuel injection means preferably comprise pilot gas-fuel injection means, pilot liquid-fuel injection means, main gas-fuel injection means and main liquid-fuel injection means, all the pilot and main fuel injection means being in communication with the burner face. Advantageously, the main liquid-fuel injection means is disposed radially outwards of the pilot gas-fuel injection means. The main gas-fuel injection means may be disposed radially outwards of the main liquid-fuel injection means.
[0020] The burner preferably includes a radial swirler disposed between the burner face and the pre-chamber, the swirler having a plurality of passages for the flow of combustion air through the swirler towards the central part of the burner face. Preferably, the main gas-fuel injection means communicates with at least one of the swirler passages adjacent a radially outer part of the passages, while the main liquid-fuel injection means communicates with at least one of the passages adjacent a radially inner part of the passages.
[0021] The combustion system includes fuel-inlet means communicating with the pilot and main gas-fuel and liquid-fuel injection means for the supply of fuel thereto, a control means being connected to the fuel-inlet means for controlling the flow of fuel into the pilot and main gas-fuel and liquid-fuel injection means such that during liquid-fuel operation, the control means diverts pilot gas-fuel away from the pilot gas-fuel injection means and connects to the latter a source of the cooling air.
[0022] The invention further provides a method of operating the above combustion system during a gas-fuel operation of the combustor, comprising the steps of:
[0023] initiating injection of pilot fuel and main fuel into the pre-chamber at predetermined respective mass flow rates, and
[0024] varying the respective mass flow rates of the injected pilot fuel and main fuel relative to a total gas-fuel mass flow rate between a start-up condition and a full-load condition of the engine, such that at the start-up condition of the engine, the total gas-fuel flow predominantly comprises pilot fuel and, at the full-load condition of the engine, the total gas-fuel flow predominantly comprises main fuel.
[0025] Preferably, at the start-up condition of the engine, the main gas-fuel provides not more than about 5% of total gas fuel flow, and the pilot gas-fuel provides not less than about 95% of total gas fuel flow, whereas at the full-load condition of the engine, the main gas-fuel provides not less than about 95% of total gas fuel flow, and the pilot gas-fuel provides not more than about 5% of total gas fuel flow, but more than 0% thereof.
[0026] The invention further provides a method of operating the above combustion system during a liquid-fuel operation of the combustor, comprising the steps of:
[0027] initiating injection of pilot liquid fuel into the pre-chamber at a predetermined mass flow rate during a start-up condition of the engine,
[0028] increasing the mass flow rate of pilot liquid fuel to increase engine power towards a full load condition of the engine,
[0029] initiating injection of main liquid fuel into the pre-chamber at a predetermined mass flow rate when a predetermined fraction of the full-load condition of the engine is attained,
[0030] continuously decreasing the supply of pilot fuel and increasing the supply of main fuel until the full-load condition of the engine is attained, and
[0031] injecting cooling air into the prechamber from the burner head using the directing means during said liquid-fuel operation of the combustor.
[0032] The above predetermined fraction of the full-load condition of the engine may be approximately 70% and at the full-load condition of the engine the main liquid fuel may provide not less than about 95% of total liquid fuel flow and the pilot liquid fuel may provide not more than about 5% of total liquid fuel flow, but more than 0% thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] An embodiment of the invention will now be described with reference to the accompanying drawings, in which:
[0034] [0034]FIG. 1 schematically illustrates a combustion system according to the invention and includes a simplified axially sectioned view of a combustor forming part of the combustion system;
[0035] [0035]FIG. 2 is the combustor of FIG. 1 operating in gas-fuel mode;
[0036] [0036]FIG. 3 is the combustor of FIG. 1 operating in liquid-fuel mode; and
[0037] [0037]FIG. 4 is a transverse section IV-IV through the burner of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] Referring now to FIG. 1, a longitudinal section of a combustor according to the invention is illustrated, consisting of a burner 10 , comprising a burner-head portion 11 attached to a radial-inflow swirler portion 12 , a combustion pre-chamber 13 and a main combustion chamber 14 . The main chamber has a diameter larger than that of the pre-chamber. The swirler 12 has a number of spaced-apart vanes 30 (see FIG. 4) which define passages 14 therebetween.
[0039] In operation, compressed air 15 , flowing in the direction of the arrows shown, is supplied to the burner (usually from the gas-turbine compressor) and moves through the passages 14 between the swirler vanes. The air mixes with fuel injected from the downstream burner-head face 16 and, on arriving in the prechamber 13 , the mixture is ignited by means such as the electric igniter unit 17 . Once lit, the flame continues to burn without further assistance from such igniter.
[0040] The gas-fuel and liquid-fuel modes of operation of the combustor will now be separately described.
[0041] The gas-fuel mode of operation will be described with reference to FIG. 1 and FIG. 2. The gas-fuel system comprises a pilot-fuel system and a main-fuel system which work together in a progressive manner to give a seamless change in operation from one to the other. When the engine is started, the fuel controller 40 controls variable valves 42 and 44 so that most of the gas-fuel from supply line 46 is directed to the pilot system, whereby gas supplied through connector 18 at the burner head 11 moves through passages in the head eventually arriving at an annular gallery 19 from where it is directed, via either a series of spaced-apart bores 32 or a continuous annular duct, to the underside of a directing means in the form of a circumferential lip 20 extending radially inwards towards the longitudinal axis 21 of the combustor. The lip 20 deflects the pilot gas across a central portion 22 of the face 16 , i.e., radially inwards in a direction generally normal to the axis 21 . The pilot gas mixes with incoming compressed air 15 and main gas-fuel exiting the swirler-vane passages 14 (the main gas-fuel exits the burner head at the openings 23 ), igniter 17 being then activated to start a pilot flame. The main gas-fuel jets 23 are located at the swirler air-inlet region, i.e., adjacent a radially outer part of the passages 14 , and are fed from connectors 24 through interconnecting ducts, as shown.
[0042] At starting of the engine and at low load, the great majority (for example, 95%) of the fuel injected is pilot gas-fuel passing through path 46 , 48 , 50 by way of valve 44 , leaving the balance to be supplied by the main gas injectors 23 by way of valve 42 , which at this stage is just cracked open. However, as engine load and speed increase, the valve 44 is progressively closed and simultaneously therewith the valve 42 is progressively opened, thereby increasing the main gas supply to the connectors 24 through path 46 , 52 so that progressively a greater proportion of the total mass flow of gas fuel in line 46 is injected into the prechamber from main jets 23 . The main gas and air mix together as they pass inwardly through the swirler passages 14 on their way to the combustion flame within the pre-chamber 13 and main chamber 14 . As load further increases, the fuel control 40 continues to progressively change the settings of valves 42 , 44 so that progressively more fuel is introduced through the main gas connector 24 and less through the pilot connector 18 , whereby eventually at full load approximately 95% of the total fuel requirement is met via the main connector 24 and the rest via the pilot connector 18 .
[0043] However valve 44 is never set to close off path 46 , 48 , 50 completely, so that there is always some flow of gas from the pilot system across the burner's center face 22 .
[0044] [0044]FIG. 2 shows a combustion-flame envelope represented by the boundary line “F” and flame front face “FF”. The flame front FF is created by the recirculation of fluid 33 entering the combustion chamber along the radially outer parts of the chamber back along the central axial part of the chamber (axis 21 ) towards the burner (see arrows 34 ) and then back again towards the main chamber (see arrows 35 ), the front face FF itself being the point at which the axial flow 34 in the direction of the burner turns back on itself ( 35 ).
[0045] It is a feature of the present burner that at all engine load settings the flame front remains adjacent the face 22 . (It should be noted that in known pre-chamber/main-chamber combustion systems it is conventional for the flame front of the main flame, though not necessarily the pilot flame, to be positioned not so far upstream in the pre-chamber.)
[0046] The present invention causes the front face FF to reach near to the burner face 22 by, for example, employing a high ratio of pre-chamber diameter to length (in a working example this ratio was 2:1); and by dispensing with axially issuing air or fuel jets which conventionally might be provided at the central region of the face 22 , such jets acting against the flow 34 to limit progress of the flame face toward the burner face 22 .
[0047] It could be supposed that having a flame front adjacent the face 22 would ordinarily cause overheating and damage to that face, and hence lead to problems of reliability. However, the curtain of pilot gas washing across the face 22 provides an effective insulation to prevent such damage. This design of the burner, whereby the front face of the flame is always maintained adjacent the downstream face 22 of the burner head, and therefore within the pre-chamber, is advantageous in the sense that the air-fuel mixture within the pre-chamber has sufficient velocity to prevent ignition flash-back into the swirler; this is due to the relatively small cross-sectional area of the pre-chamber 13 in relation to the mass flow rate of fuel and air passing through it.
[0048] Turning now to the liquid-fuel mode of the present combustor (see FIGS. 1 and 3), this mode of operation employs, as with the gas-mode, both pilot and main-fuel systems controlled through variable valves 62 and 68 and the flame front in this mode is also situated adjacent the burner face 22 at all load settings.
[0049] At least one, but preferably several, liquid-fuel pilot jets 25 , located at the periphery of the central part 22 of the burner face 16 , are provided and are fed liquid fuel for pilot-flame operation from line 60 by way of valve 62 , line 64 , connection(s) 26 and appropriate ducts in the burner head. Such pilot jets 25 are positioned in the burner face outside the outer circumference of the combustion flame adjacent the face 22 . Main liquid-fuel jets 27 are also fed from line 60 by way of line 66 , valve 68 , line 70 , fuel connectors 28 and suitable passageways in the burner head. Jets 27 are situated in the burner face 16 at or near the air-exit region of the swirler 12 , i.e., near a radially inner portion of the swirler passages 14 .
[0050] When the engine is started, liquid pilot fuel is injected from pilot jets 25 into the pre-chamber 13 in an axial direction parallel, or approximately parallel, to the central longitudinal axis 21 , where it mixes with air 15 exiting the swirler passages 14 , the air-fuel mixture being ignited by a spark from the igniter unit 17 . On start-up fuel control 40 controls valves 62 , 68 so that valve 68 is shut and all the fuel requirement is met by the pilot jet(s) 25 , the main fuel jets 27 playing no part at this stage.
[0051] As engine load increases from start-up to approximately 70% full load, valve 62 is controlled so that a progressively greater proportion of the total liquid fuel mass flow rate in line 60 is fed through the pilot jet(s) 25 until at approximately 70% full load there occurs a change in the fuel scheduling whereby valve 68 is opened and main fuel is introduced from jets 27 . The main fuel supply then takes over to provide approximately 95% of the total engine fuel requirement between 70% and 100% of full load, so that in that load range about 5% only is supplied from the pilot jet(s) 25 . It is significant that the valve 62 is kept at least slightly open so that there is at all times some pilot fuel flow, even at full-load conditions.
[0052] The main liquid-fuel jets 27 are located on the burner face 16 in the air-exit region of the swirler passages 14 and inject fuel in a direction approximately perpendicular to the airstream flow 15 . It is important that all the liquid-fuel injected should be carried into the airstream and none be allowed to contact the upstream/downstream sidewalls of the swirler 12 , or the vane walls, to the extent that a wall becomes wetted. To this end, the fuel jet bodies are positioned proud of the mounting surface 16 with the jet orifices distant from the surface so that at low fuel-pressure settings the fuel does not dribble onto the surface. For similar reasons, when operating at higher fuel-pressure settings, the pressure is controlled so that it is not sufficient to force the fuel into contact with a downstream passage wall 29 of the swirler.
[0053] Importantly, while operating on liquid fuel and to avoid overheating of, and consequent damage to, the face 22 , air under pressure from line 72 is routed through multi-position variable valve 44 and line 50 to the pilot-gas injector to wash over the face 22 in the same manner that pilot gas is brought into contact with the face during gas operation. Such air functions as a coolant and an insulating barrier to protect the face 22 from the heat of the flame.
[0054] [0054]FIG. 4 is a section taken on line “IV-IV” through FIG. 3 and illustrates the configuration of the swirler vanes and passages and the disposition of the gas and liquid fuel jets as employed in the embodiment of the invention described above. The hatched triangular areas 30 are the vane sections, while the clear areas between the vanes are the air passageways 14 .
[0055] While the preferred method of conveying cooling air to the downstream face of the burner head is to employ the pilot gas ducts themselves to carry the air, an alternative scheme is to use dedicated outlets (not shown) in the head, situated, for example, between the spaced-apart gas outlets 32 . These dedicated outlets will be fed from similarly dedicated passageways (also not shown) supplied from suitable inlets and a separate valve controlled by fuel control 40 .
[0056] Also, although the igniter 17 has been represented as being located at a radius between that of the pilot liquid-fuel jets 25 and that of the annular gallery 19 , it may alternatively be at the same radius as the jets 25 .
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A gas-turbine engine combustion system has a combustor with a burner head having both pilot gas and pilot liquid-fuel injection arrangements, the pilot gas arrangement comprising an annular gallery communicating with a downstream face of the head and a deflecting arrangement adjacent the gallery for directing the pilot gas-fuel towards a longitudinal axis of the combustor and over a central part of the downstream face. The combustion system is designed so that, during both gas- and liquid-fuel operations, the flame front face is located close to the burner head and, during liquid-fuel operation, air is forced across the downstream face to cool the head. Advantageously, the cooling air is made to replace the pilot gas-fuel in the annular gallery, so that it is deflected, like the gas-fuel, and contacts the central part of the downstream face. The burner head also features main gas and liquid-fuel injection arrangements, these communicating with one or more passageways in a radial swirler attached to the head.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional application Ser. No. 60/193,228 filed Mar. 30, 2000.
FIELD OF THE INVENTION
The present invention relates to the monitoring of physical systems, processes or machines, and more particularly to systems and methods for discerning signal differentiation using an operator to detect deviations in one or more sets of signals from monitored sensors.
BACKGROUND OF THE INVENTION
Generally, there is a need to detect when one or more of a set of signals from sensors monitoring a system, whether a machine, process or living system, deviates from “normal.” Normal can be an acceptable functioning state, or it can be the most preferred of a set of various acceptable states. The deviation can be due to a faulty sensor, or to a change in the underlying system parameter measured by the sensor, that is, a process upset.
While threshold-type sensor alarms have traditionally been used to detect when parameters indicate that a component has strayed away from normal, acceptable or safe operating conditions, many deviations in sensor or underlying parameter values go unnoticed because threshold detection can only detect gross changes. Often such detection may not occur early enough to avoid a catastrophic failure. In particular, there is a critical need to detect when a component, as indicated by a signal or underlying parameter value, is deviating from an expected value, given its relationship to other system components, i.e., in the monitored machine, process or living system. This detection should occur even though the corresponding signal in question is still well within its accepted gross threshold limits.
A number of methods exist that try to use the relationships between sensors, signals, data or the underlying parameters that correspond thereto, to detect notable component changes that otherwise would be missed by “thresholding.” Such methods are often data-intensive and computationally demanding. There is a need for accurate empirical modeling techniques that provide computationally efficient and accurate system state monitoring.
SUMMARY OF THE INVENTION
The present invention provides an improved monitoring system and method for ultrasensitive signal differentiation that achieves the detection of changes to and faults in one or more sensor signals in a set that characterizes an underlying “process or machine.” The invention achieves accurate results with improved computational efficiency without relying on thresholding. Therefore, less memory and CPU power are needed to perform the necessary calculations. Also, because of the improved computational efficiency, more data “time-slices” can be processed with a given CPU speed. This is useful particularly in systems where signals or data must be sampled at a high rate, or in an application where the CPU or micro-controller is limited.
An empirical model is developed of the process or machine to be monitored, and in real-time sensor data from the monitored process or machine is compared to estimates of same from the model. The results of the comparison are statistically tested with an ultrasensitive difference test that indicates alerts on a sensor-by-sensor basis, thereby providing early warning of process upsets, sensor failures, and drift from optimal operation, long before these would be noticed by conventional monitoring techniques. According to the invention, an improved similarity operator is used in generating the estimates.
The invention provides an improved operator that can be implemented in software on a variety of systems. A typical implementation would be in a programming language like C or C++ on a Unix or Windows workstation, either as a standalone program sampling data via a National Instruments-like pc-card, or as a part or module of a broader process control software system. The program can be a Windows-like DLL or callable routine, or can comprise an entire suite of presentation screens and settings modification screens. The software can be reduced to a PCMCIA card for addition to a computer with such a port. Then, the data being input to the computation could be fed through a dongle attached to the PCMCIA card. An alternative would be to put the program into microcode on a chip. Input and output of the requisite data to a broader system would depend on the design of the overall system, but it would be well known to circuit designers how to build in the microchip version of this invention. In yet another embodiment, the computation could take place on a server remote (WAN) from the sensors that feed to it. As contemplated in another embodiment, the internet could be used to deliver real-time (or semi-real-time) data to a server farm which would process the data and send back either alarm level data or higher-level messages. In that case, it would become necessary to ensure that the asynchronous messaging “delay” of the internet was of sufficiently unobtrusive to the semi-real-time monitoring taking place over the internet/WAN. For example, bandwidth could be guaranteed so that the asynchronicity of the messaging was not any kind of delay. Alternatively, the sampling rate of the system could be slow enough that the delivery time of Internet messages was negligible in comparison.
Briefly, the present invention relates to a computationally efficient operation for accurate signal differentiation determinations. The system employs an improved similarity operator for signal differentiation. Signals or data representative of several linearly and/or non-linearly related parameters that describe a machine, process or living system are input to the inventive system, which compares the input to acceptable empirically modeled states. If one or more of the input signals or data are different than expected, given the relationships between the parameters, the inventive system will indicate that difference. The system can provide expected parameter values, as well as the differences between expected and input signals; or the system can provide raw measures of similarity between the collection of input signals and the collection of acceptable empirically modeled states.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as the preferred mode of use, further objectives and advantages thereof, is best understood by reference to the following detailed description of the embodiments in conjunction with the accompanying drawings, wherein:
FIG. 1 shows a block diagram of an exemplary laboratory workbench arrangement for gathering process or machine behavior data for distillation;
FIG. 2 shows an example of an embodiment of the present invention in an on-board processor;
FIG. 3 shows an example embodiment wherein a process is shown to be instrumented with sensors having output leads;
FIG. 4 illustrates an implementation of a statistical modeling operator in accordance with the invention;
FIG. 5 shows a method for selecting training set vectors for distilling the collected sensor data to create a representative training data set;
FIG. 6 shows computation of an expected “snapshot,” given the real-time actual “snapshot” of the underlying system;
FIG. 7 and FIG. 8 show snapshot numbers 1 - 6 as deviating signals and noise additive signals respectively with associated vector similarity values using a similarity operator in accordance with the invention;
FIGS. 9A and 9B illustrate a sensor input signal from an air conditioning condenser thermocouple showing positive drift, with FIG. 4A illustrating the residual signal resulting from the drift as deviating over time;
FIGS. 10A and 10B illustrate the residual signal generated in response to negative drift on the sensor input; and
FIGS. 11A and 11B illustrate the introduction of additive noise to the sensor input and the corresponding residual signal.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention is a system, method and program product for monitoring operation of a machine, process, living system or any other such system to accurately predict individual component failures, i.e. component end of life, such that failure or process upset can be anticipated to reduce planned downtime, reduce unplanned downtime and provide for process or product quality optimization.
It is directed to the employment of an improved similarity operator within an empirical modeling engine for use in generating estimates of sensor values for a monitored process or machine based on input of the actual sensor values. Advantageously, the similarity operation carried out in the modeling according to the invention has comparatively low computational needs as compared to other similarity operators that can be used in such an empirical model-based monitoring system, such as is described in U.S. Pat. No. 5,987,399 to Wegerich et al., wherein is disclosed a similarity operator employing computationally intensive trigonometric variables. In particular a representative “training” set of data is compared against monitored signal data in a similarity engine and a statistical significance engine. Techniques for achieving ultrasensitive signal differentiation are similar to what is generically described in U.S. Pat. No. 5,764,509, directed to the application of a sequential probability ratio test (“SPRT”). Parameter data are gathered from signal sensors monitoring a system such as a machine, process or living system. The number of sensors used is not a limiting factor, generally, other than respecting computational overhead. The present invention is highly scalable. Preferably, the sensors should capture component parameters of at least some of the primary “drivers” of the underlying system. Furthermore, all sensor inputs to the system are best interrelated in some fashion (non-linear or linear).
Turning to FIG. 1 , a block diagram of an exemplary laboratory workbench arrangement 100 is shown for gathering process or machine behavior data for distillation. In this example, the monitored system is depicted as a machine prototype 102 and may be, for example, a combustion engine, an electric motor, a pump, a compressor, a refrigerator, and so on. It is understood that, as further indicated herein, the monitored system may be any machine, living system or system carrying out a process. In this example, the machine 102 is termed a prototype, but importantly, its function is to generate sensor data that is substantially the same as the actual parameter values expected in a production model of the machine, as would be measured by the same sensors. Of course, the training may be in situ wherein the prototype is a production model itself, and ideally, not different in any way from other production models. In addition, when sufficient data has already been accumulated, that previously accumulated data may be used as the training data source, the prototype machine being a virtual machine derived from production machines contributing data to the accumulation.
The machine 102 may be connected to and controlled by a control system 104 , generally comprising a microcontroller- or microprocessor-based digital system with appropriate analog digital and digital/analog inputs and outputs as are known to those skilled in the art. Machine 102 is instrumented with sensors monitoring machine components or reactions thereto (e.g., chamber temperature or pressure) and providing resultant sensor values along outputs 106 . During training, the machine 102 is operated through an expected range of operations, and data acquisition system 108 records values of all sensors 106 with which machine 102 is instrumented. Additionally, control signals from control system 104 may also be recorded by data acquisition system 108 , and may be used as “sensor signals” that correlate with the other sensor signals.
Data acquired by data acquisition system 108 can, accordingly, be processed using a computer module 110 for producing a distilled training data set representing the operational ranges of machine 102 , using the preferred training method, or other appropriate such methods as may be known in the art.
The monitoring system described herein includes an empirical modeling engine and a statistical decision-making engine supported by a suite of software routines for data preconditioning, training, and post-decision reporting. This system is modular and can be applied separately depending on the requirements of the particular monitoring application. Typically, process monitoring equipment employs sensors having some common characteristics. A sensor data set is acquired as being representative of the normal or desired operation range of the system. The parameters monitored by sensors should be chosen for the model to be correlated, either linearly or nonlinearly. Generally, multiple sensor inputs may be necessary, however, the described algorithms may apply to single sensor applications by using signal decomposition of the single sensor signal into components that can be treated as multiple, correlated inputs for modeling and monitoring. The identification of small deviations in signals from normal operation is provided as indicative of the status of the sensor's associated physical parameter.
The inventive monitoring system can be adapted to provide not just monitoring of existing sensor data, but also generation of derived “virtual” sensor data based on other actually-monitored sensors. Thus, an example 120 of an embodiment of the present invention in an on-board processor is shown in FIG. 2 , wherein a system, machine or process, represented by machine 122 , is controlled by a control system 124 that is located on the machine. Machine 122 is instrumented with sensors for some of the physical or logical parameters of interest that may be controlling the machine, and the outputs for these sensors are shown as output conductors 126 , which feed into the control system 124 . These are also fed to a processor 128 located within or on the machine, disposed to execute a computing program for monitoring sensor signals and an optional computing program for generating a set 130 of virtual signals on output conductors 126 . The processor is connected to a local memory 132 , also on or in the machine 122 , which stores data comprising the training set distilled to represent the expected operational states of the machine 122 . Memory 132 can also advantageously store programs for execution by the processor 128 . Virtual signals 130 , if included, previously generated by the processor 128 are provided to the control system 124 , in lieu of genuine sensor values. Generation of virtual sensor estimates using the improved similarity operator of the present invention can be more fully understood with reference to copending patent application Ser. No. 09/718,592 of Wegerich, filed Nov. 22, 2000, and entitled “Inferential Signal Generation for Instrumented Equipment and Process.” Virtual signals may be generated as a cost saving measure to reduce sensor count or for unmonitorable physical or logical parameters of the machine 122 .
Processor 128 can also be a part of the control system 124 , and in fact can be the processor on which the control system routines are executed, in the event the control system is a digital computed control system. Ideally, the processor 128 and memory 132 are powered by the same power source as the control system 124 . However, under certain circumstances, it may also be preferable to provide for a processor 128 and memory 132 independent from another processor and or memory (not shown) of the control system 124 , in order to provide for example virtual signals 130 in a timely fashion, as though they were truly instrumented parameters. For example, processor 128 may operate at a higher clock speed than the control system processor.
FIG. 3 shows an example embodiment 140 , wherein a process 142 is shown to be instrumented with sensors having output leads 144 . These leads 144 provide sensor signals to a control system 146 that controls the process. These signals are also provided to a remote communications link 148 , which is disposed to communicate digital values of the sensor signals to a second remote communications link 150 , located at a physically remote place. A processor 152 is provided, which may comprise a computing system and software, that uses the sensor signals received by link 150 to monitor the process 142 for sensor failures, process upsets or deviations from optimal operation and optionally generate at least one virtual sensor signal indicative of an inferred physical parameter of process 142 . A memory 154 is provided to store training set data representative of the expected operational behavior of the process 142 , according to the distillation method described above.
Furthermore, a display 156 may be provided at the remote location for displaying data descriptive of the process 142 , i.e., sensor signals 144 and any virtual signals derived therefrom or both. The virtual signals generated by processor 152 can also be transmitted from link 150 back to link 148 and input over leads 158 to control system 146 for advantageous control of the process. Data from original sensor signals and or virtual sensor signals (if included) can also be transmitted to a third remote communications link 160 , located at yet a third distant place, for display on display 162 , thereby providing valuable information concerning the process to interested parties located at neither the physical process site nor at the monitoring system site.
The remote communications links can be selected from a variety of techniques known in the art, including internet protocol based packet communication over the public telecommunications infrastructure, direct point-to-point leased-line communications, wireless or satellite. More specifically, remote links 148 , 152 and 160 may be internet-enabled servers with application software for accumulating, queuing and transmitting data as messages, and queues for receiving and reconstituting data arriving as messages. Alternatively, communications can be synchronous (meaning in contrast to asynchronous, message-based communications) over a wireless link.
The embodiment of the invention shown in FIG. 3 allows computation of signals using computing resources that are located geographically distant from the system being monitored and/or controlled. One benefit of remote monitoring is that the monitoring and analysis resources may be shared for a multitude of systems, where the memory 154 may hold multiple training sets characterizing the various monitored systems, processes and machines or distributed combinations thereof. Another benefit is that results may be displayed and also potentially used in further analysis by interested parties located distant from the system being monitored.
A preferred method of employing the improved similarity operator of the present invention is shown in FIG. 4 , which illustrates an implementation of the operator according to a method 170 for monitoring a process or machine instrumented with sensors. In a training step 172 a model is derived that captures the normal operating ranges for the sensors. Upon initiating the software system at step 174 , training is determined to occur either on-line or not in step 176 . Previously archived data 180 may also be used to provide data characteristic of normal or acceptable operation, or data characteristic of normal or acceptable operation may be obtained from the real-time operation of the monitored system 178 . According to the method 170 , training patterns (the D matrix) are chosen at step 184 to generate the empirical model at 186 , as further described below. The training set is a matrix of vectors in which each vector represents one of the normal operating states of the system.
Real time monitoring stage 190 is indicated at step 188 , whereupon the model generated at 186 is employed in the steps 192 for estimation. Real-time data is acquired in 192 and an estimate of what the sensor values should be is generated based thereon in view of the model. For each snapshot of data acquired in 192 , the similarity operator of the invention is used to compare the actual real-time sensor values to vectors of sensor values in the training set.
The differences between the expected values and real-time sensor signals, i.e., the residual signals formed in 192 , are sent to a decision-making engine in the process deviation decision-making step 182 . The decision-making engine continuously renders a reliable decision at 194 based on a SSCADI index calculated at 198 over a moving window of successive residual observations, determining whether or not the residual signals reveal a statistically relevant abnormality.
The described embodiment uses a platform with an operating system for real-time monitoring 190 and sampling of the real-time sensor data via a National Instruments feed, with a monitor including an estimation module 192 with a windowing environment to provide feedback in the form of alarms 194 or other high-level messages 196 to an operator of equipment. The program embodying the invention can be written in C or in LabView, a product available from National Instruments Company. The operator portion itself comprises a callable Windows DLL that the LabView software calls. The software may be written as components, including: (1) a training component 172 (for selecting the D matrix from a set previously obtained of “normal” input data), (2) an estimation module component 192 for modeling (to provide the similarity operations both on matrix D and on the real-time input vector, and also to provide an estimated output or an output of the degree of similarity of the vector to the states recognized in the D matrix), and (3) a statistical test component 198 (which tests data such as using SPRT on the similarity measurement or residual between the input and the estimate).
Monitoring begins by providing signal data as vectors, each with as many elements as there are sensors. A given vector represents a “snapshot” of the underlying system parameters at a moment in time or time correlated. Additional pre-processing can be done, if necessary for time correlation to insert a “delay” between cause and an identified effect between sensors. That is to say, for example, if sensor A detects a parameter change that will be reflected at sensor B three “snapshots” later, the vectors can be reorganized such that a given snapshot contains a reading from sensor A at a first moment, and a corresponding reading from sensor B three snapshots later. Each snapshot is representative of a “state” of the underlying system. Methods for time-correlating in this way are known to those skilled in the art.
Turning to FIG. 5 , a method for selecting training set vectors at step 184 is graphically depicted for distilling the collected sensor data to create a representative training data set. In this simple example, five sensor signals 202 , 204 , 206 , 208 and 210 are shown for a process or machine to be monitored. Although the sensor signals 202 , 204 , 206 , 208 and 210 are shown as continuous, typically, these are discretely sampled values taken at each snapshot. As indicated hereinabove, snapshots need not be ordered in any particular order and so, may be ordered in chronological order, parametric ascending or descending order or in any other selected order. Thus, the abscissa axis 212 is the sample number or time stamp of the collected sensor data, where the data is digitally sampled and the sensor data is temporally correlated. The ordinate axis 214 represents the relative magnitude of each sensor reading over the samples or “snapshots.”
In this example, each snapshot represents a vector of five elements, one reading for each sensor in that snapshot. Of all the collected sensor data from all snapshots, according to this training method, only those five-element snapshots are included in the representative training set that contain either a global minimum or a global maximum value for any given sensor. Therefore, the global maximum 216 for sensor 202 justifies the inclusion of the five sensor values at the intersections of line 218 with each sensor signal 202 , 204 , 206 , 208 , 210 , including global maximum 216 , in the representative training set, as a vector of five elements. Similarly, the global minimum 220 for sensor 202 justifies the inclusion of the five sensor values at the intersections of line 222 with each sensor signal 202 , 204 , 206 , 208 , 210 . Collections of such snapshots represent states the system has taken on. The pre-collected sensor data is filtered to produce a “training” subset that reflects all states that the system takes on while operating “normally” or “acceptably” or “preferably.” This training set forms a matrix, having as many rows as there are sensors of interest, and as many columns (snapshots) as necessary to capture all the acceptable states without redundancy.
Turning to FIG. 6 , the training method of FIG. 5 is shown in a flowchart. Data collected in step 230 has N sensors and L observations or snapshots or temporally related sets of sensor data that comprise an array X of N rows and L columns. In step 232 , an element number counter i is initialized to zero, and an observation or snapshot counter t is initialized to one. Two arrays “max” and “min” for containing maximum and minimum values respectively across the collected data for each sensor, are initialized to be vectors each of N elements which are set equal to the first column of X. Two additional arrays Tmax and Tmin for holding the observation number of the maximum and minimum value seen in the collected data for each sensor, are initialized to be vectors each of N elements, all zero.
In step 234 , if the sensor value of sensor i at snapshot t in X is greater than the maximum yet seen for that sensor in the collected data, max(i) is updated to equal the sensor value and Tmax(i) stores the number t of the observation in step 236 . If not, a similar test is done for the minimum for that sensor in steps 238 and 240 . The observation counter t is incremented in step 242 . In step 244 , if all the observations have been reviewed for a given sensor (t=L), then t is reset and i is incremented (to find the maximum and minimum for the next sensor) in step 246 . If the last sensor has been finished (i=N), step 248 , then redundancies are removed and an array D is created from a subset of vectors from X.
First, in step 250 , counters i and j are initialized to one. In step 252 , the arrays Tmax and Tmin are concatenated to form a single vector Ttmp having 2N elements. These elements are sorted into ascending (or descending) order in step 254 to form array T. In step 256 , holder tmp is set to the first value in T (an observation number that contains a sensor minimum or maximum). The first column of D is set equal to the column of X corresponding to the observation number that is the first element of T. In the loop starting with decision step 258 , the ith element of T is compared to the value of tmp that contains the previous element of T. If they are equal (the corresponding observation vector is a minimum or maximum for more than one sensor), it has already been included in D and need not be included again. Counter i is incremented in step 260 . If they are not equal, D is updated to include the column from X that corresponds to the observation number of T(i) in step 262 , and tmp is updated with the value at T(i). The counter j is then incremented in step 264 . In step 266 , if all the elements of T have been checked, then the distillation into training set D has finished, step 266 .
Once the D matrix has been determined, in the training phase 172 , the preferred similarity engine may begin monitoring the underlying system ( 122 , 142 or 178 ) and through time, actual snapshots of real sensor values are collected and provided to the similarity engine. The output of the similarity engine can be similarity values, expected values, or the “residual” (being the difference between the actual and expected values).
One or all of these output types are passed to the statistical significance engine, which then determines over a series of one or more such snapshots whether a statistically significant change has occurred as set forth hereinbelow. In other words, it effectively determines if those real values represent a significant change from the “acceptable” states stored in the D matrix. Thus, a vector (Y) of expected values:
{right arrow over (y)} out ={overscore (D)}·{right arrow over (W)}
(i.e., estimates) is determined for the sensors. The expected state vector (Y out ) is equal to contributions from each of the snapshots in D, which contributions are determined by the weight vector W. The multiplication operation (·) is the standard matrix/vector multiplication operator. W has as many elements as there are snapshots in D. W is determined by:
W → = W ^ → ( ∑ j = 1 N W ^ ( j ) )
W _ = ( D _ ′ ⊗ D _ ) - 1 · ( D _ ′ ⊗ y → input )
D is again the training matrix, and D′ is the standard transpose of that matrix (i.e., rows become columns). Y input includes the real-time or actual sensor values from the underlying system, and therefore it is a vector snapshot.
The similarity operator {circle around (x)} can be selected from a variety of mechanisms for providing a measure of the similarity of one snapshot as compared to another. One general class of similarity operators performs an element for element comparison, comparing a row of the first matrix with a column containing an equal number of elements from the second matrix. The comparison yields a “similarity” scalar value for each pair of corresponding elements in the row/column, and an overall similarity value for the comparison of the row to the column as a whole, e.g., for one snapshot to another.
The similarity operator has been improved in the present invention to define the similarity s i between ith elements as:
θ i = max ( x i , m i ) - min ( x i , m i ) ( Max range - Min range ) ; s i = 1 - θ i λ ρ
where:
Max(range) is the maximum value of that “sensor” across the matrix (typically across the transpose of the D matrix), that is the maximum value of x in a given column of x in the above matrix, or in other words the maximum value for that corresponding sensor in the training set; Min(range) is the minimum value of that “sensor” in the same manner; X i =the i th component of the row of the first matrix (x matrix above); M i =the i th component of the column of the second matrix (m matrix above); ρ=an analysis parameter that can be manually varied for enhanced analysis and is defaulted to 1; and λ=a sensitivity analysis parameter that also can be manually varied for enhanced analysis and is defaulted to 1.
Accordingly, vector identity yields s i =1.0 and complete dissimilarity yields s i =0.0. Typically s i falls somewhere between these two extremes.
Overall similarity of a row to a column is equal to the average (or some other suitable statistical treatment) of the number N (the element count) of s i values:
S = ∑ N 1 S i N
or alternatively the similarity S of a row to a column can also be calculated:
S = 1 - [ ( ∑ N 1 θ i ) / N ] λ ρ
that is, the average of the θ i , divided by ρ, raised to the power of λ, and subtracted from one. Accordingly, the S values that are summed from θ i or s i are the S values depicted in the result matrix above. This operator, having been described generically above, works as follows in the determination of W. The first factor, D′{circle around (x)}D, is referred to herein as matrix G, i.e.,
{overscore (G)}={overscore (D)}′{circle around (x)}{overscore (D)}
So, for example, with D and its transpose for 4 sensors a, b, c, d and for n training set snapshots are:
D _ ′ = [ a 1 b 1 c 1 d 1 a 2 b 2 c 2 d 2 ⋮ ⋮ ⋮ ⋮ a n b n c n d n ] D _ = ( a 1 a 2 ⋯ a n b 1 b 2 ⋯ b n c 1 c 2 ⋯ c n d 1 d 2 ⋯ d n )
then the matrix G is:
G _ = [ g 11 g 12 ⋯ g 1 n g 21 g 22 ⋯ g 2 n ⋮ ⋮ ⋮ ⋮ g n1 g n2 ⋯ g nn ]
where, for example, element g 12 in the matrix G is computed from row 1 of D-transpose (a 1 , b 1 , c 1 , d 1 ) and column 2 of D (a 2 , b 2 , c 2 , d 2 ) as either:
S 12 = ∑ i = a , b , c , d s i 4 or S 12 = 1 - [ ( ∑ i = a , b , c , d θ i ) / 4 ] λ ρ
where the elements s i and θ i are calculated as:
θ a = max ( a 1 , a 2 ) - min ( a 1 , a 2 ) ( Max a - Min a ) ; θ b = max ( b 1 , b 2 ) - min ( b 1 , b 2 ) ( Max b - Min b ) ; θ c = max ( c 1 , c 2 ) - min ( c 1 , c 2 ) ( Max c - Min c ) ; θ d = max ( d 1 , d 2 ) - min ( d 1 , d 2 ) ( Max d - Min d ) ; and s i = 1 - θ i λ ρ
The resulting matrix G is symmetric around the diagonal, with ones on the diagonal. To further calculate W, the computation of (D′{circle around (x)}Y input ) is performed in a similar fashion, except Y input is a vector, not a matrix:
D _ ′ ⊗ y → input = [ a 1 b 1 c 1 d 1 a 2 b 2 c 2 d 2 ⋮ ⋮ ⋮ ⋮ a n b n c n d n ] ⊗ [ a in b in c in d in ] = [ S 1 S 2 ⋮ S n ]
The G matrix is inverted using standard matrix inversion, and the result is multiplied by the result of D′{circle around (X)}Y input . The result is W:
W → = G _ - 1 · [ S 1 S 2 ⋮ S n ] = [ W 1 W 2 ⋮ W n ]
These weight elements can themselves be employed, or expected values for the sensors can be computed, applying the training matrix D to the weight vector W:
y _ expected = D _ · W → = [ a 1 a 2 ⋯ a n b 1 b 2 ⋯ b n c 1 c 2 ⋯ c n d 1 d 2 ⋯ d n ] · [ W 1 W 2 ⋮ W n ] = [ a ex b ex c ex d ex ]
Turning to the analysis or tuning parameters λ and ρ, while either value can remain set to its default value of 1, analysis parameter ρ can be varied to all values greater than or equal to 1. The sensitivity analysis parameter λ can be varied to any value and, preferably, to any positive value and more particularly, can be selected in the range of 1-4.
The computation results of the expected sensor values is subtracted from the actual sensor values to provide a “residual”. The residual is also a vector having the same number of elements as the sensor-count, with each element indicating how different the actual value is from the estimated value for that sensor.
So, for example, set forth below is an example of C code for the overall functionality of the inventive similarity operator based upon a modeling technique for the calculation of the similarity between two vectors.
First user specified selectable parameters include:
D: Training matrix; M rows by N columns, where M is the number of variables in the model and N is the number of training vectors chosen from a training data set. λ: Non-linearity exponent, i.e., an analysis or coarse tuning parameter. ρ: Scaling factor, i.e., an analysis or fine tuning parameter.
Then, inputs include:
D: The two dimensional training matrix. M: The number of variables or rows in the D matrix. N: The number of training vectors or columns in the D matrix. lambda: OP Non-linearity (coarse) tuning parameter. pRow: Scaling (fine) tuning parameter.
Outputs are defined as:
R: A range vector defined externally to avoid dynamic memory allocation. G: The model matrix G calculated as set forth below.
Before real-time monitoring can begin, the global range R for each of the i=1,2, . . . , M variables in the model must be calculated using a representative data set as described hereinabove with reference to FIGS. 5 and 6 . If X is a data matrix with rows corresponding to observations and columns to variables, then the range is calculated for each variable as follows.
“ R i =max( X ( n,i ))−min( X ( n,i )), over all n”
for (column=0; column<M; ++column)
{
min = X[column];
max = X[column];
for (row=1; row<N; ++row)
{
if (X[row*M + column] < min) min = X[row*M + column];
if (X[row*M + column] > max) max = X[row*M + column];
}
R[column] = max − min;
}
Then after determining the ranges R t for each variable, the OP operator model matrix C can be constructed from an appropriate training matrix D. The model matrix is an N by N square matrix calculated using the OP operator, as follows:
“ G= t{circle around (x)} SSCOP D , (where,{circle around (x)} SSCOP is the SSCOP operator)”
The SSCOP operator measures the similarity between vectors. When calculating C, the similarities between all pairs of column vectors in D are calculated. The SSCOP operator uses the ranges R i , non-linearity analysis parameter λ, and the scaling analysis parameter ρ to calculate similarity measurements. Performing the following procedure carries out the similarity between two vectors, d 1 and d 2 in D using SSCOP.
If D contains N column vectors, each including M elements,
D=[d 1 |d 2 | . . . |d N ]
d k =[d 1 ( t ) d 2 ( t ) . . . d M ( t )]
then vector similarity is measured as follows:
i) Calculate the elemental similarity angles θ i for the i th sensor and each pair of elements in d 1 and d 2 .
θ i = max ( d 1 ( i ) , d 2 ( i ) ) - min ( d 1 ( i ) , d 2 ( i ) ) R i
ii) Calculate the elemental similarity measurements.
s i = 1 - θ i λ ρ
iii) Next, calculate the overall vector similarity.
first, if (S i <0), then S i =0
S = 1 M ∑ i = 1 M S i
These steps are used to calculate the similarity between all combinations of vectors in D to produce G.
So, for example:
Given a data set X, the Range of each variable is
X = [ [ 2.5674 - 1.1465 0.3273 1.3344 1.1909 0.1746 3.1253 1.1892 0.1867 3.2877 - 0.0376 0.7258 ] ] ; .
Setting ρ=2, λ=3, and D is
D = [ [ 2.5674 1.3344 3.1253 3.2877 - 1.1465 1.1909 1.1892 - 0.0376 0.3273 0.1746 - 0.1867 0.7258 ] ] ;
the resulting model matrix G is then
G = [ [ 1.0000 0.7906 0.8000 0.9600 0.7906 1.0000 0.8612 0.7724 0.8000 0.8612 1.0000 0.8091 0.9600 0.7724 0.8091 1.0000 ] ] ;
and the inverse is (condition number equals 91.7104):
Gi = [ [ 13.8352 - 1.8987 0.3669 - 12.1121 - 1.8987 4.3965 - 2.8796 0.7568 0.3669 - 2.8796 4.8407 - 2.0446 - 12.1121 0.7568 - 2.0446 13.6974 ] ] ; .
// Next, calculate G from Dt SSCOP D
for (row=0; row<N; ++row)
{
for (column=0; column<N; ++column)
{
G[row*N + column] = 0;
for (i=0; i<M; ++i)
{
if (D[i*N + row] > D[i*N + column])
{
theta = (D[i*N + row] − D[i*N + column]) / R[i];
}
else
{
theta = (D[i*N + column] − D[i*N + row]) / R[i];
}
s = 1 − pow(theta, lambda) / pRow;
if (s < 0) s = 0;
G[row*N + column] += s;
}
G[row*N + column] /= M;
}
}
A statistical significance test is applied to the elements of the residual, or to the residual as a whole. More particularly, a test known as the sequential probability ratio test (“SPRT”) is applied to the residual for each sensor. This provides a means for producing an alarm or other indicator of statistically significant change for every sensor in real-time.
The SPRT type of test is based on the maximum likelihood ratio. The test sequentially samples a process at discrete times until it is capable of deciding between two alternatives: H 0 μ=0; and H A :μ=M. It has been demonstrated that the following approach provides an optimal decision method (the average sample size is less than a comparable fixed sample test). A test statistic, Ψ t , is computed from the following formula:
ψ t = ∑ i = 1 + j t ln [ f H A ( y i ) f H 0 ( y i ) ]
where ln(·) is the natural logarithm, f Hs ( ) is the probability density function of the observed value of the random variable Y i under the hypothesis H s and j is the time point of the last decision.
In deciding between two alternative hypotheses, without knowing the true state of the signal under surveillance, it is possible to make an error (incorrect hypothesis decision). Two types of errors are possible. Rejecting H 0 when it is true (type I error) or accepting H 0 when it is false (type II error). Preferably these errors are controlled at some arbitrary minimum value, if possible. So, the probability of a false alarm or making a type I error is termed α, and the probability of missing an alarm or making a type II error is termed β. The well-known Wald's Approximation defines a lower bound, L, below which one accepts H 0 and an upper bound, U beyond which one rejects H 0 .
U = ln [ 1 - β α ] L = ln [ β 1 - α ]
Decision Rule: if Ψ t <L, then ACCEPT H 0 ;
else if Ψ, <U, then REJECT H 0 ; otherwise, continue sampling.
To implement this procedure, this distribution of the process must be known. This is not a problem in general, because some a priori information about the system exists. For this purpose, the multivariate Normal distribution is satisfactory.
For a typical sequential test
ψ t + 1 = ψ t + M 1 _ ∑ - 1 ( y _ t + 1 + M 1 _ 2 )
where M is the system disturbance magnitude and {overscore (Y)} is a system data vector.
FIG. 7 shows deviating signals for snapshots numbered 1 - 6 with associated vector similarity values using the inventive similarity operator. These six separate examples show vector-to-vector similarity graphically depicted. In each snapshot chart, the x-axis is the sensor number, and the y-axis is the sensor value. Each snapshot comprises 7 sensor values, that is, seven elements. The two lines in each chart show the two respective snapshots or vectors of sensor readings. One snapshot may be from real-time data, e.g., the current snapshot, and the other snapshot may be from the D matrix the comprises the model. Using the inventive similarity operator described above, element-to-element similarities are computed and averaged to provide the vector-to-vector similarities shown in the bar chart in FIG. 7 . It can be seen that the similarity comparison of snapshot chart # 6 renders the highest similarity scalar, as computed using the similarity operator of the present invention. These similarity scalars are used in computing estimates as described above, with regard to the generation of W.
FIG. 8 shows noise additive signals for snapshots numbered 1 - 6 with associated vector similarity values using the inventive similarity operator. The output of the similarity engine can be similarity values, expected values, or a “residual,” i.e., the difference between the actual and expected values. A more typical set of examples of sensor data with noise are depicted in six snapshot charts, this time comprising 40 sensor elements. Each chart again contains two lines, one for each of two snapshots being compared using the similarity operator of the present invention, these charts are far more difficult to compare visually with the eye. The similarity operator scalar results are shown in the bar chart of FIG. 8 , which provides an objective measure of which vector-to-vector comparison of the set of six such comparisons actually has the highest similarity. Again, the similarity values can be output as results (e.g., for classification purposes when comparing a current snapshot to a library of classified snapshots) or as input to the generation of estimates according to the equations described above, which ultimately can be used for monitoring the health of the monitored process or machine.
FIGS. 9A and 9B illustrate a sensor input signal from an air conditioning condenser thermocouple showing positive drift, with FIG. 9A illustrating the residual signal resulting from the drift as deviating over time. In FIG. 9A , it can be seen that the drifted “actual” sensor signal and the estimated signal generated using the similarity operator of the present invention generate a difference or “residual” that grows in FIG. 9B as the estimate and actual diverge. The estimate clearly follows the original pre-drift sensor value that the drifted sensor was based on.
FIGS. 10A and 10B illustrate an example of a residual signal generated in response to negative drift on the sensor input. Because the drift is in the opposite direction, it is negative and the estimate again follows what the sensor should have been. Note that the residual shown in FIG. 10B is actually growing in the negative direction.
FIGS. 11A and 11B illustrate an example of the introduction of additive noise to the sensor input and the corresponding residual signal. Note that the failing sensor is actually getting noisier, and the similarity estimate remains close to the pre-failed sensor signal on which the noisy signal was based. The residual in FIG. 11B swings wider and wider, which would be easily detected in the SPRT-based statistical decision engine and alarmed on.
Thus, the present invention provides a superior system modeling and monitoring tool for ultra sensitive signal differentiation accurately detecting system parametric deviations indicative of more subtle underlying system or system component changes, whether the system is a machine, a process being carried out in a closed system, a biological system or any other such system. The tool differentiates between anomalous results caused by defective sensors and component related failures, allowing adjustment therefor. Further, the signal differentiation sensitivity of the tool far exceeds prior art thresholding results using less memory and computer power to consider larger volumes of data, interactively if desired, irrespective of available computer power.
It will be appreciated by those skilled in the art that modifications to the foregoing preferred embodiments may be made in various aspects. The present invention is set forth with particularity in the appended claims. It is deemed that the spirit and scope of that invention encompasses such modifications and alterations to the preferred embodiment as would be apparent to one of ordinary skill in the art and familiar with the teachings of the present application.
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A system for detecting subtle differences in a signal in a set of linearly and/or non-linearly related signals that characterize a sensor-instrumented machine, process or living system. The system employs an improved similarity operator for signal differentiation. Signals or data representative of several linearly and/or non-linearly related parameters that describe a machine, process or living system are input to the inventive system, which compares the input to acceptable modeled states. If one or more of the input signals or data are different than expected, given the relationships between the parameters, the inventive system will indicate that difference. The system can provide expected parameter values, as well as the differences between expected and input signals; or the system can provide raw measures of similarity between the collection of input signals and the collection of acceptable modeled states. The system can be embodied in software or in a micro-controller.
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FIELD OF THE INVENTION
This invention relates to an improved honing device for honing an interior cylindrical wall and, in particular, to an improved abrasive honing element for use in conjunction with a honing device.
BACKGROUND OF THE INVENTION
Honing devices have long been and are still extensively utilized for finishing interior cylindrical walls, such as cylinder walls of internal combustion engines. Such devices typically employ a rotary body having several circumferentially-spaced slots formed radially thereof, which slots mount therein axially elongated abrasive honing elements. These honing elements are typically expanded radially outwardly of the body for contact with the cylinder wall by an actuator which, while it may assume many conventional forms, typically comprises a cone movable axially of the rotary body. Honing devices of this type are well known, and reference is made to U.S. Pat, Nos. 1,846,371, 1,982,836, 2,263,781, 3,154,893, 3,216,155, 3,645,050 and 3,861,091 which illustrate various such devices.
The conventional honing device has, for many years, employed a plurality of abrasive tools and wood guides disposed in circumferentially spaced relationship around the body so that both the tools and guides rubbingly engage the cylindrical wall. The device typically employs at least a pair of abrasive tools and a pair of guides, the tools and guides being conventionally positioned diametrically opposite one another and circumferentially alternately spaced so that the tools are hence disposed at substantially 180° intervals, the guides are similarly disposed at substantially 180° intervals, and the guides and tools are spaced approximately at 90° intervals. Arrangements of this general type are illustrated by U.S. Pat. Nos. 1,846,371, 1,982,836, 2,263,781 and 3,645,050. With arrangements of this latter type, it has been observed that use of at least one pair of guides is necessary, particularly when using only a pair of abrasive tools, to minimize vibration, noise and chatter.
In an attempt to increase the honing rate, others have attempted to eliminate the guides and increase the number of circumferentially-spaced abrasive tools. In some instance the number of tools has been dramatically increased. Examples of such structures are illustrated by U.S. Pat. Nos. 3,154,893 and 3,861,091. With such arrangements, however, it has been discovered that the increased contact area between the abrasive tools and the cylinder wall appears to increase the harmonic vibrations created during the honing operation, whereby noise and chatter increases and the quality of finish decreases, and hence such devices have normally proved less than desirable.
In an attempt to improve upon the noise and chatter characteristics associated with the typical honing device employing a diametrically opposed pair of stones (i.e. tools) and an intermediate diametrically opposed pair of guides, there has also been developed a honing device wherein the stones and guides are nonsymmetrically positioned. In this known device, as illustrated by U.S. Pat. No. 3,216,155, both the stones and guides are nonsymmetrically related, and in fact the stones are both disposed within one diametric half of the body, and both guides are disposed in the opposite diametrical half of the body. This arrangement, however, still employs large abrasive stones and separate guides for rubbing contact with the cylindrical wall and hence does not optimize finishing of the wall.
In the conventional honing devices, it has been a standard practice to utilize abrasive stones having a width (as measured in the direction of rotation) which is typically a minimum of about 3/8 inch to 1/2 inch. It has generally been believed that stones of substantial widths are required to permit effective finishing (i.e., honing) of the cylindrical wall. Further, these widths have been utilized so as to avoid cracking of the axially-elongated abrasive strips which define the stones. Such stones, however, are believed by Applicants to have been detrimental to the honing process in that they have increased the contact area, causing a corresponding increase in noise and chatter, and generation of substantial heat. Such stones have also generally resulted in increased use of greater contact pressure between the wall and stone so that the abrasive has been observed to crush and wear rapidly, and hence is unable to carry out an effective finishing operation.
In addition, conventional honing devices have typically required that the cylindrical wall be honed or finished using a two-step process. Initially, a rough finishing step is carried out utilizing abrasive elements of rather course grit, such as 150 to about 180 grit. Thereafter, the honing device must be removed from the cylinder and the course-grit abrasive elements removed and replaced with fine-grit elements, such as in the order of about 240 to 320 grit. The device is then reinserted into the cylinder and additional finishing carried out so as to provide the desired smooth finish on the cylindrical wall. Needless to say, this two-step process is undesirably labor intensive and time consuming, but nevertheless has been typically utilized in order to provide the cylinder wall with the desired finish.
Further, abrasive elements of fine grit are substantially more costly than abrasive elements of course grit, and hence users attempt to minimize the extent of use of fine grit stones due to the significant cost thereof.
Accordingly, it is an object of this invention to provide an improved abrasive honing element for use in conjunction with a honing device so as to overcome many of the disadvantages associated with prior art devices of this general type.
More specifically, it is an object of this invention to provide an improved honing tool for use on a honing device which employs a plurality of radially-displaceable tools mounted circumferentially around a rotary body, which tools are each preferably constructed as a laminate formed by the axially elongated abrasive strip bonded to a backing strip, the latter preferably being of wood. The abrasive strip has a width (as measured in the direction of rotation) which is relatively small and generally significantly less than the width of the backing strip, and both the abrasive and backing strips are radially urged for simultaneous contact with the cylinder wall which is being honed.
In a preferred embodiment, the honing device is normally provided with at least two pairs of said tools mounted circumferentially therearound, with the tools of each circumferentially-adjacent pair being reversely circumferentially oriented so that the abrasive strips on each adjacent pair of tools are reversely circumferentially oriented. The tools are preferably mounted such that the abrasive strips as located circumferentially around the body are disposed in a nonsymmetric or nonuniform arrangement, this preferably being achieved by mounting the plurality of tools uniformly angularly around the body so that the reverse circumferential orientation of the tools hence results in the abrasive strips being nonuniformly angularly spaced.
The improved tool of this invention, as utilized in a honing device, such as described above, preferably employs an abrasive strip having a width of about 1/8 inch, which width is significantly smaller than that typically utilized in the honing industry, and the backing strip of wood preferably has a width which is greater than the width of the abrasive strip. This hence provides proper strength and backing for the thin abrasive strip, and at the same time permits the abrasive strip to be radially urged against the cylinder wall with significantly high contact pressures if desired. At the same time, the tool of the present invention results in the face of the wood backing strip also being pressed against the cylinder wall simultaneous with the face of the abrasive strip so that both the abrasive and wood faces effectively perform a finishing operation.
Initial experimental evaluation indicates that this invention enables the use of lower contact pressure between the tool and the cylinder wall in conjunction with the use of a stone of large grit in the order of 150 to 180 grit size, while still enabling the honing operation to be carried out at a more rapid rate and providing a finish of high quality which is more comparable to a finish which could previously be achieved only by utilizing a stone of high grit such as in the order of at least about 240. It is believed that the improved tool of this invention is able to achieve this highly desirable result inasmuch as the contact of the wood face against the cylinder wall directly adjacent the abrasive face provides a much more uniform distribution of pressure throughout the contact area, and at the same time significantly minimizes vibration and chatter directly at the contact area. Further, this also provides better control over the wear and penetration of the abrasive face into the cylinder wall so that the larger grit can more effectively perform a cutting action so as to effect material removal. It is believed that this improved cutting action is due to the fact that the large grits remain bonded to the stone, rather than being broken from the stone as in conventional tools, whereupon the grit gradually wears down to a smaller size so as to create a finer finish on the cylinder wall. The wood face also appears to significantly assist the cutting action by effecting a smoother finishing or polishing so that the resultant cylindrical wall is hence of smooth finish, and in fact is of a much higher degree of smoothness than would otherwise be obtainable using an abrasive strip of such large grit. In fact, it has been observed that the desired quality finish can be achieved using the tool of this invention, employing a strip of large size grit, while performing only a one-step finishing operation, in contrast to the required two-step process required by prior art devices.
Hence, the improved tool and honing device of this invention is believed to represent a significant improvement in the honing art since it permits the use of a coarser grit for the complete finishing operation so as to provide economy of material, it permits the finishing to be carried out at a higher speed which is typically accomplished solely when using coarse grit but at the same time provides a finish which could previously be accomplished solely using fine grit, it permits the finishing to be accomplished using a lower contact pressure so as to minimize wear of the honing device, it provides greater life for the tools since the grit appears to permit the desired finishing to be accomplished by a true cutting action rather than a crushing of the grit, it permits the use of a stone requiring less quantity of expensive abrasive and bonding agent, and it permits the overall finishing operation to be accomplished in a significantly more efficient manner which is both less time consuming and less labor intensive since the finishing operation can be effectively accomplished in one-step rather than two-steps as normally previously required.
In a variation of the improved tool of this invention, an abrasive strip is bonded to both sides of the wood backing strip. The total width of the two abrasive strips is less than the width of the wood strip. This tool is preferred for use on honing devices using a large number of tools, such as power-driven devices employing six or more tools.
Other objects and purposes of the invention will be apparent to persons familiar with structures of this general type upon reading the following specification and inspecting the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view which illustrates a honing device according to the present invention as taken substantially along line I--I in FIG. 2.
FIG. 2 is a fragmentary sectional view taken substantially along line II--II in FIG. 1.
FIG. 3 is a perspective view of the improved honing tool according to this invention.
FIG. 4 is a view like FIG. 3 but showing a variation of the tool.
Certain terminology will be used in the following description for convenience in reference only, and will not be limiting. For example, the words "upwardly", "downwardly", "rightwardly" and "leftwardly" will refer to directions in the drawings to which reference is made. The words "inwardly" and "outwardly" will refer to directions toward and away from, respectively, the geometric center of the device and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.
DETAILED DESCRIPTION
Referring to the drawings, there is illustrated a honing device 10 according to the present invention. This device includes a body 11 which is typically constructed as a sleeve and is provided with structure defining recesses 12 therein, which recesses are spaced circumferentially around the body and open radially thereof. Each recess is provided with a holder or mounting structure 13 adapted for releasable engagement with an abrasive tool or element 14. The abrasive element 14 is designed for effecting finishing, i.e. honing, of an internal cylindrical work surface 15, such as the cylinder wall of an internal combustion engine.
The honing device includes an actuator 16 which may be of any conventional configuration, this actuator 16 being illustrated as a cone-type actuator having conical surfaces 17 thereon which react against individual actuator plates 18, the latter being disposed in engagement with the holders 13 so as to urge the abrasive tools radially outwardly in response to axial displacement of the actuator.
The structure of the body, actuator and holder is conventional, and in fact may assume many different conventional configurations, some of which are illustrated by the aforementioned patents. Hence, the structure which has been briefly illustrated and described above is solely to facilitate an overall understanding of the honing device and is not intended to be restrictive as to the basic structure of the device.
Considering now the improved structure associated with the improved tool or element 14, same includes an abrasive member or strip 21 and a backing member or strip 22 disposed so that the side surfaces 23 and 24 thereof overlap and in fact are fixedly joined together, as by a suitable adhesive such as a two-part epoxy, whereby the strips 21 and 22 are effectively rigidly bonded together and thus form a rigid laminated structure. The abrasive member 14 is, as is conventional in the honing art, constructed of an abrasive grit which, while it can be of any size, is preferably in the range of 150 to 180 grit size since it has been observed that this larger grit size provides economy of manufacture and quality of finish, while permitting the operation to be carried out at a highly desirable speed. The grit size can, however, be varied and selected in accordance with any specific use requirements.
As to the backing member 22, it is preferably constructed of a wood, such as oak. However, the hardness of the wood as well as the type of bonding material for the grit can be varied in accordance with the hardness of the metal being finished, and hence other woods such as pine or walnut can also be used in some circumstances.
The tool 14, when the strips 21 and 22 have been laminated together, defines thereon an edge surface or face 25 which extends along the abrasive strip and effectively functions as a cutting face. Similarly, the wood backing member 22 has an edge surface or face 26 which is substantially coplanar with the cutting face 25. This wood face 26 functions as a supporting and polishing face.
The abrasive strip 21, when used on a manual honing device for finishing bores in the range of three to five inch diameter, preferably has a width "W 1 " (which width is measured in the circumferential direction of the honing device) of about 1/8 inch, this width "W 1 " preferably being in the range of from about 3/32 to about 5/32 inch. The wood backing strip 22, on the other hand, preferably has a width "W 2 " which is at least equal to and is preferably about twice the width "W 1 ". The tool 14 also preferably has a thickness "t" (as measured radially of the honing device) which is preferably a minimum of 3 to 4 times the width "W 1 ". The overall length of the tool 14, which length extends axially of the honing device, is obviously several times greater than the thickness "t", this length being selected in accordance with the requirements of the honing device and of the cylinder wall being finished.
The improved honing device 10 of the present invention is preferably provided with at least four tools 14 mounted thereon (these tools being designated 14, 14A, 14B and 14C in FIG. 1 for convenience in illustration), such tools being used for manual finishing of small bores (3 to 5 inch) of internal combustion engines. The tools are preferably disposed in circumferentially adjacent pairs, such as a pair of tools 14 and 14A in FIG. 1, with the tools of adjacent pairs being reversely circumferentially oriented. For example, assuming the honing device to be rotating in the direction of the arrow 27, which direction is clockwise in the illustrated embodiment, then the circumferentially adjacent pair of tools 14 and 14A are preferably disposed so that the abrasive strips 21 thereon are reversely circumferentially oriented. As illustrated, the abrasive strip 21 on the tool 14 faces in the counterclockwise direction and hence trails the respective wood strip 26, whereas the abrasive strip 21 of the tool 14A faces in the clockwise rotational direction and hence leads its respective wood strip. The other pair of tools 14B and 14C are similarly oriented.
Most conventional honing devices mount the tools on the body such that the tools are uniformly angularly spaced. As illustrated by FIG. 1, the body 11 has perpendicular axes 28 and 29 which intersect the recesses 12, which recesses mount therein the tools and the respective holders. Hence, the four tools illustrated in FIG. 1 are uniformly angularly spaced apart substantially at 90° intervals. However, by reversely orienting the adjacent pairs of tools as explained above, this hence results in the abrasive strips 21 of the adjacent tools 14 and 14A being spaced apart by an angle less than 90°, and similarly the abrasive strips associated with the tools 14B and 14C are also spaced apart by an angle less than 90°. This hence results in the angle between the abrasive strips associated with the tools 14 and 14C, and also between the tools 14A and 14B, being greater than 90°. The abrasive strips associated with the four tools are hence disposed in an nonuniform angularly spaced relationship, and this hence minimizes noise and chatter caused by harmonic vibration created during the honing operation.
Initial experimental evaluation of surfaces finished using the improved honing tool of this invention, particularly when oriented as illustrated by FIG. 1, has indicated that a high-quality finish can be obtained utilizing a single-step process, in contrast to the prior two-step processes typically utilized, and the one-step process of this invention can be accomplished in from one-third to one-fourth the time previously required. Hence, the present invention would appear to permit the finishing of cylinder walls to be accomplished at a rate three to four times greater than previously possible, which rate is due in part to the fact that the process can be accomplished in one-step rather than two. The increase in speed is also due to the fact that it has been observed that approximately only one half as many revolutions are required to provide the required finish on the surface when using the honing tool of the present invention. At the same time, further economies are achieved by the use of stones formed solely of larger grit, whereby the use of stones formed from expensive small grit material is hence avoided.
Referring now to FIG. 4, there is illustrated a variation of the improved honing tool of the present invention. The tool 14' as illustrated by FIG. 4 is substantially identical to the tool 14 of FIG. 3 except that it has abrasive strips 21' bonded to opposite sides of the wood strip 22. Each of the abrasive strips 21' preferably has a width which is one-half the width of the abrasive strip 21 of FIG. 3, whereby the total width of the two abrasive strips 21' thus equal the width W 1 of the abrasive strip 21. The tools 14 and 14' hence both have the same total width, and also have the same width of abrasive relative to wood.
The honing tool 14' is preferably utilized in honing devices which employ a large number of tools mounted thereon, such as the automated or power-driven honing devices which typically employ between 6 and 12 honing tools mounted circumferentially therearound.
While the tool 14' is illustrated as employing separate abrasive strips 21' adhesively bonded to opposite sides of the wood strip 22, it is also contemplated that the tool could be formed by initially providing a large rectangular block of abrasive having a width corresponding to the tool, which abrasive would have a rectangular slot machined longitudinally thereof so as to define the abrasive strips 21' on opposite sides of the slot, following which the wood strip 22 would then be bonded within the slot so that the tool would hence again define thereon a working face involving two narrow abrasive strips bonded to opposite sides of a wood strip substantially as illustrated by FIG. 4. Such would again constitute a laminated tool having the wood bonded to and between the abrasive strips.
While it is anticipated that the total width of the abrasive will normally be in the aforementioned range when the tool is used for finishing cylinder walls of internal combustion engines, nevertheless it is also contemplated that the improved tool of this invention will also be highly advantageous for use with other industrial applications, such as finishing the interior cylindrical wall of large diameter bores of the type utilized in fluid pressure cylinders and other industrial equipment. In such applications, particularly involving large diameters, the width of the tool and hence the width of the stone may have to be increased significantly somewhat in proportion to the bore diameter, and in fact it is contemplated that a tool having a stone face width of one-half inch and a wood face width of at least one-half inch may be used.
Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.
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A honing device which employs a plurality of radially-displaceable tools mounted circumferentially around a rotary body. The tools are constructed as a laminate formed by the axially elongated abrasive strip bonded to and overlying a wood backing strip. The abrasive strip has a width, as measured in the direction of rotation, which is normally less than the width of the backing strip. The abrasive and backing strips are radially urged for simultaneous contact with the cylinder wall being honed.
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BACKGROUND OF THE INVENTION
Position finding with radar is widely used, particularly in fog and other low-visibility weather conditions. It is desirable, particularly at sea, to be able to recognise even small objects (for example rescue islands, small boats, etc) at a range of up to about 10 km. However, position finding is complicated in heavy seas because water alone provides a relatively high reflection (approximately 50%) of radar waves. Accordingly, the objects in question are required to have a reflective power of at least 90%. In many cases, compact materials which reflect radar beams with minimal losses cannot be used for external applications. For technical or weight reasons, the outer wall of small objects at sea cannot be provided with a compact metallic surface.
SUMMARY OF THE INVENTION
An object of the present invention is to improve the recognisability of relatively small objects by radar beams, particularly at sea, in the air and in the rescue field. It has now been found that the recognisability of objects by radar, particularly of small objects, is improved if metallised sheet-form textile materials are applied to the objects, the metal having been applied to the sheet-form textile material after activation thereof in a total metal layer thickness of from 0.02 to 2.5 μm by currentless wet-chemical deposition. In the context of the invention, sheet-form textile materials are understood to be woven fabrics, knitted fabrics and non-woven fabrics. The invention relates to the use of metallised sheet-form textile materials as a reflecting material for microwave and decimeter wave radiation.
Polarisation of the radiation reflected by stretched metallised fabrics may be utilised to facilitate or improve object recognition. By periodic stretching and relaxation, it is possible to obtain a pulsating polarisation of the reflected microwaves.
It is of particular advantage that even thin metal layers have a sufficiently high reflective power. The surface conductivity of the sheet-form textile materials is considerably higher than it would be had the same amount of metal been applied by vapour deposition. Their surface resistance, as measured in accordance with DIN 54 345 at 23° C./50% relative humidity, is of the order of or less than 1.10 2 Ω. It is surprising that even layer thicknesses in the region of skin depth still have a reflective power which would appear to be associated with the textile support. In the case of nickel layers for example, the skin depth is 0.27 μm at 3 GHz and 0.16 μm at 9 GHz.
The improved recognition even of small objects, achieved by the surface being covered at least partly by metallised sheet-form textile materials, increases safety, particularly at sea, in the air and in the rescue field.
One particular advantage of the use according to the invention is the lightness in weight and flexibility of the material. It may be attached to uneven surfaces and may be cut to any size. It is so light that the additionally applied material hardly affects the overall weight. It is a novel technique of increasing the reflective power of a non-metallic object for radar beams. The strength of the layer applied by currentless deposition is also higher than would be expected in the case of metal layer applied by vapour deposition. Further it is possible additionally to protect the metal layer by another protective layer applied for example by lacquering, lamination or coating. The reflective power is very high over a range of from 0.02 to 1000 GHz, i.e. over a considerably wider range than simply the "classical" radar range.
The sheet-form textile material may consist of cotton, polyacrylonitrile, polyamide, aramide, polyester, viscose, modacrylics, polyolefin, polyurethane, PVC either individually or in combination with one another. The metal layer applied by currentless deposition preferably consists of nickel, cobalt, copper, silver, gold, even in combinations or as an alloy.
The mesh width or crossing points of the weft and warp filaments of woven fabrics should be smaller than half the wavelength of the radiation to be reflected. It is preferred to use a sheet-form textile material of which the mesh width does not exceed one tenth of the wavelength. The reflection level is also governed by the form of the textile construction. Accordingly, an isotropic textile construction will be selected if the reflection is intended to be isotropic. Alternatively, it is possible, by applying tension, to obtain a looser, wider-mesh sheet-form textile material so that the microwave beams are partly polarised after reflection if the incident radiation is unpolarised or, where the incident radiation is linearly polarised, reflection is particularly high when the mechanical tension and the vector of the electrical field strenth are vertically superposed on one another.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of two crossing fibers metallised according to the present invention;
FIG. 2 is a schematic representation of parallel running filiments of a fiber thread metallised according to the present invention;
FIG. 3 is a schematic representation of one embodiment of a system using mechanically stressed fabric, metallised according to the present invention; and
FIG. 4 is a schematic representation of another embodiment of a system using mechanically stressed fabric, metallised according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, a fiber 1 of polyacrylonitrile, polyamide or cotton, etc. has a coating 2 thereon formed by currentless wet chemical deposition. The coating 2 has a thickness of 0.02 to 2.5 μm and is substantially equally thick around the fiber. Between the fibers there is no agglutination of the fibers.
In FIG. 2, fiber thread 3 includes filaments 4 each coated with a metallised coating 5 by wet chemical currentless deposition. Each filament 4 has the coating 5 therearound, but the filaments 4 and not flued, that is, there is no coalescing.
The invention is illustrated by the following Examples:
EXAMPLE 1
A woven fabric of 100% polyacrylonitrile filament yarn has the following textile construction:
Warp and weft: 238 dtex (effective) of dtex 220 f 96 Z 150, 38.5 warp filaments/cm and 27 weft filaments/cm;
Weave: twill 2/2;
weight: 155 g/m 2 .
It is immersed at room temperature in a hydrochloric acid bath (pH≦1) of a colloidal palladium solution according to German Auslegeschrift No. 1,197,720. After a residence time in the bath of up to about 2 minutes, during which it is gently moved, the fabric is removed and washed with water at room temperature. It is then immersed for about 1.5 minutes in a 5% sodium hydroxide solution at room temperature. The fabric is then washed with water at room temperature for about 30 seconds and subsequently introduced at room temperature into a solution consisting of 0.2 mole/l of nickel-II-chloride, 0.9 mole/l of ammonium hydroxide, 0.2 mole/l of sodium hypophosphite, into which ammonia is introduced in such a quantity that the pH-value at 20° C. is approximately 9.4. After only 10 seconds, the fabric begins to darken in colour through the deposition of nickel. After 20 seconds, the fabric floats to the top, giving off hydrogen gas, and even at this stage is completely covered with nickel. The material is left in the metal salt bath for about 20 minutes, removed, washed and dried.
During these 20 minutes, the material (dry weight 7.2 g) takes up about 3.1 g, i.e. approximately 40% by weight, of nickel metal. The rapid activatability and the high deposition of metal at room temperature are surprising. The nickel layer thickness on the fibre surface amounts to 0.77 μm .
Various sheet-form textile materials thickly coated with nickel were produced by the above-described process and the reflection losses between 2 and 25 GHz measured. The measuring process used is described for example in "Mikrowellenmeβtechnik" by H. Groll, F. Vieweg & Sohn, Brunswick, 1969, pages 353 et seq. The reflection loss is expressed in dB. To eliminate the effect of standing waves in the region before the object to be measured (interfacial reflection), a wide-band frequency-modulated radiation of constant power, for example 1.9 to 2.4 GHz, 7 to 8 GHz, is used.
______________________________________Nickel LayerThickness in Frequency range in GHzμm 1.9-2.4 7-8 11-12 22-24.8______________________________________0.08 2.9 2.6 2.2 3.20.10 2.4 2.4 2.2 2.70.13 1.9 2.0 2.0 2.90.19 1.3 1.5 1.5 2.10.29 1.1 1.4 1.4 1.90.38 1.0 1.3 1.3 1.80.79 0.7 1.1 0.9 2.3______________________________________
EXAMPLE 2
Reflection losses in dB on metallised sheet-form textile materials for oblique incidence:
The sheet-form textile materials used are the same as in Example 1; they are also coated with nickel in the say way as in Example 1. The incidence angle is 30°.
______________________________________Nickel layer Frequency range in GHzthickness in μm 7-8 11-12______________________________________0.08 1.0 1.20.10 1.5 1.10.13 1.1 1.00.19 0.4 0.40.29 0.4 0.40.38 0.1 0.1______________________________________
EXAMPLE 3
A coarse fabric woven from spun polyacrylonitrile fibres in linen weave with a large interval separating the crossing points between warp and weft filaments (1.5 mm gap between the two warp and weft filaments; 50.4 warp filaments/10 cm, 42.2 weft filaments/10 cm, L l/l) shows a reduction in reflection power with increasing frequency.
______________________________________Nickel layerthickness in Frequency range in GHzμm 1.7-2.4 7-8 11-12 23-24.5______________________________________0.2 0.7 1.0 1.2 3.20.78 0.3 0.9 1.1 2.4______________________________________
Accordingly, dense fabrics are required for obtaining good reflection at short wavelengths.
EXAMPLE 4
Combination of two metal layers
A sheet-form textile material corresponding to Example 1 is coated as described in that Example with 0.2 μm thick nickel layer. Immediately after washing, it is introduced still wet into a gold cyanide bath at 78° C. The gold bath based on potassium gold cyanide (gold content 4 g/l) is adjusted with ammonia to a pH-value of 10.5. After 20 seconds, a metal film with a gold-like shine has been deposited onto the shining nickel layer. Within 5 minutes, the gold layer thickness on the nickel-coated surface amounts to 0.2 μm. The reflection losses in dB for vertical incidence are as follows:
______________________________________ Frequency range in GHzLayer thickness in μm 1.7-2.4 23-24.5______________________________________0.2 Ni + 0.38 Au 0.3 0.8______________________________________
EXAMPLE 5
The reflection level depends on mechanical tensions as illustrated in FIGS. 3 and 4.
Linearly polarised microwave radiation impinges vertically on a knitted fabric 14 of an acrylonitrile copolymer on which a 0.75 μm thick nickel layer has been deposited. Line II shows the reflection losses in dB when the knitted fabric 14 is not subjected to mechanical tension. Line I shows the losses in the event of tensile stressing (tension direction parallel to the E-vector) by drive 15.
______________________________________ Frequency range in GHz 1.7-2.4 7-8 11-12 23-24.5______________________________________I 0.9 0.8 1.3 3II 2 1.3 2.6 6______________________________________
A periodic variation in the tensile stress leads to a periodic variation in the reflected microwave intensity. In this way, it is possible to considerably increase the recognisability of an object being sought by radar in surroundings which reflect isotropically or at least constantly as a function of time (sea emergency rescue service, friend-foe recognition, etc). Either linearly polarised radiation generated by generator 10' through antenna 12a is used and the variation in intensity of the reflector evaluated by detectors 11', 11" through antennae 12b, 12c as shown in FIG. 4 or circularly polarised radar beams created by generator 10 through circulator 13 and antenna 12 are used as shown in FIG. 3, in which case the reflected signal shows a periodic variation in the ellipticality of the polarisation which may be detected by an analyzer 11 through antenna 12 and circulator 13 at the receiving end.
EXAMPLE 6
A polyethylene paper, i.e. a non-woven material of polyolefin fibres, is provided as described above with a nickel layer applied by currentless deposition. For a 0.4 μm thick nickel layer, the reflection losses in dB are as follows:
______________________________________Frequency range in GHz7-8 11-12______________________________________1.5 0.9______________________________________
This metallised sheet-form textile material is particularly suitable for use as a recognition material, for example in the form of a cross for searching helicopters. By virtue of its light weight, it may be conveniently be taken on expeditions.
EXAMPLE 7
A blended polyester/cotton fabric consisting of 65% by weight of polyester staple fibres based on polyethylene terephthalate and 35% by weight of cotton shows the following reflection losses in dB for a 0.7 μm thick nickel layer:
______________________________________Frequency range in GHz1.7-2.4 7-8 11-12______________________________________0.7 0.7 0.7______________________________________
This metallised material is suitable for tents, rucksacks or articles of clothing for skiers and walkers. The weight of the fabric is only negligibly increased by metallisation; it does not lose any of its textile-elastic properties. It it is coated with a layer of flexible PVC to make it rainproof, it may additionally be provided with warning colours. Persons carrying rucksacks or wearing articles of clothing such as these can be located by radar should they lose their way in desert regions or in the tundra.
EXAMPLE 8
A balloon fabric, for example of a woven polyester filament yarn fabric or woven nylon-6,6 fabric, is coated with an approximately 0.7 μm thick nickel layer applied by currentless deposition. In addition, it is given a protective coating of PVC, rubber or polyurethane lacquer. This subsequent lamination does not affect the reflective power of the sheet-form material. Line I shows the reflection losses in dB of this fabric when it is only coated with a 0.7 μm thick nickel layer. Line II shows the losses with an additional rubber coating.
______________________________________ Frequency range in GHz 1.9-2.4 7-8 11-12 22-24.5______________________________________I 0.6 1.2 0.7 1.6II 0.7 1.2 0.8 1.6______________________________________
A free balloon made of a material such as this may readily be located by the on-board radar of a commercial aircraft.
In the construction of gliders, the fabric may also be embedded as the last layer in polyester resin which increases the radar locatability of gliders.
EXAMPLE 9
The use of metallised laminated fabrics in the rescue field is in accordance with the following
A woven polyamide or polyester filament yarn fabric is provided with an approximately 0.65 μm thick nickel layer. Line I of the following Table shows the reflection losses in dB. Lamination with a PVC-coating (line II) or with a polyethylene coating (line III) hardly affects the reflective power of the metallised fabric.
______________________________________ Frequecy rage in GHz 1.8-2.4 7-8 11-12______________________________________I 0.5 0.8 0.8II 0.5 0.5 0.8III 0.5 0.5 0.9______________________________________
Life jackets may advantageously be produced from this metallised fabric and may additionally be coated with the prescribed warning paint RAL 2002. The fabric may also be used on rescue islands. When the fabric is applied to the mast tops of sailing boats, the boats are easier to locate by radar without being made top-heavy.
Another advantage of the metallised sheet-form materials is that they may be electrically heated.
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Metallized sheet-form textile materials of synthetic polymers or natural fibres, to which a metal layer has been applied by currentless wet-chemical deposition, are particularly suitable for use as reflectors for electromagnetic waves in the range from 10 MHz to 1000 GHz. In the case of stretched metallized fabrics, the reflecting radiation is partly polarized which can facilitate or improve the recognition of an object by radar beams. By periodically stretching and relaxing the fabric, it is even possible to modulate the reflected microwaves.
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FIELD OF THE INVENTION
The present invention relates to a fuel injector.
BACKGROUND INFORMATION
U.S. Pat. No. 4,766,405 describes a fuel injector having a valve closing body connected to a valve needle and working together with a valve seat face designed on a valve seat body to form a sealing seat. For electromagnetic operation of the fuel injector, a solenoid works together with an armature connected in a friction-locked manner to the valve needle. An additional mass is provided in the form of a cylinder around the armature and the valve needle and is connected to the armature by an elastomer layer. One disadvantage is the complicated design featuring an additional component. The large-area elastomer ring is also a disadvantage for the variation of the magnetic field and makes it difficult for the field lines to close and thus interferes with achieving high attraction forces in the opening movement of the fuel injector.
U.S. Pat. No. 4,766,405 also describes an embodiment of a fuel injector; a cylindrical mass which is movably held and secured in position by two elastomer rings is provided around the armature and the valve needle for damping and reducing rebound. When the valve needle strikes the valve seat, this second mass can move relative to the armature and the valve needle and prevent rebounding of the valve needle. One disadvantage of the embodiment described there is the additional complexity and space required. The armature itself is not isolated and its momentum thus increases the tendency of the valve needle to rebound.
U.S. Pat. No. 5,299,776 describes a fuel injector having a valve needle and an armature which is movably guided on the valve needle and whose movement is limited by a first stop in the stroke direction of the valve needle and by a second stop against the stroke direction. Within certain limits, the axial movement play of the armature defined by the two stops results in isolation of the inert mass of the valve needle from the inert mass of the armature. This counteracts within certain limits the rebound of the valve needle from the valve seat face in closing of the fuel injector. However, since the axial position of the armature with respect to the valve needle is completely undefined due to the free mobility of the armature with respect to the valve needle, rebound pulses are prevented only to a limited extent. In particular, the design of the fuel injector known from U.S. Pat. No. 5,299,776 does not prevent the armature from striking the stop facing the valve closing body in the closing movement of the fuel injector and transmitting its momentum abruptly to the valve needle. This abrupt transfer of momentum can cause additional rebound pulses of the valve closing body.
It is also known from practice that the armature guided on the valve needle can be movably secured in its position by an elastomer ring. To do so, the armature is held between two stops, with an elastomer ring located between the armature and the bottom stop. However, then the problem arises that a bore through the armature is necessary to supply fuel to the valve seat face. The bore through the armature is provided close to the valve needle, and the valve seat side end of the bore is partially covered by the elastomer ring. This results in irregular pressure on the elastomer ring and finally the bore edges result in the destruction of the elastomer ring due to edge pressure. Furthermore, the vibrations are induced in the unsupported elastomer ring, which also contributes to destruction by the bore edges. This occurs especially at low temperatures, when the elastomer enters a rigid vitreous state.
SUMMARY OF THE INVENTION
The fuel injector according to the present invention has the advantage over the related art that the elastomer ring is supported axially over its full surface. Thus, there cannot be any edge pressure on the elastomer ring. This improves the long-term stability of the elastomer ring.
This is achieved in that the fuel injector has a flat supporting ring between the elastomer ring and the armature, supporting the elastomer ring axially over its entire surface and thus also in the area of the fuel channel.
This is achieved in that the longitudinal axis of the fuel channel is inclined to the longitudinal axis of the armnature so that the fuel channel opens radially outside the elastomer ring. In this way, the elastomer ring is also supported over its entire surface on an end face of the armature. In this embodiment, no vibration is induced in the elastomer ring by fuel flowing past it.
The supporting ring may advantageously have an integrally molded shoulder. Therefore, the elastomer ring is also supported radially and is protected from vibration induced by the fuel flowing past it. Accordingly, the end face of the armature may have a projection which provides radial protection.
A conventional inexpensive O ring may be used to advantage as the elastomer ring.
The elastomer ring may be made of an elastomer having a high internal damping and a great low-temperature elasticity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an axial section through a generic fuel injector.
FIG. 2 shows a detail of a first embodiment of a fuel injector according to the present invention.
FIG. 3 shows a detail of a second embodiment of a fuel injector according to the present invention in a partially cutaway diagram.
FIG. 4 shows a detail IV from FIG. 2 on an enlarged scale.
FIG. 5 shows a detail V from FIG. 2 on an enlarged scale in a modified form.
FIG. 6 shows a detail VI from FIG. 3 on an enlarged scale.
DETAILED DESCRIPTION
FIG. 1 shows a detail of a generic fuel injector 1 in a sectional diagram to better explain the present invention. Fuel injector 1 injects fuel into an internal combustion engine having fuel mixture compression and spark ignition. The embodiment illustrated here is a high pressure fuel injector opening inward for direct injection of fuel into the combustion chamber of the internal combustion engine.
Fuel injector 1 has a valve closing body 3 which is connected in one piece to a valve needle 2 in this embodiment and works together with a valve seat face designed on a valve seat body 4 to form a sealing seat. Valve seat body 4 is connected to a tubular valve seat carrier 5 which can be inserted into a receiving bore of a cylinder head of the internal combustion engine and is sealed with respect to the receiving bore by a gasket 6 . On its inlet end 7 , valve seat carrier 5 is inserted into a longitudinal bore 8 of a housing body 9 and is sealed with respect to the housing body 9 by a sealing ring 10 . Inlet end 7 of valve seat carrier 5 is under pre-tension by a threaded ring 11 , with a lift adjusting disk 14 clamped between a step 12 of housing body 9 and an end face 13 of inlet end 7 of valve seat carrier 5 .
A solenoid 15 wound onto a coil frame 16 is used for electromagnetic actuation of fuel injector 1 . When solenoid 15 is electrically energized, an armature 17 is pulled upward until its end face 19 on the inlet end is in contact with a step 18 of housing body 9 . The gap width between the upstream end face 19 of armature 17 and step 18 of housing body 9 determines the valve lift of fuel injector 1 . In its stroke movement, armature 17 entrains valve needle 2 which is connected to first stop body 20 and valve closing body 3 which is connected to valve needle 2 because of the contact of its upstream end face 19 with a first stop 21 provided on a first stop body 20 . Valve needle 2 is welded to first stop body 20 by a weld 22 . Valve needle 2 moves against a restoring spring 23 which is secured between an adjusting sleeve 24 and first stop body 20 .
Fuel flows through an axial bore 30 of housing body 9 and at least one fuel channel 31 , which is provided in armature 17 and is designed here as an axial bore, as well as through axial bores 33 provided in a guide disk 32 , into an axial bore 34 of valve seat carrier 5 and from there to the sealing seat (not shown) of fuel injector 1 .
Armature 17 is movable between first stop 21 of first stop body 20 and a second stop 26 designed on a second stop body 25 , with armature 17 in this embodiment being held in contact with first stop 21 by a bearing spring 27 in the resting position, so that a gap is formed between armature 17 and second stop 26 , thus permitting a certain movement play of armature 17 . Second stop body 25 is secured on valve needle 2 by a weld 28 .
Due to the movement play of armature 17 between stops 21 and 26 , isolation between the inert masses of armature 17 and valve needle 2 with valve closing body 3 is achieved. Therefore, in the closing movement of fuel injector 1 , only the inert mass of valve closing body 3 and valve needle 2 strikes against the valve seat face, in which case armature 17 is not decelerated abruptly when valve closing body 3 strikes the valve seat face, but instead it moves further in the direction of second stop 26 . The isolation of armature 17 from valve needle 2 improves the dynamics of fuel injector 1 . However, end face 29 of armature 17 on the spray end striking second stop 26 does not cause any valve rebound. This is achieved through an elastomer ring 35 shown in FIG. 2 between second stop body 25 and armature 17 . Bearing spring 27 may optionally also be eliminated because of the damping by elastomer ring 35 .
FIG. 2 shows a detail of armature 17 with valve needle 2 of a fuel injector according to the present invention; elements that have already been described are shown with the same reference numbers to facilitate a correlation.
The drawing shows armature 17 of fuel injector 1 according to the present invention having fuel channel 31 , valve needle 2 , second stop body 25 welded onto valve needle 2 by weld 28 and second stop 26 , as well as end face 29 opposite second stop 26 . Valve needle 2 is welded to first stop body 20 by weld 22 .
FIG. 4 shows an embodiment according to the present invention as illustrated in detail IV from FIG. 2 on an enlarged scale. Between end face 19 of armature 17 and second stop 26 there is an elastomer ring 35 , a flat supporting ring 36 between elastomer ring 35 and armature 17 supporting elastomer ring 35 over its entire area, i.e., in particular also in the area of fuel channel 31 , and thus preventing edge pressure at the edge of fuel channel 31 .
FIG. 5 shows an alternative embodiment according to the present invention as illustrated in detail V from FIG. 2 on an enlarged scale. Between end face 19 of armature 17 and second stop 26 there is an elastomer ring 35 , designed as an O ring 37 in this embodiment. This O ring 37 is supported by flat supporting ring 36 over its entire area, i.e., also in the area of fuel channel 31 in particular, flat supporting ring 36 also supporting O ring 37 radially by an integrally molded, axially angled shoulder 39 . Thus a commercially available component such as O ring 37 can be inexpensively used. Inducement of vibration in O ring 37 by fuel passing by it is prevented by the larger coverage of O ring 37 , which also extends laterally. This counteracts destruction of elastomer ring 35 due to the edge pressure on fuel channel 31 and due to inducement of vibration.
In particular due to the radial support of O ring 37 , use of an elastomer with a greater internal damping is possible. High damping by an elastomer is usually also associated with a low elasticity modulus. Since O ring 37 is protected against the forces mentioned above which shorten the lifetime of an O ring 37 , such an elastomer may be used for O ring 37 without having a negative effect on the service life of O ring 37 .
A low elasticity modulus of an elastomer at low temperatures usually results in an even greater sensitivity to edge pressure and inducement of vibration at the operating temperature. Therefore, in the embodiment described here as an example, it is also possible to achieve a great low-temperature elasticity of O ring 37 and thus favorable operating performance of fuel injector 1 at low temperatures, e.g., after a cold start of the engine.
FIG. 3 shows an enlarged detail of armature 17 and valve needle 2 of a fuel injector 1 according to another embodiment of the present invention.
FIG. 3 shows armature 17 of fuel injector 1 according to the present invention, valve needle 2 , second stop body 25 welded by weld 28 onto valve needle 2 and having a second stop 26 , and end face 29 of armature 17 opposite second stop 26 . Valve needle 2 is welded by weld 22 to first stop body 20 . The at least one fuel channel 31 opens radially outside of elastomer ring 35 because it is inclined with respect to the axis of valve needle 2 .
Elastomer ring 35 which is designed as O ring 37 is shown in FIG. 6 with its area facing the environment according to detail VI from FIG. 3 in an enlarged view. In the embodiment illustrated here, fuel channel 31 opens into a tangential groove 36 which accommodates bearing spring 27 . This embodiment is especially advantageous because there is no inducement of vibration of O ring 37 by fuel flowing past it, and no enlargement of the diameter of armature 17 is necessary due to the inclination of fuel channel 31 to the axis of valve needle 2 .
In the embodiment illustrated in FIG. 6, end face 29 of armature 17 has a projection 40 . Due to the fact that O ring 37 is also covered laterally, it is possible to use an elastomer having a high internal damping and therefore a relatively low elastic modulus without any negative effect on its service life. The fact that O ring 37 is also supported radially prevents it from swelling forward and thus prevents the destruction of O ring 37 by compressive forces.
It is thus also possible to achieve a great low-temperature elasticity of O ring 37 without causing a shortened service life at the operating temperature of fuel injector 1 .
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A fuel injector for fuel injection systems of internal combustion engines, having a valve needle which works together with a valve seat face to form a sealing seat, has an armature acting on the valve needle. The armature is movably guided on the valve needle and is damped by an elastomer ring made of an elastomer. The armature has at least one fuel channel for supplying fuel to the sealing seat. A flat supporting ring which axially supports the elastomer ring in the area of the outlet end of the fuel channel is arranged between the elastomer ring and the armature.
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This application is a continuation of application Ser. No. 07/284,331, filed on Dec. 14, 1988, now abandoned.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to Ser. No. 07/284,368 filed on Dec. 14, 1988 concurrently herewith entitled HUMAN LIVER EPITHELIAL CELL LINE, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The culture of hepatocytes represents a valuable approach for studying specific mechanisms of xenobiotic metabolism, chemical carcinogenesis, as well as pathology related to inherent or induced metabolic or biochemical abnormalities. Cultures of human hepatocytes can provide a more relevant view of human liver metabolism and disease processes than data obtained from hepatocyte cultures derived from other animal species.
Several problems have hindered in vitro studies of human hepatocytes. One problem is the availability of viable, normal adult human liver. In the past several years we have been involved with the development of an immediate autopsy program which has allowed us to obtain adult human liver tissue within 1 hr following death from patients free of liver disease.
Another problem associated with culture of human hepatocytes, as with most differentiated cells, is that these cells rarely divide in culture. By modifying a serum-free culture medium that was shown to support longterm multiplication of liver epithelial cells from Rhesus monkeys, we have developed replicative cultures of adult human liver cells. However, as with all normal cells, these liver epithelial cells eventually undergo senescence in culture.
The present invention is related to serum-less culture medium (denatured serum) for growth of continuous and non-continuous cell lines. More particularly the present invention is related to culture medium for liver epithelial cells with extended life spans.
The human liver is one of the few organs in adult man capable of regeneration. However, cultures of adult hepatocytes have never been adequately established. Those that have been established are only viable for a limited period of time and are produced in insufficient quantities for research in pharmacology, chemotherapy or oncogenesis.
There are several examples of animal liver cell cultures derived from experimental laboratory animals such as rats (Tsao et. al., Exp. Cell Res. 154: 38-52 (1984); Enat et al., "Proc. Nat. Acad. Sci. USA" 87: 1411-1415 (1984)) but these are not suitable for long term studies due to the limited life span of the culture.
Rat liver cells have been transformed by transfection with SV40 DNA (Woodworth et al, Cancer Res. 46: 4018-4026 (1987); Ledley et al., "Proc. Nat. Acad. Sci. USA" 84: 5335-5339 (1987)) but they are not suitable for human drug metabolism or carcinogenesis studies because of xenobiotic metabolism differences between rat and human liver cells. Further Woodworth reports that immortalized cell lines did not arise spontaneously. Woodworth points out that exposure to hormones and mitogenic factors, in particular EGF, insulin and glucogan, serum factors and virus infection stimulate hepatocyte DNA synthesis.
Clonally-derived cultures of human hepatocytes have been reported (Kaighn and Prince, Proc. Nat. Acad. Sci., 68, 2396-2400 (1971)), but no new data has been generated to support or refute these observations. In addition the medium used contained 17% serum. Several studies have shown that serum (Hashi and Cart J. Cell Physiol., 125, 82-90 (1985)), and more specifically transforming growth factor-beta (TGF-β) present in serum (Nakaruma et al., Biochem Biophys Res Commu., 133 1042-50 (1985); Lin et al., Biochem. Biophys. Res. Commu., 143, 26-30 (1987); and Strain et al., Biochem. Biophys. Res. Commu., 145, 436-442 (1987)) cause a marked decrease in DNA synthesis of rat hepatocytes in culture.
Rat liver epithelial cells from adult rat liver tissue have been established using serum free medium (Chessebeuf and Padieu In Vitro, 20, 780-795 (1984); Enat et al. Proc. Natl. Acad. Sci., 81, 1411-1415, (1984)).
Human hepatoma cell lines have been cultured and are available (e.g. Knowles et al., U.S. Pat. No. 4,393,133, Jul. 12, 1983, Human Hepatoma Derived Cell Line) but, are not usable in carcinogenesis studies because they are tumorigenic. They were also cultured in medium containing serum.
As is known in the art, the field of tissue culture medium is empirical in nature, and there is little or no predictability as to whether conditions developed for one species will be operable in another.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an improved aqueous culture medium to produce a normal human liver epithelial cell line that is prolific, enduring and has an unlimited life span in culture. As a result, it has been found that a suitable basic culture medium which provides nutrients may be modified with the addition of insulin, epithelial growth factor (EGF), hydrocortisone, transferrin, cholera toxin, aqueous bovine pituitary extract (Lechner, J. and Laveck, M. J., J. Tissue Cult. Method 9, 43-48 (1985)), denatured serum and HepG2 conditioned medium (Hoshi, H. and McKeehan, W. L. In Vitro Cell Dev. Biol., 21:125-128 (1985)) accomplishes the intended result. The medium described herein contains chemically denatured serum that contains no active TGF-β.
It is a further object of the invention to produce a cell culture medium containing ornithine, fatty acids, insulin, EGF, hydrocortisone, transferrin, cholera toxin, aqueous pituitary extract and denatured serum added to commercially available PFMR4 medium (without arginine), conditioned with medium from HepG2 hepatoma cells for liver cell lines which can be used in experiments that require large numbers of homogenous (identical and cloned) cells for: drug metabolism studies; evaluating chemical compounds which require liver metabolism for functional activation; chemical carcinogenesis studies with the potential for screening compounds with human carcinogenic and or tumor promoting potential; investigation of controls of differentiation for possible use with anti-liver cancer drugs which act by inducing terminal differentiation; growth of Hepatitis virus in replicating hepatocytes; growth of human parasites; and transfection of additional oncogenes to evaluate their effect on these cells.
It is a further object of the invention to provide a culture medium for an "continuous" cell line, i.e. that grow continually without senescence when cultured in vitro in a suitable medium. These and other objects, features and advantages of the invention will be better understood upon a reading of the following detailed description of the invention.
The above objects of the invention have been substantially achieved by the development of an improved serum free culture medium. The culture medium is prepared using the basal medium PFMR4 (described in Lechner et al. Methods in Cell Biol., 21, 195 (1980)) with arginine, calcium, glutamine, trace elements and iron not included.
The mammalian cell culture medium of the present invention may contain an effective cell growth promoting amount of calcium ions; an effective cell growth promoting amount of glucose; an effective amount of insulin to aid cells in glucose uptake; an effective cell growth promoting amount of hydrocortisone; an effective amount of epidermal growth factor to bind to epidermal growth factor receptors on cells; an effective amount of transferrin to increase DNA synthesis in cells; an effective amount of cholera toxin to increase DNA synthesis in cells; an effective amount of triiodothyronine to increase DNA synthesis in cells; and an effective growth promoting amount of mammalian hormones.
In a more preferred embodiment of the invention the mammalian cell culturing medium contains an effective cell growth promoting amount of the essential amino acids; an effective cell growth promoting amount of water soluble vitamins; an effective cell growth promoting amount of coenzymes; an effective cell growth promoting amount of sodium ions; an effective cell growth promoting amount of calcium ions; an effective cell growth promoting amount of glucose; an effective amount of insulin to aid cells in glucose uptake; an effective cell growth promoting amount of hydrocortisone; an effective amount of epidermal growth factor to bind epidermal growth factor receptors on cells; an effective amount of transferrin to increase DNA synthesis in cells; an effective amount of cholera toxin to increase DNA synthesis in cells; an effective amount of triiodothyronine to increase DNA synthesis in cells; an effective amount of retinoic acid to increase DNA synthesis in cells; and an effective growth promoting amount of mammalian hormones.
In a most preferred embodiment of the invention the cell culturing medium is an aqueous cell culturing medium suitable for culturing normal adult human liver epithelial cells which contains water; an effective cell growth promoting amount of all of the essential amino acids; an effective cell growth promoting amount of water soluble vitamins; an effective cell growth promoting amount of coenzymes; an effective cell growth promoting amount of sodium ions; an effective amount of calcium ions high enough to promote cell growth but low enough to avoid cellular differentiation; an effective cell growth promoting amount of glucose; insulin in an amount of 1 to 10 μg/ml; hydrocortisone in an amount of 0.05 to 1 μM; epidermal growth factor in an amount of 1 to 25 ng/ml; transferrin in an amount of 1 to 10 μg/ml; cholera toxin in an amount of 5 to 50 ng/ml; triiodothyronine in an amount of 1 to 100 nM; retinoic acid in an amount of 1 to 300 nM; an effective amount of a mammalian pituitary extract to provide hormones necessary for culturing normal adult human liver epithelial cells; an effective cell growth promoting amount of conditioned medium derived from HepG2 hepatoblastoma cells or a mutant thereof; and an effective amount of a buffer to maintain the pH between 6.7 and 7.6.
The glucose is a energy source for the cells and is preferably present in an amount of 0.5 to 0.5 mg/ml. Insulin should also be included in an amount sufficient to aid the cells in glucose uptake. This amount is preferably 1 to 10 μg/ml.
The hydrocortisone, cholera toxin and retinoic acid are potentially toxic and therefore should be present in amounts sufficient to achieve their desired effects, but low enough not to inhibit cell growth due to the inherent toxicity of these materials.
The epidermal growth factor, transferrin, cholera toxin, triiodothyronine, retinoic acid and bovine pituitary extract aid DNA synthesis. Mitogenic factors should be present in an amount sufficient to aid DNA synthesis.
The pH of the culturing medium may be adjusted to achieve an optimal effect depending on the cell line to be cultured. The pH is usually between 6.7 and 7.6, preferably 7.0 and 7.4, more preferably 7.1 to 7.3, and most preferably about 7.2.
The bovine pituitary extract is present in an amount sufficient to provide the necessary hormones for cell growth. The bovine pituitary extract may be present in an amount of 0.75 to 75 μg/ml.
The culture medium should contain a source of an aqueous mixture of lipoprotein, cholesterol, phospholipids and fatty acids with low endotoxin. A suitable source of these ingredients is EX-CYTE® V sold by Miles Inc., Miles Diagnostics.
The Ex-cyte products including V have the following characteristics:
Animal virus and mycoplasma free.
Certification of freedom from animal viruses and mycoplasma available.
All components heat-treated equivalent to 10 hr. at 60° C.
Contains no IgG or IgM.
Water soluble.
Low level of endotoxin.
Stable for years at -20 degrees C. EX-CYTE® products are unique aqueous (or water soluble) lipoprotein fractions that cause the modulation of cell membrane proteins. They are a mixture of lipoprotein cholesterol, phospholipids, and fatty acids and consequently are a source of lipids the cells can use to design membrane structure and optimize surface protein positioning. Idealized protein orientation can enhance membrane receptor accessibility and permeability of solutes. In addition, by supplying the cells with the preformed cholesterol and phospholipids, the cells need not biosynthesize the lipids from base ingredients such as exogenous fatty acids. Fortification with the transport proteins, albumin and transferrin, provides cells with many of the factors required for growth with basal media. The fatty acids are an energy source for liver cells for DNA synthesis when the cells start to divide.
The Ex-cyte products have the following general composition:
TABLE III______________________________________CHARACTERISTICS______________________________________Lipoprotein Profile of EX-CYTE HumanBovine Trigly-Cholesterol Triglycerides Cholesterol cerides(mg/mL) (mg/mL) (mg/mL) (mg/mL)______________________________________Total: 9.48 0.05 5.24 2.87VLDL: 0 0 0.40 1.07LDL: 3.36 0.03 4.80 1.78HDL: 6.12 0.02 0.04 0.02______________________________________Phospholipid Profile of EX-CYTE Bovine Human______________________________________Total Phospholipids, mg/mL 10.53 5.54Phosphatidyl Choline, mg/mL 7.15 2.49Lysophosphatidyl Choline, mg/mL 0.93 0.69Sphingomyelin, mg/mL 2.34 2.36Phosphatidyl Ethanolamine, mg/mL 0.02 0Total Cholesterol, mg/mL 9.48 5.24Cholesterol, Phospholipid Ratio 0.90 0.95______________________________________Free Fatty Acid Analysis of EX-CYTE Bovine______________________________________Total Cholesterol 15.2 mg/mL______________________________________ Approx. Conc. μg fatty acid/Fatty Acid μg/ml mg cholesterol______________________________________Linoleic, C 18:2 546 35.9Palmitic, C 16 233 15.3Oleic, C 18:1 156 10.3Stearic, C 18 348 22.9______________________________________
The EX-CYTE should be present in an amount of 100 to 1500 μg/ml, preferably 150 to 500 μg/ml, most preferably about 312 μg/ml.
A broad spectrum antibiotic such as gentamicin and antimycotic agents may be included in the culture medium to prevent bacterial, yeast, fungal or other contamination.
Normal human adult liver cells are cultured at a density sufficient to allow cell growth. Typical concentrations are 5×10 1 to 1×10 4 cells/cm 2 of surface area of the cell culture container, preferably 5×10 2 to 3×10 3 cells/cm 2 , most preferably about 1 3×10 3 cells/cm 2 . The cells are cultivated under moist aerobic conditions at a temperature between 33° to 40° C., preferably about 37° C. The cell culture is passaged as the cells approach confluence on the surface on which they are being cultured. The normal human adult liver cells can be cultured for at least two rounds of DNA synthesis, preferably at least five rounds of DNA synthesis and more preferably at least 10 rounds of DNA synthesis. Transformed cells can be cultured under much less restrictive or controlled conditions.
The present invention is also directed to a method for culturing various types of mammalian cells, including normal adult human liver epithelial cells as well as other types of human cells, which comprises culturing the cells in the above-described culturing medium.
DETAILED DESCRIPTION OF THE INVENTION
The above and other objects and advantages of the present invention are achieved by human liver epithelial cell line continually growing when cultured in vitro in the growth medium. Unless defined otherwise, all technical and scientific terms used herein have the same meanings commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned hereunder are incorporated herein by reference. The term "immortalized" as used herein means that the cell line grows continually without senescence when cultured in vitro in a suitable growth medium.
The successful culturing of liver epithelial cells in the medium of the present invention results from the unexpected finding that ornithine, fatty acids, insulin, EGF, hydrocortisone, transferrin, cholera toxin, aqueous pituitary extract and denatured serum and conditioned with HepG2 medium to provide factors necessary in the successful proliferation of liver cells.
General Method for Preparation of the Basic Medium
Basal PFMR4 medium prepared is as described in Lechner, J. F. et al. Normal human prostate epithelial cell cultures are described in Harris, C. C. , Trump B. F., Stoner G. D. (eds) Methods in Cell Biology, Vol. 21B, Academic Press, New York, pp 195-225.
The basal medium was supplemented with additives previously listed.
ILLUSTRATIVE EXAMPLES OF THE INVENTION
It is, of course, to be understood that the following examples are for purposes of illustration only and that numerous alterations may be made in the components, precise proportions and conditions set forth herein without departing from the spirit of the invention as defined in the appended claims.
EXAMPLE I (PREPARATION OF MEDIUM)
The medium was prepared in three steps. Step 1 was the preparation, by a commercial source of "basic medium" which contains the basic nutrients and some other components. The second step was the addition to the medium of various key ingredients and salts which if included in the "basic medium" when prepared by the commercial source would curtail the shelf life of the product. Therefore step 2 is usually conducted only shortly before the medium is to be used. The third step was the conditioning of the medium on certain cells to extract factors which are essential for the medium.
The medium is formulated in accordance with good laboratory procedure as known in the art.
TABLE I______________________________________1. Basic MediumThe formula is as follows: A custom basal medium PFMR4 (Lechner et al. Methodsin Cell Biol., 21, 195 (1980)) is commercially availablefrom facilities such as Biological Research Faculty &Facility, Inc., Ijamsville, MD 21754. The custom mediumused omitted certain ingredients specified in Lechner,above e.g. arginine (has been taken out of the base mediumbecause fibroblasts present in the original isolationcannot live without arginine and so the culture becomesalmost totally hepatocytes), calcium (has been used atdifferent concentrations so it is not added into theoriginal medium), glutamine (left out due to shelf lifedegradation of the glutamine), trace elements and iron(tend to precipitate out of solution after long periods oftime so they are added fresh). The main reason for theomission is to obtain a longer shelf life for the "basicmedium."The custom basal medium contains:______________________________________INGREDIENT mg/liter______________________________________Essential Amino AcidsL-Cystine.2HCl 47.0L-Histidine 41.9L-Isoleucine 7.9L-Leucine 26.2L-Lysine.HCl 73.0L-Methionine 9.0L-Phenylalanine 9.9L-Threonine 23.8L-Tryptophan 4.1L-Tyrosine.2Na.2H.sub.2 O 15.7L-Valine 23.4Nonessential Amino AcidsL-Alanine 17.8L-Asparagine.H.sub. 2 O 30.0Aspartic Acid 26.6Glutamic Acid 29.4L-Glycine 15.0L-Proline 69.1L-Serine 21.0or derivativesAmino Acid DerivativesPutrescine.2HCl 0.32Water Soluble Vitaminsand Coenzymesd-Biotin 0.07Folic Acid 1.32DL-A-Lipoic Acid (Thioctic) 0.21Nicotinamide 0.04D-Pantothenic Acid 0.24Pyridoxine.HCl 0.06Riboflavin 0.04Thiamine.HCl 0.34Vitamin B12 (Cynacobalamine) 1.36Carbohydrate/DerivativesPyruvic Acid 174.0Sodium Acetate 295.6Nucleic Acid DerivativesHypoxanthine 4.1Thymidine 0.7Lipids/DerivativeCholine Chloride 14.0i-Inositol 18.0Bulk Inorganic Ions (Salts)NaCl 5844.0KCl 283.3Na.sub.2 HPO.sub.4 126.4KH.sub.2 PO.sub.4 58.5MgSO.sub.4 19.3MgCl.sub.2.6H.sub.2 O 105.7Inorganic Trace ElementsCuSO.sub.4.5H.sub.2 O 0.002Buffers and IndicatorsNaHCO.sub.3 1176.0HEPES buffer (Made by 7149.0Biofluids)Phenol Red 1.1______________________________________
TABLE II______________________________________2. Additional SubstancesTo the commercial medium the following substances wereadded to bring the final concentration to the indicatedconcentrations:______________________________________Item Amount______________________________________L-glutamine 2 mMinsulin 10 μg/mlhydrocortisone 0.2 μMepidermal growth factor 5.0 ng/mltransferrin 10 μg/mlphosphoethanolamine 0.5 μMcholera toxin 25 ng/mltriiodothyronine 10 nMretinoic acid 10 nMornithine 2 mMCaCl.sub.2 0.4 mMglucose 2.0 mg/mlbovine pituitary extract 7.5 μg/ml"Ex-cyte ® V (Miles 312 μg/mlDiagnostics, Pentex ProductsKankakee, IL)FeSO.sub.4.7H.sub.2 O 2.7 μMZnSO.sub.4.7H.sub.2 O 0.5 μMFactor Free Serum 10%(Van Zoolen et al.,J Cell Phvsiol., 123: 151 (1985))Na.sub.2 SeO.sub.3 3.0 × 10.sup.-8 MMnCl.sub.2.4H.sub.2 O 1.0 nmNa.sub.2 SiO.sub.3.9H.sub.2 O 5.0 × 10.sup.-7 M(NH.sub.4).sub.6 Mo.sub.7 O.sub.24.4H.sub.2 O 1.0 nMNH.sub.4 VO.sub.3 5.0 nMNiSO.sub.4.6H.sub.2 O 0.5 nMSnCl.sub.2.2H.sub.2 O 0.5 nMGentamicin 50 μg/ml______________________________________
Unless otherwise indicates, the quantities may be varied by a factor of 1 log or plus or minus 20% depending on toxic effect of the ingredient at higher levels and minimal requirements for growth; which modifications are considered to be "about" those required to function as does the listed formula.
The Serum free medium (growth-factor-inactivated serum) was prepared as follows: Fetal bovine serum (FBS; Flow Laboratories, Irvine, Scotland) was incubated with 100 mM dithiothreitol (DTT; Boehringer, Mannheim, GFR) for 2 hr at room temperature while stirring, resulting in turbid solution. The suspension was then dialyzed (molecular weight cutoff 8-10 kDa) overnight at 4° C. against a 50-100 fold excess of phosphate-buffered saline without Ca ++ and Mg ++ (PBS; 137 mM NaCl, 2.7 mM KCl, 6.5 mM Na 2 HPO 4 , 1.5 him KH 2 PO 4 , pH 7.4). Subsequently iodoacetamide (Sigma, St. Louis, Mo., USA) was added at 5 g/liter, and the suspension incubated for another 2 hr at room temperature while stirring, followed by dialysis for 2 days against several aliquots of PBS, and an additional day against PBS containing in addition 0.9 mM CaCl 2 and 0.5mM MgCl 2 . Subsequently the SH-FCS was centrifuged at 25,000 g for 30 min at 4° C., and the supernatant again at 100,000 g for 60 min at 4° C. The clear supernatant was sterilized by passage through a Millex-GV 0.22 nm filter (Millipore, Bedford Mass., USA). (Prepared from protocol in Van Zoelen et al J. Cell Physiol., 123, 151-160 (1985)).
The Ex-cyte® used had the following characteristics
______________________________________PENTEX ® EX-CYTE ® V, 50XGrowth Enhancement Media SupplementAlbumin Enriched(Salt Poor)______________________________________PROTEIN 786 mg/g powderBy BiuretCHOLESTEROL (1) 64.3 mg/g powderBy Enzymatic AssaySODIUM CHLORIDE 5.0 mg/gpH (7% Solution) 7.9 mg/gENDOTOXIN LEVEL 0.03 ng/mgBy Limulus Amebocyte LysateMOISTURE Less than 5%By Karl Fischer when packagedSTORAGE -20° C. or belowRECONSTITUTE WITH (2) Pyrogen-free H.sub.2 O or redissolve directly in nutrient medium______________________________________ (1) It has been previously determined that there is approximately a 1:1 ratio of phospholipids and cholesterol in EXCYTE preparations. (2) 625 mg of powder is sufficient for one liter of final nutrient medium containing 40 μg cholesterol/mL and 0.49 mg albumin/mL. Endotoxin leve at working concentration of cholesterol and albumin is 0.02 ng/mL.
The conditioned medium is prepared by placing the HGM medium on medium density monolayer cultures of 1) HepG2 hepatoblastoma cells (American Type Tissue Collection #HB80-65) or 2) Human liver epithelial cells transformed by transfection with SV-40 DNA (NCI/NIH, patent pending) for 72 hours. This conditioned medium is added to normal HGM at a 35% concentration.
EXAMPLE 2 (TRANSFECTED CELLS)
Development of HLC-Cell Line
Normal human hepatocytes were isolated from immediate autopsy tissue from non-cancerous individuals by a 2O combination of perfusion and digestion techniques as described by Hsu et al, In Vitro Cell Develop. Biol., 21:154-160 (1985). The left lobe of the liver was removed from non-cancerous patients within 2 hr of cessation of cardiac function, immersed in ice cold Lebowitz-15 cell medium (L-15) and transported to the site of liver cell isolation.
The hepatocytes were dissociated into cell suspensions by perfusing the liver with a calcium and magnesium free Hank's balanced salt solution containing 0.5 mM EDTA, and 0.05M Hepes at 37° C., at a flow rate of 30-40 ml/min for 15 min.
The perfusate was then changed to a digestion solution containing collagenase (185-200 U/ml) at 37° C. at a flow rate of 30-40 ml/min for 20 min. The dissociated hepatocytes were purified from debris and red blood cells by 3 successive washes with L-15 and filtration through a 10μ nylon filter The hepatocytes were suspended in Waymouth's medium supplemented with 10% fetal bovine serum (FBS), 1 μg/ml insulin and 50 μg/ml gentamicin. The yield estimated counting the cells with a hemocytometer were 1-2×10 7 cells/g of liver tissue. Over 90% of the hepatocytes excluded trypan blue.
Following isolation the cells (hepatocytes) were seeded into T-75 tissue culture flasks (Lux, Miles Scientific. Naperville, Ill.) whose surfaces had been coated with collagen (Michalopoulos, G. and Pitot, H. Exp Cell Res., 94:70-73 (1975) (Flow Lab, Rockville, Md.) at 3-5×10 5 cells/flask using Waymouth's cell medium with insulin (1 μg/ml), gentamicin (50 μg/ml), and fetal bovine serum (10%).
Twenty-four hours after initial seeding, the medium was changed to serum-free medium HGM (Hepatocyte Growth Medium) PFMR4 described below. The medium made without arginine and supplemented with ornithine (2 mM), insulin (10 μg/ml), hydrocortisone (0.2 μM), epidermal growth factor (5 ng/ml), transferrin (10 μg/ml), phosphoethanolamine (0.5 μM), cholera toxin (25 ng/ml), triiodothyronine (10 nM), bovine pituitary extract (7.5 μg/ml) and factor-free serum (10%). Additionally, this medium was supplemented (35%) with conditioned medium obtained by placing medium described above in contact with high density cultures of human hepatoblastoma cell line (HepG2) for 72 hrs.
Forty-eight hours after the original isolation and 3 hours prior to transfection the cells were fed with 10 ml of LHC-9 cell medium (Lechner, J. F. and Laveck, M. A. Tissue Cult. Method, 9:43-48 (1985). The cells were transfected with a plasmid pRSV-T (obtained from NCI), which contained SV40 ori-construction containing the SV40 early region genes and the Rous sarcoma virus long terminal repeat (LTR). Transfection was accomplished by using the strontium phosphate co-precipitation method described by Brash, D. et al, Molec. Cell Biol., 7:2031-2034 (1987).
3-5×10 5 cells/flask (T-75 cm) were transfected with 10 μg of DNA precipitate at pH 7.8. After two hours of exposure, the hepatocytes were rinsed twice with serum-free cell medium at 37° C. prior to glycerol shock (15% glycerol for 3 minutes).
Two weeks following transfection, the cells were passaged. Thereafter, upon confluence the cells were passaged twice more. The appearance of transformed colonies occurred 6-8 weeks following original transfection in passage 3 at a frequency of 1×10 -4 . The transformed colonies primarily contained epithelial looking cells, however, the morphology of cells in the foci was variable, some cells having a fibroblastic appearance.
Attempts to clone single cells or loci from the original cultures resulted in death of the cells within 2-3 days. Thereafter, the flasks were serially passaged. The first two passages following foci appearance were passaged using the collagenase/Dispase solution used for original isolation due to the extreme sensitivity of the cells to trypsin. The remaining passages were done with a PVP-trypsin-EGTA solution. With increasing passage, the cells became more homogeneous, and at the 5th passage following transfection, virtually 100% of the cells expressed SV40 large T antigen.
With increasing passage the cells became more homogenous and at passage 8 virtually all the cells expressed SV40 large T antigen (as determined by indirect immunofluorescence), as well as cytokeratin 18 (a cytokeratin known to be expressed in normal human hepatocytes (Moll, R. W. et al, Cell, 31:11-24 (1982)).
All subsequent culture of the liver epithelial cells was in HGM, and these cells continued to proliferate for about 14 weeks at which time the culture senesced (i.e., entered crisis). Currently, 3 months after the cells entered crisis, colonies of dividing cells are present but have not been characterized.
To establish the expression of SV40 large T antigen cells from passage 3 were grown on culture chamber slides and using indirect immunofluorescence, the culture was found to contain approximately 30% T antigen positive cells. By passage 5, the transformed liver cells were found to be uniformly positive for T antigen as determined by immunofluorescence. T antigen expression was maintained throughout subsequent culturing.
To establish that these transformed liver cells were epithelial, cells from early and late passages were examined for keratin expression using a general cytokeratin primary antibody and a fluorescent secondary antibody and found to be uniformly positive in both early (p.3) and late (p.11) passages.
Further examination using monoclonal antibodies against cytokeratin 18 and 19 was performed. At early and late passage the liver cells were positive for cytokeratin 18 but negative for cytokeratin 19. However, in late passages (p.10 and 11) some cells became positive for cytokeratin 19 as well as 18.
We examined the transformed liver epithelial cells for the production of proteins that are expressed by normal hepatocytes. The transformed cells were analyzed using fluorescent immunocytochemistry for expression of albumin, alpha 1 antitrypsin and alpha 2 macroglobulin. Albumin was detected in several colonies on the slide. Overall, approximately 20% of the cells taken from passage 9 were positive for albumin expression. When the cells were exposed to serum containing medium for 48 hrs prior to staining, more cells were positive for albumin expression (30-40%) .
Materials used in this example include Dispase (0.5 U/mg) obtained from Boehringer Mannheim (Indianapolis, Ind.), collagenase (156 U/mg) from Worthington Biochemical Corp. (Freehold, N.J.) and standard tissue culture media and components from Biofluids Inc. (Rockville, Md.). Epidermal growth factor from Collaborative Research Inc. (Bedford, Mass.). Trypsin inhibitor, DNase and chemicals from Sigma Chemical Co. (St. Louis, Mo.) PFMR4 cell culture medium and factor free serum were prepared by Biological Research Faculty and facility (Ijamsville, Md.). Ex-cyte V® (Miles Laboratories, Diagnostics Division) a bovine lipoprotein, was used as a source of lipoprotein cholesterol, phospholipids and fatty acids with low endotoxin.
Serum free medium (growth-factor-inactivated serum) was prepared as follows: Fetal calf serum (FCS; Flow Laboratories, Irvine, Scotland) was incubated with 100mM dithiothreitol (DTT; Boehringer, Mannheim, GFR) for 2 hr at room temperature while stirring, resulting in turbid solution. The suspension was then dialyzed (molecular weight cutoff 8-10 kDa) overnight at 4° C. against a 50-100 fold excess of phosphate-buffered saline without Ca ++ and Mg ++ (PBS; 137 mM NaCl, 2.7 mM KCl, 6.5MM Na 2 HPO 4 , 1.5 mM KH 2 PO 4 , pH 7.4). Subsequently iodoacetamide (Sigma, St. Louis, Mo., USA) was added at 5 g/liter, and the suspension incubated for another 2 hr at room temperature while stirring, followed by dialysis for 2 days against several aliquots of PBS, and an additional day against PBS containing in addition 0.9 mM CaCl 2 and 0.5 mM MgCl 2 . Subsequently the SH-FCS was centrifuged at 25,000 g for 30 min at 4° C., and the supernatant again at 100,000 g for 60 min at 4° C. The clear supernatant was sterilized by passage through a Millex-GV 0.22 nm filter (Millipore, Bedford Mass., USA). Prepared from protocol in Van Zoelen et al, J. Cell Physiol., 123: 151-160 (1985)
The final serum-free medium (Lechner et al. Methods in Cell Biol. 21, p. 195, 1980) was prepared without arginine, calcium, glutamine, trace elements and iron. The medium was supplemented with:
______________________________________L-glutamine 2 mMinsulin 10 μg/mlhydrocortisone 0.2 μMepidermal growth factor 5.0 ng/ml(Collaborative Research Inc. Bedford Mass.)transferrin 10 μg/mlphosphoethanolamine 0.5 μMcholera toxin 25 ng/mltriiodothyronine 10 nMretinoic acid 10 nMornithine 2 mMCaCl.sub.2 0.4 mMglucose 2.o mg/mlbovine pituitary extract 7.5 μg/ml"Ex-cyte" ® V (Miles 312 μg/mlDiagnostics, Pentex ProductsKankakee, IL)FeSO4.7H.sub.2 O 2.7 uMZnSO.sub.4.7H.sub.2 O 0.5 uMFactor Free Serum (Van 10%Zoolen et al., J Cell Physiol., 123: 151 (1985))Na.sub.2 SeO.sub.3 3.0 × 10.sup.-8 MMnCl.sub.2.4H.sub.2 O 1.0 nmNa.sub.2 SiO.sub.3.9H.sub.2 O 5.0 × 10.sup.-7 M(NH.sub.4).sub.6 Mo.sub.7 O.sub.24.4H.sub.2 O 1.0 nMNH.sub.4 VO.sub.3 5.0 nMNiSO.sub.4.6H.sub.2 O 0.5 nMSnCl.sub.2.2H.sub.2 O 0.5 nMGentamicin 50 μg/ml______________________________________
The conditioned medium was isolated from high density monolayer cultures of HepG2 hepatoblastoma cells (American Type Tissue Collection #HB80-65) after 72 hours of cultivation. This conditioned medium is added to normal HGM at a 35% concentration. (Alternatively, human liver epithelial cells transformed by transfection with SV40 DNA (NCI/NIH, patent pending) in contact with HGM may be used instead of HepG2.
EXAMPLE 3 (NORMAL CELLS)
Isolation of hepatocytes: Human hepatocytes were isolated by a combination of perfusion and digestion as previously described. Upon removal of human livers, the tissue was kept in ice cold L-15 medium and transported to the site of liver cell isolation. The hepatocytes were dissociated into cell suspensions by perfusing the liver with a calcium and magnesium free Hank's balanced salt solution containing 0.5 mM EDTA, and 0.05M Hepes at 37° C., at a flow rate of 30-40 ml/min for 15 min.
The perfusate was then changed to a digestion solution containing collagenase (185-200 U/ml) at 37° C. at a flow rate of 30-40 ml/min for 20 min. The dissociated hepatocytes were purified from debris and red blood cells by 3 successive washes with L-15 and filtration through a 10μ nylon filter. The hepatocytes were suspended in Waymouth's medium supplemented with 10% fetal bovine serum (FBS), 1 μg/ml insulin and 50 μg/ml gentamicin. The yield estimated counting the cells with a hemocytometer were 1-2×10 7 cells/g of liver tissue. Over 90% of the hepatocytes excluded trypan blue.
Primary culture of human hepatocytes: Following isolation, all hepatocytes were seeded into collagen coated flasks (Flow Lab, Rockville, Md.) in T-75 tissue culture flasks (Lux, Miles Scientific, Napperville, Ill.) at a density of 5×10 5 cells/flask. All flasks were maintained in a humidified 3.5 humidified incubator at 37° C. Twenty-four hrs after isolation, the medium was changed to a semidefined serum-free medium consisting of a basal medium PFMR4 made without arginine and supplemented with ornithine (2 mM), insulin (10 μg/ml), hydrocortisone (0.2 μM), epidermal growth factor (5 ng/ml), transferrin (10 μg/ml), phosphoethanolamine (0.5 μM), cholera toxin (25 ng/ml), triiodothyronine (10 nM), bovine pituitary extract (7.5 μg/ml) and factor-free serum (10%). After two weeks, this medium was supplemented (35%) with conditioned medium obtained by placing the medium described above in contact with high density cultures of human hepatoblastoma cell line (HepG2) for 72 hrs.
These cells continued to proliferate slowly for about 15 weeks at which time the culture scenesced. The original culture was subcultured four times and the cells underwent approximately 12 replications.
These cells were keratin positive and 20% retained the ability to produce albumin as demonstrated by immunocytochemistry.
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The present invention relates to cell medium developed to support long term multiplication and permanent establishment of a cell line of human liver epithelial cells. The medium may contain an effective cell growth promoting amount of calcium ions; an effective cell growth promoting amount of glucose; an effective amount of insulin to aid cells in glucose uptake; an effective cell growth promoting amount of hydrocortisone; an effective amount of epidermal growth factor to bind epidermal growth factor receptors on cells; an effective amount of transferrin to increase DNA synthesis in cells; an effective amount of cholera toxin to increase DNA synthesis in cells; an effective amount of triiodothyronine to increase DNA synthesis in cells; and an effective growth promoting amount of mammalian hormones and mitogenic factors, including lipoprotein, cholesterol, phospholipids and fatty acids.
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TECHNICAL FIELD
The invention relates to a time-division communication switching system, and more particularly, to such a system having a plurality of interface circuits, having buffer memories for temporarily storing PCM data words representing speech segments and control memories for controlling the transfer of data words through the interface circuits.
BACKGROUND OF THE INVENTION
A time-division telephone switching system employing a time-shared space division network and interface circuits having input and output buffer memories and control memories is disclosed in U.S. Pat. No. 3,736,381 of Johnson et al. In order to attain the desired degree of reliability in an independently operating telephone switching system, it is common practice to duplicate the system's critical hardware and to operate such hardware in parallel. Customarily, such hardware is designated to be either in the "active" or "stand-by" mode and only the output information produced by the active units of the system is recognized as the system's output. In the event that an error is detected in an active unit, the roles of the two units are switched such that the unit which was the stand-by unit becomes the active unit. In normal operation, both units will contain the same data and control information due to continuous updates of both units. Thus, a switch of the equipment from active to stand-by can be made without significant time delay or loss of information. Such duplication of equipment, while reliable, adds significantly to the cost of the system and an arrangement of equivalent reliability but requiring less than full duplication is desirable. Systems, such as multiprocessor configurations, have been suggested in the prior art which employ several "active" and one "stand-by" or spare unit to be called into operation in event of failure of one of the "active" units. Generally, such arrangements are not satisfactory in real time communications switching systems since a significant loss of data may result during the time required to activate a spare unit, particularly since control information which changes in time must be transferred to the spare unit.
In time-division switching systems such as described in the aforementioned Johnson et al., patent, PCM data words representing speech samples are received from a time-division transmission line in serial form, buffered and switched through a network in serial form. In another prior art arrangement disclosed in British Pat. No. 1,349,823, the data words are switched simultaneously in parallel paths. For example, an eight-bit word will simultaneously occupy eight switching paths, one switching path for each bit. For reliability, one additional path is provided for each eight-bit word which may be used as a spare path in the event of failure of one of the eight other paths. Such a parallel switching arrangement, however, is too costly to be practical in any large capacity switching system.
SUMMARY OF THE INVENTION
In accordance with this invention, communication lines connected to a time-division switching system and their associated line interface circuits are divided into groups and a spare line interface circuit is provided for each group of lines. Error detection circuit is provided for detecting faults in the line interface units and for generating error signals which identify a particular unit in which a fault has occurred. Circuitry is provided which is responsive to the error signals to divert data from a line connected to a faulty unit to the spare unit and further to control the network to establish paths to the spare unit in place of the faulty unit.
In one embodiment of the invention each time-division line is provided with an input interface unit connected to the input side of the switching network and an output interface unit connected to the output side of the switching network. Each input interface unit is adapted to convert an incoming serial stream of data bits into data words each having several bits, and to temporarily store the data words. In the illustrative time-division telephone switching system described herein, each of these data words represents a segment of encoded speech which is transferred from an input interface unit through a time-shared space division network to an output time-slot interface unit, under control of time-slot memories. At the output time-slot interchange unit data words are multiplexed into a serial data stream for transmission on an outgoing time-division multiplex line.
Error detection circuitry is provided in each interface unit and when an error is detected in an active unit, an error signal is generated unique to the faulty unit. The error signal is used to activate a transfer control circuit which operates to divert further incoming data from the faulty unit to the spare unit. Thereafter, such incoming PCM data words will be channeled through the spare unit to the network terminal to which the spare unit memory is connected. The transfer control circuit, activated by the error signal, also alters the information in the slot memories to effect a change in network connection. In accordance with this invention such alteration is accomplished by means of autonomous control circuitry and without affecting the systems other call handling functions. Furthermore, the change of equipment is accomplished without significant loss of encoded speech.
In one illustrative time-division switching system, such as described in the aforementioned Johnson et al., patent, a data stream comprises 128 PCM channels; a network cycle is divided in 128 time slots and the switching network is reconfigured 128 times in each cycle. In that system, the time-slot memories which contain the information used to control the transfer of data words to and through the network have 128 entries. To alter the path of data through the network in the event of failure of an interface unit, 128 time-slot memory entries have to be altered. To modify all 128 entries under control of the system's central processor would require a substantial amount of real time, resulting in the loss of a significant amount of the data being switched by the system. Furthermore, the processor time required for such a transfer tends to interrupt and take away from the normal call-handling operations of the central processor. Advantageously, in accordance with this invention, circuitry is provided for autonomously altering the time-slot information of an entire memory within one network cycle. Since in each network cycle at most one speech sample from each of a plurality of voice frequency lines is transferred through the network, the one network cycle period required for altering time-slot memory information will result in the loss of at most one speech sample of any conversation being switched through the network. In ordinary voice conversation, the loss of one such segment will go unnoticed.
The above-noted features of this invention are illustrated in the following description in which reference is made to the figures of the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a time-division switching system having input and output time-slot interchange units, including spare units;
FIG. 2 illustrates a group of time-slot interface circuits;
FIG. 3 depicts time-slot memories for storing control information for input time-slot interchange units;
FIG. 4 depicts a spare input time-slot interchange unit in accordance with the invention, including control circuitry for activating the spare unit;
FIGS. 5 and 6 illustrate network time-slot memories for storing information to control the network switch, and including circuitry for altering memory contents;
FIG. 7 shows output time-slot memories for storing information for controlling output time-slot interchange units;
FIG. 8 depicts a group of output time-slot interchange units;
FIG. 9 shows a spare output time-slot interchange unit in accordance with the invention, including control circuitry for activating the spare unit;
FIG. 10 shows a network switch; and
FIG. 11 is a composite showing the relationship between FIGS. 2 through 10.
DETAILED DESCRIPTION
With reference to the drawing, FIG. 1 is a representation of a time-division switching system similar to that disclosed in the aforementioned Johnson et al. patent. Such a system may comprise a multiplex terminal 153 for multiplexing information from a plurality of communication lines 152 onto time-division path, and vice versa, in a well-known manner. In the illustrative system input information from 128 communication lines, such as the lines 152, may be multiplexed onto a single time-division path 154. A group of such time-division paths 154 are connected to input time-slot interchange units which, in turn, are connected to a network switch 180. The output terminals of the network switch 180 are connected to output time-slot interchange units 170, and output signals of the time-slot interchange units 170 are transmitted to the multiplex terminal 153 by means of time-division communication paths 155.
A central processor 150 controls the operation of the system through access to the various units of the system by means of peripheral bus 158. The processor 150 may, for example, be similar to the 1A Processor described in The Bell System Technical Journal, Vol. 56, No. 2, pages 119 through 312, February, 1977. By means of a combined scanner and signal distributor unit 151, the functions of which are well-known in the telephony art, the central processor 150 detects the operational state of the communication lines connected to the system and controls the multiplex terminal 153. The time-slot interchange units 110 and 170 and the network 180 are controlled by means of time-slot memories 125, 165, and 145, respectively. The time-slot memories receive the control information from the central processor 150 via the peripheral bus 158. The system further comprises a system clock 130 and a time-slot counter 131. Together these units provide the necessary timing for the system, in a manner that is well-known in the art. In this illustrative system, each system time cycle or time frame is divided into 128 time slots. In this system the time-slot counter 131 is an eight-bit binary counter adapted to count from 0 to 255. By means of such a counter the various circuits of the system may receive up to two pulses per time slot.
A communication switching system generally employing the principles set forth herein is disclosed in the September, 1977, issue of The Bell System Technical Journal, Vol. 56, No. 7, pages 1015 through 1320.
FIG. 2 represents an affiliated group of seven input time-slot interchange units, TSI-0 through TSI-6. A spare unit, TSI-7, is shown in FIG. 3. The units TSI-0 through TSI-6 are identical in structure and, hence, only one of these units namely TSI-0, will be described herein. TSI-7 incorporates additional gating circuits and will be described in subsequent paragraphs. Under normal operation units TSI-0 through TSI-6 will be activated to handle input data and the spare unit will be idle. This particular group of seven affiliated units and one spare unit have been selected for illustrative purposes and it is envisioned that a large switching system will have a plurality of such groups and that the size of the groups may vary depending upon the system requirements.
Input conductors PC-0 through PC-6 represent seven of the conductors 154 shown in FIG. 1. As shown in FIG. 2, input conductor PC-0 is connected to a serial-to-parallel converter circuit 210 which changes the serial stream of the data bits into a series of data words each having eight bits. The eight-bit words are presented in parallel on the conductors D0 through D7 which connect the circuit 210 to a buffer memory 220. The conductor PC-0 is also connected to a write address counter 211 which generates a next sequential address for the buffer memory 220 each time after eight serial data bits have been received from the conductor PC-0. The generated address is applied to the buffer memory 220 by means of the address select circuit 221 and one of the data words appearing in parallel on the conductors D0 through D7 is written in the buffer memory each time a new write address is applied.
A time-slot memory is provided for each input time-slot interchange unit. Eight time-slot memories TSM-0 through TSM-7, shown in FIG. 3, correspond to time-slot units TSI-0 through TSI-7, respectively. Each time-slot memory contains a plurality of data words, each representing a buffer memory read address. From each of the time-slot memories, one of these addresses is transmitted to the corresponding time-slot interchange unit, once during each time-slot time period. Such address is applied to the memory 220 by means of the address select circuit 221.
The address select circuit 221 is responsive to signals from the time-slot counter 131 occurring on conductor TSCNT to apply write and read control signals and write and read addresses to the buffer memory 220. The time-slot counter 131 provides two signals during each time-slot period, as discussed earlier herein, defining a first half and a second half for each time slot. The address select circuit 221 is activated during the first half cycle of the time-slot period to apply a write address and corresponding write control signals to the buffer memory 220 and is activated during the second half cycle of the time-slot period to apply a read address and corresponding read control signals to the buffer memory 220.
Parity circuits 224, 225, and 226 are provided to generate parity and to detect parity errors. Circuits of this type are well-known in the art. The parity circuit 224 receives the eight parallel data bits occurring on conductors D0 through D7 and the write address, and generates a parity bit over the combined address and data word. When the write signal and address are applied to the buffer memory 220 by means of the address select circuit 221, the buffer memory stores the eight-bit data word occurring on the conductors D0 through D7 together with the parity bit generated by the parity circuit 224 on the conductor PAD1. When the buffer memory 220 is read, an eight-bit data word is transmitted to the parallel-to-serial converter 240 and applied to parity circuit 225. Additionally, the stored parity bit is applied to the parity circuit 225 on conductor PAD2. The parity circuit 225 also receives the read address, via cable M0. In parity circuit 225 a new parity bit is computed over the data word memory and the read address, and compared with the parity bit received from the memory on conductor PAD2. If a mismatch occurs, an error signal will be generated on conductor E02. The parity circuit 225 also generates parity over the eight data bits separate from the address and transmits this parity bit to the parallel-to-serial converter 240 on conductor PD. The converter inserts the parity bits in a serial data stream generated from the parallel bits received from the buffer memory 220 via conductors R0 through R7. The parity circuit 226 receives the serial stream of data and parity from the conductor I0, computes parity over the data only, and compares it to the accompanying parity bit. Any mismatch will result in the generation of an error signal on conductor E02. The arrangement employing parity circuits 224, 225, and 226 is just one example of a fault detection scheme. Any number of other fault detection schemes could be used to provide error signals. A single error signal instead of two error signals as shown herein may also be adequate.
Time-slot interchange units TSI-1 through TSI-6 are equipped in a manner similar to unit TSI-0 and are adapted to generate error indications on error leads E11, E12 through E61, E62, respectively. The error leads E01, E02 through E61, E62 are connected to control circuitry shown in FIG. 4 and described in subsequent paragraphs. Additionally, the error signals are transmitted to the processor 150 via peripheral bus 158 for maintenance purposes. Advantageously, in accordance with our invention activation of a spare unit in the event of an error takes place autonomously without attention from the processor thereby avoiding any significant loss of time or data.
FIG. 4 represents the input time-slot interchange unit TSI-7 which is the spare unit for time-slot interchange units TSI-0 through TSI-6. TSI-7 comprises circuitry for autonomously enabling the spare unit when an error signal occurs on any of the conductors E01, E02 through E61, E62. The circuitry of FIG. 4 comprises a plurality of OR gates 450 and a plurality of AND gates 452 and a corresponding plurality of flip-flops EN0 through EN6. An error signal on any one of the error leads E01, E02 through E61, E62 will activate one of the OR gates 450 and one of the AND gates 452 to set a corresponding one of the flip-flops EN0 through EN6. For example, an error signal on conductor E61 or E62 will cause the flip-flop EN6 to be set. Similarly, an error signal on conductor E01 or E02 will result in the setting of the flip-flop EN0. The Q outputs of these two flip-flops and related flip-flops EN5 through EN1 (not shown in the drawing) are connected to OR gate 453, the output of which is used to set the input enable flip-flop 455. The output of this flip-flop is connected to AND gates 452 and used to inhibit these AND gates to prevent the setting of more than one of the flip-flops EN0 through EN6 in the event that more than one of the time-slot interchange units generates an error signal. In case it is desired to provide an alternate path in the event of multiple interface unit failures, additional spare units may be provided and enabled in a similar fashion.
Output conductors of the flip-flops EN0 through EN6, respectively, are connected to respective ones of a plurality of AND gates 461. Each of the AND gates 461 has an input terminal connected to one of the conductors PC-0 through PC-6, which conductors function to transfer serial streams of data bits from the multiplex terminal 153 to corresponding input time-slot units. The output terminals of AND gates 461 are connected to the series-to-parallel converter 410 and the write address counter 411 through OR gate 462. Thus, activation of one of the AND gates 461 by a signal on one of the conductors EN01 through EN61 causes data from the corresponding one of the conductors PC-0 through PC-6 to be transferred to the converter 410 and the write address counter 411. These last-mentioned units operate in a manner similar to the series-to-parallel converter 210 and write address counter 211 referred to earlier herein with respect to FIG. 2. Similarly, the buffer memory 420, the parallel-to-serial converter 440, the address select circuit 421 and the parity circuits 424, 425, and 426 perform the same functions as like named circuits in FIG. 2 and described with respect to that figure.
The operation of the circuitry of FIG. 4 may be further understood with reference to a specific example. By way of example, an error detected by the parity circuit 225 will produce an error signal on conductor E01 which will result in the setting of the flip-flop EN0 in FIG. 4. The setting of this flip-flop, through operation of OR gate 453 results in the setting of the enable flip-flop 455 and the inhibiting of the AND gates 452 to prevent further activation of the circuit from errors occurring in other of the related time-slot interchange units. Furthermore, setting of flip-flop EN0 will result in the enabling of one of the AND gates 461 which has as one of its inputs the conductor PC-0. After enabling of that particular AND gate, the serial stream of data bits normally occurring on the conductor PC-0 will be applied to the serial-to-parallel converter 410 and the write address counter 411 via the conductor 412. At the serial-to-parallel converter 410, the serial stream of data bits will be converted to eight-bit words which will be presented in parallel on the conductors 415 and transmitted to the buffer memory 420. Concomitantly, the write address counter 411 will present an address to the address select circuit 421, which is connected to the buffer memory 420 by means of the conductor 422, causing data words to be written into the buffer memory 420 at sequential addresses under control of signals from time-slot counter 131 on conductor TSCNT.
The output signals of the flip-flops EN0 through EN6 are also applied via conductors EN01 through EN06, respectively, to a plurality of AND gates 320, shown in FIG. 3. Each of these AND gates also has an input from one of the time-slot memories TSM-0 through TSM-6 and activation of any of the AND gates 320 causes the contents of a memory location of one of the time-slot memories occurring on the corresponding memory output conductor M0 through M6 to be gated through the activated AND gate and OR gate 321 to the time-slot memory TSM-7. During normal operation the contents of one memory location of each time-slot memory is gated onto its output conductor (e.g., M0) in every time slot under control of a signal from the time-slot counter 131 on conductor TSCNT. Thus, in one time frame of 128 time slots, the contents of one time-slot memory of a faulty unit may be transferred to the time-slot memory TSM-7.
Continuing with the example of a prior paragraph, the setting of the flip-flop EN0 results in activation of the one of the AND gates 320 to which the memory output cable M0 is connected and the information appearing thereon will be transferred in sequence under control of pulses on the conductor TSCNT, to the memory TSM-7. The contents of the time-slot memory TSM-7 will be gated to the address select circuit 421, thereby causing contents of the buffer memory 420 to be transferred via conductors 416 and the parallel-to-serial converter 440 to conductor I7. The parity circuits 424 through 426 may be provided to perform parity generation and checking functions in the same manner as described with respect to parity circuits 224 through 226 in FIG. 2. However, these parity circuits in the TSI-7 do not generate signals which result in activation of the circuitry of TSI-7. They will function only as an error indication to the central processor 150 via the peripheral bus 158. Error signals on conductors E71 and E72 are transmitted to the signal processors as well as error signals on conductors E01, E02 through E61, E62 via the peripheral bus 158.
FIG. 6 shows a representation of basically an 8 by 8 switching matrix 180 having AND gates for crosspoints which are selectively activated under control of information obtained from time-slot memories 145 shown in FIGS. 5 and 6. A group of seven time-slot memories is provided, with one time-slot memory associated with each input terminal of the switch 180. For example, memory NM0 through NM6 of FIG. 5 are associated with input terminals I0 through I6 of the switch 180, respectively. Additionally, an eighth memory, memory NM7 shown in FIG. 6 in the block labeled 600, is associated with the input terminal I7 of the switch 180. The memories NM0 through NM6 depicted in FIG. 6 are identical in structure each including memory change control circuitry 500, described in the following paragraphs. For the sake of convenience, only the circuitry of memory NM0 is described. It will be understood that the circuitry of other memories, i.e., memory NM1 (not shown) through memory NM6 comprise the same structure performing equivalent functions in the same way. The memory NM0 comprises a memory unit 503 and a read/write access circuit 501 which is shown as having an input from the peripheral bus 158 and from the time-slot counter on the conductor TSCNT. The memory may be written by means of the processor from the peripheral bus by the application of a write address and data to the read/write access circuit 501 which will cause the data to be written into the memory at the specified address under the control of a pulse from the time-slot counter 131 appearing on the conductor TSCNT. As mentioned earlier, a pulse occurs on the conductor TSCNT twice in each time slot, and the read/write access circuit 501 may respond to a first pulse to write information into the memory and responsive to a second pulse to read information from the memory. Accordingly, during any time-slot period new information may be written into the memory or, if a write is not required the information in the memory will remain unchanged. The read/write access circuit will cause the memory to read its location sequentially to produce a data word on the memory output terminal 504 once every time-slot period. This information is applied to the decoder 505 where it is decoded to generate a unique output signal on cable 506 to activate AND gate 620 or one of the seven AND gates 630 connected to the cable 506. When activated, one of these AND gates will transmit a serial steam of data occurring on the conductor I0 to one of the output conductors O0 through O7.
As discussed earlier with respect to FIGS. 2 and 4, an error signal on error conductors E01, E02 through E61, E62 will result in the setting of one of the flip-flops EN0 through EN6 and an output signal on the corresponding one of the conductors EN01 through EN61. These conductors are shown in FIG. 6 to be connected to a corresponding group of AND gates 601. Each of these AND gates itself is symbolic of a plurality of AND gates. For example, the AND gate 601 to which the conductor EN01 is connected shows as another input the cable 504. The cable, in this illustrative embodiment, depicts a three-conductor cable capable of carrying a three-bit data word which may be decoded by means of the decoder 505 to produce a one-out-of-eight signal on the conductors of cable 506. A signal on the conductor EN01 will cause activation of the plurality of AND gates 601 to which this conductor is connected, causing a three-bit data word read from memory unit 503 to be gated through AND gates 601 and OR gate 603, which is symbolic of three separate OR gates having seven inputs each, to the read/write access circuit 605. In a similar manner, a signal on the conductor EN61 may be employed to gate a three-bit data word from memory NM6 to the read/write access circuit 605. The read/write access circuit 605 receives control signals from the conductor TSCNT produced by the time-slot counter 131 to write information into the memory 610 during a first portion of a time-slot period at sequential addresses of the memory upon activation by means of a signal produced by the OR gate 604. The OR gate 604 simply combines the signals on conductors EN01 through EN61 to produce an activation signal when a signal occurs on any of these conductors, i.e., when an error condition has occurred and one of the error flip-flops EN0 through EN6 has been set. As discussed earlier herein, the time-slot counter 131, is an eight-bit binary counter capable of counting to 256. When the count represented by the conductors of the cable TSCNT reaches 0, the read/write access circuit 605, when activated by means of OR gate 604, will initiate writing a data word occurring at the output of OR gate 603 into the memory at a location 0. Since the system operates on the basis of 128 time slots, a new word may be written into the next sequential location of the memory at every other advancing count of the counter 131. In this manner, a data word may be written into the memory 610 during a first half of each time slot and the read/write access circuit 605 is responsive to a time-slot counter output signal during the second half of each time slot, when activated from OR gate 604, to read a data word out of the memory 610 and apply the data word to the decoder 612.
As discussed earlier herein with respect to FIGS. 2 through 4, the occurrence of an error in one of the input time-slot interchange units causes input information to be applied to the spare input time-slot interchange unit TSI-7 and further causes this information to be applied to the conductor I7 in the proper sequence. The information appearing on conductor I7 is applied to, among others, the AND gates 631 which are activated by means of control signals occurring on the conductor 613 as generated by the decoder 612. The information which was applied to the conductor I7 by the time-slot interchange unit TSI-7 was obtained under control of signals on one of the conductors EN01 through EN61. The same signals are used in FIG. 6 to activate AND gates 601 to transfer information from the corresponding one of the network time-slot memories, memory NM0 through memory NM6, to the spare network time-slot memory, NM7. Thus, for example, an error in time-slot interchange unit TSI-0 results in the transfer of information from conductor PC-0 to input time-slot interchange unit TSI-7 and application of this information to the conductor I7 under control of time-slot information transferred from time-slot memory TSM-0 to time-slot memory TSM-7 shown in FIG. 3. Concomitantly, time-slot information is transferred from memory NM0 shown in FIG. 5 to the network time-slot memory, memory NM7, shown in FIG. 6. In this manner, information appearing on the conductor I7 is switched through the time-division switch 615 by the selective operation of AND gate 631 and is applied to one of the output conductors O0 through O6 in exactly the same fashion, and under control of the same information, as would have occurred in the absence of an error in time-slot interchange unit TSI-0. It will be appreciated that some real time is required to perform the transfer of data. However, the transfer of data is accomplished between time-slot memories simultaneously and the entire transfer of time-slot memory can take place during one time frame comprising 128 time slots. During this period of transfer certain of the information received on the conductor PCO0 may be lost. However, such information represents speech samples of 128 different telephone conversations and will go unnoticed in most telephone calls.
The conductors O0 through O7 of FIG. 6 are connected to output time-slot interchange units shown in greater detail in FIGS. 7 through 9. In this illustrative embodiment, an output time-slot interchange unit consists of seven identical circuit arrangements referred to in FIG. 8 as TSI-0 through TSI-6 and a spare unit labeled output TSI-7. For the sake of simplicity, only one of the seven identical units will be described, namely, output TSI-0 as shown in FIG. 8. As will be apparent from the description in the foregoing paragraphs, the conductor O0 will carry a serial stream of data bits which is applied to the serial-to-parallel converter 810. This circuit converts the serial stream of data into a parallel data word comprising seven data bits which are applied to a corresponding number of conductors designated 821 in FIG. 8, and a parity bit over the data which is applied to the conductor PDN at the output of the converter 810. The seven-bit data word is applied to the buffer memory 820 via conductors 821 while write address and control signals are applied to the memory on conductor 813 from the address select circuit 812. An appropriate write address is applied to the address select circuit 812 on the cable 710 from the time-slot memory TSMO-0 which provides a new write address once during each time slot. The write address is also applied to the parity circuit 824. In this circuit, the parity bit on conductor PDN is compared with the parity computed over the data word on conductors 821 and in case an error is found an error signal is generated on the conductor E04. Additionally, parity over the write address and data word is generated and produced on the conductor PADN1 to be written in memory at the time that the write operation occurs. The address select circuit 812 operates under control of signals produced on the cable TSCNT from the time-slot counter to select a write address during a first portion of each time-slot period and a read address during a second portion of the time-slot period. A read address counter 811 is incremented once every time slot to produce a next sequential read address to be applied to the buffer memory 820, such that the contents of the memory is read therefrom and applied to the conductors 823 in the sequence in which it is stored in memory. In the reading operation, the parity information stored at the time of the writing is provided on the conductor PADN2 and the parity circuit 825 compares this parity information with the parity over the read address and data and generates an error signal on the conductors E03 in the event that an error is detected. The data word read from the buffer memory and applied to the conductors 823 in parallel, is converted in the parallel-to-serial converter 840 to produce a serial stream of data on the output conductor PC00. In a similar manner, information received from conductors O1 (not shown) through O6 may be handled by the corresponding output time-slot interchange circuits TSI-1 (not shown) through TSI-6 generating error signals and data on the corresponding error signal conductors and data conductors, respectively.
An error signal on any of the error leads E03, E04 through E63, E64 will cause a corresponding one of the flip-flops EX0 through EX6 to be set through operation of the OR gates 950 and AND gates 952. AND gates 952 have input terminals connected to an output enable flip-flop 960 to enable these gates when the flip-flop is set. It will be assumed that this flip-flop is set in the absence of errors under control of signals from the central processor transmitted via the peripheral bus which is connected to the set input of the enable flip-flop 960. When any one of the flip-flops EX0 through EX6 is set, the enable flip-flop will be reset through operation of OR gate 962 to which each of the flip-flops EX0 through EX6 are connected. The AND gates 952 will be inhibited when flip-flop 960 is reset.
A fault in any of the output time-slot interchange units, which will be evidenced by an error signal on one of the error leads E03, E04 through E63, E64 causes the faulty time-slot interchange unit be removed from the transmission path and causes the data which is switched through the network 640 must be transferred to output TSI-7. This requires a modification of the information defining operation of the gates 630 to activate one of the gates 620 thereby transferring information appearing on one of the input conductors I0 through I6 to the output conductor O7. As discussed earlier and as shown in FIGS. 5 and 6, the information of one of the time-slot memories, NM0 through NM6, controls all gates associated with a single corresponding input conductor I0 through I6 independent of the output designation. Accordingly, information in all of the memories, NM0 through memory NM6, may require modification if the spare output time-slot interchange unit is to receive all data designated for one of the other units. By way of example, assume that an error is detected in the output time-slot interchange unit TSI-0 evidenced by an error signal on one of the conductors E03 or E04. Assuming further, that there is no prior error condition in the time-slot interchange units, the enable flip-flop 960 will be set allowing the flip-flop EX0 to be set. As a result thereof, the enable flip-flop 960 will be reset through operation of OR gate 962 inhibiting further operation of AND gates 952. Further, as a result of the setting of flip-flop EX0, and by operation of the one of the inverters 961 connected to the flip-flop EX0 and the corresponding one of the AND gates 958, the flow of information from TSI-0 on conductor PC00 will be inhibited. At the same time, enablement of the one of the AND gates 954 connected to the flip-flop EX0 and operation of the corresponding one of the OR gates 956, information appearing on the conductor PC07 will be transferred to the output conductor PC10 which is connected to the multiplex terminal 153 as one of the conductors 155 shown in FIG. 1.
Output conductors EX01 through EX61 of the flip-flops EX0 through EX6, respectively, are connected to each of the network time-slot memory circuits, NM0 through NM6, each including a memory change control circuit 500, as shown in FIG. 5. Memory NM0 is representative of the network time-slot memories. As mentioned earlier, the memory unit 503 contains 128 three-bit words which define which one of the gates 630 of the switch 180 connected to conductor I0 is to be activated. In the case of the example mentioned in the prior paragraph wherein an error has been detected in output time-slot interchange unit TSI-0, all seven of the AND gates 630 connected to the output conductor O0 must be disabled and in their stead a corresponding ones of the AND gates 620 connected to output conductor O7 must be selectively activated. To accomplish this, every code in the memory which designates output time-slot interchange unit 0, e.g., 000, must be modified to designate output time-slot interchange unit 7, e.g., 111. The output conductors EX01 through EX61 of the error flip-flops EX0 through EX6, respectively, are connected to an encoder 520 which produces a three-bit binary data word representing the decimal values 0 through 6. In the case of the example under discussion, the decoder will produce a binary word 000 to be stored in the compare word register 522. As mentioned earlier, the network time-slot memory 503 is read at sequential locations under control of a clock pulse in such a manner that each location will be read during each time frame having 128 time slots. Each data word, as it is read from the memory 503, is applied to the comparator 524 and in the event of a match between the word read from the memory 503 and from the compare word register 522 (e.g., 000) an output signal is generated by the comparator at the AND gates 525. One of these AND gates, e.g., the one connected to conductor EX01, will be enabled and one of the adder circuits 527, e.g., the one labeled "add 7", will be enabled. This circuit is envisioned to be a standard adder circuit which will add the decimal number 7 to the data appearing on the cable 504, e.g., 000, to produce a data word, i.e., 111. This data word will be applied to what is identified as an OR circuit 528 which will apply the data word and an appropriate memory write enable signal to the read/write access circuit 501 for entry into the memory under control of clock pulse in a time period immediately succeeding the read access time period, as has been explained earlier herein. Alternatively, a circuit for producing the data word 111 in response to a signal from the comparator 524, may be used instead of AND gates 525, adders 527, and OR circuit 528.
It will be apparent from the drawing that in the circuitry of FIG. 5, a binary word equivalent to decimal numbers between 1 and 7 will be added to words read from memory having decimal values between 0 and 6, depending upon the states of the conductors EX01 through EX61, such that a data word having the decimal value of 7 is produced to replace the number of the faulty time-slot interchange unit as indicated by the states of the conductors EX01 through EX61. As is apparent from the foregoing description, the memory update operation is carried out autonomously and the same sequence of operation takes place in each of the network time-slot memory circuits, NM0 through NM6. In this manner, all of the memories are updated in a time period equivalent to one cycle having 128 time slots in this illustrative example. The advantages of the autonomous operation are immediately apparent since the memory may be updated and to accomplish the switch from a faulty time-slot interchange to the spare time-slot interchange within one cycle, not taking into consideration delays introduced by the electronic circuitry in activating the comparator circuit and the like, which will be minimal compared to the time of one cycle. Furthermore, at worst, data switched through the network during one frame may be lost in part or in its entirety. However, such data represents a single coded element of each of a large number of simultaneous telephone conversations and will not be noted in any normal conversation.
The above-described arrangement is intended to be merely an illustrative application of the principles of this invention; numerous other arrangements may be devised by those skilled in the art without departing from the spirit and scope of the invention.
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Time-slot interchange circuitry for use in a time-division switching system is disclosed having n+1 input interface units and n+1 output interface units to serve n PCM lines. One of each group of n+1 interface units is designated a spare unit and control circuitry is disclosed for autonomously channeling incoming data words or outgoing data words through a spare unit and for autonomously altering the control for the spare unit in the event of failure of a unit in service.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation of Ser. No. 08/414,066 filed Mar. 31, 1995, now abandoned.
FIELD OF THE INVENTION
This invention relates, generally, to communications modules and more particularly to a communication module in which the physical link may be reconfigured to a fiber-optic or other communication medium interface which may be used with voltage regulator controllers and other power and distribution control apparatus.
SUMMARY OF THE INVENTION
It is well known that there is an increasing tendency to provide communications capabilities with and between power distribution and control apparatus. Typically, such distribution and control apparatus includes power circuit breakers, switchgear, transformer tap systems, voltage regulator controllers and the like. Such communication schemes typically include interconnection between controllers, controller to supervisory device (RTU) or a combination of the above in a network configuration.
Therefore, it is necessary for any controller or distribution equipment to have an appropriate communications module adapted to the medium or connection scheme contemplated as well as the appropriate protocol scheme. This module typically allows for communication between proprietary communications schemes inherent in a particular controller. Therefore, an additional component must be added to any communications module inherent in a controller to thereafter allow direct interfacing through standard physical interfaces and communications protocols. In this regard, typical physical interfaces may use RS-232 or RS-485 electrical wire connections or different communication media such as fiber optic transmission.
Unfortunately, it has been found that various physical interfaces and communications protocols are frequently used, all of which require completely different communication modules in order to adapt to particular interface requirements. This necessarily increases engineering and manufacturing costs as well as the requirements for inventory and the like.
Accordingly, it is desirable to provide a communication module which lowers the amount of engineering and manufacturing costs. It is also desirable and yet another object of the present invention to produce a communications module which reduces inventory count.
Still another object and desirable feature is to have a communications module which is reconfigurable to accommodate different communications protocol schemes or physical interface. It would also be advantageous and is an object of the present invention to produce a communications module whereby only substitution of a sub-component facilitates communication over different physical link/transmission media while the remainder of the unit which actually interacts with the power control apparatus remains the same. It is also an object of the present invention to produce a communications module which has inherent therein a plurality of communications protocols thereby allowing selection from a predetermined menu without changeout of the communications module.
It is yet another object of the present invention and it is also desirable to produce a reconfigurable communication module for facilitating communication to or between electric power control apparatus, comprising a reconfigurable communication module adaptable to communicate over a plurality of communication mediums, the reconfigurable communication module connectable to the electric power control apparatus, module communication processor board contained in the communication module for communicating with electric power control apparatus and for also communicating with one of a group of replaceable module transceivers, a replaceable module transceiver board contained in the communication module for communicating with the module communication processor board and for facilitating external communication over a predetermined communications medium, the replaceable module transceiver board consisting of one of a group of replaceable module transceiver boards, wherein each of the group of replaceable module transceiver boards is adapted to communicate over a different communications medium or physical interface.
DESCRIPTION OF THE DRAWINGS
Reference may now be had to the accompanying Figures in which:
FIGS. 1A and 1B are perspective views of a fiber optic and wire based module respectively according to the present invention;
FIGS. 2A, 2B and 2C are elevational views of the construction of the communication modules according to the present invention;
FIG. 3 is a block diagram representation of a fiber optic communication link according to the present invention;
FIG. 4 is a block diagram indicating interconnection of RS-232 based communication modules according to the present invention;
FIG. 5 is a modem based communication scheme according to the communication module of the present invention; and
FIG. 6 are exemplary block diagrams of different RS-485 network configurations utilizing the communication module according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1A and 1B there is shown communication modules 10, 12 for fiber optic and wire interconnection respectively according to the present invention. Preliminarily, it is to be understood that communication between power distribution and control apparatus and supervisory computers and/or other power control apparatus is extremely important for a variety of reasons, such reasons typically including load shedding, load management, process control and the like. However, it has frequently been found that such communication is not always between the same type of equipment or produced by the same manufacturer. Therefore, standard protocol schemes are frequently utilized. Further, physical plant requirements require the use of different types of interconnection methods or media (sometimes referred to as physical links) such as hard wire or fiber optic interconnection in a variety of configurations as described more fully below with respect to FIGS. 3-6. In any event, it is effectively required that a manufacturer have a communication module which is not only interconnectable with a particular piece of control apparatus, but a multitude of such modules having different configurations. Therefore, different situations and equipment typically require different physical links (i.e., hard-wire e.g. RS-232 or RS-485, fiber optic, RF, light such as infrared) and different software based protocol schemes.
It has also been found that there are certain requirements which are basic to each communication module regardless of the interconnection modality and thereby it is only necessary to adapt or modify the transceiver to the particular physical or link layers.
Therefore, in the preferred embodiment of the present invention a communication module 10, 12 is preferably utilized with a voltage regulator control panel or tap changer. However, it is to be understood that other types of power control apparatus may also be utilized therewith such as, for example, circuit breakers, switchgear, current interrupters and the like. Accordingly, each communication module 10, 12 is comprised of a communication module housing 14 which is sized and configured so as to be insertable into an exemplary voltage regulator control panel 11 which is shown in phantom.
Disposed on the face of each module 10, 12 are a plurality of indicators. In this regard, indicator light 16 is preferably an LED which indicates that the communication module 10, 12 is receiving power. Watch dog (Wdog) indicator 18 is configured so that when blinking steadily, it indicates that the communication module 10, 12 microprocessor and software are functioning properly. Communication light 20 indicates that communication activity is actually taking place with modules 10, 12. Test connector 22 is utilized to communicate with and test the communication module and at the particular piece of equipment and in the preferred embodiment of the present invention is a standard subminiature connector. However, since such type of features are readily known and understood to one skilled in the art, a more detailed description will not be had. Also on the face of each communication module 10, 12 are receive (RxD) and transmit (Txd) indicators 24, 26 which indicate respectively that the communication module 10, 12 is receiving or transmitting data.
It is to be understood that indicators 16-20, 24, and 26 are commonly used in the industry to provide supervisory annunciation capability to a module such as the communication module of the present invention and therefore a more detailed description will not be had.
In the preferred embodiment of the present invention there are a number of transmission medium methods which may be utilized. Accordingly, fiber optic communication module 10 has disposed on the front thereof fiber optic input and fiber optic output connectors 28, 30 respectively which facilitate communication over a fiber optic media as described more fully below. Similarly, RS-232/485 communication module 12 has disposed on the face thereof a terminal block connector 32 which provides communication according to RS-232 and 485 interface schemes over a wire medium. However, it is to be understood that other physical interfaces can be utilized without departing from the spirit and scope of the present invention.
Further, as can be seen from viewing FIGS. 1A and 1B, the overall dimensions and functionality of communication modules 10, 12 are identical with the exception of the transmission medium (physical link) utilized.
Referring now to FIGS. 2A, 2B and 2C there is shown elevational views of the fiber optic communication module 10 of the present invention. In this regard, FIG. 2A illustrates the use of two circuit boards in order to form the communication module of the present invention. More particularly, shown is a communication board 36 which may also be referred to as a microprocessor board and a transceiver or fiber optic board 38. Connecting the two boards 36, 38 together is cable 40. In the preferred embodiment of the present invention microprocessor board 36 is used with all communication modules (i.e., fiber optic communication module 10, RS-232/485 communication module 12 or a wireless module--not shown).
Microprocessor board 36 connects directly to the voltage regulator controller 11 (shown in phantom in FIG. 1A) or would interconnect directly with any other distribution control apparatus and in essence operates as an interface between transceiver board 38 and the distribution and control apparatus (not shown). In this fashion, communication module housing 14 stays the same size and configuration regardless of the communication module utilized and only the transceiver board 38 is changed to fit the various physical links or mediums utilized for communication purposes. A faceplate 46 (FIG. 2C) is specifically configured to suit the different transceivers 38 utilized. Moreover, although not required, in the preferred embodiment of the present invention, the communication module housing 14 is inserted into a "rack" style chassis, sometimes referred to as an expansion rack which is part of the voltage regulator controller 11. This therefore allows communication module 14 to be more easily field installable and interchangeable.
Moreover, by use of the above features, substantial cost and logistic savings are realized since an end user may change the transceiver 38 in the field if so desired without purchasing or replacing the entire communication module or voltage regulator controller 11. This is particularly advantageous to affect repairs due to the "modularity" of the communication module. The transceiver 38 as well as microprocessor board 36 are connected to housing frame 41 by use of board fasteners 39, while module end cover 35 which is fastened to housing frame 41 by module end cover screws 37 encloses the microprocessor and transceiver boards 36, 38. The entire module 10 is fastened by module fasteners 34 to the enclosure encompassing the voltage regulator controller or distribution equipment (not shown).
Additionally, in the preferred embodiment of the present invention, microprocessor board 36 has embedded therein a number of different communications protocols such as, for example, DNP 3.0. These different protocols are selected or enabled by the processor inherent in Regulator Control Panel 11 (power distribution processor not shown). Therefore, by communication directly with Panel 11, the microprocessor board 36 is "directed" to enable the desired protocol. However, it is to be understood that in alternate embodiments, the "selection" may be made by directly communicating with the microprocessor board 36 or, for example, by specific jumper selection, etc. without departing from the spirit and scope of the present invention.
Referring now to FIGS. 3, 4, 5 and 6 there are shown different interconnecting schemes for use with the present invention. Accordingly, FIG. 3 shows the looping of a plurality of fiber optic communication modules 10a, 10b and 10c by use of fiber optic cable 45 which cooperates with remote terminal unit (RTU) 42a. It is to be understood that in the preferred embodiment of the present invention the RTU such as RTU 42a may be any supervisory device, such as a computer or the like which collects, interrogates or processes the data communicated to and from each communication module. Such RTUs are readily known and available to one skilled in the art and therefore a further description will not be had. As previously recited, a fiber optic communication module 10 is available in order to provide communications in electrically noisy environments, over significant distances or the like.
Similarly, different operating environments or physical spacing/distance requirements dictate different types of mediums or physical links as well as communications protocols. These become evident when considering, for example, the physical link found in the RS-232 type interface such as found in FIG. 4 whereby simple wires use standard connectors 44 where RS-232 limits the distance to a length of (50) feet. Alternatively, through use of modems 48 such as found in FIG. 5, RTU 42c may communicate to a communication module 12 over any desired length.
Referring to FIG. 6, the use of an RS-485 physical link is shown which thereby allows interconnection to a plurality of communication modules 12 in a plurality of networks such as a LOOP network, a STAR network or an OPEN-ENDED network as desired. In this manner, RTU Units 42d can communicate over twisted pair or other suitable cabling as desired without departing from the spirit and scope of the present invention.
It is to be understood that many variations of the present invention may be practiced without departing from the spirit and scope of the present invention. For example, different modes of connection other than a ribbon cable may be facilitated between the microprocessor board and the transceiver board. Further, different indicator lights may be utilized while, a different communication medium such as wireless or communication over light (i.e. infrared) may be used rather than a fiber optic or RS-232/485 Type module as shown. Accordingly, it is to be understood that the present invention is not to be limited by the specific embodiments described herein but rather by the claims appended hereto.
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A reconfigurable communications module for power distribution and control apparatus is taught. Briefly stated, a communication module is rack insertable into a voltage regulator controller and has disposed therein a microprocessor board for communicating with host power distribution control apparatus and which also communicates with a transceiver board. The transceiver board may be one of several types of boards which provide a physical link with other equipment. Such boards may, for example, include a fiber optic, an RF based board, or a wire based board which is interchangeable in the communications module thereby allowing reconfiguration of the communication module to different media.
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RELATED APPLICATIONS
This application claims priority from provisional application No. 61/519,178 filed on May 18, 2011.
FIELD OF THE INVENTION
The present invention relates to a stretchable sheet such as a hammock for a chair underside configured to attach to the chair legs. The sheet may be used for holding a household pet or for storing various household items.
BACKGROUND OF THE INVENTION
Pet owners commonly purchase furniture made specifically for their pets to sleep on. A common piece of furniture for cats is the cat hammock. A typical hammock consists of a piece of fabric attached to a support frame, allowing the cat to sit comfortably on top of the fabric portion. U.S. Pat. No. D431,695 to Burt (1999) discloses the common form of cat hammock design. This form of cat hammock requires a specific support frame to be built and utilized only by the cat hammock.
Similar cat hammock designs disclosed by U.S. Pat. No. D379,682 to Rafaat (1993) and U.S. Pat. No. 5,860,389 to Caldwell (1997) and U.S. Pat. No. D127,808 to Mcgillicuddy (1941) all use the same basic design of an integral support frame. All of these designs require unique frame parts that cannot be used anywhere but the cat hammock itself.
Similar designs disclosed by U.S. Pat No. D374,512 to Kiley (1996) and U.S. Pat. No. D294,752 to Palier (1988) utilize a built in shade but still utilize the specific, required, frame to support the fabric. While the shade will give a cat some degree of comfort by allowing it to hide from the added cover, the shade does not give total overhead protection.
All of these designs require the manufacturer to use extra resources and time in order produce a specific support frame for the hammock. This results in wasted materials for the manufacturer, additional shipping requirements for the retail establishments selling the item, and additional cost to the consumer.
Additionally, a specific volume of space in the consumer's home is taken up by the required frame of the hammock. In small apartment dwellings, it is undesirable to dedicate this space to pet furniture. Designs disclosed in U.S. patent application Ser. No. 12/648,732 from Edmonds (2009) and Ser. No. 12/141,576 from Howard (2008) attempt to address the space requirements of cat hammocks. One attaches the cat hammock to a window and the other utilizes a fold-able frame. However, both designs still require the use of support frames and the frames are a higher degree of complexity over the previously mentioned designs.
One design that is currently available for sale eliminates the built in frame of the cat hammock. This design however is dependent upon a specific style of table that utilizes support pegs for the fabric to drape over. This design replaces the specific integral frame of the hammock with a specific integral table design which does not aid in minimizing complexity or cost.
Generally, the prior art pet hammock designs are deficient in a number of respects:
(a) They require a specific frame be built for the function of the hammock. Additional manufacturing steps, materials, and costs are the result of this required frame.
(b) The required support frame results in a specific volume of space being taken up by the hammock. Valuable floor space in the owner's dwelling is taken up by the previous designs.
(c) In order to clean around and under the hammock, the owner must move the entire support frame resulting in unnecessary steps.
(d) The shipping cost of the hammock to consumers is unnecessarily high due to the large required support frame.
(e) Through the uncovered design of existing hammocks, the cat is exposed without any cover while sleeping. This may be undesirable to the cat and result in limited adoption of the hammock and buyer's remorse for the consumer.
SUMMARY OF THE PRESENT INVENTION
The objects and advantages of the sheet of the present invention are as follows:
(a) The sheet design requires no integral support frame. The support for the sheet comes from the consumer's existing chair. The sheet is attached to the legs of the chair and rests beneath the chair seat. This results in lower manufacturing costs due to less complexity and lower material requirements.
(b) The sheet design does not take up any additional floor space. The existing space taken up by the chair is utilized by the sheet resulting in no additional clutter or lost space.
(c) Since the sheet is attached to the chair, a broom or vacuum can easily be moved underneath for cleaning. Since the chair would most likely be moved in the event of cleaning, an extra step of moving the sheet itself is not needed.
(d) By removing the support frame from the design, the sheet can be shipped in a smaller amount of space resulting in a cost savings to both the retailer and consumer.
(e) By attaching the sheet to a chair's legs and situating the sleeping area underneath the chair's seat, a cat will have a covering overhead. This will be desirable to the cat and result in further use of the sheet and buyer satisfaction of the consumer.
Further objects and advantages of my invention will become apparent from a consideration of the drawings and ensuing description.
In an embodiment of the present invention, a sheet for a chair underside adapted for outstretching, the chair having a first leg, a second leg, a third leg and a seat having an area and an outer perimeter, the sheet comprises an outstretched area not exceeding the seat area; an outer perimeter; a first strap having a first end and a second end, the first end of the first strap being attached to a first attaching point disposed on the outer perimeter of the sheet, the second end of the first strap being attached to the first leg of the chair; a second strap having a first end and a second end, the first end of the second strap being attached to a second attaching point disposed on the outer perimeter of the sheet the second end of the second strap being attached to the second leg of the chair; and a third strap having a first end and a second end, the first end of the third strap being attached to a third attaching point disposed on the outer perimeter of the sheet the second end of the third strap being attached to the third leg of the chair.
In another embodiment of the present invention, the chair comprises four legs, and the sheet further comprises a fourth strap having a first end and a second end, the first end of the fourth strap being attached to a fourth attaching point disposed on the outer perimeter of the sheet, the second end of the fourth strap being attached to the fourth leg of the chair.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A to 1C show the sheet of the present invention attached to a chair in different views.
FIGS. 2A to 2C show the sheet of the present invention in standard configuration and alternative configurations with stiffening bars and side flaps.
FIGS. 3A to 3C show the stiffening bar configuration of the sheet of the present invention attached to a chair in different views.
FIGS. 4A to 4C show the side flap configuration of the sheet of the present invention attached to a chair in different views.
FIGS. 5A , 5 B and 6 illustrate a sheet attached to a three legged chair indicating a front view, rear view and top view respectively.
DETAILED DESCRIPTION OF THE INVENTION
The main features and components related to the present invention are as follows:
Three Leg Chair
10 . Attachment patch to support attaching the sheet to the leg
11 Sheet seating area
12 . Fastening strap for attaching the sheet to the leg.
13 Chair seating area
14 Chair leg
15 Strap—leg interface and closure point
Four leg chair
1. Chair
1A. Chair Leg
1B. Chair Seat
2. Attachment point
3. Sheet seating area
4. Sheet strap
5. Sheet strap interface to seating area
6. Stiffening bar
7. Flap
8. Flap attachment point to the chair
9. Flap attachment point to the sheet
10 3 leg chair attachment point
The sheet of the present invention may be attached to a chair having three or four legs.
A typical embodiment of the sheet of the present invention installed on a chair having four legs is illustrated in FIG. 1A (isometric view), FIG. 1B (side view), and FIG. 1C (front view). The sheet strap 4 is attached to the chair leg 1 A at four attachment points 2 on the chair. One strap will connect to one leg of the chair providing support for the sheet area 3 which may be made of fabric, plastic, wood, metal, or composites. The attachment point 2 of the sheet strap to the chair leg is accomplished by any of the following means: string, hook and loop connections, buttons, snaps, buckles, zipper, strap, magnets, hooks, or other similar devices.
The typical embodiment of the invention is shown by itself in the non-installed state in FIG. 2A . The sheet seating area 3 is of a size sufficient to accommodate a reclined pet. The straps 4 are shown attached to the sheet seating area at the interface point 5 .
One possible alternate design that utilizes stiffening rods is shown in FIG. 2B . This configuration utilizes stiffening rods 6 attached to two opposite sides of the seating area 3 . The rods are attached to the sheet on the entire length of two sides of the seating area 3 . The straps 4 and interface point 5 are unchanged from the configuration shown in FIG. 2A . These stiffening rods could make it easier for a pet to enter or exit the sheet when installed. The installation of this configuration is shown on FIG. 3A (isometric view), FIG. 3B (side view) and FIG. 3C (front view). Similar to FIG. 1A-1C , the strap 4 is attached to the chair leg 1 A at the attachment point 2 by any of the following means: string, hook and loop connections, buttons, snaps, buckles, zipper, strap, magnets, hooks, or other similar devices.
Another possible alternate design that utilizes side flaps is shown in FIG. 2C . This configuration utilizes side straps 7 attached to three sides of the seating area 3 at the strap interface area 9 . These side flaps will provide more of an enclosed area for the pet to sit on the seating area 3 when in the installed configuration. The installed configuration is shown in FIG. 4A (isometric view), FIG. 4B (side view) and FIG. 4C (front view). Similar to FIG. 1A-1C , the strap 4 is attached to the chair leg 1 A at the attachment point 2 by any of the following means: string, hook and loop connections, buttons, snaps, buckles, zipper, strap, magnets, hooks, or other similar devices. The side flaps 7 are attached to the chair at the flap attachment point 8 by any of the following means: string, hook and loop connections, buttons, snaps, buckles, zipper, strap, magnets, hooks, or other similar devices.
From the description above, a number of advantages of the pet sheet invention become evident:
(a) The simple construction of the sheet eliminates the need for any special support framework by utilizing the inherent frame created by a chair's legs. This eliminates a large cost requirement of typical pet sheets.
(b) The space normally wasted underneath a chair is utilized by this invention. Therefore, additional floor space will not be required to utilize a pet sheet in the home.
(c) The sheet can be removed from in its installed state on the chair or left in place for cleaning. For cleaning operations such as sweeping or vacuuming of the floor, the sheet can be left attached to the chair and not present an additional item to be moved as opposed to conventional styles of cat sheets. If desired, the sheet can be removed from the chair for simple cleaning of the fabric.
(d) By having a simple design not requiring any framework, the packaging and shipping of the sheet will be more economical for both the manufacturer and consumer.
(e) By providing a covered area for a cat to lie, a pet will be more likely to utilize this style of sheet as opposed to an “open air” design of a typical pet sheet without any overhead covering. Therefore, the consumer will be more satisfied with a sheet their pet uses compared to one that the cat does not use very often.
The manner in which the invention is installed is the same for any of the previously mentioned designs. The main seating area 3 of the sheet is placed underneath of the chair 1 and in between the four chair legs 1 A. The seating area of the sheet is placed equidistant from all four legs resulting in an equal amount of sheet strap 4 to be available for attachment to the chair legs 1 A at the attachment point 2 . Each of the sheet straps 4 are then individually attached at the attachment point 2 to the chair legs 1 A at a level below the chair seat 1 B to allow sufficient access to the sheet by the pet.
The installation of the design utilizing the side flaps 7 will follow the previous installation instructions with the following addition: once the sheet straps 4 are attached to the chair legs 1 A at the attachment point 2 each side flap 7 is installed to the chair at the flap attachment point 8 .
In an alternate embodiment shown in FIGS. 5A , 5 B and 6 , a sheet 11 attached to legs 14 of a three legged chair 13 using strap 12 and attachment patch 10 at interface point 15 .
Accordingly, the reader will see that the configuration of this pet sheet invention will allow the user to save space in their home by using the wasted space underneath their existing chairs. Through the simple installation, the user will have the flexibility to use the sheet on virtually any type of chair with four legs. The cost will also be greatly reduced for both the manufacturer and consumer by eliminating the dedicated support structure of the sheet.
it eliminates the necessary dedicated support frame of the sheet, instead using chair legs for structural support. it saves floor space by utilizing the wasted area underneath a chair it makes cleaning around the sheet easy since vacuums and brooms can reach underneath it easily and when the chair is moved for cleaning, the sheet moves with it. it saves shipping costs by the elimination of the bulky and heavy support frame. it increases consumer satisfaction by the pet's repeated use.
While the above description contains specifics, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible, and a few were shown in the drawings. Variations such as the style, pattern, outline of the sheet straps and seating area were not mentioned or the manner in which the straps are attached both to the sheet seating area and to the chair. The straps themselves could be eliminated, thereby attaching the sheet seating area directly to the chair. This variation was not mentioned since the same end effect of creating a seating area for a pet attached to the chair legs would be achieved.
Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.
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A sheet disposed in a chair underside and attachable to the legs of the chair is disclosed. The sheet is configured for forming a downward droop from the weight of a pet and is designed to provide a comfortable resting place for a household cat and other pets as well as provide storage for various household items. The sheet may be attached to the chair by straps connected to and protruding from the perimeter of the sheet. Stiffening bars may be used to reinforce the sides of the sheet. Flaps attached to the sheet perimeter and attachable to the seat may be used to provide a dark and concealed environment for the pet to rest.
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FIELD OF THE INVENTION
[0001] The present invention allows for the investigation for the use of ponytail (“PT”)-sulfonates as leaving groups in direct 18 F-fluorination reactions followed by F-SPE purification using [ 18 F] fluoromethyl benzene as a model compound. The present invention further relates to a radiopharmaceutical composition of [ 18 F] fluoromethyl benzene as well as a method of generating an image together with one or more pharmaceutically acceptable adjuvants, excipients or diluents. The present invention also relates to the use of [ 18 F] fluoromethyl benzene for the manufacture of a radiopharmaceutical for use in a method of in vivo imaging. The present invention further relates to a method of monitoring the effect of treatment of a human or animal body with a drug to detect a wide variety of diseases where said method comprising administering to said body a compound such as [ 18 F] fluoromethyl benzene.
BACKGROUND OF THE INVENTION
[0002] Positron emission tomography (“PET”) is a non-invasive imaging technique which allows in vivo measurements and quantification of biological and biochemical process at the molecular level, and thus it is considered as a Molecular Imaging technique. Czermin J and Phelps M. Annu Rev Med 2002; 53: 89-112. PET is not only a valuable diagnostic tool in oncology, cardiology and neurology but is also becoming a valuable tool in nuclear medicine for drug development. Id. There are a number of positron emitting radionuclides of interest, such as 15 O, 13 N, 11 C, 18 F, 76 Br, 124 I and metals like 68 Ga, 69 Cu and 64 Cu. They all have properties of interest for various applications, especially 11 C, 18 F and the other halogens are of interest because of their properties in a synthetic labeling perspective. Additionally, 18 F is of interest due to its physical properties. There are also a number of drugs containing one or more fluorine atoms. In some studies within drug development the need of specific radioactivity is less, for example in straightforward distribution studies, so in these cases F-exchange could be used as the labeling method.
[0003] In general, fluorine is a small atom with a very high electronegativity. Id. Covalently bound fluorine is larger than a hydrogen atom but occupying a smaller van der Waal's volume than a methyl, amino or hydroxyl group. Id. Fluorine substituent effects on pharmacokinetics and pharmacodynamics are very obvious. Eckelman W C. Nucl Med Bio 2002; 29: 777-782. Therefore, the replacement of a hydrogen atom or a hydroxy group by a fluorine atom is a strategy frequently applied in both PET tracer and drug developments. Id. The replacement of a hydrogen atom by a fluorine atom can alter the pKa, the dipole moments, lipophilicity, hydrogen bonding, the chemical reactivity, the oxidative stability, the chemical reactivity of neighboring groups or metabolic processes. Smart B. E. J Fluorine Chemistry 2001; 109: 3-11. The replacement of a hydroxyl group is based on the hypothesis that fluorine is a hydrogen acceptor like the oxygen of a hydroxyl group. Czermin J and Phelps M. Annu Rev Med 2002; 53: 89-112.
[0004] As regards of its use for PET, fluorine-18 has excellent nuclear properties such as low positron energy that results in low radiation dose, short maximum range in tissue and convenient half-life (t 1/2 =109.7 min) considering distribution to other hospitals and performing longer acquisition protocols.
[0005] Furthermore, the application of radiolabelled bioactive peptides for diagnostic imaging is gaining importance in nuclear medicine. Biologically active molecules, which selectively interact with specific cell types, are useful for the delivery of radioactivity to target tissues. For example, radiolabelled peptides have significant potential for the delivery of radionuclides to tumours, infarcts, and infected tissues for diagnostic imaging and radiotherapy. 18 F is the positron-emitting nuclide of choice for many receptor-imaging studies. Therefore, 18 F-labelled bioactive peptides have great clinical potential because of their utility in PET to quantitatively detect and characterise a wide variety of diseases.
[0006] Radiolabeling of compounds with [ 18 F]-fluoride can be achieved either by indirect displacement using fluoroalkylation agents or direct displacement of a leaving group. Using fluoroalkylation agents or direct displacement is not always convenient for all pharmaceutical substrates due to the formation of by-products, low yield, and the difficulties in purification processes.
[0007] Therefore, the aim of this invention is to develop fluorous chemistry also known as ponytail chemistry, (”PT″) in a no carrier added (“n.c.a.”) nucleophilic 18 F-fluorination. Using PT chemistry offers simplifications of the overall process going from [ 18 F]-fluoride in target water to pure radiopharmaceutical since the compounds containing the ponytail can easily be removed by SPE-purification where the SPE-matrix contains a ponytail matrix and would then be applied as an alternative to solid phase or surface based chemistry. The ponytail matrix disclosed herein is defined as any fluorous compound that is removed and purified from a reaction with a PT-precursor.
[0008] Discussion or citation of a reference herein shall not be construed as an admission that such reference is prior art to the present invention.
SUMMARY OF THE INVENTION
[0009] Perfluoroalkyl sulfonates are not suitable leaving groups for n. c. a. nucleophilic 18 F-fluorination for synthesis of [ 18 F]fluoromethyl benzene. However, using the corresponding pentafluorobenzenesulfonate precursor has shown promising results and thus is a suitable leaving group for 18 F-labeling with moderated reactivity. The ponytail (“PT”) PT-precursor seems to be quite stable for at least 4-6 months. In an attempt to purify the crude 18 F-labeled product using fluoride-solid phase extraction (“F-SPE”), the radio labeled impurities decreased significantly by about 70%.
[0010] The present invention investigates the use of PT-sulfonates as leaving groups in direct 18 F-fluorination reactions followed by F-SPE purification to form simple fluorous model compounds such as [ 18 F]fluoromethyl benzene.
[0011] One embodiment of the present invention encompasses a method for radiofluorination comprising a reaction of the following compounds:
[0000]
[0000] wherein (II) is purified using SPE, solid phase extraction.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Fluorous compounds contain a perfluoroalkyl group and virtually any molecule can have a fluorous analog. The perfluoroalkyl chain remains chemically inert during the reaction, while imparting unique properties to the reagents and sorbents during separation. These properties are due to a highly selective affinity (fluorous affinity interaction) between the reagent fluorous groups and the sorbent fluorous groups.
[0013] During separation, the chromatographic properties of the perfluoroalkyl group dominate the molecule's other functional groups. This critical property makes the organic domains of the fluorous molecules become chromatographically irrelevant to the fluorous sorbent. Hence the immense benefit of fluorous technology: diverse chemical structures containing the same fluorous group can be purified by simply using a single chromatographic method.
[0014] Fluorous Solid Phase Extraction (“F-SPE”) quickly separates fluorous compounds from non-fluorous compounds in three easy steps. First, the reaction mixture is loaded onto a chromatograph column. Second, the non-fluorous compounds are eluted with a fluorophobic solvent in one fraction. Third, the fluorous compounds are eluted with a fluorophilic solvent.
[0015] Furthermore, fluorous substrates are used to deliver a product that contains a fluorous tag. SPE can then be used to recover the individual, highly pure fluorous product from non-fluorous reagents. In the reverse approach, fluorous reagents can be used such that the byproducts are fluorous while the desired product is non-fluorous. Simple separation by F-SPE yields a high purity product.
[0016] The aim of the present invention is to develop fluorous chemistry, also known as ponytail (“PT”) chemistry, via n. c. a. nucleophilic 18 F-fluorination. Using PT chemistry offers potential simplifications of the overall process going from [ 18 F]-fluoride in target water to pure radio-pharmaceutical since the compounds containing the ponytail easily can be removed and the product purified using solid phase extraction where the SPE contains a ponytail matrix.
[0017] There are various advantages of using a solid phase extraction approach over conventional liquid synthesis approaches in labeling reactions.
[0018] One advantage in using a solid phase approach over conventional liquid synthesis in labeling reactions is the simplified kit-concept of using the solid phase approach i.e. direct 18 F fluorination reactions. Another advantage is the easy cleanup in between consecutive reaction steps using the solid phase approach. Yet one other advantage of using the solid phase approach is the improved purification the solid phase approach delivers in labeling reactions in comparison. Still a further advantage of the present invention presents that the solid phase approach has a much easier automated process in comparison to the conventional liquid synthesis. Another advantage of the present invention's use of a solid phase approach depicts an improved yield of product through a time optimized process that is in comparison to other conventional synthesis.
[0019] One embodiment of the present invention depicts a method for radiofluorination comprising a reaction of a compound of formula (I) with a compound of formula (II) or benzyl bromide or benzyl iodide or any other halogen thereof where:
[0000]
[0000] to give a compound of formula (III):
[0000]
[0000] where
R1 is SO 2 Cl, SO 2 Br, or SO 2 I attached to said vector and then SO 2 Cl, SO 2 Br, or SO 2 I attached to said vector are treated with water to form SO 2 OH attached to said vector and next SO 2 OH attached to said vector are treated with silver carbonate to form SO 3 Ag attached to said vector R3 is
[0000]
[0000] to give formula (IV):
[0000]
[0000] wherein formula (IV) is purified with SPE and contains a ponytail matrix.
[0022] A further embodiment of the present invention shows a method according to the above scheme wherein the vector comprises:
[0000]
[0023] and where R1 can be attached to any of the carbons on the benzene ring or any of the attached fluorine atoms can be attached at any place along the benzene ring.
[0024] Another embodiment of the present invention encompasses a method for radiofluorination comprising a reaction of the following compounds:
[0000]
[0000] wherein (II) is purified using SPE, solid phase extraction and contains a ponytail matrix.
[0025] A vector used herein is a fragment of a compound or moiety having affinity for a receptor molecule. An example of such a vector used herein comprises a pentafluorobenzene structure.
[0026] A further embodiment of the present invention depicts the SPE contains a ponytail matrix. The present invention shows that the SPE occurs at least twice as fast as conventional liquid synthesis processes. As mentioned earlier, the ponytail matrix disclosed herein is defined as any fluorous compound that is removed and purified from a reaction with a PT-precursor.
[0027] Still another embodiment of the present invention shows a radiopharmaceutical composition comprising an effective amount of a compound of formula (IV); together with one or more pharmaceutically acceptable adjuvants, excipients or diluents.
[0028] Another further embodiment of the present invention depicts a method of generating an image of a human or animal body comprising administering a compound of formula (IV) to said body and generating an image of at least a part of said body to which said compound is distributed using positron emission tomography (“PET”). PET is a type of nuclear medicine imaging. Nuclear medicine imaging procedures are noninvasive and usually painless medical tests that help physicians diagnose medical conditions. These imaging scans use radioactive materials such as [ 18 F] fluoromethyl benzene.
[0029] A further embodiment of the present invention depicts the use of a compound of formulas (IV) for the manufacture of a radiopharmaceutical for use in a method of in vivo imaging.
[0030] Yet another embodiment of the present invention shows a method of monitoring the effect of treatment of a human or animal body with a drug to combat a condition associated with cancer, preferably angiogenesis, said method comprising administering to said body a compound of formulas (X and (Y) and detecting the uptake of said conjugate by cell receptors said administration and detection optionally but preferably being effected before, during and after treatment with said drug.
Examples
[0031] The invention is further described in the following examples, which is in no way intended to limit the scope of the invention.
[0032] The invention is illustrated by way of examples in which the following abbreviations are used:
hr(s): hour(s) min(s): minute(s) Bn: benzyl group Ph: phenyl Me: methyl RT: room temperature SPE: solid phase extraction Benzyl chloride: Pentafluorobenzenesulfonate: CH2Cl 2: methyl chloride: KHPO 4 : MeCN: methyl cyanide
Precursor Synthesis
[0045] Proof of concept in this study was obtained using compound (A), Scheme 1. 2,3,4,5,6-pentafluoro-benzenesulfonyl chloride was treated with water followed by silver carbonate. The resulted silver salt was reacted with benzyl chloride as shown in Scheme 1.
[0000]
[0000] Method for Preparing the Precursor benzyl pentafluorobenzenesulfonate (A)
[0046] 2,3,4,5,6-pentafluoro-benzenesulfonyl chloride (3.030 grams, 11.37 millimoles) was added to 8 milliLiters H 2 O. The reaction mixture was heated at 100° Centigrade for 22 hours and thereafter concentrated under reduced pressure. The resulting 2,3,4,5,6-pentafluoro-benzenesulfonic acid was redissolved in 10 mL H 2 O and silver carbonate (3.125 grams, 11.33 millimoles) was added. After stirring the reaction mixture for 25 hours at room temperature in darkness excess silver carbonate was filtered off and the filtrate was concentrated under reduced pressure. The resulting silver salt was dissolved in 9 milliLiters dry acetonitrile and benzyl chloride (1.301 grams, 10.28 millimole) was added. Thereafter the mixture was stirred at 85° Centigrade in darkness for 17 hours and concentrated under reduced pressure. The residue was purified by column chromatography (100% CH2Cl 2 ) yielding I as yellow crystals (0.350 grams, 10%).
Radiochemistry
[0047] The materials setforth below were used to obtain radio-labeled compounds with [ 18 F] fluoride.
[0048] 1 Water (95%) enriched in 18 O;
[0049] 2 QMA Accell Plus quaternary methylammonium anion-exchange resin;
[0050] 3 Kryptofix 2.2.2;
[0051] 4 Anhydrous potassium carbonate;
[0052] 5 Anhydrous acetonitrile;
[0053] 6 The corresponding precursor such as compound (I);
[0054] 7 Millipore Millex GV sterilizing filter;
[0055] 8 Glass reaction vessels: ReactiVials (5 ml) from Altech;
[0056] 9 Analytical column: Discovery ODS.5 ␣m 250 mm×4.6 mm; and
[0057] 10 F-SPE, FluoroFlash®, (Si(CH 2 ) 2 C 8 F 17 )).
Analytical HPLC Methods Used:
[0058] Linear gradient elution of 40% KHPO 4 (25 mM) and 60% MeCN/H 2 O (50:7) to 10% KHPO 4 (25 mM) and 90% MeCN/H 2 O (50:7) for 5 minutes with a flow rate 1.5 milliliter/minute.
[0059] Sample Preparation:
[0060] An analytical sample was prepared from reaction mixture in 70% Ethyl Alcohol (EtOH).
18 F Production
[0061] [ 18 F] Fluoride was produced at Uppsala Imanet by an 18 O(p, n) 18 F nuclear reaction through proton irradiation of enriched (95%) 18 O water using Scanditronix MC-17 cyclotron.
[0000] Method for Preparing 18 F-Labeling Benzene (B) Using Precursor Benzyl pentafluorobenzenesulfonate (A)
[0000]
[0062] A solution of benzyl pentafluorobenzenesulfonate (5.0 milligrams) in 0.2 milliliter of acetonitrile was added to a dry residue containing the complex [Kryptofix/Kryptofix 2.2.2] + 18 F in 0.2 millilitter of acetonitrile. The reaction was performed in a closed vessel at 150° C. for 15 minutes.
[0063] The results using precursor A, containing pentafluorobenzenesulfonate, showed that this is one suitable leaving group for n. c. a. nucleophilic 18 F-fluorination. The possibilities for fluorous SPE purification methods was illustrated using FluoroFlash® which in using this example gave a substantial purification of the labeled product.
[0064] Furthermore, the solid phase extraction is applicable in essentially all areas from traditional synthesis through parallel synthesis, and is especially useful for parallel synthesis of intermediates.
[0065] The PT-precursor seems to be stable for at least 4-6 months. New PT-precursors should be synthesized for exploring the scope and limitation of this methodology. This example is a proof of concept for the idea of using suitable perfluoro-substituted leaving groups combined with fast Fluorous SPE purification approaches.
F-SPE Conditions:
[0066] 2 g SPE-column (FluoroFlash®, (Si(CH 2 ) 2 C 8 F 17 )).
1) The cartridge was washed with 1 ml DMF, all DMF pushed out. 2) Preconditioning with 2 ml 80:10 MeOH:H 2 O, all MeOH:H 2 O pushed out. 3) Reaction mixture loaded. All solvent pushed out. 4) Fluorophobic elution: 2 ml 80:10 MeOH:H 2 O, all MeOH:H 2 O pushed out.
Specific Embodiments, Citation of References
[0071] The present invention is not to be limited in scope by specific embodiments described herein. Indeed, various modifications of the inventions in addition to those described herein will become apparent to those skilled in the art from the foregoing description and accompanying figures. Such modifications are intended to fall within the scope of the appended claims.
[0072] Various publications and patent applications are cited herein, the disclosures of which are incorporated by reference in their entireties.
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The present invention discloses the reactivity of ponytail (“PT”) sulfonates as leaving groups in nucleophilic fluorination reactions. The results showed that using a pentafluorobenzenesulfonate precursor is a suitable leaving group for n. c. a. nucleophilic 18 F-fluorination in synthesis of [ 18 F]fluoromethyl benzene, wherein this is a suitable leaving group for 18F-labeling with moderate reactivity. The PT-precursor seems to be quite stable. In an attempt to purify the crude 18F-labeled product using fluorous solid phase extraction (F-SPE), the radio labeled impurities decreased significantly. This provides an opportunity for utilizing PT methodology in both simple and fast purification methods.
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BACKGROUND OF THE INVENTION
The present invention relates to the deposition of chromium onto other metals. The use of chromium electrodeposited onto other metals is a well established industrial practice because of the wide need for the superior wear and corrosion resistance provided by chromium coated surfaces.
In the past chromium coating was achieved by the deposition of hexavalent chromium. This provided for hard, smooth coatings of chromium. However, undesirable waste products are created by the process of coating with hexavalent chromium and the hexavalent chromium coating process is energy inefficient.
There is a need for a coating system which provides the properties of hard chromium without the waste treatment problems or physical hazards associated with the deposition processes for hexavalent chromium.
Trivalent chromium deposits in the past have had a slightly darker appearance and have been softer than the hexavalent chromium coatings. Thick chromium coatings with hard wear resistant surfaces were not available from trivalent processes.
Trivalent chromium can not be plated directly in a simple electrolyte but requires highly complex systems with coordinating ligands including water and complexes. Chromium chloride has three kinds of complexes: [Cr(OH 2 ) 4 Cl 2 ]Cl.2H 2 O in the green form; [Cr(OH 2 ) 5 Cl]Cl 2 .H 2 O in the blue-violet form; and [Cr(OH 2 ) 6 ]Cl 3 in the violet form. Dissolution of these forms in water gives an equilibrium mixture of the tetra, penta and hexa aqua complexes. The exact composition is dependent on pH, temperature and concentration. The equilibrium of these complexes is slow.
SUMMARY OF THE INVENTION
This invention was developed in view of the foregoing background and to overcome the foregoing drawbacks.
It is accordingly an object of the present invention to provide an electrodeposition process for the electrodeposition of hard smooth coatings and a bath for performing this process.
It is a further object of the present invention to provide a method and a bath for depositing hard smooth coatings of chromium which is energy efficient.
To achieve these objects a chromium chloride bath is provided which includes chromium chloride as a source of chromium, citric acid to complex the chromium, and a non-sulfur containing wetting agent (preferably Triton X-100). Preferably, bromide is also provided in the solution to keep the hexavalent chromium production at the anode low. Ammonium chloride is preferably provided to improve the conductivity and also the current distribution in the bath. Boric acid is also preferably provided to advance the reaction kinetics. The bath is preferably free of sulfur containing salts.
The pH of the bath is maintained at between 1.8 and 4.9 and preferably at pH=4.0 ±0.5 using formic acid as a buffer. The temperature of the bath is maintained at between 20 and 50° C. and preferably at 35° C.±10° C.
A trivalent chromium coating is deposited by either a direct current (galvanostatic deposition) in the range of approximately 200-500 mA/cm 2 or by pulsed galvanostatic deposition at approximately 500 mA/cm 2 peak at 250 μs on and 750 μs off, however, a broad range of conditions exist at which good coatings can be obtained. Preferably, the pulsed current is applied.
BRIEF DESCRIPTION OF THE FIGURES
The above objects, features and advantages of the present invention will become more apparent from the description of the invention which follows, taken in conjunction with the accompanying drawings, wherein like reference numerals denote like elements, and wherein:
FIG. 1 is a graph showing the change in current efficiency with the change in temperature for baths having three different compositions;
FIG. 2 is a graph showing the change in the percentage of current efficiency with the change in current density for three different baths having different compositions;
FIG. 3a shows the SEM microstructure (X1000) of trivalent chromium as deposited at a bath temperature of 20° C. and a current density of 30 A/dm 2 ;
FIG. 3b shows the SEM microstructure (X1000) of trivalent chromium as deposited at a bath temperature of 30° C. and a current density of 30 A/dm 2 ;
FIG. 3c shows the SEM microstructure (X1000) of trivalent chromium as deposited at a bath temperature of 40° C. and a current density of 30 A/dm 2 ;
FIG. 3d shows the SEM microstructure (X1000) of trivalent chromium when deposited at a bath temperature of 40° C. and a current density of 40 A/dm 2 ;
FIG. 3e shows the SEM microstructure of trivalent chromium as deposited from a bath at a temperature of 40° C. and a current density of 50 A/dm 2 ;
FIG. 4a is a cross-sectional view of trivalent chromium (X1000) deposited from a bath having a temperature of 20° C. using a current density of 30 A/dm 2 ;
FIG. 4b is a cross-sectional view of trivalent chromium (X1000) deposited from a bath having a temperature of 30° C. using a current density of 30 A/dm 2 ;
FIG. 4c is a cross-sectional view of trivalent chromium (X1000) deposited from a bath having a temperature of 40° C. and a current density of 30 A/dm 2 ;
FIG. 4d is a cross-sectional view of trivalent chromium (X1000) deposited from a bath having a temperature of 40° C. and a current density of 40 A/dm 2 ;
FIG. 4e is a cross-sectional of trivalent chromium (X1000) deposited from a bath having a temperature of 40° C. and a current density of 50 A/dm 2 ;
FIG. 5 is a graph showing the change in the potentiostatic measurement of current as a function of time at 2.5V;
FIG. 6a is an x-ray diffraction line of a (110) plane of a trivalent chromium deposit;
FIG. 6b is an x-ray diffraction line of a (110) plane of bulk chromium;
FIG. 7 is a graph showing the variation of microhardness with current density and bath temperature for the trivalent and hexavalent (55° C.-40 A/dm 2 ) chromium deposits; and
FIG. 8 is a graph of the variation of weight-loss with bath temperature and current density for the trivalent and hexavalent (55° C.-40 A/dm 2 ) chromium deposits.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following detailed description of the invention illustrates a preferred embodiment according to the present invention.
An electroplating bath is provided which contains chromium in solution. The chromium is preferably provided in the form of CrCl 3 .6H 2 O at a concentration of between 50-150 g/l of solution. The preferred concentration is approximately 100 g/l of solution. The bath further comprises a complexing agent which is preferably either gylcolic acid at a concentration of between 25 and 50 g/l or sodium citrate at a concentration of between 30 and 100 g/l. Sodium citrate at a concentration of approximately 80 g/l is preferred. Glycolic acid is not as desirable since it causes an anodic decomposition product. The complexing agent forms complexes with the chromium ions. Borate is also preferably included in the bath in the form of H 3 BO 3 at a concentration of between 20 and 40 g/l but preferably at a concentration of approximately 40 g/l.
An alkali halide and/or amonium halide is also preferably added to the electroplating bath. Bromide is the most preferable of the alkali halides. An advantageous way to add bromide is in the form of KBr at a concentration of between 5 and 20 g/l. However, fluoride or fluoride ions also may be used. The halide functions to deoxidize and to be released at the anode. Without the halide a certain percentage of the chromium will be oxidized from the trivalent to the hexavalent state. The halide therefore functions to reduce the amount of hexavalent chromium at the anode.
A wetting agent is also employed. Preferably, this wetting agent is a non-sulfur containing nonionic surfactant such as polyethylene glycol ethers of alkylphenols, such as Triton X-100 (registered trademark of Rohm and Haas Company). The wetting agent is important because it ensures that the size of the hydrogen bubbles are small so that they do not stick to the surface of the anode and block the reaction. The wetting agent is preferably added in a concentration of approximately 1 to 2 drops /1.
A buffer is preferably employed to maintain the pH of the solution at 4.0±0.5. Formic acid is a convenient buffer which is readily available. Formic acid is generally employed at between 5 and 75 g/l.
The coating can be deposited by direct current (galvonostatic deposition) which is applied in the range of approximately 200-500 mA/cm 2 . Preferably, however, the current is deposited by pulsed galvonostatic current applied at approximately 500 mA/cm 2 . The pulsed galvonostatic deposition peaks at 250 μs on and 750 μs off. However, a broad range of conditions exist over which good coatings can be obtained.
The pulsed current is found to have important advantages over the direct current deposition such as reducing hydrogen films which can block the current and halt the reaction. Using pulsed current for the electrodeposition thereby helps to provide smooth crack-free surfaces and corrosion-resistant coatings.
The process of this invention provides thick coatings of chromium. Prior art processes for the deposition of trivalent chromium yield coatings of less than 20 microns. The process of this invention, on the other hand, can yield coatings which are not limited in thickness, e.g., coatings of greater than 125 microns have been produced. The hardness of the coatings produced have been found to be in excess of 700Vhm 50 . The coating produced is crack-free and the corrosion performance in 3.5 wt %, sodium chloride (see the data from the examples) is good. The appearance of the coating is similar to chromium deposited from an electrolyte containing hexavalent chromium ion.
The invention is additionally illustrated in connection with the following examples which are to be considered as illustrative of the present invention. It should be understood, however, that the invention is not limited to the specific details of the examples.
EXPERIMENTAL EXAMPLES
Plating Cell
Plating was carried out in a 3L beaker and electrolytes were made up from reagent grade chemicals and distilled water. Electrolyte compositions are shown in Table 1. Two types of platinum anodes were used, a cylinder-screen for steel ball cathodes and a platinum sheet for flat copper panel cathodes. Temperature was controlled with ±2° C. and agitation of the electrolyte was achieved by means of a hot plate-magnetic stirrer arrangement.
TABLE 1______________________________________Trivalent chromium bath compositions.Chemicals 1 2 3______________________________________CrCl.sub.3.6H.sub.2 O (g/l) 100 100 100KBr (g/l) 15 15 15H.sub.3 BO.sub.3 (g/l) 40 40 40HCOOH (ml/l) 30 30 30Triton X-100 (drop/l) 1 1 1Glycolic Acid (g/l) 32 32 --Sodium Citrate (g/l) -- 94 94______________________________________
Except for the current efficiency study, bath 1 was selected as the basis for the work reported here. The temperature was adjusted to 20°-50° C. and current density to 30-50 A/dm 2 . The pH was held constant at 1.5.
Specimen Preparation
It was necessary to prepare two kinds of specimens as described above. These were 52,100 steel balls for the abrasive wear testing and 14 mm×28 mm×1 mm thick copper panels for scanning electron microscopy [SEM], microhardness testing and optical metallography.
Before plating, the steel balls were connected to Ni-Cr wire by spot welding and degreased in solvent, rinsed, electroetched in 30 v/o H 2 SO 4 , rinsed, plated in a Woods nickel electrolyte at 3A/dm 2 for 3 minutes, rinsed and then plated in a trivalent chromium bath to a coating thickness of about 50 μm.
Copper panels were polished with metal polish, degreased, rinsed and then plated to a thickness of about 50 μm for the microhardness and optical metallography and to about 15 μm for SEM microstructure observation.
Testing and Structure Observation
The micro (Vickers) hardness measurements were carried out at a load of 50 g and 400x magnification on the cross-section of 50 μm thick coatings. The values reported are averages of 10 measurements.
The surface structures of as-plated chromium were observed by SEM at a magnification of 1000X and cross sections were studied by optical microscopy after etching in 20 volume percent HCl at 60° C. for 15 sec to 1 minute at a magnification of 1000X.
Powder X-ray diffraction was used to investigate crystal structure, orientation and the grain size of the deposits. Each specimen was reported from values of 34° to 140° in increments of 2° and measured with CuKa with a Mn filter.
A modified abrasive wear tester was used for testing the properties of chromium deposits. An abrasive slurry, consisting of 5μm Al 2 O 3 (10g) and fumed silica (5g) mixed with water and adjusted to pH=4.0 using ferric chloride, was used in this testing instrument. The wear cycle was 400 rpm, corresponding to an average speed of 40 cm/second. The initial load on the ball specimen was 4.4. The weight loss was determined on a microbalance with an accuracy of ±10 -3 mg by mass difference before and after testing. The current efficiency was calculated from the mass gain determination before and after plating.
In order to investigate the effect of mass transport on the deposition process a potentiostatic study was carried out at 40±2° C. and 2.5V with respect to SCE (Saturated Calomel Electrode) with a rotating disk electrode as the cathode. The speed of this rotating platinum electrode was 200 rpm. A platinum sheet was used as the counter electrode.
RESULTS AND DISCUSSION
Current Efficiency
The reactions occurring at the cathode are chromium deposition and evolution of hydrogen gas. The cathodic current efficiency of chromium is the ratio of current producing chromium I Cr to the applied current I tot which I tot is equal to I Cr +I H2 .
The effect of temperature on current efficiency of trivalent chromium for the various solutions is shown in FIG. 1. The current efficiency decreases with increasing temperature for all three of the electrolytes considered here. These results indicate that at the higher temperature, Cr(III) is complexed more strongly by either glycolate or citrate ion. An alternative explanation for these results may be that hydrogen always deposits below its limiting current. However, the chromium is mass transport limited. As the temperature increases it would normally (if chromium were not mass transport limited) be expected that both the rate for deposition (evolution) of hydrogen and of chromium would increase. However, unless the mass transport of chromium is increased only the hydrogen deposition (evolution) would increase and so current efficiency for the deposition of chromium would decrease.
In the trivalent electrolyte the chromium chloride forms complexes with coordinating ligands including water and the complexing agent. In the green form of the electrolyte the chromium is bonded with 4 water molecules and in the violet form with 6 water molecules. The energy to dehydrate these ligands results in a further increase (more cathodic or negative) in the potential necessary for the reduction of chromium to metal. Therefore the violet form needs more energy than the green form because there are 6 molecules of water to remove.
The glycolic acid bath in blue-green form has a higher current efficiency than the citrate-based bath. Hence, the energy required to break the bonding and to deposit chromium in glycolic electrolytes is less than that of citrate-based processes. That is, the citrate forms a stronger complex than the glycolic acid.
The effect of current density on the current efficiency for deposition of trivalent chromium from the various solutions investigated here is shown in FIG. 2. The current efficiency increases with current density. These results can be explained in the following way. As the current density increases, then the pH in the vicinity of the cathode also increases. In the case of citrate alone, this results in an increase in the degree of complexation, but in the case of glycolic acid alone, any increase in the degree of complexation is overcome by the decrease in the rate of hydrogen evolution with increasing pH. In the case of the mixed electrolyte (Bath 2), most of the chromium seems to be tied up with citrate (94 g/l citrate, 32 g/l of glycolic acid) therefore the current efficiency would be expected to be similar to that of Bath 3 (pure citrate). This is verified in FIG. 2.
Morphology and X-ray Diffraction Study of Deposits
The surface morphology as shown in FIG. 3a, b and c demonstrates the effect of changes of surface morphology with temperature (20°-40° C.). FIGS. 3c, d and e show the surface morphology as a function of current density (30-50 A/dm 2 ). All deposits have a microcrack pattern. Increasing the deposition temperature to 40° C. resulted in decreasing the crack density and increasing the current density to 50 A/dm 2 resulted in increasing the crack density. The nodular deposits appear in all deposits. The size and number of nodular deposits increase with temperature as well as current density. This kind of nodular deposit is believed to be a consequence of concentration polarization due to the high average current density used.
Cracks in the deposits are believed to be formed by the decomposition of chromium hydride. This decomposition results in a volume change, thereby restraining the deposits in the plane of the base metal and creating surface cracks. During the reaction, chromium hydride decomposes to chromium and hydrogen gas. This process seems to have created the cracks and holes shown in FIG. 3 and FIG. 4.
Although all deposits show a nodular surface, the cross sectional view reveals the two dimensional laminar structure as shown in FIG. 4. The distance between laminae increases with increasing temperature and with decreasing current density. It is possible that a viscous cathode film forms and then is broken down in a periodic way as shown in FIG. 5. These phenomena take place more frequently at lower temperatures and higher current densities.
X-ray diffraction patterns of bulk chromium and as-deposited trivalent chromium are shown in FIG. 6. Electroplated hexavalent chromium has a (111) preferred orientation and BCC structure while trivalent chromium reveals only the (110) peak and not at the same position as aged bulk chromium as shown in FIG. 6 (B). Trivalent chromium was believed to have a simple cubic structure with (210) preferred orientation, but results in this work reveal the BCC structure with (110) preferred orientation.
The grain size of as-deposited chromium is about 30-35Å. These extremely fine grains in chromium deposits have been explained as resulting from hydride decomposition.
Microhardness and Wear Performance
The variation of microhardness with electrolyte temperature and the variation with current density of both trivalent and hexavalent chromium deposited at 55° C.-40 A/dm 2 are shown in FIG. 7.
The microhardness increases with the temperature and decreases with current density. The microhardness of trivalent chromium is nearly the same value as that of hexavalent chromium at higher current densities. The reason for the high hardness of electrodeposited chromium compared to that of bulk chromium is due to the hydrogen content, preferred orientation, internal stress and grain size. The hardness increases as the grain size decreases and also as the number of fine cracks increases.
The mechanism by which internal stress contributed to increases in the microhardness is not clear. However, internal stress as well as preferred orientation do have minor effects on hardness. The major parts of hardness increment is due to the fine grain size and internal stress. This is a well-known phenomenon.
The grain size of trivalent chromium was inferred from line width broadening and was found to be extremely small, about 30-35Å.
The crack density, as shown in FIG. 3, decreases with increasing temperature and increases with current density. The higher the crack density, the lower the hardness is. It is probable that cracks in deposits are due to the relief of internal stress and therefore the microhardness increases with decreasing crack density. As shown in FIG. 4, the lower the hardness, the smoother the etched surface. The distance between laminae increases with increasing hardness. FIG. 8 shows the results of abrasive wear testing with a viscous solution of 10g 5μmAl 2 O 3 and 5 g fumed silica mixed with water and adjusted to pH=4. The weight-loss decreases with increasing temperature and current density and has about the same magnitude, 10 -4 g units: g/cm 2 as hexavalent chromium at higher current density. From this, it can be seen that weight-loss is affected by microhardness and structure. As is indicated in FIG. 3, 4 and 7, the temperature effect on the weight-loss is due to the hardness of deposit, and the current density effect on weight loss is due to the structure of the deposit, that is, the deposits have a nodular structure at higher current density.
CONCLUSION
1. Higher current efficiency, up to 35%, can be obtained using a glycolic acid process than with the citrate process. Thick coatings can be made.
2. All trivalent chromium deposits have cracks and nodules like hexavalent deposits, but the trivalent coatings have laminar structures.
3. The microhardness increases with increasing temperature and decreasing current density.
4. The wear rate in abrasive wear decreases with increasing temperature and current density. The mechanical properties of trivalent chromium obtained at higher current density are comparable to those of hexavalent deposits.
While the present invention has been described in its preferred embodiments, it is to be understood that the invention is not limited thereto, and may be otherwise embodied within the scope of the following claims.
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An electrodeposition process and a bath therefore are disclosed for performing the electrodeposition of hard smooth coatings of trivalent chromium. The electrodeposition process is accomplished energy efficiently. The bath includes chromium chloride as a source of chromium, citric acid to complex the chromium, and a wetting agent which is preferably Triton x-100. Preferably, bromide is also provided in the solution to maintain the hexavalent chromium production at the anode at a low level. Ammonium chloride is also preferably provided to improve the conductivity and also the current distribution in the bath. Boric acid is provided to advance the reaction kinetics. The pH of the bath is maintained at approximately 4.0 and the temperature is maintained at approximately 35° C. Either a direct current or pulsed current is used for the deposition process. Hard smooth coatings of trivalent chromium are deposited through use of the process and the bath of the claimed invention.
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